This study was aimed to determine the effects of temporary sealing materials on microtensile bond strength between resin-coated dentin and resin inlay and to compare the bonding effectiveness of delayed dentin sealing and that of immediate dentin sealing.

The teeth were divided into 4 groups: group 1, specimens were prepared using delayed dentin sealing after temporary sealing with zinc oxide eugenol (ZOE); group 2, specimens were prepared using immediate dentin sealing and ZOE sealing; group 3, specimens were prepared using immediate dentin sealing and Dycal (Dentsply) sealing; group 4, specimens were prepared using immediately sealed, and then temporarily sealed with a resin-based temporary sealing material.

After removing the temporary sealing material, we applied resin adhesive and light-cured. Then the resin inlays were applied and bonded to the cavity with a resin-based cement. The microtensile bond strength of the sectioned specimens were measured with a micro-tensile tester (Bisco Inc.). Significance between the specimen groups were tested by means of one-way ANOVA and multiple Duncan's test.

Group 1 showed the lowest bond strength, and group 4 showed the highest bond strength (p < 0.01). When temporary sealing was performed with ZOE, immediate dentin sealing showed a higher bonding strength than delayed dentin sealing (p < 0.01).

Based on these results, immediate dentin sealing is more recommended than delayed dentin sealing in bonding a resin inlay to dentin. Also, resin-based temporary sealing materials have shown the best result.

The purpose of this study was to determine the setting time, compressive strength, solubility, and pH of mineral trioxide aggregate (MTA) mixed with glass ionomer cement (GIC) and to compare these properties with those of MTA, GIC, IRM, and SuperEBA.

Setting time, compressive strength, and solubility were determined according to the ISO 9917 or 6876 method. The pH of the test materials was determined using a pH meter with specified electrode for solid specimen.

The setting time of MTA mixed with GIC was significantly shorter than that of MTA. Compressive strength of MTA mixed with GIC was significantly lower than that of other materials at all time points for 7 days. Solubility of 1 : 1 and 2 : 1 specimen from MTA mixed with GIC was significantly higher than that of other materials. Solubility of 1 : 2 specimen was similar to that of MTA. The pH of MTA mixed with GIC was 2-4 immediately after mixing and increased to 5-7 after 1 day.

The setting time of MTA mixed with GIC was improved compared with MTA. However, other properties such as compressive strength and pH proved to be inferior to those of MTA. To be clinically feasible, further investigation is necessary to find the proper mixing ratio in order to improve the drawbacks of MTA without impairing the pre-existing advantages and to assess the biocompatibility.

The purpose of the present in vitro study was to evaluate the biocompatibility of mineral trioxide aggregate (MTA) mixed with glass ionomer cement (GIC), and to compare it with that of MTA, GIC, IRM and SuperEBA.

Experimental groups were divided into 3 groups such as 1 : 1, 2 : 1, and 1 : 2 groups depending on the mixing ratios of MTA powder and GIC powder. Instead of distilled water, GIC liquid was mixed with the powder. This study was carried out using MG-63 cells derived from human osteosarcoma. They were incubated for 1 day on the surfaces of disc samples and examined by scanning electron microscopy. To evaluate the cytotoxicity of test materials quantitatively, XTT assay was used. The cells were exposed to the extracts and incubated. Cell viability was recorded by measuring the optical density of each test well in reference to controls.

The SEM revealed that elongated, dense, and almost confluent cells were observed in the cultures of MTA mixed with GIC, MTA and GIC. On the contrary, cells on the surface of IRM or SuperEBA were round in shape. In XTT assay, cell viability of MTA mixed with GIC group was similar to that of MTA or GIC at all time points. IRM and SuperEBA showed significantly lower cell viability than other groups at all time points (p < 0.05).

In this research MTA mixed with GIC showed similar cellular responses as MTA and GIC. It suggests that MTA mixed with GIC has good biocompatibility like MTA and GIC.