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.

Assessment of apical extrusion in regenerative endodontics: a comparative study of different irrigation methods using three-dimensional immature tooth models

“…According to our findings, although there was a tendency to extrude more irrigant as the closer to working length; for XP-F and CSI groups, there was not a significant difference among the methods when performing 1 mm and 2 mm short of the WL, thus rejecting the first null hypothesis. The current study's findings are consistent with a study [45], which showed that irrigant extrusion increases as the apical diameter increases, regardless of needle insertion depth.…”

Effect of treatment variables on apical extrusion of debris during root canal retreatment: A systematic review and meta-analysis of laboratory studies

“…Standardization of samples in terms of apical diameter and root canal shape may significantly impact the reliability of the results. 4 , 30 , 128 Root canal shape could affect the volume of filling materials in the initial treatment, and apical diameter could affect the extrusion potential. Less than half of the included studies (41%) reported that initial apical diameter was standardized during sample selection, while only 22% of the included studies reported that the root canal shape of samples was standardized.…”

Endodontic Irrigants: A Review

“…Hacer Aksel conducted a study of 30 extracted straight-rooted uniradicular teeth in which he demonstrated the amount of irrigant that exceeds the apical foramen during lavage at different levels of needle application in the canal, which is at 2 and 4 mm from the apical foramen and at different apical-enlargement, so that the teeth were separated in two groups, one with a diameter of 1.10 mm and the other one with a diameter of 1.70 mm. He concluded that the extrusion of the irrigation solution is greatly influenced by the apical diameter of the canal and the level at which the needle is inserted, so that the largest extrusion of the irrigant was found to be in teeth with an apical diameter of 1.10 mm, if the needle was placed at 2 mm from the apical foramen [23].…”