title: A comparison of the marginal and internal adaptation of amalgam and resin composite restorations in small to moderate-sized Class II preparations of conventional design.
abstract: OBJECTIVE
  The purpose of this study was to compare the marginal and internal adaptation of a non-gamma-2 amalgam and an ultrafine compact-filled light-cured composite in small to moderate-sized Class II restorations of conventional design.
  
  
  METHODS
  Fifty recently extracted human premolar and permanent molar teeth were selected for the study. The teeth were restored with either a non-gamma-2 amalgam alloy or a light-cured resin composite. The marginal adaptation of the restorative materials to the proximal surface outline form of each preparation was assessed. The mean percentages of perfect margins, marginal fissuring, and underfilled margins for the 2 restorative materials were recorded and statistically analyzed.
  
  
  RESULTS
  Both materials performed equally well in the buccal and lingual segments of the proximal box. At the cervical margin, the resin composite restorations showed a significantly greater number of imperfect margins and marginal fissuring. The incidence of underfilled margins was low for both restorative materials even at the cervical margin.
  
  
  CONCLUSIONS
  Although there was some cause for concern about the marginal adaptation of the resin composite restorations along the cervical margin, the findings support contemporary teaching that small to moderately sized conventional Class II preparations may justifiably be restored with an appropriate resin composite.
authors.affiliation: Unit of Operative Dentistry and Endodontology, Turner Dental School, University Dental Hospital of Manchester, Higher Cambridge Street, Manchester M15 6FH, England.
authors.forename: W V
authors.initials: WV
authors.lastname: Duncalf
authors.forename: N H
authors.initials: NH
authors.lastname: Wilson
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003737:Dental Cavity Preparation / Q000145:classification* / Q000379:methods; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003775:Dental Polishing; D003793:Dental Restoration, Permanent / Q000145:classification* / Q000379:methods; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008963:Molar; D019279:Resin Cements; D012822:Silicon Dioxide; D018709:Statistics, Nonparametric; D013499:Surface Properties; D019237:Tooth Cervix / Q000648:ultrastructure; D015040:Zirconium
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; C033470:Dispersalloy; D012822:Silicon Dioxide; D003723:Dental Amalgam; D015040:Zirconium