Behavioural modifications after repeated conscious sedations: a three year study

Objectives: Despite extensive literature on nitrous oxide sedation, the longitudinal effect of repeat sedation sessions on patient behaviour has not been fully evaluated. This prospective study examined the evolution of behaviour for patients undergoing repeat sedation for dental care. Method: 543 patients undergoing sedation (range 1 to 94 years, mean (SD):17 years (±16)) were recruited over 3 years in a special care dental unit. Inhalation sedation using a 50% N2O/O2 premix (Kalinox) was administered via a nasal or a facial mask. The modified Venham scale was used to evaluate patient behaviour at 5 steps during each dental session. Completion of the planned dental treatment and adverse side effects of sedation were additional criteria. Results: Patients experienced inhalation sedation for the first time for 378 treatment sessions and the session was a repeat experience for 843 sessions. The number of visits per patient ranged from 1 to 16. Of the 164 patients that underwent at least three sequential sedation sessions, the behaviour score significantly improved during subsequent visits at time 0 (first contact with the dentist) and time 1 (on applying the mask) (p<0.0001, between first and second sessions, Wilcoxon test). Among the 64 sessions that led to a failure, 6 cases were a new attempt after a failure to treat and led to a second failure. Minor adverse events were recorded during 6.5% of all the sessions: nausea (n=24), vomiting (n=48), and other (n=14) (agitation, euphoria, sudation, etc.). Conclusion: The experience of treatment under N2O/O2 sedation may be a therapeutic tool in the de-conditioning of dental fear.