Effects of Calcium Hypochlorite and Sodium Hypochlorite, as Root Canal Irrigants, on the Bond Strength of Glass Fiber Posts Cemented with Self-Adhesive Resin Cement

Abstract

Objectives:Calcium hypochlorite (Ca(OCl)2) is currently used as a root canal irrigant. The aim of this study was to compare the effects of calcium hypochlorite and sodium hypochlorite (NaOCl), as root canal irrigants, on the bond strength of posts cemented with a self-adhesive resin cement.Materials and Methods:In this in-vitro study, 40 maxillary central incisors with similar root lengths were decoronated. The teeth were randomly divided into five groups based on the irrigant used: Group 1: normal saline (control), Group 2: 2.5% sodium hypochlorite, Group 3: 5.25% sodium hypochlorite, Group 4: 2.5% calcium hypochlorite, and Group 5: 5% calcium hypochlorite. Root canal treatments were performed with Gates-Glidden drills and the irrigant corresponding to each group was used upon changing the file and for irrigating the post space. Then, glass fiber posts were cemented by BisCem self-adhesive cement. After applying 1,000 thermocycles at 5–55°C, three samples of the mid-section of each root were prepared: one for scanning electron microscopy (SEM), and the rest for push-out testing. Data were analyzed with SPSS 23 software using one-way analysis of variance and post-hoc Tukey’s test.Results:The highest and lowest mean bond strengths were recorded in groups 5 and 1, respectively. There was a significant difference between the 5% calcium hypochlorite group and the other groups (P<0.001). The difference between the other groups was not significant.Conclusion:The use of 5% calcium hypochlorite with self-adhesive cements increases the push-out bond strength of fiber posts to radicular dentin.

Bond strength and failure mode of glass fiber posts with different surface treatments prior to silanization: An in vitro comparative study

“…Studies using self-adhesives as luting material for glass fiber posts showed similar results in all three root regions (cervical, middle, and apical). [ 30 31 32 33 ] However, this differs from the findings obtained in the present study, since a significantly higher bond strength was obtained in the apical region when the post surface was pretreated with 37% phosphoric acid and 1.23% APF, coinciding with the reports of Vildósola et al [ 34 ] and Boing et al [ 35 ] It is possible that the bond strength was better in the apical region because of root anatomy, since the glass fiber posts used in this study were conical in shape, making them better adapted to this region. In addition, the self-adhesive cement used (RelyX U200) showed, in other studies, better volume and fluidity at the apical region of root,[ 1 36 ] which favors good bonding.…”

Effect of calcium hypochlorite as an irrigant alternative in the removal of methylene blue after photodynamic therapy under the post-space adhesive interface

“…After irrigation of the root canals, these by-products tend to precipitate into the root dentin [17,23]. Considering that the adhesion mechanism of self-adhesive resin cements and conventional glass ionomer involves the chemical reaction with the calcium from the hydroxyapatite of the dentinal substrate, it is possible that a synergism of action between the precipitated residues of CH with these cementation systems occurred, increasing the bond strength values [13,30]. On the other hand, our results diverge from those shown by Seballos et al [31], but the concentration of CH used in our study was 6%, which crucially tends to provide greater precipitation of calcium hydroxide, compared to other solutions with lower concentrations.…”

“…Considering these shortcomings, the use of 6% calcium hypochlorite (CH) solution (Ca(OCl) 2 ), which also has the ability to clarify tissues, has been purposed [11]. Although Ca(OCl) 2 has chlorine in its composition, more chemical stability compared to SH is observed, allowing a more gradual ionic dissociation which tends to minimize the impact on the adhesive interface with conventional resin cement [12][13][14].…”

Collagen-depletion strategies in dentin as alternatives to the hybrid layer concept and their effect on bond strength: a systematic review

“…Besides from NaOCl, other alternative irrigants able to dissolve organic content have been proposed and studied in the endodontic field over the years 67 – 69 . Irrigants such as calcium hypochlorite or chlorine dioxide have been for their organic dissolution capacity 70 , 71 . In fact, 5% chlorine dioxide has been reported to show interesting and comparable results, to NaOCl, in bond strength outcomes 69 .…”