Biomedical subjects

J B Gonzalez

Publications and source records attributed to J B Gonzalez.

5 recordsLinked to original sources

PubMed1978

Polyurethane elastomers for facial prostheses.

A review of the polyurethane elastomers used for facial prostheses has been presented. A description of the casting technique was given. The materials require accuracy and care in handling to insure the successful casting of a prosthesis. They seem to simulate the characteristics of the facial tissues and are more durable and comfortable than previously used materials. Over 300 patients have been exposed to or treated with these materials without evidencing significant adverse tissue reaction. In spite of the improvements that these materials present over previous ones (PVC and silicones), much work is still required to understand their behavior and their physical and mechanical characteristics and to compensate for the metameric phenomenon.

Biocompatible Materials↗

PubMed1978

Physical and mechanical behavior of polyurethane elastomer formulations used for facial prostheses.

The initial results of this study of the physical and mechanical behavior of polyurethanes used for facial prostheses are presented. The parameters studied were surface hardness, modulus of elasticity (M), strength (S), percentage of elongation, and S/M ratio. Results showed that the physical and mechanical behavior of the polyurethanes can be altered by variations in the basic composition of the material accomplished through changes in the ratio of Part A to Part B and by the addition of catalysts. Properties of compositions with low quantities of Part B (isocyanate) and no catalyst reached or approximated those parameters proposed as ideal goals to simulate living tissue. When preparing polyurethane material, proper mixing is essential to avoid entrapment of air and phase separation of the catalyst. These conditions, which may render the prostheses less durable, are masked by the addition of colorants in the prearation of a sample for clinical application.

Chemical Phenomena↗

PubMed1978

Recently developed elastomers for facial prostheses.

Ever since ancient times, man has been searching for the proper artificial substitute for living tissue. This has been a most frustrating and challenging task for the scientific community involved. Prosthetic restoration is the only alternative to reconstructive surgery for the facially deformed. This paper reviews the progress that has been made in recent years in developing a suitable material for the prosthetic restoration of facial defects. There is encouraging evidence that the development of an ideal material for facial prostheses is an attainable goal.

Acrylic Resins↗

PubMed1977

Use of tissue conditioners and resilient liners.

The application of elastomer polymers in the prevention and treatment of chronic tissue irritation from dentures is an excellent alternative to the use of hard polymer resins and it is useful for preserving the health of the remaining denture-supporting tissues. Wider applications will be found in the future once the present shortcomings of the available materials are overcome, whether by improving these materials or by developing new ones. Specific uses for these materials have been outlined with an awareness that the readers may be able to add other applications to the list. At the same time, it is not the intent of this article to imply that the use of elastomer polymers is the panacea for all prosthodontic problems or that fundamental principles can be neglected.

Acrylates↗

PubMedDate not supplied

Polyurethane elastomer as a possible resilient material for denture protheses: a microbiological evaluation.

A polyurethane elastomer was microbiologically evaluated in vitro for its potential use in resilient denture liners. Specimens were immersed in suspensions of ten selected oral microorganisms; this was followed by viable cell counts at intervals during a 16-week period. Results indicated that the polyurethane neither supported the growth of the organisms nor was it degraded.

Candida↗