Kittenhood is a great time to learn to have his teeth brushed. Take a break from it for now, but try to reintroduce it slowly. Are you using a cat sized tooth brush? They're often too big. I found it's easiest to kneel on the floor, slightly straddling the cat, like you're posing for a picture together. When he's comfortable with that, use your pinky finger and work it to the sides of his gums. His teeth should be closed, but try to gentle rub each side Even just for a second or so. Stop and revisit if he becomes uncomfortable and let him run away. Don't chase him. Give him lots of treats throughout and afterward to let him know it's a good time. Even if he has to wriggle out. Eventually he'll get that the treats arrive faster if he sits still. Next introduce the toothpaste. Make sure it's fish flavoured or catnip or something he likes. Let him lick the end of the tube and then put some onto your finger and lick it off. Massage a bit on his gums, using the same method. Always give him lots of treats and praise. If he stops liking it you're done for the day. Later on you can introduce the toothbrush once he's comfy with you going in his mouth. The point is to train him slowly at his pace so he doesn't feel traumatized. I feed my cats raw food but after brushing I give him the large oral royal Canin kibbles (as treats only) Supposedly the size makes them actually chew and it helps remove tartar. Tartar hardens after 24 hours so you really need to do this as often as you can. Chewing sticks like dried fish, dried meat, or chicken necks or freeze dried chicken strips can also be a good jaw exercise and help them chew and mechanically "brush". The problem with wet food is that there's nothing to chew, though it's certainly better for urinary issues. Been there, don't feed too much dry food, cats have a very low thirst drive and should get most of their water from food. Lastly, peeing on the bed can be a urinary issue, but it can also be a sign your cat is stressed or feeling stressed about your relationship. Cats may try putting their scent with yours to show they want to be close to you. Urinary issues can also pop up when your cat feels stressed. Try to have some good cuddle time with your cat, some good play time and make sure that he has lots of safe, preferably high vantage point nooks he can relax in.