J Adhes Dent 21 (2019), No. 4 23. Aug. 2019
J Adhes Dent 21 (2019), No. 4 (23.08.2019)
Page 329-335, doi:10.3290/j.jad.a42932, PubMed:31432047
Effect of Er:YAG and Burs on Coronal Dentin Bond Strength Stability
Comba, Allegra / Baldi, Andrea / Michelotto Tempesta, Riccardo / Cedrone, Aristea / Carpegna, Giorgia / Mazzoni, Annalisa / Breschi, Lorenzo / Alovisi, Mario / Pasqualini, Damiano / Scotti, Nicola
Purpose: To evaluate the immediate and aged bond strength and interfacial nanolaekage of different adhesives and protocols on dental elements prepared with diamond burs and Er:YAG laser.
Materials and Methods: Forty molar crowns were flattened and a standardized smear layer was created. Teeth were divided into two main groups according to the dentin cutting technique: 1. Er:YAG laser for 30 s at 30 Hz repetition rate, 250 mJ energy per pulse, and water spray irrigation set at level 8; and 2. diamond bur. Each group was then divided into subgroups according to the adhesive protocol: SG1: dentin etching for 15 s followed by universal adhesive application (All Bond Universal, Bisco); SG2: universal adhesive application (All Bond Universal); SG3: two-step self-etch adhesive application (Clearfil SE Bond 2, Kuraray Noritake); SG4: etching followed by 3-step etch-and-rinse adhesive application (Optibond FL, Kerr). After curing the adhesives, resin composite buildups of 4 mm were made and specimens were sectioned to obtain 1-mm-thick sticks in accordance with the μTBS test technique. Sticks were stressed to failure at baseline and after 6 months of storage in artificial saliva. Three teeth per group were prepared for nanoleakage interfacial analyses. Data were statistically analyzed with three-way ANOVA and Tukey's post-hoc test (p < 0.05).
Results: A significant difference in bond strengths was found for treatment, aging, and adhesive protocol. Nanoleakage analysis showed higher marginal infiltration in Er:YAG-treated groups both at baseline and after aging.
Conclusions: Surfaces prepared with diamond burs presented higher bond strengths than did those prepared with Er:YAG laser. Adhesive protocols and aging could influence the adhesive-dentin interface. Further studies are necessary to validate the results obtained.
Keywords: adhesion, adhesive interface, bond strength testing, Er:YAG laser