Gluteraldehyde for Disinfection of Hand Pieces Used in Dentistry

The oral cavity harbors a large number of microorganisms including bacteria, fungi, parasites, and viruses. This poses a risk of transmission of infections through aerosols and splatters that are normally generated during dental treatment. The aerosol generated spreads in the surroundings that reach more than 3 feet of distance from the patient. The hand pieces used in dental treatment can act as a source of infections to the patients as well as the dentist.

HIGH RISK OF TRANSMISSION: BIOFILMS

The biofilm formed in dental unit waterlines (DUWLs) could be spread by aerosols created by dental hand-pieces, presenting a risk for both the patient and members of the dental team. The dental chair consists of water reservoir bottles to supply water to the DUWLs. These bottles are manually filled with water and are easily contaminated with the bacteria present in the skin such as Staphylococcus epidermidis and S. aureus. The dental unit waterlines must be cleaned periodically. Clean, dry dental hand pieces harbor few bacteria, but contamination of the handpiece lumen with salivary bacteria occurs during its use. Wiping the outside of the handpiece with disinfectant does not eliminate the potential cross-infection risk. Water samples from dental units is heavily infested with bacteria, some are of oral origin, which colonizes the water piping of the units.

STERILISATION VS  DISINFECTION. 

There is a distinction between the terms sterilization and disinfection. Sterilization refers to the destruction of all microbial forms including viruses. Disinfection refers to the destruction of pathogenic microorganisms only and is often a term applied to procedures that are incapable of destroying spores. Today’s concern for the spread of type B hepatitis in dental offices and the carrier state of this disease has led to a number of methods of disinfection from clinical dentistry.

WHY GLUTARALDEHYDE?

Glutaraldehyde solution was accepted in 1973 by the council of dental therapeutics(3) of the American dental association for sterilisation and disinfection. Glutaraldehyde is a chemical that is used as a cold sterilizer to disinfect and clean heat-sensitive medical, surgical, and dental equipment. It provides high-level disinfection in 10 minutes. The time required for proper sterilization is 10 – 12 hours and for disinfection is 10 minutes.

The disadvantage of this disinfectant may include lesser efficacy in the presence of organic matter and greasy residue after sterilization. 

WHAT SHOULD YOU BE AWARE OF?  SIDE EFFECTS

The adverse effects of this drug include

• Breathlessness
• Rhinitis
• Eye Irritation
• Dermatitis.

BACTERIAL AEROSOLS VS  MASK USE 

Oral fluids become aerosolized during dental treatment and oral microbes have been used as the markers of their spread that may carry blood-borne pathogens. Aerosol is defined as a small droplet usually 5µm or less in diameter, which can remain suspended in the air for some time. Bacterial aerosols are an important consideration for infection control and occupational health in the dental clinic since infective agents can be transmitted via aerosols to patients or dental staff.

DISINFECTION OF LUMENS LUMEN AND FISSURES

Since the dental handpiece consists of lumen and fissures, they retain the infective material from the patients and this makes it inconvenient to clean and disinfect. The spores existing inside the lumen may survive autoclaving unless it is treated on its interior surface with chemical disinfectants. Since these microorganisms are anchored to this equipment, they may not readily detach on flushing but may shed pathogens on high-speed operations. The lumen poses to be a potential site of internal contamination which may lead to its high risk of cross-contamination unless it is sterilized in between patients.

DISINFECTION OF BIOFLIMS

To avoid bacterial contamination in the dental unit Waterlines, protective valves can be installed to prevent the backflip of water from the handpiece into the Waterlines. Studies suggest that there is a high risk of transmission of HIV from dental personnel to the patient than from patient to patient. Studies reveal that bacterial biofilms were found on the inner wall of the plastic tubing supplying water to constituents of dental units using scanning electron microscopy. These biofilms could be found in any tubing that supplies water to the dental units. The source of this biofilm comes from environmental aquatic bacteria which can cause disease in vulnerable patients. The most commonly found micro-organisms in the handpiece include Legionella, Lactobacillus spp, Acinetobacterspp, Micrococcus spp, Staphylococcus spp, Pseudomonas aeruginosa , Klebsiella pneumonia, Streptococcus spp , Burkholderiacepacia.