ABSTRACT
Introduction: Most of techniques for determining the occlusal vertical dimension (OVD) of edentulous patients are based on soft tissues references, which lead to measurement discrepancies. Objective: To propose a method to obtain the OVD of edentulous patients during the confection of complete dentures considering the lower facial height established by Ricketts (LFHr) or the lower facial height obtained from cephalometric analysis of dentulous patients (LFHd). Material and methods: The OVD of 11 edentulous patients was determined by the association of 3 clinical methods. On each patient's bite plates a metallic ball was fixed and the patient was submitted to lateral radiographic to obtain the lower facial height (LFHe) from cephalometric analysis. Additionally, from 40 lateral cephalograms of dentulous patients the LFHd was obtained. After that, the distance between metallic balls (DMB, in mm) was calculated to verify the linear difference when LFHe was changed to LFHd or LFHr, which provided the amount of wax to be added or removed from the bite plates, establishing a new method of OVD determination. LFHe, LFHd and LFHr values were submitted to t e z statistical tests and DMB differences were analyzed by Student's t-test (α=0.05). Results: LFHr (47.0±4.0o a) was statistically higher than LFHd (44.9±5.6o b) and LFHe (43.5±3.5o b). There was statistical difference on linear discrepancies calculated between the LFHe and LFHd (1.7±4.1mm a) or LFHr (4.2±4.1mm b). Conclusion: The use of the cephalometric analysis showed to be a useful auxiliary tool in determining the intermaxillary relationship. However, this method must be associated with different clinical methods of OVD determination and it is recommended that regional references are used to calculate the linear discrepancies.
ABSTRACT
Introdução: As cerâmicas são consideradas uma excelente alternativa como material estético restaurador, entretanto questões relevantes, como adaptação marginal, exigem um maior critério na confecção quando comparadas aos sistemas convencionais. Objetivo: Este trabalho avaliou a adaptação marginal de uma coroa In-Ceram confeccionada sobre um dente que, após 3 anos, teve sua extração indicada pela ortodontia. Material e métodos: A avaliação deu-se por meio de microscópio eletrônico de varredura. Resultados e conclusão: Foram encontrados valores de falta de adaptação entre 157 e 390 um, obtendo uma média estatística acima do considerado aceitável clinicamente pela literatura.
Introduction: Ceramics are considered an excellent choice as esthetic restorative material, but relevant questions like marginal fit require more attention in manufacturing than conventional systems. Objective: This work evaluated the marginal adaptation of an In-Ceram crown over a tooth that, after three years, had been indicated to extraction by orthodontics. Material and methods: The evaluation was by mean scanning electron microscope. Results and conclusion: It was found values of gaps between 157 and 390 um, getting a statistic average considered greater than the accepted by literature.