title: The effect of occlusal loading on the microleakage of class V restorations.
abstract: OBJECTIVE
  This in vitro study evaluated the microleakage of Class V cavities restored with a resin composite and different adhesive systems after occlusal loading.
  
  
  METHODS
  Standardized box-shaped Class V cavities were prepared on the buccal side of 135 non-carious human premolars. The teeth were randomly divided into three groups of 45 premolars each and restored as follows: Group 1-two-step total-etch adhesive (Single Bond, 3M) + resin composite (Supreme, 3M ESPE); Group 2-two-step self-etch adhesive (Clearfil SE, Kuraray) + resin composite and Group 3-one-step self-etch adhesive (Xeno III, Dentsply) + resin composite. The restorations were finished with aluminum oxide discs (Sof-Lex, 3M). Fifteen teeth in each group received 10,000 x 100 N and 250 N occlusal loads, respectively, and the remaining 15 teeth served as the control. The premolars were immersed in 2% methylene blue for 24 hours. The dye penetration was examined under a stereomicroscope, and the results were statistically analyzed by Kruskal Wallis, Mann-Whitney U and Wilcoxon Signed Rank tests to determine differences between the groups.
  
  
  RESULTS
  Gingival margins showed more dye penetration than occlusal margins in all the tested groups (p<0.05). In all the tested adhesive systems, 100 N occlusal loading did not change dye penetration; however, Groups 1 and 2 exhibited better marginal sealing than Group 3 at the enamel margins under 250 N occlusal loading.
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, it may be concluded that enamel margins provided better marginal sealing than dentin/cementum margins and the two-step self-etch adhesive exhibited better marginal sealing than an all-in-one adhesive at the enamel margins under 250 N occlusal loading.
authors.affiliation: Faculty of Dentistry, Department of Operative Dentistry & Endodontics, University of Gazi, Emek-Ankara, Turkey. hacer@gazi.edu.tr
authors.forename: Hacer Deniz
authors.initials: HD
authors.lastname: Arisu
authors.forename: Mine Betül
authors.initials: MB
authors.lastname: Uçtasli
authors.forename: Evrim
authors.initials: E
authors.lastname: Eligüzeloglu
authors.forename: Suat
authors.initials: S
authors.lastname: Ozcan
authors.forename: Hüma
authors.initials: H
authors.lastname: Omürlü
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001732:Bite Force; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification; D003739:Dental Cementum / Q000473:pathology; D003743:Dental Enamel / Q000473:pathology; D003763:Dental Leakage / Q000145:classification*; D018772:Dental Marginal Adaptation; D003775:Dental Polishing / Q000379:methods; D003793:Dental Restoration, Permanent / Q000145:classification*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008751:Methylene Blue; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
chemical_list: C438313:Clearfil SE Bond; D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C487957:Xeno III; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D000537:Aluminum Oxide; D008751:Methylene Blue