This study aimed to describe patients’ demographic characteristics and treatment delivered in private and public dental emergency clinics and to compare them with a pre-pandemic period. A retrospective cross-sectional study was carried out on patients attending the University Dental Hospital of the University of Buenos Aires and on one private dental clinic, situated in Buenos Aires, between March and June of 2019 and 2020. The sample considered all the patients’ medical records of those requiring emergency dental treatment at these centers during that period. We systematize the treatments required and delivered by the emergency providers into categories. In 2019, 36,071 patients were treated at the university dental hospital and the private clinic. In 2020, 7485 patients received emergency treatment, showing a fivefold reduction. During a pre-pandemic period, in 2019, both oral care centers provided 44,894 treatments, around three times the treatments provided in 2020 during the same period. We have found significant differences in the age groups of people who required emergency treatment in the pandemic period compared to the pre-pandemic period. During the pandemic period, the most represented types of treatment were radiographic exams (3061) and tooth extractions (2583). Conversely, during the pre-pandemic period, the most frequent treatments were radiographic examinations (16,649) and general consultations (10,591). The percentages of all types of treatments differ significantly between the two years except for pediatric consultations and prosthetics emergencies. As the pandemic is still an ongoing sanitary problem, urgent dental care patterns should be considered.

The aim of the present study was to evaluate the presence of maxillary first and second molars with a C-shaped canal system in an Argentine subpopulation, and to classify them. Materials and Method: Of the 332 CBCTs initially evaluated, 120 met the selection criteria. Once the presence of a C-shaped canal system had been established, the teeth were classified following Martins et al. Data were expressed as absolute frequencies, percentages with of 95% confidence intervals, according to the score test. Comparisons were analyzed by Chi-square test and Fisher’ exact test, with 5% significance level. Results: It was found that 5 out of 120 first molars (4%) and 17 out of 152 second molars (11%) had a C-shaped canal system. Regarding the classification applied, of 5 C-shaped first molars, 2 corresponded to type E2 (40%), 2 corresponded to type C (40%), and 1 corresponded to type B1 (20%). Of 17 C-shaped second molars, 4 resembled a type A (24%), 7 resembled a type B1 (41%), 5 resembled a type B2 (29%), and 1 resembled a type C (6%). UC1 and UC2 configurations were the most common at all levels except apical level. Conclusion: The prevalence of C-shaped canal system pattern in maxillary first and second molars was estimated for the first time in an Argentine subpopulation, in vivo. Knowledge of these data should help clinicians during endodontic treatment. Keywords: maxillary molars - C-shaped root canal - cone-beam computed tomography

Identifying the presence, size, type and location of voids in an endodontic obturation is of great clinical importance because it enables evaluation of the three-dimensionality of the sealing techniques, which can be related to the success of the endodontic treatment. Aim: To analyze by micro-CT the presence of voids in lower single-rooted premolar root canal obturations prepared using the single cone and ultrasound vibration technique. Materials and methods: Twenty extracted single-rooted lower premolars were selected, and the root canal prepared surgically and chemically. In GROUP 1 - Without Vibration, the canal was obturated with a single cone and bioceramic, without applying vibration. In GROUP 2 - With Vibration, the gutta-percha cone inside the root canal was held with a cotton plier to which ultrasound vibration was applied for 3 periods of 3 seconds each. A micro-CT scanner was used to acquire and reconstruct images for analysis. Results: No significant difference was found between obturation techniques, though there were differences between thirds, with the cervical third having a higher percentage of voids than the middle and apical thirds. Conclusions: The results suggest that the volume of closed, open and total voids does not differ between treatments with and without ultrasound vibration. In the cervical third, the highest volume of voids was related to oval geometry in the teeth evaluated.