Does SDF stain when molar-incisor hypomineralization, not from caries, is present?

When dental hygienist Casey Taylor’s child’s mandibular permanent first molars erupted, they displayed a yellowish discoloration of the enamel that did not appear typical. In addition, they reported moderate sensitivity to cold on those molars. She assessed her child’s molars both clinically and radiographically with her dentist, and bitewing radiographs showed no radiographic evidence of caries or visible cavitations.

Together, they considered the possibility of fluorosis. Casey’s water supply is not fluoridated, but her child takes an age-appropriate fluoride supplement and uses over-the-counter toothpaste. Overall, the clinical appearance and pattern did not align with fluorosis.

They agreed the teeth exhibited molar-incisor hypomineralization (MIH), as the discoloration was more localized and well defined rather than diffuse, and appeared more yellow in color versus the white to brown mottling appearance typical of fluorosis (figure 1).

Casey did not recall her child experiencing any known contributing factors, such as vitamin D or calcium deficiencies, early childhood illness or high fever, or prenatal factors including maternal illness or infection during pregnancy. Nonetheless, she wanted to ensure these weakened teeth had the best possible protection against caries.

Application of SDF

Given her child’s sensitivity and questionable enamel integrity, silver diamine fluoride (SDF) was applied to help fortify potential demineralization and protect the tooth structure. Casey understood that the tooth could darken, as the American Dental Association¹ notes that mature, sound enamel does not stain; however, defects and immature enamel do allow silver ions to penetrate and form black stains due primarily to the precipitation of silver phosphate (Ag₃PO₄).

She had hoped the enamel was mature and sound, but after applying SDF, the resulting discoloration confirmed that the area was hypomineralized with compromised enamel, as shown in Figure 2.

SDF preferentially stains hypomineralized tooth structure, whether due to caries, developmental defects, or potentially even newly erupted teeth that are still undergoing posteruptive mineralization.

Despite the potential for staining, Casey knew from the CariedAway school-based trial that caries prevention rates with SDF were comparable to sealants (0.81 for SDF versus 0.82 sealant/ART group), and that caries arrest was greater with SDF (0.56) than with the sealant/ART group (0.46).² These results reinforced SDF as a highly effective, minimally invasive option, particularly in cases involving compromised or hypomineralized enamel where traditional restorative approaches may be less predictable.

SDF, a valuable strategy for stabilizing weakened enamel

As both a mother and a dental hygienist, Casey was reminded that SDF is not only a tool for arresting active caries, but also a valuable strategy for stabilizing weakened enamel and preventing future breakdown.

This area will require ongoing protection, monitoring, and patient education. SDF can be reapplied annually, and if staining becomes a cosmetic concern, the tooth can later be restored with a sealant or filling without compromising treatment outcomes.

References

1. Silver diamine fluoride. American Dental Association. Updated September 19, 2023. https://www.ada.org/resources/ada-library/oral-health-topics/silver-diamine-fluoride

2. Ruff RR, Barry-Godín T, Niederman R. (2023). Effect of silver diamine fluoride on caries arrest and prevention: the CariedAway school-based randomized clinical trial. JAMA Network Open. 2023;6(2):e2255458. doi:10.1001/jamanetworkopen.2022.55458