Relato de caso Association between bleaching techniques for the treatment of teeth with chromatic alteration-Case report

Dental trauma is one of the most common causes of post-eruptive intrinsic color changes in teeth. The dissatisfaction with smile aesthetics is one of the main motivators for seeking dental procedures such as tooth bleaching, which stands out for being a little-invasive procedure with immediate and satisfactory aesthetic results. The objective of this paper is to describe a case report of a 24-year-old patient who attended the Postgraduate Program in Dental Clinic Practice at the Piracicaba Dental School – University of Campinas, which involved as main complaint tooth darkening after trauma in childhood. Internal bleaching of a dental element was performed using sodium perborate and distilled water associated with in office external bleaching with 37% hydrogen peroxide to provide a more harmonious smile to the patient. The association of bleaching techniques is an alternative widely indicated and effective in cases where it is desirable to maintain the integrity of dental elements, especially in young patients, avoiding more invasive restorative procedures and resulting in patient satisfaction.

increasing the chances of occurrence of postoperative hypersensitivity (Beatriz et al., 2013).
However, this effect can be mitigated by using a bleaching agent in lower concentration or by reducing the exposure time of the dental structure to the product (Beatriz et al., 2013).
In cases of color changes in traumatized teeth, internal bleaching is a widely recommended treatment, especially when elements with great structural integrity are involved without the presence of wide restorations that justify performing indirect restorative treatment, which would create the need for dental wear (Attin, Paqué, Ajam, & Lennon, 2003). In view of this-and since the association of bleaching techniques are presented as a minimally invasive treatment with great efficacy and good acceptance by the patient-, this study describes a case report involving external bleaching (in office) associated with internal bleaching of a posttrauma dental element to provide an aesthetically harmonious smile to the patient.

Materials and Methods
The case report presented composes an article with demonstrative and descriptive, exploratory purposes, exposing a qualitative approach. For Pereira et al (Pereira, Shitsuka, Dorlivete Moreira Parreira, & Shitsuka, 2018) the interpretation of the researchers, in the development of the clinical case and in view of the results obtained, is of great significance. In other words, it is important for the dentist to analyze, reflect and obtain his opinions from the junction: clinical practice and scientific knowledge, on the subject of the study, considering all the possibilities diagnostics and therapeutics on the combination of whitening techniques.

Case Report
The present study was approved by the local Research Ethics Committee, under report number 4.059.579. A 24-year-old female patient, in good general and oral health, attended the Undergraduate Dentistry Clinic at the Piracicaba Dental School -University of Campinas, complaining about her smile aesthetic due to the changed color of her teeth, in particular dental element 12. Upon clinical examination and visual inspection, it was found that the crown of tooth 12 was darkened ( Figure 1). During anamnesis, the patient reported that during childhood she suffered a fall from her own height, from which trauma to tooth 12 was generated, which possibly led to pulp necrosis. The patient reports that the tooth gradually darkened over time, however, endodontic treatment was performed only in adulthood. Upon physical examination, great coronary integrity of the tooth was observed, with direct resin restoration only on the palatal surface, due to the access performed for endodontic treatment. During periapical radiographic examination, the quality of endodontic treatment was evaluated, resulting in satisfactory filling and absence of periapical lesion (Figure 2), discarding the need for endodontic retreatment.  Color registration of the lower central incisor after bleaching -M1 0.5. Source: authors. Research, Society and Development, v. 9, n. 8, e278985863, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.5863 After each clinical session of external bleaching, active application of Sensodyne repair and protection paste (GlaxoSmithKline Brasil Ltda, Rio de Janeiro, RJ, Brazil) was made to the vestibular surface of the teeth ( Figure 6) for one minute in order to minimize sensitivity, followed by removal with water. With the same purpose, after the second session of external bleaching, the low-power Laser Duo (660nm to 808nm) (MM Optics LTDA., São Carlos -SP -Brazil) was applied, according to the protocol recommended by the manufacturer, for 1 minute at one cervical point of each tooth subjected to bleaching treatment (Figure 6). At the end of the treatment, it was possible to observe homogeneous staining of the teeth (Figure 7). Research, Society and Development, v. 9, n. 8, e278985863, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.5863