Root canal configurations of third molar teeth. A comparison with first and second molars in the Turkish population.

The purpose of the current study was to determine the similarities of maxillary and mandibular third molars with the other molar teeth. A total of 2016 extracted maxillary and mandibular permanent teeth were evaluated. The teeth were divided into six groups. The teeth were stored in 5% nitric acid solution for 7 days, then placed in increasing concentrations of ethyl alcohol. The teeth were rendered transparent by immersion in xylene solution for 4 days until complete transparency was achieved. Three roots were present in 93.0% of the maxillary molars, and 91.3% of the second molars. Among the maxillary third molars, 35.5% were single-rooted and 24.9% of the mandibular third molars had single roots. Double roots were present in 69.2% of the mandibular third molars, and 5.4% had three roots. Four new root canal configurations were encountered in this study. The root canal configurations of the mandibular and maxillary teeth showed similarities with the results of other studies performed in different populations.

The location and accessibility of the second mesiobuccal canal in maxillary first molar.

OBJECTIVES: The purpose of this study was to examine the location and accessibility of the second mesibuccal canal in maxillary first molar of a Turkish sub-population. METHODS: Presence and accessibility of the MB2 canal in 110 extracted maxillary first molars was examined with unaided vision, dental loups and the DOM. To characterize the geometrical location of MB2 canals, photographs of pulp chambers were obtained. RESULTS: With the unaided vision, 58 MB2 canal orifices and after evaluation with the dental loup, DOM an additional 28 MB2 canal orifices were detected. In 65 molars, the MB2 canal orifices was located 0.87 mm distally and 1.73 mm palatally to the main mesiobuccal canal and in the remaining 21 molars was 0.72 mm mesially and 1.86 mm palatally. CONCLUSIONS: Presence of second mesiobuccal canal was similar to the other studies but in a Turkish sub-population it originates mainly distal to the main MB canal.

Quantitative evaluation of the amount of apically extruded debris using 3 different rotary instrumentation systems.

OBJECTIVE: To comparatively evaluate the amount of apically extruded debris when ProTaper, ProFile, and HERO Shaper were used for the instrumentation of root canals. STUDY DESIGN: Sixty human mandibular central incisor teeth were randomly assigned to 3 groups, 20 teeth in each. The teeth in the 3 groups were instrumented according to the manufacturers' instructions until the working length, with ProTaper, ProFile, and HERO Shaper rotary instruments respectively. The debris produced was collected in polyethylene tubes. The liquid inside the tubes was removed by lyophilization and the remaining debris was calculated for each group and compared. RESULTS: All instruments tested produced a measurable amount of debris. No statistically significant difference was observed between ProTaper and HERO Shaper in terms of debris extrusion (P > .05). Similarly, no statistically significant difference was observed between ProFile and HERO Shaper even though HERO Shaper extruded a relatively higher amount of debris (P > .05). On the other hand, ProTaper extruded significantly more amount of debris compared to ProFile (P < .001). CONCLUSIONS: ProTaper caused a significantly higher amount of debris extrusion compared to ProFile. No statistically significant difference was observed among the other groups tested. As the quantity of debris extrusion is not the only factor responsible for acute exacerbations, future studies can be planned that focus on the types of bacteria causing flare-ups and methods for their elimination.

Comparative evaluation of the preparation efficacies of HERO Shaper and Nitiflex root canal instruments in curved root canals.

OBJECTIVES: To comparatively evaluate the shaping efficacies of HERO Shaper rotary instruments and Nitiflex hand files. STUDY DESIGN: The mesial roots of 40 mandibular molars were used. In 20 teeth, the mesiobuccal canals were instrumented with HERO Shaper and the mesiolingual canals with Nitiflex. In the remaining 20 teeth, the mesiobuccal canals were instrumented with Nitiflex and the mesiolingual canals with HERO Shaper. Pre- and postoperative sections were obtained from the coronal, middle, and apical portions and analyzed. Statistical analysis was performed using the Student t test. RESULTS: More dentin was removed from the middle portion with HERO Shaper (P < .05). No statistically significant difference was observed in terms of transportation (P>.05). No instrument fracture or deformation was noted. CONCLUSIONS: Both HERO Shaper and Nitiflex can be recommended for clinical practice. Further studies can focus on the comparison of HERO Shaper with other rotary instruments as there is an increasing trend for the utilization of these systems.

Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population.

A key objective of successful nonsurgical endodontic treatment is obturation of the root canal systems. One factor in achieving this goal is the knowledge of possible root canal morphologies. Root canal morphology may exhibit variation as a result of many factors, including ethnic origin. In this study, 1400 male and 1400 female extracted mandibular and maxillary permanent teeth were evaluated for patterns in root canal morphology. The mandibular and maxillary teeth were divided into seven groups of tooth type (e.g. centrals, laterals, canines, first premolars, second premolars, first molars, and second molars), subdivided into gender, and classified by root canal morphologies. Vertucci's classification was taken as a reference during the evaluation. Although a majority of the specimens corresponded to this classification scheme, the analysis of this large data set revealed 14 additional root canal morphologies.