Management of Deep Caries Flashcards
what is considered “deep caries”?
- caries that extend to the pulpal third of dentine
when spotting deep caries what should be looked out for?
- shadowy patch on tooth surface, usually reveals a deep cavity
what are the 2 layers of carious dentine? describe each layer
- outer zone: demineralized, denatured, infected and not remineralizable (infected zone)
- inner zone: dentine is demineralized, minimally infected, collagen fibres still intact, dentine remineralizable (affected zone)
occlusal caries: lesions radiographically visible extend to where? how infected are they?
- lesions radiographically visible extend down to middle third of dentine and beyond
- heavily infected
proximal lesions: how different is the clinical depth and radiographical depth of the lesion?
- lesions are deeper clinically than they appear radiographically.
in deep caries, where do bacteria within lesion obtain substrate? x2
- oral cavity
- possibly pulp: tissue glucose
liquefaction foci: formed by?
formed by breakdown of dentinal tubule
which zone of caries need to be removed?
the outer zone only
what are 3 issues brought about by deep caries?
- complete caries removal run risk of damage to pulp dentine complex
- pulpal exposure
- loss of pulp vitality
what are 2 pulpal responses to caries?
- tubular sclerosis
- reactionary dentine formation
reactionary dentine formation: regularity and quality depend on? how so?
- regularity and quality depend on how rapidly the lesion progresses:
- slow progressing lesion: more regular with tubular structure
what are the aims of the pulpal responses to caries?
- reduce diffusion of bacterial byproducts towards pulp, therefore slowing down rate of progression
- balance between rate of lesion progression and pulpal responses
how does pulpal inflammation vary with the distance of the lesion from the pulp?
- lesion more than 1mm from pulp: little pulpal inflammation
- lesion less than 0.5mm from pulp: inflammatory change
what are the principles of caries removal? x5
- gain access to caries: high speed
- remove peripheral caries: slow speed
- pulpal caries removal: excavator
- what materials to use?
- modify cavity design if necessary
indirect pulp cap: process?
excavate pulpal caries
until firm, leathery stained dentine reached
- line with setting calcium hydroxide
direct pulp cap: when to consider?
if the pulp is exposed at final excavation, consider direct pulp cap with setting calcium hydroxide
*only in small exposure, in absence of symptoms of pulpitis
what is stepwise excavation?
caries removed over 2 appointments, 6-12months apart
stepwise excavation: what happens on the first visit?
- remove superficial layer of infected necrotic dentine
- ensure peripheral caries removal complete
- place calcium hydroxide lining and glass ionomer
- leave for 6-12months for pulp dentine complex reactions
stepwise excavation: what happens on the second visit?
re-clean cavity
restore
what changes after the first excavation and before the final excavation?
- colony forming unit (CFU) decreases
- dentine color darkens
- dentine hardens
- sites of excavation dried up
microbiological changes after before final excavation?
- decrease in microbial load
- reduction in microbial diversity
- reduction in nutrient amount and complexity
- pulpal nutrient decrease in time with pulp dentine complex reactions
how to restore teeth permanently? what are the two methods of restoration and what do each involve?
- occlusal restoration: glass ionomer and composite sandwich technique
- proximal restoration: composite, bonded amalgam
- these restorations bond to tooth structure, no further preparation for retention. provides tooth reinforcement
