For patients in Cookeville and the surrounding Upper Cumberland communities, fillings are the most frequently performed restorative treatment, used to repair cavities caused by tooth decay before the damage requires a crown or root canal. Cookeville’s position between Tennessee Tech University and Cookeville Regional Medical Center puts a restorative dental practice within reach for families, students, and professionals.
This guide explains how fillings work, compares the available materials, walks through the procedure step by step, and outlines how long each type lasts. For a broader view of how fillings fit alongside crowns and bridges, see the guide to restorative dentistry.
Table of Contents
Key Takeaways (TL;DR)
- A filling repairs a cavity when the tooth still has enough healthy structure to support it: Fillings work best in small to medium cavities with sound remaining walls.
- Composite resin and amalgam are the two main materials: Composite is tooth-colored and bonds to enamel, while amalgam is stronger, less expensive, and silver in appearance.
- Modern fillings last seven to fifteen years or longer: Composite and amalgam have similar survival rates, and the dentist’s technique matters more than the material itself.
- A crown replaces a filling when too much tooth structure is lost: When more than half the tooth’s width is compromised, a crown provides stronger protection against fracture.
What a Dental Filling Does
A dental filling restores a tooth after a dentist removes decayed tissue from a cavity. The filling replaces the missing structure, seals the opening against bacteria, and restores the tooth’s ability to withstand chewing force. Fillings are the least invasive restorative option and preserve more natural tooth structure than crowns or onlays.
A filling works best when the cavity is small to medium and the remaining tooth walls are thick enough to support the material under pressure. Once a cavity grows large enough to undermine the tooth’s walls, the tooth flexes under chewing force and the filling can crack or fall out. At that point, a crown becomes the stronger restoration.
Types of Cavities and Where They Form
Cavities form where plaque accumulates and where toothbrushing has difficulty reaching. The location of a cavity affects which filling material a dentist chooses and how long the filling lasts.
Tooth decay begins when bacteria in dental plaque convert sugars and starches from food into acids that dissolve enamel. Early decay can be reversed with fluoride before a cavity forms. Once the decay reaches the dentin beneath the enamel, the tooth cannot repair itself, and a dentist must remove the decayed tissue and place a filling.
Filling Materials: A Closer Look
Dental fillings are made from several materials, each with a different profile of strength, appearance, and cost. The American Dental Association notes that no single material is best for every situation, and the choice involves discussing the tooth’s location and function with the dentist.
Composite Resin
Composite resin combines acrylic resin with powdered glass particles to create a tooth-colored filling. Composite bonds to enamel through a micro-etched surface, which allows the dentist to remove less healthy tooth structure than amalgam requires. Composite works well in small to mid-sized restorations on both front and back teeth. Its limitations are a longer placement time, a sensitivity to moisture during placement, and faster wear than amalgam under heavy biting force.
Dental Amalgam
Dental amalgam is a mixture of mercury with silver, copper, and tin, commonly called a silver filling. Amalgam is strong, durable, resistant to further decay, and the least expensive filling material. It is typically used in back teeth where strength matters more than appearance. Amalgam does not bond to tooth structure and requires removal of some healthy tooth to create retention. Agencies including the FDA, CDC, and WHO have not found evidence of harm from dental amalgam in dental restorations.
Glass Ionomer and Resin-Modified Glass Ionomer
Glass ionomer fillings release fluoride and bond chemically to tooth structure, which makes them useful for root cavities and for pediatric patients with primary teeth. They are less durable than composite or amalgam and are usually limited to low-stress areas or restorations expected to last only a few years. Resin-modified glass ionomer combines glass ionomer’s fluoride release with composite’s strength and light-curing capability.
Filling Material Comparison
The table below compares the main filling materials across the factors that matter most to patients and dentists.
Filling Procedure: Step by Step
A dental filling procedure follows a predictable sequence and usually takes less than an hour for a single tooth. The steps protect the tooth at every stage and end with a sealed, functional restoration.
- Numbing the tooth. The dentist applies a topical anesthetic to the gum, then injects a local anesthetic to numb the tooth and surrounding tissue.
- Removing decay. The dentist uses a drill, air abrasion, or laser to remove decayed enamel and dentin, shaping the cavity so the filling will hold.
- Cleaning the preparation. The cavity is cleaned of debris and bacteria. For composite, the dentist etches the enamel with an acid gel, rinses it, and applies a bonding agent.
- Placing the filling. Composite is placed in layers and hardened with a curing light after each layer. Amalgam is packed into the cavity and carved to match the tooth’s shape.
- Shaping and polishing. The dentist shapes the filling to match the bite and polishes it to smooth the surface and reduce plaque accumulation.
How Long Do Dental Fillings Last?
Most dental fillings last between seven and fifteen years, and some remain in place for twenty years or longer. Research on posterior composite fillings shows annual failure rates of 1 to 2.5 percent for modern materials, which matches or exceeds the 1 to 2 percent annual failure rate of amalgam. The critical variable is the dentist’s technique, since a well-placed composite outlasts a poorly placed amalgam.
Factors that shorten filling lifespan include poor oral hygiene, smoking, a diet high in sugar and acid, grinding teeth during sleep, and chewing hard objects such as ice or pens. Regular dental checkups allow a dentist to detect marginal leakage or wear early and replace the filling before the tooth is damaged.
Filling vs Crown: When a Filling Is Not Enough
A filling and a crown solve different problems. A filling replaces decayed tissue inside a tooth that still has sound walls. A crown covers the entire visible portion of a tooth that has lost too much structure to support a filling. A dentist recommends a crown when a cavity is too large, when a tooth has cracked, when multiple fillings have weakened the tooth, or when a tooth has had root canal therapy and needs protection from fracture.
Caring for a Tooth After a Filling
A filling restores the tooth’s structure, but the tooth and the filling still require daily care. Plaque accumulates at the filling margin just as it does on a natural tooth, and bacteria can leak under a failing filling to create a new cavity.
- Brush twice daily with fluoride toothpaste and clean the filling margin carefully.
- Floss daily to remove plaque from between teeth and around the filling edge.
- Avoid chewing ice, hard candy, and other hard objects that can crack the filling or the tooth.
- Wear a night guard if you grind or clench your teeth during sleep.
- Schedule dental checkups every six months so the dentist can inspect the filling for wear or leakage.
Sensitivity to cold or pressure after a filling is common and usually fades within a few days. Persistent pain, pain when biting, or a rough edge on the filling warrants a return visit to check the bite and the margins.
What Affects the Cost of a Filling
Filling costs vary by material, the number of surfaces involved, the tooth’s location, and whether the filling is a new restoration or a replacement of an old one. Amalgam typically costs less than composite resin. A one-surface composite filling costs less than a multi-surface filling, and a replacement filling that requires removal of old material and additional preparation costs more than a first-time filling.
Insurance coverage for fillings depends on the plan. Many dental plans cover a percentage of the cost after a deductible, but coverage limits and waiting periods vary. Patients should ask for a written treatment estimate before scheduling. The American Dental Association notes that costs and insurance coverage should be discussed with the dentist when choosing a restoration material.
Frequently Asked Questions
How long does a dental filling last?
Most fillings last seven to fifteen years, and some last longer. Amalgam fillings tend to last slightly longer than composite fillings, but modern composite has annual failure rates comparable to amalgam when placed well.
Are composite fillings as durable as amalgam?
Modern composite fillings have annual failure rates of 1 to 2.5 percent, matching or exceeding amalgam’s 1 to 2 percent failure rate. The dentist’s technique and the filling’s location matter more to longevity than the material choice.
Does getting a filling hurt?
The procedure is performed under local anesthesia, so the patient feels no pain during treatment. Mild sensitivity to cold or pressure for a few days afterward is common and usually fades as the tooth adjusts.
Can a filling fall out?
Yes. Fillings can loosen or fall out when the bond between the filling and the tooth fails, when the filling wears down, or when decay develops underneath. A loose filling should be replaced promptly to protect the tooth from further decay.
How do I know if I need a filling or a crown?
A filling is sufficient when the cavity is small and the remaining tooth walls are sound. A crown becomes necessary when the cavity is too large for a filling, when the tooth has cracked, or when the tooth has had root canal treatment and needs protection from fracture.
Can I eat after getting a filling?
Patients should wait until the anesthesia wears off before eating, because numbness makes it easy to bite the tongue or cheek. Composite fillings harden immediately with the curing light, so normal eating can resume once sensation returns. Amalgam fillings set within a few hours, and patients should avoid chewing on that side until the material hardens.
People Also Ask
What is the best filling material?
No single material is best for every situation. Composite works well for visible teeth and small cavities, while amalgam offers strength and lower cost for back teeth. The dentist selects the material based on the tooth’s location and function.
How much does a filling cost?
Filling costs depend on the material, the number of surfaces involved, and the tooth’s location. Amalgam typically costs less than composite. Insurance often covers a portion of the cost, so patients should request a written estimate.
Can a cavity heal on its own?
Early decay can be reversed with fluoride before a cavity forms. Once the decay reaches the dentin and creates a cavity, the tooth cannot repair itself and requires a filling to remove the decayed tissue and restore the tooth.
Why does my filling hurt?
Pain after a filling usually comes from the tooth adjusting to the restoration or from a filling that sits too high on the bite. Sensitivity to cold or pressure typically fades within a few days. Persistent pain or pain when biting warrants a return visit to check the bite and the margins.
Are silver fillings safe?
Dental amalgam has been used for more than a century, and agencies including the FDA, CDC, and WHO have not found evidence of harm from amalgam in dental restorations. Patients with concerns about mercury exposure can discuss composite alternatives with their dentist.
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About the Author
Dr. Kevin Hayes, DMD, practices at Hayes Family Dentistry in Cookeville, Tennessee. The practice provides restorative care including dental fillings, dental crowns, same-day crowns, bridges, and dental implants to patients throughout Putnam County and the Upper Cumberland region.
Hayes Family Dentistry is located at 620 E 10th St, Cookeville, TN 38501, near Tennessee Tech University and Cookeville Regional Medical Center. The practice serves patients from Cookeville, Algood, Baxter, Bloomington Springs, and surrounding communities.
Dr. Hayes places both composite and amalgam fillings and helps patients choose the material that best fits each tooth’s location and function. Learn more about Dr. Hayes or explore the practice’s general dentistry services.
Sources
- American Dental Association (ADA). Dental Fillings Facts. ada.org
- American Dental Association (ADA). Dental Amalgam. ada.org
- National Institute of Dental and Craniofacial Research (NIDCR). The Tooth Decay Process. nidcr.nih.gov
- National Institute of Dental and Craniofacial Research (NIDCR). Ask the Expert: Why is fluoride good for dental health? nidcr.nih.gov
- Centers for Disease Control and Prevention (CDC). Oral Health. cdc.gov
- U.S. Food and Drug Administration (FDA). Dental Amalgam. fda.gov
- Clove Dental. Filling vs. Crown: When Do You Need a Crown for Teeth After a Filling? clovedental.in
A Filling Repairs Decay Before It Requires a Crown
A dental filling repairs a cavity by replacing decayed tooth structure with composite resin, amalgam, or glass ionomer. Fillings work best in small to medium cavities where the remaining tooth walls are sound, and they preserve more natural tooth structure than crowns or onlays.
Material choice determines how the filling looks, how it wears, and how long it lasts. Composite matches natural tooth color and bonds to enamel, amalgam offers strength and lower cost for back teeth, and glass ionomer releases fluoride for root cavities and pediatric teeth. Most fillings last seven to fifteen years with good hygiene and regular dental care.
For patients in Cookeville, Algood, Baxter, and across the Upper Cumberland, Hayes Family Dentistry places composite and amalgam fillings and helps patients decide when a filling is enough and when a crown is the stronger choice. The practice is located at 620 E 10th St, near Tennessee Tech University and Cookeville Regional Medical Center. Call (931) 526-1614 to schedule a consultation.
Last reviewed: September 2026
