Regeneration of oxytalan fibres in different types of periodontal defects: a histological study in monkeys.

The aim of the present study was to investigate in monkeys the regrowth of oxytalan fibres in different types of acute and chronic periodontal defects following regenerative periodontal treatment. One-wall intrabony and mandibular furcation III-defects were produced surgically in 3 monkeys (Macaca fascicularis). After a 6-wk dental plaque accumulation period the defects were exposed using a full thickness flap procedure. The granulation tissue was removed and the root surfaces were scaled and planed. Additionally, fenestration-type defects were produced at the vestibular surfaces of the maxillary and mandibular canines by surgically removing the vestibular bone plates and the root cementum. Subsequently, the defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMP), combination of EMP and GTR or with coronally repositioned flaps. The postoperative care included tooth cleaning once a week during the experiment. After 5 months the animals were sacrificed and and the block sections were embedded in paraffin. Eight microns histological sections were cut and stained with the oxone-aldehyde-fuchsin-Halmi method. The results revealed that in all specimens where a regenerated periodontal ligament could be observed newly formed oxytalan fibers were present. They had a mainly apico-occlusal orientation and were localized closer to the cementum than to the alveolar bone. The regenerated oxytalan fibers had a similar morphological appearance than those observed in the original periodontal ligament regardless of the treatment modality by which regeneration was accomplished. Their presence was related to that of newly formed cementum suggesting a strong relationship between these 2 tissues. The neoformation of oxytalan fibres can thus be observed in some types of periodontal defects where the cementum and the periodontal ligament have been regenerated.