MATERIALS AND METHODS: Unstimulated saliva samples were collected from 60 participants, 30 smokers and 30 non-smokers in Kuala Lumpur and Klang Valley, Malaysia. DNA extraction was performed using the Qiagen DNA mini kit, and the 16S rRNA bacterial gene was amplified and sequenced using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and the alpha and beta diversity of the bacterial community was assessed. Significantly differentiated taxa were identified using LEfSe analysis, while differentially expressed pathways were identified using MaAsLin2.

METHODS: We conducted a systematic search on PubMed, Web of Science, and Cinhal databases for literature published until 15 December 2023, to identify studies that have evaluated the oral microbiome with culture-independent next-generation techniques comparing the oral microbiome of tobacco users and non-users. The search followed the PECO format. The outcomes included changes in microbial diversity and abundance of microbial taxa. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS) (PROSPERO ID CRD42022340151).

RESULTS: Out of 2,435 articles screened, 36 articles satisfied the eligibility criteria and were selected for full-text review. Despite differences in design, quality, and population characteristics, most studies reported an increase in bacterial diversity and richness in tobacco users. The most notable bacterial taxa enriched in users were Fusobacteria and Actinobacteria at the phylum level and Streptococcus, Prevotella, and Veillonella at the genus level. At the functional level, more similarities could be noted; amino acid metabolism and xenobiotic biodegradation pathways were increased in tobacco users compared to non-users. Most of the studies were of good quality on the NOS scale.

CONCLUSION: Tobacco smoking influences oral microbial community harmony, and it shows a definitive shift towards a proinflammatory milieu. Heterogeneities were detected due to sampling and other methodological differences, emphasizing the need for greater quality research using standardized methods and reporting.

METHODS: The aim of this paper is to describe informed consent regulations for dental care in a selection of countries, focusing on children and patients with special health care needs. An online survey was shared with a convenience sample of dental professionals from 13 countries. The information was explored and the processes of consent were compared.

RESULTS: Findings suggest that there are variations in terms of informed consent for medical practice. In Tanzania, South Africa, India, Kenya, Malaysia and Brazil age is the determining factor for competence and the ability to give self-consent. In other countries, other factors are considered alongside age. For example, in Singapore, the United Kingdom, and the United States the principle of Gillick Competence is applied. Many countries' laws and regulations do not specify when a dentist may overrule general consent to act in the "best interest" of the patient.

METHODS: A total of 16 probiotic toothpastes and 6 probiotic mouthrinses, available on the European and American markets, were analysed for the number of culturable (CFU; agar plating), live (viability qPCR), and total bacteria (qPCR), and if they indeed contain the probiotic species proclaimed (16S rRNA sequencing). The products with viable probiotics were further evaluated for their impact on an in vitro oral biofilm model. Additionally, culturable probiotic isolates from these products were tested for potential inhibitory effects against individual oral pathogens.

RESULTS: Not all of the examined products contained viable bacteria; instead, they contained ferments or inactivated probiotics. Only 2 toothpastes were found to contain culturable bacteria consistent with the probiotic species declared on their labels. Additionally, traces of DNA from actual probiotics were detected in 68% of the toothpastes and 50% of the mouthrinses. Furthermore, the tested products did not show any beneficial effect on an in vitro oral biofilm model. Similarly, the culturable probiotic isolates recovered from the products showed no inhibitory activity against selected oral pathogens.