title: Proximal contact formation with different restorative materials and techniques.
abstract: OBJECTIVE
  To determine, whether different tooth colored materials and application techniques influence the proximal contact strengths (PCS) in vitro.
  
  
  METHODS
  Standardized MO-cavities for direct restorations were prepared into 360 artificial lower first molars. Eight groups were formed (n = 45) and restored with amalgam (1), low (2, 3), medium (4, 5) and high (6, 7) viscosity hybrid composites and compared to the original contact strengths of the unprepared teeth (8). The restored teeth were mounted into a socket simulating physiological tooth mobility. PCS were quantified by measuring the forces necessary for passing the proximal contact with floss under standardized conditions using a universal testing machine.
  
  
  RESULTS
  PCS ranged from 1.32 +/- 0.56 N for the low viscosity composite to 9.90 +/- 1.98 N for the Amalgam restoration. Medium (5.65 +/- 1.08 N) and high viscosity hybrid composites (5.90 +/- 1.45 N) inserted in a multi-layer technique showed no statistically significant differences to the original PCS of the unprepared teeth (5.76 +/- 0.53 N).
authors.affiliation: Department of Restorative Dentistry, School of Dental Medicine, Ruprecht-Karls-University, Heidelberg, Germany.
authors.forename: Filip
authors.initials: F
authors.lastname: Klein
authors.forename: Agnes K
authors.initials: AK
authors.lastname: Keller
authors.forename: Hans Jörg
authors.initials: HJ
authors.lastname: Staehle
authors.forename: Christof E
authors.initials: CE
authors.lastname: Dörfer
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins; D003723:Dental Amalgam; D003742:Dental Devices, Home Care; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003970:Diastema / Q000517:prevention & control*; D005502:Food; D006801:Humans; D008422:Materials Testing; D008434:Matrix Bands; D008963:Molar; D018709:Statistics, Nonparametric; D014783:Viscosity
chemical_list: D003188:Composite Resins; C113049:Solitaire composite resin; C121818:Tetric ceram; C452226:tetric flow composite resin; D003723:Dental Amalgam