Erwin M. Schaffer

Cartilage transplants into the periodontium of Rhesus monkeys.

Abstract Three autotransplants and three homeotransplants of cartilage, from the ears to surgical periodontal pockets, were completed in four Rhesus monkeys. At first the cartilage was surrounded by new connective tissue; then it was invaded by fibroblasts and by endothelial cells that formed capillaries. Later, presumably after differentiation from mesenchymal cells, osteoblasts formed new bone. The new bone formed on the outer surface of the cartilage and extended outward from it into the surrounding tissues. By continuous apposition on the bone that first formed on the surface of the cartilage, new bone formed inward toward the middle of the cartilage. The bone formed in the areas in which the cartilage matrix was removed and around spicules of cartilage including both matrix and chondrocytes. Whenever lacunae adjacent to fibroblasts were opened, new bone was deposited in the place of the chondrocyte. New bony trabeculae were formed in the tissues distant to the cartilage. This might indicate that the cartilage acted as an inductor to the new periodontium by activating its osteogenetic potency. The fresh cartilage was nonviable, and it did not grow. The cartilage preserved in alcohol was nonvital and exhibited varying degrees of degeneration. Nevertheless, the replacement ossification appeared to be more rapid than in fresh cartilage. The histologic differences between the replacement ossification in this study and normal endochondral bone formation during growth and development were discussed. A new periodontal membrane was formed with the fibers embedded in new cementum matrix of the teeth on one side, and in new bone matrix or cartilage on the other side. The periodontal membrane appeared to be functionally arranged, regardless of whether the fibers were embedded in bone or in the perichondrium of the cartilage. The functional arrangement was observed in all the transplants from the twenty-four-day specimen on. However, new cementum was formed on the root of the fourteen-day transplant, and collageneous fibers were embedded in it. A new epithelial attachment was formed.

About 8- and ∼84-h rhythms in endotheliocytes as in endothelin-1 and effect of trauma

Population densities (PD) of capillaries (C) and endotheliocytes (E) were determined in pinnal dermis of C57BL mice before and after trauma. Moving (and overall) least-squares spectra before trauma detected in EPD (versus CPD) pronounced 3.5-day (circasemiseptan) and 8-h oscillations corresponding to components of the endothelin-1 chronome in human blood plasma reported earlier. Circadians were more pronounced in CPD. After trauma, circasemiseptan oscillations appeared also in CPD; their period gradually shortened and in two weeks split into about 2.5- and about 4.5-day oscillations; and circadian components became very pronounced. The pre-traumatic chronome was not restored within three weeks following trauma.

The new attachment operation in subcrestal pockets

Abstract Ideally, the new attachment operation should be confined to subcrestal pockets. The objective of the new attachment operation is to raise the attachment coronally to eliminate the periodontal pocket and to refill the subcrestal defect with new bone. The step-by-step procedure has been described. A partial gingivectomy will remove the marginal epithelium and reduce part of the pocket, namely, a portion of the soft tissue coronal to the alveolar crest. The most common reasons for failure are (1) the lack of complete and thorough root curettage, (2) mobility of the tooth, and (3) leaving some of the soft tissue in the subcrestal defect. If the operation should fail to eliminate the pocket, repetition of the procedures will result in success in the majority of cases. When the alveolar bone refills the subcrestal defect, a new functional periodontal membrane will be formed. This operation, rather than ostectomy or extraction, is the treatment of choice. The new attachment operation can be done successfully by the general practitioner as well as by the periodontist.

Improved pontic/tissue relationships using porous coralline hydroxyapatite block.

Porous coralline hydroxyapatite blocks were implanted in the anterior region of several patients to improve the pontic/ridge relationship for a fixed prosthesis, thereby improving esthetic appearance and oral hygiene performance. A beveled incision on the palate was used to displace the flap coronofacially without leaving an area of denuded bone or graft. Flap margins were sutured to the adjacent palatal tissues. At the 2 1/2- and 3-year postgrafting follow-up, the implant area was healthy and ridge contours have been maintained. The permanent fixed partial denture is functional, and radiographic evaluation indicates the continued presence of the porous coralline hydroxyapatite implant. Three-year results have been promising enough to warrant continuing the procedure in patients requiring localized ridge augmentation.