**3.2.1 Unstimulated saliva**

160 Contemporary Approach to Dental Caries

The principal diseases originated by dental plaque are caries and periodontal diseases, they

A number of plaque indices have been developed for assessing individual levels of plaque control and are also have been used in several epidemiological studies. Some of the most

The plaque control record evaluating the presence of soft debris on the tooth surfaces and dentogingival junction, as well as toothbrushing efficacy. (Butler et al., 1996; O'Leary et al.,

According to O'Leary index, plaque is disclosed with a chewable tablet and its amount estimated. To determine an individual's score, the clinician multiplies the number of surfaces with plaque by 100, and divides that by the number of tooth surfaces examined.

Saliva is a fluid present in mouth that comes from major and minor glands. Saliva is essential for the protection of the tooth against dental caries and protects the integrity of the soft oral tissues, facilitates the mastication, the swallowing and the speech, as well as the sensibility and the digestive functions in the oral cavity. Near 99 % of saliva is water, 1% remaining consists of a complex mixture of constituent to different concentrations (Harris & García Godoy, 2001; Featherstone, 2000; Fenoll-Palomares et al., 2004; Larmas, 1992; Leone,

1. Protection functions (lubrication, preserve the integrity of the oral mucous, cleanliness,

buffer capacity, dental remineralization and antimicrobial).

originate in sites where the dental plaque is more abundant and is stagnant.

Simplified Oral Hygiene Index (OHI-S, Greene and Vermillion, 1964)

The Plaque Control Record (O' Leary T, Drake R, Naylor, 1972).

Oral Hygiene Index (Greene and Vermillion, 1960)

Quigley Hein Index (Modified by Turesky et al, 1970)

Silness-Löe Index (Silness and Löe, 1964)

1972).

(WHO, 2011a) (Fig. 2).

Fig. 2. Plaque control record.

The principal functions of the saliva are:

**3.2 Salivary markers** 

2001).

well - known indices, which have been used in numerous studies, are listed below:

The average of total saliva flow is 0.3 to 0.4 ml/min in adults, exist approximately a saliva secretion of 1500 ml/24 hrs. This rate of unstimulated saliva flow is based to a circadian rhythm, with a major flow in the middle of the evening and minor about 4 a.m. The flow changes considerably in persons who are resting. During sleep, the flow is very low or nonexistent and increases during the day, especially with the food ingestion.

An unstimulated salivary <0.30 mL/min it is considered like risk factor (Ansai et al., 1994; Harris & García-Godoy, 2001; Fenoll-Palomares et al., 2004; Larmas, 1992; Leone, 2001; Zárate et al., 2004).

All salivary components neutralize the acids produced by cariogenic bacterias. For this reason the saliva production is important to support the oral health. Any agent or condition that reduces the quantity of saliva increases the risk of dental decay.

One way to measure this is by the formation time (in seconds) of small saliva drops in the inner mucous of the lower lip and compared with a chart. (Saliva Check®1) (Varma et al., 2008) (Fig. 3)


Fig. 3. Unstimulated saliva flow measured by Kit Saliva Check.

#### **3.2.2 Stimulated saliva**

Physiologically the stimulus can be mechanic as mastication. It can be gustatory as result of the stimulation of the gustatory or psychological papilla on having imagined the favorite food. Inversely, it can diminish with fear, radiation causing destruction of the salivary

<sup>1</sup> Saliva Check®, GC America Inc., Alsip, IL, USA.

Clinical, Salivary and Bacterial Markers on the Orthodontic Treatment 163

The Saliva Check®1 reactive strip is submerged in stimulated saliva for 10 to 20 seconds and

Buffer capacity is the saliva ability to neutralize acids, salivary pH back to normal parameters after bacterial acidogenesis. After exposure to fermentable carbohydrate occur a series of reactions with decreasing pH, as it decreases, some salivary minerals and proteins are liberate to avoid the salivary pH drop. Increased salivary buffering minimizes the final products of the acidogenic bacteria. Magnesium and carbonate ions are adsorbed to the enamel crystals, and then they are dissolved and added to the oral environment. Even calcium and phosphate ions are available for remineralization when the pH begins to return

If acid production continues after 30 to 45 minutes, the pH rises and minerals in ionic form incorporate into the tooth structure. At this time reverse the demineralization process

This salivary function is one of the best indicators of caries susceptibility because it reveals the host response. Patients with high buffering capacity are resistant to the caries process. The low capacity may indicate: decreased salivary flow, reduced host response to cariogenic

Buffer capacity might be determined quickly placing stimulated saliva using a pipette in the reactive strip of the Saliva Check®1 test and will be compared with the chart after 2 minutes;

To determine salivary pH, you can use a ph-meter or by the reactive strip.

the color obtained is compared with categorical levels in the chart:

Highly acidic red section (pH de 5.0 to 5.8) Moderately acidic yellow section (pH de 6.0 to 6.6) Healthy saliva green section (pH de 6.8 to 7.8).

agents, possible malnutrition or pregnancy (Larmas, 1992).

the final result was obtained by adding the scores of 3 reactive zones:

**3.2.4 Buffer capacity** 

to normal parameters.

(Monterde et al., 2001).

Green 4 points Green/blue 3 points Blue 2 points Red/blue 1 point

Red 0 points (Fig. 6).

Fig. 6. Buffering capacity (Saliva Check®).

glands, thyroid insufficiency, Sjögren's syndrome or medicaments (neuroleptics, antidepressants and antihypertensives) (Harris & García-Godoy, 2001) (Fig. 4)

Fig. 4. Stimulated salivary flow.

Stimulated saliva could be obtained during 5 minutes by chewing an unflavored piece of wax or chewing gum; the result was expressed in mL/min. With a moderate stimulation, it can collect 1 to 2 mL/min. When the stimulated salivary flow is lower than 0.7 ml/min, it could be xerostomia with a caries risk (Harris & García-Godoy, 2001; Heintze et al., 1999).

### **3.2.3 Salivary pH**

Salivary pH is the acidity or alcalinity of the saliva, normally presents a pH of 6.3, but could be modified by the oral health (Prieto & Yuste, 2010).

If salivary pH diminished can increase the enamel demineralization. There is no exist an exact pH at which demineralization begins, it may be in the range of 5.5 to 5.0 (critical pH). This is a very large range due to the mineralization is given according to pH and duration of exposure of the enamel surface to the acid environment (Anderson et al., 2001; Dawes, 2003).

The concept of critical pH is applicable only to solutions that are in contact with a particular mineral, such as enamel. Saliva and plaque fluid, for instance, are normally supersaturated with respect to tooth enamel because the pH is higher tan the critical pH, so our teeth do not dissolve in our saliva or under plaque (Featherstone, 2000; Dawes, 2003) (Fig. 5).

Fig. 5. The reactive strip comparate with the manufactured chart.

To determine salivary pH, you can use a ph-meter or by the reactive strip.

The Saliva Check®1 reactive strip is submerged in stimulated saliva for 10 to 20 seconds and the color obtained is compared with categorical levels in the chart:


#### **3.2.4 Buffer capacity**

162 Contemporary Approach to Dental Caries

glands, thyroid insufficiency, Sjögren's syndrome or medicaments (neuroleptics,

Stimulated saliva could be obtained during 5 minutes by chewing an unflavored piece of wax or chewing gum; the result was expressed in mL/min. With a moderate stimulation, it can collect 1 to 2 mL/min. When the stimulated salivary flow is lower than 0.7 ml/min, it could be xerostomia with a caries risk (Harris & García-Godoy, 2001; Heintze et al., 1999).

Salivary pH is the acidity or alcalinity of the saliva, normally presents a pH of 6.3, but could

If salivary pH diminished can increase the enamel demineralization. There is no exist an exact pH at which demineralization begins, it may be in the range of 5.5 to 5.0 (critical pH). This is a very large range due to the mineralization is given according to pH and duration of exposure of the enamel surface to the acid environment (Anderson et al., 2001; Dawes,

The concept of critical pH is applicable only to solutions that are in contact with a particular mineral, such as enamel. Saliva and plaque fluid, for instance, are normally supersaturated with respect to tooth enamel because the pH is higher tan the critical pH, so our teeth do not

dissolve in our saliva or under plaque (Featherstone, 2000; Dawes, 2003) (Fig. 5).

antidepressants and antihypertensives) (Harris & García-Godoy, 2001) (Fig. 4)

Fig. 4. Stimulated salivary flow.

be modified by the oral health (Prieto & Yuste, 2010).

Fig. 5. The reactive strip comparate with the manufactured chart.

**3.2.3 Salivary pH** 

2003).

Buffer capacity is the saliva ability to neutralize acids, salivary pH back to normal parameters after bacterial acidogenesis. After exposure to fermentable carbohydrate occur a series of reactions with decreasing pH, as it decreases, some salivary minerals and proteins are liberate to avoid the salivary pH drop. Increased salivary buffering minimizes the final products of the acidogenic bacteria. Magnesium and carbonate ions are adsorbed to the enamel crystals, and then they are dissolved and added to the oral environment. Even calcium and phosphate ions are available for remineralization when the pH begins to return to normal parameters.

If acid production continues after 30 to 45 minutes, the pH rises and minerals in ionic form incorporate into the tooth structure. At this time reverse the demineralization process (Monterde et al., 2001).

This salivary function is one of the best indicators of caries susceptibility because it reveals the host response. Patients with high buffering capacity are resistant to the caries process. The low capacity may indicate: decreased salivary flow, reduced host response to cariogenic agents, possible malnutrition or pregnancy (Larmas, 1992).

Buffer capacity might be determined quickly placing stimulated saliva using a pipette in the reactive strip of the Saliva Check®1 test and will be compared with the chart after 2 minutes; the final result was obtained by adding the scores of 3 reactive zones:


Fig. 6. Buffering capacity (Saliva Check®).

Clinical, Salivary and Bacterial Markers on the Orthodontic Treatment 165

The average value for any possibility of decay should be more than 250,000 colony-forming unit (CFU) per milliliter of saliva, the higher values of 1'000, 000 CFU / mL indicate a high

The bacitracin disc may be placed in the selective culture Dentocult® SM2; 15 minutes before sampling. Let the patient chew a paraffin pellet for 1 minute. This stimulates the secretion of saliva and transfers mutans streptococci from toothsurfaces into the saliva. Press the rough

surface of the strip against the saliva remaining on the patient´s tongue (Fig. 8).

Fig. 7. Dentocult SM® strip mutans.

risk of caries (Heintze et al., 1999).

Fig. 8. Specimen collection, and model chart.

2 Dentocult® SM Strip Mutans (Orion Diagnostica, Helsinki, Finland)

Interpreting the result:


#### **3.3 Bacterial markers**

The acids produced by bacterial fermentation in plaque dissolve the mineral matrix of the tooth. A reversible chalk-white spot is the first manifestation of the carious lesion, which can lead to cavitation if the mineral continues to be exposed to acid. Early detection of carious lesions provides a great opportunity to limit enamel demineralization associated with this process.
