The discussion revolves around the sudden onset of cavities in individuals who previously had none, exploring potential reasons such as age, dietary changes, and genetic factors. It highlights that cavities result from bacteria producing acid that degrades teeth, and as people age, their sensitivity to this acid may increase due to dietary shifts and changes in oral microflora. The conversation also touches on the impact of consuming soda, which is acidic and harmful to teeth, and the importance of maintaining a healthy diet to strengthen teeth. Chewing sugar-free gum is suggested as a beneficial practice to promote saliva production, which helps prevent plaque buildup. Concerns about fluoride use are raised, with caution advised regarding its potential effects on bone health. Genetic predisposition to cavities is acknowledged, with personal anecdotes shared about family dental issues. Overall, the thread emphasizes the multifaceted nature of cavity development and the importance of oral hygiene practices.