Non Vital Tooth Bleaching .pptx- conservative and endodontics

conservative and endodonts. walking bleaching, thermocatalytic bleaching, inside-outside bleaching, laser blraching

1. Non Vital Tooth Bleaching Anishma Krishnan 008​

2. content 20XX Presentation title 2 INTRODUCTION CLASSIFICATION of NONVITAL BLEACHING INDICATION CONTRAINDICATION ADVANTAGE AND DISADVANTAGE PRELIMINARY TREATMENT WALKING BLEACHING TECHNIQUE INSIDE/OUTSIDE BLEACHING LASER BLEACHING THERMOCATALYTIC TECHNOQIUE COMPLICATIONS AND RISKS RECENT ADVANCEMENTS CONCLUSION REFFERENCE

3. Introduction A esthetics is a field of growing importance An aesthetic smile I t has a psychosocial impact and influences the individual’s esthetic self-perception 3

4. DEFINITION "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" 20XX Presentation title 4

5. Difference between vital and nonvital bleaching Vital bleaching Applied by dentist or by patient (using home bleaching techniques) Applied on - external tooth structure only Protection of the gingival tissues is of main importance Nonvital bleaching Applied by the dentist. Applied mainly inside thepulp chamber. Endodontically treated root canal must be protected using GI or RMGI to prevent leakage of the bleaching material. 5 Presentation title 20XX

6. CAUSES Non-vital tooth discoloration may have many causes, Dental trauma-Necrotic pulp Root canal treatment Blood decomposition in p ulp chamber presence of necrotic debris on the pulp horns and dentinal tubules, poor irrigation, or sealing materials located in the pulp chamber or chamber walls . The most commonly described cause is intracoronal blood decomposition. Hemolysis of erythrocytes in the dentin tubules is accompanied by the release of iron. This, combined with hydrogen sulfate, forms ferric sulfide, a black compound, responsible for the discoloration of the tooth 6 Presentation title 20XX

7. There are several internal tooth bleaching techniques, the most common being the walking-bleach technique , first described by Spasser , in 1961. Other techniques include thermocatalytic technique and inside-outside technique . Commonly used Bleaching agents Hydrogen peroxide, C arbamide peroxide S odium perborate These three agents promote reversion of the chromatic change through oxidative reactions 7 Presentation title 20XX

8. CLASSIFICATION The walking bleach I nside - outside bleaching Thermocatalytic Laser bleaching Internal tooth bleaching is a minimally invasive, conservative, relatively simple, effective, and low-cost method in the treatment of discolored endodontically treated teeth

9. INDICATION A sealed root-canal filling is an important requirement for allowing an endodontically treated tooth to be bleached. The tooth must be symptom-free , but a waiting period is called for in the case of a radiologically detectable periapical radiolucency . Such lesions should be observed to determine whether the alteration is increasing or if a healing process is apparent. In every case, the root-canal filling material should be sealed with a base material, in order to prevent penetration of the bleaching agent into the periodontal space or root canal. The ubiquitous cements used to close perforations must also be covered with a base. Prior to bleaching, insufficient coronal restorations must be replaced by restorations providing an excellent marginal seal. 9 Presentation title 20XX

10. INDICATION Discolored non vital teeth Stable restoration After intentional RCT of abutment tooth Esthetic requirements-for non vital teeth Patient compliance 10 Presentation title 20XX

11. 11 Presentation title 20XX The indication for nonvital bleaching, also known as internal bleaching, is primarily for teeth that have become discolored due to factors within the tooth, such as pulp tissue damage, root canal therapy, or the presence of blood byproducts. Here are the key indications for nonvital bleaching: Discolored Non-Vital Teeth : The primary indication for nonvital bleaching is discolored, non-vital teeth. This discoloration is often due to: Pulp Necrosis: When the pulp (nerve) of a tooth dies or becomes non-vital due to infection or trauma, it can lead to discoloration over time. Root Canal Treatment: Teeth that have undergone root canal therapy can develop internal staining because the pulp chamber and root canal system are sealed off from the bloodstream, causing the tooth to darken.

12. 12 Presentation title 20XX Stable Restorations : Nonvital bleaching is most effective on teeth with stable restorations, such as crowns or fillings, as the restorations do not respond to bleaching agents. The restorations should match the shade of the surrounding natural teeth before bleaching. Patient Desire for Aesthetics : When patients with discolored non-vital teeth desire an improvement in the aesthetics of their smile, nonvital bleaching can be a suitable treatment option. Patient Compliance : Patients should be willing to comply with the treatment process, which may involve multiple appointments and good oral hygiene practices during and after the bleaching .

13. CONTRAINDICATION 13 Presentation title 20XX What are the contraindications for internal bleaching The most important factor in bleaching effectiveness seems to be precise removal of all restorative materials from the access cavity without additional dentin elimination. Dentin has to be cleaned in order to facilitate diffusion of the bleaching agent through the dentinal tubules. If a fiber post was cemented in the root canal and the pulp chamber was filled with composite resin, removing the restorative material and post can compromise the amount of sound dentin. Therefore, such a case calls for careful evaluation of aesthetic benefits vs. structural sacrifice.

14. CONTRAINDICATION VITAL TEETH UNRESOLVED PERIAPICAL PATHOLOGY UNSTABLE RESTORATION PREGNANCY SEVERE STRUCTURAL DAMAGE SEVERE ALLERGY OR SENSITIVITY PULPAL INFLAMMATION YOUNG PATIENTS WITH DEVELOPING TEETH

15. 15 Presentation title 20XX Other contraindications for internal bleaching include: – discolourations caused by amalgam or other metallic materials (not bleachable) – Significant dentin loss in the cervical portion (risk of fracture and leakage of bleaching agent) – Extensive restorations – Visible cracks, especially with subgingival extension (risk of bleaching agent penetrating towards periodontal ligaments) – Young patients (<19 years old) Vital Teeth : Nonvital bleaching is intended for discolored non-vital teeth. It should not be used on vital (living) teeth, as the bleaching agents are designed to act within the pulp chamber and may cause unnecessary harm to healthy dental pulp. Unstable Restorations : If a tooth has unstable or leaking restorations (e.g., old and faulty fillings or crowns), it is not a suitable candidate for nonvital bleaching. The bleaching agents can potentially seep under the restorations and cause complications.

16. 16 Presentation title 20XX Severe Structural Damage : Teeth with severe structural damage, such as extensive cracks, fractures, or large cavities, are not ideal candidates for nonvital bleaching. The structural integrity of the tooth should be sufficient to withstand the procedure. Pulpal Inflammation or Infection : Nonvital bleaching should not be performed if the tooth has active pulpitis (inflammation of the dental pulp) or untreated pulp infection. Addressing the underlying dental issue should be the priority before considering bleaching. Unresolved Periapical Pathosis : If there are unresolved periapical pathologies, such as abscesses or cysts at the root tip, these should be treated before attempting nonvital bleaching. Pregnancy : The safety of nonvital bleaching during pregnancy has not been well studied, and it's generally advisable to avoid elective dental procedures during pregnancy unless necessary for health reasons.

17. 17 Presentation title 20XX Severe Allergies or Sensitivities : Patients with known allergies or sensitivities to the bleaching agents or materials used in the procedure should not undergo nonvital bleaching. Unrealistic Patient Expectations : If a patient's expectations are unrealistic or they seek an extreme level of tooth whitening that may compromise the integrity of the tooth structure, it's important to communicate and manage these expectations appropriately. In such cases, alternative treatments should be considered. Youthful Patients with Developing Teeth : Nonvital bleaching is typically not recommended for young patients with developing teeth (e.g., children or teenagers) as it can interfere with normal tooth development. A good cervical seal is decisive in young teeth, as the diffusion rate of the bleaching agent through the tooth is much higher than in older patients Inadequate Informed Consent : A patient should be adequately informed about the risks, benefits, and alternatives to nonvital bleaching. If the patient is unable or unwilling to provide informed consent, the procedure should not be performed. In cases where the internal bleaching technique compromises the remaining tooth structure, other options, such as porcelain or composite veneers should be considered .

18. 18 Presentation title 20XX ADVANTAGE DISADVANTAGE Aesthetics : Nonvital bleaching can have a significant positive impact on a patient's appearance. It can help restore the natural whiteness of teeth, resulting in a brighter and more attractive smile. Minimally Invasive : Nonvital bleaching is a conservative treatment option. It doesn't require removing or altering healthy tooth structure, as is often the case with restorative procedures like crowns or veneers. Preservation of Tooth Structure : Unlike some other cosmetic dental treatments, nonvital bleaching doesn't involve reshaping or removing tooth structure. This means that more of the natural tooth is preserved. Limited Effectiveness : Nonvital bleaching may not be effective for all types of tooth discoloration. It works best for extrinsic stains caused by factors like tea, coffee, or tobacco, but it may not be as effective for intrinsic stains resulting from factors such as dental decay, certain medications, or genetics. Temporary Results : The results of nonvital bleaching are not permanent. Over time, teeth can gradually revert to their original color, especially if patients continue to consume staining substances. Sensitivity : Some patients may experience tooth sensitivity during and after the bleaching process. This sensitivity is typically temporary, but it can be uncomfortable for some individuals.

19. 19 Presentation title 20XX ADVANTAGE DISADVANTAGE Cost-Effective : Nonvital bleaching is generally more cost-effective compared to restorative treatments like crowns or veneers, making it an attractive option for patients looking to enhance their smile without breaking the bank. Quick Results : Patients can typically see noticeable improvements in tooth color within a few weeks of starting nonvital bleaching treatment, which is relatively quick compared to other dental procedures. Uneven Results : Achieving uniform whitening across all teeth can be challenging, especially if some teeth are more discolored than others. In such cases, it may be necessary to combine bleaching with other cosmetic treatments for a consistent look. Multiple Sessions : To achieve the desired level of whitening, patients may need multiple bleaching sessions. This can be time-consuming and require careful patient compliance. Supervision : Nonvital bleaching should be performed under the supervision of a dentist to ensure that it is done safely and effectively. Over-the-counter whitening products may not provide the same level of care and expertise as a dental professional

20. PRELIMINARY TREATMENT PHOTODOCUMENTED WITH COLOUR KEY RADIOGRAPHIC ASSESMENT–PRE&POSTOPERATIVE INFORM THE RISK OF TREATMENT AND ALTERNATIVE MTHODS EDUCATING PATIENT NO GARUNTEE-PERSISTING RESTORATON-COST-ALLERGY CONSENT-YOUNG PATIENTS DETERMINE THE CAUSE OF DISCOLORATION INTRINSIC STAIN AND EXTRINSIC STAIN1

21. Deficient restorations should be identified and replaced; carious lesions should be restored. If restorations do not match the shade of the tooth, they should be replaced at the end of the treatment with materials matching the whitened tooth. The final shade of the tooth as a result of bleaching cannot be reliably predicted, and this makes it difficult to select the correct shade of filling material before bleaching. Therefore, it is advisable to restore carious lesions or replace deficient fillings with temporary materials before treatment or to replace restorations after completion of bleaching. It should be emphasized that the tooth be restored with high quality fillings to ensure the effectiveness of the bleaching agent and to avoid leakage of the agent into the oral cavity. Furthermore, it is of great importance to apply rubber dam to isolate the treated tooth, to prevent reinfection of the root canal, and to protect the adjacent structures from the bleaching agent. For difficult cases it is possible to use a liquid dam. 21 Presentation title 20XX

22. 20XX Presentation title 22 OPG was made to have a general overwiev of the situation. Looking at tooth 11, the root filling seems to be correct and no periapical pathology is visible. Furthermore, we can see a very large coronal access cavity, partially filled by guttapercha, what can presumably cause the coronal discoloration.

23. WALKING METHOD The name "walking bleach" is derived from the process itself and how it involves a gradual, controlled approach to whitening the tooth. T he whitening agent is placed inside the tooth, and the patient "walks away" with the bleaching agent left in the tooth.

24. HISTORY The first description -with a mixture of sodium perborate and distilled water was mentioned in a congress report by Marsh and published by Salvas. In this procedure, the mixture was left in the pulp cavity for a few days, and the access cavity was sealed with provisional cement. The mixture of sodium perborate and water was reconsidered by Spasser and modified by Nutting and Poe , who advocated the use of 30% hydrogen peroxide instead of water to improve the bleaching effectiveness of the mixture. A mixture of sodium perborate and water or hydrogen peroxide continues to be used today and has been described many times as a successful technique for intracoronal bleaching 24 Presentation title 20XX

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26. 1.Preparation of access cavity 26 Before preparation of the access cavity, rubber dam should be applied to protect the adjacent structures. The access cavity should be shaped in such a way that remnants of restorative materials, root-filling materials, and necrotic pulp tissue are completely removed .

27. For this reason, in particular for maxillary incisors, it is very important to include the mesial and distal pulp horns in the access cavity, because they can contain necrotic pulpal remnants, which can cause discoloration Additional cleaning of the pulp cavity with sodium hypochlorite is also recommended In some reports, conditioning of the dentin surface of the access cavity with 37% orthophosphoric acid is suggested to remove the smear layer and to open the dentinal tubules. This promotes the penetration of the bleaching agent deep into the tubules and increases its effectiveness . 27 Presentation title 20XX

28. It has also been recommended to clean the pulpal cavity with alcohol before application of the bleaching agent to dehydrate dentin and reduce surface tension; consequently the bleaching agent will penetrate with greater ease into the dentin, achieving improved efficacy . However, studies have shown that removal of the smear layer with 37% orthophosphoric acid does not improve the bleaching effectiveness of either sodium perborate or a high concentration of hydrogen peroxide . Furthermore, the pre-treatment of dentin with acid might lead to an increased diffusion of bleaching agents into the periodontium . Therefore, removal of the smear layer from the dentin of the pulp chamber before the bleaching procedures is still a controversial issue. 28 Presentation title 20XX

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30. 2) Cervical seal 30 The root filling should be reduced 1–2 mm below the CEJ. This can be determined by using a periodontal probe placed in the pulp cavity, while reproducing the corresponding external probing to the CEJ. To remove filling material up to this level, Gates-Glidden or Largo burs can be used.

31. 31 Presentation title 20XX It is important to clean the cavity surfaces from debris and remnants of endodontic materials, because the presence of contaminants on the surfaces might negatively influence the efficacy of the bleaching agent. A root filling does not adequately prevent diffusion of bleaching agents from the pulpal chamber to the apical foramen

32. Sealant used Hansen-Bayless and Davis the root filling with a base is essential, for dental materials such as glass-ionomer cements, intermediate restorative material (IRM), hydraulic filling materials ( Cavit , Coltosol ), resin composites, photo-activated temporary resin materials ( Fermit ), zinc oxide–eugenol cement, and zinc phosphate cement have been suggested as an interim sealing agent during bleaching techniques McInerney and Zillich found that Cavit and IRM provided better internal sealing of the dentin than did zinc phosphate cement 32 Presentation title 20XX

33. The sealing material should reach the level of the epithelial attachment or the CEJ, respectively, to avoid leakage of bleaching agents into the periodontium . The shape of the cervical seal should be similar to the external anatomic landmarks, thus reproducing CEJ position and interproximal bone level. A flat barrier, level with the labial CEJ, leaves a large portion of the proximal dentinal tubules unprotected. Therefore, the barrier should be determined by probing the level of the epithelial attachment at the mesial, distal, and labial aspects of the tooth barrier. 33 Presentation title 20XX

34. 3) Application of bleaching agent 34 . Opalescence Endo whitening gel contains 35% hydrogen peroxide and is available in convenient ready-to-use syringes. A suitable Black MiniTM tip or a Micro 20 ga tip, which is attached onto the syringe, allows for a quick and targeted application of the whitening gel.

35. 35 Presentation title 20XX Sodium perborate (tetrahydrate) mixed with distilled water in a ratio of 2:1 (g/mL) is a suitable bleaching agent . In case of severe discoloration, 3% hydrogen peroxide can be applied in lieu of water . The bleaching agent can be applied with an amalgam carrier or plugger and should be changed every 3–7 days Successful bleaching becomes apparent after 2–4 visits, depending on the severity of the discoloration. The patients should be instructed to evaluate the tooth color on a daily basis and return when the bleaching is acceptable to avoid “over-bleaching”

36. 4) Temporary filling 36 Before application of the bleaching agent, the enamel margins of the cavity should be etched with 37% orthophosphoric acid to accomplish an adhesive temporary filling. The walking bleach technique requires a sound seal around the access cavity with a resin composite or compomer to ensure its effectiveness and to avoid leakage of the bleaching agent into the oral cavity

37. 37 Presentation title 20XX This cannot be guaranteed if temporary filling materials are being used ( 103 ). In addition, a good seal prevents recontamination of the dentin with microorganisms and reduces the risk of renewed staining. It is often difficult to place filling materials on a soft bleaching agent. A small sterile cotton pellet impregnated with a dentin bonding agent, placed on the bleaching agent and then light-cured, simplifies the placement of a filling material. The temporary filling should only be attached to the enamel margins of the access cavity. During this phase of the treatment, the pulp chamber is filled with the bleaching agent and not with an adhesively attached restorative material, so that no internal stabilization of the tooth is provided. Therefore, the patient should be informed about an increased risk of fracture

38. 5) Restoration of the Access Cavity and Postoperative Radiograph 38 After bleaching, the access cavity should be restored with a resin composite, which is bonded by means of the acid-etch technique to enamel and dentin. This avoids recontamination with bacteria and staining substances and improves the stability of the tooth.

39. 39 Presentation title 20XX A sound restoration with sealed dentinal tubules is a prerequisite to successful bleaching therapy . Some author recommend using resin composites with lighter shades to compensate for bleaching that was not completely successful. The adhesive strength of resin composites and glass-ionomer cements to bleached enamel and dentin is temporarily reduced It has been established that remnants of peroxide or oxygen inhibit the polymerization of resin composites It is less likely that changes in the enamel structure might influence resin composite adhesion . Nevertheless, the appearance of the hybrid layer in bleached enamel is less regular and distinct than in unbleached enamel . This might explain why access cavities of bleached teeth that are restored with resin composite occasionally show marginal leakage.

40. 40 Presentation title 20XX The negative influence of hydrogen peroxide–containing bleaching agents on adhesion can be reduced by moderate bevelling of the cavity before acid etching . The same can be achieved by pre-treatment of enamel with dehydrating agents such as alcohol and the use of acetone-containing adhesives . To dissolve remnants of peroxide, the cavity can also be cleaned with sodium hypochlorite . A contact time of at least 7 days with water is recommended to avoid the reduction of adhesion of composites to enamel . Optimal bonding to bleached dental hard tissue can be achieved after a period of about 3 weeks . During this period, the color of the bleached tooth should be stable and a calcium hydroxide dressing placed in the pulp cavity for buffering the acid pH that can occur on cervical root surfaces after intracoronal application of bleaching agents. The calcium hydroxide suspension temporarily placed into the pulp chamber after completion of the bleaching procedure does not interfere with the adhesion of composite materials used for final restoration of the access cavity. Furthermore, compromised bonding to bleached enamel can be reversed with sodium ascorbate, an antioxidant

41. Case 1 a ) Pre-treatment photograph of right maxillary central incisor showing severe discoloration due to a necrotic pulp caused by trauma. Endodontic treatment was performed before bleaching. ( b ) Appearance after bleaching with the walking bleach technique for 3 consecutive treatments shows considerable whitening. ( c, d ) Esthetic restoration was completed 7 days after bleaching. ( e ) Immediate postoperative view after placement of a composite resin. ( f ) Esthetic appearance after 1 year. 41

42. Case 2 ( a ) Pre-treatment photograph shows a yellow-brown discoloration of tooth #8 caused by endodontic treatment. ( b ) Clinical results after 3 applications of the walking bleach technique, resulting in a slightly overbleached tooth. 42

43. Thermocatalytic technique Same as walking bleach technique But heat is applied using a different instrument Due to the heat and high concentration of bleaching agent ,cervical root resorption could occur Not recommended for routine use

44. 44 Presentation title 20XX This technique has been proposed for many years as the best technique to bleach nonvital teeth because of the strong interaction between hydrogen peroxide and heat . Moreover, a common clinical technique is to use 30%–35% hydrogen peroxide placed in the pulp chamber between appointments . Preparation of the access cavity consists of cleaning, removal of filling materials, and all the preparation procedures described for discolored teeth when using the walking bleach technique. However, this technique involves placement of 30%–35% hydrogen peroxide in the pulp chamber followed by heat application by electric heating devices or specially designed lamps. It has been observed that heat application causes a reaction that increases bleaching properties of the hydrogen peroxide . Heat might be applied by using a heated metal instrument or other commercial heat applicators ( Touch’n Heat, System B; Analytic Technology, Orange, CA). Heat application is repeated 3 or 4 times at every appointment, changing the pellet with “fresh” bleaching agent at each visit. When heat is applied, a reaction produces foam and releases the oxygen present in the preparation. At the end of each appointment the bleaching agent is sealed into the pulp chamber for additional bleaching between appointments as in the walking bleach technique

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47. Case 1 b  ) Pre-treatment photograph demonstrates dark discoloration of right upper canine . Root canal treatment had been completed many years ago. d  ) Post-bleaching photograph before replacement of the stained distal composite resin restoration. A thermocatalytic intracoronal bleaching technique was used. The distal composite resin was replaced 2 weeks after bleaching. f  ) Two-year postoperative/bleaching results show very nice esthetic appearance. 47

48. Inside outside bleaching

49. Settembrini introduced the inside-outside bleaching technique, in which bleaching occurs simultaneously with in the tooth structure and on tooth external surface. In this technique, generally 10% carbamide peroxide gel applied to tooth structure internally and externally in root-filled, discolored teeth and refreshed on a regular basis. This bleaching agent (CH4N2O • H2O2) has undergone extensive research. An in vitro study showed that carbamide peroxide has a bleaching capacity comparable to that of hydrogen peroxide [20]. Inside-outside technique is a fast technique because the oxygen reactive species released from the hydrogen peroxide freely diffuse inside and outside of the tooth structure to effect tooth whitening. 49 Presentation title 20XX

50. Laser bleaching

51. 51 Presentation title 20XX Laser Assisted BleachingTechniqueThis technique achieves power bleaching process withthe help of efficient energy source with minimum sideeffects.Laser whitening gel contains thermally absorbedcrystals, fumes silica and 35 percent hydrogenperoxide.In this, gel is applied and is activated by light sourcewhich further activates the crystals present in gel,allowing dissociation of oxygen and therefore betterpenetration into enamel matrix.Following laser have been approved by FDA for toothbleaching:Argon laserC02 laser

52. Complication and risk Temporary tooth sensitivity Root resoption Gum irritation Colour uniformity Over bleaching

53. relapse External cervical root resorption changes in the dentin structure and permeability Fracture risk penetration of hydrogen peroxide in the dentinal tubules

54. 54 Presentation title 20XX External cervical resorption- There is speculation that hydrogen peroxide can diffuse through the dentinal tubules, cement, and periodontal ligament and can reach bone directly induces an inflammatory resorption process. On its own, hydrogen peroxide is not very reactive, and the body has mechanisms in place to deal with it However, in the presence of inflammation, proinflammatory agents activate reduced nicotinamide adenine dinucleotide phosphate oxidase, which produces superoxides that can react with hydrogen peroxide. It is speculated that the resultant hypochlorous acid, N- chloroamines , and reactive hydroxyl ions might initiate some disease processes ( 178 ). .

55. 55 Presentation title 20XX Temporary Tooth Sensitivity: During nonvital bleaching, a bleaching agent (typically hydrogen peroxide or carbamide peroxide) is applied inside the tooth. This process can cause temporary tooth sensitivity, especially when the bleaching gel is in contact with the dentin, the inner layer of the tooth. The sensitivity is often transient and can be managed with desensitizing toothpaste or by reducing the duration and frequency of bleaching sessions. Root Resorption: Root resorption is a rare but severe complication. It occurs when the internal bleaching agents come into contact with the root structure of the tooth and start to break it down. This can weaken the tooth's integrity and may lead to tooth loss. Proper isolation and precise application are crucial in preventing this complication. Gum Irritation: The bleaching agents can sometimes seep out of the tooth and come into contact with the surrounding gums and oral tissues. This can lead to irritation, inflammation, and chemical burns. To prevent this, a protective barrier is usually placed around the tooth to isolate it from the gums. Careful monitoring and adjustments during the procedure are necessary to avoid gum-related complications.

56. 56 Presentation title 20XX Color Uniformity: Achieving even and consistent whitening results can be challenging, especially if the tooth being treated has various colors or shades. Different areas of the tooth may bleach at different rates, leading to uneven results. Proper assessment and customization of the bleaching process are important to minimize this risk. Overbleaching: Overusing bleaching agents, leaving them on for too long, or using a higher concentration than recommended can lead to overbleaching. This can result in a chalky or translucent appearance of the tooth, which may look unnatural. Patients attempting at-home bleaching without professional guidance are more prone to this risk. Relapse: After nonvital bleaching, there's a risk of the tooth slowly reverting to its original color over time. This can occur due to intrinsic staining, dietary habits, or other factors. Patients should be aware that the results of nonvital bleaching may not be permanent, and retreatment may be necessary to maintain the desired level of whiteness.

57. 57 Presentation title 20XX Fracture Risk: In some cases, overbleached teeth can become more brittle. This increased fragility may raise the risk of tooth fractures, especially if the tooth has been compromised by previous dental procedures or structural issues. It's crucial for dental professionals to carefully evaluate each patient's specific case and take precautions to minimize these risks. Additionally, thorough patient education is important to manage expectations and ensure they understand the potential complications associated with nonvital bleaching

58. conclusion In conclusion, non-vital bleaching techniques represent a valuable and effective approach in enhancing the esthetics of discolored teeth with pulp-related issues. Throughout this presentation, we have explored various methods, including walking bleach and thermocatalytic bleaching, highlighting their advantages, considerations, and outcomes. As we conclude, it's essential to emphasize the significance of proper diagnosis, treatment planning, and patient communication in the success of non-vital bleaching procedures. Each case is unique, and a thorough assessment by the dental practitioner is crucial to determine the most suitable technique, concentration, and duration . 58 Presentation title 20XX

59. Thank you