Lactobacillus is considered secondary invaders, can contribute to tooth demineralization once they are established carious lesions. Lactobacilli can be found in the mouth before the teeth erupt, even when the diet is rich in fermentable carbohydrates and no active carious lesions.
They are present in small numbers on the plaque and tend to be found in saliva and in deep carious lesions. Weakly bind to the enamel surfaces, are lazy in their nutritional requirements, are acidogenic and aciduric. They are located in the undercut areas of the tooth, such as defects or margins of fillings or orthodontic bands (Ansai et al., 1994; Heintze et al., 1999; Menaker et al., 1986; Tanzer et al., 2001).
The development of caries should be considered in two-stage process: in Streptococcus mutans involved in lesion initiation and lactobacilli in progression it.
The standard method for determining the presence of lactobacilli is through the selective medium Rogosa SL agar. An alternative was established by Larmas in 1975 with the introduction of the test Dentocult LB®. The advantage is that it can be used in the dental office and the results can be shown to make the patient aware of the presence of lactobacilli in the mouth (Fig. 9).
Values greater than 100,000 CFU / mL indicate a high risk of caries (Heintze et al., 1999; Larmas, 1992).
Dentocult® LB3 procedure (Fig. 10) consists in pour the collected saliva over both agar surfaces, ensuring that they are well moistened. If the saliva is very viscous, the sample can also be applied using a sterile swab, then screw the slide tightly back into the tube and place
3 Dentocult® LB (Orion Diagnostica, Helsinki, Finland)
the tube in an incubator for 72 hours at 37° C. To obtain a colony count remove the slide from the tube and compare the colony density with the model chart provided in the kit:
NC Non count or few colonies
1 10 000 UFC/ml (medium)
3 1 000 000 UFC/ml (higher)
Actually exists the CRT bacteria test (Ivoclar Vivadent AG, Schaan, Liechtenstein) which allows clearly identify and semi-quantitatively determine both cariogenic bacterias.
Prognosis of caries becomes more effective when the lactobacilli and streptococci tests are combined.
Fig. 10. Collect the lactobacillus sample, manufactured chart. 3.4 Plaque pH
Acidogenic bacteria in dental plaque metabolize carbohydrates rapidly getting acid as final product. The result is a change in pH of the plaque, as it relates to the time called the Stephan curve as a scheme to bring it takes a curve. The pH decreases rapidly in the first few minutes to gradually increase; it suggests that in 30 minutes should return to normal levels.
The caries activity test Cariostat®4, developed by Shimono, is used to measure the decrease of pH caused by bacterial action in the plaque. It has been reported positive correlations between caries activity test score and the counts of SM and LB.
Not only can determine whether establishing new carious lesions, but also diagnose active or chronic lesions present (Nishimura et al., 1988; Lara-Carrillo et al., 2010b).
4 Cariostat® (Dentsply-Sankin KK, Tokyo, Japan)
Munshi et al. (1999) reported a Cariostat® sensitivity of 96.7% and a specificity of 93.3%.
The procedure of Cariostat® is by changing color as a result of increased production of acids produced by fermentation of bacteria, is very sensitive and its relevance lies in its ability to predict the presence of caries in the future (Munshi et al., 1999).
It contains a high concentration of sucrose tryptose growth inhibitor of Gram-negative bacteria, with two types of indicators (green bromocresol and purple) to reveal visually the pH decrease in dental plaque (Ansai et al., 1994; Kornman, 2005; Nishimura et al., 1988a, 2008b).
A pH range of 4.0 ± 3 is considered high risk or marked caries activity.
Plaque is collected from buccal surfaces of first upper molars, using a sterilized cotton swab supplied in the kit, which was put into a test medium and incubated 48 hours at 37° C. The test color change is compared with the pattern provided by the manufacturer as follows:
Blue negative value = pH 5.8-7.2
Yellow greenish two positives value = pH 4.8 + 0.3
Yellow three positives value = pH < 4.4 (Fig. 11).
Fig. 11. Caries activity test Cariostat®. 3.5 Occult blood in saliva
The use of saliva for periodontal diagnosis has been subject to several investigations, which have been proposed for disease markers including proteins, cells, hormones, volatile components, ions, bacteria and bacterial products, among others.
It has become the leukocytes counts, in these salivary markers as an indicator of periodontal disease, since most of the salivary leukocytes entering to the oral cavity through the crevicular fluid when exist gingival inflammation, but these cells vary from person to person and even in one person can change during the day (Kaufman & Lamster, 2000).
Actually exists another colorimetric salivary test used as indicator at inflammation which involves determining occult blood derived from the gingival tissue for evaluates periodontal disease in initial stages, called Salivaster®5 (Hashimoto et al., 2006; Niwa, & Fukuda, 1989).
The Salivaster® is a colorimetric test based on a catalytic reaction of hemoglobin in saliva inducing the formation of different colors ranging from yellow to dark green. The principle of the color reaction is similar to the test for blood in urine, but was developed for the particular viscosity of saliva (Fig. 12).
Fig. 12. Initial indicator of periodontal disease through occult blood in saliva (Salivaster®)
It is reported that this method has a sensitivity of 75.9% and a specificity of 90.5% for the detection of gingival inflammation (Kaufman & Lamster, 2000).
The procedure involves dipping the test paper in stimulated saliva for 2-3 seconds and then judging by comparing to the standard color change chart, divided into 3 levels:
Yellow 0.0 mg of blood per dL of saliva (no periodontal disease)
Llight blue 1.0 mg/dL (incipient periodontal disease)
Dark blue 2.5 mg/dL (periodontal disease present).
5 Salivaster ® (Showa Yakuhin Kako Co. LTD, Tokyo, Japan)
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