J Clin Periodontol 2002: 29: 580–585 Copyright C Blackwell Munksgaard 2002 Printed in Denmark . All rights reserved 0303-6979 L. Bergmans 1 , Cervical external root resorption J. Van Cleynenbreugel 2 , E. Verbeken 3 , M. Wevers 4 , B. Van Meerbeek 1 and in vital teeth P. Lambrechts 1 Departments of 1 Operative Dentistry and Dental Materials, BIOMAT, 2 Radiology and X-ray microfocus-tomographical and Electrical Engineering, ESAT, 3 Morphology and Medical Imaging, 4 Metallurgy and histopathological case study Materials Engineering, MTM, Catholic University of Leuven, Belgium Bergmans L, Van Cleynenbreugel J, Verbeken E, Wevers M, Van Meerbeek B, Lambrechts P. Cervical external root resorption in vital teeth. X-ray microfocus- tomographical and histopathological case study. J Clin Periodontol 2002; 29: 580– 585. C Munksgaard, 2002 Abstract External resorptions associated with inflammation in marginal tissues present a difficult clinical situation. Many times, lesions are misdiagnosed and confused with caries and internal resorptions. As a result inappropriate treatment is often initiated. This paper provides three-dimensional representations of cervical external resorption, based on X-ray microfocus-tomographical scanning of a case, which Key words: cervical resorption; external root resorption; peripheral inflammatory root will aid the dental practitioner in recognizing characteristic features during clin- resorption; tooth resorption; XMCT ical inspection. In addition, histopathological examination reveals the cellular morphology of the adjacent tissues. Accepted for publication 21 May 2001 Introduction External resorption is a process that leads to an (ir)reversible loss of ce- mentum, dentin and bone. It takes place in both vital and pulpless teeth and the identification is mostly made during routine radiographic or clinical examination as the majority of cases are asymptomatic. External resorptions may be physiological or pathological. Andreasen suggested an advanced classification in 1985 (Andreasen 1985). Today, his categories of surface, in- flammatory and replacement-ankylosis resorption are commonly used. How- ever, other investigators have intro- duced subgroups or new categories. Consequently, a lack of uniformity in nomenclature is still present, thus con- fusing the dental practitioner. Cervical external resorption, fre- quently called invasive cervical resorp- tion (Heithersay 1999a) or peripheral inflammatory root resorption (PIRR) (Gold & Hasselgren 1992), presents a special type of pathological tooth con- dition that could be classified in the group of inflammatory resorptions. In recent years, several etiologic factors have been advocated and some morphological descriptions were made. Nevertheless, prediction and prevention are still impossible and an exact diag- nosis and treatment is often far from easy, depending on the severity and localization of the defect. Clinically, cervical external resorp- tion is associated with inflammation of the periodontal tissues and does not have any pulpal involvement (Frank & Torabinejad 1998). The pulp remains protected by a thin layer of predentin until late in the process and it has been postulated that bacteria in the sulcus sustain the inflammatory response in the periodontium (Tronstad 1988, Hei- thersay 1999a). This feature differen- tiates cervical external resorption from another type of inflammatory resorp- tion called external inflammatory re- sorption, which is continued by necrotic pulp tissues and an infected root canal content (Andreasen 1985). Cervical external resorption occurs immediately below the epithelial attach- ment of the tooth. As a result, it must be noticed that the location is not al- ways cervical but related to the level of the marginal tissues and the pocket depth. Unless proper treatment is in- itiated, this type of resorption continues and a large irreversible loss of tooth structure may appear by time. As mentioned before, the pulp plays no role in cervical external resorption and is mostly normal in these situ- ations. However, a number of cases ob- served in recent years have suggested that part of this pathology may be as- sociated with intracoronal bleaching procedures in endodontically treated teeth (Harrington & Natkin 1979). Al- though this relationship has not been firmly established by scientific study, strong suspicions exist that bleaching agents such as 30% H 2 O 2 were able to penetrate the dentin from the inside