Repair Responses of Pulp Tissues after Different Direct Pulp Capping Materials at Different Storage Time

Objective: The objective of this study was to evaluate and compare histologically the repair response following direct pulp capping of mechanically exposed dogs' teeth with: Dycal, UltraBlend Plus and TheraCal LC: at different time intervals (1 week, 1 month and 3 months) Materials and methods: A total of 54 permanent teeth of six healthy male mongrel dogs were used, divided into three groups (n=18) according to pulp capping material used. Group I: Dycal, Group II: UltraBlend Plus and Group III: TheraCal LC. All cavities were restored with Riva LC Resine Modified Glass Ionomer. Each group was subdivided into three subgroups according to storage time (n=6). Control samples (3 teeth) were added representing normal untouched teeth. The specimens were fixed, decalcified, processed to paraffin blocks. Serial sections of 5 microns thickness were prepared and stained with H&E then examined under light microscope for histologic examination and were evaluated histologically for pulp tissue organization and reparative tissue formation following scoring system used by Nowicka et al. Results: As regards calcific barrier, all three materials, by the end of third month showed: continuity (score 3) with irregular dentin bridge formation, the morphology showed mostly irregular hard tissue and the tubules were mild in most specimens. Conclusion: Theracal is superior to Dycal and UBP for pulp capping of mechanically exposed human teeth, it can be used as an effective direct pulp capping material. There was no statistically significant difference between the three capping agents by end of third evaluation period as regards calcific barrier and odontoblastic layer.