Comparative Evaluation of Bioactive Materials and Their Nano-Counterpart as Pulp Capping Agents in Dogs’ Teeth

Introduction: Direct pulp-capping is an alternative procedure to extraction or endodontic therapy, in which a medicament is placed directly over the exposed pulp to maintain pulp vitality and facilitate the formation of protective barrier. Aim of study: The purpose of this study was to evaluate and compare the histological response of dog’s pulp after direct pulp capping with 3 different materials; MTA, Bioactive glass, CEM and their nanoparticles, at 1 month and 3 month time intervals.
Materials & Methods: A total of 112 teeth in 8 dogs were used for this study, where 96 teeth were pulp capped with the investigated materials and 16 teeth were serving as negative control. The 14 teeth of each dog were classified into 6 experimental groups and one control (2 teeth each) as follows: Group A: was capped with MTA, Group B: was capped with NMTA, Group C: was capped with CEM, Group D: was capped with NCEM, Group E: was capped with Bioactive glass, Group F: was capped with Nano Bioactive glass and Group G: unprepared tooth (negative control). Dogs were randomly divided into 2 groups (4 dogs each), relative to the observation periods tested, 1 month and 3 months for histomorphological evaluation of pulp response after direct pulp capping with tested materials.
Results: Regarding the dentin bridge formation, both NMTA and NCEM groups induced thick dentin bridge with irregular dentin pattern in 1 and 3 months evaluation time period while MTA and CEM induced thinner dentin bridge with regular dentin pattern. BG and NBG groups showed the lowest mean dentin bridge thickness values with no tubular dentin pattern. About the inflammatory reaction of the dental pulp to materials with conventional particle size; MTA displayed the highest prevalence of no inflammation followed by CEM while BG showed the highest prevalence of moderate inflammation and the highest inflammatory cell counts. All nanomaterials showed the highest mean inflammatory cell counts at both evaluations time periods.
Conclusion: MTA and CEM can be considered favorable materials for direct pulp capping, while BG and NBG produced the worst inflammatory cell reaction, dentin bridge thickness and quality. Nanoparticles although increased dentin bridge thickness, they also increased the inflammatory cell reaction.