Sodium Hypochlorite as a Deproteinizing Agent Optimize Orthodontic Brackets Adhesion using Resin Modified Glass Ionomer Cement

Aim: The main aim of this study was to test the effect of deproteinization of human dental enamel surfaces, with 5.25% sodium hypochlorite (NaOCl) before etching on orthodontic bracket shear bond strength (SBS) of Resin Modified Glass Ionomer Cement (RMGI) adhesive system. Materials and Methods: Sixty extracted human premolar teeth were randomly divided into two groups. Group1as an experimental and group II control, with 30 teeth each. Both groups; brackets were bonded to the teeth using, Fuji Ortho LC. The buccal surface of the premolars in the experimental group was deproteinized with 5.25% NaOCl before acid etching and orthodontic brackets were bonded with RMGI. The same protocol was used in the control group except NaOCl was not applied. The debonding force (SBS) was measured using Instron machine and the residual adhesive remain on the tooth surface was scored as well enamel roughness was measured using profilometry. Independent t test was used to determine whether there is a significant difference in SBS and the adhesive remnant index (ARI) scores between the 2 groups. Kurskal-Wallis test was used to test for Ra, Rq and Rt data analysis. Results: The mean SBS for Fuji Ortho LC with NaOCl, was 17 (±5.37) MPa; and for Fuji Ortho LC without NaOCl, 13.86 (±4.41) MPa, the difference between the 2 groups was significant P =0.029. The mean (SD) adhesive remnant index scores for group 1 & 2 were 3.97 (±.718) and 2.90 (±.712) respectively with significant difference between the 2 groups P > 0.001..No significant difference was found in enamel roughness between cleanup methods P for Ra, Rq and Rt was = 0.340 , 0.483 and 0.280 respectively. Conclusion: It was concluded that enamel treatment with NaOCl increase bonding strength of brackets bonded with RMGIC, and was statistically significant when compared to the untreated group.