Effect of Er: YAG laser irradiation on bonding reliability of cervical resin composite restorations

• Published in: Adhesive Dentistry Vol. 26; no. 1; pp. 17 - 29
• Main Authors: SUZUKI, Takanori, NARA, Yoichiro
• Format: Journal Article
• Language: Japanese
• Published: Japan Society for Adhesive Dentistry 2008
• Subjects: bonding reliability; Er: YAG laser; micro-tensile bond strength; Weibull analysis
• ISSN: 0913-1655; 2185-9566
• DOI: 10.11297/adhesdent1983.26.17

The purpose of this study was to examine the effect of Er: YAG laser irradiation on the bonding reliability of cervical resin composite restorations. The efficiency of an antibacterial self-etching primer adhesive system was also investigated. Standardized V-shaped cavities were prepared finally with an Er: YAG laser unit (L) or a rotary cutting unit (R); 20cavities by each were prepared in the cervical region of extracted human lower premolars. The cavities were restored with two types of self-etching primer adhesive systems, an antibacterial system, Clearfil Mega Bond FA (F, Kuraray Medical), and a conventional system, Clearfil Mega Bond (M, Kuraray Medical), and with a resin composite, according to the manufacturer's instructions. Four types of restored specimen, 10each, were subjected to a combination stress load test simulating an intra-oral environment. The micro-tensile bond strength (μ-TBS) to the gingival dentin wall of the specimens after the combination stress load was measured. The data were examined using ANOVA and Weibull analysis. The μ-TBS (SD) of LF/RF/LM/RM restorations were7.0 (4.6)/12.4 (4.8)/9.0 (4.9)/15.4 (6.1) MPa. The μ-TBS of L restorations was significantly smaller than that of R restorations at p<0.01, regardless of the system. There was a significant difference in Weibull modulus between L and R restorations at p<0.01, regardless of the system, and the bonding reliability of L restorations was statistically inferior to that of R restorations. There was no significant difference in Weibull modulus between F and M restorations, regardless of the unit used for final cavity preparation, and similar bonding reliability was recognized in both restorations.