A simple dental filling takes as few as 20 minutes, while most fillings are done in an hour or less. The exact time depends on the size of the cavity, the filling material, and how many teeth need work in the same visit.
What Happens During the Appointment
The filling process follows a predictable sequence: numbing, drilling, cleaning, filling, and polishing. Understanding each step helps explain why some visits are quick and others take closer to an hour.
First, your dentist injects a local anesthetic near the tooth. This typically takes 7 to 9 minutes to fully numb the area. While you wait for it to kick in, the dental team may prepare materials or take X-rays if they haven’t already. Once you’re numb, the dentist uses a drill to remove the decayed portion of the tooth, then cleans the cavity to make sure no bacteria remain. The filling material goes in next, shaped to match your bite. A final round of polishing smooths everything out so the surface feels natural against your tongue and opposing teeth.
For a small cavity on an easy-to-reach tooth, the actual hands-on work can be finished in 15 to 20 minutes. A deeper cavity, one in an awkward location like a back molar, or one that wraps around multiple surfaces of a tooth pushes the appointment closer to 45 minutes to an hour.
How Filling Material Affects the Time
The two most common filling materials are composite resin (tooth-colored) and amalgam (silver-colored), and they don’t take the same amount of time to place.
Composite fillings require a more involved technique. The dentist applies the resin in layers, curing each layer with a blue UV light before adding the next. This layering process adds time but produces a filling that matches the color of your natural tooth. Amalgam fillings are mixed and packed into the cavity in a single step, making placement consistently faster. If your appointment feels longer than expected, a composite filling is often the reason.
The tradeoff extends beyond the chair. Composite fillings harden immediately under the UV light, so you can chew on that side as soon as the numbness wears off. Amalgam fillings take about 24 hours to fully harden, so dentists recommend avoiding chewing on that side for a full day.
Multiple Fillings in One Visit
If you need two or more fillings, your dentist can often do them in a single appointment, especially when the cavities are on the same side of your mouth (since that area is already numb). Expect the visit to run longer, but not by a full hour per tooth. Once the numbing and setup are done, each additional small filling may only add 10 to 20 minutes. For three or four fillings, or fillings on both sides of the mouth requiring separate numbing injections, the appointment could stretch to 90 minutes or more.
Some dentists prefer to split larger cases across two visits to reduce the time you spend with your mouth open and to keep each session comfortable.
Replacing an Old Filling
Replacing a worn or cracked filling follows the same basic steps, with one addition: the dentist first drills out the old filling material before cleaning the cavity and placing the new one. This removal step adds a few minutes, but the overall appointment still falls in the same general range of 20 minutes to an hour for a single tooth. If the tooth has developed new decay underneath the old filling, the cavity may be larger than the original, which can extend the procedure.
How Long the Numbness Lasts Afterward
The filling itself is done quickly, but the numbness lingers. Local anesthetics used in dentistry typically keep the tooth numb for 60 to 90 minutes, though your lips, cheek, and tongue can stay numb for two to four hours depending on which anesthetic was used and where the injection was placed. Lower teeth generally require a deeper nerve block that produces longer-lasting numbness than upper teeth.
This matters mostly for eating. Even with a composite filling that’s fully hardened, dentists suggest waiting one to three hours before chewing, simply because you can’t feel your bite properly while numb and risk biting your cheek or tongue. Plan to eat before your appointment or bring a smoothie for afterward if you’re scheduling a midday visit.
What Makes a Filling Take Longer
- Cavity depth: A cavity that reaches close to the nerve requires more careful drilling and sometimes an extra protective liner before the filling goes in.
- Location: Back molars are harder to access and have more complex surfaces than front teeth.
- Patient comfort: If the anesthetic doesn’t fully take effect, the dentist may need to give a second injection and wait for it to work.
- Large restorations: A cavity that covers multiple surfaces of a tooth may need an inlay or onlay, which is a custom-shaped piece rather than a standard filling. Many offices can fabricate these in a single appointment using digital milling technology, but the process takes longer than a traditional filling.
If you’re short on time, let your dental office know when you schedule. They can give you a realistic estimate based on your X-rays and help you plan accordingly.