title: Bond strength of self-adhesive resin cements to dry and moist dentin.
abstract: This study evaluated the effects of humidity conditions and evaluation times on the dentin bond strength (DBS) of two self-adhesive resin cements (RC). The RC used were: RelyX Unicem (3M ESPE) and Clearfil SA Cement (Kuraray Med.). One hundred and twenty coronal portions of bovine incisors (n = 10) were used. Buccal surfaces were abraded in order to expose a flat dentinal surface (180-grit SiC) and to standardize the smear layer formation (600-grit SiC). The humidity conditions tested were: dry (air-dried for 10 s), slightly moist (water application with disposable applicator on dried dentin and water excess removed with absorbent paper), and moist (same application without water removal). The RC were used according to the manufacturers' recommendations and were applied to prepolymerized resin discs (2 mm thick; Sinfony, 3M ESPE), which were subsequently bonded to the dentin surfaces. After 24 h, half of the teeth were prepared for the microtensile bond strength test, while the other half were stored in water for 6 months and tested in tension (0.5 mm/min) until failure. A 3-way analysis of variance and the Tukey test were performed (preset alpha of 0.05). No RC showed any reduction of DBS after 6 months, and no significant difference was observed between them. The moist dentin increased the bond strength of Clearfil SA Cement for both periods of time. Humidity conditions can change the DBS; however, the study's results were product-dependent.
authors.affiliation: State University of Campinas, Piracicaba Dental School, Department of Restorative Dentistry, PiracicabaSP, Brazil.
authors.forename: Carolina Bosso
authors.initials: CB
authors.lastname: André
authors.forename: Thaiane Rodrigues
authors.initials: TR
authors.lastname: Aguiar
authors.forename: Ana Paula Almeida
authors.initials: AP
authors.lastname: Ayres
authors.forename: Glaucia Maria Bovi
authors.initials: GM
authors.lastname: Ambrosano
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003804:Dentin / Q000737:chemistry* / Q000187:drug effects; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006813:Humidity; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C581302:Clearfil SA; D017220:Dentin-Bonding Agents; C483701:Rely X Unicem; D019279:Resin Cements; D014867:Water