title: In vivo and in vitro evaluation of Class II composite resin restorations with different matrix systems.
abstract: OBJECTIVE
  To investigate in vivo and in vitro Class II composite restorations performed with two matrix and wedge systems.
  
  
  METHODS
  One hundred nine Class II restorations were performed in 23 patients, 59 with metallic matrices and wooden wedges (group 1) and 50 with polyester matrices and reflective wedges (group 2). All cavities were restored using Single Bond and P-60 (3M ESPE). In the metal matrix group, polymerization was performed from the occlusal, and in the polyester group through the reflective wedge. To assess microleakage, 40 proximal standard slot cavities were prepared in 20 noncarious human third molars. In the mesial cavity, the gingival margin was located at the enamel level, and in the distal cavity at the cementum/dentin. Specimens were randomly divided into two groups (n = 20) and restored with Single Bond, Z-250 (3M ESPE), and the same techniques used in the in vivo study: metal matrix/wooden wedge (group 1) and polyester matrix/reflective wedge (group 2). Specimens were thermocycled (500 times, 5 degrees C to 55 degrees C), then isolated with nail varnish and immersed in fuchsin for 8 h. Specimens were sectioned longitudinally and microleakage was assessed under magnification (40X) using a standard scoring system.
  
  
  RESULTS
  Data were subjected to the chi-square test, Mann-Whitney U-test, and Kruskal-Wallis H-test. Matrix systems presented similar results in the clinical evaluation and the in vitro microleakage test of Class II composite restorations. Dye leakage was minimal at enamel margins, and statistically lower (p < 0.05) than at cementum/dentin margins.
  
  
  CONCLUSIONS
  The different matrix systems had no influence on clinical performance or in vitro sealing ability of Class II composite restorations.
authors.affiliation: School of Dentistry, Federal University of Pelotas, RS, Brazil.
authors.forename: Maximiliano Sérgio
authors.initials: MS
authors.lastname: Cenci
authors.forename: Rafael Guerra
authors.initials: RG
authors.lastname: Lund
authors.forename: Cecília Luiz
authors.initials: CL
authors.lastname: Pereira
authors.forename: Ricardo Marins
authors.initials: RM
authors.lastname: de Carvalho
authors.forename: Flávio Fernando
authors.initials: FF
authors.lastname: Demarco
mesh_terms: D000293:Adolescent; D000328:Adult; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation; D003739:Dental Cementum / Q000473:pathology; D003743:Dental Enamel / Q000473:pathology; D003763:Dental Leakage / Q000145:classification; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000145:classification* / Q000295:instrumentation; D003804:Dentin / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008422:Materials Testing; D008434:Matrix Bands / Q000145:classification*; D008875:Middle Aged; D011091:Polyesters; D013499:Surface Properties; D014934:Wood
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; C438835:Filtek P60 Composite Resin; C444701:Filtek Z250; D011091:Polyesters; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate