Reconstituted collagen membranes (thickness 20-40 microns), used in periodontal guided tissue regeneration, were prepared by solubilization of bovine serosa and bovine tendon using an alkaline treatment and by solubilization of bovine serosa in acetic acid. Dielectric properties of these materials were determined in the frequency range of 10(-5)-10(6) Hz (poling temperature = 313 K, poling time = 3 h, E = 10(7) V/m), using a General Radio Bridge system (high frequencies) and a discharge current technique (low frequencies). The true pyroelectric coefficient p(T) was determined for these materials by a direct method over an appropriate temperature range. Their magnitude appear to be in the range of 10(-4) to 10(-5) C/m(2) K-1, which is considerably higher than that of the ferroelectric poly(vinylidene fluoride) (PVDF) and its copolymer vinylidene fluoride-trifluorethylene (VDF-TrFE).