White spot lesions (WSL) around orthodontic attachments are unsightly, and one of the common side effects of fixed orthodontic treatment. Poor oral hygiene during fixed orthodontic treatment leads the plaque accumulation around the brackets which produces demineralization of enamel or subsurface lesions or WSL. Treatment options for WSL vary widely from natural self-recovery to extensive restorative treatment. The severity of the WSL acts as the key determent factor for choosing the best treatment option. Till date various studies were conducted to confirm the reports on remineralisation and to understand the mechanism which is still unknown. Many new concepts are emerging to better understand the factors which promote remineralisation and produce morphologically stable results. Recent investigations have primarily focused on various calcium phosphate-based technologies which are designed to supplement and enhance fluoride’s ability to restore tooth mineral. The purpose of this article is to provide an overview regarding the new diagnostic methods and recent techniques available for early detection and management of WSL.

Keywords: White spot lesion; Fluoride application; Fixed orthodontic treatment.

Orthodontic treatment helps to establish a balance between functional harmony, structural balance, and improved aesthetics, yet, rendering such treatment comes across with potential risks in terms of both hard and soft tissue damage Such potential risks to various hard and soft tissue damages may include-enamel demineralization and periodontal problems. Subsurface enamel demineralization around the brackets makes the enamel more porous that will change the refractive index of the affected area and this area loss the shine and appear more opaque than normal enamel. These opaque areas are known as White Spot Lesions (WSL).

Fejerskov and colleagues defined WSLs as, “the first sign of a caries lesion on enamel that can be detected with the naked eye” [1]. The milky white appearance is caused by an increased scattering of light that is attributable to the loss of crystal structure and is exaggerated when the enamel is dried [2]. Sometimes these WSL re-mineralize naturally after the orthodontic treatment, however, if this WSL persists, there are several treatment options available for the management of this problem. The management of WSL involves preventive measures; they enhance the remineralization and inhibit the demineralization process and therapeutic measures will help to restore the WSL.

This article reviews the prevalence, diagnosis, prevention and various treatment methods mentioned in the literature to manage the white spot lesions. In context of presently available literature, the management of enamel white spot lesion can be done either through remineralization techniques or with other non-invasive and invasive techniques. This article attempts to review all presently available methods and their philosophy behind management of enamel white spot lesion.

Formation of white spot lesions

During fixed orthodontic treatment, plaque accumulation and retention occurs around the irregular surfaces of the attachments, limiting the self-cleansing mechanism of salivary flow [3,4]. Furthermore, the levels of acidogenic bacteria, such as S. mutans, become significantly elevated in orthodontic patients. These bacteria produce acid by-products which lowering the pH of the plaque. As the pH drops below the threshold for remineralization, carious decalcification occurs. The first clinical evidence of this demineralization is visualized as a WSL [5].

Prevalence of white spot lesions

The reported proportion of patients with WSLs after fixed orthodontic treatment widely varies in the literature between 2% and 96%. This variation can be attributed to differences in the standardization of clinical examinations, as well as the use of various detection tools, with different sensitivities and specificities in diagnosing demineralization. Some differences can also be found in the literature about which teeth are most affected with WSLs during orthodontic treatment. Several studies conclude that maxillary incisors are particularly susceptible, whereas other studies found that canines and molars are more frequently affected [6]

1.Visual Assessment

Visual assessment by clinical or photographic examination is one of the relevant approaches for the assessment of WSLs [Figure 1]. With clinical photography, consensus can be reached between examiners, permitting quantification of the lesions. However, reproducible assessment of photographs is contingent on consistent lighting to reduce reflections, which can mask or mimic WSLs [7].

Figure 1: White spot lesions observed in a patient immediately following the removal of fixed orthodontic appliances.

2. Transverse Microradiography

It is the accepted gold standard method of measuring Demineralization and remineralization. A major disadvantage of the TMR process is that either the tooth must be removed from the mouth and destroyed, or a small enamel sample attached to the appliance must be removed [6].

3. DIAGNOdent

DIAGNOdent is a laser examination tool that is very effective in spotting even the smallest lesions at the earliest stages. The readings can also be affected by stains, calculus, and plaque so should be interpreted with caution because statistically significant differences might not necessarily have clinical significance [8].

4. Quantitative Light-Induced

Fluorescence QLF is a non-destructive diagnostic technique that uses visible light for the early detection of demineralization in enamel. The principle behind the technique is that enamel will undergo autofluorescence under certain conditions. Demineralized enamel will fluoresce less, and this loss of fluorescence can be detected, quantified, and longitudinally monitored using QLF [9] [Figure 2].

Figure 2: The clinical photograph with demineralized white lesions on the day of debonding (A) and the corresponding quantitative light-induced fluorescence image (B).

5. Quantitative Light-Induced Fluorescence–Digital

It is based on QLF technology. It takes two successive images, a white light (WL) image and a QLF image [Figure 3] which ensures consistency regarding magnification and allows for comparisons between the images [6].

Figure 3: White light (A) and quantitative light-induced fluorescence (B) images, simultaneously taken with the quantitative light-induced fluorescence–digital Biluminator, demonstrating demineralization

Patients wearing orthodontic appliances should be considered as patients at risk, for whom a preventive, prophylactic approach should be implemented before, during, and after the orthodontic treatment [10,11].

• Before orthodontic treatment

Patient education

The complex design of fixed orthodontic appliances (FAs) makes it difficult to perform proper oral hygiene, which causes accumulation of plaque around the brackets so regular oral hygiene maintains by the patient is necessary for the prevention of WSL. Oral hygiene instructions, periodic professional cleaning, and reinforcement by an orthodontist may motivate the patient to maintain proper oral hygiene. Tooth brushing and mouth rinse twice a day should be recommended as an integral part of the oral hygiene program.

• During the orthodontic treatment

Often the first approach to eliminate WSLs is remineralization. There are several professional and home-applied products in different forms: solutions, varnishes, cream pastes, and chewing gums for topical remineralization treatment. Remineralization procedures require following strict oral hygiene measures, repeated multiple applications, a treatment plan that could take a long period, and first, the compliance of a motivated patient.

1. Topical Fluoride Application

(A) Fluoride Containing Varnish: The regular professional application of fluoride varnish protects enamel by the formation of fluorhydroxyapatite crystalline lattice which is more resistant to dissolution.

(B) Fluoride releasing toothpaste and mouth rinses: Conventional toothpaste usually contains around 1000ppm of fluoride, toothpaste with a higher concentration of fluoride (1,500-5,000 ppm) for the prevention of WSL is recommended. 0.025% sodium fluoride mouth rinse containing 100ppm of fluoride for 30 seconds, twice daily should be recommended.

2. Fluoride in Orthodontic Adhesive: Glass ionomer cement and Resin modified glass ionomer cement is recommended by various clinicians for the bonding of orthodontic brackets to reduce the WSL because of their cariostatic action but the shear and tensile bond strength of these materials are very less in comparison to composites. Recently fluoride-releasing composites are introduced to reduce the incidence of WSL.

3. Fluoride in elastomeric modules and ligature ties: Fluoride releasing elastomeric chain and modules are developed for the prevention of WSL but not get popularized because of the inconsistent release of fluoride and inadequate force delivery.

4. Xylitol Gum and mints: They can significantly increase the flow of saliva and have antimicrobial properties. They also prevent the attachment of S mutans to the teeth. For the moderate and high-risk adult patients, 2 pieces of xylitol chewing gum 3-5 times a day, at least for 10 minutes per episode is recommended.

After debonding, the treatment of WSL depends upon its severity and location [12]. There are multiple treatment options -

(A) Natural Remineralization: After debonding, within few weeks, the size and severity of WSL will reduce by the natural remineralization process. Most of the time mild lesions remineralize within 6 months without any additional treatment. Active lesion have good prognosis whereas arrested lesion leads to staining of enamel after remineralization.

(B) Casein Phosphopeptide-amorphous calcium phosphate (CPP-ACP): This is a potent remineralizing agent. It is derived from milk casein and is capable of absorbed by enamel and enhance the remineralizing process. CPP-ACP binds with the wall of microorganisms and enamel surfaces. Whenever PH will decrease, calcium and phosphate ions are released into the saliva and the remineralization of the exposed tooth surface started [13-15]. The topical application of CPP-ACP (GC Tooth mousse) on the affected tooth surfaces twice daily after brushing is recommended.

(C) Vital Bleaching: Many clinicians suggest the use of whitening or vital bleaching for the inactive WSL. By this approach, unaffected enamel becomes lighter than the WSL, so which will reduce the contrast between unaffected enamel and WSL.

(D) Micro-abrasion: Affected teeth can be treated with a slurry of 18% hydrochloric acid and pumice. Teeth should be isolated with a rubber dam and clean with a rubber cup in a contra-angle hand piece at slow speed. Teeth must be agitated with slurry at least for 30 seconds and then washed off with water spray.

(E) Resin- infiltration: WSL gives the white and opaque unesthetic appearance to teeth due to the refractory index of demineralized enamel. Low viscosity resin penetration into porous demineralized enamel fills the voids and creates the refractory index near similar to normal enamel.

(F) Resin Restorations/Indirect Restorations: Frank cavitated lesions, or more severe WSL can be restored with composite restoration or direct or indirect porcelain veneers to improve the esthetic.

WSLs are one of the common complications of fixed orthodontic treatment. The responsibility of an orthodontist is to minimize the risk of the WSL by educating and motivating the patients for excellent oral hygiene practice. Prophylaxis with topical fluoride application should be implemented: high-fluoride toothpastes, fluoride mouthwashes, gels and varnishes during and after the orthodontic treatment, especially for patients who have high risk of caries.

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Corresponding Author: Amit Khera  Kumar, Department of Orthodontics, Subharti Dental College, India.

Copyright: © 2021 All copyrights are reserved by Amit Khera  Kumar, published by Coalesce Research Group. This work is licensed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.