Dental patients are often alarmed when symptoms of discomfort emerge after having a tooth filled. They experience shockwaves of pain when biting/chewing food or drinking abnormally hot or cold beverages near the treated tooth. Fortunately, this is usually a normal part of the recovery process. The decayed tooth undergoes trauma as damaged structure is removed in preparation for filling. This trauma may be mild or more serve depending on the extent of decay and even the choice of restorative material, among other factors.
Tooth Sensitivity is Normal After a Filling
When a tooth undergoes preparation for a filling, a disturbance erupts in the dentin layer of the tooth, compromised of a network of fluid-filled tubes. When this fluid is displaced due to rapid changes in temperature or pressure, both common during tooth drilling, the nerve endings inside the tooth become excited, producing the sensation of pain. In a healthy tooth, the outermost protective layer known as the enamel helps guard against everyday sensitivity. Decay can eat through the enamel and other underlying structures, amplifying tooth sensitivity. When the decay is localized in the enamel, the dentist can remove the decay while minimizing disturbance to the dentin. However, in the case of a deep cavity, the likelihood of post-treatment sensitivity is far greater.
Filling Material Matters
Filling materials also play an important role in post-operative sensitivity. White dental fillings form a chemical bond with the existing tooth structure, ensuring maximum life longevity of the restoration. This strong bond also contributes to tooth pain after a filling. The composite material contracts as it cures, placing stress on the tooth and thus activating nerve receptors. Many dentists have adopted techniques to minimize this sensitivity, including lining the dentin prior to filling placement or simply gradually curing the filling material. Amalgam (metal) fillings present other challenges due to microleakage, which can occur immediately after placement of the filling due to its delayed self-sealing properties. Cold beverages or foods can penetrate the margins of recently placed silver fillings causing a nerve response within the tooth.
Wait Two Weeks
In the large majority of cases, tooth pain gradually subsides within a week or two. In the event that it persists or even becomes worse, something may be running afoul. A few things may be to blame:
• Poor biting relationship due to high spots on the filling
• Improper placement of the restoration causing leakage (ability for cavity-causing bacteria to re-enter the tooth structure)
• Aggressive finishing of composite restoration causing leakage
• Untread underlying decay
• Undiagnosed problems like tooth cracks
The first point is relatively common. After a tooth your tooth is filled, the dentist has you bite down on articulating paper to mark pressure points on the tooth from opposing surfaces. You are also asked to confirm that the biting relationship feels “right,” which is difficult to do when you are anesthesized. The dentist can trim the high points on the filling to eliminate the excess pressure.
Improper placement and finalization of a filling can also contribute to tooth pain. A filling that has been cured too much can shrink, causing bond integrity to diminish and thus increasing the risk for bacterial re-entry. A filling that has been under-cured can also compromise bond strength and the physical integrity of the restoration itself. Aggressive fine-tuning of a cured filling alters its chemical properties leading to a weaker restoration and can cause irritation to the pulp from the heat generated.
Active tooth decay under the restoration can infiltrate the pulp chamber, causing inflammation and infection. Furthermore, restorations that are bonded to infected tissue are prone to leakage. Undiagnosed problems at the time of exam may also be to blame for the ongoing sensitivity. Tooth chips and cracks are two common examples.
Report Persistent Symptoms to Your Dentist
It is very important that you report recurring bouts of tooth pain after a filling to your dentist. Minor adjustments may need to be rendered on the filling or a new restoration may have to be put in place. It is never a good idea to potentially let tooth decay go unabated, so be prompt in scheduling your appointment.
Porto I. Post-operative sensitivity in direct resin composite restorations: clinical practice guidelines. Ind Jour Rest Dent. 2012; 1:1-12. https://www.researchgate.net/publication/235977564_Post-operative_sensitivity_on_direct_resin_composite_restorations_clinical_practice_guidelines. Accessed February 11, 2018.
Al-Omari QD, Al-Omari WM, Omar R. Factors associated with postoperative sensitivity of amalgam restorations. J Ir Dent Assoc. 2009; 55(2):87-91. http://www.lenus.ie/hse/bitstream/10147/235774/1/FactorsAssAprilMay09.pdf. Accessed February 11, 2018.