title: Effect of needle insertion depth and apical diameter on irrigant extrusion in simulated immature permanent teeth.
abstract: The aim of this study was to compare the amount of irrigant extrusion in simulated immature permanent teeth when the apical diameter and needle insertion depth were varied. Thirty single-rooted maxillary incisors with straight root canals were selected. The root length was standardized to a length of 9 mm. The teeth were divided into two experimental groups according to the degree of apical enlargement (n = 15). The apices were enlarged to a diameter of 1.10 mm or 1.70 mm by using a #3 or #6 peeso reamer, respectively, to simulate immature teeth. The irrigation solution was applied 2 or 4 mm short of the working length (WL) in each experimental group. The glass vial model was used for the collection of extruded irrigant beyond the root apex. A two-way repeated measures analysis of variance test showed that there was no significant difference between different needle insertion depths (2 and 4 mm short of the WL) in the group with an apical diameter of 1.70 mm (p > 0.05). In the group with an apical diameter of 1.10 mm, a 32% increase in irrigant extrusion was observed when the needle was positioned at 2 mm (p < 0.05). Regarding the effect of apical diameter, the group with a diameter of 1.70 mm showed more apical extrusion of the irrigant (34% increase for the needle positioned at 2 mm and 68% increase for the needle positioned at 4 mm). It was observed that the needle insertion depth and apical diameter have a significant effect on irrigant extrusion in immature permanent teeth.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Hacer
authors.initials: H
authors.lastname: Aksel
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Sevinc
authors.initials: S
authors.lastname: Askerbeyli
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Cigdem
authors.initials: C
authors.lastname: Canbazoglu
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Serper
mesh_terms: D000704:Analysis of Variance; D019229:Dentition, Permanent; D004867:Equipment Design; D006801:Humans; D008422:Materials Testing; D009339:Needles; D011677:Punctures / Q000379:methods*; D012388:Root Canal Irrigants; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D007507:Therapeutic Irrigation / Q000295:instrumentation; D019227:Tooth Apex / Q000033:anatomy & histology*
chemical_list: D012388:Root Canal Irrigants