Evaluation of Different Heights of Prosthetic Crowns Supported by an Ultra-Short Implant Using Three-Dimensional Finite Element Analysis.

PURPOSE: To apply finite element analysis (FEA) to investigate the stress distribution in a 4-mm-high ultrashort implant when supporting crowns of different heights in order to test the possibility of using this implant unitarily in the posterior edentulous mandible. MATERIALS AND METHODS: Three models of atrophic mandibles were created (M1, M2, and M3). Each model contained a 4-mm-length implant of a titanium-zirconium alloy, screw-type with internal connection, supporting nonsplinted screwed-in crowns of 10, 12.5, and 15 mm in height. Axial and oblique loads were simulated in the three model crowns. RESULTS: In an oblique load, the stress tended to be concentrated in the lingual region. In the qualitative results of the axial load, peaks of tension occurred in the lower angle between the inner groove and the inner conical portion of the implant. Regarding the differences in crown height, the 15-mm height produced a higher stress peak due to the lever effect of the crown under an oblique load. CONCLUSION: Within the limits of this study, the results suggest the possibility of using single crowns of proposed heights with unitary ultrashort implants installed in the posterior edentulous mandible, so long as there is no oblique load on the crown.

Reabilitação oral de paciente portador de displasia ectodérmica anidrótica / Oral rehabilitation of a patient with anhidrotic ectodermal dysplasia

O presente trabalho teve como objetivo relatar um caso de reabilitação bucal de um paciente portador de displasia ectodérmica, através de próteses totais fixas aparafusadas sustentadas por implantes zigomáticos e convencionais. Os aspectos clínicos e radiográficos serão descritos juntamente com a sequência de tratamento realizada até a finalização do caso. Esse tipo de tratamento tem apresentado resultados satisfatórios.

This case reports on the use of total fixed implant-supported screwed prostheses with zygomatic and conventional implants in the treatment of a completely edentulous patient with anihidrotic ectodermal dysplasia. Clinical and radiographic aspects are demonstrated during treatment sequence. This kind of rehabilitation has presented satisfactory results.