title: Polymerization shrinkage of different types of composite resins and microleakage with and without liner in class II cavities.
abstract: OBJECTIVE
  To determine the volumetric polymerization shrinkage of four different types of composite resin and to evaluate microleakage of these materials in class II (MOD) cavities with and without a resin-modified glass ionomer cement (RMGIC) liner, in vitro.
  
  
  METHODS
  One hundred twenty-eight extracted human upper premolar teeth were used. After the teeth were divided into eight groups (n=16), standardized MOD cavities were prepared. Then the teeth were restored with different resin composites (Filtek Supreme XT, Filtek P 60, Filtek Silorane, Filtek Z 250) with and without a RMGIC liner (Vitrebond). The restorations were finished and polished after 24 hours. Following thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24 hours, then midsagitally sectioned in a mesiodistal plane and examined for microleakage using a stereomicroscope. The volumetric polymerization shrinkage of materials was measured using a video imaging device (Acuvol, Bisco, Inc). Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U-tests.
  
  
  RESULTS
  All teeth showed microleakage, but placement of RMGIC liner reduced microleakage. No statistically significant differences were found in microleakage between the teeth restored without RMGIC liner (p>0.05). Filtek Silorane showed significantly less volumetric polymerization shrinkage than the methacrylate-based composite resins (p<0.05).
  
  
  CONCLUSIONS
  The use of RMGIC liner with both silorane- and methacrylate-based composite resin restorations resulted in reduced microleakage. The volumetric polymerization shrinkage was least with the silorane-based composite.
authors.forename: E
authors.initials: E
authors.lastname: Karaman
authors.forename: G
authors.initials: G
authors.lastname: Ozgunaltay
mesh_terms: D003188:Composite Resins / Q000009:adverse effects* / Q000627:therapeutic use; D003731:Dental Caries / Q000601:surgery*; D003736:Dental Cavity Lining / Q000009:adverse effects / Q000379:methods*; D003763:Dental Leakage / Q000209:etiology* / Q000517:prevention & control; D003793:Dental Restoration, Permanent / Q000009:adverse effects / Q000401:mortality*; D005899:Glass Ionomer Cements / Q000627:therapeutic use; D006801:Humans; D058105:Polymerization; D062047:Silorane Resins / Q000627:therapeutic use
chemical_list: D003188:Composite Resins; C438835:Filtek P60 Composite Resin; C474035:Filtek Supreme; C444701:Filtek Z250; D005899:Glass Ionomer Cements; D062047:Silorane Resins; C555513:silorane composite resin; C067790:Vitrabond