COMPENSATORY-RESTORATIVE PROCESSES IN CALF (GASTROCNEMIUS) MUSCLES AFTER A MONTH OF BEING EXPOSED TO ACRYLIC RESIN

Morphological changes in calf (gastrocnemius) muscle of rats one month after implantation of acrylic resin samples “Ftoraks” and “Biocryl-C” were studied. Materials and methods. Experimental studies were performed on 30 white male rats of Wistar line weighing 180-200 gr. Animals were divided equally into 3 groups. The first group (the control group) included animals with punctured skin, subcutaneous fat and calf muscles by means of puncture needle. The second group consisted of animals with implanted resin samples “Ftoraks”. The thirdgroup was composed of animals with implanted resin samples “Biocryl-C”. Histologic colouring (according to Hart with additional colouring according to Van Hizon, colouring with hematoxylin and eosin) and electronic and microscopic methods of investigation were used. Results. On the 30th day of the experiment histio-lymphocytic infiltration with foreign body cells, sclerosis and destruction of muscle fibers were noticed around acrylic resin samples “Ftoraks”. Profuse growth of connective tissue in the endo- and perimysium was observed in the adjacent muscle bundles. There was detected an increase in the diameter of striated muscle fibers (21.73 ± 3.47 mm, p = 0.002) and the area of their nuclei (23.31 ± 2.86 mkm2, p = 0.00004) compared to control indices. But at the same time slight proliferation of connective tissue in the epi, peri- and endomysium, restoration of the blood vessels walls of hemomicrocirculatory channel at histological and ultrastructural levels helping to normalize blood supply were observed in the adjacent muscle bundles around acrylic resin samples “Biocryl-C”. These phenomena lead to compensatory-restorative processes in the muscle fibers of gastrocnemius, which was confirmed with morphometric analysis: diameter of striated muscle fibers was (14.61 ± 0.96 mm, p = 0.48) and the area of their nuclei was (15.61 ± 2.07 mkm2, p = 0.23). Conclusions. It has been established that resin “Biocryl-C” caused smaller morphological and functional changes in the surrounding tissues that were absolutely reversible in comparison with resin “Ftoraks”. Thus, resin “Biocryl-C” is more promising for use in dental practice as a base material for laminar removable prostheses.