Management Of Occlusal Lesions Flashcards
Dental caries definition
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
Tooth structure
- 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
What is primary caries
Caries occurring on previously sound tooth surface
What is (recurrent) secondary caries?
Primary caries occurring at the margin of a failing restoration
What is occult caries
Hidden caries
Occurs due to remineralised lesion on surface from fluoride
What is residual caries
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
Earliest point of caries identification is
White spot lesion
White spot lesion - what is it
Why is it important to air dry tooth on examination?
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
Brown spot lesions what are they
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
Caries process
• 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
Caries process if lesions doesn’t arrest
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
If if continues further
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)
Pain history - healthy pulp
No symptoms
Responds normally to sensitivity tests
Pain history - reversible pulpitis
- 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
Pain history - irreversible pulpitis
- 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
Should you reconvene and put tooth on restorative cycle of carry on with preventative approach?
If patient is recurrent with appointments then preventative treatment (take X-rays to monitor is approach is working)
Treatment decisions - when to intervene
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
Treatment decisions - when to intervene - Remineralisation
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
Detection of caries
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
Caries management
Biological approach
Conventional approach
- full caries removal
- selective caries removal
- stepwise
Preventative management
• 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
Biological management
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
CONVENTIONAL CARIES MANAGEMENT
• 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
Sensitivity tests
• 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)
Radiographs
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
Radiographs
• 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
Operative procedure
• 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
High speed bur for..
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.
Clearing the ADJ
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.
REMOVE INFECTED AND LEAVE AFFECTED DENTINE
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.
WHEN TO STOP REMOVING DENTINE
• 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”
SEALING THE CAVITY
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
CLINICAL PROCEDURES TO AVOID EXPOSURE
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
OPTIMIZE CAVITY FOR MATERIAL CHOICE
• 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
Ideal properties of pulp protection material
• 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
Pulp protection
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
Pulpal exposure
3 main types
- Iatrogenic - the dentist exposes the pulp during caries removal
- Carious-caries had reached the pulp
- Traumatic-trauma causes a fracture of the tooth involving the pulp
MANAGEMENT OFIATROGENIC EXPO
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
Calcium hydroxide properties
• 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
DIRECT PULP CAPPING IS MOST SUCCESSFUL WHEN.
• 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)
