U.S. federal appeals court sent a patent infringement lawsuit against Procter & Gamble back to district court in Oklahoma, passing on a summary judgment in favor of the company. The plaintiff, Alfred Salazar, holds a patent for a toothbrush that both polishes teeth and stimulates gums, using special rods for each task. He sued P&G for alleged infringement of that patent, according to Reuters. P&G argued that its toothbrushes do not include an elastic feature as claimed in Salaz...