Ignorance. First of all genetics are a factor. Some people can go their whole lives never flossing, getting their teeth cleaned once a year and never have a problem even into their 90s. It depends upon how fast plaque builds up. WHEN plaque builds up it dips below the gumline toward the bone and the bone “backs away” from it and so on and so on...This forms pockets between the gum and bone that gives bacteria a place to multiply and exude toxins that further attack the bone. This process has by the way been linked to heart attacks. The stuff stewing under your gums gets into the blood stream and poof off some people go.. I never flossed growing up and by the time I was 35 I needed “full quadrant” surgery. They take off the gum, plane down the nobs and hollers that have formed then put the gum back into place. I am now 57, I have flossed every night since and I haven’t lost a millimeter of bone and my gums barely bleed anywhere when I go for a cleaning. No recurrence of gingivitis at all since.
Yes...genetics....I had an ulcerated tooth at age 5, and many cavities all thru my youth...my 2 siblings...nada. And, I was the one who brushed my teeth the most.
Same story here.