Under the specific conditions reported for the separate tests delta9-tetrahydrocannabinol (THC) did not elicit a mutagenic response in microbial and eukaryotic in vitro test systems. THC treatment to histidine auxotrophs of Salmonella typhimurium strains TA 98 (susceptible to frame shift mutation) and TA 100 (susceptible to base pair substitution) were investigated. Analysis for possible revertance in the presence and absence of S9 microsomal activation system indicated an absence of induction of gene mutation. Cultured fibroblasts from healthy individuals and DNA repair deficient Xeroderma pigmentosum patients display similar survival activity upon exposure to THC. There was no observable increase in the number of chromosome breaks or chromatid exchanges following exposure to THC or THC plus S9 microsomal fraction. THC, 11-OHdelta9-THC, cannabinol, and cannabidiol did not induce unscheduled DNA repair synthesis in cultured human fibroblasts. Moreover, THC did not suppress UV-induced DNA repair synthesis.

Adult↗

PubMed1978

[The accumulation of osteocementum around a dental implant under physical loading].

Hollow cylinder implants of titanium with a titanium spray surface were implanted in macaca speciosa, as previously described (Schweiz.Mschr.Zahnheilk.86: 713, 1976). This time, however, the implants were submitted to masticatory forces. Histologically it can be shown that the ankylotic contact between implant and bone, which is initially obtained, remains after 6-16 months. In one case the substance encasing the implant at its deepest part was identified as genuine osteocementum.

Animals↗

PubMed1978

[Biocermics in rat experiments (preliminary report)].

Bioactive ceramics in the shape of small plates was implanted into the femoral diaphysis of rats. The specimens were examined 2 months later by optical and mechanical methods for their behaviour of incorporation into the tissues. The composition of materials, the technique of implantation, the methods of histological preparation and the examination of adhesive resistance are described. The inadequacy of current methods of examination and their replacement by better ones is pointed out.

Animals↗

PubMedDate not supplied

Supraplant, a novel implant system based on the principle of guided bone generation. A preliminary study in the rabbit.

Supraplant, a novel implant system is tested on the top of the skull i n 6 rabbits. The results demonstrate that an implant which is placed on top of bone can be osseointegrated by the guided generation of new bone using membrane barriers.

Animals↗

PubMedDate not supplied

Biocement--a new material. Results of its experimental use for osseous repair of skull cap defects with lesions of the dura mater and liquorrhea, reconstruction of the anterior wall of the frontal sinuses and fixation of alloimplants.

A newly developed material, which we call biocement, consisting of bisphenol-a-glycidyl methacrylate ("epoxide methacrylate') as organic matrix and Bioceramic Battelle, Bioglass Hench and/or pentacalcium hydroxide triphosphate ("tri-calcium phosphate') powder as filling particles is presented. In an extension of previous experiments, various types of this biocement, containing different admixtures of particulate matter, were employed to test their usefulness in head surgery, in particular maxillo-facial reconstruction, on dogs and a rhesus monkey. Encouraging results were obtained with regard to (a) fixing a titanium alloimplant under some degree of mechanical stress; (b) covering a defect in the skull cap, including the closure of an artificially induced meningeal fistula with liquorrhea; and (c) reconstruction of defects in the anterior wall of frontal sinuses. Special emphasis is placed on direct contact between biocement and bone, interdigitations between these two, reactions of meningeal tissue, and regeneration of ciliated epithelium underneath fixed reimplants over the frontal sinus.

Acrylates↗