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Pediatric  Dental  Health

May 22, 2004


Children want nice looking teeth, as well as an attractive smile. They can be very self-conscious about dental stains and discolorations. Tooth bleaching and esthetic dentistry is now available to treat these problems in children and adolescents. This article will discuss the causes of stained teeth in children, and what can be done about it.

Tooth discoloration may be classified as either extrinsic (external) or intrinsic (internal). Extrinsic discoloration may be caused by food, beverages, or medications. Intrinsic discoloration may be sub-classified into superficial enamel discoloration, and deep internal discoloration.

          External tooth surface discoloration can be caused by either direct or indirect staining. These external stains can usually be removed by a dental cleaning.

  • Direct external staining is caused by organic compounds in food and drink which are incorporated into the tooth pellicle (tooth film) An example of direct staining is the coffee stain.
  • Indirect external staining is associated with cationic antiseptics ( such as chlorhexidine) and metal salts (such as iron).
  • Non-metallic indirect stains can be caused by quarternary ammonium compounds such as chlorhexidine rinses.
  • Metallic indirect stains can be caused by metallic salts, such as iron supplements.

    Factors known to cause intrinsic discoloration include:
    metabolic disorders, systemic syndromes, dentin defects, tetracycline stains, fluorosis, trauma, and enamel hypoplasia.

    The following list eumerates various causes of dental stains:
  • Alkaptonuria causes a brown discoloration of the teeth.
  • Congenital erythropoietic porphyria causes a red-brown discoloration.
  • Congenital hyperbilirubinemia will cause a yellow-green discoloration due to elevated levels of biliverdin in the blood.
  • Systemic syndromes often cause enamel hypoplasia (inadequate development) and pitting of the enamel.
  • In Dentinogenesis imperfecta II, both the primary and permanent teeth are affected. They are opalescent when trans-illuminated, and have a brown or bluish color.
  • In Dentinogenesis imperfecta I, associated with osteogenesis imperfecta IB, the teeth are also opalescent, but the esthetic problem may not be as severe as in Dentinogenesis imperfecta I.
  • In Dentinogenesis imperfecta III, the teeth are also opalescent.
  • In dentinal dysplasia type I, the primary and secondary teeth may have an amber translucency.
  • In dentinal dysplasia type II, a brown discoloration is sometimes observed.
  • With tetracycline staining, the dentin and enamel are stained a brown-gray color. The most critical time to avoid taking tetracyclines is from 4 months in-utero until 7 years of age.
  • In fluorosis, the resulting dental discoloration ranges from chalky white to a brown-black appearance. Fluorosis is caused by excessive fluoride intake.
  • Trauma may cause tooth discoloration. The cause of this is capillary breakage inside of the tooth, which allows hemosiderin to enter to dentinal tubules.
  • In traumatized primary teeth, the color may become very dark due to the accumulation of hemoglobin products. Primary teeth with a gray-black color often need endodontic treatement.
  • In cases of enamel hypoplasia, the development of the tooth germ was disturbed by trauma, infection, or systemic disturbance.
  • Amelogenesis imperfecta (with 14 subtypes) will cause discolorations which vary from “snow-capped” enamel to yellow-brown enamel.

    Tooth bleaching can be a good first step for treating certain kinds of dental staining problems. It is usually reserved for a mild, uniform, discoloration of the teeth. The bleaching is time and dose related. The bleach oxidizes the organic pigments in the tooth, breaking down the long-chain stain molecules.

    In-Office Vital Bleaching Hydrogen peroxide 30-38% is applied directly on the teeth. A special light may also be used to accelerate the whitening process. When there are only a few discolored teeth. Temporary tooth sensitivity. Gingival irritation.
    Overnight Vital Bleaching Carbamide peroxide 10% is used in a custom tray. When there are multiple discolored teeth. Effective for yellow, orange, or light-brown discoloration in primary and permanent teeth. Temporary tooth sensitivity in 55-75% of cases.
    Whitening Strips Hydrogen peroxide 6.5% or 14% is delivered via a thin, flexible polyethylene strip. Multiple discolored teeth. Works slightly better on upper than lower teeth. Temporary tooth sensitivity and oral tissue irritation.

    In-office vital bleaching produces immediate results. For those patients who urgently need whiter teeth, and for whom cost is not an issue, in-office bleaching may be the answer.

    The technique is as follows:
  • First, a protective gel or rubber dam is applied over the gum tissue to protect them.
  • Then, the in-office bleaching agent is applied directly to the teeth. The in-office products contain 15 to 35 percent hydrogen peroxide.
  • The whitening process is accelerated with a special heat or laser light that is directed at the coated teeth.

    Home bleaching is becoming increasingly popular. It is a process whereby patients apply a peroxide gel to their teeth for the purpose of whitening them. Dentist–prescribed overnight bleaching is the most commonly used technique to whiten teeth. The cost is reasonable, and the results are predictable.

    The major advantages include: simplicity, safety of the materials, and a relatively short time spent in the dental office. The active ingredient of the gel is usually carbamide peroxide or hydrogen peroxide.

    The bleaching mechanism involves the decomposition of unstable peroxides into unstable free radicals which then break down organic pigmented molecules. Carbamide peroxide decomposes into hydrogen peroxide and urea. The urea is safely eliminated by the kidneys. The hydrogen peroxide opens the pigmented carbon ring compounds, and converts them into chains which are lighter in color. This results in fewer pigmented molecules in the enamel.

    The technique is as follows:
  • The dentist takes an impression of the patient’s teeth, and makes a custom tray (a mouthpiece) which fits the teeth exactly. The custom-made tray minimizes the bleaching gel’s contact with the gum tissue. The bleaching tray should be made of soft material and should be scalloped so that it does not touch the gingival or touch soft tissue.
  • The 10% carbamide peroxide gel is placed in the custom tray by the patient at home. The custom tray resembles a mouth guard. Patients wear the whitening tray twice a day for 30 minutes to 2 hours.

    Treatment times are as short as 2 weeks. A whitening effect will be seen after daily bleaching within two to six weeks. The shade change will be stable for 6 to 12 months, or longer. All patient should return to the dental office after one week for a post-operative check-up appointment.

    Tooth sensitivity occurs in 55 to 75% of cases. The treatment for dental sensitivity is a 2% neutral sodium fluoride gel, applied with a tray after each bleaching session, which reduces tooth sensitivity during the whitening procedure. Some patients will have to alternate “whitening days” with self-administered neutral sodium "fluoride days." The patients with sensitivity will eventually have successful outcomes, but the whitening process may take a few days longer.

    Young patients can also benefit from this technique. Young patients with yellow or orange fluorosis stains can often be successfully treated with overnight vital bleaching. Darkened primary teeth may also benefit from 10% carbamide peroxide application. Note that any whitening procedure should be done at least two weeks prior to the placement of composite fillings or veneers. This is because dental bleaching can affect the bond strength of subsequent composite restorations.

    Rapid innovations in vital bleaching have increased the popularity of at-home whitening. The whitening strip is a novel bleaching system which uses a flexible polyethylene strip to deliver a hydrogen peroxide bleaching gel to the front teeth. The effectiveness and safety of bleaching strips which deliver 6.5% hydrogen peroxide has been established in numerous randomized clinical trials. Children as young as 10 years of age may use the 6.5% hydrogen peroxide whitening strips.

    In 2003, an improved bleaching strip was introduced which contains 14% hydrogen peroxide (Crest® Whitestrips® Supreme). The main advantage of the 14% hydrogen peroxide strip is more effective whitening. The peroxide molecules diffuse through the enamel down to the dentinoenamel junction, where stains are oxidized, resulting in whiter teeth. These strips can be applied twice daily, for 30 minutes, for 14 days. Initial results are seen in a few days and final results persist for about 4 months. Tooth sensitivity and oral tissue irritation do occur, but resolve during or after treatment.

    Deep internal dental stains are due to:
    pulpal trauma, fluorosis, hypocalcification, tetracycline, hereditary opalescent dentin, or mottled enamel – and require more complex treatment.
  • Brown discoloration caused by fluorosis is an example of enamel dysmineralization – a defect in enamel mineral content. The white enamel “snowcaping” seen in some upper incisors is another example of enamel dysmineralization.
  • Other enamel discolorations are acquired – such as the enamel decalcifications seen around orthodontic brackets.
  • A third category of discoloration are the deep dentinal stains seen in children with tetracycline staining. Tetracycline stains are impossible to remove with simple bleaching techniques.

    Etch, Bleach, and Seal technique Phosphoric acid 37%, sodium hypochlorite 5%, and clear sealant. Shallow yellow-brown enamel discolorations. Does not remove stains which are deeper than a few tenths of a millimeter.
    Microabrasion with Dental Bleaching Abrasive slurry consisting of silicon carbide and hydrochloric acid 11%. Isolated brown or white discolorations with shallow depth. May not be able to remove the stain completely.
    Composite Veneers Dental composite. Deep tetracycline stains. A layer of enamel must first be removed from the surface of the tooth.

    Yellow-brown enamel discolorations can be caused by uptake of organic material into hypomineralized enamel, or by retention of enamel matrix proteins.

    Bleaching of yellow-brown hypomineralized discolorations may be accomplished using 5% sodium hypochlorite (household bleach). This simple and conservative technique should be used first for treatment of deep internal stains in young permanent incisors.

    To bleach the teeth using this conservative technique:
  • The teeth are cleaned with flour of pumice and a rubber cup.
  • The teeth are isolated with a rubber dam and ligature.
  • The enamel surfaces are etched for 60 (sixty) seconds with 37% phosphoric acid – and then rinsed.
  • Sodium hypochlorite 5% is then applied to the teeth continuously for 10 minutes with a cotton swab – keeping the tooth surfaces moist with the bleach.
  • The etching, rinsing, and bleaching steps are repeated if there is inadequate color change after the initial 10 minute application.
  • The treated teeth then need to be etched, rinsed, dried, and coated with a bonding agent or a clear sealant - which is then cured. This is done to prevent new organic material from re-staining the enamel.

    Enamel microabrasion is useful for removing certain enamel dysmineralization defects and decalcification lesions. It is only effective if the defect is located in the outer few tenths of a millimeter of enamel. This technique is therefore well suited for the removal of white spots as well as dysmineralization defects (discolorations).

    Parents and patients need to be told beforehand that there is a chance the discoloration might be too deep to correct with microabrasion. This technique is not successful in cases of severe fluorosis. Microabrasion also has the disadvantage of requiring the removal of enamel from the tooth.

    The microabrasion technique, with bleaching, is as follows:
  • Pretreatment photos should be taken.
  • A rubber dam is applied to isolate the affected teeth. There is no need for local anesthetic.
  • The patient needs to wear protective glasses.
  • A fine diamond bur is used to initiate the “microreduction” of the enamel discoloration.
  • PREMA® Compound is applied to the stained areas using a special synthetic rubber tip, in a high torque - low rpm handpiece. PREMA® Compound contains 11% hydrochloric acid, as well as silicon carbide. Progress should be evaluated every minute.
  • After the discolored enamel has been removed, a 1.1% neutral sodium fluoride gel is applied to the enamel for four minutes.
  • An alginate impression is then taken of the upper teeth, and a stone cast is then made from the impression. A soft custom .035 inch vinyl tray is then made on the stone mode. Optional facial reservoirs can be added to the tray.
  • Once the tray is ready to give to the patient, a small amount of carbamide peroxide bleaching solution is applied into the facial area of the tray, and the tray is then worn for 60 minutes per day by the child.
  • At the end of the three-week bleaching period, the patient applies a 1.1% neutral sodium fluoride solution inside of the tray. This “fluoride tray” is then worn 10 minutes per day for one week by the patient.

    If the stain on the tooth is deeper than a few tenths of a millimeter, the best treatment may be a composite veneer. Composite veneers may be needed in cases of moderate or severe fluorosis.

    A small, partial veneer may be used to restore a well-circumscribed enamel defect. If the entire tooth is affected by deep staining, a full composite veneer may be needed - which will cover the entire facial surface of the tooth.

    An article in Journal of Contemporary Dental Practice discusses the new 14% hydrogen peroxide whitening strips made by The Procter & Gamble Company. The article discusses the research designs and the clinical trails which verified the safety and efficacy of Crest® Whitestrips® Supreme.

    Gerlach RW, Barker ML. Professional vital bleaching using a thin and concentrated peroxide gel on whitening strips: an integrated clinical summary. Journal of Contemporary Dental Practice, 2004 February; 5(1)

    Copyright ©2004 Daniel Ravel DDS, FAAPD

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