Lots of luck convincing anyone on these threads. There's been a noticeable shift toward the anti-medical, bordering on quack theories that I've noted here since the whole Terri Schiavo mess. The site seemed to attract people who were so single-minded as to believe a single quack with a theory rather than accumulated research. (Hammesfahr in the case of Schiavo).
For sake of your sanity I recommend you also stay away from vaccine threads, autism threads, and mercury threads in particular. My husband (another dentist) has learned that clicking on them is bad for the digestion, LOL.