Operative: Intro to Carious Lesions & Tissue removal

Guiding Principles of Carious Tissue Removal 

• to retain tooth and pulpal health as long as possible = AIM


• Preservation of dental tissues → non demineralized and remineralizable 


• Avoidance of pulp exposure 


• Provision of sound cavity margins to achieve an adequate peripheral seal 


• Controlling the lesion and inactivating remaining bacteria 

Reversible vs irreversible pulpitis; pulpal inflamm/pain

Reversible Pulpitis = instances where the inflammation is mild and tooth pulp reminds healthy enough to save 

• Normal responses to:




• thermal tests


• EPT 




• Patients may experience pain/sensitivity 

Irreversible pulpitis = may experience pain without action to induce pain, sensitivity, and throbbing 

Cause of pulpal inflammation

• active caries = mild/severe


• Cavity preps = mild/severe 


• dental materials = mild/transient 

Pulpal pain

• Intra-pulpal pressure on nerve endings secondary to an inflammation response 


• w/ absence of inflammation = Hydrodynamic inflammation 

Pulpal protection

When does the pulp need protection?

1. Full crown preps 


2. cervical dentin exposure due to erosion causing pain 


3. Presence of mechanical pulp exposure 


4. after selective Caries removal that have led to medium or deep cavity preps 

Why must we protect the pulp?

1. Preserve pulpal vitality


2. avoid thermal sensitivity (pain) after restos 


3. Avoid removal of sound structure to provide resistance to resto material (amalgam/gold) 

How to protect pulp 

1. eliminate progression of carious lesions 


2. collect appropriate information regarding pulpal health before doing restos 


3. Using appropriate cutting instruments, use water during prep, no water during caries removal 


4. selecting/applying appropriate biological and mechanically resistant dental protective materials 

Protective materials = provide a protective coat for freshly cut enamel/dentin 

Cavity liners 

• Cement/resin coating of minimal thickness (<0.5mm)


• Physical barrier to bacteria and their products 


• provides therapeutic benefit = F- release, dentinal seal, and bacterial action = promoting pulpal health 


• do not place on enamel 


• RMGI (vitrebond)




• Apply after partial caries removal to → areas nearest the pulp… STAY AWAY FROM MARGINS 


• Chemical bond to tooth structure


• F- release 


• Good mechanical properties


• favorable pulpal response due to → F- release, initial low pH, physical barrier to bacterial penetration 




• RM Calcium silicates (TheraCal LC)




• Place the Ca[OH]2 liner in the deepest part of the prep covering the pulp exposure 


• place liner on moist dentin only 




• pulpal and axial walls, alway from all margins and enamel 




• Establishes a tight seal to prevent bacterial invasion 


• stimulates apatite formation and secondary dentin formation 


• Maintain an antibacterial alkaline-related biological environment 


• after placing and curing, follow w layer of → Vitrebond and/or normal bonding procedures 

Cavity sealers

• provide a protective coating to the walls of a prepared cavity and a barrier to leakage at the interface


• all walls in their entirety are coated 

• oxalates → place prior to amalgam restos 




• Superseal




• Acidic nature → demins smear layer and peritubular dentin 


• reacts with CaHydroxyapatite to form → fine granular calcium oxalate precipitate 


• Precipitate occludes → dentinal tubules 

• dental adhesives

Moderate lesions vs. extensive lesions

Moderate lesions (not reaching inner third of dentin) = restoration longevity may be more important → clinically means removing more tissue so that foundation is stronger 

Extensive-deep lesions (radiographiaclly involving inner pulpal third or quarter of dentin or with clinically assessed risk of pulpal exposure) 

• preservation of pulpal health should be prioritized → clinically means LESS tissue removed, soft area left, and cavity liner placed to prevent sensitivity that may arise from caries near pulp 




• Do NOT place cavity liners peripherally. Messes w/ RBC adhesion to enamel walls. 




• everything around lesion should stay intact to promote adhesion  


• Avoid pulp exposure, UNLESS pulpal Dx = reversible pulpitis