title: Comparing microleakage and the layering methods of silorane-based resin composite in wide Class II MOD cavities.
abstract: OBJECTIVE
  This in vitro study compared the effects of different layering techniques and different monomer-based composites on microleakage.
  
  
  METHODS
  Thirty-two freshly extracted caries-free human third molars were used. A wide mesio-occlusal-distal (MOD) cavity was prepared in each third molar, with the occlusal dimension being approximately two-thirds of the intercuspal dimension, and the cervical limit of one proximal box was stopped 1 mm below and the other 1 mm above the cementoenamel junction. The cavities were filled with a methacrylate-based nanohybrid composite (Grandio, VoCo) and a silorane-based microhybrid composite (Filtek Silorane, 3M ESPE). All samples were subjected to 1000 thermal cycles of 5 degrees C/55 degrees C in water with a 30-second dwell time and, after the procedure, the teeth were immersed in a 0.5% basic fuchsin dye at 23 degrees C for 24 hours. Sectioned samples were examined under a stereomicroscope (Leica MZ12, Leica Microsystems), and microleakage scores were statistically analyzed using the Kruskal-Wallis and the Mann-Whitney U tests.
  
  
  RESULTS
  No microleakage was observed for silorane-based resin composite restorations. The nanohybrid-based resin composite restorations showed different levels of leakage. Statistical analysis of microleakage scores showed differences only at the enamel margins for nanohybrid material for both layering techniques (p < 0.05). The nanohybrid-based resin composite restorations showed better results with the vertical layering technique for enamel margins.
authors.affiliation: Ankara University, Operative Dentistry, Besevler, Ankara, Turkey. bagis@dentistry.ankara.edu.tr
authors.forename: Yildirim Hakan
authors.initials: YH
authors.lastname: Bagis
authors.forename: Ismail Hakki
authors.initials: IH
authors.lastname: Baltacioglu
authors.forename: Savas
authors.initials: S
authors.lastname: Kahyaogullari
mesh_terms: D003188:Composite Resins / Q000008:administration & dosage* / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000145:classification; D003763:Dental Leakage / Q000517:prevention & control*; D003793:Dental Restoration, Permanent / Q000379:methods*; D006801:Humans; D008964:Molar, Third; D053761:Nanocomposites / Q000008:administration & dosage
chemical_list: D003188:Composite Resins; C543062:Filtek LS Low Shrink resin; C509998:Grandio