A comparative study of inter-abutment distance of dies made from full arch dual-arch impression trays with those made from full arch stock trays: An in vitro study.

Objectives: The dual-arch impression technique is convenient in that it makes the required maxillary and mandibular impressions, as well as the inter-occlusal record in one procedure. The accuracy of inter-abutment distance in dies fabricated from dual-arch impression technique remains in question because there is little information available in the literature. Materials and Methods: This study was conducted to evaluate the accuracy of inter-abutment distance in dies obtained from full arch dual-arch trays with those obtained from full arch stock metal trays. Results and Conclusion: The metal dual-arch trays showed better accuracy followed by the plastic dual-arch and stock dentulous trays, respectively, though statistically insignificant. The pouring sequence did not have any effect on the inter-abutment distance statistically, though pouring the non-working side of the dual-arch impression first showed better accuracy.

Influence of anatomic reference on the buccal contour of prosthetic crowns

During clinical practice, when performing prosthetic rehabilitation with single crowns, improper reproduction of the dental contour by the dental laboratory is a common occurrence. Therefore, the present study evaluated the fidelity of the reproduction of the buccal contour in an upper left canine performed by three Dental Prosthesis Technicians (DPT) using the indirect laminate veneer technique. First, the DPTs confected the veneers based on a model obtained from the upper arch of a dental dummy, containing a replica of an upper left canine with a prosthetic preparation for a laminate veneer. Then, the same DPTs received other identical models, now with the replica of the upper left canine with no preparation, to be used as an anatomical reference for confecting the laminate veneers. The laminate veneers were then bonded to the plaster models and had their buccal contour individually measured. Measurements were also made of the buccal contour of the reference canine. The data were analyzed by ANOVA and the t-test (p = 0.05). Results showed 100 percent of buccal overcontour when the laminate veneers were compared to the reference canine, regardless of which DPT confected the veneer and regardless of using or not the anatomical reference. The DPTs who participated in the present study were unable to acomplish a faithful anatomical reproduction of the buccal contour, creating an overcontour in all samples. This situation may be responsible for increasing the probability of periodontal and esthetic harm in clinical practice.

Enceramento de diagnóstico para um contorno anatômico / Diagnostic waxing for anatomic contour

Os autores através de uma revisäo da literatura, ressaltam a importância do enceramento de diagnóstico frente ao contorno das restauraçöes protéticas. Tentam deixar claro a importância do enceramento de diagnóstico tanto na fase de planejamento como durante o tratamento. Avaliam as teorias de contorno segundo seus autores, concluindo que devemos evitar o sobrecontorno das regiöes cervicais, através de um preparo adequado e um melhor entrosamento com o técnico de laboratório

Enceramento dos casquetes para retentores com problemas periodontais / Metallic coping's waxing for abutments with periodontal diaseases

Os autores fazem uma revisäo da literatura e analisam o inter-relacionamento Prótese/Periodontia na restauraçäo de dentes com doenças periodontais e chegam às seguintes conclusöes: o protesista e o periodontista devem trabalhar em perfeita sintonia. Todos os esforços devem visar a obtençäo de preparos corretos e restauraçöes sem sobrecontorno, para evitar o acúmulo de placa bacteriana e, ao mesmo tempo, facilitar o acesso à higienizaçäo. Sempre que possível, as margens cervicais das restauraçöes devem ser supragengivais. Por isso, o enceramento dos casquetes deve ser bem planejado