S No comments Intracoronal bleaching is the procedure where a discolored non-vital tooth is whitened using oxidizing agents inside the coronal portion of the non-vital tooth to decrease the discoloration. With Intracoronal bleaching we can decrease or completely eliminate discoloration and increase the degree of translucency. The result of Intra-coronal bleaching depends on the cause of non-vitality, proper diagnosis, case selection and following the steps in a proper manner. Intracoronal bleaching is done in Non-vital teeth with discoloration, the other types of bleaching are done on Vital teeth mostly like — Walking bleaching or sealed bleaching, Office bleaching and photo or thermo bleaching.
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Placing glass ionomer restoration 30 minutes 8. Apply a sufficiently thick layer, at least 2 mm see Figure 8. The coronal height of the barrier should protect the dentin tubules and conform to the external epithelial attachment Steiner and West It is best to use a bleaching syringe with a finer nozzle tip to allow for ease of placement of the gel. It is thus not considered appropriate to use this technique recently anymore; there are other, higher concentration materials that are safer and equally effective.
With a plastic instrument, pack the pulp chamber with the paste. Remove excess liquid by tamping with a cotton pellet. This also compresses and pushes the paste into all areas of the pulp chamber. Remove excess bleaching paste from undercuts in the pulp horn and gingival area and apply a thick, well-sealed temporary filling directly against the paste and into the undercuts. Carefully pack the temporary filling, at least 3 mm thick, to ensure a good seal.
A good seal is essential for a successful bleaching technique. It may be useful to use polytetrafluoroethylene PTFE tape as a dressing directly over the gel and then place glass ionomer as an interim restoration. Remove the dental dam and inform the patient that the bleaching agent works slowly and that significant lightening may not be evident for several days.
Evaluate the patient approximately 2 weeks later; if necessary, repeat the procedure several times. Repeat treatments are similar to the first one. The more potent oxidizers may have an enhanced bleaching effect but are not used routinely because of the possibility of permeation into the tubules and damage to the cervical periodontium by these more caustic agents.
In such cases, a protective cream, such as Orabase, Vaseline, or cocoa butter must be applied to the surrounding gingival tissues before dental dam placement. In most cases, discoloration will improve after one or two treatments. If after three attempts there is no significant improvement, reassess the case for correct diagnosis of the cause of discoloration and treatment plan. Sodium perborate is stable when dry but, in the presence of acid, warm air, or water, decomposes to form sodium metaborate, hydrogen peroxide, and nascent oxygen.
It can act synergistically with hydrogen peroxide Nutting and Poe Various types of sodium perborate preparations are available: monohydrate, trihydrate, and tetrahydrate. They differ in oxygen content, which determines their bleaching efficiency Weiger et al. Commonly used sodium perborate preparations are alkaline, and their pH depends on the amount of hydrogen peroxide released and the residual sodium metaborate Rotstein and Friedman Sodium perborate is more easily controlled and safer than high concentrations of hydrogen peroxide solutions.
However, sodium perborate has been banned by the European directive. It is not permissible to use any sodium perborate materials in dentistry in Europe. Care must be taken when using these heating devices to avoid overheating the teeth and surrounding tissues.
Intermittent treatment with cooling breaks is preferred over one long continuous session. In addition, the surrounding soft tissues should be protected with Vaseline, Orabase, or cocoa butter during treatment to avoid heat damage. This is possibly attributed to hydrogen peroxide combined with heat Madison and Walton , Rotstein et al. Therefore, application of highly concentrated H2O2 and heat during intracoronal bleaching should not be carried out routinely.
This technique is now not used much owing to the high heat generated. In general, the technique involves the following steps: 1. Familiarize the patient with the probable causes of discoloration, the procedure to be followed, the expected outcome, and the possibility of future rediscoloration. Assess the status of periapical tissues and the quality of endodontic obturation see Figure 8. Endodontic failure or questionable obturation should be re-treated before bleaching see Figures 8.
Evaluate tooth color with a shade guide and take clinical photographs before and throughout the procedure. Assess the quality and shade of any restoration present and replace if defective. Apply a protective cream to the surrounding gingival tissues and isolate the teeth with rubber dam and waxed dental floss ligatures. If a heat lamp is used, avoid placing rubber dam metal clamps; they are subjected to heating and may also be painful to the patient.
Do not use anesthesia. Apply a sufficiently thick layer, at least 2 mm, of protective white cement barrier, such as polycarboxylate cement, zinc phosphate cement, glass ionomer, or IRM on top of the endodontic obturation. It is best to use glass ionomer as a barrier because it does not interfere with the hydrogen peroxide in the gel.
A bleaching gel containing hydrogen peroxide may be used instead of the aqueous solution. Apply heat with a heating device or a light source. Re-wet the cotton pellet and pulp chamber with hydrogen peroxide as necessary. If the tooth becomes too sensitive, discontinue the bleaching procedure immediately. Preferably, bleaching should be limited to separate 5-minute periods rather than being performed during a long continuous period Rotstein et al.
Remove the heat or light source and allow the teeth to cool down for at least 5 minutes. Then wash with warm water for 1 minute and remove the dental dam. Dry the tooth and place walking bleach paste of sodium perborate mixed with water in the pulp chamber. Recall the patient approximately 2 weeks later and evaluate the effectiveness of bleaching. Take clinical photographs with the same shade guide used in the preoperative photographs for comparison purposes.
If necessary, repeat the bleaching procedure. It should not be done routinely and should be offered to patients only in limited clinical situations. This technique was mainly advocated for treating severe intrinsic tetracycline discolorations. Such discolorations and other similar stains are incorporated into tooth structure during tooth formation, mostly into the dentin, and therefore are very difficult to treat from the external enamel surface.
Intracoronal bleaching of tetracycline-discolored teeth has been shown to be predictable and to improve tooth shade without significant clinical complications Abou-Rass These days it is not necessary to intentionally devitalize a tooth merely for the sake of bleaching the tooth because the home bleaching technique can bleach the most severe discoloration over a period of time.
Normal home bleaching techniques using higher carbamide peroxide are used instead. The mechanism of bleaching-induced damage to the periodontium or cementum has not been fully elucidated. Presumably, the irritating chemical diffuses via unprotected dentinal tubules and cementum defects Rotstein et al.
The process may be enhanced if heat is applied Rotstein et al. Previous traumatic injury see Figure 8. When such solutions are used, the soft tissues should always be protected with Vaseline, Orabase, or cocoa butter. High-strength hydrogen peroxide may not be used in Europe. The lower strength has the advantages of causing less chemical burning and less soft tissue discomfort.
Scanning electron microscopy observations suggest a possible interaction between composite resin and residual peroxide causing inhibition of polymerization and increase in resin porosity Titley et al. This presents a clinical problem when immediate esthetic restoration of the bleached tooth is required. It is therefore recommended that residual hydrogen peroxide be totally eliminated from the pulp chamber before composite placement.
This may be done by treating the dentin surface with catalase before bonding Rotstein Catalase removes the residual oxygen from the dentin.
A glass ionomer restoration can be placed immediately and the rest cut back 2 weeks later for the composite restoration. Intracoronal bleaching should always be carried out with dental dam isolation.
Interproximal wedges and ligatures may also be used for better protection. Protective cream, such as Orabase, Vaseline, or cocoa butter, must be applied to the surrounding oral mucosa to prevent damage associated with chemical burns by caustic oxidizers.
Animal studies suggest that catalase applied to oral tissues before hydrogen peroxide treatment totally prevents the associated tissue damage Rotstein et al.
Internal bleaching should be done by an endodontist and can be performed only after successful root canal therapy. Internal bleaching is not for everyone; Dr. Cohenca will evaluate and determine treatment on an individual basis. What are the different reasons for teeth discoloration?
Intracoronal Bleaching of Nonvital Teeth
Intracoronal Bleaching of Nonvital tooth – Teeth Whitening