title: Longevity of posterior restorations in primary teeth: results from a paediatric dental clinic.
abstract: OBJECTIVE
  The aim of this retrospective study was to evaluate the longevity of restorations in the posterior primary teeth of children attending to a public paediatric dental clinic and to test the factors associated with failures.
  
  
  METHODS
  Patient records of 329 children (162 boys and 166 girls) were used for collecting and analyzing data. A total of 565 restorations in primary teeth were included in the study. All children enrolled in the study were classified as high caries risk. The longevity of restorations from their placement until failure (up to 4 years of follow-up) was assessed using the Kaplan-Meier survival curves with log-rank test. Multivariate Cox regression analysis with shared frailty (p<0.05) was used to assess the factors associated with failures.
  
  
  RESULTS
  Up to 4 years of follow-up, the annual failure rates were 9.5% for composite fillings, 12.2% for light-cured glass ionomer restorations, and 12.9% for conventional glass ionomer restorations with statistical difference between the materials (p=0.014). Glass ionomer restorations had a higher risk of failure over time compared with composites (HR 1.86, 95% CI 1.17-2.97). In crude analysis, Class II restorations showed lower survival rate than Class I restorations (p=0.031) but lost significance after adjustments.
  
  
  CONCLUSIONS
  Our findings suggested that the material influenced the survival rate of primary posterior restorations, with composite presenting the best performance.
  
  
  CONCLUSIONS
  Differences were observed between restorative materials with different properties in primary teeth up to 4 years of follow-up. This study provides valuable information regarding the primary teeth posterior restoration longevity in a paediatric population with restorations performed under daily life clinical environment.
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Gabriela Dos Santos
authors.initials: Gdos S
authors.lastname: Pinto
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Luísa Jardim Corrêa
authors.initials: LJ
authors.lastname: Oliveira
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil; Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Pelotas, UFPel, Pelotas, RS, Brazil.
authors.forename: Ana Regina
authors.initials: AR
authors.lastname: Romano
authors.affiliation: Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Pelotas, UFPel, Pelotas, RS, Brazil.
authors.forename: Lisandrea Rocha
authors.initials: LR
authors.lastname: Schardosim
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil; Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Pelotas, UFPel, Pelotas, RS, Brazil.
authors.forename: Maria Laura Menezes
authors.initials: ML
authors.lastname: Bonow
authors.affiliation: Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Pelotas, UFPel, Pelotas, RS, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: Pacce
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Marcos Britto
authors.initials: MB
authors.lastname: Correa
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil; Post-Graduate program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil. Electronic address: ffdemarco@gmail.com.
authors.forename: Flávio Fernando
authors.initials: FF
authors.lastname: Demarco
authors.affiliation: Post-Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil; Department of Social and Preventive Dentistry, School of Dentistry, Federal University of Pelotas, UFPel, Pelotas, RS, Brazil.
authors.forename: Dione Dias
authors.initials: DD
authors.lastname: Torriani
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D001641:Bicuspid / Q000473:pathology; D002648:Child; D003188:Composite Resins / Q000737:chemistry; D004245:DMF Index; D003733:Dental Caries Susceptibility / Q000502:physiology; D003737:Dental Cavity Preparation / Q000145:classification; D003738:Dental Cements / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000145:classification / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008963:Molar / Q000473:pathology; D019279:Resin Cements / Q000737:chemistry; D012189:Retrospective Studies; D012822:Silicon Dioxide / Q000737:chemistry; D016019:Survival Analysis; D014094:Tooth, Deciduous / Q000473:pathology*; D015040:Zirconium / Q000737:chemistry
chemical_list: C554641:Adper single bond 2; C084111:Charisma composite resin; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D005899:Glass Ionomer Cements; D019279:Resin Cements; C577192:Vitrofil LC; C083568:Z100 composite resin; C065770:Herculite XR; D012822:Silicon Dioxide; D015040:Zirconium
keywords: Glass ionomer cements; Longevity; Posterior restorations; Primary teeth; Resin composite; Survival