Chapter 34 Fluorides (Notes)

Vocabulary flashcards covering key fluoride concepts, mechanisms, products, and clinical guidelines from the lecture notes.

Fluoride

A mineral used to prevent dental caries; delivered systemically (pre-eruptive) and topically (posteruptive) to support enamel health.

Systemic fluoride

Fluoride intake that reaches developing teeth through circulation before eruption (pre-eruptive exposure).

Topical fluoride

Fluoride applied directly to erupted tooth surfaces (posteruptive exposure) to prevent decay.

Pre-eruptive exposure

Systemic fluoride exposure of developing teeth before tooth eruption.

Posteruptive exposure

Topical fluoride exposure on erupted teeth after eruption.

Remineralization

Process of restoring minerals to demineralized enamel; fluoride promotes formation of fluorapatite, strengthening the tooth.

Fluorapatite

A fluoridated mineral (replaces hydroxyapatite) that is more resistant to acid attack.

Hydroxyapatite

The natural mineral form of tooth enamel that fluoride can replace to form fluorapatite.

Hypomineralized enamel

Enamel with reduced mineral content that absorbs more fluoride and mineralizes with fluorapatite.

Demineralized enamel

Enamel that has lost minerals; remineralization with fluoride enhances fluoride concentration in the enamel.

Fluoride uptake

Amount of fluoride incorporated into enamel, dependent on environmental fluoride level and duration of exposure.

Fluoride metabolism

Body processes of fluoride intake, absorption, distribution (plasma), and excretion (mainly via kidneys).

Fluoridated water

Water with added fluoride used to reduce dental caries in the community.

Root caries

Caries on root surfaces; incidence is lower in lifelong residents of fluoridated communities.

Enamel surface fluoride concentration

Outer enamel has the highest fluoride concentration, which decreases toward the interior.

Dentin fluoride

Fluoride levels in dentin can exceed those in enamel, especially at inner surfaces; newly formed dentin absorbs fluoride rapidly.

Cementum fluoride

Cementum has high fluoride levels that increase with exposure and are available from saliva and other sources.

Anterior teeth protection

Anterior teeth typically receive more fluoride protection than posterior teeth.

Caries reduction due to fluoridation

Fluoridation lowers caries incidence in populations; e.g., significant reductions observed in permanent and primary teeth with sustained fluoride exposure.

Topical fluoride applications

Fluoride delivered topically via self-applied products (toothpaste, rinses, gels) or professionally applied products (gels, foams, varnishes, SDF).

Self-applied topical fluorides

Fluoride products used by patients at home (dentifrices, mouthrinses, gels); often OTC ≤1500 ppm; Rx options may exceed OTC limits.

APF (Acidulated Phosphate Fluoride)

Acidic topical fluoride (pH ~3.0–3.5) around 12,300 ppm; enhances fluoride uptake but can etch some restorations.

Sodium fluoride (NaF)

Neutral pH fluoride used in OTC toothpaste and some gels; availability also as higher-concentration professional varnishes (e.g., 5% NaF).

Stannous fluoride (SnF2)

Fluoride with antimicrobial properties; available as 0.4% home gel and up to 8% in-office forms; acidic pH can cause staining.

Silver diamine fluoride (SDF)

38% SDF—a noninvasive caries-arresting agent with silver (antimicrobial) and fluoride (remineralizing); may stain carious areas black.

38% Silver Diamine Fluoride

Concentration used to stop tooth decay; causes black staining of decay while sparing healthy enamel.

5% NaF varnish

Professional fluoride varnish with 5% sodium fluoride; high fluoride delivery for caries prevention; specific dosing and timing guidelines.

1.23% APF gel

Acidulated phosphate fluoride gel (1.23% APF) used professionally; high uptake but potential for etching restorations.

2% NaF gel

Sodium fluoride gel (2% NaF) used for professional topical fluoride applications.

Neutral NaF foam

Sodium fluoride foam at neutral pH (~7.0); safe for all restorations and exposed root surfaces; slightly lower uptake than APF.

APF foam

Acidulated phosphate fluoride foam (≈1.23% APF) with acidic pH; greater uptake and faster effect on enamel surfaces.

Fluoride mouthrinses

Self-applied fluoride rinses (e.g., 0.05% NaF); beneficial for moderate/high caries risk but not for children ≤6 years or those who cannot rinse.

ADA recommendations for professional fluoride

Endorsed products and frequencies: 1) 1.23% APF gel or 5% NaF varnish or 38% SDF; frequency typically every 3–6 months depending on risk.

Box 34-2 indications for professional fluoride

Indications include active/secondary caries, exposed root surfaces, orthodontic appliances, low fluoride exposure, xerostomia.

Post-application instructions (gel/foam)

Do not rinse, eat, drink, brush, or floss for at least 30 minutes after tray gel/foam application.

Post-application instructions (varnish)

Avoid hot drinks and hard foods; do not brush or floss for 4–6 hours after varnish; varnish residue is removed the next day.

SDF staining mechanism

Silver in SDF reacts with carious dentin to form black silver compounds, staining only demineralized tissue.

SDF application steps

Apply 1 drop to carious lesion, allow absorption 1–3 minutes, then dry area 60 seconds; reevaluate later.

Stannous fluoride vs sodium fluoride

SnF2 offers antimicrobial effects and gingivitis control but can stain; NaF is widely used for caries prevention and is less staining.