The Impact of Smoking on Subgingival Microflora: From Periodontal Health to Disease

Tobacco-enhanced biofilm formation by Porphyromonas gingivalis and other oral microbes

Microbial biofilms promote pathogenesis by disguising antigens, facilitating immune evasion, providing protection against antibiotics and other antimicrobials and, generally, fostering survival and persistence. Environmental fluxes are known to influence biofilm formation and composition, with recent data suggesting that tobacco and tobacco-derived stimuli are particularly important mediators of biofilm initiation and development in vitro and determinants of polymicrobial communities in vivo. The evidence for tobacco-augmented biofilm formation by oral bacteria, tobacco-induced oral dysbiosis, tobacco-resistance strategies, and bacterial physiology is summarized herein. A general overview is provided alongside specific insights gained through studies of the model and archetypal, anaerobic, Gram-negative oral pathobiont, Porphyromonas gingivalis.

Systemic Factors Affecting Prognosis in Periodontics: Part II

This study gives an insight into certain systemic conditions and factors such as nutrition, age, hematological disorders, hypertension, smoking, obesity, and metabolic syndrome that have a notable effect on the periodontium. The review highlights the importance of taking these factors into consideration in periodontal therapy and their impact on the prognosis of periodontal therapies. The other systemic factors are discussed in detail elsewhere in the special issue.

Association of the severity and progression rate of periodontitis with systemic medication intake

Background/purpose

Information on the systemic medication profiles of patients with periodontitis is limited. Therefore, this retrospective cross-sectional study aimed to analyze the relationship between the severity and rate of progression of periodontitis and systemic medication intake using a database of patients who attended the Clinic of Periodontics of the Faculty of Dentistry of the University of Costa Rica.

Methods

Electronic health records of patients diagnosed with periodontitis based on the Classification of Periodontal and Peri-Implant Diseases and Conditions (2017) were evaluated. Individuals were further categorized based on the severity (stage) and rate of progression (grade). Data extracted from the patient records included age, sex, and self-reported medication intake.

Results

In total, 930 records were included. Most of the studied population was middle-aged (36-64 years old); 43.01% were male, and 56.99% were female. Four hundred and fifty-seven patients (49.14%) reported taking at least one systemic medication for a chronic condition. Regarding the periodontal treatment phase, 62.37% underwent steps 1-3, and 37.63% underwent step 4. The most common systemic medications taken were for cardiovascular diseases (42.28%), followed by medications for diabetes (14.46%) and neurologic disorders (14.46%). Most patients (59.35%) were diagnosed with Stage III periodontitis. Grade B (48.28%) was the most prevalent. Calcium channel blockers demonstrated a disease severity-dependent association with the periodontal stage (p = 0.021). In addition, systemic medications for diabetes mellitus were associated with periodontal disease severity and rate of progression (all Ps < 0.05).

Conclusions

This study provides indirect evidence of the association between systemic diseases and periodontitis. The positive association between medications used to treat diabetes and the severity and rate of progression of periodontitis may be due to the underlying disease rather than the medications per se.

Effect of scaling on levels of interleukin 1-beta and clinical periodontal parameters among e-cigarette users and non-smokers: A prospective study

INTRODUCTION

This cohort study aimed to compare the effect of ultrasonic scaling on the expression of IL-1β in the gingival crevicular fluid (GCF) among ENDS users and non-smokers (NS) with gingivitis.

METHODS

Self-reported current electronic nicotine delivery system (ENDS) users and NS with generalized gingivitis were included in this study. All the patients underwent scaling at the baseline visit (T0). Clinical measures, periodontal parameters [probing depth (PD), plaque index (PI), and bleeding on probing (BOP)], and GCF IL-1β were measured at T0, after 1 week (T1) and after 3 weeks (T2). Wilcoxon signed rank test was used to assess the changes in the periodontal measurements and IL-1β levels at different time points and Mann-Whitney U Test was used to compare the two groups.

RESULTS

A total of 38 individuals (18 NS and 20 ENDS users) participated in the study. The PD was significantly higher in ENDS users than in NS at baseline. However, the PI and BOP were similar in all groups at baseline. At T1, the PI was significantly lower for NS than for ENDS users (p=0.045). At T2, there were no significant differences in any of the parameters assessed between the two groups. For ENDS users, BOP was significantly lower at T1 than at baseline. For NS, the BOP at T1 and T2 and the PI at T1 were significantly lower than at baseline. There was no difference in the GCF IL-1β levels in NS and ENDS users at baseline, T1, and T2. At T2, there was a significant reduction in IL-1β (p<0.05) than at baseline in both groups.

CONCLUSIONS

Both ENDS users and NS with gingivitis responded similarly to scaling. GCF IL-1β levels were significantly higher at baseline (p<0.05) compared with their levels at T1 and T2 for both the groups.

CLINICAL TRIAL REGISTRATION

The study was registered on the official website of ClinicalTrials.gov.

IDENTIFIER

ID NCT05745324.

Alcohol and Periodontal Disease: A Narrative Review

The scientific literature dealing with alcohol and alcoholic beverages revealed that these drinks possess an adverse impact on periodontal tissues. Additionally, other principal risk factors include tobacco, smoking, poor oral hygiene, etc. It has been observed that among chronic alcoholics, there are further issues, such as mental, social, and physical effects, that promote alcoholism. These people may have weak immunity for defense against pathogenic organisms and bacteria. Thus, chances of gingival bleeding, swollen gums, bad breath, and increased bone loss are there. Different alcoholic beverages in the market cause less salivation; these beverages contain sugars that promote acid production in the oral cavity by pathogens that demineralize the enamel and damage gum and teeth. This chronic alcohol consumption can progress into different types of oral disorders, including cancer, halitosis, and caries, and is also associated with tobacco and smoking. Chronic alcohol consumption can cause alteration of the oral microbiome and increase oral pathogens, which lead to periodontal disease and an environment of inflammation created in the body due to malnutrition, diminished immunity, altered liver condition, brain damage, and gut microbiota alteration. Heavily colored alcoholic beverages produce staining on teeth and, due to less saliva, may cause other toxic effects on the periodontium. Over-dependency on alcohol leads to necrotizing lesions such as necrotizing gingivitis, necrotizing periodontitis, and necrotizing stomatitis. These pathological impairments instigate severe damage to oral structures. Therefore, proper counseling by the attending dental surgeon and related health professionals is urgently required for the patient on the basis that the individual case needs to go away from the regular heavy consumption of alcohol.

A multi-platform analysis of human gingival crevicular fluid reveals ferroptosis as a relevant regulated cell death mechanism during the clinical progression of periodontitis

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases, yet its association with progressive periodontitis remains unexplored. To investigate the involvement and significance of ferroptosis in periodontitis progression, we assessed sixteen periodontitis-diagnosed patients. Disease progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid (GCF) collection was performed for further analyses. Clinical metrics, proteomic data, in silico methods, and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with ferroptosis. Subsequent western blot analyses validated key findings. Finally, a single-cell RNA sequencing (scRNA-seq) dataset (GSE164241) for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis progression. Periodontitis progression was identified as occurring at a faster rate than traditionally thought. GCF samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic profiles. In addition, specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins, including SNCA, CA1, HBB, SLC4A1, and ANK1 was strongly associated with the clinical progression status of periodontitis. Moreover, we found specific proteins - drivers or suppressors - associated with ferroptosis (SNCA, FTH1, HSPB1, CD44, and GCLC), revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of periodontitis. Additionally, the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to ferroptosis. Our analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients, which offer new insights into the molecular mechanisms of progressive periodontal disease. These findings may lead to novel diagnostic and therapeutic strategies.

Smoking induced salivary microbiome dysbiosis and is correlated with lipid biomarkers

BACKGROUND

The oral microbiome plays an essential role in maintaining oral homeostasis and health; smoking significantly affects it, leading to microbial dysbiosis. The study aims to investigate changes in the oral microbiome composition of smokers in the Qatari population and establish a correlation with lipid biomarkers.

METHODS

The oral microbiota was profiled from saliva samples of 200 smokers and 100 non-smokers in the Qatari population, and 16s rRNA V3-V4 region were sequenced using the Illumina MiSeq platform. The operational taxonomic units (OTUs) were clustered using QIIME and the statistical analysis was performed by R.

RESULTS

Non-smokers exhibited a more diverse microbiome, with significant alpha and beta diversity differences between the non-smoker and smoker groups. Smokers had a higher abundance of Firmicutes, Bacteroidota, Actinobacteriota, Patescibacteria, and Proteobacteria at the phylum level and of Streptococcus, Prevotella, Veillonella, TM7x, and Porphyromonas at the genus level. In contrast, non-smokers had more Bacteroidota, Firmicutes, Proteobacteria, Fusobacteriota, and Patescibacteria at the phylum level, and Prevotella, Streptococcus, Veillonella, Porphromonas, and Neisseria at the genus level. Notably, Streptococcus was significantly positively correlated with LDL and negatively correlated with HDL. Additionally, Streptococcus salivarius, within the genus Streptococcus, was substantially more abundant in smokers.

CONCLUSION

This study highlights the significant influence of smoking on the composition of the oral microbiome by enriching anaerobic microbes and depleting aerobic microbes. Moreover, the observed correlation between Streptococcus abundance and the lipid biomarkers suggests a potential link between smokers-induced salivary microbiome dysbiosis and lipid metabolism. Understanding the impact of smoking on altering the oral microbiome composition and its correlation with chemistry tests is essential for developing targeted interventions and strategies to improve oral health and reduce the risk of diseases.

Oral microbiome dysbiosis among cigarette smokers and smokeless tobacco users compared to non-users

Tobacco use significantly influences the oral microbiome. However, less is known about how different tobacco products specifically impact the oral microbiome over time. To address this knowledge gap, we characterized the oral microbiome of cigarette users, smokeless tobacco users, and non-users over 4 months (four time points). Buccal swab and saliva samples (n = 611) were collected from 85 participants. DNA was extracted from all samples and sequencing was carried out on an Illumina MiSeq, targeting the V3-V4 region of the 16S rRNA gene. Cigarette and smokeless tobacco users had more diverse oral bacterial communities, including a higher relative abundance of Firmicutes and a lower relative abundance of Proteobacteria, when compared to non-users. Non-users had a higher relative abundance of Actinomyces, Granulicatella, Haemophilus, Neisseria, Oribacterium, Prevotella, Pseudomonas, Rothia, and Veillonella in buccal swab samples, compared to tobacco users. While the most abundant bacterial genera were relatively constant over time, some species demonstrated significant shifts in relative abundance between the first and last time points. In addition, some opportunistic pathogens were detected among tobacco users including Neisseria subflava, Bulleidia moorei and Porphyromonas endodontalis. Overall, our results provide a more holistic understanding of the structure of oral bacterial communities in tobacco users compared to non-users.

Biofilm volume and acidification within initial biofilms formed in situ on buccally and palatally exposed bracket material

PURPOSE

Acidification by bacterial biofilms at the bracket/tooth interface is one of the most common problems in fixed orthodontic treatments, which can lead to white spot lesions (WSL) and caries. As lingual brackets were shown to exhibit reduced WSL formation clinically, the aim of this in situ study was to compare initial intraoral biofilm formation and acidification on bracket-like specimens placed buccally and palatally in the upper jaw as a possible cause for this observation.

METHODS

Intraoral biofilm was collected from splints equipped with buccally and palatally exposed test specimens, which were worn by 12 volunteers for a total of 48 h. The test specimens consisted of standard bracket material cylinders on top of a hydroxyapatite disc to represent the bracket/tooth interface. They were analyzed for three-dimensional biofilm volume and live/dead distribution by fluorescence staining and confocal laser scanning microscopy as well as for acidification by fluorescence-based pH ratiometry.

RESULTS

Similar general biofilm morphology with regard to volume and viability could be detected for buccally and palatally exposed specimens. For pH values, biofilms from both positions showed increased acidification at the bottom layer. Interestingly, the pH value at the top layers of the biofilms was slightly lower on palatally than on buccally exposed specimens, which may likely be due to anatomic conditions.

CONCLUSION

Based on the results of this study, initial intraoral biofilm formation and acidification is almost similar on the bracket material/biomimetic tooth interface when placed buccally or palatally in the upper jaw. As lingual brackets were shown to exhibit reduced WSL formation clinically, future studies should investigate further factors like bracket geometry.

Effect of different forms of tobacco on the oral microbiome in healthy adults: a systematic review

Objective

The study aimed to evaluate the impact of tobacco use on the composition and functions of the oral microbiome in healthy adult humans.

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.

Systematic Review Registration

CRD42022340151.

Antibacterial properties and abrasion-stability: Development of a novel silver-compound material for orthodontic bracket application

PURPOSE

Bacteria-induced white spot lesions are a common side effect of modern orthodontic treatment. Therefore, there is a need for novel orthodontic bracket materials with antibacterial properties that also resist long-term abrasion. The aim of this study was to investigate the abrasion-stable antibacterial properties of a newly developed, thoroughly silver-infiltrated material for orthodontic bracket application in an in situ experiment.

METHODS

To generate the novel material, silver was vacuum-infiltrated into a sintered porous tungsten matrix. A tooth brushing simulation machine was used to perform abrasion equal to 2 years of tooth brushing. The material was characterized by energy dispersive X‑ray (EDX) analysis and roughness measurement. To test for antibacterial properties in situ, individual occlusal splints equipped with specimens were worn intraorally by 12 periodontal healthy patients for 48 h. After fluorescence staining, the quantitative biofilm volume and live/dead distribution of the initial biofilm formation were analyzed by confocal laser scanning microscopy (CLSM).

RESULTS

Silver was infiltrated homogeneously throughout the tungsten matrix. Toothbrush abrasion only slightly reduced the material's thickness similar to conventional stainless steel bracket material and did not alter surface roughness. The new silver-modified material showed significantly reduced biofilm accumulation in situ. The effect was maintained even after abrasion.

CONCLUSION

A promising, novel silver-infiltrated abrasion-stable material for use as orthodontic brackets, which also exhibit strong antibacterial properties on in situ grown oral biofilms, was developed. The strong antibacterial properties were maintained even after surface abrasion simulated with long-term toothbrushing.

Dental anxiety and oral health-related quality of life before and after non-surgical periodontal treatment

OBJECTIVES

To (1) investigate dental anxiety (DA) and oral health-related quality of life (OHRQOL) before and after non-surgical periodontal treatment (NSPT) and (2) determine correlations between these patient-reported measures.

MATERIALS AND METHODS

Demographics, smoking habits, dental pain, Modified Corah's Dental Anxiety Scale (MDAS), and Oral Health Impact Profile (OHIP-14) were assessed in eighty-two participants.

RESULTS

Mean age was 48.3 years ± 11.5. At baseline, 8.5% reported being active smokers. Of non-smokers, 11% reported being an ex-smoker. After NSPT, 11.0% reported smoking. Patients' maximal pain in the last month decreased after therapy. Before treatment, participants reported higher DA. Extreme DA was observed in 8.5% of participants before therapy. Afterwards, 2.4% of participants reported extreme DA. Fear of having a foreign object in the mouth decreased after NSPT. All OHIP-14 scores, except functional limitation, improved post-treatment. Higher DA was associated with worse OHRQoL before treatment. After treatment, total MDAS score was associated with OHIP-14 global score, physical pain, psychological disability, and social disability. Worse MDAS sub-scores were associated with a higher OHIP-14 global score. Individuals with "normal/slight anxiety" had a significant improvement in OHRQoL, whereas people in the "moderate and extreme anxiety" group did not report a significant improvement. Patients diagnosed with generalized periodontitis (GP) stage III grade B and GP stage IV grade B reported less anxiety after NSPT.

CONCLUSIONS

Associations of MDAS subcategories with OHIP-14 domain scores were found before and after therapy. DA decreases and OHRQoL enhances after NSPT in patients with "normal/slight" anxiety to dental treatment. Dental practitioners should plan strategies to cope with anxiety to dental treatment and prevent decreases in OHRQoL.

CLINICAL RELEVANCE

Within the limitations of this study, DA and OHRQoL were positively correlated in patients with periodontitis, before and after NSPT, using the MDAS and OHIP-14 questionnaires. The results of our study suggest that treatment is effective in terms of alleviating DA and improving oral health, along with quality of life, in patients that report "normal/slight" anxiety to dental treatment. Nonetheless, results must be interpreted with caution since patients are generally anxious before any type of dental treatment. DA may not just be confined to NSPT per se. According to our results, evaluation of both outcomes should be an integral part of routine periodontal clinical evaluation and periodontal reevaluation of initial therapy. It is important that clinicians learn to identify patients that suffer from anxiety and take time to explain the treatment procedures to the patient, to strive for patient's emotional well-being before, during, and after dental care services. The use of specific questionnaires for both DA and OHRQoL may be more appropriate to demonstrate the psychological and quality of life differences due to periodontal disease and NSPT.

ASSOCIATION OF ORAL MICROBIOTA AND PERIODONTAL DISEASE WITH LUNG CANCER: A SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

Evidence of oral microbiota perturbations has been accumulated for lung cancers. This review focused on the oral microbiota alterations in population suffering from lung cancer. In addition, we also discussed conflicting data about the association between oral microbiota dysbiosis and risk of lung cancer.

METHODS

A systematic search was conducted in Medline, Embase, PubMed, and Cochrane Library databases. The studies evaluated diversity and abundance of oral microbes in healthy and lung cancer individuals as well as association of periodontal disease and pathogens with lung cancer. Of 3559 studies, 28 included studies were performed in qualitative analysis, and 25 studies were used in meta-analyses for quantitative assessment. Heterogeneity was analyzed by using I² and chi-squared Q test statistics. Statistical analyses were performed by using the RevMan 5.4 software.

RESULTS

Compared with the control, lung cancer patients had lower alpha diversity (Shannon: SMD = -0.54; 95% CI, -0.90 to -0.19; P < .01, I2 = 71%). In nested case-control studies, individuals with decreased alpha diversity tended to have an increased risk of lung cancer (observed species: HR = 0.90; 95% CI, 0.85-0.96; P < .01, I2 = 0%; Shannon: HR = 0.89; 95% CI, 0.83-0.95; P < .01, I2 = 0%). Overall, no strong evidence of association of relative abundance with specific oral microbes with lung cancers was found because of inconsistent data. No associations were found between periodontal pathogens and lung cancer risk (red complex: HR = 1.12, 95% CI: 0.42-3.02, P = .82, I2 = 62%; orange complex: HR =1.77, 95% CI: 0.78-3.98, P = .17, I2 = 36%), expect for Fusobacterium nucleatum (HR = 2.27, 95% CI: 1.13-4.58, P = .02, I2 = 0%). The positive association of periodontal disease with lung cancer risk was found (HR = 1.58, 95% CI: 1.25-2.00, P < .001, I2= 0%) with increase of periodontal diseases severity (HR = 2.39, 95% CI: 1.57-3.66, P < .001, I2 = 0%). However, such association was not found in never-smoker participants (HR = 1.00, 95% CI: 0.76-1.31, P = .37, I2= 7%).

CONCLUSIONS

Lower alpha diversity of oral microbiome may be associated with a greater risk of lung cancer and might serve as a predictive signal of lung cancer risk. There was no strong evidence of relative abundance of oral microbial taxa and periodontal pathogens in lung cancer patients. Fusobacterium nucleatum might be a potential microbial candidate of biomarkers in lung cancer. Periodontal disease may be positively associated with lung cancer risk by confounding of smoking, but not an independent risk factor.

Longitudinal changes in subgingival biofilm composition following periodontal treatment

BACKGROUND

Current periodontal treatment involves instrumentation using hand and/or ultrasonic instruments, which are used either alone or in combination based on patient and clinician preference, with comparable clinical outcomes. This study sought to investigate early and later changes in the subgingival biofilm following periodontal treatment, to identify whether these changes were associated with treatment outcomes, and to investigate whether the biofilm responded differently to hand compared with ultrasonic instruments.

METHODS

This was a secondary-outcome analysis of a randomized-controlled trial. Thirty-eight periodontitis patients received full-mouth subgingival instrumentation using hand (n = 20) or ultrasonic instrumentation (n = 18). Subgingival plaque was sampled at baseline and 1, 7, and 90 days following treatment. Bacterial DNA was analyzed using 16S rRNA sequencing. Periodontal clinical parameters were evaluated before and after treatment.

RESULTS

Biofilm composition was comparable in both (hand and ultrasonics) treatment groups at all time points (all genera and species; p[adjusted] > 0.05). Large-scale changes were observed within groups across time points. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30% to 40% of the relative abundance. When reassessed at day 90 a subset of samples reformed a microbiome more comparable with baseline, which was independent of instrumentation choice and residual disease.

CONCLUSIONS

Hand and ultrasonic instruments induced comparable impacts on the subgingival plaque microbiome. There were marked early changes in the subgingival biofilm composition, although there was limited evidence that community shifts associated with treatment outcomes.

Association between inflammatory potential of diet and periodontitis disease risks: Results from a Korean population-based cohort study

AIM

To examine the association between a pro-inflammatory diet, estimated using the energy-adjusted dietary inflammatory index (E-DII), and the risk of periodontitis.

MATERIALS AND METHODS

Study subjects from the Korean Genome and Epidemiology Study Health Examinee (KoGES_HEXA) cohort were included for cross-sectional analysis (n = 168,378) using multivariate logistic regression and prospective analysis (n = 160,397) using Cox proportional hazard models respectively. DII and E-DII scores were calculated based on the intake reported on a validated semi-quantitative food frequency questionnaire (SQ-FFQ).

RESULTS

Cox proportional hazard models revealed a significantly increased risk of incident periodontitis in individuals consuming high E-DII (more pro-inflammatory) diets in the total population (HRquartile4vs1  = 1.29; 95% CI: 1.13-1.48; ptrend <.001) and in both men (HRquartile4vs1  = 1.36; 95% CI: 1.07-1.73; ptrend  = 0.02) and women (HRquartile4vs1  = 1.27; 95% CI: 1.08-1.50; ptrend  = .002). The association remained significant even after excluding cases diagnosed early in the follow-up. In the cross-sectional analysis, a significant association was observed between the E-DII score and the prevalence of periodontitis among all study subjects (ORquartile4vs1  = 1.17; 95% CI: 1.03-1.34; ptrend  = 0.01) and men (ORquartile4vs1  = 1.28; 95%CI: 1.01-1.63; ptrend <.001); however, the association did not reach statistical significance in women (ORquartile4vs1  = 1.13; 95% CI: 0.96-1.33; ptrend <.001).

CONCLUSIONS

Findings from the current study support the hypothesis that diets with high pro-inflammatory potential increase the risk of periodontitis.

The Impact of Smoking on Peri-implant Microbiota: A Systematic Review

OBJECTIVES

Peri-implantitis is associated with bacterial plaque biofilms and with patients who have a history of periodontitis. Smoking is a risk factor for periodontitis, but the relationship between smoking and peri-implantitis is unclear. The aim of this systematic review was to assess evidence ascertaining the relationship between smoking and peri-implant microbiota.

DATA SOURCES

An electronic search was conducted in the MEDLINE/PubMed, Embase and Scopus® databases in duplicate up to January 2023 without language restrictions. Studies were considered eligible for inclusion if they involved evaluation of the peri-implant microbiota of smokers and nonsmokers. Methodological quality was assessed with the adapted Newcastle-Ottawa scale.

STUDY SELECTION

Fourteen studies were identified for inclusion in the present study, and 85.7% of the studies were defined as medium to high methodological quality. Overall, the evidence presented in this review was limited to medium to high methodological quality. The data indicates that significantly higher frequencies of anaerobic pathogens are detectable in healthy peri-implant tissues of smokers. A lower diversity of microbiota was observed in healthy peri-implant sites of smokers. In the transition from clinically healthy to a diseased status, smoking shaped a reduced peri-implant microbiota by depleting commensal and enriching pathogenic species.

CONCLUSIONS

The composition of peri-implant microbiota may be influenced by smoking. More studies are needed to determine the impact of smoking on peri-implant microbiota.

CLINICAL SIGNIFICANCE

In the transition from clinically healthy to a diseased status, smoking shaped a reduced peri-implant microbiota by depleting commensal and enriching pathogenic species. The composition of peri-implant microbiota may be influenced by smoking.

Influence of Smoking on Periodontal and Implant Therapy: A Narrative Review

BACKGROUND

smoking is considered the most modifiable risk factor for periodontal disease.

OBJECTIVE

the aim of this narrative review is to emphasize the effect of smoking on periodontal and implant therapy.

METHODS

The authors reviewed the literature reporting the clinical outcomes of smoking on periodontal surgical and nonsurgical treatment. The impact of smoking on implant therapy and sinus lifting procedures were also reviewed.

RESULTS

Periodontal and implant therapy outcomes are adversely affected by smoking. Smokers respond less favorably to periodontal therapy and periodontal flap procedures as compared to nonsmokers. Clinical outcomes for smokers are 50-75% worse than for nonsmokers. Studies reveal that smokers experience a significantly lower reduction in pocket depth compared to nonsmokers as well as less bone growth after treating infra-bony defects with guided tissue regeneration. The relative risk of implant failure is significantly higher in patients who smoke 20 cigarettes or more per day compared to nonsmokers. Additionally, smoking has also been shown to increase postoperative wound dehiscence and infection rates following sinus floor elevation. Longitudinal studies on smoke cessation have shown a reduction in bone loss and probing depths for periodontitis patients after cessation compared to those who smoke.

CONCLUSION

Smoking cessation can reduce probing depths and improve clinical attachment after nonsurgical periodontal therapy. There is insufficient evidence regarding the effect of smoking on peri-implantitis, as well as the loss of implants in the long-term.

Osteoimmunology in Periodontitis and Orthodontic Tooth Movement

PURPOSE OF REVIEW

To review the role of the immune cells and their interaction with cells found in gingiva, periodontal ligament, and bone that leads to net bone loss in periodontitis or bone remodeling in orthodontic tooth movement.

RECENT FINDINGS

Periodontal disease is one of the most common oral diseases causing inflammation in the soft and hard tissues of the periodontium and is initiated by bacteria that induce a host response. Although the innate and adaptive immune response function cooperatively to prevent bacterial dissemination, they also play a major role in gingival inflammation and destruction of the connective tissue, periodontal ligament, and alveolar bone characteristic of periodontitis. The inflammatory response is triggered by bacteria or their products that bind to pattern recognition receptors that induce transcription factor activity to stimulate cytokine and chemokine expression. Epithelial, fibroblast/stromal, and resident leukocytes play a key role in initiating the host response and contribute to periodontal disease. Single-cell RNA-seq (scRNA-seq) experiments have added new insight into the roles of various cell types in the response to bacterial challenge. This response is modified by systemic conditions such as diabetes and smoking. In contrast to periodontitis, orthodontic tooth movement (OTM) is a sterile inflammatory response induced by mechanical force. Orthodontic force application stimulates acute inflammatory responses in the periodontal ligament and alveolar bone stimulated by cytokines and chemokines that produce bone resorption on the compression side. On the tension side, orthodontic forces induce the production of osteogenic factors, stimulating new bone formation. A number of different cell types, cytokines, and signaling/pathways are involved in this complex process. Inflammatory and mechanical force-induced bone remodeling involves bone resorption and bone formation. The interaction of leukocytes with host stromal cells and osteoblastic cells plays a key role in both initiating the inflammatory events as well as inducing a cellular cascade that results in remodeling in orthodontic tooth movement or in tissue destruction in periodontitis.

Evaluation of red-complex bacteria loads in complete denture patients: a pilot study

OBJECTIVE

This pilot study aimed to evaluate red-complex bacteria (RCB) loads in edentulous patients, before and after dentures' insertion.

MATERIALS AND METHODS

Thirty patients were included in the study. Deoxyribonucleic acid (DNA) isolated from bacterial samples were obtained from the dorsum of the tongue before and 3 months after complete dentures (CDs) insertion in order to identify the presence of RCB (Tannerella forsythia, Porphyromonas gingivalis, and Treponema denticola) and quantify their loads, using real-time polymerase chain reaction (RT-PCR). Bacterial loads were represented as "Lg (genome equivalents/sample)" and the data classified according to the "ParodontoScreen" test.

RESULTS

Significant changes in bacterial loads were observed before and 3 months after the CDs insertion for: P. gingivalis (0.40 ± 0.90 vs 1.29 ± 1.64, p = 0.0007), T. forsythia (0.36 ±0.94 vs 0.87 ± 1.45, p = 0.005), and T. denticola (0.11 ± 0.41 vs 0.33 ± 0.75, p = 0.03). Before the CDs insertion, all patients had a normal bacterial prevalence range (100%) for all analyzed bacteria. Three months after the insertion, 2 (6.7%) of them had a moderate bacterial prevalence range for P. gingivalis, while 28 (93.3%) had a normal bacterial prevalence range.

CONCLUSION

The use of CDs has a significant impact on increasing RCB loads in edentulous patients.

Emerging Oral Nicotine Products and Periodontal Diseases

Oral nicotine pouches are emerging as a new "modern oral" nicotine product. These prefilled pouches contain nicotine, flavorings, and filling agents that dissolve in the mouth. Nicotine can be derived from tobacco leaf or chemical synthesis. Traces of TSNAs and toxic chromium were detected in the pouch products. This raises the concern about general and periodontal health. This review aims to update the current oral nicotine products research relating to periodontal disease and its relevance in periodontal inflammation. Nicotine interacts with host cells and affects inflammatory responses to microbial challenges. It may directly or indirectly deteriorate periodontal tissues by activating nicotinic acetylcholine receptors, repressing PDL fibroblasts cells, increasing cellular ROS and cytokines/chemokines, growth factors, breaking microbiota balance, and dysregulating miRNAs expression. Studies show that appealing flavorings contained in nicotine pouches pose harm to periodontal innate immune responses and increase penetration of nitrosamines. In addition, flavored ONPs increase the risk of dual or poly-tobacco products among young adults, stacking up detrimental effects on the periodontium. Given the recent growth of users, further studies are needed to elucidate the impact of ONPs, even poly-tobacco use, on systemic and periodontal health. Moreover, policymakers should ensure to avoid generating a new wave of nicotine addiction among youths in the U.S.

Tooth Loss and Associated Factors in Mexican Older Adults in Nursing Homes: A Multicenter Cross-Sectional Study

The objective of this study was to determine the experience of tooth loss and associated factors in older adults and elderly residing in nursing homes. A cross-sectional study was conducted in Mexican older adults and elderly aged ≥60 years living in four nursing homes (two in Mexico City, Mexico: one in Cuernavaca, Morelos, and one in Oaxaca, Oaxaca). The data were collected at the facility (home nursing) by two dentists in 2019. To determine the number of tooth loss and DMFT, a clinical oral examination was performed. In addition, a questionnaire was applied to determine diverse independent variables (demographic, socioeconomic, and behavioral). The analysis was performed using nonparametric tests and negative binomial regression (p < 0.05). 257 subjects were included. The mean age was 81.25 ± 9.02 years, and 60.7% were women. The mean number of lost teeth was 18.78 ± 9.05 (women = 19.43 ± 8.59 and men = 17.77 ± 9.68; p > 0.05). In the multivariate negative binomial regression model, it was found that, for each one-year increase in age, the mean tooth loss increased 0.92% (p < 0.05). In current smokers (p < 0.01) and in those who brush their teeth < 2 times a day (p < 0.01), the average of tooth loss increased 22.04% and 61.46%, respectively. The experience of tooth loss in Mexican older adults and elderly was high. Demographic (age) and habit of behavior (tobacco use and less frequent tooth brushing) were associated with increased tooth loss. It is important to promote oral health programs for institutionalized older adults.

Impact of diabetes mellitus and co-morbidities on mortality in patients with COVID-19: A single-center retrospective study

OBJECTIVES

To describe the effect of diabetes mellitus (DM) on clinical outcomes of patients admitted with COVID-19 infection.

METHODS

We carried out a single center, observational, retrospective study. We included adult patients with laboratory-confirmed diagnosis of COVID-19 admitted to a tertiary hospital in Jeddah, Saudi Arabia, from April 2020 to December 2020. Electronic medical records were reviewed for demographics, clinical status, hospital course, and outcome; and they were compared between the patients with or without DM.

RESULTS

Out of 198 patients included in the study, 86 (43.4%) were diabetic and 112 (56.5%) were non-diabetic. Majority of the patients were males 139 (70.2%) with a mean age of 54.14±14.89 years. In-hospital mortality rate was higher in diabetic patients than in non-diabetic patients (40 vs. 32; p=0.011). The most common comorbidity was hypertension (n=95, 48%) followed by ischemic heart disease (n=35, 17.7%), chronic kidney disease (n=17, 9.6%), and bronchial asthma (n=10, 5.1%).

CONCLUSION

The risk of SARS-CoV-2 infection is higher among diabetic patients; particularly, those with preexisting co-morbidities or geriatric patients. Diabetic patients are prone to a severe clinical course of COVID-19 and a significantly higher mortality rate.

Evaluation of Salivary Biomarkers of Periodontal Disease Based on Smoking Status: A Systematic Review

Saliva is a useful biomarker for diagnosing oral health conditions, including periodontal disease (PD). Smoking is a risk factor for PD. The aim of this systematic review was to summarize the salivary biomarkers associated with PD based on smoking status. A comprehensive search of the MEDLINE (via PubMed), EMBASE, Cochrane, SCOPUS, and Web of Sciences databases was conducted up to 1 January 2021 using key terms relevant to the topic of our research and Cochrane methodology and improved with searching a gray literature resource. The methodological quality of all included studies was assessed with the revised Quality Assessment of Diagnostic Accuracy Studies-2. Seven studies were included. Smokers had increased levels of malondialdehyde, sialic acid, salivary cortisol, salivary interleukin 1β, albumin, tissue inhibitor of matrix metalloproteinase (TIMP), and the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), as well as decreased levels of superoxide dismutase, activity of lactate dehydrogenase, activity of enzyme activity of β-glucuronidase, uric acid, matrix metalloproteinase-8 (MMP-8)/TIMP-1 ratio, and combinations of MMP-8 and ICTP. However, mixed results were observed some studies in detecting glutathione peroxidase, MMP-8, and MMP-14. The results were interpreted with caution because of limitations in the number of included studies and the study design. Some salivary biomarkers are potentially useful in combination or alone for diagnosing PD. Methodological and systematic studies are needed to develop more effective biomarkers.

Osteoporosis and Alveolar Bone Health in Periodontitis Niche: A Predisposing Factors-Centered Review

Periodontitis is a periodontal inflammatory condition that results from disrupted periodontal host-microbe homeostasis, manifested by the destruction of tooth-supporting structures, especially inflammatory alveolar bone loss. Osteoporosis is characterized by systemic deterioration of bone mass and microarchitecture. The roles of many systemic factors have been identified in the pathogenesis of osteoporosis, including endocrine change, metabolic disorders, health-impaired behaviors and mental stress. The prevalence rate of osteoporotic fracture is in sustained elevation in the past decades. Recent studies suggest that individuals with concomitant osteoporosis are more vulnerable to periodontal impairment. Current reviews of worse periodontal status in the context of osteoporosis are limited, mainly centering on the impacts of menopausal and diabetic osteoporosis on periodontitis. Herein, this review article makes an effort to provide a comprehensive view of the relationship between osteoporosis and periodontitis, with a focus on clarifying how those risk factors in osteoporotic populations modify the alveolar bone homeostasis in the periodontitis niche.

Smoking negatively impacts the clinical, microbiological, and immunological treatment response of young adults with Grade C periodontitis

OBJECTIVE

This study aimed to investigate the influence of smoking on clinical, microbiological and immunological parameters in young adult with stage III-IV Grade C periodontitis after full-mouth ultrasonic debridement (FMUD) associated with Amoxicillin and Metronidazole (AMX + MTZ), comparing smokers (PerioC-Y-Smk) with non-smokers (PerioC-Y-NSmk).

MATERIALS AND METHODS

Fifteen PerioC-Y-NSmk and 14 PerioC-Y-Smk patients underwent FMUD associated with AMX + MTZ for 10 days. All parameters were collected at baseline and 3 and 6 months after treatment. Plaque index (PI), bleeding on probing (BoP), probing depth (PD), clinical attachment level (CAL)- the primary variable-, and gingival recession (GR) were clinically assessed. The impact of PI on CAL change at 6-month was verified by a regression analysis. Samples of the subgingival biofilm was collected for detection of levels of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P.gingivalis), Tannerella forsythia (T. forsythia), and Fusobacterium nucleatum ssp (F. nucleatum), and were analyzed by real-time qPCR; gingival crevicular fluid was collected for detection of levels of interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, which were analyzed using an enzyme immunoassay.

RESULTS

PerioC-Y-Smk had significantly higher PI, BOP, and GR at baseline compared to non-smokers (p < .05). PerioC-Y-Smk presented higher PD, CAL, and GR at 3 and 6 months (p < .05) compared with PerioC-Y-NSmk in the same periods; PI negatively affected CAL gain in PerioC-Y-NSmk at 6-month follow-up (p = .052) and did not impact on clinical response in PerioC-Y-Smk (p = .882). Lower levels of IFN-γ, IL1-β, and IL-4 were observed at 3 months in the PerioC-Y-NSmk (p < .05) compared with PerioC-Y-Smk. Lower proportions of P. gingivalis were observed in PerioC-Y-NSmk at baseline and at 3 months (p < .05) and lower proportions of F. nucleatum were observed at 6 months, in the PerioC-Y-NSmk (p < .05).

CONCLUSIONS

PerioC-Y-Smk presents an unfavorable clinical, microbiological, and immunological response after 3 and 6 months after FMUD associated with AMX + MTZ.

CLINICAL RELEVANCE

Smoking worsens periodontal condition of young treated adults presenting stage III/IV Grade C periodontitis.

Smoking as a Risk Factor for Dry Socket: A Systematic Review

Dry socket is one of the postoperative complications of tooth extraction. It is the partial or total loss of the post-extraction blood clot, resulting in severe pain that usually starts one to five days postoperatively, with clinical evidence of exposed alveolar bone, necrotic debris, halitosis, and tenderness on examination. The purpose of our systematic review was to answer the question "Is there a relationship between smoking and dry socket?". After meeting the inclusion and exclusion criteria, eleven studies were included in this systematic review (according to the PRISMA statement guidelines). Based on a meta-analysis, tobacco smokers had a more than three-fold increase in the odds of dry socket after tooth extraction. Overall, the combined incidence of dry socket in smokers was found to be about 13.2% and in non-smokers about 3.8%. Despite the heterogeneity of the included studies (different types of teeth extracted, different age groups), cigarette smoking was related to an increased risk of dry socket after tooth extraction.

Radiographically screened periodontitis is associated with deteriorated oral-health quality of life: A cross-sectional study

Periodontitis is greatly related to worse perceived oral health-related quality of life (OHRQoL), yet this association has never been explored using radiographically screened periodontal bone loss. Here we have radiographically screened patients for periodontitis via a validated method and assessed its association with measures of OHRQoL. From a total of 10,267 participants (6,112 females and 4,155 males), self-reported general health questionnaire, body mass index, self-reported oral health behaviours, panoramic x-rays and the oral health impact profile (OHIP-14) were gathered. Radiographically screened periodontitis was measured through a radiographic-based periodontal bone loss (R-PBL) approach. We compared the respective variables according to the R-PBL status and explored using multiple logistic regression adjusted for the significant variables. Overall, patients with periodontitis shown significantly different sociodemographic, health measures and oral hygiene characteristics. All domains of the OHIP-14 were significantly worsened in the periodontitis group, and further confirmed through adjusted logistic regression (p<0.001). Active smoking, number of missing teeth, sex and age were the most impactful variables in this relationship. Our results demonstrate the existence of a link between radiographically screened periodontitis and OHRQoL, mostly upheld by active smoking, number of missing teeth, sex and age.

Inverse PCR-based detection reveal novel mobile genetic elements and their associated genes in the human oral metagenome

The human oral cavity is one of the hotspots harboring multiple mobile genetic elements (MGEs), which are segments of DNA that can move either within bacterial genomes or between bacterial cells that can facilitate the spreading of genetic materials, including antimicrobial resistance genes. It is, therefore, important to investigate genes associated with the MGEs as they have a high probability of dissemination within the bacterial population under selective pressure from human activities. As one-third of oral bacteria are not yet culturable in the laboratory condition, therefore, in this work, it is aimed to detect and identify the genetic contexts of MGEs in the oral cavity through an inverse PCR (IPCR)-based approach on the oral metagenomic. The human oral metagenome was extracted from saliva samples collected from healthy individuals in Tromsø, Norway. The extracted DNA was partially digested with the HindIII restriction enzyme and self-circularized by ligation. DNA primers targeting each MGE were designed to amplify outwards from the MGEs and used for the IPCR on the circularized DNA products. The IPCR amplicons were cloned into a pCR-XL-2-TOP vector, screened, and sequenced. Out of 40 IPCR amplicons, we confirmed and verified the genetic contexts of 11 samples amplified with primers targeting integron gene cassettes (GCs), IS431 composite transposons, and Tn916 conjugative transposons (tet(M) and xis-int). Novel integron GCs, MGEs, and variants of Tn916 conjugative transposons were identified, which is the first report using the IPCR technique to detect the genetic contexts of MGEs in the oral metagenomic DNA.

Association between osteoporosis and periodontal disease among menopausal women: The 2013-2015 Korea National Health and Nutrition Examination Survey

BACKGROUND

This cross-sectional study aimed to investigate the association between osteoporosis and periodontal disease among Korean menopausal women, as well as the association between osteoporosis and periodontal disease according to duration after menopause.

METHODS

Of a total of 22,948 subjects who participated in the Korea National Health and Nutrition Examination Survey, from 2013 to 2015 the final study population was limited to 2,573 subjects with no missing values. The subjects were divided into two groups, normal bone mineral density (BMD) and osteoporosis, according to the T-score obtained from bone densitometry. Scores of ≥ 3 points for the community periodontal index of treatment needs were reclassified as periodontal disease. Moreover, after stratification of the variable 'duration after menopause' into 0-4, 5-9, and ≥10 years, binary logistic regression analysis was performed to investigate the association between osteoporosis and periodontal disease according to the duration after menopause.

RESULTS

There was an association between osteoporosis and periodontal disease. The osteoporosis group had an adjusted odds ratio [OR] of 1.25 (95% confidence interval [CI]: 1.00-1.56) for periodontal disease compared to the normal BMD group. Of note, the osteoporosis group in the menopausal transition stage (0-4 years after menopause) showed an adjusted OR of 2.08 (95% CI: 1.15-3.77) for developing periodontal disease.

CONCLUSIONS

Osteoporosis was associated with periodontal disease and the association was strongest among women in the menopausal transition stage, 0-4 years after menopause. Oral health promotion, including regular oral examination and oral hygiene care, is particularly useful for menopausal transition women with osteoporosis.

Characterization of Salivary Microbiota in Patients with Atherosclerotic Cardiovascular Disease: A Case-Control Study

AIMS

Oral bacteria have been reported to be associated with the pathogenesis of atherosclerosis; however, the relationship between the oral microbiota and atherosclerosis remains unclear. The present study aimed to investigate whether or not salivary microbiota of patients with atherosclerotic cardiovascular disease (ACVD) differs from that of subjects without ACVD, and to characterize the salivary microbiota of patients with ACVD.

METHODS

This study included 43 patients with ACVD and 86 age- and sex-matched non-ACVD individuals. 16S rRNA metagenomic analysis were performed using DNA isolated from the saliva samples of the participants. To select unique operational taxonomic unit (OTU) sets of ACVD, we conducted the random forest algorithm in machine learning, followed by confirmation via 10-fold cross-validation Results: There was no difference in richness or evenness between the ACVD and non-ACVD groups (alpha diversity; observed OTU index, p=0.503; Shannon's index, p=0.478). However, significant differences were found in the overall salivary microbiota structure (beta diversity; unweighted UniFrac distances, p=0.001; weighted UniFrac distances, p=0.001). The Actinobacteria phylum was highly abundant in patients with ACVD, while the Bacteroidetes phylum was less abundant. The random forest classifier identified 43 OTUs as an optimal marker set of ACVD. In a 10-fold cross validation using the validation data, an area under the curve (AUC) of 0.933 (95% CI, 0.855-1.000) was obtained.

CONCLUSIONS

The salivary microbiota in patients with ACVD was distinct from that of non-ACVD individuals, indicating that the salivary microbiota may be related to ACVD.

A20 alleviated caspase-1-mediated pyroptosis and inflammation stimulated by Porphyromonas gingivalis lipopolysaccharide and nicotine through autophagy enhancement

Periodontitis is the leading cause of tooth loss, and patients with smoking habits are at an increased risk of developing periodontitis. A20 (the tumor necrosis factor alpha-induced protein 3, TNFAIP3) is one of the key regulators of inflammation and cell death in numerous tissues. Emerging researches indicated A20 as a fundamental molecule in the periodontal tissue. This study was to evaluate the role of A20 against cell death and inflammation in periodontitis and to elucidate the underlying mechanisms. In our study, western blot, autophagy detection, and transmission electron microscopy showed that lipopolysaccharide from Porphyromonas gingivalis (Pg.LPS) and nicotine (NI) could enhance the activation of autophagy. Pg.LPS and NI induce the pyroptosis of human periodontal ligament cells (hPDLCs), as evidenced by the decrease of membrane integrity and the increase of NLRP3, GSDMD, GSDMD-N, caspase-1 activity, and the pro-inflammatory cytokines of IL-1β, IL-6, TNF-α. Further researches were focused on that A20, an ubiquitin-editing enzyme, was linked to hPDLCs pyroptosis. Overexpression or silencing A20 could diminish or aggravate pyroptosis in hPDLCs by the modulation of autophagy. The above results demonstrated that A20 dictated the cross-talk between pyroptosis and autophagy. Overexpression of A20 enhanced autophagy to reduce pyroptosis, and thus alleviating inflammation, suggesting that A20 may be a potent target in the treatment of periodontitis.

The Relationships Among Periodontitis, Pneumonia and COVID-19

Periodontitis is a chronic inflammatory disease of the supporting structures of the teeth that affects approximately half of adults 30 years and older. There is increasing interest in the direct and indirect relationships between periodontitis and systemic diseases, including respiratory diseases. The aim of this study was to assess the evidence on links among periodontitis, pneumonia, and COVID-19. Oral and periodontal bacteria may be linked to respiratory disease directly by aspiration of pathogens into the lungs causing pneumonia. As SARS-CoV-2 began to spread worldwide in 2020, questions have arisen of how periodontal disease may also be connected to SARS-CoV-2 infection and severity, including potential replication and dissemination of the virus from periodontal pockets. Some proposed mechanisms include the oral cavity acting as a reservoir or point of entry for SARS-CoV-2, overgrowth of periodontal pathogens, and increased production of proinflammatory cytokines. Due to potential links between periodontal disease and respiratory infections like pneumonia and SARS-CoV-2, oral hygiene and management of periodontitis remain essential to help reduce infection and transmission of SARS-CoV-2.

Subgingival Microbiota Profile in Association with Cigarette Smoking in Young Adults: A Cross-Sectional Study

While smoking is recognized as one of the factors for the development and progression of periodontal diseases, a relation between the composition of the subgingival microbiota and smoking is yet to be elucidated. The aim of this study was to investigate the prevalence of subgingival bacteria in young smokers and non-smokers without clinical signs of periodontal disease. In this cross-sectional study, performed at the Department of Pharmacology, School of Dental Medicine, University of Zagreb, we enrolled 32 periodontally healthy smokers and 32 non-smokers, aged 25–35 years old. The number of oral bacteria and the prevalence of particular bacteria were assessed for each subject. Subgingival plaque samples were collected with sterile paper points from two first molars for microbiological analyses with MALDI-TOF mass spectrometry. In smokers, a significantly higher prevalence of Actinomyces odontolyticus was observed compared to non-smokers, and a significantly lower prevalence of Streptococcus sanguinis was observed compared to non-smokers. Smoking affects the composition of subgingival microbiota, either via depletion of beneficial bacteria or the increase in pathogenic bacteria.

A Literature Review and Framework Proposal for Halitosis Assessment in Cigarette Smokers and Alternative Nicotine-Delivery Products Users

Halitosis is a health condition which counts cigarette smoking (CS) among its major risk factors. Cigarette smoke can cause an imbalance in the oral bacterial community, leading to several oral diseases and conditions, including intraoral halitosis. Although the best approach to decrease smoking-related health risks is quitting smoking, this is not feasible for many smokers. Switching to potentially reduced-risk products, like electronic vapor products (EVP) or heated tobacco products (HTP), may help improve the conditions associated with CS. To date, there have been few systematic studies on the effects of CS on halitosis and none have assessed the effects of EVP and HTP use. Self-assessment studies have shown large limitations owing to the lack of reliability in the participants' judgment. This has compelled the scientific community to develop a strategy for meaningful assessment of these new products in comparison with cigarettes. Here, we compiled a review of the existing literature on CS and halitosis and propose a 3-layer approach that combines the use of the most advanced breath analysis techniques and multi-omics analysis to define the interactions between oral bacterial species and their role in halitosis both in vitro and in vivo. Such an approach will allow us to compare the effects of different nicotine-delivery products on oral bacteria and quantify their impact on halitosis. Defining the impact of alternative nicotine-delivery products on intraoral halitosis and its associated bacteria will help the scientific community advance a step further toward understanding the safety of these products and their potentiall risks for consumers.

Effect of smoking on periodontal health and validation of self-reported smoking status with serum cotinine levels

OBJECTIVE

To investigate whether self-reported smoking and serum cotinine levels associate with periodontal pocket development and to determine the accuracy of self-reported smoking using serum cotinine.

MATERIALS AND METHODS

This 4-year prospective cohort study included data from 294 dentate adults, aged ≥30 years, who participated in both the Health 2000 Survey and the Follow-up Study of Finnish Adults' Oral Health. Subjectively reported smoking status (daily smokers n = 62, occasional smokers n = 12, quitters n = 49, and never-smokers n = 171), serum cotinine levels, demographic factors, education level, dental behaviours and medical history were collected at baseline. The outcome measure was the number of teeth with periodontal pocketing ≥4 mm over 4 years.

RESULTS

Self-reported daily smokers had 1.82 (95% CI: 1.32-2.50) higher incidence of deepened periodontal pockets than never-smokers. A positive association was observed between serum cotinine (≥42.0 μg/L) and the development of periodontal pockets. The misclassification rate of self-reported smoking was 6%.

CONCLUSIONS

Both self-reported daily smoking and higher serum cotinine were associated with periodontal pocket development. Self-reported smoking was fairly accurate in this study. However, higher cotinine levels among a few self-reported never-smokers indicated misreporting or passive smoking. Thus, self-reports alone are not enough to assess the smoking-attributable disease burden.

Testing the association between tobacco smoking, alcohol consumption, and risk of periodontitis: A Mendelian randomization study

AIM

To investigate the associations of tobacco smoking and alcohol consumption with periodontitis using Mendelian randomization (MR) analysis.

MATERIALS AND METHODS

We used 17 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for the number of cigarettes per day from a genome-wide association study (GWAS) of 337,334 individuals, 109 SNPs for a lifetime smoking index from GWAS of 462,690 participants, and 33 SNPs for the number of drinks per week from GWAS of 941,280 individuals. The periodontitis GWAS included 12,289 cases and 22,326 controls. Wald ratios were obtained by dividing the SNP-periodontitis effects by SNP-exposure effects and pooled using an inverse-variance weighted model.

RESULTS

Genetic liabilities for higher number of cigarettes per day (odds ratio [OR] per one standard deviation (1SD) increment = 1.56; 95% CI: 1.18-2.07, p-value = .0018, Q-value = .0054), lifetime smoking index (OR per 1SD = 1.26; 95% CI: 1.04-1.53, p-value = .0161, Q-value = .0242), and drinks per week (OR per 1SD = 1.41; 95% CI: 1.04-1.90, p-value = .0265, Q-value = .0265) were associated with increased odds of periodontitis. Estimates were consistent across robust and multivariable MR analyses.

CONCLUSIONS

The findings of this MR analysis suggest an association between tobacco smoking and alcohol consumption with periodontitis.

Salivary metabolites associated with a 5-year tooth loss identified in a population-based setting

BACKGROUND

Periodontitis is among the most common chronic diseases worldwide, and it is one of the main reasons for tooth loss. Comprehensive profiling of the metabolite content of the saliva can enable the identification of novel pathways associated with periodontitis and highlight non-invasive markers to facilitate time and cost-effective screening efforts for the presence of periodontitis and the prediction of tooth loss.

METHODS

We first investigated cross-sectional associations of 13 oral health variables with saliva levels of 562 metabolites, measured by untargeted mass spectrometry among a sub-sample (n = 938) of the Study of Health in Pomerania (SHIP-2) using linear regression models adjusting for common confounders. We took forward any candidate metabolite associated with at least two oral variables, to test for an association with a 5-year tooth loss over and above baseline oral health status using negative binomial regression models.

RESULTS

We identified 84 saliva metabolites that were associated with at least one oral variable cross-sectionally, for a subset of which we observed robust replication in an independent study. Out of 34 metabolites associated with more than two oral variables, baseline saliva levels of nine metabolites were positively associated with a 5-year tooth loss. Across all analyses, the metabolites 2-pyrrolidineacetic acid and butyrylputrescine were the most consistent candidate metabolites, likely reflecting oral dysbiosis. Other candidate metabolites likely reflected tissue destruction and cell proliferation.

CONCLUSIONS

Untargeted metabolic profiling of saliva replicated metabolic signatures of periodontal status and revealed novel metabolites associated with periodontitis and future tooth loss.

Tobacco Use and Periodontal Disease-The Role of Microvascular Dysfunction

Periodontal disease consists in highly prevalent wide-ranging inflammatory conditions that affect the supporting apparatus of teeth. Tobacco use is the most important risk factor for periodontal disease as it increases disease severity and periodontal surgery complications. Tobacco use is harmful for the vasculature by causing microvascular dysfunction, which is known to negatively affect periodontal disease. To the author's knowledge this paper is the first comprehensive review on the mechanisms by which tobacco use affects oral microcirculation and impacts the pathophysiology of periodontal disease. In healthy subjects, acute nicotine administration or tobacco use (smoking/smokeless forms) increases the blood flow in the oral mucosa due to local irritation and increased blood pressure, which overcome neural- and endocrine-mediated vasoconstriction. Chronic tobacco smokers display an increased gingival microvascular density, which is attributed to an increased capillary recruitment, however, these microcirculatory units show higher tortuosity and lower caliber. These morphological changes, together with the repetitive vasoconstrictive insults, contribute to lower gingival perfusion in chronic smokers and do not completely regress upon smoking cessation. In periodontal disease there is considerable gingival inflammation and angiogenesis in non-smokers which, in chronic smokers, are considerably suppressed, in part due to local immune suppression and oxidative stress. Tobacco exposure, irrespective of the form of use, causes long-term microvascular dysfunction that increases the risk of complications due to the natural disease course or secondary therapeutic strategies.

Sociodemographic, Behavioral and Oral Health Factors in Maternal and Child Health: An Interventional and Associative Study from the Network Perspective

Oral healthcare during pregnancy needs to be part of the assistance routine given to pregnant women by health professionals as a way to encourage self-care and strengthen the general health of the mother and the baby. The aim of this study was to evaluate the effectiveness of an integrated oral healthcare intervention for pregnant women and to analyze the association of sociodemographic, behavioral, oral health and general maternal and child health factors in prenatal care at usual risk in primary care in a city in the northeast of Brazil, in 2018–2019. A controlled, randomized, single-blinded community trial was conducted. The intervention group (IG) received dental assistance and collective health education actions in conversation circles, while the control group (CG) received the usual assistance. All pregnant women (146 in total, 58 from IG and 88 from CG) that took part in the trial answered a questionnaire and underwent a dental examination at the beginning of prenatal care and at the puerperal visit. To assess the effect of the intervention, a network analysis was used. The results have shown that being in the control group was associated with neonatal complications (0.89) and prematurity (0.54); the use of tobacco and alcohol are associated with high risk in initial and final oral health; lower educational level of the pregnant women implicates high risk for initial oral health (−0.19), final oral health (−0.26), pregnancy complications (−0.13), low birth weight (−0.23), prematurity (−0.19) and complications in the newborn (−0.14). Having a low family income (≤261.36 USD) has shown a high risk for initial oral health (−0.14), final oral health (−0.20) and prematurity (−0.15). The intervention based on integrated oral healthcare for pregnant women indicated that socioeconomic and behavioral factors must be considered as determinants for the quality of women and children’s health and that multi-professional performance during prenatal care contributes to the positive outcomes of pregnancy.

The impact of smoking different tobacco types on the subgingival microbiome and periodontal health: a pilot study

Smoking is a risk factor for periodontal disease, and a cause of oral microbiome dysbiosis. While this has been evaluated for traditional cigarette smoking, there is limited research on the effect of other tobacco types on the oral microbiome. This study investigates subgingival microbiome composition in smokers of different tobacco types and their effect on periodontal health. Subgingival plaques were collected from 40 individuals, including smokers of either cigarettes, medwakh, or shisha, and non-smokers seeking dental treatment at the University Dental Hospital in Sharjah, United Arab Emirates. The entire (~ 1500 bp) 16S rRNA bacterial gene was fully amplified and sequenced using Oxford Nanopore technology. Subjects were compared for the relative abundance and diversity of subgingival microbiota, considering smoking and periodontal condition. The relative abundances of several pathogens were significantly higher among smokers, such as Prevotella denticola and Treponema sp. OMZ 838 in medwakh smokers, Streptococcus mutans and Veillonella dispar in cigarette smokers, Streptococcus sanguinis and Tannerella forsythia in shisha smokers. Subgingival microbiome of smokers was altered even in subjects with no or mild periodontitis, probably making them more prone to severe periodontal diseases. Microbiome profiling can be a useful tool for periodontal risk assessment. Further studies are recommended to investigate the impact of tobacco cessation on periodontal disease progression and oral microbiome.

Revealing oral microbiota composition and functionality associated with heavy cigarette smoking

BACKGROUND

Heavy tobacco smoking, a hallmark feature of lung cancer, is drastically predominant in Middle Eastern populations. The precise links between nicotine dependence and the functional contribution of the oral microbiota remain unknown in these populations.

METHODS

We evaluated the composition and functional capabilities of oral microbiota with relation to cigarette smoking in 105 adults through shotgun metagenomics using buccal swabs.

RESULTS

The oral microbiota composition in our study subjects was dominated by the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes, in addition to the genera Prevotella and Veillonella, similar to previously described westernized cohorts. Furthermore, the smoker's oral microbiota represented a significant abundance of Veillonella dispar, Leptotrichia spp. and Prevotella pleuritidis when compared to non-smokers. Within the smoking groups, differential relative abundance testing unveiled relative abundance of Streptobacillus hongkongensis, Fusobacterium massiliense, Prevotella bivia in high nicotine dependent compared to low nicotine dependent profiles based on Fagerström Test for Nicotine Dependence. Functional profiling showed marked differences between smokers and non-smokers. Smokers exhibited an enrichment of Tricarballylate utilization and Lactate racemization when compared to the non-smokers. According to their nicotine dependence, enrichment of Xanthosine utilization, p-Aminobenzoyl-Glutamate utilization, and multidrug efflux pump in Campylobacter jejuni biosynthesis modules were detected in the high nicotine dependent group.

CONCLUSIONS

These compositional and functional differences may provide critical insight on how variations in the oral microbiota could predispose to respiratory illnesses and smoke cessation relapse in cigarette smokers. In particular, the observed enrichment of Fusobacterium and Prevotella in the oral microbiota possibly suggests an intriguing linkage to gut and lung cancers.

Is periodontal disease a risk factor for severe COVID-19 illness?

Periodontal disease (PD) comprises a group of diseases involving inflammatory aspects of the host and dysbiotic events that affect periodontal tissues and could have systemic implications. Diverse factors and comorbidities have been closely associated with PD such as diabetes, obesity, aging, hypertension, and so on; although, underlying mechanisms or causal associations have not been established completely. Interestingly, these same factors have been widely associated with progression or severe coronavirus disease 2019 (COVID-19), an illness caused by coronavirus SARS-CoV-2. Since inflammatory and dysbiotic factors as well as comorbidities affect systemic health, it is possible that periodontal status indicates the risk of complication of COVID-19. However, assessment of oral health history including periodontal status in COVID-19 patients has not been reported. Knowing PD is associated with severe COVID-19 could help identify risk groups and establish pertinent recommendations.

Presenting the characteristics, smoking versus diabetes, and outcome among patients hospitalized with COVID-19

METHODS

We designed a cross-sectional, observational follow-up for 284 COVID-19 patients involving healthy patients, smokers, diabetics, and diabetic plus smokers recruited from May 1, 2020 to June 25, 2020. The clinical features, severity, duration, and outcome of the disease were analyzed.

RESULTS

Of 284 COVID-19 patients, the median age was 48 years (range, 18-80), and 33.80% were female. Common symptoms included fever (85.56%), shortness of breath (49.65%), cough (45.42%), and headache (40.86%). Patients with more than one comorbidity (diabetes and smoking) presented as severe-critical cases compared to healthy patients, diabetics, and smokers. Smokers presented with a lower rate of death in comparison to diabetic patients and diabetic + smoking, furthermore, smoking was less risky than diabetes. Although the mortality rate was high in patients with smokers compared to healthy patients (4.22%, the hazard ratio [HR], 1.358; 95% confidence interval [CI], 1.542-1.100; p = .014), it was less than in diabetics (7.04%, HR 1.531, 95% CI: 1.668-1.337, p = .000), and diabetic plus smoker (10.00%, HR, 1.659; 95% CI, 1.763-1.510; p = .000).

CONCLUSION

Multiple comorbidities are closely related to the severity of COVID-19 disease progression and the higher mortality rate. Smokers presented as mild cases compared to diabetic and diabetic + smoking patients, who presented as severe to critical cases. Although a higher death rate in smokers was seen compared with healthy patients, this was smaller when compared to diabetic and diabetic + smoking patients.

The relationship between periodontal status and rheumatoid arthritis - systematic review

There have been numerous publications investigating the relationship between periodontitis (PD) and rheumatoid arthritis (RA) so far.

This publication presents the common risk factors for the development of PD and RA. The major impact of the pathological bacterial factor and cigarette smoking with chronic inflammation playing the key role in both diseases has been confirmed by numerous studies in various populations over the years. More research focuses nowadays also on the role of improper diet and obesity. Pathophysiological pathways, such as increased concentration of proinflammatory cytokines, indirectly affecting the cardiovascular complications and coagulation disorders, which has an impact on function disorders of tissue metalloproteinase inhibitors and the plasminogen activation system, were also researched.

This systematic review of current literature has shown numerous discrepancies in previous analyses and the need for further detailed research on the relationship between periodontal status and RA.

Evaluation of the Papillary Gingival Vasculature in Smokers and Nonsmokers with Chronic Periodontitis: A Clinical In Vivo Study

Aim:

Cigarette smoking has been recognized as an important risk factor in periodontal diseases. One of the suggested mechanisms behind this association is that nicotine alters the microcirculation and causes vasoconstriction and reduced blood flow through the periodontal tissues. Scarce information is currently available relative to the microvascular alterations associated with smoking and the distribution of capillaries through the various areas of the gingival tissues. The aims of this study were to assess, in human interproximal gingival biopsies, the number and diameter of gingival capillaries in periodontally affected smokers and nonsmokers using the CD34 immunohistochemical staining method. The pattern of distribution of vessels in the different areas of the gingival tissues was also assessed.

Materials and Methods:

Systemically healthy patients with moderate chronic periodontitis and ranging in age between 30 and 60 years were recruited for the study from the patient population attending the Periodontology Department of the Faculty of Dental Medicine at the Lebanese University of Beirut. The patients were selected to have a group of 10 patients (Group SP) of smokers (>10 cigarettes/day for the last 10 years) and a second group (Group NP) consisting of nonsmoking periodontally affected patients. Three to four weeks following initial preparation, one interproximal gingival biopsy was obtained from each patient. Immunohistochemical staining with CD34 mouse monoclonal antibody was used to identify the endothelial cells of the blood vessels within each sample. Twelve biopsy samples (five in Group NP and seven in Group SP) were chosen for the measurement of the number and diameter of vessels in three regions of the connective tissue of the biopsy under a blinded protocol.

Results:

In the two groups, the quantitative distribution of small, medium, and large vessels followed a similar trend with the number of small vessels being significantly greater than both medium and large vessels. Small vessels prevailed in the peripheral regions, whereas large vessels were more abundant in the deeper connective tissue areas. The total number of vessels seemed unaffected by chronic cigarette smoking in both groups in the entire biopsy area and in the separate connective tissue regions. Quantitative alteration in the total number of gingival capillaries was not observed in chronic smokers. A redistribution of small and large vessels in the superficial and deeper connective tissue areas of the gingival papilla was noted as a result of smoking in periodontal patients.

Conclusion:

The quantitative distribution of small, medium, and large vessels follows a similar trend with the content in small vessels being significantly more important than both medium and large vessels. Smoking and periodontitis result in a redistribution of small and large vessels in the superficial and deeper connective tissue areas of the gingival papilla compared to nonsmoking periodontal patients. The significance and clinical implications of such rearrangement of vasculature within the gingival tissue need to be further investigated.

Cognitive-Behavioural Correlates of Dysbiosis: A Review

Evidence suggests an association between an altered gut microbiota (dysbiosis), cognitive performance and behaviour. This paper provides an overview of the current literature regarding the cognitive-behavioural correlates of dysbiosis, with special attention on the clinical and biochemical mechanisms underlying the association between dysbiosis, cognition (mild cognitive impairment and dementia) and behaviour (depression, schizophrenia, addiction). After providing an overview of the evidence, the review discusses the molecular aspects that could account for the cognitive-behavioural correlates of dysbiosis. Shedding light on this topic could provide insights regarding the pathogenesis of these burdening neuropsychiatric disorders and even suggest future therapeutic strategies.

A case study of salivary microbiome in smokers and non-smokers in Hungary: analysis by shotgun metagenome sequencing

Objective

To investigate the role of cigarette smoking in disease-development through altering the composition of the oral microbial community. Periodontitis and oral cancer are highly prevalent in Hungary; therefore, the salivary microbiome of smoker and non-smoker Hungarian adults was characterized.

Methods

Shotgun metagenome sequencing of salivary DNA samples from 22 individuals (11 non-smokers and 11 current smokers) was performed using the Ion Torrent PGM^TM platform. Quality-filtered reads were analysed by both alignment-based sequence similarity searches and genome-centric binning.

Results

Prevotella, Veillonella and Streptococcus were the predominant genera in the saliva of both groups. Although the overall composition and diversity of the microbiota were similar, Prevotella was significantly more abundant in salivary samples of current smokers compared to non-smokers. Members of the genus Prevotella were implicated in the development of inflammatory diseases and oral cancer. The abundance of the genus Megasphaera also increased in current smokers, whereas the genera Neisseria, Oribacterium, Capnocytophaga and Porphyromonas were significantly reduced. The data generated by read-based taxonomic classification and genome-centric binning mutually validated the two distinct metagenomic approaches.

Conclusion

Smoking-associated dysbiosis of the salivary microbiome in current cigarette smokers, especially increased abundance of Prevotella and Megasphaera genera, may facilitate disease development.