Mock 2018/2019 Flashcards
What are the 3 components of RPI system?
- rest seat on mesial
- distal proximal plate
- I bar
RPI system is used to allow vertical rotation of a distal extension saddle into denture bearing mucosa without damaging periodontitis of abutment tooth. How is this achieved?
- as saddle sinks into denture bearing mucosa, there is rotation of denture about mesial rest
- both distal guide plate and I bar rotate downwards and mesial and disengage from the tooth
- potentially damaging torque is avoided
Why is lingual bar chosen?
- sufficient depth of sulcus
- good oral hygiene
- requirement for rigidity
- materials could be cobalt chromium/ gold alloy
Name 2 fixed restorative tx options the pt may wish to consider as an alternative to lower removable partial denture?
- distal cantilever adhesive bridges to replace 35 and 45 using 34 and 44 as abutments
- implant retained restoration
What are the 3 main criteria must be fulfilled before the RC system can be obturated?
- no symptoms
- canal must be able to be dried
- full biomechanical cleaning
3 constituents of GP cones
- radiopacifier - barium salts
- zinc oxide 59-75%
- waxes, coloring agents, anti- oxidants
What is the function of root canal, sealer when used with GP?
- to fill space between GP and the root canal wall
- provide a fluid tight seal
Give. 3 generic type sealer that is commonly used in root canal obturation?
- zinc oxide eugenol
- resin based
- calcium hydroxide
- calcium silicate
2 options which could be provided to provisionally restore tooth whilst ends tx is performed
- provisional overdenture
- provisional post crown
4 materials a post core can be made of?
- gold
- ceramic
- zirconia
- carbon fiber
2 factors which will guide your decision on length of post
- post will extend beyond the level of alveolar bone
- post must be at least as long as height of crown being replaced
- 4-5mm of GP must remain apical to post to maintain adequate apical seal
2 materials used to cement a definitive post and core
- resin modified glass ionomer luting cement
- composite resin luting cement with a dentine bonding agent
What is the likely cause of gingival recession seen in lower anterior sextant?
- traumatic overbite
Where else may you see signs of gingival stripping from traumatic overbite?
- palatal gingiva of upper anteriors
5 investigations you would perform after charting?
- BPE
- sensibility testing
- periapical radiograph of lower anteriors and any other teeth with advanced attachment loss
- mobility scores
- clinical photographs
- full mouth periodontal pocket chart
2 general approaches to patient’s initial tx
- hygiene phase therapy
- upper anterior bite raising appliance for night time use
At reevaluation, there are no deep pockets and OH is excellent. Lower incisors are mobile, causing patient concerns. what would you offer to manage mobility?
- splinting
To which group of chemicals does chlorhexidine digluconate belong?
- bisbiguanides
Describe the mechanism of action of chlorhexidine digluconate?
- chlorhexidine binds to microbial cell walls (negatively charged phospholipids) causing cell wall damage (membrane disruption) and interfering with cell wall permeability (osmotic damage)
- leakage of cell contents leading to cell death
- dicationic, one ion binds to oral surfaces and one to bacterial cell wall
The activity of an oral antiseptic depends on its substantivity. Define substantivity and provide 2 examples of factors that may influence substantivity of chlorhexidine in oral cavity?
- defined as the capacity of a chemical agent to continue its therapeutic effect for a prolonged period after initial application
- it depends on:
- adsorption to oral surfaces
- maintenance of anti microbial activity
- slow neutralization of antimicrobial activity
- concentration of chlorhexidine
- presence/ levels of anionic neutralizing agents
4 indications of use of chlorhexidine MW?
- post surgery
- maintain OH in patients with jaw fixation
- acute necrotising ulcerative gingivitis
- recurrent oral ulceration
- denture stomatitis
- preoperative rinsing
- tx of dry socket
- endodontic irrigant
List a set of published guidelines for removal of wisdom teeth?
- SIGN Scottish Intercollegiate Guidelines Network
- NICE National Institution for Health and Clinical Excellence
3 reasons for removal of impacted lower wisdom teeth
- pericoronitis
- caries
- periodontal disease
- pathology
What is the incidence of temporary and permanent loss of sensation following wisdom teeth removal?
- temp: approx 5-20%
- perm: < 1%
4 further post-op complications of removing wisdom teeth
- pain
- swelling
- trismus
- bruising
- bleeding
- dry socket
8 year old child attends surgery with enamel- dentine pulp fracture to 11- what 2 things do you need to know about the injury to decide whether to pulp cap or pulpotomy?
- size of exposure
- length of time since injury occurred
You decided to provide pulpotomy for tooth 11. Explain the stages of procedure you now carry out.
- apply rubber dam
- remove pulp tissue at 2-3mm radius around exposed area
- assess bleeding- no bleeding then remove more tissue
- gain hemorrhage control using saline soaked cotton wool ball
- assess bleeding, if hyperaemic then remove more tissues
- once bleeding stops, apply non setting CaOH
- seal with GI
- restore tooth with acid etched composite tip
Pulp remained vital. What signs would you expect to see in radiograph?
- continued root development
- continued thickening of dentine in root walls
- apical development
- no pathology
3 uses of URA apart from tipping and tilting of teeth
- as a space maintainer
- habit breaker
- reduce overbite
- retainer
What other types of space maintainer could be used?
- fixed palatal arch
How would you gauge if the patient has been wearing their appliances as instructed? Give 8 signs of good wear.
- ask them
- can they speak with the appliances in their mouth
- is it in when they enter the surgery
- can they handle the appliances
- does it look worn
- has teeth move
- is the active component passive
- does it fit adequately
- signs of wear on palate
- no excess of salivation
A 68 yr old has been given medication to prevent her from getting another fracture. What 2 drugs is she likely to be on?
- bisphosphonate
- calcium
What oral condition may arise from these drugs?
- osteonecrosis of jaw
How could this condition be managed?
- conservative approach
- Antiseptic MW
- antibiotics
- surgical debridement
- primary closure
How to best avoid jaw fracture in the first place?
- avoid extractions
- avoid trauma
- good OH
Stage 1 of oral transport
- food gathered on tongue tip
- tongue retracts taking food back to level of posterior teeth
Stage 2 of oral transport
- sufficiently masticated food is transferred to oropharynx by a squeeze back mechanism in which the bolus is squeezed between tongue and palate
2 biological factors that can affect masticating performance of a human being
- number of occluding teeth/ occlusal contact area
- biting force
Shortened dental arch
- dentition in which posterior teeth have been lost
- Usually consists of 6 anteriors and 4 premolars in each jaw: 20 teeth in all
3 aspects of oral function that are regarded by proponents of SDA as acceptable in older patients
- acceptable masticatory performance
- acceptable aesthetics
- can maintained in healthy state by the patient
