The Antibacterial Potential of Tannin from Mangosteen pericarp Extract against Lactobacillus casei

Background: Deep dentinal caries cannot defect the vitality of dental pulp. The microbial populations involved in dental caries are known to be highly complex and variable. Lactobacillus casei is one of the most common carious dentine bacteria. Tannin contained in mangosteen pericarp extract is known to have an antibacterial potency. Purpose. This study aims to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration of tannin from mangosteen pericarp extract against Lactobacillus casei. Method. This study is an experimental laboratory with a post-test only control group design. Tannin from mangosteen was extracted by 96% ethanol. Lactobacillus casei was diluted into several concentrations using the serial dilution method in the Brain Heart Infusion Broth (BHIB) medium and inserted in several reaction tubes. Every reaction tube was incubated for 24 hours. After being incubated, each concentration was taken and swabbed into Mueller Hinton in the petri dish. Then, every petri dish was incubated for 24 hours and colonies' growth was counted manually in the Colony Forming Unit (CFU). Result. Bacterial colonies' growth at a concentration of 1.56% was 90% less than the positive control group and there was no bacterial colonies growth at the concentration of 3.12%. Conclusion. Tanin from mangosteen pericarp extract has an antibacterial effect against Lactobacillus casei. The MIC of tannin from mangosteen pericarp extract against Lactobacillus casei was at 1.56% and MBC was at 3.12%.

Chemo-mechanical characterization of carious dentine using Raman microscopy and Knoop microhardness

One of the aims in the clinical operative management of dental carious lesions is to remove selectively the highly infected and structurally denatured dentine tissue, while retaining the deeper, repairable affected and intact, healthy tissues for long-term mechanical strength. The present study examined the correlation of chemical functional groups and the microhardness through the different depths of a carious lesion using Raman spectroscopy and Knoop microhardness testing. The null hypothesis investigated was that there was no correlation between Raman peak ratios (amide I : phosphate ν1 ) and equivalent Knoop microhardness measurements. Ten freshly extracted human permanent teeth with carious dentine lesions were sectioned and examined using high-resolution Raman microscopy. The ratio of absorbency at the amide I and phosphate bands were calculated from 139 scan points through the depth of the lesions and correlated with 139 juxtaposed Knoop microhardness indentations. The results indicated a high correlation ( p < 0.01) between the peak ratio and the equivalent Knoop hardness within carious dentine lesions. This study concluded that Raman spectroscopy can be used as a non-invasive analytical technology for in vitro studies to discriminate the hardness of carious dentine layers using the peak ratio as an alternative to the invasive, mechanical Knoop hardness test.

ANTIBACTERICAL POTENCY OF CALCIUM HYDROXIDE AND PROPOLIS MIXTURE ON MIXED BACTERIA OF CARIOUS DENTIN

Background: Calcium hydroxide has been known as the gold standard of pulp capping process, but still has some weaknesses such as a pH that is too high to be potentially toxic, resistant to certain bacteria, causing necrosis of the pulp, and causing a tunnel defect. This weakness causes researchers to look for alternative ingredients that have antibacterical properties that can be combined with calcium hydroxide. Propolis has antibacterial properties such as flavonoids, tannins, saponins, and terpenoids which can work as the best carrier that allows dissociation of ions from calcium hydroxide so the combination of both that has antibacterial power is expected to have an effective antibacterial potency against the number of bacterial colonization with mixed dentine carious. Aims: This study aims to determine the antibacterial potency produced by a combination of calcium hydroxide and propolis against mixed bacteria of carious dentine. Methods: The research was carried out using 4 treatment groups with each of 7 samples. Group I is a combination of calcium hydroxide and propolis with a ratio of 1: 1, group 2 with a ratio of 1: 1.5, group 3 with a ratio of 1: 2, and a positive control group. Each sample was put into a suspense of mixed bacteria of carious dentine, grown for 24 hours. Suspense is vortexed for 1 minute so the solution becomes homogeneous. Put 0.1 ml of suspended mixed bacteria of dentine carious from BHIB media, grown for 24 hours on MHA media and counted the number of colonies. Results: The highest number of colonies in the positive control group, then group 1, group 2, and the least number of colonies in group 3 with the most extract of propolis. Conclusion: The combination of calcium hydroxide and propolis with a ratio of 1: 2 has the best antibacterial power in inhibiting colonization of mixed bacteria of carious dentine.

Extraction and purification of RNA from human carious dentine: an approach to enable bacterial gene expression studies

Background: RNA isolation from bacteria within dentine caries lesions could be difficult due to reduced amount of collectable biomass and high mRNA instability. Attempting to overcome this challenge we describe one protocol developed to extract and purify total RNA from dentine lesions. Objective: customize a bacterial RNA extraction and purification method from human carious dentine. Methods: quantity and purity of extracted RNA were measured with a microvolume UV-VIS spectrophotometer, RNA integrity was assessed by standard denaturing agarose gel electrophoresis and images were captured under ultraviolet light with camera and analyzed. DNase treatment removed genomic DNA and an additional step of purification was carried out in silica spin column. Results: final yield (ng/μl) was 67.01 ± 22.33, absorbance ratio A260/A280 = 2.0 ± 0.07 and RNA integrity were obtained. The purified samples were reversely transcribed and the expression of atpD and fabM gene from Streptococcus mutans analyzed by quantitative real-time PCR. Conclusion: the extraction methodology developed produced high-quality RNA from dentine microbiota for transcriptional analysis.