Effect of Fabrication Technique on the Microgap of CAD/CAM Cobalt-Chrome and Zirconia Abutments on a Conical Connection Implant: An In Vitro Study.

The aim of this in vitro study was to investigate the microgaps at the implant-abutment interface when zirconia (Zr) and CAD/CAM or cast Co-Cr abutments were used. METHODS Sixty-four conical connection implants and their abutments were divided into four groups (Co-Cr (milled, laser-sintered and castable) and Zirconia (milled)). After chewing simulation (300,000 cycles, under 200 N loads at 2 Hz at a 30° angle) and thermocycling (10,000 cycles, 5 to 50 °C, dwelling time 55 s), the implant-abutment microgap was measured 14 times at each of the four anatomical aspects on each specimen by using a scanning electron microscope (SEM). Kruskal-Wallis and pair-wise comparison were used to analyze the data (α = 0.05). RESULTS The SEM analysis revealed smaller microgaps with Co-Cr milled abutments (0.69-8.39 μm) followed by Zr abutments (0.12-6.57 μm), Co-Cr sintered (7.31-25.7 μm) and cast Co-Cr (1.68-85.97 μm). Statistically significant differences were found between milled and cast Co-Cr, milled and laser-sintered Co-Cr, and between Zr and cast and laser-sintered Co-Cr (p < 0.05). CONCLUSIONS The material and the abutment fabrication technique affected the implant-abutment microgap magnitude. The Zr and the milled Co-Cr presented smaller microgaps. Although the CAD/CAM abutments presented the most favorable values, all tested groups had microgaps within a range of 10 to 150 μm

Encerado diagnóstico digital de los pacientes por parte de los alumnos de quinto de carrera. Estudio piloto

Con este proyecto nos proponemos introducir un aspecto básico del diagnóstico protésico y estético, el encerado digital. El objetivo final es proporcionar al alumno material de trabajo y herramientas que le permitan estudiar, aprender y practicar este procedimiento diagnóstico sin su presencia física en la facultad, o sin la necesidad de utilizar herramientas analógicas como se viene haciendo desde hace años.Depto. de Odontología Conservadora y PrótesisFac. de OdontologíaFALSEsubmitte

Influence of the use of transepithelial abutments vs. titanium base abutments on microgap formation at the dental implant–abutment interface: an in vitro study

2023 Descuentos MDPIThis in vitro study aimed to assess the presence of microgaps at the implant-abutment interface in monolithic zirconia partial implant-supported fixed prostheses on transepithelial abutments versus Ti-base abutments.Methods: Sixty conical connection dental implants were divided into two groups (n = 30). The control group consisted of three-unit bridge monolithic zirconia connected to two implants by a transepithelial abutment. The test group consisted of monolithic zirconia three-unit restoration connected to two implants directly by a titanium base (Ti-base) abutment. The sample was subjected to thermocycling (10,000 cycles at 5 degrees C to 55 degrees C, dwelling time 50 s) and chewing simulation (300,000 cycles, under 200 N at frequencies of 2 Hz, at a 30 degrees angle). The microgap was evaluated at six points (mesiobuccal, buccal, distobuccal, mesiolingual, lingual, and distolingual) of each implant-abutment interface by using a scanning electron microscope (SEM). The data were analyzed using the Mann-Whitney U tests (p > 0.05).Results: The SEM analysis showed a smaller microgap at the implant-abutment interface in the control group (0.270 mu m) than in the test group (3.902 mu m). Statistically significant differences were observed between both groups (p < 0.05).Conclusions: The use or not of transepithelial abutments affects the microgap size. The transepithelial abutments group presented lower microgap values at the interface with the implant than the Ti-base group in monolithic zirconia partial implant-supported fixed prostheses. However, both groups had microgap values within the clinically acceptable range.Sociedad Española de Prótesis Estomatológica y EstéticaDepto. de Odontología Conservadora y PrótesisFac. de OdontologíaFac. de Ciencias FísicasTRUEpubDescuento UC