A spreader plate assembly intended for use with an arbor carriage includes two congruent rectangular plates, one overlying the other. Each feeding reservoir is provided with a semicircular end wall located adjacent opposing ends of the device. The denatured collagen results in tightening of the skin, further enhancing the benefits of the procedure. A tapered surface of the first face cooperates with a tapered surface of the second face to enhance centering of the first face with respect to the second face. A pressure sensor measures the pressure inside the void. The material comprises a liquid or semi-solid matrix phase and an expanded Perlite included phase.