Q:My 6 year old daughter recently had her dental check up. Because she now has her second teeth in at the back, the dentist wants to give her "pit and fissure sealant". She has never required fillings in the past, and to me it seems this treatment i
I was shocked then to see a TV programme a month ago about men's falling sperm count, where it stated that the plastic from these sealants was leaking estrogen into the system, contributing to reduced sperm count in males and breast cancer in females.
Please can you give me any information to help me make an informed stand against my dentist's wishes. A M, Airdrie.......
A:Fissure sealants that is, sealing off the fissures of the back teeth with a composite filling is all the rage now among dentists to prevent future decay in children. Dentists hand out leaflets extolling the possibility that children can grow up without any cavities.
The latest controversy surrounding fillings has to do with the potential of most composites (also used for fissure sealing), which are made of the petrochemical bisphenol, to give off estrogen like substances. Theoretically, this could cause a reduction in male infertility and possibly cause female breast cancer.
Most resins are based on the reaction product of two chemicals bisphenol A and glycydyle methacrylate called Bowen's resin. The biggest problem, says Dr Dunne, is a lack of research on products that are only about 10 years old. However, some lab studies, largely on cell lines and very limited number on animals (not as well designed as those for amalgam), have shown that the resin based materials can inhibit RNA synthesis, damage cell nucleus, cause cytotoxic reaction to cells and liberate formaldyhyde, although only for a limited period after the fillings are placed a few hours to a few weeks.
As with most other plastic materials, bis-phenol leeches out estrogen like substances. Therefore, it's conceivable that estrogen like substances can be released from the placement of fillings. "I'm not saying that composite fillings will feminize males," insists Dr Dunne, " and I'm also not saying any effect has been demonstrated in humans."
At the moment, any arguments about the dangers of composites remain theoretical. It's also important to keep in mind that these dangers are being hyped up by the pro amalgam filling backlash.
At present, we have no idea how large a risk this presents. Mats Hansen, head of Swedish Mercury Patient's Association, estimates that the amount of estrogen released in the entire lifetime of a composite filling would be the equivalent of what you might get from opening a tin can lined with plastic. We also have to put fillings in context of our overwhelming exposure to plastics in the environment and every phase of our lives. Bottles, cans, bin bags, cling film, styrofoam cups, even toys (put in toddler's mouths) will be emitting the same substance, although perhaps without the same theoretical intensity as something constantly in your mouth.
It's one thing exposing yourself to any theoretical risk when you already have fillings and it's been demonstrated that your amalgam fillings are having a clear toxic effect on you. It's another issue altogether to expose children with healthy teeth to the possible risk as a preventive measure.
WDDTY panellist Jack Levenson, president of the Society for Mercury Free Dentistry, maintains that fissure sealing isn't necessary. As long ago as 1911, a survey in New Zealand of 1500 schoolchildren found that if they ate alkaline, saliva producing food after a meal, this food would neutralize the acidity of bacteria. This reduced the incidence of tooth decay enormously. One of the best alkaline saliva producers is fruit.
Levenson also believes that children's teeth are becoming decay free because parents are more careful about limiting sweets and providing a good diet. It also has a lot to do with the fact that dentists no longer automatically fill the fissures in the back teeth with amalgam. Twenty years ago, he says, dentists (including himself) were taught "extension for prevention". This practice held that a person's back teeth were bound to rot anyway, so the best thing to do was to automatically fill back fissures with amalgam in order to "extend" the tooth's life. Oftentimes the tiniest prick found by the dentist's probe would prompt a back tooth filling.
"Hundreds of thousands of teeth were filled unnecessarily," says Levenson. And once a tooth was filled, that caused further decay.
Dr Dunne's line is to consider the lifestyle of the child. For breastfed children following all the right preventive measures, including regular brushing and good low sugar diet, even the theoretical risks of composite fissure sealants are not worth it. For those with soft teeth consuming lots of sugar, particularly sugary drinks, a tiny fissure sealant may avoid exposure to a giant composite or mercury filling later.
Avoiding sugary drinks like Ribena and too much candy, being breastfed, engaging in regular brushing, and eating fruit after meals will go along way to preventing decay naturally, says Levenson. "If children eat the right food, it will also remineralize teeth."