IADR Abstract Archives
Pulp Capping and Repair Activities Responsible for Dentin Bridge Formation
Objectives: The importance of pulp capping variables which mediate pulp repair activities and dentin bridge formation following pulp exposure are not well understood. Consequently, the aim of this study was to evaluate the effects of pulp capping variables on dentin bridge formation. Methods: Calcium hydroxide [Ca(OH)2], resin modified glass ionomer (RMGI) and resin composite (RC) were used to restore pulp exposures prepared in 161 nonhuman primate teeth, according to ISO usage guidelines. Teeth were collected between 7 and 720 days to observe the pulp repair activities leading to dentin bridge formation. The dimensions of pulp exposures and dentin bridges were measured histomorphometrically using a grid eyepiece graticule under light microscopy. The presence of operative debris and tunnel defects were noted. Bacteria were detected using McKays stain. Pulp inflammatory activity were categorized according to ISO standards. Analysis of variance (ANOVA p values) statistics were used to correlate pulp capping variables with dentin bridge area. Results: The pulp capping variables in order of their relationship to dentin bridge area, from the most important to the least important were; pulp capping materials (p=0.0252), bacterial microleakage (p=0.0358) and area of operative debris in the dentin bridge (0.0362). A further 10 pulp capping variables were found to be less important (p values > 0.05). Bacteria contaminated 18.6% of RC, 22.2% of RMGI and 46.97% of Ca(OH)2 capped pulps, this caused pulpal inflammation and impaired dentin bridge formation. Operative debris increased the incidence of tunnel defects (p=0.0008) which disrupted dentin bridge formation. Conclusions: We conclude that to achieve ideal dentin bridge formation, attention should focus on avoiding the infiltration of operative debris into pulp tissue, to prevent the development of tunnel defects and complications. Most important is the placement of pulp capping materials which prevent bacterial microleakage.