Board Review #2: Using Preventative Agents

Each of the following statements are applicable to neutral sodium fluoride (NaF) EXCEPT one. Which one is the EXCEPTION?

• The first fluoride used for topical application

• Available in 2% foam or gel and 55 varnish concentrations

• Fluoride varnish contains a 5% NaF concentration

• Should not be used when porcelain crowns and composite resins are present

Answer explanation

Because of its neutral formulation, neutral sodium fluoride (NaF) is safe for use in dentitions with porcelain crowns and composite restorations. Neutral sodium fluoride was the first fluoride used for topical application and is available in 2% foam or gel and 5% varnish concentrations. Fluoride varnish, approved by the US food and Drug Administration (FDA) for use as a desensitizing agent and cavity liner but commonly used as a topical fluoride treatment contains 5% neutral sodium fluoride.

Each of the following is a characteristic of acidulated phosphate fluoride EXCEPT one. Which one is the EXCEPTION?

• Low pH of 3.5

• High level of patient acceptance

• Discolors tooth structure

• Enhanced fluoride uptake

Answer explanation

Acidulated phosphate fluoride (APF) does NOT discolor tooth structure. Stannous fluoride is the formulation that causes tooth staining. Although the low pH (3.5) of acidulated phosphate fluoride (APF) enhances fluoride uptake, it may cause etching of dental sealants, porcelain, and some composite restorations. Acidulated phosphate fluoride has a high level of patient acceptance and is the most commonly used in-office fluoride treatment. The enhanced fluoride uptake of acidulated phosphate fluoride (ACP) is a result of its low pH (3.5).

The LEAST desirable classification of mouth protectors is the

• “boil and bite”.

• custom-made.

• stock.

• mouth-formed.

Answer explanation

Stock protectors are the least desirable classification of mouth protectors because they generally have a poor fit. Mouth-formed protectors, also called “boil and bite” are made by the client. Compared with stock protectors, their fit is better. Custom-made protectors are fabricated by dentists and are preferred due to durability, low levels of speech impairment, and comfort.

Hydrogen peroxide, an oxidizing agent, is

• not safe for daily use.

• an active ingredient contained only in prescription-grade mouthrinses.

• effective at rinsing an area, but does not decrease inflammation.

• an effective debridement agent.

Answer explanation

Hydrogen peroxide is an oxygenating agent with properties that debride wound sites (including periodontal lesions) by releasing oxygen; this action constitutes oxygenation. In recent years there was concern with hydrogen peroxide being used on daily basis, but it now has FDA approval (authorizing its safety) for inclusion in commercially prepared mouthrinses and dentifrices. Oxidizing agents decrease clinical signs of inflammation, but can be irritating to soft tissues. They should be used with caution.

Products that contain amorphous calcium phosphate (ACP) can be appropriately substituted for fluoride therapy because ACP contains the same minerals as the hydroxyapatite crystals of tooth enamel.

• Both the statement and reason are correct and related.

• Both the statement and reason are correct but NOT related.

• The statement is correct, but the reason is NOT.

• The statement is NOT correct, but the reason is correct.

Answer explanation

Although amorphous calcium phosphate (ACP) contains the same minerals as the hydroxyapatite crystals of tooth enamel, ACP should not be substituted for fluoride therapy. Rather, ACP should be used in conjunction with fluoride to enhance fluoride uptake.

Which of the following is MOST important for dental sealant effectiveness?

• Complete occlusal coverage

• Abrasion resistance

• Adequate developmental groove depth

• Effective etching and bonding in dry conditions

Answer explanation

Salivary contamination of etched enamel surfaces is a major reason for resin failure. Isolation using a rubber dam or cotton rolls and bibulous (absorbent) pads is essential for consistent success. Sealant bonding and retention in pits and fissures is dependent on effective etching, and bonding of the sealant in dry conditions. It is not advisable to cover the entire occlusal surface with sealant material; a sealant only needs to be retained in pits and fissures to prevent caries. Abrasion resistance is not important because the sealant is only abraded away from areas that are naturally self-cleansing. A common misconception is that sealants should be wear resistant. Similarly, developmental groove depth is unimportant because etching and bonding occur around the entrance of the pit or fissure and not down into the defect space.

Mrs. Hernandez is a 69-year-old client who comes to the dental office every 3 to 4 months for supportive periodontal maintenance visits. She retired approximately 1 year ago and plays cards almost daily. She takes several prescription medications for arthritis and blood pressure control and reports having a "very dry mouth." She finds that sucking on hard candies, which her friends have recently been serving, effectively relieves her dryness. At home, she drinks copious amounts of water. Although she has been caries-free and periodontally stable for a number of years, at this appointment, four early root carious lesions have been found.

What is the MOST likely risk factor for her new root caries?

• Inappropriate oral hygiene practices

• Lack of fluoride toothpaste

• Inappropriate management of xerostomia

• Lack of in-office fluoride therapy

Answer explanation

Xerostomia places the client at extremely high risk for caries. Sucking on hard candies to relieve xerostomia further contributes to root surface caries. The dental hygienist should recommend xylitol-containing gum or candies; sucking (not chewing) on ice chips; chewing tart sugarless gum; avoiding products containing alcohol and caffeine; and avoiding juices and soft drinks to reduce the risk of dental caries. As evidenced by her long-term control of periodontal disease and dental caries, her oral hygiene is adequate. It would be appropriate for the hygienist to confirm that Mrs. Hernandez is using fluoridated toothpaste. It must be stressed that the most obvious change in her recent habits is increased use of hard candy. Considering her history, Mrs. Hernandez has had no previous indication for in-office fluoride treatments. However, the presence of active caries should prompt the dental hygienist to recommend fluoride varnish therapy.