If a filling felt fine at first but now hurts, the most common causes are a slightly high bite, a small crack in the tooth, or nerve inflammation from decay that was close to the pulp. Sharp pain when biting usually means a bite adjustment. Lingering cold pain or throbbing at night needs prompt evaluation.

At Line Dental Aloha, we hear this question every week. A patient leaves the office with a fresh composite filling, everything feels normal for a few days, and then a dull ache shows up while sipping coffee at their desk. The tooth was supposedly fixed. So why is it hurting now?

Here is how we walk patients through it.

Is delayed pain after a filling normal?

Mild sensitivity in the first one to two weeks is normal. Composite fillings can leave the tooth reactive to cold air and cold drinks while the nerve settles down. According to the American Dental Association, this thermal sensitivity typically resolves within two to four weeks as the pulp recovers from the drilling and bonding process.

What is not typical: pain that starts fresh after week two, pain that gets worse instead of better, or pain that changes character. A tooth that felt fine for three weeks and then began throbbing is telling you something changed. That is worth a phone call.

Pay attention to three patterns. Cold sensitivity that fades in a few seconds. Sharp pain only when you bite down. Spontaneous throbbing that shows up on its own. Each one points somewhere different.

What are the most common causes of delayed filling pain?

There are six usual suspects, and most of them are fixable in a single short visit.

• High bite. The filling sits a fraction of a millimeter proud. Your other teeth close normally, but this one hits first every time you chew. The nerve gets bruised from repeated pressure.

• Reversible pulpitis. The decay was close to the pulp. The nerve is inflamed but not dying. It calms down with time and a protective liner already placed under the filling.

• Irreversible pulpitis. The nerve damage has crossed a line. The tooth needs a root canal to stay in your mouth. The American Association of Endodontists defines this by lingering pain to cold that lasts longer than 30 seconds.

• Cracked tooth under or near the filling. A hairline fracture that the filling did not address, or one that developed later from grinding. Very common in patients who clench.

• Galvanic response. A new metal filling touches an older metal restoration on the opposite arch, and the two metals produce a tiny electric current. Sharp, brief, weird.

• Recurrent decay. The margin of an older filling is leaking. New cavity forms under the restoration. Sweet foods and cold water find their way in.

How can I tell which type of pain I have?

You cannot diagnose yourself. But you can give us better information before you walk in.

Sharp pain only when you bite, gone the moment you release, usually points to a high bite or a cracked tooth. The American Association of Endodontists notes that cracked tooth syndrome classically presents as pain on biting and release, and it is a leading cause of persistent pain in a previously restored tooth.

Lingering cold sensitivity that hangs on for 30 seconds or more after you sip ice water suggests pulpitis. If it fades in a couple of seconds, the nerve is probably still healthy.

Throbbing when you lie down at night is a red flag. Blood pressure to the head increases when you are horizontal, and an inflamed pulp does not have room to swell. That is why the ache gets louder at 2 a.m.

Pain triggered by sweets almost always means a leaking margin or new decay. Sugar diffuses through the tiny gap and irritates the nerve.

A tooth that felt fine for three weeks and then began throbbing is telling you something changed.

Try this at home before you call: tap the tooth gently with the back of a fork. If it hurts to tap but not to bite soft food, the ligament around the root is inflamed. Note whether cold water gives a quick zing or a slow burn. Write down when the pain shows up. Bring that log with you.

When is post-filling pain a dental emergency?

Call the same day if you notice any of the following.

• Swelling of the gum, cheek, or under the jaw

• Fever alongside the tooth pain

• Pain that wakes you up at night or that requires around-the-clock ibuprofen or acetaminophen to control

• A visible fracture line, or a piece of the filling or tooth missing

• A bad taste that keeps coming back, which can signal drainage from an abscess

The CDC notes that untreated dental infection can spread to surrounding tissues and, in rare cases, cause serious complications requiring emergency care. Do not wait it out.

We keep space in the schedule Tuesday through Friday for urgent evaluations. A software engineer commuting off Highway 217 from Intel Jones Farm called us on a Wednesday morning about a filling that had been fine for a month and had started aching over the weekend. We saw him at 8:15 a.m., adjusted the bite in under ten minutes, and he made his 10 a.m. standup. Not every case is that simple. Many are.

What will your dentist do to fix it?

The treatment depends entirely on which cause is behind the pain.

Bite adjustment. If the filling is high, we use articulating paper to mark the exact spot and polish it down. Takes minutes. Journal of the American Dental Association literature on occlusal adjustment confirms this is the standard fix for a hyperoccluded restoration, and relief is usually immediate.

Replacement filling. A leaking margin or recurrent decay means we remove the old filling, clean out any new cavity, and place a fresh restoration. Sometimes with a protective liner if the new prep is deeper.

Root canal and crown. If the pulp is irreversibly inflamed, saving the tooth means removing the nerve, cleaning the canals, and protecting the tooth with a crown afterward. This sounds worse than it feels with modern techniques.

Crown or onlay for a cracked tooth. A fractured tooth needs full coverage to keep the crack from propagating down the root. A large filling cannot hold a cracked tooth together long-term.

We serve families across Aloha, Beaverton, and Hillsboro, and we know how tight schedules are for Nike and Intel employees. If your filling started hurting and you are not sure what to do, call us at (503) 259-8641. We will figure it out together.

Frequently Asked Questions

How long should sensitivity last after a new filling?

Cold sensitivity from a fresh composite filling should fade within two to four weeks. A quick zing from cold water is normal. Sharp pain that lingers longer than 30 seconds, or pain that gets worse rather than better after the first week, is not normal and should be evaluated.

Can a filling cause pain months later?

Yes. Late-onset pain from an old filling usually means one of three things: a hairline crack that developed over time, recurrent decay under the margin of the restoration, or pulp inflammation from a filling that was originally very deep. Any of these deserves a look, not a wait-and-see approach.

Is it normal for a filling to hurt when I bite down?

No. If the tooth hurts specifically when you close your teeth together or chew on that side, the filling is likely sitting slightly too high, or there is a crack in the tooth. Both are treatable, and a bite adjustment is often a five-minute visit.

Will a painful filling always need a root canal?

Not at all. Most post-filling pain is resolved with a simple bite adjustment or by replacing a leaking filling. Root canals are only needed when the nerve inside the tooth is irreversibly inflamed or infected. An exam and often an x-ray will tell us which category you are in.

Should I go to the ER for tooth pain after a filling?

The emergency room can manage pain and infection but cannot actually treat the tooth. Go to the ER only if you have facial swelling that affects breathing or swallowing, a high fever, or trauma involving injury beyond the tooth. Otherwise, call your dentist. We can usually see urgent cases the same day.

If a filling that felt fine has started giving you trouble, do not push through it. Call Line Dental Aloha at (503) 259-8641 and we will get you seen. Our office is at 18425 SW Alexander St, just off TV Highway.