When highly anxious children are treated with nitrous oxide for a number of consecutive sessions, their anxiety remains significantly lower during a following control period, even without use of nitrous oxide.
In analgesia stage, the patient is conscious, has all vital reflexes intact, can communicate and cooperate with the dentist, and quickly returns to a normal state following a few minutes of oxygenation.
1967 (Vaisman) - report showing increased incidence of spontaneous abortion among femal Russian anesthesiologists
1980 (Cohen, et al) - report showing increased spontaneous abortion rates (2.3) for DAs and unexposed wives of DDSs who used N2O in their practices; also higher rates of liver, kidney and neurological disease
1992 (Rowland, et al.) - demonstrated reduced fertility among female DAs exposed to ambient levels of unscavenged N2O for longer than five hours per week; the concentration and length of exposure that produce any of these effects remain undocumented.
Chronic Exposure to N2O “ Long-term (chronic) exposure to nitrous oxide in sufficient concentrations can produce irreversible, toxic changes, and should be a concern for dental personnel working in environments in which nitrous oxide is administered to patients.” Howard, JADA, March 1997
NIOSH - recommended exposure limit (REL) 25ppm during administrations
ACGIH (American Conference of Governmental Industrial Hygienists) 50 ppm threshold limit value (TLV) over 8 hour TWA (time weighted average)
Safe Concentrations of N2O Nitrous Oxide Guidance ADA met with OSHA's second in command, Deputy Assistant Secretary James Stanley, Sept. 18 after learning that a draft OSHA "technical guidance" document on anesthetic gases apparently imposes on dental offices a nitrous oxide level of 25 ppm, a level technologically out of reach and far below that associated with adverse health effects. ADA pointed out that the Association's expert panel, which met Sept. 12 and 13 and included an OSHA engineer, agreed the 25 ppm level is unjustified by scientific data. ADA will submit written comments on the OSHA draft by the end of October. (September 26)