Thank you to those that contacted me in response to prior posts! I appreciate all feedback! One recurrent topic that was requested was modern advancements in dental technology. Ask and you shall receive! Over the next three blog posts, we will touch on three of my favorite modern dental advancements. The first is my silver filling substitute – Resin Modified Glass Ionomer (RMGI). This material bridges the gap between silver amalgam fillings and white resin fillings because it possesses properties of both. Because of this, it has become my modern tooth colored version of silver fillings. To appreciate this one must understand the ideal situation and conditions in which to place a white filling. White fillings are bonded (glued) to the tooth and require very dry conditions. In the mouth, a dry field is not always an easy thing to create. We use rubber dams or cotton and work efficiently before saliva compromises the bonding site. Despite all our efforts, situations sometimes occur where a dry field is impossible to achieve. The traditional solution to these circumstances has been to place silver amalgam because amalgam can be placed in a slightly wet field. For several years now when the rare occasion a silver amalgam is indicated, I reach for the RMGI with wonderful results. In addition to completely lacking mercury, another advantage RMGI has over amalgam is that it chemically bonds to tooth structure and comes in different tooth colored shades. The chemical adhesion allows for minimal removal of tooth structure and the ability to place RMGI where amalgams cannot be placed. The ability to match the color shade to the surrounding teeth is an obvious improvement over the silver color of amalgam. This is often quite appreciated when RMGI is indicated in a baby tooth. Finally, RMGI functions like a fluoride reservoir. It soaks up tooth hardening fluoride from a source such as toothpaste or tap water and disseminates it to surrounding tooth structure over time. This fact makes RMGI very useful in certain cases where a patient has cavities on the root surfaces of their teeth.
RMGI sounds so great! Why don't I use it all the time? A good question! Despite all its many positives, RMGI does not possess some of the wonderful qualities of traditional white resin filling. It does not polish as well to a glossy finish as the white resin filling. Additionally, it does not bond as strongly as the resin and therefore is not used where high bond strength is needed (i.e. cosmetic bonding). For these reasons, white resin filling is always my material of choice whenever possible and I typically reserve the placement of RMGI for special situations rather than silver amalgam.
If you have any questions or would like to speak further, please do not hesitate to contact me. I love discussing the practical application of new technology that improves modern comprehensive dentistry.
Eric G. Jackson, DDS, FAGD, FICOI, FADI