The effects of XeCl laser etching of Ni-Cr alloy on bond strengths to composite resin: a comparison with sandblasting procedures

摘要

Objectives. The aim of this study was to determine the effect of laser surface treatment of Ni-Cr alloy on the tensile bond strength of a proprietary composite resin (Panavia 21) in comparison with a conventional sandblasting technique. Methods. Eighty cylinders of Ni-Cr were randomly allocated into the following groups: Group Ⅰ-sandblasting only; Group Ⅱ-low laser fluence (3.0 J/cm~2); Group Ⅲ-medium laser fluence (4.0 J/cm~2); Group Ⅳ-high laser fluence (4.9 J/cm~2); Group Ⅴ-sandblasting in combination with medium laser fluence (4.0 J/cm~2). Specimens within groups were bonded into pairs with resin cement as per manufacturer's instructions. They were then de-bonded using a tensile test. Results. The mean de-bond strengths (SD) were: Group Ⅰ-13.1 (4.2) MPa; Group Ⅱ-17.6 (5.8) MPa; Group Ⅲ—25.7 (11.8) MPa; Group Ⅳ-22.6 (6.6) MPa; Group Ⅴ-41.8 (13.2) MPa. A statistically significant improvement (Bonferroni, p < 0.05) in bond strength was found for the specimens which had been both lased and sandblasted (Group V) compared to all other groups, including those which were only sandblasted. Significance. Laser pre-treatment of Ni-Cr alloy increases bond strength to composite resin compared with sandblasting; laser pre-treatment in combination with sandblasting further increases the de-bond strengths.