title: Effect of proximal box elevation with resin composite on marginal quality of ceramic inlays in vitro.
abstract: OBJECTIVE
  The objective of this study was to evaluate the marginal quality and resin-resin transition of milled CAD/CAM glass-ceramic inlays in deep proximal cavities with and without 3-mm proximal box elevation (PBE) using resin composites before and after thermomechanical loading.
  
  
  METHODS
  MOD cavities with one proximal box beneath the cementoenamel junction were prepared in 48 extracted human third molars. Proximal boxes ending in dentin were elevated for 3 mm with different resin composites (RelyX Unicem, G-Cem, and 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. IPS Empress CAD inlays were luted with Syntac and Variolink II (n = 8). Marginal quality as well as the PBE-ceramic interface were analyzed under an SEM using epoxy resin replicas before and after thermomechanical loading (100,000 × 50 N and 2,500 thermocycles between +5°C and +55°C).
  
  
  RESULTS
  Bonding glass-ceramic directly to dentin showed the highest amounts of gap-free margins in dentin (92%, p < 0.05). Bonded resin composite applied in three layers achieved 84% gap-free margins in dentin; PBE with self-adhesive resin cements exhibited significantly more gaps in dentin (p < 0.05).
  
  
  CONCLUSIONS
  With a meticulous layering technique and bonded resin composite, PBE may be an alternative to ceramic bonding to dentin. Self-adhesive resin cements seem not suitable for this indication.
  
  
  CONCLUSIONS
  For deep proximal boxes ending in dentin, a PBE may be an alternative to conventional techniques.
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. frankbg@med.uni-marburg.de
authors.forename: Roland
authors.initials: R
authors.lastname: Frankenberger
authors.forename: Julia
authors.initials: J
authors.lastname: Hehn
authors.forename: Jan
authors.initials: J
authors.lastname: Hajtó
authors.forename: Norbert
authors.initials: N
authors.lastname: Krämer
authors.forename: Michael
authors.initials: M
authors.lastname: Naumann
authors.forename: Andreas
authors.initials: A
authors.lastname: Koch
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Roggendorf
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry*; D001732:Bite Force; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D017076:Computer-Aided Design; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007284:Inlays; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D019237:Tooth Cervix / Q000648:ultrastructure
chemical_list: D000180:Acrylic Resins; C489662:AdheSE cement; D000538:Aluminum Silicates; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C528107:G-Cem resin cement; C520133:IPS e.max CAD LT; C515955:Maxcem; C483701:Rely X Unicem; D019279:Resin Cements; C078484:Syntac dentine adhesive; C541508:clearfil majesty; D003776:Dental Porcelain; C078519:leucite; C103502:Variolink; C023506:Glass ceramics