Different Esthetic Techniques Used in Combination to Recover the Smile

Today, dental esthetics attempts to imitate natural teeth by making them white, well-shaped, and aligned with no spots. This has enabled the development of several esthetic techniques, such as microabrasion to remove dental enamel surface stains and surface irregularities,^1-6 and vital tooth bleaching to treat yellowish teeth.⁷

The enamel microabrasion technique uses different abrasive agents associated with chemical solutions,^1,2,4,6 allowing the removal of intrinsic, hard-texture stains, and different coloring spots on the enamel surface, as well as correction of irregularities on the dental buccal surface.^1,8

The various microabrasive products include the Opalustre® (Ultradent Products, https://www.ultradent.com)or Prema® Compound (Premier Dental Products, https://www.premusa.com), a low-concentration hydrochloric acid product associated with silica microparticles that is certainly effective for microabrasion technique,^4,6,9,10 providing a good safety profile for the patient and professional.

The microabrasion technique also promotes micro-reduction on the adamantine surface.^4,5,10 In some cases, after its completion, microabrasion may cause teeth to become darker or yellowish because of the thinner remaining enamel surface, leading to more evident observation of the dentinal tissue, which in general determines tooth color. In these clinical conditions, correction of the color pattern of dental elements can be obtained with carbamide peroxide products applied in custom trays, such as the bleaching products Whiteness Perfect at 10% or 16% (FGM Productos Odontologicos, https://www.fgm.ind.br) or Opalescence® at 10% or 15% (Ultradent Products), with a considerable margin of clinical success, provided it is well indicated, well performed, and supervised by the professional.^4,6,9,10

Considering all the aforementioned aspects, the authors present a clinical case about a dental-enamel microabrasion technique used to remove buccal enamel surface stains associated with dental vital bleaching and restorative procedures in the proximal aspect of anterior teeth.

Case Report

A 16-year-old patient exhibited white, hard-texture stains in the buccal and proximal surfaces of anterior and posterior teeth (Figure 1A). Surgical procedures were performed with dental prophylaxis, using pumice and water. A previous application of a fine-tapered diamond bur (No. 3195 FF, KG Sorensen Indústria e Comércio Ltda, https://www.kgsorensen.com.br) using water as a coolant, had been done to remove the superficial white enamel stains (Figure 1B), followed by placement of a rubber dam. After provisions for eye protection for the patient, assistant, and professional were made, enamel microabrasion was performed for 1 minute on each of the three teeth, using Opalustre, (Figure 1C) with a rubber cup, mounted on a standard low-speed handpiece on a gear reduction of 10:1 to avoid product splattering. The microabrasion product was applied twice, and the teeth were flushed with water between each application (Figure 1D). After the compound was removed with a water spray, the teeth were dried and then polished with fluoride paste. A 2% neutral-pH sodium fluoride gel was applied on the enamel surfaces submitted to microabrasion and allowed to act for 4 ms. The rubber dam was removed, and the patient was instructed not to ingest solid food for 30 mins.

One month after the microabrasion procedure, tooth bleaching could be initiated, using a bleaching agent containing carbamide peroxide as the active ingredient. Custom bleaching trays for the maxillary and mandibular arches were made from alginate impressions. The patient was instructed to place a small drop of the bleaching product 16% Whiteness Perfect into each tooth well in the trays (Figure 1E). The patient was told to use the bleaching products placed in the trays for 4 hours daily for 6 weeks. After attaining a satisfactory color (Figure 1F), the patient was advised to perform topical applications of 2% neutral-pH sodium fluoride gel for 1 week, 4 mins daily.

After enamel microabrasion and vital tooth bleaching, the stains in the proximal aspect of teeth that were not removed by the microabrasion technique were removed using a fine-tapered diamond bur (No. 1014, KG Sorensen Indústria e Comércio Ltda) with water as the coolant (Figure 1G). The enamel and dentin surfaces were etched, using 37% phosphoric acid (DENTSPLY, https://www.dentsply.com) for 30 and 15 secs, respectively. The cavity was thoroughly rinsed for 15 secs and gently air dried to remove excess moisture. The adhesive Adper™ Single Bond 2 (3M ESPE, https://www.3MESPE.com) was applied with a microbrush and gently spread with an air syringe to remove excess adhesive and to evaporate the solvent. The adhesive was light-cured for 20 secs at 400 mW/cm2 (Ultralux, Dabi Atlante Indústria). The cavities were restored with composite resin 4 Seasons (Ivoclar Vivadent, https://www.ivoclarvivadent.com) for dentin (DA1) and high value resin (Figure 1H and Figure 2). The cervical and buccal aspects of the maxillary right canine received a composite resin restoration in the region submitted to microabrasion because of the depth of enamel stain.

Discussion

In 1986, Croll and Cavanaugh2 reported a new technique to treat enamel stains that provided considerable esthetic success, which motivated other researchers to adopt and report other studies about this procedure.^4-6,8-11

With time, microabrasive products were made using a lower concentration of hydrochloric acid associated with microparticles of hard silica, such as the microabrasive product Opalustre. However, the use of this notable technique takes time to completely remove superficial intrinsic stains and to perform surface regularization. Thus, some studies have suggested^3-6,8-11 initiating the microreduction procedures in the affected dental enamel using a fine-tapered diamond bur. As a result, less time would be required to remove the spots and then normalize the dental enamel surface using the microabrasive products.

Moreover, previous use of a diamond bur to remove enamel stains usually requires only two or three applications of microabrasive products, which significantly reduces the procedure time as well as the amount of microabrasive product used to obtain a satisfactory esthetic effect.

Sometimes it seems to be clinically difficult to determine the intrinsic stains or even the depth of dental enamel surface irregularity, which leads to application of the microabrasion technique in all intrinsic stains of any extent or depth. Moreover, according to the excellent results obtained in this clinical case, it may be assured that the etiology of stains is not the prior determinant for the use of the microabrasion technique but rather the texture. Thus, hard texture and different coloring spots that compromise the ideal esthetics are indications for treatment.

It has been clinically certified that teeth submitted to microabrasion demonstrate a considerably regular enamel surface associated with a smooth and lustrous appearance, which will enhance in subsequent years,^1,4-6,8-13 and durable results are obtained. When enamel spots are removed, they do not appear again, as long as the patient does not present deficient lip closure, which hinders the humid layer formation in dental enamel uncovered by the upper and lower lips. These patients need to be evaluated by an orthodontist or a speech therapist for correct repositioning of the lips, which may be followed by dental enamel microabrasion.^4-6,8-11

Microabrasion of the dental enamel promotes microreduction of the adamantine surface.^4,5,9,10 In some cases, after completion, teeth submitted to microabrasion can become darker or yellowish because of the thinner remaining enamel that may reveal the dentinal tissue with greater evidence. Correction of the color pattern dental elements can be obtained with products containing carbamide peroxide. There are no reports4 of clinical alterations in hard- or soft-oral tissues, and the authors did not observe any sensitivity in bleached teeth, confirming their findings that vital tooth bleaching accomplished in custom trays can be safely prescribed if applied in nondecayed or well-restored teeth and in teeth without exposed dentinal tissue at the cervical or incisal region, as long as it is well supervised by the professional.

Moreover, the authors have observed throughout the years that the enamel microabrasion technique13 successfully removes buccal surface stains, which may not be achieved on proximal stains because the proximal contour is altered during removal. In this clinical report, proximal stains were removed using restorative procedures. The restorative procedures employing composite resin were performed 7 days after bleaching procedures because Sundfeld et al¹⁴ and Da Silva Machado15 had found the accomplishment of restorative procedures immediately after completion of bleaching significantly interfered with the penetration of adhesive agents into the enamel surface. This suggests a period of at least 7 days should be allowed between the use of peroxide bleaching material and restorative procedures that require acid-etching and adhesive bonding materials.

Conclusion

The enamel microabrasion technique, whether associated or not with tooth bleaching using carbamide peroxide and proximal restorative procedures using composite resin, are considerably sufficient, safe, and effective procedures and optimized the esthetic results.

References