Expert: Lawrence Spindel DDS, www.lspindeldds.com - 11/16/2008

Question
Dear dr Spindel,
       I recently lost a filling in my lower wisdom tooth for the second time. My dentist told me that I would lose it soon and than we would talk. This is my second filling in that tooth in three years. I feel I have very good oral hygiene and I am a little perplexed as to why I keep losing this filling in this tooth. I was going to wait till after the new year to make an appointment with my dentist but I seem to be having jaw pain now . Why do you think I keep losing fillings in this tooth?

Thanks for your time and advice
Christina

Answer
Dear Christina,

Without actually examining you, I am not in position to determine why you are loosing your filling, I will attempt to give you some general information that maybe helpful.

Wisdom teeth are sometimes more difficult to place filling in, since they are very far back in the mouth and often the access for the dentist is not ideal.  Often the cavities in these teeth are large and not perfect for restoring with a filling.  Dentists are sometimes not as likely to suggest crowning wisdom teeth and may suggest extraction as an alternative.

I am assuming that your fillings were composite resin material.  Although, these fillings should last for an average of five to 15, Some last much longer. If your filling keeps coming out something involved is not ideal.

Possibly, your tooth is not a good candidate for a filling, but should have a crown or onlay placed. Some teeth, that commonly lose their fillings, are 'over filled'. When examining these teeth in my practice, I find that These teeth have very large bonded fillings and not much tooth structure to hold the fillings. Bonded fillings are retained better if they have sufficient retentive walls and enamel surfaces to help retain the composite material.  If there isn't sufficient tooth structure, then fillings can fail.

Often teeth that have very large fillings have a high amount of dentinal surfaces in proportion to enamel surfaces.  Bonding is better to enamel than to dentin. If a filling is 'wide' and takes up most of the tooth this can increase the likelihood of failure from breakage or debonding.

These teeth usually should not be filled, but should have a crown placed.  Crowns cover 360 degrees of the tooth and can protect the remaining tooth structure.

Another reason that fillings fail prematurely, would be technical short comings in the technique used.  Bonded fillings should be placed in a moisture controlled environment and must not get saliva on them while the filling is being placed. Wisdom teeth can be especially challenging when it comes to isolation from oral fluids. A filling can be compromised during its placement if it gets contaminated before it has set by the bonding light.

I would ask your dentist to explain why your filling has come out and what should be done. If you are not satisfied with the answer, do not be embarrassed about getting a second opinion from another dentist.

I hope I have answered your question and please feel free to contact me with future dental questions.