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Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of UCLA Abutments Attached to External Hexagon Dental Implants
Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of Cast UCLA Abutments Attached to External Hexagon Dental Implants. Coatings2023, 13, 1976.
Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of Cast UCLA Abutments Attached to External Hexagon Dental Implants. Coatings 2023, 13, 1976.
Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of Cast UCLA Abutments Attached to External Hexagon Dental Implants. Coatings2023, 13, 1976.
Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of Cast UCLA Abutments Attached to External Hexagon Dental Implants. Coatings 2023, 13, 1976.
Abstract
Purpose: The objective of the study was to qualitatively assess micro-gap dimensions, connecting fitting surface profile and bacterial leakage of machined and cast high gold alloy UCLA abutments, with or without electrodeposited gold coatings attached to external hexagon implants. Materials and methods: 16 plastic UCLA (PUCLA) and 5 machined cast-to UCLA (GUCLA) abutments were cast with a high gold content alloy. 10 were electrolytically gold plated (8 - PUCLA, 2 - GUCLA). All abutments were attached to implants giving 21 implant-abutment combinations (IACs). External perimeter micro-gaps measured with SEM under different illumination and magnification conditions were averaged over three regions. The IACs were examined for E.coli leakage following an initial sterility test. Disassembled combinations were examined with SEM and surface profiles qualitatively assessed. Results: External micro-gap measurements did not reflect the variable connecting surface profiles but average values < 3.5 μm were observed for all IACs. Bacterial transfer was observed in 3 of 5 PUCLA plated and 2 of 5 PUCLA non-plated IACs. No transfer occurred in the 3 GUCLA non-plated or 2 GUCLA plated IACs. Abutment connecting surfaces, both Au plated and not Au plated, showed plastic deformation (smearing) in variable mosaic patterns across the micro-gap. External micro-gap dimensions although not truly reflective of surface connecting profiles averaged < 3.5 μm measured under shadow eliminating silhouette illumination for both cast and pre-machined external hexagon abutments with and without Au plating. Conclusions: Micro-gap dimensions < 5 μm were obtained with both high noble metal cast and pre-machined external hexagon abutments with and without Au electrodeposited on the abutment connecting surface. Regions of intimate contact due to plastic deformation (smearing) of these surfaces was observed. A continuous smeared region around the circumference of the surfaces can provide an effective barrier to egress of E.coli bacteria from the internal regions of the implant under static loading.
Copyright:
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