TEETH DISCOLORATIONETIOLOGY AND MANAGEMENT

Prepared by :Ahmed Salah Abbas .

Under supervision of :Dr . Nermin Alsayed .

Lecturer of operative dentistry .Minia university .

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 . In this presentation , we will talk about classification , etiology , management of tooth discoloration .

A. Intrinsic discoloration .

B. Extrinsic discoloration .

Intrinsic discoloration :

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

Intrinsic discoloration include the following :

A . Dental fluorosis :is a dental defect results from increased level of flourides in the drinking water during the period of teeth development .With level >1.2 ppm .

Clinically :there are several grades of dental flourosis :

Grade Description

Very mild Small paper white or chalky white areas less than 25 % of the surface .

Mild Opaque areas up to 50 % of the surface .

Moderate Paper white or brownish areas involving nearly the whole surface .

Severe The enamel is opaque , brown , pitted , brittle and easily chipped away from the tooth surface .

Treatment :

A. bleaching : effective with simple cases as brown staining on the surface , but it`s less effective for opaque cases , it will make it less noticeable but will not remove it completely .

B. veneering : can be applied for mild and moderate cases and gives results better than bleaching in these cases .

C. crowns : indicated for severe cases where there is a surface mottling .

Tetracycline is taken by calcifying tissues .

It produces its effect when given during teeth development , so tetracycline is contraindicated for pregnant woman and child under the age of (12) years old.

When tetracycline stained teeth are exposed to sun light ,they convert from yellow to darker color ( brown , gray ) , this explains the lighter color of molars when compared with anteriors due to longer duration of exposure to sun light .

Clinically :

Grade Clinical description Treatment

First degree

Light yellow or light gray , uniformly distributed throughout the crown without banding or concentrated in a local area .

it`s highly amenable to vital bleaching ,provides good results within less than four sessions .

Second degree

Darker or more extensive yellow or gray staining without banding

It`s amenable to vital bleaching , but it takes more sessions .

Third degree

Severe staining characterized by dark gray or bluish discolorationwith banding .

Vital bleaching lighten the discoloration but don`t give a satisfactory result ,so veneers withopaquers are necessary .

fourthdegree

stains that too dark for bleaching and don’t`t follow one of the previous categories .

Veneers with opaquers .

1. Porphria : a group of disorders of heme biosynthesis

,characterized by excessive excretion of porphyrins .

Clinically : occur in deciduous and permanent teeth , appear pink

or lavender in color , fluoresce bright red under ultraviolet light .

Treatment : bleaching .

2 . Erythroblastosis fetalis : grave hemolytic anemia results from development of ( Rh –antibody ) in response to (Rh –factor ) in the fetal blood .Clinically : teeth are bluish or greenish in color .

Treatment : bleaching .

3 . Other systemic diseases : as amelogenesisimperfecta, deficiency in vit. C , D .

Clinically : opaque white patches which may be stained in the cases of

hypomineralized enamel .Pitted and grooved tooth surface in the cases of hypoplastic enamel .

Treatment : bleaching isn`t appropriate treatment , the treatment for

such cases is veneering or crowning for such teeth .

D. Aging :

With age there will be a change in the color of teeth due to the enamel will be thin and dentin will be thicker due to deposition of secondary dentin so the tooth will appear darker , also there will be staining of teeth and this will depend on individual variations of consumption of tea , coffee , beverages , alcohol , smoking .

Clinically : the teeth more yellowish ,darker .

Treatment : bleaching is effective , especially when there is a sufficient thickness of enamel .

• Degraded tooth colored restorations can cause teeth to appear gray or discolored .

• Also metallic restorations as amalgam and gold restorations can reflect their colors through tooth surfaces .

• In such cases replacement the old restorations by more accurate and invisible restorations as composite restorations and bleaching isn`t necessary in such cases .

F . Non – vital teeth discoloration :

• In cases of teeth with necrotic pulps , teeth show gray discoloration .

• In such cases we should perform endodontic treatment to save the teeth , then we perform walking bleaching , in attempt to restore normal color of the teeth .

Extrinsic discoloration :

The most common discoloration of vital teeth , caused by food and beverages as coffee , tea , somking , tobacco , marijuana .

Clinically : produces yellowish brown to black discoloration usually on the cervical portion of the lingual surface of teeth .

Treatment : microabrasion usually sufficient for such cases , also vital bleaching can be performed if the enamel is slightly stained .

Bleaching

• Because tooth bleaching does not affect the structural integrity of the dentition, there is no relationship of tooth function and de-coloration.

• In general, tooth de-coloration should be undertaken before restorative treatment, but not for functional reasons. It makes sense to establish the baseline coloration of the overall dentition so that all restorative efforts can be directed toward a definitive goal.

A. Vital bleaching .

B. Non – vital bleaching .

C. Home bleaching .

Factors affecting bleaching :

Surface CleanlinessAll extrinsic stains and surface films must be removed from the

tooth surface before bleaching. This will maximize the contact

area between the whitening agent and the tooth as well as minimize

the chance of diluting the bleaching agent.

ConcentrationHigher concentrations of carbamide peroxide produce a more

rapid whitening effect15 as well as increased tooth sensitivity.2,15

This speed effect is not linear .

The Use of a LightMeta-analysis studies on the use of light during in-office vitalbleaching demonstrated that light-activated systems produced betterimmediate bleaching results than non-light systems whenlower concentrations of hydrogen peroxide (15%-20%) wereused.At higher concentrations of HP (25%-35%), no differenceswere noted. In addition, light-activated systems produced a higherpercentage of tooth sensitivity than the non-light systems .

Temperature increasing temperature doesn`t increase the speed of bleaching , but cause overheating of the pulp .

Buffering AgentsTo maintain a more neural pH, buffering agents areadded to the gel. These agents protect the pulp and promote thecontinued production of free radicals .

TimeThe longer the duration of bleach exposure, the greater thedegree of whitening. However, extended exposure to bleachingagents increases the likelihood of sensitivity .

Whitening Gel Viscosity and Solubilityin-office gels are mixed with even higher viscosity

base to prevent the gel from running off the teeth. However,

high viscosity anhydrous bases exhibit high surface tension , which can slow the absorption of gel into the microstructure of teeth .

Vital bleacingIn-office bleaching is useful in the removal of stains throughout the arch (e.g., age, diet or tetracycline staining), for lightening a single tooth in an arch (e.g., post-endodontically , non – vital bleaching )Indications : • Developmental or acquired stains• Stains in enamel and dentin• Yellow-brown stains• Age-yellowed smiles• White or brown fluorosis• Mild to moderate tetracycline stains

• ContraindicationsA . should be avoided for teeth with large pulp chambers or those

that have exhibited sensitivity.

B. Patients with erosions, whether chemical, abrasive, or caused by recession, may experience more bleaching sensitivity through and after treatment.

C . Factors that can limit the success of bleaching are the degree

and quality of the discoloration. If the teeth are extremely dark, no matter what the cause , so bleaching should be supported with restorative treatment .

Bleaching agents :either 30%-35% hydrogen peroxide or carbamideperoxide concentrations that yield high concentrations of

hydrogen peroxide) in liquid or gel form.

Armamentarium:A . Tinted protective eye glasses with side shields (for patientand operator).B . shade guide to record shade.

C . Bleaching agent .

D . Bite block/retractor .

E . Saliva ejectors .

Clinical technique :A . Pretreatment photographs .

B . Pretreatment shade determination .C . Clean the teeth with flour of pumice in a prophylaxis cup .

D . Petroleum jelly can be applied to the lips for protection. Because petroleum jelly can cause latex to degrade, nitrile gloves should be used .

E . Place “liquid rubber dam” over the gingiva and polymerize with a curing light according to the manufacturer’s instruction .

F . Apply bleaching agent for the time and duration as specified

in the manufacturer’s instructions .

G . After the appropriate bleaching time remove the gel withcopious amounts of water and suction .

H . Repeat the procedure according to the manufacturer’ instructions if required.

Note : Repeated bleaching sessions may be required to achieve the

desired results. It is important that the patient is aware of this and that financial arrangements .

• Bleaching with an argon laser, a carbon dioxide laser, or a combination of the twoas a light source have been introduced in the past but sufficient long-term or controlled clinical studies of safety and effectiveness currently are lacking .

• Studies have shown that the use of ultraviolet-assisted bleaching did not significantly increase the intrapulpal temperature of teeth when used for the recommended exposure time.

• Laser-assisted bleaching also may be no more effective than nonlaser techniques .

Note : dentist and patient should wear protective eye glasses .

Note : A sensitivity prevention regimen of 5% potassium nitrate

toothpaste two times a day for 10 to 14 days before treatment

and 600 mg of Ibuprofen 1 hour before treatment can be prescribed

at this visit in cases in which sensitivity is a concern .

B . Non – vital bleaching :Agent : sodium perborate and 30% to 35% hydrogen peroxide used alone or in combination.The most commonly used agent has been reported to be 30% hydrogen peroxide

Techniques : A . Walking bleaching .

B . Thermocatalytic technique .

Walking bleaching 1. Evaluate the high smile line.

2. If the gingival portion of the clinical crown is not visible during function or maximum smiling, the incisal termination of the base should be appropriately positioned to further reduce the chance of external cervical root resorption .

5 . Remove excess gutta-percha and endodontic sealer. Remove

gutta-percha to 2 to 2.5 mm gingival to the gingival-most

point on the coronal extension of the planned base .

6 . Place a 2- to 2.5-mm thick protective base that conforms to

the predetermined design and location .

7 . Mix a thick paste of sodium perborate and sterile water ona glass slab and place the mixture into the tooth.

8 . Tamp the mixture into place with a moist cotton pellet sothat appropriate space is provided for the temporary restorativematerial .

9 . Seal the access with temporary restorative material .

10 . Schedule the next appointment for the patient for 3 days later.

11 . If a successful result is achieved after 3 days , Isolate the tooth with rubber dam, remove the temporary filling, and carefully wash the internal tooth chamber with water. Mix a thick paste of calcium hydroxide powder and sterile water and place the mixture into the tooth .

15 . After 7 to 14 days, remove the calcium hydroxide paste and

restore the tooth .

Note : External root resorption is a possible sequela of internal

bleaching.Hydrogen peroxide occasionally has been associated with this development.The exact cause or causes of this response are still

not entirely understood .

Possible mechanisms of external root resorption :A . In 10% of all teeth, the cementoenamel junction is defective or absent, resulting in a portion of the tooth being devoid of cementum coverage.177 Thirty-five percent hydrogen peroxide may denature the dentin, invoking a foreign body response .

B . Internally applied 35% hydrogen peroxide may directly contact the periodontal membrane by passing through patent dentinal tubules179 or through lateral root canals or accessory foramina.180 This may elicit an inflammatory reaction, ultimately resulting in cervical resorption .

C . Bleaching agents may infiltrate between the gutta-perchaand the root canal walls. They could then communicate with the periodontal membrane through the dentinal tubules,lateral canals, or apex. This may invoke a resorptive process anywhere along the root area, including the apical regions.

D . Heat application during treatment may invoke a resorptive process .

Patient self-application of bleaching agents performed at home is perhaps the most popular method of bleaching vital teeth. It is alternately referred to as “home bleaching” or “matrix bleaching.”

• Bleaching agent : 10% carbamide peroxide , decomposes into

approximately 3.5% hydrogen peroxide and 6.5% urea , Carbopoland other thickeners often are incorporated to enhance the material’s properties to produce a gel or paste.

• General Considerations : 1 . this technique should not be used by

pregnant women

• 2 . Calculus should be removed .

• 3 . Teeth to be bleached should be free of caries and have no defective restorations .

• Technique 1 . The material options for at-home bleaching include bleaching trays .

2 . In most cases a custom-made tray is fabricated by the dental office or laboratory and given to the patient .3 . The patient injects the bleaching agent into the tray during the day, overnight, or both .4 . typically requires about 2 to 4 weeks .

Bleaching maintenance :

• Avoidance of chromogenic food as possible .

• Continuous brushing , flossing , scalling teeth from 2-4 times per year .

• Rinsing mouth with water roughly after using mouth wash preparations .

• It has been observed that bleaching effects regress over time. It is not the bleaching effect that changes, but simply the dietary and habit-induced staining that is undoing the whiteness of the teeth. For many individuals, re-staining can take years, but for some, particularly heavy drinkers of red wine and smokers .

Microabrasion

Definition : is a procedure in which a microscopic layer of enamel

is simultaneously abraded and eroded with special compound , leaving a perfect enamel surface behind , it`s used for treatment of dysmineralization cases .

Difference between bleaching and microabrasion :Bleaching : improves tooth color by whitening , lightening , preserving fluoride rich layer of enamel .

Microabrasion : improves tooth color by removing discolored enamel superficial layer which is permanent , usually used when isolated surface discoloration is present .

Advantages :

Disadvantages:

Indications :

Contraindications :

Technique :

microabrasion results :enamel appears smooth , lustrous , normally about 200µm of enamel is removed or less . Remineralisation can occur , enamel appears not to retain plaque , stains .

• References :

A . A concise textbook of oral pathology , Ain Shames university .

B . Contemporary esthetics textbook .

C .Bleaching and related agents (Kenneth W. Aschheim ) .

D . Esthetics in dentistry textbook .

E . Linda Greenwall`s article .