Effect of Surface Treatment With Er:YAG and CO۲ Lasers on Shear Bond Strength of Polyether Ether Ketone to Composite Resin Veneers

Abstract Introduction: Polyether ether ketone (PEEK) has low surface energy and high resistance to chemical surface treatments. Therefore, different surface treatments such as laser conditioning should be investigated. There is a gap of information regarding the efficacy of laser irradiation in the surface treatment of PEEK, and the efficacy of several laser types needs to be evaluated for this purpose. This study aimed to assess the effect of surface treatment with erbium-doped yttrium aluminum garnet (Er:YAG) and carbon dioxide (CO۲) lasers on shear bond strength (SBS) of PEEK to composite resin veneers.Methods: In this experimental study, ۶۰ rectangular-shaped PEEK samples (۷ x ۷ x ۲ mm) were used. The samples were mounted in auto-polymerizing acrylic resin in such a way that only one surface measuring ۷x۷ mm remained exposed. The samples were then randomly divided into ۳ groups (n = ۲۰) of control, Er:YAG laser surface treatment (Power = ۱.۵ W, energy density = ۱۱۹.۴۲ J/cm۲, irradiation time = ۲۰ s) and CO۲ laser surface treatment (Power = ۴ W, energy density = ۱۵۹.۲۲ J/cm۲, irradiation time = ۵۰ s). The bonding agent and PEEK opaque were applied on the surface of samples and they were veneered with a composite resin using a hollow plastic cylinder with an internal diameter of ۴ mm. The SBS was then measured and the data were analyzed using one-way ANOVA, Tukey HSD test and Dunnett’s test at ۰.۰۵ level of significance.Results: The SBS of the ۳ groups was significantly different (P < ۰.۰۰۱). The Tukey HSD test revealed that the Er:YAG laser had higher SBS than the CO۲ laser group (P < ۰.۰۰۱). The Dunnett’s test showed that both Er:YAG and CO۲ laser groups yielded higher SBS than the control group (P < ۰.۰۰۱).Conclusion: The Er:YAG and CO۲ laser treatments can increase the SBS of PEEK to composite resin veneers, although the Er:YAG laser seems to be more effective for this purpose. Keywords: Er-YAG Lasers CO۲ Lasers Polyether ether ketone Surface treatment