1. Flexible membrane for dental surgery, which is a chitosan membrane thickness from about 100 microns to about 0.5 mm and having pores through which atmospheric oxygen can penetrate the usual red blood cells in the human oral cavity environment, wherein the molecular weight of chitosan is dalton.2 least 400,000. The membrane for dental surgery according to Claim. 1, wherein the chitosan has a molecular weight sufficient to ensure that the membrane is not resorbed over a period of about 12 weeks to about 16 nedel.3. The membrane for dental surgery according to Claim. 1, wherein the chitosan has a molecular weight ranging from about 400,000 Daltons to about 2,000,000 dalton.4. The membrane for dental surgery according to Claim. 1, wherein the chitosan has a molecular weight ranging from about 400,000 daltons to about 800,000 dalton.5. The membrane for dental surgery according to claim. 1, 2 or 3, having a pore size distribution wherein at least about 90% of the pores have a diameter from about 10 microns to about 20 mk.6. The membrane for dental surgery according to Claim. 5, in which about 95% of the pores have a diameter from about 10 microns to about 20 mk.7. The membrane for dental surgery according to claim. 1, 2 or 3, wherein the chitosan used permitted for use in medical tselyah.8. A method of manufacturing an elastic membrane for dental surgery, comprising: a) dissolving chitosan having a molecular weight of at least 400,000 daltons in an aqueous acid solution b) adding an aqueous acid solution porogen particles to form a slurry of solid particles of blowing agent,1. Эластичная мембрана для хирургической стоматологии, представляющая собой хитозановую мембрану толщиной от примерно 100 микрон до примерно 0,5 мм, имеющую поры, через которые может проникать атмосферный кислород и обычные красные кровяные тельца в среде полости рта человека, причем молекулярный вес хитозана равен по меньшей мере 400′000 дальтон.2. Мембрана для хирургической стоматологии по п. 1, в
