My 6 yr old tucker is at the vet today to have his yearly and to have his teeth cleaned. My vet just called and said that she has to pull one of his incisors

He's already list one of his bottom teeth. I've always feed him dry food and try to brush his teeth. He just had his teeth cleaned last year! I also have to put him on a 10 day antibioticfor bacteria in his mouth. .
Has anyone else had to deal with this? It makes me sad .