Thaís Manzano Parisotto

Relationship among microbiological composition and presence of dental plaque, sugar exposure, social factors and different stages of early childhood caries

OBJECTIVE This cross-sectional study aimed to investigate the relationship among microbiological composition of dental plaque, sugar exposure and social factors, as well as the presence of visible plaque in preschoolers with different stages of early childhood caries. DESIGN A total of 169 children were clinically examined according to the World Health Organisation criteria + early caries lesions and were divided into three groups: caries-free (n=53), early caries lesions-ECL (n=56), and cavitated caries lesions-CCL (n=60). The presence of clinically visible dental plaque on maxillary incisors was recorded. After that, dental plaque from all buccal and lingual smooth surfaces was collected and the number of colony-forming units of mutans streptococci and total microorganism, as well as the presence of lactobacilli was determined. Daily frequency of meals containing sugar was assessed by a diet chart whereas social factors were evaluated by a questionnaire. The data were analysed by chi-square test followed by multiple logistic regressions (alpha=0.05, confidence interval=95%). RESULTS High levels of mutans streptococci (OR=2.28), high total sugar exposure (OR=5.45) and presence of dental plaque (OR=2.60) showed significant association with ECL (p<0.05). High total microorganism count (OR=5.18), high solid sugar exposure (OR=2.50) and the presence of lactobacilli (OR=24.99) revealed significant association with CCL (p<0.05). CONCLUSIONS These results support the conclusion that dietary sugar experience influenced the microbiological composition of dental plaque. Moreover, the early stage of caries is highly affected by mutans streptococci and visible dental plaque on maxillary incisors whereas cavities are strongly related to lactobacilli and total microorganism.

Immunological and Microbiologic Changes during Caries Development in Young Children

We explored the association between caries development, colonization with caries-associated microflora, and immunity as children begin the transition to mixed dentition. Forty children received dental examinations at 3–4 years of age, repeated a year later. Children were grouped into caries-free (n = 23; CF) and caries-active (n = 17; CA ≧3 new lesions on follow-up). Salivary IgA and IgA antibody to Streptococcus mutans virulence epitopes were measured by Luminex assay. Mutans streptococci (MS), lactobacilli and total microorganisms were enumerated on selective media from plaque samples. There was no significant difference in baseline levels of MS or lactobacilli between CF and CA groups. However, both MS and lactobacilli levels were higher at follow-up in the CA group. Furthermore, children with detectable lactobacilli at baseline had significantly higher caries risk. Salivary IgA concentrations increased significantly in both groups during the study. Both CF and CA groups also displayed significant increases in salivary IgA antibody levels to glucosyltransferase, glucan-binding protein (Gbp) and antigen I/II salivary binding region. CF antibody levels to seven peptides associated with domains of biological importance increased at follow-up, in contrast to increases to only three peptides in CA saliva samples. Multivariate modeling showed that a lower baseline level of salivary IgA anti-GbpB was associated with higher caries risk. These data indicate that MS and lactobacilli are associated with caries in this population, that the secretory immune system is undergoing significant maturation during this period, and that the breadth of mucosal IgA response to epitopes of S. mutans virulence components may influence the degree to which these cariogenic microorganisms can cause disease.

Can insoluble polysaccharide concentration in dental plaque, sugar exposure and cariogenic microorganisms predict early childhood caries? A follow-up study

BACKGROUND Insoluble polysaccharide (IP) has been associated with caries prevalence in young children. However, the power of IP to predict ECC needs to be demonstrated. AIMS To assess the relationships between early childhood caries (ECC) and extracellular insoluble polysaccharides (IP) in dental plaque, sugar exposure and cariogenic microorganisms. DESIGN Visible plaque on maxillary incisors was recorded, followed by caries diagnosis in 65 preschoolers (3-4 years) at baseline and after 1 year. Plaque was collected for mutans streptococci (MS), total microorganism (TM) and lactobacilli (LB) enumerations in selective media, as well as for IP analysis, which was later assessed by colorimetry. Sugar/sucrose exposure was assessed by a diet chart. RESULTS Positive correlations were found among the prevalence of caries and MS, TM, LB, solid sucrose and visible dental plaque. Additionally, children with IP concentrations in dental plaque higher than 2.36 μg/mg (odds ratio-OR=6.8), with visible plaque on maxillary incisors (OR=4.3), harbouring LB (OR=13) and exposed to solid sugar more than twice/day (OR=5) showed higher risk of developing caries (p<0.05). CONCLUSION Extracellular insoluble polysaccharides, solid sugar/sucrose, visible dental plaque and cariogenic microorganisms could predict caries development, partially explaining the ECC pattern.

Assessment of cavitated and active non-cavitated caries lesions in 3- to 4-year-old preschool children: a field study.

BACKGROUND The prevalence of early childhood caries (ECC) is high in developing countries; thus, sensitive methods for the early diagnosis of ECC are of prime importance to implement the appropriate preventive measures. AIM To investigate the effects of the addition of early caries lesions (ECL) into WHO threshold caries detection methods on the prevalence of caries in primary teeth and the epidemiological profile of the studied population. DESIGN In total, 351 3- to 4-year-old preschoolers participated in this cross-sectional study. Clinical exams were conducted by one calibrated examiner using WHO and WHO + ECL criteria. During the exams, a mirror, a ball-ended probe, gauze, and an artificial light were used. The data were analysed by Wilcoxon and Mc-Nemars tests (α=0.05). RESULTS Good intra-examiner Kappa values at tooth/surface levels were obtained for WHO and WHO+ECL criteria (0.93/0.87 and 0.75/0.78, respectively). The dmfs scores were significantly higher (P<0.05) when WHO+ECL criteria were used. ECLs were the predominant caries lesions in the majority of teeth. CONCLUSIONS The results strongly suggest that the WHO+ECL diagnosis method could be used to identify ECL in young children under field conditions, increasing the prevalence and classification of caries activity and providing valuable information for the early establishment of preventive measures.

Relationship between the IgA antibody response against Streptococcus mutans GbpB and severity of dental caries in childhood.

OBJECTIVE Explore the associations between the severity of dental caries in childhood, mutans streptococci (MS) levels and IgA antibody response against Streptococcus mutans GbpB. Moreover, other caries-related etiological factors were also investigated. DESIGN 36-60 month-old children were grouped into Caries-Free (CF, n=19), Early Childhood Caries (ECC, n=17) and Severe Early Childhood Caries (S-ECC, n=21). Data from socio-economic-cultural status, oral hygiene habits and dietary patterns were obtained from a questionnaire and a food-frequency diary filled out by parents. Saliva was collected from children for microbiological analysis and detection of salivary IgA antibody reactive with S. mutans GbpB in western blot. RESULTS S-ECC children had reduced family income compared to those with ECC and CF. There was difference between CF and caries groups (ECC and S-ECC) in MS counts. Positive correlations between salivary IgA antibody response against GbpB and MS counts were found when the entire population was evaluated. When children with high MS counts were compared, S-ECC group showed significantly lower IgA antibody levels to GbpB compared to CF group. This finding was not observed for the ECC group. CONCLUSIONS This study suggests that children with S-ECC have reduced salivary IgA immune responses to S. mutans GbpB, potentially compromising their ability to modify MS infection and its cariogenic potential. Furthermore, a reduced family income and high levels of MS were also associated with S-ECC.

Dental caries and related factors in Brazilian children from fluoridated and non-fluoridated areas

Purpose: To compare the caries prevalence, saliva buffering capacity (SBC), oral hygiene (OH), dietary habits, family income (FI) and frequency of visits to a dental office (Do) between Brazilian children living in areas with and without fluoridated public water supply. Methods: Forty-six 5-7-year-old preschoolers were selected in Itatiba, SP, Brazil; 19 were from a fluoridated area, and 27 were from a non-fluoridated area. The caries index was determined according to the World Health Organization criteria, and the SBC was assessed by titration with hydrochloric acid. The FI, frequency of OH and visits to Do were estimated by questionnaire. The dietary habits were assessed with a diet chart. The differences between the groups were analyzed with Mann-Whitney-U tests (α=0.05). Results: Children from the non-fluoridated area showed significantly higher dmft/DMFT than those from the fluoridated area, but they showed significantly lower SBC, OH frequency and FI. No significant differences were observed between the areas for dietary habits and visits to Do. Conclusion: Children from fluoridated areas showed higher salivary buffering capacity, family income and oral hygiene frequency as well as lower caries prevalence, supporting the beneficial effect of fluoride in the tap water for caries prevention.

Relationship among α amylase and carbonic anhydrase VI in saliva, visible biofilm, and early childhood caries: a longitudinal study

AIM This longitudinal study investigated the relationship among early childhood caries (ECC), α amylase, carbonic anhydrase VI (CA VI), and the presence of visible biofilm, besides detecting if these variables could predict risk for ECC. DESIGN One hundred children were divided into two groups: caries group (n = 45) and caries-free group (n = 55). Visible biofilm on maxillary incisors was recorded, followed by caries diagnosis in preschoolers at baseline and at follow-up. Saliva samples were collected, and activities of CA VI and α amylase were determined. Data normality was assessed by Shapiro-Wilk test and then Mann-Whitney, Spearman correlation, and chi-square tests followed by multiple logistic regression analysis (α = 0.05, 95% confidence interval). RESULTS CA VI activity was significantly higher in saliva of children with caries (P ≤ 0.05), and α amylase activity was significantly higher in saliva of caries-free children (P < 0.0001). Children with α amylase activity in saliva lower than 122.8 U/mL (OR = 3.33 P = 0.042) and visible biofilm on maxillary incisors (OR = 3.6 P = 0.009) were more likely to develop ECC than caries-free children. A negative correlation between caries and α amylase activity was found (P = 0.0008). CONCLUSIONS The presence of visible biofilm and low salivary activity of α amylase may be considered risk predictors for ECC.

CO2 laser and fluoride on the inhibition of root caries—an in vitro microbial model

An increase in the dental caries prevalence on root surfaces has been observed mainly in elderly. This research assessed, in vitro, the effectiveness of a pulsed CO2 (λ = 10.6 μm) laser associated or not with fluoride, in reducing human root dentine demineralization in conditions that mimic an oral high cariogenic challenge. After sterilization, root dentine specimens were randomly assigned into 6 groups (n = 30), in triplicate. The groups were Control (C), Streptococcus mutans (SM), Fluoride (F), Laser (L), Fluoride + laser (FL), and Laser + fluoride (LF). Except for the control group, all the specimens were inoculated with SM and immersed 3 times a day in a 40% sucrose bath. After a 7-day cariogenic challenge, the mineral loss and lesion depth were evaluated by transverse microradiography and fluoride in the biofilm was determined using an ion-selective electrode. Results were statistically analyzed by analysis of variance, at 5% of significance level. For groups C, SM, F, L, FL and LF, the means (standard-deviation) of mineral loss were 816.3 (552.5)a, 3291.5 (1476.2)c, 2508.5 (1240.5)bc, 2916.2 (1323.7)c, 1839.7 (815.2)b and 1955.0 (1001.4)b, respectively; while lesion depths were 39.6 (22.8)a, 103.1 (38.9)c, 90.3 (44.6)bc, 91.7 (27.0)bc, 73.3 (26.6)b, 75.1 (35.2)b, respectively (different superscript letters indicate significant differences among groups). In conclusion, irradiation of root dentine with a pulsed CO2 laser at fluency of 12.0 J/cm2 was able to inhibit root surface demineralization only when associated with fluoride. No synergy effect on the inhibition of root dentine mineral loss was provided by the combination of fluoride application and laser irradiation.

In vitro study of the effect of a pulsed 10.6μm CO 2 laser and fluoride on the reduction of carious lesions progression in bovine root dentin

The aim of the present study was to evaluate the combined in vitro effects a pulsed 10.6 μm CO2 laser and fluoride on the reduction of carious lesion progression in root dentin. Sixty five slabs of previously demineralized bovine root dentin were assigned into five groups (n=13): control (no treatment), acidulated phosphate fluoride gel 1.23% (FFA), CO2 Laser (L), FFA+L, L+FFA. The lasered groups were irradiated with 4.0J/cm2. After a 7 day pH cycling regime, the knoop hardness number (KHN) was determined by cross-sectional microhardness testing (5g, 5s, 10-60 μm, 10 μm interval). The data was analyzed by ANOVA and Students t-test (α= 0.05). A significant interaction between KHN and the indentation depths was found (p<0.05). At 10-20 μm, FFA+L (KHN:12.12±0.95/13.07±1.03) and FFA (KHN:12.86±4.54/12.60±3.93) inhibited caries progression when compared to control group (KHN:8.76±0.95/9.50±1.03) (p<0.05), but did not differ with neither each other nor from group L (p>0.05). At 30 μm, the KHN was significantly higher than the control only in the FFA group (KHN:15.35±1.16). At 40 μm, the groups FFA (KHN: 15.87±3.76), L (KHN: 15.57±5.71) and L+FFA (KHN:15.50±5.08) were capable of significantly inhibiting caries progression, however they did not differ each other (p>0.05). At depths of 50-60 μm, only group L (KHN:17.05±1.29/18.26±1.30) differed statistically from the control (KHN:13.43±1.24/13.81±1.25), but not from the other groups. In conclusion, CO2 laser alone was able to inhibit caries progression in the deepest layers. However, no synergistic effect was obtained when CO2 laser irradiation and FFA application and were combined.