How Long Should a Tooth Hurt After a Filling?

You just got home from our office in Forest Hills. The numbness has worn off, you go to eat dinner, and… ouch.

It is a sinking feeling. You came to the dentist to fix a tooth, so why does it still hurt?

First, take a deep breath. Post-operative sensitivity is one of the most common concerns I hear from patients, and 90% of the time, it is temporary and completely fixable.

However, there is a difference between “healing pain” and “something is wrong pain.” Here is how to tell the difference.

The “Normal” Timeline: What to Expect

In an ideal world, you would feel nothing. But a dental filling is microsurgery. We have removed decay and placed a new structure inside a living tooth. The nerve inside that tooth (the pulp) needs time to calm down after the vibration and work.

Here is the general timeline for recovery:

• The First 24-48 Hours: This is the peak of tenderness. You may feel a “zing” when breathing cold air or drinking ice water.
• 3 to 7 Days: The sensitivity should noticeably decrease. It may still be tender, but it shouldn’t be keeping you awake.
• 2 to 4 Weeks: For very deep cavities, mild sensitivity to cold can linger this long. As long as it is improving day by day, this is usually considered “Reversible Pulpitis“—meaning the nerve is healing.

Why White Fillings (Composites) Can Be More Sensitive

In our practice, almost all the fillings we place are Composite Resins (tooth-colored fillings). While these look better and require less drilling than old-fashioned silver (amalgam) fillings, they do have one quirk: they can be slightly more sensitive initially.

Why does this happen? It comes down to chemistry.

• The Bonding Process: Unlike silver fillings, which are just packed into the hole, white fillings are chemically bonded to the tooth. This involves using a mild acidic gel to “etch” the tooth surface, creating microscopic pores for the adhesive. While safe, this process opens the pores of the tooth, which can temporarily shock the nerve.
• Shrinkage Stress: When we use the curing light to harden the filling, the material shrinks microscopically. This creates a tiny amount of tension on the walls of your tooth (think of a tight wetsuit squeezing your tooth). It takes time for your tooth to adjust to this new tension.

This is why you might feel a specific sensitivity to cold air or sweets with a new white filling that you didn’t experience with old metal ones. It is a trade-off for a stronger, better-looking restoration, and it almost always fades.

Scenario 1: It Hurts Only When I Bite Down

The Diagnosis: Your Filling might be “High.”

This is the most common reason patients call us back, and fortunately, it is the easiest to fix.

When you are numb in the chair, it is difficult to tell if your bite feels perfect. Even if the filling is just a fraction of a millimeter too high, it hits the opposing tooth first every time you close your mouth.

Scenario 2: It Hurts With Cold or Air

The Diagnosis: Post-Operative Sensitivity (The “Zing”)

Composite (white) fillings bond directly to your tooth structure. Sometimes, this bonding process or the depth of the cavity causes the nerve to be hypersensitive to temperature.

Scenario 3: The Pain is Throbbing or Lingering

The Diagnosis: Irreversible Pulpitis

This is the “Red Flag” category. If the decay was extremely deep (near the nerve), the bacteria may have already damaged the pulp before we placed the filling.

The Mystery of “Referred Pain” (Why Does the Wrong Tooth Hurt?)

Here is a scenario that panics many patients: We fill a molar on your upper right side, but the next day, you swear you feel pain in your lower right teeth.

Did we treat the wrong tooth? Did the cavity spread? The answer is usually Referred Pain.

The nerves in your teeth are wired somewhat like a household circuit breaker. The nerves from your upper and lower teeth often share a main trunk line back to the brain. When the nerve in the treated tooth is inflamed, it sends a strong distress signal. Sometimes, your brain gets confused about exactly where along that “wire” the signal is coming from.

How to tell if it’s Referred Pain:

• The pain is on the same side of the face (it rarely crosses from left to right).
• The untreated tooth looks healthy.
• The pain in the “wrong” tooth diminishes as the actually filled tooth heals.

If you are experiencing this, don’t panic. It is a well-documented biological quirk, not a sign that your other teeth are suddenly failing.

Your 24-Hour Survival Guide: Dos and Don’ts

While you wait for the tooth to settle, how you treat it in the first 24 hours makes a massive difference. You wouldn’t run a marathon on a sprained ankle; don’t force your tooth to work hard immediately after surgery.

The “Don’ts”

• Don’t Chew While Numb: This sounds obvious, but it is the #1 cause of post-filling pain. If you chew while your tongue and cheek are anesthetized, you can bite the soft tissue raw. This pain is often worse than the tooth sensitivity!
• Skip the “Extreme” Temps: For the first day, avoid very hot soup or ice-cold smoothies. Your tooth is currently hypersensitive to thermal changes. Lukewarm food is your friend.
• Avoid “Testing” It: It is tempting to keep biting down or clenching to check if it still hurts. Please stop. Every time you clench to “check,” you are bruising the ligament further.

The “Dos”

• Chew on the Opposite Side: Give the treated side a 2-day vacation.
• Salt Water Rinses: If your gums are sore from the injection site or the rubber dam clamp, rinse gently with warm salt water (1 teaspoon of salt in a cup of warm water). This reduces gum inflammation naturally.

Anti-Inflammatories: Unless you are medically advised otherwise, Ibuprofen (Advil/Motrin) is typically more effective for dental pain than Acetaminophen (Tylenol) because it specifically targets inflammation.

How Forest Hills Dental Minimizes Sensitivity

We know nobody wants to leave the dentist in pain. That is why Dr. Mark and the team take extra steps during your procedure to ensure comfort:

1. Desensitizing Agents: We apply Gluma or similar desensitizers under your fillings to act as a shield for the nerve.
2. Incremental Layering: We place white fillings in thin layers. This prevents the material from shrinking too much as it hardens, reducing stress on the tooth walls.

Precise Bite Checks: We use specialized articulating paper to check your bite, but if numbness masks the issue, we prioritize getting you back in for a quick adjustment.