Management Of Occlusal Lesions

Question 1

Dental caries definition

Answer 1

A reversible (in its earliest stages) but progressive disease of the dental hardtissues, instigated by the action of bacteria upon fermentable carbohydratesin the plaque biofilm on tooth surfaces, leading to bacterially generated acid demineralization and ultimately proteolytic destruction of the organic component of the dental tissues

Question 2

Tooth structure

Answer 2

• nerves

A delta = myelinated - fast response
- short sharp pain
- tooth sensitivity
- electric shock

C = Unmyelinated
- slow response time
- dull throbbing ache

Pulp and dentine complex as they’re highly related
They have the ability to regenerate and repair - this relies on having goof blood / nutrient supply
Pulp tissue is vascular and includes the nerve fibres
Cementum lies over root surfaces and anchors tooth to the periodontium

Question 3

What is primary caries

Answer 3

Caries occurring on previously sound tooth surface

Question 4

What is (recurrent) secondary caries?

Answer 4

Primary caries occurring at the margin of a failing restoration

Question 5

What is occult caries

Answer 5

Hidden caries
Occurs due to remineralised lesion on surface from fluoride

Question 6

What is residual caries

Answer 6

A portion of caries affected, demineralised tissue left behind before a restoration is places

Can be..
- intentional
- unintentional

Treatment - Remove tissue that is not capable of repair (affected dentine) but keep sound and effected dentine to protect the pulp

Question 7

Earliest point of caries identification is

Answer 7

White spot lesion

Question 8

White spot lesion - what is it

Why is it important to air dry tooth on examination?

Answer 8

Plaque accumulation + acid = loss of calcium ions = crystals shrink so pore volume between crystals increase

Initial lesion - first demeinerlaistaion occurs = moisture in mouth is enough to fill pores so drying with 3in1 is required to see the white spot

If progression, pore volume increases as crystals shrink more causing a white spot lesion that is visible under a wet surface

At this stage, lesions are reversible

Question 9

Brown spot lesions what are they

Answer 9

Stained white spot lesions

Repeated demineralisation and remineralisationcan lead to pigments from blood / food beingincorporated into the enamel, this is then calleda ‘brown spot lesion

Question 10

Caries process

Answer 10

• Arterial blood flow in the pulp increases (pulp undergoes inflammatory changes)
• This causes an increase in the rate of flow of dentinal tubular fluid - dilutes bacterial acids
• The fluid acts to flush out bacterial toxins.
• It also carries antibacterial components (IgG,lactoferrin etc)
• Peritubular dentine gets laid down making the tubules narrower, this reduces the flow of the fluid but also creating a barrier to the bacteria - sclerosis (protects pulp) - reduces permeability and reduces toxins from reaching
• Affected odontoblasts produce reactionary dentine (pulp backing away from threat)
• At this stage the lesion can be arrest

Question 11

Caries process if lesions doesn’t arrest

Answer 11

Further dentine is laid down to protect the pulp

Cavitation may occur due to undermined enamel

Caries starts spreading laterally at ADJ

Affected (demineralised) dentine precedes infected dentine.

When the caries gets close to the pulp it becomes inflamed.

There’s a further increase in blood flow and painreceptors Aδ are activated.

Reversible pulpitis

At this stage removal of the caries can allow the pulp to heal

Demineralisation always precedes bacteria

Question 12

If if continues further

Answer 12

As bacteria approach the pulp level of inflammationbecomes irreversible.

Removing caries at this point may not preserve thevitality of the pulp but can relieve painful toothache.

(irreversible pulpitis

(Reversible - sensitivity to cold, Irreversible - sensitivity to hot)

Question 13

Pain history - healthy pulp

Answer 13

No symptoms
Responds normally to sensitivity tests

Question 14

Pain history - reversible pulpitis

Answer 14

• short sharp pain with hot / cold, often worse with cold
• pain caused by movement of fluid in dentinal tubules
• pulp is responding to stimulus which once removed will fully heal

Question 15

Pain history - irreversible pulpitis

Answer 15

• pulp is inflamed
• hot/cold may initiate pain, but once there it can last for 30+ mins
• often worse with hot
• pulp is irreversibly damaged and will not recover

Question 16

Should you reconvene and put tooth on restorative cycle of carry on with preventative approach?

Answer 16

If patient is recurrent with appointments then preventative treatment (take X-rays to monitor is approach is working)

Question 17

Treatment decisions - when to intervene

Answer 17

Preventive measures to promote remineralisation

• Restoration results in destruction of tooth tissue
• Replacement of restorations result in more toothtissue loss weakening tooth.

Difficult to predict the rate of progression
The progress of caries through the enamel seems to be fairly slow but once the dentine is reached it accelerates
Small surface lesion may hide a much larger areaof destruction below the surface

Question 18

Treatment decisions - when to intervene - Remineralisation

Answer 18

Early smooth surface lesions are reversible inthe right conditions

Evidence suggests that remineralisation canoccur in lesions into dentine, if uncavitated.

Remineralised tissue is less susceptible tofurther caries

Question 19

Detection of caries

Answer 19

Examine wet and dry

Bitewing radiographs - difficult to detect occlusal caries

Visual, tactile methods with the aid of probe

Dry tooth
- Minimal demineralisation only visible on dry surface
- Distinct enamel lesions visible under wet conditions

Question 20

Caries management

Answer 20

Biological approach

Conventional approach
- full caries removal
- selective caries removal
- stepwise

Question 21

Preventative management

Answer 21

• Diet Assessment and Advice
• Oral Hygiene Assessment and Advice
• Fluoride Use• Fissure Sealing/Sealing
• Xylitol
• Casein Phosphopeptide - ACP (tooth mouse) - aids remineralisation and enamel repair
• Probiotics

Question 22

Biological management

Answer 22

Therapeutic Fissure Seal - To inhibit theprogression of non-cavitated carious lesions

Sealing over caries
• Determine patients risk of disease progression
• Low caries risk and the caries does NOT extendbeyond the outer third of dentine
• NO cavitation/enamel breakdown
• Record ICDAS code and discussions with patient

• If the caries extends into the middle third of dentine, a PRR is indicated

Question 23

CONVENTIONAL CARIES MANAGEMENT

Answer 23

• History
• Assess extent of caries
• Assess the pulp status
• How to preserve the pulp vitality duringrestoration• How much caries to remove?
• Pulp protection
• Avoiding pulpal exposure

Question 24

Sensitivity tests

Answer 24

• Not 100% reliable
• Many false positives and false negatives• Electric pulp test and ethyl chloride (cold) are the most likelytests
• The numbers given by the EPT shouldn’t be inferred as meaningsomething (any number under 80 means probably alive, youcan’t deduce the state of the pulp by the actual number)

Question 25

Radiographs

Answer 25

Affects how you restore the tooth -
• Proximity to the pulp
• Lateral extent of the caries
• Approximal enamel

May also be able to see
• Apical Pathology
• Widening of Periodontal Ligament space
• Loss of Lamina D

Can only see clinically once bone has been damaged

Question 26

Radiographs

Answer 26

• Caries on a radiographic image may only show 60-80% of the actual caries present
• Minimum of 55-60% demineralization must occur before radiographic changes are apparent
• Caries will always be deeper and more extensivethan you think
• Deep caries is at least three quarters (75%) ofthe way to the pulp from the ADJ, so high risk ofpulp exposure.

A degree of minerals have to be lost before seeing it radiographically

Question 27

Operative procedure

Answer 27

• It is bacteria and dental operators that kill pulps
• Aim of procedure is to remove caries without introducing any bacteria to the pulp

• Use rubber dam
• Remove caries from the walls of the cavity first
• Never use a high speed for removing caries
• On the floor of the cavity only use excavators, gently scrape away anything soft, never use force
• Leave affected dentine over the pulp
• Use RMGIC liner to seal affected dentin

Question 28

High speed bur for..

Answer 28

Gain access to various lesions

Cut back the walls of the cavity using the high-speed handpiece just enough to permit you togain access to the caries.

Question 29

Clearing the ADJ

Answer 29

Keeping to the amelodentinal junction, use the slow speed handpiece andthe largest bur that will fit into the carious lesion to remove the carioustissue.

Leave the deeper caries over the pulp untouched

Using an excavator, check the texture of the dentine remaining at theamelodentinal junction.

If the dentine can still be removed easily with theexcavator go back to the slow speed handpiece

Repeat the cycle as often as necessary

If you need to cut back the margins a bit more for betteraccess to the caries go back to the high speed handpiece.

Question 30

REMOVE INFECTED AND LEAVE AFFECTED DENTINE

Answer 30

Think of the lesion as a spectrum• Use the slow speed, begin at the margins and workinwards towards the deepest part of the lesion.

Stop frequently and use the excavator to checking theconsistency of the dentine

Use in a raking motion motion

STOP either when you suspect that you are very closeto the pulp chamber or when the dentine no longer furrows up.

Question 31

WHEN TO STOP REMOVING DENTINE

Answer 31

• Aim to remove….
• Dentine that contains bacteria – “infected dentine”
• May leave…
• Softened dentine, demineralized by acid diffusing ahead of bacteria – “affected dentine”

“The correct amount to remove is the minimum required to restore the tooth successfully and prevent disease progression”

Question 32

SEALING THE CAVITY

Answer 32

Not all bacteria have to be removed

SEALED from oral environment

EDJ must be cleared of caries

Provides good seal (& prevents any lateral spread of caries)

Consider carrying out a stepwise restoration

Question 33

CLINICAL PROCEDURES TO AVOID EXPOSURE

Answer 33

Stepwise (2 stage operative technique) saa- excavation

• Principal is that caries is removed until very near the pulp then stop –even if it is soft

• Fill the cavity with GIC

• Re-evaluate 6 months later and replace restoration if symptom free and still vital

Question 34

OPTIMIZE CAVITY FOR MATERIAL CHOICE

Answer 34

• Make a final choice of material and modify the cavity to ensure optimum material success
• Consider resistance and retention of restoration
• Remove any unsupported enamel, ensure there are no weak edges that willfracture under occlusal loading
• Make sure the margins are smooth, continuous and curving

Question 35

Ideal properties of pulp protection material

Answer 35

• Bactericidal / Bacteriostatic
• Mildly irritant to stimulate tertiary dentinebridge formation
• High pH alkalinity
• Adhesive
• Create effective seal
• Low water solubility
• Easily applied and strong in thin section
• Ability to infiltrate ionically into remaining dentine overlying the pulp helping to providereinforcement.
• Biocompatible

Question 36

Pulp protection

Answer 36

MATERIALS
• Glass Ionomer Cements
• Dentine Bonding Agents
• Setting Calcium Hydroxide
• Tricalcium Silicate Cements
- Mineralised trioxide sugars aggregate MTA
- Biodentine

Indirect pulp cap
• When the floor of the cavity is close to thepulp but the pulp chamber has not beenbreached.

Direct pulp cap
• If a small breach or pulp exposure hasoccurred

Question 37

Pulpal exposure

Answer 37

3 main types

1. Iatrogenic - the dentist exposes the pulp during caries removal
2. Carious-caries had reached the pulp
3. Traumatic-trauma causes a fracture of the tooth involving the pulp

Question 38

MANAGEMENT OFIATROGENIC EXPO

Answer 38

If tooth previously asymptomatic
• Rubber dam if not already
• Wash cavity
• Dry with cotton wool pledget (try to stop bleeding)
• Then get tutor!

• Assess whether the dentine around the exposure is carious or not
• If Carious –RCT is required

• Assess the size of the exposure
• If >2mm then RCT
• If not Place setting Ca(OH)2(Dycal) over the exposure and dress thetooth with GIC
• monitor

Question 39

Calcium hydroxide properties

Answer 39

• Very high pH (>pH 11)
• Creates an alkaline environment i.e. bactericidal (highly toxic tobacteria)
• Stimulates odontoblasts to lay down new reparative dentine in thedentinal tubules
• Stimulates stem cells in the pulp tissue to create new odontoblast-likecells to create dentine bridges across pulpal exposures

Question 40

DIRECT PULP CAPPING IS MOST SUCCESSFUL WHEN.

Answer 40

• Absence of signs or clinical symptoms of pulpitis before you start opening the tooth up
• Normal response to vitality tests by the tooth
• Younger patients without previous history of restorative work on the tooth in question
• Tooth is isolated (Rubber dam) and there is no salivary contamination
• Small exposure <2mm in diameter
• Exposure is not probed, or blown dry (damaging pulp tissue directly)