Per Otteskog

The effect of the phenytoin metabolite p-HPPH on proliferation of gingival fibro-blasts in vitro

The effect of the major phenytoin metabolite-5-(parahydroxyphenyl)-5-phenylhydantoin (p-HPPH) was studied on cultures on human fibroblast-like cells grown out from explanted gingival biopsies. The explants were taken from children undergoing phenytoin medication. The results showed that the number of cells per culture decreased whereas the protein and DNA-contents remained relatively unaffected. This effect was most pronounced at the concentrations of 0.20 micrograms/ml p-HPPH. The results indicate that the metabolite interfere with cell division without affecting protein or DNA synthesis.

A clinical and radiographic evaluation of cultivated and autotransplanted human teeth

A vital periodontal membrane (PDM) is of ultimate importance for a successful periodontal healing of auto-transplanted teeth. It has been suggested that a damaged PDM may heal during an intermediate tissue culture period. In the present study, 26 canines, bicuspids and third molars were surgically removed and cultivated in a modified Eagles medium for 3 to 17 weeks. The teeth were then transplanted to their new positions. 11 out of 18 (61%) transplanted teeth with complete root formation and 7 out of 8 (88%) transplanted teeth with incomplete root formation healed with an apparently normal periodontal ligament. 5 teeth, all canines, became ankylotic. Tissue cultivation of teeth to be transplanted resulted in approximately the same healing rate as has been reported for autotransplanted teeth without the tissue culture procedure.

Potentiation of fibroblast spreading by extracellular matrix from fibroblasts derived from phenytoin-induced gingival overgrowth

Cell attachment and spreading appear when a cell, on contact with an appropriate substratum, adheres and changes its shape and accommodates to the substratum. The transition from a non-spreading to a spreading state is a prerequisite for growth. Cell-free extracellular matrix (ECM) was produced by fibroblast-like cells from normal gingiva (N-ECM) and phenytoin-induced gingival overgrowth (PHT-ECM). The effect of the ECM on cell attachment and spreading of human gingival fibroblasts was studied in the presence of 2% serum. Within 30 min after seeding 40% of the normal fibroblast cells showed an advanced flattening on PHT-ECM-prepared dishes, compared with 10% on normal ECM-prepared dishes and 5% on uncoated plastic dishes. The results indicate that cells derived from PHT-induced gingival overgrowth produce an ECM with special properties, which could regulate cell functions such as cell attachment and spreading.

Cultivation of fibroblasts on human teeth. Ultrastructural observations of cells cultivated in multilayers.

The periodontal ligament in a traumatically lost tooth is often destroyed due to drying. In attempts to restore the periodontal ligament, a technique has been worked out for using gingival biopsies as an alternative cell source. A biopsy from the attached gingiva was set up for tissue cultivation. After the establishment of a pure fibroblast culture, cells were repeatedly added to the root surfaces of 12 human teeth from which the cells and the original periodontal ligament had been removed. The teeth were examined in the transmission electron microscope. The root surface of specimens from all 12 teeth was covered with a pelliclelike material arranged in a layered pattern. The cells frequently appeared in multilayers on top of the pellicle. The cells were flattened and appeared elongated in sections. Areas of close proximity between cells and the pellicular material were seen and were interpreted as adherence junctions. The possibility that these multicellular arrangements can replace the periodontal ligament in transplantation has to be further investigated.

Use of acrylate root reproductions in replantation and transplantation of teeth

A method to prepare and test the fitness of the alveolus in the jaw before transplantation of teeth is carried out. An impacted canine from a 30-year-old woman was extracted and stored in tissue culture for 3 weeks. The tooth was then transferred to a semisolid tissue culture medium for preparing an artificial alveolus. Methylacrylate was then poured into the alvelous and was left to solidify at room temperature. Thereafter the root model was removed from the medium and a screw was fixed in the upper part. This root model was used in testing the fitness of the prepared alveolus before the root was transplanted. The advantage of the technique is that the reproduction of the root could replace the transplant during the fitting procedure to avoid damage to the periodontal membrane.