The OPTISMILE Podcast 123 - The Amalgam and Mercury Debate

IntroductionFew subjects in dentistry generate more heat and less light than the silver amalgam filling. One camp insists the fillings are entirely safe and should be left alone. The other insists that anything containing mercury should come out at the first opportunity. Both camps are loud, and neither is right in every case. In this episode Dr Clifford Yudelman works through what the published evidence actually shows about mercury exposure from amalgam, why two dentists can look at the same filling in the same week and give a patient opposite advice, and how to tell a genuine clinical reason for removal from a business model built on fear.The episode also separates the mercury question from the mechanical one, which is where most of the real clinical decision-making sits. Old amalgams expand, they do not bond to the tooth, and they respond to hot and cold at a different rate to enamel, which is why they crack teeth and leak over the years. Dr Yudelman covers the SMART removal protocol and why high-volume suction matters more than most patients realise, whether removal automatically commits you to a crown, what an amalgam tattoo is and why it needs no treatment, what to do during pregnancy, and whether South Africans should be alarmed by international phase-outs of amalgam. The overriding message is that fear is not a clinical indication for treatment.Questions and AnswersQuestion 1   [1:27]Are silver amalgam fillings actually dangerous or toxic?Dr Yudelman's short answer is that his own wife still has two of them in her mouth, which tells you what he thinks of the risk. Mercury in amalgam is bound into a stable alloy rather than sitting loose, and one review calculated that you would need somewhere in the region of 450 to 530 amalgam surfaces, roughly a hundred large fillings, to reach the World Health Organization urinary threshold associated with the most subtle preclinical effects. A Cochrane review by Worthington and a further systematic review found no consistent or clinically important difference in harm between amalgam and composite.Question 2   [8:12]Why do some dentists say to remove them all, while others say to leave them alone?It comes down to philosophy and training, and sometimes to a business model, but that does not mean either side is lying. The precautionary camp removes amalgam to eliminate any mercury risk at all, while the minimal intervention camp leaves stable fillings alone and monitors them. Both positions are defensible in the right context, and the problem only arises when one is sold as a universal truth for every patient regardless of individual risk.Question 3   [10:05]What is the SMART protocol, and why does isolation such as the rubber dam matter so much during removal?SMART stands for Safe Mercury Amalgam Removal Technique, which Dr Yudelman describes as common sense with an acronym. The filling is not the hazard while it sits quietly in the tooth; the vapour and particles are generated when it is drilled out, so the protocol relies on isolation, copious water spray and, above all, properly maintained high-volume suction positioned right next to the tooth. Research indicates that without high-volume suction, mercury vapour levels in the operating environment can run several times higher than the recommended threshold.Question 4   [16:11]Is it true that amalgam fillings can eventually crack the tooth around them?Yes, and this is the reason Dr Yudelman actually removes most of the amalgams he removes, not the mercury. Amalgam does not bond to the tooth; it is mechanically wedged in, so as the tooth flexes under biting the filling does not flex with it, and many old fillings continue to expand over the years. Large old amalgams are monitored so that a crack can be caught before a cusp breaks off, which is a different conversation entirely from the mercury debate.Question 5   [18:32]Separately from cracking, do old silver fillings expand and contract with temperature differently to the natural tooth, and does that cause its own problems?Metal and tooth structure respond to hot and cold at different rates, so every coffee and every cold drink creates a small mismatch. Thousands of those cycles over the years open up gaps at the margins, which is how decay eventually gets underneath an old filling. It happens slowly and quietly, which is precisely why it is not usually an emergency and does not justify panic.Question 6   [19:48]If I have my metal fillings removed, do I automatically need a crown, or is there a more conservative option?You do not automatically need a crown, and the old default of grinding the whole tooth down has cost patients a great deal of money over the years. Depending on how much tooth is left, the options run from a bonded composite through to an inlay or onlay that covers only what genuinely needs protecting. Before agreeing to any removal, ask what is replacing the filling and why that option was chosen, and if no clear biological reason is offered, seek a second opinion.Question 7   [21:39]What is an amalgam tattoo on the gum, and if I have one, should I be worried?An amalgam tattoo is a grey or blue mark in the gum caused by a tiny fragment of amalgam left behind, often decades earlier when a baby tooth with a silver filling was extracted. It is purely cosmetic, it does not spread and it does not cause disease, and the fragments usually show up as small white specks on an x-ray near the mark. There is no need for removal, and no need for the biopsies that some patients are unfortunately sent for.Question 8   [23:33]Do you get more mercury exposure over the years from chewing on an old filling than you would from having it removed properly?Chewing, grinding, clenching and particularly chewing gum release very small amounts of vapour from an old filling continuously, year after year. A properly conducted removal with high-volume suction and water spray is a single controlled exposure rather than an ongoing one, so a filling left in place for decades can plausibly amount to more total exposure than one removal appointment. That is not an argument for removing stable fillings for the sake of it, but it does cut against the idea that leaving them forever is automatically the safer choice.Question 9   [26:46]What about pregnant women, should they have their amalgam fillings removed?Generally no. Stable amalgams are left alone during pregnancy, and elective or non-urgent dental work is avoided as a matter of course. If there is a genuine clinical need such as active decay or a cracked filling, it is treated with the appropriate precautions, but fear on its own is not a clinical indication for treatment.Question 10   [27:51]Some countries have restricted or phased out amalgam altogether. Should South Africans be worried about the fillings they already have?No. Dr Yudelman sees no good reason to place new amalgam fillings, but the international phase-out is driven by environmental policy on mercury rather than by evidence of patient harm, and mercury waste regulations are now coming into force locally. In lower-resourced settings amalgam still saves teeth, although newer materials such as glass ionomers and resin-reinforced glass ionomers now handle similarly and offer a mercury-free alternative. A ban in Switzerland is not a reason to come home and have all your fillings replaced.Closing ThoughtsThe consistent thread through this episode is that the mercury conversation and the mechanical conversation are two separate things, and confusing them costs patients money. The evidence to date does not support removing stable, well-sealed amalgam fillings on toxicity grounds, and removing a sound filling out of fear means losing more tooth structure, which compounds over a lifetime. Every removal takes away more of the tooth, and that is not free.Where removal is genuinely justified is when a filling is leaking, decayed underneath, or expanding and cracking the tooth around it, and even then the replacement should be the most conservative option that will do the job rather than an automatic crown. If a dentist cannot give a clear biological reason for what they are recommending, that is the moment to ask for a second opinion. Do not panic, do not act on a social media post, and have the individual risk properly assessed before anything is drilled.Further ResourcesAll links below have been verified on the OptiSmile website.Unveiling Dental Fillings: Preservation Meets Aestheticshttps://optismile.co.za/blog/unveiling-dental-fillings-preservation-meets-aesthetics/Beyond Fillings and Crowns: The Magic of Inlays and Overlayshttps://optismile.co.za/blog/beyond-fillings-and-crowns-the-magic-of-inlays-and-overlays/Dental Inlays and Overlays Treatmenthttps://optismile.co.za/dental-solutions/dental-inlays-overlays/Comprehensive Guide: Dental Inlay versus Crownhttps://optismile.co.za/blog/dental-inlay-vs-crown/Cracked Teeth: Causes, Symptoms and Treatmentshttps://optismile.co.za/blog/can-cause-cracked-tooth/Toothache Troubles: Managing Dental Pain and Costshttps://optismile.co.za/blog/toothache-troubles-managing-dental-pain-and-costs/Parafunctional Habits: Ice Chewinghttps://optismile.co.za/blog/parafunctional-habits-ice-chewing/Dental Bonding at OptiSmile Sea Pointhttps://optismile.co.za/dental-solutions/dental-bonding/Disclaimer: The content provided in this podcast, "Save Your Money Save Your Teeth" on Medical Mondays, is for informational and educational purposes only. It is not intended to serve as dental or medical advice. The insights and opinions expressed by Dr. Clifford Yudelman and any guests are designed to foster a better understanding of dental health, preventive measures, and general well-being, but should not be interpreted as professional dental or medical recommendations. Dr. Clifford Yudelman does not diagnose, treat, or offer prevention strategies for any health conditions directly through this podcast. This platform is not a substitute for the personalized care and advice provided by a licensed dental or healthcare professional. We strongly encourage our listeners to consult with their own dental care providers to address individual dental health needs and concerns. The information shared here aims to empower listeners with knowledge about dental health but must not be used as a basis for making health-related decisions without professional guidance. Your dental care provider is the best source of advice about your dental and overall health. Please always seek the advice of your dentist or other qualified health professionals regarding any questions or concerns about your dental health.