Study group
This longitudinal study was performed as follow up of randomized control study previously presented by Dolic and al [29].The study population consisted of 96 pregnant women who were between 20 and 42 years old (average age 27, 4 years) at the start of the study. They lived in different socio-economic areas of the city of Banja Luka, Bosnia and Herzegovina. They were recruited at Pregnancy counseling center at Public Hospital Banja Luka. Among the 213 pregnant women who were initially eligible, 96 fulfilled the inclusion criteria and were included in the study. The study included only pregnant women a) who were in last trimester of a normal, single fetus pregnancy, b) who didn’t have high-risk pregnancies, C) who didn’t have previous medical conditions, pregnancy complications, or pregnancy-related issues that required hospitalization, d) who did not have any chronic disease, e) who had not taken antibiotics or other drugs during pregnancy, f) who gave their written consent to participate in research.
The follow-up study was initiated 4 years later and the mother and their children (from that pregnancy) were re-examined by the same examiner, using the same procedure as that followed at baseline. The follow-up sample included 80 pairs of mother-child (83, 33 % recall rate), with 16 participants dropout- 10 did not want to participate in the follow up study and 6 had moved from the area.
In Banja Luka, pregnant women and children up to the age of 15 have access to free and regular dental care at public dental clinics. At baseline and follow-up the women were given detailed written and verbal information about the outline of the study, and they signed an informed consent for themselves and their children. During the study period, the participants were not informed about any result and they received regular dental care. All the participants were residents in areas with low natural fluoride content in the drinking water supply (<0.30 mg/l).
The research has been conducted in full accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards and ethical approval for the study was obtained from The Research Committee of Faculty of Medicine, University of Banja Luka.
Clinical examination
The study consisted of five steps: a questionnaire, interview, clinical examination, saliva sampling, and assess of caries risk using the Cariogram. The questionnaire contained questions about: general health and medication, diet and oral hygiene habits including tooth brushing frequency and the use of fluoride.
All examinations were performed by one trained and calibrated examiner in the morning, between the meals and at least one hour after a meal and after teeth brushing. A plane mirror, WHO-CPI probe and air syringe were used in the clinical visual–tactile examination following WHO criteria [26]. Clearly visible lesions with cavities on tooth surfaces were classified as dental caries (i.e.d3-level cavities), whereas changes in transparency, initial enamel demineralization with intact surfaces and no cavitation were noted as intact teeth. The teeth were not professionally cleaned and no radiographs were taken. Caries prevalence was registered at the Decayed-Missed-Filled-Teeth (DMFT) level. The oral hygiene and oral biofilm amount were estimated using a mirror and periodontal probe in accordance with the Sillness and Löe plaque index.
Saliva sampling consisted of: measurement of the saliva secretion rate, measurements of saliva buffer capacity using a Dentobuff® Strip test, measurements of mutans streptococci in the saliva using a Dentocult® SM Strip mutans test and measurements of lactobacilli in the saliva using a Dentocult® LB test according to the manual of the manufacturer. Paraffin-stimulated whole saliva was collected for 5 minutes and the secretion rate was expressed as ml/min. Buffer capacity was categorized as high, medium or low. The density of colonies (Streptococcus mutans and Lactobacillus) was compared with a chart provided by the manufacturer (Orion Diagnostica, Finland).
Data for the computerized caries risk assessment were entered into the Cariogram to obtain an individual caries risk profile. The following five Cariogram categories were used: “very high risk” = 0-20% chance to avoid caries; “high risk” = 21-40% chance to avoid caries; “moderate risk” = 41-60% chance to avoid caries; “low risk” = 61-80% chance to avoid caries; and “very low risk” =81-100% chance to avoid caries.
The patient and the patient’s ordinary dental team were not informed about calculated Cariogram risk category. The patient's regular dental team was responsible for preventive and restorative dental care during the entire study period.
Statistical methods
All data were processed with the SPSS software (version 16.0, Chicago Ill., USA). χ2 test of contingency was used to compare the difference between groups. Parametric ANOVA and Student's test for independent samples (if the difference variance observed characteristics were not statistically significant) and nonparametric Mann-Whitney test (if the difference in the variance of the observed characteristics statistically significant) were used to compare the mean values of the characteristics. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated from two-by-two tables. P values less than 0.05 were considered as statistically significant.