Enamel and dentin irradiation with 9.6 μm CO2 and2.94 μm Er:YAG lasers: bondstrength evaluation

Abstract

Background and objective: The objective of this studywas to evaluate the bond strength between a composite resin anddental hard tissues, which have been previously irradiated with anEr:YAG (2.94 μm) or CO2 (9.6 μm) laser. Materials andmethods: A total of 156 bovine teeth were divided into 6 groups:Group 1 – Enamel control: acid etched enamel (Single Bond); Group2 – Dentin control: acid etched dentin (Single Bond); Group 3 –Irradiated enamel (CO2 laser – 3 W) followed by acid etching;Group 4 – Irradiated dentin (CO2 laser – 3 W) followed byacid etching; Group 5 – Irradiated enamel (Er:YAG laser –0.16 W) followed by acid etching; Group 6 – Irradiated dentin(Er:YAG laser – 0.16 W) followed by acid etching. Results:Treatment only with acid etching and also the Er:YAG laserirradiation followed by acid etching showed the highest bondstrength value while the CO2 laser irradiation followed by acidetching treatment produces the lowest bond strength values in bothtissues. Conclusion: Acid etching of non-irradiated and Erbium YAGlaser irradiated tissues produces better adhesion than acidetching of CO2 laser irradiated surfaces.