977 resultados para Open circuit potential


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Background: Matrix metalloproteinase (MMP) inhibitors reduce dentine erosion. This in vitro study evaluated the effect of the supplementation of soft drinks with green tea extract, a natural inhibitor of MMPs, on their erosive potential against dentine. Methods: For each drink tested (Coca-Cola (TM), Kuat (TM) guarana, Sprite (TM) and light Coca-Cola (TM)), 40 dentine specimens were divided into two subgroups differing with respect to supplementation with green tea extract at 1.2% (OM24 (R), 100% Camellia sinensis leaf extract, containing 30 +/- 3% of catechin; Omnimedica, Switzerland) or not (control). Specimens were subjected to four pH cycles, alternating de-and remineralization in one day. For each cycle, samples were immersed in pure or supplemented drink (10 minutes, 30 mL per block) and in artificial saliva (60 minutes, 30 mL per block) at 37 degrees C, under agitation. Dentine alterations were determined by profilometry (mu m). Data were analysed by two-way ANOVA and Bonferroni`s test (p < 0.05). Results: A significant difference was observed among the drinks tested with Sprite (TM) leading to the highest surface loss and light Coca-Cola (TM) to the lowest. Supplementation with green tea extract reduced the surface loss by 15% to 40% but the difference was significant for Coca-Cola (TM) only. Conclusions: Supplementation of soft drinks with green tea extract might be a viable alternative to reduce their erosive potential against dentine.

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Purpose: The objective of the present in vitro study was to evaluate the effect of different minerals in combination with 1% citric acid on dental erosion. Materials and Methods: Ninety enamel samples were randomly allocated to nine groups (G1. pure 1% citric acid solution [control]. G2. with 1 mM Ca: G3 with 0 047 mM F, G4. with 1 mM Fe. G5. with 1 mM P, G6 with 1 mM Ca and 0 047 mM F. G7. with 1 mM Ca and 1 mM P: G8: with 1 mM Fe and 0.047 mM F, G9. with 1 mM Ca, 1 mM P. 0 047 rnM F and 1.0 mM Fe) The samples were subjected to six pH cycles, each consisting of immersion in pure or modified 1% citric acid (1 min) followed by storage in artificial saliva (59 min) Enamel wear was assessed using profilometry. Results: Data were analysed using analysis of variance and Tukey test (P < 0 05) Enamel loss (mean +/- SD) amounted to between 0 87 +/- 0 30 and 1 74 +/- 0 74 mu m but did not significantly differ among the groups Conclusions: The modification of 1% citric acid with different minerals did not have a protective effect on enamel erosion

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Inflammatory cytokines contribute to periapical tissue destruction. Their activity is potentially regulated by suppressors of cytokine signaling (SOCS), which down-regulate signal transduction as part of an inhibitory feedback loop. We investigated the expression of the cytokines tumor necrosis factor alpha (TNF-alpha); interleukin (IL)-10 and RANKL; and SOCS-1, -2, and -3 by real-time polymerase chain reaction in 57 periapical granulomas and 38 healthy periapical tissues. Periapical granulomas exhibited significantly higher SOCS-1, -2, and -3, TNF-alpha, IL-10, and RANKL messenger RNA levels when compared with healthy controls. Significant positive correlations were found between SOCS1 and IL-10 and between SOCS3 and IL-10. Significant inverse correlations were observed between SOCS1 and TNF-alpha, SOCS1 and RANKL, and SOCS3 and TNF-alpha. Increased SOCS-1, -2, and -3 messenger RNA levels in periapical granulomas may be related to the downregulation of inflammatory cytokines in these lesions; therefore, SOCS molecules may play a role in the dynamics of periapical granulomas development. (J Endod 2008;34:1480-1484)

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Objective: As resin-modified glass-ionomer cement (RMGIC) is an adhesive material, its association to dentin bonding agents (DBAs) was previously proposed. This study investigated the adjunctive behavior of an RMGIC with etch-and-rinse bonding systems under in situ/ex vivo cariogenic challenge. Method and Materials: Bovine enamel blocks (3 3 2 mm) were randomly assigned to group VP, Vitremer + its own primer (3M ESPE); group VSB, Vitremer + Single Bond (3M ESPE); and group VPB, Vitremer + Prime & Bond 2.1 (Dentsply). Two blocks of each group were randomly placed in an acrylic palatal appliance, so each appliance included six blocks. Volunteers (n = 10) wore these appliances according to given instructions to promote a sucrose challenge eight times/day for 15 days. After this period, the blocks were removed from the devices and cleaned, and demineralization was assessed through longitudinal microhardness analysis (Knoop indenter, 25 g/5 s). Data were submitted to three-way ANOVA and Tukey test (P < .05). Results: No treatment was able to completely avoid demineralization. All materials showed a statistically significant difference in mineral loss when the microhardness on the outer enamel was compared with deeper regions (P < .05). Conclusion: Association of the tested RMGICs with etch-and-rinse DBAs did not seem to be more beneficial against caries than the conventional treatment with RMGIC. (Quintessence Int 2010; 41: e192-e199)

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An anterior open occlusal relationship and diastemata may negatively interfere with the harmony of the smile, often requiring a multidisciplinary intervention. This clinical report presents an integrated orthodontic, periodontal, and restorative solution for an anterior open occlusal relationship associated with multiple diastemata and discusses the most relevant aspects related to Its etiology and treatment planning.

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Permanent hearing loss is a leading global health care burden, with 1 in 10 people affected to a mild or greater degree. A shortage of trained healthcare professionals and associated infrastructure and resource limitations mean that hearing health services are unavailable to the majority of the world population. Utilizing information and communication technology in hearing health care, or tele-audiology, combined with automation offer unique opportunities for improved clinical care, widespread access to services, and more cost-effective and sustainable hearing health care. Tele-audiology demonstrates significant potential in areas such as education and training of hearing health care professionals, paraprofessionals, parents, and adults with hearing disorders; screening for auditory disorders; diagnosis of hearing loss; and intervention services. Global connectivity is rapidly growing with increasingly widespread distribution into underserved communities where audiological services may be facilitated through telehealth models. Although many questions related to aspects such as quality control, licensure, jurisdictional responsibility, certification and reimbursement still need to be addressed; no alternative strategy can currently offer the same potential reach for impacting the global burden of hearing loss in the near and foreseeable future.

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Introduction: In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. Methods: The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. Results: Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. Conclusions: Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients. (Am J Orthod Dentofacial Orthop 2010; 138:14.e1-14.e7)

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We describe the orthodontic treatment of a patient with Klippel-Trenaunay-Weber syndrome (KTWS) who received orthodontic treatment that included rapid palatal expansion and orthognathic surgery. There is no report in the literature with this orthodontic treatment protocol, that was considered successful. The pros and cons of this approach as well as the risks involved are discussed. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e17-e25)

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Because of their multifactorial etiologies, dental and skeletal open bites are among the most difficult malocclusions to treat to a successful and stable result. Etiologic factors include vertical maxillary excess, skeletal pattern, abnormalities in dental eruption, and tongue-thrust problems. The purpose of this article was to report the treatment of an adult patient with a lateral open bite and a unilateral posterior crossbite. The treatment involved nonextraction therapy, including intermaxillary elastics, to obtain dentoalveolar extrusion in the region of the lateral open bite. The treatment results were successful and remained stable 2 years later. (Am J Orthod Dentofacial Orthop 2010;137:701-11)

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Introduction: The purpose of this study was to evaluate the cephalometric and occlusal changes, the functional occlusion, and the dentinal sensitivity of anterior open-bite treatment with occlusal adjustment. Methods: The sample comprised 20 patients who experienced relapse of the anterior open bite (mean, -1.06 mm). Occlusal adjustment was performed until a positive overbite was established. Cephalometric changes were evaluated on lateral cephalograms taken before and after the occlusal adjustment. The functional occlusion analysis consisted of evaluating immediate anterior and canine guidance and the number of teeth in contact before and after the procedure. Dentinal sensitivity was evaluated before, shortly after, and 4.61 months after the occlusal adjustment. Pretreatment and posttreatment cephalometric changes and the number of teeth in contact were compared with dependent t tests. Percentages of anterior and canine guidance before and after the adjustment procedure were compared with the McNemar test. To compare dentinal sensitivity at several stages, the nonparametric Friedman test was used, followed by the Wilcoxon test. Results: Significant increases in overbite and mandibular protrusion were seen, as were significant decreases in apical base discrepancy, facial convexity, and growth pattern angles. The percentages of immediate anterior and canine guidance increased significantly, as did the number of teeth with occlusal contacts. Dentinal sensitivity increased immediately after the adjustment but decreased to normal levels after 4.61 months. Conclusions: Occlusal adjustment is a viable treatment alternative for some open-bite patients; it establishes positive vertical overbite and improves the functional occlusion with only transient dentinal sensitivity.