Effect Of Autoclave Sterilization Research Articles

Effect of autoclave sterilization on the cyclic fatigue resistance of EdgeFile X7, 2Shape, and F-one nickel-titanium endodontic instruments.

Rotary nickel-titanium files have become the most commonly used engine-powered endodontic instruments due to their improvement in fatigue resistance and flexibility. The autoclaving is the most commonly used method for sterilization. However, the risk of instrument fracture, mainly due to cyclic fatigue during rotation within a curved canal, is still a matter of critical concern. This study aimed to measure and compares the cyclic fatigue resistance of EdgeFile X7, 2Shape, and F-One files in a single curved simulated canal before and after autoclave sterilization. Twenty-four files each of EdgeFile X7, 2Shape, and F-One files were used in this study. They were grouped as group A: EdgeFile X7, group B: 2Shape, and group C: F-One files. Then, each group was subdivided into two, sterilized and nonsterilized, subgroups. The files were tested using a custom-made artificial canal. The number of cycles to fracture (NCF) was calculated. One-way analysis of variance, post hoc Tukey's test, and independent t-test were used. In nonsterilized instruments, the NCF of the EdgeFile X7 group was significantly higher than that in the other groups (P < 0.05). In sterilized instruments, there was a nonsignificant difference in NCF between EdgeFile X7 and F-One files (P > 0.05). The NCF of 2Shape was significantly lower than other files (P ≤ 0.05) in sterilized and nonsterilized groups. The autoclaving significantly decreased (P ≤ 0.05) the cyclic fatigue resistance of the tested files. EdgeFile X7 was the most fatigue resistant. Autoclaving reduced the cyclic fatigue resistance of the tested files.

Gellan gum improves the gel properties and thermal stability of tilapia ( Oreochromis spp.) skin gelatin sterilized at 121°C

The gel strength and thermal stability of fish gelatin are poorer than mammal gelatin. It's very important to improve the thermal stability which can sustain autoclave sterilization so as to expand the application of fish gelatin. In this study, 10% (w/v) tilapia skin gelatin sols with or without 1% (w/v) low acyl gellan gum were sterilized at 121°C before gelation, and the effects of autoclave sterilization on the textural properties and gel structures were investigated. The results showed that autoclave sterilization decreased the hardness (from 661.8 g to 505 g) and chewiness (from 27.44 mJ to 20.33 mJ) of the gels, which were raised more than four times by gellan gum. The gel point and melting point were increased from 16.7°C and 24.3°C to 40°C and 57°C respectively by gellan gum, both of which could sustain autoclave sterilization. Autoclave sterilization significantly decreased the relative intensity of the secondary structures and increased the interaction between proteins and water. The polypeptide chains in fish gelatin formed spherical aggregates and further formed a spatial network structure, which was destroyed by autoclave sterilization. Gellan gum prevented the damage by forming a continuous phase of a tight network that could sustain autoclave sterilization. So gellan gum strengthened the gelatin network and further increased the gel strength and gel point of the mixed gel. Novelty impact statement The gel point and melting point of tilapia skin gelatin were lower than room temperature, which limited its application. Gellan gum significantly improved the gel properties and thermal stability of tilapia skin gelatin, both of which could sustain autoclave sterilization. Gellan gum formed a continuous phase of a tight network in the mixed gel, which strengthened the gel structures and would not be damaged by autoclave sterilization.

Effect of autoclave sterilization, gamma irradiation and high-pressure processing on the migration of 4,4’-MDA and its isomers in laminated food packaging bags

An ultra-high-performance liquid chromatography-tandem mass spectrometry method was used to evaluate the migration levels of primary aromatic amines (PAAs) in 147 laminated food bags on the market (Single-sided migration test), and 3 % of them were non-compliant. 4,4’-methylenedianiline (4,4’-MDA), 2,4’-methylenedianiline (2,4’-MDA) and 2,2’-methylenedianiline (2,2’-MDA) (MDAs) were the main migrating substances, while 2,2’-MDA was the main contributor to the excess of total migration of PAAs. In addition, migration test (60 ℃, 10 days) of laminated bags to food simulants were conducted to investigate the effects of autoclaving, irradiation and high-pressure processing (HPP) on the migration of MDAs. Furthermore, the mechanism affecting migration were discussed and revealed. The migration of 4,4'-MDA and 2,4'-MDA to food simulants was increased after autoclaving (121 °C/15 min). 60Co-γ irradiation (5, 10 and 25 kGy) resulted in a significant decrease in the migration of MDAs (P < 0.05). Irradiation and HPP are relatively safe ways of sterilization in terms of PAAs migration.

The effect of autoclave sterilization on Cyclic fatigue ‎resistance of two Ni-Ti systems (an In-Vitro study)‎

The aim of this study was to evaluate the effect of sterilization on the cyclic ‎fatigue resistance of Reciproc Blue rotary files and One Curve rotary files.‎ Methods: ‎For each test of the cyclic fatigue thirty files of each system were used. Ten ‎of the thirty rotary files were used new, ten rotary files after three sterilization cycles and ten rotary files after ‎six sterilization cycles. For cyclic fatigue ‎testing a static model was used ‎with a specific device, which allowed the instruments to ‎rotate freely ‎inside a Stainless-Steel artificial canal. Results: The results showed higher ‎cyclic fatigue of Reciproc Blue than One Curve with no effect of ‎sterilization on Reciproc Blue and decreeing in the cyclic fatigue resistance ‎for One Curve. Conclusions: Reciproc Blue has higher cyclic fatigue ‎resistance than One Curve. With no effect of sterilization on cyclic ‎fatigue of some files while have negative effect on others.

Reproducibility, Accuracy and Effect of Autoclave Sterilization on a Thermoplastic Three-Dimensional Model Printed by a Desktop Fused Deposition Modelling Three-Dimensional Printer.

The main purpose of this study was to determine the reproducibility and accuracy of a three-dimensional (3D) bone model printed on a desktop 3D-printer based on fused deposition modelling (FDM) technology with polylactic acid (PLA) and the effect of autoclave sterilization on the printed models. Computed tomographic images of the tibia were obtained from 10 feline cadavers, used to create a bone surface-rendering file and sent to the 3D printing software. Right and left tibias were each printed five times with the FDM desktop 3D printer using PLA plastic material. Plastic models and cadaveric bones were measured with a profile projector device at six predetermined landmarks. Plastic bones were then sterilized using an autoclave before being re-measured applying the same method. Analyses of printed model size reliability were conducted using intra-class correlation coefficients (ICC) and Bland-Altman plots. The ICC always showed an almost perfect agreement when comparing 3D-printed models issued from the same cadaveric bone. The ICC showed moderate agreement for one measurement and strong/perfect agreement for others when comparing a cadaveric bone with the corresponding 3D model. Concerning the comparison of the same 3D-printed model, before and after sterilization, ICC showed either strong or perfect agreement. Rapid-prototyping with our FDM desktop 3D-printer using PLA was an accurate, a reproducible and a sterilization-compliant way to obtain 3D plastic models.

The effects of autoclave sterilization on the cyclic fatigue resistance of ProTaper Universal, ProTaper Next, and ProTaper Gold nickel-titanium instruments.

ObjectivesIt was aimed to compare the cyclic fatigue resistances of ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG) and the effects of sterilization by autoclave on the cyclic fatigue life of nickel-titanium (NiTi) instruments.Materials and MethodsEighty PTU, 80 PTN, and 80 PTG were included to the present study. Files were tested in a simulated canal. Each brand of the NiTi files were divided into 4 subgroups: group 1, as received condition; group 2, pre-sterilized instruments exposed to 10 times sterilization by autoclave; group 3, instruments tested were sterilized after being exposed to 25%, 50%, and 75% of the mean cycles to failure, then cycled fatigue test was performed; group 4, instruments exposed to the same experiment with group 3 without sterilization. The number of cycles to failure (NCF) was calculated. The data was statistically analyzed by using one-way analysis of variance and post hoc Tukey tests.ResultsPTG showed significantly higher NCF than PTU and PTN in group 1 (p < 0.05). Sterilization significantly increased the NCF of PTN and PTG (p < 0.05) in group 2. PTN in group 3 had significantly higher cyclic fatigue resistance than PTN group 4 (p < 0.05). Also, significantly higher NCF was observed for PTG in group 2 than in groups 3 and 4 (p < 0.05).ConclusionsPTG instrument made of new gold alloy was more resistant to fatigue failure than PTN and PTU. Autoclaving increased the cyclic fatigue resistances of PTN and PTG.

The effect of autoclave sterilization on the fracture resistance of ProTaper rotary files

The effect of autoclave sterilization on the fracture resistance of ProTaper rotary files

Effects of autoclave sterilization on the physical properties of storage bags and granulocyte function.

Autoclave sterilization altered the leaching of plasticizer, CO2 gas permeability, surface area and the surface wettability of bag films. These changes affected granulocyte cell counts and functions during storage. Four types of polyvinyl chloride bags, with di-(2-ethylhexyl)phthalate (DEHP) or tri-(2-ethylhexyl)trimellitate (TOTM) as plasticizer, with or without treatment by glow discharge (H2), were sterilized with ethylene oxide (EO) or autoclaving (AC). The greatest amounts of plasticizer leached from DEHP-EO bags. TOTM plasticizer did not leach into plasma. CO2 gas permeability was greater with TOTM than DEHP. AC sterilization decreased the surface area of bags. Wettability of film surfaces was greatest with H2-TOTM-EO. After storage in these bags for 24 and 48 h at 22 degrees C, the granulocyte cell counts and functions were greatest in H2-TOTM-EO bags with the nonleaching plasticizer, higher CO2 gas permeability and higher wettable surface due to glow-discharge treatment. The H2-TOTM-EO bag was useful as a granulocyte storage container.

Effects of Autoclave Sterilization on the Physical Properties of Storage Bags and Granulocyte Function

Effects of Autoclave Sterilization on the Physical Properties of Storage Bags and Granulocyte Function

Coliform Analyses at 30 C

The literature directly pertinent to coliform analyses at 30 C was reviewed. Original data were presented on effects of time of incubation of violet red bile (VRB) agar plates at 30 C and the effects of autoclave-sterilization and storage of VRB agar. When boiled VRB agar was used, an incubation period of at least 24 h was required for dairy products; an incubation period of 48 h was required for water, frozen vegetables, and other materials that contained coliforms that were slow in growth initiation. Additional observations should be made after incubation of plates for another 24 h to discover if substantial increases in colony count occurred. If autoclave-sterilized VRB agar was used, the recommended incubation periods should be extended for an additional 12–24 h. The pH of prepared VRB agar should be 7.2. A pH of 6.9 or below was indicative of extensive flaws in the method of preparation and/or storage. although some deterioration occurred in the absence of marked pH changes.