594 resultados para Microdureza esmalte
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Hypomineralized first molar often in combination with hypomineralized incisors (MIH - molar incisor hypomineralization) is a common finding in everyday practice. In this condition, hypomineralized dental enamel is fragile and soft, and it can break easily leading to an exposed dentin, and causing dental sensitivity and progression of caries lesions. The prevalence of MIH range from 3.6 to 25% in North of Europe that consider this condition a public health problem. No conclusive information was reported about the etiologic factors of MIH, however, systemic causes seem to be of importance. Several aetiological factors are mentioned as the cause of this condition and they are frequently associated with complications during pregnancy and childhood diseases during the first three years of life. MIH is frequently misinterpreted as fluorosis, hypoplasia or amelogénesis imperfect, however, this condition presents defined clinical aspects that can distinct it from the other defects.
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Following the introduction of the acid-etching technique in enamel surface, direct attachment of orthodontic appliances on the surface of the tooth and/or restorations became a routine procedure in the assembly of the fixed devices. The attainment of a success result is related to the criterion attention to the details and the steps of the bonding technique, as well as, to the knowledge of the characteristics of the adhesive materials and orthodontic brackets. This paper presents some aspects of various types of brackets and adhesives materials.
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Direct bonding of orthodontics attachments to the teeth or restoration has become a routine in fixed appliance therapy. The technique used seems to be simple, but meticulous attention to detail and steps, a thorough understanding of factors involved are needed to ensure a successful outcome into different surfaces. It is the purpose of this article to review concerning aspects to orthodontic bonding in enamel and restorations fabricated from different materials; affording assistance to the reader wiser accomplishment and successful procedure.
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This study aimed to evaluate the clinical and microscopic changes of MIH, and compare them to areas of healthy dental enamel. Methodology: epoxy resin replicas of healthy incisors and affected by MIH were evaluated qualitatively by scanning electron microscopy (SEM) photographs. Results: Clinically it was observed that MIH incisors showed changes in color and surface, with significant structural losses. By SEM, these had irregular surfaces and margins with structural losses. Conclusions: The teeth affected by HMI have clinical and morphological characteristics that are important for the definition of patient's treatment plan.
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The aim of this in vitro study was to evaluate the trans-enamel and transdentinal cytotoxic effects of two in-office tooth bleaching techniques that employ bleaching gels containing 20% and 38% of H2 O2 on cultured odontoblast-like cell line (MDPC-23). Sixty enamel/dentin discs were obtained from bovine central incisors and placed individually in artificial pulp chambers. Six groups were formed according to the following enamel treatments: G1- 20% H2 O2 (1 application); G2- 20% H2 O2 (2 applications); G3- 38% H2 O2 (1 application); G4- 38% H2 O2 (2 applications); G5- 38% H2 O2 (3 applications); and G6- control (no treatment). In G1 and G2, the bleaching gel was left in contact with the enamel surface for 45 min in each application. However, in G3, G4, and G5 the bleaching gel was applied for only 10 min per application. After the last application, the extracts were collected and applied on previously cultured cells (30.000 cells/cm2 ) for 24 h. Cell metabolism was evaluated by the MTT assay and cell morphology was analysed by scanning electron microscopy. Cell metabolism decreased by 96.29%; 96.11%; 96.42%; 95.62%; and 97.18% in G1, G2, G3, G4, and G5, respectively. All treated groups differed significantly from non-treated control group (G6) (p < 0.05). However, the difference in cell metabolism among treated groups was not significant statistically. In addition, significant morphological cell alterations were observed in all treated groups. Under the tested experimental conditions, the extracts collected after both tooth bleaching techniques evaluated in this study caused severe toxic effects on cultured odontoblast-like cell MDPC-23.
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The etiology of gingival smile is multifactorial and the correct diagnosis eill determine a successful treatment planning. Altered passive eruption occurs during the final stages of tooth eruption, when apical migration of the periodontal tissues does not occur, resulting in a distance > 2mm between the alveolar crest and the cement-enamel juncrion. This change leads to the shortening of the clinical crown and even further may lead to excessive gingival exposure. For treatment, there is a necessity for the combined removal of gingiva and bone tissue. This article discusses the literature on the issue and reports a case where periodontal plastic surgery was performed for the correcrion of a gingival smile.
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The treatment of aggressive periodontitis is a challenge to the clinician, therefore the search for effective treatment protocols of this disease is important. The aim of this case report was demonstrate the effectiveness of the combination of systemic antibiotics with non-surgical periodontal therapy in the treatment of generalized aggressive periodontitis. a 27-year-old patient (RCS), smoker for 11 years (10 cigarettes/day on average), with no systemic alteration, attended the periodontal clinic with a complaint abnormal dental position. After the clinical examination, the diagnosis of generalized aggressive periodontitis was defined. The non-surgical periodontal treatment was executed associated with administration of amoxicillin plus metronidazole for ten days. Clinical parameters (Clinical Attachment level, marginal gingival level, periodontal probing depth, bleeding on probing, plaque index and gingival index) and radiographic parameters (distance between the cemento-enamel junction and the bone crest) were evaluated before and after non-surgical periodontal treatment, after antibiotic therapy and three, six and 12 months after the treatment. After one year follow-up, the results showed improvement in clinical and radiographic parameters with stabilized and decreased tooth mobility and absence of tooth loss. It was concluded that the association of non-surgical periodontal therapy with the administration of amoxicillin/metronidazole was effective in the treatment of generalized aggressive periodontitis.
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The present study aimed to analyze the effects of tooth bleaching with 10% carbamide peroxide (CP) gel on the bond strength of resin composite restorations to dentin. Material and Methods: Twenty cavities were prepared on the buccal surface of bovine teeth. After acid etching and application of bonding agent on dentin and enamel, the cavities were restored with composite resin. The specimens were divided into groups according to treatment on the surface of enamel / restoration: G1 - control (no treatment) and G2 (10% PC gel application for 8h/day during 14 days). After this period, the teeth were cut to produce beams with 0.81 mm2 cross-sectional area, which were subjected to microtensile test. The fractures were examined with a stereomicroscope and classified as cohesive in resin or dentin, adhesive, or mixed. Results: The statistical analysis (ANOVA / χ2) revealed that the factor treatment interfered with the bond strength, which was significantly higher for specimens of G2 (p <0.05). Adhesive fractures occurred in most of specimens of both groups with values ranging from 48.3% to 75%. Mixed fractures were the second more frequent in G1 and cohesive resin failure in G2. Conclusion: It was concluded that tooth bleaching with 10% of PC increased the bond strength of adhesive restorations to dentin.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introduction: Currently, there are many questions regarding the cleaning methods seeking greater efficiency and less loss of burs. Aim: the aim of this study was to evaluate the influence of cleaning methods on the cutting efficiency and morphological characteristics of stainless steel burs tungsten carbide (carbide). Materials and method: Thirty burs were divided into five groups (n = 5) according with the cleaning method: L1 - steel brush, L2 - nylon brush, L3 - ultrasound + distilled water, L4 - ultrasound + descaling solution and L5 - no cleaning method (control). The burs were used for the cutting of bovine enamel during six periods of 12 minutes each. After each period, the burs were cleaned (except L5 ) following the protocol established for each group. The cutting efficiency was determined by mass loss and morphological characteristics. Result: The average amount of wear after 72 minutes of use were L1 = 0.3558 g; L2 = 0.4275 g; L3 = 0.4652 g; L4 = 0.4396 g e L5 = 0.4854 g; significant differences in the time of use (p < 0.001) and cleaning method (p < 0.001). The L1 group showed the worst performance. Regardless of the experimental group, morphological analysis revealed alterations in the cutting blades soon after the first 12 minutes, being L1 the most affected group. Conclusion: The cleaning with wire brush was the most damaging method to the cutting efficiency and to the morphology of carbide burs.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.
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The aim of this study was to evaluate the correlation of color change on bleaching tooth through delta E (ΔE) by the spectrophotometer Spectroshade (SS) and digital program Scanwhite (SW). Methods: 25 patient volunteers were recruited from Operative Dentistry at Universidad de Chile Dental School, between 18 to 30 years, with good oral hygiene. Exclusion criteria: Previous experienced tooth bleaching, anterior restorations, cervical lesions, pain dental, pregnant patient, stained teeth, malposition of the teeth and periodontal pathology. The bleaching was made in two sessions with three different bleaching systems which were randomly. The assessment of color change through ΔE was made on the two upper central incisors (N=50) by the SS and SW. The color in the same teeth were measured before (T0) and after (T1) of the bleaching treatment. Data were analyzed using test Spearman correlation coefficient (Rho) with a significant level of 95%. Results: The results showed a positive and significant correlation (0.676), with a statistically significant difference (p<0.05). Conclusion: There is correlation in the measurement of color change on bleaching tooth by SS and SW.
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The demand for cosmetic dentistry, including teeth whitening, has increased in recent years. The home teeth whitening and in-office, are widely used in dental practice. The mechanism by which it works is by oxidation of the chromogenic existing tooth structure. This is an effective and minimally invasive procedure that achieves tooth lighten the color, however, may cause alterations in the enamel surface, such as a dental permeability increase. Another effect caused by this procedure is tooth sensitivity, being the most common side effect, up to 65% of individuals have had a secondary effect at least once during treatment. This sensitivity and gingival irritation caused by bleaching may vary depending on the patient and used bleaching product