RESUMO
OBJECTIVE: To determine the influence of two adhesion boosters on shear bond strength and on the bond failure location of indirectly bonded brackets. MATERIALS AND METHODS: Sixty bovine incisors were randomly divided into three groups (n = 20), and their buccal faces were etched using 37% phosphoric acid. In group 1 (control), brackets were indirectly bonded using only Sondhi adhesive. In groups 2 and 3, the adhesion boosters Enhance Adhesion Booster and Assure Universal Bonding Resin, respectively, were applied before bonding with Sondhi. Maximum bond strength was measured with a universal testing machine, and the location of bond failure was evaluated using the Adhesive Remnant Index (ARI). One-way analysis of variance followed by the Tukey test (P < .05) was used to compare the shear bond strength among groups, and the differences in ARI scores were evaluated using the Kruskal-Wallis test (P < .05). The Pearson correlation coefficient was calculated to determine whether there was any correlation between bond strength and ARI scores. RESULTS: The mean shear bond strength in group 3 was significantly higher (P < .01) than in the other groups. Evaluation of the locations of bond failure revealed differences (P < .05) among the three groups. There was a moderate correlation between bond strength and ARI scores within group 3 (r â=â 0.5860, P < .01). CONCLUSION: In vitro shear bond strength was acceptable in all groups. The use of the Assure adhesion booster significantly increased both the shear bond strength of indirectly bonded brackets and the amount of adhesive that remained on the enamel after bracket debonding.
Assuntos
Colagem Dentária/métodos , Cimentos Dentários/química , Braquetes Ortodônticos , Condicionamento Ácido do Dente/métodos , Animais , Bovinos , Compômeros/química , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário/instrumentação , Teste de Materiais , Ácidos Fosfóricos/química , Distribuição Aleatória , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Temperatura , Fatores de Tempo , Água/químicaRESUMO
INTRODUCTION: Moyers analysis is widely used for analyzing mixed dentition, however, the accuracy of its theoretical probability tables has been recently questioned. Taking into consideration the fact the mixed dentition analysis is of paramount importance to precisely determine the space needed for alignment of canines and premolars, this research aimed at objectively assessing in the literature such an important step for orthodontic diagnosis. METHODS: A computerized search involving articles published on PubMed and Lilacs between 1990 and September, 2011 was conducted in accordance with the method described in the Cochrane 5.1.0 handbook. RESULTS: The research resulted in a sample composed of 629 articles. The inclusion criteria were: Articles using the Moyers analysis with a sample greater or equal to 40 patients. Conversely, the exclusion criteria were: Dental casts of patients with syndromes or oral cleft, researches conducted with a literature review, only, or clinical case reports and researches conducted before 1990. For this systematic review, 19 articles were selected. CONCLUSIONS: Based on the literature available, we can conclude that Moyers mixed dentition analysis must be carefully used, since the majority of the articles analyzed showed that the probability of 75% was not as accurate as expected, leading to the need of adapting the probability levels depending on the study population.
Assuntos
Dente Pré-Molar/anatomia & histologia , Dente Canino/anatomia & histologia , Arco Dental/anatomia & histologia , Dentição Mista , Coroa do Dente/anatomia & histologia , Previsões , Humanos , Probabilidade , Dente não Erupcionado/anatomia & histologiaRESUMO
OBJECTIVE: To measure condylar displacement between centric relation (CR) and maximum intercuspation (MIC) in symptomatic and asymptomatic subjects. MATERIALS AND METHODS: The sample comprised 70 non-deprogrammed individuals, divided equally into two groups, one symptomatic and the other asymptomatic, grouped according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD). Condylar displacement was measured in three dimensions with the condylar position indicator (CPI) device. Dahlberg's index, intraclass correlation coefficient, repeated measures analysis of variance, analysis of variance, and generalized estimating equations were used for statistical analysis. RESULTS: A greater magnitude of difference was observed on the vertical plane on the left side in both symptomatic and asymptomatic individuals (P = .033). The symptomatic group presented higher measurements on the transverse plane (P = .015). The percentage of displacement in the mesial direction was significantly higher in the asymptomatic group than in the symptomatic one (P = .049). Both groups presented a significantly higher percentage of mesial direction on the right side than on the left (P = .036). The presence of bilateral condylar displacement (left and right sides) in an inferior and distal direction was significantly greater in symptomatic individuals (P = .012). However, no statistical difference was noted between genders. CONCLUSION: Statistically significant differences between CR and MIC were quantifiable at the condylar level in asymptomatic and symptomatic individuals.
Assuntos
Relação Central , Oclusão Dentária Central , Côndilo Mandibular/patologia , Transtornos da Articulação Temporomandibular/patologia , Adolescente , Adulto , Estudos Transversais , Articuladores Dentários , Dor Facial/fisiopatologia , Feminino , Humanos , Imageamento Tridimensional , Registro da Relação Maxilomandibular , Luxações Articulares/patologia , Luxações Articulares/fisiopatologia , Masculino , Côndilo Mandibular/fisiopatologia , Músculos da Mastigação/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Fatores Sexuais , Transtornos da Articulação Temporomandibular/fisiopatologia , Dimensão Vertical , Adulto JovemRESUMO
The purpose of the present study was to assess the correlation between transverse expansion and the increase in upper arch perimeter, after maxillary expansion. Dental casts of eighteen patients were obtained before treatment and again five months after maxillary expansion. Measurements of intermolar width, intercanine width, arch length and arch perimeter were made with a digital caliper on photocopies taken from the dental casts. After assessment of the method error, a multiple regression model was developed following the identification of the best subset of variables. The resulting equation led to the conclusion that the increase in arch perimeter is approximately given by the addition of 0.54 times the intercanine expansion, and 0.87 times the arch length alteration.