Influence of Storage Solution on Shear Bond Strength Values

Objectives: Evaluating the influence of the storage solution on shear bond strength (SBS) values of an experimental total-etch bonding system (DMG, Germany) in vitro. Methods: 100 bovine teeth were prepared, cleaned, randomly assigned to five groups and stored for sixty days in different storage solutions (A: tap water, B: 0.9% NaCl, C: 0.1% thymol, D: 10% formalin and E: 3% hydrogen peroxide). After this period, the vestibular surfaces were removed and roughened to expose both a flat enamel (e) and a dentin (d) surface, respectively. A split mold (inner diam. 3.5 mm) was placed onto the prepared surfaces, composite resin (Ecusit, DMG) was placed in increments and light cured to build resin sticks on the enamel and the dentin surfaces. Samples were stored in distilled water for 24 hours. The specimens were subjected to SBS tests using an Instron Model 4202 with a crosshead speed of 0.5 mm/min. Statistical analysis (ANOVA, t-test) was performed using the SPSS program. Results: The mean SBS (in Mpa) are as follows: Ae – 25.2 ± 4.7, Ad – 20.3 ± 3.7, Be – 23.8 ± 6.1, Bd – 12,4 ± 3.9, Ce – 24.1 ± 6.3, Cd – 15.4 ± 5.2, De – 29.6 ± 7.0, Dd – 18.4 ± 6.5, Ee – 28.1 ± 8.2, Ed – 16.1 ± 5.4. ANOVA showed significant differences between groups (p < 0.01). In detail, t-tests proved that groups D and E had significantly higher SBS values than B and C with respect to enamel. Regarding dentin, groups D and A had significantly higher SBS than B and C. Conclusion: The obtained values for shear bond strength on bovine specimens are influenced by the composition of the storage solution.