Different doses of remimazolam for induction of general anesthesia in pediatric dental surgery

INTERVENTION: R1 group:Low dose remimazolam 0.2 mg/kg;R2 group:Medium dose remimazolam 0.3mg/kg;R3 group:High dose remimazolam 0.4mg/kg;P group:Conventional dose propofol 2.5 mg/kg; CONDITION: general anesthesia PRIMARY OUTCOME: MOAA/S score;Time from administration to loss of consciousness;Heart rate;Time from discontinuation of medication to recovery of consciousness;bispectrum index;blood pressure;oxygen saturation;respiratory rate ; SECONDARY OUTCOME: Total dose of anesthetic drugs used;Adverse reactions; INCLUSION CRITERIA: 1.pediatric patients aged 4 ‐ 10 years undergoing elective surgery at our hospital; 2.American Society of Anesthesiologists (ASA) physical status I or II; 3.The expected duration of the surgical process is no more than 1 hour;