Effect of “Apical Clearing” and “Apical Foramen Widening” on Apical Ramifications and Bacterial Load in Root Canals

Abstract

The purpose of the study was to determine the effect of apical clearing and apical foramen widening in reducing apical ramifications and bacterial load in the apical third of root canals. The mesio-buccal roots of 21 maxillary first molar teeth were inoculated with Enterococcus faecalis suspension using a sterile pipette. Samples were incubated at 37°C for 72 hrs and divided into 3 groups: Group A, control group (n=5), no preparation; Group B (n=8) conventional preparation alone; and Group C (n=8), apical clearing and foramen widening in addition to conventional preparation. Bacterial counts were semi-quantitatively analyzed pre-and post-preparation. Samples were demineralized with 5% nitric acid after injection of India ink. Cross sections were obtained at every 0.5 mm from the apex to 3 mm of the root using a vibratome and viewed under a stereomicroscope at 64×magnification to locate any debris or apical ramifications. The Kruskal-Wallis and Mann-Whitney U tests were used for the statistical analysis. A statistically significant difference was observed (p value 0.006) in the number of ramifications among the 3 groups. Group C had a lower average number of ramifications (1) than Group B (2.5) or A (4). The debris score was analyzed at each level (0.5-3 mm). A statistically significant difference was observed at 0.5 mm and 1 mm between Group A and C (p=0.0041) and Group B and C (p=0.0050), whereas no difference was found between Group A and B (p>0.05). These results indicate that there was less debris and fewer apical ramifications in Group C. The microbiological study revealed a lower number of colony forming units (10 ). These results suggest that apical widening and clearing facilitates removal of apical ramifications and bacterial load within root canals.

A novel conservative approach combining “SealBio” and “Surgical Fenestration” for healing of large periapical cystic lesions of endodontic origin: A pilot study

“…This helps to remove all accessory canals, bifurcations, deltas, etc., present in the apical third. [ 9 10 ] “Apical foramen widening” to size #25 helps to clean the cemental part of the canal,[ 11 ] which is generally nacrosed and harbors large quantity of microbes. The root canal is then irrigated with copious volume of 2.5% NaOCl and final flush with Betadine solution.…”

“…It was first reported in 2012, and successful outcome was documented in 14 cases. [ 8 ] The technique incorporates “apical clearing”[ 9 10 ] and “apical foramen widening”[ 11 ] to achieve more effective disinfection. It is then followed by intentional overinstrumentation into the periapical region to induce bleeding near the apical foramen and to provide a scaffold of a blood clot.…”

Comparative evaluation of canal cleaning ability of various rotary endodontic filesin apical third: A scanning electron microscopic study

“…The apical area in the root canal system is the critical zone for instrumentation. [ 5 ] Ramification can be observed anywhere along the the root canal but occur more frequently in the apical portion of root canal and in the posterior teeth. [ 6 ] The treatment outcome will be guarded if these anatomical anomalies are not identified, prepared, and obturated.…”

Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial

“…conducted a study to determine the effect of apical clearing and foramen widening on apical ramifications and bacterial load in root canals and found it to be effective in removing apical ramifications and results in a decrease in colony forming units. [ 16 ] On the contrary, conventional approach entails enlarging the apical constriction three sizes larger (MAF) than the first apical binding file. [ 5 ] This is based on the presumption that this initial file gauges the apical canal diameter and by using three successively larger files to the same working length, the layer of heavily infected dentine can be removed.…”