Salivary cystatin S levels in children with early childhood caries in comparison with caries-free children; statistical analysis and machine learning.

BACKGROUND: Early childhood caries is the most common infectious disease in childhood, with a high prevalence in developing countries. The assessment of the variables that influence early childhood caries as well as its pathophysiology leads to improved control of this disease. Cystatin S, as one of the salivary proteins, has an essential role in pellicle formation, tooth re-mineralization, and protection. The present study aims to assess salivary cystatin S levels and demographic data in early childhood caries in comparison with caries-free ones using statistical analysis and machine learning methods. METHODS: A cross-sectional, case-control study was undertaken on 20 cases of early childhood caries and 20 caries-free children as a control. Unstimulated whole saliva samples were collected by suction. Cystatin S concentrations in samples were determined using human cystatin S ELISA kit. The checklist was collected from participants about demographic characteristics, oral health status, and dietary habits by interviewing parents. Regression and receiver operating characteristic (ROC) curve analysis were done to evaluate the potential role of cystatin S salivary level and demographic using statistical analysis and machine learning. RESULTS: The mean value of salivary cystatin S concentration in the early childhood caries group was 191.55 ± 81.90 (ng/ml) and in the caries-free group was 370.06 ± 128.87 (ng/ml). T-test analysis showed a statistically significant difference between early childhood caries and caries-free groups in salivary cystatin S levels (p = 0.032). Investigation of the area under the curve (AUC) and accuracy of the ROC curve revealed that the logistic regression model based on salivary cystatin S levels and birth weight had the most and acceptable potential for discriminating of early childhood caries from caries-free controls. Furthermore, using salivary cystatin S levels enhanced the capability of machine learning methods to differentiate early childhood caries from caries-free controls. CONCLUSION: Salivary cystatin S levels in caries-free children were higher than the children with early childhood caries. Results of the present study suggest that considering clinical examination, demographic and socioeconomic factors, along with the salivary cystatin S levels, could be usefull for early diagnosis ofearly childhood caries in high-risk children; furthermore, cystatin S is a protective factor against dental caries.

Comparison of salivary nitric oxide and oral health in diabetic patients with and without xerostomia.

BACKGROUND AND OBJECTIVE: Diabetes mellitus (DM) is a chronic multi-systemic metabolic disorder; diabetic patients are more prone to xerostomia and oral health problems than others. There are evidences that nitric oxide (NO) plays an important role in healthy salivary gland function, prevention of insulin resistance and progression of diabetes mellitus. The aim of this study was to compare the salivary NO level between type 2 diabetic (T2DM) patients with and without xerostomia. METHODS: In this case control study, 70 patients with T2DM, which were matched according to age, sex, type of disease control, were enrolled conveniently. The subjects based on abeslang test were allocated to the two groups; 35 patients with xerostomia and 35 patients without xerostomia. Unstimulated whole saliva was collected by spitting method. NO levels was measured by ELISA method using Griess reaction. Data was analyzed using t-test, ANOVA and logistic regression analysis to examine the association of salivary NO and xerostomia. RESULTS: The mean and standard deviation of salivary NO in the diabetic subjects with xerostomia was significantly lower than diabetic subjects without xerostomia (138 ± 94.58 µmol/L vs. 356.61 ± 302.81 µmol/L (P-value = 0.001). In logistic regression analysis, salivary NO level was associated with 0.994 fold decreased risk of xerostomia in diabetic subjects after adjustment for age, gender, FBS and HbA1c. CONCLUSIONS: The present study indicates salivary nitric oxide level was a predictor of xerostomia in diabetic patients. More longitudinal studies are necessary to understand the association of salivary NO level with diabetes-induced xerostomia.

Histopathological Evaluation of Primary Teeth after Pulp Capping with Calcium-Enriched Mixture and Bioactive Glass.

Introduction: Direct pulp capping (DPC) is a conservative vital pulp therapy, which has some limitations in primary dentition. The aim of this study was to evaluate pulpal response of primary teeth after DPC with two biocompatible materials naming calcium-enriched mixture (CEM) and bioactive glass (BAG). Methods and Materials: This study was designed as a randomized clinical trial. After obtaining informed consent, 20 sound primary canines scheduled for orthodontic extraction, were selected. Following mechanical pulp exposure, the exposed site was capped with either CEM cement or BAG and then restored with amalgam. Teeth were extracted after two months and examined histopathologically. Parameters of hard tissue bridge (HTB) formation, its type and pulpal inflammation scores, were compared between the two groups. Data were analysed using the Fisher's exact test. Results: All CEM specimens showed inflammation scores of 0 (less than 10%). In the BAG group, inflammation scores of 0, 1 and 2 were observed in 7, 2 and 1 specimens, respectively. Fisher's exact test showed no significant differences (P>0.05). All CEM specimens (100%) formed HTB, which was irregular in all cases. In 7 of 10 teeth in BAG, HTB formed and was irregular. Fisher's exact test revealed no significant differences between the two groups in this regard (P<0.001). Conclusion: Both CEM and BAG are suitable DPC agents in terms of HTB formation and pulp inflammation scores.