title: Is an oxygen inhibited layer required for bonding of resin-coated gutta-percha to a methacrylate-based root canal sealer?
abstract: Removal of the oxygen inhibition layer from the surface of resin-coated gutta-percha cones during packaging has been hypothesized for their weak adhesion to a methacrylate-based root canal sealer, resulting in their frequent delamination from the sealer after root canal obturation. This study examined the feasibility of creating oxygen inhibition layers on resin-coated gutta-percha cones via the adjunctive application of a dual-cured dentin adhesive just before bonding. Composite cylinders were bonded with EndoREZ to flat, resin-coated gutta-percha disks and similar disks that were post-treated with Prime&Bond NT Dual Cure adhesive and stressed to failure using a modified microshear testing design. Although shear strengths for both groups were relatively low, a 5-fold increase in shear strength was observed after adhesive application, with complex interfacial failures instead of complete sealer delamination from the resin-coating. In-situ dentin adhesive application appears to have merits in enhancing the coupling of resin-coated gutta-percha to methacrylate sealers.
authors.affiliation: Pediatric Dentistry and Orthodontics, The University of Hong Kong, Pokfulam, China.
authors.forename: Noriko
authors.initials: N
authors.lastname: Hiraishi
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Loushine
authors.forename: Michele
authors.initials: M
authors.lastname: Vano
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Chieffi
authors.forename: R Norman
authors.initials: RN
authors.lastname: Weller
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
mesh_terms: D000704:Analysis of Variance; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004356:Drug Storage; D006171:Gutta-Percha / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010100:Oxygen; D019279:Resin Cements / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D003188:Composite Resins; C095997:DCR cement; D017220:Dentin-Bonding Agents; C481259:EndoRez; D019279:Resin Cements; D012387:Root Canal Filling Materials; D006171:Gutta-Percha; D010100:Oxygen