Root surfaces affected by periodontal disease undergo various forms of changes. Cementum exposure from gingival recession may result in absorption of calcium, phosphorus, and fluoride and subsequent hypermineralization and increased radiodensity. Although some reports have suggested that inorganic content with root cementum might show various changes depending upon age or extent of periodontal disease, but no consensus can be reached regarding the the distribution of various elements.

The present study examines the difference in mineral content between healthy and periodontal diseased roots by analyzing three areas per tooth along the root surface in cervico-apical direction using electron probe and scanning electron microscope.

Healthy tooth that was extracted for orthodontic purpose was used as control. Experimental teeth include those with periodontal pocket depth exceeding 6mm and those with gingival recession and periodontal pocket depth of 2-4mm. Levels of Ca, P, Mg and Na were measured using wavelength dispersive x-ray spectrometer at three areas per tooth. The examined areas were located apical to cemento-enamel junction in control and periodontal ligament-depleted areas in experimental teeth. The corresponding areas were also examined with scanning electron microscope(×70).

The results are as follows.

1. Minerals were detected in order of Ca, P, Mg and Na. In all root surfaces, levels of Ca and P were higher in dentin than in cementum.

2. Level of Mg was twice as high in dentin than in cementum. There was no significant difference in the level of Mg and Na between normal and periodontal diseased roots or between the various locations in the same root.

3. Level of Ca and P in the surface cementum showed no difference between normal and periodontal diseased root, although the areas in dentin with high level of either ion also showed high level of corresponding ion incementum.

4. Difference in the Ca and P content between various locations within the same root was noted, although no coherent pattern existed.

These results suggest that although the mineral content of the root cementum in periodontitis-affected tooth is affected by exogenous ions from saliva and food, but there was no difference in the mineral contents between normal and periodontally diseased root.