Other safety concerns include ergonomics (see Unit 2), eye protection, use of visible light cure units, noise control, and ventilation.
Both oral health professionals and patients are at risk of suffering eye-related injuries during dental procedures. Vision impairment or damage associated with oral health treatment can be caused by physical trauma, chemical irritation, infectious agent, and light radiation associated with visible-light-curing (VLC) units.
Physical eye trauma is quite common. High-speed and ultra-speed handpieces rotate at 180,000 to 500,000 rotations per minute, causing particles to be projected up to 50 mph. Projectiles include pieces of amalgam, tooth enamel, calculus, pumice, and broken dental burs.
With the advent of four-handed dentistry, the patient’s risk for eye trauma has increased. Great care must be taken when passing instruments over the patient. Dental items should be transferred over the patient’s chest rather than over the face. Patients who wear glasses should continue to wear them during treatment. Safety goggles should be provided during treatment for patients who do not normally wear glasses.
Many chemical substances used in dental clinics can cause eye damage or trauma if mishandled. Substances that should be handled with extra care are varnish, bleach, formocreosol, eugenol, hydrogen peroxide, phosphoric acid, methyl methacrylate, chloroform, glutaraldehyde, alcohol, and radiograph photochemicals. These potentially hazardous chemicals must be used carefully at all times.
Aerosols containing infectious organisms are a source of contamination in the dental clinic. Coolant spray or mist associated with high-speed handpieces and ultrasonic scalers can transmit bacteria, which may contaminate the eyes and the respiratory system.
Also, removal of bacteria-laden calculus can cause both physical and microbial infections if projected into the unprotected eye. Of utmost concern is the spread of viral pathogens through aerosols of blood or saliva. Protection and prevention are the key to avoiding exposure to contaminated aerosols in the dental clinic.
Increased use of VLC composite resins has been accompanied by the development of many VLC units. Most units emit light in a specific range of 380 nanometers (nm) to 6000 nm with peaks of 467 nm to 502 nm. This is the blue light in use today. Evidence exists that photochemical injury to the retina can occur as a result of exposure to this short-wavelength light. The ADA Council on Scientific Affairs recommends that caution be exercised when operating VLC units and that the appropriate protective eyewear be used.
The possibility for numerous types of eye injuries exists in the dental clinic for the health professional and patient. As required by OSHA, oral health professionals should wear either a face shield or shatter-resistant eyeglasses with side shields when performing or assisting any procedure that could result in projectiles, chemicals, or aerosols entering the eye.
An eyewash station must also be readily available in case a foreign substance does enter the eye. A station should be located within 25 feet (or 10 seconds) of all employees. Eyewash stations can either be directly plumbed or faucet-mounted, but they should be capable of a minimum flow rate of approximately one-half gallon per minute. Eyewash stations should be identified with an “Eyewash Station” label or sign.
All oral health professionals also must be educated concerning eye safety in the dental clinic. Most eye-related injuries can be prevented with proper education, adequate protective eyewear, and the correct handling of dental instruments and materials.
If an accident occurs, oral health professionals should be able to perform first aid.
Non-penetrating Injury
- Assess
- Irrigate
- Reassess
- Refer if needed
Penetrating Injury
- Assess
- DO NOT apply pressure
- Lightly patch
- Refer
Acid Splash
- Irrigate
- Continue irrigation for 30 minutes
- Emergency referral
Base (Alkali) Splash
- Irrigate
- Continue irrigation for 1 hour
- Emergency referral
Other Liquids
- Irrigate
- Assess
- Advise patient to seek treatment if needed
Infections
- Should always be treated by physician
The possibility for numerous types of eye injuries exists in the dental clinic for health professionals and patients. As required by OSHA, oral health professionals should wear either a face shield or shatter-resistant eyeglasses with side shields when performing or assisting any procedure that could result in projectiles, chemicals, or aerosols entering the eye. An eyewash station must also be readily available in case a foreign substance does enter the eye. A station should be located within 25 feet (or 10 seconds) of all employees. Eyewash stations can either be directly plumbed or faucet-mounted, but they should be capable of a minimum flow rate of approximately .5 gallons per minute. Eyewash stations should be identified with an “Eyewash Station” label or sign.
All oral health professionals also must be educated concerning eye safety in the dental clinic. Most eye-related injuries can be prevented with proper education, adequate protective eyewear, and the correct handling of dental instruments and materials.
Noise levels at a given intensity and duration in any environmental situation are a potential health hazard. Since the development of new dental instruments and equipment, the potential for auditory problems has been a concern for the oral health profession. Factors influencing the risk of acoustic trauma are age, physical condition, existing hearing condition of the individual, intensity or loudness (measured in decibels [Db]) of the equipment, length of exposure, and time between exposures.
The air-driven high-speed handpiece is often identified as a potential noise hazard. Early-model handpieces had increased noise levels reported between 80 and 94 Db at 12 inches and 75 to 104 Db at 6 inches, which posed some risk of causing hearing impairment. Currently available models have decibel levels equal to or lower than the standards set by the OSH Act of 90 Db maximum for 8 hours of permissible continuous exposure per day (OSHA requires a hearing-conservation program for any exposure above an 8-hour average of 85 Db).
Studies have shown that the risk of developing noise-induced hearing loss in the dental clinic is minimal. However, oral health professionals should be aware that some potential hazards due to noise levels do exist in the dental clinic environment and that everyday noise exposures such as those associated with transportation, power tools, and entertainment produce an additive effect. Hearing loss also increases with years of exposure and in a logarithmic relation to exposure duration. There is no way to undo damage caused by noise once it has occurred, so prevention is essential.
Air has long been recognized as a route of transmission for infectious, toxic, or carcinogenic agents. The agents involved in an oral health care environment are anesthetic gases, dental materials, chemical fumes, and pathogenic microorganisms aerosolized from staff, patients, and dental equipment. The persons inhaling these airborne materials are stressed by them. Short of death or overt disease, this stress becomes part of the total stress on professionals, and, therefore, affects their quality of life in an insidious manner. Purity of air is clearly of prime concern in a health care facility, since patients are often in a generally weakened condition.
The heating, ventilation, and air conditioning of oral health facilities have, by tradition, been based on concepts of prevention of nosocomial infection, elimination of toxic hazards, and comfort of patients and staff. Provision of efficient heating, ventilation, and air conditioning is a major part of providing a healthful environment for patients and staff. Healthful air has as few contaminants as possible. This can be attained either by the introduction of outside air into facilities for dilution purposes or by filtration.
Unfortunately, there are currently no national consensus standards for ventilation in the dental environment. Each state’s department of public health will have individual requirements. When planning your dental clinic layout and construction, you should consult with your dental equipment and dental supply company, which should be familiar with individual state regulations.