enamel microabrasion: case selection and clinical guidelines

66 Spring 2018 • Volume 34 • Number 1

CE — CLINICAL APPLICATION

CECREDIT

AbstractEnamel microabrasion (EM) is a conservative procedure used to remove superficial enamel discolorations. Identifying the types of discolorations that can be treated with EM is critical to achieving a favorable outcome. Several methods can be used to help determine the source of the discoloration, including a thorough dental and medical history of the patient and visual observation of the lesion from frontal, lateral, and transilluminated views. Two EM compounds are available and are composed of hydrochloric acid and silicon carbide abrasive particles in a moist silica gel. This article presents two clinical cases and offers a clinical protocol for EM and supplemental steps to achieve esthetic outcomes.

Key Words: enamel microabrasion, fluorosis, white spot lesion, enamel, dysmineralization

Augusto A. Robles, DDS, MSNathaniel C. Lawson, DMD, PhD

Enamel Microabrasion:Case Selection and Clinical Guidelines

Learning Objectives

After reading this article, the participant should be able to:

1. Utilize methods to help determine the source of tooth discolorations.

2. Identify which types of tooth discolorations are appropriately treated with enamel microabrasion.

3. Understand a clinical protocol for enamel microabrasion and supplemental steps to achieve esthetic outcomes.

Disclosures: The authors did not report any disclosures.

67 Journal of Cosmetic Dentistry

Case Selection and Clinical Guidelines

Robles/Lawson



IntroductionEnamel microabrasion (EM) can produce dramatic and gratifying results if the case is selected properly, the patient is informed thoroughly, and the procedure is performed judiciously. Even if the outcome is not ideal, significant improvements in the patient’s ap-pearance may be achieved and supplemented with other treatments. This article summarizes causes of tooth discoloration to aid with case selection, the characteristics of commercially available EM products, and a protocol to guide the clinician.

Case SelectionThe most important criterion for successful EM treat-ment is proper case selection. Poorly selected cases can lead to disappointment for the patient and the clinician. Because EM removes superficial enamel dis-colorations, dentin discolorations such as those due to tetracycline staining or dentinogenesis imperfecta will not be affected by this procedure. The first step for the clinician is to rule out the stain as being dentinal in origin.

Once it has been established that the stain is in the enamel the next step is to determine whether the enamel’s altered appearance is due to extrinsic or in-trinsic causes. Ingested substances such as coffee, tea, colas and other soft drinks, red wine, soy sauce, or an iron supplement in vitamins are common extrinsic causes, as are some dental products such as chlorhexi-dine and stannous fluoride. Tobacco products also will cause stains that can be difficult to remove with conventional polishing using pumice pastes. Intrinsic causes of enamel discolorations are associated with alterations in the mineralization process, leading to areas of hypo- or hypermineralization.

DysmineralizationDysmineralization is a term coined by Croll to describe a disturbance in the formation of the inorganic com-ponent of enamel.1 Exposure to excess fluoride dur-ing the years of amelogenesis also can lead to brown or white discolorations, known as fluorosis. Accord-ing to the Centers for Disease Control and Preven-tion, approximately 23% of Americans between 1999 and 2004 were affected by some form of fluorosis.2 The severity and presentation of fluorosis stains var-ies and treatment options such as EM and EM fol-lowed by dental whitening should be reviewed with each patient (no treatment also is an option). Some enamel mineral stains attributed to excess fluoride consumption in the first decade of life actually may be idiopathic white or brown enamel dysmineralization.

Clinicians would be prudent to avoid routinely attributing any enamel discoloration to fluoride ingestion as doing so can provide erroneous evi-dence for the antifluoridation movement.

To help differentiate internal and external staining, thorough medical and dental histories should include any incidence of trauma, high fe-ver episodes, or medications taken during childhood (including fluoride supplements). Such factors could be responsible for altering the enamel mineralization process and aid in diagnosis of intrinsic staining.3 Stains attributed to systemic conditions should be present on all teeth mineral-izing at the same time during development. The clinician also should ask the patient about the onset of the discoloration. A discoloration that has developed during the patient’s span of memory is more likely to be extrinsic staining than is one that is related to tooth development.

Discoloration versus Decalcification Discoloration from changes in emamel also should be differentiated from caries-initiated white spot lesions, known as decalcification. Decalci-fication lesions typically are located at the cervical aspect of the tooth or surrounding orthodontic brackets because these surfaces are more likely to accumulate acid-producing plaque.4 White spot lesions also may be suspected based on the patient’s caries risk. Patients with poor oral hy-giene, a diet that lowers intraoral pH, significant plaque accumulation, or a history of orthodontic treatment may be more likely to develop white spot decalcification lesions. Although clinicians can treat these decalcifi-cation lesions with EM,5 other treatment options include techniques such as remineralization with calcium phosphate pastes or resin infiltration.6 There is no consensus, however, on which technique is most effective.7

Practically, the clinician will need to determine two aspects of a sus-pected intrinsic stain prior to initiating treatment: its depth into the enamel and its thickness. A stain on the surface of enamel that has a more shallow penetration depth will be easier to treat than a deeper stain located underneath a layer of enamel. A clinical technique to determine whether the lesion is superficial enough to be treated effectively by means of EM is to take a lateral view. If the stain appears to be “painted” on the surface of the tooth, it is closer to the surface than a stain that appears to be behind a wall of translucent enamel. The clinician can imagine viewing a glass plate with either a splash of white paint on top of or behind the glass surface. When the view shifts to the side of the glass plate, the glass with paint behind its surface will demonstrate a translu-cent edge, whereas the glass with paint on its surface will demonstrate an opaque edge.

Some enamel mineral stains attributed to excess fluoride consumption in the first decade of life actually may be idiopathic white or brown enamel dysmineralization.


The color and texture of the discoloration also can provide clues about the stain’s location. Stains that are opaque and matte are more likely to be on the surface than those that are glossy and murky. The borders of a surface stain often are more defined than those that are deeper in the enamel. The incisors shown in Figure 1 have murky white, nondefined discolorations that appear to be subsurface when observed from a lateral view (Fig 2). On the other hand, the incisors shown in Figure 3 have white opaque, defined discolorations that appear, from a lateral view, to be painted on the surface (Fig 4). Investigators in a clinical trial determined that EM produced more improvement in brown stains than in white opaque stains.8 The authors suggested that brown stains originate from discoloration of dysmineralized surfaces and, therefore, are more superficial than white stains.8

Figure 1: Frontal view of murky white, nondefined discolorations on the central incisors.

Figure 2: When observed from the right lateral view, the discolorations appear to be subsurface.

Figure 3: Frontal view of white opaque, defined discolorations on the central incisors.

Figure 4: Right lateral view; the discolorations appear to be “painted” on the surface.

Robles/Lawson

The most important criterion for successful enamel microabrasion treatment is proper case selection.



Figure 5: Incisor with a milky white discoloration under direct light (left) and transillumination (right).

Figure 6: The incisor shown in Figure 5 has been sectioned faciolingually to demonstrate that discoloration is present approximately 446 microns into the enamel.

A method to help determine the thickness of a stain is to transilluminate the tooth with a dental light-curing unit. If the lesion becomes significantly darker with transillumination, the lesion likely is deeper within the enamel.9,10 Figure 5 shows a central incisor with a milky white discoloration under direct light and transillumination. The stain appears as a uniform dark area with transillumination. After the tooth was sectioned, the depth of the discoloration was measured as being 446 microns (Fig 6).

In Figure 7, a different central incisor is shown with defined opaque brown and white staining under direct lighting. Under transillumination, the area of white staining at the bottom left corner of the tooth allows some light to transmit through the stain,

suggesting it is shallow. After the tooth was sectioned, it was deter-mined that the staining was on the outermost 34 microns of the tooth (Fig 8). These cross sections demonstrate that stains with a uniform dark appearance likely are too deep to be removed with enamel microabra-sion, whereas stains that allow some light transmission may be shallow enough for this treatment. Once a clinician gains experience with the EM procedure, determining which brown and white discolorations can be eliminated in this manner becomes much easier.

In brief, intrinsic enamel discolorations caused by fluorosis, idiopathic dysmineralization, hypo- or hypermineralization, or white spot decalci-fication lesions can be improved permanently by means of EM if the dis-coloration is in the outermost layer of enamel. Before initiating treatment clinicians need to ascertain a suspected intrinsic stain’s depth into the enamel as well as its thickness. Transillumination with a dental curing light can aid in determining this.


Figure 7: Incisor with opaque matte brown and white discoloration under direct light (left) and transillumination (right).

Figure 8: The incisor shown in Figure 7 has been sectioned faciolingually to demonstrate that discoloration is present approximately 34 microns into the enamel.

ProductsTwo current EM products have shown clinical effectiveness in improving the appearance of enamel discolor-ations.11,12 Prema Compound (Premier Dental Products; Plymouth Meeting, PA) comprises a paste of 9% to 10% hydrochloric acid and 30- to 60-microns silicon carbide abrasive particles. Opalustre (Ultradent Products; South Jordan, UT) comprises 6.6% hydrochloric acid and 20- to 160-micron silicon carbide abrasive particles.9 Both products provide a rubber cup that attaches to a slow-speed handpiece to be used at approximately 500 rpm. Some authors recommend pretreating the surface of the lesion with a diamond bur to remove heavy staining, a technique sometimes referred to as macroabrasion.13 The manufacturers’ instructions recommend applying the paste with the rubber cup for 60 seconds at a time, suctioning, and rinsing, as many times as necessary. In a study by Sundfeld and colleagues, 60 seconds of EM removed 25 microns of enamel while 10 minutes of EM removed 200 microns.14

In addition to removing superficial stains, EM improves a tooth’s appearance by creating a dense, prismless mineral layer on the tooth’s surface15 that changes the way in which light is reflected off and transmitted through the tooth, camouflaging some underlying discolorations. Results from several long-term follow-ups (at 11, 20, 23, and 60 years) have demonstrated that the results of EM maintain their appearance over time.10,16,17

Robles/Lawson



Figure 11: Application of 1 mm of paste to the affected surface.

Figure 9: Case 1, initial intraoral presentation.

Figure 10: Anterior teeth isolated with a rubber dam.

EM Treatment Protocol

Case 1 A 25-year-old female with a noncontribu-tory medical history presented to the un-dergraduate clinic of the University of Ala-bama at Birmingham (UAB) School of Dentistry for comprehensive care and to have her discolored maxillary central incisors “fixed” (Figs 3, 4, & 9). Based on the criteria described previously the enamel discoloration was deter-mined to be superficial. The patient was given de-tailed information about her condition and the proposed treatment with EM.

After rubber dam placement (Fig 10), the EM paste (Opalustre) was applied over the facial surface of the affected teeth (Fig 11). A rubber cup (OpalCups, Ultradent) was used to com-press the paste utilizing slow speed (500 rpm) and moderate pressure for 60-second applica-tions (Fig 12) followed by intermittent rins-ing and inspection. After the first application, the white discolorations remained on the teeth (Fig 13). After a second application, the white discolorations were no longer visible but the teeth exhibited an amber hue from the dentin showing through the translucent enamel (Fig 14).

Whitening can be an effective adjunctive pro-cedure after EM.18-21 Some clinicians prefer to whiten the teeth first because whitening can help to determine the extent of and areas in which EM is necessary (there also is some concern that microabraded teeth will be more susceptible to hydrogen peroxide penetration, with possible pulpal considerations).22 The authors prefer to perform whitening after EM to address any pos-sible dentin show-through.

Finally, fluoride varnish (MI Varnish, GC America; Alsip, IL) was applied over the treated enamel surfaces (Fig 15). At the next day’s ap-pointment alginate impressions were made for fabrication of at-home whitening trays. The trays were tried in and the patient was given carbamide peroxide (Opalescence 10%, Ultradent) and sy-ringes, along with written and verbal instructions. Two weeks later the patient returned and final photographs were taken (Figs 16 & 17).


Figure 12: The paste was applied for 60 seconds with firm pressure. Figure 13: After the first application, some white discolorations remained.

Figure 14: After the second application, the discolorations were gone but the teeth developed an amber hue.

Figure 15: Application of 5% sodium fluoride varnish to the facial enamel.

Figure 16: Case 1, final intraoral presentation. Figure 17: Case 1, final extraoral presentation.

Robles/Lawson



Case 2A 35-year-old male presented to the undergradu-ate clinic of the UAB School of Dentistry wish-ing to have veneers placed to mask dark stains on his maxillary central incisors. His medical history revealed no contraindications to dental treatment and no history that would indicate an etiology for enamel or dentin discoloration. On clinical examination the discolorations appeared to be opaque white and brown (Fig 18). Idio-pathic white and brown enamel dysmineraliza-tion was diagnosed and treatment with EM was planned. The patient was informed that if the discolorations did not improve acceptably there were other treatment options, such as removal of persistent stained areas and restoration with resin composite, resin composite veneers, or (the most invasive approach) bonded porcelain veneers.

Before the patient began treatment, the teeth were transilluminated with a light-curing unit (Fig 19). The brown discolorations appeared to allow some light to transmit through the teeth; this finding suggested that the stains were located superficially within enamel.

The clinical protocol utilized in Case 1 also was followed for this case (Figs 20 & 21). The amount of enamel loss was monitored during the procedure by observing the facial surface of the incisors from the incisal edge with a dental mirror (Fig 22). Two consecutive applications of EM paste were done to achieve the desired results. Some brown and white staining was still pres-ent on the teeth at the completion of treatment but the patient was satisfied with the outcome. The teeth were coated with fluoride varnish and the patient was provided with at-home whiten-ing trays and 10% carbamide peroxide gel. Three weeks later he returned and final photographs were taken (Figs 23 & 24).

Figure 20: Paste applied to areas of discoloration.

Figure 18: Case 2, initial intraoral presentation.

Figure 19: Transillumination with a light-curing unit shows some light transmitted through discolorations.

This minimally invasive approach not only preserved tooth structure but also provided a permanent solution for each case’s esthetic problems.


Figure 21: Paste was applied for 60 seconds with firm pressure. Figure 22: Teeth monitored from the incisal edge to prevent removal of too much enamel.

Figure 23: Case 2, final intraoral presentation. Figure 24: Case 2, final extraoral presentation.

Robles/Lawson

Acknowledgments

The authors thank Dr. Theodore Croll (Doylestown, PA) for his insightful suggestions during the preparation of this article. The authors also acknowledge Ms. Ashley Mechay Rush and Ms. Bradee Aiyer, dental students at the University of Alabama at Birmingham, for their assistance with diagnosing and treating the patients whose cases were discussed here.

SummaryEnamel microabrasion can produce dramatic and gratify-ing results but proper case selection is crucial to a successful outcome. Even if an outcome is not ideal, significant esthetic improvements may be achieved and supplemented with other treatments. The two clinical cases described in this article typify what can be achieved with EM and tooth whitening. This mini-mally invasive approach not only preserved tooth structure but also provided a permanent solution for each case’s esthetic problems. Both patients and their dentists were pleased with the improvements in tooth color.



References

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dental enamel defects: etiology, research and contemporary

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5. Croll TP, Bullock GA. Enamel microabrasion for removal of

smooth surface decalcification lesions. J Clin Orthod. 1994

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6. Khoroushi M, Kachuie M. Prevention and treatment of white

spot lesions in orthodontic patients. Contemp Clin Dent. 2017

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7. Sonesson M, Bergstrand F, Gizani S, Twetman S. Management

of post-orthodontic white spot lesions: an updated systematic

review. Eur J Orthod. 2017 Apr 1;39(2):116-21.

8. Celik EU, Yildiz G, Yazkan B. Clinical evaluation of enamel mi-

croabrasion for the aesthetic management of mild-to-severe den-

tal fluorosis. J Esthet Restor Dent. 2013 Dec;25(6):422-30.

9. Pini NI, Sundfeld-Neto D, Aguiar FH, Sundfeld RH, Martins LR,

Lovadino JR, Lima DA. Enamel microabrasion: an overview of

clinical and scientific considerations. World J Clin Cases. 2015

Jan 16;3(1):34-41.

10. Sundfeld RH, Sundfeld-Neto D, Machado LS, Franco LM, Fa-

gundes TC, Briso ALF. Microabrasion in tooth enamel discolor-

ation defects: three cases with long-term follow-ups. J Appl Oral

Sci. 2014 Jul-Aug;22(4):347-54.

11. Loguercio AD, Correia LD, Zago C, Tagliari D, Neumann E,

Gomes OM, Barbieri DB, Reis A. Clinical effectiveness of two mi-

croabrasion materials for the removal of enamel fluorosis stains.

Oper Dent. 2007 Nov-Dec;32(6):531-8.

12. Price RB, Loney RW, Doyle MG, Moulding MB. An evaluation of

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Am Dent Assoc. 2003 Aug;134(8):1066-71.

13. Croll TP. Hastening the enamel microabrasion procedure eliminating defects, cut-

ting treatment time. J Am Dent Assoc. 1993 Apr;124(4):87-90.

14. Sundfeld RH, Rahal V, Croll TP, De Aalexandre RS, Briso AL. Enamel microabra-

sion followed by dental bleaching for patients after orthodontic treatment—case

reports. J Esthet Restor Dent. 2007;19(2):71-7; discussion 78.

15. Donly KJ, O’Neill M, Croll TP. Enamel microabrasion: a microscopic evaluation of

the “abrosion effect”. Quintessence Int. 1992 Mar;23(3):175-9.

16. Croll TP. A case of enamel color modification: 60-year results. Quintessence Int.

1987 Jul;18(7):493-5.

17. Donly KJ, Croll TP. Enamel microabrasion for removal of superficial coloration and

surface texture defects. In: Perdigão J, editor. Tooth whitening: an evidence-based

perspective. Cham, Switzerland: Springer International; 2016. p. 201-9.

18. Sundfeld RH, Franco LM, Gonçalves RS, de Alexandre RS, Machado LS, Neto DS.

Accomplishing esthetics using enamel microabrasion and bleaching—a case re-

port. Oper Dent. 2014 May-Jun;39(3):223-7.

19. Croll TP. Enamel microabrasion followed by dental bleaching: case reports. Quin-

tessence Int. 1992 May;23(5):317-21.

20. Castro KS, Ferreira AC, Duarte RM, Sampaio FC, Meireles SS. Acceptability, efficacy

and safety of two treatment protocols for dental fluorosis: a randomized clinical

trial. J Dent. 2014 Aug;42(8):938-44.

21. Celik EU, Yıldız G, Yazkan B. Comparison of enamel microabrasion with a com-

bined approach to the esthetic management of fluorosed teeth. Oper Dent. 2013

Sep-Oct;38(5):E134-43.

22. Briso AL, Lima AP, Gonçalves RS, Gallinari MO, dos Santos PH. Transenamel and

transdentinal penetration of hydrogen peroxide applied to cracked or microabra-

sioned enamel. Oper Dent. 2014 Mar-Apr;39(2):166-73. jCD

Dr. Lawson is an assistant professor and director of the Division of Biomaterials at UAB School of Dentistry. He can be contacted at [email protected]

Dr. Robles is an assistant professor and director of the Operative Dentistry Curriculum at the University of Alabama at Birmingham (UAB) School of Dentistry. He can be contacted at [email protected]


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This Continuing Education (CE) self-instruction exam is based on the article Enamel Microabrasion: Case Selection and Clinical Guidelines by Dr. Augusto Robles and Dr. Nathaniel Lawson (pages 66-76).

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1. Which of the following is best suited for treatment with enamel microabrasion (EM)?

a. superficial enamel discolorations

b. mild enamel and dentinal discolorations

c. tetracycline staining

d. dentinogenesis imperfecta

2. To help differentiate extrinsic staining, medical and dental histories should include which of the following?

a. An incidence of high fever altering the enamel mineralization on all

teeth.

b. Medication taken during childhood affecting all primary teeth.

c. Discolorations that have developed during a patient’s span of memory.

d. An incidence of trauma altering isolated enamel mineralization.

3. What is a key difference between decalcification, discolor-ation, and dysmineralization?

a. Dysmineralization is a disturbance in the formation of the organic

component of enamel.

b. Decalcification results from changes in enamel formation.

c. Brown discoloration due to extrinsic staining is easier to treat with EM

than dentin demineralization.

d. Additional techniques such as remineralization with calcium phosphate

pastes are always required in the treatment of discoloration.

4. What aspect or aspects of a suspected intrinsic stain should a clinician determine prior to initiating treatment with EM?

a. The depth into the enamel and the thickness of the stain.

b. Whether the discoloration is associated with alterations in the

mineralization process.

c. Whether the discoloration is an area of hypomineralization or

hypermineralization.

d. The exact cause of the discoloration.

5. Which of the following is true and will help a clinician determine the depth of a discoloration?

a. When the tooth is viewed laterally, a superficial stain will appear to

fluoresce.

b. When the tooth is viewed from the incisal aspect, a superficial stain will

appear darker than when viewed directly from the facial.

c. When the tooth is viewed from the incisal aspect, a superficial stain will

appear more opaque than when viewed directly from the facial.

d. When the tooth is viewed laterally, a superficial stain will appear to be

“painted” on the surface.

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enamel microabrasion: case selection and clinical guidelines

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