title: 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(2) -10(3)) in Group B or C than in Group A (>10(5)). These results suggest that apical widening and clearing facilitates removal of apical ramifications and bacterial load within root canals.
authors: Department of Conservative Dentistry and Endodontics, Center for Dental Education and Research, All India Institute of Medical Sciences.
authors: Sukhwant Singh
authors: SS
authors: Yadav
authors: Naseem
authors: N
authors: Shah
authors: Ajay
authors: A
authors: Naseem
authors: Tara Sankar
authors: TS
authors: Roy
authors: Seema
authors: S
authors: Sood
mesh_terms: D000293:Adolescent; D000328:Adult; D019412:Anatomy, Cross-Sectional; D058491:Bacterial Load / Q000145:classification*; D004396:Coloring Agents; D003648:Decalcification Technique; D003786:Dental Pulp Cavity / Q000382:microbiology* / Q000473:pathology; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D006801:Humans; D008963:Molar / Q000382:microbiology / Q000473:pathology; D017942:Nitric Acid; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D016369:Smear Layer / Q000382:microbiology / Q000473:pathology; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000382:microbiology* / Q000473:pathology; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D012388:Root Canal Irrigants; D017942:Nitric Acid; D012973:Sodium Hypochlorite