The Effect of Four Endodontic Irrigants on the Shear Bond Strength of a Self Etch Resin Based Sealer to Dentin - An In Vitro Study

This in vitro study was undertaken to evaluate the effect of four different irrigants namely Sodium hypochlorite, Chlorhexidine, Triphala and Morinda citrifolia on the shear bond strength of a self etch sealer, RealSeal SE to dentin by using EDTA as the final wash as well as without EDTA as the final wash. The bond strength was evaluated in shear mode by using a Universal testing machine. Methods: The study was done using 120 extracted human molars. A low speed diamond disk saw with water coolant was used to slice off the occlusal 2mm of the samples whereby a flat dentinal surface surrounded by a thin rim of enamel was obtained. This section of tooth, was embedded in a self cure acrylic resin. A smear layer was created on the sectioned teeth using a 320 grit silicon carbide paper attached to the Handimet grinder (Buehler,Ltd) under water irrigation for a time period of 15 seconds. The dentin disks with the smear layer were then randomly divided into 2 groups namely Group I-without EDTA and Group II-with EDTA. Each of the Group was further divided into four Subgroups namely Sodium hypochlorite, Morinda citrifolia, Triphala and Chlorhexidine respectively. The dentin discs were then air dried using a air-water syringe. A brass tube was placed onto the dentin surface and was filled with the sealer RealSeal SE, which was mixed according to the manufacturer's instructions. The sealer was then light cured for 40 seconds and then allowed to set for 45minutes. The samples were then immediately stored in a closed container containing distilled water at 37oC and maintained at 100% humidity for 7 days. Each specimen was evaluated for its shear bond strength value at a cross head speed of 1mm/minute. The shear force required to separate the cylinder from dentin for each specimen was recorded in Newtons (N), then divided by the contact surface area to determine the shear bond strength in Megapascals. Results: The results revealed that Subgroup Sodium hypochlorite had the highest shear bond strength in Group I and Group II followed in order by Subgroups Morinda citrifolia, Triphala and Chlorhexidine in both groups. Conclusion: Morinda citrifolia and Triphala can be used as a better alternative to Chlorhexidine.