J Adhes Dent 19 (2017), No. 6 12. Jan. 2018
J Adhes Dent 19 (2017), No. 5 (19.12.2017)
Page 409-416, doi:10.3290/j.jad.a38999, PubMed:28944377
Mini-interfacial Fracture Toughness of a Multimode Adhesive Bonded to Plasma-treated Dentin
Ayres, Ana Paula Almeida / Pongprueksa, Pong / De Munck, Jan / Gré, Cristina Parise / Nascimento, Fábio Dupart / Giannini, Marcelo / Van Meerbeek, Bart
Purpose: To investigate the bonding efficacy of a multimode adhesive to plasma-treated and -untreated (control) dentin using a mini-interfacial fracture toughness (mini-iFT) test.
Materials and Methods: Twenty human molars were used in a split-tooth design (n = 10). The adhesive Scotchbond Universal (SBU; 3M ESPE) was applied in etch-and-rinse (E&R) and self-etch (SE) modes. Mid-coronal dentin was exposed and covered with a standardized smear layer ground to 320 grit. One half of each dentin surface received 15 s of non-thermal atmospheric plasma (NTAP), while the other half was covered with a metallic barrier and kept untreated. Following the E&R mode, dentin was plasma treated immediately after phosphoric acid etching. SBU and a resin-based composite were applied to dentin following the manufacturer's instructions. Six mini-iFT specimens were prepared per tooth (1.5 x 2.0 x 16 to 18 mm), and a single notch was prepared at the adhesive-dentin interface using a 150-μm diamond blade under water cooling. Half of the mini-iFT specimens were immediately loaded until failure in a 4-point bending test, while the other half were first stored in distilled water for 6 months. After testing, the exact dimensions of the notch were measured with a measuring optical microscope, from which ΚIc was determined.
Results: Three-way ANOVA revealed higher mini-iFT for SBU applied in E&R than SE mode for both storage times, irrespective of NTAP treatment.
Conclusion: Overall, mini-iFT did not decrease for any of the experimental groups upon 6-month aging, while plasma treatment did not show a direct beneficial effect on mini-iFT of SBU applied in either E&R or SE mode.
Keywords: plasma, dentin, bonding, interface, multimode adhesive, fracture toughness