engleski

The influence of resin infiltration pre- treatment on orthodontic bonding to demineralized human enamel

AIMS: To investigate, in vitro, the differences in shear bond strength (SBS) of molar tubes bonded with three different adhesives to demineralized human enamel pre-treated with a low viscosity resin infiltrant (Icon, DMG, Germany), as well as to compare the achieved bond strengths to those of sound enamel. MATERIALS AND METHOD: A total of 48 freshly extracted third molars were randomly divided into four groups (n = 12). Group 1: sound enamel + Transbond XT (3M Unitek, Monrovia, California, USA) ; Group 2: demineralized enamel + Icon + Transbond XT ; Group 3: demineralized enamel + Icon + Scotchbond Universal (3M Espe, St Paul, Minnesota, USA) ; Group 4: demineralized enamel + Icon + Assure Plus (Reliance Orthodontic Products, Itasca, Illinois, USA). All the teeth in groups 2, 3 and 4 were exposed to a demineralization procedure. Prior to adhesive application all the specimens were etched with 37 per cent phosphoric acid for 15 seconds. In all groups molar tubes were bonded with Transbond XT Paste. Prior to SBS testing, all specimens were thermocycled (10, 000 times between 50°C and 550°C). SBS was measured in MegaPascals (MPa). Failure mode was assessed according to the Adhesive Remnant Index (ARI). One-way analysis of variance (ANOVA) and Tukey test for post hoc comparisons were applied to analyze SBS data. The Kruskal-Wallis ANOVA followed by a series of Mann-Whitney U tests was used to compare between-group differences in the ARI scores. In all the statistical tests significance level was set at P ≤ 0.05. RESULTS: The highest bond strength (20.3 MPa) was measured for molar tubes bonded with Assure Plus on demineralized enamel and the difference was statistically significant (P < 0.05). No statistically significant differences were found among groups 1, 2 and 3. No statistically significant between-group difference was observed for ARI scores. CONCLUSION: Pre-treatment of demineralized enamel with resin infiltrant does not impair the SBS of orthodontic tubes. Significantly higher strength to Icon pre- treated demineralized enamel was achieved using the Assure plus adhesive. Acknowledgment: This study was funded by the Croatian Science Foundation, ‘Investigation and development of new micro and nanostructure bioactive materials in dental medicine’. Biodentmed No. IP-2018-01- 1719

shear bond strength ; orthodonticbracket ; resin infiltration

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