Effects of different energy levels of Er: YAG laser-assisted bleaching on teeth bleaching efficacy and immediate resin bonding: a study on safety and clinical applicability.

PURPOSE

The study aimed to evaluate the teeth bleaching effect of Er: YAG laser at different energy levels and its impact on immediate resin bonding shear strength.

MATERIALS AND METHODS

72 human premolar teeth were randomly divided into six groups. Group A served as the blank group without any treatment, while Group B underwent teeth bleaching using a 37% hydrogen peroxide gel. Groups C, D, E, and F received the same 37% hydrogen peroxide gel for bleaching with additional Er: YAG laser radiation at energy levels of 40 mJ, 60 mJ, 80 mJ, and 100 mJ respectively. After completing the bleaching process, resin bonding was immediately performed in each group followed by measuring the shear strength.

RESULTS

The results showed that Er: YAG laser energy levels below 40 mJ did not enhance teeth bleaching compared to Group B; however significant differences were observed when comparing Group B with Groups D-F. Shear strength test results indicated no significant differences among experimental groups. These findings suggest that Er: YAG laser radiation can improve teeth bleaching effectiveness without affecting immediate resin bonding shear strength.

CONCLUSION

The energy level of Er: YAG laser (40, 60, 80, and 100 mJ) significantly correlates with teeth bleaching, particularly at energy levels above 40 mJ, without compromising immediate resin bonding strength. These findings support the safe and effective use of Er: YAG laser-assisted bleaching in clinical practice, providing a practical parameter for clinicians to achieve desirable aesthetic outcomes.