Oral Exam CARIES

Blacks classification

Class 1: occlusal + buccal cusps posterior

Class 2: interprox posterior

Class 3: ant interprox anterior

Class 4: ant incisal edge

Class 5: ant cervical margin

Erosion

shiny surface, proud restorations, fractures off incisal edge, shadowy depressions

1. Intrinsic: bulimia, pregnancy, alcoholism

2. Extrinsic: acidic foods and drinks, pickling farms

Abrasion

Pathological wearing away tooth structure resulting from repetitive mechanical process or habit

Tb, whitening toothpaste

signs - exposed root surface, wear facets at cervical margin

Attrition

Loss of tooth substance due to mastication or occlusal contact between the teeth

Bruxism: strong flexural force

Pathological: worn down mamelons + occlusal cusps, exposed dentine may be dark brown

Abfraction

V shaped at cervical margin due to biomechanical loading force resulting in flexing and failure of enamel and dentine

Treatment for NCTSL

• mouth gaurd - for bruxism

• Refer to GDP: for bulimia erosion, discuss diet (extrinsic + intrinsic), if medication discuss with GP different options

• OHI:

  • erosion wait 30mins before brushing teeth

  • Abrasion: heavy handed with tb: med rough brush, show demonstration

• Restore exposed dentine if causing sensitivity or risk of pulpal exposure

• Flouride varnish or px HSFT

Constituents of amalgam

• mercury

• Zinc

• Tin

• Copper

• Silver

Why is amalgam getting phased out

• minimata convention - environment concerns re mercury

  • No amalgam <15 yrs or pregnancy as passes through placenta

• Tooth preservation - amalgam needs more removal for retention

• Health concerns (mercury vapour)

What are the types of amalgam

• conventional 6% copper → Gamma 2 phase is most corrodible but can be inhibited by phosphate in saliva

  • Most creep phase - overhangs and deficiency at gingival margin

• high copper amalgam (30% copper)

  • G2 replaced with copper tin phase

  • Copper provides strength and more corrosion resistance

What are the classifications of composite

• flowable and conventional

• How it’s set - hear, chemical and light

• Particle size - nano hybrid, macro and micro

  • Nano hybrid - stronger, more wear resistant, harder to polish, opaque and less shrinkage

Hydrocolloid

• reversible - agar

• Irreversible - alginate

Xerostomia

• caused by reduced saliva flow eg smoking, meds, sjogrens

• increases risk of periodontal gram -ve bacteria

• increase risk of caries: strep. mutants

• reduced buffer protection:

• Mirror sticks to mucosa and can be uncomfortable for pt

Stephan’s curve

Describes how the pH in the mouth changes over time after eating

• X axis represents time

• Y axis represents pH Levels

• the normal resting pH of plaque is around 7.5, but it starts at around 8 on the graph

• when we consume fermentable carbohydrates, oral bacteria metabolise them and produce acid which drops pH

• the critical pH for enamel demineralisation is 5.5 - once the pH falls below this, tooth enamel starts dissolving

• the pH reaches its lowest point within minutes and then gradually rises as saliva buffers the acids

• it takes around 40 mins to 1 hr for the pH to return to it's pre-meal level, allowing remineralisation to occur

• remineralisation doesn't occur if interuppted by frequent sugar exposure.

What’s sealant restoration

You’re removing caries but then sealant over - not placing a full restoration

• its minimally invasive, preserving tooth structure

Indications

• non - cavitated or early cavitated lesions

What are the 4 zones of WSL

Four Zones of an Early Carious Lesion (Enamel Caries)

1. Surface Zone → Intact enamel (due to saliva & fluoride), highly mineralised

2. Body of the Lesion → Largest part, most demineralised

• this is the zone seen on the radiographs

3. Dark Zone → Some remineralisation happening.

• mineral re-deposition, showing an attempt at natural repair

4. Translucent Zone → Earliest sign of demineralisation.

• this is the first carious change

• apatite has been dissolved by acid

Zones of dentine lesion

1. Advancing Front - zone nearest to the pulp (affected dentine)

·      demineralisation caused by acids diffusing ahead of bacterial invasion

·      no bacteria are present here, it's predominantly chemical damage

2. Zone of bacterial invasion (infected dentine)

·      bacteria begin to penetrate this zone 

·      tubules become colonised by bacteria, leading to structural weakening

3. zone of destruction - most advanced part of lesion

·      enzymatic degradation occurs as bacteria digest dentine

·      cavitation and significant structural damage are present

Treatment plan

·      Emergency care – pain, infection

·      Prevention – OHI, diet, advice, F toothpaste

·      Stabilisation – prevent current disease getting worse by perio therapy, XLA

·      Restorative + rehab – perio then rest, start worst one first

·      Maintenance – establish recall period

·      Referrals

What does etch do

create porosities and micromechanical tags

type 1 - removes the core and leaves the periphery intact OR

type 2 - removes the periphery pf the enamel prism and leaver core intact OR

type 3 - haphazardly and does both all over the place

Dentine conditioning - removes smear layer

What does prime do

tooth surface is hydrophobic + bond has a lot of solvent so water base for bond is incompatible. Primer changes the tooth surface to become hydrophillic.

Bond

glue to hold composite in place

How do you diagnose caries

• Visual inspection

  • wsl

  • brown/dark discoloration

  • cavitation

• translumination

  • fiber optic translumination - shining light though a tooth, dark areas indicate decay

  • digital imaging

• caries detecting dyes that stain demineralised areas

• radiographs

  • bws

  • PA

  • OPG

• electrical conductivity & laser flurescence

  • electical - measures porosity; more porosity = more decay

  • laser fluorescence - detects early caries by measuring fluorescence

• brielle probe

How is caries classified

• Location

  • position - anterior or posterior

  • specific location on the tooth - occlusal caries, interproximal caries, cervical caries, root caries

• radiographic appearance

  • enamel caries

  • dentine caries (D1, D2, D3, P)

  • pulpal involvement

• severity

• status - secondary or primary

• activity

  • active caries

  • arrested caries

• DMFT

• ICDAS (International caries detection and access system)

Risk factors for caries

Factors that increase caries risk

• past caries history (DMFT score - decayed, missing, filled teeth)

• poor OH (high plaque levels)

• diet

• low fluoride exposure

• socioeconomic status

• medical history (medication that cause dry mouth or contain sugar)

• smoking and alcohol (reduce saliva)

• family history

• patient cooperation

Types of bonding systems

• Three-Step (Total-Etch) – Most effective, longest-lasting.

• Two-Step (Self-Etch or Etch & Rinse) – Moderate effectiveness.

• One-Step (All-in-One Bonding) – Quick but least effective.

Pulp cap / treatments

• Indirect Pulp Cap: Close but not exposed. Line with Ca(OH)₂ or Biodentine.

• Direct Pulp Cap: Tiny mechanical exposure, clean site, control bleeding, MTA/Biodentine.

• Stepwise Excavation: For deep lesions—partial removal, seal, reassess later.

• Significant exposure: Usually → RCT or referral. But keep isolated and seek advise from dentist

Describe composite advantages and disadvantages

• aesthetic

• Binds to tooth

• Good longevity

• Preserves more tooth structure

• Good wear resistance

• Command set - more working time

Disadvantages

• highly sensitive in dry fields

• High technique sensitivity and moisture

• Post op sensitivity common

• More expensive compared to amalgam

Amalgam advantages and disadvantages

Advantages

• less sensitive to moisture

• Easy to place

• Traditionally longer lasting - be careful cause can start debate

• Excellent wear resistance

• cheap

Disadvantages

• Less aesthetic

• Mechanical retention only

• May require more tooth removal

• Contains mercury (minimata concerns)

• Less working time

What’s inside a local anaesthetic cartridge

• anaesthetic

• Vasoconstrictor

• Ringer solution (water and salt)

• Preservative

• Buffer

What does the vasoconstrictor in LA do?

• prolongs anaesthesia - reduces blood flow and keeps the anaesthetic in the area for longer

• Minimises bleeding

• Enhances moisture control due to less bleeding

Why is rubber dam the best form of moisture control

• complete isolation

• Prevents aspiration

• Protects soft tissues

• Improves efficiency

• Better pt experience

• Minimises cross contamination

• Psychological benefit - some pts feel distracted from procedure

What a side effect of anti - anxiety meds (antidepressants)

Dry mouth

Why do we give diet diary to patients

• hidden sugars and acids

• Frequency of sugar

• Amount of sugar

How do we know that sugar causes caries

Studies that have been done

• vipeholm

• Turku

• Inuits

• Tristan da cuhna

• Hopewood house

Different ways to diagnose caries

• clinically

• Translumination

• Radiographically

• Fluorescence