OBJECTIVES: In this study, the effect of the Piper betle L. extract towards S. mutans (with/without sucrose) using scanning electron microscopy (SEM) and on partially purified cell-associated glucosyltransferase activity were determined.

MATERIAL AND METHODS: S. mutans were allowed to adhere to glass beads suspended in 6 different Brain Heart Infusion broths [without sucrose; with sucrose; without sucrose containing the extract (2 mg mL(-1) and 4 mg mL(-1)); with sucrose containing the extract (2 mg mL(-1) and 4 mg mL(-1))]. Positive control was 0.12% chlorhexidine. The glass beads were later processed for SEM viewing. Cell surface area and appearance and, cell population of S. mutans adhering to the glass beads were determined upon viewing using the SEM. The glucosyltransferase activity (with/without extract) was also determined. One- and two-way ANOVA were used accordingly.

RESULTS: It was found that sucrose increased adherence and cell surface area of S. mutans (p<0.001). S. mutans adhering to 100 µm² glass surfaces (with/without sucrose) exhibited reduced cell surface area, fluffy extracellular appearance and cell population in the presence of the Piper betle L. leaves extract. It was also found that the extract inhibited glucosyltransferase activity and its inhibition at 2.5 mg mL(-1) corresponded to that of 0.12% chlorhexidine. At 4 mg mL(-1) of the extract, the glucosyltransferase activity was undetectable and despite that, bacterial cells still demonstrated adherence capacity.

METHODS: The cross-sectional study was conducted from January to May 2016 in seven schools of Bhakkar district in the Punjab province of Pakistan, and comprised of school children aged 11-12 years. Diet diaries were used to assess the frequency of sugar intake while caries was assessed using the Modified International Caries Detection and Assessment System. Bivariate analysis was used to assess the association of sugar consumption and early carious lesion with selected sociodemographic variables, and regression analysis was performed to evaluate the factor that matters most in caries occurrence.

RESULTS: Of the 226 subjects, 115(51%) had early carious lesion. Mean frequency of sugar intake was 5.2±3.2 times per day. Children who consumed sugar between main meals (p=0.01) and within two hours before bedtime (p=0.04) had significantly higher history of having caries. Cariogenic intake before bedtime was significantly associated with overall caries risk (p=0.02).

MATERIALS AND METHODS: In this experimental study, female ICR mice (6-8 weeks old) were superovulated and cohabited with fertile males for 24 hours. Afterwards, their ovi- ducts were excised and embryos harvested. Embryos at the 2-cell stage were catego- rized as EC embryos, while zygotes with two pronuclei were categorized as LC embryos. Embryos were cultured in M16 medium supplemented with 3% bovine serum albumin (BSA) in a humidified 5% CO2atmosphere. Control embryos were cultured until the blastocyst stage without vitrification. Experimental embryos at the 2-cell stage were vitri- fied for one hour using 40% v/v ethylene glycol, 18% w/v Ficoll-70 and 0.5 M sucrose as the cryoprotectant. We recorded the numbers of surviving embryos from the control and experimental groups and their development until the blastocyst stage. Results were analyzed using the chi-square test.

RESULTS: A significantly higher proportion of EC embryos (96.7%) from the control group developed to the blastocyst stage compared with LC embryos (57.5%, P<0.0001). Similarly, in the experimental group, a significantly higher percentage of vitrified EC embryos (69.4%) reached the blastocyst stage compared to vitrified LC embryos (27.1%, P<0.0001).