title: Bonding effectiveness and multi-interfacial characterization of two direct buildup resin core systems bonded to post-space dentin.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the bonding effectiveness of two resin core buildup systems using conventional methods in the field of adhesive dentistry and a new non-destructive method.
  
  
  METHODS
  Twenty-four single-rooted human teeth were built up with dual-cure one-step self-etch adhesive and composite systems (SY1: Clearfil DC bond and Clearfil DC core automix, SY2: Clearfil bond SE one and Clearfil DC core automix one). The prepared samples were sectioned into approximately 1 × 1-mm-thick beams and subjected to micro-tensile bond strength (μTBS) testing (n = 24). The fractured beams after μTBS testing were analyzed by SEM and energy-dispersive X-ray (EDX) spectrometry. The three teeth filled with each resin core system were sectioned and embedded in epoxy resin to observe the dentin-bonding interface under TEM (n = 6). Moreover, three of each resin core-filled teeth without any processing were examined using μCT (n = 6).
  
  
  RESULTS
  Two-way ANOVA revealed that the two factors "root region" (p < 0.001, F = 15.22) and "system" (SY1 < SY2; p < 0.001, F = 22.52) had a significant influence. The μTBS gradually decreased from the coronal side to the apical side of the root canal. Morphological evaluation revealed that SY2 was superior in terms of resin curing at the apical side. μCT non-destructive evaluation clearly revealed gap formation in SY1.
  
  
  CONCLUSIONS
  SY2, which included a new light-independent catalyst, showed better bonding effectiveness and adhesive interface to dentin compared to that of SY1.
  
  
  CONCLUSIONS
  The new catalyst, which is activated by contact with adhesive and resin composite, can be used for resin core buildup restorations.
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan. mine@dent.osaka-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mine
authors.affiliation: Division for Interdisciplinary Dentistry, Osaka University Dental Hospital, Osaka, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Miura
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Minamino
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Taichi
authors.initials: T
authors.lastname: Iwashita
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Hayaki
authors.initials: H
authors.lastname: Nakatani
authors.affiliation: Research Center for Ultra-high Voltage Electron Microscopy, Osaka University, Osaka, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishida
authors.affiliation: Division for Interdisciplinary Dentistry, Osaka University Dental Hospital, Osaka, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Takeshige
authors.affiliation: Department of Fixed Prosthodontics, Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita City, Osaka, 565-0871, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yatani
mesh_terms: D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013718:Tensile Strength; D055114:X-Ray Microtomography
chemical_list: C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D019279:Resin Cements
keywords: Bonding effectiveness; Direct buildup resin core; Interfacial characterization; Micro-computed tomography; Mild self-etch adhesive; Non-destructive observation