What are Disinfection and Sterilization procedures in Dental Clinic

Disinfection and Sterilization of Dental instruments and equipment in a Dental Clinic is a very important and integral part of running a successful Dental Practice to make sure that your practice is not a place of cross-contamination or cross infection. Sterilization is a process in which an object, surface or medium is freed of all micro-organisms either in the vegetative or spore state. Surgical Instruments are used in everyday procedures performed in a Dental clinic and one of the most important aspects of the procedure to be successful is to make sure that all the surgical instruments are decontaminated and disinfected to prevent any infection to the patient.

There are four important principles to achieve proper cleanliness and all these needs to be achieved in your Dental Practice:

• Asepsis: Process to reduce or eliminate contaminants like a virus, bacteria, fungi parasites etc from entering the surgical field to prevent infection.
• Disinfection: A process by which a surface, object or medium is reduced of viable micro-organisms to the acceptable level as complete removal of micro-organisms is not possible. It is not possible to inactivate all bacterial spores and Viruses.
• Disinfectant: A chemical used on non-vital or non-living objects to kill surface vegetative pathogenic organisms but not Bacterial Spores or Viruses.
• Antiseptic: A chemical substance applied to living tissues such as mucous membrane or skin to prevent infection by inhibiting the growth of bacteria

Classification of Dental Instruments based on Requirement of Sterilization:

Dental Instruments have been classified into three categories based on how critical is it achieves Sterilization in order to prevent infection of the surgical field.

Critical Instruments: This category includes instruments which come in direct contact with soft tissue or bone during surgical procedures. Sterilization is the preferred choice to make sure that these instruments are properly Disinfected.  Examples – Surgical Burs, Forceps, Elevators, Curettes, Scalers etc.

Semicritical Instruments: Includes instruments which do not penetrate tissues but come in contact with oral tissues during procedures. High level of disinfection is required to achieve proper sterilization.

Non-critical Instruments: The instruments which do not come in contact with oral tissues and body fluids. These require minimal disinfection. The dental equipment/instruments are Restorative materials, Liners, varnishes etc.

Procedures of Disinfection in Dental Clinics:

Glutaraldehyde: It is a type of chemical disinfectant which is a broad-spectrum antimicrobial agent having bactericidal property. It penetrates blood, pus, and organic debris. Its main advantage is the solution is not Corrosive to stainless steel. The activated life of Glutaraldehyde solution is 6-10 hours and hence the instruments must be immersed for the said duration.

Ethylene Oxide: This disinfectant is used to sterilize instruments which are sensitive to moisture and heat such as motors, sharpening stones, polishing cups, etc.

Steps to achieve proper Sterilization in Dental Clinic:

Achieving proper Sterilization is a meticulous process and there are multiple steps which need to be followed without missing any steps. Let us mention all the steps in detail –

The complete process of Sterilization just does not include the Sterilizing machines like Autoclave or liquids like Gluteraldehyde but it starts right from the handling of instruments before and after the procedure and also storing them in a sterile environment to prevent any contaminations. Let us look at the step by step procedure of Sterilizing Dental instruments in a Dental clinic from start to end.

1. Presoaking: This is a procedure which is performed after cleaning the used dental instruments under running water, all the debris and body fluids cannot be cleaned with water and hence presoaking of instruments in a presoaking solution such as (phenolic solutions) is required to soften debris, dissolve or soften organic debris like blood, tissue etc and it also helps in eliminating certain types of microbes as well.
You need to have a dish with the Presoaking solution filled in it and place the instruments in the solution and leave it for sometime for the solution to act on the debris and organic substances. This makes cleaning the debris easier.

2. Cleaning: As the name suggests it is cleaning of the instruments after presoaking to remove the soft debris and organic tissues, to prepare the instruments for Sterilization. You can clean the instruments using your Hand (with Rubber gloves) or using a scrub and in some cases using an Ultrasonic instrument is also recommended.

3. Lubrication and Corrosion Prevention: Non-Stainless steel instruments tend to Rust when sterilized in techniques like Autoclaving or Hot water baths etc. To prevent Rusting instruments must be dried prior to Sterilizing and Anti-corrosion or rust inhibitor solutions must be applied. This is an important step as it helps in increasing the life cycles of instruments.

4. Packaging: This step is a must as it helps in keeping the instruments clean after Sterilizing and prevents it from being exposed to dust etc. The packaging of Instruments before Sterilizing can be done using Autoclave Pouches or see-through poly film bags to help in storing the instruments after sterilizing and directly supplying the same to the Dental chair without having to handle them. Instruments can be packed individually or in groups based on your requirement. Sharp items can be marked or places in see-through packs to prevent any injury while handling them.

5. Sterilization Procedure:

This is the heart of the Sterilizing procedure and it is important to determine what type of Sterilization procedure is performed on the specific instrument. For Ex. all surgical instruments can be sterilized using Autoclave and it is the most accepted and most used technique in dental clinics. For water-based liquids, Dry heat ovens or unsaturated chemicals are used. In case of Cloth or paper or Cotton items, Ultraviolet light sterilization is preferred.

Autoclave: It helps in eliminating bacteria, viruses, fungi, and spores as well, thus it the most preferred and most used mode of sterilization in dental clinics also because it is economical and it sterilizes all the surfaces of an instrument which other methods cannot achieve. Package the Instruments in an Autoclave pouch and place them in the Autoclave, it needs to work at 15 lb pressure at 121 degrees Centigrade for 20 minutes or 30 lb pressure at 134 degrees Centigrade for 3 minutes to properly sterilize instruments.

6. Handling of Sterilized Instruments: Poststerilization handling of instruments is also very important to make sure that sterilization is maintained. It involves drying of the instrument, cooling, storage, and distribution without reinfecting the instruments. If you are using Autoclave pouches, it makes it quite easy as you need to just store the pouches directly and supply it to the dental chair. In case you do not use pouches, store the instruments in trays with a lid and these should not be handled until the need arises to prevent recontamination.

7. Storage: Storing sterilized instruments should be done to keep them dry, prevent dust, away from any contact with wet surfaces like sinks, not close to garbage bins etc. UV Steralization chambers are available now which let us keep the instruments sterile until they reach the patient. The instruments should be placed or stored at least 1 feet above the surface of the floor.

8. Distribution: It is best to use separate pouches to sterilize instruments like – Mouth mirror, probe and tweezers in a single pouch, Surgical instruemnts like Elevators in seperate pouches or Forceps in seperate pouches etc. In caes sterilization is performed by a chemical such as liquid germiside the instruements should be handles using Sterile tongs and sterile trays. Placing these instruments in draws etc uncovered is not recommended as it might lead to contamination.