Sterilization of re-usable instruments in general dental practice

Impact of Steam Autoclaving on the Mechanical Properties of 3D-Printed Resins Used for Insertion Guides in Orthodontics and Implant Dentistry

Guided implant placement has been shown to be more accurate than free-handed insertion. Still, implant position deviations occur and could possibly pose risks. Thus, there is a quest to identify factors that might impair the accuracy of implantation protocols using templates. This study aimed to investigate the influence of autoclaving cycles (cycle 1: 121 °C, 1 bar, 20.5 min; cycle 2: 134 °C, 2 bar, 5.5 min) on the Vickers hardness and flexural modulus of five different materials used for 3D-printed insertion guides. The specimens were subjected to Vickers hardness tests, showing significant changes in the Vickers hardness for two and three materials out of five for cycle 1 and 2, respectively. The results of the three-point bending tests (n = 15 specimens per material) showed decreasing flexural moduli after autoclaving. However, changes were significant only for one material, which presented a significant decrease in the flexural modulus after cycle 2. No significant changes were detected after cycle 1. In conclusion, our findings show that autoclaving can alter the mechanical properties of the templates to some extent, especially with cycle 2. Whether these modifications are associated with dimensional changes of the templates and reduced accuracy of the implantation protocols remains to be investigated.

Compliance of primary and secondary care public hospitals with standard practices for reprocessing and steam sterilization of reusable medical devices in Nepal: findings from nation-wide multicenter clustered audits

BACKGROUND

Reusable medical devices in healthcare facilities are decontaminated and reprocessed following standard practices before each clinical procedure. Reprocessing of critical medical devices (those used for invasive clinical procedures) comprises several processes including sterilization, which provides the highest level of decontamination. Steam sterilization is the most used sterilization procedure across the globe. Noncompliance with standards addressing reprocessing of medical devices may lead to inadequate sterilization and thus increase the risk of person-to-person or environmental transmission of pathogens in healthcare facilities. We conducted nationwide multicenter clustered audits to understand the compliance of primary- and secondary-care public hospitals in Nepal with the standard practices for medical device reprocessing, including steam sterilization.

METHODS

We developed an audit tool to assess compliance of hospitals with the standard practices for medical device reprocessing including steam sterilization. Altogether, 189 medical device reprocessing cycles which included steam sterilization were assessed in 13 primary and secondary care public hospitals in Nepal using the audit tool. Percentage compliance was calculated for each standard practice. Mean percentage compliances were obtained for overall primary and secondary care hospitals and for each hospital type, specific hospital and process involved.

RESULTS

For all primary and secondary care hospitals in Nepal, the mean percentage compliance with the standard practices for medical device reprocessing including steam sterilization was 25.9% (95% CI 21.0-30.8%). The lower the level of care provided by the hospitals, the lower was the mean percentage compliance, and the difference in the means across the hospital types was statistically significant (p < 0.01). The mean percentage compliance of individual hospitals ranged from 14.7 to 46.0%. The hospitals had better compliance with the practices for cleaning of used devices and transport and storage of sterilized devices compared with the practices for other processes of the medical device reprocessing cycle.

CONCLUSION

The primary and secondary care hospitals in Nepal had poor compliance with the standard practices for steam sterilization and reprocessing of medical devices. Interventions to improve compliance of the hospitals are immediately required to minimize the risks of person-to-person or environmental transmission of pathogens through inadequately reprocessed medical devices.

The experience of dental practices that use automatic washer disinfectors

Background

Understanding the collective sociotechnical experiences of the staff in dental practices with automatic washer disinfectors (AWDs) may help shape future strategies that encourage the transition towards best practice in dental instrument decontamination and reprocessing.

Objectives

To find the emerging themes that reflect the experience of working with an AWD in dental practice. To compare the experience of practice owners to that of the dental nurses.

Methods

A qualitative semi-structured interview-based methodology was applied using a convenience sample of dentists and dental nurses. Verbatim transcripts of audio recordings underwent thematic analysis.

Results

Dental practice owners and dental nurses were interviewed. Four themes were common to both groups: impact on daily routine; mundane technology; the decontamination cycle; and safety. Three themes were unique to the dentists: impact on the business; professionalism; and external motivators for change.

Discussion

AWDs are a mundane form of technology that dental nurses find simple to operate. The extended time it takes to reprocess instruments using an AWD means that dental nurses must adapt their daily working practices to accommodate this. Initial funding to purchase an AWD, especially where there is a professional expert leading a campaign championing their use, can be effective.

Sterilisation in Dentistry: A Review of the Literature

In a small and medium-sized dental facility, the correct management of the sterilisation and presterilisation phases plays a fundamental role in good management of instruments and personnel, in order to ensure conditions that are more efficient with less down time. Nowadays, instrument sterilizers are increasingly efficient in achieving results, both in terms of time and size, and ensure that materials are sterile and ready to be stocked in a reasonable time. A literature search for articles related to revision work was performed using electronic databases such as PubMed, Scopus, and Google Scholar. The following keywords have been entered in the previously mentioned databases: sterilisation instruments; dental autoclave; precleaning; instruments disinfectants. The records obtained were screened by three reviewers, and only relevant articles were read full text. In addition, the timings of dental and sterilisation procedures were measured, and from these, suggestions are made in order to improve the efficiency of instrumentation management (facility used as study subject: University Dental Clinic, University of Foggia) as a function of the health-care interventions. We arrived at the conclusion that without doubt, sterilisation of instruments and products plays a fundamental role, but the efficiency of the sterilisation and presterilisation procedures cannot be separated from managing the personnel in charge by giving them specific and precise tasks.

Observance of Sterilization Protocol Guideline Procedures of Critical Instruments for Preventing Iatrogenic Transmission of Creutzfeldt-Jakob Disease in Dental Practice in France, 2017

Effective sterilization of reusable instruments contaminated by Creutzfeldt–Jakob disease in dental care is a crucial issue for public health. The present cross-sectional study investigated how the recommended procedures for sterilization were implemented by French dental practices in real-world settings. A sample of dental practices was selected in the French Rhône-Alpes region. Data were collected by a self-questionnaire in 2016. Sterilization procedures (n = 33) were classified into 4 groups: (1) Pre-sterilization cleaning of reusable instruments; (2) Biological verification of sterilization cycles—Monitoring steam sterilization procedures; (3) Autoclave performance and practitioner knowledge of autoclave use; (4) Monitoring and documentation of sterilization procedures—Tracking and tracing the instrumentation. Answers were provided per procedure, along with the global implementation of procedures within a group (over 80% correctly performed). Then it was verified how adherence to procedure groups varied with the size of the dental practice and the proportion of dental assistants within the team. Among the 179 questionnaires available for the analyses, adherence to the recommended procedures of sterilization noticeably varied between practices, from 20.7% to 82.6%. The median percentages of procedures correctly implemented per practice were 58.1%, 50.9%, 69.2% and 58.2%, in Groups 1, 2, 3 and 4, respectively (corresponding percentages for performing over 80% of the procedures in the group: 23.4%, 6.6%, 46.6% and 38.6%). Dental practices ≥ 3 dental units performed significantly better (>80%) procedures of Groups 2 and 4 (p = 0.01 and p = 0.002, respectively), while no other significant associations emerged. As a rule, practices complied poorly with the recommended procedures, despite partially improved results in bigger practices. Specific training regarding sterilization procedures and a better understanding of the reasons leading to their non-compliance are needed.

Should Surgical Burs Be Used as Single-Use Devices to Avoid Cross Infection? A Case-Control Study

OBJECTIVE

The purpose of this study was to evaluate and compare the rate of bacterial contamination of reused and new unused burs after different sterilization sessions.

MATERIALS AND METHODS

The test group consisted of 40 used fissure burs, and the control group of 40 unused new fissure burs (total n = 80). The burs from both groups were precleaned according to standard protocols and then subjected to two sterilization sessions (high- and low-steam pressure autoclaving). After each sterilization session, the burs were transferred into incubation tubes which contained thioglycollate culture medium and were monitored daily for a period of 48 h to detect any bacterial growth. Data were collected and statistical analysis was done using Fisher's exact test.

RESULTS

Of the 40 burs of the test group, 2 burs (5%) showed positive bacterial growth, whereas no bur from the control group showed any sign of bacterial growth after high-pressure autoclaving. The colony structure and Gram staining were compatible with the growth of Staphylococcus epidermis. After a second sterilization session at low-pressure steam autoclaving, no bacterial growth was observed for the test group, but 1 bur (2.5%) from the control group showed bacterial growth and Gram-positive staining matched well with the growth of Brevibacterium species.

CONCLUSIONS

The new and unused burs were 100% sterile after high-pressure steam autoclaving, whereas 5% of the reused burs appeared positive with bacterial contamination. After low-pressure steam autoclaving, reused burs were 100% sterile, but 1 new bur demonstrated bacterial contamination.

Biologic monitoring and causes of failure in cycles of sterilization in dental care offices in Mexico

BACKGROUND

Biologic indicator tests (BIs) are considered the most meaningful way to verify sterilization.

OBJECTIVE

To monitor the cycles of sterilization using BIs in dry heat sterilizers and steam autoclaves and to identify the causes of failures in the cycles of sterilization in dental offices in San Luis Potosí, México.

METHODS

An invitation to participate was sent to 400 dental offices, and 206 practitioners of 200 dental offices were included. A questionnaire was given to each of the participants, asking for the following information: sterilizer type, operational parameters used (eg, temperature, pressure, and length of exposure), frequency of sterilization cycles per day, use of BIs, and maintenance procedures of the sterilizer. Two hundred thirty sterilizers were monitored using BIs. The sterilizers with positive results were monitored a second and third time to identify the cause of the failure.

RESULTS

Twenty-two percent of practitioners (n = 46) used BIs, and 17% (n = 39) of the sterilizers reported positive results (bacterial growth). The detected failures were a mistake in the procedure (eg, temperature, time, or pressure), an absence of supervision of the procedure performed by the assistant, and improper maintenance.

CONCLUSIONS

There are opportunities to increase information on infection control, to improve the adoption of standard quality control methods for sterilization as a routine process, to improve training on proper testing, and standardize processes.