title: Influence of adhesive system and placement technique on microleakage of resin-based composite restorations.
abstract: OBJECTIVE
  To analyze the influence of two placement techniques and two adhesive systems on the marginal microleakage of Class II resin-based composite restorations using different resin composite materials.
  
  
  METHODS
  Two hundred standardized Class II cavities (5 mm x 3 mm x 1.5 mm) were cut in human premolars and restored using five resin composite materials (A.L.E.R.T.-AL, Solitaire-SO, SureFil-SU, Filtek A110-A, and Z100-Z), two adhesive systems (Bond 1-B1 and Etch & Prime 3.0-EP), and two placement techniques (incremental or bulk). Specimens were thermocycled (700 cycles, 5 degrees - 55 degrees C, 1 min dwell time), immersed in 0.5% methylene blue solution for 4 h, and sectioned longitudinally to evaluate the extent of microleakage. Data were submitted to statistical analysis using the Kruskal-Wallis test.
  
  
  RESULTS
  It was observed that both adhesive systems presented similar results (p > 0.05), and neither achieved complete marginal sealing. The bulk placement technique led to greater microleakage than the incremental technique (p < 0.001). Restorations prepared using SO resin composite showed greater microleakage than those performed using Z or AL materials. However, SO obtained similar values of microleakage when compared to SU and A materials.
  
  
  CONCLUSIONS
  The use of incremental placement technique resulted in less microleakage for Class II resin-based composite restorations. No difference was observed among adhesive systems regarding prevention of marginal dye penetration. Furthermore, the type of resin composite material employed for restoration may have an influence on the extent of microleakage.
authors.affiliation: Department of Dental Materials, University of São Paulo, São Paulo, Brazil.
authors.forename: Laiza T
authors.initials: LT
authors.lastname: Poskus
authors.forename: Eliane
authors.initials: E
authors.lastname: Placido
authors.forename: Paulo E Capel
authors.initials: PE
authors.lastname: Cardoso
mesh_terms: D001641:Bicuspid; D003188:Composite Resins; D001840:Dental Bonding; D003737:Dental Cavity Preparation; D003763:Dental Leakage / Q000209:etiology*; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000009:adverse effects / Q000379:methods*; D000431:Ethanol; D006801:Humans; D008689:Methacrylates; D044367:Phase Transition; D010710:Phosphates; D019279:Resin Cements; D012822:Silicon Dioxide; D015040:Zirconium
chemical_list: C406265:Alert composite resin; C115611:BOND-1 adhesive; D003188:Composite Resins; C469823:Etch&Prime 3.0; C452225:Filtek A110 composite resin; D008689:Methacrylates; D010710:Phosphates; D019279:Resin Cements; C113049:Solitaire composite resin; C403464:SureFil packable composite; C083568:Z100 composite resin; D000431:Ethanol; D012822:Silicon Dioxide; D015040:Zirconium