What Causes Sensitive Teeth?
Sensitivity is encountered whenever odontoblasts and there processes are stimulated. The outer covering of tooth I.e. the enamel is the strongest substance in the body and protects the crowns of healthy teeth and cementum protects the tooth root under the gum line. Under enamel and cementum is the dentine. This dentine contains dentinal tubules. When dentine loses its outer covering that is the enamel, the tubules become fluid filled channels from the cut surface directly to the pulp. This stimulates the nerves and cells inside the tooth and leads to hypersensitivity.
Various factors that cause teeth sensitivity have been noticed. Hard tooth brushing leads to severe abrasions caused by wearing of enamel mostly in the cervical portion of neck of teeth. Also teeth can be abraded by improper use of dental instruments. Exposure of root portion of teeth due to gingival recession can cause sensitivity. Tooth decay near the gum line can also cause sensitivity as cementum can be abraded very easily as compared to enamel hence dentine gets exposed fast when cementum is exposed hence the sensitivity. Chipped or broken teeth may wear the enamel and expose dentin. Tooth sensitivity is highest between 25 – 20 years of age. Long term use of certain mouthwashes may cause sensitivity as they contain acids which may worsen tooth sensitivity if already the dentin is exposed. Regular consumption of foods with a high acid content like citrus fruits , tomatoes,pickles,colas, aerated drinks can cause enamel erosion hence lead to dentin exposure thus increased sensitivity. Recent routine dental procedures like teeth cleaning root planning, crown placement and tooth restoration may cause temporary sensitivity. This sensitivity may disappear within 4-6 weeks. Sensitive teeth may cause pain while eating cold and hot stuff and even while brushing and flossing.
Teeth Whitening Procedures and Sensitive Teeth
Tooth whitening is a cosmetic dental procedure which is done to improve the overall appearance of the tooth. But it is not safe or effective for everyone. Sensitive teeth can be considered a reason for that.
Different causes of sensitive teeth influence on the whitening procedures in a different manner. The main root cause of sensitivity should be found out first and proper treatment should be given to reduce it. As bleaching procedures themselves may cause sensitivity as a side effect proper precautions and treatment should be given to a patient before starting the bleaching procedure for sensitive teeth. For example, if sensitivity is caused by hard brushing, it would be better not to bleach your teeth in this period of time because enamel is worn down. If root surface is exposed as a result of gingival recession this will cause hindrance in bleaching and may lead to periodontal problems. So proper restorative procedures should be carried out in such a situation. Also if the tooth is cracked or chipped off even then it should be restored first and only then the bleaching procedures should be carried.
Before staring with the bleaching procedures for sensitive teeth, steps should e carried out to reduce the sensitivity as bleaching itself may cause increased sensitivity
Treatment Plan for a Patient with History Of Sensitive Teeth
Methods to Reduce the Pre-Existing Sensitivity:
2 weeks prior to commencing the bleaching procedures the patient can brush regularly with desensitizing toothpaste containing either 2 hydoxyethylmethacrylate or potassium nitrate.
Neutral fluoride in the bleaching tray can be applied to the teeth 3 weeks prior to commencing the treatment to reduce sensitivity.
A patient can begin to wear the empty tray at night for a few nights then slowly increase the wear time from 1 hour per day for the first week to overnight on second week.
Good oral hygiene should be maintained. Proper brushing and flossing should be continued but with a soft bristled brush and desensitizing toothpaste. A soft bristled toothbrush results in less abrasion to the tooth surface and less irritation to the gums. A desensitizing tooth paste containing either 2 hydroxy ethyl methacrylate or potassium nitrate should be used. Most tooth desensitizers treat pain by blocking the dentinal tubules thus preventing excitation of tooth nerves. 2 hydroxy ethyl methacrylate blocks the dentinal tubules within one day thereby relieving pain in just one day. Potassium nitrate 5% is also used which can take up to 2 weeks to reduce pain. It reduces sensitivity via thermal interference that prevents the pulpal sensory nerves from repolarisation after initial depolarization. Potassium nitrate has a numbing effect that may reduce the discomfort. Sodium fluoride gels can be given to the patient as well to reduce sensitivity as fluoride blocks the exposed tubules. This restricts the ingress of fluids according to hydrodynamic theory of pain. Popular desensitizers used are ULTRA EZ desensitizing gel and syringe, ORAGEL etc.
Modifications Done To the Normal Home Bleaching Techniques for Sensitive Teeth:
Ensure that all the excess material is removed.
Patient can use a bleaching gel with a lower concentration. Instead of the using 20% carbamide peroxide gel patient can use 15% 10% or 5 % concentration of carbamide peroxide gel.
Patient can reduce daily treatment time and bleach every alternate night.
Patient should not replenish the bleaching solution more than once.
Patient can use less bleaching material in the tray and not overfill it to avoid extrusion of material.
Methods Used For Bleaching Sensitive Teeth:
Dentist's Chair Side Bleaching
In this bleaching method, the dentist uses a bleaching agent that contains only 10% of hydrogen peroxide. The low peroxide content is just enough to whiten the teeth and at the same time prevent the teeth from becoming more sensitive. During the procedure, the dentist will apply a rubber shield or protective gel in order to protect the overly sensitive gums and tissues. He will then apply the 10% whitening solution on the teeth. He may even speed up the whitening process by shining a light onto the gel applied teeth. The duration of this teeth whitening method takes about 30 minutes to an hour to complete.
In this method of teeth whitening procedure, the dentist makes a mouthpiece tray after taking the impression of one's teeth. This is also called a customized mouth guard and it fits perfectly onto the teeth. A gel containing carbamide peroxide is added to the tray and the mouthpiece is worn by the patient. The in-office bleaching method last for almost two weeks.
Also CREST WHITE STRIPS are also available which have a minimum concentration of hydrogen peroxide. The crest classic strip contains about 6 % hydrogen peroxide and the crest professional strip has about 6.5% hydrogen peroxide which can be used easily and effectively for sensitive teeth. But it has to be used carefully as its overuse may cause extreme sensitivity. In case of sensitive teeth while using whitening strips, make sure you reduce the time (by half) when the bleaching agent is placed onto your teeth. Appropriation of using whitening gels, whitening toothpastes, whitening strips for sensitive teeth, whitening teeth rinse etc. will depend on the level of sensitivity of one's teeth.
So bleaching the sensitive teeth is not at all difficult provided proper care is being taken about the necessary precautions and treatment planning.
Frequently Asked Questions
How Does Tooth Whitening Work?
Teeth come in many colors. Some have a yellowish tone, some orange, some brown and some gray. The outside of your teeth, the enamel, is clear. The color that you see show through from the tooth structure under the enamel called the dentin.
To whiten teeth a peroxide-type chemical is applied and it goes through the enamel into the dentin. There are different ways this chemical can be applied. Both the character of your teeth and the whitening technique used determines how long it will take for your teeth to whiten, how white your teeth will get, and how long the whiter color will last.
What Are The Agents That Can Help Reducing Sensitivity?
Various desensitizing agents containing potassium nitrate, 2 hydroxyethylmethacrylate and sodium fluoride gels are available in the market that can reduce sensitivity to a greater extent. . Popular desensitizers used are ULTRA EZ desensitizing gel and syringe, ORAGEL etc.
What Causes Sensitivity In Teeth?
Tooth sensitivity occurs when the underlying layer of your teeth – the dentin – becomes exposed as a result of receding gum tissue (the protective blanket that covers the tooth roots). The roots, which are not covered by hard enamel, contain thousands of tiny tubules leading to the tooth's never center (the pulp). These dentinal tubules (or channels) allow the stimuli – for example, the hot, cold, or sweet food – to reach the nerve in your tooth, which results in the pain you feel.