title: Effect of proximal box elevation with resin composite on marginal quality of resin composite inlays in vitro.
abstract: OBJECTIVE
  To evaluate marginal quality and resin-resin transition of lab made resin composite inlays in deep proximal cavities with and without 3 mm proximal box elevation (PBE) using resin composites before and after thermo-mechanical loading (TML).
  
  
  METHODS
  MOD cavities with one proximal box beneath the cementoenamel junction were prepared in 40 extracted human third molars. Proximal boxes ending in dentine were elevated 3 mm with different resin composites (G-Cem, Maxcem Elite as self-adhesive resin cements and Clearfil Majesty Posterior as restorative resin composite in one or three layers bonded with AdheSE), or left untreated. Clearfil Majesty Posterior inlays were luted with Syntac and Variolink II (n = 8). Marginal quality as well as the PBE-composite inlay interface was analyzed under an SEM using epoxy resin replicas before and after thermomechanical loading (100,000 × 50 N and 2500 thermocylces between +5 °C and +55 °C).
  
  
  RESULTS
  Bonding resin composite inlays directly to dentine showed similar amounts of gap-free margins in dentine compared to PBE applied in three consecutive layers (p > 0.05). The groups with self-adhesive resin cements for PBE exhibited significantly more gaps in dentine (p < 0.05).
  
  
  CONCLUSIONS
  With layered resin composite, PBE is effective in indirect resin composite bonding to deep proximal boxes. Self-adhesive resin cements are not suitable for this indication.
authors.affiliation: Department of Operative Dentistry and Endodontics, Dental School, University of Marburg and University Medical Center Giessen and Marburg, Campus Marburg, Georg-Voigt-Strasse 3, 35039 Marburg, Germany.
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Roggendorf
authors.forename: Norbert
authors.initials: N
authors.lastname: Krämer
authors.forename: Christoph
authors.initials: C
authors.lastname: Dippold
authors.forename: Vera E
authors.initials: VE
authors.lastname: Vosen
authors.forename: Michael
authors.initials: M
authors.lastname: Naumann
authors.forename: Anahita
authors.initials: A
authors.lastname: Jablonski-Momeni
authors.forename: Roland
authors.initials: R
authors.lastname: Frankenberger
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001732:Bite Force; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure; D006801:Humans; D007284:Inlays / Q000592:standards*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016628:Replica Techniques; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D019237:Tooth Cervix / Q000648:ultrastructure
chemical_list: D000180:Acrylic Resins; C489662:AdheSE cement; D003188:Composite Resins; D003764:Dental Materials; C528107:G-Cem resin cement; C515955:Maxcem; D019279:Resin Cements; C078484:Syntac dentine adhesive; C541508:clearfil majesty; C103502:Variolink