title: Evaluation of Microleakage of Silorane and Methacrylate Based Composite Materials in Class I Restorations by Using Two Different Bonding Techniques.
abstract: BACKGROUND
  To evaluate the microleakage of silorane-based composite material (Filtek P90) with that of two homologous methacrylate-based composites materials (Filtek Z250 and Filtek Z250 XT), by using two different bonding techniques.
  
  
  METHODS
  Sixty extracted human maxillary first premolars prepared for standardized Class I cavities (4 mm × 2 mm × 2 mm) were randomly divided into three groups. Group A (n = 20) was filled with Filtek Z250 (Methacrylate) using single bond universal total etching technique, Group B (n = 20) was filled with Filtek Z250 XT (Methacrylate) using single bond universal self-etching technique and Group C (n = 20) restored with Filtek P90 (Silorane) with dedicated two-step self-etching prime and bond adhesive system (P90 system adhesive). Teeth were subjected to thermocycling regime (500×, 5-55°C), and dye penetration by immersing in 2% methylene blue for 24 h. Tooth sectioning was performed, and extent of the dye penetration was scored based on dye penetration scale to evaluate the microleakage. Statistical analysis included descriptive statistics and inferential statistics of Kruskal-Wallis test to compare the mean ranks between groups.
  
  
  RESULTS
  There was no significant difference observed for microleakage among the three composite materials tested in the present study. However, the cavities restored with silorane (Filtek P90) based composite displayed higher microleakage than the Filtek Z250, Z250 XT.
  
  
  CONCLUSIONS
  All the restorative systems tested in this study exhibited microleakage, but the silorane technology showed more microleakage when compared to the methacrylate-based composite systems.
authors.affiliation: Specialist, Department of Conservative Dentistry, East Riyadh Specialized Dental Centre, Ministry of Health, Riyadh, Saudi Arabia.
authors.forename: Mohsen S
authors.initials: MS
authors.lastname: Alshetili
authors.affiliation: Consultant, Department of Restorative Dentistry, King Abdulaziz Medical City, Riyadh, Saudi Arabia.
authors.forename: Sultan S
authors.initials: SS
authors.lastname: Aldeyab
keywords: Bonding; composite; microleakage; nano-hybrid; self-etch; silorane; total etch