# Laser Applications in Metal Orthodontic Bracket Debonding: A Systematic Review
## 4 Discussion
Comparisons of the SBS between laser-assisted and conventional debonding methods have yielded mixed results. Most studies reported no significant differences in SBS values between the two approaches [41; 46]. [PERSON] et al. [46] specifically found that using a 445-nm diode laser for irradiating metallic brackets before debonding did not significantly affect the SBS values or the amount of adhesive residue left on the enamel. The absence of a significant decrease in the SBS suggests that the laser-assisted debonding of metal brackets carries a risk to the enamel's prismatic structure comparable to that of conventional plier-based removal methods. However, the variability in outcomes across studies employing different laser wavelengths and systems highlights the need for further research to determine the optimal laser parameters for effective and safe bracket removal [26]. According to a study by [PERSON] et al., enamel damage occurred in a greater extent in ceramic brackets compared to metallic brackets when using the conventional removal method. This suggests that the greater bond strength of ceramic brackets poses more problems considering enamel damage, and therefore laser removal seems as a much more needed tool for this type of bracket [52]. Moreover, in one of the studies included in our work, [PERSON] et al. reported that the laser debonding of metallic brackets was not feasible compared to ceramic brackets, which debonded with greater success [43]. The third evaluated parameter was the adhesive remnant index (ARI), which quantifies the amount of adhesive residue left on the tooth surface following bracket debonding. Studies by [PERSON] et al. [44] and [PERSON] et al. [45] demonstrated that laser-assisted debonding methods generally resulted in less adhesive residue compared to conventional techniques, potentially minimizing the risk of enamel damage during the removal of residual adhesive. In contrast, investigations by [PERSON] et al. [46] and [PERSON] et al. [47] found no statistically significant differences in the ARI between laser-assisted and traditional methods. These discrepancies could be attributed to differences in the laser parameters, experimental designs, or the types of bracket systems employed. This underscores the necessity for standardized methodologies and protocols in future research to ensure consistent and reliable comparisons across studies [53]. With conventional methods alone, there were significant differences in ARI scores between the two bracket types reported in the literature. Much more adhesive was left on the tooth surface when compared to metallic brackets in a study by [PERSON] et al. [54]. On the other hand, [PERSON] et al. pointed out that the amount of adhesive that remained on the tooth surface when debonding ceramic brackets was dependent on the adhesive used. This suggests that this factor also has to be taken into consideration in further studies, as it can influence the results [21]. The primary limitations of this study included the lack of long-term evaluations addressing potential enamel microstructural changes, pulp vitality, or overall tooth health following laser-assisted debonding, as most studies focused on immediate outcomes like temperature changes and the shear bond strength (SBS). Additionally, findings from ceramic brackets are often extrapolated to metallic brackets, despite differences in the thermal and material properties, which may not yield accurate conclusions. The variability in laser types, power settings, cooling techniques, and study methodologies further complicates the comparison of results and highlights the need for standardized protocols. The predominance of in vitro studies limits the clinical applicability due to the absence of real-world factors like blood flow and tissue interactions, while the inconsistent reporting of adhesive residue (ARI) and underexplored patient-centered outcomes such as comfort and pain perception add to the gaps [55].