title: Surface roughness and wear of resin cements after toothbrush abrasion.
abstract: Increased surface roughness and wear of resin cements may cause failure of indirect restorations. The aim of this study was to evaluate quantitatively the surface roughness change and the vertical wear of four resin cements subjected to mechanical toothbrushing abrasion. Ten rectangular specimens (15 × 5 × 4 mm) were fabricated according to manufacturer instructions for each group (n = 10): Nexus 3, Kerr (NX3); RelyX ARC, 3M ESPE (ARC); RelyX U100, 3M ESPE (U100); and Variolink II, Ivoclar/Vivadent (VL2). Initial roughness (Ra, µm) was obtained through 5 readings with a roughness meter. Specimens were then subjected to toothbrushing abrasion (100,000 cycles), and further evaluation was conducted for final roughness. Vertical wear (µm) was quantified by 3 readings of the real profile between control and brushed surfaces. Data were subjected to analysis of variance, followed by Tukey's test (p < 0.05). The Pearson correlation test was performed between the surface roughness change and wear (p < 0.05). The mean values of initial/final roughness (Ra, µm)/wear (µm) were as follows: NX3 (0.078/0.127/23.175); ARC (0.086/0.246/20.263); U100 (0.296/0.589/16.952); and VL2 (0.313/0.512/22.876). Toothbrushing abrasion increased surface roughness and wear of all resin cements tested, although no correlation was found between those variables. Vertical wear was similar among groups; however, it was considered high and may lead to gap formation in indirect restorations.
authors.affiliation: Endodontics and Dental Materials, Department of Operative Dentistry, Bauru School of Dentistry, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Sérgio Kiyoshi
authors.initials: SK
authors.lastname: Ishikiriama
authors.affiliation: Endodontics and Dental Materials, Department of Operative Dentistry, Bauru School of Dentistry, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Ordoñéz-Aguilera
authors.affiliation: Endodontics and Dental Materials, Department of Operative Dentistry, Bauru School of Dentistry, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Rafael Massunari
authors.initials: RM
authors.lastname: Maenosono
authors.affiliation: Endodontics and Dental Materials, Department of Operative Dentistry, Bauru School of Dentistry, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Fernanda Lessa Amaral
authors.initials: FL
authors.lastname: Volú
authors.affiliation: Endodontics and Dental Materials, Department of Operative Dentistry, Bauru School of Dentistry, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Rafael Francisco Lia
authors.initials: RF
authors.lastname: Mondelli
mesh_terms: D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D019554:Dental Restoration Wear; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012016:Reference Values; D019279:Resin Cements / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors; D014072:Tooth Abrasion; D014099:Toothbrushing
chemical_list: C433206:Nexus; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; C103502:Variolink; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate