Notes

Spectral polarization photographic camera according to ghost imaging by way of sparsity limitations.
05). Thus, time was considered an important factor for the fluoride release system. Nanotechnology can be a promising system for caries remineralization as it makes fluoride available on the dental surface for a longer time.Dental anatomy can vary significantly between different populations from different countries. Dental anatomical variations are of great interest to the dental professional, especially to endodontists, since they can influence the outcome of endodontic treatment. The purpose of the present study was to describe the anatomical variations of the root canal in mandibular first premolars in a population from Colombia, using micro-computed tomography. Fifty mandibular first premolars were scanned on a SkyScan 1174 and the microcomputed tomographic images were reconstructed. Anatomy was assessed using three-dimensional models. The parameters used were Vertucci's classification, area and volume, perimeter, circularity, and major and minor diameter at 1, 2 and 3 mm from the apical foramen. According to the Vertucci's classification, teeth were classified as types I (40%), V (24%), VII (4%) and III (4%), with 28% not classifiable. C-shaped canals were found in 1.8% of the sample. Mean evaluations at 1, 2, 3 mm of the foramen were as follows, respectively perimeter 1.07 ± 0.57, 1.27 ± 0.78 and 1.57 ± 0.84 mm; circularity 0.59 ± 0.19, 0.57 ± 0.20 and 0.56 ± 0.22; maximum diameter 0.41 ± 0.23, 0.48 ± 0.33 and 0.60 ± 0.37 mm; minimum diameter 0.24 ± 0.10, 0.26 0.11 and 0.21 ± 0.13 mm. Mean total area and volume were 61.27 ± 16.47 mm2 and 12.47 ± 4.95 mm3, respectively. There was wide anatomical variation in mandibular first premolars from Colombian individuals, reinforcing the need for proper anatomical knowledge to establish more effective strategies for endodontic treatment.The masticatory system changes as time passes. The vertical dimension of occlusion (VDO) undergoes alterations due to temporomandibular joint disorders which in turn may be caused by related muscle modifications or pathological tooth wear. There are many methods to measure VDO. Galunisertib in vivo Among these, the anthropometric method and Knebelman's craniometric method have been shown to be the most closely related to facial biotype. The aim of this study was to compare data recorded with those two methods. A descriptive cross-sectional study was performed with a total 200 patients. A vernier caliper was used to measure facial landmarks. Results were analyzed using paired t-test, setting the level of significance at p less then 0.05. There was no significant difference between the two methods but Knebelman's method had less variability. Results suggest that Knebelman's method should provide more reliability for determining VDO in all the facial biotypes studied.The aim of this study was to compare jaw relation record in the completely edentulous patient using acrylic rim trays with curved or flat registration plates or using the manual guidance technique. The study included 17 patients - 11 female and 6 male, average age 70 years. Three jaw relation records were taken during one session, in the same vertical dimension, using acrylic rim trays (1) with manual guidance (IM), (2) with self-guided recording system with acrylic rim tray and central support using a curved plate (BYC) and (3) with self-guided recording system with acrylic rim tray and central support using a flat plate (BYR). The models were mounted on a Whip Mix 2240 articulator to which a condyle position device (Orthodent) was added to register, at the level of the condyle box and incisal table, the differences among the positions recorded with the different setups (IM, BYC and BYR). The distances were measured on millimeter paper provided by the recording system manufacturer. For statistical analysis, confidence intervals (95%) were calculated for the mean differences and Student's t-test for paired data (significance level alpha less then 0.05). On both the mesiodistal plane and the vertical plane at the level of each condyle box and the incisal table, there were statistically significant differences among the three systems (p less then 0.001). At the level of incisal table, BYC and BYR provided more retrusive records than IM [arithmetic means (standard deviations) in millimeters 3.82 (2.10) and 4.53 (2.18), respectively). The records obtained with BYR were significantly more retrusive with BYC [arithmetic mean (standard deviation) in millimeters 1.41 (1.00)]. We reject the null hypothesis that proposes that all three registration systems described are clinically equivalent for establishing a jaw relation record in completely edentulous patients.The risk of fracture or strain in mini-screws is higher if diameter, length, type of alloy or insertion angle is selected inappropriately. The aims of this study were to test the structural resistance of two types of orthodontic mini-screws -one made of stainless steel and another of titanium- from an international brand and to evaluate the efficacy of two other titanium miniscrews of Brazilian origin, during an extra-alveolar anchorage procedure. The mini-screws analyzed were Bomei stainless steel and Bomei titanium / Taiwan, Morelli titanium and Neodent titanium/ Brazil. Experiments were conducted on pig mandibles to simulate the process of extra-alveolar anchorage. Two insertion processes were used Direct at 30º, and Indirect, starting at 60º and ending at 30º with gradual continuous movement. Strain was evaluated using Optical and Scanning Electron Microscopy. Data were evaluated using Kruskal-Wallis non-parametric statistical analysis and post hoc Tamhane test. Significant statistical differences in strain were observed among the mini-screws used in the extra-alveolar insertions, both for the direct and indirect procedures. In the indirect insertion tests, both stainless steel and titanium mini-screws suffered deformation, showing that angling can be an important factor in mini-screw failure rates. The change in angle during the insertion movement increased deformation rates independently of alloy type, increasing the risk of failure. These results could help orthodontists in choosing mini-screws for extra-alveolar anchorage, which can be performed with direct or indirect insertion. In vivo studies should be conducted to confirm the findings of this study.
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