Cavity Preparation* Flashcards
1
Q
Advantages and disadvantages to direct and indirect restorations?
A
Direct: - quick - one operator - simpler - cheaper Indirect: - increased fit - better margins - less shrinkage - better aesthetically
2
Q
Main reasons for teeth restoration?
A
Caries
Non-carious tooth substance loss
Failed restorations
Aesthetics
3
Q
Aims of restorations - step 1/2?
A
Step 1: remove diseased tissues
Step 2: restore integrity, function and appearance of tooth
4
Q
Describe the restorative cycle?
A
A cycle which indicates the possible outcome for teeth
5
Q
Main reasons for dental caries?
A
Plaque - from digestion of glucose to produce acid
Diet - affects pH
6
Q
Caries - minimal intervention technique - definition?
A
The aim of restorations are to be minimally invasive and mainly preventative rather than reactionary.
Also, to identify and control aetiological factors and stabilise.
7
Q
Types of non-carious tooth substance loss?
A
Attrition - tooth on tooth
Abrasion - wear
Erosion - chemical
Abfraction - functional (V/C shaped)
8
Q
Main aim for cavity preparation?
A
Removal of infected dentine
Sealing dentinal tubules
9
Q
Micro-preparation technique - what is involved?
A
Reduced size of instruments and size
Magnification necessary
10
Q
Atraumatic restorative treatment technique - what is involved?
A
Hand excavation then restored with adhesive material
Nervous patients
Doesn’t removal all caries
11
Q
The stages of treatment - Identify? Prevent? Restore? Maintenance?
A
Identify:
- history, examination, detection, radiographs and aetiological factors
Prevent:
- lesion type, patient susceptibility and proposed action
Restore:
- decide on productive treatment
Maintenance:
- susceptibility related and recall variable
12
Q
Advantages of minimally invasive technique?
A
Less unexpected exposure of the pulp
Less pulp stress
Also, repair and refurbish where possible
13
Q
Repair and refurbish technique - dependent upon? what is involved?
A
Depend: Patient wish History Caries risk Marginal defects existing Involved: - polishing, recontouring margin, or small replacement
14
Q
Factors which affect the life of a restoration?
A
Caries risk Cavity size Cavity Ste Operator skill Trauma Lifestyle
15
Q
Factors for failure of restorations?
A
Secondary caries Tooth wear Pulpal problems Trauma Fracture Ditching Defective contact Defective margins Aesthetics Lack retention
16
Q
Secondary caries - cause failure?
A
Caries at margin
Gap left in restoration allowing food and bacteria to accumulate, and no cleaning potential leading to caries
17
Q
Tooth wear - cause failure?
A
From attrition or erosion
Lose attachment
18
Q
Pulpal problems - cause failure?
A
Causes pain
Direct or infection
Needs RCT or extraction
19
Q
Trauma - cause failure?
A
Loss of restoration through force
20
Q
Fracture - cause failure?
A
Incorrect placement
Material too thin
Tooth sections too thin
Occlusion
21
Q
Ditching - cause failure?
A
At tooth-amalgam interface
Due to creep or corrosion
Plaque retentive -> 2nd caries
22
Q
Defective contact - cause failure?
A
Food packing
Recurrent caries
23
Q
Aesthetics - cause failure?
A
Look bad, replaced
24
Q
Poor margins - cause failure?
A
Plaque retention, food trapping, recurrent caries and perio disease
25
Lack retention - cause failure?
Nothing to attach to
| Break off
26
During cavity prep - what happens to the dentinal tubules?
Insult the pulp leads to increased inflamm cell infiltrate
| Prep leads to smear layer which occludes dentinal tubules with bacteria, collagen slurry and hydroxyapatite
27
Pulpal chemical attacks - sources?
From restorative material such as acrylic resin and acids in dentine bonding agents
or residue acid from bacteria
28
Pulpal galvanic shock - what causes it?
2 different adjacent material restorations such as silver and gold can form a electrolyte cell with the saliva causing pain
29
Pulpitis - definition? causes? symptoms?
Pulpitis is the inflammation of the dental pulp
Causes:
- carious progression into dentine
- tooth has multiple procedures
- trauma to lymphatics or blood supply
Symptoms:
- increased response to hold and cold stimuli
30
Reversible pulpitis - definition? causes? symptoms?
```
Reversibility damaged but can recover
Mainly due to bacterial invasion into dentine
Symptoms:
Transient pain to hot, cold, sweet, water and touch
Lasts seconds
Pulp still vital
Can return to healthy state
Referred pain
```
31
Irreversible pulpitis - definition? causes? symptoms?
```
Irreversible damage
Mainly due to bacterial invasion of the pulp
Symptoms:
Dull aching from hot or cold
Lasts hours
Constant
Spontaneous
Sleep loss
CS: more painful to heat
```
32
Reasons not to restore cavities?
Patient access to lesion is good
No active cavies
Possibility of remineralisation
33
What does minimally invasive mean and involve?
Remove unrepairable diseased enamel and dentine only
Physically and chemically modify the remaining cavity
Restore cavities with suitable material which supports and strengthens the structure, promotes remineral and seal of any remaining bacteria from nutrition arresting the carious process
34
Black's classification of cavities? I - VI?
I: occlusal surfaces of molar and premolars, buccal pits of molars and palatal pits of anteriors
II: interproximal surfaces of posteriors
III: interproximal surfaces and anteriors
IV: incisal edges of anteriors
V: cervical margins
VI: cusp tips of posteriors and canines
35
Classification of caries - anatomical sites? overall type? speed?
```
Site:
Pit or fissures
Smooth surfaces
Enamel
Root
Overall:
Primary - on unrestored surfaces
Secondary - develop adj to restoration
Residual - demineral left before filling tooth
Speed:
Active
Rampant - multiple lesion on uncommon sites
Early childhood
Arrested
```
36
Levels of disease (depth - D)? treatment response?
D1 - enamel lesions with intact surface
D2 - limited to enamel
D3 - in dentine
D4 - in pulp
D1/2 - preventative measures
D3/4 - restorative treatment
37
Black's I - treatments? how to identify? what to do? maintenance? outdated?
```
Fissure sealants:
RA
BW radiographs (not good)
Clean, wash and dry then transilluminate
No sharp probes
Preventive resin restoration:
investigate minimal caries
resin into cavity, then seal
routinely checked
Amalgam is outdated - removal of more tissues to create retention
```
38
Black's II - how to identify? site? cavity access? amalgam vs composite?
Interproximal areas are stagnation areas where plaque can form
Found on BW radiographs:
- confined to enamel allows encourage to arrest via fluoride application
- visible in dentine needs restorative treat
Restored with amalgam or composite
Accessed via marginal ridge, with matrix band
Needs undercuts to facilitate retention of amalgam
Composite can shrink and the bonding agent is humidity sensitive (need rubber dam)
39
Black's III - treatment material? how to identify? access cavity?
Difficult to spot
Access from palatal
Restored with composite
40
Black's IV - treatment material? occlusion?
Involve anterior guidance
| Composite/Glass ionomer
41
Black's V - treatment material? site?
Composite
| At the cervical margin
42
Basics of cavity preparation? (5p)
```
Access caries via outline form
Small as possible
Remove caries (mechanical and chem)
Complete prep (fill, function, tidy and clean)
Restore and maintain
```
43
Correcting enamel margins - why they are a problem? solution?
Unsupported enamel is weak and can fracture
Thin restorations can fracture
Bevel to increase SA for bonding
44
Cavity preparation - enamel, dentine and restoration? (what to do during each stage)
Enamel:
- gain access 'outline form'
- remove unsupported prims and demineralised margins
- high speed with TC/diamond bur
Dentine:
- remove soft wet caries dentine
- identify peripheries
- excavate peripherally then towards pulp
- hand excavator and slow speed TC/steel rosehead
What material to use and if there is any further carious dentine remaining
45
Angles formed for cavity preparation?
Line angle where 2 lines meet
Cavosurface angle where cavity wall meets tooth surface should be between 90-110
Point angle where 3 or more lines meet
46
Cavo-surface angles - difference between amalgam and composite?
Amalgam:
- ideally 90
Composite:
- less than 90 with bevel
47
Cavity modification once the carious lesion has been removed - what to think about?
Improve retention
Cavity support
Improve material function
48
Retention techniques of cavity preparation - types? how they're formed?
Physical:
- make small grooves so restorative material is added and locks into place
Chemical:
- acid etch and bond
49
Cavity structural terms to know - occlusal floor, gingival floor, isthmus, proximal box and pulpo-axial wall
Occlusal floor - base of cavity
Gingival floor - floor of cavity near gingiva
Isthmus - connecting piece of cavity from one area to another, needs to be narrow to keep strong
Proximal box - box prepared for access to caries interproximally
Pulpo-axial wall - side wall of cavity that runs along the pulpal wall
50
Internal cavity preparation features - what to avoid and what to aim for?
Avoid sharp line angles
Aim for rounded angles to reduce stresses
Minimally invasive technique
51
Key structural components to preserve when cutting cavities?
Preserve oblique ridges (transverse ridge joining the BD triangular ridge and the distal cusp ridge of the ML cusp) in max molars
Marginal ridges in anterior and premolar teeth
52
Restorational failure - new disease? trauma? technical failure?
New disease:
- secondary caries (poor margins)
- heavily restored can lead to pulpal inflamm
- pulpal necrosis
Trauma:
- contact sport
Technical failure:
- fractured restorations (2nd caries or fault in prep)
- tooth fracture (weakened tooth or poor margins)
- appearance (wrong shade, shape, aesthetic and staining)
53
Cervical caries - where are they? why they occur? treatment? risk? when to intervene? cavity design? clinical technique for placement (process and problems assoc)?
Where:
- top of the teeth right at the gingival margin
Why:
- missed by brushing and a plaque retentive factor
Treatment:
- high caries risk and treated accordingly (OHI)
Intervene:
- painful, pulp threatened, poor aesthetics and hinder plaque control
Design:
- limited to carious tissue (no extra retention needed)
Tech:
- rubber dam for retraction and isolation
- remove caries minimal
- etch, prime and bind then place composite
- problems such as access, moisture control and use of composite for morphology
54
Root surface caries - common with? why form? rate? primary? secondary formation (cause)? risk factors? treatment (OH and restorations)? rehydration tips (examples of products)?
```
Common:
- with older generation
Why:
- gingival recession
Rate:
- spread into dentine
Primary:
- lesion on root surface (no enamel involvement)
Secondary:
- due to an existing restoration
Risk:
- xerostomia
- repeated carbs
- partial denture
- poor OH
- high caries experience
- high bacteria
Treatment:
- OHI, F therapy (higher PPM, gel and varnishes) dietary advice and regular appointments
- shallow; if cleansable can be left
- deeper; remove caries restore with GIC for fluoride (moisture control) (hand excavate)
Rehydration:
- vaseline
- atomisers
- biotene
- gum
- sip water
```
55
Cervical caries - location? age group? cause?
```
Location:
- closest to the gingival margin
Age group:
- younger patients
- elderly (following root)
Causes:
- Poor OH
- orthodontic treatment
```
56
Root caries - located? caused by? increase in prevalence why? treatment (silver diamine F - contraindications, MoA?)
Located:
- caries on the root surface below ACJ
Caused:
- due to root surface exposure following perio support loss
Increase:
- ageing
- retaining teeth
Treatment:
- silver diamine fluoride; stops cavity development, more effective than F varnish
- stains black
- contraindicated with silver allergy, exposed pulp, oral ulcer, sores or advanced perio
- MoA: antibacterial, preserve collagen degrad and reacts with Ca2 and PO4 to produce FHA
57
Root caries treatment - biotene? Arg-based paste? ACP-CCP (adv and MoA)?
```
Biotene:
- toothpaste, gel and spray
Arg-based paste:
- most toothpastes
ACP CCP:
- good for remineral and sensitivity
- MoA: supply Ca, PO4 and F to drive diffusion of ions into tooth
- formation of hydroxyapatite
```
58
Non-carious tooth surface loss - definition? types of loss?
```
Definition:
- irreversible loss of hard tooth structure caused by factors other than those responsible for dental caries
Types:
- erosion
- abfraction
- abrasion
- attrition
```
59
Erosion - clinical appearance? common imperfections? causes? intrinsic acid (examples and conditions)? extrinsic acid (examples and conditions)? common surface? Bulimia (CS?) management of erosion?
```
Appearance:
- any surface, smooth and polished
- shallow depression can occur
Common:
- chipping of incisal edges
- cupping of lower molar cusps
Causes:
- substances which dissolve teeth (lower than 5.5pH)
Intrinsic:
- acid from within the body
- reflux: alcohol, stress reflux and gastric ulcer
- vomiting: bulimia, drugs, preg and rumination
Surface:
- palatally of upper and occlusal of lower molars
Bulimia: CS
- teeth marks on fingers
- malnutrition and dehydration
- lesions on palate
Extrinsic acid:
- acid external to the body
- chlorinated water
Management:
- basic erosion wear examination (4 point scale - 0 - non, 1 - initial loss of surface texture, 2 - distinct loss <50% and 3 - >50% tissue loss)
- cumulative score across all sextants (none 0-2, low 3-8, med 9-13 and high 14)
- prevent further with fluoride
```
60
Abrasion - definition? cervical? habitual? iatrogenic (abrasiveness)?
Definition:
- process of scraping or wearing something away
- an abnormal wearing away of the tooth substance by causes other than mastication
Cervical:
- horizontal brushing
- hard toothpaste and brush
Habitual:
- pipe, wind instruments, pins and grips
Iatrogenic:
- dental treatment
- abrasive dental materials (most porcelain and least is resin)
61
Attrition - definition? physiological (surfaces?) pathological (differences? cause?) bruxism - definition? assoc signs, symptoms and management?
Definition:
- loss of tooth substance or of a restoration as a result of mastication or of occlusal or proximal contact between teeth
Physiological:
- increases with ageing
- affects occlusal surfaces or incisal edges
- also proximal surfaces due to mastication
Pathological:
- loss at a greater rate than with ageing
- caused by parafunction, malalignment or premature loss of teeth
Bruxism:
- involved in grinding and clenching teeth
- stress
- signs: TMJ pain, muscle tenderness and hypertrophy of masticatory muscles
- management: manage cause and teeth shield
62
Trauma - enamel fracture? dentine fracture?
```
Enamel fracture:
- loss of enamel
- radiographic evidence
- restoration
Enamel dentine fracture:
- loss of enamel and dentine
- TTP
- radiographic evidence
- close to pulp give it a base CaOH
- restoration
```
63
Abfraction - definition?
Definition:
- pathological loss of hard tooth substance caused by biomechanical loading forces
- such loss is thought to be due to flexure and chemical fatigue degrad of enamel and dentine at some location distant from the actual point of loading
64
Clinical examination - patient complaint (identify injury? pain information? appearance? dental? medical? social history?) dietary analysis?
```
Identify:
- when, what, where, why and how
Pain:
- site, onset, character, radiates, assoc symptoms, timeline, exacerbating or relieving factors and severity
Appearance:
- discoloured
Dental:
- brushing habit, brush type, paste, freq and treatment
Medical:
- reflux or sick
Social:
- alcohol, drug, sport and stress
Diet:
- identify acidic foods
```
65
Refurbish and repair - why can it be better than replacement? definitions of review? refurb? reseal? repair? replace? clinical indications for repair?
```
Better:
- tooth weakening
- repeated insult to pulp
- pulp death
- time/cost and tolerance
Review:
- minor defects only if not plaque retentive
Refurb:
- small defects
Reseal:
- using flowable
- seal defects
Repair:
- addition to a restoration removal or mod of part of the restoration
Replace:
- complete removal and replacement
Clinical indications:
- secondary caries
- marginal defects
- colour corrections
- bulk fracture
- adj tooth fracture
- wear
```
66
Repair - secondary caries treatment? staining treatment? contraindications for repair?
```
Treat as new lesion
Secondary:
- minimally invasive coupled with partial replacement
- remove any part of restoration that is undermined or hindered
- leave sound restoration
Staining:
- polishing and refinishing
- resurface with different shade
Contraindications:
- high caries risk
- history of failure
- patient reluctance
- irregular attender
- caries that undermines most of the restoration
```
