Preventive and Desensitizing Materials (Ch. 7)(2)
Preventive and Desensitizing Materials
Introduction
Author: Samantha Kelley, CDA, RDH, MEd
Overview of Preventive Methods
Dental assistants and hygienists play crucial roles in preventing diseases and maintaining patient health. This chapter focuses on preventive measures for caries management, which include:
Fluoride treatments
Antibacterial mouth rinses
Sealants
Objectives
Applications of fluoride in prevention.
Mechanism of fluoride in protecting teeth from caries.
Various methods of fluoride delivery.
Benefits of combining antibacterial rinses with fluoride.
Antibacterial effects of chlorhexidine.
Mechanism of sealants in protecting pits and fissures.
Components of sealant material.
Steps for applying sealants.
Causes of tooth sensitivity.
Mechanism of desensitizing agents.
Types of materials for treating sensitive teeth.
Remineralization process of enamel.
Action of remineralization products.
Resin infiltration process of early white spot lesions.
Fluoride
Importance and Sources
Fluoride is a naturally occurring mineral that significantly prevents dental decay.
Found in well water, certain foods, and various dental products.
Optimal fluoride level in drinking water is 0.7 mg/L (ppm).
Fluorosis
Excess fluoride consumed during tooth formation can cause:
Severe Fluorosis: Brown staining and pitting of the enamel (mottled enamel).
Mild/Moderate Fluorosis: Opaque white spots or bands on teeth.
Demineralization and Caries
Structure of Enamel and Dentin: Composed of hydroxyapatite crystals.
Minerals constantly interchange between tooth surfaces and saliva.
Bacterial metabolism of sugars leads to acid production, causing more demineralization than remineralization, initiating the caries process.
Fluoride Types
Systemic vs. Topical Fluoride
Systemic Fluoride: Incorporates into developing tooth structure.
Topical Fluoride: Most effective post-eruption for caries prevention, aiding in remineralization and creating fluorapatite, which is less soluble than hydroxyapatite.
Dissolves at different pH levels: Hydroxyapatite at pH 5.5 and fluorapatite at pH 4.5.
Protection Against Erosion
Erosion primarily affects surface minerals of teeth due to highly acidic foods and certain medical conditions (e.g., acid reflux, anorexia).
Fluoride can mitigate erosion, but repeated acid exposure may negate its benefits.
Bacterial Inhibition
Fluoride impedes bacterial enzyme activity. It penetrates bacterial cells in the form of hydrofluoric acid (HF), separating into fluoride and hydrogen ions that inhibit bacterial function and provoke cell death.
Fluoride with Antibacterial Rinses
Fluoride is more effective in caries management when used with antibacterial rinses like chlorhexidine gluconate (0.12% concentration max).
It provides prolonged therapeutic effects but can cause side effects such as tooth staining and a bitter taste.
Methods of Delivery for Fluoride
Dietary Supplements based on age.
In-office Applications: Gels, foams, and varnishes.
Self-applied products: Over-the-counter rinses and fluoride toothpaste.
Silver Diamine Fluoride (SDF)
Approved for treating dentinal hypersensitivity, providing both anti-cariogenic and antimicrobial effects, effective in arresting caries in over 90% of lesions when applied biannually.
Composition: 25% silver, 5% fluoride, 8% ammonia, and 65% water.
Fluoride Safety
Required to use fluoride as directed and keep out of reach of children.
Lethal doses are approximately 700-1500 mg for a 20-pound child; induce vomiting and administer milk of magnesia if ingestion occurs.
Sealants
Purpose and Application
Sealants protect non-cariogenic pits and fissures in both deciduous and permanent teeth, predominantly on posterior teeth. Approximately 88% of caries in children occur here.
Early application before cavitation prevents caries by blocking food sources.
Indications for Sealants
Not all teeth require sealants. Suitable for teeth with steep cuspal inclines, deep fissures, and based on age, caries risk, and oral hygiene history.
Sealant Composition
Made of dimethacrylate monomers, polymerizing via chemical or light activation, reinforced with small filler particles for durability.
Sealant Application Process
Working Times: 2 minutes (self-cured), 20 seconds (light-cured).
Placement Steps:
Clean surface with pumice.
Etch enamel (37% phosphoric acid).
Rinse and dry enamel.
Apply bonding (optional).
Place and cure sealant.
Wipe the surface.
Key to success: Isolation from moisture during placement.
Causes and Treatment of Tooth Sensitivity
Causes
Exposure of dentinal tubules, usually triggered by cold temperatures, sugars, acidic foods, or root structure exposure.
Treatment Options
Desensitizing Agents:
Toothpastes: Requires consistent use.
Fluoride gels/varnishes: Can take time for effects.
Inorganic salt solutions: Varying results.
Resin bonding agents: Immediate results.
Glass ionomer sealers for chronic sensitivity.
Remineralization
Restores mineral content lost via acids from diet or bacteria.
Effective agents include fluorides and amorphous calcium phosphate.
Resin Infiltration: Helps repair early white spot lesions by blocking porosity in enamel and preventing caries progression by a specific drilling process.
Summary Questions
Important preventive measures for caries management?
Optimal level of fluoride in drinking water?
Severities of fluorosis?
Process of demineralization?
Define fluorapatite?
Mechanism of fluoride ion crossing bacterial cell walls?
Benefits and drawbacks of chlorhexidine gluconate?
Mechanism of SDF?
Uses of sealants?
Key considerations during the sealant procedure?
Applications of resin infiltration?
References
Eakle, W. S., & Bastin, K. G. (2021). Dental materials: Clinical applications for dental assistants and dental hygienists. Elsevier.