Procter & Gamble Co. today filed a federal lawsuit claiming that its patented technology for tooth-whitening strips had been infringed upon by a competitor, Ranir, in a “flagrant act of piracy.” The maker of Crest Whitestrips claims that Ranir sells its own version of the P&G products through Walmart, Kroger and possibly other retailers. “Ranir is … the most recent private label supplier in a long line that have tried to ride on the coattails of P&G’s success by selling to...