Shear bond strength of metallic brackets bonded to enamel pretreated with Er,Cr:YSGG LASER and CPP-ACP

Abstract

Background Increased risk of enamel demineralization during and after orthodontic treatment raises the demand for better preventive measures including combinations of laser, CPP-ACP, and fluoride. The combination of Er,Cr:YSGG laser with CPP-ACP was proved to have a synergetic effect compared to each of them alone. Shear bond strength (SBS) of orthodontic brackets bonded to the enamel surface after being treated with preventive measures is critical. The aim of this study was to compare the SBS and failure mode of metallic brackets bonded to teeth with no pretreatment and pretreated enamel surface, either with Er,Cr:YSGG laser alone or combined with CPP-ACP. Methods Sixty sound extracted human premolar teeth were allocated randomly to 3 groups: In Group 1 (control), teeth were etched and bonded directly; in Group 2, laser pretreatment of the enamel surface was done followed by etching and bonding as in the control group; in Group 3, the enamel surface was lased then CPP-ACP was applied according to the manufacturer instructions, etched and bonded. SBS and Adhesive remnant index (ARI) were evaluated. Results No significant differences were found between the 3 groups neither in the SBS nor in the ARI scores. Conclusions The use of combined Er,Cr:YSGG laser with CPP-ACP as a preventive measure before bonding orthodontic brackets does not endanger the bracket’s bonding strength.

Effects of Er, Cr: YSGG Laser on Shear Bond Strength of the Orthodontic Brackets for 5 and 10 Seconds: An In Vitro Study

“…Recently, the Er, Cr: YSGG hydrokinetic laser that contains a cooling system (a mixture of air and water vapor) and does not involve vibration or heat has become one of the most widely used lasers for reducing enamel demineralization [ 29 ]. Moreover, the thermal ablation produced by Er, Cr: YSGG laser irradiation has been sufficient to alter the crystallinity and composition of enamel (e.g., the removal of carbonate, creation of new crystalline phases, and the increase in the hydroxyapatite minerals), and these changes may explain why laser-etched enamel is more resistant to the early development caries [ 30 ].…”

Comparative Evaluation of Two Bracket Systems’ Bond Strength: Conventional and Self-Ligating

“…Enamel surface deproteinization with sodium hypochlorite before etching increased the bond strength of glass ionomer cement to similar values of Transbond XT, potentially reducing the incidence of white spot lesions [ 38 ]. Pretreating enamel with an Er,Cr:YSGG laser and CPP-ACP as a preventive measure before bonding brackets does not reduce bond strength [ 26 ]. Still, Er:YAG laser irradiation does not represent an option for enamel conditioning according to Contreras-Bulnes et al [ 39 ]…”

“…Each tooth with the bonded bracket was firmly placed in a load cell that was locked into the lower hydraulic grip in a fixed, repeatable position. The upper hydraulic grip with a metal pin in place would perpendicularly press against the bracket between the wings and the base at the selected crosshead speed, as can be seen in Figure 5 and Figure 6 [ 26 , 27 ].…”