Hamadan University of Medical Sciences Avicenna Journal of Dental Research 2423-7582 10 3 2018 09 01 Effect of Trypsin/EDTA Conditioning on Marginal Microleakage of Class V Composite Restorations Bonded With a One-Step Selfetch Adhesive 101 106 10.34172/ajdr.2018.21 EN Shahin Kasraei https://orcid.org/0000-0003-0167-4704 Matin Kordestani https://orcid.org/0000-0002-3122-1311 Ebrahim Yarmohammadi Hesamaldin Pashaei Journal Article 10.34172/ajdr.2018.21 2018 07 23 2018 09 03 Background: Sodium hypochlorite and EDTA solutions are used in the preparation of dentin surfaces, which may increase the bond strength of the composite restorations and decrease their microleakage scores. This in-vitro experimental study aimed to assess the effect of dentin surface conditioning with EDTA/trypsin solution prior to bonding procedure with Clearfil S3 Bond on the microleakage of class V composite restorations. Methods: Class V cavities were prepared on the buccal and lingual surfaces of 18 human premolars (n=18) and randomly assigned into two groups. In the control group, Clearfil S3 Bond was applied on the dentin surfaces. While in the experimental group, before applying Clearfil S3 Bond, the surfaces were conditioned with EDTA/trypsin solution. The cavities on the teeth were then incrementally filled with Filtek Z250 light-cure composite. Afterward, all the samples were thermocycled for 500 cycles. Next, the specimens were immersed in methylene blue solution for 72 hours. The restorations were sectioned buccolingually through the center of the restorations with a diamond disk. Then, microleakage at the tooth- restoration interface was evaluated in the enamel and dentin margins blindly using dye penetration under a stereomicroscope at ×40 magnification. Finally, data were statistically analyzed by Mann-Whitney U test. Results: The results showed no significant differences between two groups regarding the microleakage scores of the enamel and dentin edges. In addition, in all sections and edges of the experimental group, decreased microleakage scores were attained compared to the control specimens (P<0.03). Conclusions: Regarding the limitations of the present study, the preparation of dentin surfaces with EDTA/trypsin solution before applying Clearfil S3 Bond resulted in the decreased microleakage scores compared to unprepared surfaces.