Exercise of the dental nurse with disinfection and sterilization of dental instruments
Aseptic - measures aimed at preventing infectious agents from entering the human body during the performance of certain therapeutic or diagnostic measures. Of great importance from the point of view of aseptic is sterilization. Sterilization - a set of stages of sequential processing tools. It includes disinfection, pre-sterilization cleaning and proper sterilization. Disinfection is a set of measures aimed at the destruction of infectious agents in the external environment. After work, the tools are placed in a container with a special disinfectant solution for an hour. As a disinfectant solution, hydrogen peroxide 6%, chloramine 3%, solution "Vircon", "Anolite", etc. can be used. After that, they are washed in a special sieve and placed in a washing solution heated to 50 ° C,for 15 minutes. The detergent solution includes detergent powder( Lotos, Astra) - 5 g, hydrogen peroxide( 17-160 ml, depending on the concentration) and distilled water( from 835 to 978 ml).After that, the tools are washed for 30 seconds in a washing solution, in running water for 10 minutes, in distilled water for 5 minutes, and dried at a temperature of 85 ° C.
In case of using some disinfectant solutions( for example, "Deconex 50 FF", "Deconex Dental BB", "Lizafin", "Deffekt", etc.), soaking tools in the cleaning solution is not required. It is possible to combine the stages of disinfection and pre-sterilization cleaning.
A number of samples are required to assess the quality of disinfection and pre-sterilization treatment. The main ones are amidopyrine and phenolphthalein. To carry out these samples, 1-2% are selected from each batch of instruments, but not less than 3-5 instruments. Amidopirinovaya assay provides the determination of blood residues on instruments. For its conduct, it is necessary to mix equal amounts of a 5% alcohol solution of amidopiprine and a 3% solution of hydrogen peroxide, adding a few drops of 30% acetic acid. The resulting reagent is moistened with a cotton swab and wipes them with tools.3-4 drops of test solution are placed in syringes and they are moved by the piston to hit the solution on the walls of the syringe. At the end of a minute, the contents of the syringe are taken out on a cotton swab or paper and evaluated. When a blue-violet stain appears, the sample is considered positive.
Phenolphthalein test is carried out to determine the quality of washing tools from the washing solution. When used in the detergent solution of detergents "Novost", "Biologist" phenolphthalein test is not informative. To conduct a sample for a cotton swab, place a 1% alcohol solution of phenolphthalein and wipe it with a portion of the randomly selected instrumentation in the same way as in the amidopyrine test. If the tools are not cleaned properly, the detergent appears pink after 1 minute.
The instruments are sterilized by physical or chemical means. Physical methods include steam sterilization( autoclaving) in steam sterilizers, dry-fire in dry-hot cabinets, sterilization with the help of infrared, radiation exposure, by filtration.
Steam sterilization is carried out in steam sterilizers, where the tools are placed in special boxes. There are steam sterilizers with vertical loading of tools, horizontal loading, and also cassette steam sterilizers. There are two modes of steam sterilization. The first is at a pressure of 2 atm., A temperature of 132 ° C for 20 minutes. The second - at a pressure of 1.1 atm., Temperature 120 ° C for 45 minutes. In the first mode, sterilized products made of glass, textiles, rubber;at the second - from latex, plastic, polyethylene. Control of sterilization is carried out with the help of physical, chemical and bacteriological methods. The physical method of control is provided by the use of thermometers in steam sterilizers and temperature control. The chemical method of control involves the use of special indicators: for the first mode, the indicator is, for example, urea, nicotinamide, for the second - benzoic acid.
The dry method of the sterilization of the dental instruments provides for the use of dry-fire cabinets, where the tools are pre-packaged in kraft bags. There are two modes of dry heat sterilization: at a temperature of 180 ° C for 1 hour and at a temperature of 160 ° C for 2.5 hours. To control the quality of sterilization, the same methods as for steam sterilization are used. Indicators for the first mode are thiourea, tartaric acid, for the second - sucrose.
Chemical method of sterilization involves the use of chemicals: hydrogen peroxide 6%( at room temperature 6 h, at 50 ° C - 3 h), "Dezakson-1"( for 45 minutes), Glutaral,".With this method, you can sterilize products made of polymeric materials, glass, corrosion-resistant metals, dental discs, etc. After sterilization, tools must be rinsed in three containers of water for 5 minutes. The instruments remain sterile for three days.