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The properties of poly(HEMA) sponges have been studied after implantation in the weight-bearing articular surfaces of young and adult rabbit knees. Only sponges with small pores (less than 50 micrometer) were able to withstand weight-bearing. After 12 weeks, the implants were overgrown by cartilaginous or fibrocartilaginous tissue, and the ingrowth of chondroid tissue into the sponges was observed.

We describe the in situ production of a burn wound dressing applied to eschar that completely isolates burned tissue from contamination with Pseudomonas aeruginosa. Anesthetized, adult rats were subjected to a scald burn over 10% of their body surfaces. One-half hour later a test dressing presumed to be a barrier to bacterial contamination of the wound was applied to the burned surface. Tannic acid, vaseline, ethyl linoleate, collodion, and polyhydroxethylmethacrylate (PHEMA) were evaluated. Each agent was applied directly to the burned surface. A solid film of the PHEMA was produced on the eschar by addition of solvent and a powdered form of the polymer. The surface of each synthetic dressing was contaminated 30 min after application by the addition of 10(8) P. aeruginosa. Also, a control set of rats was burned and their eschars were directly contaminated without application of the test dressing. Seven days later the contaminated muscle under the burned area in 10 control rats had P. aeruginosa counts of 10(7) to 10(8) per g of muscle (wet weight). Of the materials tested, only PHEMA consistently acted as an effective barrier dressing, reducing bacteria in the muscle to undetectable levels in 11 of 14 tests. It was also possible to treat contaminated eschar through this synthetic dressing by topical application of antibiotics to the barrier surface. The results suggest a novel clinical approach in which a barrier dressing could be used to isolate a burn eschar from environmental and subject contamination until the wound site is ready for grafting.

The preparation and the physical characterization of poly(2-hydroxyethyl methacrylate) thermally grafted onto polybutadiene (PHEMA/PB) are reported. The presence of polybutadiene increases the tensile properties of the film and prevents water diffusion through it while it does not affect the oxygen permeability of the PHEMA. The potential use of this material as burn wound cover is suggested.

This 7-year evaluation of the Augusta study reinforces earlier conclusions regarding the long-term retention of sealants and their efficacy in caries protection. Although more time will be required to answer all the questions about sealants, sufficient data are now available to document their efficacy as caries-preventive agents. It is imperative that the dental profession provide this safe and effective preventive technique for the public so that dental disease can either be reduced or further postponed.