Study on the marginal seal of composite restorations to dental hard tissues irradiated by Er : YAG laser

• Published in: Journal of Osaka Dental University Vol. 46; no. 1; pp. 165 - 181
• Main Authors: Yasuno, Kenzo, Onda, Kohei, Iwata, Naohiro, Yoshikawa, Kazushi, Yamamoto, Kazuyo
• Format: Journal Article
• Language: English
• Published: Osaka Odontological Society 2012
• Subjects: Composite restoration; Er: YAG laser; Marginal seal
• ISSN: 0475-2058; 2189-6488
• DOI: 10.18905/jodu.46.1_165

We often use the Er: YAG laser for dental treatment as it has been shown to be excellent for preparing the hard tissues of teeth. However, it has been reported that the bond strength and marginal seal of composite restorations is adversely affected in dentin irradiated by the Er: YAG laser compared with non-irradiated dentin. We used the marginal leakage test and the shear bond test to evaluate the marginal seal of restorations placed in laser-irradiated cavities. The teeth were restored using the composite resin filling method with glass ionomer cement and flowable composite resin as lining materials. We found that the shear bond strength of conventional composite resin, flowable composite resin and low-shrinkage composite resin was significantly decreased for laser-irradiated dentin compared with that for conventionally prepared dentin, and that the bond strength of resin-modified glass ionomer cement to laser-irradiated dentin. Although the marginal seal of the laser-irradiated dentin wall was not improved when the dentin was lined with conventional glass ionomer cement and flowable composite resin or when it was filled by conventional methods, it was improved when lined with resin-modified glass ionomer cement or filled with low-shrinkage composite resin. Our results suggest that lining with resin-modified glass ionomer cement or the use of low-shrinkage composite resin improves the marginal seal of composite resin restorations placed in Er: YAG laser-irradiated cavities.