The Effect of MDPB on Dentin Bridging of Exposed Pulps

Objectives: The aim of this study was to evaluate histopathological changes and exposure repair performance of human dental pulp following 90 days of direct capping with a self-etch adhesive system containing an antibacterial monomer MDPB (Clearfil Protect Bond, Kuraray, Japan) in deep carious teeth.

Methods: Eight non-inflammated wisdom teeth with deep carious lesions scheduled for extraction were used in the study after receiving signed consent of patients. Following caries removal, the pulps of teeth were exposed (approximately 1 mm in diameter) with sterile round steel burs. Four teeth of experimental group were restored with adhesive system and composite resin (Clearfil APX, Kuraray, Japan). The control group was capped with Dycal (Dentsply/Caulk, USA) and composite resin. Two teeth from experimental group were not extracted because of patient's comfort and demand. Six teeth were extracted at 90 days after testing their pulp vitality. The teeth were fixed, sectioned and stained for histopathological evaluation. The following parameters were evaluated: pulp tissue disorganization, inflammotory cell infiltration, reparative dentin formation and dentin bridging over the exposure sites.

Results: All teeth were asymptomatic and responded positively to electric pulp testing. Dycal-capped teeth exhibited no severe pulp inflammation, but odontoblast density was reduced beneath the cavities. Dentin bridge formation was not found on exposure sites. In Clearfil Protect Bond-capped teeth, the odontoblast layer close to the exposure was reduced or eliminated with presence of some vacuoles. A few inflammatory cells were observed in all specimens with presence of blood vessels. The signs of irregular and osteodentin type bridge formation was observed at the exposed surfaces.

Conclusion: Acceptable biologic compatibility was found with Clearfil Protect Bond in exposed cavities.It may be considered as an adequate pulp capping agent.But further studies are needed.This study will continue with new patients.

This Project was supported by Selcuk University Research Grant.