Introduction

Vital pulp therapy is the treatment initiated on an exposed pulp to repair and maintain the pulp vitality - Grossman. The main aim of viral pulp therapy is to treat reversible pulpal injuries to maintain pulp vitality and to induce the formation of a protective hard tissue barrier.

The broad approaches used in vital pulp therapy are

• Indirect pulp capping 

• Direct pulp capping 

• Partial pulpotomy

• Complete pulpotomy

In this blog, we will learn about direct and indirect pulp capping.

It is said that the decision between direct and indirect pulp capping is usually by the clinician's ability to identify soft dentin and firm dentin.

Indirect Pulp Capping 

Indirect pulp capping is defined as a procedure wherein the deepest layer of the remaining rm carious dentin is covered with a layer of biocompatible material in order to prevent pulpal exposure and further trauma to the pulp - Grossman.

The main aim is to preserve the pulp vitality by removing the soft dentin (most bacteria is removed) and placing a suitable material to remineralise the firm dentin by stimulating odontoblast to produce tertiary dentin.

The physiological remineralisation takes place only if the firm dentin has sound collagen fibres and living odontoblastic processes. Here, the sound collagen fibres act as templates to which hydroxy apatite crystals attach; the living odontoblastic processes supply calcium phosphate from pulp.

Rationale

• Disinfection of the residual firm dentin.

• It arrests the caries activity and allows the pulp to repair. 

• Patient comfort is immediate. 

• Rampant caries are halted if all carious teeth are treated.

Procedure 

Clinical evidence of a large carious lesion without pulp exposure and radiological evidence of large carious lesion approaching pulp with normal lamina dura is ideal for indirect pulp capping.

Stepwise excavation:

Instrument used: Endodontic spoon excavator.

Here, caries is removed in increments over a few months. It is indicated for deep carious lesions with no symptoms of irreversible pulpitis. A part of the soft dentin caries is removed at the first visit and the cavity is restored with calcium hydroxide and reopened after a few weeks. Further excavation is done and definitive restoration is given.

Advantages 

• It avoids unintentional pulpal exposure.  

• Dentists can assess the reaction of the tooth to the excavation. 

• Two-step appointment removes the slowly progressing lesion in slightly infected, discolored, demineralized dentin before the final restoration. 

• It is easier to remove the dry carious dentin.

Factors determining success

• Remaining dentinal thickness of 0.5 - 2mm.

• Indirect pulp capping agent used: all bacteria are destroyed under calcium hydroxide dressing sealed in deep carious lesions due to its high alkalinity and its ability to produce a dentinal barrier or a dentinal bridge.

Direct pulp capping 

Direct pulp capping is defined as a procedure in which the exposed vital pulp is covered with a protective dressing or base placed directly over the site of exposure in an attempt to preserve pulpal vitality - Grossman.

Indications

• Asymptomatic tooth 

• Small exposure (less than 0.5 mm)

• Hemorrhage is easily controlled (within 10 minutes) 

• Clean and uncontaminated exposure (rubber dam isolation) 

• Atraumatic exposure and little desiccation of the tooth with no evidence of aspiration of blood into the dentin (dentin blushing)