Conservative Therapy for White Spots and Dental Fluorosis

Written by: Drs. Richard Trushkowsky, Amy Chen, Peter Irving, Guy E. Carnazza, and Juliana Gil Andrade e Silva

Introduction

Aesthetic dentistry is a growing branch of dentistry that focuses on enhancing a patient’s appearance. Aesthetic dentistry encompasses a range of procedures, including conservative restorative treatments, smile design, orthodontic procedures, veneers, microabrasion, bleaching, and resin infiltration (Icon [DMG America]). A variety of surface imperfections can create critical aesthetic considerations. These qualities can also show a disturbance in normal tooth development. This has led to various aesthetic techniques, with varying levels of invasiveness and tissue preservation. Dental fluorosis, a demineralization of enamel caused by excessive fluoride intake, results in opaque white areas or discolorations ranging from yellow to deep brown, as well as porosities on the enamel surface.^1,2

Dental fluorosis is not the only cause for enamel demineralization. Opaque white areas or discolorations, even with porosities, might result from some disruptions in the mineralization process, and they might be confused with fluorosis stains. We find that their location can distinguish them: stains caused by dental fluorosis are generally encountered on all teeth that mineralize at the same time, and fluorosis stains are also characterized as non-discrete, opaque conditions of the enamel.³

We must consider a range of factors before treatment, including the patient’s age, oral health, the severity of fluorosis, and aesthetic goals. Considering that a sizable proportion of individuals seeking treatment for dental fluorosis are usually young, selecting prosthodontic treatment can lead to premature and irreversible loss of substantial tooth structure and long-term consequences. Therefore, we typically recommend minimally invasive procedures. Fluorosis stains are usually treated based on 3 concepts: vital bleaching, microabrasion, a combination of both methods, and resin infiltration. Direct or indirect composite restorations, porcelain veneers, or crowns are other, more invasive options.^4-6

The clinical presentations of milder fluorosis include narrow white lines following the parenchyma, cuspal snow capping, and a snow-flaking manifestation that lacks a clear border with the unaffected area of enamel.⁷ While in severe fluorosis, there is yellow to deep brown staining, and the most severe cases show pitting of the surfaces due to extrinsic mechanical breakdown.^8,9

The 2 case reports will illustrate several conservative techniques, including bleaching, microabrasion, resin infiltration, and direct composite, used to enhance the aesthetic appearance of 2 patients. The first case primarily presents dark teeth and white spots, while the second case shows severe fluorosis.

Case Report 1

A 28-year-old female patient presented to the clinic with the chief complaint of discoloration and chipping on anterior teeth. Initial photographs, a series of radiographs, videos, and intraoral scans of both arches were taken during the patient’s first visit following the consultation. Intraoral examination revealed multiple regions of white spot lesions on the labial surface of upper anterior teeth and chipping on the No. 8 incisal edge (Figure 1). The patient wanted to preserve the tooth structure and have her teeth whiter, with the discolorations improved in the most economical way possible. A treatment plan of in-office external bleaching in combination with Icon Smooth Surface (DMG America), and composite bonding was proposed, and the patient accepted it.

The initial shade of teeth was A3 (Figure 2). External bleaching was performed in the clinic with Opalescence Boost Teeth Whitening, 40% hydrogen peroxide (Ultradent). Liquid dam (OpalDam resin barrier [Ultradent]) was first placed for protection of the gingiva, followed by placement of a 0.5- to 1-mm thick layer of bleaching gel on the labial surface of anterior teeth (Figure 3).

A total of 2 rounds of bleaching were done. For the first round, the bleaching gel remained on the teeth for 20 minutes. After removing all the bleaching agents, shade evaluation was done. 

A decision was made to proceed to the second round for only 10 minutes due to pronounced white spots observed after the bleaching procedure. The resulting shade was A2 (Figure 4). The patient still exhibited white spots, and it was believed that resin infiltration of these spots would yield improved results, as illustrated by transillumination (Figure 5).

After the bleaching, the patient was instructed to wait for 2 weeks before the resin infiltration treatment.¹⁰ The Icon Smooth Surface treatment (DMG America]) was performed on the upper premolar to premolar regions (Figure 6). The treatment procedure is as follows: The upper arch was adequately isolated with a rubber dam and double-ligature floss (Figure 7). Before the resin infiltration was applied, Figure 7 shows that an ample amount of Icon-Etch (Hydrochloric acid 47%) (DMG America) was applied to each tooth, with constant scrubbing of the tooth surface using adequate pressure, focusing on the lesion location with the provided tip for 3 minutes. Excess etch was aspirated with high-power suction, and the teeth were rinsed for 30 seconds with water, then air-dried with water-free/oil-free air. One to 2 drops of Icon-Dry (Ethanol 99%) (DMG America) were applied to each tooth as a preview of the results. The etchant was reapplied to the affected tooth for better results, with a total of 4 rounds of etching applied. After finishing the last 2 rounds, the etchant was applied only to the lesion spots that were still visible. A preview of the results with Icon-Dry was confirmed after each round of etchant application. Icon-Infiltrant (Methacrylate base resin matrix, 99%) (DMG America) was applied to each tooth, with the syringe occasionally twisted and the material dabbed onto the tooth to allow it to absorb. Infiltrate was left on the tooth for 3 minutes, then dispersed with water-free, oil-free air. The interproximal areas were flossed to prevent closure of the contact points. Infiltrate was light-cured for 40 seconds on all surfaces. After the Icon-Infiltration was applied, the white spots were no longer visible (Figure 8).

The patient was satisfied with the results, and a follow-up appointment was scheduled 6 weeks later. As the results met the patient’s satisfaction, the restoration of the No. 8 incisal edge was performed using composite resin (3M Filtek [Solventum]) (Figure 9).

Case Report 2 

A 21-year-old female presented with the chief complaint of being self-conscious about her smile due to brown discolorations and pitting on her anterior teeth (Figure 10). She also exhibited a narrow arch form, with mild crowding in the maxillary arch and moderate crowding in the mandibular arch.

Clinical and Medical History

• Medical Status: Generally healthy, taking amitriptyline (25 mg qhs) and naproxen (500 mg BID) for chronic tension headaches, plus magnesium supplements.
• Dental Findings: Severe fluorosis noted across anterior teeth, including brown spots and areas of hypoplastic enamel. Orthodontic evaluation revealed a V-shaped mandibular arch and Class I molar/canine relationships.

Diagnostic Assessment

• Visual and Tactile Examination: Significant enamel pitting and discoloration consistent with severe fluorosis.
• Transillumination: Confirmed that most stains were within the superficial and mid-enamel layers.
• Radiographic Examination: Used to rule out any underlying pathology and to assess overall tooth structure in preparation for restorative and orthodontic needs.
• Orthodontic Analysis: Revealed narrow arches and crowding, indicating a need for future orthodontic intervention.

Initial photographs, a series of radiographs, videos, and intraoral scans of both arches were taken during the patient’s first visit following the consultation. After reviewing the patient’s history, which included previous residence in Kenya, it was determined that the discolorations were likely due to fluorosis. Excess fluoride in drinking water is a significant public health concern in Kenya, particularly in areas that rely on groundwater. High fluoride levels, often exceeding the World Health Organization’s recommended guideline of 1.5 mg/L, can lead to dental and skeletal fluorosis. Kenya’s Rift Valley region is known for its volcanic rocks, which can contribute to high fluoride concentrations in groundwater.¹¹ After a 4-week whitening protocol using 10% carbamide peroxide (Opalescence 10% [Ultradent]), residual deep lesions were removed via microabrasion (Figure 11).

Opalustre (Ultradent) is a 6.6% hydrochloric acid slurry with silicon carbide microparticles, created to provide the strength of a chemical stain removal product while offering the gentle scrubbing power of an abrasion slurry. OpalCups (Ultradent) are great for micro-polishing newly treated enamel surfaces. The latch-type bristle polishing cups facilitate a more aggressive action and minimize splatter when used in conjunction with the Opalustre microabrasion technique. It is recommended to apply a 1-mm thick layer of Opalustre over the discolored area using a rubber prophy cup. Apply medium to heavy pressure at approximately 500 rpm for 60 seconds at a time. Opalustre, along with OpalCups, can be used to quickly remove unsightly enamel decalcification defects that are less than 0.2 mm in depth. It is especially important to adequately protect the soft tissues by using a rubber dam and, if desired, a light-cured resin barrier at the gingival margin. Once complete, suction the paste from the teeth and rinse. 

Tip: If the product starts to thin out during the procedure, you can add more Opalustre, which will keep the tooth moist and prevent overheating.

Once you have suctioned and rinsed, evaluate results and repeat, as necessary (Figure 12). 

Note: For patients with hypomineralization greater than 0.1 to 0.3 mm, use a fine-grit, water-cooled, tapered diamond bur and lightly sweep over the stained area for 5 to 10 seconds before applying Opalustre. This may allow greater penetration. 

There will be some patients with areas of deep hypo-mineralization and staining that may not respond to treatment and may require aesthetic bonded restorations. This can be evaluated by transillumination (Microlux 2 Transilluminator [AdDent Inc])  as shown in Figure 13. 

• Transillumination confirmed that most stains were within the superficial and mid-enamel layers.

In this case, we recommend waiting at least 2 weeks after all whitening before placing the needed aesthetic restorations. This was done to ensure appropriate bond strengths and color stability.

Composite Resin Restorations

• Selective Removal: Residual brown areas were conservatively excavated with a round diamond bur at low speed.
• Isolation: Rubber dam placement to ensure a clean, dry field.
• Adhesive Protocol: 35% phosphoric acid etchant applied for 15 seconds, rinsed, and lightly air-dried. Then, a universal bonding agent was applied, air-thinned, and light-cured per manufacturer guidelines.
• Composite Placement: Incremental layering with BL Dentine and BL Enamel shades (Ivoclar) to mimic natural translucency. Each layer was assessed for shade before final curing.
• Finishing and Polishing: Contouring with fine-grit diamond burs. Polishing with disks and pastes to achieve a high-luster surface.
• Occlusal Adjustment: Verified to ensure no premature contacts on the new restorations.

The patient’s smile improved considerably, with no postoperative complications reported. She was then referred for orthodontic treatment to address malocclusion, functional alignment, and to finalize aesthetic treatment.

The patient expressed high satisfaction with the conservative treatment approach. No adverse effects were observed, and the restorations blended seamlessly with the adjacent teeth (Figures 14 and 15).

DISCUSSION 

Tooth discoloration may arise from multiple etiologies, making accurate diagnosis essential for selecting appropriate treatment. Clinicians must identify the cause, location, and extent of defects before initiating therapy. Discolorations may occur during tooth formation or after eruption. Enamel opacities can result from damage to the dental follicle, carcinogenic activity, fluorosis, traumatic hypocalcification, molar-incisor hypomineralization (MIH), or caries-related white spot lesions (WSLs). In the second case presented, fluorosis was identified as the cause, while the etiology of the first case remained undetermined.

A favorable result of diverse treatment approaches suggested that managing fluorosis cases depends on the extent of the defect.¹² Numerous clinical studies focusing on the conservative management of these defects have blended various techniques, including teeth whitening, abrasion (micro/macro), and infiltration with resin. The primary distinction among these cases lies in the order of these treatments.¹³ Dental fluorosis is an enamel malformation caused by excessive systemic fluoride input during the maturation of the enamel tissue. The late secretion and maturation stages of enamel tissue are affected by excessive fluoride.¹⁴  

Fluoride interferes with enamel matrix protein reabsorption and increases calcium-driven mineralization,¹⁵ leading to subsurface porosity and color changes ranging from opaque white to yellow-brown, sometimes accompanied by tissue loss.¹⁶ Microabrasion and bleaching remain the most conservative and predictable treatments for mild to moderate fluorosis.^17,18

Microabrasion involves softening enamel with acid and mechanically removing surface discoloration using abrasive agents. Croll¹⁹ described an early technique using 18% hydrochloric acid and pumice. The procedure produces a smoother, more reflective aprismatic enamel surface that masks discoloration and creates a denser, more mineral-rich, and resistant structure.²⁰

Developmental white enamel lesions affect 9% to 68% of permanent dentition,^21-25 while acquired lesions—commonly after orthodontic treatment—range from 2% to 96%. These lesions compromise aesthetics, particularly on maxillary anterior teeth.²⁶ WSLs appear white due to mineral loss and altered refractive indices between enamel, water, and air within porous structures, resulting in reduced translucency and luster.^27,28 Lesion color intensity correlates with lesion volume,²⁹ and lesion depth strongly influences treatment selection.

Depth assessment may be performed using transillumination, in which a curing light is placed on the lingual surface. Superficial areas transmit light easily, while deeper lesions appear darker.^30,31 Deeper lesions often require surface modification to permit resin infiltration, originally designed for superficial carious lesions. After mechanical and chemical conditioning, lesions exhibit more un