I would wait on both. A cleaning or two should be less than $328, assuming he even needs that much. If he turns up with a cavity, get a price quote so you know whether to add him for the next round.
The premium for our dental insurance just shot up to $800 a year for all of us... I'm contemplating dropping it, but I have to see how much a cleaning is out of pocket. There are 4 of us who currently have teeth, and we may want to get the baby in towards the end of the year. But 8 cleanings are probably $800 a year. Grumble.