How to maintain the good quality of the sterilization?

  During the disinfection and sterilization, we should be noted the nature and characteristics of the method, and also pay attention to the usable method and external factors about the disinfection efficacy. 

    Regardless of which method we use to disinfection or sterilization, the disinfection effect will be affected by many factors, so if we can control and use the advantage of these factors, it can increase the disinfection effect. Otherwise, it will lead the disinfection or sterilization to failure.

The main factors are the following points:

1) Sterilize dose:

      The sterilize dose is the basic condition to kill microorganisms, include the strength and time. If increase the sterilize strength, also can increase the speed of the sterilization. While decrease the sterilization time, it also decrease the efficacy. Of course, if the sterilize strength is lower than the standard, it can’t reach the sterilize goal even if increase the time.

2)The types and quantities of microbial contamination:

     According to the different types of biology, so there are the different disinfection effects. In addition, the number of microbes also affect the result. So before the disinfection, we should be noted the types and quantities of microbes contamination. In general, the microbial resistance is stronger or more serious pollution, then the disinfection is also more difficult.

3) PH value:

      Changing the PH value can affect the results of some sterilizations. One side, the disinfectant will be impacted by the PH value, it result of increased or decreased the disinfectant activity. On the other hand, the PH value will impact the microorganism.

4) Antagonism:

    For the chemical disinfection, pay attention to the interference about the antagonistic substances. For example, the quaternaries effects will be neutralized by the soap or anionic detergents. And acidic or alkaline disinfectant will be neutralized by the alkaline or acidic substances, then decrease the disinfect efficacy.

5) Penetration:

   When the instruments are disinfected, the bactericidal factors must be applied to the microorganism itself directly. Otherwise, it won’t have the bactericidal effect. For example, UV disinfection effect only can apply the microorganisms on the surface and shallow liquid, a piece of paper can reduce 95% the bactericidal effect.

Finally, there are many factors will affect the efficacy of disinfection and sterilization. No matter which method we use, we must check whether there is any factor will affect the result or not.

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Are you sure that your sterilizer conform to the standards?

        Along with the time progresses, continuous development, the develop of globalization also become the trend. Then, the globalization will increase the interpersonal have more contact, it induce the new disease and mutant bacteria will be more and more indirectly. In order to avoid and decrease the chance to contact or spread the contagious disease, the medical standard are also become more strict and careful. According to the acceptance criterion, the instruments and materials must have proper sterilization, so the sterilizer monitoring become an essential part of the medical approval standard.

        The sterilizer monitoring means that periodically checked the instruments are really clean and sterility after the sterilization or disinfection. But it is impossible to check each processed item for sterility. Instead, a set of monitoring processes increase the probability that sterilization did occur. There are three types of the sterilizer monitoring. But using a combination of physical, chemical, and biological indicators is the best way to monitored.

sterile equipment

1) Physical Indicator:

The handlers should record the cycle time, the temperature, and the pressure which is displayed on the sterilizer gauges for each sterile equipment. To make sure the all standards are accomplished.

2) Chemical Indicator:

Use the chemical indicators, such as visual indicator tapes. This indicators will change color after exposure to the proper sterilization environment. But this is not the reliable indicator, because when the temperature increased, the indicator color will be changed. But it does not display how long had been maintained at the highest temperature. So this indicator can’t ensure the temperature and the time whether accomplish the approval standard during the sterilize process, and it also can’t make sure the steam have infiltrated into the sterilization pouches.

Chemical Indicator

 Biological Indicator

3) Biological Indicator:

The biological indicator is use for the high-pressure steam sterilizers and dry-heat sterilizer. This process uses the pouch which include highly resistant, nonpathogenic bacterial endospores as microbial challenges, and put this pouch on the center space of the sterilizer. After the sterilization, we culture this endospore pouch in the suitable environment. If the positive spore test result indicates that the pouch still grew the bacteria, it means this examine process failed, either the sterilize time or the temperature is not enough.

        According to the control disease center, they recommended the medical equipments should be examined by the biological indicator every week. In addition, if the biological indicator test is positive, or the physical or chemical test results indicate failure, the sterilizer should not be used until the reason for failure has been identified and corrected.


References: 
Picture 2: Chemical Indicator http://www.danaproducts.com/index.html
Picture 3:  Biological Indicator  http://www.bge.com.tw/BIOINDI/BIOINDI/engEZS6.htm

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Keeping the operating environment clean to protect both the patient and dentist.

       The clinical or hospital is the place which need very strict and serious requirements for disinfection and isolation. The probability of cross-infection between people and objects is relatively higher. So the hospital how control effectively the problem of cross infection and nosocomial infection is an important symbol.

       For the dentistry is easier to contact the infection than other professional. We must pay more attention to the infection both the patient and dentist, so we should remember many ways that can decrease the probability of the infection. 

Take the gloves and mask 

Before the treatment, we should clean all the tables or instruments before the patient sit in the dental chair. But we should take the gloves and mask before we use the detergent to clean the device.

 Use the detergent on the paper and wipe the dental chair

1) We use the detergent on the paper and wipe the dental chair, because the dental chair is the most contact to the patient.

Clean the table

     

  2) Because we always put the materials on the table and the instruments which we use and put into the patient’s mouth, so we also need to clean the table, it decrease the contact with the bacteria.

Clean the operating lam

3)  We always use the operating lamp, we should clean the handle of the lamp. This part is very easy forget to clean it.

Clean the suction and the tube

 4) We suck the wastewater from the patient’s mouth by the suction. So we don’t forget to clean the suction and the tube.

5)After  the treatment, we should clean the infected instruments by the brush. Then, we put the instrument into the box which fill the glutaraldehyde solution for few minutes. The glutaraldehyde solution make further to clean the bacteria on the instruments.

  6) After the instrument immerse the glutaraldehyde solution for few minutes. We take out the instruments and use the paper wipe the excess water. Final, we encase the instruments in the sterilization pouches. Bring all the sterilization pouches to do the sterilization.

 Finally, it’s important to keep the operating environment clean and decrease the probability to contact the bacteria. The medical personnel should make sure the instruments are clean and asepsis for the patients. We should change the gloves for the different patient and we should not touch other objects when we wear the gloves. Those behaviors is not only to protect the patients, but also to protect ourselves when we doing the treatment.

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Which disinfect method can keep the nutrients and taste of the milk ?

Louis Pasteur 

         As everyone knows, the mother feed the human milk for the infant directly is the best way, but the human milk doesnot sterilize by the sterilization. However, the quality of the different kinds milks will be affected through pressed, collected, transported, packaged and stored process by the machine. In order to protect the health and safety for the milk, so the milk must be sterilized before the consumer buy and drink the milk.

         In 1863, the French microbiologist, Louis Pasteur. From the many scientific studies and experiments, he developed the method that can sterilize the milk and keep the nutrition in the milk. If the milk through the temperature higher than 85°C , the nutrients of the milk will be damaged. But if the temperature lower than 85°C, the nutrients can be retained and almost harmful bacteria will be killed. So the sterilization use the temperature lower than 85°C, is called "Pasteurization".

There are two general methods of the Pasteurization:

1) Low-temperature long-time pasteurization (L.T.S.T): The milk heated between 62°C - 65°C, for 30 mins.

2)High-temperature short-time pasteurization (H.T.S.T): The milk heated between 72°C - 75°C, at least 15 seconds.

Pasteurization

         The biggest effect for the different sterilizations is the taste. The milk is sterilized by the temperature lower than 65°C ,the taste is close to the original. Because the low temperature can retained most nutrients(ex: immunoglobulin, lactoferrin and vitamins). However, during the heating process, the nutrition loss about 10% vitamin B and 25% vitamin C. If the heating time is longer or the temperature is higher, it will lose more nutrients. 

         In addition, the study shows that uses the pasteurization to sterilize the milk or the food ,it can retained most nutrients and vitamins and the expiry date also increase for 21 days. So the Low-temperature long-time pasteurization is really useful and become the new mainstream in the future.




Source:
Picture 1: http://biologyblockb.blogspot.com.es/2011/02/pasteurization.html
Picture 2: http://insta20.com/Post/pasteurization/

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Do you choose the right way to do the sterilization or disinfection?

           There are many methods to keep the life, environment and medical instruments free from the bacteria or microorganisms. According to the material and the effect which we want to achieved, we must choose the efficient method which ensure the sterilization or disinfection is complete.

Sterile

According the unlike material and the effect, we can following points:

1) Heat Sterilization: It is the simplest, most effective and cheap method. Use saturated steam above 100°c for 10-15 minutes. This procedure make the bacteria protein coagulation, then can be achieved the sterilization effect. But the material should tolerate the high heat, otherwise the material will be damaged.

2) Radiation Sterilization: Ultraviolet is the good procedure for sterilization. After the ultraviolet irradiated, the microorganism can’t produce the protein, then the microorganisms are killed immediately and lose the capacity reproductive. But you must check the material whether to be bad after the ultraviolet irradiated for a long time.

Unsterile 

3) Chemical disinfection:

Destruction the number of microorganism to a level low enough that disease is unlikely to occur.

-Using the phenolic compounds component destroy the membrane of microorganisms.

-Using 70% ethanol in water to 100% for surface which denatures proteins of microorganisms.

-Use soap containing hexachlorophene to wash the hands.

   Finally, the different materials want to achieve complete sterility, we should choose the efficient methods, then can save the time, the cost and also protect the material stay the same.

References: 
Sterilization methods and impact on electronics in medical devices , 7/8/2011 http://www.eetimes.com/document.asp?doc_id=1278906

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