E. Clinical considerations

1.     Cementum is essential for normal anchorage of the tooth.   By serving as the attachment for Sharpey's fibers on the tooth side, it mediates the attachment of the tooth to the gingival connective tissue, as well as to the periodontal ligament and, hence, the alveolar bone. 

2.     Cementum also provides a protective function to the tooth itself, as it is less susceptible to  resorption than bone.  This allows pressure induced movement of the tooth through bone, as in orthodontics, while minimizing resorptive damage to the tooth.

3.     Scaling and root planing, aimed at removing calculus and bacterial deposits, also readily removes the relatively thin cementum layer.  The procedure often leaves the underlying surface, either cementum or dentin, covered with a "smear layer" that consists of powdered tooth scrapings. It is not clear whether new cementum formation over such a smear layer has a weaker bond with the underlying tooth surface than one without this layer, at least during normal function.  In the presence of a smear layer, new cementum readily splits off the underlying root-planed surface during demineralization of specimens prior to histologic sectioning, a finding that has led to the speculation that a smear layer may result in a clinically weaker junction.

3.      New cementum formation is a key process during therapeutic procedures aimed at gaining new attachment, as it mediates new attachment of the tooth to the periodontal ligament and bone.  While it is possible for bone to fuse directly with the dentin and cementum of the tooth through ankylosis, this is considered an undesirable process, as it results in progressive resorption of the tooth structure because of ongoing osteoclastic (odontoclastic) activity.

4.    Cemental deposition in the apical portion of the root compensates to some degree for the slow tooth eruption that takes place throughout life to compensate for occlusal attrition.

5.     Anomalies in cementogenesis may have significant clinical implications.  For example, enamel pearls often mimic subgingival calculus deposits and may lead to similar patterns of periodontal tissue destruction.  Enamel projections may lead to pockets in furcations.  Neither enamel pearls, nor enamel projections can be removed by scaling.  Their removal necessitates grinding the enamel off the root surface.  Hypercementosis may interfere with tooth extractions.

University of Pennsylvania and Temple University © 1999. All rights reserved. Created: May 8, 1999  Revised: URL: Max A. Listgarten: Comments to author: max@listgarten.com (Technical Support: TU Department of Dental Informatics: Heiko Spallek)