Seminar on

Tooth discoloration and its management

By:Aditi ChandraMDS-12Department of Conservative Dentistry and EndodonticsSubharti Dental College

TOOTH DISCOLOURATION AND ITS MANAGEMENTINTRODUCTION Discoloration of the tooth is one of the most frequent reasons why a patient seeks dental care. Tooth is usually esthetically displeasing and psychologically traumatizing. An understanding of the etiology of tooth discoloration is important to a dentist in order to make the correct diagnosis. The knowledge of the cause of discoloration will also help the dental practitioner to explain the exact nature of the condition to the patient. In some instances, the mechanism of staining may have an effect on the outcome of treatment and influence the treatment options offered by the dentist to the patients.

DEFINITION Tooth discolouration is defined as any change in the hue, colour, or translucency of a tooth due to any cause; restorative filling material, drugs(both topical and systemic), pulpal necrosis, or hemorrhage may be responsible. (Ingle)

ETIOLOGYAccording to Ingle

Dentist related causesPatient related causes

EXTRINSIC STAINSFeinman et al. in 1987, described extrinsic discolouration as that occuring when an agent or stain damages the enamel surface of teeth. Extrinsic staining can easily be removed by a normal prophylactic cleaning.

Intrinsic stainsIntrinsic staining is defined as endogenous staining that has been incorporated into the tooth matrix and thus cannot be removed by prophylaxis.

Pulp Tissue RemnantsTissue remaining in the pulp chamber disintegrates and cause discoloration. Pulp horns must always be included in the access cavity to ensure removal of pulpal remnants. Intracoronal bleaching in these cases is usually successful.AgeIn elderly patients, color changes in the crown occur physiologically, a result of excessive dentin apposition,thinning of the enamel and optical changes. Food and beverages also have a cumulative discoloration effect. These become more pronounced in the elderly, owing to the inevitable cracking, crazing, and incisal wear of enamel and underlying dentin. Bleaching can be successfully done for many types of discolorations in elderly patients.

Dentin HypercalcificationMost frequently seen in anterior teeth. It is a pulpal response to trauma, characterised by rapid deposition of hard tissue within the root canal space. Traumatic injuries lead to temporary disruption of blood supply Destruction of odontoblasts which are replaced by undifferentiated mesenchymal cells which rapidly form irregular dentin. The translucency of the crowns of such teeth gradually decreases, giving rise to a yellowish or yellow brown discoloration. Extracoronal bleaching may be attempted first. If unsuccessful, alternative approaches like laminates ,veneers etc can be given.Tooth formation defectsDiscoloration may result from developmental defects during enamel and dentin formation.

HypoplasticHypocalcific

Enamel hypocalcification: Distinct brownish or whitish area, commonly found on the facial aspect of affected crowns. The enamel is well formed with an intact surface.Enamel hypoplasia : Condition may be hereditary, as in amelogenesis imperfecta, or a result of environmental factors such as infections, tumors, or trauma. Disturbance of the developing tooth germ may also occur in a large number of fetal or maternal conditions eg; maternal vitamin D deficiency, rubella infection, drug intake during pregnancy and in paediatric hypocalcaemic conditions. Enamel formation, the matrix is altered and does not mineralize. There may be pitting or grooving which predisposes to extrinsic staining of the enamel in the region of tooth disturbed, often then becoming internalised. Bleaching effect may not be permanent depending on the severity and extent of hypoplasia and the nature of the discoloration.

Systemic conditions1. Erythroblastosis fetalis Massive systemic lysis of erythrocyte releases large amounts of hemosiderin pigment which penetrate and discolor the forming dentin. Stain does not involve teeth developing after cessation of hemolysis . Stain is usually green, brown or bluish in colour. Such discoloration is now uncommon and is not amenable to bleaching.2. Congenital erythropoietic porphyria Rare, recessive, autosomal, metabolic disorder. There is an error in porphyrin metabolism leading to the accumulation of porphyrins in bone marrow, red blood cells, urine, faeces and teeth. A red-brown discolouration of the teeth The affected teeth show a red fluorescence under ultra-violet light.3. Sickle cell anemia Inherited blood dyscrasia. Increased hemolysis of red blood cells Involves both dentitions. Cause intrinsic blue, brown, or green discolorations. Does not resolve with time.4. Alkaptonuria This inborn error of metabolism. Incomplete metabolism of tyrosine and phenylalanine, which promotes the build up of homogentisic acid. This affects the permanent dentition by causing a brown discolouration5. Congenital hyperbilirubinaemia Massive haemolysis will lead to deposition of bile pigments in the calcifying dental hard tissues, particularly at the neonatal line. The breakdown products of haemolysis will cause a yellow-green discolouration6. Amelogenesis imperfecta In this hereditary condition. Enamel formation is disturbed with regard to mineralization or matrix formation. The appearance depends upon the type of amelogenesis imperfecta, varying from the relatively mild hypomature snow-capped enamel to the more severe hereditary hypoplasia with thin, hard enamel which has a yellow to yellow-brown appearance7. Dentinogenesis imperfecta This is an autosomal dominant condition affecting both deciduous and permanent dentition. Dentinogenesis imperfecta I: Teeth are blue gray or amber brown and opalescent. Dentinogenesis imperfecta II: Teeth are usually bluish or brown in colour, and demonstrate opalescence on transillumination. Dentinogenesis imperfecta III: Teeth may be outwardly similar to both types I and II of Dentinogenesis imperfecta.

Endemic FluorosisIngestion of excessive amounts of fluoride during tooth formation may produce a defect in mineralized structures, particularly in the enamel matrix, causing hypoplasia. Fluoride intake may arise from naturally occurring water supplies or from fluoride delivered in mouthrinses, tablets or toothpastes as a supplement. The severity is related to age and dose, with the primary and secondary dentitions both being affected in endemic fluorosis. The teeth are not discolored on eruption, but their surface is porous and will gradually absorb colored chemicals present in the oral cavity. Discoloration is usually bilateral, affecting multiple teeth in both arches. It presents as various degrees of intermittent white spotting, chalky or opaque areas, yellow or brown discoloration, and, in severe cases, surface pitting of the enamel. Fluoride only causes fluorosis in concentrations of greater than 1 ppm in drinking water and is not distinguishable, clinically or histologically, from any other type of hypoplastic or hypomineralised enamel. Since the discoloration is in the porous enamel, such teeth can be bleached externally.

Drug-Related DefectsAdministration or ingestion of certain drugs during tooth formation may cause severe discoloration both in enamel and dentin.TetracyclineTooth shades can be yellow, yellow-brown, brown, dark gray, or blue, depending on the type of tetracycline, dosage, duration of intake, and patients age at the time of administration. Discoloration is usually bilateral, affecting multiple teeth in both arches. Deposition of the tetracycline may be continuous or laid down in stripes depending on whether the ingestion was continuous or interrupted.Mechanism of tetracycline discoloration: Tetracycline bound to calcium is thought to be incorporated into the hydroxyapatite crystal of both enamel and dentin. However, most of the tetracycline is found in dentin.Repeated exposure of tetracycline-discolored tooth to ultraviolet radiation can lead to formation of a reddish- purple oxidation by-product that permanently discolors the teeth. In children, the anterior teeth often discolor first, whereas the less exposed posterior teeth are discolored more slowly. In adults, natural photobleaching of the anterior teeth is observed, particularly in individuals whose teeth are excessively exposed to sunlight.Tetracycline discoloration has been classified into three groups according to severity:Two approaches have been used to treat tetracycline discoloration: (1) Bleaching the external enamel.(2) Intracoronal bleaching following intentional root canal therapy.

Minocycline Staining is common in adoloscents and adults whose teeth have already formed. Unlike tetracycline, which can be used in adults without the risk of discolouration, minocycline is absorbed from the gastrointestinal tract Chelates with iron and forms Insoluble calcium-minocycline complexes. Some minocycline stains may be responsive to bleaching. Others with severe banding may require porcelain laminate veneers

PlaquePellicle and plaque on tooth surface give rise to yellowish appearance of tooth.

Food and beverages Tea, coffee, red wine, curry and colas if taken in excess causes brown stains on the outer (buccal, labial) and inner (lingual, palatal) surfaces of the teeth.Tobacco Results in brown to black appearance of teeth that cover the cervical one third to one half of the tooth.

Poor oral hygieneA. Green stains / Orange stains: Occur due to Poor oral hygiene and Chromogenic bacteria . Usually in cervical & gingival areas of tooth. More common in mouth breathers & young persons . Occur more readily on the labial surface of the maxillary anterior teeth.

B. Brown stains: Due to caries and Chromogenic bacteria. Discolouration is due to surface decalcification.

Swimmers calculus Swimmers calculus is defined as being a hard, brown tartar deposit that usually appears on the front teeth. It normally occurs in swimmers who spend more than 6 hours a week submerged in chlorinated or chemically treated water in swimming pools. The pool water contains chemicals which give the water a higher pH than saliva, that cause salivary proteins to break down quickly and form organic deposits on teeth.

Chemicals1. Chlorhexidine stains: Chlorhexidine rinse (0.12%) causes brown staining after several weeks of use, particularly on acrylic and porcelain restorations.

2. Metallic stains: These are caused by metals and metallic salts introduced into the oral cavity in metal containing dust inhaled by industry workers or through orally administered drugs. Mechanism of stain production is related to the production of the sulphide salt of the particular metal involved. Stains caused by different metals: Copper dust: green stains Iron dust: brown stains Mercury: greenish-brown stains Nickel: green stains Silver: black stains Potassium permanganate: violet-black stain Stannous fluoride: golden-brown stain

Intracanal Medicaments Several intracanal medicaments are liable to cause internal staining of the dentin. Phenolics or iodoform-based medicaments sealed in the root canal and chamber are in direct contact with dentin, allowing penetration and oxidization. These compounds have a tendency to discolor the dentin gradually. Phenolic compounds- brown black stain Iodoform- white silver stain Intracoronal bleaching may be used to correct the problem.

Obturating Materials This is a frequent and severe cause of single tooth discoloration. Incomplete removal of obturating materials and sealer remnants in the pulp chamber, mainly those containing metallic components, often results in dark discoloration. This is easily prevented by removing all materials to a level just below the gingival margin Intracoronal bleaching is the treatment of choice. Prognosis depends on the type of sealer and duration of discoloration.

Amalgams Sometimes the dark appearance of the crown is caused by the amalgam restoration that can be seen through the tooth structure. Silver alloys have severe effects on dentin owing to dark-colored metallic components that can turn the dentin dark gray. Amalgam blues: Dark discolouration seen in the tooth structure adjacent to amalgam restoration. They mimick secondary caries. It is caused by the gradual diffusion of metallic ions from amalgam restoration into the dentin or by light passing through the transluscent, thin enamel that is reflected from the underlying amalgam.

Pins and Posts Metal pins and prefabricated posts are sometimes used to reinforce a composite restoration in the anterior dentition. Discoloration from inappropriately placed pins and posts is caused by the metal seen through the composite or tooth structure. In such cases, coverage of the pins with a white cement or removal of the metal and replacement of the composite restoration is indicated.

Composites Microleakage around composite restorations causes staining. Open margins may allow chemicals to enter between the restoration and the tooth structure and discolor the underlying dentin. In addition, composites may become discolored with time, affecting the shade of the crown. These conditions are generally corrected by replacing the old composite restoration with a new, well-sealed one.

Management of tooth discolourationDiet and habitsExtrinsic staining caused by foods, beverages, or habits (eg, smoking, chewing tobacco; see Causes and Pathophysiology) is treated with a thorough dental prophylaxis (Dental pumice to remove the stain, and then prophylaxis paste to smoothen the tooth surfaces)Prophyjet utilizing air to spray a mixture of fine baking soda powder and water onto the surfaces of teeth.Cessation of dietary or other contributory habits. Toothbrushing: Effective toothbrushing twice a day with a dentifrice helps to prevent extrinsic staining. Most dentifrices contain an abrasive, a detergent, and an antitartar agent. In addition, some dentifrices now contain tooth-whitening agents. Professional tooth cleaning: Some extrinsic stains may be removed with ultrasonic cleaning, rotary polishing with an abrasive prophylactic paste, or air-jet polishing with an abrasive powder.However, these modalities can lead to enamel removal; therefore, their repeated use is undesirable.Enamel microabrasionIndicated for the removal of superficial intrinsic tooth discoloration, including that caused by fluorosis and decalcifications secondary to orthodontic brackets or bands. 2 main technique : Hydrochloric acid/pumice technique Phosphoric acid/pumice technique Simple to perform and the depth of enamel removed in 10 applications is approximately 100 m . (0.1 mm ). The resultant surface is smooth and has a glazed appearance. Enamel microabrasion may be used in conjunction with bleaching.Enamel macroabrasion ADVANTAGES: Faster. Does not require the use of a rubber dam or special instrumentation. Gross removal of the defect can be easily accomplished. DISADVANTAGES: High-speed instrumentation is technique sensitive. Makes way for the active reagents of bleaching system to penetrate.

Bleaching (Tooth whitening)The lightening of the color of a tooth through the application of a chemical agent to oxidize the organic pigmentation in the tooth BLEACHING MATERIALS:1st generation liquid form, did not remain in tray for long, required frequent replishment.2nd generation viscous & gel form , prevents leaching out and soft tissue irritation3rd generation different vehicle & color, more patient friendly. DIFFERENT BLEACHING AGENTS:Hydrogen PeroxideCabarmide peroxideSodium perborate McInnes solution (five parts 30% hydrogen peroxide, five parts 36% hydrochloric acid, and one part ethyl ether) Hydrogen Peroxide Various concentrations of this agent are available, but 30 to 35% stabilized aqueous solutions are the most common. Silicone dioxide gel forms containing 35% hydrogen peroxide are also available, some of them activated by a composite curing light. Hydrogen peroxide is caustic and burns tissues on contact, releasing toxic free radicals, perhydroxyl anions, or both. High-concentration solutions of hydrogen peroxide must be handled with care as they are thermodynamically unstable and may explode unless refrigerated and kept in a dark container.Sodium Perborate Available in a powdered form or as various commercial preparations. When fresh, it contains about 95% perborate, corresponding to 9.9% of the available oxygen. Stable when dry. In the presence of acid, warm air, or water, it decomposes to form sodium metaborate, hydrogen peroxide, and nascent oxygen. Three types of sodium perborate preparations are available: monohydrate, trihydrate, and tetrahydrate. Commonly used sodium perborate preparations are alkaline, and their pH depends on the amount of hydrogen peroxide released and the residual sodium metaborate. More easily controlled and safer than concentrated hydrogen peroxide solutions. Material of choice in most intracoronal bleaching procedures.

Carbamide Peroxide Also known as urea hydrogen peroxide. Available in the concentration range of 3 to 45%. Commercial preparations contain about 10% carbamide peroxide, with pH of 5 to 6.5. Solutions of 10% carbamide peroxide break down into urea, ammonia, carbon dioxide, and approximately 3.5% hydrogen peroxide. Bleaching preparations containing carbamide peroxide usually also include glycerine or propylene glycol, sodium stannate, phosphoric or citric acid, and flavor additives. In some preparations, carbopol, a water-soluble polyacrylic acid polymer, is added as a thickening agent. Carbopol also prolongs the release of active peroxide and improves shelf life. Mechanism of bleaching According to Kihn : Hydrogen peroxide (oxidizing agent) Diffuses into the tooth Breaks down to produce unstable free radicals Attack organic pigmented molecules Smaller, less heavily pigmented constituents Smaller molecules reflect less light, thus creating whitening effect. The mechanisms of Non-hydrogen peroxide containing materials are that the moist tooth structure and the gel interact and activate the gel. The oxygen complex interacts with the tooth structure and saturates and changes the amino acids and double bonds of oxygen which are responsible for tooth discoloration.

Factors affecting success1. Age - younger patients experience a greater reduction in yellowness immediately.2. Type of bleaching - carbamide peroxide-based products stay active for a lot longer than hydrogen peroxide-based products.3. Concentration of bleaching agent used - higher the concentration of the agent, the more likely there will be side effects. 4. Amount of discolouration and the cause of the discolouration.5. How much you decide to whiten you teeth at home; if you only whiten your teeth once a twice a month, there will be minimal improvement.6. The design of the tray .7. The number of bleaching treatments done and the time bleached for.Types of bleaching

Vital bleachingIn-office vital bleaching/Power bleaching Power bleaching of vital teeth generally uses a high concentration of peroxide solution (35- 50% hydrogen peroxide) placed directly on the teeth, often supplemented by a heat or light source to activate or enhance peroxide release (Feinman et al 1987). Indications: Treatment of generalised gross staining such as tetracycline staining Dentine sclerosis Patients who may have difficulty in compliance with the nightguard vital bleaching technique.Lights that are typically within the blue light spectrum have been found to contain the most effective wavelengths for initiating the hydrogen peroxide reaction.DN Dederich et al. (2004) reported that the best wavelength of light used to facilitate power bleaching was in the 457 to 502 nm visible blue light spectrum because of its significant aid in bleaching the teeth while it did not produce the internal tooth heating that other wavelengths of light might cause. They definitely also were against the use of infrared wavelengths that tend to heat the tooth, such as those employed by a CO2 laser. Treatment sequence is as follow:1. Gingivae are protected with Vaseline or Orobase .2. Rubber dam is applied to isolate the teeth and to provide maximum retraction of tissue.3. The teeth are cleaned with a slurry of pumice and water, then rinsed and dried.4. The operator and the assistant should wear rubber gloves. The eyes of the patient, assistant, and dentist must be protected with safety glasses.5. 30 to 35% hydrogen peroxide solution or a gel form is placed on the teeth using a cotton-tipped applicator.6. The bleaching light is positioned 25 to 30 cm from the teeth for up to 30 minutes. The light produces heat, which hastens the decomposition and penetration of hydrogen peroxide.7. The area is rinsed with water and rubber dam is removed 8. Mild analgesics are prescribed to relieve possible postoperative sensitivity and the patient is instructed to avoid taking hot and cold foods or drinks during the first few hours following bleaching.9. The procedure may be repeated at 2- to 4-week intervals or more as in the case of severe tetracycline staining,

Disadvantages:1. Neither the patient nor the dentist can exactly control the amount of lightening. The technique runs the risk of both over- and under-bleaching.2. The fee is usually higher as a greater amount of chair time is required.3. There is a possibility of soft tissue damage due to the caustic nature of the high concentrations of peroxide.4. There is a greater risk of post-operative sensitivity. A higher incidence of tooth sensitivity (67-78%) was reported after power bleaching (Heywood and Berry 2001, Cohen and Chase 1979) compared with the nightguard vital bleaching, using 10% carbamine peroxide (15-65%) (Nathanson and Parra 1987, Heywood 1996, Leonard 1998, Schulte et al 1994). Clinical comparison between the bleaching efficacy of light-emitting diode and diode laser with sodium perborate Aim: To test the efficacy of a light-emitting diode (LED) light and a diode laser, when bleaching with sodium perborate. In group A, sodium perborate and distilled water were mixed and placed into the pulp chamber, and the LED light was source applied. In group B, the same mixture was used, and the 810nm diode laser was applied. Conclusion: Both devices successfully whitened the teeth. No statistical difference was found between the efficacy of the LED light and the diode laser. Efficacy of intracoronal bleaching techniques with different light activation sources Aim: To evaluateex vivothe efficacy of 35% hydrogen peroxide for intracoronal bleaching when activated by LEDs, halogen lamp or by the walking bleach technique.Methodology: Forty extracted human maxillary central incisors were selected. Samples were divided randomly into five groups: group I received 35% hydrogen peroxide gel activated by LEDs. Group II received 35% hydrogen peroxide gel activated by a halogen lamp-based light curing unit. Group III received 35% hydrogen peroxide gel followed by the walking bleach technique. Group IV was neither artificially stained nor bleached (positive control) and group V was stained, but not bleached (negative control). The shade of the teeth was assessed visually before and after bleaching. Results: No statistical differences regarding sample shades were found amongst groups for the tested internal bleaching techniques (P>0.05).Conclusions: Hydrogen peroxide for intracoronal bleaching when activated either by LEDs, halogen lamp or by the walking bleach technique presented similar efficacy.Mouth guard bleaching This technique has been widely advocated as a home bleaching technique, with a wide variety of materials, bleaching agents, frequency, and duration of treatment. Numerous products are available, mostly containing either 1.5 to 10% hydrogen peroxide or 10 to 15% carbamide peroxide, that degrade slowly to release hydrogen peroxide. The carbamide peroxide products are more commonly used. Higher concentrations of the active ingredient are also available and may reach up to 50%.Technique 1. An alginate impression of the arch to be treated is obtained and cast in dental stone.2. A spacer (reservoir) is provided over the teeth to be bleached using suitable material (such as light-cured resin or three layers of die relief or nail varnish applied in an even coat 0.5- to 1 .O-mm thick). 3. A bleaching tray is fabricated on the cast, using a heat- and vacuum-forming machine and a plastic sheet 0.6- to 0.9-mm thick. 4. The edges of the tray are trimmed, using curved scissors, to fit about 0.5 mm short of the gingivae. 5. Close fitting at the gingival margin in the patients mouth is ensured. 6. The patient is supplied with a 10% carbamide peroxide bleaching gel, such as Opalescence (Ultradent Products Inc., South Jordan, Utah).7. The patient is instructed to brush his or her teeth before bleaching.8. The gel is dispensed evenly into the deepest portion of the tray and toward the facial sides of each tooth to be bleached. 9. After the tray is seated completely and firmly over the teeth, excess material should be wiped off with a toothbrush and then the mouth is rinsed. 10. The time interval between changing the bleach depends upon the product used: usually it is replaced every 2 to 3 hours during the day or a single application of bleaching gel is used at bedtime for night bleaching. 11. It is recommended to bleach every second or third night. 12. Total treatment time usually is 2 to 6 weeks with 80% of the success being achieved after 2 weeks. Comparison of short term effectiveness of four different tooth whitening systemsAim: To compare the short term effectiveness and major side effects of 4 popular bleaching systems.Materials and Methods: A sample of 300 subjects were divided equally into 4 groups and treated with ( home bleaching - Opalescence 20%, in office Bright Smile, in office - Zoom, and in office - Zoom plus home bleaching - Day White 9.5%).Results: The four whitening systems were significantly effective at 3 days (T1) and 3 months (T2) after the whitening treatment. At T2, there was no significant difference in whitening effectiveness among the four whitening systems. Tooth sensitivity and gingival irritation were associated with the 4 whitening systems.Conclusion: The bleaching procedures tested in this study are equally effective with high satisfaction level and with self-limiting tooth and gingival sensitivity.Whitening strips The whitening strip is a novel bleaching system which uses a flexible 5.3% hydrogen peroxideimpregnated polyethylene strip, offer an at-home alternative to the above methods and can be recommended for maintaining already whitened teeth.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 daysAdverse effects Approximately two thirds of patients have short-term, minor tooth sensitivity to cold and/or gingival irritation. Tooth surfaces, particularly exposed roots or enamel surfaces with defects secondary to incomplete amelogenesis, are porous to the bleaching agent and are more likely to develop cold sensitivity. Mucosal irritation and ulceration: A high concentration of hydrogen peroxide (from 30 to 35%) is caustic to mucous membranes and may cause burns and bleaching of the gingiva.Alteration of enamel surface. Nonvital bleachingNonvital (intracoronal) bleaching refers to lightening endodontically treated teethThe two techniques used to bleach pulpless tooth are in-office thermocatalytic and out-of office walking bleach . The thermocatalytic technique involves placing 30 to 35% hydrogen peroxide into the debrided pulp chamber and heating it with a controlled rheostat, photoflood lamp, or heated metal instrument, such as a ball burnisher. The walking bleach is called so because the bleaching takes place between appointments, which are 3 to 7 days apart. Walking Bleach Technique The walking bleach technique that was introduced in 1961.Involves the use of a mixture of hydrogen peroxide and sodium perborate or sodium perborate mixed with water. Sodium perborate is a stable white powder, when dissolved in water, it decomposes into sodium metaborate and hydrogen peroxide, releasing nascent oxygen. In vitro studies have shown that three applications of sodium perborate mixed with water are equally as effective as application of sodium perborate and 30% hydrogen peroxide solution . Sodium perborate mixed with water is potentially safer than when mixed with hydrogen peroxide. Technique 1. The discolored tooth is isolated using a rubber dam and the gingiva are protected with Vaseline. 2. Any coronal filling materials are removed to a depth of 2 mrn below the cementoenamel junction and 1-mrn layer of dental cement such as glass ionomer or polycarboxylate, is placed over exposed root canal filling and allowed to harden. 3. The pulp chamber is cleaned of any organic debris with a cotton pledget soaked in chloroform or xylene, then rinsed and dried.4. The coronal internal dentin is etched with a 37% phosphoric acid solution or gel for 30 seconds, then rinsed thoroughly and dried. This removes the smear layer and allows better penetration of the bleaching agent within the dentinal tubules.5. One drop of 30 to 35% hydrogen peroxide is mixed with sodium perborate in a dappen dish to a consistency of a thick paste. Alternatively, sodium perborate may be mixed with distilled water. The paste is placed into the pulp chamber with a large spoon excavator or a plastic instrument, avoiding contact with the enamel margins.6. Excess mixture is excavated 2 mm into the access opening. A small pledget of cotton wool is placed over the paste, then the area is sealed with a temporary filling (e.g., IRM). Materials that may result in a leaking seal must not be used.7. The rubber dam is removed and the occlusion is examined. The patient is required to return in 3 to 7 days for assessment of the degree of whitening. The patient is instructed to return to the clinic immediately should the temporary filling become dislodged.8. The bleaching mixture is active for 24 hours and in most instances, a single application will suffice. T he procedure may be repeated if necessary, usually every 3 to 5 days for a mixture of hydrogen peroxide and sodium perborate and biweekly for sodium perborate alone. 9. When satisfactory result is attained, a rubber dam is placed, the temporary dressing and the bleaching paste are removed, and the area is washed and dried. 10. A thin layer of lightactivated glass ionomer is placed against the axial dentin wall and the access cavity is restored with composite resin.Thermo-catalytic bleaching This technique involves placement of 30%35% hydrogen peroxide in the pulp chamber followed by heat application by electric heating devices or specially designed lamps. It has been observed that heat application causes a reaction that increases bleaching properties of the hydrogen peroxide. When heat is applied, a reaction produces foam and releases the oxygen present in the preparation.Technique 1. The discolored tooth is isolated using a rubber dam and the gingiva are protected with Vaseline. 2. Any coronal filling materials are removed to a depth of 2 mrn below the cementoenamel junction. such as glass ionomer or polycarboxylate, is placed over the 3. A 1-mrn layer of dental cement, exposed root canal filling and allowed to harden. 4. The pulp chamber is cleaned of any organic debris with a cotton pledget soaked in chloroform or xylene, then rinsed and dried.5. The coronal internal dentin is etched with a 37% phosphoric acid solution or gel for 30 seconds, then rinsed thoroughly and dried. This removes the smear layer and allows better penetration of the bleaching agent within the dentinal tubules.6. A loose cotton pledget saturated with 30 to 35% hydrogen peroxide is placed in the pulp chamber. 7. Heat is applied, using a commercial heat applicator or metal instrument, alternately for 15 to 30 minutes while the hydrogen peroxide-saturated pellet is changed frequently. If the patient feels discomfort, the heat source is removed. The endodontically treated tooth is believed to be able to withstand heating to 71C without patient discomfort. 8. The area is rinsed then dried, using a water-clearing solution, such as acetone or ethanol, to remove traces of bleaching material, which adversely affects the bond strength of both composite and glass ionorner to enamel and dentin.9. The tooth is restored by placing a thin layer of glass ionomer cement.10. The glass ionomer and the enamel walls are etched, then rinsed and dried. The cavity is filled with composite resin, and polymerized.Adverse effects 1. Cervical root resorption: The underlying mechanism for this effect is unclear, but it has been suggested that the bleaching agent reaches the periodontal tissue through the dentinal tubules and initiates an inflammatory reaction (Cvek and Lindvall, 1985). It has also been speculated that the peroxide, by diffusing through the dentinal tubules, denatures the dentin, which then becomes an immunologically different tissue and is attacked as a foreign body (Lado et al., 1983).2. Tooth crown fracture has also been observed after intracoronal bleaching (Grevstad, 1981), most probably due to extensive removal of the intracoronal dentin. 3. In addition, intracoronal bleaching with 30% hydrogen peroxide has been found to reduce the micro-hardness of dentin and enamel (Lewinstein et al., 1994) and weaken the mechanical properties of the dentin (Chng et al., 2002). Dental restorationsTeeth discolored by dental caries or dental materials require the removal of the caries or restorative materials, followed by proper restoration of the tooth. Partial or full-coverage dental restorations may be used to treat generalized intrinsic tooth discoloration in which bleaching is not indicated or in which the aesthetic results of bleaching fail to meet the patient's expectations.Porcelain laminate veneers for the treatment of tetracycline staining.Composite Resin Restorations The large size of the immature pulp chamber and pulp horns, and the immature gingival contour of the adolescent patient contra-indicates the use of porcelain veneers. Composite resin offers a satisfactory alternative and should be used in child and adolescent patients.Resin can be used by either to camouflage/replace discrete localised areas of abnormal enamel ( localised composites ) or to cover the entire enamel surface (veneer ).

Composite Veneers Technique(i) Use a tapered diamond bur to reduce labial enamel thickness. Identify a finish line at the gingival margin and also mesially and distally just labial to the contact points. (ii) Clean tooth with a slurry of pumice in water. Wash and dry the tooth. Select the shade. (iii) Isolate the tooth either with rubber dam or contoured matrix strip. (iv) Etch the enamel for 60 secs, wash and dry. (v) Apply a thin layer of bonding resin to the labial surface with a brush and cure for 15 secs. (vi) Apply composite resin of the desired shade to the labial surface and smooth it into the desired shape. Cure 60 secs gingivally, mesio-incisally, and disto-incisally, In addition cure 60 secs inciso-palatally if there has been extension to the palatal surface. Different shades of composite can be combined to achieve a transition from darker gingival areas to lighter more translucent incisal region.(vii) Finish the margins with diamond finishing burs and interproximal strips and the labial surfaces with finishing discs. Porcelain Veneers Porcelain veneers are indicated for hypoplastic and discoloured teeth in patients aged 16 years and over, when techniques such as microabrasion, non-vital bleaching and composite resins have failed to produce a satisfactory clinical result.

SummaryTreatment options for different kind of discoloration Alkaptonuria:Bleaching should be tried first, but the blue or grey stains are difficult to change. When the stains do not respond to bleaching, they have to be either removed by abrasion or masked by restorative treatment. Congenital erythropoietic porphyria: To improve the aesthetics in teeth with red-brown porphyrin pigments deposited, treatment options are crowns and/or laminated veneers. Congenital hyperbilirubinaemia:Treatment for the condition is bleaching or placement of esthetic crowns. Amelogenesis imperfecta:Management in affected children and adolescents have to be focused on improving esthetics, reducing sensitivity, correcting or maintaining vertical dimension and restoring the masticatory function .Early diagnosis is important in order to offer proper preventive and restorative treatments over several phases. The temporay phase starts soon after diagnosis in the primary or mixed dentition and is continued with a transitional phase, providing the patient with a functional and esthetic permanent teeth before the permanent treatment phase in adulthood.The treatment depends on the AI type and the phenotype of the affected enamel and can range from preventive care using sealants, tooth whitening, microabrasion , and bonded technique for esthetic improvement to prosthetic reconstruction. Dentinogenesis imperfecta:Bleaching and prosthetic crowns.

Tetracycline:Haywood has shown that tetracycline-stained teeth may respond to long bleaching treatments, some tetracycline discolorations can require from 1 to 12 months of treatment every night. Leonard et al. (2003) stated in their study that nightguard vital bleaching indicates that tetracycline-stained teeth can be whitened successfully using a 6 month active treatment with 10% carbamide peroxide, and that shade stability may last at least 90 months post treatmentPrognosis of vital bleaching : Degree I - Good Degree II Variable Degree III & IV poor. In cases where the teeth are severely stained in the gingival area and a bleaching treatment has no effect, porcelain veneers or placement of a crown will be options to restore esthetics and function. Fluorosis:The choice between different treatments depends on the severity of the fluorosis. Mild fluorosis - bleaching . Moderate fluorosis - bleaching or in combination with microabrasion . Severe fluorosis - porcelain laminate veneers, restorations or crowns.

Pulpal haemorrhagic product:Pinkish hue seen initially after trauma might disappear in 2-3 months if the tooth becomes revascularized . It is therefore wise to wait for 3 months before a bleaching treatment. Pulp necrosis:Intracoronally bleaching is the treatment of choice. According to Plotino trauma- or necrosis-induced discoloration can be successfully bleached in about 95% of the cases, compared with lower percentages for teeth discolored as a result of medicaments or restorations . Tooth wear and gingival recession:To improve appearance of discolored roots of teeth, the exposure to bleaching materials requires usually treatments of long periods, longer than what is common for the bleaching of the enamel.

ConclusionThe correct diagnosis for the cause of discolouration is important as, invariably, it has a profound effect on treatment outcomes. Brown and yellow stainings are easier to change, while gray and blue stains are mostly resistant to bleaching and the discolorations located in the gingival area have a poor prognosis . There are no guidelines telling the dental practitioner when it is correct to carry out operative treatment. Therefore, in cases with esthetic problems a grasp of the pathological processes involved in tooth staining along with prevention of avoidable causes of tooth staining is important.Refrences Ingles Endodontics 6 : Ingle, Bakland, Baumgartner. Textbook of Endodontics (2nd edition): Nisha Garg, Amit Garg. Tooth discolouration and staining: a review of the literature: A. Watts and M. Addy- British dental journal volume 190 no.6 march 24 2001. Complete dental bleaching: Ronald E. Goldstein Sturdevants Art and Science of Operative Dentistry 5th Edition Sruthy Prathap et al. Extrinsic stains and management: A new insight. J. Acad. Indus. Res. Vol. 1(8)J anuary 2013. Manuel ST, Abhishek P, Kundabala M. Etiology of tooth discoloration- a review. Nig Dent J, Vol 18 (2), July - Dec 2010. Faiez n. hattab et al. Dental Discoloration: An Overview. Esthet Dent 11:291-310, 1999.