title: Pain levels and typical symptoms of acute endodontic infections: a prospective, observational study.
abstract: BACKGROUND
  This study aimed to identify key symptoms that could be associated with the diagnosis of acute forms of symptomatic apical periodontitis (SAP) and symptomatic irreversible pulpitis (SIP), and to identify a diagnostic algorithm based on these symptoms.
  
  
  METHODS
  In this prospective, observational study 173 emergency patients diagnosed with acute pain of endodontic origin and no swelling or fistula were included. Patients were asked 11 specific questions from a checklist with a possible discerning value between acute SAP and acute SIP. Pain levels were recorded using the numeric rating scale (NRS-11). Subsequently, the painful tooth was diagnosed. Logistic regression was used to evaluate the checklist regarding its differentiation between SAP (N = 103) and SIP (N = 70). Moreover, a decision tree was constructed based on recursive partitioning to identify a hierarchy in differentiating symptoms.
  
  
  RESULTS
  With identical median NRS-11 scores of 8, the teeth diagnosed with acute SAP and SIP were severely painful. The decision tree analysis resulted in a tree with splits according to pain on cold, perceived tooth extrusion, and pain duration. The overall sensitivity of the tree to detect SAP based on key symptoms was 95 %, its specificity was 31 %.
  
  
  CONCLUSIONS
  The best indicator for SAP was a reported absence of pain to cold stimuli. In teeth that did have a history of pain triggered by cold stimuli, the decision tree correctly identified SAP in 72 % of the teeth that felt too high and had hurt for less than one week.
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Switzerland, Plattenstrasse 11, CH-8032, Zürich, Switzerland. dan.rechenberg@zzm.uzh.ch.
authors.forename: Dan-Krister
authors.initials: DK
authors.lastname: Rechenberg
authors.affiliation: Department of Internal Medicine, Horten Center for Patient Oriented Research and Knowledge Transfer, University of Zürich, Zürich, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Held
authors.affiliation: Department of Internal Medicine, Horten Center for Patient Oriented Research and Knowledge Transfer, University of Zürich, Zürich, Switzerland.
authors.forename: Jakob M
authors.initials: JM
authors.lastname: Burgstaller
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Switzerland, Plattenstrasse 11, CH-8032, Zürich, Switzerland.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Bosch
authors.affiliation: Department of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zürich, Switzerland, Plattenstrasse 11, CH-8032, Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
mesh_terms: D006801:Humans; D010146:Pain / Q000209:etiology*; D010147:Pain Measurement; D010485:Periapical Periodontitis / Q000150:complications*; D011446:Prospective Studies; D011671:Pulpitis / Q000150:complications*
keywords: Diagnostic; Pain; Root canal; Symptom