Shear bond strength of a RMGIC for orthodontic bracket bonding to enamel

Objective To evaluate the shear bond strength (SBS) of a restorative resin-modified glass ionomer cement (RMGIC) for orthodontic bracket bonding. Materials and methods One hundred twenty-one human teeth were randomly divided into 11 groups ( n = 11) according to the surface treatment applied (H 3 PO 4 ± Transbond Plus (TSEP) or Scotchbond Universal (SU)), and the adhesive used (Riva LC HV (RIVA), Fuji Ortho (FUJI), and Transbond XT (TXT)). For each sample, a metal button was bonded. SBS tests were performed at 1 week and debonded specimens were observed for failure modes determination. One-way ANOVA followed by Tukey’s post hoc test was used to compare SBS differences and Fisher’s exact test to analyze the failure modes ( p < 0.05). Results TSEP + FUJI and H 3 PO 4 + SU + TXT showed the highest SBS values while H 3 PO 4 + TSEP + RIVA showed the lowest value. Cohesive failure and mixed failure were found in the groups with SU and TXT and adhesive failure in the other groups. Discussion/Conclusions The bonding of orthodontic attachments to enamel could be performed with any of the three materials studied. The use of a universal adhesive in the bonding protocol could optimize the adhesion values. Clinical studies would be needed to confirm the results obtained.