BDS4 Flashcards
How does an RPI work?
rotation about mesial rest allows for the saddle to sink into denture bearing mucosa.
2 Reasons to use lingual bar?
Depth of sulcus
OH- allow for cleansing
What factors would guide the decision of the length of a post?
4-5mm of GP apical must be present
post must be at least the height of the crown.
Materials which may be used to cement a definitive post and core?
RMGI
GIC
What would bcause gingival recession on the palate?
traumatic OB
What may occur in the mouth if patient is taking bisphophonates?
Oesteonecrosis of the jaw
How would you manage a patient who has oesteonecrosis?
Be conservative Antiseptic MW surgical debidment primary closure monitor
What are the uses of an URA?
tipping and tilting space maintainer retainer habit breaker reduce overbite maxillary expansion
What is the design for a space maintainer?
Adams clasp - 16 and 26, 0.7HSSW
Southend clasp -11 and 21 )0.5 HSSW
What are the types of space maintainer?
Fixed palatal arch
Nance palatal arch
Fixed band and loop
What would the fluoride plan for an 8 year old?
MW- 225ppm
Toothpaste- 1450ppm
Varnish- 22600ppm
Tablets 1ppm
What is involved in a d3mft graph?
D3= decayed deciduous teeth M= missing teeth xla due to decay) Ft= filled teeth
How does a d3mft graph show a difference between 2 areas?
shows socioeconomical status
ethnicity status
individual health board involvement
what does the 3 in d3 mean?
Obv decay into dentine of dentine which can been seen visually
What interventions are carried out in scotland on a population level?
sugar tax
smoking ban
living wage
What is PICO?
Population- who is the studying involving
Intervention- what the thing being studied is
Comparison- what the control is
Outcome- what the final result was
What are confidence intervals?
the range of values the absolute risk difference will take in the population.
if CL overlaps 0 = not enough evidence
if CL does not overlap= sufficient evidence
a narrow CL if better as it implys a larger group
What is relative risk?
is the ratio of incidence in exposed to non-exposed groups
What are tge 5 steps of clinical audits?
identify problem or issue
set criteria or standards
observe practice/data collection
compare performance with criteria and standards
Implementing change
What are other options can you do instead of a clinical audit?
Peer review
quality improvement programme
CPD
What are the 6 dimentions of healthcare and explain each?
Safe – avoiding harm to patients from the care that is intended to help them Effective – providing services based on scientific knowledge to all who could benefit and reframing from providing services to those not likely to benefit
Patient centred – providing care that is respectful of and responsive to individual patient preferences, needs and values Timely – reducing waits and delays for both those who receive and those who give care Efficient – avoiding waste, equipment, supplies, ideas and energy Equitable – providing care that does not vary in quality because of personal characteristics such as gender, ethnicity, location and socioeconomic status.
What head neck and oral features of cocaine use?
Perforation of nasal septum/palate xerostomia erosion and attrition of tooth surfaces TMJD GORD Orofacial pain?
What is the risk of sugar free methadone?
may cause diarrhoea
can be injected due to the fact that it does contain chloroform
Give 3 types of consent?
Implied
Verbal
written
What must be discussed with the patient to gain consent?
Options for treatment with the risks and benefits of all.
The consequences, risks, benefits of the treatment you propose.
The likely prognosis.
The cost of proposed treatment.
Your recommended option.
What will happen if treatment is not carried out.
Patient can change their mind.
How long the treatment options will last for.
What are the 6 factors which make up consent?
Not manipulated. Valid- recnet, specific, remains appropriate. Given with capacity. Informed. Voluntary. No coerced.
Who would carry consent for a 3 year old patient?
Birth mum has automatic right to consent.
What problems would wearing scrubs to practice have?
Infection control.
scrubs may state where the nurse works and can have an impact on reputation.
How would you ensure that correct PPE procedure was carried out?
clinical audits
Regular inspections
Reflections
CPD
Why is manual cleaning carried out?
To remove gross contamination.
To remove materials from the instruments.
to aid disinfection and sterilization.
remove organic material.
Why do we need to test the washer disinfector/sterilizer?
To ensure it is working correctly and to its optimum.
to ensure validity of the machine and the warranty.
Helps to detect errors in the procedure.
To ensure that all areas of the instrument to be sterilised correctly.
What are the 5 stages of the washer disinfector?
- pre-wash/flush- <45 degrees to remove gross contamination.
2.Washing- physical force of water , chemical action of the detergents, thermal heat. - Rinsing- removal of cleansing agents.
- Disinfecting- temp only with holding time of 1-10 mins.
%. Drying circulation of air heated to 90 degrees for 20 mins to clear chamber of remaining moisture.
Who are the 4 key personnel involved in the decontamination process and what are their roles?
Operator/decontamination user- trained in the operation of the equipment, carry out simple housekeeping and maintenance. Keep records and ensure tests.
Manager- person ultimately responsible for decon. Generally the practice owner.
Authorising engineer- provide expertise and performs audits (annually and quarterly), advises on maintenance, testing and validation.
Test person- conducts and reports on validation and periodic tests, must be qualified for 2 years or more.
what are the 7 components of clinical governance?
Audit Risk Management Education and training Service user, carer and public involvement Clinician effectiveness and research Clinical information and IT Staffing and staff management
What is a clinical audit and what is its use?
A process which is used in order to review and assess patient care and its outcomes as a method of improving practices.
It is used to consider the gaps in knowledge, learning, protocols, training and attitudes.
What is the cycle of an audit?
Identify the problem/issue Set criteria and standards Observe practice/data collection. Compare performance with criteria and standards Implementing changes.
What are the stages of significant event analysis?
Step 1- identify the significant event
Step 2- collect and collate as much info possible relating to the event.
Step 3- orginise a meeting with educational focus (no blame).
Step 4- undertake a structured analysis.
Step 5- monitor the progress of that actions/changes which have been decided on.
Step 6- write up event analysis.
Step 7- peer review.
What are the stages of the chain of infection?
infectious agent reservoir portal of exit mode of transmission portal of entry susceptible host
What are the principles of waste disposal?
Segregation
Storage
Disposal
Document
in regards to waste, what document is legally required?
Consignment note which should be kept for 3 years - description of waste quantity of waste origin of waste transport of waste
What are the 3 divisions of NHS Scotland dental services?
Primary care- general dental practices
Public dental services- community settings
Secondary care- hospital services
What are the GDC standards?
Patients intrests are put first
communicate effectively with patients
obtain valid consent
Maintain and protect patients information
Have a clear and effective complaints procedure
Work with colleagues in a way which is in the patients best interests
Maintain, develop and work within your professional knowledge and skills
Raise concerns if patients are at risk
Make sure your personal behaviour maintains patients confidence in you and the dental profession.
what are the 4 aspects of the sinners circle?
Time
Temperature
Chemicals
Energy/mechanics
What are the 10 SICP?
PPE Hand hygiene. patient placement. Safe disposal of waste. Safe management of care environment. Safe management of blood spillages. Safe management of linen. Safe management of care equipment. Respiratory and cough etiquette. Patient placement. Occupational safety.
What are the 4 pillars of ethics?
Respect for autonomity
Non-maleficence
Beneficence
Justice
What is negligence?
The failure to meet standards of care which result in harm. May involve the omission to do something which a reasonable dentist would not do or to not do something a reasonable dentist would do.
What is the criteria for clinical negligence?
the dentist owes a duty of care
that duty of care is breached
the breach caused or materially contributed to damage
The damage was foreseeable and had negative consequences.
What should clinical notes be?
Confidential concise accurate legible current complete retained retrievable
What type of study provides the highest level of evidence?
Cochrane reviews - systemic assessments of all the relevant randomised controlled trials (RCTs) to provide the highest levels of evidence.
What are 4 aspects of cochrane reviews?
randomised double blind test reduces bias
inclusive and exclusive criteria
randomisation facilitates statistical analysis
compares one treatment to a control to show effects
What are 3 other types of study designs?
Cohort studies -prospective study
Case control studies- retrospective study
Case studies- single report
RCT- effectiveness and efficacy of treatments against no treatment
What is incidence?
the number of new disease cases developing over a specific period of time in a defined population
What is prevalence?
is the number of disease cases in a population at any given time
What is SIMD?
Scottish index of multiple deprivation- a postcode based index which uses a range of data to rate areas based on deprivation. 1 being the most deprived to 5-10 which is least deprived.
What 7 factors influence deprivation?
Employment status. Crime. Health and health care services. Geographical access to services. Income. Housing, living and working conditions. Education, skills and training available.
What are the characteristics of split mouth study design?
both control and intervention group are exposed to same environment.
intervention and control are randomly assigned to one half of dentition,
What are the disadvantages of split mouth study design?
patients are not blinded
Adds bias
Incorrect reporting of risk
What are the advantages of split mouth study design?
no carry over effect for intervention or outcome
It removes the variable from the possibility of estimating treatment effect.**
What is a P value?
Used to determine the significance of your results.
If the P value is <0.05 means that you reject the null hypothesis and your results are statistically significant.
What are confidence intervals?
The range of values the absolute risk difference will take in the population..
CI should not over lap 0 = sufficient evidence
if CI overlaps 0 = null hypothesis
A narrow CI is better as it shows show that a larger sample group has been used.
What are the signs and symptoms of Parkinsons?
Aphasia - problems with speech Confusion Memory and cognition problems muddled over daily activities mood swings may become withdrawn lack of confidence communication difficulties mask like face resting tremor rigidity instability on feet and may loose balance shuffling gait loss of protective reflexes
How do the signs and symptoms complicate dental treatment?
reduction in manual dexterity - struggles with OH capacity to consent? reduced self care ability poor communication tremor protective reflexes are lost access to oral cavity may be difficult
what is the incapacity act (2000) and what are its principles?
refers to the capacity and consent issues and allows for people who are able to consent to do so on their own behalf.
Principles-
the benefits to the adult
minimal intervention
take into consideration the patients current and past wishes
consultation with adult and any involved relevant others
encourage the patient to use the skills that they have
What is defined as having capacity?
can retain the memory of a decision They can act (make their decision) Can make a reasoned decision Can coommunicate the decision Can understand the decision - repeate it back in their own words
Who can consent under the AWI2000 act?
Power of attorney- medically and financially decisions can be made by a named person. appointed by a court prior to the person loosing capacity.
Welfare guardian- looks after welfareand make their decisions which are not money based. Appointed by the court.
What is the english equivalent of AWI2000?
Mental capacity act 2005
What is the decontamination cycle?
purchase or loan cleaning disinfection inspection disposal (if not suitable) packaging sterilisation transport storage use transport
4 legislation for decontamination?
the health and safety at work act (1974)
COSHH
The national health service (Scotland ) legislation 2010
Medical device directive
5 common reasons for handpiece faults?
incorrect compressor setting (may involve lack of maintenance) damage to chuck incorrect instrument usage poor or inadequate cleaning incorrect or inadequate lubrication
What is involved in a alcohol brief intervention?
raise the issue if they consume alcohol
screen and give possible risks
listen and gauge rediness for change
suitable referral/information and advice
What are the options for smoking brief intervention?
5As- Ask, advice, assist, assess, arrange
3As- Ask, advise, Act (signpost)
2A1R- Ask, Advice, Refer
What is the primary appraisal in stress?
Assessment of stressor- irrelevant benign harmful/threat harmful/challange
What is the secondary appraisal to stress?
Reaction to primary appraisal-
Harm
Resistance
Exhaustion
4 responses to stress?
Direct action
Seek information
Do nothing
coping
What is burnout?
when a professional disengages from their work due to the stresses and strains which have been experienced during job. Mental and physical exhaustion causing a negative or indifferent attitude towards life/work.
$ examples of coping mechanisms for stress?
keeping a good work/life balance exercise setting personal goals and/or targets knowing personal limits self care
Factors for the aetiology of fear?
previous negative experiences experience and attitude of parent or peers social media influence emotional development delay poor understanding
What is the cycle of behavior change?
pre-contemplation contemplation preparation action maintenance with progress - may relapse at any time
How do ultrasonic baths work?
high frequency sound waves produce micro bubbles which cause the cavition of instruments when the microbubbles implode which helps to remove the debris present on instruments.
What tests should be carried out for an automatic washer disinfector?
daily- carried out on the first cycle of the day
weekly done at the same time on a weekly basis as the daily test
quarterly/annually- carried out and tested again the manufacturers specification carried out by authorised testing personnel
What are the tests carried out for sterilisers?
daily- check door safety, drain and refill, run and print out a cycle run, use a helix or bowie-dick device- chemical change from blue to yellow.
weekly- automatic control test and air detection test
Why is RMGI considered better than GIC?
RMGI has a higher tensile strength, compressive strength, bond stregnth and decreased soluability compared to GIC.
why is RMGI better than GI for ED fractures?
prevents leakage, and has a better seal to the oral cavity.
Why should GCI not be used as a conventional restorative material?
low mechanical properties, low fracture strength , toughness is poor and wears easy. shorter working time.
why is RMGI not a good luting cement?
contains HEMa which absorbs water and expands
What are the ideal properties of a luting cement?
viscosity high compressive strength easy of use radiopaque cariostatic bio compatable low soluability thickness below (25microns)
what luting cement would you use for cementing a fiber?
dual cure composite resin cement
what luting cement would you use for ceramic veneers?
resin luting cement
What luting cement would you use for a MCC adhesive bridge?
RMGI
What are the constitutes of temp bond?
2 parts -
Base = zinc oxide, starch and mineral oils
Accelerator= EBA, eugenol and carnauba wax.
Can you bond to zirconia?
no but it can be etched and thus micromechanical retention occurs.
How do you bone to non-precious metals?
sand blast with aluminium oxide first
What bacteria are involved in denture stomotitis?
candida albicans, candida tropicalias, straphyococcus aueus, strapococcus epideridermidis
what is the drug treatment for denture stomatitis?
Fluconazol caps-50mg
7 caps/ 1 a day
topical miconazole oral gel 20mg/g
send 80g tube
* apply a pea sized amount to fitting surface of upper denture after food 4 times daily after food.
Should be used for one week after cleared up
what denture adjustments would you make to a denture if patient presents with denture stomatitis?
may need a reline, tissue conditioner? if the fungal infection continues- may suggest making a new denture.
Ill fitting denture can be causative to DS.
What 2 topical treatments may be use to treat Denture stomatitis?
Miconazole oralmucosal gel 50mg/g
Nystatin oral suspention 100,000 unit/ml
What may occur orally from steroid inhaler use?
erosion due to acidic nature of inhaler
patient should rinse the mouth out after use
may place fluoride varnish on teeth
what are the methods to improve the fit of a denture?
Reline
Rebase
Remake denture
What is the concept of a shortened dental arch?
3-5 units required not including anteriors
occluding premolars= 1 unit
occluding molar = 2 units
What are the indications for SDA?
enough remaining units which occlude to provide a large enough occlusal table.
prognosis of remaining teeth must be sufficient
patient doesn’t want to have dentures
might be financial issues
What are contraindications for SDA?
poor prognosis of remaining teeth avanced perio or unstable perio preexisting TMD signs of pathological wear sever class II or class III
Why would periodontal disease be contraindicated for SDA?
Drifting or perio comprimised teeth under occlusal load
loss of alveolar bone
loss of space in the neutral zone
may be increase iinterdental spacing due to increase in anterior load and thus distal migration of teeth
What is the definition of retention?
resistance to displacement in a vertical direction -tested by pulling denture
What is the definition of indirect retention?
resistance to the displacement in a rotational manner
Describe how composite bonds to dentine.
dental conditioner (37% phosphoric acid) for 10 seconds - 20 seconds on enamel . this causes micromechanical retention due to having an increased surface area and removal of smear layer (0.5-5microns). Decalcification of the of dentine happens and the exposure of the collagen network allows for bonding agent to penetrate. The hydrophillic end of the DBA adherse to the dentine via penetration the hydrophobic ends bond to the composite which causes a hybrid layer of collagen and resin.
How is porcelain is treated to improve its retention?
treated with hydrofluric acid which causes roughening of the bonding surface of the allowing for the placement of surface wetting agent to create a stronger bond
Other than resin based luting cements, what can be used?
Zinc phosphate cement
GIC
Advantage to placing a crown as a posterior restoration?
reinforces and strengthens the underlying tooth
What are the intraoral signs of ANUG?
halitosis
crater like ulcers
grey necrotic slough which bleed when wiped off
painful ulceration of interdental papilla
reverse gingival architecture
What would your treatment for ANUG be?
LOCALLY- remove supra and sub gingival deposits OHI smoking ceassation 6% hydrogen peroxide or 0.2% CHX mouthwash
SYSTEMICALLY-
Metronidazole tabs 200mg for 3 days
1 x three times daily
REVIEW-
further scaling and HPT
consider the general health of the patient if no improvement- may consider blood tests
What ways would you remove a fractured post which is still visible?
Ultrasonic vibration
miskito forceps
eggler
masseran kit
What are the characteristics of generalised aggressive perio?
Generalised pattern of attachment loss affecting at least 3 teeth except from incisors and 6s
generally under age of 30
vertical boney defects present
rapid progression of bone loss
plaque levels not consistent with the levels of disease
How would you mange periodontal abscess with systemic involvement?
subgingival scaling of pocket (under LA)
drained via incision or through perio pocket if pus is present
analgesics
Antibiotics due to systemic involvement -
AMOXICILLIN 500mg for 5 days
1x 3 times daiy
METRONIDAZOLE 200mg for 5 days
1x 3 times a day
what are the 4 method of obturation?
Cold lateral compaction
Warm vertical compaction
Continual wave compaction
Carried based obturation (themafil)
Give 3 examples of sealers and their brand names?
calcium hydroxide (dycal)
Epoxy resin sealer ( AH plus)
ZOE
What are the 2 factors determining post length?
Post placement- 4-5mm of root filling should be left apically
Sufficient alveolar bone support -at least 1/2 of of the post length must go into the root= at least 1:1 ratio of post legnth/crown height
Post width- no more than 1/3 of the roots width at its narrowest and 1mm of remaining circumferential coronal dentine
Ferrule- at least 1.5mm height and width of remaining coronal dentine.
prior to the placement of an implant, what should be considered?
GENERAL- smoking?, general health, medical history- bisophosphates
LOCAL- alveolar bone level, quality of bone and quantity.
7mm required to place the crown.
What are the interventions for inadequate bone levels?
guided tissue regeneration
bone grafting
Why would a sub alveolar fracture make a tooth unrestorable?
lack of coronal tissue- problems with moisture control and impression taking will be more difficult
may indicate for a post core, however the furrel would not be sufficient
What is a possible out come if only an upper denture is provided?
combination syndrome can occur which can further result in a flabby ridge . caused by rapid and excessive bone loss in maxillary ridge from forces being directed at the anterior region of the denture when it displaces. This causes the ridge to be replaced by excess fibrous tissue.
How would you manage combination syndrome?
mucostatic impression so that tissues are recorded at rest. Ror secondary impression there should be an impression teaken with alteration the the special tray- may have a window cut from it can be done in clinic or in the lab) then a low body impression material would be used. You may also consider taking a chunk of medium body impression material which then would be filled with light body impression material to gain detail of the flabby ridge area.
What are the 4 principles of caries removal and what does each include?
Access- dam, remove overlying enamel with highspeed and follow caries to ADJ
Extent- spread of caries at ADJ determines the outline form of the cavity. Remove all caries and check if any staining is present that it is hard. smooth enamel at cavo-surface margins.
Remove dentinal caries- using sharpe probe check softness of dentine caries. Remove carious dentine from the ADJ before removing from the cativy floor using slow speed or excavator.
Modifications- Carried out in order to prep the tooth for the restoration material.
What materials or alternative preparation techniques would you use is amalgam was not retaining in the cavity?
Undercuts./ dovetails Could use composite dental pins adequate bulk- at least 2mm in depth cavosurface margin angles between 90-120 degrees
What is the Cvek pulpotomy?
Used for partial pulpotomy after traumatic exposures. Pulp below the exposure is removed by 1-3mm untill non-inflamed healthy tissue is reached
Bleeding is controlled by the use of sodium hypochloride or CHX and then calcium hydroxide or MTA is used to cover followed by RMGI
What is the standard pulpotomy?
removal of coronal aspect of the tooth. Heamostatis of the pulp is achievedusing with ferric sulphate. Cover over with calcium hydroxide or MTA and place RMGI or GIC for crown placement.
What are the compents of composite?
resin- bis-GMA Glass- silica or quarts Light activator- camphorquinone Saline couplin agent Low weight dimethacrylate
What are the 4 different types of composite?
microfilled nanofilled hybrid flowable bulk fill
What are the clinical disadvantages of composite and how can they be reduced?
Polymerisation contraction stresses- low configuartion factor when placing (small increment)
Post op sensitivity- correct placement, moisture control, lining, correct bonding
Moisture sensitivity- use of dental dam
soggy bottom- no more than 2mm thickness placed at any time unless with bulk fill.smaller incraments
What is a healthy periodontium response to occlusal trauma compared to physiological and pathological responses?
healthy- widening of the PDL no LOa or imflammation. Returns to normal once occlusion is fixed
Healthy but with reduced periodontium- same as healthy but due to reduced PDL there is an increase in mobility
Periodontitis- Widening of PDL, LOA, mobility may increase BOP and plaque present.
Why might pagents disease cause issues with a denture fitting?
pagets disease causes an increase in bone turnover which can cause the swelling of bones. Thus maxilla or mandible may swell and cause ill fit of denture
What precautions would you take prior to an XLA on a patient who is taking bisphosphates?
Is patient taking oral or IV Bis and for how long have they been taking the medication
may consider speaking with their GP/ bis provider to consider temp stop in medication
CHX daily as pre op, immediatly prior to XLA and post op 2x daily for 2 months
OHI
atraumatic XLa as possible and suture to aid healing
post op follow up at 1 week and 2 months
refer if complications occur .
What is sodium hypochlorite extrusion and what are the signs and symptoms ?
high pressure injkesction causes SH to escape through the apex of the tooth and into surrounding tissues. May also happen if CWL of the tooth has not been determined.
SIGNS and SYMPTOMS-
inflammation around the area and/or hemorrhage of the tissue through the tooth. Both of which can cause necrosis of the tissue. Patient will also experience extreme pain.
What would your immediate action be in the event of a sodium hypochlorite extrusion?
reassurance and explination to patient LA for pain relief Copious amounts of saline dress with non-setting calcium hydroxide make note in patients records and review in 24hrs suggest analgesics
Following initial treatment for a sodium hypochlorite extrusion what would the next steps be?
analgesics
cold compress for first few days (5 times) for swelling followed by warm compress to prevent swelling and heamatoma
review in 24 hours
antibiotics if indicated refer if severe reaction
If a patient is concerned about having amalgam placed, what would you tell them ?
would require 350-400 fillings in order to beconsidered toxic
been used for 150 + years
no evidence based studies- apart from suggestion not to be used in pregnant or breastfeeding patients
what is the distribution of LA?
infiltration- placed around the terminal branches of the nerve
Block - placed around the nerve trunk (mandibular branch of the tri nerve which allows for the lingual branch to be anesthetized also)
What is the mechanism of LA ?
LA binds to the NA channels of nerves block the possible influx of NA and thus preventing action potential and the propagation of the nerve. last as long as as many NA channels are blocked
What fibers are most likely to be affected by LA?
A delta fibers and C fibers due to having less Na gates.
What are the consitutes of LA?
aromatic region- hydrophobic ester/amide bond- anesthetic Basic amine side chain- hydrophillic Preservatives - methyl paraben Buffers
Name one ester and three 3 amide anesthetics?
ester- benzocaine, procaine
amide-lignocaine, prilocaine, articaine
What is the maximum does of lignocaine?
max dose - 4mg per kg.
4.4mg per cart,
What are the clincial signs of erosion?
loss of surface detail
surface become flat and smooth and if leftto continue, dentine will become exposed and lead to cupping of the occulasal surfaces.
typically bilateral concaved lesions without a chalky appearance
increased translucency of the anterior teeth
What are the causative factors of erosion?`
repeated exposure of tooth tissue/ enamel to acidic environment
Instrinsic- GORD, Bulimia,
Extrinsic- fruit, fizzy drinks, fruit drinks
What is the hybrid layer?
the layer of dentine which has been conditioned to remove the smear layer and exposing the collagen matrix, it then has a resin adhesive placed which flows into collagen matrix and creates a hybrid layer.
What are the different types of dentine and how do they affect binding?
primary dentine ( laid down during development)- open tubuals and good for bonding Secondary dentine- (laid that down during function)- allows for sufficient bonding Tertiary dentine( reactionary and laid down due to mild stimuli and reparative to intense stimuli)- poor bonding due to sclerosed and poorly orginised tubules.
What is the content of inorganic matter in dentine?
calcium hydroyapitite (70%)
What percentage of max first molars have a mb2 canal?
93% have 4 canals and 7% have 3 canals`
What are the 3 design objectives of endodontics?
Create a continuously tapering funnel shape
maintain apical foramen in original position
keep apical opening as small as possible
What are 3 of the law of pulpal floor anatomy?
law of colour - always dark
law of symmetry 1 - orifices lie equal distance from MD line through chamber**
Law of symmetry 2 - orifices lie perpendicular on MD line**
** except maxillary molars
3 rules for finding the pulpal floor and locating orifices?
always at the floor and junctional walls
Always at angle in floor and wall junction
always at terminus of developmental fusion lines
Why irrigate during endo treatment?
to disinfect
to remove debris and disolve inorganic matter
to lubricate for instrumentation
to remove smear layer
Why is sodium hypochlorite a good irrigant?
can disolve pulp remenamts and collagen
potent antimicrobial action
dissolves both vital and necrotic tissue * only irrigant to do this*
helps disrupt smear layer