A new hypothesis for cervical root lesions. a paradigm for dental archeology

Aim: An extensive search of the literature disclosed that there were numerous investigations on caries and the interplay between teeth and tools in studies of hominid fossils. However, there has been little information published on the presence of noncarious cervical lesions (NCCLs) among archaeological populations. Prompted by a paucity of information available at this time which has disclosed that NCCLs.existed among archaeological samples dating back to the Upper Paleolithic and among more recent groups, this investigation was initiated. Methods: In order to make a more precise diagnosis of the NCCLs it is essential for researchers and clinicians to understand and accept the mechanisms of stress, friction, and corrosion and to use the Schema of Pathodynamics Mechanisms of tooth surface lesions to determine their etiology. Current literature abounds with confusion as to the etiology of NCCLs which is still contentious.The authors maintain that much of this confusion is a result of the teaching in dental schools, because of the studies of WD Miller in 1907 and the publication of the widely used text of GV Black in 1908. Their studies and misuse of terms which were upheld throughout the twentieth century still exist in various publications, journals, and textbooks since many researchers and clinicians viewed these lesions as being caused by the mechanisms of friction by means of abrasion, or by erosion, a physical mechanism which they term chemical degradation. Results: In this study the term erosion was supplanted by using the more precise term biocorrosion to designate the loss of tooth substance due to chemical activity. NCCLs result from cyclic occlusal loading whereupon the resulting stress produces molecular microfracture of the hydroxyapatite crystals in the cervical region of teeth where stress is most concentrated. Caries prior to 1991 had been only considered as an acidogenic bacterial and proteolytic process. However, the presence and rapid progression of caries in the cervical area strongly indicates that occlusal loading forces during function creates stress concentration in the cervical region, thus becomes an important mechanism and cofactor in the etiology and exacerbation of root caries.Conclusion: In view of the resistance to change for the past 100 years, the authors contend that it is time for a paradigm shift, utilizing updated terminology and concepts to designate the mechanisms involved in tooth surface lesions. As a consequence, this will improve communication with our related sciences just like archeology.