Availability of manufacturers' information on efficacy and compatibility of detergents used for cleaning dental instruments

Efficacy of Ultrasonic Cleaning Products With Various Disinfection Chemistries on Dental Instruments Contaminated With Bioburden

OBJECTIVES

The effective cleaning of reusable dental instruments that removes organic bioburden is a crucial process in infection prevention and control in dental clinics. Despite widespread use, the parameters affecting the efficacy of ultrasonic cleaning products with different chemistries remain underexplored. In the present study, we comprehensively evaluated the cleaning efficacy of commonly available cleaning detergent products against organic bioburden on dental instruments.

METHODS

Thirteen commercially available cleaning detergent products were assessed using Browne STF Load Check Indicators under both static and ultrasonic cleaning conditions at room temperature (25°C) and warm temperature (40°C). Experiments evaluated the effect of product concentration and contact time (1, 5, 10, and 30 minutes), and the economic impact of cleaning detergent dilution. Cleaning efficacy was also tested against artificially soiled dental instruments using ProReveal fluorescence technology.

RESULTS

Significant variability in cleaning efficacy among test products was observed. Optizyme Ultra (6 mL/L), Asepti Multizyme (8 mL/L), and Getinge Enzymatic Plus (20 mL/L) demonstrated superior cleaning performance, particularly when used in ultrasonic cleaners at 40°C. In general, enzymatic products consistently outperformed nonenzymatic products for the removal of organic bioburden. Products performed better with ultrasonic agitation than under static conditions, and optimal results were obtained after 10 minutes exposure time at 40°C.

CONCLUSION

The present study for the first time provides a comprehensive insight into the role of product selection, optimal concentration, temperature, and cleaning duration in maximising soil removal from dental instruments.

Current Challenges in Environmental Decontamination and Instrument Reprocessing

Decontamination of the clinical working environment and reprocessing of reusable dental instruments and devices are key components of modern infection control. This narrative review, which is part of a special issue devoted to contemporary infection control practices, highlights the latest evidence and the potential role of emerging technologies. The underpinning concepts of environmental decontamination and reprocessing have remained unchanged for many years, and key principles such as cleaning before disinfection or sterilisation remain true to the present day. What has changed in recent years are the range of options available, most notably for no-touch decontamination as an adjunct to regular environmental cleaning methods, including vapourised hydrogen peroxide, hydroxyl radicals, and ultraviolet C irradiation. In the realm of sterilisation, newer approaches include solar autoclaves and hydrogen peroxide gas plasma sterilisation. With all new and emerging technologies, greater attention is now being paid to safety as well as effectiveness, with stronger consideration of environmental impacts. This is especially relevant to the use of fully disposable surgical instruments vs reusable instruments. Because dental clinics have many configurations and sizes, each clinic needs to undertake local risk assessments to inform their decisions regarding suitable decontamination and reprocessing methods.

Cleaning Challenges: Can Extended Soil Dry Times Be Reversed?

Background: Cleaning is essential to ensuring the safe processing of reusable medical devices, and most manufacturers' instructions for use (IFUs) specify that clinical soil should not be allowed to dry on devices. If soil is allowed to dry, the cleaning challenge could be increased due to change in soil solubility. As a result, an additional step could be needed to reverse the chemical changes and return a device to a state where cleaning instructions are appropriate. Methods: Using a solubility test method and surrogate medical devices, the experiment described in this article challenged eight remediation conditions to which a reusable medical device might be exposed if soil is dried on a device. These conditions included soaking with water or neutral pH, enzymatic, or alkaline detergent cleaning agents, as well as conditioning with an enzymatic humectant foam spray. Results: The results demonstrated that only the alkaline cleaning agent was able to solubilize the extensively dried soil as effectively as the control, with a 15-minute soak being as effective as a 60-minute soak. Discussion: Although opinions vary, the overall data demonstrating the risk and chemical changes that occur when soil dries on medical devices are limited. Further, in cases in which soil is allowed to dry on devices for an extended time outside of the guidance from leading practices and manufacturers' IFUs, what additional steps or processes may be necessary to ensure that cleaning can be effective? Conclusion: This experiment demonstrated the effectiveness of a soaking step with an alkaline cleaning agent as an additional step if soil is dried on reusable medical devices, thus reversing the effect of an extended soil dry time.

Assessing Detergent Residuals for Reusable Device Cleaning Validations

Cleaning chemistries are detergent-based formulations that are used during the processing of reusable medical devices. Manufacturers are responsible for demonstrating the safety of cleaning formulations when they are used during a device processing cycle, including the risk of device-associated cytotoxicity over the concentration ranges for recommended use and rinsing during cleaning. However, no regulation currently exists requiring manufacturers to demonstrate such safety. Although manufacturers' safety data sheets (SDSs) provide information on the safe use of chemicals for users, this information may not provide sufficient detail to determine the risks of residual chemicals on device surfaces. SDSs are not required to contain a comprehensive list of chemicals used, only those of risk to the user. They should be supplemented with information on the correct concentrations that should be used for cleaning, as well as instructions on the rinsing required to reduce the levels of chemicals to safe (nontoxic) levels prior to further processing. Supporting data, such as toxicity profiles or cytotoxicity data that support the instructions for use, would provide medical device manufacturers and healthcare personnel with the necessary information to make informed decisions about selection and correct use of detergents. In the current work, cytotoxicity profiles for eight commonly used cleaning formulations available internationally were studied. Although all of these products are indicated for use in the cleaning of reusable medical devices, results vary across the serial dilution curves and are not consistent among detergent types. The information presented here can be leveraged by both medical device manufacturers and processing department personnel to properly assess residual detergent risks during processing. This work also serves as a call to cleaning formulation manufacturers to provide this information for all chemistries.

Assessing Detergent Residuals for Reusable Device Cleaning Validations

Cleaning chemistries are detergent-based formulations that are used during the processing of reusable medical devices. Manufacturers are responsible for demonstrating the safety of cleaning formulations when they are used during a device processing cycle, including the risk of device-associated cytotoxicity over the concentration ranges for recommended use and rinsing during cleaning. However, no regulation currently exists requiring manufacturers to demonstrate such safety. Although manufacturers' safety data sheets (SDSs) provide information on the safe use of chemicals for users, this information may not provide sufficient detail to determine the risks of residual chemicals on device surfaces. SDSs are not required to contain a comprehensive list of chemicals used, only those of risk to the user. They should be supplemented with information on the correct concentrations that should be used for cleaning, as well as instructions on the rinsing required to reduce the levels of chemicals to safe (nontoxic) levels prior to further processing. Supporting data, such as toxicity profiles or cytotoxicity data that support the instructions for use, would provide medical device manufacturers and healthcare personnel with the necessary information to make informed decisions about selection and correct use of detergents. In the current work, cytotoxicity profiles for eight commonly used cleaning formulations available internationally were studied. Although all of these products are indicated for use in the cleaning of reusable medical devices, results vary across the serial dilution curves and are not consistent among detergent types. The information presented here can be leveraged by both medical device manufacturers and processing department personnel to properly assess residual detergent risks during processing. This work also serves as a call to cleaning formulation manufacturers to provide this information for all chemistries.

Assessing the efficacy and cost of detergents used in a primary care automated washer disinfector

Background

Cleaning of re-usable medical devices is a critical control point in the decontamination cycle, although defined end-points of the process are controversial.

Objective

Investigate cleaning efficacy and cost of different detergent classes in an automated washer disinfector (AWD) designed for dental practice.

Methods

Loads comprised test soiled dental hand instruments in cassettes and extraction forceps. Residual protein assayed using the International standard method (ISO 15883-5:2005) 1% SDS elution with ortho-phthalaldehyde (OPA) or GBox technology (on instrument OPA analysis). Short (60 minutes) and long (97 minutes) AWD cycles were used with four different classes of detergents, tap water and reverse osmosis water.

Results

SDS elution analysis (N = 612 instruments) demonstrated four detergents with both wash cycles achieved equivalent cleanliness levels and below a threshold of 200 μg protein/instrument. GBox methodology (N = 575) using UK Department of Health threshold of 5 μg/instrument side demonstrated that tap water performed with the greatest efficacy for all types of instruments and cycle types.

Conclusions

Using International standard methodology, different detergent classes had equivalence in cleaning efficacy. Cheaper detergents used in this study performed with similar efficacy to more expensive solutions. Findings emphasise the importance of validating the detergent (type and concentration) for each AWD.

Summary of: availability of manufacturers' information on efficacy and compatibility of detergents used for cleaning dental instruments

AIM

To review physico-chemical data supplied for commercially available detergents marketed for manual and/or ultrasonic cleansing of reusable dental instruments.

METHOD

Manufacturers/suppliers of commercially available detergents for manual or ultrasonic cleaning of dental instruments within primary dental care were invited to supply product information. A structured questionnaire requested details on a range of physical and chemical properties for each detergent.

RESULTS

Seventeen detergent manufacturers/suppliers, encompassing 31 commercially available detergents were identified. Ten of the 17 manufacturers provided information on 23 (74%) of the detergent formulations. Nine detergents were of neutral pH, ten mild alkalis (pH 7.5-10.5) and four strong alkalis (pH >10.5). Sixteen detergents were recommended for ultrasonic and manual cleaning, four stated ultrasonic use and three manual only. Ten detergents cited enzymatic activity as their main mode of action, but only six manufacturers provided detailed information. Four detergents recommended by manufacturers as suitable for manual washing had a strong alkaline pH (>10.5), presenting chemical hazards to users. Two strong alkaline detergents did not warn users of potential adverse effects of such alkaline solutions (corrosion) upon aluminium containing instruments. Only one detergent had investigated the potential toxicity of detergent residuals remaining on instruments after reprocessing.

CONCLUSION

It has proven challenging to collate physico-chemical data on detergents suitable for use in manual and/or ultrasonic cleaning of dental instruments in general dental practice. Standardisation of information on the nature and efficacy of dental detergents in a readily accessible form would be beneficial to dental practice.