Ibero-Panamerican Federation of Periodontology Delphi study on the trends of periodontology and periodontics by the year 2030. A Latin American consensus.

BACKGROUND AND OBJECTIVE: As elsewhere in the world, the prevalence of periodontitis in stages I-II is high in the Latin American population, this scenario emphasizes the need for identification of urgent needs for allocating adequate resources to provide diagnosis, prevention, and treatment of these diseases. The aim of this Delphi study was to predict the trends in periodontology/periodontics in the Latin American region by the year 2030. METHODS: A steering committee and an advisory group of experts in periodontology/periodontics were selected from 16 countries. An open questionnaire of 60 questions was validated and used following the Delphi methodology. RESULTS: Two hundred and twenty-five experts from Latin America answered the two rounds of the questionnaire. Moderate to strong consensus was reached on 45 questions (75%). The prediction was that the prevalence of gingivitis and periodontitis in stages I and II will be maintained, the importance of the link with systemic diseases will increase, and the impact of prevention and periodontal treatment will also increase, mainly in the private sector. There was a strong consensus that plastic and regenerative surgical procedures will increase, as well as the demand for training in the specialty of periodontology. CONCLUSIONS: The present study has provided relevant and useful information on predictions in periodontology/periodontics in Latin America, with important level of consensus among experts. It has been predicted that periodontitis will still be a highly prevalent disease, and its links with other medical conditions should demand more attention by health authorities to develop adequate prevention and management policies and strategies.

Consensus report of the second European Consensus Workshop on Education in Periodontology.

BACKGROUND: The second European Consensus Workshop on Education in Periodontology was commissioned, as a result of the changes in the discipline and the advances in educational methods/technology, to update the 2009 Consensus report of the first European Federation of Periodontology (EFP) Workshop on the same topic that was jointly authored by the Association for Dental Education in Europe. AIM: To identify and propose changes necessary in periodontal education at three levels, namely undergraduate, specialist and continuing professional development (CPD), with respect to learning outcomes, competencies and methods of learning/training and evaluation. METHODS: Four working groups (WGs) considered education in periodontology at the undergraduate, specialist and CPD levels, and education methods. Four commissioned position papers, one per WG, summarized the relevant information. Workshop participants gathered at an in-person consensus meeting to discuss the individual reviews, and this consensus report summarizes the conclusions. RESULTS: The learning outcomes for undergraduate and specialist education in periodontology have been updated, and a proposal for learning outcomes for CPD programmes was made. Learning/teaching/training and evaluation methods were proposed for each level of education, which included face-to-face, virtual and blended learning methods. CONCLUSION: Developments in oral/dental medicine and in contemporary educational technologies have been translated into updated learning outcomes and learning/teaching/ training/evaluation methods relevant to education in periodontology.

Structure, governance and delivery of specialist training programs in periodontology and implant dentistry.

AIM: To update the competences and learning outcomes and their evaluation, educational methods and education quality assurance for the training of contemporary specialists in periodontology, including the impact of the 2018 Classification of Periodontal and Peri-implant Diseases and Conditions (2018 Classification hereafter) and the European Federation of Periodontology (EFP) Clinical Practice Guidelines (CPGs). METHODS: Evidence was gathered through scientific databases and by searching for European policies on higher education. In addition, two surveys were designed and sent to program directors and graduates. RESULTS: Program directors reported that curricula were periodically adapted to incorporate advances in diagnosis, classification, treatment guidelines and clinical techniques, including the 2018 Classification and the EFP CPGs. Graduates evaluated their overall training positively, although satisfaction was limited for training in mucogingival and surgical procedures related to dental implants. Traditional educational methods, such as didactic lectures, are still commonly employed, but they are now often associated with more interactive methods such as case-based seminars and problem-based and simulation-based learning. The evaluation of competences/learning outcomes should employ multiple methods of assessment. CONCLUSION: An update of competences and learning outcomes of specialist training in periodontology is proposed, including knowledge and practical application of the 2018 Classification and CPGs. Harmonizing specialist training in periodontology is a critical issue at the European level.

Cross-sectional association between severe periodontitis and diabetes mellitus: A nation-wide cohort study.

AIM: To evaluate the cross-sectional association between severe periodontitis and diabetes mellitus (DM), in a representative sample of Spanish population. MATERIALS AND METHODS: The di@bet.es epidemiological study is a population-based cohort study aimed to determine the prevalence and incidence of DM in the adult population of Spain. The at-risk sample at the final examination (2016-2017) included 1751 subjects who completed an oral health questionnaire. This questionnaire, together with demographic and risk factors, had been previously validated to build an algorithm to predict severe periodontitis in the Spanish population. Logistic regression models were used to evaluate the association between severe periodontitis and DM with adjustment for confounding factors. RESULTS: In total, 144 subjects developed DM, which yielded 8.2% cumulative incidence. Severe periodontitis was detected in 59.0%, 54.7% or 68.8% of the subjects depending on three different selected criteria at the 2016-2017 exam. All criteria used to define severe periodontitis were associated with DM in unadjusted analysis, but the magnitude of the association decreased after adjusting for significant confounders. The criteria '≥50% of teeth with clinical attachment loss ≥5 mm' presented an odds ratio of 4.9 (95% confidence interval: 2.2-10.7; p ≤ .001) for DM. CONCLUSIONS: Severe periodontitis is associated with DM in the Spanish population.

The Impact of Candida albicans in the Development, Kinetics, Structure, and Cell Viability of Biofilms on Implant Surfaces-An In Vitro Study with a Validated Multispecies Biofilm Model.

This study aimed to evaluate the impact of Candida albicans on subgingival biofilm formation on dental implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare biofilm structure and microbial biomass in the presence and absence of the fungus after periods of 24, 48, and 72 h. Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total micro-organisms for each of the biofilm-forming strains. A general linear model was applied to compare CLSM and qPCR results between the control and test conditions. The biofilm developed with C. albicans at 72 h had a higher bacterial biomass and a significantly higher cell viability (p < 0.05). After both 48 and 72 h of incubation, in the presence of C. albicans, there was a significant increase in counts of Fusobacterium nucleatum and Porphyromonas gingivalis and in the cell viability of Streptococcus oralis, Aggregatibacter actinomycetemcomitans, F. nucleatum, and P. gingivalis. Using a dynamic in vitro multispecies biofilm model, C. albicans exacerbated the development of the biofilm grown on dental implant surfaces, significantly increasing the number and cell viability of periodontal bacteria.

What is the science underpinning the prescription of antibiotics in dentistry?

DESIGN: A critical review on the use of antimicrobials in dentistry. AIM: To provide a general overview of the use of antimicrobials in dentistry. METHODS: The paper was divided into different topics, starting with an approach to understanding both commensal and pathogenic oral microbiota. Subsequently, emphasis was placed on the main categories of antibiotics used in dentistry (ß-lactams, tetracyclines, macrolides, lincosamides, nitroimidazoles and quinolones), and the basis for their prescription. Finally, the implications between systemic diseases and the use of orally-administered antibiotics are presented. RESULTS: The study suggests that an adequate medical history can minimize the risk of systemic adverse effects, unwanted drug interactions, and allergies related to the use of antibiotics. In this regard, when facing a potential history of allergy to a particular group of antibiotics, the prescription of a different group is mandatory. In most indications, ß-lactam antibiotics represent the first-choice in dentistry. Moreover, a short-term prescription of antibiotics when treating acute oral infections is recommended. The use should be extended for 2 to 3 days following the resolution of the infection, with an average duration of 6 days in order to prevent the development of antibiotic resistance. CONCLUSIONS: Oral infections should be managed with interventions aiming at the elimination/reduction of the associated pathogens. Furthermore, inadequate prescription of antibiotics can lead to potential risks to the patient such as allergy, adverse effects, and development of microbial resistance.

Minimal invasiveness in the reconstructive treatment of peri-implantitis defects.

Peri-implantitis is a plaque-associated pathologic condition occurring in tissues around dental implants, clinically characterized by increased peri-implant probing pocket depth and progressive loss of supporting bone. Consequently, to arrest further disease progression and to increase the chance to obtain re-osseointegration, surgical reconstructive procedures have been adopted. In particular, following a paradigm gathered from periodontal therapy, recent protocols have underlined the importance of a minimally invasive approach to optimize the outcomes of therapy while minimizing the risks of postoperative complications. The present review summarizes the level of evidence on the surgical reconstructive protocols focusing on the new approaches aiming to minimize surgical trauma and patients' postoperative discomfort, underlining the pros and cons of each treatment modality.

The association between respiratory diseases and periodontitis: A systematic review and meta-analysis.

AIM: To evaluate (1) whether periodontitis has an influence on the prevalence/incidence of respiratory diseases (chronic obstructive pulmonary disease [COPD], asthma, community-acquired pneumonia [CAP], obstructive sleep apnoea [OSA] and COVID-19), and (2) what is the impact of periodontal therapy on the onset or progression of respiratory diseases. MATERIALS AND METHODS: An electronic search was performed on Pubmed, Cochrane Library and Scopus databases up to October 2021, to identify studies answering the PECOS and PICOS questions. RESULTS: Seventy-five articles were selected. Meta-analyses identified statistically significant associations of periodontitis with COPD (nstudies  = 12, odds ratio [OR] = 1.28, 95% confidence interval [CI] [1.16; 1.42], p < .001), and OSA (ns  = 6, OR = 1.65, 95% CI [1.21; 2.25], p = .001), but not for asthma (ns  = 9, OR = 1.53, 95% CI [0.82; 2.86], p = .181). For acute conditions, two studies were found for CAP, while for COVID-19, significant associations were found for the need of assisted ventilation (ns  = 2, OR = 6.24, 95% CI [2.78; 13.99], p < .001) and COVID-related mortality (ns  = 3, OR = 2.26, 95% CI [1.36, 3.77], p = .002). Only four intervention studies were found, showing positive effects of periodontal treatment on COPD, asthma and CAP. CONCLUSIONS: A positive association between periodontitis and COPD, OSA and COVID-19 complications has been found, while there is a lack of intervention studies.

Subgingival microbiome in periodontal health, gingivitis and different stages of periodontitis.

AIM: To characterize the subgingival microbiome in subjects with different periodontal health statuses. MATERIALS AND METHODS: In this cross-sectional observational study, subgingival samples were harvested from Spanish subjects with different periodontal health statuses, based on the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions. Samples were processed using high-throughput sequencing technologies (Illumina MiSeq). Taxa differentially abundant were identified using Analysis of Compositions of Microbiomes with Bias Correction (ANCOM-BC). α- and ß-diversity metrics were calculated using q2-diversity in QIIME2. The analyses were adjusted for age, gender and smoking status. RESULTS: The identified subgingival microbiome showed statistically significant differences among subjects, categorized into periodontal health, gingivitis and stages I-II and III-IV periodontitis (p < .05). In patients with severe (stages III-IV) periodontitis, the genera Filifactor and Fretibacterium were detected 24 times more frequently than in periodontally healthy subjects. Similarly, the genera Porphyromonas, Prevotella and Tannerella were detected four times more frequently (p < .05). The genera Granulicatella, Streptococcus, Paracoccus, Pseudomonas, Haemophilus, Actinobacteria, Bergeyella and Capnocytophaga were significantly associated with healthier periodontal status (p < .05). CONCLUSIONS: Significant differences were detected in the subgingival microbiome among periodontal health, gingivitis and stages I-II or III-IV periodontitis, suggesting overlapping, yet distinguishable microbial profiles.

Prevention and treatment of peri-implant diseases-The EFP S3 level clinical practice guideline.

BACKGROUND: The recently published Clinical Practice Guidelines (CPGs) for the treatment of stages I-IV periodontitis provided evidence-based recommendations for treating periodontitis patients, defined according to the 2018 classification. Peri-implant diseases were also re-defined in the 2018 classification. It is well established that both peri-implant mucositis and peri-implantitis are highly prevalent. In addition, peri-implantitis is particularly challenging to manage and is accompanied by significant morbidity. AIM: To develop an S3 level CPG for the prevention and treatment of peri-implant diseases, focusing on the implementation of interdisciplinary approaches required to prevent the development of peri-implant diseases or their recurrence, and to treat/rehabilitate patients with dental implants following the development of peri-implant diseases. MATERIALS AND METHODS: This S3 level CPG was developed by the European Federation of Periodontology, following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, formulation of specific recommendations, and a structured consensus process involving leading experts and a broad base of stakeholders. RESULTS: The S3 level CPG for the prevention and treatment of peri-implant diseases culminated in the recommendation for implementation of various different interventions before, during and after implant placement/loading. Prevention of peri-implant diseases should commence when dental implants are planned, surgically placed and prosthetically loaded. Once the implants are loaded and in function, a supportive peri-implant care programme should be structured, including periodical assessment of peri-implant tissue health. If peri-implant mucositis or peri-implantitis are detected, appropriate treatments for their management must be rendered. CONCLUSION: The present S3 level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to maintain healthy peri-implant tissues, and to manage peri-implant diseases, according to the available evidence at the time of publication.

Neuroinflammation related to the blood-brain barrier and sphingosine-1-phosphate in a pre-clinical model of periodontal diseases and depression in rats.

AIM: To explore the potential mechanisms of neuroinflammation (microglia, blood-brain barrier [BBB] permeability, and the sphingosine-1-phosphate [S1P] pathways) resulting from the association between periodontitis and depression in rats. MATERIALS AND METHODS: This pre-clinical in vivo experimental study used Wistar rats, in which experimental periodontitis (P) was induced by using oral gavages with Porphyromonas gingivalis and Fusobacterium nucleatum. Then, a chronic mild stress (CMS) model was implemented to induce a depressive-like behaviour, resulting in four groups: P with CMS (P+CMS+), P without CMS (P+CMS-), CMS without P (P-CMS+), and control (P-CMS-). After harvesting brain samples, protein/mRNA expression analyses and fluorescence immunohistochemistry were performed in the frontal cortex (FC). Results were analysed by ANOVA. RESULTS: CMS exposure increased the number of microglia (an indicator of neuroinflammation) in the FC. In the combined model (P+CMS+), there was a decrease in the expression of tight junction proteins (zonula occludens-1 [ZO-1], occludin) and an increase in intercellular and vascular cell adhesion molecules (ICAM-1, VCAM-1) and matrix metalloproteinase 9 (MMP9), suggesting a more severe disruption of the BBB. The enzymes and receptors of S1P were also differentially regulated. CONCLUSIONS: Microglia, BBB permeability, and S1P pathways could be relevant mechanisms explaining the association between periodontitis and depression.

Association between periodontal diseases and cardiovascular diseases, diabetes and respiratory diseases: Consensus report of the Joint Workshop by the European Federation of Periodontology (EFP) and the European arm of the World Organization of Family Doctors (WONCA Europe).

AIM: To explore the implications for dentists and family doctors of the association between periodontal and systemic diseases and the role of dentists and family doctors in managing non-communicable diseases (NCDs) and promoting healthy lifestyles. MATERIALS AND METHODS: The consensus reports of the previous Focused Workshops on the associations between periodontitis and diabetes (2017) and periodontitis and cardiovascular diseases (2019) formed the technical reviews to underpin discussions on both topics. For the association with respiratory diseases, a systematic review was specifically commissioned for the Workshop discussions. Working groups prepared proposals independently, and then the proposals were discussed and approved at plenary meetings. RESULTS: Periodontitis is independently associated with cardiovascular diseases, diabetes, chronic obstructive pulmonary disease (COPD), obstructive sleep apnea and COVID-19 complications. Dentists and family doctors should collaborate in managing NCDs, implementing strategies for early detection of periodontitis in primary care centres and of cardiovascular diseases or diabetes in dental settings. Family doctors should be informed about periodontal diseases and their consequences, and oral health professionals (OHPs) should be informed about the relevance of NCDs and the associated risk factors. CONCLUSIONS: Closer collaboration between OHPs and family doctors is important in the early detection and management of NCDs and in promoting healthy lifestyles. Pathways for early case detection of periodontitis in family medicine practices and of NCDs in dental practices should be developed and evaluated.

Electrochemical decontamination of titanium dental implants. An in vitro biofilm model study.

OBJECTIVES: The objective of this study is to study the effect of electrochemical treatment on biofilms developed on titanium dental implants, using a six-species in vitro model simulating subgingival oral biofilms. MATERIALS AND METHODS: Direct electrical current (DC) of 0.75 V, 1.5 V, and 3 V (anodic polarization, oxidation processes) and of -0.75 V, -1.5 V, and -3 V (cathodic polarization, reduction processes) was applied between the working and the reference electrodes for 5 min on titanium dental implants, which have been previously inoculated with a multispecies biofilm. This electrical application consisted of a three-electrode system where the implant was the working electrode, a platinum mesh was the counter electrode, and an Ag/AgCl electrode was the reference. The effect of the electrical application on the biofilm structure and bacterial composition was evaluated by scanning electron microscopy and quantitative polymerase chain reaction. A generalized linear model was applied to study the bactericidal effect of the proposed treatment. RESULTS: The electrochemical construct at 3 V and -3 V settings significantly reduced total bacterial counts (p < .05) from 3.15 × 106 to 1.85 × 105 and 2.92 × 104 live bacteria/mL, respectively. Fusobacterium nucleatum was the most affected species in terms of reduction in concentration. The 0.75 V and -0.75 V treatments had no effect on the biofilm. CONCLUSION: Electrochemical treatments had a bactericidal effect on this multispecies subgingival in vitro biofilm model, being the reduction more effective than the oxidative treatment.

Biofilm formation on dental implants with a hybrid surface microtopography: An in vitro study in a validated multispecies dynamic biofilm model.

OBJECTIVES: The objective of this study is to qualitatively and quantitatively evaluate biofilm formation on hybrid titanium implants (HS), with moderately rough and turned surface topographies. MATERIALS AND METHODS: A validated dynamic in vitro multispecies biofilm model, based on bacterial growth under flow and shear conditions resembling the oral cavity, was used to evaluate biofilm formation on the tested implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare the biofilm structure and microbial biomass deposited on either the moderately rough or the turned surface of HS. Quantitative polymerase chain reaction (qPCR) was used to evaluate the total bacterial counts and counts of each specific bacterium in biofilms formed on implants with either the moderately rough or the turned surfaces, as in the hybrid titanium implants, after 24, 48 and 72 h. A general linear model was applied to compare the CLSM and qPCR results between the tested implant surfaces. RESULTS: A significantly higher bacterial biomass grew on the moderately rough implant surfaces, compared to the turned surface area of HS implants (p < .05), at all incubation times, as evidenced with both CLSM and SEM. qPCR analysis also demonstrated an important increase in the total and specific bacterial counts in moderately rough surface implants at the three incubation times. CONCLUSIONS: Implant surface topography (moderately rough versus turned) significantly influenced in vitro biofilm formation in terms of biofilm structure, bacterial biomass and quantity of the specific species selected for the model used.

Clinical, microbiological and biochemical impact of a supportive care protocol with an air-polishing device, after surgical treatment of peri-implantitis: Randomized clinical trial.

OBJECTIVES: The aim of the present study was to evaluate the efficacy of a supportive peri-implant care (SPIC) protocol after surgical therapy of peri-implantitis, combining ultrasonic mechanical debridement and glycine powder air polishing. MATERIALS AND METHODS: Thirty subjects diagnosed with peri-implantitis and treated by means of access flap were randomized 6 months later into two different SPIC groups: the test group combined a piezoelectric ultrasonic instrumentation with a specific implant PEEK tip and glycine powder air polishing, while control group received the same ultrasonic instrumentation together with a rubber cup and a polishing paste. Patients were followed for 12 months, with intermediate SPIC visits every 3 months. Clinical, radiological, microbiological and biochemical outcome variables were registered and calculated. RESULTS: After 12 months of SPIC, probing depths (PD) showed a mean reduction of 0.33 ± 0.11 mm, with significant differences (p < .001) between the test (-0.84 ± 0.43 mm) and the control group (+0.18 ± 0.73 mm). Healthy peri-implant tissues defined by PD <5 mm, absence of BoP (or in only one site around the implant), and no additional bone loss (<0.5 mm), were observed at the final visit in 83% of the implants (87% in the test group and 80% in the control group, p = .255). No adverse events were reported by the subjects participating in the study. CONCLUSIONS: The SPIC protocol including mechanical ultrasonic debridement and glycine powder air-polishing demonstrated significantly better efficacy in terms of PD reductions. A strict SPIC protocol can maintain for 1 year, or even improve, the results obtained after surgical treatment of peri-implantitis.

Oral and systemic health: is there a "new" link with COVID-19?

OBJECTIVES: The objective of the present narrative review was to evaluate the evidence of a possible association between periodontitis and COVID-19, and its biological plausibility, using as models the potential associations with cardiovascular diseases, diabetes, and some respiratory diseases. METHODS: A recent systematic review was used as main reference to explore the associations of periodontitis with different respiratory diseases, including COVID-19, following two focussed questions: a PECOS question, aimed to explore epidemiological evidence, and a PICOS question, designed to explore the evidence derived from intervention studies. In addition to that evidence, other relevant scientific documents, including consensus papers, were carefully selected and appraised. FINDINGS: Convincing evidence was found to support the association of periodontitis and cardiovascular diseases, diabetes, and some respiratory diseases. The biological plausibility behind those associations is based on four factors: (1) bacteraemia of oral bacteria and periodontal pathogens, (2) increased systemic inflammation, (3) common genetic factors, and (4) common environmental risk factors. Limited initial evidence is available to support an association between periodontitis and COVID-19 complications. Among the proposed factors to explain the suggested association, a combination of the previously mentioned factors, plus additional factors related with SARS-CoV-2 characteristics and pathogenicity, has been suggested. CONCLUSIONS: Initial evidence suggests that periodontitis may be associated with a more severe COVID-19 and with a higher risk of death due to COVID-19. CLINICAL RELEVANCE: Due to the possible association between periodontitis and an increased severity for COVID-19, additional efforts should be made to improve oral and periodontal health, including the promotion of oral healthy habits, such as oral hygiene.

Differential analysis of culturable and unculturable subgingival target microorganisms according to the stages of periodontitis.

OBJECTIVES: Culturable and unculturable microorganisms have been associated with periodontitis. Their differential proportions and composition have not been evaluated by their severity and complexity defined by stages in the 2018 AAP-EEP classification. METHODS: One hundred eighty subgingival biofilm samples were collected in Spain and Colombia from subjects categorized as health/gingivitis: periodontitis stages I/II periodontitis stages III/IV. Target culturable microorganisms (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Eubacterium nodatum) and target unculturable microorganisms (Filifactor alocis, Eubacterium saphenum, Eubacterium brachy, Desulfobulbus oralis) were evaluated by quantitative PCR analysis. In addition, their differences and association with periodontal status were analyzed by ANCOVA and logistic regression models once adjusted to age, current smoking, and country. RESULTS: P. gingivalis was significantly associated with periodontitis stages I/II, OR 2.44 (CI 95% 1.08-5.47) and stages III/V, OR 6.43 (CI 95% 2.43-16.9). T forsythia, OR 7.53 (CI 95% 2.07-27.4); D. oralis, OR 5.99 (CI 95% 2.71-13.23); F. alocis, OR 10.9 (CI 95% 4.56-23.2); E. brachy, 3.57 (CI 95% 1.40-9.11); and E. saphenum, 4.85 (CI 95% 1.99-11.7) were significantly associated only with stages III/IV periodontitis. P. gingivalis evidenced significant differences with the increase in the severity of the periodontal lesion: 2.97 colony forming unit (CFU)/µL (CI 95% 2.32-3.54) health/gingivitis, and 4.66 CFU/µL (CI 95% 4.03-5.30) and 5.90 CFU/µL (CI 95% 5.20-6.48) in stages I/II and III/IV respectively (p < 0.0001). Unculturable microorganisms only evidenced differences in concentration in stages III/IV compared with health-gingivitis (p ≤ 0.001). CONCLUSION: Culturable and unculturable are strongly associated with stages III/IV periodontitis. Classic culturable microorganisms are more sensitive to differentiate between stages of periodontitis in the quantitative analysis. CLINICAL RELEVANCE: Future interventional studies of periodontal disease should include Filifactor alocis, Eubacterium saphenum, Eubacterium brachy, and Desulfobulbus oralis as possible markers of therapy response and as indicators of progressive disease.

The Antimicrobial Activity of Curcumin and Xanthohumol on Bacterial Biofilms Developed over Dental Implant Surfaces.

In search for natural products with antimicrobial properties for use in the prevention and treatment of peri-implantitis, the purpose of this investigation was to evaluate the antimicrobial activity of curcumin and xanthohumol, using an in vitro multi-species dynamic biofilm model including Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of curcumin (5 mM) and xanthohumol (100 µM) extracts, and the respective controls, were evaluated with 72-h biofilms formed over dental implants by their submersion for 60 seconds. The evaluation was assessed by quantitative polymerase chain reaction (qPCR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). For the data analysis, comparisons were tested applying ANOVA tests with post-hoc Bonferroni corrections to evaluate the antimicrobial activity of both extracts. With qPCR, statistically significant reductions in bacterial counts were observed for curcumin and xanthohumol, when compared to the negative control. The results with CLSM and SEM were consistent with those reported with qPCR. It was concluded that both curcumin and xanthohumol have demonstrated antimicrobial activity against the six bacterial species included in the dynamic in vitro biofilm model used.

Chemical Recycling of Polystyrene to Valuable Chemicals via Selective Acid-Catalyzed Aerobic Oxidation under Visible Light.

Chemical recycling is one of the most promising technologies that could contribute to circular economy targets by providing solutions to plastic waste; however, it is still at an early stage of development. In this work, we describe the first light-driven, acid-catalyzed protocol for chemical recycling of polystyrene waste to valuable chemicals under 1 bar of O2. Requiring no photosensitizers and only mild reaction conditions, the protocol is operationally simple and has also been demonstrated in a flow system. Electron paramagnetic resonance (EPR) investigations and density functional theory (DFT) calculations indicate that singlet oxygen is involved as the reactive oxygen species in this degradation process, which abstracts a hydrogen atom from a tertiary C-H bond, leading to hydroperoxidation and subsequent C-C bond cracking events via a radical process. Notably, our study indicates that an adduct of polystyrene and an acid catalyst might be formed in situ, which could act as a photosensitizer to initiate the formation of singlet oxygen. In addition, the oxidized polystyrene polymer may play a role in the production of singlet oxygen under light.

Intra- and inter-examiner reliability in classifying periodontitis according to the 2018 classification of periodontal diseases.

AIM: To evaluate the inter-examiner reliability in classifying periodontitis using the 2018 classification of periodontal diseases, when used by postgraduate students, academics, and specialist clinicians trained in European Federation of Periodontology (EFP) and American Academy of Periodontology (AAP) postgraduate-accredited programmes. MATERIALS AND METHODS: An online survey including five patients with periodontitis was sent twice to seven specialists in periodontology to provide the staging and grading characteristics. After agreeing on a "gold-standard" classification, the same questionnaire was sent to 16 EFP and 73 AAP postgraduate programmes, to be answered by their faculty, graduates, and students. The responses were compared with the gold-standard classification, and the inter-examiner agreement was calculated. RESULTS: One-hundred and seventy-four participants completed the survey. The inter-examiner agreement resulted in 68.7% in assigning the stage, 82.4% in assigning the grade, and 75.5% in assigning the extent. The academic position and the experience of the participants did not have any significant influence on classifying periodontitis as the gold standard. CONCLUSIONS: The use of the 2018 periodontitis classification resulted in high inter-examiner reliability when used by a specialist group of clinicians, postgraduate students, and academicians, irrespective of their current position and experience. Given the low response rate and potential selection bias, results pertaining to the use of this system in classifying periodontitis should be interpreted with caution.