title: Comparison of pattern of failure of resin composite restorations in non-carious cervical lesions with and without occlusal wear facets.
abstract: OBJECTIVE
  Many studies have reported the clinical problems associated with resin composite restorations in NCCLs. None has compared these clinical problems in NCCLs with and without occlusal wear facets. The present study sets out to determine the proportion of NCCLs that presents occlusal wear facets, and to compare the failure pattern of resin composite restorations in NCCLs with and without occlusal wear facets.
  
  
  METHODS
  Teeth with NCCLs were classified into two groups, those with and without occlusal wear facets. Both groups were restored using micro hybrid resin composite. The restorations were evaluated at the end of 2 years concerning post-operative sensitivity, retention, marginal integrity, marginal discolouration, wear, and secondary caries, using the USPHS criteria. Statistical analysis compared the ratings of each criterion between the two groups using Pearson's χ(2) or Fisher's exact test.
  
  
  RESULTS
  About one-third (33.8%) of teeth with NCCLs presented with occlusal wear facets, more NCCLs with occlusal wear facets in mandibular teeth (44.7%) than maxillary teeth (24.5%). Retention rate of composite resin restorations in NCCLs with and without occlusal wear facets was 63.9% and 74.4% respectively at the end of 2 years. More marginal discolouration and defects were observed in restorations in NCCLs with occlusal wear facets, the differences were not statistically significant (p>0.05).
  
  
  CONCLUSIONS
  The decline in ratings of marginal discolouration and defects, and the lower retention rate of restorations in NCCLs with occlusal wear facets may support the role of occlusal stress and tooth flexure as a cause of failure of restorations in NCCLs.
  
  
  CONCLUSIONS
  The ability to distinguish between stress induced lesions (with occlusal wear facets) and other cervical lesions will have important ramifications for the success of their restorations because they are not subjected to the same physical forces that are responsible for the deterioration of the restoration.
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Obafemi Awolowo University, Ile-Ife, Nigeria. Electronic address: adelekeoginni@yahoo.co.uk.
authors.forename: Adeleke Oke
authors.initials: AO
authors.lastname: Oginni
authors.affiliation: Department of Dental Surgery, Ekiti State University Teaching Hospital, PMB 5355, Ado-Ekiti, Nigeria.
authors.forename: Adeyinka Adedayo
authors.initials: AA
authors.lastname: Adeleke
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000328:Adult; D000368:Aged; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental / Q000145:classification; D001840:Dental Bonding / Q000379:methods; D003731:Dental Caries / Q000145:classification; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear / Q000145:classification; D003793:Dental Restoration, Permanent / Q000379:methods*; D003807:Dentin Sensitivity / Q000145:classification; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010756:Phosphoric Acids / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D019237:Tooth Cervix / Q000473:pathology*; D019228:Tooth Crown / Q000473:pathology*; D057085:Tooth Wear / Q000473:pathology / Q000628:therapy*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D010756:Phosphoric Acids; C030242:phosphoric acid
keywords: Non-carious cervical lesions; Restoration; Wear facets