166 resultados para apical pericardial adhesion


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundacao de Amparo a Pesquisa do Estado de sao Paulo (FAPESP)

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AIM: To evaluate the occurrence of external apical root resorption (EARR) in the incisors after anterior retraction in corrective orthodontic treatment with first premolar extractions and whether it was related with the type of root apex movement and its inclination. METHOD: The maxillary and mandibular incisors of 22 patients (12 to 25 years of age; 9 males and 13 females) were treated with fixed appliances and premolar extraction. EARR was defined as the difference in root length before and after incisal retraction on periapical radiographs. Distortion of radiographic images and changes due to incisal tipping were controlled for. Pre- and post-incisal retraction lateral cephalometric radiographs established the relationship between EARR and the tipping of the incisors, along with the vertical, horizontal, and total movement of the root apex. RESULTS: There was significant EARR (1.51 to 2.37 mm) during incisor retraction, but this was not related to the movement or the tipping of the root apex of almost all teeth. It was observed that after the retraction stage, EARR occurred in all evaluated incisors, but it was more significant (P < .05) in the mandibular right lateral incisor. CONCLUSION: The EARR that did occur was unrelated to movement or tipping of the root apex, except for the vertical root apex movement of the mandibular left central incisor and the inclination of the maxillary right lateral incisor.

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The aim of this study was to evaluate the morphology and adhesion of blood components on root surfaces instrumented with piezoelectric ultrasonic Piezon Master Surgery. Methods 10 teeth were used in this study. The teeth had their proximal divided into four areas that received different treatments: Group 1: untreated control Group 2: scaling with manual instrument; Group 3: scaling with ultrasound; Group 4: Scaling with manual instruments and ultrasound. We obtained 20 samples, 10 of which were used to analyze the morphology and the other 10 were used for analysis of adhesion of blood components. The specimens were analyzed by scanning electron microscopy. Photomicrographs were analyzed by the scores of adhesion of blood components and the index of root morphology. The results were statistically by the Kruskall-Wallis and Mann-Whitney with a significance level of 95%. Results The morphological analysis showed that the Group 1 had a surface unchanged in relation to other groups (Group 1 X Group 2 = 0.0025; Group 1 X Group 3 = 0.0003; Group 1 X Group 4 = 0.0003) and Group 2 presented a smoother surface compared to Group 1 and groups instrumented with ultrasound (Group 2 X Group 3 = 0.0025; Group 2 X Group 4 = 0.0025) there were no statistical differences between the Groups 3 and 4. analysis of adhesion of blood components showed that the Groups 2, 3 and 4 had no statistically significant differences between themselves, but more biocompatible surfaces promoted the surface untreated control (Group 1 X Group 2 = 0.02; Group 1 X Group 3 = 0.04; Group 1 X Group 4 = 0.005). Conclusion The instrumentation with piezoelectric ultrasonic promoted an irregular root surface, but did not negatively affect the adhesion of blood components.

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Aim: The role of saliva on Candida adhesion to biomaterials has not been clearly defined. The present study investigates whether different periods of preconditioning with saliva would influence the adhesion of Candida albicans to a denture base resin. Methods: Ninety samples of acrylic resin with smooth surfaces were made and then divided into five groups: one control without saliva, and four experimental groups conditioned in saliva for periods of 30 min, 1, 3, or 12 h. Candida adhesion was evaluated by crystal violet staining and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-([phenylamino] carbonyl)-2H-tetrazolium-hydroxide assay. Results: The one-way analysis of variance revealed that there were no significant differences among the mean number of adherent cells or among the mean absorbance for all groups. No significant correlation was found between the two methods used for assessing Candida albicans adhesion. Conclusion: The different periods of preconditioning with saliva had no significant influence on the adhesion of Candida albicans to the denture base acrylic resin.

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Objective In studies on Candida albicans adhesion to surfaces, diverse protocols have been used for collection and preparation of saliva samples. Thus, this study investigated whether variations in the centrifugation parameters and number of donors of saliva would influence the adhesion of C. albicans to a denture base resin. Methods Resin acrylic samples (n = 72) were made and then divided into four groups: (a) control – specimens were left without preconditioning in saliva; (b) three experimental groups, in which the specimens were preconditioned with saliva collected from 15 volunteers and centrifuged at 12 000 g for 5 min (G1); from 15 volunteers and centrifuged at 18 000 g for 30 min (G2); and from one volunteer and centrifuged at 12 000 g for 5 min (G3). Candida adhesion was evaluated by both the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction method and crystal violet staining. Data were analyzed by one-way analyses of variance (P = 0.05). Results For XTT reduction assay, groups G2, G3, and control were not significantly different, whereas group G1 showed significantly higher absorbance value than control. For crystal violet staining there were no significant differences among all groups. Conclusion Variations in the centrifugation parameters and number of donors of saliva may influence C. albicans adhesion to denture base resins.

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The aim of this study was to evaluate in vitro the apical leakage after the apical re-preparation and replacement of the principal gutta-percha point plus endodontic sealer (Sealer 26TM). Sixty extracted human canines were prepared by using a step back technique up to size 50 K type file apically. At each change of instrument the canals were irrigated with distilled water. After that step, the external surface roots were coated and subdivided into six groups with ten roots each: I – single gutta percha point technique; II – lateral condensation and III – hybrid technique. The IV, V and VI groups were similar to others groups but after to place the principal gutta percha point, it was removed, re-prepared up to size 60K file and in sequence replaced the principal gutta percha point and the root canal filling finished. The specimens were immersed in 2% Rhodamine BTM for 7 days at 37 oC. The apical leakage was measured by Image ToolsTM program. With Kruskal Wallis test statistical analysis showed that there was no significant difference between the techniques (p > 0.05).

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The Portland cement has shown similar biological properties to calcium hydroxide, but its radiopacity is lower. Therefore, the addition of materials that minimize this deficiency should be considered. OBJECTIVE: To evaluate the apical sealing ability and pH of a white Portland cement added of several radiopacifying agents. MATERIAL AND METHODS: Forty bovine roots with incomplete apices were selected, and the foraminal openings were standardized to PM 720G bur. After the external root sealing, an apical intracanal barrier 10.0 mm thick was executed with the white Portland cement powder, pure or added of a radiopacifying agent (iodoform, zinc oxide or bismuth subnitrate), and distilled water (0.37 mL). The apical roots were immersed 24h in water in humid atmosphere, and after that they were immersed 24h in 2% Rhodamine B, under vacuum. In sequence, the roots were longitudinally sectioned, the root fragments were photographed, the images were digitalized and the apical infiltration was measured by the Image Tool program. The pH solutions were also evaluated, in 24h and 48h and 7 and 30 days. Data were submitted to Anova test. RESULTS: The zinc oxide solution has the lowest apical infiltration in relation to the other groups (p < 0.05). The pH behavior varied during the analysis, and in the period of 24h all groups showed the highest values (p < 0.05). CONCLUSION: The type of radiopacifying agent used interferes in the sealing ability of the apical barrier, and zinc oxide showed to be the most beneficial one. The pH varies according to the period of analysis, and the highest values were obtained in the first 24h (p < 0.05).