AIM: Aim of this study was to evaluate the effect of Er,Cr-YSGG caries removal on the microtensile bond strength (μTBS) of a universal adhesive to dentine.

MATERIAL AND METHOD: In present study 8 extracted human molars (6 with occlusal dentine caries and 2 without caries) were used. Coronal caries lesions in teeth were removed convensionally with burs or using the Er,Cr-YSGG laser (Waterlase MD, Biolase Technology Inc, Irvine, CA, USA) until a hard dentine layer was reached. A universal adhesive system (G-Premio Bond,GC Europe N.V., Leuven, Belgium) was applied to the entire tooth surface. Resin composite (Charisma Smart) was built up to the adhesive treated dentine surface. For μtbs analyses, sticks with a thickness of 1x1 mm (± 0.2 mm) were obtained from the samples. Three teeth were used for each caries removal method. Sticks (n=10) of caries-affected dentine were obtained just above the discoloured affected dentine. Sticks from caries- free extracted teeth were used to evaluate the μTBS of sound dentine. Prepared sticks were subjected to tension at a head speed of 1 mm/min in a universal test device for μTBS test. Data were analysed with One-way ANOVA and Tukey HSD post-hoc tests.

RESULTS: Sound dentine had significantly higher bond strength results (36.7±5.9 MPa) than the other groups (24.3±6.5 MPa for Er,Cr-YSGG group, 22.6±6.0 MPa for bur rounded group) (p≤0.05). There was no statistical difference between rounded burs and Er,Cr:YSGG groups (p≥0.05).

CONCLUSION: The Er,Cr:YSGG laser caries removal did not effect on the bonding performance of the tested universal adhesive to dentine affected by caries, and could be used as an alternative to burs for caries removal.