Search

Introduction The aim of this study was to investigate the number of roots and the morphology of the root canals of maxillary and mandibular premolars in a selected German population. Methods Randomly selected full-size cone-beam computed tomographic images were collected from 700 patients (45% men and 55% women, average age = 50.21 years). This resulted in a total of 644 first and 512 second maxillary premolars as well as 1044 first and 871 second mandibular premolars. The total number of roots and root canals, the frequency and correlations between the left and right sides, and the incidence in men and women were recorded and statistically analyzed using the Fisher exact and chi-square tests. Canal configurations were classified according to the Vertucci classification. Results First maxillary premolars mainly had 2 roots (1 root: 36.4%, 2 roots: 62.4%, and 3 roots: 1.2%) with predominantly 2 canals (88.4%). The majority of second maxillary premolars had 1 root (82.6%), but 2 root canals (56.3%) occurred more frequently than 1 canal (43.1%). In the first and second mandibular premolars, 1 root was found predominantly (90.76% and 98.16%, respectively) with 1 canal (77.9% and 96.0%), whereas 2 canals were less common (21.9% and 3.6%). Three roots (0%, <0.11%) and 3 canals (0.2%; 0.4%) were rarely found. Vertucci classifications were heterogeneously distributed. Men showed significantly more roots and root canals compared with women ( P < .05), with the exception of the second mandibular premolars. Conclusions This cone-beam computed tomographic study confirmed previous anatomic and morphologic investigations. When treating premolars, the likelihood of additional root canals should be considered. [ABSTRACT FROM AUTHOR]

Introduction The purpose of this study was to study the root canal morphology of South Asian Indian mandibular premolars using a tooth clearing technique. Methods Two hundred mandibular premolar teeth were collected from different dental schools and clinics in India. After pulp tissue removal and root canal staining with Indian ink, the specimens were decalcified with 5% nitric acid, dehydrated in ethyl alcohol, and subsequently cleared in methyl salicylate. Results Of the 200 mandibular premolars, 100 were first premolars and 100 were second premolars. Of the first premolars, 94% had a single root, whereas 6% were 2 rooted. Seventy-six percent had a single canal, 22% had 2 canals, and 2% had 3 canals. Eighty-two percent had a single apical foramen, 16% had 2 foramens, and 2% teeth had 3 apical foramens. Eighty percent of teeth had type I, 6% had type II, 10% had type IV, 2% had type V, and 2% teeth had type IX root canal anatomy. Of the 100 second premolars, 92% had a single root, whereas 8% teeth were 2 rooted and fused. Fifty-eight percent of teeth had a single canal, and 42% had two canals. Eighty-eight percent had a single apical foramen, and 12% had 2 foramens. Sixty-six percent had type I, 30% had type II, and 4% had type V root canal anatomy. Conclusions A high prevalence of 2 canals was noted in the first and second premolars. Also, 20% of first premolars and 34% of second premolars had a root canal anatomy other than type I. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to describe the anatomy of mandibular premolars with type IX canal configuration by using micro–computed tomography. Methods: Mandibular premolars with radicular grooves (n = 105) were scanned, and 16 teeth with type IX configuration were selected. Number and location of canals, distances between anatomic landmarks, occurrence of apical delta, root canal fusion, and furcation canals, as well as 2-dimensional (area, perimeter, roundness, major and minor diameters) and 3-dimensional (volume, surface area, and structure model index) analysis were performed. Data were statistically compared by using analysis of variance and Kruskal-Wallis tests (α = 0.05). Results: Overall, specimens had 1 root with a main canal that divided into mesiobuccal, distobuccal, and lingual canals at the furcation level. Mean length of the teeth was 22.9 ± 2.06 mm, and the configuration of the pulp chamber was mostly triangle-shaped. Mean distances from the furcation to the apex and cementoenamel junction were 9.14 ± 2.07 and 5.59 ± 2.19 mm, respectively. Apical delta, root canal fusion, and furcation canals were present in 4, 5, and 10 specimens, respectively. No statistical differences were found in the 2-dimensional and 3-dimensional analyses between root canals (P > .05). Conclusions: Type IX configuration of the root canal system was found in 16 of 105 mandibular premolars with radicular grooves. Most of the specimens had a triangle-shaped pulp chamber. Within this anatomic configuration, complexities of the root canal systems such as the presence of furcation canals, fusion of canals, oval-shaped canals in the apical third, small orifices at the pulp chamber level, and apical delta were also observed. [ABSTRACT FROM AUTHOR]

Introduction The purpose of this study was to compare the effectiveness of mental incisive nerve block (MINB) and inferior alveolar nerve block (IANB) that were given alone or in combination to provide anesthesia to symptomatic mandibular premolars. Methods One hundred fifty-three patients participated in this randomized, double-blind clinical trial. The patients were divided into 3 groups; first group received MINB with 2 mL 2% lidocaine with 1:200,000 epinephrine and a mock IANB with 2 mL sterile saline, patients in group 2 received mock MINB and an IANB with 2 mL 2% lidocaine, and patients in group 3 received both MINB and IANB with 2 mL each of 2% lidocaine. Access cavity preparation was initiated after 10 minutes. Success was defined as no pain or faint/weak/mild pain during endodontic access preparation and instrumentation. The anesthetic success rates were analyzed with Pearson χ 2 test at 5% significance levels. Results The MINB and IANB gave 53% and 47% anesthetic success rates, respectively, with no significant difference between them. Adding an IANB to MINB significantly improved the success rates to 82%. Conclusions A combination of MINB and IANB can provide improved local anesthesia for symptomatic mandibular premolars. [ABSTRACT FROM AUTHOR]