Molinero Mourelle, PedroRoccuzzo, AndreaYilmaz, BurakLam, Walter Yu HangPow, Edmond Ho NangRío Highsmith, Jaime delGómez Polo, Miguel Ángel2023-06-222023-06-222022-07-120905-716110.1111/clr.13973https://hdl.handle.net/20.500.14352/72098Objective: To assess the marginal and bacterial microleakage in zirconia and CADCAM or cast Co-Cr implant abutments. Methods: Sixty-four conical connection implants with their respective abutments were divided into four groups (Co-Cr (milled, laser-sintered, and cast) and Zirconia (milled)). All specimens were subjected to a chewing simulation and thermocycling. After aging process, specimens were submerged in a 0.2% methylene blue solution with Porphyromonas gingivalis (P.g) for 48 h. The marginal microleakage was measured using a 40× optical microscopy at the internal part of the implant, and when positive microleakage was observed, a DNA isolation with a polymerase chain reaction (PCR) test was used. The microbiological assessment was based on colony forming units (CFUs). Results: Thirty (47%) implant-abutments presented microleakage and the PCR was performed on those specimens (1 Zirconia, 1 Co-Cr milled, 14 Co-Cr laser-sintered and 14 cast). Seven specimens (1 Co-Cr laser-sintered and six cast) presented values below the PCR detection limit t (<100 CFUs). The lowest CFUs count occurred in the Co-Cr milled group (5.17E+02 CFUs/ml) followed by zirconia (7.70E+03 CFUs/ml). The Co-Cr cast (9.39E+03 CFUs/ml) and laser-sintered (2.4E+05 CFUs/ml) groups had higher bacterial count. The CFU count comparison performed between Co-Cr cast and laser-sintered resulted in a statistically significant differences in favor of Co-CrCL (p<.05). Conclusions: The abutment material and fabrication technique affected the implantabutment microleakage. Although the CAD-CAM abutments presented favorable results, all tested groups presented microleakage.engAtribución-NoComercial-SinDerivadas 3.0 Españajournal articlehttps://doi.org/10.1111/clr.13973open accessdental implant abutment connectiondental implant abutment designdental implantsimplant supported dental prosthesismicroleakagepolymerase chain reactionOdontología (Odontología)Implantes dentalesPrótesis dental3213.13 Ortodoncia-Estomatología3213.13 Ortodoncia-Estomatología3314.02 Prótesis