Abstract Resin CAD/CAM guides for the maxilla are widely used and differ from custom miniplates essentially in that they do not have drill guides for screw fixation and use miniplates that must be modeled in surgery. To solve this problem, we have developed a new Maxillary guide bone-supported indicated for osteotomy, drilling, and maxillary positioning in orthognathic surgeries using standard modeled miniplates. In this study were included sixteen patients who had bimaxillary orthognathic surgery. The technique for its manufacturing is described, and its surgical accuracy was analyzed using the planning image (CT0) superimposed on the computed tomography scan post-treatment (CT1). The mean positional differences between pre-treatment and post-treatment were obtained Tri-dimensionally on the X, Y, and Z axes using four landmarks points: one bone (SNA), and three dentals (CI, RM, and LM). At Sixty-four points analyzed on the X axis of the four landmarks, only eight points were greater than 1 mm; 87.5 % of the deviations were <1 mm. For the Y-axis 78.12% of the deviations were <1 mm and for Z-axis, 76.56 %. The mean and standard deviation of the error was 0.36 (0.28) mm, 0.93 (1.07) mm, and 0.73 (0.86) mm on the X, Y, and Z axes, respectively. The X-axis demonstrated the best results among the three axes. The results of the accuracy and reliability tests were satisfactory and support the use of the proposed technique.

OBJECTIVE: The objective of this work was to evaluate, using radiographic images, the behavior of four materials used to repair root perforations in dogs' teeth. Material and METHODS: Second and third premolars of 6 dogs were used. The 48 teeth were randomly divided into 4 groups (n=12) and the perforations were sealed with one of the following materials: MTA, AH Plus, Vitremer and gutta-percha. Dogs were submitted to general anesthesia, teeth were radiographed and pulp was accessed. Perforations were done, at the maximum curve of the pulp floor, sealed and the accessed coronal cavity was filled with glass ionomer cement (Vidrion R). After 90 days, the dogs were sacrificed and the last x-ray image was taken. Images were analyzed for the presence/absence of periodontal lesions at the perforation region. Data were analyzed statistically by chi-square test at 5% significance level. RESULTS: There were no statistically significant differences (p>0.05) among AH Plus, Vitremer and gutta-percha groups. MTA produced the smallest number of periodontal lesions (p<0.05). CONCLUSIONS: It may be concluded that none of the tested materials was able to preserve the integrity of the periodontal tissues in the furcation region, and the use of MTA resulted in the least formation of adjacent periodontal bone lesions revealed by the radiographic comparisons.