Influence of Apical Patency and Cleaning of the Apical Foramen on Periapical Extrusion in Retreatment

Abstract

This study evaluated the influence of apical patency, root filling removal technique and cleaning of the apical foramen, concerning the amount of debris extruded during root canal retreatment. Forty mandibular incisors were randomly assigned to 4 groups - GIM (n=10), GIIM (n=10), GIPT (n=10) and GIIPT (n=10), which were named according to leaving (I) or not (II) apical patency during canal preparation and filling removal technique (manual - M or ProTaper system - PT). After filling material removal, each specimen of each group had the apical foramen cleaned by sizes 15, 20 and 25 instruments, generating 12 subgroups: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 and GIIPT25. Extruded filling debris was collected by a Milipore filtration system, an HV-durapore, 0.45 µm pore filter with a 25 mm diameter. The filters were weighed before and after the collection on an analytical scale (10-5 g), and the difference was calculated. The mean weight of extruded filling debris was analyzed statistically by Kruskal-Wallis and Friedman ANOVA tests (α=0.05). The mean values found in the groups (in mg) were: GIM (0.95 ± 0.94), GIIM (0.47 ± 0.62), GIPT (0.30 ± 0.31) and GIIPT (0.32 ± 0.44). There was no statistically significant difference among any of the groups or subgroups (p>0.05). ProTaper provided the smallest amount of extruded filling material, regardless of presence or absence of apical patency, followed by manual technique, without and with apical patency. Additional amounts of debris were collected during cleaning of the apical foramen, regardless of the instrument, presence/absence of patency or root filling removal technique.

Apical Extrusion of Debris in Flat-oval Root Canals after Using Different Instrumentation Systems

“…It uses Eppendorf tubes to store the extruded debris, and it is reliable, simple, and reproducible. Other methodologies might be used to measure debris extrusion including collecting and weighing paper filters (29), an aluminum crown (30), an acrylic resin container (31), and a Durapore filter (3M, St Paul, MN) (32).…”

“…Variations in the root canal anatomy may influence the amount of apical extrusion of debris (1,10,24,32). Extrusion of debris in mandibular incisors has not been largely studied.…”

Evaluation of Apically Extruded Debris Using Positive and Negative Pressure Irrigation Systems in Association with Different Irrigants

“…Although most studies associate the extrusion of debris caused by different preparation techniques and by the instruments used (2,3,(15)(16)(17)(18) the literature is scarce on the correlation between different irrigation techniques and irrigant substances. Therefore, the current ex vivo study was designed to evaluate the amount of apically extruded debris after CMP of root canals with two different irrigation techniques (EV and CI) in association with four different root canal irrigants [(6% NaOCl (NaOCl), 2% CHX gel (CHXg) + saline solution (SS), 2% CHX solution (CHXs) and SS].…”

Establishing Apical Patency: To be or not to be?

“…Tinaz et al 32 found more extruded debris with manual preparation techniques in cases the apical patency be used. Deonizio et al 33 showed that apical patency cannot affect amount of extruded materials when using ProTaper Rotary System, but it may happen by manual techniques.…”