Smile Restoration through Use of Enamel Microabrasion Associated with Tooth Bleaching

Abstract

Enamel microabrasion can eliminate enamel irregularities and discoloration defects, improving the appearance of teeth. This article presents the latest treatment protocol of enamel microabrasion to remove stains on the enamel surface. It has been verified that teeth submitted to microabrasion acquire a yellowish color because of the thinness of the remaining enamel, revealing the color of dentinal tissue to a greater degree. In these clinical conditions, correction of the color pattern of these teeth can be obtained with a considerable margin of clinical success using products containing carbamide peroxide in custom trays. Thus, patients can benefit from combined enamel microabrasion/tooth bleaching therapy, which yields attractive cosmetic results.

Esthetics plays an important role in contemporary dentistry, especially because the media emphasizes beauty and health. Currently, in many countries, a smile is considered beautiful if it imitates a natural appearance, with clear, well-aligned teeth and defined anatomical shapes.^1-3 Enamel microabrasion is one technique that can be used to correct discolored enamel. This technique has been elucidated and strongly advocated by Croll and Cavanaugh since 1986,⁴ and by other investigators^1,2,5-13 who suggested mechanical removal of enamel stains using acidic substances in conjunction with abrasive agents. Enamel microabrasion is indicated to remove intrinsic stains of any color and of hard texture, and is contraindicated for extrinsic stains, dentinal stains, for patients with deficient labial seals, and in cases where there is no possibility to place a rubber dam adequately during the microabrasion procedure.^1,2 It should be emphasized that enamel microabrasion causes a microreduction on the enamel surface,^3,6,10 and, in some cases, teeth submitted to microabrasion may appear a darker or yellowish color because the thin remaining enamel surface can reveal some of the dentinal tissue color. In these situations, according to Haywood and Heymann in 1989,¹⁴ correction of the color pattern of teeth can be obtained through the use of whitening products containing carbamide peroxide in custom trays. A considerable margin of clinical success has been shown when diligence to at-home protocols is achieved by the patient and supervised by the professional.³ Considering these possibilities, this article presents the microabrasion technique for removal of stains on dental enamel, followed by tooth bleaching with carbamide peroxide and composite resin restoration, if required.

Case Report 1

An adolescent patient presented at Araçatuba Dental School—UNESP, Araçatuba, Brazil. When examined under dentistry light device, the dental enamel of the anterior teeth exhibited color alterations (Figure 1). After dental prophylaxis with pumice and water, a fine-tapered diamond bur (No. 3195 FF, KG Sorensen Indústria e Comércio Ltda, www.kgsorensen.com.br) was used with water cooling to remove the superficial layer of the stained enamel (Figure 2), followed by placement of a rubber dam with application of a layer of solid petroleum jelly between the rubber dam and gingival tissue to protect the tissue from the microabrasion product. It is important to protect the patient's, assistant's, and professional's eyes during this procedure. The microabrasion product, Whiteness RM (FGM, www.fgm.ind.br), was pressed against the tooth surfaces using a rubber cup designed for this purpose (Ultradent Products, Inc, www.ultradent.com), which was mounted on a standard low-speed handpiece on a gear reduction of 10:1 to avoid splattering of the product (Figure 3). The compound was carefully applied for 1 minute, in three intervals. Between each interval, the teeth were flushed with water. After completing all three applications, the compound was rinsed off the teeth with a water spray, the teeth were dried and then polished with fluoride paste (Figure 4). A 2% neutral-pH sodium fluoride gel was applied on the enamel surfaces submitted to microabrasion and left in place for 4 minutes. The rubber dam was then removed, and the patient was asked not to ingest solids for 30 minutes.¹ When a diamond bur is used to remove the superficial layer of stains before application of the microabrasion product, usually only two or three applications of the microabrasion product are required to achieve a satisfactory esthetic effect. One month after the microabrasion procedure, tooth bleaching may be initiated using a bleaching agent with carbamide peroxide as the active ingredient (Figure 5). In this case, custom bleaching trays for the maxillary and mandibular arches were made from alginate impressions. After initial fabrication, the trays were adapted to the patient's oral cavity. Then the patient was instructed to place a small drop of the bleaching product (10% Whiteness Perfect, FGM) into each tooth well of the trays. Immediately after placement onto the arches, the patient was to remove the excess product with a toothbrush (Figure 6). The patient was directed to use the trays for 4 hours daily for 4 weeks. After attaining satisfactory color (Figure 7 and Figure 8), the patient was advised to apply topical applications of 2% neutral-pH sodium fluoride gel for 1 week for 4 minutes daily.

Case Report 2

An adolescent patient presented at Araçatuba Dental School—UNESP, Araçatuba, Brazil, with color alterations and surface irregularities on the buccal aspect of the maxillary right central incisor, and a composite resin restoration on the buccal aspect of the maxillary left central incisor that exhibited color alteration and marginal leakage (Figure 9). The color alterations were removed, the enamel surface of the maxillary right central incisor was evened, and the superficial layer of composite resin on the buccal aspect of the maxillary left central incisor was smoothed with a fine-tapered diamond bur, No. 3195 FF. Then, enamel microabrasion was performed for 1 minute on each tooth using Opalustre^® (Ultradent Products, Inc) (Figure 10) with a rubber cup especially designed for this purpose, mounted on a standard low-speed handpiece on a gear reduction of 10:1 to avoid splattering of the product. The microabrasion product was applied three times and the teeth were flushed with water between each application (Figure 11). After 1 month, vital tooth bleaching was performed using a carbamide peroxide gel (Opalescence® 15%, Ultradent Products, Inc) as described in Case Report 1, except in this case the patient was instructed to bleach daily for 3 weeks. One week after bleaching was completed, the maxillary left central incisor was restored using composite resin (Opallis, FGM). Two different shades were applied, each one in its own proper area of the tooth. First, the dentin color (which is more opaque) was placed, and after that the enamel color (which is more translucent) (Figure 12).

Discussion

The enamel microabrasion technique is an excellent method to remove intrinsic enamel stains of any etiology and color, as well as to correct superficial irregularities on the buccal aspect of enamel, caused by either amelogenesis imperfecta or defects acquired after removal of orthodontic appliance.^{2-7,9-12,15-19} These alterations, however, should have a hard texture and may affect the superficial layers of dental enamel. Because it is very difficult to determine the real depth of intrinsic stains or surface irregularities, the application of the microabrasion technique on intrinsic stains, regardless of their dimensions and depths, should always be considered before trying a restorative procedure.^1,2

Sundfeld et al⁶ analyzed the amount of enamel loss using optical microscopy analysis under polarized light. They observed enamel loss ranging from 25 µm to 140 µm for 3 and 15 applications, respectively, when using a microabrasion paste containing 18% hydrochloric acid and pumice; and from 25 µm to 200 µm for 1 and 10 applications, respectively, when using the Opalustre product.¹⁰ The authors concluded that this enamel loss may be considered clinically irrelevant when compared with the remaining enamel surface.^6,10

Microabrasion can be performed solely with microabrasion products in cases presenting with only enamel spots, especially if the spots affect the full buccal aspect. However, this procedure may require an extended period of time to remove staining. Thus, as suggested in some studies,^{1,2,9-11,16,18,20} it may be convenient to initiate microreduction procedures on the affected enamel using a fine-tapered diamond bur. Incorporating this into the procedure can reduce the application of microabrasion products to two or three intervals, significantly reducing the overall time of the procedure, as well as the amount of microabrasion product used.

On microscopic evaluation, one study⁸ found that teeth submitted to microabrasion demonstrated a markedly regular enamel surface with a smooth and lustrous appearance, which enhanced over the years because of compaction of minerals remaining from the erosive and abrasive action of the microabrasion compound on the enamel surface. Another study⁵ using polarized light microscopy demonstrated that a surface submitted to microabrasion tends to show higher resistance to demineralization and protects the teeth from Streptococcus mutans colonization.

Since 1990, Sundfeld et al⁶ have verified the clinical and laboratory efficacy of the microabrasion technique using the hydrochloric acid pumice Prema^® Enamel Microabrasion Compound (Premier Products Co, www.premusa.com),⁷ or its use in conjunction with the previous diamond bur application.^{1,2,9-11,20,21} Newer microabrasion products such as Opalustre and Whiteness RM also have been shown to achieve safe and excellent clinical results.^2,22

Enamel microabrasion, however, promotes microreduction on the enamel surface; in some cases, teeth submitted to microabrasion may acquire a darker or yellowish color, because of the thinness of the remaining enamel surface, revealing the dentinal tissue (which usually determines the tooth color) with greater evidence. In these conditions, according to Haywood and Heymann,¹⁴ correction of the color pattern of teeth may be obtained with products containing carbamide peroxide in custom trays. In their studies, the bleached teeth did not show sensitivity during or after application of bleaching products, which confirms the authors' clinical findings that the use of carbamide peroxide-based bleaching agents in custom trays can be prescribed safely, if applied on nondecayed or well-restored teeth, without exposed dentinal tissue at the cervical or incisal regions, and under the supervision of a dental professional.^1,2 Considering the present cases and according to the authors' clinical experiences^1,2,9-12,20 they believe that enamel microabrasion used in conjunction with a carbamide peroxide-based bleaching agent is a conservative, safe, and effective clinical procedure with satisfactory and significant esthetic results.

References

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2. Sundfeld RH, Rahal V, Croll TP, et al. Enamel microabrasion followed by dental bleaching for patients after orthodontic treatment—case reports. J Esthet Restor Dent. 2007;19(2):71-78.

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4. Croll TP, Cavanaugh RR. Enamel color modification by controlled hydrochloric acid-pumice abrasion. I. Technique and examples. Quintessence Int. 1986;17(2):81-87.

5. Segura A. The Effects of Microabrasion on Colonization and Demineralization on Enamel Surfaces [master's thesis]. Iowa City, IA: University of Iowa; 1993.

6. Sundfeld RH, Komatsu J, Russo M, et al. Remoção de manchas no esmalte dental: estudo clínico e microscópico. Rev Bras Odontol. 1990;47(3):29-34.

7. Sundfeld RH, Komatsu J, Mestrener SR, et al. Remoção de manchas e de irregularidades superficiais no esmalte dental. Ambito Odontol. 1991;1(3):63-66.

8. Donly KJ, O'Neill M, Croll TP. Enamel microabrasion: a microscopic evaluation of the "abrosion effect." Quintessence Int. 1992;23(3):175-179.

9. Sundfeld RH, Mauro SJ, Briso AL, et al. Recuperação do sorriso II. Efeitos das técnicas da microabrasão e do clareamento dental. Rev Bras Odontol. 1999;56(6):311-318.

10. Sundfeld RH, Croll TP, Killian CM. Recuperação do sorriso VII—comprovação da eficiência e versatilidade da técnica da microabrasão do esmalte dental. J Bras Dent Estet. 2002;1:77-86.

11. Sundfeld RH, Croll TP, Mauro SJ, et al. Recuperação do sorriso. A comprovação da eficiência e versatilidade da técnica da microabrasão do esmalte dental. Rev Bras Odontol. 1995;52(3):30-65.

12. Sundfeld RH, Menegazzo MM, Pásqua Neto JD. Recuperação do sorriso VI—associação da microabrasão do esmalte dental com o clareamento dentinário. J Bras Clin Estet Odontol. 2001;5:217-222.

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14. Haywood VB, Heymann HO. Nightguard vital bleaching. Quintessence Int. 1989;20(3):173-176.

15. Croll TP. Enamel microabrasion for removal of superficial dysmineralization and decalcification defects. J Am Dent Assoc. 1990;120(4):411-415.

16. Croll TP. Hastening the enamel microabrasion procedure eliminating defects, cutting treatment time. J Am Dent Assoc. 1993;124(4):87-90.

17. Croll TP, Segura A, Donly KJ. Enamel microabrasion: new considerations in 1993. Pract Periodontics Aesthet Dent. 1993;5(8):19-28.

18. Croll TP, Bullock GA. Enamel microabrasion for removal of smooth surface decalcification lesions. J Clin Orthod. 1994;28(6):365-370.

19. Killian CM, Croll TP. Enamel microabrasion to improve enamel surface texture. J Esthet Dent. 1990;2(5):125-128.

20. Sundfeld RH, Mauro SJ, Komatsu J, et al. Recuperação do sorriso. Uma conquista promissora no campo da odontologia estética. Rev Bras Odontol. 1997;54(6):351-155.

21. Limeback H, Vieira AP, Lawrence H. Improving esthetically objectionable human enamel fluorosis with a simple microabrasion technique. Eur J Oral Sci. 2006;114(suppl 1):123-129.

22. da Silva SM, de Oliveira FS, Lanza CR, Machado MA. Esthetic improvement following enamel microabrasion on fluorotic teeth: a case report. Quintessence Int. 2002;33(5):366-369.

About the Authors

Renato Herman Sundfeld, DDS, MS, PhD
Full Professor, Discipline of Restorative Dentistry
Araçatuba Dental School
Universidade Estadual Paulista
Araçatuba, Brazil

Vanessa Rahal, DDS, MD
Graduate Student, Discipline of Restorative Dentistry
Araçatuba Dental School,
Universidade Estadual Paulista
Araçatuba, Brazil

Rodrigo Sversut de Alexandre, DDS, MD
Graduate Student, Department of Restorative Dentistry
Guarulhos Dental School, UNG
Guarulhos, Brazil

André Luiz Fraga Briso, DDS, MS, PhD
Assistant Professor, Discipline of Restorative Dentistry
Araçatuba Dental School,
Universidade Estadual Paulista
Araçatuba, Brazil

Daniel Sundfeld Neto
Undergraduate Student,
Piracicaba Dental School,
Unicamp
Piracicaba, Brazil