RESUMO
BACKGROUND: Dental scanners play a critical role in computer-aided design/computer-aided manufacturing technology. This study aimed to compare the accuracy (precision and trueness) of eight dental scanners for dental bridge scanning. MATERIALS AND METHODS: In this in-vitro experimental study, a typodont model with a missing maxillary right first molar was prepared for a 3-unit fixed partial denture. Each scanner (Sirona inEos inLab, Sirona X5, Dentium, Imes icore 350I I3D, Amann Girrbach map 100, 3Shape D100, 3Shape E3) performed seven scans of the typodont, and the data were analyzed using 3D-Tool software. The abutment length, abutment width, arch length, and interdental distance were measured. To assess the accuracy of each scanner, trueness was evaluated by superimposing the scanned data on true values obtained by the 3shape Triosscanner as the reference. Precision was evaluated by superimposing a pair of data sets obtained from the same scanner. Precision and trueness of the scanners were compared using the one-way ANOVA followed by the post-hoc Tukey's HSD test and one-sample t-test (P<0.05 was considerer significant). RESULTS: The precision of scanners ranged from 14 µm (3Shape Trios) to 45 µm (Imes icore 350i), whereas the trueness ranged from 38 µm (3Shape d700) to 71 µm (Sirona X5). CONCLUSION: The reported trueness values for 3Shape Trios, Sirona inEos inLab, Sirona x5, Dentium, Imes icore350i, Amann Girrbach, 3Shape d700, and 3Shape e3 were 63, 45, 71, 67, 70, 53, 38, and 42 µm, respectively, whereas the precision values were 14, 29, 44, 34, 45, 44, 30 and 28 µm, respectively.
RESUMO
CONTEXT: Early detection of peri-implant bone defects is highly important to prevent further bone loss and implant failure. AIMS: This study aimed to assess the diagnostic accuracy of three cone-beam computed tomography (CBCT) systems and periapical radiography for detection of fenestration around dental implants. METHODS: Thirty-one titanium implants were placed in the bovine ribs, in which peri-implant fenestration were simulated. Using a round fissure bur, fenestration defects were created in the apical-third region of implants. CBCT and PA radiographs were obtained before and after creating the defects. The results were analyzed using Chi-square test; kappa coefficient; Cochran's Q-test; McNemar's test; and sensitivity, specificity, positive predictive value, and negative predictive value; and receiver operating characteristic curve. RESULTS: A significant agreement was noted between the two observers in the detection of defect-free samples in all imaging systems (P < 0.05). In detection of samples with defects, a significant agreement was observed between the two observers in use of Cranex three-dimensional and NewTom 3G systems (P < 0.05), but the agreement was not significant for detection of defects in use of Promax 3D (P > 0.05). The results showed no significant difference among the four imaging systems in detection of defect-free samples while the difference was significant among the four groups for detection of defects (P < 0.05). NewTom had the highest sensitivity (75.81%) and specificity (100%) for detection of fenestration. CONCLUSIONS: Within the limitations of CBCT systems different kVp used by different systems, artifacts and noises that influences image quality, difference in diagnostic value of different CBCT systems is due to the differences in type of detector and voxel size. In terms of the type of detector, our results showed that NewTom 3G, which has a higher (kVP) than other systems and the highest accuracy for detection of fenestration.
RESUMO
OBJECTIVE: To determine the diagnostic value of blood cells surface markers in patients with acute appendicitis. METHODS: In this cross-sectional study, 71 patients who underwent appendectomy following a diagnosis of appendicitis were recruited during a one-year period. The patients were divided into two groups: patients with histopathologically confirmed acute appendicitis and subjects with normal appendix. Blood cell surface markers of all patients were measured. Univariate and multivariate analytical methods were applied to identify the most useful markers. Receiver operating characteristics (ROC) curves were also used to find the best cut-off point, sensitivity, and specificity. RESULTS: Overall we included 71 patients with mean age of 22.6±10.7 years. Of the 71 cases, 45 (63.4%) had acute appendicitis while 26 (36.6%) were normal. There was no significant difference between two study groups regarding the age (p=0.151) and sex (p=0.142). The initial WBC count was significantly higher in those with acute appendicitis (p=0.033). Maximum and minimum area under the ROC curve in univariate analysis was reported for CD3/RA (0.71) and CD38 (0.533), respectively. Multivariate regression models revealed the percentage of accurate diagnoses based on the combination of γ/δ TCR, CD3/RO, and CD3/RA markers to be 74.65%. Maximum area under the ROC curve (0.79) was also obtained for the same combination. CONCLUSION: the best blood cell surface markers in the prediction of acute appendicitis were HLA-DR+CD19, a/ß TCR, and CD3/RA. The simultaneous use of γ/δ TCR, CD3/RA, and CD3/RO showed the highest diagnostic value in acute appendicitis.