title: Clinical evaluation of microhybrid composites in noncarious cervical lesions: 24-month results.
abstract: OBJECTIVE
  To evaluate the clinical performance of two different microhybrid resin composites in noncarious cervical lesions (NCCLs) after 24 months.
  
  
  METHODS
  Ninety-seven NCCLs were restored with either TPH Spectrum (n = 48) or Filtek Z250 (n = 49) using an etch-and-rinse adhesive in 20 patients. The restorations were clinically evaluated using modified United States Public Health Service criteria for retention, color match, marginal discoloration, marginal adaptation, surface texture, anatomic form, postoperative sensitivity, and secondary caries. The restorations were assessed 1 week after placement (baseline) and after 6, 12, and 24 months. Restoration survival rates were calculated using the Kaplan-Meier procedure estimator, and a log-rank test was used to compare the survival distributions (P < 0.05). Statistical analysis was undertaken using Pearson's Chi-square test and Fisher's exact test to assess differences among the restorative materials (P < 0.05). Cochran's Q-test was employed for evaluating differences in the same restorative material between recall periods.
  
  
  RESULTS
  The retention rates were 100% at 6 months, 89.6% and 91.8% at 12 months, and 85.4% and 89.8% at 24 months for TPH and Z250, respectively. TPH showed a statistically significant difference in marginal discoloration between the baseline and 24 months results (P < 0.05). Both TPH and Z250 showed statistically significant differences in marginal adaptation between the baseline and 24 months results (P < 0.05).
  
  
  CONCLUSIONS
  Over the 24-month period, both microhybrid resin composites demonstrated acceptable clinical results in NCCLs.
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Baskent University, Ankara, Turkey.
authors.forename: D
authors.initials: D
authors.lastname: Tuncer
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Baskent University, Ankara, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Çelik
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Baskent University, Ankara, Turkey.
authors.forename: K
authors.initials: K
authors.lastname: Yamanel
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Baskent University, Ankara, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Arhun
mesh_terms: D000328:Adult; D003116:Color; D003188:Composite Resins / Q000737:chemistry; D003731:Dental Caries; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003807:Dentin Sensitivity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019237:Tooth Cervix; D055815:Young Adult
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C444701:Filtek Z250; C467914:TPH spectrum