Comparison of Pulpal Response Following Direct Pulp Capping Using MTA and Zinc-doped Bioglass

Management of deep caries and pulp exposures depends on the severity of the disease. The rapid development of preventive materials and techniques has significantly influenced restorative treatment methods. Therefore, the aim of this study is to produce and evaluate a type of bioactive glass containing Zn (Zn-BAG= Zinc-doped Bioglass) and to investigate its performance on the pulp and the formation of dental bridges following direct pulp capping in comparison to the standard gold material MTA (Mineral Trioxide Aggregate).

The conventional sol-gel method synthesized bioglass 45S5 with 2%mol zinc. In this experimental animal study, 10 maxillary first molars of 10 Wistar rats were subjected to direct pulp capping and divided into two groups of five according to the materials used: group 1 (DPC [Direct pulp cap] + MTA) and group 2 (DPC + Zn-BAG). After 8 weeks of direct pulp capping, the rats were sacrificed, and teeth were sectioned and prepared for histological analysis. The degree of inflammatory pulpal response (no inflammation, mild inflammation, moderate inflammation, severe inflammation, necrosis), location of a dentin bridge (at the site of pulp exposure, not adjacent to the site of exposure, and combination), percentage of dentin bridge formation (%) (25%>, 25%-50%, 50%-75%), and the quality of dentin bridge formation (without tubules, irregular tubular pattern, regular tubular pattern) were analyzed and scored.

In the electron microscope view, Zn-BAG particles exhibited a plate-like shape with less than 100 nm particle size. The EDS analysis confirmed the presence of zinc in the Bioglass structure. There was no significant difference between the type of pulp capping agent and the degree of inflammatory pulpal response, location of a dentin bridge, percentage of dentin bridge formation, and the quality of dentin bridge formation.

Zn-BAG and MTA pulp capping materials showed similar desirable cellular and inflammatory responses over pulpal exposure. Zn-BAG is a promising candidate for pulp capping material.