Thesis in the CVC - "Descemetocele". The training took place at the sculpture faculty. Awarded the title of artist-sculptor.
In 1932 he graduated from the national art and technical Institute (VHUTEIN), in 1936 the Institute of painting, sculpture and architecture the Russian Academy of arts in Leningrad. For the shown courage and heroism at the front, he was awarded the Order of the red star, Patriotic war of II degree, and many medals. After being seriously wounded in 1944, P. Dobrynin returned from the Army to Moscow and continued his creative activity.
Dobrynin worked in the decorative sculpture of small and large forms. He owns the original decision of fountains "the Stone flower" (1952-1954) and Zolotoy Kolos (1951-1953; architect K. T. Topuridze) on the territory of VDNH (now VVC). The leitmotif in the work of Dobrynin is the theme of Yakutia. In easel sculpture he created portraits, subject compositions of ceramic, marble, bronze. A lot of work and in different types of ceramic plastics, making faience, majolica, porcelain and biscuit images of the Russian and Yakut folk tales.