title: Two-year clinical performance in primary teeth of nano-filled versus conventional resin-modified glass-ionomer restorations.
abstract: OBJECTIVE
  The hypothesis to be tested was that the clinical performance of nano-filled resin-modified glass ionomers (RMGIs) in Class I primary molars will differ from that of its preceding conventional RMGI.
  
  
  METHODS
  The shear bond strengths of each material to primary molar dentin were measured (n = 10) using a notched-edge crosshead. Independent sample t test was used for statistical analysis. A split-mouth designed clinical trial was performed in which nano-filled RMGI (Ketac Nano; KN) and conventional RMGI (Vitremer; VR) were used to restore Class I cavities of primary molars. Each material group (n = 30) was evaluated according to United States Public Health Service (USPHS), regarding marginal discoloration, marginal adaptation, color match, anatomic form, and recurrent caries, at baseline, after 1 year, and after 2 years. Wilcoxon signed-rank test and chi-square test were used for statistical analysis.
  
  
  RESULTS
  Shear bond strength (mean ± SD) of KN (6.3 ± 3.9 MPa) was significantly lower (P < .05) than that of VR (9.5 ± 2.7 MPa). After 2 years, KN restorations showed significantly increased wear (92% Alpha and 8% Charlie) and marginal discoloration (23% Bravo and 8% Charlie) with secondary caries (8%). Color match was significantly decreased for both KN and VR (69% and 73% Bravo, respectively). When parameters were compared for materials at each recall, there was no statistically significant difference between KN and VR.
  
  
  CONCLUSIONS
  Nano-filled RMGI may not be better than conventional RMGI; its wear resistance deteriorates with time, and it has low bond strength to dentin.
authors: Sahar E
authors: SE
authors: Abo-Hamar
authors: Shaimaa S
authors: SS
authors: El-Desouky
authors: Nahed A
authors: NA
authors: Abu Hamila
mesh_terms: D002648:Child; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003731:Dental Caries / Q000628:therapy*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008963:Molar; D014094:Tooth, Deciduous; D016896:Treatment Outcome
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; C000613151:Ketac Nano; C084550:Vitremer