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Discoloration

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Various types of Discolorations of teeth and their management

Various types of Discolorations of teeth and their management

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  • 1. Good morning
  • 2. DISCOLORATION and its MANAGEMENT
  • 3. Contents • Introduction • Classifications • Extrinsic discolourations • Intrinsic discolourations • Tetracycline discolourations • Enamel hypoplasias • Management
  • 4. Contents • Management of Extrinsic stains 1. Prophylaxis 2. macroabrasion • Management of Intrinsic stains 1.Microabrasion 2.Bleaching • Non-Vital Bleaching • Vital Bleaching 3.Composite Resin Restorations 4.Porcelain Veneers Combination Management
  • 5. Introduction • Tooth colour varies between the edge and the neck of the tooth, from one group of teeth to the next, and from person to person. • Incisal /occlusal 3rd • Middle 3rd • Cervical 3rd
  • 6. • Only enamel alone is not responsible for the colour of the tooth, four dental tissues are involved in creating the final shade. • Teeth are formed of : 1. Pulp, vital non-mineralised but richly innervated and vascularised; 2. A layer of Dentin situated around the pulp, thickens with age, with a rate of apposition of approximately 4 micrometres per day. Consequently, teeth take on a deeper shade with time;
  • 7. 3. Enamel, which covers the dentin in the coronal portion of the tooth; 4. Cementum, which covers the dentin in the root of the tooth – the colour of the cementum is involved quite late in the overall shade of the tooth, as it only appears in cases of dysfunctional upper lips, and after gingival recession.
  • 8. • Tooth colour is determined by certain physical properties of enamel and dentin, and successive stages of dental tissue development. • Studies show that dentin plays major part in final shade of a tooth. • Various assumptions and experimental evidence have led to the conclusion that enamel has a certain degree of translucency, but no intrinsic colour.
  • 9. Enamel as a „bioglass‟ • Enamel acts as a bioglass that filters the natural colour of the dentin. • With regard to physical properties, tooth colour depends on the trajectory of the light that hits the tooth, on how this trajectory is deviated and on how the light is absorbed.
  • 10. Ingle defines tooth discoloration as “Any change in the hue, colour or translucency of a tooth due to any cause; restorative filling materials, drugs ( both topical & systemic), pulpal necrosis, or hemorrhage may be responsible.” Tooth discoloration
  • 11. Ingle classifies tooth discoloration acc. to etiology: Patient related cause Dentist related cause Pulp Necrosis Intra-pulpal hamorrhage Pulp tissue remanants Calcific metamorphosis Age related Intracanal medicaments Obturating materials Developmental defects in tooth structure •Enamel hypoplasia •Dental fluorosis •Eryththroblastosis fetalis •AI & DI Amalgam Pins & posts Tetracyclines Resin composites
  • 12. P r e - e r u p t i v e
  • 13. Extrinsic discoloration
  • 14. Extrinsic Staining • Located on the outer surface of teeth • The etiology for extrinsic stains include: – Non-enzymatic browning (maillard reactions which are the natural process of degradation of glycosylated proteins), – protein denaturation, – formation of pigmented metal sulfides, – precipitation of dietary chromogens and their subsequent incorporation into the salivary pellicle.
  • 15. Extrinsic discoloration
  • 16. Classifications The Nathoo classifies extrinsic dental stain under 3 categories as follows : • Nathoo type 1 (N1) direct dental stain : N1- type colored material (chromogen) binds to the tooth surface. The color of the chromogen is similar to that of dental stains caused by tea, coffee, wine, chromogenic bacteria, and metals.
  • 17. • Nathoo type 2 (N2) direct dental stain : N2-type colored material changes color after binding to the tooth. The stains actually are N1-type food stains that darken with time. • Nathoo type 3 (N3) indirect dental stain : N3-type colorless material or prechromogen binds to the tooth and undergoes a chemical reaction to cause a stain. N3- type stains are caused by carbohydrate-rich foods (eg, apples, potatoes), stannous fluoride, and chlorhexidine .
  • 18. • Classification based on origin of stain – Non-metallic – Metallic in origin. • Non-metallic extrinsic stains arise from chromogens released into the oral cavity during ingestion of dietary components, beverages (specifically coffee and tea), mouth rinses, medicaments, or the habitual use of tobacco products. These dietary chromogens get absorbed into dental plaque or the acquired tooth pellicle.
  • 19. – Chlorhexidine antiseptic mouth rinse has been observed to cause diffuse brown staining with prolonged use especially around composite restorations. – Tobacco staining results from the deposition of tar products on the tooth surface and may penetrate enamel.
  • 20. • Metallic stains have been reported to be associated with occupational exposure to metallic salts and dietary supplements that get incorporated into dental plaque and acquired pellicle. – Black staining has been linked to individuals using iron supplementation and iron factory workers. – Green staining has been seen on the teeth of factory workers exposed to metallic copper as well as mouth rinses containing copper salts.
  • 21. • Data regarding the role of oral chromogenic bacteria leading to tooth discoloration has not been substantiated in the literature. As a result its location on the external tooth surface substrates, external stains overall have relatively good prognosis. • The extrinsic staining of teeth is a growing esthetic concern for business, social, and other reasons. The consideration attached to stained teeth correlates to poor oral and general hygiene.
  • 22. Intrinsic discoloration
  • 23. Intrinsic discoloration • Intrinsic discoloration can be defined as discoloration which is incorporated into the structure of either enamel or dentine and which cannot be removed by prophylaxis with toothpaste or pumice. • It can be a significant cosmetic, and in some instances, functional, problem. • Loss of vitality secondary to trauma or infection frequently results in tooth discoloration which is not responsive to conventional endodontic therapy. • Similarly fluorosis, tetracycline staining, localised and chronological hypoplasia, and both amelogenesis and dentinogenesis imperfecta can all produce a cosmetically unsatisfactory dentition.
  • 24. History • Specifically: • Details of the mother‟s obstetric history and the delivery; • Medical history including neo-natal or early childhood illness and any drugs taken; • Dental history - infections relating to primary teeth; trauma to the primary and permanent teeth; • Family history of discoloured or abnormal teeth; • Fluoride history including supplementation, residence in natural water fluoridation areas, • Tooth-brushing habits including the amount of paste used, the type of paste in childhood and any admitted swallowing of paste.
  • 25. Etiology Within Enamel: • Local: caries; idiopathic; injury/infection of primary predecessor; internal resorption. • Systemic: amelogenesis imperfecta; drugs,eg.Tetracycline; fluorosis; idiopathic; systemic illnesses during tooth formation. Within Dentine: • Local: caries; internal resorption; metallic restorative materials; necrotic pulp tissue; root canal filling materials. • Systemic: bilirubin (haemolytic disease of the newborn); congenital porphyria; dentinogenesis imperfecta; drugs,eg.Tetracycline.
  • 26. Clinical examination • Specifically – • Both dentitions are affected or not, • Whether all teeth in one dentition are equally affected. • Whether or not there is a symmetrical or chronological pattern. • If possible, the extent of discoloration should be identified with respect to the depth of affected enamel or dentine.
  • 27. Tetracycline discolouration • Tetracycline broad-spectrum antibiotics - introduced in 1948 • Used for treatment of many common infections found in both children and adults. • Tetracyclines - its compounds consist of four fused cyclic rings • Many systemic side effects – pregnant women are particularly susceptible to tetracycline-induced hepatic damage (Madison 1963). • It also crosses the placenta and has toxic effects on the developing foetus-therefore contraindicated during pregnancy. • Tetracycline antibiotics are still commonly used in the treatment of acne in adolescents and young adults. This long term use of tetracycline in particular Minocyline (Minocin) which is a semi synthetic tetracycline derivative can also cause staining of the adult teeth (Cheek and Heymann 1999).
  • 28. Effects of tetracyclines on teeth • One of the most obvious and well-documented side-effects of tetracycline use is it‟s incorporation as a fluorescent pigment into tissues that are calcifying at the time of administration. • It has the ability to chelate calcium ions and to be incorporated into teeth, cartilage and bone, to form a tetracycline-calcium orthophosphate complex (Eisenberg 1975) resulting in discoloration and enamel hypoplasia of both the primary and permanent dentitions if administered during the period of tooth development. • The severity of the discolouration is considered to be related to dose, frequency, duration of therapy and critically the stage of odontogenesis.
  • 29. • The administration of tetracycline to pregnant women must be avoided during the second or third trimester of gestation and to children up to eight years of age because it may result in discoloration and enamel hypoplasia (Conchie 1970). • The drugs should not be given to nursing mothers, as they are also excreted in human milk (van der Bijl 1995). Adult-onset tooth discoloration following long- term ingestion of tetracycline (Di Benedetto 1985) has also been reported.
  • 30. • The discoloration is permanent and varies from yellow or gray to brown depending on the dose or the type of the drug received in relation to body weight. • After tooth eruption and exposure to light, the fluorescent yellow discoloration gradually changes over a period of months and years to a non-fluorescent brown color. • The labial surfaces of yellow-stained anterior teeth will darken in time while the palatal surfaces and buccal surfaces of posterior teeth will remain yellow. These changes are due an oxidation product of tetracycline, which is light induced (Bevelander 1961; Atkinson 1962) The affected teeth will also fluoresce bright yellow under UV light in a dark room.
  • 31. • Feinman et al. (1989) - clinical classification of the various degrees of tetracycline staining, indicating for each category the treatment prognosis: I. First degree staining: minimal, uniformly distributed, light yellow, light brown or light grey discoloration, restricted to three quarters of the incisal part of the crown. Good treatment prognosis. II. Second degree staining: staining varies more in quantity and location, ranging from deep yellow to brown or grey with no banding. Treatment prognosis is variable, as it depends entirely on the intensity of the staining.
  • 32. III. Third degree staining: dark brown, dark grey, purple or blue staining with marked banding. Prognosis for an efficient and aesthetic outcome is not good, although teeth may be lightened to some degree. IV. Fourth degree staining: intense pigmentation combining very dark stains with highly pronounced bands. Bleaching is inefficient in such cases.
  • 33. IJDA, 3(1), January-March,
  • 34. ENAMEL HYPOPLASIA • Its a defect in tooth enamel resulting in less quantity of enamel than normal. • The defect can be a small pit or dent in the tooth or can be widespread that the entire tooth is small and/or mis- shaped. • It may cause sensitivity, may be unsightly or may be more susceptible to dental caries. • Can occur one tooth or on multiple teeth. • It can appear white, yellow or brownish in color with a rough or pitted surface.
  • 35. • Environmental, genetic factors that interfere with tooth formation may cause EH. • Includes trauma to the teeth and jaws, • Intubation of premature infants, • Infections during pregnancy or infancy, • Poor pre-natal and post-natal nutrition, • Hypoxia, • Exposure to toxic chemicals and a variety of hereditary disorders.
  • 36. Management
  • 37. Extrinsic stains
  • 38. • Prophylaxis – The science and practice of preventing the onset of diseases of the teeth and adjoining mouth tissues. It involves removing bacterial plaque, food debris, stains, and calculus from the crowns and roots with hand scaling or ultrasonic scaling instruments and hand or electric polishers.
  • 39. Macroabrasion • Indicated for removal localized surface stains • 12 fluted composite finishing bur or a fine grit finishing diamond is used. • Light intermittent pressure is applied to avoid unnessecary removal of tooth structure. • After removal of defects 30 fluted composite finishing bur removes any striation on the surface • Surface is polished byabrasive rubber points.
  • 40. Intrinsic stains • Microabrasion • Bleaching – Non-Vital Bleaching – Vital Bleaching • Composite Resin Restorations • Porcelain Veneers
  • 41. Microabrasion • Involves the removal of a small amount of surface enamel • Classically incorporates both „abrasion‟ with dental instruments and „erosion‟ with an acid mixture, the term „abrosion „ has been used by some authors. • Superficial demineralisation. • Modifies the optical properties of enamel. • The treated enamel no longer reflects or refracts light in the way it used to, thus hiding the underlying stains.
  • 42. • There are two main techniques for microabrading discoloured or hypoplastic teeth. – hydrochloric acid/pumice technique – phosphoric acid/pumice technique • These techniques are simple to perform and the depth of enamel removed in 10 applications is approximately 100 μm. (0.1 mm.). If a satisfactory clinical outcome is not achieved the technique should not be repeated but an alternative treatment is selected.
  • 43. • Microabrasion is indicated for fluorosis, post- orthodontic demineralisation, localised hypoplasia due to infection or trauma, and idiopathic hypoplasia where the discoloration is limited to the outer enamel layer. • Analysis of the effectiveness of microabrasion should be delayed for approximately one month post- treatment, as the appearance of the teeth will continue to improve during this time. • Pre-operative sensitivity tests, radiographs and photographs are advised.
  • 44. Hydrochloric Acid / Pumice Microabrasion i. Clean teeth with pumice, water, wash and dry. ii. Isolate - rubber dam and either apply vaseline to the gingiva prior to rubber dam application or paint Copalite varnish around the necks of the teeth after dam application. iii. Mix 18% hydrochloric acid with pumice into a slurry and apply a small amount to the labial surface with either slowly rotating rubber cup, a wooden stick or flat plastic instrument over the surface for 5 seconds. Wash for 5 seconds directly into the aspirator. Repeat until the stain is reduced, up to a maximum of 10 x 5 second applications per tooth. Any improvement possible will have occurred by this time.
  • 45. iv. Apply fluoride drops to the teeth for 3 minutes. v. Remove the rubber dam. vi. Polish the teeth with graded Soflex discs or polishing pastes. vii. Polish the teeth with fluoridated toothpaste for one minute. viii.Review in one month for sensitivity tests and photographs. ix. Review in six months to check pulpal status.
  • 46. Phosphoric Acid / Pumice Microabrasion i. Apply phosphoric acid 35% to enamel surface for 30 secs, wash and dry. ii. Remove frosted enamel with tungsten carbide composite finishing bur using minimal pressure, until a shiny enamel surface reappears. iii. Clean teeth with pumice and water slurry in a slowly rotating rubber prophylaxis cup, and then wash again.
  • 47. • McInnes Microabrasion technique • McInnes solution is used, it‟s a mixture of o 30% Hydrogen peroxide – 5 parts (bleaches tooth) o 36% Hydrochloric acid – 5 parts (etches enamel) o Diethyl ether – 1 part (acts as solvent, stabilzes the solution) • Modified McInnes solution contains 20% Sodium hydroxide instead of Hydrochloric acid
  • 48. BLEACHING • It‟s a treatment modality involving an oxidative chemical that alters the light absorbing nature of a material structure, thereby increasing its perception of whiteness. • The chemical oxidation-reduction reaction takes place between the colouring substance (reducing agent) and the bleaching molecule (oxidising agent).
  • 49. Tooth Reducing agent takes up electron Bleaching agent Oxidizing agent gives free electron Free reactive radical reacts with the unsaturated bond Simpler molecules are formed Reflects less light or becomes colorless Larger stain molecules are converted to smaler ones
  • 50. • Oxidation reaction - molecular oxygen that penetrates into the mineralised dental tissues without altering them and degrades the pigments responsible for their coloration. • The oxygen molecules enter the organic enamel- dentin matrix and react with the organic molecules, i.e. dissociate the pigments by modifying the long dark-coloured molecular chains and splitting them into smaller and lighter-coloured molecules.
  • 51. Ideal bleaching agent 1. It should have neutral pH. 2. It should be easy to apply, maximum patient compliance. 3. It should not irritate or dehydrate oral tissues. 4. It should not cause any adverse effect to the teeth being bleached. 5. It should adhere to tooth structure i.e., controllable flow 6. It should have contrasting colour with the oral structure 7. Should have adjustable peroxide concentraion 8. It should give desired results within short time 9. Be well controlled by dentist to customize the t/t to the patient‟s need.
  • 52. BLEACHING AGENTS SODIUM DIOXIDE • Historical interest - limited use. • When sodium dioxide is combined with water, the reaction yields sodium hydroxide and oxygen: Na2O2 + H2O → 2 NaOH + 1/2 O2 • The molecular oxygen produced is a powerful antiseptic and bleaching agent. • When used in high concentrations on pulpless teeth, it has strong caustic effects that render it dangerous for the periodontium.
  • 53. CHLORINE AND CHLORINE DERIVATIVES • Chlorine acts indirectly as it is capable of releasing the oxygen from a water molecule: Cl2 + H2O → 2 HCl + 1/2 O2
  • 54. HYDROGEN PEROXIDE • It is the main bleaching agent used for tooth whitening, produced by the following reaction: H2O + 1/2 O2 → H2O2 • The resulting molecule is unstable and ready to split and release a molecule of oxygen. • The concentrations of H2O2 solutions are usually given in percentages or in volumes that indicate the quantity of oxygen released as a result of the breakdown reaction.
  • 55. • Because molecular dissociation occurs differently depending on the pH, the efficacy of H2O2 can be improved by modifying the pH of solution. • In an alkaline solution, the hydroxyl groups neutralise the protons and accelerate the bleaching process (Frysh, 1995). • The consumption of an element produced by the oxidation- reduction reaction will modify the balance, leading to the yielding of highly reactive HO2-, a molecule with a low molecular weight, far more oxidative than molecular oxygen, and which diffuses easily through the enamel barrier.
  • 56. SODIUM PERBORATE (BO3Na 4H2O) • Its a fine white powder, which is antiseptic and chemically stable when anhydrous. • When combined with water, it reacts to produce metaborate (BO3NA) and molecular oxygen: Na2 [B2(O2)2(OH)4] + 2H2O → 2NaBO3 + 2H2O2 BO3Na + H2O → 1/2 O2 + H2O • Metal peroxides, persulphates, calcium perborate and magnesium perborate (acting as anion breakdown activators) may also yield molecular oxygen, and are used by some in preference to sodium perborate. • The final product is an oxidising molecule produced by the breakdown of the hydrogen peroxide.
  • 57. CARBAMIDE PEROXIDE (H2NCONH2) a.k.a UREA-HYDROGEN PEROXIDE • Approved by FDA as an oral antiseptic in 1979 and as a medicament in 1991. • It is the most widely used vital-tooth bleaching product. • Obtained by the syncrystallisation of H2O2 and urea into colourless and odourless crystals. • Its chemical formula contains about 30% hydrogen peroxide. In other words, a 10% carbamide peroxide solution breaks down into 3% H2O2 : H2N -CO-NH2* H2O2 → H2NCONH2 +H2O2 In water
  • 58. • Carbamide peroxide yields urea, that further decomposes into CO2 and ammonia. • A high pH facilitates the bleaching process, i.e. in an alkaline solution, the formation of free radicals requires less energy, and the reaction yield is higher, with larger quantities of H2O2 being produced than in an acidic solution.
  • 59. ADJUVANTS  Improve the efficacy of tooth bleaching products.  Not always clearly mentioned by manufacturers: • Thickeners such as carbopol (acrylic acid polymer resin), which help to maintain contact between the gel and the dental tissues as long as possible and thus allow a progressive release of the oxidising agents; • Urea, which stabilises the hydrogen peroxide, increases the solution pH, and has an anti-cariogenic effect; • Glycerine, which increases the viscosity of the preparation and facilitates its manipulation. The only problem is the tooth dehydration it incurs; • Stabilisers (e.g. Citroxain, citric acid, phosphoric acid), which increase the shelf-life of bleaching products; • Flavourings, which make the products pleasanter to use.
  • 60. Bleachin g Vital At home In office Thermo/ Photo bleaching Non Vital Walkin g bleach In office Thermo catalytic UV Photo- Oxidation Intentional endo t/t & Intracoronal bleaching
  • 61. VITAL TOOTH BLEACHING Indications • Moderate tooth discoloration – Healthy teeth with perfectly sealed coronal fillings (preferably composite resin fillings), and teeth with no significant structural defect. • Discoloration related to genetic disorders; • Permanent acquired discoloration: – Fluorosis staining, with stains ranging from simple, white, opaque spots to a darker discoloration, or other types of staining caused by an excessive intake of fluoride.
  • 62. • Discoloration related to the physiological aging of teeth • Post-traumatic discoloration (vital tooth with sclerotic dentin). Relative indications • Improvement of the teeth's natural colour before the placement of a prosthetic restoration in the adjacent area. The patient should be warned that the lighter colour obtained after bleaching has a limited lifespan and that the procedure may eventually have to be repeated to adjust the colour of the ageing natural teeth to that of the prostheses.
  • 63. Relative contraindications • Very pronounced tooth stains with a dull and saturated coloration, where "colour bands" are visible, treatment in this case is a prosthetic alternative, i.e. the application on the affected teeth of a thin layer of covering material (veneer). • Tooth bleaching will be used here primarily to lighten the underlying tooth colour, thus limiting tissue destruction and improving the overall appearance of the restorations (Magne, 1997); • Teeth with extensive crown fillings; • Presence of cervical lesions due to wear, and dentin "islands" caused by occlusal attrition; • Stains mainly due to permeation by metal salts (amalgam).
  • 64. • Relative contraindications specific to the night-guard technique (bleaching trays): 1. Advanced periodontal disease (the bleaching tray must be trimmed precisely along the gingival margin) 2. Multiple and extensive amalgam restorations or temporary fillings (IRM) (Rotstein, 1995) 3. Articulation disorders (bleaching tray not suited to these cases) • Up to date, there are no scientific data to justify any reservations with regard to bleaching treatments in expectant or nursing mothers. Pregnancy gingivitis certainly constitutes a relative limitation, but is not a contraindication. • The marginal leakage problems that dental restorations may develop after bleaching can lead to the postponement of these non- priority treatments.
  • 65. Absolute contraindications • Young patients aged under 15-16 (immature tissues and large pulp volume); • Teeth that show initial hypersensitivity during the presurgical clinical examination; • Teeth with non leak-proof fillings, and initial or recurring caries. It is an absolute prerequisite to any bleaching treatment that carious lesions be fully treated and that all restorations fit perfectly; • Smoking (possible interactions with peroxides, according to Dahl and Pallesen, 2003).
  • 66. VITAL TOOTH BLEACHING TECHNIQUES • Vital tooth bleaching procedures, whether performed at home or in the office, are based on the fact that enamel acts as a semi-permeable membrane. They are therefore external procedures. These techniques use the bleaching agent that is released by the oxidation process, i.e. active oxygen, which filters into the dental tissues and progressively discolours the pigments inside the enamel, at DEJ and in external part of dentin.
  • 67. At-home bleaching (Claisse et al., 2000; Ritter et al., 2002; Haywood, 1997; McEvoy, 1989) • Its aka “nightguard” bleaching technique involves the use of a mouthguard to deliver the bleaching agent. • The first stage of the treatment – after the possibilities and limits of the technique have been explained to the patient – is to record the base line shade of the teeth or to take photographs of the dentition.
  • 68. Fabrication of the “bleaching tray” • Alginate impressions of the arches are made • Plaster casts are poured • Reservoirs are made that deliver the bleaching agent, at a distance of 1 mm from the gingiva. The light-cured resin spacers should be 0.5 mm to 2 mm thick, depending on the technique that will be used and above all, on the concentration of the product and the intensity of the stain;
  • 69. • Thermo forming a polyvinyl sheet over these models; • Trimming the tray along the gingival line using scissors once the tray has cooled down – or better still, directly on the model using a scalpel with an 11 mm blade; • Smoothing the edges using a micro-torch; – • Cleaning and cold sterilising the mouthguard before delivery.
  • 70. Fitting of the mouthguard and choice of bleaching product • The mouthguard should fit the patient‟s mouth perfectly. • The tray should be in close contact only with the hard tissues, as this prevents leakage of the bleaching product in the area of the gingiva, and encourages an in-depth action of lower-concentration bleaching agents (Barghi, 1998; Haywood, 1992). • The mouthguard should have a constricting effect in the critical area of the neck of the tooth.
  • 71. • The operator should choose the bleaching product and its conc according to the case, and determine the length of time during which the mouthguard should be worn. • The active compound is carbamide peroxide, which breaks down into urea and H2O2. It usually comes as a gel in a syringe, with conc ranging from 10% to 35%. It may be combined with thickeners (such as Carbopol) that slow down the degradation process of the carbamide peroxide, and with sodium fluoride that prevents dental sensitivity.
  • 72. Instructions to the patient • After thorough tooth-brushing, the patient should use the needle- tipped syringe to fill the reservoirs with moderate quantities of gel, • Then place the tray inside the mouth and finally rinse off any gel that may have leaked onto the gingiva. • The dentist will determine the length of time the mouthguard should be worn according to the product used. • Wearing time will last between three to five hours in one or two sessions every day, depending on the patient‟s availability and motivation, on any dental sensitivity observed during treatment, and on the results aimed at.
  • 73. • Nightguard systems with concentrations ranging from 10% to 16% are highly effective, owing to the fact that the salivary flow is reduced at night and that the bleaching agent & the tooth therefore stay in contact much longer (Ritter et al., 2002). • After removal, the mouthguard should be washed in cold water and the teeth cleaned thouroughly.
  • 74. Monitoring • The practitioner should check results every five to six days, in order to adapt the treatment to changes in tooth-shade and to clinical signs. To facilitate the monitoring of the process both by the practitioner and by the patient, and for psychological reasons. It is recommended to bleach 1st the upper &then the lower arch.
  • 75. Outcome • The outcome depends on 1. The length of time during which the mouthguard is worn, 2. The duration of the treatment 3. Concentration of and sensitivity to the product 4. On the intensity of the staining (Leonard et al., 1998; Matis et al., 2000). – • In cases of light staining, teeth are lightened up to 80% in 5-6 days. • In cases of severe staining (tetracycline), tooth shade may be improved to a more or less important extent in the first month of treatment, particularly in the occlusal third, by increasing the duration of the treatment. In such cases, the at home t/t may be continued over many weeks,some times even for months.
  • 76. In-office bleaching • Used for more severe cases and patients who are “in a hurry” (Baumgartner et al. 1983; Claisse et al., 2000; Feinman et al., 1989; Goldstein, 1976,1995; Torres-Zaragoza, 1984). • Many techniques have been developed since the 1970s They all involve the use of H2O2 in various concentrations: o Torres-Zaragoza (1984) - 70% H2O2 be used in association with a reagent, a pH-modifying agent, and a source of heat. o Goldstein - etched enamel - 35% H2O2 exposed to a beam of light with an adjustable temperature of 45 to 60 C (Goldstein, 1976; Goldstein and Garber, 1995). o Baratieri et al. (1995) employed 35% H2O2 activated by the light of a curing lamp.
  • 77. • Chairside bleaching techniques, contain either 15% H2O2 or 35% carbamide peroxide: • The in-office protocol starts with proper isolation (rubber dam or light-cured resin), the barrier should prevent the highly irritant bleaching agents from reaching the tissues around the teeth.
  • 78. • After the surfaces selected for t/t have been cleaned with a paste of pumice, whiting and water (prophylaxis pastes should be avoided as they contain glycerine which reduces the effectiveness of the peroxide), they are coated with a layer of bleaching product that will stay in place for 5 - 30 mins depending whether or not an activator is used • The application is renewed regularly (three times on average) throughout the procedure.
  • 79. • Acc. to some authors, the light from a traditional halogen lamp, a plasma lamp or an operating lamp placed in close proximity to the tooth surfaces being treated accelerates the breakdown process and improves the reaction (Glodstein, 1976; Goldstein and Garber, 1995; Torres-Zaragoza, 1984; Stabholz et al., 2003). • Other authors use the light (argon laser) or heat (CO2 laser) produced by laser beams. • The outcome is optimised by the cumulated effects of the photothermal, photomechanical and photochemical reactions. • The argon laser is particularly effective in treating darker stains. The CO2 laser is more versatile. However, the heat produced is partially absorbed (Smigezi, 1996) and appears to be the most harmful feature of the treatment (Luk and Hubert, 20Tavares et al., 2003). The use of these devices is considerably limited by their cost.
  • 80. dental materials ( 2 0 0 6 )
  • 81. dental materials ( 2 0 0 6 )
  • 82. • At the end of the session, the teeth are thoroughly rinsed, cleaned and polished, before being coated with a layer of sodium bicarbonate that neutralises the reaction. • The bleaching procedure may be repeated 2-3 times on each dental arch, at an interval of 1-4 weeks and that fluoride is applied to the teeth for a few days after the treatment, to limit temporary postoperative hyperaesthesia and to prevent any risks of pulpal or periodontal complications, which remain considerable.
  • 83. • Although these chairside techniques do achieve results, they are not entirely satisfactory, they are long to carry out, and often tiresome for the patient, they require specific and costly equipment (Goldstein, 1976; Goldstein and Garber, 1995; Torres-Zaragoza, 1984) and, because of their aggressive nature (Claisse et al., 2000; Luk et al., 2004; Nyborg and Brannstrom, 1968; Robertson and Melfi, 1980), they can only be performed and by specialists.
  • 84. • The latest chairside techniques use compression methods in conjunction with viscous or compact gels (Miara and Miara, 2003). The 35% H2O2 bleaching gel (Opalescence Xtra) is placed in a delivery tray sealed around the gingival margin, where it is compressed and activated during 10-15 min. • During the oxygen evolution, the compression and blocking induced by the perfectly-fitting delivery tray, combined with the use of a viscous or compact gel, encourages the oxygen ions to migrate towards the inside of the enamel rather than to be released into the surrounding air.
  • 85. • Current techniques use 35% H2O2, combined with a copolymer, with sodium and calcium fluoride, and with titanium dioxide. • These adjuvants give the gel a putty-like consistency and contrast colour from the gingiva. • The products used here generally have a slightly acid pH, rendering fluoridization indispensable at the end of the treatment to remineralise the treated dental surfaces and to prevent secondary dentin sensitivity.
  • 86. Combination bleaching • Combination techniques achieve faster results than at-home t/t and are more effective than procedures alone (Zekonis et al., 2003). • There are two possible options: I. In the first option, the bleaching procedure starts in the dental office, to be immediately continued by the patient at home. II. In the second option, the treatment starts at home and may be followed by one or two in-office sessions if the stains are particularly resistant. • Combination bleaching techniques help to save time without loosing the advantages of the at home and in-office techniques. Unfortunately, they also have the same disadvantages as the techniques they combine.
  • 87. COMPLICATIONS • Complications in non-vital teeth – External cervical resorption – Secondary crown fractures – Stain recurrence
  • 88. • Complications in vital teeth – Post-operative sensitivity – Enamel surface alterations – Effects on dental restorations – Stain recurrence – Effects on the oral mucosa (caustic & cytotoxic effects)
  • 89. • A study was done to evaluate Bleaching efficacy of whitening agents activated by xenon lamp and 960-nm diode radiation & it was concluded that both are effective to provide brighter teeth. However, according to the conditions used in this study, only the xenon arc lamp induced a safer temperature increase. (LASER JOURNAL 2/2005)
  • 90. • A study was done using Group 1 H2O2 (35%) Group 2 Curing light Group 3 LED Group 4 LASER & results were compared with Vita Easyshade Spectrophotometer that showed equality between shades of no statistical significance Operative dentistry 2008, 33-1, 15-
  • 91. NON-VITAL TOOTH BLEACHING Indications • Any discoloration secondary to: – a loss of pulp vitality, and more particularly to a pulp haemorrhage or to the decomposition of residual pulp tissues that were not removed during root canal therapy (pulp horns). – the use of medication, or the placement of root canal filling materials or non leak-proof restoration materials. • Blackish coloration of the root, which is visible under a thin gingiva. The bleaching treatment will have to reach deep into the root.
  • 92. Relative contraindications • Stains incurred by root canal filling pastes (phenolic resins, radiopacifiers) or metal salts (amalgams), for which treatment prognosis is guarded. • Teeth with extensive crown restorations. Absolute contraindications (Particularly for hydrogen peroxide-based techniques) • Permanent teeth in children and young adolescents; • Teeth that have undergone a periodontal treatment and root planing procedure; • Traumatised teeth (luxation, avulsion, intrusion...); • Teeth that show external or internal root resorption.
  • 93. NON-VITAL TOOTH BLEACHING TECHNIQUES • Rely on the permeability of the dentin, which allows the oxidising agent to reach the pigments directly, the latter being concentrated mostly (according to some authors) at the dentin - enamel-junction. Prognosis is usually extremely good when case selection is correct.
  • 94. • The bleaching protocol starts with a 1. Thorough clinical examination of the tooth and surrounding supporting tissues. 2. X-rays are - assess the quality of the endodontic treatment and to visualise any root and/or periodontal defects. 3. Photographs are taken to keep record of the state of the tooth prior to treatment. 4. Conscent - to guarantee that all legal and ethical obligations are met, the practitioner gives the patient a precise quote for the bleaching treatment, as well all the usual recommendations and any other relevant information.
  • 95. • Non-vital tooth bleaching – at-home or – in-office techniques, or – both techniques in combination. • For in office procedures, the first phase of the treatment will focus on the protection of the oral tissues (Vaseline, dam...) and the preparation of the tooth.
  • 96. 1. Remove the gutta percha from the Coronal portion of the tooth and sealed with the glass ionomer cement 2. Remove all the debris and surface stains 3. Place a cotton pellet saturated with bleaching solution into the pulp chamber 4. Fill the remaining pulp chamber with cotton pellet impregnated with bleaching paste 5. Seal the pulp chamber with zinc phosphate cement 6. After reaching the desired color, remove all the bleaching material clean the chamber and fill it with light shaded composite resin.
  • 97. The “Walking bleach" technique (Claisse et al., 2000; Feinman et al., 1989; Nutting and Poe, 1963; Spasser, 1961) • It uses a paste of a mixture of sodium perborate and distilled water (Silvas, 1938) or hydrogen peroxide in a 100 to 130 volume solution (Bizhang et al., 2003). • Paste is placed in the pulp chamber & covered with cotton pellet and sealed with a leak-proof dressing such as Cavit or IRM. • The paste is left in place for – 3-6 days if the sodium perborate is mixed with H2O2, – twenty days if it is mixed with distilled water. • Commercially available preparations such as Superoxol (30% aqueous H2O2 solution) or carbamide peroxide may be used, but gels tend to spread and to weaken the seal formed by the temporary dressing.
  • 98. • The combination of sodium perborate and H2O2 achieves rapid and excellent results, but the technique is contraindicated as it may cause external cervical resorption. • The mixture of sodium perborate and distilled water is safe and risk-free, but less rapid, and results are generally satisfactory, although the bleaching procedure often needs to be repeated 2 or 3 times before an acceptable shade is achieved.
  • 99. • The final restoration phase is important when composite materials are involved, as the quality of the bonding will greatly determine the longevity of the result. • When products with high concentrations of H2O2 are used, the residual oxygen that remains after the procedure is finished momentarily inhibits the polymerisation of the composite resin. The final restoration should therefore be placed 1 week after the full completion of the bleaching treatment.
  • 100. In-office bleaching • It‟s a.k.a “chairside” or “power” bleaching, uses an activator such as heat, light or, more recently, a laser beam. • In the Thermocatalytic technique, cotton pellets saturated with 100 or 130 volume H2O2 and placed in the pulp chamber, where the oxidation reaction is then activated by heat. • The tip of the heat-producing inst is placed directly onto the saturated cotton pellet, resulting in immediate gas evolution.
  • 101. • The instrument shouldn't touch the dentinal walls, as this may cause infractions and secondary fractures. • The procedure is repeated 5 - 6 times every 5 mins. If the shade achieved is not satisfactory, a provisional seal is placed and the treatment is repeated during a later visit. • While heat activation considerably increases the speed and efficiency of reaction, it also increases the risk of complications, which renders this technique obsolete.
  • 102. • Ultraviolet Photo-Oxidation technique applies ultraviolet light to the labial surface of the tooth to be bleached. • A 30 to 35% hydrogen peroxide solution is placed in the pulp chamber on a cotton pellet followed by a 2-minute exposure to ultraviolet light. • Supposedly, this causes oxygen release, like the thermocatalytic bleaching technique.
  • 103. • A laser beam can activate high conc H2O2 (35%) extremely quickly and thus help to achieve a satisfactory lightening of pulpless teeth with pathological or acquired stains in just 1 or 2 30minute sessions. • The erbium:YAG laser are used for this type of t/t as its beams are rapidly absorbed by water. • Diode lasers that have a deeper penetration depth are also used, although less frequently because of the high increases in temperature they induce.
  • 104. procedure 1. A 35% H2O2 gel is placed inside the pulp chamber and on the labial and lingual surfaces of the prepared tooth, that is perfectly isolated. 2. The tooth is then covered with a clear film (e.g. Whitestrip) fastened to the gingival barrier (light cured protection) so that the gel remains slightly compressed during breakdown and stays in place at each new irradiation (frequency: 30 Hz, energy: 60 M j, distance: 1 to 1.5 mm, duration: 3 seconds; exposure is repeated 4 - 5 times, with 30-second intervals).
  • 105. 3. Air jet cools the spot where the beam is focused. The gel should be renewed 2-3 times during the procedure. 4. At end of the session, the gel and the gingival barrier are removed. Catalase or CaOH should be placed inside the pulp chamber and left there over 8-15 days prior to the placement of the final composite restoration so as to neutralise the effects of the H2O2 (Rotstein, 1993). • Combination bleaching couples the techniques described above and is used to treat the most difficult cases. It is efficient but not without risks and should therefore be excluded from our array of therapeutic choices.
  • 106. Composite restorations • Bleaching factor • Shade match • Polishing of restoration • Staining of restoration, • Marginal leakage, black lines • Recurrence of dicolouration • Bond strength.
  • 107. Good morning
  • 108. Intracoronal protective bleach barrier • Atleast 2mm thick • Should follow the contour of the external epithelial attachment. • Protective white cement barrier can be used such as Polycarboxylate cement, Zinc phosphate or Glass ionomer cement, intermediate restorative material or Cavit.
  • 109. Products for vital bleach
  • 110. Systems for extracoronal bleaching
  • 111. Systems for „In Office Bleach‟
  • 112. External root resorption • Increased penetration of bacteria into dentinal tubules after the bleaching treatment (Heiling et al., 1995), especially • Developmental defects or pathological alterations of the cementum provide bacteria with convenient entrance routes (Rotstein et al., 1991). • The permeability of the tooth in the cervical area. • Assessibility to the cervical area.
  • 113. Laminate veneers • The use of laminate veneers (usually ceramic) is the most commonly-used way of treating discoloured teeth. Directly-applied composite is by and large inadequate to mask discolouration
  • 114. • Difficulties exist in using thin ceramic veneers to mask extreme levels of discolouration and increasingly, their use is combined with tooth-whitening conducted over a considerable period of time prior to tooth preparation. • If bleaching be carried out it is important to leave a period of at least two weeks between the final bleaching and bonding otherwise the bond strength will likely be compromised (Titley 1988).
  • 115. • The highest levels of retention occur when a veneer is bonded to a predominantly enamel substrate (Friedman 1998). • This can be done in „normal-coloured‟ teeth, in discoloured teeth, there is risk that the dark shade of the underlying preparation will shine through the relatively translucent porcelain. • To overcome this, include using more opaque ceramics and luting agents, cutting deeper into the tooth to allow a greater thickness of overlaying ceramic or manipulation of the prepared tooth to lighten its shade.
  • 116. • The principles of veneer preparation should be followed (Newsome 2008) : 1. Preparation margins should be placed slightly sub-gingivally and interproximally to hide the transition between veneer and dark tooth. 2. All margins should be clear, it is usually advisable to break the contact points to hide the interproximal margins. 3. The shade of the prepared tooth (if possible together with photographs) should be sent to the laboratory to help them achieve the best possible result. 4. At the bonding stage it is vital to use a selection of different water-soluble try-in pastes to determine the most appropriate shade of luting cement. The more translucent the veneer the more critical this step becomes.
  • 117. Full coverage restorations • The covering layer of porcelain is thicker. Full coverage also places less reliance on bonding as a means of retention. • Although there are usually more aesthetic alternatives for anterior teeth, zirconia crowns are useful in the treatment of tetracycline teeth, especially if the preparation has a deep enough chamfer to allow a sufficiently thick veneering layer of esthetic porcelain. The need to use porcelain fused to metal crowns would appear to be limited except in the most extreme cases where great strength is an advantage, for example when parafunctional habits, such as bruxism, are combined with deep tooth discolouration.
  • 118. Management of tetracycline discoloured teeth 1. Tooth whitening only 2. Composite bonding (full or partial) over discoloured areas 3. Combination treatment starting with tooth whitening and continuing to direct veneers. 4. Laminate veneers (with or without prior tooth whitening) 5. Full coverage restorations
  • 119. ENAMEL HYPOPLASIA - TREATMENT OPTIONS Treatment for posterior teeth: 1. For sensitive teeth with minimal weardesensitizing agent can be applied . 2. For mildly hypoplastic molars, place pit and fissure sealant on the occlusal surface. 3. Remove demineralized enamel and restore with composite. at 6 month re-evaluation, if composite is lost, replace using good isolation techniques. 4. Perform minimal reduction of tooth and cement a stainless steel crown evaluate clinically and radiographically as indicated 5. For permanent molars, stainless steel crowns are intended for temporary use only. These teeth should be restored with a permanent cast crown in the late teen years or early adulthood.
  • 120. 6. In cases where the first permanent molars are unrestorable or marginally restorable, extraction prior to the eruption of the second molars may be a reasonable alternative. Treatment for anterior teeth: 1. For sensitive teeth with minimal wear desensitizing agent can be applied . 2. If there are esthetic concerns, direct or indirect composite veneers may be bonded to the affected tooth. 3. For permanent anterior teeth, composite or porcelain veneers or porcelain crowns may be used.
  • 121. Conclusion • Teeth being the mirror of a person‟s hygeine to the society, a discoloration of teeth is seen as sign negligence. • Whitening teeth can be a relatively simple way to have a younger appearing smile. • It is the obligation of oral health care professionals to educate the public about the true economic value and safety of dentist prescribed whitening treatments.
  • 122. Probable questions • Aetiology & treatment of discolored teeth 25 marks • Discuss causes of discoloration of teeth & discuss treatment method for Vital discolored tooth. 35 marks • Discuss various bleaching agents used & discuss management of Vital discolored teeth. 20 marks
  • 123. REFERENCES • INGLE’s Endodontics - 6th edition. • GROSSMAN’s Endodontic practice - 12th edition. • McLaughlin’s Atlas of teeth whitening • Goldstein’s Esthetics in dentistry Volume 2 • NEVILLE Oral & maxillofacial pathology – 2nd edition • TOOTH BLEACHING TREATMENTS - A Review, ADF Dossiers, Goldberg et al.

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