This study aimed to evaluate the effectiveness of a synthetic implant material Hard Tissue Replacement polymer (HTR) for:
(1) compatibility with bone and soft tissues, (2) capacity to physically attach to bone and soft tissues, and (3) capacity for bone induction and metaplasia. HTR was implanted for a 3-week test period in femur bones, connective tissue, and skeletal muscle of 15 Sprague-Dawley descent rats for histological examination and implanted in bone in 6 rats for infrared absorption analyses to determine t h e presence of new bone. Compatibility (de-fined as absence of significant inflammation) was present in 13/14 (93%) bone sites, 7/9 (78%) connective tissue, and 4/4 (100%) muscle sites. Physical attachment of HTR occurred in 10/14 (71%) bone sites, 4/9 (44%) connective tissue, and 1/7 (14%) muscle sites. Density of new bone appeared to be greater with HTR than in controls. However, no metaplastic bone was formed in nonbony sites indicating that this material is nonosteogenic. These preliminary findings demonstrated the effectiveness of HTR as an implant material.