Deep carious lesions management
Remaining dentin thickness Shallow cavity depth Preparation 0.5 mm into dentin (ideal depth) Moderate cavity depth Remaining dentin over pulp of at least 1-2 mm Deep cavity depth Depth of preparation with less than 1.0 mm of remaining dentin over pulp
Before placing a restoration into cavity you must decide if a cavity base or cavity liner should be placed. This decision is not always easy because of types and number of bases and lininig materials. Nowadays research gives new protocols - bases are not necessary to protect the pulp
DENTIN THICKNESS We must remember that no material can provide better protection for the pulp than dentin The remaining dentin thickness, from the depth of cavity preparation to the pulp, is the most important factor in protecting the pulp from insult
Remaining dentin thickness The studies have shown that 0.5 mm thickness of dentin reduces the effect of toxic substances on the pulp by 75%, 1.0mm thickness of dentin reduces the effect of toxins by 90%, little if any pulpal reaction occurs when there is a remaining dentinal thickness of 2mm or more It helps us to make a decision concerning the use of bases and liners
Why do we use bases and liners? to preserve pulpal health to create barrier to external irritation to seal the marginal gaps between tooth and restoration
Causes of pulpal inflammation Bacterial toxins penetrating the dentinal tubules Bacterial can cause Pulpal irritation Pulpal necrosis Recurrent caries Leakage at the restoration-tooth tooth interface due to gaps at that interface Trauma of tooth preparation
Bacterial penetration- pulpal inflammation Bacterial invasion at gap between restorativetooth interface Mutans Streptococci Restorative material Bacteria penetrating gap, invading dentinal tubules inflammation
Sensitivity after treatment Recent evidence demonstrates that pulpal inflammatory reactions to dental materials are mild and significant adverse pulpal responses occur more as the result of pulpal invasion by bacteria or their toxins But instrumentation techniques elicit pulpal responses as well: rotary instruments- overheating, desiccation, pressure.
Sensitivity after treatment The explanation of pulpal pain in the absence of inflammation is the hydrodynamic theory, in a vital tooth with exposed dentin, there is a slow constant movement of fluid outward through the dentilal tubules. When a stimulus causes the slow fluid movement to become more rapid, nerve endings in the pulp are deformed and the response is interpreted as pain
Decision making in the use of sealers, liners and/or bases Remaining dentin thickness in tooth preparation Thermal conductivity of restorative material Presence or absence of pulpal symptoms-pain pain to stimuli Thermal Sweets (osmotic changes) Duration of symptom Spontaneous pain
Materials to seal the tooth for pulpal protection Cavity sealers: protective coating on the cavity walls creating a barrier to leakage Resin bonding systems (i.e. i.e.optibond Solo) Cavity liners: cement or resin coating of minimal thickness (less than 0.5 mm) placed as a barrier to bacteria or to provide a therapeutic effect (pulpal sedative or antimicrobial effect). Applied to cavity walls adjacent to pulp ( calcium hydroxide liners:life,dycal;glass-ionomer ionomer liners:vitrebond; Jonosit,) Cavity bases: placed to replace missing dentin, placed in thicknesses of 0.5-1 mm; these are :glass-ionomers: VitreBond, Fuji IILC, modified glass-ionomers: Jonosit; zinc-phosphate cements, carboxylate cements)
Cavity Sealers Provide protective coating for freshly cut tooth structure in a cavity preparation Cavity sealers provide a transition between cut tooth and restorative material In cavities of shallow or medium depth adhesive sealers s may be used without the use of bases nor liners
Cavity sealers-bonding systems
Cavity liners Materials placed as thin coatings Function:barrier against chemical irritation Not thermal isulators Materials laid down in a thin layer (less than 0.5 mm)to protect the pulp tissue from irritation from chemical insult These materials are generally not strong and are not intended to be placed in thick amounts Materials that can be used as cavity liners: calcium hydroxide liners:dycal,life; glass-ionomer liners, resin-modified glass-ionomers: Jonosit, Interface- Kerr; zinc-oxide and eugenol liner,
Guidelines for lining Liners should be applied with a minimal thickness (less than 0.5 mm) Use minimal amount of liner to achieve result Calcium hydroxide should be placed only where needed adjacent to pulp
WHY do we use that small amount of calcium hydroxide liners? Many studies have shown that calcium hydroxide liners have poor physical properties and their high solubility may result in softening of the liner and material loss under the restoration that is not properly sealed. These unfavorable properties of Ca(OH)2 materials restrict their use to application over the smallest area that would suffice to aid in the formation of reparative dentin
Cavity bases Barrier against chemical irritation Provide thermal insulation Resist forces of condensation Restore internal form Are intended to form a thick layer of material to protect the pulp tissue from irritation from chemicals or thermal insult, and to provide a solid base to resist condensation forces Commonly used base materials include: glass ionomer cement: Kavitan, Photac Fil, Fuji, Ketac Molar; polycarboxylate cement, resin-modified glass-ionomer cement, zinc phosphate cement
Guidelines for basing (best base is always the tooth structure itself) Do not remove healthy, sound tooth structure to provide space for base Use base as build-up up and block-out out for cemented restorations If using base for amalgam or composite restorations minimize extent of base. Always try to leave a dentin seat for the restorative material Do not base a preparation to create an ideal depth. This is contraindicated and can lead to increased risk of restoration fracture.
Recommendations for composite resin Shallow cavity depth adhesive composite resin Moderate cavity depth glass ionomer liner adhesive composite resin Deep cavity depth Calcium glass adhesive Hydroxide ionomer composite resin
Deep cavities Indirect pulp capping Direct pulp capping
Direct and Indirect Pulp Capping The tooth must be vital and have no history of spontaneous pain The result of pulp tesing should not linger A periapical X-ray should show no evidence of pathology Bacteria must be excluded from the side by permanent restoration
Indirect pulp capping Placing calcium hydroxide liner over a thin layer of remaining dentin over the pulp, this procedure concerns most of deep carious lesions with thin layer of remaining healthy dentin Involves the partial or total removal of carious dentin-removing the carious tooth structure to a point- demineralized dentin may be left only over the pulp to avoid the exposure Demineralized dentin not near the pulp should be completely removed Setting calcium hydroxide liner placed over the (Dycal,Life)
Indirect pulp cappingping Restorative Life Glass-ionomer Leathery dentin
Direct pulp capping in case of accidental or carious pulp exposure non-setting calcium hydroxide is placed on exposed pulp (Biopulp) and setting calcium hydroxide (Dycal,Life) on non-setting it stimulates pulp to form odontoblasts which can produce a layer of reperative dentin- dentin bridge Direct pulp exposures can heal normally but a bacteria-free environment is required
Direct pulp cappingping Restorative Life Biopulp Glass-ionomer
Direct pulp capping-the prognosis The chance that direct pulp capping will cause the formation of a dentin bridge and the tooth will become vital is only under the ideal conditions: -small mechanical exposure has better prognosis comparing to carious exposure -young pulp -no bacterial contamination of the exposure -the degree of bleeding- increased bleeding is associated with increased likelihood of failure -the tooth must be isolated and a proper hemostasis achieved -the tooth has to be restored with well sealed restoration
Technique for direct and indirect pulp capping Deep cavity depth Carious pulpal exposure Life G-i over Life
Caries Control When to do treatment with caries control: Deep caries without pulpal invasion as determined by radiographs, symptoms and vitality testing. Note: deep caries with pulpal involvement requires total caries removal to evaluate tooth restorability and endodontic therapy if tooth is restorable Multiple teeth with extensive caries requiring placement of temporary restorations to stabilize active disease As a diagnostic tool, will pulp survive treatment; tooth may be become symptomatic after treatment
Caries control treatment Removal of gross caries (very soft consistency caries) from the pulpal,axial axial and lateral walls; leathery carious dentin adjacent to the pulp on the pulpal and axial wall may remain. In order to cause remineralization and reperative dentin formation we place materials that stimulate odontoblasts for production of reperative dentin. Treatment: Calcium hydroxide and Glass-ionomers or Zinc-Oxide Eugenol Reevaluation of the cavity after 3 months and replacing temporary material for the permanent restoration.
Caries control with glass ionomer Not all Caries removed On axial wall Deep caries Glass ionomer placement