Investors in Premier Laser Systems Inc. have filed a class-action lawsuit charging the company with fraudulent business practices that artificially inflated the price of Premier's stock. The Irvine, Calif.-based company developed an Er:YAG laser for hard-tissue dental applications that received clearance from the US Food and Drug Administration last year. The shareholders charge that Premier lied about its expertise and its ability to manufacture the laser in significant quantities. Investors also charge the firm with covering up lagging sales by falsifying its third-quarter fiscal '98 results. They also accuse the company of improperly recognizing more than $2.5 million in revenue on shipments made to medical distributor Henry Schein Inc. that either had not occurred or were made on a conditional basis whereby Schein was not obligated to pay for the lasers unless they were resold. In the wake of the charges, trading of the Premier stock was halted.