Bleaching

bleaching in endodontics

1. B L E A C H I N G

2. INTRODUCTION HISTORY CAUSES OF DISCOLORATION INDICATIONS AND CONTRAINDICATIONS MATERIALS USED IN BLEACHING CHEMISTRY AND MECHANISM BLEACHING TECHNIQUES ADVANTAGES AND DISADVANTAGES CONCLUSION Contents

3. The lightening of the color of a tooth through the application of a chemical agent to oxidize the organic pigmentation in the tooth is referred to as bleaching. Sturdevant Definition

4. In 1300’s the most requested dental service other than extraction was tooth whitening. In 14 th century, Guy De Chauliac cleaned teeth gently with honey and burnt salt to which some vinegar was added. In 18 th century, barbers surgeons applied, “ Aquafortis ” a solution of nitric acid, after abrading enamel with coarse metal files to whiten teeth. In1864 Truman used chlorine and acetic acid for non vital tooth bleaching. The commercial derivative of this, known as Labarrque’s solution. The first publication of bleaching was in 1877 by Chapple , the agent of his choice was oxalic acid. History

5. In 1884, Harlan used hydrogen peroxide for the first time which he called as hydrogen dioxide. In 1961, Spasser described Walking Bleach Technique. In the late 1960’s , a successful technique for home bleaching was introduced by Klusmier , at which time he discovered that 10% carbamide peroxide loaded in a mouth guard with the intent to improve the gingival condition also resulted in a bleaching effect. In 1976, Nutting and Poe introduced the walking bleach technique which uses 35% hydrogen peroxide and sodium perborate for nonvital bleaching. In 1989, Haywood and Heymann introduced “Night guard vital bleaching” (10% carbamide peroxide). In 1996 Reyto introduced Laser tooth whitening. History

6. Extrinsic discoloration Extrinsic stains are located on the outer surfaces of the teeth. Intrinsic discoloration Intrinsic stains are those which are internal or present with in the tooth structures. Stain internalization Those circumstances where extrinsic stain enters the tooth through defects in the tooth structure . Causes of tooth discoloration

7. Metabolic causes Alkaptonuria ,-brown congenital erythropoitic porphyria –red -brown congenital hyperbilirubinaemia -yellow green Inherited causes of discoloration Amelogenesis Imperfecta Dentinogenesis Imperfecta Dentinal dysplasias systemic syndromes Vitamin D dependent rickets Pseudohypoparathyroidism Epidermolysis bullosa Ehlers- Danlos Syndrome Intrinsic discoloration

8. Pulpal necrosis Bacterial, mechanical, or chemical irritation to the pulp may result in tissue necrosis and release of disintegration by-products that may penetrate tubules and discolor the surrounding dentin. Trauma related discoloration

9. Dentin hypercalcification During trauma temporary disruption of blood supply occurs, followed by destruction of odontoblasts . These are replaced by undifferentiated mesenchymal cells that rapidly form irregular dentin on the walls of the pulp lumen. As a result, the translucency of the crown gradually decreases, giving rise to a yellowish or yellow-brown discoloration. Pre-eruption trauma Discoloration of a permanent tooth may occur after trauma to its primary counterpart.

10. Intra pulpal haemorrhage

11. Endodontic Restorative Pulp tissue remnants Amalgam fillngs Intracanal medicaments Pins& posts Obturating materials Composites Iatrogenic discoloration

12. Pulp tissue remnants: Tissue remaining in the pulp chamber disintegrates gradually and may cause discoloration. Pulp horns must always be included in the access cavity to ensure removal of pulpal remnants and to prevent retention of sealer at a later stage. Intracoronal bleaching in these cases is usually successful. Intra canal medicaments: Phenolics or iodoform -based medicaments

13. Obturating materials: 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. Silver amalgam : Silver amalgam produces a stain ranging from slate gray to dark gray. Stains from amalgam are likely to occur when dentinal wall is thin and the filling material almost shimmers through the enamel. , periapical inflammation of a primary tooth, or other infections in the area of a developing tooth bud. Discoloration is usually white or yellow-brown it usually is limited to the facial enamel surface of one or two teeth, usually the maxillary incisors.

14. First reported in mid-1950s, less than a decade after widespread use of this antibiotic. Most susceptible to tetracycline discolouration during their formation i.e. during the II trimerster in utero to roughly 8 years after birth. Tetracycline staining

15. Severity of the stains depends on the time, duration and the dosage of the drug and also the type of tetracycline. Chlortetracycline (Aureomycin): Gray-brown Dimethylchlortetracycline (Ledermycin): Yellow Doxycycline (Vibramycin): Does not cause staining Oxytetracycline (Terramycin): Yellow Tetracycline staining Under fluorescent light

16. Depending on severity(Jordan & Boksman ) I-Light yellow or gray stain II-Yellow-brown or deeper gray stain III-Brownish-yellow or blue-gray stain with distinctive banding

17. May arise endemically from naturally occuring water supplies or from fluoride delivered in mouth rinses, tablets or toothpastes as a supplement. High concentration of fluoride in excess of 1ppm is believed to cause a metabolic alteration in the ameloblasts resulting in defective matrix and improper calcification. Fluorosis staining Mild- brown pigmentation Moderate- flat gray or white flakes Pitting- dark pigmentation with surface defects

18. Discoloration due to aging Enamel becomes thinner Dentin becomes thicker More yellow or grayish yellow Discoloration due to dental caries : opaque, white halo or gray discoloration. Bacterial degradation of food debris in areas of tooth decay or decomposing filling can cause even deeper brown to black discolorations.

19. Extrinsic tooth discoloration has been classified according to its origin Metallic Non-metallic. Metallic staining of teeth may be associated with occupational exposure to metallic salts and with a number of medicines containing metal salts. Extrinsic discoloration Black staining iron supplements and iron foundry workers Violet to black color Potassium permanganate in mouth rinses. Golden brown Stannous fluoride Grey color silver nitrate salt

20. Non-metallic extrinsic stains are adsorbed onto tooth surface deposits such as plaque or the acquired pellicle . Non-metallic stains Tobacco(smoking) Tea stain Coffee stain Stain induced by use of chlorhexidine mouthwash Stain from use of antibiotics Green stain from chromogenic bacteria

21. Classification of extrinsic stain Based on chemistry of the discoloration – Nathoo 1997 N1 type dental stain: The chromogens binds to the tooth surface to cause tooth discoloration. N2 type dental stain : The chromogen changes color after binding to the tooth. N3 type dental stain : The pre- chromogens binds to the tooth and under goes a chemical reaction to cause a stain.

22. Mild discoloration on surface Evenly distributed discolorations without bands or white spots Teeth discolored as their innate colors or ageing Hemorrhagic discoloration Discoloration of anterior teeth after rct Medication discoloration Indications

23. Sensitive teeth i.e. severe cases of attrition, abrasion, erosion or abfraction . Cracks, hypoplastic or severely undermined enamel. Extensive restorations. Discolorations in the gray, blue gray or black range . Discolouration by metallic salts, particularly silver amalgam, Enlargement of the pulp or other disease that makes the tooth sensitive to bleaching solutions Contraindications

24. Generalized dental caries Lack of compliance Pregnancy and nursing Peroxide allergy: A carefully applied rubber dam can help prevent reactions. Contraindications

25. Bleaching materials

26. Individual materials HYDROGEN PEROXIDE CARBAMIDE PEROXIDE SODIUM PERBORATE

27. Hydrogen peroxide Various concentrations of this agent are available, but 30 to 35% stabilized aqueous solutions ( Superoxol ) are the most common. Clear, colorless, odorless liquid, stored in lightproof amber bottles. Unstable and should be kept away from heat, which could cause it to explode. Can alone be used or mixed with sodium perborate into a paste for use in the ‘Walking bleach’. Caustic and burns tissues on contact. Delivery in an alkaline medium improves its oxidizing efficiency.

28. Sodium perborate Oxidizing agent is 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. Sodium perborate is stable when dry. S.P + H2O  S.M.Borate + H2O2 S.P + H2O2  S.M.Borate + H20 + O2 THREE TYPES OF SODIUM PERBORATE PREPARATIONS ARE AVAILABLE: Monohydrate Trihydrate Tetrahydrate They differ in oxygen content, which determines their bleaching efficacy.

29. THREE TYPES OF SODIUM PERBORATE PREPARATIONS ARE AVAILABLE: They differ in oxygen content, which determines their bleaching efficacy.

30. Carbamide peroxide Also known as urea hydrogen peroxide, Is a bi-functional derivative of carbonic acid Available in the concentration range of 3 to 45%. Popular commercial preparations contain about 10% carbamide peroxide, mean Ph of 5 to 6.5.

31. C.P  3% H2O2 + 7% Urea H2O2  H2O + 2(O) and Urea  NH3 + CO2 H2O2 is the active ingredient whereas urea raises the ph of the solution Bleaching preparations containing carbamide peroxide usually also include Carbopol , urea, glycerine , preservatives and flavoring agents.

32. CARBOPOL A water-soluble polyacrylic acid polymer Thickening agent, resulting in better retention in the night guard Increase in length of bleaching-solution strength for carbamide peroxide Slows rate of oxygen release extending duration of bleaching action. Improves shelf life.   Increase in length of bleaching-solution strength for carbamide peroxide bleaching preparations with carbopol vs those without carbopol .

33. Chemistry The bleaching process is based on the oxidation of the bleaching agent. Oxidation is the chemical process by which organic materials are converted into carbon dioxide and water. The oxidation-reduction reaction that takes place in the bleaching process is called the REDOX REACTION. Before the bleaching process, tooth is the reducing agent and bleaching material is the oxidizing agent. After bleaching, tooth is oxidized i.e. organic pigment of tooth is oxidized and the bleaching material is reduced.

34. Low PH High PH The free radicals produced by the peroxides are perhydroxyl and nascent oxygen. Of these, the perhydroxyl is a more potent free radical, which is responsible for a better bleaching action The buffering of peroxide to a pH range of 9.5 to 10.8 provides a greater amount of perhydroxyl free radicals.  

35. Mechanism High molecular weight Complex organic molecules ( chromogens )-unsaturated double carbon bonds + Bleaching agent Low molecular weight organic molecules (relatively colorless)-saturated carbon bonds

36. Oxidation of beta carotene. A free radical acts at the unsaturated (double) bond (jagged line), producing two molecules of colorless vitamin A.

37. Saturation point Prolonged use of a bleaching agent causes the whitening action to slow down beyond a point during the treatment. Ideally, this is the point at which whitening should be terminated. If the degradation process continues, there is further decomposition of organic matrix, resulting in a total loss of enamel matrix protein.

38. Diagnosis and Treatment Planning

39. Pt education and informed consent Careful diagnosis a) Visual examination : Thorough visual examination, which will generally indicate the cause of dental staining and the extent and depth of discoloration. b) Behavioral history : Previous and current use of tobacco, coffee or tea, and highly colored beverages and foods.

40. c) Medical history: Focus on any systemic problems or medications that might have affected . problems begin during critical periods of tooth development needs to be investigated through the prenatal period. d) Determining soundness of individual teeth vitality Periapical or other pathologic condition. Caries Defective restorations Any enlargement of the pulp

41. 3. Record keeping with photographs and shade selection Use intra oral video camera or high quality 35-mm camera. These photographs will provide an excellent record of pre-treatment state. It also will help the patient to later recall how he or she looked before any treatment and to recognize the cumulative effect of what may be a gradual improvement in tooth colour . Before After

42. 4) Preperation of the patient Protective draping and eye wear No local anesthesia is administered (vital)

43. Application of Orabase /Vaseline on labial and lingual tissues And vaseline on lips Rubber dam of heavy gauze is used Punched holes –smaller in size

44. Stabilization in the cervical areas with dental floss

45. 5)Oral prophylaxis A thorough prophylaxis, using Prophy -Jet 30 ( Dentsply ), will enable visualization of the extent of deep stains better prepare the teeth for treatment. may remove enough of extrinsic stain, calculus and plaque to satisfy some patients without further bleaching.

46. Bleeching techniques v Bleaching procedures can be classified depending upon   A. Tooth vitality - into: a. Vital tooth bleaching procedures b. Non-vital tooth bleaching procedures B. Site/Venue of acquiring treatment, into: a. In - Office / chair-side b. Home bleaching / out of the office

47.   Bleaching Non vital vital In office Night guard Walking bleach In office

48. Bleaching of vital teeth

49. The techniques used for bleaching of vital teeth IN-OFFICE BLEACHING: Also called as Chairside bleaching. Thermo/Photo Bleaching Bleaching using Mc Innes solution Power Bleaching DENTIST PRESCRIBED HOME-APPLIED BLEACHING: - Matrix bleaching-or night guard vital bleaching OVER-THE-COUNTER KITS Whitening strips Whitening pastes Tray-based bleaching systems

50. In office bleaching a) Thermocatalytic method Moisten gauze Place cool wet gauzes

51. Apply etching solution (37%phosphoric acid) Wash the etching solution After 10 secs Chalky white appearance In office bleaching

52. SUPEROXOL Wet the gauze Apply saturated gauze to labial surface

53. On lingual surface Protection lenses for the pt

54. Keep the light about 30 cms (13 inches) from the teeth and direct the beam to the surface to be bleached temperature ranges from 115°-140°F.

55. Add new solution at every 4 to 5mins Use a timer Removal of dam, wiping, rinsing and neutralization with Na gel

56. Disavantages of conventional bleaching light Great heat is generated during bleaching which can result in tooth sensitivity. Causes tooth dehydration Uncomfortable for patient Slower in action

57. Power bleaching In this technique, high intensity light, which was used as a heat source, is replaced with conventional halogen units, plasma arc lamps, LED lights, Xeno halogen lights and lasers. ADVANTAGES Time factor(fast result) Avoids problems of home bleaching DISADVANTAGES Caustic nature of 35-50% HP Increased in office time Dehydration of teeth resulting in false light shade Expensive

58. Energizing/activating source Dental chair light Halogen curing lamp Plasma arc bleaching unit Diode laser Ultrasonics

59. Tungsten-Halogen curing light: - Curing light provides heat - Time consuming process(40-60sec/tooth) Xenon Plasma arc light Non laser, high-intensity light Adv: Very fast 3sec/tooth Dis adv: Thermal trauma to the pulp and surrounding soft tissues

60. Laser bleaching technique When the source of activation is laser it is known as laser bleaching technique. Types of lasers 1)Carbon dioxide 2)Argon 3)Diode

61. Argon laser: A true laser is delivered to chemical agent 488nm WL, Blue light, absorbed by dark stains Action is to stimulate the catalyst in the chemical. Adv: - No thermal effect, -Less dehydration of enamel, -Less time(10sec/tooth)

62. Carbon dioxide laser : (10,600nm) Invisible infrared light, energy is emitted in the form of heat Directly interacts with catalyst/peroxide Deeper penetration Diode laser light: - 830 and 980 nm - It is ultra fast 3-5 sec to activate the bleaching agent Adv: Produce no heat

63. Mixing hydrogen peroxide: (a) the powder is introduced to the liquid by pressing down to the release cap; (b) arrow shows the broken seat; the powder and liquid can now be mixed by gentle agitation; (c) the activator is added and the contents begin to gel; (d) the finished product – a thick glue that can be placed on to the teeth.

64. Adv of laser bleaching Faster It may act as a jump start for difficult cases by helping to remove difficult stains caused by tetracycline and fluorosis Disadvantages Expensive Post operative sensitivity can be high.

65. Ultrasonic technology( Soni white) Uses ultrasonic technology with 6-7.5% HP gel Two cycles of 5 mins

66. Gel is mixed to get good consistency A 2-3 mm layer of freshly mixed gel should be applied to all the labial surfaces of teeth in the smile zone and lipped over to cover the incisal edges and extend slightly lingually or palatally Activation with or without light source depends on the bleaching system used. Procedure:

67. The gel is left in place for a length of time dependent on the system and the cocentration of HP used, usually about 10mins, but can range from 3-20 mins at a time. Gel is suctioned off the teeth using high volume suction, rinsed , wiped using damp gauze before being lightly dried

68. The application and activation procedure is repeated one more time before final washing and drying of the teeth. Power bleaching procedures usually involve three 10-minute passes. Surrounding mucosa are examined for blanching or areas of redness indicating hydrogen peroxide seepage through the isolation. Areas of damage should be thoroughly washed with copious amounts of water before the application of a neutralizing agent, such as vitamin E, usually supplied within the bleaching kits Antioxidants

69. Polishing with a diamond polishing paste gives a high lustre . Application of a neutral colorless fluoride gel. Final shade assessment and postoperative photographs. Patients should be given postoperative instructions.

70. NIGHT GUARD BLEACHING/ HOME BLEACHING TECHENIQUE Introduced by Dr. Van Haywood and Dr. Harald Haymann in 1989. Dentist prescribed home bleach technique.

71. Home bleaching is a simple technique whereby, after an initial consultation with the dentist, a mouth guard or tray is made for the patient to bleach the teeth at home. The patient is given the bleaching materials (normally 10% carbamide peroxide) to take home together with a bleaching protocol. The patient applies the bleaching material into the tray. The tray with the material is worn for several hours during the day or at night depending on the patient's schedule, while the teeth lighten.

72. Various names have been associated with home bleaching are : Nightguard Vital Bleaching Matrix bleaching Dentist-assisted / prescribed home-applied bleaching Dentist-supervised at-home bleaching At-home bleaching

73. Advantages Simple and fast Simple for dentists to monitor without extended clinical time. It is cost effective It is not usually a painful procedure. Patients can bleach their teeth at their convenience Results relatively quick.

74. Disadvantages Patients need to participate actively in their treatment. The color change is dependent on the amount of time the trays are worn. The system may be open to abuse by using excessive amounts of bleach for too many hours per day. It is difficult for patients who react easily to tolerate the bleaching trays in their mouth.

75. Clinical steps Clinical examination of all teeth Pre-existing shade evaluation Alginate impression of the arch to be taken.

76. Tray :step by step Model prepared Block resin applied on the labial surface of the teeth to be bleached to form a small reservoir for the bleaching agent. Cast a model

77. BIOSTAR Fabrication of bleaching tray is done using BIOSTAR Place the model on the base section of the vacuum tray forming machine. Ensure that the plastic sheet is properly placed over the model. Model and tray material in position

78. Plastic sheet is now more easily removed from the press. Scalloping the tray on the buccal / facial surface of the model using a heated scalpel blade. Tray trimmed 1mm above the gingival margin . Molded plastic tray Polishing of the tray is done gently with a special soft cotton wheel. Finished tray placed back on the cast to prevent distortion. Finished upper tray

79. BRUSHING FLOSSING Bleaching material is placed on the buccal surfaces of the tray

80. Gentle finger pressure is applied to the tray to improve retention and suction while removing the excess material at the same time. Insufficient material is placed into the tray. The tray is over extended. More material is added

81. STORAGE

82. Familiarize the patient with the use of bleaching agent and wearing the guard, instruct the patient that this procedure should be performed 3-4 hours per day or over night . Recall the patient every 2 weeks to monitor stain lightening.10% carbamide peroxide is used for this technique ,this can be later increased to 16%,or up to 20% as per the case reqirements .

83. Side effects of night guard Gingival irritation Soft tissue irritation. Altered taste sensation Tooth thermal sensitivity

84. Active treatment Passive treatment Active treatment Fluoride toothpaste Neutral sodium fluoride gel Potassium nitrate-fluoride gel Treatment of tooth sensitivity

85. Passive treatment The bleaching technique can be modified: Excess material is removed. Patient can use a bleaching gel with a lower concentration. Reduce daily treatment time or bleach every other night. Patient should not replenish the bleaching solution more than once. Dentist can ensure that the tray is trimmed back further so that it is not impinging on the gingiva .

86. Bleaching agent – Old / New McInnes solution   Old Mc Innes(Acidic medium -4.6) New Mc Innes(Alkaline medium-9) Ratio Ratio Bleaching enamel 30% H 2 O 2 5 parts 30% H 2 O 2 1 part Etches enamel 36% HCl 5 parts     Removes surface debris 0.2% ether 1 part constituent constituent 20% NaOH 1 part 0.2% ether 1 part

87. New Mc Innes solution HCL has some deliterious effects such as Loss of contour Irritation of gingiva Sensitivity of teeth Chen,Xu and Shing (1993) HCL replaced by NaOH 20% NaOH is highly alkaline in nature and therefore dissolves calcium at a slower rate. Loss of contour is minimized.( Nagarani et al )

88. Procedure: The solution should be freshly mixed and applied directly to the enamel surface for 5min at 1-min interval On completion of the bleaching, the solution is neutralized with a baking soda solution and copious irrigation with water. Bleached surface should be poolished with cuttle disc and a prophylactic paste. Procedure may have to be repeated 2 or 3 times before the desired shade is obtained.

89. Preoperative photograph Postoperative photograph Fig. 20.13; Materials used for bleaching Fig. 20.14 : Application of Vaseline Fig. 20.15:Application of rubber dam Fig. 20.16:Application McInnes solution Fig. 20.17:Irrigation done with warm water 20.15:Application of rubber dam

90. ASSISTED BLEACH TECHNIQUE OR WAITING ROOM BLEACH TECHNIQUE This bleaching technique was invented by Den- Mat. The dentist applies the 35% carbamide peroxide into a custom-made bleaching tray. After the excess material is removed, the patient returns to the waiting room for a period of about 30 minutes with the bleaching tray in the mouth. After 30 minutes, the bleach is suctioned off the teeth before rinsing. The procedure can be repeated 2 -3 times more in one session.

91. COMPRESSIVE BLEACHING TECHNIQUE This technique, reported by Miara , suggests that the Power bleaching technique can be made more effective by compressing the gel against the teeth. In order to enable the permeation of oxidizing ions through the enamel, the nascent oxygen must be guided under pressure. The procedure involves the usual isolation and placement of 35 % hydrogen peroxide gel in custom made tray, which is put in place and any excess material is removed before the lingual and buccal edges of the tray are sealed with light cured resin material to prevent any leakage during decomposition.

92. Once edges are sealed , the gel is activated using either a halogen light or plasma arc. After 30 minutes the gel and isolation are removed and teeth are washed . Sealing the margin of the tray with composite resin

93. Vivastyle paint on The professional varnish system for whitening teeth

94. Why use a varnish system ? Vivastyle paint on is insoluable in water. Consequently, the varnish is not prematurely washed off the teeth by saliva. Vivastyle paint on contains 6% carbamide peroxide when applied. This component releases oxygen , which gently lightens stains. Once it has dried, its concentration is about five times higher.

95. Steps of application Available as standing tube with brush and dispensing dish for single use

96. Brushing and flossing of teeth before application of varnish

97. Drying with blotting Paper Applying protective Gel

98. Vivastyle paint on is applied directly to the teeth with a brush and allowed to dry for 30 seconds

99. The dried varnish remains on the teeth for 20 minutes and is subsequently removed with a toothbrush. APPLICATION OPTIONS Once daily for 20 min. over a period of 14 days. Twice daily for 20 min. over a period of 7 days .

100. CLINICAL RESULTS - Noticeable whitening of teeth after just a few days -Less irritation

101. Advantages professional tooth whitening without a tray, as Patients find tray application uncomfortable Patients are looking for a more cost-effective alternative smooth integration into daily schedule gentle application touching up of previously whitened teeth

102. OVER THE COUNTER PREPARATIONS Whitening strips (The Trayless Approach to Tooth Whitening) Thin,flexible polyethylene strips coated one side with a film of H 2 O 2 Worn for 30mins , twice a day

103. Duration: 6% coated H 2 O 2 worn over 14 days 10% coated H 2 O 2 worn over 10 days Adv: No tray is needed Less visible No gagging, salivation, speech problem, jaw joint problem. More convenient & compatible

104. Fig. 20.31

105. Microabrasion It is a procedure in which a microscopic layer of enamel is simultaneously eroded and abraded with a special compound leaving a perfectly intact enamel surface behind. INDICATIONS All surface stains from external sources such as tea, coffee , tobacco Incipient carious lesion, usually located near the gingival margin, appear as opaque or chalky white when dried but are invisible when hydrated. Developmental discoloured spot ,may be traumatic event or idiopathic Surface discolouration due to fluorosis , if the discolouration is within 0.2 – 0.3 mm removal depth limit.

106. Contraindications Deep enamel and dentin stains Compound used( Croll ) Paste containing 11%HCl and silicon carbide particles (marketed as Prema )

107. M ICROABRASION TECHNIQUE Compound applied with ahand application device or with a rubber cup in a low-speed hand piece. Periodically the paste is rinsed away to assess defect removal. Care must be taken not to remove exessive tooth structure. The treated area is polished with a fluoride containing prophy paste to restore surface luster. Immediately following treatment a topical fluoride is applied to enhance remineralization. Final results are seen in fig.

108. Non vital tooth bleaching/ Intra coronal bleaching

109. NON VITAL BLEACHING Darkening and loss of translucency may follow loss of vitality, both before and subsequent to endodontic therapy. In case of Acute trauma. Seepage of toxins from a necrotic pulp Staining form medicaments, cements, metal posts , or the optical effects of dehydration

110. Successful bleaching depends upon two important criteria- The root canal obturation must be complete. In order to prevent an endodontic failure, the root canal system must be filled in three dimensions The remaining tooth structure must be intact

111. Intracoronal bleaching : The material is sealed into the access cavity during in-office visits and requires frequent changing of dressings: Walking Bleaching Technique: Sodium perborate and water sealed into the tooth . Modified intracoronal bleaching technique : Various increasing hydrogen peroxide concentrations and sodium perborate is used. Intracoronal bleaching using the thermocatalytic technique or other forms of heat or heating instruments

112. Open chamber bleaching. Combining intra- and extracoronal bleaching; the material is applied into the pulp chamber directly and retained with a home bleaching matrix. Inside/Outside technique with bleaching tray using different concentrations of Carbamide peroxide Closed chamber bleaching The bleaching material is placed on the external surfaces of the tooth. Power bleaching using 35% hydrogen peroxide Nightguard Vital Bleaching using 10%, 15% or 20% applied only to the non-vital tooth in the tray

113. INDICATIONS CONTRAINDICATIONS Discoloration of pulp chamber origin Superficial enamel discolorations Dentin discolorations Defective enamel formation Discolorations not amenable to extra coronal bleaching Presence of caries Discolored composite restoration Severe dentin loss

114. Familiarize the patients with possible causes of discoloration. Radiograph to assess the status of periapical tissues and quality of endodontic obturation . Evaluate tooth color with the shade guide Isolate the tooth with rubber dam

115. Cavit and GIC base at least 2 mm thick to cover the endodontic obturation.

116. Remove all restorative material from the access cavity. Remove all the materials to a level just below the labial gingival margin Apply a sufficient thick layer , at least 2mm of protective white cement barrier ,such as zinc phosphate cement ,GIC, intermediate restorative materials The material is placed at correct depth snugly, using a flat plastic or endodontic plugger

117. Prepare the walking bleach paste by mixing sodium perborate and inert liquid , such as water etc. Pack the pulp chamber with the paste. remove the excess liquid by tamping with a cotton pellet. Carefully pack the temporary filling at least 3mm thick, to ensure a good seal

118. PRE AND POST OPERATIVE Before After

119. Hydrogen peroxide gel (30-35%) is placed in the pulp chamber and activated either by light or heat. The temperature is usually between 50 and 60°C maintained for 5 minutes The gel is removed by washing with water for a further minute. The tooth is dried and the 'walking bleach technique' is used between visits until the tooth is reviewed 2 weeks later to assess if further treatment is necessary. THERMO/PHOTOCATALYTIC BLEACHING PROCEDURE

120. External root resorption Chemical burns Damage to the restoration Suggestions for safer non vital bleaching Isolate the tooth effectively Protect oral mucosa- Vaseline, catalase applied to oral tissues Verify adequate endodontic obturation . Use protective barriers. Avoid acid etching Avoid excessive heat Recall patients periodically. Complications and adverse effects

121. Combined bleaching technique Inside/Outside bleaching technique Internal/External bleaching, Patient-administered intracoronal bleaching technique Modified walking bleach technique. The technique combines the intracoronal bleaching technique with the home bleaching technique. It is used to lighten non-vital teeth in a simple manner. After barrier replacement the access cavity is left open so that the bleaching material which is normally 10% carbamide peroxide, can be placed into the pulp chamber while the bleaching tray is applied to the tooth to retain the material on the tooth. Bleaching can thus take place internally and externally at the same time. This technique is a modification of the intracoronal bleaching technique.

122. Benefits More surface area is available both internally and externally for the bleach to penetrate. A lower concentration (10% Carbamide peroxide with neutral pH) of the bleach is used. This technique will hopefully eliminate the incidence of cervical resorption that has been reported with the conventional intracoronal bleaching technique. The need to change the access cavity dressing is eliminated as the access cavity is left open. Treatment time is reduced to days rather than weeks No heat is required to activate the bleaching material.

123. There have been many reports regarding the relationship between bleaching agents and the bond strength of composite materials to enamel following bleaching. Many investigators have reported a severe decrease in the average bond strength of composite to bleached versus unbleached enamel . Surface roughening and etching may occur and tensile strength is affected (Singleton and Wagner ,1992) It has been noted that the resin tags are reduced in number , less defined and shorter in bleached enamel . Bleaching has been shown to increase the micro leakage of existing restorations. Effects of bleaching on composite restorative materials

124. Effect of bleaching agents on other materials: Microstructural changes in amalgam. Alteration in the matrix of glass ionomers . IRM becomes cracked and swollen. Provisional crowns made from methyl methacrylate discolor and turn orange.

125. BriteSmile Whitening Pen Easy to use Dries rapidly. Just two easy 30-second applications a day for two weeks, then use as desired. Each Whitening Pen last for 30 days of whitening applications

126. Colgate visible white ZOOM whitening system Dr- collins - bleaching system

127. Nite White ACP has been clinically proven to remineralize teeth while also whitening them. Nite White rebuilds tooth enamel, making teeth stronger and less susceptible to caries .

128. Conclusion

129. Thank you

130. The use of bleaching agents provides an effective and conservative approach to the removal of unesthetic discolorations from vital & non-vital teeth. As with all therapeutic modalities, proper diagnosis and planning is essential.   conclusion

131. Argon laser: A true laser is delivered to chemical agent 488nm WL, Blue light, absorbed by dark colour Action is to stimulate the catalyst in the chemical. Adv: No thermal effect, Less dehydration of enamel, Less time(10sec/tooth) TYPES OF LASERS IN BLEACHING

132. Carbon dioxide laser: (10,600nm) Invisible infrared light, energy is emitted in the form of heat Directly interacts with catalyst/peroxide and Deeper penetration Diode laser light (power bleaching) - 830 and 980 nm - It is ultra fast 3-5 sec to activate the bleaching agent Adv: Produce no heat

133. Other techniques Waiting room bleaching (35% CP) Uses custom made tray gel injected from syringe under hot water Placed in mouth, excess wiped Asked to sit in waiting room for 30 mins Gel suctioned ,rinsed and dried .

134. Compressive Bleaching technique Power bleaching technique reported by Miara 35% HP gel Custom made tray is sealed using light cured resin material Light activated for 30 mins Ultrasonic technology( Soni white) Uses ultrasonic technology with 6-7.5% HP gel Two cycles of 5 mins each

135. Diagnosis and treatment planning HISTORY CLASSIFICATION BUR BLADE DESIGN ADDITIONAL FEATURES IN HEAD DESIGN MODIFICATIONS OF BLADE DESIGN FACTORS AFFECTING CUTTING EFFECIENCY

136. Diagnosis and treatment planning HISTORY CLASSIFICATION BUR BLADE DESIGN ADDITIONAL FEATURES IN HEAD DESIGN MODIFICATIONS OF BLADE DESIGN FACTORS AFFECTING CUTTING EFFECIENCY

137. Thank you