Rehabilitación de rebordes severamente atróficos mediante prótesis híbridas confeccionadas con tecnología de sinterización láser cromo-cobalto: reporte de caso / Rehabilitation of severely atrophic full arches using hybrid prostheses made with chrome-cobalt laser sintering technology: A case report

Prótesis híbridas metal-acrílico implanto-retenidas han brindado solución funcional y estética para rehabilitar arcos completos severamente atróficos, constituyendo una alternativa a cirugías reconstructivas más complejas. La subestructura protésica debe ajustar pasivamente sobre los implantes. Con la tecnología CAD-CAM el diseño manual de las subestructuras, mediante cera perdida, se ha reemplazado por diseño digital mediado por software. La tecnología de sinterizado láser en la confección de subestructuras metálicas tiene como ventajas la disminución de acumulación de errores, rapidez y diseño de geometrías complejas según las necesidades del caso. Caso Paciente desdentada total. Se planifica prótesis híbrida maxilar (8 implantes) y mandibular (Revitalize®) con subestructuras en aleación Cr-Co mediante sinterizado láser, que presenta resultados a largo plazo similares a estructuras nobles, con menor costo y alta predictibilidad. Conclusiones Prótesis híbridas con subestructura Cr-Co mediante sinterizado láser podrían mejorar el pronóstico al incorporar CAD-CAM en su confección al obtener ajustes de precisión.

Abstract Implant-retained metal-acrylic hybrid prostheses provide a functional and aesthetic solution to rehabilitate severely atrophic complete arches, and are an alternative to more complex reconstructive surgeries. the prosthetic substructure must adjust passively on the implants. With the CAD-CAM technology, the manual design of the substructures, by lost wax, has been replaced by digital design. Laser sintering technology in the production of metal substructures has advantages, such as, decreased accumulation of errors, fabrication speed and design of complex geometry, according to the needs of the case. Case report Hybrid prostheses in the maxilla (8 implants) and jaw (Revitalize®) were planned in a patient with no teeth, using Co-Cr alloy substructures by laser sintering, which have similar long-term results as obtained with noble structures, but with lower cost and high predictability. Conclusions Hybrid prostheses with Co-Cr substructures using laser sintering could improve prognosis by incorporating CAD-CAM in their preparation to obtain fine adjustments.

Evaluation and comparison of the marginal adaptation of two different substructure materials

PURPOSE: In this study, we aimed to evaluate the amount of marginal gap with two different substructure materials using identical margin preparations. MATERIALS AND METHODS: Twenty stainless steel models with a chamfer were prepared with a CNC device. Marginal gap measurements of the galvano copings on these stainless steel models and Co-Cr copings obtained by a laser-sintering method were made with a stereomicroscope device before and after the cementation process and surface properties were evaluated by scanning electron microscopy (SEM). A dependent t-test was used to compare the mean of the two groups for normally distributed data, and two-way variance analysis was used for more than two data sets. Pearson's correlation analysis was also performed to assess relationships between variables. RESULTS: According to the results obtained, the marginal gap in the galvano copings before cementation was measured as, on average, 24.47 +/- 5.82 microm before and 35.11 +/- 6.52 microm after cementation; in the laser-sintered Co-Cr structure, it was, on average, 60.45 +/- 8.87 microm before and 69.33 +/- 9.03 microm after cementation. A highly significant difference (P<.001) was found in marginal gap measurements of galvano copings and a significant difference (P<.05) was found in marginal gap measurements of the laser-sintered Co-Cr copings. According to the SEM examination, surface properties of laser sintered Co-Cr copings showed rougher structure than galvano copings. The galvano copings showed a very smooth surface. CONCLUSION: Marginal gaps values of both groups before and after cementation were within the clinically acceptable level. The smallest marginal gaps occurred with the use of galvano copings.