PURPOSE OF A DENTIFRICE

Clients look to the dental hygienist to recommend a daily use dentifrice that will meet the clients’ unique oral health needs. A dentifrice or toothpaste is a substance used with a toothbrush or other oral hygiene device to clean the teeth, tongue, and gingiva and to deliver cosmetic and therapeutic agents to the teeth and oral environment. A dentifrice can yield the following types of effects:

Cosmetic effect—Prevents or removes stains, inhibits supragingival calculus formation, whitens teeth, freshens breath, controls oral malodor

Hygienic effect—Removes food particles and oral biofilm

Therapeutic effect—Prevents or reverses dental caries; reduces gingivitis, oral biofilm, or dentinal hypersensitivity¹

Toothpastes that carry the American Dental Association (ADA) Seal of Acceptance or the Canadian Dental Association Seal of Recognition have been shown through rigorous research to be safe and therapeutically effective (antiplaque, antigingivitis, anticaries, and anti–dentinal hypersensitivity). The ADA Seal has also been awarded to dentifrices that safely and effectively remove tooth stain. (See the discussion of product selection and evaluation in Chapter 29.)

CHOOSING A DENTIFRICE

Dentifrice is selected to meet particular client needs, but the array of dentifrices on the market can be confusing to the consumer as well as the professional. Manufacturers develop dentifrices for cleaning dentures; nonfoaming to low-foaming dentifrices for use with power toothbrushes and children; ingestible dentifrices for persons with special needs; and dentifrices free of preservatives, sodium lauryl sulfate (SLS), fluoride, dyes, peroxide, and artificial flavors for persons who may be allergic or who desire a “natural” product. There are also dentifrices that contain bioavailable fluorides² to strengthen or remineralize tooth enamel or exposed roots and amorphous calcium phosphate (ACP) to remineralize teeth and add luster.³ Others have antibacterial ingredients such as chlorhexidine gluconate (CHG), triclosan⁴ with copolymer, or stannous fluoride (SnF₂) to control gingivitis and oral biofilm; and some contain fluoride, ACP, potassium nitrate, and/or strontium chloride to reduce dentinal hypersensitivity. Dentifrices have been formulated for persons with health problems such as diabetes (with sweeteners that have no effect on blood sugar), xerostomia (with salivary enzymes, lubricant, and salivary enhancers), recurrent aphthous ulcers (SLS-free), and hypertension (sodium bicarbonate–free or sodium chloride–free).

TOOTHPASTE TUBE CONTAMINATION

The orifice of the tube can be a source of cross-contamination. Transmission of bacteria responsible for oral and systemic disease is possible when family members’ toothbrushes come into contact with the neck of the same tube of dentifrice. Each family member should have his or her own tube of toothpaste to prevent cross-contamination, to control infection among people living in the same household, and to meet his or her unique oral care needs (Figure 23-1).

Figure 23-1 Comparison of factors related to choice of a dentifrice.

(Courtesy France Lavoie.)

FORMS OF DENTIFRICES

Dentifrices come in powders, liquid gels, gels, pastes, and gel-paste combinations (Figure 23-2). A fluoridated liquid gel dentifrice is effective in caries prevention, as it reaches both the interproximal surfaces and deep grooves of the teeth.^5,6

Figure 23-2 Forms of dentifrices.

(Courtesy Comité Dentifrice, Collège François-Xavier-Garneau, Québec, Canada.)

COMPONENTS OF DENTIFRICES (FIGURE 23-3 and TABLE 23-1)^7-9

Toothpastes are complex formulas of therapeutic, active, and inactive ingredients that must be compatible to be effective. An active ingredient is an additive that produces a therapeutic or beneficial effect on either the hard or soft tissues. Some authors use the terms active ingredient and therapeutic ingredient interchangeably; however, in order for an active ingredient to be therapeutic, it must improve oral health status in a safe end effective way—for example, fluoride for caries control; triclosan-copolymer for control of gingivitis and oral biofilm; desensitizing agents such as sodium fluoride (NaF) and SnF2 to achieve desensitization and caries control; and potassium chloride and potassium citrate to control dentinal hypersensitivity. An active ingredient may be beneficial but still not be therapeutic (e.g., pyrophosphate zinc systems to inhibit calculus formation). An inactive ingredient is an additive that is necessary to make the formulation thick, hold together, clean efficiently, or have a particular color or flavor for consumer appeal. Listing specific ingredients on the packaging of oral care products would make it possible to meet client needs and avoid risks of allergies and intolerances. Active, therapeutic, and inactive ingredients found in dentifrices are discussed in the following sections.

Figure 23-3 Components of dentifrices and percentage by weight. Pres., Preservative; Sweet., sweetener.

Abrasives

Abrasive agents are used to clean and polish teeth to a smooth, lustrous surface; they establish the abrasive capacity of the dentifrice (see Tables 23-1, 23-2, and 23-3 and Figure 23-4). If abrasive capacity is too low, the abrasive agent is less effective in removing the soft deposits and stains. If it is too high, it will increase abrasion of tooth structure and restored tooth surfaces. A client who toothbrushes without dentifrice must brush longer, as there is no abrasive agent on the toothbrush to help remove soft deposits and stains adequately.¹ Dentrifice powders, gels, and pastes contain abrasive agents.^1-9

TABLE 23-1 Components of Dentifrices

Components	Examples	Quantity
Cleansing and polishing agents (10%-40%)	Calcium carbonate, sodium bicarbonate, calcium pyrophosphate, dicalcium phosphate dihydrate, anhydrous dicalcium phosphate, hydrated aluminium oxides, insoluble calcium metaphosphate (IMP), silica, silicates and dehydrated silica gels, synthetic amorphous silicates in gel form, complex salt of synthetic amorphous aluminium silicate, magnesium carbonate	NA
Humectants (20%-70%)	Glycerin, sorbitol, mannitol, propylene glycol, vegetable oils, synthetic cellulose	NA
Water (5%-30%)	Distilled water, deionized water, spring water	NA
Binders (1%-2%)	Hydrophilic organic colloids such as alginates and synthetic cellulose derivatives (e.g., cellulose gum, carboxymethylcellulose), glycerol, glycerin mineral colloids, polyethylene glycol (PEG)Natural products: carrageenan, carbomer, xanthan gum, seaweed colloids or algae, agar-agar	NA
Detergents (1%-3%)	Sodium lauryl sulfate, N-lauryl sodium sarcosinate, sodium cocomonoglyceride sulfonate, cocamidopropyl betaine or betaine de cocamidopropyl, steareth-30, sodium monoglyceride sulfate, ethionates of fatty acid	NA
Flavoring agents or aromatizers (1%-2%)	Essential oils, menthol, noncariogenic artificial sweetener	NA
Preservatives (2%-3%)∗	Alcohols, sodium benzoates, formaldehydes, dichlorinated phenols, methylparaben, ethylparaben	NA
Sweeteners (2%-3%)∗	Noncariogenic artificial sweetener, sorbitol, glycerin, sodium saccharin, sodium cyclamate, xylitol	NA
Dyes or coloring agents (2%-3%)∗	Vegetable coloring, titanium dioxide	NA
Therapeutic agents (0.10%-0.50%)∗		% minimal
	Anticaries Agents Sodium fluoride (NaF)† Sodium monofluorophosphate (MFP) Stannous fluoride (SnF2) Amine fluoride (AmF) Antibacterial enzymes	0.24% 0.76% 0.4% 0.125% (sold in Europe) NA
	Desensitizing Agents Potassium nitrate Strontium chloride SnF2 Sodium fluoride Sodium citrate Calcium sodium phosphosilicates (NovaMin) Amorphous calcium phosphate Potassium citrate	5% 10% 0.4% 1% NA 5% Accepted by British Department of Health
	Antigingivitis and Oral Biofilm Reduction Agents Triclosan with copolymer PVM/MA SnF2 Chlorhexidine Essential oils (combination): Eucalyptol Menthol Methyl salicylate Thymol Zinc citrate Antibacterial enzymes: Lactoperoxidase Oxydase glucose Lysozyme Triclosan and zinc citrate	0.3% 0.4% 0.12% 0.738% 0.340% 0.480% 0.511% NA 15,000 units 10,000 units 16 mg NA
Active ingredients but not considered therapeutic	Anticalculus Agents Pyrophosphates and derivated: Tetrasodium pyrophosphate Sodium hexamethaphosphate Sodium tripolyphosphate Triclosan with copolymer PVM/MA Zinc and derivated: Zinc citrate Zinc chloride Sodium hexametaphosphate SnF2 (stabilized) Triclosan and zinc citrate	1% (ADA) to 5% (CDA) 0.3% 0.5%-2% NA NA 0.4% NA
Other ingredients	Antistain agents Abrasives in dentifrice, hydrogen peroxide, carbamide peroxide, sodium tripolyphosphate, sodium hexametaphosphate, papain/sodium citrate, dimethicone	NA

ADA, American Dental Association; CDA, Canadian Dental Association; NA, not applicable; PVM/MA, polyvinylmethoxyethylene and maleic acid.

∗ Total for preservatives, sweeteners, and dyes.

† Italic typeface denotes acceptance by the ADA or CDA.

TABLE 23-2 Comparison of Abrasiveness in Gel and Paste Dentifrices

TABLE 23-3 Variables Influencing Dentifrice Abrasiveness

Particle size (grit)	The larger the particles, the more they wear on dental surfaces (see Figure 23-5).
Particle shape	The more irregular the shape, the more dental surfaces are worn and abraded. A round particle is less detrimental to the tooth (see Figure 23-5).
Particle hardness	The harder the particles, the more the dental surfaces are abraded (see Figure 23-10).
pH level	The more acidic and abrasive, the more the dentifrice increases tooth surface mineral loss, particularly if dentin or cementum is exposed (see Figure 23-6 and Table 23-9).
Quantity of glycerin and water in dentifrice	The higher the level of glycerin in a dentifrice, the higher its level of abrasiveness, as the dissolution of insoluble materials is reduced. The greater the amount of water in a dentifrice, the more soluble particles can dissolve, making them less abrasive to dental surfaces (see Table 23-2).

Data from Lavoie F, Dubreuil N: Variables associated with the choice of a dentifrice. In press.

Figure 23-4 Size and shape of particles.

(Courtesy Comité Dentifrice, Collège François-Xavier-Garneau, Quebéc, Canada.)

The three common dentifrice abrasives are phosphates, carbonates, and silicas.

Phosphates help the dentifrice make the teeth look white and feel clean, and include the following:

○ Dicalcium phosphate dihydrate (DCPD)

○ Calcium pyrophosphate (CalPyro)—used in toothpaste with SnF₂

Carbonates help to clean and deodorize the mouth and make it fresh-smelling.

○ Sodium bicarbonate (baking soda)—used in toothpastes with NaF; bactericidal

○ Calcium carbonate (chalk)—used in toothpastes with MFP

Some silicas mechanically clean the teeth, and some thicken the dentifrice. Silicas are chemically compatible with NaF and MFP. Silicas are nonreactive and therefore are frequently used as abrasives in toothpaste.

In 1812 Mohs created a 10-point scale of mineral hardness. With this scale the hardness of materials can be rated, with 1 being the softest and 10 being the hardest. The hardness of abrasive agents found in dentifrices and the hardness of a tooth are compared in Figure 23-5.

Figure 23-5 Comparison of hardness scales, abrasives, and dental surfaces.

(Courtesy Nadia Dubreuil. Adaptation of Mohs Scale [1812]).

Mohs Hardness Scale is useful for understanding abrasiveness of cleaning and polishing agents. For example, the threshold of 2 to 4 is important because it is equal to the hardness of cementum or dentin, often exposed because of gingival recession. Dentifrices whose level of abrasiveness is ≤2 are recommended to avoid tooth structure loss on exposed roots. Children can use a more abrasive dentifrice when their tooth enamel is mature (hardness level of 4 to 5). A dentifrice containing alumina is efficient for stain removal but has a higher risk for damaging tooth surfaces because its hardness level is higher than that of the tooth’s enamel. Even hard agents can be made safe by varying their particle size and shape in the manufacturing process.

Therapeutic Agents and Active Ingredients

Ingredients added for specific preventive, treatment, or beneficial purposes are referred to as therapeutic agents or active ingredients. For example, CHG is available in different concentrations and is used to control dental plaque formation and gingivitis.^12-14 GUM Gingidex dentifrice contains 0.06% CHG; GUM dental floss contains 0.12% CHG,¹⁵ and Mirafluor dental floss contains 0.4% CHG. Others products such as GUM Paroex dentifrice contain 0.12% CHG, and some prescription oral rinses contain 0.12% CHG to control gingivitis and plaque.¹⁴ These products vary by country. For a dentifrice to be considered therapeutic, the manufacturer must follow strict pharmaceutical standards with regard to the quantity and bioavailability of therapeutic agents used, their safety, and their efficacy.¹⁶ The main therapeutic and active agents found in dentifrices follow.^14-17

Fluoride

Fluoride plays a key role in keeping the remineralization-demineralization process in favor of remineralization.¹² Common fluorides found in daily-use dentifrice formulas include SnF₂, NaF, MFP, and SnF₂-sodium hexametaphosphate. A dentifrice with 0.24% NaF has an efficacy equivalent to a dentifrice containing 0.76% MFP. These two concentrations differ because the agents do not have the same molecular weight. Fluoride levels in dentifrices vary among countries. In Europe dentifrices may contain from 250 ppm¹⁸ to 10,000 ppm of fluoride.¹⁹ In North America the levels are between 400 ppm (for children) and 5000 ppm of fluoride. Most products contain about 1000 ppm. Fluoride neutralizes the antibacterial effect of CHG; therefore a client brushing with a fluoride-containing oral care product should wait for 30 minutes before using a CHG-containing product.¹²

Xylitol

Xylitol, a sugar alcohol and sugar substitute derived from fruits, mushrooms, and birch bark, has anticaries and antiplaque properties. Streptococcus mutans cannot metabolize xylitol; therefore their acids that demineralize tooth structure are decreased. Xylitol in a therapeutic dose of 1.55 g (minimum of 5 g used daily in the oral cavity) decreases S. mutans levels and plaque biofilm and its adhesion to the tooth.

Amorphous Calcium Phosphate

Other minerals, such as calcium and phosphates, may be added for the remineralization of tooth structure, as mild abrasive agents for tooth cleaning, as lubricants, and for enhancement of ambient calcium and phosphate in the saliva.

Desensitizing agents (see Chapter 38)

Chemotherapeutic agents may be added to do the following:

Mechanically block dentinal tubules—for example, NovaMin 5%, a calcium sodium phosphosilicate (in Oravive, SoothRx, and DenShield); SnF₂ 0.4%; strontium chloride 10% (Sensodyne Original¹⁴); or high levels of fluoride (10,000 ppm) such as in Elmex 1.25% (12,500 ppm), an amine fluoride (AmF) that remineralizes enamel.

Chemically prevent the depolarization of nerve fibers in the tooth (transmission of nervous influx), as potassium nitrate or potassium citrate does.

Reducing dentinal hypersensitivity. After tooth bleaching or mechanical oral debridement, use of a 5000-ppm fluoride product is efficient in reducing dentinal hypersensitivity (Oral-B NeutraCare with 1.1% NaF or Colgate PreviDent 5000 ppm Sensitive 1.1% NaF and 5% potassium nitrate.)¹⁴ A low abrasive sensitivity-control dentifrice and meticulous oral biofilm control should also be recommended.

Triclosan

Triclosan, a bisphenol, is a broad-spectrum antimicrobial agent that has antiplaque and antigingivitis properties. Polyvinylmethoxyethylene and maleic acid (PVM/MA) copolymer (Gantrez) is added to the triclosan to increase its duration in the mouth (substantivity) and hence its antibacterial effect. A dentifrice formulation (Colgate Total) with triclosan, PVM/MA copolymer and NaF has the ADA Seal of Acceptance for its safety and efficacy as an anticaries, antiplaque, antigingivitis, and anticalculus dentifrice. In North America, triclosan with copolymer PVM/MA (Gantrez), used in Colgate Total, is available as an antigingivitis, antiplaque ingredient.¹⁴ Triclosan slows periodontal disease progression in 3- to 5-mm periodontal pockets.¹¹ (Note that in some countries, triclosan is regarded as an active ingredient with restricted use.⁴ The long-term safety of this ingredient for the microbial ecosystem and general health is unknown.)

Chlorhexidine Gluconate

CHG is an efficacious ingredient for the treatment of gingivitis. Although it cannot be found in over-the-counter dentifrices in North America, a CHG mouthwash is available by prescription. CHG-containing dentifrice is available in Europe.

Sodium Hexametaphosphate, Tetrapotassium Pyrophosphate, Gantrez, Zinc Chloride, and Zinc Citrate

Chlorites, derivatives of sodium, phosphate, and stabilized SnF₂, are accepted by the ADA¹⁴ as supragingival calculus-inhibiting agents (see Table 23-1). Disodium pyrophosphate, tetrasodium pyrophosphate, and tetrapotassium pyrophosphate inhibit the mineralization of biofilm before it is transformed into supragingival calculus. Zinc chloride and zinc citrate prevent or break down calculus formation. Pyrophosphate and zinc chloride also have minor abrasive properties.

Dentifrice formulations with zinc citrate or pyrophosphates are very effective as antitartar toothpastes. Extrinsic stain removal ingredients or whitening agents work mechanically with the help of abrasives such as silicate or alumina. However, the dental hygienist must be cautious in recommending toothpastes containing alumina because this abrasive is harder than enamel and cementum, and if the particle size is large and irregular, the toothpaste can increase tooth surface lost. A dentifrice formulation with SnF₂–sodium hexametaphosphate (Crest Pro-Health) has the ADA Seal of Acceptance for its safety and efficacy as an anticaries, antiplaque, antigingivitis, antistain, and anti–dentinal hypersensitivity dentifrice. It also has anticalculus benefits. Note that the ADA Seal is not given for anticalculus properties because calculus does not cause disease.

Hydrogen Peroxide

Hydrogen peroxide or carbamide peroxide can remove stains, chemically whiten teeth, assist in the control of oral malodor, and have antigingivitis properties. If the percentage of hydrogen peroxide is higher than 6% in toothpaste,²⁰ it can damage soft tissues^14-21 and cause dental erosion.²¹ If the percentage of hydrogen peroxide in the dentifrice is <1%, the product is considered safe.

Sodium Bicarbonate

Baking soda, a mild abrasive, has been shown to neutralize acids produced by acidogenic bacteria that cause demineralization, effectively control extrinsic staining, reduce oral malodor, and have a mild antibacterial effect. It can be combined with hydrogen peroxide for tooth whitening and fluoride for an anticaries effect. It can be delivered for persons at extreme risk for caries (high risk plus dry mouth or special needs) in gum or toothpaste or in a solution for individuals with low saliva flow.

CONCEPT OF BIOAVAILABILITY

Bioavailability occurs when the therapeutic agent is stable during storage and biologically active when used in the mouth to achieve the desired therapeutic effect.² It corresponds to the proportion of the therapeutic agent available in a pharmaceutical substance that will produce the desired effect when used as recommended. Some manufacturers use cocamidopropyl betaine as a detergent instead of SLS to increase the bioavailability of fluoride ions. For example, Colgate-Palmolive Canada (Colgate Luminous) or GlaxoSmithKline (Sensodyne Pronamel) use this detergent. The percentage of available fluoride ions can be lower in the case of a dentifrice containing 1000 ppm of fluoride, such as NaF (Table 23-4). This difference could be attributed mainly to the following three elements:

Type of fluoride: some types have less bioavailability, such SnF₂, than others, such as NaF or AmF.

A pH lower than 6 in dentifrice or in saliva supports the incorporation of fluoride ions.

SLS may interfere with fluoride effectiveness.¹²

TABLE 23-4 Comparison of Bioavailability among Dentifrices

AMF, Amine fluoride; MFP, sodium monofluorophosphate; NaF, sodium fluoride, SnF₂, stannous fluoride.

Some manufacturers, such as Meridol, Homéodent, and Colgate, purport to have more fluoride in their toothpaste by mixing fluorides such as MFP, NaF, and AmF with SnF₂ to makes the dentifrice more effective against caries. However, bioavailability is not proportional to the quantity of fluoride contained in the toothpaste. As an example, Colgate Cavity Protection contains 1450 ppm MFP/NaF and has only 839 ppm fluoride (57.8%) available.²

DENTIFRICE: PREVENTIVE MEASURE OR RISK FACTOR?

A dentifrice can prevent or control an oral disease or condition when it provides a therapeutic function.¹ It can also be a risk factor if it causes dentin hypersensitivity, erosion, or abrasion (Figures 23-6, 23-7, 23-8, and 23-9). Therefore dentifrices must be selected to meet the needs of each client. For example, a client with root exposures must be given advice regarding abrasiveness, role of pH, and insoluble materials contained in dentifrices.

Figure 23-6 Erosion.

(Courtesy Nadia Dubreuil.)

Figure 23-7 Abrasion.

(Courtesy Nadia Dubreuil.)

Figure 23-8 Abfraction.

(Courtesy Nadia Dubreuil.)

Figure 23-9 Attrition.

(Courtesy Nadia Dubreuil.)

Insoluble and Soluble Materials

Dentifrices contain insoluble and water-soluble ingredients.¹ Ingredients in toothpaste that cannot dissolve in water are insoluble materials. Ingredients that dissolve in water are soluble materials, such as sodium bicarbonate. Insoluble abrasives such as silica remain intact in water. Insoluble ingredients can increase a dentifrice’s abrasiveness (Figure 23-10 and Table 23-5).

Figure 23-10 Insoluble materials found in various dentifrices tested.

TABLE 23-5 Insoluble Materials and Dentifrices

	Example	Insoluble Materials
High: ≥40	Pearl Drops Whitening Toothpaste, mint	42.80%
Moderate: 20-39.99	GUM Whitening Plus	20.09%
Low: 0-19.99	Prospec MI Paste, Recaldent, mint	11.35%

Courtesy Descriptive Guide to Dentifrices of Collège François-Xavier-Garneau, Québec, Canada.

For some dentifrices the level of insoluble materials is <20%, making them gentle on tooth surfaces.²² For others the insoluble material level is 30% to 55% (Figure 23-11). Colgate Gel-Kam Fruit and Berry flavor dentifrice contains no insoluble materials, has 0% abrasiveness, and has a pH of 3.6.

Figure 23-11 Abrasiveness scale of various dentifrices tested.

DENTIFRICE pH

The potential of the hydrogen molecule (pH) of a substance is measured on a scale from 1 to 14. Level 1 is very acidic, 7 is neutral, and 14 is basic (alkaline). The pH of a dentifrice can be beneficial or detrimental to dental structures while interfering in the demineralization-remineralization process. Decay caused by acids from the fermentation of sugars by S. mutans occurs at a pH of 6.5 on cementum and dentin,^2-25 at a pH of 5.5 on enamel (hydroxyapatite),^2-25 and at a pH of 4.5 on fluorapatite enamel.²⁶ The majority of dentifrices have a neutral pH, but some products have an acidic pH.

Neutral and Basic pH

Advantages for Teeth and Mucous Membrane

Because of similarities to healthy saliva, a neutral or basic pH is less irritating for soft tissues and will not demineralize teeth.

Disadvantages for Teeth and Gums

Neutral or basic pH levels promote the mineralization of biofilm (calculus formation), which in turn supports the retention of biofilm and extrinsic stains.

More than 86% of dentifrices (Figure 23-12 and Table 23-8) have a neutral or basic pH.²³ The pH of acidic or highly acidic dentifrices (14% of dentifrices) is below the critical threshold of demineralization. A dentifrice with a pH under 6.5 demineralizes and weakens exposed root surfaces. A combination of dentifrice acidity and abrasiveness further increases the loss of dental substance.^21-28 According to the ADA,¹⁴ dentifrices bearing the Seal of Acceptance contain a safe level of abrasives, but the organization makes no mention of pH levels. For example, Crest Pro-Health,⁹ which carries the ADA Seal of Acceptance,¹⁴ has a pH of 5.5; some believe that this pH might risk root surface demineralization in persons with gingival recession, yet it is important for fluoride uptake.^1,9,23 More research is needed on dentifrice pH and its role in tooth remineralization and demineralization.

Figure 23-12 pH of various dentifrices tested.

TABLE 23-8 pH Measurements and Dentifrices

	Example	pH
Basic (alkaline) (≥8)	Tom’s of Maine with propolis and myrrh, spearmint	9.9
Neutral (7 ± 1)	Colgate Total Advanced Fresh, Gel	7.0
Acidic (4-5.9)	Crest Pro-Health, clean mint	5.5
Highly acidic (<4)	OmniiGel Natural	3.2

Courtesy Comité Dentifrice, Collège François-Xavier-Garneau, Québec, Canada.

Thus, pH levels are relevant in the analysis of dentifrices. Loss of dental substance of chemical origin (erosion) can be increased further by mechanical actions such as toothbrush abrasion. Table 23-9 provides a comparison of various dental products. Persons who experience dietary acid or gastroesophageal reflux should wait 60 minutes^28,29 before toothbrushing to minimize loss of tooth structure. If waiting is not an option, the client should first rinse with water, fluoride-containing mouthwash, water and baking soda solution, or milk before toothbrushing.²² Persons who have cancer, chronic xerostomia, or chronic vomiting from bulimia or pregnancy and persons who take antidepressants, antiparkinsonian medications, antihistamines, or antihypertensives that cause chronic xerostomia¹⁴ need the same approach.

TABLE 23-9 Comparison of Dental Products in Terms of Abrasiveness, Insoluble Materials, and pH

RECOMMENDING DENTIFRICES TO CLIENTS

A comparison of commercial dentifrices, professionally dispensed dentifrices, and professionally applied dental products is important in order to recommend and use available products with confidence.^1-9 For example, no commercially available dentifrice is as abrasive as Nupro Fine prophylaxis paste, which is 7.9 on the abrasiveness scale and very alkaline as well. Products such as water, hydrogen peroxide, and sodium bicarbonate have no abrasiveness and contain no insoluble materials; however, they differ in pH. Water is neutral, peroxide is acidic with a pH of 4.9, and sodium bicarbonate is basic. Thus, a client who uses peroxide-containing toothpaste daily increases risk of tooth surface erosion over time. As for sodium bicarbonate, its relatively high solubility contributes to its low level of abrasiveness.¹ It can abrade dentin if used dry, as its particles are very irregular. Certain dentifrices contain micronized abrasive particles to reduce abrasiveness. (The finer the particle size or grit, the less abrasive the material, even if the material scores very high on the Mohs Hardness Scale.)

LOSS OF TOOTH STRUCTURES

Saliva plays several roles: lubrication, predigestion (contains ptyalin), immunity, and buffering capacity to neutralize mouth acids. Therefore quality and quantity of saliva affect the demineralization and remineralization process. Medications that cause xerostomia, an individual’s condition (stress, fatigue, and dehydration), time of the day (saliva is more abundant in the morning and at mealtimes), and certain health problems (Sjogren’s syndrome, radiotherapy in the salivary gland region) influence the quantity and quality of saliva as well.

Loss of dental substance may occur by erosion, abrasion, abfraction, and attrition and has diverse causes such as dentifrice used, frequency of brushing, toothbrush filament hardness, pressure during brushing, the direction of the brush strokes, choice of manual or power toothbrush, the surface substrate being brushed (dentin, cementum, or enamel), and an insufficient amount of saliva.^10,30

Erosion: Dissolution of organic and inorganic tooth structure as a result of chemical agents (see Figure 23-6)

Abrasion: Pathologic tooth wear caused by a foreign substance that is harder than the tooth structure (see Figure 23-7)

Abfraction: Cervical tooth structure loss of noncariogenic origin caused when the tooth is subjected to a high occlusal load—that is, the occlusal stress is high enough to cause cervical cracking and mineral loss of tooth structure (see Figure 23-8)

Attrition: Loss of tooth structure on surfaces resulting from tooth-to-tooth contact (proximal or biting surfaces) from normal (chewing) or pathologic (bruxing or clenching) friction with adjacent or opposite teeth (see Figure 23-9)

COMPARISON OF METHODS TO EVALUATE DENTIFRICE ABRASIVENESS

Dentifrice abrasiveness is not easily compared because of the various methods used to evaluate abrasiveness.^31-33 Manufacturers use different protocols and laboratory products, making direct comparisons among dentifrices difficult.³² Therefore one can only compare dentifrices from the same manufacturer¹ or resort to an independent laboratory that conducts testing using the same protocol (Figure 23-13).

Figure 23-13 Methodologies: advantages and disadvantages. ADA, American Dental Association; RDA, Radioactive Dentin Abrasivity; REA, Radioactive Enamel Abrasivity.

(Courtesy France Lavoie.)

An interdisciplinary team representing dental hygiene, chemistry, physics, and biology independently studied the abrasiveness, the pH, and the insoluble materials found in dentifrices using the Collège François-Xavier-Garneau protocols.^1,9,32 This team’s findings have been reported in this chapter.

CLIENT EDUCATION TIPS

Link relevant therapeutic agents in dentifrices to unique client oral problems.

Explain importance of abrasiveness, pH, and insoluble materials when choosing a dentifrice.

Explain importance of the daily use of dentifrices with fluoride and amorphous calcium phosphate in the remineralization process.

Understand that dentifrices, depending on the one used, can be a risk factor or a therapeutic agent for clients. The American Dental Association Seal of Acceptance and the Canadian Dental Association Seal of Recognition are designed to help the consumer and dental hygienist make informed oral care product choices.

Balance risk of dental caries with risk of future dental fluorosis on permanent teeth in young or disabled children who cannot expectorate.

Analyze the effects of combining over-the-counter fluoride and ingested fluoride to avoid dental fluorosis and acute fluoride toxicity.

Demonstrate the quantities of fluoride dentifrices recommended for different age groups. Avoid fluoridated dentifrice until children are 2 years of age, then use minimal quantity (pea size or smear on the toothbrush head) for young children^18,19 with primary teeth. A young child risks acute poisoning if he swallows a complete tube of fluoride toothpaste.⁸ There are established tables that make it possible to determine the maximum tolerated dose (MTD) and the lethal dose (LD) according to the weight and age of the individual8 (see Chapter 31). Keep oral healthcare products out of young children’s reach.

Keep in mind the child’s age and weight in relation to the quantity of fluoride ingested during the period of permanent tooth formation (7 months to 4 years), brushing frequency, and ability to expectorate.

LEGAL, ETHICAL, AND SAFETY ISSUES

Recognize that persons may be using dentifrices that place them at risk.

Assess client’s health, dental, and pharmacologic histories to make sure there are no conditions, allergies, or medications that would contraindicate a particular dentifrice recommendation.

Make recommendations based on a client’s assessed needs and expectations and product evidence. Use the American Dental Association (ADA) Seal of Acceptance or the Canadian Dental Association (CDA) Seal of Recognition as a guide to help make product recommendations.

Document recommendations in client’s record, including the product, frequency, dosage, and reasons for use. Confirm, with client’s signature, that the client understands these recommendations and agrees to the regimen.

Review client’s self-care regimen regularly; offer advice based on evolving research evidence to reach optimal oral health.

Make sure that products recommended to clients have been accepted by the ADA¹⁴ or CDA¹⁷ and contain ingredients that have been approved by the U.S. Food and Drug Administation,¹⁶ Health Canada,⁴ or other regulatory organization. In 2007 about 30 dentifrices were taken off the market because of the presence of dangerous amounts of toxic ingredients and high levels of harmful bacteria. It is therefore of utmost importance to consult these organizations regularly via their websites.

KEY CONCEPTS

The majority of manufacturers produce dentifrices effective against calculus, gingivitis and oral biofilm, dentinal hypersensitivity, or a combination of the above. Studies to date indicate that these products make toothpastes more therapeutically efficacious but more abrasive than first-generation products.

When developing a care plan, it is necessary to verify the dentifrice and the quantity and frequency with which it is to be used. Evaluate whether the product meets client needs, taking into consideration root exposure, erosion, abrasion, dental caries, stains, calculus, and brushing habits (e.g., pressure applied, soft- or stiff-bristled toothbrush, brushing method).

Variables about level of abrasion, the pH of dentifrices, and the insoluble materials must be considered when recommending dentifrices to clients. Various sources of references exist, such as the American Dental Association,¹⁴ Radioactive Dentin Abrasivity, and Radioactive Enamel Abrasivity, but the Descriptive Guide to Dentifrices considers all of these variables, making it useful for comparison of dentifrices.

Flavoring agents, dyes, and detergents in dentifrices may cause side effects (burning sensation, oral tissue desquamation, aphthous ulcers).

Health conditions of the client (hypertension, allergies, or intolerance) are considered when recommending a dentifrice.

CRITICAL THINKING EXERCISES

Role-play each of the following case scenarios. One person should be the clinician and one the client. Analyze each scenario by noting the following:

Client’s significant clinical findings

Therapeutic agents used in each case

Abrasiveness and the pH level of dentifrices used

What information should be given to the client (or caregiver) to ensure safe, effective dentifrice use?

Example: A 3-year-old child with healthy teeth, no composite restorations, a thin biofilm at the lingual surface of the mandibular molars, healthy eating habits, and good oral hygiene. The child brushes twice daily with a dentifrice for children with 0.24% NaF, which completely covers bristles of a small-headed toothbrush. Parental supervision of brushing occurs once daily.

Clinical Findings: None except for biofilm on molars

Therapeutic Agent: Fluoride is used as primary prevention against caries. The quantity of dentifrice is equal to the size of a grain of rice to reduce the risk of fluorosis.

Abrasiveness: Low-abrasiveness dentifrice is used for primary teeth, because in this case the child has only a thin biofilm

pH: Slightly acidic or neutral to promote fluoroapatite formation (the more acidic a dentifrice, the more it demineralizes, allowing for a greater remineralization and incorporation of fluoride onto dental structures).

Scenario 1: An 8-year-old boy with one area of decalcification (white spot lesion), two untreated carious areas, no sealants, generalized gingival redness, materia alba, and oral biofilm. Daily he chews one package of sugarless chewing gum (nine pieces), and he has variable eating habits, including two glasses of regular cola (pH 3).

Daily Oral Care Regimen: Rapid brushing once daily with whichever dentifrice is available at home

Scenario 2: A 22-year-old woman with four dental sealants, two composite restorations, two areas of gingival recession on maxillary first premolars causing no sensitivity, a slight supragingival calculus, moderate gingivitis , and generally good eating habits.

Daily Oral Care Regimen: Uses dental floss once weekly, brushes twice daily using a power toothbrush and a small amount of dentifrice because of too much foam. Choice of dentifrice depends on price.

Scenario 3: A 58-year-old smoker (one pack of cigarettes per day) with generalized moderate tobacco stains, periodontitis (four sites at 4 PSR), heavy subgingival calculus, and occasional bleeding on probing.

Daily Oral Care Regimen: brushes once or twice daily with a dentifrice chosen by his spouse. Never uses an interdental cleaning aid.