2014 Volume 57 Issue 1 Pages 29-42
Purpose: We measured the hardness of demineralized dentin over time using the Cariotester to determine the effectiveness of several types of pulp-capping agent for IPC.
Methods: Extracted human molars were used to prepare dentin samples with a diameter of 10 mm and thickness of 2 mm. Sound dentin samples were immersed in lactic acid solution and were regarded as demineralized when the value obtained using the Cariotester was approximately 20 KNH. HY-Bond Temporary Cement Soft (Shofu), Neodyne-α (Neo Dental Chemical Products), Dycal (Dentsply), and Calcipex Plain II (Nippon Shika Yakuhin) with a 60% calcium hydroxide mixture were used as the pulp-capping agents in the present study. Each pulp-capping agent was applied to the surface of demineralized dentin and covered with base cement. After the base cement solidified, pulp-capped dentin samples and controls were divided into two groups: those placed in a container with 100% humidity and those immersed in remineralization solution, and stored at 37°C in a thermostatic chamber for 1 and 3 months. The hardness of the capping agent-applied region was then measured. Data were analyzed using a one-way analysis of variance and Tukey's test (α=0.05). Pulp-capping agent-applied surfaces were also observed under SEM.
Results: The hardness of demineralized dentin increased with the application of Dycal, Calcipex Plain II, and the 60% calcium hydroxide mixture, and mineralized substance-like aggregates were deposited on the surface of and between collagen fibrils. It was suggested that the remineralization of demineralized dentin depended on the calcium hydroxide concentration contained in a pulp-capping agent.
Conclusion: The hardness of demineralized dentin increased and remineralization features were noted following the application of a pulp-capping agent containing over 27% calcium hydroxide.
