Evaluation of residual contamination on healing abutments after cleaning with a protein-denaturing agent and detergent

Objective: This study evaluated the cleaning potential of a protein-denaturing agent with or without anionic detergent by monitoring the residual contamination on healing abutments used for dental implant treatment. Method and materials: Forty contaminated healing abutments removed from patients were randomized and immediately treated with differing cleaning methods; either Method A (presoaking in 1% sodium dodecyl sulfate followed by ultrasonication with 4 mol/L guanidine hydrochloride), or Method B (soaking in distilled water followed by ultrasonication with 4 mol/L guanidine hydrochloride) was used. Samples were stained with phloxine B and photographed using a light microscope. The proportion of stained and contaminated areas on each healing abutment was then calculated using Image J. The surface was examined with a scanning electron microscope and energy-dispersive x-ray spectroscopy. Results: The percentages of contaminated surfaces of the screwdriver engagement region, upper body, and lower body for methods A and B were 50% and 38%, 10% and 80%, and 38% and 18%, respectively. There was a statistically significant difference (engagement region [P .001], upper body [P = .043], and lower body [P = .017]; Mann-Whitney) regarding the residually stained areas between the two cleaning methods. No surface alterations were seen by scanning electron microscopy. Energy-dispersive x-ray spectroscopy confirmed that the cleaned surfaces of the healing abutments revealed no signs of organic contamination. Conclusion: Although the combination of a strong denaturing agent and detergent effectively cleaned contaminated healing abutments, perfect cleaning was not always possible, indicating that the reuse of healing abutments in different patients is not recommended. Keywords: anionic detergent, decontamination, healing abutments, protein denaturing agent, ultrasonic cleaning