Shear strength of metal brackets using LED lamps with different wavelengths: An in vitro comparative study

AIM: To evaluate the shear strength of Orthocem and BracePaste polymerizable cement light‑cured with light‑emitting diode (LED) units with different wavelengths (Bluephase N) with their high power, low power, and soft start programs in the bonding of metal brackets. MATERIALS AND METHODS: In vitro experimental research was performed. Mini Roth 0.022 metal brackets (Roth Orthometric brackets) were used. The adhesives were placed on the metal brackets with Orthocem and BracePaste resin cement. To compare the average strengths, the analysis of variance (ANOVA) test was used (P < 0.05). RESULTS: The average shear strength was better with Bracepaste polymerizable cement compared to Orthocem cement in all its high power, low power, and soft star programs; the highest was Bracepaste with soft start of 26.52 MPa, and the lowest was Orthocem with soft start of 13.92 MPa. When evaluating the differences, it was found that these were statistically significant in all groups (P < 0.05). CONCLUSIONS: Differences were found in the shear strength of light‑curing Orthocem and Bracepaste light‑curing cement cured with LED units with different wavelengths in bonding metal brackets to the tooth in vitro.