Objectives: Many restorative materials are claimed to be successful in preventing bacterial microleakage and minimizing pulp inflammation. However, information regarding the in vivo performance of materials in comparison with each other is limited. The aim of this study was to evaluate and compare the pulp response of nine types of restorative materials when placed in non-exposed non-human primate cavities.
Methods: 279 standardized non-exposed Class V cavities, were prepared into buccal dentin. Cavities were restored with: Zinc oxide eugenol (ZnOE), Calcium hydroxide [Ca(OH)
2], zinc phosphate (ZP), Resin-modified glass ionomer (RMGI), Composite resin (CR), Bonded amalgam (BA), Gutta-percha (GP), Compomer and Silicate. Pulp tissues were extracted and evaluated for inflammation according to ISO guidelines;—employing histomorphometric analysis and ANOVA (p values) statistics. Bacteria were detected using McKay stains.
Results: Pulp inflammation was found to increase with bacterial microleakage around the restoration (p < 0.0001). The frequency of bacterial microleakage was found to vary between restorative materials (p < 0.0001). In rank order of preventing bacterial microleakage from best to the worst; RMGI (100%), BA (88%), ZnOE (86%), CR (80%), GP (64%), Ca(OH)
2 (58%), compomer (42%), silicate (36%) and ZP (0%).
Conclusions: We conclude that the most effective restorative materials to prevent bacterial microleakage and pulp injury from inflammatory activity were RMGI, BA, ZnOE and CR restorations. Bacterial microleakage and pulp inflammation can be largely avoided, provided the most appropriate restorative materials are used.