In vitro evaluation of shear bond strength of ceramic bonded to remineralized enamel

Abstract Aim The aim of this work was to evaluate shear bond strength (SBS) of ceramic bonded to enamel in different conditions. Patients and methods This controlled experimental laboratory study was carried out, at Faculty of Dentistry, Tanta University, on 40 sound and freshly extracted lower second molars that were collected from patients aged between 20 and 40 years old and randomly allocated into four groups: group I: specimens with sound enamel. The other groups underwent demineralization process. Groups III and IV received resin infiltrant (DMG Icon) and fluoride varnish (OliNano SEAL); respectively. Afterwards all four groups were bonded to ceramic bars. The specimens were tested for SBS in a universal testing machine at 0.5 mm/min until bonding failure. Collected data were statistically analysed using one-way analysis of variance ( P = 0.05) and Tukey’s post-hoc test and χ 2 test was done to compare failure mode patterns. Results Mean SBS data of the groups in mega Pascal were: 20.243 ± 2.507 for sound enamel (group I); 10.299 ± 1.904 for demineralized (group II); 19.023 ± 2.046 for Icon (group III); and 11.094 ± 1.856 for Nano SEAL (group IV). Intergroup comparison revealed statistically significant differences in SBS between groups I and II ( P < 0.001), groups II and III ( P < 0.001), and groups III and IV ( P < 0.001). There was no significant difference between groups II and IV. All groups delineated that the adhesive failure was significantly more among all groups. Conclusion Using an infiltrating resin as a pretreatment method can effectively enhance SBS between ceramic and demineralized enamel.