# Laser Applications in Metal Orthodontic Bracket Debonding: A Systematic Review
## 3 Results
### Main Study Outcomes  
The goal of the studies was to evaluate the effectiveness of different laser systems (such as Nd:YAG, Er,Cr:YSGG, diode, and Er:YAG lasers) for debonding orthodontic metal brackets. The results varied across the studies, focusing on the shear bond strength (SBS), adhesive remnant index (ARI), enamel damage, and temperature changes during laser-assisted debonding.  
The lasers used in these studies included Nd:YAG [41], Er,Cr:YSGG [44; 45], diode lasers [46; 47], and Er:YAG [5; 42; 43]. Generally, laser-assisted debonding led to a reduction in the amount of adhesive left on the tooth surface compared with conventional methods [44; 45]. In studies measuring temperature changes [5; 41; 42; 45; 47], it was observed that the use of lasers could cause an increase in pulp temperature. However, these increases were usually within safe limits, particularly when water cooling was employed [5; 42; 43]. Temperature increases during laser irradiation depended on the laser type and power settings. The 2 W Nd:YAG laser led to significant temperature rises [41]. In terms of power of the diode laser, the 5 W diode laser produced a higher increase in pulp temperature (+3.60 \({}^{\circ}\)C) than the 2 W diode laser [47].  
Several studies assessed the SBS to compare the efficiency of laser-assisted debonding with traditional plier-based methods. In most cases, there were no significant differences in the SBS between the two approaches [41; 46].  
In terms of ARI, two [44; 45] out of the four included studies [34; 35; 36; 37] provided detailed data, indicating that laser-assisted debonding generally left fewer adhesive remnants on the enamel compared to conventional methods (see Table 2).  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Authors** & **Laser Parameters** & **Protocol of Debending** & **Brackets** & **SSS** & **Results Aiki** & **Temperature Increase** \\ \hline  & Group 1- & & & & Group 1- 1- 4,2- 2,3-4 & \\  & 1 W Nd/YAG laser frequency = 20 Hz, & & & & 4+ 5-2 & \\  & pulse duration = 0.2 nanoseconds, & & & & Group 2- 1- 4,2- 3,3-7 & Pulp temperature \\ [PERSON], [PERSON] et.al. [41] & Group 2- & 10 s irradiation at the & brackets (Discovery)\({}^{\circ}\), & No significant & 4+ 5-2,5-0 & 1 W group-3-2-5 C\({}^{\circ}\), \\  & 15 W Nd/YAG laser, & & & Both 1s, Dentaurum, Germany, & & Groovy 1- 2- 2-3,3-6 & 1.5 W group-4-2-5 C\({}^{\circ}\), \\  & Group 3- & & & & Group 4- 1-0,2- 1-3,5 & 2 W group-5-5-74 C\({}^{\circ}\), \\  & 2 W Nd/YAG laser, & & & & 4+ 5-2 & \\  & no information about cooling & & & & 4+ 5-2 & \\ \hline  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ \end{tabular}
\end{table}
Table 2: Detailed characteristics of the studies.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Authors** & **Laser Parameters** & **Protocol of Debending** & **Basducts** & **SSS** & **Results ARI** & **Temperature Increase** \\ \hline  & \multicolumn{1}{c}{_EXAFS_} & \multicolumn{1}{c}{_Circular motion_} & \multicolumn{1}{c}{_Basducts_ (Victory Series)_} & \multicolumn{1}{c}{_Cropiv_} \\  & power 3.4 W, energy 170 mJ. & 6 s. & 3 M