Effects of GLUMA Desensitizer and Low-Level ۹۸۰ nm Diode Laser on the Retention of the Metal Frames of the PFM Crowns Cemented by Self-adhesive Resin Cement (RelyX U۲۰۰) Effects of GLUMA and ۹۸۰nm diode laser on the retention of metal frameworks

Abstract Introduction: Sometimes, dentinal tubules are exposed to the oral cavity during the preparation of vital teeth for crowns, and patients show various signs of tooth hypersensitivity. Some treatments have been suggested for dental hypersensitivity after tooth preparation, such as low-level diode laser (۹۸۰ nm) and GLUMA desensitizer. The pretreatment of dentin with desensitizers may affect retention. The aim of this study was to ascertain the effects of the ۹۸۰nm Diode laser and GLUMA Desensitizer on the retention of the metal frames cemented by self-adhesive resin cement (RelyX U۲۰۰).Methods: Thirty intact permanent maxillary first premolars were used in this study. After preparing teeth with ۰.۵ to ۰.۷ finishing line above CEJ, casting full metal crowns with a ۵-diameter ring on the occlusal surface was done. Then the samples were divided into ۳ groups: (۱) Control Group (n=۱۰), (۲) ۹۸۰ nm diode laser (n=۱۰), and (۳) GLUMA desensitizer (n=۱۰). Frames were cemented with self-adhesive resin cement (RelyX U۲۰۰) and the bond strength was measured by a universal testing machine. Data were analyzed by ANOVA and Tukey post hoc tests in SPSS version ۲۵ (P<۰.۰۵).Results: Frame retention in the ۹۸۰ nm diode laser group (۴۰.۹۰±۲۷.۰۷N) was significantly lower than the control group (۱۳۸.۱۷±۴۰.۸۱ N) and the GLUMA desensitizer group (۳۱۸.۵۹±۵۶.۳۱N) (P<۰.۰۵), and frame retention in the GLUMA Desensitizer group was significantly higher than the other groups (P<۰.۰۵).Conclusion: The GLUMA desensitizer has a positive effect and the ۹۸۰ nm diode laser has a negative effect on the retention of frames cemented by self-adhesive resin cement (RelyX U۲۰۰). Keywords: Retention; GLUMA desensitizer; ۹۸۰nm diode laser; Metal frame; Resin cement