title: Using ultrasound transmission velocity to analyse the mechanical properties of teeth after in vitro, in situ, and in vivo irradiation.
abstract: Ultrasound transmission velocity (UTV) in isotropic material as a measure for the modulus of elasticity was correlated to mechanical properties. Changes in micromechanical properties of radiated teeth and influence of the oral cavity were to be evaluated nondestructively. UTV was measured in extracted teeth after 36 Gy and 62 Gy of in situ (enorally, with no contact to the oral cavity) and in vitro irradiation. Relative to controls, teeth subjected to 62 Gy in vivo showed higher UTV values for dentine and enamel. Sound teeth irradiated with 60 Gy in situ also showed higher UTV values for enamel, whereas dentine values were not significantly different from those of control. The mechanical properties of teeth irradiated in vitro were affected only after high experimental doses of up to 500 Gy. The difference between in vivo and in vitro mechanical properties may be due to radioxerostomia-induced damages as well as the status of dentine vitality. This supports the concept of direct radiation-induced damage in synergy with radioxerostomia-induced caries.
authors.affiliation: Clinic for Oral and Maxillofacial Surgery, University Hospital Mainz, Augustusplatz 2, 55131 Mainz, Germany. al-nawas@mkg.klinik.uni-mainz.de
authors.forename: B
authors.initials: B
authors.lastname: al-Nawas
authors.forename: K A
authors.initials: KA
authors.lastname: Grötz
authors.forename: E
authors.initials: E
authors.lastname: Rose
authors.forename: H
authors.initials: H
authors.lastname: Duschner
authors.forename: P
authors.initials: P
authors.lastname: Kann
authors.forename: W
authors.initials: W
authors.lastname: Wagner
mesh_terms: D016371:Cranial Irradiation / Q000009:adverse effects*; D003731:Dental Caries / Q000209:etiology; D003743:Dental Enamel / Q000000981:diagnostic imaging / Q000528:radiation effects; D003804:Dentin / Q000000981:diagnostic imaging / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004548:Elasticity / Q000528:radiation effects; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000000981:diagnostic imaging / Q000528:radiation effects; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D014070:Tooth / Q000000981:diagnostic imaging* / Q000528:radiation effects*; D019228:Tooth Crown / Q000000981:diagnostic imaging / Q000528:radiation effects; D014463:Ultrasonography