Shear bond strength of resin modified glass ionomer with and without prior conditioning with sodium hypochlorite before conventional etching: ex vivo study

Abstract

Introduction: Resin modified glass ionomers (RMGIs) provide an alternate to composite resins for bonding brackets in orthodontics. The aim of this study was to compare the mean shear bond strength (SBS) of RMGIs with and without prior conditioning with 5.25% sodium hypochlorite (NaOCl)
Material and Methods: 68 extracted human premolars were divided into two groups. In the experimental group, pre-conditioning with 5.25% NaOCl was performed followed by conventional etching whereas in the control group, conventional etching was performed only before bonding brackets with Fuji Ortho LC. All the brackets were stored in distilled water for 24 hours and debonded using universal testing machine. SBS values were recorded in megapascals. Mean and standard deviation for both the groups was evaluated and paired t-test was used to analyze the data using SPSS version 20.

Results: There was a significant difference in the SBS of the two groups (p<0.05). The mean SBS for the experimental group was 24.2+/-6.35MPa and for the control group was 9.68 +/-5.26 MPa.

Conclusion: Conventional etching of enamel surface before bonding brackets with RMGIs give adequate SBS value, whereas pre-conditioning with 5.25% NaOCl before etching gives a very high mean SBS value.