OBJECTIVES: This review aimed to systematically evaluate the published literature and summarise the available evidence about the impact of vitamin D deficiency (VDD) on the oral diseases mentioned above.

METHODS: PubMed, Web of Science, Scopus and ScienceDirect databases were used. The search terms included were vitamin D, caries, periodontitis, and oral cancer. All papers published between January 2017 and November 2022 were included. The PRISMA process was used for the screening and selection studies.

RESULTS: Initially, 3001 studies were identified. However, after evaluating 46 full-text articles that explored the link between VDD and caries, periodontitis, and oral cancer, only 32 studies met the inclusion criteria for this systematic review. Among these, 15 studies focused on caries, 16 on periodontitis, and only one on oral cancer. Regarding study quality and risk of bias, 25 out of the 32 studies were deemed to have low risk. A total of 12 studies on periodontitis showed the impact of VDD.

METHODS: Literature search on PubMed, Medline, and science direct databases was carried out for in vitro studies published in English from 1990 to 2016, and the reported outcomes of minimum inhibitory concentration (MIC), minimum bactericidal concentrations (MBC), zone of inhibition (ZOI) and bacterial count method using colony forming unit (CFU) were used to assess the antibacterial effectiveness of zinc.

RESULTS: Seventeen studies were included in this review. Seven studies reported MIC and MBC. Four studies reported ZOI, and eight studies reported CFU. MIC values using zinc chloride and zinc oxide nanoparticles were ranged from 0.025 to 0.2 mM and 0.390 to 500 ± 306.18 µg/ml respectively. MBC values using zinc oxide nanoparticles have ranged from 3.125 to 500 µg/ml. ZOI ranged from no inhibition zone to 21 ± 1.4 mm using 23.1% zinc oxide. A considerable reduction in the bacterial count was reported after adding zinc. However, only two studies have reported no inhibitory effect of zinc.

OBJECTIVE: This study aimed to explore the antibacterial activity of HA synthesized using microwave against two of the most common cariogenic bacteria, Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus).

METHODS: HA was chemically synthesized using a microwave. To verify the existence of the crystalline phase and the calcium and phosphate content, X-ray diffraction (XRD) and energy-dispersive X-ray (EDX) analysis were employed, respectively. Reduction in bacterial growth was used to assess the antibacterial effects of 10 %, 20 %, and 30 % HA against the tested bacteria.

RESULTS: The presence of the hydroxyapatite crystallite phase was verified using XRD, while EDX revealed the Calcium to Phosphorus (Ca/P) ratio to be 1.6. In response to the 10 %, 20 %, and 30 % HA, S. mutans were reduced by 14.5 %, 15.6 %, and 23.4 %, whereas S. sobrinus decreased by 17.1 %, 60.8 %, and 98.6 %, respectively.

MATERIALS AND METHODS: One hundred and twenty primary school children were included. They were divided into caries and caries-free groups. Unstimulated whole saliva was collected from each participant using spitting method. The salivary elements were measured using an Atomic Absorption Spectrophotometer. Descriptive statistics, bivariate and Pearson's correlation analysis were performed.

RESULTS: Salivary Cu and Zn levels were significantly higher in children with dental caries compared to those caries-free (p < 0.05). Moreover, these elements had a positive correlation with dental caries (Cu: r=0.698, p<0.001; Zn: r=0.181, p<0.05). No significant variations in Mn and Fe were observed between caries and caries-free group (p>0.05). Additionally, there were significant differences in salivary Zn and Fe among different age groups (p<0.05) and highly significant differences in salivary Cu, Mn and Fe among different ethnic groups (p<0.001). However, all elements exhibited no significant differences between males and females.

METHODS: A total of 200 YouTube™ videos were selected and screened, and the video characteristics and engagement indicators were recorded. They were then reviewed for consistency with current professional guidelines on this topic. Two independent reviewers scored the videos using a customized 8-point scoring and 5-point Global Quality Scale (GQS) to assess the content information and the overall quality of each video. These videos were further classified into good, moderate, and poor videos. Kruskal-Wallis, Chi-squared, and Spearman's correlation tests were used for the statistical analysis.

RESULTS: 110 videos met the inclusion criteria. The median total content score was 3 (IQR = 4) and the median GQS score was 2 (IQR = 2). Less than half (n = 49; 45.5%) of the videos were uploaded by healthcare professionals. The video content was classified as good (n = 26; 23.64%), moderate (n = 43; 39.09%), and poor (n = 41; 37.27%). Good-quality videos have a significantly higher information content score than the other groups (P = 0.001). A strong correlation was found between the total content score and GQS score (rho = 0.970, P = 0.001). Longer duration, higher interaction index, and recent upload are associated with higher content and quality scores.

METHODS: Antibacterial susceptibility assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were undertaken to evaluate the inhibitory activities of different zinc salts against the tested bacteria. A scanning electron microscope (SEM) was used to evaluate the morphological changes of bacterial cells following exposure to zinc salts. Kruskal-Wallis and Mann-Whitney tests were used to compare the inhibitory effect of the different zinc salts.

RESULTS: All zinc salts tested against S. mutans and S. sobrinus had a statistically and significantly smaller inhibition zone when compared to chlorhexidine, (P  0.05). Zinc chloride, zinc sulfate and zinc acetate demonstrated higher MIC and MBC values against S. mutans compared to S. sobrinus. However, zinc citrate revealed the highest MIC and MBC values of 1 mg/mL and > 8 mg/mL for S. sobrinus and > 8 mg/mL for S. mutans, respectively.

Materials and methods: The antimicrobial effects of vitamin D3 were evaluated against Strep. sobrinus and Strep mutans using the agar disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of vitamin D3 were determined using a microdilution method following the guidelines by the Clinical Laboratory Standards Institute (CLSI). Scanning electron microscope (SEM) was used to evaluate the morphological changes of bacterial cells following exposure to vitamin D3.

Results: Strep. sobrinus was more sensitive to vitamin D3 compared to Strep. mutans bacteria. The MIC values of vitamin D3 against Strep. sobrinus and Strep. mutans were 60 μg/ mL and 250 μg/mL respectively whereas the MBC values were 120 μg/mL and 500 μg/mL, respectively. Moreover, significant changes in the bacterial morphology were observed in treated bacterial cells with vitamin D3 as compared to the untreated control bacteria using SEM.