4.1 This practice covers a test protocol for comparing the local tissue response evoked by biomaterials, from which medical implantable devices might ultimately be fabricated, with the local tissue response elicited by control materials currently accepted for the fabrication of surgical devices. The materials may include metals (and metal alloys), dense aluminum oxide, and polyethylene that are standardized on the basis of acceptable, well recognized, long-term response. The controls consistently produce cellular reaction and wound healing to a degree that has been found to be acceptable to the host.

1.1 This practice provides a series of experimental protocols for biological assays of tissue reaction to nonabsorbable biomaterials for surgical implants. It assesses the effects of the material on animal tissue in which it is implanted. The experimental protocol is not designed to provide a comprehensive assessment of the systemic toxicity, immune response, carcinogenicity, teratogenicity, or mutagenicity of the material since other standards deal with these issues. It applies only to materials with projected applications in humans where the materials will reside in bone or soft tissue in excess of 30 days and will remain unabsorbed. It is recommended that short-term assays, according to Practice F763, first be performed. Applications in other organ systems or tissues may be inappropriate and are therefore excluded. Control materials will consist of any one of the metal alloys in Specifications F67, F75, F90, F136, F138, or F562, high purity dense aluminum oxide as described in Specification F603, ultra high molecular weight polyethylene as stated in Specification F648 or USP polyethylene negative control.

1.2 This practice is a combination of Practice F361 and Practice F469. The purpose, basic procedure, and method of evaluation of each type of material are similar; therefore, they have been combined.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.