Rate of Apical Extrusion of Sodium Hypochlorite: Open Ended versus Closed Ended Needles

The objective was to compare the role of needles design (open ended versus closed ended) on the apical extrusion of sodium hypochlorite irrigant during root canal treatment. This was an in vitro study performed at the Department of Operative Dentistry, Liaquat University of Medical & Health Sciences, Jamshoro from March 2011 to October 2011. Access cavities were prepared in one hundred extracted human maxillary first molars. The mesiobuccal canal was left open whereas the remaining canals were sealed. The acrylic receptacles were used to hold the teeth in a position as they are present in maxillary arch naturally. The starch/KI solution (A reagent that changes into blue color when comes in contact with sodium hypochlorite) was used to fill the receptacles. The teeth were divided into two groups (G1 and G2) each contained 50 specimens respectively. G1: Irrigation of the mesiobuccal canals with 5.25% sodium hypochlorite with open ended beveled needle. G2: Irrigation of the mesiobuccal canals with 5.25% sodium hypochlorite with closed ended side vented needle. Patency file was #10 K in both the groups. The change in any color of starch/KI solution was captured with digital photographs. Results showed overall frequency of apical extrusion of sodium hypochlorite is 43% (43/100). There was higher extrusion incidence with open ended beveled needle which was 62% (31/50) than with closed ended side vented needle which showed 24% (12/50). It was concluded that rate of extrusion was significantly high with open ended beveled needle than with closed ended side vented needle. A closed ended side vented needles appeared significantly safer than open ended beveled needles.