management of discolored teeth

Management of Discolored Teeth

Dr. Hakan ÇolakDDS. PhD

Ishık University School of Dentistry

Chapter Online

CLASSIFICATION OF DISCOLORATION

• Tooth discoloration varies with etiology, appearance, localization, severity and adherence to the tooth structure.

• It may be classified as extrinsic or intrinsic discoloration or combination.


• Feinman et al 1987– Extrinsic discoloration as that occurring when an agent

or stain damages the enamel surface of the teeth. – Extrinsic staining can be easily removed by a normal

prophylactic cleaning.


Gradual assembly of complex stains within the teeth. Note

the contrastwith the old crown at the upper

left lateral incisor, which previously matched

the teeth.


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

• Combination of both is multifactorial in nature, e.g. nicotine staining

Etiology of tooth discoloration• Intrinsic Stains

– Preeruptive causes• Disease

– i. Alkaptonuria– ii. Hematological disorders– iii. Disease of enamel and dentin– iv. Liver diseases.

– Medications• i. Tetracycline stains and other antibiotic use• ii. Fluorosis stain.

– Posteruptive causes of discoloration• Pulpal changes• Trauma• Dentin hypercalcification• Dental caries• Restorative materials and operative procedures• Aging• Functional and parafunctional changes

Etiology of tooth discoloration

• Extrinsic Stains– Daily acquired stains

• Plaque• Food and beverages• Tobacco use• Poor oral hygiene�• Swimmer’s calculus�• Gingival hemorrhage.�

– Chemicals • Chlorhexidine�• Metallic stains�

ETIOLOGY OF TOOTH DISCOLORATION

• Intrinsic Stains– Pre-eruptive Causes• These are incorporated into the deeper layers of

enamel and dentin during odontogenesis and alter the development and appearance of the enamel and dentin

ETIOLOGY OF TOOTH DISCOLORATION-Hematological Disorders-

• Intrinsic Stains– Pre-eruptive Causes

– These are incorporated into the deeper layers of enamel and dentin during odontogenesis and alter the development and appearance of the enamel and dentin

– Alkaptonuria: Dark brown pigmentation of primary teeth is commonly seen in alkaptonuria. It is an autosomal recessive disorder resulting in complete oxidation of tyrosine and phenylalanine causing increased level of homogentisic acid


• Erythroblastosis fetalis: – It is a blood disorder of neonates due to Rh

incompatibility. In this, stain does not involve teeth or portions of teeth developing after cessation of hemolysis shortly after birth. Stain is usually green, brown or bluish in color


• Congenital porphyria:– It is an inborn error of porphyrin metabolism,

characterized by overproduction of uroporphyrin. Deciduous and permanent teeth may show a red or brownish discoloration.

– Under ultra- violet light, teeth show red fluorescence

Congenital porphyria

Congenital erythropoietic porphyria. Brownish teeth fluoresce under Wood lamp examination.

(From Kliegman R, Behrman R, Jenson H, Stanton B: Nelson textbook of pediatrics, ed 18, St Louis, 2008, Saunders.)


• Sickle cell anemia: – It is inherited blood dyscrasia (defect in the

composition of the blood) characterized by increased hemolysis of red blood cells.

– In sickle cell anemia infrequently the stains of the teeth are similar to those of erythroblastosis fetalis, but discoloration is more severe, involves both dentitions and does not resolve with time.

ETIOLOGY OF TOOTH DISCOLORATION-Disease of Enamel and Dentin-

• Amelogenesis imperfecta• Fluorosis• Vitamin and mineral deficiency• Chromosomal anomalies• Inherited diseases• Tetracycline• Childhood illness• Malnutrition• Metabolic disorders


• Defects in Dentin Formation• Dentinogenesis imperfecta• Erythropoietic porphyria• Tetracycline and minocycline (excessive

intake)• Hyperbilirubinemia


• Amelogenesis imperfecta (AI):– It comprises of a group of conditions, that

demonstrate developmental alteration in the structure of the enamel in the absence of a systemic disorder.

– Amelogenesis imperfecta (AI) has been classified mainly into hypoplastic, hypocalcified and hypomaturation type

Amelogenesis imperfecta

Amelogenesis imperfecta, hypoplastic type,

Amelogenesis imperfecta, hypomaturated type,


• Fluorosis:– In fluorosis, staining is due to excessive fluoride

uptake during development of enamel. – Excess fluoride induces a metabolic change in

ameloblast and the resultant enamel has a defective matrix and an irregular, hypomineralized structure

Fluorosis. A,Mild form of fluoride mottling, exhibiting white opaque flecks near the incisal edges with the surface remaining smooth and intact. B,Moderate form of fluoride mottling with ridges of hypoplasia and white and brownish enamel. C,Severe form of fluoride-induced hypoplasia and discoloration with associated cracking and chipping of the enamel. (From Sapp JP, Eversole L, Wysocki G:Contemporary oral and maxillofacial pathology, ed 2, St Louis, 2004, Mosby.)


• Dentinogenesis imperfecta (DI) : – It is an autosomal dominant developmental

disturbance of the dentin which occurs along or in conjunction with amelogenesis imperfecta.

– Color of teeth in DI varies from gray to brownish violet to yellowish brown with a characteristic usual translucent or opalescent hue


• Tetracycline Staining– Tetracycline can cross the placental barrier,

tetracycline affects both the deciduous and permanent dentitions, making the teeth vulnerable throughout odontogenesis.

– Even an exposure as short as 3 days can cause discoloration of the teeth at any time between 4 months in utero and age 9 years.


• Tetracycline Staining– The mechanism of the staining caused by

tetracyclines is related to the calcium binding in the tooth.

– Tetracycline binds to the tooth calcium, forming a tetracycline−calcium phosphate complex. It occurs throughout the tooth but is most highly concentrated in the dentin near the dentino-enamel junction. Both the quality and the severity of the discoloration are directly related to the specific tetracycline ingested as well as the dose

Posteruptive Causes

• Pulpal changes: Pulp necrosis usually results from bacterial, mechanical or chemical irritation to pulp. In this; disintegration products enter dentinal tubules and cause discoloration

Posteruptive Causes

• Trauma: – Accidental injury to tooth can cause pulpal and

enamel degenerative changes that may alter color of teeth

– Pulpal hemorrhage leads to grayish discoloration and nonvital appearance. Injury causes hemorrhage which results in lysis of RBCs and liberation of iron sulfide which enter dentinal tubules and discolor surrounding tooth

Posteruptive Causes

• Dental caries: In general, teeth present a discolored appearance around areas of bacterial stagnation and leaking restoration

• Restorative materials and dental procedures: Discoloration can also result from the use of endodontic sealers and restorative materials

Posteruptive Causes

• Aging: Color changes in teeth with age result from surface and subsurface changes. Age related discoloration are because of:– Enamel changes: Both thinning and texture

changes occur in enamel.– Dentin deposition: Secondary and tertiary dentin

deposits, pulp stones cause changes in the color of teeth

Yellowish discoloration of teeth because of secondary/tertiary dentin deposition

Extrinsic StainsDaily Acquired Stains• Plaque: Pellicle and plaque on tooth surface gives rise to

yellowish appearance of teeth• Food and beverages: Tea, coffee, red wine, curry and colas if

taken in excess cause discoloration• Tobacco use results in brown to black appearance of teeth.• Poor oral hygiene manifests as: Green stain, Brown stain,

Orange stain.• Swimmer’s calculus: It is yellow to dark brown stain present

on facial and lingual surfaces of anterior teeth. It occurs due to prolonged exposure to pool water.

• Gingival hemorrhage

Extrinsic Stains

• Chemicals– Chlorhexidine stain: The stains produced by use of

chlorhexidine are yellowish brown to brownish in nature.

– Metallic stains: These are caused by metals and metallic salts introduced into oral cavity in form of metal containing dust inhaled by industry workers or through orally administered drugs

BLEACHING

• Bleaching is a procedure which involves lightening of the color of a tooth through the application of a chemical agent to oxidize the organic pigmentation in the tooth

Chemistry and Safety of Dental Bleaching

• Bleaching is a chemical process involving the oxidation of organic material which is broken down to produce less complex molecules.

• Most of these smaller molecules are lighter in colour than the original larger molecules

Chemistry

• The oxidation/reduction reaction which takes place with bleaching is known as a redox reaction.

• In a redox reaction hydrogen peroxide – the oxidising agent –releases free radicals with unpaired electrons, thereby becoming reduced.

• The discoloured molecules within the teeth accept the unpaired electrons and become oxidised, with a reduction in the discolouration

Chemistry

• Hydrogen peroxide is an oxidising agent which produces free radicals HO 2 • and O• which are very reactive. The perhydroxyl ion HO 2 • is the stronger and more reactive of the two free radicals.

Free radical bleaching factors from H2O2 attack dark, long-chain stain and pigment molecules, breaking them down to tiny colorless

and white molecules.

How Hydrogen Peroxide Works

• The whitening effect is caused by the degradation of high molecular weight complex organic molecules that reflect a specific wavelength of light responsible for the colour of the stain.

• The degradation products have relatively low molecular weights and, as such, are relatively simple and with less colour reflectance. Bleaching results in a reduction or elimination of the discolouration.

• Both enamel and dentine change colour as a result of the passage of the peroxide through the tooth.

Degradation of hydrogen peroxide (H2O2) into water and bleaching factors: molecular oxygen, double and single anionic oxygen, and free radicals. The ability of

tooth structure to absorb bleaching factors determines the predictability of whitening.

hydrogen peroxide (low molecular weigh)

Organic molecules

free radicals have unpaired electrons they readily react with, and attack, most organic molecules. In the process, they generate other radicals.

radicals react with unsaturated bonds, resulting in the disruption of theelectron configuration of those molecules.

Complexmolecules (look dark) simpler molecules look lighter

By breaking down the larger molecules intosmaller ones, most are dissipated.

In the process of bleaching, highly pigmented carbon ring compounds within the tooth can be broken down and turned into relatively simple chain molecules.

• Many of these chains have consecutive conjugated double bonds which are further broken into single bonds.

Breakdown of Stain

CONTRAINDICATIONS FOR BLEACHING

• Poor Case Selection– Patient having emotional or psychological

problems are not right choice for bleaching.– In case selection, ifclinician has opinion that

bleaching is not in patient’s best interest, he should decline doing that.


• Dentin Hypersensitivity• Hypersensitive teeth need extra protection before going

for bleach

• Teeth with Hypoplastic Marks and Cracks– Application of bleaching agents increase the contrast

between white opaque spots and normal tooth structure:– In these cases, bleaching can be done in conjunction with:

• Microabrasion• Selected ameloplasty• Composite resin bonding


• Extensively Restored Teeth– These teeth are not good candidate for bleaching

because:• They do not have enough enamel to respond properly

to bleaching.• Teeth heavily restored with visible, tooth colored

restorations are poor candidates as composite restorations do not lighten, infact they become more evident after bleaching

An extensively restored and discoloured toothunsuitable for bleaching. A new restoration (core) and crown

would be more appropriate

MEDICAMENTS USED AS BLEACHING AGENTS

• An ideal bleaching agent should– Be easy to apply on the teeth– Have a neutral pH– Lighten the teeth efficiently– Remain in contact with oral soft tissues for short

periods– Be required in minimum quantity to achieve desired

results– Not irritate or dehydrate the oral tissues– Not cause damage to the teeth– Be well-controlled by the dentist to customize the

treatment to the patient’s need

BLEACHING

• Tooth bleaching today is based upon hydrogen peroxide as an active agent.

• Hydrogen peroxide may be applied directly or produced in a chemical reaction from sodium perborate or carbamide peroxide.

• Hydrogen peroxide acts as a strong oxidizing agent through the formation of free radicals, reactive oxygen molecules and hydrogen peroxide anions.

• These reactive molecules attack the long chained, dark colored chromophore molecules and split them into smaller, less colored and more diffusible molecules.

BLEACHING

• The outcome of bleaching procedure depends mainly on the concentration of bleaching agents, the ability of the agents to reach the chromophore molecules and the duration and number of times the agent is in contact with chromophore molecules

CONSTITUENTS OF BLEACHING GELS

• Carbamide peroxide• Hydrogen peroxide and sodium hydroxide• Sodium perborate• Thickening agent-carbopol or carboxy polymethylene• Urea• Surfactant and pigment dispersants• Preservatives• Vehicle-glycerine and dentifrice• Flavors• Fluoride and 3 percent potassium nitrate.


• Carbamide Peroxide (CH6N2O3)– It is a bifunctional derivative of carbonic acid. It is

available as:– Home bleaching• 5 percent carbamide peroxide• 10 percent carbamide peroxide• 15 percent carbamide peroxide• 20 percent carbamide peroxide.

– In office bleaching• 35 percent solution or gel of carbamide peroxide.


• Hydrogen Peroxide (H2O2)– H2O2 breaks down to water and nascent oxygen. – It also forms free radical perhydroxyl (HO2) which

is responsible for bleaching action


• Sodium Perborate– It comes as monohydrate, trihydrate or

tetrahydrate. – It contains 95 percent perborate, providing 10

percent available oxygen


• Thickening Agents– Carbopol (Carboxy polymethylene): Addition of

carbopol in bleaching gels causes: • Slow release of oxygen• Increased viscosity of bleaching material, which further

helps in longer retention of material in tray and need of less material

• Delayed effervescence–thicker products stay on the teeth for longer time to provide necessary time for the carbamide peroxide to diffuse into the tooth

• The slow diffusion into enamel may also allow tooth to be bleached more effectively.


• Urea– It is added in bleaching solutions to:• Stabilize the H2O2

• Elevate the pH of solution• Anticariogenic effects.


• Surfactants– Surfactant acts as surface wetting agent which

allows the hydrogen peroxide to pass across gel tooth boundary

FACTORS AFFECTING BLEACHING

• Amount of time, – the bleach is in contact with the teeth:– Increase in contact time, increases the bleaching

effect• Cleanliness of tooth surface:– Cleaner the enamel surface, better is the effect of

bleaching• Concentration of solution:– Increase in peroxide concentration, increases the

effect of bleaching


• Location and depth of discoloration• Temperature: – Increase in temperature increases the release of oxygen free

radicals which increases bleaching effect• Rate of oxygen free radical release:– More is the oxygen free radical release, better is the effect

of bleaching• Viscosity of solution:– Addition of agents like glycerine, glycol to increase the

viscosity of bleaching solution decrease the efficacy of bleaching agent


• Age of patient• Original shade and location of discoloration.• Frequency with which bleaching solution is

changed• Degradation rate of bleaching agent

that is rate of oxygen release

MECHANISM OF BLEACHING

• Discolorations arise due to the formation of chemically stable, chromogenic products. Pigments consist of long-chain organic molecules. In bleaching, these compounds are oxidized: they are split into smaller molecules which are usually lighter.

• During bleaching, the long-chain organic molecules are transformed into carbon and water, and – together with nascent oxygen – are released

Home Bleaching Technique/Night Guard Bleaching

• Indications for Use– Mild generalized staining– Age related discolorations– Mild tetracycline staining– Mild fluorosis– Acquired superficial staining– Stains from smoking tobacco– Color changes related to pulpal trauma or

necrosis.


• Contraindications– Teeth with insufficient enamel for bleaching– Teeth with deep and surface cracks and fracture lines– Teeth with inadequate or defective restorations– Discolorations in the adolescent patients with large

pulp chamber– Severe fluorosis and pitting hypoplasia– Noncompliant patients– Pregnant or lactating patients– Teeth with large anterior restorations


• Contraindications (con’t)– Severe tetracycline staining– Fractured or malaligned teeth– Teeth exhibiting extreme sensitivity to heat, cold

or sweets– Teeth with opaque white spots– Suspected or confirmed bulimia nervosa.

Advantages of Home Bleaching Technique

• Simple method for patients to use• Simple for dentists to monitor• Less chair time and cost effective• Patient can bleach their teeth at their

convenience.

Commonly used Solution for Night Guard Bleaching

• 10 percent carbamide peroxide withor without carbopol

• 15 percent carbamide peroxide• Hydrogen peroxide (1 to 10%)

Steps of Tray Fabrication• Take the impression and make a stone model• Trim the model• Place the stock out resin and cure it• Apply separating media• Choose the tray sheet material• Nature of material used for fabrication of bleaching tray is flexible

plastic• Most common tray material used is ethyl vinyl acetate• Cast the plastic in vacuum tray forming machines• Trim and polish the tray• Checking the tray for correct fit, retention and over extension• Demonstrate the amount of bleaching material to be placed.

Treatment Regimen

• When and how long to keep the trays in the mouth, depends on patients lifestyle preference and schedule?

• Wearing the tray during day time allows replenishment of the gel after 1 to 2 hours for maximum concentration.

• Overnight use causes decrease in loss of material due to decreased salivary flow at night and decreasedocclusal pressure.

• Patient is recalled 1 to 2 weeks after wearing the tray

Side Effects of Home Bleaching

• Gingival irritation—Painful gums after a few days of wearing trays

• Soft tissue irritation—From excessive wearingof the trays or applying too much bleach

to the trays• Altered taste sensation—Metallic taste

immediately after removing trays• Tooth sensitivity—Most common sid

effect.

In-office Bleaching

• Thermocatalytic Vital Tooth Bleaching– Equipment neededfor in-office bleaching are:• Power bleach material• Tissue protector• Energizing/activating source• Protective clothing and eye wear• Mechanical timer

In-office Bleaching

• Light Sources Used for In-office Bleach– Various available light sources are:• Conventional bleaching light• Tungsten halogen curing light• Xenon plasma arc light• Argon and CO2 lasers• Diode laser light.

In-office Bleaching

• Xenon Plasma Arc Light– High intensity light, so more heat is

liberated during bleaching– Application requires 3 seconds per tooth– Faster bleaching– Action is thermal and stimulates the catalyst

in chemicals– Greater potential for thermal trauma to pulp

and surrounding soft tissues.

Xenon Plasma Arc Light

Indications of In-office Bleaching

• Superficial stains• Moderate to mild stains.

Contraindications of In-office Bleaching

• Tetracycline stains• Extensive restorations• Severe discolorations• Extensive caries• Patient sensitive to bleaching agents

Advantages of In-office Bleaching

• Patient preference• Less time than overall time needed for home

bleaching• Patient motivation• Protection of soft tissues.

Procedure In-office Bleaching

• Pumice the teeth to clean off any debris present on the tooth surface

• Isolate the teeth with rubber dam• Saturate the cotton or gauze piece with bleaching

solution (30-35% H 2O2) and place it on the teeth• Depending uponlight, expose the tooth/teeth • Change solution in between after every 4 to 5 minutes• Remove solution with the help of wet gauge• Repeat the procedure until desired shade is produced

Procedure In-office Bleaching (Con’t)

• Remove solution and irrigate teeth thoroughly with warm water

• Polish teeth and apply neutral sodium fluoride gel

• Instruct the patient to avoid coffee, tea,etc. for 2 weeks

• Second and third appointment is given after 3 to 6 weeks. This will allow pulp to settle.

management of discolored teeth

Education