2021 Volume 64 Issue 3 Pages 227-236
Purpose: The purpose of this study was to determine the influence of a tooth conditioner containing phosphoric acid ester monomer on the bond performance of a resin-based luting cement to saliva contaminated surfaces based on shear bond strength (SBS) tests and surface free energy (SFE) measurements.
Materials and Methods: Three conditioners for saliva contaminated tooth surfaces were used: Katana Cleaner (KC, Kuraray Noritake Dental), Ultra-Etch (UE, Ultradent Products), and Multi Etchant (ME, Yamakin). Panavia V5 (Kuraray Noritake Dental) was used as a resin-based luting agent. Bovine enamel and dentin surfaces were ground with SiC papers, ending at #320 grit. For saliva contaminated tooth surfaces, 10 μl of human saliva was applied to the ground surface. Uncontaminated tooth surfaces were set as a control group. The saliva contaminated specimens were divided into four groups, treated with the different conditioners described above (KC, UE, and ME group) or without any treatment (SC group). A stainless-steel metal ring was placed over the bonding area, and the luting agent was condensed into the ring and light irradiated. The assembled specimens were stored in 37°C water for 24 h. Half of the specimens in each group were subjected to thermal cycling (TC) 10,000 times between 5 and 55°C, with a dwell time of 30 s. The other half of the specimens in each group formed a baseline group. SBS tests were conducted after each storage condition. For SFE determinations, specimens were prepared as for the SBS tests. The contact angles of three test liquids that have known SFE parameters were measured using a contact angle meter. In addition, SEM observations were performed of surfaces treated with the three different conditioners after saliva contamination.
Results: In the baseline groups, although the SC groups showed a significantly lower SBS value than the control groups in both enamel and dentin, the conditioner treated groups showed higher SBS values than the SC groups. In the TC groups, UE showed a significantly higher enamel SBS than the other groups, but KC showed a significantly higher dentin SBS than the other groups. Although the SC groups showed significantly lower SFEs than the control groups in both enamel and dentin, the SFEs after conditioner treatment were material dependent.
Conclusion: After salival contamination of tooth surfaces, the conditioners tested might be useful in enhancing the bond performance of the resin-based luting cement due to modification of the contaminated tooth surfaces. The SFEs of treated surfaces differed with different conditioners depending on their conditioning mechanisms.
