T1 Flashcards
1
Q
What type of resorption occurs in a mature apex after an avulsion injury?
A
Replacement resorption
2
Q
What is the best solution to keep a tooth in following avulsion?
A
Milk
3
Q
Why is a composite bandage important in young permanent teeth?
A
Seals the dentine tubules to stop infection from reaching the pulp. You want to prevent young children from having an RCT.
4
Q
What makes a splint flexible?
A
It is flexible, passive and is only attached to one tooth either side of the ones being held in place.
5
Q
How do you treat a root fracture?
A
Reimplant the fragment, the aim is to get the two fragments to reunite. Can RCT up to fracture line. (if fracture in coronal third - refer).
6
Q
What 2 injuries in permanent teeth will always result in pulpal necrosis?
A
Severe intrusion and avulsion
7
Q
What medical conditions should you not reimplant a tooth?
A
Infective endocarditis risk and immunosuppressed.
8
Q
What is the definition of a concussion injury?
A
Trauma to the tooth with no displacement or mobility, it’s like a bruise.
9
Q
What is the difference between apexification and apexogenesis?
A
Apexification is the placement of a barrier at the apex (such as MTA), apexogenesis is stimulating the apex and root development via Cvek/pulp cap.
10
Q
What are the 3 outcomes for the pulp following trauma?
A
Survival, obliteration, necrosis.
11
Q
When do you pulp cap following a complicated crown fracture? What is the other option?
A
Pin point exposure, within 24 hours, clean tooth = pulp cap. Large exposure, more than 24. hours, dirty = Cvek.
12
Q
Why is sensibility testing unreliable in young people?
A
Already in high stress condition, pulp is larger, more sensitive.
13
Q
What pulpal outcome is common in open apex teeth who have undergone severe luxation?
A
Necrosis
14
Q
What injuries is replacement resorption most likely in?
A
Severe intrusion and avulsion.
15
Q
What is first indicator for replacement resorption?
A
Infra-occlusion.
16
Q
What is surface resorption?
A
Present early, as part of normal healing, radiographically looks like you have gone from open to closed apex, transient apical breakdown.
17
Q
What is inflammatory resorption?
A
Due to necrotic pulp and PDL damage. Is preventable and treatable, pulp should be extirpated ASAP with non-setting for 1 week or corticosteroid for 6 weeks.
18
Q
What is a smear layer?
A
A layer that sits on the wall of the canal that contains dentine debris, left over pulp and bacteria.
19
Q
What is guidance ALL children/parents for 0-3?
A
Brush teeth twice a day (once at night and one other time), using 1000ppm fluoride toothpaste as soon as teeth start to come through, smear amount, limit sugar intake to mealtimes, children should be supervised whilst brushing, spit don’t rinse. Don’t have any drinks for 30mins after brushing. Fizzy drinks should be avoided. Children should be breastfed up to 6months with solids introduced after that (experience less tooth decay), babies should not be fed with a bottle during the night and a cup should be introduced from 6 months with no bottle from 1 year old.
20
Q
What is guidance for high caries risk 0-6?
A
Use 1350-1450 ppm fluoride toothpaste, dental recall every 3 months. When big teeth start to come through can place fissure sealants and all teeth should be monitored. Fluoride varnish should be applied every 3 months to all teeth. Diet diary should be given to patient to assess.
21
Q
What is guidance for ALL children/parent for 3-7?
A
- 3-7 same as 0-3 however use a pea sized amount of 1000ppm toothpaste. Fluoride varnish should be applied twice a year. Sugar-free medicine should be had wherever possible.
22
Q
What is guidance for ALL children 7+?
A
- Same as 3-7, however can be unsupervised with a 1350-1450ppm toothpaste used. If possible, use electric toothbrush and interdental cleaning can also begin. If using mouthwash, ensure to use at a different time to brushing. Sugary foods and snacks should be avoided before bedtime and especially after brushing. High caries risk 8+ can be prescribed 0.05% NaF mouthrinse.
23
Q
What is recall intervals for children?
A
High risk, 3 months.
Medium risk, 6 months.
Low risk, 12 months.
24
Q
What is recall intervals for adults?
A
High risk, 4-6 months.
Medium risk, 12 months.
Low risk, 18-24 months.
25
How do you know when a child can brush their teeth unsupervised?
Tie their shoe laces.
26
What can be prescribed at age 10?
2800ppm NaF toothpaste.
27
What can be prescribed age 16?
5000ppm NaF toothpaste.
28
What is fluoride varnish, how often can it be prescribed, how does it work?
As the tooth demineralises it diffuses in to form fluorapetite which is stronger and has a higher pH than hydroxyapatite therefore strengthening the tooth. It can be given from 3 years and should be given twice a year and up to 4 times a year.
29
What special investigations do we carry out on teeth to aid clinical diagnosis?
Mobility, colour, pharma-ethyl/EPT, pocketing, TTP, percussion.
30
What is attrition and its clinical presentation?
The wearing of teeth due to contact from opposing teeth. Teeth appear flat with loss of enamel and wear faucets with shorter crowns.
31
What is abrasion and its clinical presentation?
Wearing of teeth from non-tooth surfaces, commonly caused by brushing and bad habits. Usually presents with semi-lunar wear marks along the cervical margin.
32
What is erosion and its clinical presentation?
Acidic breakdown of the tooth that does not involve bacteria. Posterior teeth you get occlusal cupping with exposed dentine. Anterior the incisal edges appear translucent with chamfer margins seen palatally. Can get shortened clinical crown height.
For lower anteriors - shorter clinical crown height + cupping.
33
What is impaction?
When a tooth is impacted it means it has been blocked from erupting into the oral cavity – an impacted tooth is one that has never reached functional occlusion, they should be extracted if they are causing resorption, bone loss or develop cysts.
34
What is Reimpaction?
When a tooth is reimpacted it has erupted then unerupted.
35
What is retention?
Retention is the tooths ability to withstand vertical forces.
36
What is resistance?
Resistance is the tooths ability to withstand horizontal forces.
37
What are the 5 principles for crown prep?
Preservation of tooth structure, retention and resistance form, structural durability, marginal integrity, preservation of the periodontum.
38
How do you carry out a jaw reg for complete dentures?
Begin with upper wax rim. Start by check labial fullness, then Ala-tragal and inter-pupillary, then record RVD. Mark midline, canine line and check smile line. Then try in lower check labial fullness and extensions. Place upper and lower in and record OVD (licking lips, swallowing, saying M), ensure FWS is 2-4mm, if not reduce lower rim ONLY. Once happy record bite in centric relation.
39
What material can be used for secondary impressions complete?
ZOE or medium body silicone. If asking for ZOE you want a non-spaced tray, for silicone you want a non-perforated, spaced tray.
40
What is written on the lab form following primary partial impressions?
Please can lab pour up models and construct a spaced, perforated special tray (angle handle 10 degrees lower, 45 degrees upper).
41
What should be looked at coronally when assessing if a tooth is suitable for endodontic treatment?
Restorations present/tooth structure remaining. If a coronal seal cannot be placed following endodontic treatment, then the tooth is not suitable. You can also assess radiographically the space between the roof and the floor of the chamber – the larger this space the easier instrumentation will be.
42
How would a tooth with dentine hypersensitivity present?
Short, sharp pain following exposure to stimuli that cannot be put into any other pathology. It is due to exposed dentine tubules.
43
What are the symptoms of reversable pulpitis?
Short, sharp localised pain that appears on stimulus and usually lasts a couple of seconds. When the pain appears, it can be made better by painkillers. It is usually due to deep restorations, new filling or caries.
44
What are the symptoms of irreversible pulpitis?
Dull, aching pain that is spontaneous and is not made better by painkillers. The pain often keeps patients awake at night and often radiates. When exposed to certain stimuli patient can experience sharp pain that doesn’t get any better.
45
What are the symptoms of symptomatic apical periodontitis?
Similar symptoms to irreversible pulpitis however patient may also get pain from biting.
46
46. How do intact periapical tissues appear radiographically?
46. Lamina dura intact and the PDL space is uniform.
47
What is the normal width of the PDL?
0.2-0.4mm.
48
What is the difference between an acute abscess and a chronic abscess?
An acute abscess has a rapid onset which is spontaneous with large pus swelling that forms around the soft tissues. A chronic abscess has an associated draining sinus with a gradual onset and little discomfort.
49
What is condensing osteitis?
A localised bone reaction to a low grade chronic inflammatory stimulus at the apex of the tooth. Radiographically appears as a diffuse radiopacity.
50
What is placed when carrying out a pulpectomy?
As it is performed only on primary teeth, ZOE should be placed as the obturation material as it is able to resorb as the primary teeth do.
51
How is an indirect pulp cap carries out?
It is carried out when caries removal is close to the pulp but has not exposed it yet (should have 0.5mm of dentine remaining). A small layer of infected dentine can remain and then non setting calcium hydroxide is placed to promote tertiary dentine deposition
52
How is a direct pulp cap carried out?
It is carried out when the pulp has been exposed and is seen as an alternative to extirpation. Non setting calcium hydroxide, MTA or biodentine are placed to stimulate reparative dentine production with a restoration placed on top.
53
What is the aim of pulp caps?
Promote reparative dentine production to keep the pulp alive.
54
What is the aim of an access cavity?
Allow straight line access to canals to prevent fracturing of instruments and allows an unobstructed view of the canal orifices. It should also conserve as much healthy tooth tissue as possible and provide retention and support for temporary fillings placed between appointments.
55
How can calcification be removed?
Spoon excavator, ultrasonic. C+ files can be used in calcified canals.
56
What are the advantages of rubber dam?
Improved comfort, protects patients from aspiration of foreign bodies and protects soft tissues by retraction. For operators it allows better vision, better moisture control and aids in infection control.
57
What are the consequences of over instrumentation?
Pain due to an acute inflammatory response, extrusion of infectious materials, overfilling with GP can lead to SAP, increases healing time and worsens prognosis.
58
What are 2 advantageous properties of Ni-Ti instruments?
They are more flexible and resistant to fracture.
59
What is the CDJ?
Cemento-dentinal junction (where the cementum and dentine meet), it is within the canal and is 0.5-3mm short of the apex.
60
What are the consequences of under instrumentation?
Accumulation of infected debris can prevent healing and can prevent an apical seal being formed therefore allowing bacteria to re-enter the pulp.
61
What are ideal properties of an irrigant?
Broad spectrum antibacterial properties, able to dissolve necrotic tissue, low toxicity, good lubricant, low surface tension, sterilise the canal, prevent formation of a smear layer, inactivate toxins that cause resorption. Accessory canals reached that can't be instrumentated.
62
What is EDTA, how is it useful?
It's a chelating agent that breaks down inorganic debris as well as also acting as a lubricant. Therefore it breaks down the smear layer.
63
What is a phoenix abscess, how would a patient present?
It is an acute exacerbation of CAP during/following endodontic treatment. Patients present with large, soft swellings.
64
Why are anterior teeth more commonly prone to radicular cysts?
Palatal invaginations which allow plaque build-up and therefore caries, small teeth therefore pulp necrosis and exposure is easier, as they are at the front they can be more prone to trauma.
65
What is modified step back technique?
MSB is used for larger canals and it is the idea of shaping the apex and then working your way back up the canal to shape the rest.
66
What is crown down technique?
CD is used for smaller canals and shapes from the crown down to the apex.
Rotary files can be used for this or hand files but the files are made out of Ni-Ti.
A glide path must be created before going in with rotary.
67
What is the difference between FFB and MAF?
FFB is the first file to passively go down to working length with no watch-winding and has tug back.
MAF is 2 sizes up from that and is the final size of the apex.
68
What are the aims of instrumentation?
Remove pulp and microbes, facilitate irrigation, allow placement of medicament and enable placement of root filling.
69
Why is orifice enlargement carried out?
Removes infected material from coronal portion, improves access to apical third, improves irrigation and removes curvature.
70
Why do we create a glide path?
Allow easier access for instrumentation and therefore prevents fracture of materials.
71
What is apical gauging - how is it carried out?
A technique used to determine the correct apical constriction to improve the apical seal and minimise extrusion of GP. If one file goes past working length but then next file is slightly too short to passively move to the apex then you know the apical constriction is in the middle.
72
What is the active ingredient of odontopaste?
Clindamycin
73
What is the active ingredient of Ledermix?
Demeclocycline hydrochloride: An antibiotic - tetracycline antibiotic
Triamcinolone acetonide: An anti-inflammatory corticosteroid
74
Why is odontopaste preferred over ledermix?
Ledermix can lead to staining of teeth
75
What is the best material to use for apexification?
MTA. Biodentine has better handling properties however it's research for endodontic use is limited.
76
What is the difference between cold lateral compaction and warm lateral?
A heated finger spreader is used in warm lateral compaction as opposed to a cold one. This allows the GP to almost melt together and from one unit.
77
What are the problems associated with extrusion of obturation materia?
Can irritate periapical tissues.
78
Why is coronal seal required post endodontic treatment?
Prevents the entrance of microorganisms into the coronal portion of the pulp.
79
Why does a pulp make a tooth stronger?
The pulp roof has a bracing effect on the enamel which when removed makes it weaker, the pulp provide the dentine tubules with water. Once gone these are much more brittle due to dehydration and there is a colour change due to non-removed pulp.
80
What 4 considerations should be taken into place when providing a patient with a fixed prosthesis?
Amount of tooth structure remaining, the occlusal forces, the aesthetic requirements and the restorative/material requirements (enamel and ceramic).
81
On an endodontically treated tooth what is the resistance form dependent on?
The amount of radicular dentine and coronal tooth structure and this is what then provides resistance and retention form to the restoration.
82
What is the biological width?
It is the distance from the crestal bone to the gingival sulcus and contains the junctional epithelium. A crown prep should not encroach this.
83
If there isn’t enough tooth structure remaining when you place a crown, what is most likely to happen to the tooth?
Root fracture, dislodgement of restoration, secondary caries, endodontic failure and attachment loss due to encroaching on the biological width.
84
What is a ferrule and what are its requirements?
When there is a minimum of 1.5-2mm of the axial wall height of 1mm thickness that runs the full way around the tooth it reduces the chance of fracture as the dentine wall creates a bracing/supportive effect. It allows the crown to brace against the remaining tooth structure therefore creating better support. When creating a post and core from this the prep must sit on the tooth structure.
85
Why would you consider a post and core after endodontically treating a tooth?
It helps to retain the core and distribute coronal stress through the radicular dentine into the root. Therefore a crown may be considered to reinforce tooth stability as long as there is an absence of all pathology
86
What are some disadvantages of composite?
Composite shrinks during polymerisation and isn’t very good at adhering to dentine on the pulp floor as well as coronal dentine therefore not good for core build up. It also requires good moisture control.
87
Why do root canals fail?
Unfilled canals, loss of coronal seal, root fracture/perforation, periodontal pathology.
88
What is periapical periodontitis?
Inflammatory lesion which can destroy the PDL, bone or root.
89
How does internal root resorption occur?
When endotoxins stimulate osteoclast like cells which are in contact with the dentine surface of the pulp (little radiolucent bubbles in the canal). It can be stopped by removal of the cells, via RCT, or if the pulp becomes necrotic.
90
How does external inflammatory resoprtion occur and how is it treated?
It occurs following trauma where microorganisms enter the canal and stimulate the osteoclast like cells which initiates the resorption. It is treated by placing non setting calcium hydroxide on the area of resorption until no other resorption occurs.
91
What is replacement resorption?
Necrosis of the PDL caused by the tooth drying out (avulsion). The teeth then become ankylosed and then permanently replaced by bone.
92
What are the different forms of endodontic surgery?
Surgical drainage, periradicular surgery, corrective surgery, replacement surgery, implant surgery
93
What are the different options for replacing a gap?
Accept and monitor, ortho closure, denture, RRB, conventional bridge, implant.
94
What are the advantages and disadvantages of a denture?
ADV: cheap, easily add on more, can replace multiple units, non invasive, easier cleaning, can be placed immediately.
DIS: is removable, can alter taste/sensation, poor aesthetics/function, bulky, patient intererance, may be unretentive and fall out.
95
What are the advantages and disadvantages of a RRB?
ADV: fixed, minimal tooth prep. DIS: only replace one unit, can have poor aesthetics, dependent on occlusion, can debond.
96
What are the advantages and disadvantages of a conventional bridge?
ADV: fixed, reinforce heavily restored teeth, aesthetics. R: requires significant tooth prep, can have poor aesthetics, limited number of teeth can replace, more costly than RRB, not immediate (6 months heal).
97
What are the advantages and disadvantages of an implant?
ADV: aesthetics, fixed, can replace multiple tooth units, long prognosis, does not damage adjacent teeth
DIS: complications, long term maintenance, expensive, complex treatment planning, requires surgery, need to stop stoking, might get peri-implantitis and lose implant in future.
98
When is a fixed prosthesis indicated?
Protect weakened tooth, fractured cusp, previous endo, vertical fracture, maintenance of occlusion, replace old crown, aesthetics.
99
When may a fixed prosthesis be contraindicated? (5)
Inadequate tooth tissue, inadequate perio support, poor OH, untreated disease, non-vital tooth.
100
Why can excess tooth reduction lead to pulpal inflammation?
High speed handpieces cause inflammation in the odontoblast nuclei, open dentinal tubules risk getting infection inside, microleakage can lead to pulpal inflammation.
101
How is structural durability maintained?
Sufficient occlusal and axial reduction.
102
What can insufficient axial reduction result in?
Flexing of the crown on occlusal forces.
103
How can periodontal tissue be maintained during crown prep?
By placing the prep supra-gingival wherever possible and never encroaching on the biological width. Also correct embrasure and contact points.
104
Why may a prep be placed sub gingivally?
Aesthetics, retention for short crown, caries/restoration on finish line therefore placed sub-gingivally so it can be placed on sound tooth tissue.
105
What tissues are present in the biological width?
Connective tissue and junctional epithelium.
106
How is marginal integrity maintained?
Fit the crown as close to the finish line, the prep must allow for sufficient thickness to provide strength to the crown, crown placed on margin line that can be cleaned and monitored by dentist.
107
What occurs if the prep encroaches on the biological width?
Attachment loss, gingival inflammation, difficulty cleaning and crestal bone loss.
108
How is periodontal disease prevented, both at home and professional intervention for ALL adults?
Toothbrushing at the gum line as demonstrated by the dentist at least twice a day using either a manual or electric toothbrush. Interdental brushing is advised, especially where there are signs of inflammation. The patient should attend the dentist regularly to ensure regular removal of supra-gingival calculus and to ensure no overhangs or plaque traps are present.
109
How is periodontal disease prevented, both at home and professionally for patients with or at high risk of periodontal disease?
Clean daily below the gum line using TePe brushes BEFORE brushing. For small spaces floss should be used. Professionals should treat patients as per the BSP guidelines for their appropriate BPE score.
110
What are some periodontal risk factors?
- Modificable local factors (acquired (4) + anatomical)(4),
- Modifiable systemic factors (5)
- Non-modifiable (6)
Modifiable Local factors:
- Local factors acquired: plaque and calculus, partial denture, open contact points, overhanging & poorly contoured restorations.
- Local factors anatomical: malpositioned teeth, furcations, root grooves & concavities, enamel pearls
Modifiable systemic factors:
- Smoking, diabetes, poor diet, certain meds, stress
- Maybe: nutrition, alcohol, obesity/overweight
Non-modifiable:
- Socio-economic status, genetics, adolescence, pregnancy, age, leukaemia.
111
What are risk factors for oral cancer and how as dentists can we prevent/detect?
Tobacco, alcohol, diet.
112
When should a patient be sent down the urgent or suspected cancer pathway (as per DBOH guidelines)?
Unexplained ulceration lasting longer than 3wks, persistent lump in the neck, persistent lump on the lip, a red patch consistent with erythroleukaplakia, red and white patch, unexplained hoarse patch, persistent pain when swallowing for more than 3wks.
113
What are 5 behaviours that support better oral health?
Improving oral hygiene, optimise fluoride exposure, reducing sugar consumption, stopping smoking, reducing alcohol consumption.
114
What are 3 important things a patient should have to allow behaviour change regarding oral health?
Capability, motivation and opportunity.
115
What are SMART goals?
Specific, measurable, achievable, relevant, timely. Help you to help your patient change their behaviour.
116
What common rehabilitation drug is usually given as a sugar-based prescription?
Methadone
117
Why are the elderly at higher risk of developing caries?
Polypharmacy (xerostomia) and the use of sugary oral nutritional suppliments.
Recession (root caries)
Insufficient OH (poor manual dexterity)
High sugar diet
Limited access to dental care
118
118. Define periodontal health, gingivitis and periodontitis?
Periodontal health is the absence of clinically detectable inflammation (<10% BoP), on an intact periodontium or a reduced periodontium (loss not through perio).
Gingivitis is an inflammatory condition resulting from the dental plaque and the host response interacting leading to inflammation contained to the gingiva.
Periodontitis is a microbially-associated, host-mediated inflammation that results in loss of periodontal attachment.
119
What are the BSP guidelines regarding a BPE of 3?
Supra-scale with 3 month 6PPC review of sextant.
120
What are the BSP guidelines regarding a BPE of 4?
6PPC of all teeth should be carried out and sub-gingival PMPR on pockets >4mm.
121
What are the BSP guidelines regarding a BPE of 0/1/2?
Risk factors should be controlled/maintained, oral hygiene should be promoted, and you should ensure patient is in dental health with regular check-ups.
122
When should advanced periodontal treatment be carried out?
Once 2 rounds of PMPR have been carried out on unresponding pockets.
123
What types of periodontal surgery are available?
Crown lengthening, gingivectomy.
124
What are some primary prevention mechanisms of periodontitis?
Management of risk factors
125
What are secondary prevention mechanisms of periodontitis?
BPE with grading and staging of periodontal status.
126
What are the guidelines regarding a BPE from 7-11?
Only score up to 2, using the 6s and 1s.
127
127. What are the guidelines regarding carrying out a BPE 12-17?
Can score up to 4 but continue to use the 6s and 1s.
128
What are tertiary prevention of periodontitis?
Supportive periodontal care: setting expectations, monitor depths (once a patient has had periodontitis they should have a 6PPC carried out every year to ensure no remission), oral hygiene advice, PMPR.
129
Define peri-implant heath, peri-implant mucositis and peri-implantitis?
Peri-implant health: absence of any signs of inflammation, no bleeding or suppuration on probing and absence of bone loss or deeper probing depth.
Peri-implant mucositis: bleeding on gentle probing with some erythema/suppuration but no increase in probing depths.
Peri-implantitis: plaque-associated disease of tissues around implant, inflammation of mucosa and surrounding bone. Bleeding, suppuration, probing increase and loss of attachment present.
130
How is peri-implantitis prevented?
Control of risk factors can be useful however regular recall and maintenance along with radiographs is more important.
131
What are the components of supportive periodontal care?
Setting expectations, monitor depth, OHI, PMPR.
132
What are cancer/ex-cancer patients at higher risk of?
Dental caries, oral mucositis, MRONJ, ORN.
133
What are the components of a BEWE?
It’s a screening tool that records the most severely affected surface for each sextant based on an estimate of how much tooth structure has been lost (not due to caries).
0: No enamel tooth wear
1: Initial loss of enamel surface texture
2: Distinct defect, hard tissue loss less than 50% of the surface area
3: Hard tissue loss more than 50% of the surface area
134
What advice should be given to prevent tooth wear?
Lower their intake and frequency of acids, control intrinsic acids (work out where from and try help in this area), effective and proper tooth brushing.
135
What are some denture hygiene instructions?
All dentures should be cleaned after eating with debris removed, removed at night and remaining teeth should be looked after. Acrylic dentures can be cleaned for 20 mins with alkaline hypochlorite but left to soak in water overnight.
136
When should daily interproximal cleaning have begun by?
Should have started by 18 years of age, or younger depending on presence of gingival inflammation.
137
What areas are still under the fluoridated water scheme?
Birmingham, Newcastle and Scunthorpe/Lincoln.
138
When does calcification of the permanent incisors occur?
30 months
139
When does calcification of the permanent premolars occur?
6 years.
140
What cements cannot be used sub-gingivally?
Resin based cements.
141
What does ceramic require to bond to?
Enamel
142
What is the purpose of a functional cusp bevel?
Allow for extra thickness and strength of the crown to deal with occlusal forces.
143
What are guide planes?
Parallel surfaces on teeth that aid in insertion and retention.
144
What are colour shades made up of?
Hue, value and chroma.
145
What is a problem of using hydrobite?
It can prop open the bite when used as a bite reg material, so you don’t get the true extent of ICP.
146
How is occlusion defined?
The static relationship between the incisal or masticatory surfaces of the teeth.
147
What is centric relation?
Jaw position where the muscles of mastication are relaxed, and the condyle is in the most anterior, superior position in the glenoid fossa. It is the most reproducible position.
148
What is a cross-bite vs scissor-bite?
Crossbite = when the buccal cusps of the lower teeth occlude buccaly to the buccal cusps of the upper teeth.
Scissorbite = when the buccal cusps of the lower teeth occlude lingually to the lingual cusps of the upper teeth.
149
What is canine guidance and why is it preferred?
Vertical and horizontal overlap of the canine teeth on the working side which leads to disengagement of the posterior teeth when moving laterally. Preferred due to their long roots which allows transmission of force, they stay in the mouth on general the longest and the palatal aspect is concave so made for lateral forces.
150
What is mandibular displacement?
Movement of over 1cm from RCP to ICP.
151
What are 3 occlusal diseases?
Occlusal dysthesia, bruxism, trauma from occlusion.
152
What is displacement without reduction?
When the articular disc is displaced anteriorly to the condyle when both open and closed.
153
What is displacement with reduction?
Closed jaw - condyle seated in fossa with disk anteriorly.
Condyle begins translation - as mouth opening a clicking or popping sound occurs as disk returns to its normal position in relation to condyle.
During closing - disk beomces anteriorly displaced sometimes accompanieed by secdonary sound (reciprocal click)
154
What are signs of soft tissues of parafunctional habits?
Linea alba, tongue scalloping, mandibular tori.
155
Why might a crown be indicated?
Protection of weakened tooth, vertical root fracture, fractured cusp, endodontically treated tooth, maintenance of occlusion, replace old crown, aesthetics.
156
What should be considered when assessing if a tooth is suitable for a crown?
Amount of enamel, quality of enamel, parafunction habits, apical radiolucencies, periodontal health, subgingival caries, patient compliance, occlusion.
157
What are the rules for cementing a ceramic crown?
Need to have sufficient enamel to allow binding of the resin-based cement. Cannot use eugenol based temporary cement.
158
Why do we use temporary crowns?
Cover exposed dentine, function, aesthetics, diagnosis, to prevent gingival overgrowth.
159
What are the 3 different options for temporary crowns and when would we use them?
Preformed crowns (metal or composite), chair-side (quick, cheap, allows assessment of sufficient tooth reduction), lab based (trial new shade/shape).
160
When thinking of ideal properties of materials what should they usually be?
Non-toxic, biocompatible, cheap, easy to use, adhere.
161
Why would you use poly F over tempbond?
For long term temporaries or when placing a ceramic crown.
162
Why would you use tempbond over Poly F?
Sedative effect and also antibacterial, is also easily removed.
163
What is an inlay?
An intracoronal restoration that replaces tooth tissue but not the cusps.
164
What is an onlay, when are they indicated?
A restoration that replaces one or more cusps and the occlusal surfaces. They are used for increasing OVD, when a direct restoration wouldn't be feasible, on endodontically treated teeth, as denture abutments.
165
What are the indications for a post and core?
Successful endo treatment, restorable tooth, good perio status, no parafunction.
166
What should be considered when placing a post?
Curvature, length, width and taper of root, any untreated disease, quality of endo treatment.
167
When is placement of a post and core not advised?
Short root, inadequate ferrule, poor endo, inadequate dentine thickness.
168
What are rules of post and core placement?
Post should be longer than the height of crown
4-5mm of GP should remain for apical seal
At least 2mm of circumferential ferrule
Tip of the post should be no more than 1/3 diameter of the root
The post diameter should ideally not exceed the diameter of the shaped and disinfected canal.
169
What does a longer post allow?
It allows even distribution of forces and better retention.
170
What is the definition of MIH?
Hypomineralisation of one or more permanent molars and/or incisors associated with illness between 0-3, illness during pregnancy or traumatic birth.
171
What are the components of a bridge?
Abutment, pontic, retainer and connector.
172
When would an RRB be chosen over a conventional bridge?
Unrestored dentition, replacing one unit, no parafunction habits.
173
In a cantilever bridge where should the abutment tooth be in comparison to the pontic?
Distal
174
What are problems associated with a fixed-fixed RRB?
Higher likelihood of debonding therefore can get caries underneath.
175
How can we increase the survival rate of an RRB?
Cantilever design, little to no prep, using rubber dam.
176
What is the Dahl effect?
When there is insufficient occlusal space an RRB can be cemented higher to allow for re-establishment of occlusion via intrusion of some teeth and eruption of others.
177
What are the options for restoring primary teeth?
GIC, compomer, composite, SSC.
178
What are options for restoring permanent teeth?
GIC, compomer, composite.
179
What 3 things help you indicate someones caries risk?
Newly formed caries, anterior caries, presence of other restorations.
180
Why are 6s most likely to get caries?
In mouth the longest, 15% of people have MIH, can partially erupt and be difficult to clean, deep pits and fissures.
181
What 2 congenital conditions increase caries risk?
Amelogenesis imperfecta and cleft palate.
182
What in a social history may increase a childs caries risk?
Social deprivation, caries in siblings, irregular attender, availability of sugar, low knowledge
183
What is the definition of early childhood caries?
Presence of DMFT in 1 or more primary tooth in 72 months or younger.
(might be presence of one or more decayed, missing or filled teeth in children aged 71 months or younger.
184
Explain bottle caries and risk factors.
Due to frequent consumption of sugary drinks in bottle leads to long exposure of cariogenic drink and low salivary rate at night.
185
When giving patients diet advice, what should be explained?
More about frequency of sugar intake than amount so should be had at mealtimes. Fizzy drinks should be had through a straw if drunk and should be infrequent and not swished or swilled around mouth. Avoid juice/milk in bottle. Only water between meals. Snack on sugar free snacks. Beware of hidden sugars.
186
What is the prescription for mouthrinse?
0.05% NaF daily.
187
How does fluoride varnish work?
It's used to arrest lesions by increasing the presence of topical fluoride in the mouth.
187
What patients should not be given fluoride varnish?
Necrotising gingivitis, allergy to colophony, asthmatics.
187
How does fluorosis occur?
Fluoride effects enamel maturation by impairing mineral acquisition therefore resulting in hypomineralisation. Teeth at greater risk whilst developing.
188
What can excess ingestion of fluoride cause?
Fluorosis can lead to more serious complications including hospitalisation.
188
At birth how does the child occlude?
Gum pads that occlude distally to allow for suckling, anterior oval opening and fleshy labial frenum.
189
At 36 months how does the child occlude?
Incisors vertically inclined, deep overbite, anthropoid spaces (mesial to maxillary canine, distal to mandibular), ovoid arch form and flush terminal plane.
189
What happens at 6 when the first molars erupt?
Begin to lose primary teeth, overbite decreases, pronounced spacing of the anterior teeth (to make way for bigger ones), noticeable attrition due to thin primary enamel.
190
When should the canines be palpatable?
Dental age 9.
191
How does thumb sucking appear clinically?
Asymmetric anterior open bite, proclined uppers, retroclined lowers, unilateral crossbite.
192
What are natal/neonatal teeth and what are issues with them?
Natal: present at birth.
Neonatal: present within 1 month.
Can cause issues feeding to mum, issues to soft tissues and due to undeveloped root can cause an aspiration risk.
193
Why may we not extract a natal tooth?
As there are not enough clotting factors present.
194
What anatomical features make primary molars at higher risk of caries?
Thin enamel, narrow occlusal table, large interproximal contact points, larger mesiobuccal pulp horn, large pulp.
195
What does ALARP stand for?
As low as reasonably practicable.
196
When should radiographs be taken for high, medium and low risk caries?
6 months. 12 months. 18-24 months.
197
When may radiographs in children be indicated?
For detection of caries, in trauma patients, examination of pathological conditions, assessment of eruption.
198
Why do we restore primary teeth when they exfoliate anyway?
To prevent infection disturbing permanent successor, to increase compliance with dentist, to remove pain, maintain function and space, avoid life threatening spread of infection.
199
Why is restoring childrens teeth difficult?
Small mouth doesn't open very wide, attention span, compliance, lack of motivation and co-operation, fear.
Large mesio-buccal pulp horn.
Large pulp.
200
When are stainless steel crowns indicated?
Interproximal caries, 2+ carious surfaces, young children.
201
What in a patients medical, social and dental history may indicate a fear of dentist?
Pain driven attendance, previous extensive/invasive treatments, previous bad experience with medical professional.
202
What is Frankl behaviour classification?
Assess behaviour of patient 1 being un-cooperative, 4 being positive.
203
What are some behaviour management techniques used in paediatric dentistry?
Tell, show, do.
Positive/negative reinforcement.
Voice control. Distraction.
204
Why are first permanent molars at high risk of caries?
Deep pits and fissures, first to erupt, MIH, partially erupted, difficult to access.
205
What patients benefit from non-operative preventative treatment?
High caries risk, patients with health impairments who would be affected by caries (IE and immunocomprised), children with deep fissures, children with 1 or more occlusal cavity.
206
What material is used for restoring anterior teeth but why may this pose a problem?
Composite due to its aesthetic component. Difficult to get moisture control so needs good compliance. Poor oral hygiene can lead to gingival bleeding, in rampant caries sometimes GIC will be placed as an intermediate.
207
When is a preventative resin restoration indicated and how is it carried out?
Occlusal caries that is just into dentine so able to remineralise. A slow hand piece is used to remove sticky caries, a small bit of composite to fill the cavity and then a fissure sealant placed on top - no LA used.
208
Why is extraction of 6s often considered and when should it be carried out?
As you don't want to begin the restorative cycle on them. Should extract when the bifurcation of the 7s has begun which is around the dental age of 8-10 however should be checked on a DPT, this allows the 7s to erupt into the space.
209
What can be seen clinically that can help aid in diagnosis of the pulp?
Draining sinus, colour change, mobility, swellings.
210
What medical, social and dental considerations should be taken into account when deciding how to treat extensive caries in a paediatric patient?
Medical (IE, immunocompromised, bleeding risk, GA risk).
Social (oral hygiene, cooperation, motivation, attendance, parental attitude)
Dental (resorption, number of carious teeth, time until exfoliation, swelling).
211
What is used when deciding whether to stoop at a pulpotomy/continue to a pulpectomy?
Depends upon bleeding with ferric sulphate is applied with a cotton wool pledget.
212
What is a desensiting pulpotomy?
Indicated when hyperaemic pulp and poor compliance when anaesthesia not working. Apply Ledermix and then GIC restoration and figure out best restorative option.
213
How can you clinically and radiographically tell that a pulp is still vital (paeds)?
Clinically - based off presenting complaint + colour/sinus/mobility. RAdiographically will see interradicular bone loss if necrosis has occurred.
214
What is the aim of pulp capping?
Stimulate tertiary dentine.
215
What is used for obturation in a pulpectomy?
ZOE as it is resorbable.
216
How does MIH present in incisors and how does it present in molars?
Incisors appear as demarcated white/brown patches. Molars appear with often post eruptive breakdown with demarcated brown/yellow/white patches.
217
How does enamel hypoplasia present?
Small pits and fissures with severe enamel defects.
218
What is seen histologically in MIH that affects the teeth's ability to be restored?
Reduced enamel hardness and less distinct enamel rods which makes etching difficult.
219
Why in general is treating a patient with MIH difficult?
Patients usually present young and treatment lasts for life, aesthetic zone is affected, poor quality teeth make restoring hard and pulp is often hyperaemic therefore LA administration doesn't always work.
220
Why are MIH teeth more sensitive?
Increased vascularity to the tooth and increased porosity of enamel lead to increased sensitivity.
221
What preventative advice can we give to patients with MIH?
CPP-ACP, fluoride, desensitising toothpaste (stannous), fissure sealants, OHI, diet.
222
How can we treat 6s and then 1s affected by MIH?
Incisors: microabrasion, vital bleaching, composite, veneers.
Molars: onlays, SCC (only temporary to maintain space until 7 ready), composite.
223
Why is endodontic treatment not indicated in newly/younger erupted 6s?
Starts restorative cycle early on, poor compliance, may make patients more anxious, root not fully developed, no need to be retained.
224
What 2 abnormalities influence extraction of 6s?
Malocclusions and hypodontia.
225
What are 7 restorative and patient factors to take into account when thinking about restoring or extracting teeth?
Extent of lesion, quality of enamel, moisture control, compliance, dentist experience, symptoms, caries risk factor.
226
What should be taken into consideration when designing a denture?
Casts should be articulated prior to denture design being completed, there should be a rest seat next to every saddle, if more than 2 teeth then rest seat should be adjacent (except for free end saddle where it is mesial), every clasp needs a rest but not vice versa, ensure it is cleansable, maximum support minimal coverage, for a lingual bar the functional sulcus (when tongue lifted to gingival margin) should be >8mm, more teeth missing means more coverage, all clasps should have reciprocating arm.
227
What are some causes of intrinsic discolouration?
Tetracycline, Dentingogenesis imperfecta, fluorosis, hypoplasia, smoking, caries, RCT, trauma.
228
What are different ways we can manage staining?
For extrinsic stains: proper oral hygiene, management of diet, scale and polish.
For intrinsic stains: microabrasion, non-vital bleaching, vital bleaching, veneer, composite restoration.
229
If carrying out vital bleaching in practise what should be placed prior to bleaching agent?
Gingival barrier placed to protect gingiva.
230
What is vital bleaching?
Vital bleaching is placement of carbamide peroxide/laser to bleach the outside of the teeth - preformed on vital teeth.
231
What concentrations are used for bleaching in the UK?
Carbamide peroxide 10% (3.5% hydrogen peroxide) and carbamide peroxide 16% (hydrogen peroxide 5.6%).
232
What are the 3 options for non-vital bleaching?
Walking bleach, inside out, selective reservoir.
233
What are the negatives of bleaching?
Can cause sensitivity, may damage gingiva, relapse, potential cervical resorption, doesn't work on stains from amelogenesis/dentinogenesis.
234
What conditions are the stains not able to be whitened?
Amelogenesis, Dentinogenesis, Enamel hypoplasia, root resorption.
235
How is microabrasion carried out?
Especially good for brown lesions (MIH patients),
- Isolate teeth w rubber dam
- Mix 18% HCL with pumice into slurry and apply small amount to labial surface with a slowly rotating rubber cup.
- Wash for 5s directly.
- Repeat up to 10 x 5 seconds
- Polish with super fine Soflex disk then with toothpaste.
236
What conditions is whitening good at removing the stains created?
Trauma, tetracycline, fluorosis, ageing.
237
What bacteria are present in caries?
Streptoccocus mutans, actinomyces and lactobacillus.
238
What is the process behind caries?
Cariogenic bacteria in biofilm metabolise simple carbs from their diet and produce acid as a waste produce of anaerobic respiration therefore lowering pH.
239
How does active caries appear?
Soft and sticky, usually white/brown.
240
How do arrested caries appear?
Hard and shiny, can have a scratch surface, yellow/black in colour.
241
What is the critical pH of enamel and dentine?
pH of enamel: 5.5
pH of dentine: 6.7
242
What ions in saliva aid in remineralisation?
Calcium and phosphate. Along with the bicarbonate buffer.
243
What is the bicarbonate buffer reaction?
The bicarbonate in saliva reacts with the acid produced by bacteria to produce water and carbon dioxide. This carbon dioxide then diffuses into the environment to maintain the concentration gradient.
244
How does saliva prevent caries?
It contains calcium and phosphate to remineralise teeth, allows for bicarbonate buffer, swallowing removes simple carbs, contains antimicrobials.
245
What factors in food have an impact on caries?
Consistency of carb and frequency of carb.
246
What are the 5 main concepts behind caries prevention?
Diet, salivary stimulation, promote remineralisation, remove plaque build up, fluoride.
247
How does xylitol aid in regression of caries?
It is taken up by S.mutans but not metabolised therefore it inhibits glycolysis.
248
How can a continual low pH in the oral cavity lead to changes in plaque biofilm?
Low pH consistently can result in a shift of the bacterial population to become more aciduric.
249
What are histological areas of enamel?
Translucent zone, dark zone, body of lesion, surface zone.
250
What are histological areas of dentine?
Zone of sclerosis, zone of demineralisation, zone of bacterial invasion, zone of destruction.
251
How does dentine respond to caries?
As the odontoblasts are irritated it leads to tertiary dentine placement.
252
What are pulp stones?
Calcified bodies within the organic matrix found in the coronal pulp.
253
What are the caries risk factors?
Initial, moderate and extensive. Then should be classified depending on active/inactive.
254
What does ICDAS radiograph 1-6 mean, what can this also be classified as?
1&2 is which half of enamel, 3&4&5 is which third of dentine and then 6 is pulp – can be classified as E,D,Pulp.
255
What is the definition of caries?
Biofilm mediated, diet modulated, multifactorial, dynamic disease resulting in net mineral loss of dental hard tissues.
256
What is seen when caries reaches the ADJ?
It spreads along the ADJ making the demineralisation wider, this is the brown discolouration seen which is the first sign of dentine breakdown.
257
What are benefits of resin infiltrations and what material do we use?
Non-invasive, one visit, arrests early initial lesions, can improve aesthetics of white spot lesions. ICON.
258
What is the main effect of fluoride?
It leads to subsequent remineralisation whilst caries is occurring.
259
How does fluoride varnish work?
It forms calcium fluoride which pools on the tooth and due to being more resistant at lower pH’s when the protein layer of phosphate is washed off this remains and causes remineralisation
260
What are the 4 concepts of complete dentures?
Stability, retention, support and balanced occlusion.
261
What 5 things can cause cracked tooth?
Parafunctional habits, occlusal accident, highly restored teeth, habits, structural issues (AI, DI).
262
What can cause retarded eruption?
Premature birth, traumatic displacement of tooth germ, nutritional deficiencies, chromosomal abnormalities, hypothyroidism.
263
What is hypophosphotasia?
Low activity in alkaline enzyme phosphatase, can result in loss of all teeth by age 5 due to disturbed cementum formation
264
What is cherubism and the clinical features?
A genetic disease that produces abnormal bone due to disruption of the signalling pathways associated with maintaining bone, excessive osteoclasts.
Bilateral swelling of maxilla and mandible, upturned eyes.
265
What is persistence of deciduous teeth associated with?
Developmentally missed permanent, trauma, failure of eruption of permanent.
- Ectopically developing permanent teeth.
- Trauma or infection affecting the primary teeth.
- Fused or germinated teeth.
- Infra-oclusion
- Cleidocranial dysplasia
266
What can cause impaction of teeth?
Abnormal position of tooth crypt, lack of space, supernumeraries, cyst, tumour, stainless steel crowns on E.
267
What causes teeth to become infra occluded?
Infraocclusion is caused by insufficient process of the alveolar process giving them the look of being submerged. Classified as mild (1mm below), moderate (at contact point), severe (at the interproximal gingiva).
268
What syndromes are associated with hyperdontia?
Gardner's and Cleidocranial.
269
What syndromes are associated with hypodontia?
Cleft palate/lip, downs, ectodermal dysplasia, gorlin-goltz.
270
What is cleidocranial dysplasia and what are its clinical features?
Facial + body features:
- Clavicular aplasia
- Short stature
- Failed fontanelle fusion.
- Facial:
- Hypertelorism (Wide set eyes)
- Flat nose
- small maxilla
- Brachycephalic skull (side, short skull)
- osteopenia (decreased bone density)
- Often class III skeletal due to small maxilla.
Dental features:
-Delayed exfoliation/retained primary teeth.
-Delayed tooth development
-Multiple impacted permanent teeth.
-Supernumerary teeth.
-Dentigerous cysts.
-Teeth appear small, irregularly spaced and crowded.
- Teeth may display malformed roots and enamel hypoplasia
- Malocclusion
- Narrow arched palate.
271
What is Gardner's syndrome?
Mutation in chromosome 5, leading to multiple dense bony islands, multiple osteomas, polyposis, epidermoid cysts, increased bowel cancer risk.
Supernumeraries - Hyperdontia
272
What are the clinical features of Down's syndrome?
Extra chromosome 21, class 3, bifid uvula, short hands broad trunk, macroglossia, hypodontia, peg shaped laterals, perio, cleft palate.
273
What are the clinical features of ectodermal dysplasia?
Mutation in ectoderms, sparse hair, thin nails, hypo/anodontia, peg shaped teeth.
274
What is cleft lip and cleft palate?
Cleft LIP = Defect in the alveolus, failure of fusion of the medial nasal prominence and the maxillary process.
Cleft PALATE = Can occur in isolation when the palatal shelves fail to fuse in the midline, or in combination with cleft lip.
275
How do turner teeth appear and how do they form?
White/yellow spots/ brown mottled appearance due to trauma/infection to the primary predecessor. Localised enamel hypoplasia/defect to the enamel.
276
What are the consequences of congenital syphilis?
Moon molars, hutchinsons incisors, mulberry molars. Due to mother having syphilis.
277
How does excess fluoride impact teeth?
Can cause fluorosis if ingested whilst permanent teeth are calcifying can lead to hyperplastic appearance of teeth. Maxillary incisors calcify between 15-30 months therefore should be aware due to the aesthetic zone.
278
What is amelogenesis imperfecta and how does it appear?
It's a hereditary disorder of enamel leading to hypoplastic and hypomatured/calcified teeth, it affects all teeth and has a different appearance depending on which type the patient has.
Type 1 - hypoplastic
Type 2 - hypomatured
Type 3 - hypocalcified
Type 4 - hypomaturation/hypoplasia/taurodontism.
279
What are 2 metabolic causes of dentine changes?
Rickets and insufficient calcium intake.
280
What is osteogenesis imperfecta and its clinical features?
Hereditary disease caused by defective type 1 collagen. Patients present with generalised osteoporosis, blue sclera, long slender limbs, multiple fractures.
281
What is dentinogenesis imperfecta and how do the teeth appear? Types + RG appearance?
Type 1 (related to osteogenesis) and type 2 (by itself) and type 3 (has marked attrition and pulp exposures, often called shell teeth due to RG appearance).
Teeth erupt amber and then turn blue/grey over time with translucent glassy appearance. Often associated with significant tooth wear (attrition)
Tulip shaped crowns, obliteration of pulp chamber.
RG- teeth can have bulbous crown, short roots and/or pulp obliteration in many teeth.
282
What is type 1 vs type 2 dentinal dysplasia?
Type 1: affects the roots - crowns are normal but with short roots, pulpal obliteration and early loss of teeth.
Type 2: crowns are tulip shaped with flame shaped pulps.
283
What is hypercemtosis and what can cause it?
Abnormal amounts of cementum around the root, can be caused by periapical inflammation, pagets, mechanical stimulation.
Excessive deposition of cementum on tooth roots. RG might appear as bulbous enlargement of root. Mandible 2:1. Molars then premolars most affected.
Cuased by supererupted tooth as it erupts into space of missing opposing tooth. Periapical inflammation. Traumatic occlusion. Pagets disease. Hyperpituitarism (acromegaly and gigantism).
No treatment. Pose problem when extracting.
284
How do dens in dente appear?
Invagination of the dental papilla by the enamel organ. An enamel linked cavity opening on the tooth surface which can act as a plaque trap and caries risk. Can be treated with a fissure sealant or prophylactic filling.
285
Where do enamel pearls arise from?
Originates from Hertwigs shealth cells differentiating into ameloblasts instead of roots.
286
What is concresence?
Roots of 1 or more teeth are joined by cementum. Only work out when you go to extract but can't.
287
What should you be wary of a delayed trauma presentation?
Non accidental injury
288
Why should you check if a patient has had any trauma to the teeth before?
Previous injuries to the pulp worsen the prognosis and when taking baseline radiographs it may account for an anomaly noticed.
289
What should you check soft tissue for following trauma?
Degloving, lacerations and any part of the tooth in the soft tissues.
290
What determines whether the pulp recovers or necroses following trauma?
Revascularisation of the PDL
291
Why do we take baseline radiographs (trauma)?
To assess further inflammation, periapical infections and pulpal status. Medicolegal reasons.
292
What sensibility tests should be included in a trauma grid?
Colour, mobility, TTP, sensibility, radiographs, swellings/sinus.
293
Why may a tooth not erupt?
Ectopic position, no permanent successor, cyst, retained primary, insufficient space.
294
What is dilaceration?
Deviation in the tooth crown to root.
295
What is an infolding defect and how is it managed?
Infolding prior to mineralisation taking place that can act as a plaque trap. Prophylactic filling however if pulp exposed then pulp treatment continue.
296
What are outfolding defects more commonly known as?
Dens evaginatus on molars or talon cusps on anterior teeth.
297
What are the problems associated with talon cusps?
Irritation of tongue, occlusal interference, attrition to opposing teeth, rapid pulp inflammation. Can place fluoride varnish to desensitise.
298
What is a turner tooth?
Turner tooth is localised hypoplasia to a permanent tooth which is concurrent with trauma to the primary predecessor.
299
What is MIH?
Hypomineralisation of 1 or more permanent molars and/or incisors associated with childhood illness between 0-3, problems during birth and illness during pregnancy. It is a chronological defect.
300
How do hypoplastic teeth appear in comparison to hypomineralised/calcified?
Hypoplastic teeth have good quality enamel but there isn't enough of it resulting in deficiencies which can be felt as pits and grooves, the enamel is thin and has a yellow appearance.
Hypomatured then onto hypocalcified teeth are of poor quality giving them white/yellow/brown flecks that crumbles and is quite soft and has high sensitivity.
301
What 2 systems are involved in calcium regulation?
Parathyroid gland and vitamin D metabolism.
302
What are the most common issues with enamel hypoplasia?
Compromised aesthetics, sensitivity, caries, TSL.
303
Why does enamel hypoplasia lead to secondary caries?
As the enamel has less resin tags making it an unfavourable etch pattern which means restorations are more prone to leakage. It is commonly prefered to use resin modified GIC as this bonds to both enamel and dentine.
304
What clinical features are dentine defects associated with?
Rapid tooth surface loss and crown fractures as the enamel has little support from the underlying dentine.
305
How does regional odontoplasia appear?
Incorrect formation of all dental hard tissues meaning the teeth are less likely to erupt. This is seen clinically as one quadrant missing all/most teeth.
306
What are Epstein's pearls?
Small and white/grey newborn cyst that develop on the midline of the palate from the epithelial inclusions in the line of fusion of the palatine process.
307
What are Bohn's nodules?
Small and white/grey newborn cyst that develop on the alveolar ridge from the cell rests of Serres undergoing cystic change. They tend to self-rupture and do not require excision.
308
What is partial ankyloglossia?
Also known as tied tongue, it is when there is a short lingual frenum attachment to the floor of the mouth. If effecting speech or feeding should be intervened.
309
What are symptoms of chronic odontogenic infection?
Pyrexia, redness, swelling, distressed. You need to be careful with children as they dehydrate very quickly.
310
What is the presentation of primary herpetic gingivostomatitis?
Fiery red gingiva, painful stomatitis, bleeding/crusting of the lips, pyrexia, excess salivation and submandibular lymphadenopathy.
311
Where do lesions appear for herpangina and what causes this?
On the fauces and soft palate, caused by coxsackie virus.
312
How does hand foot and mouth present?
Sore throat, high temperature, ulcers in mouth, lesions on hand and feet and no appetite.
313
What causes erythema multiforme and how does it present?
It is caused by systemic infection, drugs or food.
It presents with target lesions, widespread ulceration, blood crusted lips, pyrexia, sore throat, desquamative gingivitis.
Stephen Johnsen syndrome is severe erythema multiforme.
314
What is an eruption cyst?
A superficial dentigerous cyst that appears 2 weeks prior to eruption that is blue-ish and fluctuant.
315
What is Sturge-Weber syndrome associated with?
Haemangiomas of the face and oral cavity, mental retardation, contralateral focal seizures and calcification of the meninges.
316
What is an epulis/fibrous epulis?
It's a hyperplastic growth due to minor chronic insult found on the gingiva.
317
What is a giant cell epulis?
Found interdentally on anterior teeth around the gingival margin, it is a hyperplastic growth characterised by its maroon, purple discoloration due to being filled with blood.
318
What is periodontitis?
The progressive and irreversible loss of clinical attachment due to the destruction of the PDL and surrounding bone.
319
What is modified BPE?
Age 7-11 (only 6s and 1s recorded up to score 2), age 11+ (only 6s and 1s however can score 4*).
320
Why is there no critical pH for erosion?
Erosion depends upon saturation of the solution within the relevant solids.
321
How does acid exposure effect enamel?
Leads to softening of the surface enamel, increased roughness giving the appearance of etched enamel, rapid bulk loss of tissue with the underlying tissue left starting to demineralise, soft/demineralised enamel is at higher risk from other forces leading to tissue loss.
322
What is the histopathology of erosion?
Softening of enamel, partial material loss with softening of underlying tissue, significant loss of surface through physical forces.
323
What is GORD and what are its symptoms?
Backflow of gastric acid into the oesophagus, characterised by heart burn, bad taste, erosion and dysphagia. It can be caused by liver disease, GI disease, respiratory disease and neuromuscular disease. Patients who are obese, heavy drinkers, pregnant or have a high fat diet are at higher risk.
324
What are early signs of erosion?
Loss of surface edges of teeth, teeth become shiny and smooth, incisal edges become more translucent.
325
What are later signs of erosion?
Incisors: thinning and chipping of incisal edge, chamfer margins, teeth become darker due to underlying dentine shining through.
Molars: proud restorations and cupping of occlusal surfaces. As time goes on teeth become more sensitive due to exposed underlying dentine.
326
What is Gillick competence?
Children under 16 can consent for treatment if they can understand what is going on by proving they have capacity.
327
What anatomical features should you look for when going to construct a partial denture?
High frenal attachments, tori, and pronounced undercuts.
328
What is muco-static vs muco-compressive?
Muco-static is an impression that doesn't displace the mucosa therefore good for recording the tissue in a non-functional state, often used for flabby ridges.
Muco-compressive is an impression that records the mucosa in its functional state as it causes displacement of the mucosa.
329
What does a special tray allow?
Even distribution of the material to get a better recording of all tissues.
330
When is primary registration required?
Its used when we cannot hand articulate so in patients with free end saddles, one edentulous arch, insufficient occlusal contact and patients with a non-reproducible bite.
331
Why do we articulate models?
To assess interocclusal space, plan for rest seats and assess occlusion.
332
What is ICP/CO?
ICP is the intercuspal contact position and is the relationship between the maxilla and mandible when the teeth are in maximum intercuspation.
Centric occlusion is the lower jaws position when this occurs.
333
What is centric relation?
Centric relation is the most reproducible position, it is the position of the teeth when the condyle is in the most anterior, superior position in the glenoid fossa, most relaxed muscular position independent of teeth position.
334
What is RCP?
Retruded contact position, this is the point in which as you bite down your teeth first touch, ideally it should be equal to ICP however this is not always the case.
335
How do we alter teeth for secondary impressions?
Add guideplanes, rest seats and bulbosities to allow for undercuts. This can be done by crowns or direct restorations.
335
How can you record centric relation?
Tongue retrusion method, temporalis muscle check, bimanual palpation.
335
What is the point of a direct retainer?
Maintain position of teeth, allow for retention and stability and clasp assembly and attachment.
336
What is the point of a minor connector?
Connects the major connector to all other parts of the denture and provides stability (bracing).
337
What is the role of the major connector?
connects one side of the denture to the other and provides support and stability to remaining teeth.
338
What is reciprocation and what is bracing?
Reciprocation is resistance to horizontal forces on abutment teeth caused by clasps.
Bracing is resistance to horizontal forces on saddles caused by oral mucosa.
339
Why do we survey models?
To identify a path of insertion, local undercuts for retention and that need to be blocked, aid in assessment of restorations and placement of clasps.
340
What do guideplanes do?
They can be either natural or artificial and they increase frictional contact between teeth and denture therefore increasing retention due to increased resistance on removal.
341
What is the aim of your path of insertion, what does this then help in?
To achieve as many parallel guide planes as possible to improve retention and aesthetics due to lack of black triangles.
342
What do rest seats do?
Direct occlusal forces along the long axis of the tooth, maintains occlusal relationship, provide indirect retention, prevents trauma to gingiva, prevents food packing and stops orthodontic movement of teeth.
343
How thick is the spacer is special trays?
3mm
344
What is the tray handle angle for upper special trays and then lower?
45 degrees upper and 10 degrees lower.
345
How can we stabilise mobile teeth when taking an impression?
Use flowable to stick together, wire, silicone/wax in embrasures, modified technique of trimming tray back and taking open impression of mobile area.
346
How should patients' clean dentures, what instructions should you be giving?
Depending upon if acrylic or metal, rinse after every meal with debris removed with soap and toothbrush, taken out at night, can use Milton for 20 mins with acrylic and sterident for 10 mins with acrylic store in water overnight.
347
What risk factors can lead to denture stomatitis?
Poor denture hygiene, immunocompromised, uncontrolled diabetes, iron deficiency.
348
What is freeway space, why is it required?
OVD-RVD allows for space for talking and the tongue and allows for complete relaxation of muscles at rest.
349
How can we check labial fullness?
Look at naso-labial angle, tension in philtrum or by using an alma gauge (6-9mm from incisive papilla).
350
What can increased freeway space lead to?
Overclosed patient, angular cheilitis and excess drooling, cheek biting, poor aesthetics.
351
What can decreased freeway space lead to?
Overopen patient, TMJ issues, instability, clicking teeth, trauma, appearance.
352
What does functional sulcus depth mean?
The measurement from gingival margin to floor of mouth when tongue is raised. For a lingual bar this should be 8mm.
353
In what order is vertical jaw relation carried - what is checked?
Upper rim: labial fullness, incisal show, ala-tragal and inter-pupillary, midline, RVD measure.
Lower rim: labial fullness then OVD measured and trimmed to get FWS = 2-4mm.
354
What is balanced occlusion?
Stable, simultaneous contacts of teeth in centric relation with smooth bilateral gliding contact to any eccentric position, within normal range, to minimise tipping and/or rotation of denture bases.
355
What patients is flabby ridge often seen in and how does it present?
Patients with one arch edentulous and a traumatic bite on the alveolar ridge of the opposing arch.
356
What is a leaf fibroma?
Fibrous overgrowth usually caused by trauma to the palate for instance by a denture.
357
How, when taking secondary impressions can we alter trays for flabby ridge?
We can cut out the area of flabby ridge off the denture and take this impression separately using light body silicone. Open tray impression technique.
358
What is the definition of a Class 1 occlusion?
The tip of the lower incisor occludes with the cingulum of the upper incisor.
359
What is the definition of a Class 2 div 1 occlusion?
The tip of the lower incisor occludes above the cingulum of the upper incisor with proclined/averagely inclined upper incisors.
360
What is the definition of a Class 2 div 2 occlusion?
The tip of the lower incisor occludes above the cingulum of the upper incisor with retroclined upper incisors
361
What is the definition of a Class 3 occlusion?
The tip of the lower incisor occludes below the cingulum of the lower incisor.
362
What are some features of the primary dentition?
Anthropoid spaces, ovoid arch form, flush terminal plane, proclined uppers with increased overbite.
363
What dental anomalies may arise in Class 1 occlusion?
Crowding, scissorbite, crossbite, displacement, missing teeth, spacing, open bites, bimaxillary proclination, cysts.
364
What is bimaxillary proclination?
Proclination of upper and lower labial segments due to soft tissues, prone to relapse.
365
What is mild, moderate and severe crowding?
Mild is 0-4mm, moderate is 4-7mm, severe 8+mm.
366
Why may spacing occur and what are the options for spacing?
Small teeth, large jaws, hypodontia.
Spaces can be either closed or opened with then prosthesis placed.
367
What is displacement?
When the difference from RCP to ICP is >1mm.
368
What is a buccal crossbite and how is it managed?
When the maxillary molar occlude lingually to the mandibular molar, is managed usually with a URA with midline expansion.
Ortho tut: When the buccal cusps of the lower teeth occlude buccal to the buccal cusps of the upper teeth.
369
What is a scissorbite, what can a local scissorbite be caused by?
When buccal cusps on lower teeth occlude lingually to the lingual cusps of upper molars.
Local problem often retated to local crowding. Digit sucking habits.
370
What are the general feature of a class 2 div 1?
Usually skeletal class 2, average vertical height, usually symmetrical. Incompetent lips with low lip line. Increased overjet and overbite with buccal segments normally class 2, increased risk of trauma.
371
How do we treat a class 2 div 1?
Functional appliance with or without fixed appiances?
372
How do we treat a class 2 div 1?
Use forces generated by orofacial soft tissues in order to move the teeth, the forces are generated from the soft tissues being stretched. They work by 3 ways: dentoalveolar (the stretched tissues apply force to the teeth which move via tipping), skeletal (growth of the mandible and restraint of maxilla), soft tissues (theory).
373
What are the general features of a class 2 div 2?
Skeletal class 2, reduced vertical dimension, well developed chin, competent lips, high lower lip line, strap like upper lip, bimaxillary retroclination, decreased overjet, increased overbite, premolar scissor bite.
374
How do we treat a class 2 div 2?
The aim is to correct the interincisal angle. First patient is converted to class 2 div 1 using either a URA or a fixed appliance and then treated the same. Can be treated using just fixed appliances.
375
When is the peak growing range for girls and boys?
Girls: 10-12, boy 12-14
376
What does a functional appliance correct?
Anterio-posterior tooth movement
377
What is dento-alveolar compensation?
When the soft tissues produce a class 1 incisor relationship when the skeletal class is 2 or 3.
378
What is transposition?
Abnormality in tooth position (usually with 3s when they swap order).
379
What is an anterior open bite and what can cause it?
No contact or vertical overlap of the lower incisors by the upper incisor when the mandible is in occlusion. Can be caused by increased lower face height, tongue-thrusting and digit sucking.
380
What is mandibular displacement associated with?
Unilateral buccal crossbite.
381
What ANB angles indicate skeletal class 1/2/3?
Class 1 is 2-4 degrees
Class 2 >4 degrees
Class 3 <2 degrees
382
Where should the resting height of the lower lip be?
Lower lip should usually cover incisal edge of upper 1&2s to control upper incisor position.
383
Why should class 2 div 1 patient be treated (from dental health point of view)?
Trauma
384
How do upper removable appliances work and when are they indicated?
They work by simple tipping movements which can then cause retroclination so used to increase overjet and mild skeletal class 2.
385
What is a functional appliance?
A removable appliance used in growing patients.
386
How does a functional appliance reduce an overbite?
Has an anterior block which allows for overeruption of posterior teeth leading to the bite open back up.
387
How do you monitor treatment progress with a URA/functional?/How can you tell if the patient has been wearing it?
Are they wearing to appointment, how is their speech, are there signs of wear, overjet should reduce by 1mm a month, lateral open bite may appear.
388
How do we often treat class 2 div 2 patients?
Just fixed appliances of by converting to a div 1 using URA and then going from there.
389
Why are fixed appliances often the only treatment for class 2 div 2?
Torque control of upper incisors to allow correction of the inter-incisal angle.
390
Why do we treat class 3 patients later rather than whilst growing?
As from 11 to end of growth patients grow 2mm more class 3, treating a patient who has already grown reduces the amount of uncertainty.
391
What is the definition of Class 1/2/3 molar relationship?
Class 1 (mesiobuccal cusp of upper first molar occludes with buccal groove of lower first molar)
Class 2 (mesiobuccal cusp of upper first molar occludes anterior to buccal groove)
Class 3 (mesiobuccal cusp of upper first molar occludes posterior to buccal groove of lower first molar).
392
How do we treat a mild, moderate and then sever class 3?
Mild is treated using a URA.
Moderate with fixed appliances to procline upper and retrocline lowers.
Severe (ANB <-1) treated with orthognathic surgery.
393
When does a patient qualify for orthodontic treatment on the NHS?
IOTN 3 with aesthetic component of 6, IOTN 4 and IOTN5.
394
How does a GDP support an orthodontic patient?
Know when to refer and what to look out for in these patients, continue to give regular oral hygiene advice, be able to fix minor orthodontic emergencies.
395
What is anchorage?
The resistance to the reactive forces to the intended tooth-moving forces.
396
What are different sources of anchorage?
Intra-maxillary, inter-maxillary, mucosa, implants, headgear.
397
How do we assess a patients IOTN classification?
MOCDO: missing, overjet, crossbite, displacement of contact points, overbite.
398
How does infra-occlusion occur? Classification?
Usually caused by insufficient building of the alveolar process and is more common in the mandible.
Can be categorised as slight (1mm below occlusal plane), moderate (occlusal surface level with contact point of adjacent teeth), severe (occlusal surface level or below the gingival margin of adjacent teeth).
399
When are interceptive extractions considered?
These are extractions which aim to minimise or eliminate the severity of the developing malocclusion. Considered to guide the eruption of permanent successor, to encourage space closure in hypodontia, preserve symmetry.
400
What is balancing extraction?
Extraction of tooth on opposite side of the same arch to allow for centre line discrepancies.
401
What is a compensating extraction?
Extraction of tooth in opposing arch on the same side to maintain molar relationships.
402
Tooth position is dictated by forces from what?
An equilibrium of forces derived from periodontal tissue, orofacial tissue, post treatment facial growth and occlusion.
403
What is the neutral zone?
When the lips, cheeks and tongue are in balance with occlusion. Where the forces exerted by the tongue are balanced with those opposing from the lips and cheeks.
404
What is the ideal/stable inter-incisal angle?
Ideal is 135 degrees, over 150 degrees in unstable and prone to relapse.
405
What occlusal factors can aid in stability following orthodontic treatment?
The more intercuspation the more stable the occlusion, adequate overbite and correct inter-incisal angle.
406
What type of bone growth occurs in the jaw?
Replacement of cartilage and periosteal activity at surface and sutures.
407
What are risk factors for ectopic canines?
Not palpable at age 10, C's not mobile, eruption of contralateral >6 months, peg shaped laterals, class 2 div 2, family history, missing laterals.
408
What should you check on a radiograph regarding ectopic 3s?
Presence, position, pathology.
409
What are treatment options for ectopic canines?
Accept and monitor, extract C's and monitor, open exposure, closed exposure.
410
What materials is used in open exposure of canines?
Copac
411
What are some possible clues for supernumeraries?
Non-mobile primary teeth, eruption >6 months, diastema, extra teeth.
412
what are some possible clues for hypodontia?
Peg shaped, missing contralateral.
413
What are some possible things to look out for regarding change in shape of size of teeth?
Slow eruption, small primaries.
414
What is restoratively driven implant placement?
This is where the implant is placed in the best position of the implant to be supported not for the bone.
415
What is McGill's consensus?
2 implants can support a lower overdenture and 4 can support an upper due to the thickness of the bone.
416
What are contraindications for placement of implants?
IV bisphosphonates, radiotherapy, allergy to titanium.
417
What are patient factors that should be taken into place when placing implants?
Oral hygiene, attendance, periodontitis, smoking, stress.
418
What is thick gingiva biotype?
Well keratinised with low scalloping, less likely to recede and better at hiding the implant.
419
What is thin gingiva biotype?
Low keratin, more translucent and high scalloping.
420
What is fremitus?
Vibration of the tooth on occlusion due to occlusal trauma.
421
What are the 3 dimensions assessed when placing implants?
Mesio-distal, bucco-lingual and apico-coronal.
422
When may implant placement be delayed?
When patient doesn't have the money, if the patient is under 18, if currently contraindicated to place (chemotherapy, recent MI).
423
What is meant by an atraumatic extraction?
Use of luxator and piezo-surgery units but no flap raised, no bucco-lingual expansion and avoiding bone removal or teeth sectioning.
424
What is peri-implant mucositits?
Inflammatory disease affecting the soft tissues around the implant which is reversible.
Bleeding on gentle probing with some erythema/suppuration but no increase in probing depths.
425
What is peri-implantitis?
Inflammatory disease affecting the hard and soft tissues, resulting in attachment loss around the implant. Fusobacterium and spirochetes.
426
What are the options for replacing a lost tooth?
RRB, conventional bridge, removable partial denture, implant.
427
What are some intra-op complications for implants?
Haemorrhage, pain, difficulties opening, time taken for procedure, lack of implant stability.
428
What are some post-op complications following implant placement?
Haemorrhage, pain, bruising, infection, swelling, paraesthesia, dysthesia, infection, wound disherence.
429
Why would a bone graft be required for an implant and what are the 3 types?
To replace bone lost to ensure sufficient levels of bone to house an implant of sufficient size and length and to be strong enough to take forces of mastication.
Allograft, autograft, xenograft.
430
What needs to occur before a prosthesis can be placed on an implant?
How long does it take for maxilla and mandible.
Osseointegration, this taken 4 months in the maxilla and 3 months in the mandible.
431
What can occlusal overload of an implant lead to and why can't they carry as much occlusal forces?
There is no PDL, so forces are transmitted directly through the implant to the bone. It can lead to screw loosening, prosthesis fracturing and bone loss.
432
Why are peri-implant tissues more prone to infection?
No PDL meaning there is no protective features of the vasculature and nerve - detect excessive pressure and infection. There is also no interface between the implant and the gingiva, so the protective cuff is weaker and more prone to infection.
433
What are the signs of peri-implant mucositis?
Bleeding on probing, erythema, suppuration and swelling.
434
What are the signs of perimplantitis?
Bone loss,, increase in probing depths, bleeding/suppuration on probing.
435
What are the signs of peri-implant health?
No inflammation, no bleeding, no bone loss.
436
What are some biomechanical problems that can occur post implant placement?
Loss of access hole restoration, screw loosening, decementation of crown from abutment.
437
What are some biomechanical problems that can occur post implant placement?
Resistance against horizontal forces.
438
What is retention?
Resistance against vertical forces.
439
What is support?
Resistance to occlusally driven forces.
440
What are some signs of non-accidental injury?
Story changes with time, teller and injury.
Multiple injuries, delayed presentation, age of child, bruising to non-bony areas.
441
Why do we take 2 radiographs in trauma patients?
To assess for root fractures.
442
When would you carry out a pulp cap following trauma?
Pinpoint exposure, less than 24 hours, clean environment.
443
When would you carry out a Cvek pulpotomy following trauma?
Large exposure happening more than 24 hours ago or in dirty environment.
444
What are some properties of calcium hydroxide?
Antimicrobial dissolves necrotic pulp and induces tissue response.
445
When would autologous transplant be considered? (extracting tooth and replanting somewhere else)
If in a growing child with open apex as pulp can revascularise.
446
What are the treatment aims of luxation injuries?
Minimise PDL damage, maintain pulp vitality and prevent inflammatory resorption.
447
Why do you surgically reposition a mature apex, severe intrusion?
As pulp necrosis is guaranteed so you want to be able to access it and place calcium hydroxide to prevent resorption asap.
448
What are the 2 options for extirpation following avulsion and how long do you leave them for before shaping and obturating?
Non setting calcium hydroxide for 1 week or Ledermix for 6 weeks.
449
What is the % survival for open apex avulsion injury?
30%
450
When is replacement resorption more likely?
When there is greater damage to PDL, the degree of displacement and when extra-oral dry time is longer.
451
What are general post-op instructions following trauma?
- Soft diet for 10 days
- 0.12% chlorhexidine mouthrinse twice a day to the area
- Brush with soft toothbrush
- Take pain relief
- Advise the post-op complications
452
What type of injury causes most damage to the permanent successor?
Intrusive luxation.
453
When should you treat trauma in primary teeth?
If there is mobility, changes in occlusion or pain.
