I've been working on my teeth in my old age (as of like 2 years ago).. Up until around 24 I actually rarely even brushed and could probably remember each time I did since I was young.
STRANGELY enough, I only needed 6 root canals and 6 more fillings, a good cleaning and I was good to go. But I've been abusing my teeth for a long time.... What I have noticed tho is people with poor diets usually have poor teeth, malnutrition and stuff. Not saying that you do, but if you came from a family with limited financial needs or always ate the same thing when younger you may have some issues because of this - or it may just really be genetics but I'm unsure of the specifics on that.
I had 12-14 fillings and 4 wisdoms that needed to come out. From this 6 of the fillings turned into root canals and crowns, and the other 6+ fillings I just had filled. I have no bone loss or issues from not taking care of my teeth for 20+ years apparently. But my wisdoms still need to come out.
I also had 4 wisdom teeth that had to get pulled out but this has nothing to do with bone loss or bacterial infection.