Clinical skills*

Question 1

Indications for use of fissure sealants?

Answer 1

High caries risk (high sugar)
Limited manual dexterity
Medically compromised (chemo, immunity and bleeding disorders)
Deep fissures
Management of non-cavitated caries
Apart of PRR
Marginal restorations (previous)
All newly erupted permanent teeth

Clinical proven - 89% reversal of carious to non carious

Question 2

Fissure sealant application technique - evaluation, etching pattern?

Answer 2

Isolate tooth (dam or cotton wool)
Clean tooth (brush or probe)
Etch (30-50% phosphoric acid) for 20-30s
Wash for 10-20s and dry until frosted and matt
Sealant applied (no air bubbles)
Light cure 20-30s
Check adequacy and retention (smooth, occlusion, undercure and no extensions)
Provides micro mechanical form of retention (core removed)

Question 3

Classifications of fissure sealants?

Answer 3

Polymerisation - self or light
Colour - translucent or opaque
Filler content - filled or unfilled

Question 4

Polymerisation types?

Answer 4

Self is chemical cured, mixture of 2 chemicals, limited time (5yrs)
Light cured is by command (20yrs)

Question 5

Importance of moisture control during fissure sealant application - solutions?

Answer 5

Main reason for failure
Etched enamel can become contaminated with saliva proteins compromising bond to the hydrophobic sealant
Rubber dam

Question 6

Contraindications for fissure sealants?

Answer 6

Poor cooperation
Isolation issues
Caries present

Question 7

Standard prevention for all children fissure sealants - indications? placement? maintenance?

Answer 7

Placed on all newly erupted teeth (resin-based)
Ensure buccal pit of lower first molars and palatal fissures of upper first molars
If uncoop apply glass ionomer fissure sealant and with fluoride varnish
Check sealant integry every recall visit (top up)

Question 8

How are caries formed and arrested?

Answer 8

Driven by the biofilm on the surface of the enamel causing a lesion due to the production for acid, via the digestion of sugars
Arrested by removal of dental plaque from the lesion or lesion isolation from the biofilm allows arrest

Question 9

Minimal intervention technique - newly found phenomenon allows?

Answer 9

Significant dentine-pulp complex repair is capable, which allows leaving small amount of affected dentine, as long as there is no bacteria present

Question 10

ICDAS - 0-6? International caries detection and assessment system

Answer 10

0 - sound tooth (after air dry)
1 - visual change in enamel (white spot on pit/fissure after dry)
2 - distinct change seen when wey
3 - localised enamel breakdown (no dentine)
4 - underlying dark shadow
5 - distinct cavity with dentine
6 - extensive cavity with dentine

Question 11

Examination of suspected caries?

Answer 11

Clean ooth
Cotton wool if wet
Remove saliva
Examine wet
Dry for 5s
Visual inspection

Question 12

Treatment options for occlusal caries?

Answer 12

Prevention:
- dietary analysis, OHI, fluoride treatment and chlorhexidine
Fissure sealants
PRR
Filling (conventional restoration)

Question 13

Topical fluoride varnish - overview?

Answer 13

Tries to produce remineralisation
NaF, APF, SnF2
Home use toothpastes, mouth washes and gel

Question 14

Stained fissure appearance and indications?

Answer 14

Discolouration not due to staining, developmental opacities or fluorosis
Found in pits and fissures (confined)
No evidence of shadow indicating dentinal caries
Radiographs if possible

Question 15

Sticky fissure - diagnosis?

Answer 15

Never use a straight probe (cause damage or introduce bacteria)
Clean and dry under good lighting, examination with the support of BW radiographs

Question 16

To seal or not to seal?

Answer 16

If in doubt = seal
No harm in sealing
Non-cavitated occlusal caries
Unethical to undertake invasive treatment when placement and maintenance of sealant is as effective

Question 17

Occlusal caries - reason for high caries risk? difficult diagnosis? hidden caries? diagnosis? when to restore?

Answer 17

Stagnation points for plaque
Surface often looks intact
Occult - surface intact, but caries underneath, bacteria enter via deepest part of fissure and spread along ACJ
Diagnosis:
- radiographs (radiolucent show infected dentine)
- caries always underestimated radiographically
Obvious cavity and infected dentine

Question 18

Preventive resin restoration (PRR) - technique? indications?

Answer 18

Outline access with pear shaped diamond high speed bur
Removed all affected fissure
Decalcified fissure left
2 lesions present, treat separately
Try to leave oblique ridges if possible
Remove caries until the ADJ (pulp protection)
Etch for 15s
Wash tooth
Dry tooth (dentine moist)
Primer to enamel and dentine
Dry for 5s (shiny appearance)
Adhesive to enamel and dentine
Cure for 10s
Build up restoration with resin composite
Cure 30s
Etch remaining fissures 30s
Wash
Dry
Sealant
Cure
Check occlusion
Used when fissure system becomes carious (localised)

Question 19

Conventional restorations - indications? technique?

Answer 19

Cavity large enough to involve most of fissure system
Occlusal registration
Outline form
Keep minimal but remove caries
Build up base as necessary
Etch, prime and bond
Apply composite in increments and cure (avoid contacting both lateral walls)
Cure (up to 2mm)

Question 20

Definition of an approximal caries - how to diagnose? when to intervene? cavity preparation technique?

Answer 20

Found interproximally (CII) of the molar and premolar teeth
Diagnosis with visual inspection with drying and transillumination with the aid of radiographs
Intervention is only necessary if the caries has reached the amelodentinal junction, cavitated or visible on the radiograph
Due to the caries located proximally, entry is necessary via the occlusal dimension

Question 21

Creating a cavity - requirements for a CII? occlusal caries also present?

Answer 21

Break through the contact point, into the embrasure area (minimal is best)
Must break contact point
Creation of a proximal box the same width as the contact point, remove the caries present and try to avoid entering the occlusal surface (parallel box walls, 1.5mm)
Ensure safety of the adjacent tooth with protection
Remove the occlusal caries by following the fissure pattern of the tooth, a reduced depth compared to the box, and combine the 2 cavities

Question 22

Materials for cavity filling - material? cavity modification? function?

Answer 22

Composite - no mod (etch and bond), removes smear, demineral prisms and forms micromechanical retention for composite tags
Amalgam - needs nudercuts, grooves and a widen base to slot in (rounded line angles), stops displacement
GIC - no mod (chemical), polyacrylic acid removes smear and chem adhesion with Ca

Question 23

Dental matrices - function? types? avoiding overhangs? how to place it?

Answer 23

Contain the cavity for the restoration
Adapts the material to form the cavity floor and walls, giving a good marginal seal without ledges
Re-establish the contact points with reducing retention factors
Circumferential or sectional
Wooden or plastic wedge to be inserted to ensure no deficiencies around the cervical portion of the matrix
Top of matric at marginal ridge height, bottom of the and fully covers the bottom of proximal box and tightly adapted, band should be tightened for desired shape

Question 24

Basic structure and reaction of a resin composite?

Answer 24

Repeating structural units (monomer) linked together as a product of free radical polymerisation. As monomers cross link between adjacent monomers the mobile monomer moves closer and convert into covalent bonds incurring bulk contraction, causing composite to undergo volumetric contraction (shrinkage)

Question 25

Polymerisation shrinkage stresses - contraction? tooth structure? tooth stability?

Answer 25

Generated by contraction of the composite on the tooth/restoration interface leading to heavily stressed areas
Tooth deformation - break
Failure of tooth - contraction forces exceed bonding strength creating gaps leading to margin staining, leakage and 2nd caries

Question 26

Factors contributing to polymerisation shrinkage or stress generation - system? conc of inhib/initiator? filler? C factor? hygroscopic expansion? glass ionomer?

Answer 26

Composite system - higher viscosity more shrinkage
Conc of initiator/inhibitor - influences shrinkage rate
Filler content - higher filler less shrinkage
C factor - configuration factor (ratio of bonded to unbonded surfaces - incremental technique)
Hygroscopic expansion - shrinkage influenced by water absorption but not throughout material thickness
Glass ionomer forms a reliable chemical free gap bond to detine and composite

Question 27

Clinical strategies to manage shrinkage - light? inhibitor? cure technique?

Answer 27

Alternative light curing method
Increased inhibitor - reduces polymerisation speed and shrinkage stress
Soft/ramped curing improves marginal adaptation

Question 28

Definition of hue and chroma?

Answer 28

Hue - describes whether the colour appears red, yellow, blue etc
Chroma - is the intensity of the shade

Question 29

Indications for use of resin composites? contraindications?

Answer 29

SML occlusal cavities in post
SML proximal cavities in premolar
SM proximal post
Cervical lesions
Incisal edges
Tooth wear
Fissure sealant
PRR

Large proximal lesions in post (cuspal replacement)
Poor isolation
Root caries
Allergies

Question 30

Cavity structure for amalgam restorations - factors needed for retention? condensation factors needed for success? condensing instructions? carving instructions?

Answer 30

Structure:
- Depth should be at least 2mm deep
- Cavity floor should be flat
- Walls should be parallel with slight convergence 
- No unsupported enamel margins
- No sharp angles
- Undercuts
Condensation:
- condenser must fit
- amalgam in small increments
- condensing time up to 4m
- caving 5 mins
- preparation is overfilled
- condense with heavy pressure (remove voids)
Instructions:
- start will small end of condenser in proximal box, after it is filled switch to the  larger end
- begin in proximal box

Question 31

Instructions - condensing and carving process?

Answer 31

Condensing:
- start will small end of condenser in proximal box, after it is filled switch to the larger end
- begin in proximal box
Carving:
- remove gross excess
- use probe around matrix band and contour the marginal ridge after carving
- using the carver follow the cuspal pattern helping to form the fissure pattern
- use burnisher to smoothen area after
- compare the marginal ridge heights for help
- aim for a smooth amalgam/enamel junction
- cotton wool for a matte finish