title: To compare the microleakage among experimental adhesives containing nanoclay fillers after the storages of 24 hours and 6 months.
abstract: OBJECTIVE
  To compare the microleakage among experimental adhesives containing nanoclay fillers after the storages of 24 hours and 6 months.
  
  
  METHODS
  Class V cavities were prepared on extracted human molars with the occlusal margins located in enamel and the cervical margins in cementum. Phosphoric acid was applied to the enamel and dentin margins.Subsequently, the cavities were treated using four groups of experimental adhesive systems and restored with a resin composite. Adper Single Bond® was used as control group. After 24- hour and 6- month storages, the samples were subjected to thermocycling shocks and then immersed in silver nitrate as well as developer solution and finally evaluated for leakage. The data were analyzed using SPSS software.
  
  
  RESULTS
  Based on Kruskal -Wallis test, significant differences were found between groups regarding microleakage. The Mann- Whitney test showed that Leakage was significantly lower in Adper Single Bond® compared to the other groups in dentinal margins after 24 hours and 6 months and in enamel margins after 6 months. The Wilcoxon Signed Ranks test showed that the enamel leakage in experimental adhesives was significantly lower than dentinal leakage after 24 hours as well as enamel leakage in Adper Single Bond and adhesive with 0.5% PMAA-g-nanoclay was significantly lower than dentinal margins after storage period of 6 months.
  
  
  CONCLUSIONS
  All the experimental adhesives were effective in reducing enamel leakage after 24 hours, but were not effective in reducing dentinal leakage after 24 hours as well as in enamel and dentinal leakage after a 6-month storage. No improvement was observed in the microleakage in dentin in both short (24 hrs) and long times (6 months). The high microleakage in the adhesives is probably attributed to the high concentration of HEMA in the recipe of the bonding agent.
authors.affiliation: Isfahan University of Medical Sciences, Dental School, Department of Operative Dentistry and Torabinejad Research Centre, Isfahan, Iran.
authors.forename: Seyed Mostafa
authors.initials: SM
authors.lastname: Mousavinasab
authors.forename: Mohammad
authors.initials: M
authors.lastname: Atai
authors.forename: Bagher
authors.initials: B
authors.lastname: Alavi