Dental fillings restore tooth function and appearance, but their strength and longevity compared to natural teeth is a nuanced topic. Understanding the distinctions between natural tooth structure and filling materials, along with factors affecting their performance, helps clarify this comparison.
The Strength of Natural Teeth
Natural teeth possess remarkable strength due to their unique composition. The outermost layer, enamel, is the hardest substance in the human body, consisting of 96% minerals, mainly hydroxyapatite. This high mineral content gives enamel a Mohs hardness of about 5, making it harder than steel. Beneath the enamel lies dentin, a softer, bone-like tissue forming most of the tooth. Dentin, with a Mohs hardness of about 3, provides elasticity and support to the more brittle enamel, allowing teeth to withstand significant biting forces, which can average up to 200 pounds of pressure.
Filling Materials and Their Properties
Dental fillings utilize different materials, each with properties affecting their strength and interaction with tooth structure. Amalgam fillings, often referred to as “silver fillings,” are a blend of metals including mercury, silver, tin, and copper. They are known for their strength, durability, and cost-effectiveness, particularly for molars which experience heavy chewing forces. Amalgam fillings typically last between 7 and 15 years and exhibit high compressive strength, though they have low tensile strength.
Composite resin fillings are tooth-colored materials made from a mixture of liquid resin and glass particles. These fillings bond directly to the tooth structure, providing additional support to weakened teeth. While aesthetically pleasing, composite fillings generally have a shorter lifespan of 5 to 10 years and may wear out more quickly in molars due to high biting stresses.
Porcelain or ceramic fillings offer a natural appearance and are resistant to staining, providing good durability. Gold fillings, typically crafted from gold alloys, are highly durable and resistant to corrosion. They are known for their exceptional longevity, often lasting 10 to 15 years. Gold is flexible enough to withstand significant biting forces without cracking or chipping, and its similar softness to enamel means it causes less wear on opposing teeth.
Factors Influencing Filling Durability
Beyond the inherent properties of the filling material, several other factors affect a dental filling’s long-term performance. The size and location of the filling play a substantial role; larger fillings or those situated on biting surfaces, such as molars, endure more stress and may have a shorter lifespan. Fillings in areas with less chewing pressure tend to last longer.
The amount of healthy tooth structure remaining after decay removal also influences durability. Fillings that require extensive removal of natural tooth material can make the tooth weaker due to reduced support. Habits such as bruxism, or teeth grinding and clenching, place excessive strain on fillings, leading to premature wear or fracture. The quality of the bonding process during placement is also important, particularly for composite fillings, as proper adhesion prevents gaps where bacteria could cause new decay.
Caring for Your Dental Fillings
Maximizing the lifespan of dental fillings involves consistent oral care and mindful habits. Maintaining good oral hygiene is fundamental, which includes brushing twice daily with fluoride toothpaste and flossing once a day. Regular brushing helps remove plaque and bacteria from around the filling, preventing new decay. Using an antibacterial mouthwash can also reduce bacteria.
Routine dental check-ups allow dentists to monitor the condition of fillings and detect any issues early. Avoiding habits that can damage fillings is also important; this includes refraining from chewing on hard items like ice, hard candies, or nuts, and sticky foods like caramel, which can dislodge or fracture the restoration. For individuals who grind their teeth, using a night guard can protect fillings from excessive forces. Limiting sugary and acidic foods and beverages also helps protect both the fillings and the surrounding natural tooth structure from decay and erosion.