I'll second
@Sean & Rufus and
@Tracey&Jones. Dimmu had a lot of under-the-gumline problems that we wouldn't have seen without xray. We had 3 vets checked his mouths in that last 2 months and all of them said it was mild gingivitis and calcium deposits. We finally found a dental specialist and took 10 xrays and found out how serious his dental issues were. He had a surgery a week ago, and although he's still recovering, he already seems happier and purrs more.
I'll share Dimmu's experience of alternative dental treatments, I'm sure some of the more knowledgeable and experienced members will step in later.
Dimmu's dental health has never been great since he was young. His teeth just rot away at a faster rate, and his gum would inflame constantly, our holistic vet told us to give him seaweed for general dental health and raw chicken wing/neck, mice or chicks (I didn't have the heart to give mice or chicks, my boyfriend tried a few times, though) to chew on to help clean his teeth naturally. Canna, our civvie does great on this, but Dimmu's teeth and gum were hurting so much he didn't like to chew. We tried brushing, but his gum would bleed, and he couldn't tolerate the pain. He had regular teeth cleaning, but the problems would come back in no time. The vet then suggested gold implants, to increase the blood flow in his gums in the hope that it would reduce pain and eventually encourage him to chew and be brushed. It helped, he could kinda chew again and there was less bleeding when we brushed his teeth. The vet also switched him to phytoplankton from seaweed (high iodine and sodium). His breath smelled better, but the foul smell was still present. With all these, we still couldn't save his teeth, he had molar extractions 2 years ago and we continued with phytoplankton after that. After he was diagnosed with FD last year, we moved to Belgium and couldn't get phytoplankton anymore, so we started him on Pet Wellbeing healthy gum, and he did pretty ok on it, chewing harder things for an extended time was still difficult, but there was rarely bleeding from brushing. We knew although all these treatments seemed to help, they were only supportive, we still need to get to the bottom of the problems, hence the xrays and the dental surgery last week.
Dental work and gold implants are costly, if affordability is a concern and Bella isn't a raw eater, maybe it's a good idea to reconsider the AB's as
@Jill & Alex (GA) suggested and give phytoplankton or healthy gum a try. For phytoplankton, there's a risk that it comes from contaminated water, you might want to do more research.