PREVENTION OF OVERGROWN TEETH

Question
My 3.5 year old male guinea pig, Murphy, has become very ill. He was not eating,squeeking, passing bowels and urinating very little. I took him to the vet after about 5 days of this behaviour. The vet found a large lesion on his back about the size of a quarter when she pulled his fur up (it was not there a few weeks ago because he had had a professional grooming)he was a bit under weight, 2.4 pounds, a runny nose, and the major problem was inside his mouth. His teeth had grown so long that he could no longer use them. He also had abraisions all inside his mouth because of this. So the vet clipped all his teeth and filed front ones while he was awake. The vet could not believe how calm and still he was. I was against putting him under. I was then given a 10 day supply of noval-trimel to clear up all his problems and to help prevent him getting pneumonia as he is at high risk of getting that right now.
I have given him gnawing devices from the pet store, but all he does is urinate on them. Any other suggestions on what I can use to keep his teeth under control? I do not want this to happen again. I was thinking of making a veggie mixture and adding a bit of brown rice flour, baking it until it is rock hard and see if that would work. Another option I was thinking about would be to take him to the vet as soon as i notice them getting too long ( now that I am more aware of this) and getting them clipped.
I would really appreciate any advice that you may have. Murphy is on his third day of medication and he is improving. He is eatting, squeeking a bit and acting a bit like his usual self. I am keeping a very close eye on him. I know he will pull through!
P.S. He actually gets excited when I pull out the syringe to give him his medication. He actually likes the cherry flavoured liquid!!!

Thank you.

Answer
I think the best thing to do would be take him to the vet again and let them clip them if they get to long, just so you can make sure that he will get better. I am glad that he pulled though. Most of the time Gp's dont' get better. Let me know what you decide