What is silver amalgam? Silver amalgam is primarily composed of a mixture of silver, tin, copper, and mercury.
As the most commonly used filling material, silver amalgam has been widely employed for over a century due to its strength and durability, yielding highly satisfactory results.Is amalgam safe? According to a 1995 joint statement by the FDI World Dental Federation and the World Health Organization, dental filling materials—including amalgam—rarely cause local side effects or allergic reactions. No scientific literature currently indicates amalgam poses health risks, so there is no need to worry about this filling material affecting your well-being.The World Health Organization sets the upper limit for mercury vapor exposure at 300-500 micrograms per day. Research data from a Swedish dentist's measurement study found that the average daily mercury vapor inhaled from silver amalgam fillings is only 1.7 micrograms—just 10% of the upper limit.Mercury exposure in our bodies comes from multiple sources. In fact, we absorb more mercury from fish consumption than from dental fillings. By comparison, the mercury vapor released from silver amalgam fillings is extremely minimal.
2. Composite Resin Materials
When are they used? Composite resin closely matches natural tooth color, offering excellent aesthetics, so it's primarily used on front teeth. In appropriate cases, composite resin can also be used to enhance tooth color, shape, and size to beautify the smile.
Issues: The composite filling procedure is relatively complex. Composite materials are less durable than amalgam because they wear down more easily. A primary reason is that after composite resin hardens, it may shrink slightly, creating tiny gaps between the composite layers. These gaps can cause tooth sensitivity and increase the risk of cavities. Composite materials may also absorb pigments from food and beverages, leading to yellowing over time.
3. Glass Ionomer Resin
When is it used? Glass ionomer resin is another tooth-colored filling material. It is typically used for baby teeth, near the gum line, and at the tooth neck. It bonds tightly to the tooth surface and releases fluoride, which helps strengthen teeth and prevent decay. Sensitivity after filling is also less common.
Issues: Its texture is weaker than composite or amalgam and wears more easily. Its color is less aesthetically pleasing than resin materials.
4. Nano and Diamond Resin
Nano and diamond resin materials represent the most advanced high-tech filling options available today. They offer advantages such as higher strength and more natural-looking color.
5. Zinc Oxide Epoxy Cement (ZOCO): Also known as temporary cement or epoxy paste. Used as a non-load-bearing base layer for deep cavity double-layer preparations, or as a single-layer non-load-bearing base material. Serves as a temporary cavity sealant for 1–2 weeks and as a root canal filling material. When mixed with a shaping agent, it functions as a periodontal packing agent.
6. Calcium Hydroxide Cement: A novel pulp-protective lining material. Used as a lining material for Class III and V cavities, as a pulp-protective lining to block composite resin stimulation of the pulp, and as a direct or indirect pulp capping agent.
7. Gutta-percha: Softens when heated to 40°C, becoming malleable, and hardens upon cooling. Used as an auxiliary material for root canal filling, for temporary cavity sealing, or heated for dental temperature testing.