PPQs Flashcards
optimal dose of fluoride in drinking water
1ppm = 1mg/L
2 foods/drinks other than fluoridated water that are good sources of fluoride & have not have fluoride added by manufacturer
fluoridated milk
fluoridated salt
4 methods of topical fluoride application for an 8 year old
- fluoride varnish 22,600ppm 2x yearly
- fluoride toothpaste 1500ppm
- fluoride tablets 1mg fluoride daily
- fluoride mouthwash 225ppm
how does topical fluoride help prevent cavities
F slows down development of decay by stopping demineralisation of dentine, it makes enamel more resistant to attack from plaque bacteria, speeds up remineralisation & can stop bacterial metabolism at high concentrations to produce less acid. the fluoride that enters the tooth produces fluorapatite which makes the tooth stronger once remineralisation occurs
what daily dose of fluoride tablet would you give a 4 year old at high risk of caries who lives in an area with <0.3mm fluoride in water suply
0.5mg/day
rationale for use of antibiotics for perio caused by cancer
perio is a side effect of cancer treatment and when ptx undergoing cancer tx become immunocompromised they may require antibiotic prophylaxis to ensure that any bacteria present in the mouth that is causing the perio does not upset the ptx systemically
what problems limit the usefulness of antibiotics in tx of perio in cancer ptx
- antibiotics may be inactivated or degraded by non target organisms
- biofilm may resist antibiotics
- allergic reactions may occur
- antibiotic resistance can occur
- super infection can result where broad spectrum antibiotics are not suitable
when is it appropriate to prescribe a systemic antibiotic (5)
- ptx colonised with A.actinomycetemcomitans need systemic antibiotics as local delivery will not kill or inhibit bacteria
- when ptx presents with periodontal abscess of ANUG where systemic symptoms occur
- indication for use when there is ongoing disease despite mechanical therapy and good OH
- if ptx medically compromised
- if aggressive periodontitis & severe recurrent cases
advantages of systemic antibiotics
- delivered via serum to tissues & reaches reservoirs such as tonsils & tongue
- less costly than time required for tx
- must be accompanied by mechanical therapy to reduce bacterial load & disrupt biofilm
types of systemic antibiotics
- amoxicillin 500mg & metronidazole 400mg
- metronidazole alone
- azithromycin
- doxycycline
- tetracycline
3 reasons for carrying out obturation of prepared root canal
- inhibits bacterial growth
- can be easily removed
- seals the canals laterally & apically
describe steps involved in obturating root canal in upper central incisor
- apply dental dam & disinfect access area
- remove provisional restoration using sterile round bur
- irrigate using sodium hypochlorite to remove CaOH medicament; starting with size 10 or 15 introduce files sequentially to confirm access to working length & prepared apical stop
- dry canal with narrow bore aspiration & correct size and length of matching paper points in locking tweezers
- select master gutta percha point which will fill canal at working length & give tug back
- mix root canal sealer (AH+) & coat walls of apical part of root canal thinly using master point itself
- coat tip of master point with sealer & reinsert slowly to working length held in sterile locking tweezers & seat point firmly to the apical stop
cold lateral compaction
- take size A finger spreader, set a silicone stop at 1-2mm from CWL and place into canal alongside master point for 20secs
- coat an extra fine ‘A’ accessory point with sealer, gently remove finger spreader by rotating & immediately insert A point into space left by sealer
- repeat until 3-4 A points have been used or use B spreaders & points if coronal area still wide
- use a heated plugger to remove excess gutta percha within pulp chamber
which part of the root canal filling is the most important in ensuring long term success
good coronal seal is most important for ensuring higher success rate & preventing infection
what is meant by Watt & Macgregor’s biometric guidelines
biometric guide is one of the methods of designing complete dentures
uses remnant of the lingual gingival margin in the buccolingual placement of prosthetic teeth
when applying biometric guides what anatomical feature is used as fixed reference point
positional relation to the central incisors which are about 8-10mm anterior to the incisive papilla
the biometric guide gives you information about the location of the maxillary canines - a perpendicular drawn posterior to the centre of the incisive papilla to the sagittal plane that passes through the canines
average horizontal bone loss for the fixed reference point in the following maxillary tooth positions
central incisors - 6.3mm
canine - 8.5mm
premolar - 10mm
molar - 12.8mm
minimum data set that should be recorded onto occlusal record block
OVD - distance between jaws with teeth in occlusion
centre line - centre of ptx mouth symmetrical with face
occlusal plane - central occlusal plane indicates where incisal level of tooth will be
high lip line
canine line - line extended from inner canthus of eye
arch form - width:lip support
give history, symptoms & presentation of periodontal abscess
localised acute exacerbation of pre existing pocket (chronic perio) caused by trauma to pocket epithelium, or obstruction of pocket entrance
symptoms - pain on biting/constant pain, swelling, discharge release causing halitosis
O/E - swelling adjacent to periodontal pocket, tooth may be TTP, suppuration (discharge through sinus or pocket), tooth mobility, more likely to have pain on lateral movement, more likely to have generalised horizontal bone loss
tx - drainage via incision or via pocket with instrumentation to dilate, gentle sub gingival debridement, hot saline mouthwash, XLA of teeth with poor prognosis, antibiotic use if systemic involvement
follow up - HPT, surgery if required & maintenance
history, symptoms & presentation of periapical abscess
can be chronic / acute but both due to inflammatory reaction to pulpal infection where there is localised collection of pus around apex of non-vital tooth as a result of necrosis
chronic characteristics - gradual onset, little or not discomfort, intermittent discharge of pus through associated sinus tract
chronic radiography - sign of osseous destruction i.e. radiolucency at apex
acute characteristics - rapid onset, spontaneous pain, extreme tenderness to pressure, pus formation, swelling of associated tissues, systemic signs of malaise, fever, lymphadenopathy
acute radiography - may be no signs
tooth can be mobile, TTP vertically, non vital tooth, loss of lamina dura
history, symptoms & presentation of occlusal trauma
causes tooth mobility which is progressively increasing & associated symptoms, radiographic evidence of increased PDL width; in combination with plaque induced inflammation this may exacerbate loss of attachment
tx - control of plaque induced inflammation, correction of occlusal relations, splinting required when:
- mobility is due to advanced LoA
- mobility causing discomfort or difficulty when chewing
- when teeth need stabilised for debridement
history, symptoms & presentation of periapical periodontitis
symptomatic / asymptomatic
symptomatic:
- represents inflammation of apical periodontium that extends beyond root canals
- causes resorption of alveolar bone & LoA
- painful response to biting, palpation, percussion
- can be accompanied by radiographic changes i.e. periapical radiolucency
- severe TTP indicative of degenerating pulp & RCT required
asymptomatic:
- inflammation & destruction of periapical periodontium of pulpal origin
- apical migration of junctional epithelium
- appears as apical radiolucency & does not present clinical symptoms i.e. TTP or palpation
risk factors = plaque accumulation, diabetes, stress
history, symptoms & presentation of chronic gingivitis
inflammation confined to gingival tissue characterised by redness & swelling of marginal gingival tissue
swelling leads to formation of gingival pocket which manifests as increase in probing depth where epithelium lining of pocket is friable & easily traumatised
there is altered microbial colonisation, increased flow of GCF, influx of neutrophils, lymphocytes, monocytes & plasma cell infiltrate
proliferation & ulceration of junctional epithelium, dilated vessels, vascular proliferation, increased collagen loss & very few plasma cells present
chronic can be localised (<30%) or generalised (>30%)
symptoms = bleeding, swollen, red gingivae, false pocketing with no LoA
risk factors = pregnancy, leukaemia, puberty related, poor OH
tx = OH, HPT if required for removal of plaque / calculus
branches of maxillary nerve & where they pass through
trigeminal nerve has 3 branches:
1. ophthalmic - exits through superior orbital fissure
2. maxillary - exits through foramen rotunda
3. mandibular - exits through foramen ovale
maxillary nerve then has branches from the pterygopalatine fossa - zygomatic through zygomatic foramen, nasopalatine through sphenopalatine foramen, posterior superior alveolar nerve, greater & lesser palatine nerve, pharyngeal nerve
maxillary nerve also has branches from infraorbital canal - middle superior alveolar, anterior superior alveolar, infraorbital nerve
recommended alcohol limit for males & females
no more than 14 units per week spread evenly over 3 or more days
what acts regulate alcohol in scotland
- licensing (scotland) act 2005
- alcohol (scotland) act 2010
- criminal justice and licensing (scotland) act 2010
- air weapons and licensing (scotland) act 2015
- local government (scotland) act 1973
what has reduced alcohol consumption in scotland (5)
- changing scotland’s relationship with alcohol; framework for action plan
- minimum pricing per unit alcohol
- ban on multi buy drink promotions
- increased investment in alcohol treatment & care services with available access
- introduction of scottish lower drink drive limit of 22mg of alcohol / 100ml
chair side interventions that can be used to help someone with an alcohol problem
5A’s - brief intervention;
- Ask ptx about alcohol consumption
- Advise ptx
- Assess ptx
- Assist ptx on getting help
- Arrange follow up for ptx
2A’s & 1R;
- ask ptx about alcohol
- advise your ptx on alcohol
- refer to stop alcohol services
ABIs - alcohol brief interventions which are opportunistic & effective
4 different types of candidosis
- pseudomembranous; thrush
- erythematous; denture induced stomatitis, atrophic HIV related & candida leukoplakia
- hyperplastic - candida leukoplakia
- angular chelitis - poor OH, dry mouth, anaemia, immunocompromised, over closed denture from reduced OVD
how to treat each candidosis infection
pseudomembranous -
- nystatin oral 1ml 4x daily for 7 days
- chlorhexidine 3ml rinse for 7 days
- fluconazole 50mg daily for 7 days
- miconazole oromucosal gel pea sized amount after food 4x daily
- itraconazole 10-20mg OD for 14 days
erythematous -
- if steroid related rinse with mouth wash after using inhaler / spacer device
- if denture induced ensure thorough hygiene instructions given with milton for 20mins or chlorhexidine, advise removing denture at night
- drug tx = fluconazole capsules 50mg for 7 days or miconazole oromucosal gel pea sized amount to fitting surface of upper denture after food 4x daily
hyperplastic -
- confirm diagnosis through microbiology & histopathology
- systemic antifungals i.e. fluconazole 50mg OD or itraconazole 10-20mg OD
- iron, folate or B12 may be required if deficient
angular chelitis -
- chlorhexidine mouthwash 3ml per rinse for 7 days
- miconazole cream (2%) apply to angle of mouth 2x daily; use for 10 days after lesions have stopped
- sodium fusidate ointment 2% apply to angles of mouth 4x daily
- miconazole 2% & hydrocortisone 1% cream applied to angles of mouth 2x daily
ensure miconazole is not prescribed for those on warfarin or statins
mechanism of antifungal medication
azoles mechanism of action is the inhibition of the cytochrome P450 dependent enzymes (particularly 14a-demethylase) which is involved in the biosynthesis of ergosterol which is required for fungal cell membrane structure & function
what is azole resistance
candida species C.krusei & C.glabrata are naturally resistant to fluconazole & some strains of C.abicans have formed sensitivity & resistance to fluconazole systemic tx
this is why it may be important to carry out sensitivity & subtyping to ensure what candida species is causing the candidosis
what features should be present on maxillary & mandibular master imps
maxillary features:
coverage of tuberosity, hamular notch, extension anterior to vibrating line for post dam, functional depth & width of sulcus to create good peripheral seal & ensure hard palate & residual ridge are functional for primary support
mandibular features:
coverage of pear shaped pad & buccal shelf, retromolar pad & extension into lingual pouch should occur, functional width & depth of sulcus, ensure area of primary support of buccal shelf & retromolar pad
general features:
ensure denture bearing areas covered, good functional sulcus, good surface detail with no airblows
what indicates posterior border of maxillary denture
- post dam should sit 1-2mm anterior of vibrating line between junction of hard & soft palate
- should be at level of hamular notch to produce a good posterior seal which is located between distal surface of tuberosity & hamular process of medial pterygoid plate of maxilla
what impression materials are used for primary & master imps
primary:
1. impression compound - non elastic material which records poorer surface detail, not cheap, can be messy but good for primary due to high mucocompressive viscosity
2. alginate - elastic material that flows into undercuts & records adequate surface detail for primary imps
master:
1. silicone - dimensionally stable & can be made into variety of consistencies which means it accurately records surface detail
2. polyether/impregum - dimensionally stable & accurate recording of surface detail
3. alginate - elastic so will flow into undercuts if present
what is parkinson’s disease
a disabling progressive disease process thought to be caused by degeneration of dopaminergic neurones in basal ganglia (substantia nigra) or brain but reason for this degeneration is unclear
4 cardinal signs of parkinsons
- postural instability; impaired gait & falls, impaired use of upper limbs
- resting tremor
- bradykinesia; slow movement & slow initiation of movement
- rigidity; increased motor tone
features noticed in ptx with parkinsons
mask like face, slow speech & difficult swallowing, impaired dexterity, abnormal posture & difficulty walking (shuffling gait), memory problems
dental relevance of parkinsons
difficulty accepting treatment; tremor of body at rest, often facial remorse reduces purposeful movement e.g. mouth opening, lack of control of oral muscles
dry mouth common due to anti-cholinergic effects of drug treatment (benztropine)
increased risk of drug interactions
signs that a ptx who can’t communicate is in pain
general - fidgeting, pacing, repetitive motions, refusal to eat or cooperate, crying, groaning
facial - frowning, grimacing, teeth clenching, biting, rubbing area that is sore
behavioural - aggressive, depression, isolation, sleep disturbances, withdrawal
difference in ptx with parkinsons & ptx with cerebral palsy in regards to tremors
parkinsons presents as intention tremors & tremor at rest; intention tremor is present when tremor amplitude increases during visually guided movements towards target at the termination of movement
ataxia cerebral palsy typically presents with action intentional tremors which is especially apparent when carrying out precise movements
what is chlorhexidine & its mechanism of action
Chlorhexidine is an antiseptic and disinfectant that helps reduce the number of bacteria in mouth / skin
mechanism of action - Chlorhexidine is a cationic surfactant synthetic biguanide with broad-spectrum antibacterial and less pronounced antifungal activity. It disrupts microbial cell membranes and coagulates cytoplasmic proteins & has a residual activity of several hours
what factors influence use of chlorhexidine
- contains bisbiguanides which is the gold standard for active use against gram +/- bacteria, fungi, yeasts & viruses
- no known bacterial resistance or superinfection reported with use
- has 12hr substantively
- good safety record, available without prescription
- requires little to no skill or motivation to use
dosage of chlorhexidine
chlorhexidine mouth rinse 0.2%
10ml x2 daily for 1 min after breakfast & before bed for 1-2wks
what is substantivity of chlorhexidine
usually 12hrs but depends on:
- absorption to oral surfaces
- maintenance of antimicrobial activity
- slow neutralisation of antimicrobial activity
- other drugs
- certain food & drinks
- sodium lauryl sulfate
indications for using chlorhexidine
- short term for specific problems such as candidosis (pseudomembranous / erythematous)
- to clean dentures causing denture stomatitis
- post oral or perio surgery
- in disabled ptx where good OH is not easy to maintain
- immunocompromised ptx can benefit from use to prevent oral infections spreading to systemic infection
- tx of ANUG
- management of aphthous ulcers
- irrigant during RCT
- management of mucositis in cancer ptx
side effects associated with use of chlorhexidine
anaphylaxis, hypersensitivity, mucosal irritation, parotid gland swelling, reversible brown staining of teeth / comp restorations, taste distrubance, tongue discolouration, burning of gums if not diluted properly
can potentially impair fibroblasts & normal periodontal healing
incidence v prevalence
incidence:
no of new disease cases developing over a specific period of time in a defined population, incidence rate = no of new cases of a disease in a period / no of individuals in the population at risk, incidence estimates are obtained from longitudinal studies
prevalence:
number of disease cases in a population in a given time, prevalence = no of affected individuals / total no of persons in population, prevalence estimates are obtained from cross sectional studies or derived from registers which can relate to attributes to absence or presence of disease
what is SIMD & what is it used for
scottish index of multiple deprivation which is an area based index which uses a range of data to decide which neighbourhoods are most deprived by ranking data zones in order of deprivation from most to least deprived, with 1 being most deprived
what are the 7 factors of deprivation
- employment status
- income
- health & health care services
- geographic access to services
- crime
- housing, living & working conditions
- education, skills, training
what does the ARAB acronym stand for
A - active component - induces a force by introducing displacement forces
R - retention - resistance to displacement forces
A - anchorage - resistance to unwanted tooth movement, newton’s 3rd law: for every action there is an equal & opposite reaction
B - baseplate - to provide anchorage, connector for retentive components, cohesion, adhesion & stability
write a prescription to correct an anterior crossbite
Aim - please construct a URA to correct an anterior crossbite on patient’s 12
A - Z spring (double cantilever spring) on 12; 0.5mm HSSW
R - 16, 14, 24, 26 Adam’s clasps; 0.7mm HSSW
A - yes
B - self cure PMMA posterior bite plane
write a prescription to correct a posterior crossbite
Aim - please construct a URA to expand the upper arch
A - midline palatal screw
R - 16, 14, 24, 26; Adam’s clasps; 0.7mm HSSW
A- reciprocal anchorage
B - self cure PMMA - posterior bite plane; most incorporate all posterior teeth to prevent unwanted tooth eruption
how often should an active component be activated
anterior - 1 activation per month
posterior - 1 activation per week
should only be 1-2 teeth moving 1mm pr month for bone remodelling
what components of a URA can be used for retention (4)
- adam’s clasps - 4s & 6s 0.7mm HSSW (0.6mm in deciduous teeth)
- southend clasps - 1s & 2s 0.7 HSSW
- labial bows - 0.7mm HSSW
- c clasps - 0.7mm HSSW
what in anchorage
anchorage is resistance to unwanted tooth movement described by newton’s 3rd law -
for every action there is an equal & opposite reaction
used to ensure only 1-2 teeth are moved at a time
what can thumb sucking cause in the skeletal pattern
proclination on upper anteriors & retro-clination of lower anteriors with localised anterior open bite (AOB) or incomplete open bite (OB); it can also narrow the upper arch with a unilateral posterior crossbite
sucking effects will also be superimposed on existing skeletal patterns & incisor relationships & can cause lisping while talking
2 types of haemorrhage that can occur post XLA
- immediate post op period:
- reactionary & rebound bleeding which occurs within 48hrs of XLA
- caused by vessels opening up as the vasoconstriction effects of LA wears off, sutures become loose / lost, or ptx traumatising socket with finger / tongue / toothbrush / food - secondary bleeding
- often due to infections commonly occurring 3-7 days post XLA
- usually a mild ooze but can cause major bleed
how do you stop bleeding after an XLA
- apply firm pressure by biting on damp gauze packs / using finger
- LA reapplied with vasoconstrictor
- surgical oxidised cellulose / gelatin sponge inserted to act as framework for clot formation
- whitehead’s varnish pack containing iodoform, gum benzoin etc ribbon gauze soaked in WHVP sutured into socket will require removal
- bone wax
- thrombin liquid & powder in socket
- fibrin foam into socket
- suture socket with interrupted / horizontal mattress suture
- ligation of vessels & diathermy may be used
nerves affected by an IBD
inferior alveolar nerve
lingual nerve
some fibres of incisive & mental branches
how to know if anaesthesia has worked
- numbness of lip & chin on same side of IDB
- numbness of lingual gingivae & 2/3s of tongue
- check teeth on that side & tooth being XLA by walking probe down long axis of tooth & checking it ptx can feel it
what is xerostomia
consistent dryness in the mouth which generally develops when flow of saliva decreases to around 1/2 the normal unstimulated rate - 0.3ml/min
very common & often seen as side effect to polypharmacy
what medications are likely to cause xerostomia
tricyclics anti depressants - amitriptyline & nortriptyline
anti psychotics - phenothiazine
benzodiazepines - diazepam, lorazepam
anti-cholinergic - atropine
beta blockers - atenolol, propanolol
antihistamines - cetirizine, loratadine
non drug causes of xerostomia
medical tx - radiotherapy of head & neck, chemotherapy, removal of salivary glands
medical conditions - sjogren’s, undiagnosed diabetes, HIV, AIDS, alzheimer’s, cystic fibrosis, rheumatoid arthritis, stroke
nerve damage
severe dehydration
how do you treat xerostomia
- stimulate salivary glands
- chew sugar free gum / sweets - substitute saliva
- oral lubricants
- biotene system which is a salivary LPE enzyme system that helps to maintain oral environment - treat / modify underlying causative disease / problems causing it in the 1st place e.g. diagnose & treat diabetes
- drug use
- pilocarpine used for tx following irrigation for head & neck cancer & for dry mouth in sjogren’s; only effective in ptx who has residual salivary gland function - management techniques
- suck on ice cubes & frequent sips of water
- avoid mouthwash containing alcohol
- avoid dry hard food
- avoid alcohol / caffeine
- avoid sweet / sugary food
- moisten food when eating with water & sauces
draw and label posselt’s envelope
working clockwise
T, R , RCP, ICP, E, Pr
what is the border position in posselt’s envelope & why is it important
- centric relation (retruded arc) which is a dynamic relationship between maxilla & mandible is not in a static position
- said to occur when condyles are in their most superior position in the articular fossa & is determined by anatomy of TMJ
- it is a border movement and is reproducible over a period of treatment
describe areas on posselt’s envelope
T - maximal mandibular opening with full anterior - inferior translation of condylar heads
R - maximal mandibular opening with the condylar heads in reproducible retruded position but no anterior-inferior condylar translation. the arc R-RCP has its centre of rotation passing through the condylar heads (terminal hinge axis). in edentulous ptx the point at which prosthetic tooth contact is made along this arc (OVD) is determined by dentist as RCP
RCP - retruded contact position
ICP - intercuspal position
RCP-ICP = path is termed a slide, has the potential for horizontal, vertical & lateral components; lateral element cannot be seen in the sagittal plane
E - edge to edge position of incisors
Pr - maximum protrusion
what 2 records are required for mounting casts
- jaw reg
- occlusal rims - setting upper teeth in wax rim and setting lowers to upper in RCP
note - tooth shade & mould should also be recorded
4 radiographic signs a tooth has become non vital
- furcation bone loss
- external and / or internal resorption
- radiolucencies
- periapical periodontitis - widening of PDL
what is included on a trauma stamp (8)
- sinus/tender in sulcus
- colour
- TTP
- mobility
- EPT
- ethyl chloride thermal testing
- percussion note
- radiographs
tx of ED#
tx:
- bond fragment to tooth or place composite bandage
- take 2 periapical x ray to rule out root fracture or luxation
- sensibility testing & evaluate tooth maturity
- place definitive restoration
follow up at 6-8wks & 1yr:
- x ray checked for width & length of root canal development, compare tooth with contralateral
- check for internal & external inflammatory resorption & periapical pathologies
prognosis:
- 5% risk of pulp necrosis in 10yrs
tx of EDP#
evaluation:
- size of pulp exposure
- time since injury
- associated PDL injuries
tx:
<24hrs = pulp cap:
- LA & dental dam ->clean area with water, disinfect with NaOH, apply CaOH (dycal) or MTA white to pulp exposure -> restore with CR
- dam not required if associated luxation injuries
- review 6-8wks, then 1yr
> 24hrs = partial (Cvek) pulpotomy:
- LA & dental dam -> clean with H2O then NaOH, remove 2mm of pulp with high speed rough diamond bur (if no bleeding or cannot arrest bleeding proceed to full coronal pulpotomy), place saline coated (ferric sulfate?) CW pellet over exposure until haemostasis achieved, apply CaOH then vitrebond then restore with CR
full coronal pulpotomy:
- begin with partial then assess haemostasis, remove all of coronal pulp if hyperaemic or necrotic, place CaOH in pulp chamber, seal with GIC lining & quality coronal restoration
follow up 6-8wks, 1yr. aim to preserve pulp vitality and avoid full extirpation unless tooth is clearly non vital
symptoms of trauma
pain
oedema
bruising
changes in bite
missing part of tooth
inability to close mouth
tooth discolouration
lacerations in mouth
different types of waste disposal streams
BLACK - non infected household waste i.e. paper towels, food containers, put in wheelie bin to be lifted by council
ORANGE bag - low risk waste; dressings, swabs, disposables i.e. PPE, other items that have been in contact with ptx. bags filled to manufacture line, securely sealed with ratchet tag / swan tie then lifted by specialist services for heat disinfection (HDS)
ORANGE bin - low risk waste i.e. broken glass, blood & contaminated liquids inc bags & tubes, filled to line, label completes & source identified on bin, picked up for HDS
YELLOW stream - high risk i.e. recognisable body parts e.g. teeth without amalgam fillings, medicines & anaesthetics, used / unsure sharps or drug vials, contaminated metal parts or surgical instruments, highly infectious waste such as infectious blood, containers filled to line, labelled & picked up for incineration
RED stream - for amalgam, amalgam capsule, teeth with amalgam etc, filled to line, label completed, picked up as it requires specialist waste reprocessing so chemicals can be recovered
4 key aspects of waste transfer note
- description of waste
- origin source of where waste has come from
- quantity
- transport & destination
how long should a waste consignment transfer note be kept for
min 3 yrs
regulations that control waste disposal
- special waste (amendment) regulations 2004
- health & safety at work act 1974
- COSHH 2002
- environmental protection act 1990
- health & safety executive HSE
- scottish environmental protection agency SEPA
types of dementia
- alzhiemer’s; reduction in size of cortex, severe in hippocampus, presence of plaques which are deposits of protein fragments of beta-amyloid that build up in spaces between nerve cells & tangles
- vascular - caused by reduced blood flow to brain which damages & eventually kills brain cells
- dementia with lewy bodies - deposits of abnormal protein (lewy bodies) inside brain cells
- frontotemporal - frontal lobe has associated ubiquitous clumps of protein linked with TDP-43 found on it
rarer forms = parkinson’s, HIV, corticobasal degeneration, MS
what legislation protects against dementia
- human rights act 2000
- disability discrimination act 2005
- equality act 2010
- adults with incapacity act (scotland)
- mental capacity act (england & wales)
who is involved in multi disciplinary team care for dementia
GP
dentist
consultant neurologist
dementia nurse
macmillan nurse
physio
carers
symptoms of early, middle & late stage dementia
EARLY - misattributed to stress, bereavement or normal ageing:
- loss of short term memory
- confusion, poor judgement, unwilling to make decisions
- anxiety, agitation, distress over perceived changes
- inability to manage everyday tasks
- communication problems; decline in ability or interest in talking, reading etc
MIDDLE - increased obvious symptoms
- more support required inc reminders to eat, wash, dress, use bathroom
- increasingly forgetful & will fail to recognise people
- distress, aggression, anger, mood changes
- risk of wandering & getting lost
- behave inappropriately
- experience hallucinations, throw back memories
LATE - progressive symptoms
- inability to recognise familiar faces, objects, surroundings
- increasing physical frailty, start to shuffle / walk unsteady
- difficulty eating & sometimes swallowing, weight loss, gradual loss of speech, associated incontinence
- progressive & irreversible
how would you reduce a tooth for a MCC
- occlusal reduction:
- retain some morphology but reduce cusps & marginal ridges
- take into consideration relative thickness of metal & porcelain
- use diamond tapered fissure bur or round/rugby ball diamond bur - separation:
- use long tapered diamond bur to separate from adjacent tooth - buccal reduction:
prepare in 2 planes:
i) using diamond tapered shoulder bur for 1st reduction plane
ii) use the same for 2nd reduction plane but keep handpiece following incline of cusp
- avoid buccal pulp horns
- interproximal margin should follow gingival contour - palatal / lingual reduction:
- completed in 1 plane for premolars & molars
- follow palatal contour for canines & incisors
- both should use diamond chamfer bur - shoulder & chamfer finish:
- use both burs to finish shoulder margins or corresponding sides
measurements for reductions for MCC
non functional cusps = 2mm
functional cusps = 2.5mm
incisal = 2mm
buccal shoulder / heavy chamfer = 1.2-1.3mm (2 plane)
palatal chamfer margin = 0.5mm (1 plane)
between 10-20o taper
ideal properties of IM for offsite laboratory construction of a crown
- silicone (addition cured silicone putty) is placed over crown prep as it is dimensionally stable, has variety of consistencies, resistant to tear & records very accurate surface detail
- alginate impression can be then placed which is cheaper to use & is elastic so can flow into undercuts
what is the index of suspicion for child abuse/neglect
- delay in seeking help & delayed presentation of injuries
- story vague, lacking in detail, vary with telling person to person
- account not compatible with injury
- parents mood is abnormal
- parental behaviour gives cause for concern i.e. refusal to allow proper tx or hospital admission, unprovoked aggression towards staff, explanation inconsistent with injuries
- child appearance & interaction with parent is abnormal
- history of previous injury
- suspicious injuries / facial bruising
- history of violence within family
what to do if you suspect child abuse
OBSERVE - child’s behaviour & injuries
RECORD - always record conversations & findings in ptx notes
COMMUNICATE - with child & parents; ask how they got injuries, does it math description, reason for delayed presentation
REFER for assessment - if still concerned contact child protection for advice, follow up in writing & speak with health visitor, GP, school etc to investigate further, continue with referral to social services
duty of care to share concern about risk to a child’s wellbeing with child’s named person
how do we manage dental neglect
3 stages -
1. preventative dental team management; single unit approach = raise concerns with parents, offer support, set targets, keep records & monitor progress
2. preventative multiagency management =
- lease with other professionals to see if concerns are shared i.e. health visitor, GP
- child may be subject to common assessment framework (CAF)
- check if child is subject to child protection plans
- agree joint plan of action, review at agreed intervals
- letter to health visitor of children u5 who fail appointments & failed to respond to letter from practice
3. child protection referral -
- in complex or deteriorating situations
- follow local guidelines
- referral to social services if required
4 types on inherited bleeding disorders
- von willebrand’s - deficiency and/or defect of blood factor (von willebrand’s factor) that promotes platelet adhesion
- haemophilia A - factor VIII deficiency, 25% cases
- haemophilia B - factor IX deficiency (Christmas factor), 5% cases
- rarer forms - 10%
what is platelet dysfunction
may be due to a problem in the platelets themselves or to an external factor that alters the function of normal platelets
can be inherited or acquired with both increasing the risk of excessive & spontaneous bleeding
what is thrombocytopenia
condition characterised by abnormally low levels of thrombocytes (platelets) in the blood
diagnosed when below the normal limit of 150x10 to the 9/L
what 3 blood tests can confirm bleeding disorders
FBC - haematology
coagulation screen - prothrombin time PT, partial thromboplastin time PTT, activated partial thromboplastin time APTT, APTT ratio, INR
thrombophilia & haemophilia factor screen
what blood test is required for warfarin patients regularly
INR screen to determine how long it takes for your blood to clot as warfarin affects Vit K dependent clotting factors 2, 7, 9, 10
INR = 1 indicates level of coagulation equivalent to an average person not on warfarin but >1 indicates longer clotting time and so longer bleeding time
INR < 4 = allow for tx to occur without interrupting anti coag medication; safest between 1.5-2.5
what types of injections can be given to people suffering from bleeding disorders
regular injections of the clotting factor they are missing
- haemophilia A; berlate P injection which is recombinant factor VIII // DDAVP
- haemophilia B; benefix injection which is recombinant Christmas factor
-vWD; desmopressin (DDAVP)
- thrombocytopenia; platelet transfusions, INR
- rare conditions; FFP intravenously to replace all factors if recombinant factors are not available
dental injections - all injections can be used except lingual infiltration & IDB
what are the risk factors for oral cancer
- tobacco use
- alcohol use
- prolonged sun exposure
- HPV
- gender
- age
- poor OH
- poor diet & nutrition
- weakened immune system
what is a biofilm
a biofilm comprises of an aggregate of microorganisms whose cells adhere to one another & embed in a surface
the adherent cells become embedded within a self produced matrix of extracellular polymetric substances which allows adherence to a surface
what is a niche
an ecological niche is the role & position a species has in its environment, how it meets its needs for food & shelter, how it survives & reproduces
a species niche includes all of its interactions with the biotic & abiotic factors of its environment
what are the stages of colonisation in a biofilm
- adhesion
- colonisation
- accumulation
- complex community
- dispersal
give examples of 2 types of biofilms
- streptococcus spp = produce linking film i.e. strep mutans in caries development
- actinomyces spp = cause coaggregation & reconditioning of the film i.e. actinomyces actimomycetemcomitans A.a in perio
or candida albicans in candidiasis
what factors are involved in the adherence of bacteria
microbial adhesion:
- fimbrillar adhesins which are virulence factors used to help invade membrane vesicles of host cells by binding to cellular inetgrins
- LPS (cell wall component of outer membrane) of gram - bacteria with potential structural diversity to mediate specific adherence
- lipotechoic acid = cell wall components of gram + bacteria that may be involved in non specific / specific adherence
- protein fimbriae are filamentous proteins on surface of bacterial cells that may behave as adhesins for specific adherence
- lectins are any proteins that bind to a carbohydrate
- cell wall proteins
host receptors = glycolipid, glycoproteins, integrins, collagen, heparin
what 3 factors are required for successful colonisation
requires adherence, substrate & liveable environment i.e.
1. host - mucosa surface, pellicle, acid rich police proteins, minerals, lectins
2. saliva - mechanical washing, bactericidal enzymes, buffering, secretor IgA
3. bacterial - adhesins, LTA, protease, virulence factors
what is the aim of suturing
- approximate & reposition tissues
- compress blood vessels
- cover bone
- prevent wound breakdown
- achieve haemostasis
- encourage healing by primary intention
4 different types of sutures
- resorbable
a) monofilament i.e. monocryl
b) multifilament i.e. vicryl rapide;
holds tissue edges together temporarily, vicryl breakdown via absorption of water into filaments causing polymer to degrade - non resorbable
a) monofilament i.e. prolene
b) multifilament i.e. mersilk - black silk
if extended retention periods are required use these but must be removed post op, usually for closure of OAF or in exposure of canine teeth
4 different types of flap design
triangular
rectangular
semilunar
envelope
general oral surgery principle that should be adhered to when carrying out flap surgery
- create maximal access with minimal trauma as bigger flaps heal just as quick as smaller ones
- wide based incision should be used for circulation
- use scalpel in 1 firm continuous stroke
- no sharp angles
- minimise trauma to dental papilla
- flap reflection should be down to bone and done cleanly
- no crushing of tissues
- keep tissues moist
- ensure flap margins & sutures lie on sound bone
- make sure sounds are not closed during tension
- aim for healing by primary intention to minimise scarring
what hand piece is used to cut bone and why
straight electrical hand piece with saline cooled bur:
round or fissure tungsten carbide burs
air drive hand piece may lead to surgical emphysema embolism to form
what are the long term effects on permanent teeth after trauma
- discolouration - immediate may indicate vitality and intermediate change over wks can indicates non-vitality
- delayed exfoliation of primary tooth - may not resorb normally after trauma so XLA necessary or permanent successor will erupt ectopically
- enamel defects (44% cases) -
- hypomineralisation; yellow/white spots, normal thickness of enamel, tx = mask with composite, localised removal & restore with composite, external bleaching
- hypoplasia; yellow/brown spots, less than normal enamel thickness, tx = repair with composite / porcelain veneers when gingival level is stabilised at 16yrs - abnormal root morphology -
- crown/root dilacerations; requires surgical exposure & ortho
- delayed eruption; premature loss of primary teeth may result in delayed eruption of up to 1yr due to thickened mucosa, take radiographs if >6mths, surgical exposure & ortho may be required - ectopic tooth positions
- arrest in tooth formation (RCT/XLA)
- complete failure of permanent tooth to form
- odontome formation (surgical removal)
- underdeveloped tooth germ; may sequester spontaneously or require removal
nursing caries pattern of decay
- usually affects all of the maxillary teeth as smooth surface caries around the gingival margin
- lower incisors are protected by tongue but mandibular canines can be infected
advice for parents whose child is suffering from nursing caries
- ensure they’re using F- toothpaste suitable for age group i.e. 1000ppm < 3 and 1500ppm <10 high risk
- ensure free flow spout from 6mths with no sugar in cup
- don’t give bottle at night, only before brushing
- keep to meal times and don’t let child sip on sugar all day
normal pattern of decay in permanent dentition
1st & 2nd molar pits & fissures susceptible & usually first
interproximal areas where there are tight contacts between teeth
normally not smooth surface unless extremely bad
what is a post & core
core gains interradicular support for definitive coronal restorations such as a crown
post then retains the core holding onto the coronal restoration; however, this will weaken the tooth
what types of posts are available
- manufactured; preformed or prefabricated / custom made
- material; cast metal (type IV gold / Au), steel, zirconia, carbon / glass fibre
- shape; parallel sided, tapered
- surface; non threaded passive, serrated, smooth, cement retained
what is the difference between parallel & tapered posts
parallel sides -> avoid wedging, greater retention than tapered, less likely to cause root fracture as load is not dispersed horizontally; transfers down long axis
tapered posts -> high strength & stiffness, conservative, less retentive than parallel or threaded posts, should be used in small circular canals & avoid in flares canals
what length & width should a post be
length:
at least equal to crown height
2/3 of root length
4-5mm root filling should be left apically so apical foramen is sealed
never extend past a bend in the root
should reach alveolar crest height
width:
no more than 1/3 of root width at narrowest point
1mm of remaining circumferential coronal dentine
should fit for AL preparation & anti-rotational design
what is the function of a baseplate
used to provide anchorage, connector for retentive components, cohesion, adhesion & stability
what forces can displace a URA (5)
- gravity
- mastication
- tongue
- talking / vibrations
- active components
what is the formula for force in a wire
force is proportional to deflection x radius4/length3
what are the instructions for fitting a URA for the first time (10)
- check it is correct appliance for ptx
- check it is correct design & matches prescription
- check for any sharp / protruding areas on polishing & fitting surface which could cause trauma
- check integrity of wire work i.e. areas of damage (dark spot where the chromium layer is damaged which can lead to corrosion/fracture) or areas of work hardening (darkness caused by bending back & forth)
- try in ptx mouth
- check for signs of blanching, damage & trauma to soft tissues
- check occlusion: 1. flyover of posterior retention; high flyover can cause metal fatigue & wire fracture, undercut area moving so it won’t engage & causes gum stripping. 2. arrowheads. 3. check anterior retention
- active components should be in passive state so this is when they can be activated to allow 1mm of movement/ month
- demonstrate to ptx correct insertion & removal & get them to demonstrate back
- book review in 4-6wks
difficulties ptx must have with URA (4)
- likely to impinge on speech so get them to read aloud with device in
- will feel big & bulky so reassure they will get used to it quickly
- once activated will feel mild discomfort so indicates appliance is working & can take analgesia if needs be at start
- likely to have excess salivation (will pass in 24hrs)
instructions to give ptx when they receive their appliance (6)
- wear 24/7 including meal times
- take out & clean with soft brush after every meal
- store in safe container if taking part in active / contact sports
- non compliance will significantly lengthen tx
- avoid hard & sticky food, caution with hot food & drink
- give emergency contact details if components fail
how would you monitor progress & what would you do at subsequent visits for URA
- check wear on acrylic
- reactivate appliance
- monitor through overjet measurement; ensuring space between UR3 & UR4 are reducing & ensuring OJ has not changed
- check overbite reduction
- check MR in case anchorage is slipping
- if compliance is good, tx should only take 6-9mths
how are ghost images formed and what would cause them
produced as the x ray tube start position directs the bra posteriorly towards then opposite TMJ region and then moved behind ptx head, when the image of the premolar is being created the beam is coming from a more posterior point on opposite side & ghost products such as earrings are usually more anterior due to this
ghost images that occur are always higher due to vertical beam angulation of 8o and be horizontally magnified & usually further forwards due to change in anterior-posterior position
ghost images can occur when there is horizontal distortion if ptx is in incorrect position relative to focal plane
typical ghost images = earrings, metal restoration, soft tissue calcification, soft palate, hyoid bone, denture & fixed appliance
indications for an OPT
when you require a full view of dentition & surrounding structures inc TMJ & condyles; it will show:
- fractures & elevation of trauma
- 3rd molar & relationship to ID canal on lowers
- bone loss in generalised perio disease
- large lesions that wouldn’t be seen on occlusal, bitewings or periapical
- retained/unerupted teeth & development of dentition
- developmental & acquired anomalies
- TMJ evaluation
- inability to tolerate intra oral radiographs
define a stroke
a stroke is an acute neurological defecit resulting from cerebrovascular disease and lasting more than 24hrs or causing earlier death due to hypoxia of brain tissue; 2 types:
1. no local cerebral flow; infarction of tissue or haemorrhage into brain tissue
2. temporary ischaemia; TIA (transient ischaemic attack)
what are the dental considerations with a stroke (6)
- impaired mobility & dexterity; reduced attendance, importance of OH & techniques for getting into mouth
- communication difficulties; dysphonia & dysarthria issues, cognitive difficulties
- risk of cardiac emergencies; MI & further stroke are at increased risk
- loss of protective reflexes; aspiration risk, techniques for managing saliva
- loss of sensory information; difficulty in adapting to new oral environment i.e. denture
- stroke pain; CNS generated pain perception may be enhanced
risk factors of stroke occurring
hypertension - DBP >110mmHg x15 risk compared to 80mmHg, sustained BP of 140/90 or above
smoking
frequent & heavy alcohol consumption
ischaemic heart disease
atrial fibrillation
diabetes mellitus
previous strokes
prolonged stress
methods to reduce stroke (5)
- reduce risk factors; smoking, stress & alcohol reduced, diabetes & hypertension controlled
- anti platelet action - decreases platelet aggregation & inhibits thrombus formation effective in arterial circulation e.g. aspirin, clopidogrel, dipyridamole
- anti coag action - suppressing synthesis or function of various clotting factors and prevent formation of blood clots in veins & arteries; if at emboli risk such as AF, left ventricular thrombus given warfarin / heparin
- carotid endarterectomy - used when there is severe stenosis & previous TIAs under age of 85
- neurosurgery - aneurysm clips or AV malformation correction
tx available for stroke
ACUTE PHASE:
1. limit damage:
- calcium channel blockers for survivable ischaemia
- thrombolysis within 3hrs to improve blood flow & O2
- achieve normal glycaemia levels
2. reduce future risk:
- remove haematoma if possible
- give 300mg aspiring daily & anticoagulants if required
CHRONIC PHASE
1. rehabilitation:
- immobility support
- speech and language therapy
- occupational therapy
2. reduce future risk with medication
where is an IDB inserted
needle injected at junction of buccal fat pad in pterygomandibular, lateral to pterygomandibular raphe and medial to coronoid notch of the ramus of the mandible, 1cm above occlusal plane of molars
position of needle is approached from opposite premolar region and advanced until you reach bone then retract 1cm; aspirate & begin slow administration
what happens if LA inserted into parotid gland
facial palsy as LA injected (too posteriorly) into facial nerve which runs through parotid
causes eye on affected side to shut similar to stroke symptoms & cannot move eyebrows as temporal branch affected
to manage - reassure, cover eye with pad until blink reflex returns to normal, book review
list common psychiatric disorders
- neuroses (person contact is retained with reality) - anxiety states, phobic, OCD, hypochondria, depressive
- psychoses (persons contact is lost with reality) - manic depression, schizophrenia, korsakoff’s psychosis
- mood disorders - dementia, depressive, dysthymia, bipolar, cyclothymia
- eating disorders
- personality disorders
difficulties in treating patients with psychiatric disorders
- anxiety - denture intolerance, oral somatostatin, parafunction, TMD issues, oral dysesthesias (dry, burning, facial pain but no cause)
- psychoses - may be hyperactive / aggressive, delusional, hallucinations, poor concentration, poor insight, reckless behaviour
- mood disorders - reduced interest & motivation, poor concentration, appetite disturbance, unreasonable self approach
- eating disorders - xerostomia, recurrent ulcers, infections, bleeding, dental erosion
general - poor attenders, local dental care facility may not be able to provide specialist care, may not accept care due to anxiety so need sedation / GA, problems with capacity & consent
what meds given to psychiatric ptx cause xerostomia
antipsychotics - phenothiazine, butryrophenones, thiozanthenes
sedatives - benzodiazepines
anti depressants - selective serotonin reuptake inhibitors (SSRIs) i.e. prozac, monoamine oxidase inhibitors (MAOIs) i.e. phenelzine, tricyclic antidepressants i.e. amitriptyline
describe mental health (scotland) act 2003
concerned purely with management and treatment of psychiatric disorders
- acknowledges person has mental disorder
- medical tx is available which could stop condition progressing or help treat some symptoms
- if tx not provided there would be significant risk for ptx / others
- ensures compulsory powers may be necessary especially if persons mental problem prevents them from making decisions about medical tx
it also deals with detention limits
describe mental capacity act (england & wales) 2005
aims to -
empower & protect people who may not be able to make decisions for themselves
- enables people to plan ahead incase they are unable to make decisions for themselves in the future
- states that over 16 you have capacity to consent
5 main principles of adults with incapacity act (scotland) 2000
- must benefit patient
- be the least restrictive option
- take into account the wishes of the patients and those involved
- consultation with relevant others i.e. carer, guardian
- encourage the person to use exercise residual capacity
explain residual capacity
identification if there are any decisions which the patient can make for themselves
in so far as it is reasonable or practicable to do so, encourage adult to exercise whatever skills they have concerning property, financial affairs or personal welfare as the case may be and to develop such new skills
what powers do certain proxy groups have with regards to dental treatment
power of attorney
1. continuing power of attorney - cannot consent to dental tx
2. welfare power of attorney - can consent for dental tx
3. combined power of attorney - can consent for dental tx
guardianship orders
1. welfare guardian - can consent for dental tx
2. financial guardian - cannot consent for dental tx
what constitutes as having ‘incapacity’
AMCUR
inability to
act on decision
make decision
communicate decision
understand decision
retain memory of decision
what are the 3 main types of study trials and explain each
- randomised control trial - gold standard for comparing the effectiveness of one treatment to another, they provide the strangers evidence on effectiveness of tx in clinical trials
- cohort studies - individuals in this study are observed over a period of time to measure frequency of occurrence of disease, amount of people exposed to risk factor and people not exposed to the risk factor
- case control studies - retrospective study which compares individuals with disease (cases) and those without disease (control) then assess risk factors through past histories & exposure to suspected harmful agents compared; less robust than cohort study but can be used as preliminary investigations of hypothesis followed by cohort
what are confidence intervals & P values & how do they relate to the null hypothesis
CI - range of values the absolute risk difference will take in the population
- 95/100; the CL will contain the true population ARD so it wouldn’t overlap 0 which means there is sufficient evidence
- a narrow CL is better as the larger the sample the narrower the CL
p values :
- used in stats to help determine significance of your results
- p value <0.05 means you reject the null hypothesis & your results are statistically significant
what dosage of fluoride tablets are given to children
6mths - 3yrs = 0.25mg / day
3-6yrs = 0.5mg/ day
6+yrs = 1mg / day
fluoride toothpaste dosage amounts
eruption of 1st tooth - 3yrs = 1000ppm
4-16yrs = 1450-1500ppm
high risk u10yrs = 1500ppm
high risk 10-16yrs = 2800ppm
high risk 16+yrs = 5000ppm
what is the fluoride dose of mouthwash
225ppm
what is the dose of fluoride varnish
22,600ppm
what is a toxic, lethal and certainly lethal dose of fluoride
toxic dose = >1mg/kg bodyweight
potentially lethal dose = 5mg/kg
certainly lethal = 32-64mg/kg
what are the symptoms of fluoride toxicity
nausea, abdominal pain, diarrhoea, vomiting
how do you treat fluoride toxicity
- <5mg/kg give calcium orally; milk, observe for a few hrs
- 5-15mg/kg give calcium orally; milk, calcium gluconate, calcium lactate & admit to hospital
- > 15mg/kg take to hospital straight away for IV calcium gluconate & cardiac monitoring
name 6 types of disability
- physical - spina bifida, cerebral palsy, arthritis
- intellectual - down’s, autism
- mental - schizophrenia, dementia, Alzheimer’s
- sensory - visually / hearing impaired
- emotional - anxiety, depression, bipolar
- social - illegal drug use, alcohol abuse, obesity, homelessness, poverty
definitions for handicap, disabled & impairment
handicap - disadvantage for given individual, resulting from impairment / disability that limits or prevents fulfilment of a role that is normal for that individual
disability - a restriction / lack (resulting in impairment) of ability to perform an activity in a manner or within the range considered normal for a human being; it is concerned with the performance of activities
impairment - any loss of abnormality of psychological, physiological or anatomical structure or function; it is concerned with abnormalities in structure or functioning of the body or its parts
how to adapt the surgery & what legislation controls this for disabled people
legislation - humans rights act 2000, disability discrimination act 2005, the equality act 2010
adaptations - designated parking close to premises, appropriate sign posting with sensory impairments, ground floor level access, area for wheelchair access, hearing loop in place, handrails for support on step & ramps, wide doors & corridors for wheelchairs, unisex disabled toilet facilities with hoist available, wide clutter free corridors, wheelchair turning circle within surgery layout
what is cystic fibrosis
inherited autosomal recessive disorder on CFTR gene on chromosome 7 that causes an inherited defect in cell chloride channels which produces excess sticky mucous affecting the lungs & pancreas
physical appearance of cystic fibrosis
lung congestion & persistent chest infections (staphylococci & pseudomonas), malabsorption by pancreas, failure to thrive, smaller than average, finger clubbing, barrel chested
what are the symptoms of cystic fibrosis
troublesome cough, repeated chest infections, prolonged diarrhoea, poor weight gain, liver dysfunction, prone to osteoporosis, diabetes symptoms, reduced fertility in males
treatment available for cystic fibrosis
- physio; help remove mucous secretions from lungs
- medication; respiratory: bronchodilators to open airways, antibiotics to reduce chest infection frequency, steroids to reduce airway inflammation, DNase to breakdown mucous & digestive system; pancreatic enzyme replacement, nutritional supplements
- exercise; necessary to keep lung functional optimal & build physical bulk & strength
- transplantation; not a cure but can be used in end stage lung disease, 70% survival up to 2yrs, longest survival 12yrs
dental aspect of cystic fibrosis (6)
- delayed dental development
- enamel opacities
- increased calculus
- cannot have GA due to pulmonary involvement
- increased bleeding if liver is impaired
- tetracycline staining
masseter muscle
origin = zygomatic arch
insertion = lateral surface of angle of mandible
action = elevates mandible
testing = clench teeth together
nerve supply = masseteric branch of mandibular division of trigeminal nerve
temporalis muscle
origin = floor of temporal fossa
insertion = coronoid process & anterior border of ramus
action = elevates & retracts mandible
testing = clench teeth together & palpate
nerve supply = deep temporal nerve branches of mandibular division of trigeminal nerve
lateral pterygoid muscle
origin = lateral surface of lateral pterygoid plate
insertion = anterior border of condyle and intra articular disc via 2 independent heads:
1. inferior belly of lateral pterygoid attaches to the head of the condyle
2. superior belly inserts into the intra articular disc
action = protrudes & laterally deviates the mandible & inferior head functions with the mandibular depressors during opening
testing = cannot test through intra/extra oral exam but can examine response to resisted movement
nerve supply = nerve to lateral pterygoid branch of mandibular division of trigeminal
medial pterygoid muscle
origin = deep head to medial surface of lateral pterygoid plate & superficial head to tuberosity of maxilla
insertion = medial surface of angle of mandible
action = elevates & assists in protrusion of mandible
testing = cannot test through IO/EO exam
nerve supply = nerve to medial pterygoid of mandibular division of trigeminal nerve
what are the types of endodontic lesions with periodontal involvement
- primary endodontic - non vital tooth, local periodontitis only present
- endodontic lesion with periodontal involvement - if suppurating primary endodontic disease remains untreated it may become secondarily involved with periodontal breakdown:
- plaque forms at gingival margin on sinus tract & leads to plaque induced perio in that area
- when plaque / calculus is detected the tx & prognosis of tooth are different than those teeth involved with only primary endo as both perio & endo tx required
- chronic drainage via gingival sulcus will result in root surface being contaminated by plaque & epithelial down growth where endo therapy will not result in complete regeneration of attachment
what is dentine hypersensitivity
dental pain sharp in character & of short duration, arising from exposed dentine surfaces in response to a stimuli i.e. thermal, tactile, osmotic, chemical, electrical and which cannot be ascribed to any other dental disease. porous enamel / exposed dentine facilitates fluid flow within dentinal tubules to activate A-delta nerve fibres known as the hydrodynamic theory which elicits responses felt by ptx
describe reversible pulpitis
inflammation that should resolve following appropriate management of aetiology i.e. no RCT
causes - exposed dentine (hypersensitivity), caries, deep restorations
radiography - no significant changes in periapical region of suspected tooth
symptoms - discomfort is experience when a stimulus is applied lasting only a few seconds, pain not spontaneous, pain to cold; lasts a short time, no change in blood flow, hydrodynamic expression; microleakage from a-delta fibres
describe chronic periodontitis
characterised by destruction of junctional epithelium & CT attachment of tooth together with bone destruction & formation of periodontal pockets, the disease progresses slowly & amount of bone loss tends to reflect the age of the patient over time. generalised affects >30% of teeth
describe localised periodontitis
same as chronic but affects <30%
describe aggressive periodontitis
severe condition usually found in younger cohort which may be associated with a family history of aggressive perio; disease progression is rapid with severe destruction of CT attachment & bone considering age of ptx, plaque levels may be inconsistent with level of disease seen
what are periodontal lesions with endodontic involvement
- primary periodontal - generalised periodontitis present, minimally unrestored tooth, usually non vital, combined perio-endo lesion occurs when ptx has not only clinical LoA but also necrotic or partially necrotic pulp
- perio lesion with endo involvement - apical progression of perio pocket may continue until apical tissues involved so pulp can become necrotic as a result of infection entering via lateral canals or apical foramen. this results in plaque colonisation of external root surfaces which has limited effect on a normal healthy pulp but pulp necrosis may occur when the perio disease has extended to involved the apical foramen. if blood supply circulating through the apex is intact, the pulp has good prospects of survival; pulpal changes resulting from perio disease are more likely to occur when apical foramen is involved & in these cases, bacteria originating from the perio pocket are the most likely source of root canal infection
what is occlusal trauma
does not cause perio, causes tooth mobility which is progressively increasing, tooth mobility with associated symptoms & radiographic evidence of an increased PDL width; in combination with plaque induced inflammation this may exacerbate LoA; tx:
- control plaque induced inflammation
- correction of occlusal relations
- splinting of teeth when; mobility is due to advanced LoA, when mobiltiy causing discomfort / difficulty when chewing, when teeth need stabilised for debridement
what is a true combined endo & perio lesion
usually formed when an endo lesion progresses coronally & joins with an infected periodontal pocket progressing apically meaning the tooth will be non vital & periodontitis will likely be detected in other areas of mouth with clear periapical & alveolar bone loss; it is the coalescence of independently rising endo & perio lesions on the same tooth
describe a periodontal abscess
localised acute exacerbation of pre-existing pocket (chronic perio) caused by trauma to pocket epithelium or obstruction to pocket entrance
symptoms - pain on biting / constant pain
o/e - swelling adjacent to periodontal pocket, tooth may be TTP, suppuration - discharge through sinus / pocket, more likely to have pain on lateral movement, more likely to have generalised horizontal bone loss
tx - drainage via incision or via pocket with instrumentation to dilate, gentle sub-gingival debridement, hot saline mouthwash, XLA of teeth with poor prognosis, antibiotic use if systemic involvement & may prevent rapid destruction of attachment (amoxicillin / metronidazole)
follow up - HPT, surgery if required, maintenance
describe periapical periodontitis
can be symptomatic / asymptomatic:
SYMPTOMATIC:
- represents inflammation usually of apical periodontium that extends beyond root canals, can cause resorption & LoA
- may be painful response to biting, palpation or percussion
- may be accompanied by radiographic changes such as periapical radiolucency
- severe pain to percussion is indicative of degenerating pulp & RCT required
ASYMPTOMATIC:
- inflammation & destruction of apical periodontium of pulpal origin
apical migration of junction epithelium
- appears as apical radiolucency & does not present with clinical symptoms; no pain on percussion / palpation
risk factors = plaque accumulation, diabetes, stress
how do you classify severity of bone loss seen on radiographs
- mild = <30% root length i.e. coronal 1/3
- moderate = 30-50% root length i.e. mid 1/3
- severe = >50% root length i.e. apical 1/3
suppurating pocket mid buccal of 46, tooth is non vital & there is no other attachment loss throughout dentition, what is the diagnosis
primary endodontic lesion with 2ndary perio involvement;
suppurating primary endo disease remains untreated, plaque forms at gingival margin of sinus tract and leads to plaque induced perio in this area
what features of anatomy determine where pus from the pocket is coming from
sinus tract - you can place gutta percha cone 25-30mm and pass it into sinus tract which allows it to follow to the point of origin of the endodontic lesion
if grade II mobility getting increasingly worse with no LoA, ptx has signs of generalised tooth loss attributed to attrition & radiograph shows widening of PDL what is the diagnosis
occlusal trauma as it does not cause periodontitis, it causes tooth mobility which is progressively increasing, associated symptoms & radiographic evidence of increased PDL width which in combination with plaque induced inflammation may exacerbate LoA
how would you manage ptx with occlusal trauma
tx -
control plaque induced inflammation
correction of occlusal relations
splinting of teeth when:
- mobility is due to advanced LoA
- when mobility is causing discomfort / difficulty when chewing
- when teeth need stabilised for debridement
50yr old ptx presents with lightly restored dentition & on examination the BPE is 4 in all quadrants; what is the diagnosis & what further investigations should be made
generalised chronic gingivitis:
- plaque & gingivitis charting
- OHI
- removal of supragingival plaque, calculus & staining
- removal of sub-gingival plaque & calculus
- correction of restoration margins
- full periodontal 6PPC of all teeth
- RSD where necessary
- take radiographs of affected areas
- re-evaluation
ptx comes into surgery with pain which keeps them awake at night & pain is persistent; what is the diagnosis & how would you manage the pain
symptomatic irreversible pulpitis; pulpectomy then RCT / XLA required, antibiotics / analgesics usually have no effect
what 2 things are required for accurately mounting study casts on an articulator
- jaw reg
- occlusal rims - setting upper teeth to wax rim & set lower to uppers in RCP
what is the relevance of FWS in complete denture construction
FWS = RVD-OVD which is ideally around 2-4mm
if FWS is negative / reduced due to increase in OVD it will cause the dentures to click
if teeth contact during speech there is not enough inter-occlusal space which means the OVD needs reduced to give more FWS
what is the main way to reduce HAIs
using standard infection control precautions (SICPs) are the basic infection prevention & control measures necessary to reduce the risk of transmission of infectious agents from both recognised & unrecognised sources of infection
name all 10 SICPs
- patient placement / assessment for infection risk
- hand hygiene
- respiratory & cough hygiene
- PPE
- safe management of care equipment
- safe management of care environment
- safe management of linen
- safe management of blood & bodily fluid spillages
- safe disposal of waste inc sharps
- occupational safety; prevention & exposure management inc sharps
name solution used to clean a blood spillage
actichlor plus (sodium hypochlorite) - 10,000ppm for 3-5mins
what is the chain of infection
- infectious agent (bacteria, viruses, fungi, parasites)
- reservoir (dirty surfaces & equipment, people, animals)
- portal of exit (open wounds, skin, aerosols, splatter of fluids)
- mode of transmission (contact, ingestion, inhalation)
- portal of entry (broken skin/incisions, mucous membranes)
- susceptible host (elderly, immunocompromised more likely)
how is the chain of infection broken for contaminated forceps
chain is broken at the reservoir where there dirty contaminated forceps
should break the chain by cleaning, disinfecting & sterilising instrument prior to use
what is the highest level of evidence study
cochrane reviews which are systematic assessments of all the relevant randomised controlled trials (RCTs) which give the highest level of evidence
what are the advantages of a cochrane review
- randomisation reduces bias & and be double blind studies
- gold standard for comparing the effectiveness of one treatment to another
- control group comparability to no treatment
how can you confirm if results are statistically significant with regards to confidence intervals & p values
- when confidence limit does not overlap 1 - statistically significant
- if P value is less than 0.05 - statistically significant
what is relative risk
it is the ratio of incidence in exposed groups to incidence rates in non exposed groups
it is the measurement of proportionate increase in disease rates of exposed groups
it makes allowance for frequency of disease amongst people not exposed to harmful agents
what other types of studies other than cochrane review & RCT
- cohort studies - prospective studies which recruit groups of people who have no manifested the disease at time of recruitment & assess risk factors, individuals in this study are observed over a period of time to measure frequency of occurrence of disease among people exposed to risk factors & people not exposed to risk factor
- case control study - a retrospective study which compares individuals with disease (cases) to those without disease (controls) and then you trace back to assess risk factor through past histories & exposure to suspected harmful agents compared, these are less robust than cohort studies but they may be used for preliminary investigations of hypothesis followed by cohort if possible, controls should be random sample of population from which cases are selected
suggest a study & example, give 4 features
randomised double blind placebo controlled study to investigate dimethyl fumarate (tecfidera) on annual relapserate, progression of disability & MRI findings in RRMS ptx. features:
1. randomised double blind reducing bias of results which meant ptx were unaware of which treatment they were receiving & were randomly selected into the 2 groups
2. compares one tx over placebo to investigate it there is any statistically significant results from use of tecfidera
3. randomisation of these studies facilitates statistical analysis
4. follow up over 2 years which will give increased results for analysing
5. rely on volunteers and would want large volunteer group who haven’t’ been on any prior DMDs
to carry out one of the key features:
making a key eligibility criterion to ensure there is a large volunteer group who have RRMS but haven’t been on previous DMDs =
- age group 18-55
- diagnosis of RRMS by McDonald Criteria
- baselines score of 0-5 on expanded disability status scale (EDSS)
- no previous DMD tx for RRMS
- radiographic evidence of relapse in last year
what are the normal dental & occlusal features you would expect to find in a 10yr old
dental -
teeth erupted, absence of crowding / spacing, good alignment, incisors of average inclination, Cs & Ds may be mobile or exfoliated, may have midline diastema with distally tipped central & lateral incisors as normal development feature due to position of upper Es relative to 3s roots = ugly duckling stage, canines palpable buccally, tooth wear on deciduous teeth
occlusal -
incisors class I = normal to have OJ & OB, molars tend to be slight class II due to relatively large size of lower Es, there should be no cross bite
clinical features present in primary hyperparathyroidism
- painful swelling of mandible
- renal stones
- bone pain elsewhere
- polydipsia / polyuria
- peptic ulceration pain
radiographic features present in primary hyperparathyroidism (4)
- generalised osteoporosis
- loss of lamina dura
- sub-periosteal resorption in fingers & resorption in terminal phalanges
- multiple bone cysts
what abnormal biochemical results would you expect from primary hyperparathyroidism (5)
- calcium raised
- phosphate & alkaline phosphatase may be raised
- hypercalciuria (calcium in urine)
- parathyroid hormone (PTH) raised
- vit D levels reduced
what are the main complications of primary hyperparathyroidism
- irreversible renal damage
- pathological features
what treatment is indicated for primary hyperparathyroidism
- parathyroidectomy
- vit D supplementation
during routine tx, ptx develops chest pain which is central & crushing & radiates to arm
a) what is the most likely diagnosis
b) what should you do
a) possibly myocardial infarction
b) priority is to transfer ptx to hospital as an emergency, give 300mg crushed aspirin, reassure ptx & loosen any tight clothing, call ambulance, initiate BLS using 100% oxygen at 15L/min, use of defibrillator until ambulance arrives if in cardiac arrest begins
ratio of compressions to ventilations in BLS & how long for
30 compressions to 2 rescue breaths using bag valve mask
until ambulance arrives while using both CPR & defib if ptx has shockable rhythm ( ventricular fibrillation & pulseless ventricular tachycardia)
emergency drugs essential for every dental practice (5)
- adrenaline IM injections (1:1000, 1mg/ml)
- aspirin dispersible (300mg)
- glucagon IM injection (1mg)
- glyceryl trinitrate GTN spray (400ug/dose)
- midazolam IM injection (5mg/ml, 2ml ampoules)
pieces of equipment essential for every dental practice (5)
- oxygen cylinder with bag valve mask
- single use sterile needles
- automated external defib (AED)
- portable powered suction machine with appropriate suction tips & tubing
- oro-pharyngeal airways adjuvants for adults & children
what 4 factors cause tooth mobility
- dental trauma
- periodontitis causing LoA
- malocclusions
- inflammation of tissues supporting teeth e.g. periapical abscess
when would you intervene with tooth mobility
splint teeth when:
- mobility due to advanced LoA
- mobility is causing discomfort / difficulty chewing
- teeth need stabilised for debridement
when trauma has occurred & requires stabilisation & correct of occlusal relations to prevent pain / loss of tooth etc
when tooth has periapical pathologies & possible pulpal involvement it may require RCT/XLA
if ptx has moderate advanced perio with successful HPT, would the mobility increase or decrease and why
mobility can increase after successful HPT as all calculus deposits that may have been giving tooth some support would now be removed
also due to advanced perio there would already be evidence of tooth mobility with obvious radiographic bone loss which cannot be replenished even after HPT
ptx has mobile lower incisors which are annoying / causing discomfort, ptx refuses XLA & there is horizontal bone loss on radiograph, what would you advise
- best option due to horizontal bone loss present would be XLA with immediate partial denture fitted then possibility of bridge after 6mths once XLA sockets have healed
- it ptx is adamant they won’t have teeth removed then carry out HPT steps & possibly splint teeth to prevent discomfort & difficulty eating but over time this will fail & if oral hygiene is not kept up to standard the bone loss will progress & eventually teeth would fall out on their own
- ptx needs to be made aware that they don’t want to end up in pain & is any periapical / periodontal pathologies arise then it wouldn’t be beneficial to RCT & would need XLA
aims for retracting a flap
- wide based incision for circulation
- use of scalpel in 1 firm continuous stroke with no sharp angles
- adequate sized flap as large flaps heal just as quickly as smaller ones
- flap reflection should be down to bone & done cleanly to minimise trauma to dental papilla
- should be no crushing of tissues & keep tissues moist
- ensure flap margins & sutures will lie on bone
- make sure wounds are not closed under tension
- aim for healing by primary intention to minimise scarring
what factors influence design of flap
- type of surgery being carried out i.e. retrieval of # roots, surgical XLA, apical lesions, periradicular surgery, OAC/OAF, apex removal
- proximity of important structures such as nerves & muscles - lingual nerve can be damaged during surgical removal of lower 3rd molars
- area of mouth - design can be influenced if area of aesthetics, if there is a narrow ridge bone augmentation may be required so wide flap designs should be utilised
what instruments are used to remove bone
use of electric straight handpiece with a saline cooled bur:
- round or fissure tungsten carbide bur should be used
- air driven hand piece may lead to surgical emphysema so use electric
how do you carry out debridement prior to suturing (3)
- physical debridement - bone file / handpieces used to remove sharp bony edges, Mitchell’s trimmer / Victoria curette used to remove soft tissue debris
- irrigation - sterile saline / water put into socket & under flap to flush out any debris
- suction - aspirate under flap to remove debris, check socket for retained apices etc
ptx has suspected bleeding disorder; what 3 blood tests would you ask for
- FBC - haematology
- coagulation screen - prothrombin time (PT), partial thromboplastin time (PTT), activated partial thromboplastin time (APTT), APTT ratio, INR, fibrinogen
- thrombophilia & haemophilia factor screen
name a disorder of platelet numbers
thrombocytopenia - condition characterised by abnormally low levels of thrombocytes (platelets) in blood; diagnosed when below normal lower limit of 150x10 to 9/L
what LA technique can be used on ptx with bleeding disorders
all techniques except lingual infiltrations & IDB
what are the ideal INR values for oral surgery
INR = 1 ; level of coagulation equivalent to an average person not on warfarin but INR > 1 indicates long clotting time and so longer bleeding time. these should be checked 72hrs prior to oral surgery
INR < 4 = allows for tx to occur without interrupting anti coag medicine, safest between 1.5-2.5
LA technique for warfarin ptx
infiltrations (except lingual), intraligamentary or mental nerve blocks are best used
if no alternative & IDB needs to be used, the injection should be administered slowly using aspirating technique
2 safety features of amalgam containers
- rigid waste bin containers with suppressant & screw top lids to prevent mercury vapour from seeping into atmosphere
- clearly labelled with amalgam & have a red lid & white body to easily differentiate from other bin types for waste which are usually yellow bodied
what is the licence regarding disposal of amalgam & how long should it be kept
the consignment note which should be kept for at least 3 years
3 forms of candida
- pseudomembranous i.e. thrush
- erythematous i.e. atrophic (HIV related), denture related, candida leucoplakia
- hyperplastic i.e. angular cheilitis
main antifungal medications used
- systemic oral azoles - fluconazole, miconazole, itraconazole
- topical polyenes & echinocandins - nystatin (polyene), caspofungin (echinocandin) these are active & resistance is rare
mode of action of anti fungals
Azole mode of action (Fluconazole, Miconazole):
— Azoles mechanism of action is the inhibition of cytochrome P450- dependent enzymes (particularly 14ademethylase) which is involved in the biosynthesis of ergosterol, which is required for fungal cell membrane
structure and function.
— Ensure that Miconazole is not prescribes for patients
taking warfarin or statins
- Polyene mode of action (Nystatin):
— These interact with fungal membrane sterols physiochemically. They bind to ergosterol in the fungal cell
membrane which weakens it, causing leakage of
potassium and sodium ions which may contribute to
fungal cell death.
- Echinocandin (Caspofungin):
— New class of antifungal drugs that inhibit the synthesis
of glucan in the cell wall, via non-competitive inhibition
of the enzyme 1,3-Beta-glucan synthase which the
yeast requires to survive
2 mechanisms that make candida resistant
- azole resistance:
- decreased drug conc; The development of active efflux pumps results in decreased drug concentrations at the site of action. Efflux pumps encoded in candida species
become overexpressed and upregulated especially MDR1 in azole resistant candida albicans
- target site alteration; It had been found that mutations in ERG11
which encodes the target enzyme lanosterol
C12-alpha-demethylase prevents binding of
azoles to the enzymatic site. - polyene resistance - Polyene resistant candida isolates have relatively low
ergosterol content which is thought to be due to a
defect in the ERG3 gene involved in ergosterol
biosynthesis - enchocandin resistance - In candida sp, secondary resistance is associated with
point mutations in the Fks1 gene of the beta-1,3-Dglucan synthase complex
name another species of candida rather than albicans & how they differ
candida glabrata
This is a non-dimorphic species of yeast as no mating is
observed compared to C. albicans which is dimorphic
— Highly opportunistic pathogen in the urogenital tract
and bloodstream of immunocompromised patients
where as C. albicans is part of the normal human gut
flora.
— Nystatin is the first line treatment for C. Glabrata
infections whereas fluconazole is generally used in C.
albicans infections
before prescribing f- mouthrinse what should you check
- age of child as they must be 6+
- check if they are on any other fluoride supplements
- ensure ptx has ability to spit & not swallow
difference in conventional vs post & crown
Conventional:
— Used when there is sufficient tooth crown tissue left to
place a conventional crown on top
— Much stronger type of crown as no preparation is
required of the root canals for a post
- Post and core:
— Used when there is significant loss of crown tooth
tissue so a core is used t gain intraradicular support for
a definitive coronal restoration such as retention for a
crown and the post then retains the core holding onto
the coronal restoration
— Root canal preparations for a post will weaken the
tooth
function of post
will retain core by holding on to coronal restoration
2 materials for core & post
post - metals (gold, SS, brass, titanium), ceramics (alumina or zirconia), fibre (glass, quartz, carbon)
core - composite, amalgam, GI
3 ways to detemine post lengths
- customs posts - cast directly from pattern fabricated in a patient’s mouth as an impression of the pot hole & wax up of post in lab occurs
- post placement - 4-5mm of root filling should be left apically which should be known from CWL and post takes up rest of canal
- sufficient alveolar bone support - at least 1/2 of post length must go into root, maximum of 1;1 post length / crown height ratio
problems associated with posts that are inserted into canals that are too wide or too narrow
narrow - risk of perforation dur to thin / tapering & narrow roots
wide - requires further prep which weakens tooth
general issues - perforations, core fractures, root fractures or cracks, post fracture, post removal required which is difficult as significant pressure has to be applied
general health effects of smoking (6)
Narrows the arteries and increases atherosclerosis
- Increased risk of stroke
- Increased chest infections, COPD, bronchitis, emphysema and
lung cancer
- Increased stomach ulcers and stomach cancer
- Increased risk of CHD and heart attacks
- Can cause macular degeneration and peripheral vascular
disease
oral health effects of smoking
Increased risk of oral cancer (2-4x higher risk)
- Increase in periodontal disease, alveolar bone loss, attachment
loss and pocket formation
- Increased risk of dry socket after dental extractions
- Bad breath (halitosis) and xerostomia
- Staining of teeth and restorations
- Black hair tongue and nicotine stomatitis
health promotion approaches in scotland that have reduced smoking
- Age of purchase increasing from 16 to 18
- Plain packaging of tobacco with health warnings on the packet
which are no longer visibly on sale - Vending machines stopped selling cigarettes
- Public smoking ban in 2006
approaches to smoking cessation that can be used in dental practice
- 5As (brief cessation):
— Ask your patient
— Advise your patient
— Assess your patient
— Assist your patient
— Arrange a follow up for your patient - Alternative model - Ask advice and refer (2As and 1R):
— Ask your patient about smoking
— Advise your patient about smoking
— Refer to stop smoking services which varies locally with
group therapy or one-to-one - ABC (brief);
— Ask your patient about smoking
— Brief advice to quit given to your patient
— Cessation support for those who want to quit - SCAPE 30 second approach (very brief):
— Smoking Cessation Action in Primary carE
crown prep for MCC incisors - incisal surface, labial surface & palatal surface
Incisal surface:
i. What is the margin design and reductions?
- 1.5-2mm reduction to accommodate porcelain and metal
b. Labial surface:
i. What is the margin design and reductions?
- 1-1.5mm reduction extending into gingival sulcus
- Labial shoulder used
ii. What are the benefits of the margin design?
- Rounds the angles and allows for resistance and retention for
the crown
- Technique preserves tooth surface which avoids weakening
the tooth structure and damaging the pulp
c. Palatal surface:
i. What is the margin design and reduction?
- 1-1.5mm reduction following contour of incisor tooth
- Palatal chamfer used (palatal chamfer for all ceramic crown)
ii. What are the benefits of the margin design?
- Rounds the angles and allows for resistance and retention for
the crown
- Technique preserves tooth surface which avoids weakening
the tooth structure and daring the pulp.
- It also keep marginal integrity to accommodate a robust
margin with close adaption to minimise microleakage
properties of impression material suitable for crown prep
- Sectional impression technique:
— Addition cured silicone putty (president):
i. Can be disinfected and kept by the patient or
clinic and can be re-used which is very
beneficial if the crown is ever lost or broken.
ii. Resistant to tearing when removing from
undercut areas.
— Alginate:
i. Cheaper to use but cannot be kept or reused
ii. Elastic material so flows into undercuts
iii. Usually used for diagnostic wax-ups
— Softened modelling wax:
i. Easy to adjust and smooth and is cheap to use
ii. It is unsuitable for deep undercuts as it distorts
and cannot be reduced
what types of custom tray & spacer used in full dentures
- Alginate use for special trays should have 3mm spacer
- Silicone/polyether use for special trays should have 2mm for
upper and 0.5-1mm spacers for lowers - Upper trays should have stops to the space prescribed in the
canine and post dam regions which will allow accurate
correction of the posterior borders of the tray and will
perform space for the impression material. - Lower trays should have stops to the space prescribed on the
retro-molar pad and on the ridge in the canine areas. This will
allow preformed space for the impression material
what IM is used for full denture primary imps & why
- Usually alginate is used as it is an elastic materials so flows into
undercut areas. It gives an accurate record of surface detail for
impressions and is cheap and easy to use.
what IM is not used for full denture primary imps & why
Silicone is dimensionally stable and is hydrophobic so can
cause small defects and blows. It is generally only used for
master impressions and not for the production of special trays
as it is very messy and technique sensitive
what 2 areas of primary support are on the maxilla
hard palate & residual ridge
area of support on mandibular arch & what muscle lies adjacent to it
- Retro-molar pad
- Muscles that lie next to it are:
— Laterally buccinator
— Posteriorly temporalis tendon
— Medically superior constrictor and the
pterygomandibular raphe
what part of mandible may interfere with maxillary impression within tuberosity regions during lateral excursion when taking a functional impression
It can interfere with the location of the occlusal plane and
reduce the space available for the denture in the retro-molar
pad region.
6 links in chain of infection
- Infectious agent
- Reservoirs
- Portal of exit
- Means of transmission
- Portal of entry
- Susceptible host
2 ways to break chain of infection
Break at portal of exit:
— Ensuring hand hygiene is always performed
— PPE is worn
— Respiratory etiquette
— Control of aerosols and splatter
- Break at mode of transmission:
— Ensuring hand hygiene is always performed
— PPE is worm
— Food safety
— Isolation of personals affected
— Cleaning, disinfection and sterilisation
how to determine if impression is suitable
- There should be a good peripheral seal
- Should have adequate surface detail recorded
- Complete reproduction of prepared margins without voids
present - No air blows present or distortion
- No tears when removing if there are undercuts present
4 potential faults & why in impression
- Impression becomes distorted:
— not dimensionally accurate or stable
— Alginate too stiff so the impression has lumpy
appearance
— Alginate tearing away from the tray - Insufficient depth in the lingual, labial or buccal sulcus:
— due to lack of Impression material
— Using low pressure to seat the tray
— Material is too cold and can’t flow - Incomplete reproduction of preparation margins:
— Insufficient retraction used
— Blood and saliva present around the presentation
which should have been cleaned
— Working time exceeded, flowability becomes impaired - Void on the margins:
— Blood and saliva contamination around preparation
— Improper syringe technique
— Working time exceeded, flowability becomes impaired
— Air bubble in elastomer syringe
— Tray not seated properly
how to decontaminate impression
- Rinse under the tap to remove gross debris and saliva
- Place in perform for 10 minutes then re-rinse and place in bag
covered in a wet paper towel to prevent the impression from
drying out - Fill out lab prescription ensuring it has been ticked that it has
been disinfected and send to lab - Perform contains:
— Potassium periximono sulphate
— Sodium benzate
— Tartanic acid
— An ionic surfactants
— Non-ionic surfactants
— Soap and phosphanate
what is hanau’s quint (5 factors affecting occlusal balanced articulation)
- The saggital condylar guidance angle
- The inclination of the occlusal plane
- Compensating curves
- The cusp height
- The Incisal guidance angle
name ideal features of CaOH & why it is a good medicament
- It has bactericidal and bacteriostatic properties
- It has a high pH making it alkaline which:
— stimulates fibroblasts for reparative dentine formation
— Stimulates recalcification of demineralised dentine by
stimulating pulpal cells
— Neutralises low pH from acidic restorative materials - They adhere directly to the dentine rather than the restorative
material - It is thin which means it won’t reduce the strength of the
restorative material - It won’t dissolve in biological liquids
3 reasons to obturate
- inhibits bacterial growth
- can be easily removed
- seals canals laterally & apically
ideal properties of sealer
- Exhibits tackiness to provide good adhesion
- Establishes a hermetic seal
- Radiopacity
- No shrinkage on setting
- Non-staining
- Bacteriostatic
- Slow setting
- Insoluble in tissue fluids
- Tissue tolerant
- Soluble on re-treatment
- Easily mixed
constituents of GP
- 20% gutta percha
- 65% zinc oxide
- 10% radio-pacifiers
- 5% plasticisers
problems associated with tooth whitening
- Sensitivity:
— Common in 60% of patients
— Worse initially then resolves over 2-3 days post
bleaching - Wears off-relapse:
— Oxidised chromosomes gradually reduce with time
— Retreatment required every 1-3 years - Cytotoxicity/multiagency:
— High concentration of hydrogen peroxide causes
problems
— No evidence for 10% carbamine peroxide - Gingival irritation:
— Related to concentration used – worse with higher
concentrations
— Must check tray extension is correct - Problems with binding to teeth:
— Residual oxygen from the peroxide remains within the
enamel structure initially but gradually dissipates over
a short time
— Restorative procedures should be delayed for at least
24 hours-1 week post bleaching
predisposing factors for experiencing sensitivity when tooth whitening
- Pre-existing sensitivity
- High concentration of bleaching agent used
- Frequency of use
- Bleaching method – less likely at home than in office
- Gingival recession
what is capacity & what acts cover capacity in england & scotland
- Capacity means the ability to use and understand information
to make an informed decision, and communicate any decision
made. - A person lacks capacity if their mind is impaired or disturbed in
some way and this mans the person is unable to make a
decision at that point in Time
1. adults with incapacity act (scotland) 2000
2. mental capacity act (england & wales) 2005
signs of parkinson’s
- Bradykinesia – slow movement
- Rigidity
- Resting tremor
- Postural instability
- Gradual symptom progression
- Mask like face
how does parkinson’s differ from cerebral palsy
- Parkinson’s typically presents with intention tremors and
Parkinsonism tremor at rest:
— Intention tremor is present when tremor amplitude
increases during visually guided movements towards a
target at the termination of movement - Ataxia Cerebral palsy typically presents with action intentional
tremors which is especially apparent when carrying out precise
movements.
causes of dry mouth
Medications and polypharmacy:
— Tricyclics antidepressants – amitriptyline
— Anti-psychotics – phenothiazine
— Benzodiazepines – diazepam
— Anti-cholinergic – atropine
— Beta blockers – atenolol
— Antihistamines – cetirizine
- Medical treatments:
— Radiotherapy and chemotherapy
- Medical conditions:
— Parkinson’s disease
— Rheumatoid arthritis
— Undiagnosed diabetes
— Sjorgen’s syndrome
— Neurological disorders
— Cystic fibrosis
tx for dry mouth
- Stimulation of salivary glands:
— With chewing sugar free gum/sweets - Supplementation or provide a substitute for saliva:
— Oral lubricants - Management:
— Taking frequent sips of water
— Moisten food when eating with water or sauces
— Avoid mouthwashes that contain alcohol
— Suck on ice chips/cubes
— Avoid dry hard food
— Avoid drinks containing alcohol or caffeine
name positioning faults & what would occur on radiograph
- Speed of beam through the teeth and image receptor through
the beam must be synchronised to produce an accurate image - Patients canine behind the canine guide line which means it is
closer to the x-ray source than the machine expects. This
causes the speed of the beam to be slower through the teeth
as it is closer to the rotation centre. If not compensated, the
image receptor will be too fast and the image will be
magnified horizontally. - Patients canine in front of the canine guide line means it is
further from the x-ray source than the machine expects. This
causes the speed of the beam to be faster through the teeth
as it is further from the rotation centre. If not compensated
the image receptor will be too slow and the image of teeth will
be reduced in width horizontally.
causes of unerupted central incisor
- supernumerary tooth
- dilaceration caused by trauma
how to treat unerupted tooth
- Surgical exposure
- Removal of supernumerary if there is one present
- Binding using gold chain
- Orthodontic traction used if over age of 9
- Fixed appliance use
- Bonded retainer
5 main ortho principles
- Improve function:
— Anterior cross bite or anterior open bite CNS make it
difficult to incise food - To facilitate other dental treatment:
— Rearrange spaces in hypodontia cases prior to bridges
or implants - Improve appearance and aesthetics
- Improve dental health as the teeth become more easy to clean
- Reduce risk of trauma
types of radiographs taken for children
- Bitewings:
— For small proximal cavities, monitoring, occult caries,
furcation pathology and restoration margin integrity - OPT:
— For poor cooperating children and when caries is more
than minimal
— Delayed development cases - Maxillary occlusal:
— trauma cases - Periapicals:
— Trauma, periapical pathologies, fracture etc.
order of paediatric treatment
- Restoration sequences:
— Fluoride varnish
— Fissure sealants
— Preventative restorations (GI)
— Simple fillings e.g. shallow cervical cavities
— Restorations requiring LA but not into the pulp
— Pulpotomy (upper arch first)
— Extractions under LA or GA - Preventative programme:
— Radiographs
— Tooth brushing instruction
— Strength of fluoride in toothpaste advice
— Fluoride varnish
— Fluoride supplementation
— Diet advice
— Fissure sealants
— Sugar free medication
why carry out HPT before surgical procedures
- The aim of HPT is to:
— Arrest the disease process
— Regenerate lost tissue
— Maintain periodontal health long term
— Prevent extractions
— Preservation of functional dentition for life - HPT allows evaluation of the patients motivation and plaque
control while improving soft tissue consistent for easier
surgical management. - Some Deep pockets that may be present can heal after HPT
meaning surgical intervention may not be required. - It is essential to carry out HPT prior to surgical procedures to
ensure that the patient can maintain good oral hygiene as any
surgical or restorative treatments carried out before HPT
would have a greater risk of failure when oral hygiene is poor
why should perio surgery be carried out
- The indications for periodontal surgery are:
— At re-evaluation at least 4-6 weeks after completion of
non-surgical phase is there is pockets of 5mm or
greater that exist in the presence of excellent oral
hygiene. - The aims of periodontal surgery are:
— To arrest the disease by gaining access to complete
root surface debridement and to regenerate lost
periodontal tissues.
what is the review period post perio surgery
- Re-evaluation at 4-6 as you don’t want to be probing tissues
that are in the process of healing and repairing - Sutures may be required to be removed after 1 week
what should GDP check when reviewing ptx with previous surgical RSD
- Poor oral hygiene with persistent inflammation:
— Supportive care or repeat cause related therapies - Good oral hygiene with inflammation resolved:
— Supportive care and proceed with treatment plan - Good oral hygiene with persistent deep pockets with bleeding
on probing:
— Surgical access or repeat SRP, then re-evaluate
what is dry socket called
localised / alveolar osteitis
it is inflammation affecting the lamina dura which causes dry socket; this is when the blood clot at the site of XLA has failed to develop / dislodges / dissolves before the wound has fully healed; usually isn’t associated with infection
who does dry socket more commonly affect
Affects 2-3% of all extractions
- 20-35% of lower 8 extractions
- Predisposing factors:
— Molars are more common – risk is increased from
anterior to posterior
— Mandible is more common than maxilla
— Smoking increases risk due to reduced blood supply
— More common in females than in males
— Oral contraceptive pill can increase risk
— Excessive trauma during extraction procedure
— Excessive mouth rinsing post extraction which washes
the clot away
— Family history of previous dry sockets
signs & symptoms of dry socket
- Signs:
— Often begins 3-4days after extraction and can take 7-14
days to resolve
— No blood clot present in the extraction socket - Symptoms:
— Moderate to severe dull aching pain
— Pain that keeps the patient awake at night
— Pain that throbs and can radiate to the patients ear
— Exposed bone is sensitive and is the source of pain
— Characteristic smell/bad odour (halitosis) with patient
complaining of bad taste
how do we manage a dry socket
- Supportive:
— Reassurance and use systemic preemptive analgesia
— Give the patient information on dry sockets - Can give LA block to relive severe pain
- Irrigate the socket with warm saline to wash put food and
debris - Curettage/debridement:
— Encourage bleeding and new clot formation - Use whiteshead varnish pack (WHVP) or Alvogyl:
— WHVP is ribbon gauze socked in WHVP often sutured
into the pocket which will need removed
— Alvogyl is a mixture of LA and antiseptic (ensure patient
doesn’t have an iodine allergy) - Advise patient on analgesia and hot salty mouthwashes or
chlorhexidine use
why do we remove air from process of ultrasonic washing
Degassing must occur, if we leave added oxygen/air in
the water this inhibits cavitation and a different bubble
is formed with less intensity
— Without degassing the cleaner would be less effective
how often should degassing occur
Always run an air purge (degassing) cycle after filling the
ultrasonic in the morning to remove air and oxygen from
water before cleaning
sterilised v sterile
Sterilised:
— When something has went through a process of
becoming free from bacteria and all other living
microorganisms.
- Sterile:
— An object that is free from all microorganisms
peri operative XLA complications
Difficulty of access due to:
— Trismus – limited mouth opening
— Reduced aperture of the mouth
— Crowded and malpositioned teeth
- Abnormal resistance:
— Thick cortical bone
— Shape/form of roots – divergent/hooked roots
— Number of roots
— Hypercementosis
— Ankylosis
- Fractures:
— Teeth fractures of crown and/or root
— Alveolar/tuberosity
— Jaw fractures
— Alveolar plate
- Root problems:
— Fused
— Convergent/divergent roots
— Extra roots
— Morphology of the roots different
— Hypercementosis
— Ankylosis
- Involvement of the maxillary antrum:
— Oro-antral fistula/communication (OAC/OAF)
— Loss of root into antrum
— Fractured tuberosity
- Loss of tooth
- Soft tissue damage
- Damage to nerves and vessels:
— Crushing injuries
— Cutting/shredding injuries
— Transaction
— Damage from surgery or damage from LA
- Haemorrhage:
— Due to damage of veins (bleeding), arteries (spurting,
haemorrhaging), arterioles (spurting/pulsating bleed)
- Dislocation of TMJ
- Damage to adjacent teeth and restorations:
— Hitting opposing teeth with forceps
— Cracking/fracturing or moving adjacent teeth with
elevators
— Cracking/fracturing/removing restorations, crown,
bridges on adjacent teeth
- Extractions of permanent tooth germ:
— When removing deciduous molars there can be
damage or extraction of the developing permanent
premolars
- Wrong tooth extracted
describe position of mental nerve & tissues that supply it
- The mental foramen is located on the anterior surface of the
mandible. It transmits the terminal branches of the interior
alveolar nerve and mental artery. - It is located roughly between the 1st and 2nd premolars on the
mandible - It provides sensory innervation to the buccal soft tissue
anterior to the mental foramen, lip and the chin and the
anterior teeth on that side of the arch
3 types of surgical flap and what they are used for
- triangular 3 sided flap for retained single roots
- envelope 2 sided flap for retained 2 rooted teeth
- semilunar 1 sided flap used for periapical involvement
4 different types of diabetes
Types 1 diabetes mellitus:
— Results from the pancreas’s failure to produce enough
insulin due to the loss of insulin producing beta cells of
the islets of Langerhans which leads to insulin
deficiency.
— Most commonly associated with juvenile onset
- Type 2 diabetes mellitus:
— Condition that begins with insulin resistance where the
pancreatic cells fail to respond to insulin properly.
— Most commonly associated with excessive body weight
and insufficient exercise
- Gestational diabetes:
— Occurs in pregnant women due who develop high
blood sugar levels during pregnancy
- Diabetes insipidus:
— Is a condition characterised by large amounts of dilute
urine and thrust due to lack of the hormone
vasopressin (ADH) which dan be caused due to damage
to the hypothalamus, pituitary gland or genetics.
how do you test for diabetes
Blood glucose levels:
— Normal 3.5-5.5mmol/l; diabetic 4-7mmol/l before
meals
— Normal less than 8mmol/l; 5-9mmol 2 hours after
meals
- Urine testing
- HbA1c 3 monthly:
— Adults with diabetes target is below 4rmmol/l
who is involved in multi disciplinary team for cancer tx
Oncologist Surgeon/consultant
- Radiotherapist (radiation oncologist)
- Chemotherapist (medical oncologist)
- Clinical nurse specialist
- Radiologist
- Others as indicated by the cancer type (gynaecologist;
urologist)
- GDP
- Maxillofacial surgeon (oral cancer)
side effects of radiotherapy
General tiredness
- Burns – clothing/shaving/sunlight issues
— May leave permanent pigmentation and telangiectasia
(spider veins)
- Hair loss in the treatment area
- Dry mouth/taste loss if head and neck radiotherapy
- Menopause induction in premenopausal women if in
pelvic/abdominal area
- Risk of osteoradionecrosis if head and neck involvement
side effects of chemotherapy
- Rapidly diving cells are killed:
— Hair loss
— Oral ulceration
— Bone marrow suppression – reduction in WBC and
platelets - Damage to DNA of remaining cells:
— Risk of lager cancers
— Damage to fertility
— Induction of menopause - Drug specific effects:
— Taste loss/drug mouth
— Nephrotoxicity can occur
what is gypsum
- Gypsum plaster is calcium sulfate dihydrate which is used to
cast a positive replica of an oral cavity. - Type 1 plaster/impression plaster is used in making primary
impressions of edentulous oral cavity in complete denture
fabrication. - Type III dental stone is an alpha form of calcium sulfate
hemihydrate which is used to make master casts
describe hanau’s quint
- It is the inter relationship of 5 factors in order to maintain a
balanced occlusion:
— The saggital condylar guidance angle
— The inclination of the occlusal plane
— Compensating curves
— The cusp height
— The incisal guidance angle
measurements required for setting teeth
Centre line, occlusal plane/central incisor plan, residual ridge
contour, canine line and occlusal vertical dimension
what anatomical areas are required for retention, support & relief
Retention:
— Mandible – retro-mylohyoid space
— Maxilla – tuberosity, peripheral seal
- Support:
— Mandible - Retro-molar pad, residual ridge, buccal shelf
— Maxilla – hard palate and residual ridge
- Relief:
— Bony prominences (tori), high frenal attachments
name 3 materials used for crowns
All metal restorations:
— Precious gold or platinum
— Non precious nickel, titanium and chromium
- Metal-ceramic Restorations:
— Porcelain fused to metal
what is the purpose of a post
A post retains the core holding onto the coronal restoration.
Where the core gains intraradicular support for a definitive
coronal restoration such as retention for a crown
3 types of post which can be used
Manufacture:
— Preformed/prefabricated or custom made
- Material:
— Cast metal (Type IV gold/Au), steel, zirconia,
carbon/glass fibre
- Shape – parallel sided or tapered:
— Parallel sided
— Non threaded passive
— Cement retained
what is the name given to the residual collar of dentine required before placing a post
Ferrule (dentine collar) which is an encirclement of 1-2mm of
vertical axial tooth structure within walls of the crown which is
present to prevent tooth fracture.
how much GP should be left in the canal space when placing a post
4-5mm of root filling should be left apocalyptic so that the
apical foramen is sealed
what is the key purpose of post placement
Posts are used to retain the core holding into the coronal
restoration
- When more than ½ of a tooth’s original crown portion has been
lost, a post is needed to assist with anchoring the core to the
tooth
describe the width of taper for the type of crown given in MCC
Non functional cusps = 2mm reduction
- Functional cusps = 2.5mm reduction
- Incisal = 2mm reduction
- Shoulder/heavy chamfer = 1.2-1.3mm reduction
- Between a 10-20o taper
name 2 forms of bone loss that can be seen on a radiograph
- Horizontal:
— Most common pattern which occurs when the path of
inflammation is to the alveolar crest which is
perpendicular to the tooth surface - Vertical:
— Less common pattern which occurs when the pathway
of inflammation travels directly into the PDL spaces
and occurs intra-dentally.
name 3 characteristics of a ghost image
- They will present higher due to vertical beam angulation of 8o
- Be horizontally magnified
- Usually further forward due to change in Antero-posterior position
give 3 ways the dose to ptx is reduced by normal radiography techniques
- Use of rectangular collimating combined with a beam-aiming
device and film holder which reduces x-ray dose by 30% - Reducing the area irradiated, and therefore volume irradiated
will also reduce the number of scattered photons produced as
well as reducing patients dose. - High tube kVp which produces higher energy photons meaning
the photoelectric interactions and the contrast between
different tissues is reduced, meaning the dose absorbed by the
patient also reduces.
compton effect v photoelectric effect
compton:
— X-Ray photon Interacts with loosely bound outer shell
electrons. The photon energy considerably greater
than the electron binding energy.
— The electron is ejected taking some of the photon
energy as kinetic energy causing a recoil electron. This
gives off an atom that is positively charged.
— Following the collision the photon has lower energy so
is called a scatter photon as it undergoes a change in
direction:
i. Forward direction – high energy
ii. Backward direction – low energy
photoelectric:
— X-ray photon interacts with inner shell electron
generally the k shell which has the highest energy. This
photon has energy higher than the binding energy of
the electron which makes the x-ray photon disappear.
— The Difference in energy between the 2 levels is
emitted as light and heat.
— Most of the photon energy used to overcome binding
energy of the electron remainder gives electron kinetic
energy meaning the electron is ejected as a
photoelectron. It results in complete absorption of
photon energy meaning the photon does not reach the
film and preventing any interaction with active
component of the image receptor – images appear
white if all photos are involved; grey is some are
involved
what metal is used to absorb the jets generated during x ray production
- Lead is used to prevent leakage >7.5uSvh-1
- Lead film is for photoelectric absorption which absorbs scatter
x-rays to prevent image degradation and its 2nd function is to
absorb some of the primary beam.
name another metal used in x ray production
- Zinc is used to prevent leakage >7.5uSvh-1 in shielding
- Aluminium and zinc used for the final spectrum of X-ray
energy filtration.
to remove retained roots of 44 what type of surgical flap should be used
Triangular (3-sided) L shaped:
— When removing a single root tooth retained root a
triangular (l-shaped) 3-sided flap design should be
utilised which will extend from the mesial aspect of the
canine to the distal aspect of the 2nd premolar
— Advantages:
i. It ensures there is an adequate blood supply,
satisfactory visualisation, very good stability
and reapproximation
ii. It is easily modified with a small releasing
incision or additional vertical incision or when
lengthening is required with a horizontal
incision.
— Disadvantages:
i. Limited access to long roots and tension is
created when the flap is held with a retractor
which can cause defects in the attached
gingivae
what is EADT & EAT
Extra-alveolar dry time (EADT):
— The EADT is critical to survival of the PDL as the longer
the EADT the more damage to the PDL which increases
the amount of resorption that can be expected.
— It is the time it takes from avulsion to placement in a
storage medium
— <30 mins better survival
— >30 mins risk of alveolar/ligament death
- Extra-alveolar time (EAT):
— This is the total extra-alveolar time from avulsion to
reimplantation which is an important indicator of
potential damage to the PDL
— Reports have found that teeth forming radiographically
normal PDLs after being stored in milk for 2 hours prior
to reimplantation
name 4 potential storage mediums for an avulsed tooth
- Saliva (or in buccal sulcus)
- Milk
- Saline/water
- Blood
give 2 points of information you would give to someone about an avulsion
- Ensure that the person holds the tooth by the crown of the
tooth and not the root and run it under cold water for no more
than 10seconds to clear any debris then reminder into the
patients mouth and bite on tissue - If they cannot reimplantation the tooth place it in a storage
medium such as Saliva, milk, saline.water) and seek immediate
dental advice ASAP
what form of splint is used for subluxation & what is the minimum time the splint should be in place for
flexible splint for 2 weeks
fluoride regime for high risk 4 year olds
- High risk children under 10 – 1500ppm of fluoride toothpaste
- Fluoride tablet supplementation – 0.5mg/day
- Fluoride varnish at least 2x yearly – 22,600ppm
what is the thickness of shimstock & articulating paper
- Shimstock - 8um in thickness used with mosquito forceps
- Articulating – 20um used with millers forceps
how does CHX act upon cells and explain
- Chlorhexidine is an antiseptic that has both bacteriostatic and
bactericidal properties against bacteria, viruses and fungi. - Chlorhexidine has a dicatonic action:
— Positively charged chlorhexidine molecule reacts with
the negatively charged clean surface of micro grains s
and damages the microbial cell envelope
— When there is a low concentration of the bacterial
membrane there will be increased permeability
— When there is high concentration of the bacteria’s
membrane there will be precipitation of the cytoplasm
and resultant cell death which also inhibits absorption
from the gut
common side effects of phenytoin
- Headaches, nausea, vomiting, constipation. Dizziness,
drowsiness trouble sleeping, nervousness - Gingival hyperplasia and bleeding gums
name 2 drugs that can cause similar side effects to phenytoin
- Calcium channel blockers – amlodipine and nifedipine
- Immunosuppressants – cyclosporine
how can gingival hyperplasia be managed
- Plaque control, OHI, sub and super gingival scaling Regularly
- Medical management where the consultant leading the
treatment of the condition can possibly reduce the dose of the
drug or use another drug which doesn’t have the side effect of
gingival hyperplasia
antibiotic tx for ANUG
metronidazole 400mg TID for 3 days for adults
metronidazole 200-250mg TID for 12-18yr olds
amoxicillin 500mg TID for 3 days if metronidazole is inappropriate
when would you give antibiotic for ANUG
only if it hasn’t gone away in a few days or if there is lymphadenopathy or systemic involvement
what is the periodontal phenomenon experienced by smokers when trying to quit
- Smoking increases periodontal disease by 2-6x fold.
- It increases rates of alveolar bone loss, attachment loss and
pocket formation but this may not be evident to the smoker as
the smoking masks the signs of gingivitis usually associated
with periodontitis which means the gums bleed less due to
vasoconstriction properties of nicotine. - This means when patients stop smoking their gums will then bleed
- Periodontal pathogens found in smokers are:
— Tannerella forsythia
— Prevotella intermedia
— Treponema denticola
2 drugs to be wary of when carrying out XLA
- warfarin
- clopidogrel
4 types of porosity that can be generated in the production of a URA or full denture
- Granular porosity:
— Granular effect on the denture surface due to low
powder liquid ratio. - Contraction porosity:
— Appears as irregular voids throughout and on the
surface of denture due to insufficient material and/or
insufficient pressure - Gaseous porosity:
— Shows fine uniform bubbles particularly in thicker
regions - Localised porosity:
— Improper mixing of components or early packing
surgery used to repair cleft lip & palate
- orthognathic surgery
- rhinoplasty
- velopharyngeal surgery
how are x rays produced
- X-rays are produced when fast-moving electrons are brought
rapidly to a stop - An electron is a negatively charged particle in an atom which
conceptually sites itself in the orbits around the nucleus as
stated by the Bohr model. - Process:
— Source of the x-ray from the x-ray machine and the
object is the teeth and jaws with the interaction of xrays with matter
— Image receptor will be digital or film
— Processing is the conversion of latent image to
permanent visible image by computer technology or by
chemical processing means
what is validation of decon equipment
- We consider validation of decontamination equipment when
we review if the practice is safe. This related to regulation15
(premises and equipment) and regulation 12 (safe care and
treatment). - Maintain and servicing decontamination equipment
appropriately is essential to ensure that equipment performs
to an optimum standard. This should be done in accordance
with the manufacturers instructions.
what is the glycocalyx
- This is known as a pericellular matrix, which is glycoproteins
and glycolipids covering that provides a protected surrounding
around the cell membranes of some bacteria, epithelial and
other cells. - This allows the bacteria to evade the immune system cells
more easily and can incorporate into biofilms. - Bacteria such as staphylococci sp., streptococcus sp., and
pseudomonas sp
how do we prevent strep mutans causing caries
- Reduce carbohydrates in saliva by changing diet habits
- Increase tooth resistance to acid attack by addition of fluoride
- Reduce tooth susceptibility by fissure sealants
- Reduce or eliminate carcinogenic micro-organisms by
mechanical removal of the biofilm - Possibility of the use of inhibitors, probiotics, vaccinations and
immunisation in the future
what is the structure of glucose
C6H12O6
dentinogenesis
— Is the formation of dentine performed by odontoblasts
which begins at the late bell stage of tooth
development
— The different stages of dentine formation after
differentiation of the cell results in different types of
dentine:
i. Mantle dentine, primary dentine, secondary
dentine and tertiary dentine
amelogenesis
— This is the formation of enamel and begins when the
crown is forming during the advanced bell stage of
tooth development after dentinogenesis.
— Although dentine must be present for enamel to be
formed, ameloblasts must also be present for
dentinogenesis to continue.
— Message are sent from newly differentiated
odontoblasts to the inner enamel epithelium (IEE)
causing the epithelial fella to further differentiate into
active secretory ameloblasts.
— Stages:
i. Pre-secretory stage
ii. Secretory stage
iii. Maturation stage
3 stages of forming a clot
- vasoconstriction
- platelet aggregation forming platelet plug
- formation of fibrin clot
NOACs
rivaroxaban, Apixaban and Dabigatran:
i. All new oral anticoagulants
ii. Factor X inhibitors that inhibits conversion of
prothrombin to thrombin stopping the
producing of the fibrin clot
iii. Short-life – effect rapidly lost
iv. If it is a short course for DVT – postpone dental
treatment until stopped especially extractions
v. Dental drug interactions:
1. safe with all except macrolides such as
erythromycin and clarithromycin
2. safe with antifungals – topical and
fluconazole
3. safe with LA
4. safe with antivirals
5. NSAID will prolong action and inhibit
platelets – AVOID
organisms involved in caries
- Streptococcus mutans
- Lactobacilli acidophilus
- Actinomycetes viscosus
- Nocardia sp.
what are the virulence factors involved in carious bacteria
- Streptococcus mutans
- Lactobacilli acidophilus
- Actinomycetes viscosus
- Nocardia sp.
what organisms are involved in periodontal disease
- Porphyromonas gingivalis
- Actinobacillus actinomycetemcomitans
- Prevotella intermedia
- Bacteroides Forsythus
virulence factors involved in periodontal disease
- Porphyromonas gingivalis:
— Host cell adherence and invasion – fimbriae
— Elaboration with proteases – collagenase, fibrinolysinl
phospholipase A and ohosphotases
— Endotoxins (LPS)
— Capsular polysaccharide and outer membrane vesicles
— Tissue toxic metabolic by products – hydrogen
sulphide, ammonia and fatty acids - Actinobacillus actinomycetemcomatins:
— Leukotoxins, cytotoxins, LPS, Fc binding proteins,
membrane vesicles, glycoproteins matrix and fimbriae
— It invaded host immune system through phase
variation, subverting the host cell and immunity
why do biofilms not allow antibiotics to penetrate them
- Biofilms can produce a penetration barrier of LPS which
prevents antimicrobials and antibiotics from penetrating. - Biofilms also require mechanical disruption do alone
medications will not work to remove them fully
describe innate immunity
recognises & responds to pathogens in similar way to adaptive but does not provide long lasting immunity to host:
— Recruits immune cells to sites of infection through the
production of chemical factors, including cytokines
— Activation of the complement cascade to identify
bacteria. Activate cells and promote clearance of
antibody complexes or apoptosis cells
— Identification and removal of foreign substances preset
in organs, tissues, blood and lymph specialised by WBC
subtypes such as macrophages
— Activation of the adaptive immune system through a
process known as antigen presentation
— It also acts as a physical and chemical barrier to
infectious agents
what is the process that leads to inflammation
- vasodilation; leads to increased blood flow causing redness & warmth (rubor & calor)
- increased permeability; leads to exudation of protein rich fluid into extravascular space causing swelling (tumour)
- loss of fluid from vessels leads to concentration of red cells resulting in decreased velocity & stasis of blood flow
- leukocyte rolling, adhesion & migration leads to accumulation of inflammatory cells
