Dentistry is predominantly a field of surgery, involving exposure to blood and other potentially infectious materials, thus it requires a high standardized protocol of infection control and safety practice in elimination of cross contamination and exposures to blood-borne diseases.
Asepsis in a dental clinic is very important part of clinical practice. Success of any dental procedure right from the dental examination depends on how the dental clinic is practicing the sterilization and disinfection in the clinical area.
Cleaning of instruments
Cleaning is a vital method that is performed before sterilization or medical aid of dental instruments. This involves cleaning of all surfaces of dental instruments to remove blood, microbes, and debris, and to prepare instruments for sterilization or disinfection. Cleaning of instruments is usually performed with water and detergents.
What is sterilization?
Sterilization is a process that eliminates, removes, kills, or deactivates all the forms of microorganisms such as fungi, bacteria, viruses, and other infective organisms that are present on a specific surface, object or fluid.
Disinfection means destruction of pathogenic and other kinds of microorganisms by any physical or chemical means. Difference between disinfection and sterilization is that the disinfection destroys the majority of recognized pathogenic microorganisms, but not necessarily all microbial forms while sterilization kills or eliminates most.
Modes of disinfection in Dental Clinic
Disinfection is a vital part of sterilization. It is always at least a two-step procedure: The initial step involves vigorous cleaning/washing/scrubbing of the surfaces to be disinfected and wiping them clean. The second step involves immersing the instruments or wetting the surface with a disinfectant and leaving it wet for the time prescribed by the manufacturer for the effectiveness.
Dental Instruments cleaning area
Each dental office should possess a separate place that is reserved for cleaning of contaminated dental instruments. Care should be taken to immerse the instruments into water or detergent immediately after use, to prevent drying of blood and debris. Dental staff should wear heavy gloves while washing instruments, to prevent accidental injury and cross-infection.
UV Disinfection chamber
Ultrasonic machines can also be used for improved cleaning. UV Disinfection chamber is most effective when instruments are kept in UV chamber for a period of 45-60 min. Thus UV Disinfection chambers can be used in dental offices as an effective tool for disinfection of instruments. The instruments can be stored in UV chambers after effective autoclaving.
Soap and water work to get rid of every type of germs from hands, whereas sanitizer acts by killing sure germs on the skin. Though alcohol-based hand sanitizers will quickly scale back the quantity of germs in several things.
Use of Shoe Covers
Shoe covers are used to prevent contamination of the exterior in clean areas of the dental clinics, without having to use specific shoes.
These Disposable Shoe Covers are especially useful for use on patients when entering the operating room that way the dirt or germs on the feet will not enter the room.
Sanitizing the door knobs / handles
This eliminates /removes the germs if someone touched the doors with unclean hands. A person who touches a contaminated surface then touches their mouth, nose or eyes can become infected.
Modes of disease transmission
There are number of modes through which the diseases get transmitted from one person to another. In dental office, all care should be taken to avoid it. Following are the common modes –
Direct contact with blood or body fluids
Indirect contact with a contaminated instrument or any of its surfaces.
Contact of mucosa of the eyes, nose, or mouth with droplets or
Inhalation of airborne microorganisms
Patient safety in Dental Clinic
Dental chair should be cleared, disinfected before next patient is taken.
Chair side assistant should take care of –
– Clearing the previous patient’s instruments.
– Changing the tumbler
– Disposing the unit covers
– Mouth wash
– Draping the patient
– Sterilized instruments to be opened just before starting the procedure to avoid contamination.
Dental Team safety
The dentist and team MEMBERS ARE always at risk of exposure to infectious diseases through the contact with blood or other potentially infectious agents. Scrupulous infection control and proper safety guidelines need to be followed to minimize the risks of disease transmission to the team and also to the patients.
Dental instruments are classified into 3 classes, relying upon their risk for sending infection among patients and dental care providers:
Critical Instruments – these embrace all instruments that penetrate oral soft tissues and bone, or area unit exposed to the blood. These instruments ought to be sterilized through heat, dry or chemical sterilization, once every use, crucial instruments employed in medicine embrace dental extractor, scalpels, bone chisels and surgical burs.
Semi-critical Instruments – these instruments don’t penetrate oral tissues. However, they are available in touch with oral membrane or non-intact skin. Such instruments embrace dental mirrors, amalgam condensers and impression trays .The CDC recommends that these instruments ought to ideally be sterilized once every use. However, just in case this is often insufferable, a high-level disinfectant registered with the U.S Environmental Protection Agency (EPA) is used.
Non-critical Instruments – these instruments solely are available contact with the intact skin or membrane. Such instruments embrace x-ray heads and pulse Oximeters.
These instruments have a low risk of cross-infection. Therefore, they can be cleaned with an intermediate or low-level disinfectant.
Packaging and storage of instruments
Instruments that are to be used in a specific procedure are placed in special packages before sterilization. This avoids cross contamination of instruments during post sterilization storage & transport. Sterilization cassettes can also be used to sterilize instruments that are required during a specific dental procedure such as an implant surgery.
Fumigation is a process that is used for cleaning and sanitizing the rooms and surfaces to make them free of germs and bacteria. Fumigator machine produces a fog that can help eradicate the germs, pests and other harmful foreign bodies that are hazardous and can cause problems to humans.
Room purifier: Air purifier purifies the air by reducing the airborne particulates. It’s wonderful for filtering dirt, smoke from candles, stove and spores, and conjointly reduces mildew and fungous growth. It prevents the particulate matter (PM 2.5) that can penetrate deeply into the lungs, irritate and corrode the alveolar walls, thereby impairing the lung function. HEPA (High Efficiency Particulate Air) filter is considered as the global standard that captures up to 99.97% of air particles as small as 0.3 micron.
Commonly transmissible infections in dental clinic
Apart from blood-borne diseases such as Hepatitis B & HIV infections, the dental health care workers are potentially at risk of acquiring respiratory diseases, childhood diseases, sexually transmitted diseases commonly encountered in dentistry.
Instruments used in infected person, if are not sterilized properly and if come in contact with the another patient or the dentist / auxiliary staff through the injuries or cuts on the hands can increase the risk of transmission.
The infection can be controlled by the use of personal protective equipments (PPE) with disposable gloves (sterile or non-sterile), protective eyewear, face-shields, masks, gowns and utility gloves, etc.
Sterilization of commonly used instruments such as –
Hand pieces – Airotor and micro motor hand pieces to be autoclaved every after a patient. Dentists need to keep at least 4-5 hand pieces well sterilized for the number of patients needing it for the day.
Cutting diamond / carbide Burs
Root canal instruments
Condensers, burnishers, plastic filling instruments etc.
Machines used for sterilization
It is the sterilization with steam under pressure. Time required at 1210 C is 15 Min at 15 lbs of pressure. This is the most effective way of sterilizing all kinds of instruments used in dental practice.
Dry heat oven
These are electrical devices that use dry heat to sterilize dental instruments. They do not need water for sterilization, abundant pressure isn’t developed within them therefore they are safer than the steam autoclaves. Since heat generation is electrically controlled, optimal temperatures for sterilization are attained immediately. Dry heat ovens may not be able to completely kill all microbes thus not much in use in dental clinical practices.
Disinfection is always at least a two-step procedure:
First step is vigorous scrubbing of surfaces to be disinfected wiping and cleaning while the second step involves wetting the surface with a disinfectant and leaving it wet for the prescribed time.
Commonly used disinfectants are
1. Alcohols, such as ethyl alcohol and isopropyl alcohol
2. Aldehydes, such as formaldehyde used for the fumigation of operatory & working area
This type of sterilization is used on heat-sensitive dental instruments.
Solutions such as glutaraldehyde or Sodium hypochlorite may be used for this purpose. However, this procedure requires a lot of time to acquire complete sterilization, and therefore it is not recommended.