94 Integra Ls, There are 7 bolts that hold the valve/engine cover in place. When I was tightening the last one?

(cont) the bolt broke off. I have 6 of the 7 bolts in place. I ran the car and drove it. There wasn't any oil leaking out or anything. Will I be okay with 6 of the 7 bolts or will it cause major problems?