Investigating of the Effects of Ultrasonic Frequency, Cleaning Solution Temperature, and Cleaning Time on the Bioburden of Machined Stainless-Steel Orthopedic Implants

Rakesh Kumar, Santosh Kumar*

Received : August 10, 2026 | Published : September 03, 2026

Citation: Kumar S, Kumar R. “Investing of the Effects of Ultrasonic Frequency, Cleaning Solution Temperature, and Cleaning Time on the Bioburden of Machined Stainless-Steel Orthopedic Implants,” Journal of Materials Science and Emerging Technologies, vol. 1, no. 3, pp. 1–9, 2026. DOI: 10.64978/jmset.2026.0903011

License: This article is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0) , which permits use, sharing, adaptation, distribution, and reproduction in any medium or format, provided appropriate credit is given to the original author(s) and the source, a link to the Creative Commons licence is provided, and any changes made are indicated.

Abstract

Subtractive manufacturing has gained widespread adoption in biomedical and advanced manufacturing applications due to its ability to produce components with high dimensional accuracy, improved surface finish, and enhanced mechanical integrity. The use of advanced multi-axis machining technologies, including CNC sliding-head (Swiss-type) machines and vertical machining centres, enables the precise and efficient manufacturing of complex biomedical components while reducing machining time and improving production efficiency compared with conventional machining processes. In the present investigation, nine products manufactured from medical-grade 316LRM stainless steel conforming to ISO 5832-1 were produced using high-precision machining equipment. A Taguchi L9 orthogonal array was employed to investigate the influence of selected cleaning parameters on the bioburden level of the machined products. The effects of cleaning parameters were evaluated through bioburden testing, and the optimum parameter combination was determined using analysis of variance (ANOVA) and signal-to-noise (S/N) ratio analysis. The optimized cleaning conditions were identified as an ultrasonic frequency of 40 kHz, chemical solution temperature of 50 °C, and cleaning time of 10 min. Under these conditions, the bioburden was reduced to 11 CFU/device from an initial average level of 23 CFU/device prior to cleaning. The findings demonstrate that systematic optimization of the cleaning parameters can effectively reduce the microbial load on machined biomedical components and provide a controlled approach for improving the cleaning process.

Keywords: Implant, Manufacturing, 316LRM Stainless Steel, Processing Parameters, Cleaning, Bioburden and Taguchi orthogonal Array L9.