Exposure to nitrous oxide and neurologic disease among dental professionals.

Questionnaires, mailed to approximately 30,000 dentists and an equal number of dental assistants requesting information regarding professional exposure to anesthetics and health problems, showed an increased incidence of neurologic complaints in dental professionals who worked with nitrous oxide. The most striking differences were noted in individuals reporting symptoms of numbness, tingling, and/or muscle weakness. For dentists heavily exposed to nitrous oxide, the rate of these complaints was 4-fold greater than for nonanesthetic-exposed dentists. For dental assistants heavily exposed to nitrous oxide, a 3-fold increase in these same complaints was noted. In view of recent evidence that nitrous oxide abuse may lead to polyneuropathy, the results suggest that occupational exposure to nitrous oxide by both dentists and dental assistants may be associated with similar neuropathy.

Occupational disease in dentistry and chronic exposure to trace anesthetic gases.

A mail survey of 30,650 dentists and 30,547 chairside assistants grouped according to occupational exposure to inhalation anesthetic and sedatives in the dental operatory indicated increased general health problems and reproductive difficulties among respondents exposed to anesthetics. For male dentists who were heavily exposed to anesthetics, the increase in liver disease was 1.7-fold, kidney disease was 1.2-fold, and neurological disease was 1.9-fold. For wives of male dentists who were heavily exposed to anesthetics, the increase in spontaneous abortion rate was 1.5-fold. Among female chairside assistants who were heavily exposed to anesthetics, the increase in liver disease was 1.6-fold, kidney disease was 1.7-fold, and neurological disease was 2.8-fold. The increase in spontaneous abortion rate among assistants who were heavily exposed was 2.3-fold. Cancer rates in women heavily exposed to inhalation anesthetics were increased 1.5-fold but this finding was not statistically significant (P = .06). Separate analysis of the data for disease rates and birth difficulties by type of inhalation anesthetic indicates that in both dentists and chairside assistants chronic exposure to nitrous oxide alone is associated with an increase rate of adverse response.

Control of occupational exposure to nitrous oxide in the dental operatory.

Methods were developed for controlling the dental team's occupational exposure to nitrous oxide. The most applicable and effective use of these methods included the use of properly maintained gas delivery equipment, a double-walled scavenging nosepiece and vented suction machine, and minimizing speech by the patients. These methods were evaluated by measuring concentrations of nitrous oxide present in the air inspired by dental personnel. Before their use, the dentist inhaled 900 ppm nitrous oxide; their application reduced his inhaled concentration to 31 ppm, representing a 97% reduction. These methods were well accepted during 157 procedures completed by a group of eight dentists engaged in private practice (four general practitioners, two pedodontists, and two oral surgeons).

A survey of anesthetic health hazards among dentists.

Measurable concentrations of waste anesthetic gases have been found in hospital dental operating rooms. A mail survey of 4,797 general dental practitioners and 2,642 oral surgeons indicated that 20.2% of the general practitioners and 74.8% of the oral surgeons had anesthetic exposures exceeding three hours per week. In the comparison of the health of individuals exposed or unexposed to inhalation anesthetics, there was a significant increase (78%) of spontaneous abortion in the spouses of exposed dentists and a significant increase (156%) in liver disease for exposed dentists. The implication of these findings and possible solutions are discussed.