An innovative Fuller's earth-based film-forming formulation for skin decontamination, through removal and entrapment of an organophosphorus compound, paraoxon-ethyl.

Organophosphorus compounds (OPs), such as VX, pose a significant threat due to their neurotoxic and hazardous properties. Skin decontamination is essential to avoid irreversible effects. Fuller's earth (FE), a phyllosilicate conventionally employed in powder form, has demonstrated decontamination capacity against OPs. The aim of this study was to develop a formulation that forms a film on the skin, with a significant OP removal capacity (>95 %) coupled with sequestration capabilities, favorable drying time and mechanical properties to allow for easy application and removal, particularly in emergency context. Various formulations were prepared using different concentrations of polyvinyl alcohol (PVA), FE and surfactants. Their removal and sequestration capacity was tested using paraoxon-ethyl (POX), a chemical that simulates the behavior of VX. Formulations with removal capacity levels surpassing 95 % were mechanically characterized and cell viability assays were performed on Normal Human Dermal Fibroblast (NHDF). The four most promising formulations were used to assess decontamination efficacy on pig ear skin explants. These formulations showed decontamination levels ranging from 84.4 ± 4.7 % to 96.5 ± 1.3 %, which is equivalent to current decontamination methods. These results suggest that this technology could be a novel and effective tool for skin decontamination following exposure to OPs.

Decontamination of a robot used to reprocess reusable surgical instruments.

BACKGROUND: Using robots to handle medical devices in the decontamination area of the Central Sterile Supply Department (CSSD) can reduce risks and address staff shortages. The gripper design must allow reliable cleaning using standard CSSD procedures to avoid build-up of biofilms and possible cross-contamination between different instrument trays and the gripper's functionality. This study explores the design of the robot's gripper regarding cleanability, aiming to determine whether successful cleaning can be achieved even after prolonged drying for a working shift of 8 h. METHODS: We optimized a gripper for cleanability and used it to assess the spread of different test soils depending on different forms of motion. Subsequently, we analysed the cleanability using sheep's blood as test soil, reprocessing the gripper in different assembly configurations after 4 and 8 h of drying, and measuring residual protein. FINDINGS: Based on our investigations, we documented the spread of contamination depending on the type of motion of the gripper's components. Sheep's blood exhibited the highest dispersion among the test soils, permeating through thin crevices. Importantly, all samples displayed residual protein levels below the warning threshold, irrespective of drying time and gripper disassembly or cleaning position. Cleaning in a device-specific optimized position achieved results comparable to cleaning the disassembled individual components. CONCLUSIONS: These findings indicate that cleaning even after one working shift of 8 h and without the labour-intensive disassembly of the gripper is feasible, supporting the future use of robots to handle contaminated medical devices in the CSSD decontamination area.

Reactive skin decontamination lotion (RSDL) safety with clinical antiseptics and hemostatic agents.

Reactive skin decontamination lotion (RSDL) is a Health Canada approved product used by the Canadian Armed Forces for removal and inactivation of toxic chemicals on skin. Although it is considered very safe when used as directed, questions have been raised regarding whether topical RSDL in the medical setting will react exothermically with antiseptic compounds on the casualty's epidermis that could result in thermal burns. Benchtop experiments were conducted to investigate reactivity of RSDL with various antiseptic compounds or hemostatic agents. Temperature changes were closely monitored in three different volume ratios, 1:10, 1:1, and 10:1 over a time course of 16 minutes. Chlorine based bleaches versus RSDL were included as a positive control and were the only combination that exhibited a significant exothermic reaction capable of causing minor thermal burns. RSDL was also evaluated with antiseptic solution applied to swine epidermal tissue without observation of visual irritation; then in lacerated skeletal muscle tissue which resulted in no measured temperature change. The conclusion of this study is that antiseptics and hemostatic agents can be used as required on a patient decontaminated with RSDL as no exothermic reaction will occur.

A green approach to efficient soil decontamination using supercritical carbon dioxide and ethanol.

As the need for global decommissioning and site remediation of aging and shut-down nuclear power plants continues to grow, it becomes increasingly crucial to efficiently treat contaminated soil while minimizing waste generation. This study explores an innovative soil decontamination approach that utilizes supercritical carbon dioxide (SCCO2) as the primary solvent, along with ethanol as a co-solvent and specific additives, including a chelate ligand (catechol ligand) and a co-ligand (NEt4PFOSA). The advantages of SCCO2, such as its penetration and solubility, coupled with its ability to separate from radioactive waste, are harnessed in this research. The study demonstrates that the combination of SCCO2, ethanol, and additives significantly enhances decontamination efficiency, particularly for cesium (Cs), strontium (Sr), and uranium (U) contamination. Results indicate that decontamination efficiency varies with soil particle size, with smaller particles presenting greater challenges. This study presents a promising eco-friendly soil decontamination technology using SCCO2 containing ethanol and specific additives to efficiently reduce radioactive contamination in soil.

Fe-N co-doped biochar derived from biomass waste triggers peracetic acid activation for efficient water decontamination.

In this study, the porous carbon material (FeN-BC) with ultra-high catalytic activity was obtained from waste biomass through Fe-N co-doping. The prominent degradation rate (> 96.8%) of naproxen (NAP) was achieved over a wide pH range (pH 3.0-9.0) in FeN-BC/PAA system. Unlike previously reported iron-based peracetic acid (PAA) systems with •OH or RO• as the dominated reactive species, the degradation of contaminants was attributed to singlet oxygen (1O2) produced by organic radicals (RO•) decomposition, which was proved to be thermodynamically feasible and favorable by theoretical calculations. Combining the theoretical calculations, characteristic and experimental analysis, the synergistic effects of Fe and N were proposed and summarized as follows: i) promoted the formation of extensive defects and Fe0 species that facilitated electron transfer between FeN-BC and PAA and continuous Fe(II) generation; ii) modified the specific surface area (SSA) and the isoelectric point of FeN-BC in favor of PAA adsorption on the catalyst surface. This study provides a strategy for waste biomass reuse to construct a heterogeneous catalyst/PAA system for efficient water purification and reveals the synergistic effects of typical metal-heteroatom for PAA activation.

A proof-of-principle for decontamination of transplantation kidney through UV-C exposition of the perfusate solution.

Kidney transplantation is a common yet highly demanding medical procedure worldwide, enhancing the quality of life for patients with chronic kidney disease. Despite its prevalence, the procedure faces a shortage of available organs, partly due to contamination by microorganisms, leading to significant organ disposal. This study proposes utilizing photonic techniques associated with organ support machines to prevent patient contamination during kidney transplantation. We implemented a decontamination system using ultraviolet-C (UV-C) irradiation on the preservation solution circulating through pigs' kidneys between harvest and implant. UV-C irradiation, alone or combined with ultrasound (US) and Ps80 detergent during ex-vivo swine organ perfusion in a Lifeport® Kidney Transporter machine, aimed to reduce microbiological load in both fluid and organ. Results show rapid fluid decontamination compared to microorganism release from the organ, with notable retention. By including Ps80 detergent at 0.5% during UV-C irradiation 3 log10 (CFU mL-1) of Staphylococcus aureus bacteria previously retained in the organ were successfully removed, indicating the technique's feasibility and effectiveness.

Bacterial Decontamination of Water-Containing Objects Using Piezoelectric Direct Discharge Plasma and Plasma Jet.

Cold atmospheric plasma has become a widespread tool in bacterial decontamination, harnessing reactive oxygen and nitrogen species to neutralize bacteria on surfaces and in the air. This technology is often employed in healthcare, food processing, water treatment, etc. One of the most energy-efficient and universal methods for creating cold atmospheric plasma is the initiation of a piezoelectric direct discharge. The article presents a study of the bactericidal effect of piezoelectric direct discharge plasma generated using the multifunctional source "CAPKO". This device allows for the modification of the method of plasma generation "on the fly" by replacing a unit (cap) on the working device. The results of the generation of reactive oxygen and nitrogen species in a buffer solution in the modes of direct discharge in air and a plasma jet with an argon flow are presented. The bactericidal effect of these types of plasma against the bacteria E. coli BL21 (DE3) was studied. The issues of scaling the treatment technique are considered.

Ultraviolet C intensity dependence of decontamination efficiency for pathogens as function of repacked metamaterials with screw channels.

A new method for repackaging optical metamaterials formed from quartz spheres (fibers) of various diameters is proposed for ultraviolet C disinfection of infected liquids by pathogens (viruses and bacteria). The main idea of the new equipment is connected with the rotation of a contaminated fluid by screw channels within a metamaterial matrix prepared from UVC fibers/spherical optics, to improve the decontamination efficiency. In demonstration of the viability of this approach, dynamic and static inactivation of Baker's yeast via Ultraviolet C radiation regimes are used in this paper to show the efficacy of decontamination within the screw channels.

Use of semi-permeable bag materials to facilitate on-site treatment of biological agent-contaminated waste.

Clean up following the wide-area release of a persistent biological agent has the potential to generate significant waste. Waste containing residual levels of biological contaminants may require off-site shipment under the U.S. Department of Transportation's (US DOT) solid waste regulations for Category A infectious agents, which has packaging and size limitations that do not accommodate large quantities. Treating the waste on-site to inactivate the bio-contaminants could alleviate the need for Category A shipping and open the possibility for categorizing the waste as conventional solid waste with similar shipping requirements as municipal garbage. To collect and package waste for on-site treatment, a semi-permeable nonwoven-based fabric was developed. The fabric was designed to contain residual bio-contaminants while providing sufficient permeability for penetration by a gaseous decontamination agent. The nonwoven fabric was tested in two bench-scale experiments. First, decontamination efficacy and gas permeability were evaluated by placing test coupons inoculated with spores of a Bacillus anthracis surrogate inside the nonwoven material. After chlorine dioxide fumigation, the coupons were analyzed for spore viability and results showed a ≥6 Log reduction on all test materials except glass. Second, filters cut from the nonwoven material were tested in parallel with commercially available cellulose acetate filters having a known pore size (0.45 µm) and results demonstrate that the two materials have similar permeability characteristics. Overall, results suggest that the nonwoven material could be used to package waste at the point of generation and then moved to a nearby staging area where it could be fumigated to inactivate bio-contaminants.

Bacterial Infections After Liver Transplantation and the Role of Oral Selective Digestive Decontamination: A Retrospective Cohort Study.

BACKGROUND: Bacterial infections are common after liver transplantation (LT) and cause serious morbidity and mortality. In our center, prolonged selective digestive decontamination (SDD) is the standard of care, which may lead to a reduced number and severity of bacterial infections. The aim of the current study was to investigate bacterial infection rates, the causative pathogens, localization, and the possible influence of SDD within the first year after LT. METHODS: A retrospective single-center cohort study was performed. Patients within their first year after LT between 2012 and 2017 were included. Patients received SDD for 3 weeks immediately after LT. The type of infection, bacterial subtype, CSI classification, severity, and potential interventions were recorded. RESULTS: One hundred eighty-six patients were included in the study. Seventy-eight patients (41.9%) had a bacterial infection within the first year after LT. The most common types of infection were cholangitis (25.8%) and secondary infected abdominal fluid collections (25.3%). The most common bacteria were Gram-positive enterococcal- (36.5%) and Gram-negative enterobacterial species (34.2%). 35.5% of the infections occurred within the first month after LT, mainly caused by Gram-positive bacteria (76.7%). CONCLUSIONS: Cholangitis and infected abdominal fluid are the most common types of infection within one year after LT, mainly caused by enterococcal- and enterobacterial species. Within the first month after LT, infections were mostly caused by Gram-positive bacteria, which could be a consequence of protocol use of SDD. The results can be used for the choice of empirical antibiotic therapy based on the most common types of bacteria and the time frame after LT.

Effectiveness of mechanical and chemical decontamination methods for the treatment of dental implant surfaces affected by peri-implantitis: A systematic review and meta-analysis.

OBJECTIVE: To assess which decontamination method(s) used for the debridement of titanium surfaces (disks and dental implants) contaminated with bacterial, most efficiently eliminate bacterial biofilms. MATERIAL AND METHODS: A systematic search was conducted in four electronic databases between January 1, 2010 and October 31, 2022. The search strategy followed the PICOS format and included only in vitro studies completed on either dental implant or titanium disk samples. The assessed outcome variable consisted of the most effective method(s)-chemical or mechanical- removing bacterial biofilm from titanium surfaces. A meta-analysis was conducted, and data was summarized through single- and multi-level random effects model (p < .05). RESULTS: The initial search resulted in 5260 articles after the removal of duplicates. After assessment by title, abstract, and full-text review, a total of 13 articles met the inclusion criteria for this review. Different decontamination methods were assessed, including both mechanical and chemical, with the most common method across studies being chlorhexidine (CHX). Significant heterogeneity was noted across the included studies. The meta-analyses only identified a significant difference in biofilm reduction when CHX treatment was compared against PBS. The remaining comparisons did not identify significant differences between the various decontamination methods. CONCLUSIONS: The present results do not demonstrate that one method of decontamination is superior in eliminating bacterial biofilm from titanium disk and implant surfaces.

Anatomical three-dimensional model with peri-implant defect for in vitro assessment of dental implant decontamination.

OBJECTIVES: Access to the implant surface plays a significant role in effective mechanical biofilm removal in peri-implantitis treatment. Mechanical decontamination may also alter the surface topography of the implant, potentially increasing susceptibility to bacterial recolonization. This in vitro study aimed to evaluate a newly developed, anatomically realistic, and adaptable three-dimensional (3D)printed model with a peri-implant bone defect to evaluate the accessibility and changes of dental implant surfaces after mechanical decontamination treatment. MATERIAL AND METHODS: A split model of an advanced peri-implant bone defect was prepared using 3D printing. The function of the model was tested by mechanical decontamination of the exposed surface of dental implants (Standard Implant Straumann AG) coated with a thin layer of colored occlusion spray. Two different instruments for mechanical decontamination were used. Following decontamination, the implants were removed from the split model and photographed. Image analysis and fluorescence spectroscopy were used to quantify the remaining occlusion spray both in terms of area and total amount, while scanning electron microscopy and optical profilometry were used to analyze alteration in the implant surface morphology. RESULTS: The 3D model allowed easy placement and removal of the dental implants without disturbing the implant surfaces. Qualitative and quantitative assessment of removal of the occlusion spray revealed differences in the mechanism of action and access to the implant surface between tested instruments. The model permitted surface topography analysis following the decontamination procedure. CONCLUSION: The developed 3D model allowed a realistic simulation of decontamination of implant surfaces with colored occlusion spray in an advanced peri-implant defect. 3D printing allows easy adaptation of the model in terms of the shape and location of the defect. The model presents a valuable tool for in vitro investigation of the accessibility and changes of the implant surface after mechanical and chemical decontamination.

N95 respirator hybrid decontamination method using Ultraviolet Germicidal Irradiation (UVGI) coupled with Microwave-Generated Steam (MGS).

The Coronavirus Disease 2019 (COVID-19) pandemic has induced a critical supply of personal protective equipment (PPE) especially N95 respirators. Utilizing respirator decontamination procedures to reduce the pathogen load of a contaminated N95 respirator can be a viable solution for reuse purposes. In this study, the efficiency of a novel hybrid respirator decontamination method of ultraviolet germicidal irradiation (UVGI) which utilizes ultraviolet-C (UV-C) rays coupled with microwave-generated steam (MGS) against feline coronavirus (FCoV) was evaluated. The contaminated 3M 1860 respirator pieces were treated with three treatments (UVGI-only, MGS-only, and Hybrid-UVGI + MGS) with variable time. The virucidal activity was evaluated using the TCID50 method. The comparison of decontamination efficiency of the treatments indicated that the hybrid method achieved at least a pathogen log reduction of 4 logs, faster than MGS and UVGI. These data recommend that the proposed hybrid decontamination system is more effective comparatively in achieving pathogen log reduction of 4 logs.

aPDI meets PPE: photochemical decontamination in healthcare using methylene blue-where are we now, where will we go?

Personal protective equipment (PPE) reuse, first recommended in the context of the SARS-CoV-2 pandemic, can mitigate shortages in crisis situations and can greatly reduce the environmental impact of typically single-use PPE. Prior to safe reuse, PPE must be sanitized and contaminating pathogens-in current circumstances viruses in particular-must be inactivated. However, many established decontamination procedures are not equitable and remain unavailable in low-resource settings. In mid-2020, an interdisciplinary consortium of researchers first studied the potential of implementing cheap and easy-to-use antimicrobial photodynamic inactivation (aPDI) using methylene blue as photosensitizer to decontaminate face masks and filtering facepiece respirators. In this perspective piece, we describe the development of this novel method, discuss recent advances, and offer insights into how equitable PPE decontamination via methylene blue-based aPDI may be integrated into circular economy policies in the healthcare sector.

Evaluation of the effects of wiping decontamination for filter cartridges of elastomeric half-mask respirators (EHMRs).

BACKGROUND: A major concern among health care experts is a shortage of N95 filtering facepiece respirators during a pandemic. If the supply of N95 filtering facepiece respirators becomes limited, reusable elastomeric half-mask respirators (EHMRs) may be used to protect health care workers. The focus of this study was to evaluate the effects on the filter performance of wiping decontamination for EHMR P100 filter cartridges. METHODS: The filter cartridge exterior of EHMR Honeywell, Moldex, and Mine Safety Appliance (MSA) models was wiped using quaternary ammonium and sodium hypochlorite wipes. These filter cartridge properties were assessed including observational analysis and filter performance tests. These wiping and assessing procedures were repeated after each set of wiping cycles (50, 100, 150, 200, and 400 cycles) to determine the effects of wiping decontamination. RESULTS: For sodium hypochlorite wipes, Honeywell, Moldex, and MSA models passed the National Institute for Occupational Safety and Health (NIOSH) liquid particulate penetration criteria for all wiping cycles from 50 to 400 (penetrations<0.014%). For quaternary ammonium wipes, filter penetrations of Moldex failed (penetrations>0.03%) after 150 cycles, while the filter penetrations of Honeywell and MSA passed for all wiping cycles (penetrations ≤0.013%). CONCLUSIONS: Wiping decontamination methods using sodium hypochlorite and quaternary ammonium wipes could be considered promising decontamination candidates for Honeywell, Moldex, and MSA reuse, except for the wiping number selection for Moldex (<150 cycles) when using the quaternary ammonium wipe.

Efficacy of a novel three-step decontamination protocol for titanium-based dental implants: An in vitro and in vivo study.

AIM: The aim of the study was to evaluate several mechanical and chemical decontamination methods associated with a newly introduced biofilm matrix disruption strategy for biofilm cleaning and preservation of implant surface features. MATERIALS AND METHODS: Titanium (Ti) discs were obtained by additive manufacturing. Polymicrobial biofilm-covered Ti disc surfaces were decontaminated with mechanical [Ti curette, Teflon curette, Ti brush, water-air jet device, and Er:YAG laser] or chemical [iodopovidone (PVPI) 0.2% to disrupt the extracellular matrix, along with amoxicillin; minocycline; tetracycline; H2 O2 3%; chlorhexidine 0.2%; NaOCl 0.95%; hydrocarbon-oxo-borate-based antiseptic] protocols. The optimal in vitro mechanical/chemical protocol was then tested in combination using an in vivo biofilm model with intra-oral devices. RESULTS: Er:YAG laser treatment displayed optimum surface cleaning by biofilm removal with minimal deleterious damage to the surface, smaller Ti release, good corrosion stability, and improved fibroblast readhesion. NaOCl 0.95% was the most promising agent to reduce in vitro and in vivo biofilms and was even more effective when associated with PVPI 0.2% as a pre-treatment to disrupt the biofilm matrix. The combination of Er:YAG laser followed by PVPI 0.2% plus NaOCl 0.95% promoted efficient decontamination of rough Ti surfaces by disrupting the biofilm matrix and killing remnants of in vivo biofilms formed in the mouth (the only protocol to lead to ~99% biofilm eradication). CONCLUSION: Er:YAG laser + PVPI 0.2% + NaOCl 0.95% can be a reliable decontamination protocol for Ti surfaces, eliminating microbial biofilms without damaging the implant surface.

Selective digestive tract decontamination to prevent healthcare associated infections in critically ill children: the PICNIC multicentre randomised pilot clinical trial.

Healthcare-associated infections (HCAIs) are a major cause of morbidity and mortality in critically ill children. Data from adult studies suggest Selective Decontamination of the Digestive tract (SDD) may reduce the incidence of HCAIs and improve survival. There are no data from randomised clinical trials in the paediatric setting. An open label, parallel group pilot cRCT and mixed-methods perspectives study was conducted in six paediatric intensive care units (PICUs) in England. Participants were children (> 37 weeks corrected gestational age, up to 16 years) requiring mechanical ventilation expected to last for at least 48 h. Sites undertook standard care for a period of 9 weeks and were randomised into 3 sites which continued standard care and 3 where SDD was incorporated into infection control practice for eligible children. Interviews and focus groups were conducted for parents and staff working in PICU. 434 children fulfilled eligibility criteria, of whom 368 (85%) were enrolled. This included 207 in the baseline phase (Period One) and 161 in the intervention period (Period Two). In sites delivering SDD, the majority (98%) of children received at least one dose of SDD and of these, 68% commenced within the first 6 h. Whilst admission swabs were collected in 91% of enrolled children, consent for the collection of additional swabs was low (44%). Recruited children were representative of the wider PICU population. Overall, 3.6 children/site/week were recruited compared with the potential recruitment rate for a definitive cRCT of 3 children/site/week, based on data from all UK PICUs. Parents (n = 65) and staff (n = 44) were supportive of the aims of the study, suggesting adaptations for a larger definitive trial including formulation and administration of SDD paste, approaches to consent and ecology monitoring. Stakeholders identified preferred clinical outcomes, focusing on complications of critical illness and quality-of-life. A definitive cRCT in SDD to prevent HCAIs in critically ill children is feasible but should include adaptations to ecology monitoring along with the dosing schedule and packaging into a paediatric specific format. A definitive study is supported by the findings with adaptations to ecology monitoring and SDD administration.Trial Registration: ISRCTN40310490 Registered 30/10/2020.

Skin decontamination of Carfentanil in vitro.

Skin decontamination of Chemical Biological Radioactive and Nuclear (CBRN) materials involves the timely and effective removal of the contaminants from the skin surface. The current work evaluated Fuller's Earth & The Reactive Skin Decontaminant Lotion Kit (RSDL®) to investigate whether they were as efficacious against free base Carfentanil skin contamination as they are against chemical warfare agents. The in vitro methodology used allowed for evaluation of decontamination regimens as specified by the decontaminant manufacturer rather than as an application of a bolus dose left in situ for the study duration. A selection of novel decontaminants, including Dermal Decontamination Gel (DDGel), Trivorex®, itaconic acid (IA), N,N'-methylenebisacrylamide (MBA), 2-trifluoromethylacrylic acid (TFMAA) and NanoSan Sorb were also tested for efficacy. All the evaluated decontaminants were successful at removing the majority of the Carfentanil skin surface contamination. The current work has shown that the Fuller's Earth decontamination kit, removes as much (or more) free base carfentanil from the skin surface in comparison to other products tested in this study series.

Descontaminación digestiva del tracto digestivo: concepto y aplicación / Selective decontamination of the digestive tract: Concept and application

La descontaminación digestiva selectiva (DDS) es una estrategia profiláctica cuyo objetivo es prevenir o erradicar el sobrecrecimiento bacteriano en la flora intestinal que precede al desarrollo de la mayoría de las infecciones en la UCI. La DDS previene infecciones graves, reduce la mortalidad, es coste-efectiva, no tiene efectos adversos, y su uso a corto o largo plazo no muestra un aumento significativo de la resistencia antimicrobiana. La DDS es una de las intervenciones más evaluadas en pacientes críticos, a pesar de lo cual su uso no se ha generalizado. El objetivo de este artículo es presentar una revisión narrativa de la evidencia más relevante y una actualización de los conceptos fisiopatológicos de control de la infección en los que se fundamenta el uso de la DDS. (AU)

Selective digestive decontamination (SDD) is a prophylactic strategy aimed at preventing or eradicating the bacterial overgrowth in the intestinal flora that precedes the development of most infections in the ICU. SDD prevents serious infections, reduces mortality, is cost-effective, has no adverse effects, and its short- or long-term use does not show a significant increase in antimicrobial resistance.SDD is one of the most evaluated interventions in critically ill patients, yet its use is not widespread. The aim of this article is to present a narrative review of the most relevant evidence and an update of the pathophysiological concepts of infection control supporting the use of SDD. (AU)

Effect of chemical and electrochemical decontamination protocols on single and multiple-used healing abutments: A comparative analysis of contact surface area, micro-gap, micro-leakage, and surface topography.

INTRODUCTION: Although the combined use of chemical and electrochemical decontamination protocols can completely remove contaminants from the surfaces of one-time used healing abutments (HAs), their effectiveness in multiple-used HAs remains unknown. We aimed to investigate the effect of reused HAs frequency on the implant-HA contact surface area, micro-gap, microleakage, and surface topography following chemical and combined chemical and electrochemical decontamination protocols. METHODS: Ninety bone level titanium implants were assembled with 90 bone level HAs, in which 80 contaminated HA samples were collected from human participants. The retrieved HAs were randomly divided into two groups according to the cleaning protocol: ultrasonication with 5.25% NaOCl solution for 15 min and steam autoclaving (group I); ultrasonication with 5.25% NaOCl solution for 15 min, followed by electrochemical cleaning and steam autoclaving (group II). The control group (group III) comprised 10 new unused HAs. The cleaning protocol was applied after each insertion as follows: (a) single-use and cleaning, (b) double-use and double cleaning cycles, (c) triple-use and triple cleaning cycles, and (d) more than triple-use and more than triple cleaning cycles. The contact surface area and micro-gap were assessed with micro-computed tomography scanning technique, microleakage test using 2% methylene blue staining, surface morphology with scanning electron microscopy, and surface elemental composition with energy-dispersive X-ray spectroscopy analysis. RESULTS: Group Id exhibited the smallest contact surface area. The values of the micro-gap volumes and microleakage were significantly different (p < 0.001) in the descending order of Id > Ic > Ib > IId > Ia, IIa, and III. Morphological evaluation of Groups IIa, IIb, and IIc revealed that residual biological debris was optimally removed without altering their surface properties. CONCLUSIONS: Chemical and electrochemical decontamination protocols are more effective than NaOCl cleaning methods, particularly for multiple consecutive uses with better decontamination levels, which decreases micro-gap volume and microleakage without surface alterations. Although the use of combined decontamination protocols for the contact surface area at the implant-HA interface showed comparable results with the control, change in the contact surface area was observed following the NaOCl cleaning methods. Therefore, titanium HA reuse can be considered in multiple times, if they are cleaned and sterilized using combined chemical and electrochemical decontamination protocols.