Ex vivo evaluation of dye penetration associated with various dentine bonding agents in conjunction with different irrigation solutions used within the pulp chamber

Abstract

To compare the effect of sodium hypochlorite (NaOCl), chlorhexidine, povidone iodine and sodium ascorbate on dye penetration associated with various dentine adhesives used within the pulp chamber. One hundred and sixteen mandibular molar teeth were divided into eight groups of 12 teeth each by irrigation regimen and adhesive system. The roof of pulp chambers and roots were removed under water cooling. The pulp chambers in the experimental groups were irrigated with 5.25% NaOCl, 0.2% chlorhexidine, 5% w/v povidone iodine or 5.25% NaOCl followed by sodium ascorbate and restored with Surefil using either Prime & Bond NT or Xeno III with each irrigation regimen. Twenty teeth were used as control specimens in which no disinfectant was used before bonding. Ten teeth from each group were immersed in 2% methylene blue dye and assessed for dye penetration. The data were statistically analysed by Kruskal-Wallis and Mann-Whitney U-tests. Two samples in each group were observed under scanning electron microscopy for interfacial gap evaluation. No significant difference was found in dye leakage between control and groups with 5.25% NaOCl pretreatment with both adhesive systems. Chlorhexidine and povidone iodine pretreatment resulted in significantly less dye penetration with Xeno III as compared with Prime & Bond NT. Sodium ascorbate treatment following NaOCl application significantly reduced microleakage and improved the marginal adaptation with both adhesive systems. The type of irrigant affected the sealing ability of bonding agents inside the pulp chamber and was material specific. Xeno III had less dye penetration with CHX and povidone iodine whilst sodium ascorbate pretreatment after NaOCl reduced dye penetration with both PBNT and Xeno III.