Glass Implants Research Articles

Refractive index profiles induced by ion implantation into silica

Ion implantation of silica glass increases the refractive index. For ions of H+, He+, Li+, B+, Na+, Ar+, Bi+ the maximum index change in the depth profile is normally between 1 and 2%. Such changes are consistent with compaction of the lattice which results from radiation damage. Greater changes are recorded for nitrogen implantation of silica; values up to 6% have been noted. This is interpreted as a chemical change in the structure of the glass. The measurements of the refractive index as a function of implantation depth were made by a technique of ellipsometry combined with a chemical stripping of surface layers. Such detailed analyses of the refractive index profile have implications for the formation of optical waveguides in silica as well as the mechanism involved in the modification of refractive index.

Untersuchungen über die Reaktion von Weichgeweben auf glaskeramische Implantate

This report describes the implantation of glass and glass-ceramics into soft tissues. These experiments revealed that our new glass and glass-ceramic materials are well compatible with soft tissues. The fibrous membrane surrounding such an implantat consists of normal dense collageneous connective tissue. The cells are fibroblasts and fibrocyt-like cells without any abnormal morphology. Macrophages could not be detected. However, the degree of implants solubility must be chosen with care, because high solubility of the implant increases the reaction of the surrounding soft tissues. The described materials are also compatible with osseous tissues. In our previous experiments we have already pointed out, that bonding developed between glass material and bone. Few weeks after implatation we have seen mature lamellar homegeneously mineralized bone opposed to the implant. There was no fibrous membrane between implant and bone. Longtime studies show that hitherto the described bonding exists about 2 years.

Iris cyst following traumatic implantation of glass splinter, with foreign body probably retained in ciliary area forty-five years.

THE LITERATURE contains many reports of traumatic cyst of the iris caused by the implantation of glass or other substances in the eye. Among others who have published articles on this subject is Perera, 1 who in 1937 read a paper before the American Academy of Ophthalmology and Oto-Laryngology on epithelium in the anterior chamber of the eye after operation and injury. On Nov. 28, 1928, I 2 presented before this Section a case in which a fragment of glass had been embedded in the eye for 28 years. In this case a high school student was experimenting in the laboratory with a mixture of sulfuric acid and potassium nitrate in a glass retort, placed over a Bunsen burner; its explosion caused a fragment of glass to penetrate the periphery of the eyeball and become embedded in the retina. The incised scleral wound was closed with three episcleral sutures. This

Comparative Notes on Radon Implants

THE present trend of radium therapy shows a divergence into two widely separated lines of endeavor. The first is the skillfully prepared and ingeniously contained radium implants, making possible the accurate introduction of a definite amount of radium emanation or radon into or in contact with an active neoplastic area. The second is the collection of radium salts in quantities large enough to permit of long range radiation similar to but productive of more gamma radiation than that of the present high voltage X-ray generator. The purpose of this paper is to consider some of the problems which confront the radiologist in his routine work, as well as the conditions which call forth the first-named type, the radium “seed,” or implant. The primary requirement is that one should be cognizant of the fact that he is in control of a very small but exceedingly potent agent which necessitates not only a comprehensive knowledge of radiology but also that skill which a well-balanced medical man must possess in all branches which enter into the successful diagnosis and treatment of neoplastic disease. This statement appears superfluous, but when one realizes that these potent radium seeds can be purchased by anyone, and that they not infrequently fall into the hands of those not qualified either by experience or training to use them, the need for caution is apparent. In this manner an agent which is extremely valuable to the trained radiologist may occasion much abuse and adverse criticism, if permitted to run amuck without proper supervision. Glass radon implants have been used for several years with remarkable success in many cases, and with disastrous results in others. Since the advent of platinum and gold filtered points, it is doubtful if the demand for glass tubes will continue much longer. The writers have entirely discontinued the use of glass implants, although in the past many good results have been obtained from the use of them in their clinic. This is especially true in tongue malignancy, where the blood supply is good and the tissue repair of the necrotic primary beta radiation effects more prompt and certain. Probably the great advantage of the filtered implant is due to the fact that a sufficient amount of radium is used to radiate thoroughly the periphery of the lesion, and at the same time serious local necrosis is avoided by the metallic nitration. Correct estimation of the size of the growth is undoubtedly the most important factor in the consideration of the use of radon implants. The work of Quick, Failla, Quimby, Cutler and others, at the Memorial Hospital, has practically solved the dosage problem. Reference to their charts and hypothetical models will guide the operator so that he may remain well within the safety zone of dosage. The previous or older method of using one millicurie per cubic centimeter of malignant tissue, and spacing the tubes one centimeter apart, often caused either overdosage or underdosage.