T1 Flashcards
What type of resorption occurs in a mature apex after an avulsion injury?
Replacement resorption
What is the best solution to keep a tooth in following avulsion?
Milk
Why is a composite bandage important in young permanent teeth?
Seals the dentine tubules to stop infection from reaching the pulp. You want to prevent young children from having an RCT.
What makes a splint flexible?
It is flexible, passive and is only attached to one tooth either side of the ones being held in place.
How do you treat a root fracture?
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).
What 2 injuries in permanent teeth will always result in pulpal necrosis?
Severe intrusion and avulsion
What medical conditions should you not reimplant a tooth?
Infective endocarditis risk and immunosuppressed.
What is the definition of a concussion injury?
Trauma to the tooth with no displacement or mobility, it’s like a bruise.
What is the difference between apexification and apexogenesis?
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.
What are the 3 outcomes for the pulp following trauma?
Survival, obliteration, necrosis.
When do you pulp cap following a complicated crown fracture? What is the other option?
Pin point exposure, within 24 hours, clean tooth = pulp cap. Large exposure, more than 24. hours, dirty = Cvek.
Why is sensibility testing unreliable in young people?
Already in high stress condition, pulp is larger, more sensitive.
What pulpal outcome is common in open apex teeth who have undergone severe luxation?
Necrosis
What injuries is replacement resorption most likely in?
Severe intrusion and avulsion.
What is first indicator for replacement resorption?
Infra-occlusion.
What is surface resorption?
Present early, as part of normal healing, radiographically looks like you have gone from open to closed apex, transient apical breakdown.
What is inflammatory resorption?
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.
What is a smear layer?
A layer that sits on the wall of the canal that contains dentine debris, left over pulp and bacteria.
What is guidance ALL children/parents for 0-3?
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.
What is guidance for high caries risk 0-6?
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.
What is guidance for ALL children/parent for 3-7?
- 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.
What is guidance for ALL children 7+?
- 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.
What is recall intervals for children?
High risk, 3 months.
Medium risk, 6 months.
Low risk, 12 months.
What is recall intervals for adults?
High risk, 4-6 months.
Medium risk, 12 months.
Low risk, 18-24 months.
How do you know when a child can brush their teeth unsupervised?
Tie their shoe laces.
What can be prescribed at age 10?
2800ppm NaF toothpaste.
What can be prescribed age 16?
5000ppm NaF toothpaste.
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.
What special investigations do we carry out on teeth to aid clinical diagnosis?
Mobility, colour, pharma-ethyl/EPT, pocketing, TTP, percussion.
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.
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.
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.
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.
What is Reimpaction?
When a tooth is reimpacted it has erupted then unerupted.
What is retention?
Retention is the tooths ability to withstand vertical forces.
What is resistance?
Resistance is the tooths ability to withstand horizontal forces.
What are the 5 principles for crown prep?
Preservation of tooth structure, retention and resistance form, structural durability, marginal integrity, preservation of the periodontum.
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.
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.
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).
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.
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.
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.
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.
What are the symptoms of symptomatic apical periodontitis?
Similar symptoms to irreversible pulpitis however patient may also get pain from biting.
- How do intact periapical tissues appear radiographically?
- Lamina dura intact and the PDL space is uniform.
What is the normal width of the PDL?
0.2-0.4mm.
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.
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.
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.
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
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.
What is the aim of pulp caps?
Promote reparative dentine production to keep the pulp alive.
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.
How can calcification be removed?
Spoon excavator, ultrasonic. C+ files can be used in calcified canals.
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.
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.
What are 2 advantageous properties of Ni-Ti instruments?
They are more flexible and resistant to fracture.
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.
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.
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.
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.
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.
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.
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.
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.
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.
What are the aims of instrumentation?
Remove pulp and microbes, facilitate irrigation, allow placement of medicament and enable placement of root filling.
Why is orifice enlargement carried out?
Removes infected material from coronal portion, improves access to apical third, improves irrigation and removes curvature.
Why do we create a glide path?
Allow easier access for instrumentation and therefore prevents fracture of materials.
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.
What is the active ingredient of odontopaste?
Clindamycin
What is the active ingredient of Ledermix?
Demeclocycline hydrochloride: An antibiotic - tetracycline antibiotic
Triamcinolone acetonide: An anti-inflammatory corticosteroid
Why is odontopaste preferred over ledermix?
Ledermix can lead to staining of teeth
What is the best material to use for apexification?
MTA. Biodentine has better handling properties however it’s research for endodontic use is limited.
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.
What are the problems associated with extrusion of obturation materia?
Can irritate periapical tissues.
Why is coronal seal required post endodontic treatment?
Prevents the entrance of microorganisms into the coronal portion of the pulp.
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.
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).
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.
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.
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.
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.
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
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.
Why do root canals fail?
Unfilled canals, loss of coronal seal, root fracture/perforation, periodontal pathology.
What is periapical periodontitis?
Inflammatory lesion which can destroy the PDL, bone or root.
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.
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.
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.
What are the different forms of endodontic surgery?
Surgical drainage, periradicular surgery, corrective surgery, replacement surgery, implant surgery
What are the different options for replacing a gap?
Accept and monitor, ortho closure, denture, RRB, conventional bridge, implant.
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.
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.
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).
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.
When is a fixed prosthesis indicated?
Protect weakened tooth, fractured cusp, previous endo, vertical fracture, maintenance of occlusion, replace old crown, aesthetics.
When may a fixed prosthesis be contraindicated? (5)
Inadequate tooth tissue, inadequate perio support, poor OH, untreated disease, non-vital tooth.
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.
How is structural durability maintained?
Sufficient occlusal and axial reduction.
What can insufficient axial reduction result in?
Flexing of the crown on occlusal forces.
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.
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.
What tissues are present in the biological width?
Connective tissue and junctional epithelium.
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.
What occurs if the prep encroaches on the biological width?
Attachment loss, gingival inflammation, difficulty cleaning and crestal bone loss.
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.
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.
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.
What are risk factors for oral cancer and how as dentists can we prevent/detect?
Tobacco, alcohol, diet.
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.
What are 5 behaviours that support better oral health?
Improving oral hygiene, optimise fluoride exposure, reducing sugar consumption, stopping smoking, reducing alcohol consumption.
What are 3 important things a patient should have to allow behaviour change regarding oral health?
Capability, motivation and opportunity.
What are SMART goals?
Specific, measurable, achievable, relevant, timely. Help you to help your patient change their behaviour.
What common rehabilitation drug is usually given as a sugar-based prescription?
Methadone
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
- 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.
What are the BSP guidelines regarding a BPE of 3?
Supra-scale with 3 month 6PPC review of sextant.
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.
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.
When should advanced periodontal treatment be carried out?
Once 2 rounds of PMPR have been carried out on unresponding pockets.
What types of periodontal surgery are available?
Crown lengthening, gingivectomy.
What are some primary prevention mechanisms of periodontitis?
Management of risk factors
What are secondary prevention mechanisms of periodontitis?
BPE with grading and staging of periodontal status.
What are the guidelines regarding a BPE from 7-11?
Only score up to 2, using the 6s and 1s.
- What are the guidelines regarding carrying out a BPE 12-17?
Can score up to 4 but continue to use the 6s and 1s.
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.
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.
How is peri-implantitis prevented?
Control of risk factors can be useful however regular recall and maintenance along with radiographs is more important.
What are the components of supportive periodontal care?
Setting expectations, monitor depth, OHI, PMPR.
What are cancer/ex-cancer patients at higher risk of?
Dental caries, oral mucositis, MRONJ, ORN.
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).
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.
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.
When should daily interproximal cleaning have begun by?
Should have started by 18 years of age, or younger depending on presence of gingival inflammation.
What areas are still under the fluoridated water scheme?
Birmingham, Newcastle and Scunthorpe/Lincoln.
When does calcification of the permanent incisors occur?
30 months
When does calcification of the permanent premolars occur?
6 years.
What cements cannot be used sub-gingivally?
Resin based cements.
What does ceramic require to bond to?
Enamel
What is the purpose of a functional cusp bevel?
Allow for extra thickness and strength of the crown to deal with occlusal forces.
What are guide planes?
Parallel surfaces on teeth that aid in insertion and retention.
What are colour shades made up of?
Hue, value and chroma.
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.
How is occlusion defined?
The static relationship between the incisal or masticatory surfaces of the teeth.
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.
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.
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.
What is mandibular displacement?
Movement of over 1cm from RCP to ICP.
What are 3 occlusal diseases?
Occlusal dysthesia, bruxism, trauma from occlusion.
What is displacement without reduction?
When the articular disc is displaced anteriorly to the condyle when both open and closed.
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)
What are signs of soft tissues of parafunctional habits?
Linea alba, tongue scalloping, mandibular tori.
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.
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.
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.
Why do we use temporary crowns?
Cover exposed dentine, function, aesthetics, diagnosis, to prevent gingival overgrowth.
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).
When thinking of ideal properties of materials what should they usually be?
Non-toxic, biocompatible, cheap, easy to use, adhere.
Why would you use poly F over tempbond?
For long term temporaries or when placing a ceramic crown.
Why would you use tempbond over Poly F?
Sedative effect and also antibacterial, is also easily removed.
What is an inlay?
An intracoronal restoration that replaces tooth tissue but not the cusps.
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.
What are the indications for a post and core?
Successful endo treatment, restorable tooth, good perio status, no parafunction.
What should be considered when placing a post?
Curvature, length, width and taper of root, any untreated disease, quality of endo treatment.
When is placement of a post and core not advised?
Short root, inadequate ferrule, poor endo, inadequate dentine thickness.
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.
What does a longer post allow?
It allows even distribution of forces and better retention.
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.
What are the components of a bridge?
Abutment, pontic, retainer and connector.
When would an RRB be chosen over a conventional bridge?
Unrestored dentition, replacing one unit, no parafunction habits.
In a cantilever bridge where should the abutment tooth be in comparison to the pontic?
Distal
What are problems associated with a fixed-fixed RRB?
Higher likelihood of debonding therefore can get caries underneath.
How can we increase the survival rate of an RRB?
Cantilever design, little to no prep, using rubber dam.
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.
What are the options for restoring primary teeth?
GIC, compomer, composite, SSC.
What are options for restoring permanent teeth?
GIC, compomer, composite.
What 3 things help you indicate someones caries risk?
Newly formed caries, anterior caries, presence of other restorations.
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.
What 2 congenital conditions increase caries risk?
Amelogenesis imperfecta and cleft palate.
What in a social history may increase a childs caries risk?
Social deprivation, caries in siblings, irregular attender, availability of sugar, low knowledge
What is the definition of early childhood caries?
Presence of DMFT in 1 or more primary tooth in 72 months or younger.
