Rapid Maxillary Expansion (RME) is an orthopaedic treatment used to correct the transverse deficit of the maxilla. Most often, this defect is diagnosed in mouth-breathing patients. Rapid Palatal Expander (RPE) treatment increases the upper airways’ volume and decreases resistance, promoting physiological nasal breathing. The aim of this study is to measure the volume of the upper airways by employing Cone-beam Computed Tomography (CBCT) to evaluate the anatomical space where the major effects of RME occurred. Twenty-four subjects (mean age, 10.17 ± 1.75 years) treated with McNamara-type rapid palatal expander were selected. Two CBCT scans were taken for each patient: the first at the beginning (T0) and the second at the end of the treatment (T1). For each CBCT scan, Total Volume (TV), Retropalatal Volume (RPV) and Retroglossal Volume (RGV) were measured with the software ITK-Snap. The statistical analysis was performed using the paired samples t-test, with a p-value of 0.05. RPV significantly increased (Δ T1-T0: 680.75 mm3 ± 792.63 mm3, P<0.05). No significant changes were found in TV (Δ T1-T0: 452.92 mm3 ± 3091.7 mm3, P>0.05) and in RGV (Δ T1-T0: 166.92 mm3 ± 666.97 mm3, P>0.05). In this study, patients showed a statistically significant increase in RPV after RPE treatment. The CBCT scans provide only quantitative volumetric data, so it would be appropriate to determine the clinical significance of the obtained results with a functional examination (for example, rhinomanometry). The radiological protocol should be standardised to overcome limitations such as tongue posture during scan recording, swallowing and breathing control. Further studies are needed to evaluate the long-term stability of these effects on the airways.

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Introduction: The removal of the filling material during the Endodontic retreatment is essential, so a better action of solvents on the gutta-percha is desired. Objective: To evaluate in vitro the gutta-percha dissolution ability of different solvents. Material and methods: Four solvents (xylol, eucalyptol, citrol, and orange oil) were applied on gutta-percha points, which had been later submitted to the weight loss analysis at 2, 5, and 10 minutes. For each solvent, 30 size #60 main cones were used, divided into three groups. Distilled water was used as control group. The statistical test applied was Kruskal-Wallis. Results: No statistically significant difference occurred among the solvents at 2 minutes (p > 0.05); however, during this period, citrol had the best performance. In longer time intervals, the xylol showed differences compared to eucalyptol at 5 minutes and to eucalyptol and citrol at 10 minutes (p < 0.05). The worst results were found for eucalyptol. Conclusion: This xylol was the solvent with improved ability to dissolve the gutta-percha points, with better results at longer time periods.

Introduction: Coronary access is the first stage of endodontic treatment and aims at direct access to root canals. Objective: To evaluate, by radiographic analysis, endodontic access cavities through radiographic analysis of the teeth of patients coming from primary care referred to the Center of Dental Specialties (CEO) Positivo, Curitiba, PR, Brazil. Material and methods: A total of 226 periapical radiographs taken previous to attending the CDS were analyzed, from August 2015 to August 2017. Three trained and calibrated examiners verified the following criteria: oral cavity region, presence of remaining caries,removal of roof of the pulp chamber, compensatory mesiodistal wear, iatrogenic (suggestive) and temporary restoration. Data were tabulated and analyzed for distribution, followed by bivariate analysis (Fisher’s Exact Test) with significance of 5%. Results: The posterior region prevailed in 70.3% of the sample. There remaining caries were found in 14.2%, insufficient roof removal in 25.2%, iatrogenic in 35.4%, and inadequate height of the temporary restoration in 11.5% of the cases. In the posterior teeth, insufficient mesiodistal compensatory wear was identified in 35.4 of the exams. The bivariate analysis revealed no significant difference when the variable region of the oral cavity was analyzed in relation to the presence of caries (p = 0.393), remaining roof (p = 0.056) and presence of iatrogenic (p = 0.304). Conclusion: It is concluded that there are relevant failures in the endodontic access received in the CDS, which indicates the need for professional training in primary care.

The removal of the filling material during the Endodontic retreatment is essential, so a better action of solvents on the gutta-percha is desired. Objective: To evaluate in vitro the gutta-percha dissolution ability of different solvents. Material and methods: Four solvents (xylol, eucalyptol, citrol, and orange oil) were applied on gutta-percha points, which had been later submitted to the weight loss analysis at 2, 5, and 10 minutes. For each solvent, 30 size #60 main cones were used, divided into three groups. Distilled water was used as control group. The statistical test applied was Kruskal-Wallis. Results: No statistically significant difference occurred among the solvents at 2 minutes (p > 0.05); however, during this period, citrol had the best performance. In longer time intervals, the xylol showed differences compared to eucalyptol at 5 minutes and to eucalyptol and citrol at 10 minutes (p < 0.05). The worst results were found for eucalyptol. Conclusion: This xylol was the solvent with improved ability to dissolve the gutta-percha points, with better results at longer time periods.