415 resultados para Tooth demineralization


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

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Impaction of maxillary canines can be prevented by early intervention in the mixed dentition phase after the correct diagnosis of malocclusion, reducing the complexity of the treatment. This article reports the case of a 10-year-old patient who possessed impacted maxillary canines and, after early extraction of primary canines, had reestablished favorable permanent successors' eruption axis. This 5-year radiographic follow-up study with panoramic radiography shows that this can be used in practice and that an effective control strategy ensures the accuracy in the inclination of the impacted canines. Treatment success is related to early diagnosis and strategic interceptive treatment choice.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This in vitro study evaluated the effect of a prolonged erosive pH cycling on the superficial microhardness change (SMHC) and the erosive wear of different restorative materials. Eighty enamel specimens with prepared cavities of 1.5 x 1.5 mm were randomly divided into eight groups according to the restorative materials used for the fillings (RMGI - resin-modified glass-ionomer, CGI - conventional glass-ionomer, CR- composite resin, A - amalgam) and immersion media used (ERO - erosive medium or SAL - artificial saliva). During 35 days, half of the specimens were immersed in a cola drink (ERO), for 5 min, three times a day, and they remained in SAL between the erosive cycles. The other half of the specimens was immersed in SAL only, for the entire experimental period (control). Data were tested for significant differences by anova and Tukey's tests (P < 0.05). Scanning electron microscopy images were made to illustrate the enamel erosive wear and restorative materials alterations. The mean SMHC (%) and mean erosive wear (mu m) of the materials were: RMGI-ERO (30/0.5); CGI-ERO (37/0.5); CR-ERO (-0.3/0.3); A-ERO (-4/0.3); RMGI-SAL (4/0.4); CGI-SAL (-6/0.4); CR-SAL (-3/0.2) and A-SAL (2/0.4). Scanning electron microscopy images showed pronounced enamel erosive wear on groups submitted to erosive pH cycling when compared with groups maintained in saliva. In conclusion, the prolonged pH cycling promoted significantly higher alterations (SMHC and erosive wear) on the glass-ionomer cements than the CR and amalgam.

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This study analyzed degrees of demineralization in bovine enamel using synchrotron microcomputed tomography (SMCT) and hardness measurements (Knoop hardness number, KHN). For 5 days, 40 bovine enamel blocks were individually subjected to a pH cycling model and treatment with fluoride dentifrices (placebo, 275, 550 and 1,100 mu g F/g) diluted in deionized water twice a day. Surface hardness number and cross-sectional profiles of hardness and mineral concentration (by SMCT) were determined. Integrated hardness (KHN x mu m) for sound and demineralized specimens was calculated and subtracted to give the integrated loss of hardness (Delta KHN) for the lesions. Increasing fluoride concentration in the dentifrices led to higher values for surface hardness after pH cycling and mineral concentration (g(HAp) cm(-3)), and lower values for Delta KHN (p < 0.05). From the present results, it may be concluded that hardness measurements revealed demineralization in all groups, which was lower in groups treated with dentifrice with a higher F concentration. SMCT and hardness measurements gave similar results in areas with higher demineralization, but diverged in areas with lower demineralization. Copyright (C) 2009 S. Karger AG, Basel

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Purpose: To compare visual inspection (VI), radiographic examination (RX) and the laser fluorescence device DIAGNOdent (L), as well as their combinations in vitro regarding treatment decisions for occlusal surfaces. Methods: 72 extracted human permanent teeth (molars and premolars) were used. Treatment decisions were recorded by three calibrated examiners, and the options available were fissure sealant and conservative restoration. For validation of treatment decisions, the teeth were sectioned and examined in a stereomicroscope. Thereafter, dental slices were scanned and the images were edited to facilitate classification of existing carious lesions. Intra and inter-examiner reproducibility for the determination of treatment plans were calculated using Cohen's kappa test (95%-CI). Sensitivity, specificity, positive and negative predictive values, and the area under the ROC curve were also calculated. Results: VI and L provided on average the greatest intra- and inter-examiner reproducibility, respectively. Although the combination of diagnostic methods may decrease both intra- and inter examiners reproducibility, combination of VI, L and RX resulted in the greatest sensitivity, being statistically superior to RX and L. There was more inter-examiner agreement for the option of restorative treatment, while the use of sealants as a treatment option yielded the lowest values. Negative predictive values were numerically inferior to positive predictive values, indicating that the examiners preferred not to restore a carious tooth than to proceed operatively in an intact tooth. The combination of the three methods studied showed the best results in determining treatment plans for occlusal surfaces, when compared to the other types of exams. on the other hand, radiographic examination and laser fluorescence were less efficient when used alone.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Reimplantation of primary teeth has been the subject of various clinical and histological studies, but very little is known about the effect of this treatment on primary teeth. The aim of the present study was to histologically evaluate the biological response of dog primary teeth after immediate reimplantation. Twelve dogs were divided into two groups according to postoperative time: 1 week and 3 weeks. Twenty-one upper and lower intermediate incisors were extracted and submitted to endodontic treatment, reimplantation and splinting. The 21 homologous teeth not submitted to treatment served as controls. The animals were killed after the respective experimental periods, and the obtained specimens were processed for histological analysis. Most dogs of the 1-week group exhibited the following alterations: gingival epithelium was inserted in the cemento-enamel junction, with a small number of chronic inflammatory cells being observed in the gingival corium; the periodontal ligament was partially reestablished, with a more expressive chronic inflammatory infiltrate being observed in the apical third; small root resorption was observed on the palatine/lingual side in the apical third. In contrast, in 3-week animals, gingival epithelial insertion was predominantly absent on the buccal side, and a moderate chronic inflammatory infiltrate was present; the periodontal ligament generally showed no bone-cementum reinsertion especially on the palatine/lingual side, with an expressive inflammatory infiltrate in the apical region, and large root resorption was mainly observed on the palatine and lingual sides. In conclusion, reimplantation causes histological alterations in the tooth and its supporting periodontal structures that suggest the impossibility of its maintenance.

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Enamel defects are common alterations that can occur in both the primary or permanent dentition. A range of etiological factors related to this pathology can be found in the literature. Molar Incisor Hypomineralization (MIH) is a kind of enamel defect alteration that requires complex treatment solutions, and for this reason, it is of great clinical interest for dental practice. This article describes the management of a clinical case of MIH in a 7-year-old child. The different treatment options depending on the extension of the defect, the degree of tooth eruption and the hygiene and diet habits of the patient are also discussed.

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This study aimed to evaluate laser fluorescence (LF) for monitoring the initial stage of subsurface de- and remineralization (<150 mu m depth). Ninety-six sound blocks of bovine enamel, selected according to surface hardness (SH) and LF were used in two experimental studies, in vitro and in situ. In vitro, blocks were exposed to a demineralizing solution, then remineralized by pH cycling for 6 days. In situ, 10 volunteers wore acrylic palatal appliances, each containing 4 dental enamel blocks that were demineralized for 14 days by exposure to 20% sucrose solution. Following this treatment, blocks were submitted to remineralization for 1 week with fluoride dentifrice (1,100 mu g F/g). In both experiments, SH and LH were measured after demineralization and after remineralization. Further, enamel blocks were selected after the demineralization/remineralization steps for measurement of cross-sectional hardness and integrated loss of subsurface hardness (Delta KHN). SH and Delta KHN showed significant differences among the phases in each study. LF values for sound, demineralized and remineralized enamel were: 5.2 +/- 1.1, 8.1 +/- 1.2 and 5.6 +/- 0.8, respectively, in the in vitro study, and 5.3 +/- 0.3, 16.5 +/- 4.7 and 6.5 +/- 2.5, respectively, in the in situ study, values for demineralized enamel being significantly higher than for sound and remineralized enamel in both studies. However, LF was correlated with Delta KHN only in situ. LF was capable of monitoring de- and remineralization in early lesions in situ, when bacteria are presumably present in the caries lesion body, but is not correlated with mineral changes in bacteria-free systems. Copyright (C) 2009 S. Karger AG, Basel

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Background: Prune belly syndrome is a rare condition produced by an early mesodermal defect that causes abdominal abnormalities. However, the literature indicates that disturbances related to ectodermal development may also be present. This is the first case report in the literature to suggest that dental abnormalities are part of the broad spectrum of clinical features of prune belly syndrome. Because the syndrome causes many serious medical problems, early diagnosis of abnormalities involving the primary and permanent dentitions are encouraged.Case presentation: The authors report the clinical case of a 4-year-old Caucasian boy with prune belly syndrome. In addition to the triad of abdominal muscle deficiency, abnormalities of the gastrointestinal and urinary tracts, and cryptorchidism, a geminated mandibular right central incisor, agenesis of a mandibular permanent left incisor, and congenitally missing primary teeth (namely, the mandibular right and left lateral incisors) were noted.Conclusion: This original case report about prune belly syndrome highlights the possibility that dental abnormalities are a part of the broad spectrum of clinical features of the syndrome. Therefore, an accurate intra-oral clinical examination and radiographic evaluation are required for patients with this syndrome in order to provide an early diagnosis of abnormalities involving the primary and permanent dentitions.

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INTRODUÇÃO: o alinhamento dentário correto, bem como sua estabilidade, representam objetivos importantes do tratamento ortodôntico. O apinhamento na região anterior é uma anomalia de posição dentária comum e para obter sua correção as opções clínicas disponíveis para o ortodontista são as extrações dentárias, a expansão do arco dentário ou os desgastes interproximais. Os desgastes freqüentemente são indicados, mas existem questionamentos quanto às indicações, técnicas e condições pré e pós-tratamento. OBJETIVO: o objetivo deste artigo é apresentar uma discussão, embasada na literatura pertinente, dos principais fatores envolvidos com este procedimento clínico.

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OBJETIVOS: comparar os valores médios normais das angulações mesiodistais dentárias, propostos por Ursi, em 1989, com as angulações mesiodistais de caninos, pré-molares e molares inferiores em indivíduos com e sem a presença dos terceiros molares inferiores e idades entre 18 e 25 anos. Além disso, foram comparados os valores das angulações mesiodistais desses dentes nessas duas situações. MÉTODOS: foram utilizadas 40 radiografias ortopantomográficas de indivíduos, de ambos os gêneros, que não receberam tratamento ortodôntico, divididos em dois grupos: Grupo I, constituído por 20 radiografias que não apresentavam os terceiros molares inferiores; e Grupo II, formado por 20 radiografias com os terceiros molares inferiores presentes. RESULTADOS E CONCLUSÕES: a análise dos resultados e a análise estatística permitiram concluir que ambos os grupos exibiram pré-molares e molares inferiores mais angulados em sentido mesial, quando comparados à oclusão normal. Por outro lado, a angulação mesiodistal de caninos inferiores mostrou-se semelhante àquela apresentada em casos de oclusão normal. Os dois grupos, quando comparados entre si, exibiram semelhantes valores angulares dos caninos, pré-molares e molares inferiores, de modo que a presença dos terceiros molares não exerceu influência sobre essas angulações mesiodistais dentárias.

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O objetivo deste estudo foi comparar as decisões de tratamento restaurador de superfícies oclusais, sem cavitação, quando realizadas através dos aspectos clínicos e radiográficos, convencional e digitalizado. Foram examinados, 33 sítios das superfícies oclusais de 30 molares permanentes extraídos, com e sem pigmentação. O plano de tratamento para cada região foi realizado por 5 cirurgiões-dentistas, professores universitários, utilizando dois tipos de exames: exame visual de fotografias e radiografia interproximal convencional (IV + RXC); e exame visual de fotografias e radiografia digitalizada (IV + DIGORA). O padrão de validação para os planos de tratamento foi realizado através do aspecto histológico. A sensibilidade em determinar a não-necessidade de tratamento restaurador foi, em média, tanto para a IV + RXC quanto para a IV + DIGORA, de 0,23. A especificidade foi, em média, de 0,83 e 0,86, para a IV + RXC e IV + DIGORA, respectivamente. Quando comparou-se os planos de tratamento intra-examinadores, não foi encontrada diferença estatisticamente significante à nível de 5%. Baseado nestes dados, pode-se concluir que os métodos radiográficos, convencional e digitalizado, não demonstraram diferenças na efetividade da determinação do plano de tratamento de superfícies oclusais sem cavitação.