title: Marginal Microleakage of Low-shrinkage Composite Silorane in Primary Teeth: An In Vitro Study.
abstract: OBJECTIVE
  Despite the increasing demand for adhesive restorations in pediatric dentistry, polymerization shrinkage and subsequent marginal microleakage remains a problem. The aim of this study was to evaluate of the sealing ability of novel low-shrinkage composite silorane in class V cavity of primary canines in comparison with three types of composite resin.
  
  
  METHODS
  Ninety-one non-carious extracted primary canines were randomly divided in six groups (n=15). Standard class V cavities were prepared on the buccal surface of each tooth that the occlusal margin was in the enamel and the cervical margin extending 1 mm below the cemento-enamel junction. The preparations were restored with the different composite materials in normal consistency with application the bonding in six groups (Filtek silorane; etch + Filtek Silorane; Z250; Filtek supreme; els saremco; Aelite LS). Teeth were then exposed to thermal cycles (1000 cycles, 5°C and 55°C), sealed and immersed in a 0.5% basic fuchsine for 24 hours, and finally sectioned. Buccolingual and mar-ginal leakage was assessed with dye penetration.
  
  
  RESULTS
  The best seal were obtained with etch + Filtek Silorane (P < 0.05) and the weakest seal with Z250 composite res-torations (P > 0.05). Except for etch + silorane, there was no significant differences in sealing ability (P > 0.05), and in the microleakage degree at the cementum and enamel margins (P > 0.05) between the groups.
  
  
  CONCLUSIONS
  According to the results, low-shrinkage silorane composite restorations with etching the cavity provide the highest seal in primary teeth.
authors.affiliation: Oral & Dental Diseases Research Center, Kerman University of Medical Sciences, Kerman, Iran  ; Associate Professor, Department of Pediatric Dentistry, Dental School, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Poureslami
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sajadi
authors.forename: Maryam
authors.initials: M
authors.lastname: Sharifi
authors.forename: Shahram
authors.initials: S
authors.lastname: Farzin Ebrahimi