Evaluation of success rate of endodontic treatment performed by students with stainless-steel K-files and nickel-titanium hand files.

A previous study by our group found nickel-titanium (NiTi) 0.02 hand files maintained the original canal shape better than similar stainless-steel K-files (SS-K). Inexperienced dental students used both file types on molar teeth. The purpose of this study was to compare the 1-yr success rate of endodontic treatment of the same teeth used in our previous study. Twelve-month follow-up radiographs were compared with the immediate follow-up radiographs. Both sets of radiographs were taken with the same customized stent. Quantification of osseous changes using digital imaging was used. Thus, a reliable numerical estimation (densitometric ratio) of disease and healing processes could be established. Sixty-seven percent of the patients returned for the 12-month radiographs (19 NiTi vs. 21 SS-K). Immediate postoperative periapical status was found to be similar (p > 0.05). Teeth instrumented with the NiTi files demonstrated a higher mean change in densitometric ratio, compared with SS-K files (p < 0.05). Further tests of success (values: > or =0) and failure (value: < or =0) with the Fisher exact test showed more success (decreasing radiographic density) with NiTi files and more failures (increasing radiographic density) with SS-K type files (p < or = 0.03). This study indicates that maintaining the original canal shape after instrumentation leads to a better prognosis of endodontic treatment.

Endodontic complications of root canal therapy performed by dental students with stainless-steel K-files and nickel-titanium hand files.

Straightening of curved canals is one of the most common procedural errors in endodontic instrumentation. This problem is commonly encountered when dental students perform molar endodontics. The purpose of this study was to compare the effect of the type of instrument used by these students on the extent of straightening and on the incidence of other endodontic procedural errors. Nickel-titanium 0.02 taper hand files were compared with traditional stainless-steel 0.02 taper K-files. Sixty molar teeth comprised of maxillary and mandibular first and second molars were treated by senior dental students. Instrumentation was with either nickel-titanium hand files or stainless-steel K-files. Preoperative and postoperative radiographs of each tooth were taken using an XCP precision instrument with a customized bite block to ensure accurate reproduction of radiographic angulation. The radiographs were scanned and the images stored as TIFF files. By superimposing tracings from the preoperative over the postoperative radiographs, the degree of deviation of the apical third of the root canal filling from the original canal was measured. The presence of other errors, such as strip perforation and instrument breakage, was established by examining the radiographs. In curved canals instrumented by stainless-steel K-files, the average deviation of the apical third of the canals was 14.44 degrees (+/- 10.33 degrees). The deviation was significantly reduced when nickel-titanium hand files were used to an average of 4.39 degrees (+/- 4.53 degrees). The incidence of other procedural errors was also significantly reduced by the use of nickel-titanium hand files.

Dentinogenesis imperfecta: endodontic implications. Case report.

Dentinogenesis imperfecta is a hereditary disorder resulting in defective dentin in both the primary and secondary dentitions. The complications of dentinogenesis imperfecta are difficult to manage and provide a challenge to the dentist. This case report concerns treating an African American patient with dentinogenesis imperfecta who appeared for treatment with endodontic pathosis. It illustrates the need for appropriate and timely restorative treatment to prevent pulpal pathosis. Also demonstrated is the difficulty of endodontically treating dentinogenesis imperfecta teeth because of pulpal obliteration and abnormal dentin mineralization. Early and correct diagnosis of dentinogenesis imperfecta is imperative to enable appropriate preventive interventions and optimal dental treatment. Although pulpal pathosis is rarely reported with dentinogenesis imperfecta, endodontic treatment is occasionally necessary and has a guarded prognosis if initiated after pulp canal obliteration has occurred.