I would be asking or demanding if they won't give you one, a referral for an ENT. It may not be the teeth that are causing the ear infections rather a short eustachian tube. Grommets would definitely help.
From experience, often a GP cannot see glue ear. An ENT will pick it up in an instant. I remember taking my DS2 at 18mths and the ENT once he scooped the wax out with his little hook, instantly diagnosed glue ear and we were in within 2days for grommets. It was an instant relief. He also commented on the amount of AB's DS2 had been on. He mentioned we should have seen him much earlier.
That's alot of AB's in a short spell of time.