Plastic fillings may now be saved by the newly discovered technique for plastic hardening in the mouth. But risk is present since it is new and not yet widely used.
Fillings of plastic* can be spotted on a digital x-ray that could not be seen on the panoramic x-ray. If such a tooth has never had an amalgam filling, you could harden the plastic with the toothbrush zappicator(page 344) instead of extracting it. Several days later, a test of the saliva should show no plastic tooth materials. If it does, repeat the zappication. If it still does, extract the tooth. They can be kept clean by once daily brushings with oregano oil tooth powder.
Only further research will reveal whether new plastic fillings can be so well hardened and kept so well fitting that no seeping occurs and no crevices develop.
Search your mouth yourself, every month, for a fresh cavity. It will be a small brown discoloration. Rub this spot twice daily, once with Dental Bleach and once with oregano oil toothpowder. Purchase a long-handled dental mirror (from automotive supply store) so your helper can see the backsides of your teeth.
There may be a time when dentistry can safely fill a small hole but it is not now. Research is progressing in other countries to bring healing methods instead of new kinds of fillings. Search the Internet to keep pace with it. Remember that teeth are bones! Your diet should have calcium and vitamin D3 in it. Ascaris parasites soften teeth and bones. Kill them regularly.