title: Influence of irrigating solution on postoperative pain following single-visit endodontic treatment: randomized clinical trial.
abstract: OBJECTIVE
  To compare 2 irrigation solutions in terms of postoperative pain after single-visit treatment of chronic apical periodontitis with pulp necrosis.
  
  
  METHODS
  A total of 126 patients requiring treatment of apical periodontitis and pulp necrosis were randomly assigned to 2 groups according to the solution used for irrigation: 5.25% sodium hypochlorite (NaOCl) or 2% chlorhexidine gel (CLX) (63 patients in each group). To assess postoperative pain, a questionnaire and pain intensity scale were administered at 24, 48 and 72 hours and 7 days after the procedure. The χ2 test was used to compare the intensity of pain with the 2 irrigation solutions.
  
  
  RESULTS
  No patients reported severe pain at any stage. Moderate pain was reported by 3% of patients (2/63 in each group) after 24 hours and by no patients beyond 24 hours, regardless of the irrigant used. Mild pain was more frequent but diminished rapidly (reported by 19% [12/63] of patients in the NaOCl group and 16% [10/63] in the CLX group at 24 hours, by 10% [6/63] in the NaOCl group and 11% [7/63] in the CLX group at 48 hours, by 3% [2/63] in both groups at 72 hours and by 2% [1/63] in both groups at 7 days). There were no statistically significant differences in postoperative pain between the 2 groups at any time point (p > 0.05).
  
  
  CONCLUSIONS
  The incidence of postoperative pain after single-visit endodontic treatment of chronic apical periodontitis with pulp necrosis was uniformly low, regardless of the irrigant used.
authors.affiliation: division of endodontics CIODONTO, Ilhéus, BA, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Almeida
authors.forename: Eduardo
authors.initials: E
authors.lastname: Marques
authors.forename: Alexandre Sigrist
authors.initials: AS
authors.lastname: De Martin
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: da Silveira Bueno
authors.forename: Anthony
authors.initials: A
authors.lastname: Nowakowski
authors.forename: Rodrigo Sanches
authors.initials: RS
authors.lastname: Cunha
mesh_terms: D000293:Adolescent; D000328:Adult; D002710:Chlorhexidine / Q000627:therapeutic use; D003188:Composite Resins / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000473:pathology; D003790:Dental Pulp Necrosis / Q000628:therapy; D003793:Dental Restoration, Permanent; D005260:Female; D005500:Follow-Up Studies; D006171:Gutta-Percha / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology*; D010485:Periapical Periodontitis / Q000628:therapy; D011446:Prospective Studies; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012390:Root Canal Therapy / Q000379:methods*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000473:pathology; D055815:Young Adult
chemical_list: D003188:Composite Resins; C444701:Filtek Z250; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; C113130:obtura II; D006171:Gutta-Percha; D012973:Sodium Hypochlorite; D002710:Chlorhexidine