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Background The objective of this study was to evaluate and present evidence from animal and human clinical studies on associations between dental caries and systemic diseases, and to suggest potential mechanisms that might explain such associations. Methods An electronic search was conducted of PubMed, Embase and Cochrane Central Register of Controlled Trials for articles published from 2010 to 2020 in the English language. From the initial search, 404 full-text studies were assessed for eligibility. After excluding studies for technical and study limitations, a total of 67 studies were included in the summary tables and additional studies were included in the review to support evidence. Results Few systemic disease and conditions were found to be clinically meaningfully associated with caries experience. Best evidence from human and animal studies described association between metabolic diseases and dental caries. Several interesting animal studies were noted that could generate clinical hypotheses and further investigations in rodent models for cardiovascular injury and hyperglycemia. Inadequate data was found to suggest any modifications to current clinical practice or prevention guidelines. Conclusions Limited clinical evidence was found connecting several systemic diseases and dental caries. Inadequate data was found to suggest any modifications to current clinical practice or prevention guidelines. Clinical significance Understanding of associations between dental caries and systemic diseases play a crucial role in the treatment planning and education of the dental patient.

The interaction between human salivary alpha-amylase (HSAmy) and amylase-binding oral streptococci (ABS) helps determine the bacteria that colonize the oral cavity by establishing dental biofilms. Streptococci are important pioneer species of the oral cavity and influence oral health as well as common diseases such as dental caries. Various oral streptococcal species express distinct amylase-binding proteins, among which amylase-binding protein A (AbpA), encoded by the abpA gene in Streptococcus gordonii and several other species, which is the most extensively studied. Amylase binding facilitates microbial adhesion to host surfaces and biofilm formation and enables bacteria to harness the host’s amylase enzymatic activity at their cell surface, enhancing their capacity to metabolize dietary starch for nutritional gain. Additionally, amylase binding may also influence bacterial cell division and stress tolerance by engaging novel bacterial signaling pathways. From an evolutionary perspective, both Neanderthals and modern humans exhibit functional adaptations in nutrient metabolism, including selection for salivary amylase-binding oral streptococci, highlighting the importance of microbial co-adaptation in response to host diet. Further research is warranted to elucidate the broader roles of amylase binding to bacteria in host-bacterial signaling, bacterial cell division and fitness and the evolutionary trajectory of the oral microbiome.

Background and Objective: The oral microbiome plays an important role in oral health and disease, including periodontitis, which affects about 40% of the adult population in the United States. Bacterial pathogens have been well studied and documented in their relationship with periodontitis; however, the role of fungi in periodontitis is still unclear. The purpose of this study is to determine the relationship of specific fungal species with periodontal pathogenic bacteria in healthy, mild periodontitis, and severe periodontitis patients. Methods: In this study, human participants were recruited, and saliva samples were collected. Twelve participants representing periodontal health (n = 2), mild periodontitis (n = 3), and severe periodontitis (n = 7) were included. Salivary samples were sequenced for analysis of their mycobiome (ITS sequencing) and microbiome (16s RNA sequencing). Results: A total of 375 species of bacteria and 39 species of fungi were identified among all samples. Clustering was observed for bacteria in healthy and mild periodontitis, but more variability was observed in the severe periodontal disease group. Variability was observed for fungi among all samples and groups. Red complex bacteria were negatively correlated with Candida species for the disease groups, although the correlation was not statistically significant. A significant correlation was observed between red-complex bacteria in the severe periodontal disease group. Additionally, a significant correlation was observed among Candida species in all groups. Conclusions: This pilot study simultaneously processed saliva samples for microbiome and mycobiome sequencing and found a trend towards negative correlation between Candida species and red complex bacteria.

Background Successful commensal bacteria have evolved to maintain colonization in challenging environments. The oral viridans streptococci are pioneer colonizers of dental plaque biofilm. Some of these bacteria have adapted to life in the oral cavity by binding salivary α-amylase, which hydrolyzes dietary starch, thus providing a source of nutrition. Oral streptococcal species bind α-amylase by expressing a variety of amylase-binding proteins (ABPs). Here we determine the genotypic basis of amylase binding where proteins of diverse size and function share a common phenotype. Results ABPs were detected in culture supernatants of 27 of 59 strains representing 13 oral Streptococcus species screened using the amylase-ligand binding assay. N-terminal sequences from ABPs of diverse size were obtained from 18 strains representing six oral streptococcal species. Genome sequencing and BLAST searches using N-terminal sequences, protein size, and key words identified the gene associated with each ABP. Among the sequenced ABPs, 14 matched amylase-binding protein A (AbpA), 6 matched amylase-binding protein B (AbpB), and 11 unique ABPs were identified as peptidoglycan-binding, glutamine ABC-type transporter, hypothetical, or choline-binding proteins. Alignment and phylogenetic analyses performed to ascertain evolutionary relationships revealed that ABPs cluster into at least six distinct, unrelated families (AbpA, AbpB, and four novel ABPs) with no phylogenetic evidence that one group evolved from another, and no single ancestral gene found within each group. AbpA-like sequences can be divided into five subgroups based on the N-terminal sequences. Comparative genomics focusing on the abpA gene locus provides evidence of horizontal gene transfer. Conclusion The acquisition of an ABP by oral streptococci provides an interesting example of adaptive evolution.

[This corrects the article DOI: 10.1371/journal.pone.0172647.].

ABSTRACTVeillonella species are known to contribute to the formation of early oral biofilms and tend to be prevalent in people with poor oral hygiene status. Here, we report the draft genome sequences of 4 oral Veillonella strains that were established recently as novel species.

We report a case of localized aggressive periodontitis (LAP), which occurred during fixed orthodontic treatment in a 16-year-old African-American female patient. Oral hygiene instruction, removal of orthodontic bands and nonsurgical periodontal therapy were followed by surgical treatment of multiple sites using calcium sulfate as a synthetic bone graft material and collagen membrane as a barrier to achieve guided tissue regeneration. One-year follow-up of the case demonstrated that use of calcium sulfate as a synthetic bone substitute may provide favorable outcome in LAP patients. Furthermore, LAP patients undergoing orthodontic treatment can be managed successfully without tooth morbidity.

A dramatic presentation of a large ulcer on the dorsal tongue of a recently hospitalized patient is presented. The lesion was found to be nosocomial in origin, and consistent with traumatic ulcerative granuloma with stromal eosinophilia (TUGSE). A review of the current pathogenic mechanisms, differential diagnosis and management of TUGSE is included.

Foreign materials in tissue sections are common findings in routine Oral and Maxillofacial Pathology practice. Most foreign materials in tissue sections in this study were localized to sites where biomaterials had been placed previously for therapeutic purposes. These foreign particles were easily identified under light microscopy on hematoxylin & eosin (H&E) stained, 5 m thick sections of fixed, paraffin embedded tissue as a reliable diagnostic modality for localizing foreign materials. It is also possible in some cases to localize but not accurately identify these particles based on pattern recognition gained over years of experience. Improved methodology is required for accurate and reliable foreign matter diagnosis, a complicated process because of the vast number of potential foreign bodies that can find their way into oral tissues. In addition, the list of available biomaterials is increasing rapidly with the advancing field of materials science. This study evaluated Fourier Transform Infrared (FTIR) spectroscopy as a diagnostic tool for characterizing foreign materials in oral and maxillofacial biopsies. A pilot study first compared spectral and visual similarities/differences between unstained (both paraffinized and non-paraffinized) and stained (hematoxylin and eosin) 5 m thick sections. Although close spectral resemblance was found between de-paraffinized, unstained sections and de-paraffinized, H&E stained sections, there was greater visual advantage in using de-paraffinized, H&E stained sections. New sections prepared for experimentation in this study were 5 m thick, hematoxylin and eosin stained and mounted on special silver coated (low-e) glass slides. The light microscope function of the FTIR microspectroscope unit was utilized to localize the foreign material of interest. Thereafter, each case was FTIR analyzed for covalently bonded material compositions by obtaining three spectra (background, sample and ratio) from an average of 100 spectra, using an analytical area of 100 m x 100 m. FTIR spectra were analyzed using IR energy ranging from 600/700-4000 cm-1 in transmission mode. Secondary analysis by Energy Dispersive X-Ray Spectroscopy (EDS) was employed to obtain elemental information and was used in conjunction with the FTIR spectra to arrive at additional conclusions regarding foreign material chemistry. Six selected cases were evaluated in greater detail, supplemented by additional literature review. These foreign materials were identified: 1) Canal sealing material, most consistent with commercial product AH 26; 2) Consistent with polysulfone-based impression material; 3) Oxidized iron fragments; 4) Oxidized endodontic silver point; 5) Obturant material with Bi and Ba compounds as filler particles and 6) Chromic acid tanned catgut suture material. FTIR spectral and EDS analyses provided unique chemical information about material composition, not available by light microscopic evaluation only. These results provide convincing evidence that applications of these techniques can be cost effective, time efficient, diagnostically specific and technically feasible.