Subgingival Biofilm Research Articles

5-Aminolevulinic Acid Gel Associated with Light-Emitting Diode Modulates the in Vitro Subgingival Multispecies Oral Biofilm.

Objective: This study assessed the impact of a 5% combination of 5-aminolevulinic acid (5-ALA) (Aladent) in a multispecies in vitro biofilm model subgingival pathogens. Methods: The 33-species biofilm model was established in the Calgary Biofilm Device during a duration of 7 days. The biofilm treatments comprised various groups: control, light-emitting diode (LED), Aladent (ALADA), and Aladent with LED (ALAD+L), administered on day 6. The Aladent was in contact with the biofilm for 45 min before to the 7-min LED treatment. The LED (λ = 630 nm, power ≈ 380 mW/cm2) was placed 2 mm from the biofilm. Subsequently, during 7 days of biofilm formation, the metabolic activity of the biofilms was assessed utilizing triphenyltetrazolium chloride, and the presence of 33 bacterial species was evaluated through DNA-DNA hybridization. Results: The findings indicated that the ALAD+L treatment was the sole intervention demonstrating a statistically significant reduction (∼70%) in the metabolic activity of the biofilms relative to the control group. Moreover, ALAD+L markedly diminished the overall biofilm count and the average counts of five bacterial species: S. intermedius, V. parvula, A. israelii, P. gingivalis, and E. saburreum. Conclusion: The integration of the photosensitizer Aladent with LED application significantly diminished metabolic activity and bacterial species count in the multispecies subgingival biofilm model, indicating substantial promise for the treatment of peri-implantitis.

Molecular detection of toxigenic Clostridioides difficile in subgingival biofilm of severe periodontitis.

Molecular detection of toxigenic Clostridioides difficile in subgingival biofilm of severe periodontitis.

Advanced biomaterials for targeting mature biofilms in periodontitis therapy.

Advanced biomaterials for targeting mature biofilms in periodontitis therapy.

The impact of Limosilactobacillus reuteri in combination with non-surgical periodontal therapy on periodontal clinical parameters and salivary and subgingival microbiota composition in individuals with stage III–IV periodontitis: a randomized controlled trial

BackgroundThe clinical and microbiological outcomes of probiotic-assisted periodontal therapy remain inconclusive in prior research. This ambiguity may stem from uncertainties regarding the duration, dosage, and administration route of probiotics. Additionally, earlier studies predominantly concentrated on the identification of individual bacterial species, thereby limiting the ability to thoroughly elucidate the intricate composition of microbial communities and the synergistic or antagonistic interactions among their constituents. The study aimed to investigate the effect of combining probiotics with non-surgical periodontal therapy on clinical and microbiota changes in patients with stage III–IV periodontitis.MethodsA total of 40 patients were randomized into two groups to receive non-surgical periodontal treatment. The test group received Limosilactobacillus reuteri for 21 days along with treatment. Periodontal indicators were examined at baseline and 1 and 6 months after treatment. Saliva and subgingival biofilm samples were collected for 16 S rRNA gene sequencing analysis.ResultsAfter treatment, both groups showed significant improvements in clinical parameters. In the test group, attachment loss and the medium pocket were significantly reduced at 6 months compared to that at 1 month. The presence of Tannerella forsythia in subgingival biofilms decreased significantly in the test group after treatment. Among salivary microorganisms, the abundance of Prevotella nanceiensis significantly increased in both groups, while that of Streptococcussp. was significantly reduced in the control group. Linear discriminant analysis indicated that the most significant distinction between the groups was observed in the subgingival biofilm samples 1 month after treatment.ConclusionsCombining L. reuteri with non-surgical periodontal therapy may not directly improve clinical indicators. The treatment showed potential benefits by changing the microbial composition of subgingival biofilm and enhancing treatment sensitivity.Trial registrationThe trial was approved by the Chinese Clinical Trial Registry (ChiCTR) on March 25, 2021, with registration number ChiCTR2100044638.

A retrospective study on the impact of different antibiotic regimens in non-surgical periodontal therapy on microbial loads and therapy outcomes.

This study aimed to analyse the impact of different antibiotic regimens during non-surgical periodontal therapy on the microbial load of selected periodontitis-associated bacteria (PAB) and the primary therapy outcomes. For this aim, 259 patients received steps I and II of periodontal therapy and were included in this clinical trial. 202 patients were treated without the adjunctive use of systemic antibiotics, 18 received amoxicillin (AMOX) as well as metronidazole (MET) and 39 only MET. Subgingival biofilm samples were quantitatively analysed for selected PAB using DNA-DNA-hybridisation-based detection assays for microbial loads of PAB before and 6 months after treatment. Changes in the microbial load of PAB and achievement of a "treat-to-target" endpoint (T2T) (≤4 sites with probing depth ≥5 mm) were analysed. Patients' subgingival microbial load was significantly reduced following therapy. 38.2% of the patients achieved T2T. Binary logistic regression adjusted for confounders indicated a relationship between residual PAB levels and not achieving T2T. In patients not receiving systemic antibiotics a 2.4-fold increased risk of not reaching T2T after steps I and II therapy was observed (none vs. MET aOR = 2.38 p = 0.44). Linear regression analysis adjusted for T0 PAB concentration and confounders revealed an increased reduction of PAB levels in patients with systemic antibiotics. No difference in PAB reduction or chance of achieving T2T was observed between MET and MET + AMOX. Microbial loads of PAB were found directly associated with periodontal status. As antibiotic treatment with both MET and MET + AMOX similarly reduced microbial loads of PAB, treatment with MET alone may be sufficiently effective as adjunctive to non-surgical periodontal treatment. To confirm this, further prospective studies with bigger sample size are needed.

Periodontitis Progression During Cardiac Rehabilitation After Acute Coronary Syndrome: Cohort Study.

To assess changes in periodontal status and factors related to periodontitis progression in acute coronary syndrome patients who undergo a cardiovascular rehabilitation program following an acute coronary incident. Fifty-two acute coronary syndrome patients with periodontitis were evaluated during a six-month follow-up period. Periodontal indices were taken at baseline and at 3 and 6 months. Progression of periodontitis was established as clinical attachment loss > 3 mm in two or more teeth at nonadjacent sites. Baseline clinical conditions, microbiological concentration of subgingival biofilm, and risk factors for cardiovascular disease were associated with the incidence of periodontitis progression by a linear mixed-effects model. 57.69% of the patients had severe periodontitis upon admission, and 64.58% presented a progression of periodontitis during the follow-up periods. Hypertension, low HDL, and high levels of T. forsythia in patients with elevated total cholesterol were the best predictors of clinical attachment loss, with a predictability of 99%. At 6 months, 35.41% of patients' high-sensitivity C-reactive protein (hs-CRP) levels remained over the cardiovascular risk range. Periodontal condition deterioration was observed. Hypertension and poor metabolic control were associated with the progression of periodontitis. T. forsythia was the most critical local factor in periodontitis progression.

Porphyromonas gingivalis induces Zbp1-mediated macrophages PANoptosis in periodonitis pathophysiology

Periodontitis is an oral immunoinflammatory disease, and macrophages play a crucial role in its pathophysiology. However, macrophage death during antibacterial activities will exacerbate inflammation and tissue damage. Porphyromonas gingivalis is a major constituent of subgingival biofilm plaques in periodontitis, but the effects and precise molecular mechanisms by which it triggers macrophage death remain unknown. Here we found that P. gingivalis infection notably activated multiple death pathways in bone-marrow-derived macrophages, including pyroptosis, apoptosis and necrosis. Furthermore, using RNA sequencing, we identified that P. gingivalis infection markedly increased the expression of Z-DNA binding protein 1 (Zbp1) in bone-marrow-derived macrophages. Initially identified as an interferon-induced tumor-associated protein, Zbp1 serves as an upstream sensor that regulates cell death by activating PANoptosis. Mechanistically, P. gingivalis induced a mitochondrial stress response, prompting the release of mitochondrial DNA. This mitochondrial DNA then interacted with Zbp1, consequently augmenting its downstream PANoptosis signals. In addition, P. gingivalis stimulated macrophage Zbp1 expression through the Tlr2/4–JNK–Stat3/5 pathway, exacerbating macrophage death. Importantly, blocking the biosynthesis of endogenous Zbp1 by pharmacological delivery with microneedles improved the survival of P. gingivalis-infected macrophages and inhibited periodontal tissue destruction. These findings highlight Zbp1 as a potential therapeutic target for P. gingivalis-induced periodontitis.

Biofilm Composition Changes During Orthodontic Clear Aligners Compared to Multibracket Appliances: A Systematic Review.

Clear aligner treatment seems to be a good option for the periodontal patient by the reason of being removable. Multibracket appliances are more difficult to mantain clean and some bacteria might prefer to adhere on the archwire. A systematic review was carried out using 4 electronic databases (Pubmed-Medline, Scopus, Cochrane and Web of Science). The selected trials included quantitative (Shannon index, Simpson index, relative abundances) and/or qualitative (alpha and beta diversity) analysis in patients using clear aligners and multibracket appliances. Initially, a total of 123 articles were found after selecting clinical trials. The inclusion and exclusion criteria were applied by two authors. Finally, 20 articles were selected for the systematic review. The results showed that clear aligner treatment produced less dysbiosis in the selected bacteria compared to multibracket appliances. However, some microbiological changes were observed in some articles during clear aligner use. Oral dysibiosis was related with intestinal dysbiosis, inflammatory response and even cancer. The Firmicutes/Bacteroidetes ratio showed to have a very important role in this development. Periodontitis is also a bacterial disease and clear aligners were recommended to periodontal risk patients. Clear aligner treatment obtained less supra and subgingival biofilm changes compared with multibracket appliances but some bacteria were altered during treatment.

An In Vitro Diacetylcurcumin Study for Periodontitis: A New Approach to Controlling Subgingival Biofilms

Background: Periodontal disease (PD) is a chronic inflammatory condition associated with dysbiotic biofilm, leading to the destruction of bone and periodontal ligament. Scaling and root planing (SRP) is the gold-standard treatment for PD, but some patients may not respond adequately, necessitating adjunctive therapies. This study investigated the antimicrobial activity of diacetylcurcumin (DAC), a modified curcumin, against multispecies subgingival biofilm associated with periodontitis. Methods: The biofilm, containing 40 bacterial species, was cultured for seven days in the Calgary apparatus. Treatments with DAC (200 μg/mL), 0.12% chlorhexidine (CHX), and a vehicle (control) were applied twice daily for 1 min, starting on the third day. On the seventh day, biofilms were analyzed for metabolic activity (MA) and bacterial counts via DNA-DNA hybridization. DAC toxicity was tested on Galleria mellonella larvae. Results: DAC reduced biofilm metabolic activity by 51%, while CHX achieved 88% reduction compared to the vehicle (p < 0.05). DAC also significantly decreased counts of key periodontal pathogens, including P. gingivalis, T. forsythia, P. intermedia, and A. actinomycetemcomitans (p < 0.05). At the tested concentration, DAC showed no toxicity in larvae. Conclusions: These findings suggest that DAC effectively reduces biofilm activity and periodontal pathogen counts, presenting a promising adjunctive therapy for PD.

Saccharibacteria (TM7) in saliva and subgingival microbiome as a predictor for gingivitis in individuals with type2 diabetes evaluated by qPCR.

Oral samples are widely used for studying oral microbiome in health and diseases. In this study, saliva and subgingival biofilm (SGB) samples obtained from patients with type2 diabetes (T2DM), without periodontitis (G1 group), with gingivitis (G2 group), and periodontitis (G3 group), were used to compare the abundance of Saccharibacteria (TM7), its host's bacteria (Schaalia odontolytica), periodontopathogen (Represented by Fusobacterium nucleatum), and nitrate-reducing bacteria (represented by Rothia mucilaginosa). The gingival crevicular fluid were also used to analyze the transcription levels of interleukin-6 (IL-6) and C-reactive protein (CRP). Healthy individuals' oral samples served as a control, and the targeted bacteria and inflammatory indicators were detected and measured using real-time PCR. The results showed that in either sample, the abundance of TM7 and other targeted bacteria showed a similar profile. Notably, within participants with T2DM, the abundance of TM7 was similar in G1 and G2 groups, but significantly decreased in G3 group. With the exception of the SGB of the G3 group, the relationship between TM7 and its bacterial host was strongly positive across all evaluated samples. Furthermore, CRP had higher transcription levels than IL-6 across the entire group. Despite the fact that the G3 group showed an adverse relationship between TM7 and CRP, patients with T2DM generally showed a positive correlation between TM7 and IL-6/CRP, which was verified by a receiver operating curve.

Linking peri-implantitis to microbiome changes in affected implants, healthy implants, and saliva: a cross-sectional pilot study.

The rising use of dental implants is accompanied by an expected increase in peri-implant diseases, particularly peri-implantitis (PI), which poses a significant threat to implant success and necessitates a thorough understanding of its pathogenesis for effective management. To gain deeper insights into the role and impact of the peri-implant microbiome in the pathogenesis and progression of PI, we analyzed 100 samples of saliva and subgingival biofilm from 40 participants with healthy implants (HI group) or with co-occurrence of diagnosed PI-affected implants and healthy implants (PI group) using shotgun metagenomic sequencing. We identified the most discriminative species distinguishing healthy from diseased study groups through log ratios and differential ranking analyses. Mogibacterium timidum, Schaalia cardiffensis, Parvimonas micra, Filifactor alocis, Porphyromonas endodontalis, Porphyromonas gingivalis and Olsenella uli were associated with the subgingival peri-implant biofilm. In contrast, Neisseria sp oral taxon 014, Haemophilus parainfluenzae, Actinomyces naeslundii, Rothia mucilaginosa and Rothia aeria were more prevalent in the healthy peri-implant biofilm. Functional pathways such as arginine and polyamine biosynthesis, including putrescine and citrulline biosynthesis, showed stronger correlations with PI-affected implants. In contrast, peri-implant health was characterized by the predominance of pathways involved in purine and pyrimidine deoxyribonucleotide de novo biosynthesis, glucose and glucose-1-phosphate degradation, and tetrapyrrole biosynthesis. Our findings reveal that healthy implants in PI-free oral cavities differ significantly in microbial composition and functional pathways compared to healthy implants co-occurring with PI-affected implants, which more closely resemble PI-associated profiles. This pattern extended to salivary samples, where microbial and functional biomarkers follow similar trends.

Subgingival Yeasts Species Amongst Smokers and Nonsmokers With Peri-implantitis

Subgingival Yeasts Species Amongst Smokers and Nonsmokers With Peri-implantitis

Role of regulatory immune cells in pathogenesis and therapy of periodontitis.

Periodontitis disease (PD) is a serious gum infection that progresses from gingivitis. PD is defined by gingival recession and bone loss and can lead to tooth loss. Bacterial infections are the main cause, as they induce inflammation and the development of periodontal pockets. Traditional therapies such as scaling and root planning aim to remove the subgingival biofilm via mechanical debridement but fail to address the fundamental inflammatory imbalance within the periodontium. The immune homeostasis linked to periodontal health necessitates a regulated immuno-inflammatory response, within which the presence of regulatory cells is critical to guarantee a managed response that reduces unintended tissue damage. Given that regulatory cells influence both innate and adaptive immunity, pathological conditions that might be alleviated through the establishment of immuno-tolerance, such as PD, could potentially gain from the application of regulatory cell immunotherapy. This review will reveal regulatory cell types, how they change phenotypes, and how they can be targets for new immunotherapies. As our understanding of regulatory cell biology advances, we can create novel therapeutics to improve their stability and function in PD.

Increased bacterial load of Filifactor alocis in deep periodontal pockets discriminate between periodontitis stage 3 and 4.

Increasing evidence supports the association of Filifactor alocis with periodontitis; therefore, this work was conducted to assess the prevalence and proportion of F. alocis in subgingival biofilm samples from patients with periodontitis stage 3 and 4, and its potential to differentiate between these stages. This cross-sectional study included 50 periodontitis patients from whom subgingival biofilm samples were collected using paper points. This was followed by recording clinical periodontal parameters including the plaque index, bleeding on probing, probing pocket depth (PPD), and clinical attachment loss (CAL). The total loads of bacteria and F. alocis were determined via quantitative PCR. All patients were diagnosed with periodontitis stage 3/4 and grade B/C, with a total of 727 periodontal pockets, which were pooled (n = 114) for microbiological analysis. Qualitative and quantitative analyses indicated that the total bacterial load and prevalence of F. alocis were highest in stage 4 and grade C cases, which were also increased with increasing PPD and severity of CAL. An ROC analysis indicated that both the total bacterial load and F. alocis concentration could significantly discriminate stage 3 and 4 periodontitis. The regression model suggested that a one-unit increase in PPD, and CAL could explain a 23.9% and 14.9% increase in the F. alocis concentration, respectively. The results demonstrate that the prevalence of F. alocis is increased in severe periodontitis cases, mainly at sites with deep periodontal pockets and greater attachment loss. Additionally, this bacterium possesses the diagnostic potential to differentiate periodontitis cases of different severities.

Elongation factor Tu promotes the onset of periodontitis through mediating bacteria adhesion

Periodontitis, a leading cause of adult tooth loss and linked to various systemic diseases, is promoted by subgingival plaque biofilms, with Streptococci as early colonizers responsible for surface adhesion. Current studies of Streptococci adhesion have focused on bacteria surface adhesins with acquired protein membranes on the tooth surface, yet no critical proteins with implications for the overall early adhesion of subgingival plaque have been reported. Here, we identified that the “Barrel-like adhesion domain” of streptococcal EF-Tu facilitates cell-surface attachment, promotes biofilm formation, and contributes to the development of periodontitis. In the adherent state, EF-Tu is transported from the cytoplasm to the cell surface through membrane vesicles. Furthermore, we first found that simeprevir, an FDA-approved drug, binds to the “Barrel-like adhesion domain” of EF-Tu and effectively inhibits the protein’s surface adhesion and secretory pathways. Simeprevir showed the ability to inhibit dental plaque formation and provided prevention and treatments for periodontitis.

Brazilian Organic Honeydew Reduces In Vitro and In Vivo Periodontal Disease-Related Subgingival Biofilm.

We investigated the antimicrobial properties and effects on bone resorption of Brazilian organic honeydew (OHD) from the Bracatinga tree (Mimosa scabrella Benth.), a rare honey certified with Denomination of Origin, using a periodontal disease model. Antibiofilm activity was assessed using a subgingival biofilm adhered to the Calgary device. Biofilms were treated with OHD, chlorhexidine (0.12%), or a vehicle twice daily for 1 min starting on day 3, at concentrations of 2× and 10× the minimum inhibitory concentration (MIC). We employed a ligature-induced chronic periodontal disease model and challenged it with Porphyromonas gingivalis in C57BL/6 mice. The chemical profile of OHD was analyzed using LC-ESI-IT-MS/MS. Results were evaluated by measuring bone loss and microbial composition of the ligature biofilm through DNA-DNA hybridization. OHD demonstrated significant activity against P. gingivalis (MIC 4%, MBC 6%) and reduced biofilm viability by 80% in vitro. In vivo, OHD decreased microbial populations and decreased bone loss associated with periodontal disease. Chemical analysis identified seven compounds in OHD, including five flavonoids and two lignans. This Brazilian honeydew from the Atlantic Forest exhibits strong antimicrobial properties and potential as a functional food for oral health, offering a promising alternative for the control and prevention of periodontal disease.

Gingivitis- and periodontitis-associated microbiota in bovine deciduous incisor teeth - A preliminary study.

Gingivitis- and periodontitis-associated microbiota in bovine deciduous incisor teeth - A preliminary study.

Photodynamic therapy in non-surgical treatment of periodontitis

Periodontitis is a chronic inflammation disease that, apart from caries, remains the main cause of tooth loss, that lead to a deterioration of the quality of life. Non-surgical treatment is the basic form of periodontal therapy, regardless of the stage of the disease. Novel supportive treatment methods are constantly implemented to improve the effects of non-surgical treatment, including photodynamic therapy that leads to a selective photosensitization of bacteria with the simultaneous participation of a photosensitizer applied into the periodontal pocket. The aim of the study is to evaluate the use of adjunctive photodynamic therapy on clinical and microbiological parameters in the non-surgical treatment of periodontitis. The clinical study involved 30 generally healthy, non-smoking patients. After a periodontal examination standard non-surgical treatment was applied. 6 weeks later a control periodontal clinical examination was performed and then periodontal pockets were subjected to a photodynamic therapy (PDT) using the FotoSan 630 cm Dental lamp with a perio tip and the FotoSan agent CMS Dental medium density photosensitizer. A significant improvement in clinical parameters including BoP (reduction 73,3%, p < 0,05), PD (reduction 1,9 mm, p < 0,05) and CAL (gain 0,6 mm, p < 0,05) and a significant reduction of red complex bacteria after application of PDT compared to SRP alone was observed. The application of supportive photodynamic therapy improve the effectiveness of periodontal non-surgical treatment including clinical parameters and reduction in subgingival bacteria biofilm.

Exploring AI-Driven Machine Learning Approaches for Optimal Classification of Peri-Implantitis Based on Oral Microbiome Data: A Feasibility Study

Background: Machine learning (ML) techniques have been recently proposed as a solution for aiding in the prevention and diagnosis of microbiome-related diseases. Here, we applied auto-ML approaches on real-case metagenomic datasets from saliva and subgingival peri-implant biofilm microbiomes to explore a wide range of ML algorithms to benchmark best-performing algorithms for predicting peri-implantitis (PI). Methods: A total of 100 metagenomes from the NCBI SRA database (PRJNA1163384) were used in this study to construct biofilm and saliva metagenomes datasets. Two AI-driven auto-ML approaches were used on constructed datasets to generate 100 ML-based models for the prediction of PI. These were compared with statistically significant single-microorganism-based models. Results: Several ML algorithms were pinpointed as suitable bespoke predictive approaches to apply to metagenomic data, outperforming the single-microorganism-based classification. Auto-ML approaches rendered high-performing models with Receiver Operating Characteristic–Area Under the Curve, sensitivities and specificities between 80% and 100%. Among these, classifiers based on ML-driven scoring of combinations of 2–4 microorganisms presented top-ranked performances and can be suitable for clinical application. Moreover, models generated based on the saliva microbiome showed higher predictive performance than those from the biofilm microbiome. Conclusions: This feasibility study bridges complex AI research with practical dental applications by benchmarking ML algorithms and exploring oral microbiomes as foundations for developing intuitive, cost-effective, and clinically relevant diagnostic platforms.

Prevalence of Epstein-Barr Virus, Cytomegalovirus, and Periodontopathic Bacteria in Patients With Periodontitis: A Case-Control Study.

Opportunistic viruses such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV) have been detected in gingival crevicular fluid (GCF) and saliva of patients with periodontal disease. However, the relationship between herpesviruses and periodontitis remains obscure. The aim of this case-control study was the detection and association of CMV and EBV with periodontitis. Forty-eight adults were included in this study: 24 patients with periodontitis (CP) and 24 periodontally healthy individuals (HS). All patients underwent periodontal examination, including probing depth (PD), clinical attachment loss (CAL), plaque index (PI), and bleeding on probing (BOP). Subgingival biofilm samples were collected from all patients and real-time PCR was performed for viral and bacterial detection. The odds ratio (OR) was calculated, and the chi-squared test or Fisher's exact test was performed to analyze the significant differences. EBV was detected only in one healthy patient meanwhile no CMV was found. No statistically significant differences were found between the periodontal clinical parameters of EBV-positive patients and the negative ones: PI (p = 0.090), PD (p = 0.857), CAL (p = 0.801), and BOP (p = 0.104). Except for Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Treponema denticola (Td) showed a statistically significant association (p < 0.001) with the clinical periodontal parameters. Aa presence was not statistically associated with periodontal sites (p < 0.296). Tf and Pg were the most frequently detected periodontopathic bacteria in the CP group (91.7% sites). The present case-control study showed that the prevalence of EBV and CMV did not show significant differences between the groups evaluated in the Spanish population.