title: [A study of the related factors and prophylactic measures of endodontic interappointment emergencies].
abstract: OBJECTIVE
  To estimate the related factors and prophylactic measures of endodontic interappointment emergencies (EIE).
  
  
  METHODS
  The clinical cases were divided into three groups. Cases in the routine group were treated according to the routine procedures of root canal therapy. Cases in the medicament group took dexamethasone tablets after the instrumentation. Root canals in the drainage group were prepared at the first visit and had been left open for two or three days. The related factors were recorded. The incidences and flare-up index (FUI) value of EIE were statistically analyzed.
  
  
  RESULTS
  The EIE incidence of the routine group was 19.1%. The EIE incidence and FUI value of the overinstrumented teeth were significantly higher than those of other teeth (P < 0.05). EIE were not significantly related to the age, gender, tooth location and pathosis of the pulpal and periapical tissue (P > 0.05). The FUI value of the medicament group was significantly lower than that of the routine group (P < 0.05). Less severe EIE occurred in the cases of the drainage group than those of the control group (P > 0.05).
  
  
  CONCLUSIONS
  The occurrence of EIE was significantly related to overinstrumentation. Taking dexamethasone may relieve EIE.
authors.affiliation: Dept. of Endodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Gen-li
authors.initials: GL
authors.lastname: Pi
authors.forename: Shi-hai
authors.initials: SH
authors.lastname: Yin
mesh_terms: D003907:Dexamethasone / Q000627:therapeutic use; D004322:Drainage; D004638:Emergency Treatment / Q000706:statistics & numerical data*; D004708:Endodontics / Q000379:methods*; D006801:Humans; D012390:Root Canal Therapy
chemical_list: D003907:Dexamethasone