Evaluation of canalis basilaris medianus using cone-beam computed tomography

The aim of this report is to present two cases of canalis basilaris medianus as identified on cone-beam computed tomography (CBCT) in the base of the skull. The CBCT data sets were sent for radiographic consultation. In both cases, multi-planar views revealed an osseous defect in the base of the skull in the clivus region, the sagittal view showed a unilateral, well-defined, non-corticated, track-like low-attenuation osseous defect in the clivus. The appearance of the defect was highly reminiscent of a fracture of the clivus. The borders of osseous defect were smooth, and no other radiographic signs suggestive of osteolytic destructive processes were noted. Based on the overall radiographic examination, a radiographic impression of canalis basilaris medianus was made. Canalis basilaris medianus is a rare anatomical variant and is generally observed on the clivus. Due to its potential association with meningitis, it should be recognized and reported to avoid potential complications.

Effect of calcium hydroxide and chlorhexidine medicaments on the apical seal

Leakage of the root canal system is an importent consideration when placing an intracanal medicament. The aim of this in vitro study was to compare the effect of calcium hydroxide and 1% chlorhexidine gel as intracanal medicaments on tooth apical seal. Seventy extracted, single-rooted maxillary anterior teeth were divided into the three experimental groups [n=20]. All root canals were instrumented with step-back technique and divided into three groups. Group 1 had root canal dressing with calcium hydroxide; group 2 had root canal dressing with 1% chlorhexidine gel and group 3, did not receive a dressing. The roots were incubated in 100% humidity at 37°C for 7 days. After removing the dressings, all canals of the experimental groups were obturated using a cold lateral condensation technique. The root surfaces of all specimens were coated with two layers of nail varnish, except for the 2 mm surrounding the apical foramen. Apical sealing ability was assessed by dye leakage method and the specimens were examined under a stereo-microscope. Dye penetrations were measured and analyzed using ANOVA and post-hoc Tukey test. Calcium hydroxide group had the least frequency of apical leakage at 2 mm level [0.46 +/- 0.40 mm], whilst chlorhexidine group showed the greatest apical leakage [0.86 +/- 0.42 mm]. There was statistical difference between group 1 and 2 [P<0.05], but no statistical difference between group 1 and 3, or between groups 2 and 3 [P>0.05]. Intracanal calcium hydroxide medicament may decrease apical leakage of gutta-percha root fillings when AH26 sealer is used; chlorhexidine may increase the leakage

ex-vivo study on the shaping parameters of two nickel-titanium rotary systems compared with hand instruments

Rotary nickel-titanium [NiTi] instruments are thought to allow shaping of narrow, curved root canals more efficiently and more effectively than stainless steel hand instruments. However, the continued search for even more effective and safer instruments has resulted in new rotary systems being introduced on a regular basis. The aim of this study was to compare shaping parameters of RaCe and Mtwo NiTi rotary files with stainless steel K-Flexofile hand instrument. A total of 60 mandibular first molars with 20-40 degree of curvature in mesial root were divided in to three groups and each was prepared with one kind of instrument [RaCe, Mtwo, stainless steel K-Flexofile]. Using pre and post-radiographs, canal curvature was measured, with the Schneider technique. Preparation time was recorded. For evaluating canal centering and transportation, the tooth was sectioned 3, 6 and 9 mm from the apex. Pre and post-preparation photographs were taken from mesiolingual canal. Data was statistically analyzed using One-way AN OVA and Chi-Square tests. RaCe and Mtwo maintained canal curvature better than K-Flexofile [P<0.001]. Mtwo prepared the canal in a shorter time [P<0.001]. Significant statistical difference was not found in the three canal sections between the various systems. RaCe resulted in significantly fewer canal aberrations and better centering ability