Bond assessment of resin modified glass ionomer cement to dentin conditioned with photosensitizers, laser and conventional regimes

Abstract

Aim: To assess different conditioning regimes on shear bond strength (SBS) of resin modified glass ionomer cement (RMGIC) bonded to dentin MATERIAL AND METHODS: Fifty non carious intact maxillary molars were cleaned, isolated and randomly divided into five groups (n = 10). Before randomization, dentin surface was exposed and finished. Samples in group 1 were conditioned with methylene blue photosensitizer (MBP) 50 mg/l and activated by photodynamic therapy (PDT), Group 2: surface treated with Er,Cr:YSGG (ECL), Group 3: surface conditioned with polyacrylic acid (PAA) (control), Group 4: surface conditioned with 17 % Ethylenediaminetetraacetic acid (EDTA), Group 5: surface conditioned with total etch (Optibond solo Plus). For SBS testing the samples were placed in universal testing machine. Fracture analysis of debonded surfaces were evaluated using stereomicroscope at 40x magnification. Means and standard deviations were calculated using analysis of variance (ANOVA) and Tukey's post hoc test at a significance level of (p < 0.05).

Results: The maximum bond strength was found in group 5 conditioned with Optibond solo plus total etch (23.15 ± 3.21 MPa). Whereas, the lowest bond values were observed in group 1 treated with MBP (15.25 ± 1.54 MPa). Moreover, samples in group 2, group 3 and group 4 resulted in comparable bond strength (p > 0.05).

Conclusion: MBP at 50 mg/l is not recommended to condition dentin prior to RMGIC application. Moreover, ECL has a potential to be suggested for dentin conditioning compared to PAA.

Keywords: Dentin; Er,Cr:YSGG; Photodynamic therapy; Photosensitizers; Resin modified glass ionomer cement.