Sterilization Cycles Research Articles

Method to Generate Chlorine Dioxide Gas In Situ for Sterilization of Automated Incubators.

Pharmaceutical preclinical tests using cell cultures are nowadays commonly automated. Incubator microbial contaminations impact such tests. Chlorine dioxide (ClO2) is widely used in aqueous solutions. However, a gaseous form, such as chlorine dioxide gas (gClO2), can effectively access unreachable spaces, such as closed cell culture incubators. Steam sterilization requires a temperature rise to at least 121 °C, thus limiting the possibility of automation elements for sensors and actuators. gClO2 sterilization is an ambient-temperature sterilization method. This article aims to demonstrate that gClO2 generated from solid powder tablets is efficient for sterilizing incubators and can be automated. We selected (i) Bacillus subtilis strain, (ii) Saccharomyces cerevisiae, and (iii) T7 phages as representatives for (i) bacteria, (ii) fungi, and (iii) viruses for each domain to evaluate the sterilization efficiency. This study demonstrated that gClO2 can be generated inside the incubator from a solid powder tablet without specific equipment and can effectively fight biological proxies in 15 min. After 30 sterilization cycles, the actuators and sensors mounted inside the incubator were still operating. Our proposed sterilization method seems to be generally applicable for automated in situ sterilization of incubators and medical robots.

Effect of Autoclave on Surface Topography of Various Rotary Files

ABSTRACT Background: Rotary files are essential tools in endodontic procedures, designed to efficiently shape and clean the root canals. However, repeated sterilization, particularly via autoclaving, may affect their surface integrity, potentially compromising their performance and longevity. This study aims to evaluate the changes in surface topography of various rotary files after multiple autoclave cycles using Scanning Electron Microscopy (SEM). Materials and Methods: In this study, three types of rotary files—NiTi, stainless steel, and gold-treated files—were selected for analysis. Each type comprised 20 samples, totaling 60 files. The files underwent 10 cycles of autoclave sterilization at 121°C for 15 minutes. SEM analysis was conducted before and after sterilization to assess changes in surface characteristics. Parameters such as surface roughness, presence of micro-cracks, and debris retention were meticulously evaluated. Results: Post-autoclave SEM analysis revealed significant alterations in surface topography across all file types. NiTi files showed an increase in surface roughness by 35%, with evident micro-cracks in 40% of samples. Stainless steel files exhibited a 25% increase in surface roughness, while 30% showed minor deformities. Gold-treated files displayed the least surface alteration, with a 15% increase in roughness and micro-cracks observed in only 10% of samples. Debris retention was notably higher in NiTi files post-sterilization. Conclusion: Autoclave sterilization significantly impacts the surface topography of rotary files, with NiTi files showing the most pronounced changes. Gold-treated files exhibited greater resistance to topographical alterations, suggesting superior durability under repeated autoclave conditions. These findings underscore the importance of selecting appropriate file types based on sterilization frequency to ensure optimal endodontic performance and tool longevity.

Microscopic Analysis and Evaluation of Thermal Elevation and Wear of Drills for Implant Site Preparation: An In Vitro Study.

Drilling for implant site preparation generates heat, which can cause bone necrosis if temperatures exceed 47 °C for over a minute. Factors influencing heat include drill size, speed, pressure, irrigation, and tool wear. Frequent drill replacement is essential, as wear from repeated use and sterilization affects performance. This study compared three pilot drills with similar designs from different manufacturers, testing each on pig ribs for 15 perforations after 15 sterilization cycles. Researchers measured temperature increase, drilling time, and surface wear. Results showed that drill no. 1 generated more heat than drills no. 2 and no. 3, though none reached critical temperatures. Drill no. 2 took the longest to reach the desired depth and displayed the most deformation. Findings highlight the importance of adhering to the recommended operational limits, suggesting that drills should be replaced after 15 cycles to ensure efficacy and patient safety.

Exploring sterilizer performance through external biological indicator testing: a retrospective study

BackgroundQuality assurance policies mitigate the risk of nosocomial infections from dental office instrument sterilization by assessing sterilizer performance through biological indicator (BIs) testing. This study aimed to evaluate the prevalence of failed sterilization cycles and their causes of failure for a period of eight years through database analysis of a quality assurance laboratory in the province of Saskatchewan, Canada.MethodsA database of BIs (n = 198,771) performed by an independent quality assurance laboratory from 2015 to 2022 was analyzed. Dental offices (n = 362) inserted Sporview® Biological Sterility Indicators strips in full sterilizer loads and mailed the processed BI tests to an external quality assurance laboratory for analysis. Samples were assessed based on a colorimetric method checking for changes in color and turbidity. Data was collected and statistical analyses were performed using IBM SPSS 28.0.ResultsThe overall failure rate throughout the study was 0.20%, and it decreased gradually from 0.51% (2015) to 0.15% (2022). On average, retests were conducted within 2 days of failure notification. The preferred method of processing was steam sterilization (98%), which had a steadily increasing utilization over time and displays a statistically lower failure rate (0.20%) as opposed to dry heat (1.30%) and chemical vapour (1.40%) sterilizers. Most BI failures were attributable to human error (91.80%), and equipment failures were significantly more likely to occur with dry heat or chemical vapour sterilizers (p < .001).ConclusionThis study significantly contributes to the understanding of dental sterilizer performance in Canada. The low and decreasing sterilizer failure rates over the study period indicate safe dental office procedures and reduced potential for disease transmissions. The study highlights the effectiveness of steam sterilizers with remarkably low failure rates, while human error remains the primary cause of failures. Further research should focus on identifying factors leading to human error and interventions to minimize sterilization failures in dental settings.

Numerical and experimental investigation of the steam penetration in narrow channels during a dynamic steam sterilization cycle

The most challenging aspect of steam sterilization is the removal of all non-condensable gases (NCGs) from the autoclave. These gases prevent the effective killing of microorganisms, impairing the sterility of medical devices. Special cycles are performed to ensure the penetration of steam, even into the deepest passages. To better understand this process, numerical models were developed to determine the spatial distribution of steam within the chamber, including its penetration into narrow channels. These are the first models that can be used to accurately determine the flow within three-dimensional cavities during a dynamic sterilization cycle. To validate the model, an experiment was designed using direct tunable diode laser absorption spectroscopy at a wavelength of 1364 nm to measure the mole fraction of steam present at the end of an aluminum pipe at a temporal resolution of 1 s. This represents a pioneering application of this technique in the field of steam sterilization. This setup was designed for installation on any autoclave. Both simulation and experimental data exhibit good agreement over the entire pressure range (0.18–3.15 bar). The most interesting observation made during the study was the increase in the steam content at the end of the tube while a vacuum was generated. The numerical results show that the mole fraction of H2O increased from 0.53 to 0.63 over the course of a single vacuum phase. This phenomenon was attributed to a stronger diffusion effect combined with small pressure gradients during low pressures. This finding inspired the idea of taking the diffusion effect more into account when designing sterilization cycles in the future to make them more sustainable and effective. The presented methodologies and models represent an excellent basis for conducting more complex investigations in the future, such as those investigating the influence of condensation effects on steam penetration in cavities.

PMCA to demonstrate the efficacy of prion inactivation methods on reusable medical devices: a relevant alternative to animal bioassays

Validation of prion inactivation processes for medical devices relies on in vivo experimental protocols. However, bioassays are costly, long (one to two years) and ethically disputable. Additionally, results obtained with one prion strain, for example 263K (hamster-adapted strain originating from sheep scrapie), cannot be easily extrapolated to relevant human prion strains, further questioning the utility of bioassays. Over the past two decades, cell-free prion amplification assays have emerged as potential alternatives to bioassays. Rather than measuring prion infectivity, they quantify prion seeding activity, i.e. the capacity to convert the normal prion protein into the disease-associated isoform. The results obtained by an optimized cell-free assay termed miniaturized-bead protein misfolding cyclic amplification (mb-PMCA), with four processes using three different prion strains, 263K and two human prions derived from variant and sporadic Creutzfeldt-Jakob diseases, were compared to published bioassays using the same three strains and processes, when available. Tests performed on reference processes (steam, sodium hydroxide, sodium hypochlorite) and low temperature H2O2 sterilization process (STERRAD NXTM Advanced cycle), showed perfect alignment between mb-PMCA and available bioassays. STERRAD NXTM Advanced cycle was efficacious on all three prion strains. These data confirm that PMCA and in particular mb-PMCA is a relevant alternative to animal bioassays for assessment of prion inactivation processes and the interest of some low temperature H2O2 sterilization cycles.

Short-Cycle Autoclave Sterilization of Instruments in Same-Day Ophthalmic Surgeries

What Is the Issue? The volume of ophthalmic surgeries is increasingly high, with cataract surgery being 1 of the most performed surgeries in Canada. Infections following ophthalmic surgeries, while rare, can cause severe complications that may lead to irreversible vision loss. Reducing postsurgery infections is a high priority in clinical practice. Running a full wrapped, terminal steam sterilization cycle for ophthalmic instruments in autoclaves may be inefficient for ophthalmic surgeries and may cause unnecessary heavy economic and environmental burdens due to high surgical volumes. Using instruments sterilized on a short cycle between sequential same-day ophthalmic surgeries may help improve efficiency and reduce resources used. These instruments are generally processed using autoclaves (i.e., steam sterilizers); the effectiveness of a shorter-cycle method of sterilization is unclear. What Did We Do? To inform decisions regarding the use of autoclaves for short-cycle sterilization for sequential same-day instrument use in ophthalmic surgery, we sought to identify and summarize evidence comparing this method to full-cycle sterilization of wrapped instruments and identify any relevant recommendations. We searched key resources, including journal citation databases, and conducted a focused internet search for relevant evidence published since 2012. One reviewer screened articles for inclusion based on predefined criteria. What Did We Find? In a laboratory setting to simulate sequential same-day procedures, short-cycle sterilization with interrupted dry time for unwrapped ophthalmic instruments is feasibly as effective as full-cycle sterilization for wrapped instruments using the STATIM autoclave. Similarly, short-cycle sterilization with interrupted dry time for contained ophthalmic instruments is feasibly as effective as full-cycle sterilization for contained instruments using the AMSCO autoclave. For sequential same-day ophthalmic procedures, wet instruments sterilized by a short-cycle process with an interrupted dry time can remain sterile for at least 3 minutes if kept in a covered sterilizer containment device. One guideline recommends that wrapped or unwrapped ophthalmic instruments sterilized by a short-cycle process without full drying should be stored in a covered containment device until retrieved by staff wearing sterile gloves and gowns in the operating room for the subsequent surgery after a short delay. Phaco handpieces should be immediately primed with a balanced salt solution and remain wet as they sit on the sterile instrument table. We did not identify any clinical setting evidence from studies or autoclave manufacturers. It is unclear if clinical outcomes differ between patients undergoing sequential same-day ophthalmic surgeries using short-cycle sterilized instruments and those undergoing surgery using full-cycle sterilized instruments. What Does This Mean? Preliminary laboratory evidence and guideline recommendations supporting the use of autoclaves for short-cycle sterilization of instruments for sequential same-day ophthalmic surgeries are available. However, there is no clinical effectiveness evidence available on this process in patient settings. Future research is necessary to understand the clinical safety of using instruments sterilized by short cycles for sequential same-day use for patients undergoing ophthalmic surgeries. In addition to the evidence and recommendations identified, other factors, such as environmental influence, may be useful considerations when making decisions about short-cycle sterilization for sequential same-day instrument use for ophthalmic surgery.

Presence and Causes of Sterilization Equipment Failures with Biological Indicators in Dental Offices in Mexico: A Longitudinal Cohort.

Background/Objectives: Sterilization in dental practice is crucial for infection prevention. The aim of this study was to identify the presence and causes of bacterial growth using biological indicators in dental sterilization equipment in San Luis Potosí, S.L.P., Mexico, with different consecutive measurements over a year. Methods: This longitudinal cohort, conducted from January 2022 to January 2024 in San Luis Potosí, Mexico, aimed to identify the presence and causes of bacterial growth in dental sterilization equipment using biological indicators. A total of 207 dental offices were approached, and 175 participated, providing data through questionnaires and monitoring sterilization cycles with BIs. The checks were bimonthly for one year, with a total of six checks. Results: (a) An 11% (n = 1188) incidence of bacterial growth was observed, with a higher percentage in dry heat equipment (13%). (b) Upon analyzing the six consecutive verifications over a year, no statistically significant differences were observed in the failures of the sterilization cycles when comparing the two pieces of equipment. (c) Error in temperature and time of the equipment (OR = 4.0, 95% CI = 1.6-3.9, p = 0.0001) was significantly associated with the presence of bacterial growth during the one-year period. Conclusions: Monitoring sterilization cycles and identifying the causes of bacterial growth with different consecutive verifications decreased the presence of bacterial growth (failures) during the one-year period.

Effect of repeated steam sterilizations on insertional torque, torque to failure, and axial pullout strength of 3.5-mm and 2.0-mm cortical bone screws.

The objective of this study was to determine the effects of repeated steam sterilization cycles on the biomechanical properties of surgical screws. 42 3.5-mm and 42 2.0-mm self-tapping, cortical screws were divided into 3 groups per size and underwent autoclave sterilization for 1 (G1), 50 (G50), or 100 (G100) cycles and testing from August 2018 through June 2021. Sixty screws were then inserted into canine cadaver femurs, and biomechanical properties were measured, including peak insertional torque, torque to failure, and pullout strength, each normalized to cortical thickness. Scanning electron micrographs were taken from 24 screws, and images were blindly analyzed by 5 trained examiners. The mean normalized insertion torque for 3.5-mm screws was significantly different between G1 and both G50 and G100. The mean normalized torque to failure for 3.5-mm screws was significantly different between G1 and both G50 and G100. Axial pullout testing was found to be significantly different for 2.0-mm screws between G1 and G100. Scanning electron micrographs surface scoring identified a significant difference in 3.5-mm screws at the screw tip. The results indicate that biomechanical changes occur with repeated steam sterilizations. Specifically, peak insertional torque and torque to failure are decreased with increased sterilizations for 3.5-mm screws, whereas 2.0-mm screws were altered in pullout testing after 100 sterilizations. It is suspected that numerous sterilizations negatively alter the physical-mechanical properties of certain screw sizes. The biomechanical properties of the bone-implant interface could negatively be affected by multiple steam sterilizations during clinical setting.

Material compatibility of epoxies exposed to repeated low temperature vaporized hydrogen peroxide sterilization

ABSTRACT Through technological advancements, medical devices have evolved in their designs and have become more complex in both their design and materials of construction. Medical grade biocompatible epoxies are widely used in reusable medical devices. Choosing an epoxy that maintains its performance characteristics when subjected to repeated sterilization throughout the reusable medical device’s lifespan is a known challenge for medical device manufacturers. This study evaluated the material compatibility of seven cured 2-part and 1-part epoxies used in medical devices following exposure to 100 cycles in a low temperature vaporized hydrogen peroxide sterilizer. Six of the seven epoxies tested were found to be compatible with vaporized hydrogen peroxide sterilization based on qualitative, hardness and weight measurements conducted post exposure to 100 VHP cycles. The epoxies deemed to be compatible displayed no visual signs of physical defects, minimal reduction in hardness (≤2%) and total weight gain (≤2.9%). One of the epoxy samples did not maintain its texture and exhibited 17% loss in hardness post exposure to 100 VHP sterilization cycles and was found to be incompatible with the low temperature vaporized hydrogen peroxide process. This study verifies the need for material compatibility evaluations of epoxies prior to designing and developing a medical device while keeping in mind the application, lifecycle and intended use of medical devices.

Comparing the impact of various sterilization methods on the cyclic fatigue resistance, bending strength, and torsional fatigue properties of NiTi rotary files

This study aimed to evaluate the influence of various sterilization techniques on the cyclic fatigue resistance, bending strength, and torsional fatigue resistance of Tornado Blue and Race Evo rotary endodontic file systems. Both the file systems underwent a series of 15 cycles of sterilization according to the following study groups: control group (G1; i.e., without treatment), chemical sterilization with 5.25% sodium hypochlorite (G2), dry heat sterilization (G3), glass beads sterilization (G4), and steam autoclaving (G5). Each group consisted of 8 samples (n = 8/group). Statistical analysis was performed using a two-way ANOVA and Tukey’s tests (p ≤ 0.05). Mean values for the number of cycles between both files were 1291 ± 52.79 rpm and 2095 ± 52.91 rpm for Tornado Blue and Race Evo, respectively. The torsional fatigue resistance was 8.00 ± 0.85 NCF and 10.70 ± 0.85 NCF and the bending strength was 486.94 ± 20.97 gf and 564.17 ± 20.97 gf for Tornado Blue and Race Evo, respectively. The results showed no significant difference in the mechanical properties followed by different sterilization protocols. However, a significant difference was observed in tested properties between the two file systems (p ≤ 0.05). The outcome is reassuring for clinicians that the essential process of routine sterilization at clinics seems safe with regards to mechanical integrity of the endodontic files.

Steam quality monitoring as a strategy to reduce wet packs and sterilization failure

Hospital articles processed by steam are widely used in the Central Sterile Supply Department (CSSD), responsible for due sterilization. Steam sterilization is discussed worldwide, aiming to protect patients. If steam is outside the specified requirements, the sterilization process may fail, resulting in the wet packs at the end of the sterilization cycle. The present study evaluated the steam quality at Santa Catarina Hospital (São Paulo, SP, Brazil) from 2016 to 2022. Saturated steam containing noncondensable gases, excess condensate, or even superheat was characterized using the methodology indicated in the European Standard EN 285:2015. From 2016 to 2020, qualification tests showed that the saturated steam quality does not achieve standardlimit parameters. Infrastructural maintenance actions were taken to adjust the saturated steam quality. In 2021, the steam quality followed technical standards, and its adequacy was confirmed in 2022. The points developed by the hospital's maintenance department, the adoption of appropriate devices for this purpose, and the correct preventive maintenance in the autoclaves, together with the correct qualification of the equipment and proof of the steam quality, contributed to improve the safety of the hospital sterilization process and reduce the incidence of wet packages.

Influence of Autoclave Sterilization on the Resistance to Cyclic Fatigue of AF- F-ONE , ProTaper Ultimate, and ProTaper Gold NiTi Instruments (A Comparative Study)

Aims: This investigation aimed to examine the impact of autoclave sterilization on the cyclic fatigue of AF-F ONE, ProTaper Ultimate, and ProTaper Gold. Materials and Methods: Sixty #25 rotary files were categorized into groups as follows: AF-F ONE (Group A), ProTaper Ultimate (Group B), and ProTaper Gold (Group C). Additionally, within each group, there were subdivisions into sterilized and non-sterilized subgroups. Sterilized instruments underwent five cycles of sterilization by autoclave. Cyclic fatigue resistance was evaluated using a simulated canal featuring a single curvature (60° angle, 5-mm radius). Files were operated until fracture, and time and number of cycles to fracture (NCF) were recorded. Statistical analysis: One-way ANOVA, Post hoc Tukey test, and independent t-test. Results: ANOVA indicated a significant difference among non-sterilized groups (p &lt; 0.05). Tukey's test showing a notable difference between AF-F ONE and ProTaper Ultimate/ProTaper Gold (p &lt; 0.05), but not between the latter two (p&gt;0.05).AF-F ONE significantly decreased after autoclave sterilization (p &lt; 0.05), while ProTaper Ultimate and ProTaper Gold remained unaffected (p&gt;0.05). Conclusion: Autoclave sterilization significantly affected the cyclic fatigue of AF-F ONE, whereas ProTaper Ultimate and ProTaper Gold demonstrated resilience. Keywords: Cyclic fatigue, ProTaper Ultimate, AF-F ONE, autoclave sterilization.

Instrument fracture in periodontal therapy: ethical disclosure and clinical management - a case report

Periodontal instrument fractures are rare events in dentistry, with limited literature available on their occurrence and management. This case report highlights an incident involving the fracture of a periodontal sickle scaler blade during manual instrumentation for the removal of calculus. The fracture occurred during instrumentation on the mesial surface of the maxillary right second molar, and the separated blade was subsequently pushed into the sulcus. A radiographic assessment was performed to verify the precise location of the fractured segment. Following confirmation, the broken blade was subsequently retrieved using curved artery forceps. The case report highlights factors contributing to instrument fractures, emphasizing the importance of instrument maintenance, sterilization cycles, and operator technique. Ethical considerations regarding patient disclosure, informed consent, and instrument retrieval methods are well discussed. This case underscores the importance of truthful communication, the proper use of instruments, equipment maintenance in dentistry, and the significance of ongoing professional development to enhance treatment safety, proficiency, and ethical standards in dental care.

Effects of sterilization on the color of ceramic shade guides used in fixed prosthetics

Aesthetic demands are very high in dentistry, and the color of prosthetic teeth is an important factor in success. Today, despite technological advances, the shade guide is still the most widely used instrument for determining tooth color. During the color selection process, the shade guide meets mucous membranes and saliva, making it a semi-critical material. To avoid any risk of cross-contamination, the shade guide can be sterilized. The aim of this study was to assess the impact of sterilization on the color of ceramic shade guides used in fixed prosthetics.: This was a quasi-experimental study. The study population was the sample teeth of the VITA 3D MASTER® shade guide and the VITA CLASSICAL® shade guide, except for the bleaching samples. Brightness, chroma, hue and delta E (∆E) were studied. Before and after each cycle of 120 sterilizations, measurements were taken using the VITA EASYSHADE V® Spectrophotometer. 2 to 2 comparisons of the mean brightness values show statistically significant differences between the two shades. For the same comparison, statistically significant differences were found for the shade and ∆E of the VITA 3D MASTER® shade guide. Sterilization leads to variations in shade guide color. Progressive wear could lead to color changes that are not clinically acceptable and could hinder the esthetic results of prostheses. It would be important to determine the number of sterilization cycles that should not be exceeded when using shade guides.

The Impact of Repeated Steam Sterilization Cycles on the Efficacy of Chairside Adjustment Kits for Polishing Monolithic Multi-Layered Zirconia Dental Restoration Material.

BACKGROUND Before insertion, chairside adjustment kits are heat sterilized for positioning and polishing dental restorations. This study aimed to evaluate the effects of 2 steam sterilization cycles on the efficacy of polishing highly translucent monolithic zirconia (HTMLZ) dental restoration material. MATERIAL AND METHODS 100 HTMLZ disc-shaped specimens were adjusted (grinding, finishing, polishing) with EVE Diacera kit. Two steam sterilization techniques [standard (Gp S), immediate/flash (Gp (F)] of CAK were further subgrouped based on number of sterilization cycles [cycle 1 (control), cycle 5, 10, 15, and 20 (experimental)] (n=10 each). Each subgroup accordingly was evaluated for average surface roughness (Ra) and root mean square roughness (Rq) using a profilometer. Mean and standard deviation of 5 subgroups were statistically analyzed using one-way ANOVA/post hoc Tukey's test. Scanning electron microscopy complemented Ra, Rq measurements. Statistical differences of P≤0.05 were considered significant. RESULTS HTMLZ specimens in both groups showed increased (Ra/Rq) values after repeated sterilization of EVE Diacera kit, with Gp F showing lesser increase than Gp S (20 cycles). Gp F at 10 cycles and Gp S at 15 cycles showed clinically unacceptable roughness threshold (0.25 μm). Differences between subgroups for Ra and Rq values were significant (P≤0.05) with less differences within groups observed in early cycles (1, 10). Results validate the manufacturer's recommendations of using flash sterilization/10 cycles for EVE Diacera kit. CONCLUSIONS Repeated sterilization reduces efficacy of chairside adjustment kit to produce smooth surfaces on HTMLZ. This study recommends flash sterilization to a maximum of 10 times to get the clinically acceptable results of Ra and Rq.

Analysis of sterilization efficiency and application cost of three low temperature sterilization methods.

This paper discusses the sterilization efficiency of three low temperature sterilization methods used in thermosensitive medical devices and makes a preliminary analysis of sterilization costs so as to provide the basis for reasonable selection of low temperature sterilizer in Central Sterile Supply Department. Medical devices compatible with the three sterilization methods were selected for sterilization, and two packaging materials were selected for the three low-temperature sterilization equipment according to the compatibility of the packaging materials. The equipment packed with the same packaging materials were sterilized for five times, and each low-temperature sterilizer was sterilized for a total of ten times. The sterilization effect, sterilization cycle time, energy consumption, and cost of the three sterilizers were compared. The cycle time of ethylene oxide sterilizer was 393.6min, and the cycle time of hydrogen peroxide low temperature plasma sterilizer was 56.1min. The cycle time of low temperature steam and formaldehyde sterilizer was 105.7min. The hydrogen peroxide low temperature plasma sterilizes single cycle power consumption at a maximum of 5 kWh. The single cycle energy consumption of compressed air ethylene oxide sterilizer is up to 12 l. In terms of sterilization application cost, hydrogen peroxide low temperature plasma sterilization has the highest cost, followed by ethylene oxide sterilization, and low temperature steam and formaldehyde sterilization is the lowest. The sterilization efficiency of hydrogen peroxide low temperature plasma sterilization is the highest, followed by low temperature steam and formaldehyde sterilization, and the lowest is ethylene oxide sterilization. The three low temperature sterilization methods can achieve effective sterilization of devices. Each hospital can choose an appropriate low temperature sterilization method according to the characteristics of thermosensitive instruments, turnover efficiency requirements, and financial status.

A Day in the Life of a Surgical Instrument: The Cycle of Sterilization.

Surgeons must be confident that the instruments they use do not pose risk of infection to patients due to bioburden or contamination. Despite this importance, surgeons are not necessarily aware of the steps required to ensure that an instrument has been properly sterilized, processed, and prepared for the next operation. At the end of an operation, instruments must be transported to the sterile processing unit. There, instruments are decontaminated before being sterilized by heat, chemical, or radiation-based methods. Following this, they are stored before being brought back into use. This review highlights the intricacies of the processing of surgical instruments at the conclusion of an operation so that they are ready for the next one.

Effects of Different Sterilization Methods on Orthodontic Wires: An In Vitro Study

ABSTRACT Objective: The purpose of this study was to determine the effect of common methods of sterilization on the tensile strength of Beta titanium, Stainless steel, Australian Stainless steel, Copper Nickel-Titanium, and Nickel-Titanium wires. It also aimed to evaluate the changes in tensile strength values caused by repeated cycles of sterilization. Materials and Methods: A sample of 225 orthodontic wires, i.e., beta-titanium, stainless steel, Australian stainless steel, copper nickel-titanium, and nickel-titanium wires, were collected from different manufacturers. These wires were divided into three groups, which consists of Groups 1, 2, and 3. Four methods of sterilization used in this study were as follows: (i) autoclave (250°F for 20 min), (ii) dry heat sterilization (375°F for 20 min), (iii) ethylene oxide sterilization (54°C for 4 hrs), and (iv) 2.45% acidic glutaraldehyde (10 hrs). Results: The results of this study showed that there was increase in tensile strength of beta-titanium and nickel-titanium wires using autoclave and dry heat sterilization. No statistically significant difference in tensile strength of stainless steel and Australian stainless steel archwires. The tensile strength of copper nickel-titanium wires decreased following 0, 1, and 5 cycles of sterilization. Conclusion: The lack of statistically significant differences established in the study of new and sterilized orthodontic archwires gives us reason to conclude that the orthodontic arch wires can be sterilized because the sterilizing processes do not affect their tensile strength and the orthodontists could thus ensure the maximum safety of their patients.

Sterilization effects on nitric oxide-releasing glucose sensors

Nitric oxide (NO) release from S-nitrosothiol-modified mesoporous silica nanoparticles imbedded in the diffusion limiting layer of a glucose sensor has been demonstrated as an effective strategy for mitigating the foreign body response common to sensor implantation, resulting in improved analytical performance. With respect to potential clinical translation of this approach, the effects of sterilization on NO-releasing biosensors require careful evaluation, as NO donor chemistry is sensitive to temperature and environment. Herein, we evaluated the influence of multiple sterilization methods on 1) sterilization success; 2) NO payload; and 3) sensor performance to establish the commercialization potential of NO-releasing glucose sensors. Sensors were treated with ethylene oxide gas, the most common sterilization method for intricate medical devices, which led to undesirable (i.e., premature) release of NO. To reduce NO loss, alternative sterilization methods that were studied included exposure to ultraviolet (UV) light and immersion in 70 % ethanol (EtOH). Sterilization cycle times required to reach a 10−6 sterility assurance level were determined for both UV light and 70 % EtOH against Gram-negative and -positive bacteria. The longest sterilization cycle times (258 s and 628 s for 70 % EtOH and UV light, respectively) resulted in a negligible impact on benchtop sensor performance. However, sterilization with 70 % ethanol resulted in a reduced NO-release duration. Ultraviolet light exposure for ∼10 min proved successful at eliminating bacteria without compromising NO payloads or durations and presents as the most promising method for sterilization of these sensors. In addition, storage of NO-releasing sensor membranes at –20 and –80 °C resulted in preservation of NO release for 6 and 12 months, respectively.