Clinical evaluation of posterior composite restorations in endodontically treated teeth.

OBJECTIVE: The purpose of this study was to evaluate the two year clinical performance of posterior composite restorations in endodontically treated premolars and molars using a hybrid composite (Filtek Z-250, 3M ESPE) and a total etch bonding system (Single Bond, 3M ESPE). METHOD AND MATERIALS: Thirty-nine class II restorations in endodontically treated premolars (n=11) and molars (n=28) of 27 patients (14 female, 13 male, mean age 36.51) in 16 maxillar and 23 mandibular teeth were placed by one operator. Restorations were evaluated by two experienced investigators at baseline, 12 months, and 24 months according to the modified United States Public Health Service (USPHS) criteria that included retention, color match, marginal discoloration, secondary caries, anatomic form, marginal adaptation, and surface texture. All restorations were able to be evaluated at baseline, 12 months, and 24 months. RESULTS: Paired samples t-test showed only marginal discoloration showed a statistically significant difference (p<0.05) at the end of 24 months, and no other significant differences were observed for the other variables examined over the duration of the study. None of the restored teeth showed periapical pathology at the end of 24 months. CONCLUSION: At two years, limited deterioration in marginal discoloration was detected. The clinical performance of posterior composite restorations in endodontically treated teeth using Filtek Z250 was found clinically acceptable after two years.

Management of the perforations due to miniplate application.

Microdimensioned osteosynthesis using miniplates has been common practice in maxillofacial surgery. However, tooth injury during the application of the miniplates have been reported in few papers. In this case, a 32-yr-old female patient, whose two teeth were necrosed because of the perforation during screw insertion was presented. The reason of the perforations during the rigid internal fixation was the lack of radiographic assessment because of the pregnancy. Maxillary right first premolar and maxillary left canine were perforated and necrosed because of the screw insertion. The necrosed teeth were detected 1 yr after the rigid internal fixation. The root canals of nonvital teeth were filed using step-down approach. Cold lateral condensation of gutta-percha was used to fill the canals. Six-month recall visits were scheduled and there was no problem after 2-yr follow-up period.

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.