title: A randomized clinical trial on proximal contacts of posterior composites.
abstract: OBJECTIVE
  The objective of this study was to investigate clinical changes in proximal contact strength inserting Class II composite resin restorations according to one of three randomly assigned protocols.
  
  
  METHODS
  Seventy-one Class II restorations (MO/DO) were placed by two calibrated operators. Restorations were randomly assigned to one of three groups: one using a circumferential and two a sectional matrix system with separation rings. Proximal contacts were measured by one independent observer with a Tooth Pressure Meter immediately before treatment, and directly after finishing the restoration.
  
  
  RESULTS
  Compared to the situation before treatment groups with a sectional matrix system resulted in a statistical significant stronger mean proximal contact strengths (p<0.05), whereas the use of a circumferential matrix system with hand-instrument resulted in a lower proximal contact strength (p<0.05).
  
  
  CONCLUSIONS
  Class II posterior composite resin restorations placed with a combination of sectional matrices and separation rings resulted in a stronger proximal contact than when a circumferential matrix system was used.
authors.affiliation: Department of Preventive and Restorative Dentistry, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. b.loomans@dent.umcn.nl
authors.forename: B A C
authors.initials: BA
authors.lastname: Loomans
authors.forename: N J M
authors.initials: NJ
authors.lastname: Opdam
authors.forename: F J M
authors.initials: FJ
authors.lastname: Roeters
authors.forename: E M
authors.initials: EM
authors.lastname: Bronkhorst
authors.forename: R C W
authors.initials: RC
authors.lastname: Burgersdijk
authors.forename: C E
authors.initials: CE
authors.lastname: Dörfer
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008434:Matrix Bands; D008875:Middle Aged; D011140:Polyurethanes / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes