The Biological Rationale for Pulp Preservation

The dental pulp is not simply a pain-sensing organ — it is a living connective tissue with immune surveillance, dentin-forming capacity, and regenerative potential. Pulp tissue produces tertiary dentin in response to injury, maintains dentinal tubule fluid dynamics that resist bacterial penetration, and provides the sensory feedback that protects the tooth from further damage. Loss of pulp vitality eliminates all of these functions permanently.

The paradigm shift toward pulp preservation is supported by a growing body of evidence demonstrating that bioceramic materials — particularly calcium silicate-based cements — can maintain pulp vitality, stimulate reparative dentin bridge formation, and support long-term tooth survival in cases that would previously have been treated by conventional root canal therapy.

The critical determinant of VPT success is not the material — it is the biological status of the pulp at the time of treatment. Accurate diagnosis of pulp inflammation is the prerequisite for all VPT procedures.

Pulp Diagnosis: The Foundation of Case Selection

Vital pulp therapy is indicated only when the pulp retains the capacity for healing. This requires accurate clinical diagnosis before any intervention:

• Normal pulp: asymptomatic, responds normally to thermal and electric pulp testing. Ideal for indirect pulp capping.
• Reversible pulpitis: symptomatic response to cold that resolves within seconds. Pulp inflammation is confined to the superficial layers. Appropriate for indirect pulp capping and, in selected cases, direct pulp capping.
• Symptomatic irreversible pulpitis: lingering pain to cold (>30 seconds), spontaneous pain, or pain to heat. Pulp inflammation extends beyond the superficial layers. Pulpotomy may be indicated in selected cases; conventional endodontics is the standard treatment.
• Asymptomatic irreversible pulpitis: no symptoms but pulp is histologically inflamed beyond reversibility. Often diagnosed incidentally. VPT outcomes are less predictable.

CBCT is increasingly used to assess periapical status before VPT. The absence of periapical pathology is a prerequisite for all VPT procedures — periapical inflammation indicates that the pulp has already lost its capacity for self-repair.

Indirect Pulp Capping

Indirect pulp capping (IPC) is indicated when caries removal approaches the pulp but the pulp remains vital and symptom-free. The objective is to avoid pulp exposure by leaving a thin layer of affected (not infected) dentin over the pulp, sealing the cavity with a biocompatible material, and allowing the pulp to form reparative dentin beneath the remaining carious dentin.

Stepwise Excavation vs. Selective Removal

Current evidence supports selective caries removal — leaving soft, caries-affected dentin over the pulp rather than risking exposure through complete excavation. The biological rationale is that affected dentin, once sealed from the oral environment, can remineralize and the pulp can form a reparative dentin bridge beneath it. Complete excavation to hard dentin at the risk of pulp exposure is no longer the evidence-based standard in deep caries management.

• Selective removal to soft dentin in the deepest portion is appropriate when pulp exposure would otherwise result.
• The cavity must be sealed hermetically — microleakage is the primary cause of IPC failure.
• Calcium silicate-based liners placed over the remaining dentin provide biocompatibility and stimulate reparative dentin formation.

Direct Pulp Capping

Direct pulp capping (DPC) is indicated when a small mechanical or carious pulp exposure occurs in a vital, minimally inflamed pulp. The objective is to place a biocompatible material directly over the exposed pulp tissue to stimulate a hard tissue bridge and maintain pulp vitality.

Exposure Size and Contamination

• Mechanical exposures (iatrogenic, during caries removal) in a non-infected field carry the best prognosis for DPC.
• Carious exposures carry a higher bacterial load at the exposure site. Prognosis depends on the extent of pulp inflammation at the time of exposure.
• Exposure size >1mm is associated with reduced DPC success rates, though bioceramic materials have improved outcomes compared to calcium hydroxide in larger exposures.

Hemorrhage Control

• Sterile saline or 2.5% NaOCl on a cotton pellet for 3–5 minutes.
• Bright red, controlled bleeding that stops within 5 minutes: proceed with DPC.
• Dark, persistent, or uncontrolled bleeding: consider pulpotomy.

Pulpotomy

Pulpotomy involves the removal of the coronal pulp tissue to the level of the canal orifices, leaving the radicular pulp intact. It is indicated when coronal pulp inflammation cannot be resolved by DPC alone.

Regenerative Endodontic Procedures (REPs)

Regenerative endodontic procedures are indicated in immature permanent teeth with necrotic pulps and incomplete root development. The objective is to stimulate continued root maturation, increase dentinal wall thickness, and potentially restore a pulp-like tissue within the canal space.