Why do you have to be so [dentin hyper]sensitive?

Dentin hypersensitivity is the sharp, shooting pain arising from the exposed dentin in response to stimuli typically thermal, chemical, tactile or osmotic and which cannot be ascribed to any other form of dental defect or pathology. The symptoms of pain can be extremely intense and continue for extended periods of time. This could impact a person’s daily life. A wide variety of materials and methods have been introduced to treat dentin hypersensitivity. Aside from toothpastes that are marketed to help with sensitivity, there are other methods to treat dentin hypersensitivity that many people may not know about. Following are some of those alternative methods:

1. Laser treatment: CO2 laser and Nd-YAG laser irradiation has the ability to occlude the dentinal tubules by coagulation and precipitation of proteins in the tubules or by the energy radiating from the laser affecting the neural activity. Use of Nd-YAG lasers in conjunction with sodium fluoride varnish shows the best results. However, use of CO2 lasers is still experimental and needs further scientific investigations.

2. Gene therapy: Gene therapy refers to treatment of sensory nerves. This decreases the production of nerve growth factor by pulpal fibroblasts near the lesion, thereby decreases the sensitivity.

3. Fluoride Iontophoresis: Iontophoresis desensitizes the dentin by influencing the ionic motion with electric current. This is used in conjunction with sodium fluoride application. However, symptoms were known to recur after few months though it gives the immediate relief.

4. Fluoride releasing device: Use of fluoride releasing devices is a fast, inexpensive and a painless method suitable for decreasing the sensitivity. Sodium fluoride is encased in an acrylic polymer or glass devices which releases fluoride slowly in the mouth and is usually bonded to the molars with adhesive resin.

5. Patients with sensitivity or gingival recession experience more pain with the use of various bleaching products. Application of 5% potassium nitrate before the use of bleaching products may alleviate the pain. Amorphous calcium phosphate is also found to be efficient.

6. Use of non-polymerizing products like varnishes (Copal varnishes, Flouride varnishes), primers with HEMA (Hydroxylethyl Methacrylate), Conventional GIC, resin re-inforced GIC etc.

7. Occlusal adjustments for tooth associated with cervical abfraction lesions, crown restorations etc.

8. Sometimes periodontal flap surgeries including GTR, connective tissue grafts are also done to reduce the dentin hypersensitivity caused mainly due to sub gingival restorations or crowns which attract the plaque that affects the biological width of periodontal tissues.

9. One of the recent studies also shows that multiple applications of GC tooth Mousse and a single application of Gluma Desensitizer had a more lasting effect.

As mentioned in the Clinician’s Guide to the Diagnosis and Management of Tooth Sensitivity, many innovations have been taking place in providing treatment options for sensitivity. For example, some synthetic polymers (poly dopamine methacrylamide – comethoxyethyl acrylate) which have the properties of the glue and the ability to adhere to the wet surfaces would be the ideal carrier for a dentinal tubule blocking agent. Synthesized fluorohydroxyapaptite crystals are added as the filler for the polymer. When viewed under a Scanning Electron Microscope, blocking of dentinal tubules by around 80% is observed. When applied on the dentinal surface, these materials have the ability to form a mineralized layer by releasing calcium, phosphate and fluoride, which helps in providing a long-lasting effect. This material was tested in wide ranges of intra-oral PH from acidic to basic, which yielded the best results in forming the mineralized layer on the exposed dentinal surface. This polymer is known to be bioactive and nontoxic, helps in providing the permanent relief. However, further studies have yet to be done.

Advanced studies are being conducted on the Nano- Fluorapatite technology and introduced flexible nanocrystal laminate with the polymer called Eudragit. This material can be cut into any size or shape. This flexibility allows the polymer to be molded on the curved surfaces of the tooth easily. This laminate is molded and bonded to the exposed dentinal surface with self-etch adhesive resin. The advantage of using this material is it helps in direct contact of the crystals to the dentinal surface and integrates into dentin, which perhaps provides immediate relief.

Dendrimers, which are artificial proteins, are the smallest nanoparticles (2 nm to 10-15nm) and they have antimicrobial and anti-inflammatory properties. Inclusion of these dendrimers into the dentinal tubule blocking agents helps in reducing the inflammation of the pulp under the dentin and this may help in providing long lasting relief.

Statistics reveal that at least one in four adults are affected by dentin hypersensitivity. Moreover, patients are tired of using a wide variety of products for reducing the sensitivity since no universal gold standard treatment has been introduced. Hopefully, in the near future, all the advanced studies being conducted yield success in finding a permanent remedy for treating sensitivity and providing immediate and long-lasting relief.

~Sindhu Rondla, predental