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Have Lingering Hot or Cold After a Dental Filling? – 4 Ways to Avoid a Root Canal


In this blog, you will learn why teeth can be sensitive to either hot, cold or sweets after getting a dental filling or crown preparation, what that means, and 4 ways to avoid getting a root canal.


It is not unusual to experience sensitivity after getting a filling. Those hot and cold sensations mean different things depending on how deep the cavity was, the materials used and how the procedure was performed.  To begin with, you need to look at the anatomy of a tooth. You have a hard outer layer of enamel , sponge-like dentin, then the nerve.  The closer you get to the nerve, the more likely you will get a sensation, either hot or cold, later, after all the anesthetic is worn off.  If the pain or sensitivity becomes hard to bear, quite often a root canal will be suggested. Before deciding to go that route, ask your dentist about other options.

Tooth Sensitivity

The sponge-like layer of dentin consists of miles of tubules or tubes that microscopically connect to the central nerve of the tooth. If you penetrate the outer enamel layer, exposing those tubules, the nerve can react to anything sweet, hot or cold as pain or “sensitivity”. Some causes can include:

  1. A very deep cavity that gets close to the nerve
  2. Excess heat from the drill, caused by not using enough water to cool the process down
  3. Not using protective liners underneath the filling
  4. Use of caustic glues and chemicals when filling the tooth
  5. Improper technique in using tooth-colored fillings
  6. Open spaces between the filling material and the tooth
  7. Open margins on temporary or permanent crowns
  8. Exposed root surfaces
  9. Bite is not adjusted properly at time the restoration is placed
  10. Incompatible dental materials

4 Things You Can Do

1) Prevention

Composite resins, or tooth-colored fillings can irritate the nerve.  A lot of times cold sensation is caused by all the glues and acids that are used in placing these types of fillings. Another cause of the sensitivity is the bacteria that are trapped in the process.  Insist that the tooth be sterilized with either ozone, anti-microbial solutions or lasers before the filling is placed.

Another possibility is that the materials used by your dentist may be be incompatible with your immune system. There is a simple blood test available called the “Serum Biocompatibility Blood Test” which can determine your body’s immune response to over 5,000 dental materials. Therefore your dentist would know which materials to use for you that you have least reactivity to!

2) Get That Bite Adjusted

When you are numb, especially on the lower teeth, your muscles don’t work the same way.  So it is very possible that the bite could be off. As soon as you feel your bite is off, even after everything wears off, DON”T WAIT.  Head back to the dentist and get that bite adjusted. That alone could help with getting rid of the sensation. Sometimes you may need additional adjustments.

Another problem arising from an improper bite can be facial pain. Constant bite discrepancies cause your muscles to go into spasms and if not addressed, can lead to permanent TMJ problems. So get back in touch with your dentist if you feel your bite is not right. It will not go away by itself!

3) Sedative Filling

If the cold sensation continues even after adjusting the bite, ask your dentist to put in a sedative filling.  This can help calm the nerve and after a few months, the permanent filling can be placed. This may prevent the nerve from dying.

It may sound counterintuitive, but this process has been known to save a lot of teeth from getting a root canal. The dentist will remove the existing filling. A sedative filling will be placed and 3 months later, the sedative filling will be removed and replaced with a new filling. It is well worth the effort.

During that 3 month period, it is recommended you obtain the “Serum Biocompatibility Blood Test” to help your dentist decide what the new filling material would be best or you!

4) Hot Sensation

So what happens with hot.  Hot indicates that the nerve is dying.  What then?  Well, it is either extraction or root canal.  The suggestion is to consider getting the tooth extracted.  Dentistry today offers so many options for tooth replacement today that are more desirable than root canals.

Such options include:

  1. Implant
  2. Bridge
  3. Resin Bonded Retainer
  4. Removable Appliance

So it is our hope that you found this blog interesting and informative. Your oral health is a marker for your overall health. When it comes to dentistry, you are urged to do your own research and make “informed” decisions!

Andy & Vinny DiLorenzo

About Us

As holistic dentists, we've recommended products and services that supported our patients’ health for decades. In experiencing our own health challenges from mercury toxicity, we worked closely with many natural, alternative, and integrative health practitioners who aided our recovery as well as our patients’. We built this site to provide you with a simple-to-use, comprehensive, informational, and functional resource for your physical, emotional, and spiritual health & well-being.

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