title: Randomised trial of resin-based restorations in Class I and Class II beveled preparations in primary molars: 48-month results.
abstract: OBJECTIVE
  This randomised clinical trial evaluated the survival rate of resin-based restorations in Class I and Class II beveled preparations in primary molars, over 48 months.
  
  
  METHODS
  Forty-eight children received 141 restorations in beveled cavosurface margin preparations in primary molars randomly assigned by a lottery method: 46 received treatment with Vitremer Tri-Cure Glass Ionomer System (33 Class I and 13 Class II restorations); 51 received treatment with Freedom (36 Class I and 15 Class II restorations); 44 received treatment with TPH Spectrum (30 Class I and 14 Class II restorations). Two calibrated examiners (weight kappa> or =0.85) evaluated the restorations using the modified USPHS criteria and visible plaque index score at baseline and after 12, 24, 36 and 48 months. Cox regression with survival analysis and logistic regression evaluated the clinical performance of restorations.
  
  
  RESULTS
  After 48 months, 11 teeth had exfoliated, 16 restorations were dropouts, 83 restorations were clinically successful of which 26 had used Vitremer, 32 had used Freedom and 25 had used TPH Spectrum. Thirty-one restorations failed because of secondary caries, fractures and loss of retention. The cumulative survival was 73.9%, 83.4% and 79.6%, respectively for Vitremer, Freedom and THP Spectrum with no differences among materials (Log Rank Mantel-Cox, p>0.05). However, the Class II cavity preparation reduced the survival of the restorations (OR=5.1) for all materials evaluated (p>0.05).
  
  
  CONCLUSIONS
  The life expectancy of Vitremer, Freedom and THP Spectrum in Class I and Class II restorations could be comparable after 48 months.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Márcia Pereira
authors.initials: MP
authors.lastname: Alves dos Santos
authors.forename: Ronir Raggio
authors.initials: RR
authors.lastname: Luiz
authors.forename: Lucianne Cople
authors.initials: LC
authors.lastname: Maia
mesh_terms: D002648:Child; D002675:Child, Preschool; D003116:Color; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000209:etiology; D003737:Dental Cavity Preparation / Q000145:classification* / Q000379:methods; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003774:Dental Plaque Index; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification*; D005260:Female; D005500:Follow-Up Studies; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000379:methods; D008297:Male; D008422:Materials Testing; D008963:Molar / Q000473:pathology*; D013499:Surface Properties; D016019:Survival Analysis; D014094:Tooth, Deciduous / Q000473:pathology*; D016896:Treatment Outcome
chemical_list: D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; C477332:Freedom Compomer; D005899:Glass Ionomer Cements; C467914:TPH spectrum; C084550:Vitremer