Dental plaque microbiota sequence counts for microbial profiling and resistance genes detection.

Shotgun metagenomics sequencing experiments are finding a wide range of applications. Nonetheless, there are still limited guidelines regarding the number of sequences needed to acquire meaningful information for taxonomic profiling and antimicrobial resistance gene (ARG) identification. In this study, we explored this issue in the context of oral microbiota by sequencing with a very high number of sequences (~ 100 million), four human plaque samples, and one microbial community standard and by evaluating the performance of microbial identification and ARGs detection through a downsampling procedure. When investigating the impact of a decreasing number of sequences on quantitative taxonomic profiling in the microbial community standard datasets, we found some discrepancies in the identified microbial species and their abundances when compared to the expected ones. Such differences were consistent throughout downsampling, suggesting their link to taxonomic profiling methods limitations. Overall, results showed that the number of sequences has a great impact on metagenomic samples at the qualitative (i.e., presence/absence) level in terms of loss of information, especially in experiments having less than 40 million reads, whereas abundance estimation was minimally affected, with only slight variations observed in low-abundance species. The presence of ARGs was also assessed: a total of 133 ARGs were identified. Notably, 23% of them inconsistently resulted as present or absent across downsampling datasets of the same sample. Moreover, over half of ARGs were lost in datasets having less than 20 million reads. This study highlights the importance of carefully considering sequencing aspects and suggests some guidelines for designing shotgun metagenomics experiments with the final goal of maximizing oral microbiome analyses. Our findings suggest varying optimized sequence numbers according to different study aims: 40 million for microbiota profiling, 50 million for low-abundance species detection, and 20 million for ARG identification. KEY POINTS: • Forty million sequences are a cost-efficient solution for microbiota profiling • Fifty million sequences allow low-abundance species detection • Twenty million sequences are recommended for ARG identification.

A Randomized, Parallel Design Study to Evaluate the Effects of Different Oral Cleaning Modalities on Gingivitis and Plaque After a 6-Week Period of Home Use.

The study objective was to evaluate the effect of different interdental oral cleaning modalities on gingivitis and plaque following a 6-week period of home use. This was a randomized, parallel, examiner-blinded study. Study subjects were routine manual toothbrush (MTB) users with moderate to severe gingivitis, aged 18 to 65 years. Subjects were required to have a gingival bleeding score of ≥1 on at least 50 gingival sites per the Gingival Bleeding Index (GBI) and to have a minimum average plaque score of ≥0.6 per the Rustogi Modified Navy Plaque Index (RMNPI) following a 3- to 6-hour plaque accumulation period. Subjects were randomly assigned to one of four groups based on the oral care cleaning modality: (1) NON group: MTB alone, (2) FLS group: MTB plus string floss, (3) MPF group: MTB plus a Philips® Sonicare® Power Flosser with the Quad Stream nozzle, or (4) PPF group: Philips Sonicare power toothbrush plus the power flosser. Safety and efficacy measures (Modified Gingival Index [MGI], GBI, and RMNPI) were assessed at baseline, 2 weeks, and 6 weeks. The primary efficacy endpoint was the reduction in gingival inflammation from baseline to week 6 as measured by the MGI. A total of 260 subjects were randomized and 256 subjects completed the study. The adjusted mean percent reduction in gingival inflammation from baseline to week 6 was 14.90% for the NON group, 13.16% for the FLS group, 33.51% for the MPF group, and 49.30% for the PPF group. Pairwise comparisons indicated that both the PPF and MPF groups were statistically significantly different from both the NON and FLS groups. In conclusion, use of either the Philips Sonicare power toothbrush with the Philips Sonicare Power Flosser or an MTB with the Philips Sonicare Power Flosser was statistically superior to an MTB alone and an MTB used with string floss in reducing gingival inflammation following 6 weeks of home use.

A Randomized, Parallel Design Study to Compare the Effects of Two Different Interdental Cleaning Modalities on Gingivitis and Plaque After a 4-Week Period of Home Use.

The study objective was to evaluate the effect of two different interdental oral cleaning modalities on gingivitis and plaque following a 4-week period of home use. This was a randomized, parallel, single-blinded study. Subjects were routine manual toothbrush (MTB) users with moderate to severe gingivitis, aged 18 to 65 years. Subjects were required at baseline to have a gingival bleeding score of ≥1 on at least 50 gingival sites per the Gingival Bleeding Index (GBI) and to have an overall plaque score of ≥0.6 per the Rustogi Modified Navy Plaque Index (RMNPI) following a 3- to 6-hour plaque accumulation period. Subjects were randomly assigned to one of three groups based on the oral care cleaning modalities: (1) NON group: MTB alone, (2) IDB group: MTB plus an interdental brush, or (3) MPF group: MTB plus a Philips® Sonicare® Power Flosser with the Quad Stream nozzle. All subjects used the MTB with fluoride toothpaste. Efficacy measures (Modified Gingival Index [MGI], GBI, and RMNPI) and safety were assessed at baseline, 2 weeks, and 4 weeks. The primary efficacy endpoint was the reduction in gingival inflammation from baseline to week 4 as measured by the MGI. A total of 189 subjects were randomized and 186 completed the study. The adjusted mean percent reduction in gingival inflammation from baseline to week 4 was 2.80% for the NON group, 11.32% for the IDB group, and 20.87% for the MPF group. The differences between the MPF group and the NON and IDB groups were statistically significant (.0001). In conclusion, use of the MTB with the Philips Sonicare Power Flosser showed statistically significant benefits compared to an MTB alone and an MTB used with an interdental brush in reducing gingival inflammation following 4 weeks of home use.

A Randomized, Parallel Design Study to Compare the Effects of Different Interdental Cleaning Modalities on Gingivitis and Plaque After a 6-Week Period of Home Use.

The objective of this study was to evaluate the effect of different interdental oral cleaning modalities on gingivitis and plaque following a 6-week period of home use. This was a randomized, four-arm, parallel design clinical trial. Study subjects were manual toothbrush (MTB) users with moderate to severe gingivitis, aged 18 to 65 years. Subjects were required at baseline to have a gingival bleeding score of ≥1 on at least 50 gingival sites per the Gingival Bleeding Index (GBI) and to have an overall plaque score of ≥0.6 per the Rustogi Modified Navy Plaque Index (RMNPI) following a 3- to 6-hour plaque accumulation period. Subjects were randomly assigned to use one of four oral care cleaning modalities: (1) NON group: MTB alone, (2) FLS group: MTB plus string floss, (3) IDB group: MTB plus an interdental brush, or (4) CPF group: MTB plus the Philips® Sonicare® Cordless Power Flosser with the Quad Stream nozzle. Efficacy measures (Modified Gingival Index [MGI], GBI, and RMNPI) and safety were assessed at baseline, 2 weeks, and 6 weeks. The primary efficacy endpoint was the reduction in gingival inflammation from baseline to week 6 as measured by the MGI. Of the 372 subjects randomized in the study, 364 completed a post-baseline MGI evaluation and were included in the analyses. The adjusted mean percent reduction in gingival inflammation from baseline to week 6 was -2.10% for the NON group, 2.82% for the FLS group, 2.60% for the IDB group, and 29.10% for the CPF group. Pairwise comparisons indicated that the CPF group was statistically significantly different from the NON, FLS, and IDB groups (.0001). In conclusion, adjunctive use of the Philips Sonicare Cordless Power Flosser with the Quad Stream nozzle and an MTB showed statistically better results in term of reducing gingival inflammation following 6 weeks of home use when compared to an MTB alone, an MTB used with string floss, and an MTB used with an interdental brush.

Quantitative analysis of the effects of brushing, flossing, and mouthrinsing on supragingival and subgingival plaque microbiota: 12-week clinical trial.

BACKGROUND: Translational microbiome research using next-generation DNA sequencing is challenging due to the semi-qualitative nature of relative abundance data. A novel method for quantitative analysis was applied in this 12-week clinical trial to understand the mechanical vs. chemotherapeutic actions of brushing, flossing, and mouthrinsing against the supragingival dental plaque microbiome. Enumeration of viable bacteria using vPCR was also applied on supragingival plaque for validation and on subgingival plaque to evaluate interventional effects below the gingival margin. METHODS: Subjects with gingivitis were enrolled in a single center, examiner-blind, virtually supervised, parallel group controlled clinical trial. Subjects with gingivitis were randomized into brushing only (B); brushing and flossing (BF); brushing and rinsing with Listerine® Cool Mint® Antiseptic (BA); brushing and rinsing with Listerine® Cool Mint® Zero (BZ); or brushing, flossing, and rinsing with Listerine® Cool Mint® Zero (BFZ). All subjects brushed twice daily for 1 min with a sodium monofluorophosphate toothpaste and a soft-bristled toothbrush. Subjects who flossed used unflavored waxed dental floss once daily. Subjects assigned to mouthrinses rinsed twice daily. Plaque specimens were collected at the baseline visit and after 4 and 12 weeks of intervention. Bacterial cell number quantification was achieved by adding reference amounts of DNA controls to plaque samples prior to DNA extraction, followed by shallow shotgun metagenome sequencing. RESULTS: 286 subjects completed the trial. The metagenomic data for supragingival plaque showed significant reductions in Shannon-Weaver diversity, species richness, and total and categorical bacterial abundances (commensal, gingivitis, and malodor) after 4 and 12 weeks for the BA, BZ, and BFZ groups compared to the B group, while no significant differences were observed between the B and BF groups. Supragingival plaque vPCR further validated these results, and subgingival plaque vPCR demonstrated significant efficacy for the BFZ intervention only. CONCLUSIONS: This publication reports on a successful application of a quantitative method of microbiome analysis in a clinical trial demonstrating the sustained and superior efficacy of essential oil mouthrinses at controlling dental plaque compared to mechanical methods. The quantitative microbiological data in this trial also reinforce the safety and mechanism of action of EO mouthrinses against plaque microbial ecology and highlights the importance of elevating EO mouthrinsing as an integral part of an oral hygiene regimen. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov on 31/10/2022. The registration number is NCT05600231.

Quantitative analysis of the effects of essential oil mouthrinses on clinical plaque microbiome: a parallel-group, randomized trial.

BACKGROUND: The rich diversity of microorganisms in the oral cavity plays an important role in the maintenance of oral health and development of detrimental oral health conditions. Beyond commonly used qualitative microbiome metrics, such as relative proportions or diversity, both the species-level identification and quantification of bacteria are key to understanding clinical disease associations. This study reports the first-time application of an absolute quantitative microbiome analysis using spiked DNA standards and shotgun metagenome sequencing to assess the efficacy and safety of product intervention on dental plaque microbiome. METHODS: In this parallel-group, randomized clinical trial, essential oil mouthrinses, including LISTERINE® Cool Mint Antiseptic (LCM), an alcohol-containing prototype mouthrinse (ACPM), and an alcohol-free prototype mouthrinse (AFPM), were compared against a hydroalcohol control rinse on clinical parameters and the oral microbiome of subjects with moderate gingivitis. To enable a sensitive and clinically meaningful measure of bacterial abundances, species were categorized according to their associations with oral conditions based on published literature and quantified using known amounts of spiked DNA standards. RESULTS: Multivariate analysis showed that both LCM and ACPM shifted the dysbiotic microbiome composition of subjects with gingivitis to a healthier state after 4 weeks of twice-daily use, resembling the composition of subjects with clinically healthy oral conditions recruited for observational reference comparison at baseline. The essential oil-containing mouthrinses evaluated in this study showed statistically significant reductions in clinical gingivitis and plaque measurements when compared to the hydroalcohol control rinse after 6 weeks of use. CONCLUSIONS: By establishing a novel quantitative method for microbiome analysis, this study sheds light on the mechanisms of LCM mouthrinse efficacy on oral microbial ecology, demonstrating that repeated usage non-selectively resets a gingivitis-like oral microbiome toward that of a healthy oral cavity. TRIAL REGISTRATION: The trial was registered on ClinicalTrials.gov on 10/06/2021. The registration number is NCT04921371.

A preliminary study on calcifying nanoparticles in dental plaque: Isolation, characterization, and potential mineralization mechanism.

OBJECTIVES: Calcifying nanoparticles (CNPs), referred to as nanobacteria (NB), are recognized to be associated with ectopic calcification. This study aims to isolate and culture CNPs from the dental plaque of patients with periodontal disease and investigate their possible role in unravelling the aetiology of periodontal disease. MATERIAL AND METHODS: Supragingival and subgingival plaques were sampled from 30 periodontitis patients for CNPs isolation and culture. Alkaline phosphatase (ALP) content changes were tracked over time. Positive samples underwent thorough morphological identification via hematoxylin and eosin (HE) staining, Alizarin red S (ARS), and transmission electron microscopy (TEM). The chemical composition of CNPs analysis involved calcium (Ca) and phosphorus (P) content determination, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). RESULTS: The subgingival plaque dental group exhibited a higher CNPs isolation rate at 36.67% (11/30) compared to the supragingival dental plaque group at 66.67% (20/30). ALP activity varied among the positive, negative and control groups. Morphological observation characterized the CNPs as round, oval, and ellipsoid particles with Ca deposits. Chemical analysis revealed the Ca/P ratio was 0.6753. Hydroxyl, methyl, carbonate, phosphate, hydrogen phosphate, and dihydrogen phosphate were detected by FTIR; the main chemical components detected by XRD were hydroxyapatite and tricalcium phosphate. CONCLUSION: CNPs were found in periodontitis-related dental plaque and exhibited the potential to develop calcified structures resembling dental calculus. However, the potential involvement of ALP in CNPs formation requires deeper exploration, as does the precise nature of its role and the interrelation with periodontitis demand a further comprehensive investigation.

Comparative characterization of supragingival plaque microbiomes in malocclusion adult female patients undergoing orthodontic treatment with removable aligners or fixed appliances: a descriptive cross-sectional study.

Objectives: This study aimed to explore the effects of removable aligners and fixed appliances on the supragingival bacterial communities in adult female patients undergoing orthodontic treatment. Methods: Supragingival plaque samples from 48 female individuals underwent microbiome analysis (16S rRNA gene sequencing) using PacBio Sequel sequencing. The study included 13 adults without orthodontic treatment needs as the control group (Group C), and 35 patients with comparable initial orthodontic conditions who received treatment at a university clinic in Beijing, China. The treatment involved either traditional fixed brackets (Group B, n = 17) or Invisalign® aligners (Group AT, n = 18). Bioinformatics methods were used for data analysis. Results: From the 48 plaque samples, a total of 334,961 valid reads were obtained, averaging 6,978 sequences per sample. The 16S rDNA sequences were classified into 25,727 amplicon sequence variants (ASVs). Significant variances in alpha and beta diversity among the groups were noted. Group B microbiome exhibited an increased presence of Gram-negative bacteria. At the phylum level, Actinobacteriota was significantly more prevalent in Group C samples, while Bacteroidota was enriched in Group B samples. Family-level relative abundance analysis showed a notable increase in Saccharibacteria (formerly TM7) and Prevotellaceae in Group B. Genus-level analysis revealed a significant rise in Lautropia in Group AT. Fixed orthodontic appliances were linked to oral microbiome changes, notably an enhanced relative abundance of anaerobes, including periodontal pathogens. Conclusion: The observation points to the impact of orthodontic appliance on the oral microbial community, highlighting the difference between traditional braces (Group B) and clear aligners (Group AT)in terms of the predominance of anaerobic and gram negative bacteria. This emphasizes the importance of considering the microbiological effects when choosing orthodontic appliance and underscores the need for tailored oral hygiene practices for individuals undergoing these treatments. This research might provide insights that could assist in the development of innovative cleaning techniques and antibacterial materials.

Efficacy of a mouthwash containing ε-poly-L-lysine, funme peptides and domiphen in reducing halitosis and supragingival plaque: a randomized clinical trial.

OBJECTIVE: To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the efficacy of a BOP® mouthwash supplemented with this combination in reducing halitosis and supragingival plaque in a clinical trial. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compound against Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were determined by the gradient dilution method. Subsequently, the CCK-8 assay was used to detect the toxicity of mouthwash on human gingival fibroblastst, and the effectiveness in reducing halitosis and supragingival plaque of the mouthwash supplemented with the combination was analyzed by a randomized, double-blind, parallel-controlled clinical trial. RESULTS: The combination exhibited significant inhibitory effects on tested oral pathogens with the MIC < 1.56% (v/v) and the MBC < 3.13% (v/v), and the mouthwash containing this combination did not inhibit the viability of human gingival fibroblasts at the test concentrations. The clinical trial showed that the test group displayed notably lower volatile sulfur compounds (VSCs) at 0, 10, 24 h, and 7 d post-mouthwash (P < 0.05), compared with the baseline. After 7 days, the VSC levels of the and control groups were reduced by 50.27% and 32.12%, respectively, and notably cutting severe halitosis by 57.03% in the test group. Additionally, the Plaque Index (PLI) of the test and control group decreased by 54.55% and 8.38%, respectively, and there was a significant difference in PLI between the two groups after 7 days (P < 0.01). CONCLUSIONS: The combination of ε-PL, FP and domiphen demonstrated potent inhibitory and bactericidal effects against the tested oral pathogens, and the newly formulated mouthwash added with the combination exhibited anti-dental plaque and anti-halitosis properties in a clinical trial and was safe. TRIAL REGISTRATION: The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2300073816, Date: 21/07/2023).

Oral health in youth with visual impairment: A longitudinal survey.

This longitudinal survey aims to demonstrate improvement in oral hygiene among a group of youth with visual impairment (VI) achieved by repeated oral hygiene training, compare their progress with healthy peers (CG) and assess their oral health knowledge. In 100 VI (55♀, 45♂; ± 17.8 years) and 45 CG (23♀, 22♂; ± 17.2 years) oral hygiene training and a Quigley-Hein Plaque Index (QHI) rating were repeated six times at three-month intervals. The VI were divided into four subgroups according to the toothbrush hardness/type. A questionnaire was given to both groups. Appropriate statistical analyses were performed at 5% significance level. Both groups showed reduction in QHI, the VI had overall higher QHI values than CG. Use of an electric toothbrush in VI led to lower QHI in the last examination (p < 0.03). 69% of participants recommended dental specialists to improve communications by acquiring more illustrative aids. VI changed toothbrush less often (p < 0.02). A higher incidence of dental plaque was confirmed in VI compared to CG. After education and individual training, gradual plaque reduction has occurred in both groups. Using an electric toothbrush in VI resulted in better QHI outcomes. Repetitive preventive intervention in youth with VI helped them to adopt healthier oral hygiene habits.

Clinical Effect of Thioglycosides Extracted from White Mustard on Dental Plaque and Gingivitis: Randomized, Single-Blinded Clinical Trial.

The antibacterial and anti-inflammatory effect of thioglycosides has already been established. This study investigates the effects of thioglycosides extracted from white mustard, specifically the "Bamberka" variety, in the context of oral hygiene. The aim of the study is to clarify an evidence-based link between the documented antibacterial and anti-inflammatory effects attributed to thioglycosides and their practical application in oral care. A randomized, single-blinded (patient-blinded) clinical study was performed on 66 patients using mustard-based toothpaste for oral hygiene. The patients were examined at baseline and after 6 and 12 months. The values of the Approximal Plaque Index (API), the Plaque Index (PI), and Bleeding on probing (BOP) were taken into consideration. The results show a significant reduction in plaque accumulation, especially after 6 months of using mustard-based toothpaste in all examined parameters. This suggests that thioglycosides from mustard contribute to a considerable decrease in dental plaque accumulation, confirming their potential in natural oral care solutions, which is indicated in the main conclusions or interpretations.

Real-Time PCR Method as Diagnostic Tool for Detection of Periodontal Pathogens in Patients with Periodontitis.

The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study was the development of a real-time PCR test as a diagnostic tool for the detection and differentiation of five periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola, in patients with periodontitis. We compared the results of our in-house method with the micro-IDent® semiquantitative commercially available test based on the PCR hybridization method. DNA was isolated from subgingival plaque samples taken from 50 patients and then analyzed by both methods. Comparing the results of the two methods, they show a specificity of 100% for all bacteria. The sensitivity for A. actinomycetemcomitans was 97.5%, for P. gingivalis 96.88%, and for P. intermedia 95.24%. The sensitivity for Tannerella forsythia and T. denticola was 100%. The Spearman correlation factor of two different measurements was 0.976 for A. actinomycetemcomitans, 0.967 for P. gingivalis, 0.949 for P. intermedia, 0.966 for Tannerella forsythia, and 0.917 for T. denticola. In conclusion, the in-house real-time PCR method developed in our laboratory can provide information about relative amount of five bacterial species present in subgingival plaque in patients with periodontitis. It is likely that such a test could be used in dental diagnostics in assessing the efficacy of any treatment to reduce the bacterial burden.

Evaluation of dental plaque reduction using microcurrent-emitting toothbrushes in orthodontic patients: a randomized, double-blind, crossover clinical trial.

This study aimed to compare the effectiveness of microcurrent-emitting toothbrushes (MCTs) and ordinary toothbrushes in reducing the dental plaque index (PI) and dental caries activity among orthodontic patients. The evaluation was performed using a crossover study design involving 22 orthodontic patients randomly assigned to the MCT or ordinary toothbrush groups. The participants used the designated toothbrush for 4 weeks and had a 1-week wash-out time before crossover to the other toothbrush. PI (Attin's index) and dental caries activity were measured at baseline and at the end of each 4-week period. Additionally, patients completed questionnaires to assess patient satisfaction for "freshness in mouth" and "cleansing degree." The results showed that the MCT group had a significant reduction in PI (p = 0.009), whereas the ordinary toothbrush group did not (p = 0.595). There was no significant difference in the dental caries activity between the two groups (p > 0.05). Patient satisfaction assessment revealed that 65% patients in the MCT group had more than "fair" experience of freshness, in contrast to 50% of patients in the ordinary toothbrush group. Satisfaction with cleansing degree was similar in both groups. Overall, these findings suggest that MCTs are more effective in reducing dental PI than ordinary toothbrushes.

Characterization and functional prediction of the dental plaque microbiome in patients with alveolar clefts.

Introduction: Alveolar cleft (AC) is a common congenital defect in people with cleft lip and palate (CLP). Alveolar bone grafting (ABG) is typically performed during adolescence, resulting in the fissure remaining in the mouth for a longer length of time. Patients with AC have a greater rate of oral diseases such as dental caries than the normal population, and the precise characteristics of the bacterial alterations caused by AC are unknown. Methods: We recruited a total of 87 subjects and collected dental plaque samples from AC adolescents (AAP), post-operative ABG adolescents (PAP), healthy control adolescents (CAP), AC young adults (AYP), post-operative ABG young adults (PYP), and healthy control young adults (CYP). The sequencing of 16S rRNA genes was performed. Results: The microbial composition of plaque from alveolar cleft patients differed significantly from age-matched healthy controls. Linear discriminant analysis effect size (LEfSe) analysis revealed that AAP was enriched for Neisseria, Haemophilus, Fusobacterium, Rhodococcus, Aggregatibacter, Gemella, and Porphyromonas, whereas AYP was enriched for Capnocytophaga, Rhodococcus, and Actinomyces-f0332. There were phenotypic differences in facultatively anaerobic, Gram-negative, Gram-positive, and oxidative stress tolerance between the AYP group with longer alveolar cleft and the healthy control group according to Bugbase phenotypic predictions. Alveolar bone grafting did not alter the functional phenotype of alveolar cleft patients but reduced the number of differential genera between alveolar cleft patients and healthy controls at both ages. Conclusions: Our study systematically characterized the supragingival plaque microbiota of alveolar cleft patients, post-alveolar bone grafting patients, and matched healthy controls in two ages to gain a better understanding of plaque ecology and microbiology associated with alveolar clefts.

Comparative analysis of microbial composition and functional characteristics in dental plaque and saliva of oral cancer patients.

BACKGROUND: The oral cavity is home to various ecological niches, each with its own unique microbial composition. Understanding the microbial communities and gene composition in different ecological niches within the oral cavity of oral cancer (OC) patients is crucial for determining how these microbial populations contribute to disease progression. METHODS: In this study, saliva and dental plaque samples were collected from patients with OC. Metagenomic sequencing was employed to analyze the microbial community classification and functional composition of the different sample groups. RESULTS: The results of the study revealed significant differences in both the function and classification of microbial communities between saliva and dental plaque samples. The diversity of microbial species in saliva was found to be higher compared to  that in plaque samples. Notably, Actinobacteria were enriched in the dental plaque of OC patients. Furthermore, the study identified several inter-group differential marker species, including Prevotella intermedia, Haemophilus parahaemolyticus, Actinomyces radius, Corynebacterium matruchitii, and Veillonella atypica. Additionally, 1,353 differential genes were annotated into 23 functional pathways. Interestingly, a significant correlation was observed between differentially labeled species and Herpes simplex virus 1 (HSV-1) infection, which may be related to the occurrence and development of cancer. CONCLUSIONS: Significant differences in the microbial and genetic composition of saliva and dental plaque samples were observed in OC patients. Furthermore, pathogenic bacteria associated with oral diseases were predominantly enriched in saliva. The identification of inter-group differential biomarkers and pathways provide insights into the relationship between oral microbiota and the occurrence and development of OC.

[Characteristics of caries-related oral microorganisms in early childhood caries].

PURPOSE: To study the structural characteristics of oral microorganisms in children with caries by 16S rRNA high-throughput sequencing technology. METHODS: Thirty healthy children aged 3-5 years were enrolled as subjects. According to the index of dmfs, they were divided into caries-free (CF) group (15) and early childhood caries (ECC) group(15). To compare the differences in bacterial community structure, samples of saliva and dental plaque were collected, and high-throughput sequencing was conducted using the Illumina Miseq sequencing platform. Bioinformatics analysis was used to analyze the difference of microbial community structure and diversity with SPSS 23.0 software package. RESULTS: Microbial diversity in ECC group was significantly lower than CF group. At phylum level, Actinobateria was more abundant in saliva samples of ECC group, while Firmicutes was more abundant in plaque samples of CF group. At genus level, the abundance of Lautropia of CF group was higher in saliva samples while Cardiobacterium, Gemella and Granulicatella were abundant in plaque samples. The abundance of Rothia of ECC group was higher in saliva samples and Corynebacterium was abundant of ECC group in plaque samples. CONCLUSIONS: There are significant differences in the species and composition of microbial community in saliva and plaque of children with or without caries. Specific microorganisms are related to the occurrence of ECC, and screening specific microorganisms is helpful for early prediction and prevention of ECC.

The effect of individuals' oral hygiene habits and knowledge levels on peri-implant health and disease: a questionnaire-based observational study.

BACKGROUND: Peri-implant disease and health are associated with microbial dental plaque. Therefore, oral hygiene plays a role in preventing and treating these diseases. This study aimed to determine the relationships among knowledge of peri-implant status, oral hygiene habits, and peri-implant disease and health. METHODS: A total of 144 implants in nonsmokers with controlled systemic disease were included in the study. Peri-implant disease and the conditions of the implants were determined with periodontal indices and radiographs based on the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions and The EFP S3 level clinical practice guideline. Individuals were asked 66 questions regarding demographic information, oral hygiene habits and history, and knowledge of peri-implant diseases. One-way ANOVA was used to compare the three peri-implant disease and condition categories. RESULTS: There was a significant difference between groups regarding toothpaste type (p < 0.05). Gum protection toothpaste was greater in the peri-implant health group. Patients' use of interdental products was very low; often, no products were used for implant prosthesis. There was no significant difference among the groups regarding oral hygiene product use or oral hygiene habits (p > 0.05). There was a significant difference between groups regarding frequency of visit (p < 0.05). The frequency of visits to the dentist for pain was greater for individuals with peri-implantitis. There is a significant difference between the groups' answers for the causative and initiating factors of peri-implant disease (p < 0.05). The peri-implant health group answered that microbial dental plaque is the most crucial initiating factor of peri-implant diseases, and bleeding on probing is the most critical determinant of peri-implant diseases at a higher rate than the other groups. CONCLUSIONS: Patients' oral hygiene habits and knowledge levels are almost similar according to peri-implant status. Knowledge does not reflect a patient's oral hygiene behavior. Clinicians should ensure that individuals' oral hygiene practices align with their increased awareness regarding peri-implant illnesses.

The application of phenylboronic acid pinacol ester functionalized ROS-responsive multifunctional nanoparticles in the treatment of Periodontitis.

Periodontitis is an inflammatory disease induced by the complex interactions between the host immune system and the microbiota of dental plaque. Oxidative stress and the inflammatory microenvironment resulting from periodontitis are among the primary factors contributing to the progression of the disease. Additionally, the presence of dental plaque microbiota plays a significant role in affecting the condition. Consequently, treatment strategies for periodontitis should be multi-faceted. In this study, a reactive oxygen species (ROS)-responsive drug delivery system was developed by structurally modifying hyaluronic acid (HA) with phenylboronic acid pinacol ester (PBAP). Curcumin (CUR) was encapsulated in this drug delivery system to form curcumin-loaded nanoparticles (HA@CUR NPs). The release results indicate that CUR can be rapidly released in a ROS environment to reach the concentration required for treatment. In terms of uptake, HA can effectively enhance cellular uptake of NPs because it specifically recognizes CD44 expressed by normal cells. Moreover, HA@CUR NPs not only retained the antimicrobial efficacy of CUR, but also exhibited more pronounced anti-inflammatory and anti-oxidative stress functions both in vivo and in vitro. This provides a good potential drug delivery system for the treatment of periodontitis, and could offer valuable insights for dental therapeutics targeting periodontal diseases.

The effectiveness of water jet flossing and interdental flossing for oral hygiene in orthodontic patients with fixed appliances: a randomized clinical trial.

BACKGROUND: Orthodontic treatment presents challenges with plaque accumulation around brackets, archwires, and elastics, leading to retained plaque and gingival inflammation. Conventional toothbrushing may not be enough, requiring additional oral hygiene aids like interproximal brushes, dental flosses, and water flossers. Limited research exists on comparing water flossing and interdental flossing in orthodontic patients. Therefore, this study aims to assess their effectiveness in maintaining oral hygiene during active orthodontic treatment. METHODS: A single-blind, randomized, parallel clinical study recruited orthodontic patients with full-mouth brackets and archwires. Thirty participants were randomly assigned to either water jet flossing or interdental flossing groups. All participants were instructed to brush twice daily with a provided toothbrush and toothpaste and use the assigned intervention once daily at night. Clinical measures, including the Gingival Bleeding Index (BI), Plaque Index (PI), and Gingival Index (GI), were recorded at baseline and day 14. Descriptive statistics and statistical tests were performed using SPSS software. RESULTS: The water jet flossing group demonstrated a slightly higher, albeit non-significant, benefit in plaque removal (median difference of 6.79%%, P = 0.279) and bleeding reduction (median difference of 5.21%%, P = 0.172) compared to the interdental flossing group after two weeks. Both groups showed significant reductions in gingival bleeding index and plaque index from baseline to the 2-week follow-up. The interdental flossing group had median mean percentage differences of 16.13%% (plaque index) and 23.57% (gingival bleeding index), while the water jet flossing group had median percentage differences of 21.87% (plaque index) and 32.29% (gingival bleeding index). No significant changes in gingival index grades were observed in either group. CONCLUSION: Both water jet flossing and interdental flossing were effective in reducing plaque accumulation and gingival bleeding among orthodontic patients. While no significant differences were found between the two methods, water jet flossing showed a potential advantage. Further research is needed to validate its effectiveness, assess long-term impact, and understand its benefits for orthodontic patients.

Preventive management of carious lesions: from non-invasive to micro-invasive operative interventions.

Understanding that dental carious lesions occur as a result of the action of micro-organisms in the dental plaque biofilm, where demineralisation on the tooth surface is the first sign of the disease, such incipient lesions can be treated using preventive, non-operative and minimally invasive operative dentistry. If the caries process is left unmanaged, the lesions progress towards cavitation, leading to more invasive treatments. This article discusses the principles of preventive, non-invasive and micro-invasive treatments of early carious lesions, outlining the clinical situations where these therapies can be applied.