How to Seal Exposed Dentin

Dentin functions as the tooth’s resilient interior, only becoming exposed when caries or cracks infiltrate the tough outer enamel. Whether from pathologies, like caries that create deep cavities or cracks in teeth, or from treatment preparation, sealing exposed dentin is essential to a long-lasting, asymptomatic restoration.

Symptoms associated with exposed dentin

Sensitivity: Dentin tubules that are not sealed will continue to move pulpal fluid, which causes sensitivity (Brannstrom M. The hydrodynamic theory of dentinal pain: sensation in preparations, caries, and the dentinal crack syndrome. Journal of Endodontics. 1986;12(10):453-457). While the tubules may partially seal themselves over time as a natural defense, sealing them with biomimetic techniques and dental bonding agents will eliminate post-operative sensitivity caused by exposed dentin.

Exposed dentin within this horizontal crack can lead to sensitivity. Case treating using the Six Lessons Approach by Dr. Davey Alleman, DMD.

Weak bonds: When exposed dentin is not properly conditioned (prepared for bonding), the exposed dentin and remaining collagen and hydroxyapatite result in lower bond strengths. Techniques including air abrasion and self-etch and total-etch conditioning allow a strong bond to form because pulpal fluid is not impeding the dental bonding agent from interacting with the dentin. The element of time maturation of the bond is Dr. David Alleman’s major insight to why bonding is weak in most protocols. He called this concept Decoupling With Time.

Dentin around this poorly bonded restoration may be exposed, which can lead to restoration failure, recurrent decay and cracks around the cavity.

How sealing exposed dentin eliminates post-operative sensitivity

Gaps under restorations are one of the main causes of post-operative sensitivity. As the dental composite shrinks during polymerization, it pulls away from the most difficult areas to bond to, which are usually under the restoration. This gap allows pulpal fluid to continue to flow through the exposed dentinal tubules underneath. Sealing exposed dentin eliminates this cause of post-operative sensitivity.

These photos show exposed dentin, the process of sealing dentin and the final sealed dentin that is ready for bonding to the enamel replacement. Six Lessons Approach case by Dr. Davey Alleman, DMD.

Immediate dentin sealing: protocols for sealing exposed dentin

Immediate dentin sealing uses dental bonding agents to seal dentin at a bond strength that mimics the strength of the dentin-enamel junction (30-50 MPa). When researching ways to eliminate post-operative sensitivity for his patients, Dr. David Alleman found immediate dentin sealing to be a key step in achieving asymptomatic restorations. In addition to researching advancements in specific dental bonding agents and their key bonding molecules, his contributions, including the hierarchy of bondability and decoupling with time, offer techniques that ensure predictability in advanced adhesive restorations. These steps are part of Lesson 3 and 4 of his Six Lessons Approach to Biomimetic Restorative Dentistry, a complete set of protocols dentists can follow for a successful biomimetic restoration.

Resin coating

While less well known than immediate dentin sealing, resin coating is an equally essential step in sealing exposed dentin. Using flowable composite, resin coating creates a secure bond to the tooth, so any failures occur in the restorative material above the resin coating rather than stressing the healthy tooth structure below. Pairing immediate dentin sealing with resin coating following the Six Lessons Approach protocols has been shown to eliminate post operative sensitivity, allow vital teeth with deep caries to heal and avoid endodontic treatment and create restorations that stay bonded for over 20 years and counting.

Immediate dentin sealing and resin coating will seal decay that is too close to the pulp to safely remove. In vital teeth, this gives the pulp a chance to heal and prevent endodontic treatment. Case by Dr. Davey Alleman, DMD.

Protecting pulp vitality with immediate dentin sealing and resin coating

When Dr. David Alleman was researching ways to eliminate post-operative sensitivity, an unexpected positive outcome was a steep reduction in the need for root canal therapy. Teeth that tested vital, even with deep caries or pulp exposures, were given a chance to heal. The ionic and micromechanical bonds of the immediate dentin sealing and resin coating created a gap too small for bacteria to enter, so remaining bacteria near the pulp went dormant and new bacteria could not reinfect the pulp. Some doctors using Dr. David Alleman’s Six Lessons Approach have seen up to a 90% decrease in the need for endodontic treatment, with teeth remaining vital for years and decades after treatment.

Learn more about immediate dentin sealing in Dr. David Alleman’s Six Lessons Approach Podcast episode.

As one of the top causes of post operative sensitivity, learning how to predictably seal exposed dentin in a long-lasting way greatly improves outcomes for patients and job satisfaction for dentists. While the protocols require more advanced techniques than a standard bulk fill composite, the increased longevity of the outcomes is worth the extra time and training.

To learn more about the advanced adhesive techniques of biomimetic dentistry that seal exposed dentin long-term, join us for our upcoming Alleman Center dental training programs.