1Folayan MO, Idehen EE, Ojo 00. The modulating effect of culture on the expression of dental anxiety in children: a literature review [ J] . Int J Paediatr Dent, 2004, 14:241 -245.
2Matharu LL, Ashley PF. What is the evidence forpaediatric dental seda- tion? [J] .JDent, 2007, 35 (1): 2-20.
4Collado V, Nicolas E, Faulks D, et al. Evaluation of safe and effective administration ofnitrous oxide after a postgraduate training course [J] . BMC Clin Pharmacol, 2008, 7 ( 11 ) : 1 - 7.
5Nicolas E, Lassauzay C. Interest of 50% nitrous oxide and oxygen premix sedation in gerodontology [J] . Clin Interv Aging, 2009, 14 (4) : 67 -72.