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White spot lesions: Prevention andtreatment

To prevent development of white spot lesions, orthodon-tists should assess each patient’s risk factors before and duringtreatment. Oral hygiene instruction is important, but patientsmight need to be assisted with additional measures, includingfluoride varnish, chlorhexidine, xylitol, dietary modification,or calcium-containing remineralization products that canhelp prevent enamel demineralization, enhance remineraliza-tion, and modify patient and biofilm factors. Restorative treat-ment for established white spot lesions can range from themost conservative (remineralization with fluoride, calcium,and phosphate) to the most aggressive (tooth reduction andporcelain veneers).

What is the prevalence of white spot lesions in orthodonticpractice?

Estimates of the overall prevalence of white spot lesions(Fig 1) arising during fixed appliance therapy range widelyfrom 2% and 96%.1-4

In a cross-sectional study, Mizrahi1 evaluated 527 patientsbefore fixed appliance orthodontic treatment and 269 patientsafter treatment. There were significant increases in both theprevalence (72.3%-84%) and the severity (opacity index,0.125-0.200) with treatment. Male patients experienced sig-nificantly greater increases in the severity of enamel opacitiesthan did female patients. However, therewas no significant sexdifference in the prevalence of enamel opacities.

In a study by Gorelick et al,2 individual teeth with fixedappliances exhibited significantly more white spot lesionsthan did the teeth in the control group. The highest incidenceof lesions was found at the labio-gingival area of the maxillarylateral incisors, and the lowest incidence was in the maxillaryposterior segment. Interestingly, no white spots were found onthe lingual surfaces of mandibular canines and incisors afterprolonged use of a canine-to-canine bonded retainer. Thesefindings suggest a relationship between resistance to whitespot formation and the rate of salivary flow and emphasizethe need for preventive regimens. Despite the lack of anypreventive fluoride program among the study groups, 50%of the patients had resistance to white spot formation.2

What is the etiology of white spot lesion development?White spot lesions are areas of demineralized enamel that

usually develop because of prolonged plaque accumulation.

*The viewpoints expressed are solely those of the author(s) and do not reflect

those of the editor(s), publisher(s), or Association.

690

Fixed orthodontic appliances create stagnation areas forplaque and make tooth cleaning difficult. The irregular surfacesof brackets, bands, and wires limit the naturally occurring self-cleansing mechanisms of the oral musculature and saliva.6

This encourages plaque accumulation and the colonization ofaciduric bacteria; over time, this results in active white spotlesions, and, if not treated, a cavitated caries lesion can develop.

White spot lesions can occur on any tooth surface in theoral cavity where the microbial biofilm is allowed to developand remain for a period of time. Also impacting their develop-ment are the patient’s modifying factors, including medicalhistory; dental history; medication history; diet; levels ofcalcium, phosphate, and bicarbonate in saliva; fluoride levels;and genetic susceptibility (Fig 2).5,6

A dynamic and continuous process of enamel demineral-ization and remineralization occurs that can progress frominitial demineralization, to noncavitated lesions, and finallyto cavitated lesions.7 Before the hypermineralized enamelsurface layer is lost or cavitated, the demineralization processmight encompass the full thickness of the enamel includingthe outer layer of the dentin. The white spot lesion’s chalkyappearance is simply an optical phenomenon caused bymineral loss in the subsurface and the surface of the enamel.2

What is the clinical differential diagnosis of white spotlesions?

White spot lesions can be either noncarious or carious.To differentiate between them, the clinician must first cleanand dry the teeth and then closely evaluate the lesions usingmagnification and adequate lighting. The consistency andtexture of the surface can be gently evaluated with a peri-odontal probe. Carious white spot lesions appear rough,opaque, and porous. Noncarious lesions appear mostlysmooth and shiny.

Enamel crystal dissolution begins with subsurface demin-eralization, creating pores between the enamel rods. The alter-ation of the enamel refractive index in the affected area ofa carious white spot lesion is a consequence of both surfaceroughness and loss of surface shine plus alteration of internalreflection, all resulting in visual enamel opacity, becauseporous enamel scatters more light than sound enamel.2,3

Commonly identified when the teeth are dry, carious whitespot lesions are typically found on the buccal surfaces beneatha thick accumulation of plaque and around the perimeter oforthodontic brackets where oral hygiene is difficult. Thelesions can extend broadly over the surface of the teeth andsometimes involve proximal extensions. Orthodontic patientswith carious buccal white spot lesions should be evaluated forproximal noncavitated and cavitated carious lesions.8

Fig 1. White spot lesion.

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Noncarious white spot lesions, classified as fluorosis,developmental enamel hypomineralization, and enamelhypoplasia, can have genetic and environmental bases.7 Thesenoncarious white spots are usually limited to a few teeth(typically, anterior teeth) or generalized throughout the denti-tion, covering the entire tooth surfaces, and are not associatedwith orthodontic brackets or bands.

How can orthodontic patients at risk for developing whitespot lesions be identified?

The likelihood of developing white spot lesions increasesif the patient has any of the following: inadequate oralhygiene, inappropriate diet (high frequency of elevated carbo-hydrate beverages and snacks), history of recent caries lesionsor high DMFS (Decay Missing Filled Surfaces), and lack ofadjunctive preventive measures, such as fluoride or antibacte-rial exposure, xylitol gum, and calcium-derived supplements.

Geiger et al9 reported a significant association betweenpoor patient compliance with home-care preventive proce-dures and the formation of white spot lesions in orthodonticpatients. Surprisingly, no statistically significant differencewas reported between the compliance levels of the sexes orthe various age groups.

Caries indicators are clinical observations that informus ofa patient’s past caries history and activity. These clinical signsof recent disease and history of caries disease can provide clearinformation of past dental history. There are 4 strong cariesdisease indicators: frank cavitation, proximal lesions, whitespot lesions, and any restorations or teeth extracted withinthe last 3 years because of active disease. Any of these indica-tors puts the patient in a high-risk category.10

The relationship between refined sugar, frequency of snacksand meals, and dental caries is well documented.11-13

Individualized diet evaluation and counseling can be used toemphasize simple concepts to help reduce exposure orfrequency of exposure to sugared beverages such as regularpop or soda, juice, and sports drinks, and sour or regularcandy. The structure of meals and snacks influences thequantity and frequency of exposure to fermentablecarbohydrates and to caries risk. An evaluation of sugared

beverage intake is a key item that should be included ina patient’s dietary assessment.13 Although orthodontists donot typically assess patients’ dietary habits because of re-source and time limitations, such evaluations are essential inpreventing white spot lesions.

As described by Derks et al,14 preventive and chemopro-phylactic products, such as high-fluoride toothpaste or gel,fluoride varnish, and chlorhexidine rinse, gel, or varnish, arerarely prescribed by orthodontists; 95% of orthodontists pro-vide oral hygiene instructions. And 52% prescribe fluoridemouth rinse.

The caries risk assessment worksheet used at the Univer-sity of Iowa College of Dentistry is based on the AmericanDental Association’s caries risk assessment form that was rec-ommended as a standard of care by its Counsel of ScientificAffairs in 2009.10 This form is used to identify risk factorsthat contribute to dental caries as well as protective factorsand is available at: http://www.ada.org/prof/resources/topics/topics_caries_instructions.pdf.

What strategies should be used to prevent white spotlesions in orthodontic patients?

Depending on the patient’s risk factors, a number of suit-able agents and therapies can be applied: fluoride toothpastes,gels, varnishes, and mouth rinses; antimicrobials; xylitol gum;diet counseling; and casein derivates.

What fluoride treatment is recommended?The use of higher-concentration fluoride toothpastes

and gels (1500-5000 ppm) twice a day during orthodontictreatment has demonstrated a demineralization-inhibitingtendency.15

For many years, fluoride toothpaste has been consideredthe most effective and widely used method of applyingfluoride, in addition to fluoridated water. The efficacy ofconventional fluoride toothpaste (1000 ppm) has been docu-mented in many studies; evidence suggests that toothpastecontaining 5000 ppm fluoride can further reduce demineral-ization and enhance remineralization.16,17 Recently, it wassuggested that patients undergoing orthodontic treatmentshould brush twice a day with 5000-ppm fluoride toothpasteor gel.16 This regimen was reported to provide greaterprevention than the daily use of 500-ppm sodium fluoriderinse.18

As part of the recommended fluoride regimen, patients withorthodontic fixed bonded appliances should have an in-officefluoride varnish application at least twice a year; this providesa high concentration of fluoride to the teeth (5% sodiumfluoridein an alcohol suspension of natural resins, approximately 22,000ppm). TheAmericanDental Association’s Council on ScientificAffairs recommends that ‘‘moderate-risk and high-risk patientsshould receive in-office fluoride varnish at six-month intervals.A fluoride varnish application at three-month intervals mayprovide an additional caries prevention benefit.’’19 In case ofpoor patient compliance with using preventive protocols athome, it would be advantageous to apply fluoride varnishmore than 2 times a year, perhaps at all orthodontic visits.

Fig 2. Caries risk-modifying factors (Chalmers 2006, modified from Ngo in Mount and Hume).

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Do fluoride mouth rinses help?In general, fluoride mouth rinses can add an extra expo-

sure of fluoride and might be beneficial to some patients, butthere is no strong evidence that fluoride mouth rinses caneffectively prevent or reduce the severity of white spot lesionsduring orthodontic treatment.

There is some evidence that a daily sodium fluoride mouth-wash is effective in reducing the severity ofwhite spots in peopleundergoing orthodontic treatment, but it is not strong. Little hasbeen published concerning its use in orthodontic patients orhow successfully it minimizes the development of white spotlesions.20 The method of fluoride delivery is important: a fluo-ride mouth rinse will work best if it is used regularly by thepatient. Geiger et al9 reported that only 42% of patients rinsedwith sodium fluoride mouth rinse at least every other day, butpatients whoweremore compliant had fewer white spot lesions.

Do chlorhexidine rinses need to be prescribed?Chlorhexidine mouthwashes might be beneficial as part of

an intensive, short-term regimen to prevent white spot carieslesions, when patients have been noncompliant with otheroral hygiene regimens.

Themain goal of antimicrobial therapy is to achieve a shiftfrom an ecologically unfavorable to an ecologically favorablebiofilm.21 Evaluation of salivary counts of Streptococcus mu-tans by using a semi-quantitativemethod for analysis is a diag-nostic tool that can identify the need for antimicrobials.22

Chlorhexidine mouthwash used as a complement to fluo-ride therapy has demonstrated demineralization-inhibiting

tendencies in patients with fixed orthodontic appliances.15

However, its use in reducing the incidence of dental cariesand its antimicrobial effect have been moderate. The materialstested that show the strongest evidence, such as 40% chlorhex-idine varnish, are not available in the United States, andclinical application protocols vary in studies (percent, time,and frequency); this produces great variations in results.23

Patients are instructed to use chlorhexidine rinse (avail-able in nonalcohol formulations for patients with xerostomiaor saliva dysfunction) for 30 seconds once a day, preferablybefore bedtime, because saliva flow diminishes overnight,and the concentration of the drug in the oral cavity remainshigh until morning.24 A 14-day regimen is usually used24;however, these cationic chemoprophylactic antimicrobialrinses cannot be used within 2 hours after using toothpastescontaining anionic sodium lauryl sulfate (eg, Prevident5000, Colgate, New York City, NY, and others). A drawbackof all chlorhexidine products is their tendency to stain theteeth; this can be objectionable to some patients.

Can xylitol gum help?Xylitol gum and mints have been shown to be effective as

caries preventive agents, in arresting caries lesions, anddecreasing the transmission of S mutans from mothers andcaregivers to children.

Xylitol is a polyol (a type of carbohydrate) that is nota metabolizable substrate for S mutans and can be used asa low-calorie sugar substitute.25 It is noncariogenic andappears to have antimicrobial properties that help to inhibit

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S mutans attachment to the teeth, thus making it a good prod-uct for decreasing the bacterial load. Since there is no metab-olism by bacteria, the salivary pH can remain stable, and theenvironment will not favor acidogenic bacteria.

Makinen et al26 showed that the systematic use of xylitolchewing gum can significantly reduce the risk of cariescomparedwith gums that contain sorbitol and sucrose. Chewingxylitol gum for 5 minutes, 3 times a day, has shown consistentlypositive results, but long-term clinical trials with a standardizedmethodology are needed.27 The protocol we recommend formoderate and high-risk adult patients is to chew 2 pieces ofxylitol gum, 3 to 5 times a day, at least for 10minutes per chew-ing episode.28 In addition, the consumption of chewing gum andmints has been demonstrated to result in increased production ofstimulated saliva containing more calcium and phosphate ionicconcentrations when compared with nonstimulated saliva.Therapeutically, it is recommended that adults use 6 g of xylitoldaily.29 However, xylitol can cause digestive problems(diarrhea) if the recommended doses are exceeded.

Do products containing casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) help preventor remineralize white spot lesions?

The application of products containing CPP-ACP mighthelp to prevent enamel demineralization. However, there isinsufficient clinical trial evidence to make a recommendationregarding its long-term effectiveness.

CPP-ACP is a nanocluster that binds calcium and phos-phate ions in an amorphous form. CPP-ACP has been shownto adhere to the bacterial wall of microorganisms and toothsurfaces.30,31 When an intraoral acid attack occurs, thecalcium and phosphate ions are released to producea supersaturated concentration of ions in the saliva, whichthen precipitates a calcium-phosphate compound onto theexposed tooth surface.31

Recaldent (CPP-ACP) is available in several forms (gum,solution, MI Paste and MI Paste Plus [GC America, Alsip, IL,USA]), has been shown to reduce dentin hypersensitivity,reduce demineralization of enamel, and enhance remineraliza-tion in laboratory studies.31 An In-vitro study have reportedthat enamel lesions remineralized with topical exposure toCPP-ACP gum were more resistant to subsequent acidchallenges compared with normal remineralized enamel.32

However, MI Paste and MI Paste Plus have not yet beenused specifically in extensive caries clinical trials, and thereis insufficient clinical trial evidence (in quality and quantityor both) to make a recommendation regarding the long-termeffectiveness of CPP-ACP in preventing caries, treating dentinhypersensitivity, and treating dry mouth.33

The exact extent of substantivity of Recaldent has beenreported to be from 30 minutes to several hours. Thus, severaldaily applications might be beneficial in high-risk patients,and, for this reason, MI Paste or MI Paste Plus can be recom-mended for daily use in patients undergoing fixed applianceorthodontic treatment.34 MI Paste Plus contains 900 ppm offluoride and so may be helpful with 1000-ppm, but not5000-ppm, fluoride toothpaste to optimize thorough reminer-

alization and minimize superficial remineralization.8 Ifrecommended, MI Paste Plus should be used after meals andsnacks (if possible) and after brushing with 1000-ppm fluoridetoothpaste before, during, and after orthodontic treatment, orMI Paste can be used, if the selected toothpaste contains5000 ppm of fluoride. A pea-size amount can be gentlybrushed on and around the teeth and orthodontic appliances.The combination of Recaldent and 900 ppm of fluoride inthe MI Paste Plus used with 1000 ppm of fluoride wouldneed to be used for several weeks or months to maximizegradual and thorough remineralization.

MI Paste contains milk products and therefore cannot beused in patients with milk-protein allergies, but lactose-intolerant patients can use it.

Is there a difference in the type of white spot lesions thatimprove over time after treatment?

The prognosis for an active carious lesion (as opposed toan arrested carious lesion) is considered favorable because ofits porosity that allows ready incorporation of calcium phos-phate into the enamel and the reaction of fluoride ions withthe enamel.

White spot lesions that develop during fixed applianceorthodontic treatment appear slightly supragingivally or sur-rounding the bracket. Usually the surface is dull, pitted, andirregular where the demineralization process has occurred,and plaque signifies an active lesion. A flat or shiny whiteand sometimes brown surface occurs when the remineraliza-tion process has started or has been completed, signifying anarrested lesion.

Active white spot lesions usually have a better prognosis torecover the translucency of the enamel than arrested white spotlesions because of their porosity and therefore easier incorpora-tion of calcium phosphate ions. After the removal of fixedappliances, these lesions improve over time with adequate oralhygiene. Arrested lesions have a tendency to result in lessfavorable esthetic results, because of the lack of enamel porosityand the formation of a remineralized layer in the outer part of theenamel. Unfortunately, after orthodontic treatment, most whitespot lesions have already been in a demineralization andremineralization cycle and are most likely arrested, so theprognosis for optimal esthetic outcomes is more questionable.

What treatment protocols should be followed after bracesare removed?

If white spot lesions occur during treatment, it is advisableto first allow the teeth to remineralize naturally. If the lesionspersist, professional bleaching of the teeth to diminish the con-trast between the white spot lesion and the rest of the enamelsurface should be considered. If the effect of bleaching is lessthan desired, microabrasion is an option. Lastly, aggressiverestorative treatment such as direct or indirect veneers couldbe considered.

Within the first fewweeks after debanding, there is usuallya significant natural reduction of white spot lesion size byremineralization. Nearly half of the original lesions will

Fig 3. Patient with inadequate oral hygiene, generalizedgingivitis, plaque accumulation, and white spot lesionsat the bucco-cervical surfaces.

Fig 4. White spot lesions first noted 1 year after the startof treatment in a noncompliant patient.

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have remineralized after 6 months with no specific additionaltreatment.

Treatments have been proposed to assist remineralization.Fluoride must not be used in high concentrations because itcan arrest remineralization and lead to staining. Low concentra-tions of fluoride might assist remineralization, but this has notbeen demonstrated in a prospective randomized study. Theapplication of CPP-ACP products and salivary stimulation bychewing gum might be effective in assisting remineralization.But there are currently no long-term clinical studies that demon-strate an improved benefit over natural remineralization.

After the natural remineralization process is allowed tohappen, external bleaching might be an option to help camou-flage white spot lesions and obtain better esthetic results forthe patient. Knosel et al35 evaluated the efficacy of externalbleaching on inactivewhite spot lesions after fixed orthodontictherapy compared with surrounding enamel areas. The light-ness values of both the white spot lesions and the surroundingenamel regions were significantly higher after bleaching com-pared with the baseline. Sound enamel values increased signif-icantly more compared with white spot lesion values,indicating better color matching of these 2 areas comparedwith the baseline. All patients were satisfied with the outcomeof the bleaching therapy.35 This study was the first attempt toprove that bleaching therapy can camouflage white spot le-sions after removal of orthodontic brackets. If bleaching ther-apy is used to mask decalcified areas, it must be consideredthat the microhardness of sound enamel surfaces and deminer-alized enamel surfaces after bleaching might be reduced.36

Moreover, the susceptibility to formation of caries-like lesionsafter bleaching increases.37 Therefore, this kind of therapyshould be restricted only to well-selected patients with perfectoral health and hygiene. Fluoridation should be performedduring and after the bleaching therapy to enhance reminerali-zation of bleached teeth.

For severe cases, acid microabrasion is recommendedwhen the esthetic results after external bleaching therapy arenot satisfactory.38 Ardu et al39 described a minimally invasivetechnique based on reactivation of enamel by elimination of

the hypermineralized external layer through microabrasion,followed by daily home application of CCP-ACP. The use ofMI Paste Plus (CPP-ACP plus 900 ppm of fluoride) has alsobeen suggested for the treatment of these lesions.31 ‘‘In casesof incipient white spot lesions, the subsurface water can beconverted back into enamel because of the neutral ions movingby diffusion through the porous surface. When it reacts withthe water, the hydroxyapatite formed will regenerate in thesubsurface space. Once 80%-85% regeneration has occurred,the enamel will appear optically normal; this means that theappearance of the white spot lesion also disappears.’’31

Ardu et al39 stated that this technique eliminated whitespot lesions without involving additional restorative proce-dures; however, this statement is based on clinical case reports.No randomized clinical studies have been published to supportthese results.

Lastly, aggressive restorative treatment such as a direct oran indirect veneer can be considered if the patient still sees theneed for further esthetic improvement when white spot lesionscannot be totally removed. No studies address when to deter-mine whether more aggressive restorative treatment, such asresin or porcelain veneers, is necessary only for esthetic pur-poses to cover white spot lesions. However, the most conser-vative approach to tooth structure should be considered first.

Putting it all together, what would you recommend in thefollowing scenarios? Apatient comes to your clinic request-ing orthodontic treatment (Fig 3). You note inadequateoral hygiene, generalized gingivitis, plaque accumulation,and white spot lesions at the bucco-cervical surfaces. Thepatient has no cavitated lesions; therefore, her generaldentist referred her to you for treatment. How do youproceed?

Discuss with the patient the risk factors, make recommen-dations according to the problems (eg, diet and oral hygienebehavioral assessment), prescribe high-fluoride (5000 ppm)toothpaste and 0.12% chlorhexidine rinses, and reevaluate infew months to assess whether she has been compliant andable to proceed with orthodontic treatment.

Fig 5. White spot lesion areas and cavitation noted atdebanding appointment.

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During treatment of a noncompliant 17-year-old, you notethe development of white spot lesions a year into her treat-ment (Fig 4). What do you recommend?

Reevaluate the risk factors and the changes in her lifestylethat could have contributed to the development of white spotlesions during treatment, reinforce oral hygiene instructions,prescribe high-fluoride toothpaste and chlorhexidine rinses,apply fluoride varnish at least 2 or 3 times a year, and alsorecommend frequent use of xylitol or sugar-free gum.

At the debanding appointment (Fig 5), you note white spotlesions and areas of cavitation on the patient. What do youdo?

Discuss with the patient possible options to treat the whitespot lesions and explain the scientific evidence behind eachpossibility: from external bleaching, microabrasion, calcium-phosphate derived applications, to a more invasive treatment,such as resin composite or porcelain veneers. Refer the patientto his or her general practitioner to treat cavitated and nonca-vitated lesions.

It is crucial to establish a caries risk assessment and rec-ommendation protocol for patients before, during, and aftertreatment to be able to provide overall successful orthodontictreatments for them.

We thank the members of the American Associationof Orthodontists Council on Scientific Affairs for theirvaluable input during the preparation of this article.

Sandra Guzman-ArmstrongClinical associate professor, Operative DepartmentCollege of Dentistry, University of Iowa, Iowa City

Jane Chalmers**Deceased, December 6, 2008; formerly, associate professor

Department of Preventive and Community DentistryCollege of Dentistry, University of Iowa, Iowa City

John J. WarrenProfessor, Department of Preventive and Community Dentistry

College of Dentistry, University of Iowa, Iowa City

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