Assessment of root surfaces of apicected teeth: A scanning electron microscopy evaluation

Objectives: The aim of this study was to determine the apical surface characteristics and presence of dental cracks in single‑rooted premolars, resected 3.0 mm from the root apex, using the Er: YAG laser, tungsten carbide bur, and diamond‑coated tip, by scanning electron microscopy (SEM).Experimental design: Thirty single‑rooted premolar teeth were collected. The instrumented and obturated teeth were divided into three groups according to the root resection method (2.94 μm, 100 mj, 20‑Hz Er: YAG laser, plain tapered fissure tungsten carbide bur at a low speed of 40,000 rpm, or a diamond‑coated SG6D tip coupled to the handpiece of a conventional ultrasound device). The specimens were prepared for SEM and analyzed by the Kruskal–Wallis and Mann–Whitney statistical tests.Results: The SEM images showed that tungsten carbide burs produced significantly smoother resected root surfaces than the diamond‑coated tip. There was no statistically significant difference between the Er: YAG and tungsten carbide bur groups. The analysis of scores obtained for the cut quality by the Kruskal–Wallis test revealed no significant differences among the groups. In our study, five teeth had no cracks after the apical resection. The mean number of cracks per tooth was 3.5 ± 1.780 (Er: YAG laser group), 2.5 ± 1.716 (tungsten carbide bur group), and 4.5 ± 2.593 (diamond‑coated tip group).Conclusions: Under the tested conditions smoother surfaces were observed in the groups treated with the tungsten carbide bur and Er: YAG laser when compared with the diamond‑coated tips.Key words: Apicoectomy, dental cracks, Er: YAG Laser, surface roughnes

Three-dimensional analysis of the physiological foramen geometry of maxillary and mandibular molars by means of micro-CT

The aim of this study was to investigate the physiological foramen diameter, shape and distance between physiological and anatomical apex of maxillary and mandibular first and second molars. Accurate knowledge of the physiological foramina morphology; thus, inherent mechanical shaping technical hindrances, is decisive when taking the corresponding root canal final preparation decision. The morphological dimensions of a total of 1727 physiological foramina were investigated by means of micro-computed tomography. Mean narrow and wide (to a high number, oval) diameters of the physiological foramen were 0.24, 0.22 and 0.33 mm and 0.33, 0.31 and 0.42 mm in mesiobuccal (MB), distobuccal (DB) and palatal (P) roots in maxillary first molars; 0.24, 0.22 and 0.33 mm and 0.41, 0.33 and 0.44 in MB, DB, and P roots in maxillary second molars. Mandibular first molars showed mean narrow and wide diameters of 0.24 and 0.30 mm and of 0.39 and 0.46 mm in mesial (M) and distal (D) roots; second mandibular molars showed 0.25 and 0.31 mm and 0.47 mm in M and D roots. The mean distance between the physiological foramina and anatomical apex was 0.82, 0.81 and 1.02 mm and 0.54, 0.43 and 0.63 mm in MB, DB and P roots of the maxillary first and second molars, respectively. A mean distance of 0.95 mm (M) and 1.05 mm (D) in the first and 0.78 mm (M) and 0.81 mm (D) in the second mandibular molars was observed. Based on the results obtained, assumable recommendations for final preparation size of the physiological foramen were calculated. However, when taking into consideration, the resulting standard deviations of marginal errors must be cautiously considered when taking a final decision in clinical endodontic treatment

Mobbing in the workplace by peers and managers: mobbing experienced by nurses working in healthcare facilities in Turkey and its effect on nurses

Aim. This research was conducted as a descriptive and cross-sectional study with the purpose of determining the mobbing experienced by nurses who work in healthcare facilities in Turkey, its emotional, social and physiological effects on the nurses and the actions that the individuals take to escape from the mobbing