title: Influence of different light curing units on the bond strength of indirect resin composite restorations.
abstract: The aim of this study was to evaluate the influence of different light sources on the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement. The superficial dentin of human third molars was exposed and acid-etched and an adhesive system was applied (Single Bond 2). Four-mm-thick indirect resin composite restorations (Gradia) were fabricated and cemented using a dual-cure resin cement (Rely X). Four light sources were used to polymerize the cement: QTH - Optilux 401; LED1 - L.E.Demetron 1; LED2 - Optilight CL; and LED3--Ultralume 5. The teeth were stored for 24 h and then sectioned, yielding stick-shaped specimens for each group with a bonded area of 1.0 mm(2). The specimens were then tested in a universal testing machine, at a crosshead speed of 1 mm/min. Data were analyzed using ANOVA. Bond strength mean values were: QTH: 22.5 (+/- 8.4); LED1: 22.7 (+/- 9.4); LED2: 21.4 (+/- 10.2); and LED3: 27.3 (+/- 13.8). No statistically significant difference was observed among the experimental groups. The bond strength values when the cement was polymerized using different LED lights were equivalent to the values when the QTH light was used. It can be concluded that the variety of light sources used in the present study did not influence the bond strength of indirect resin composite restorations cemented with a dual-cure resin cement.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, PR, Brazil.
authors.forename: Veridiana
authors.initials: V
authors.lastname: Camilotti
authors.forename: Patricia Grau
authors.initials: PG
authors.lastname: Grullón
authors.forename: Márcio José
authors.initials: MJ
authors.lastname: Mendonça
authors.forename: Paulo Henrique Perlatti
authors.initials: PH
authors.lastname: D'Alpino
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Gomes
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D002484:Cementation / Q000379:methods*; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D055117:Curing Lights, Dental; D003764:Dental Materials / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000379:methods*; D006801:Humans; D008027:Light; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D008422:Materials Testing; D011140:Polyurethanes / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D033081:Shear Strength; D013674:Technology, Dental / Q000295:instrumentation; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; C095997:DCR cement; D003764:Dental Materials; C470230:Gradia; D011140:Polyurethanes; D019279:Resin Cements