title: Measurement of mechanical allodynia and local anesthetic efficacy in patients with irreversible pulpitis and acute periradicular periodontitis.
abstract: An essential feature of symptomatic periradicular inflammation is mechanical allodynia, defined as reduced mechanical pain thresholds. A previous study evaluating a new digital force transducer showed that it reliably measures mechanical pain thresholds of teeth with normal periradicular tissues. In this study, we tested the hypothesis that the force transducer quantitatively measures mechanical allodynia in teeth with acute periradicular periodontitis (APP) and detects the effects of local anesthetic injection. Mechanical pain thresholds were measured in patients (n = 30) with irreversible pulpitis (IP) and APP and compared with their contralateral teeth. The results show that the mechanical pain thresholds of teeth with IP and APP were reduced by 77% compared with contralateral control teeth. The administration of local anesthesia reversed the mechanical allodynia by 62%, and significant sex-specific effects were observed. In addition, the normal teeth contralateral to the symptomatic teeth had lower mechanical thresholds than those observed in healthy volunteers, suggesting that central sensitization occurs during this type of odontalgia. Thus, we show that the mechanical pain thresholds are significantly reduced in teeth with IP and APP and that the force transducer has potential application as a diagnostic aid in measuring mechanical allodynia and as an outcome measure in endodontic clinical trials such as pharmacologic studies and mechanistic research.
authors.affiliation: Department of Endodontics, University of Texas Health Science Center, San Antonio, Texas, USA. khana2@uthscsa.edu
authors.forename: Asma A
authors.initials: AA
authors.lastname: Khan
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Owatz
authors.forename: William G
authors.initials: WG
authors.lastname: Schindler
authors.forename: Scott A
authors.initials: SA
authors.lastname: Schwartz
authors.forename: Karl
authors.initials: K
authors.lastname: Keiser
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Hargreaves
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000779:Anesthetics, Local / Q000627:therapeutic use; D001732:Bite Force; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000295:instrumentation*; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D010485:Periapical Periodontitis / Q000503:physiopathology*; D011671:Pulpitis / Q000503:physiopathology*; D012737:Sex Factors; D018709:Statistics, Nonparametric; D014098:Toothache / Q000175:diagnosis* / Q000188:drug therapy; D014160:Transducers, Pressure