title: Creating tight proximal contacts for MOD resin composite restorations.
abstract: OBJECTIVE
  The purpose of this study was to compare proximal contact tightness (PCT) of MOD resin composite restorations placed with different matricing protocols.
  
  
  METHODS
  Forty-five ivorine lower right first molars with standardized MOD cavities were equally divided into three groups according to the restoration protocol. Group 1: Sectional matrix (Standard matrix, Palodent, Dentsply) secured with a wedge (Premier Dental Products Co.) and separation ring (BiTine I, Palodent, Dentsply, York, PA, USA) was used to restore the mesial surface first and then removed and repeated for the distal surface. Group 2: Identical to group 1, but separation rings were placed at both the mesial and distal sides (BiTine I+II, Palodent) prior to restoration. Mesial surface was restored followed by distal. Group 3: Walser matrix (O-form, Dr. Walser Dental GmbH) was used. Following composite resin restoration, PCT was measured using the tooth pressure meter. Data were analyzed using analysis of variance and a Tukey post hoc test (p<0.05).
  
  
  RESULTS
  PCT values for mesial contacts were 2.99 ± 0.47N for group 1, 4.57 ± 0.36N for group 2, and 3.03 ± 0.79N for group 3. For the distal contacts, the values were 4.46 ± 0.44N for group 1, 5.12 ± 0.13N for group 2, and 0.76 ± 0.77N for group 3. Significantly tighter contacts were obtained for mesial and distal contacts for group 2 compared to groups 1 and 3 (p<0.05). For groups 1 and 3, mesial contacts were not significantly different (p=0.993), while distal contacts for group 1 were significantly tighter (p<0.001).
  
  
  CONCLUSIONS
  Within the limitations of this study, tighter contacts can be obtained when sectional matrices and separation rings are applied to both proximal surfaces prior to placement of the resin composite in MOD cavities.
authors: Herman Ostrow School of Dentistry, USC, Los Angeles, CA, USA.
authors: M H
authors: MH
authors: Saber
authors: W
authors: W
authors: El-Badrawy
authors: B A C
authors: BA
authors: Loomans
authors: D R
authors: DR
authors: Ahmed
authors: C E
authors: CE
authors: Dörfer
authors: A
authors: A
authors: El Zohairy
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental; D003737:Dental Cavity Preparation / Q000145:classification*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000295:instrumentation / Q000379:methods*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004867:Equipment Design; D006801:Humans; D008348:Manikins; D008434:Matrix Bands; D003765:Models, Dental; D058105:Polymerization; D011312:Pressure; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C092987:Optibond; D019279:Resin Cements; C113300:TPH hybrid