Role of "diseased" root cementum in healing following treatment of periodontal disease. An experimental study in the dog.

Abstract

This study was undertaken to examine if root debridement in the treatment of periodontal disease must include the removal of the exposed cementum in order to achieve periodontal health. Five beagle dogs were used. Periodontal tissue breakdown around the second, third and fourth mandibular premolars was accomplished by placing plaque‐collecting cotton floss ligatures around the necks of the teeth. When the destruction of the attachment apparatus after 4 months had progressed to a level corresponding to half the length of the roots, the ligatures were removed. During a subsequent period of 2 months the experimental teeth were left without ligatures but the dogs were still allowed to accumulate plaque. On day 180. the experimental teeth were subjected to (lap surgery. Following elevation of the Iiaps, the teeth on one side of the jaw were scaled and the exposed root cementum was removed using diamond burs. On the contralateral side no scaling was performed and the roots were only polished with the use of rubber cups, interdental rubber tips and a polishing paste. After irrigation of the roots with sterile saline the flaps were repositioned at their original level and sutured. Following a healing period of 2 months, during which both test and control teeth were subjected to regular plaque control, the dogs were sacrificed and the jaws placed in fixative. After decalcification. histological sections of the experimental teeth and their periodontal tissues were produced. The histometric data demonstrated that the result of healing was similar whether or not the previously exposed root cementum had been removed. In both situations a junctional epithelium with a non‐inflamed subjacent connective tissue was formed. In addition, new connective tissue attachment was frequently observed at the apical extent of the wounds following both types of treatment. The results suggest that the removal of the root cementum for the purpose of eliminating endotoxins possibly present within the cementum is not necessary for accomplishing periodontal health.