Value and significance of tooth mobility measurements]

1. The measurement of tooth mobility by manual and instrumental techniques is necessary for establishing a diagnosis, since it is of considerable importance for decisions in the framework of prophylaxis and therapy. 2. The significance of the measurement of tooth mobility depends upon the respective problem and the sensitivity of the measuring technique used. 3. The specifications for the precision of the measuring technique will be determined by the specific objective of the examination. 4. The instrumental measuring techniques are reproducible and, therefore, imperative in scientific studies.     

The fate of vital and devitalized bone grafts in the healing of interradicular lesions

The fate of vital and devitalized grafts of mature concellous bone from the jaws were studied in interradicular lesions in monkeys. 98 bifurcation defects were produced in premolars and molars and maintained by periodontal dressing inserted for four weeks. Ten to 15 weeks later fresh cancellous bone was transplanted into 32 defects. Other cancellous bone grafts were divitalized by boiling and transplanted into 34 bifurcations. The remaining 32 defects received no grafts. The animals were sacrificed to yield observation periods from 0 to 90 days. After decalcification of the specimens and embedding in paraffin, serial sections were cut at 8 microns and stained. The fate of viable and dead transplants were similar during the healing of the interradicular lesions. Except for a few osteocytes which seemed to survive transplantation in the fresh cancellous bone, the osteocyte lacunae were devoid of cells in both types of transplants after 1 week. The deepest located bone grafts became incorporated in new bone developed from the interradicular septum. The more superficially located grafts were rejected or were surrounded by a cementum-like substans. The influence of the grafts on bone regeneration was small and based solely on their osteoconductive effect.