Effect of the Er: YAG laser on the shear bond strength of conventional glass ionomer and BiodentineTM to dentine

摘要： Objectives: The purpose of this study was to determine if Er: YAG laser etching improves the shear bond strength (SBS) of Biodentin? and GC Fuji IX? to dentine. Materials and Methods: Forty human dentine specimens were standardized and embedded in stone. The specimens were randomized into four groups (n = 10). Twenty samples were treated with the Er: YAG laser radiation and 10 of these restored with GC Fuji IX? and 10 with Biodentine?. The remaining 20 specimens acted as controls (no laser treatment); 10 were restored with GC Fuji IX? and 10 with Biodentin?. All samples were then stored in an incubator at 37.5°C and 100% humidity for 7 days. The SBS was determined using a Zwick universal testing machine. A two-way analysis of variance test was used to evaluate the statistical difference in SBS between the groups. An independent sample t?test was used to determine the statistical significance of differences between control and lased groups within the same material. Results: A highly statistically significant difference in SBS was found with the laser treatment (P = 0.0001) and material (i.e., Biodentin? or Fuji IX? (P = 0.0001). The GC Fuji IX? group recorded the highest mean SBS required to dislodge the material from the laser-treated dentine surface (1.77 ± 0.22 Mega-Pascal [MPa]). The mean SBS of Biodentin? to dentine following the laser radiation (1.12 ± 0.16 MPa) was significantly greater compared to the nonlased dentine (0.53 ± 0.09). Pearson Chi?square test indicated a nonsignificant relation between shear strength and mode of failure (P = 0.467). Conclusion: Laser etching of the dentine surfaces yielded a significant increase in the bond strength for both GC Fuji IX? and Biodentin?. The SBS of Biodentin? to dentine is greater than with conventional glass ionomer (Fuji IX?).