Assessment of the Effect on Periodontitis of Antibiotic Therapy and Bacterial Lysate Treatment.

Periodontitis is an inflammatory process that starts with soft tissue inflammation caused by the intervention of oral bacteria. By modulating local immunity, it is possible to supplement or replace current therapeutic methods. The aim of this study was to compare the effects of an immunostimulatory treatment with the antibiotherapy usually applied to periodontitis patients. On a model of periodontitis induced in 30 rats (divided into three equal groups) with bacterial strains selected from the human oral microbiome (Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Streptococcus oralis), we administered antibiotics, bacterial lysates and saline for 10 days. Clinically, no significant lesions were observed between the groups, but hematologically, we detected a decrease in lymphocyte and neutrophil counts in both the antibiotic and lysate-treated groups. Immunologically, IL-6 remained elevated compared to the saline group, denoting the body's effort to compensate for bone loss due to bacterial action. Histopathologically, the results show more pronounced oral tissue regeneration in the antibiotic group and a reduced inflammatory reaction in the lysate group. We can conclude that the proposed bacterial lysate has similar effects to antibiotic therapy and can be considered an option in treating periodontitis, thus eliminating the unnecessary use of antibiotics.

Oral microbiome research - a call for equity and inclusion.

Over 700 oral bacterial species have been identified in human populations, with ~200 bacterial species identified in any given individual mouth. The relationship between the oral microbiome and health is evidenced in many studies, with dysbiosis (a shift from a healthy to less healthy state of microbial community) associated with dental caries, periodontitis, halitosis and oral cancer. However, oral microbiome research to date has focused primarily on European populations, particularly those in large urban centres housing academic institutions with access to research funding. Key anthropological perspectives examining the sociocultural, epidemiological, genetic and environmental factors that influence the oral microbiome have also been Euro-centric. Very little is known about how the oral microbiome mediates both oral and general disease risks specifically within Indigenous and other vulnerable populations. Undertaking oral microbiome research in under-served communities requires consideration of many issues often unfamiliar in the broader research community, including being acceptable, relevant and of perceived benefit to the communities being studied. Research materials need to be managed respectfully in a culturally safe way, sharing/translating the knowledge obtained. These approaches will likely provide unique insights into the complex connections between environment and biology, people and place, and culture and science in relation to the oral microbiome. The ongoing development of oral microbiome research must facilitate frameworks that are equitable and inclusive to better enable clinical and scientific expertise within marginalised communities.

[The assessment of a role of muramyl peptides in the treatment of patients with aggressive form of periodontitis]. / Izuchenie roli kompozitsii muramilpeptidov pri lechenii patsientov s agressivnoi formoi parodontita.

THE AIM OF THE STUDY: Was to determine the effect of the drug based on the composition of muramyl peptides isolated from the cell walls of gram-negative bacteria on the production of α-defensins and the detectability of Porphyromonas gingivalis in patients with an aggressive form of periodontitis. MATERIAL AND METHODS: 60 patients aged 28 to 40 years with an aggressive form of periodontitis were randomized into two equal groups, the main and control. In both groups, patients were removed dental deposits and taught the rules of oral hygiene, followed by three-fold control. In the main group, 200 micrograms of the drug based on the composition of muramyl peptides were additionally administered intramuscularly daily for 7 days. Initially and after 7, 21, 90 days, the level of human neutrophil peptides (hnp1-3) in blood serum and periodontal pockets was determined by the enzyme immunoassay, as well as the presence of P. gingivalis in periodontal pockets by polymerase chain reaction (PCR). RESULTS: In patients of the control group, the concentration of hnp1-3 in periodontal pockets and blood serum did not change significantly during the entire study. The use of PM in the main group caused an increase in the local and systemic levels of hnp1-3, which correlated with a persistent decrease in the detectability of P. gingivalis. CONCLUSION: The drug based on the composition of muramyl peptides of the cell wall of gram-negative bacteria potentiates the eradication of P. gingivalis by stimulating the production of hnp1-3 in patients with an aggressive form of periodontitis.

Assessment of the half-life of cationic periodontal pocket irrigation.

BACKGROUND: The concentration and persisting time of antimicrobial agents in the periodontal pockets are important factors for their antimicrobial efficacy. Increased clearance time in the periodontal pocket is a significant criterion for the selection of intrapocket irrigants. The aim of this study was to estimate the clearance time of a cationic agent from the periodontal pocket. METHODS: Thallium-201(Tl-201) was chosen as a tracer to simulate the clearance of cationic substance because of its electrical activity. Twenty patients with periodontitis and probing depths 6 to 9 mm were included in this study. In each patient, 3 Mega Becquerel (MBq) of Tl-201 were inserted into the periodontal pocket. Dynamic imaging was performed and clearance of radioactivity was measured. RESULTS: Clearance of radioactivity was 67.1 ± 16.9, 83.1 ± 13.9, 90.4 ± 10.4, 93.39 ± 8.0% at 30, 60, 90 and 120 min, respectively. Half-life of wash-out was determined as 20.3 ± 10.2 min. CONCLUSION: The results of this study demonstrate that the half-life of the cationic solution applied subgingivally was approximately 20 min and labelling of oral irrigants with radiotracers may be used to determine their clearance in further research.

Molecular imaging assessment of periodontitis lesions in an experimental mouse model.

OBJECTIVE: We aimed to evaluate molecular imaging as a novel diagnostic tool for mice periodontitis model induced by ligature and Porphyromonas gingivalis (Pg) inoculation. MATERIALS AND METHODS: Twelve female mice were assigned to the following groups: no treatment as control group (n = 4); periodontitis group induced by ligature and Pg as Pg group (n = 4); and Pg group treated with glycyrrhizinic acid (GA) as Pg + GA group (n = 4). All mice were administered a myeloperoxidase (MPO) activity-specific luminescent probe and observed using a charge-coupled device camera on day 14. Image analysis on all mice was conducted using software to determine the signal intensity of inflammation. Additionally, histological and radiographic evaluation for periodontal inflammation and bone resorption at the site of periodontitis, and quantitative enzyme-linked immunosorbent assay (ELISA) were conducted on three mice for each group. Each experiment was performed three times. RESULTS: Levels of serum IgG antibody against P. gingivalis were significantly higher in the Pg than in the Pg + GA group. Histological analyses indicated that the number of osteoclasts and neutrophils were significantly lower in the Pg + GA than in the Pg group. Micro-CT image analysis indicated no difference in bone resorption between the Pg and Pg + GA groups. The signal intensity of MPO activity was detected on the complete craniofacial image; moreover, strong signal intensity was localized specifically at the periodontitis site in the ex vivo palate, with group-wise differences. CONCLUSIONS: Molecular imaging analysis based on MPO activity showed high sensitivity of detection of periodontal inflammation in mice. CLINICAL RELEVANCE: Molecular imaging analysis based on MPO activity has potential as a diagnostic tool for periodontitis.

Assessment of periodontitis and its role in viridans streptococcal bacteremia and infective endocarditis.

OBJECTIVES: To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE). METHODS: A total of 200 subjects including two groups. Group A- 34 subjects undergoing tooth extraction with periodontitis, 46 subjects undergoing tooth extraction without periodontitis and 40 healthy controls. Group B: 40 confirmed cases of IE (17 with and 23 without periodontitis) and 40 healthy controls. Subgingival plaque and blood samples were obtained and processed by standard procedures. RESULTS: A total of 53 blood samples (66.25%) yielded positive cultures after tooth extraction. The relationship between the presence of periodontitis and a positive blood culture was significantly higher (p=0.05) for tooth extraction cases with periodontitis (79.40%) than tooth extraction cases without periodontitis (56.50%). Periodontitis was observed in 42.5% of IE cases. Out of the 40 patients of IE, the blood samples yielded 40 different isolates, majority were viridans streptococci 15 (37.5%) and staphylococci nine (22.5%). No statistically significant difference was observed between the subgingival plaque and blood isolates of periodontitis in both the groups, indicating similarity of biotypes of viridans streptococci isolated from the blood and the subgingival plaque. Similarity was also observed between the antibiogram profiles of viridans streptococci from both the groups. CONCLUSIONS: Periodontitis enhances viridans streptococcal bacteremia and may be a potential risk factor for IE.

Clinical, microbiologic and radiologic assessment of soft and hard tissues surrounding zygomatic implants: a retrospective study.

OBJECTIVES: To assess the clinical, microbiologic, and radiologic status of soft and hard tissues surrounding zygomatic implants. STUDY DESIGN: Patients who had at least two zygomatic implants were eligible for the study. Their soft tissues were analyzed, and microbial samples were collected. Cone beam computed tomography (CBCT) and orthopantomography were used to measure bone levels. The patients were also asked to complete a Visual Analogue Scale (VAS) questionnaire assessing their satisfaction. RESULTS: A total of 65 zygomatic implants placed in 20 patients were assessed. As one zygomatic implant was lost, the cumulative survival rate was 98.5%. All the prostheses were successful. Peri-implant soft tissues were generally in a healthy condition. The patients with a history of periodontitis had worse mean peri-implant clinical parameters and showed more bacterial colonization with respect to their nonperiodontal counterparts. The implant recipients had low levels of crestal and zygomatic bone loss and high VAS scores indicating their general satisfaction. CONCLUSIONS: Although zygomatic implants were confirmed to be a reliable treatment option, patients with a history of periodontitis were, nevertheless, found to have special needs, such as frequent dental hygiene sessions.

A longitudinal assessment of changes in bacterial community composition associated with the development of periodontal disease in dogs.

Periodontal disease is the most widespread oral disease in dogs. Whilst the involvement of bacteria in the aetiology of periodontitis is well established the role of individual species and their complex interactions with the host is not well understood. The objective of this research was therefore to perform a longitudinal study in dogs to identify the changes that occur in subgingival bacterial communities during the transition from mild gingivitis to the early stages of periodontitis (<25% attachment loss). Subgingival plaque samples were collected from individual teeth of 52 miniature schnauzer dogs every six weeks for up to 60 weeks. The microbial composition of plaque samples was determined using 454-pyrosequencing of the 16S rDNA. A group of aerobic Gram negative species, including Bergeyella zoohelcum COT-186, Moraxella sp. COT-017, Pasteurellaceae sp. COT-080, and Neisseria shayeganii COT-090 decreased in proportion as teeth progressed to mild periodontitis. In contrast, there was less evidence that increases in the proportion of individual species were associated with the onset of periodontitis, although a number of species (particularly members of the Firmicutes) became more abundant as gingivitis severity increased. There were small increases in Shannon diversity, suggesting that plaque community membership remains relatively stable but that bacterial proportions change during progression into periodontitis. This is the first study to demonstrate the temporal dynamics of the canine oral microbiota; it showed that periodontitis results from a microbial succession predominantly characterised by a reduction of previously abundant, health associated taxa.

Assessment of periodontal and opportunistic flora in patients with peri-implantitis.

AIM: To assess the presence of periodontal and opportunistic organisms in patients with peri-implantitis. MATERIAL AND METHODS: Thirty-three partially edentulous subjects (22 women, 11 men), aged 32-90 years, who had one or more implants with peri-implantitis were included. Peri-implantitis was defined as: (i) the presence of bleeding on probing and/or suppuration and (ii) radiographic images showed marginal bone loss >1.8 mm after 1 year in function. Criteria for inclusion were: (i) partially edentulous patients having at least one implant diagnosed with peri-implantitis; (ii) no antibiotic therapy for 6 months prior to clinical examination. Following this definition, a total of 48 implants were diagnosed with peri-implantitis. Subgingival bacterial samples were obtained with sterile paper points from infected implants and selected teeth of each individual. Periodontopathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola) were detected by multiplex PCR targeting 16S rDNA. Samples were placed in reduced transport medium and cultured for opportunistic pathogens (Staphylococcus aureus, enteric bacteria, Pseudomonas and yeasts). RESULTS: Twenty-two patients yielded positive results for P. gingivalis, 25 for T. forsythia, eight for P. intermedia and 13 for T. denticola. None of the patients yielded a positive result for A. actinomycetemcomitans. Non-periodontal species were found in five patients (15% of total). P. aeruginosa was found in four (12%) patients, and C. albicans (3%) and S. aureus in one patient (3%) each. In two cases of peri-implantitis, none of the periodontal or opportunistic microorganisms studied were detected in either implant or tooth samples. When results of the periodontopathic bacteria from the implant and tooth samples of the same patient were compared, 18 patients (54%) showed the same results for both samples and 15 (45%) patients different results. CONCLUSIONS: The implant surface may be colonized with pathogens different from periodontal bacteria. Opportunistic pathogens such as P. aeruginosa, S. aureus and C. albicans may be associated with implant failure.

Periodontitis and cardiovascular disease.

Periodontal medicine has been studied and reviewed extensively since its introduction to the dental fraternity. The association of periodontal disease with and its effects on the cardiovascular system are amongst the many topics explored. A summary of the research into these associations and the possible mechanisms of any relationship is presented. Although a link between these two chronic inflammatory diseases is evident, the very heterogeneity of the relevant studies has not provided evidence sufficient to support an actual causal relationship. More stringent epidemiologic and intervention studies are required.

Assessment of viable periodontal pathogens by reverse transcription quantitative polymerase chain reaction.

BACKGROUND AND OBJECTIVE: Molecular biological methods for the detection of periodontitis-associated bacteria based on DNA amplification have many advantages over classical culture techniques. However, when it comes to assessing immediate therapeutic success, e.g. reduction of viable bacteria, DNA-based polymerase chain reaction is unsuitable because it does not distinguish between live and dead bacteria. Our objective was to establish a simple RNA-based method that is easily set up and allows reliable assessment of the live bacterial load. MATERIAL AND METHODS: We compared conventional quantitative real-time PCR (qPCR), propidium monoazide-qPCR and reverse transcription qPCR (RT-qPCR) for the detection of periodontal pathogens after antibiotic treatment in vitro. Applicability was tested using clinical samples of subgingival plaque obtained from patients at different treatment stages. RESULTS: The bacterial load was remarkably stable over prolonged periods when assessed by conventional qPCR, while both propidium monoazide intercalation as well as cDNA quantitation showed a decline according to decreasing numbers of viable bacteria after antibiotic treatment. Clinical samples of subgingival plaque were directly subjected to DNase I treatment and RT without previous extraction or purification steps. While the results of the DNA- and RNA-based methods are comparable in untreated patients, the classical qPCR frequently detected substantial bacterial load in treated patients where RT-qPCR no longer indicates the presence of those pathogens. The disagreement rates ranged between 4 and 20% in first visit patients and 8-50% in the group of currently treated patients. CONCLUSION: We propose to use RNA-based detection methods to verify the successful eradication of periodontal pathogens.

Aggregatibacter actinomycetemcomitans serotypes infections and periodontal conditions: a two-way assessment.

This study investigated a large population of individuals positive for A. actinomycetemcomitans and performed a two way analysis assessing the relation between the different serotypes of the bacterium and periodontal conditions. The serotypes analysis (serotypes a, b, c, d, e, f) showed that out of the 204 selected individuals positive for A. actinomycetemcomitans, 152 were positive for a single serotype, 27 showed a variable mixed infection and 25 individuals were not positive for any of the serotypes tested. Serotypes a, b and c were largely found (98%), and serotype c was the most prevalent. Serotypes d, e, and f were either not detected or relatively rare. It was also verified that in non-periodontitis individuals, serotypes a and c were more prevalent (p<0.05); in individuals with mild or moderate/severe chronic periodontitis serotype c was also more common (p<0.05); and aggressive periodontitis subjects showed high prevalence of both serotypes b and c (p<0.05). In conclusion, our study showed that serotype c was the most prevalent in both diseased and healthy subjects. Aggressive periodontitis subjects were not exclusively associated with A. actinomycetemcomitans serotype b. Non-typeable strains were either not detected or were relatively infrequent, and serotypes d and f were not detected in the examined Brazilian population.

Histomorphometric and microbiological assessment of photodynamic therapy as an adjuvant treatment for periodontitis: a short-term evaluation of inflammatory periodontal conditions and bacterial reduction in a rat model.

OBJECTIVE: The aim of this study was to investigate the short-term effects of photodynamic therapy (PDT) in periodontal tissue when it is used as an adjuvant treatment for periodontitis. BACKGROUND DATA: PDT has been used as an adjuvant in the combat of local infections, such as periodontitis, and combines a photosensitizer (PS) with a light source to induce reactive oxygen species (ROS) and kill microbial cells. METHODS: Fifty healthy male rats were used in this study. Periodontitis was induced by placing a cotton ligature around the upper left second molar in a subgingival position. Posterior maxillas were removed and histologically prepared with hematoxylin & eosin (H&E) staining techniques. PDT was performed with a diode laser (λ=660 nm) with an output power of 100 mW. Methylene blue aqueous solution (100 µM) was used as the PS while control group used phosphate buffered saline (PBS). Collagen organization, inflammatory infiltrate, and bone loss were evaluated. Bacterial samples were collected before and immediately after treatment to determine bacterial reduction. RESULTS: The experimental group that was treated with PDT presented better periodontal healing, as measured by collagen organization, inflammatory infiltrate, and bone loss. Significant bacterial reduction was achieved following treatment with or without PDT compared to control, with a higher microbial reduction observed in the PDT group. CONCLUSIONS: PDT used as an adjuvant treatment showed effective short-term control of periodontitis infection.

Clinical and immunological assessment of periodontal disease in Japanese leprosy patients.

Periodontitis is a chronic inflammatory disease caused by the infection of periodontopathic bacteria in dental plaque. However, an individual's susceptibility to this disease appears to be associated with multiple genetic factors, as seen in the case of leprosy. In order to gain a better understanding of the pathophysiology of periodontal disease in subjects with leprosy, we investigated the clinical features of periodontitis and the immunological responses against periodontopathic bacteria in 382 subjects with a history of leprosy and 451 age-matched control subjects. The prevalence of periodontitis and the degree of periodontal pocket depth were found to be significantly higher in leprosy patients than in age-matched controls. Furthermore, a comparison of the clinical parameters of lepromatous leprosy (L-lep) and tuberculoid leprosy (T-lep) patients showed that the probing pocket depth of L-lep patients with periodontal disease was significantly higher than that for T-lep patients. In contrast, serum IgG titers against Porphyromonas gingivalis in L-lep patients were significantly lower than in T-lep patients. These results imply that L-lep patients show more severe periodontal disease than T-lep patients or age-matched control subjects, and that low humoral immunity against P. gingivalis might be one of the genetic factors determining periodontal disease susceptibility in leprosy patients.

Effectiveness of ultrasonic instruments in the therapy of severe periodontitis: a comparative clinical-microbiological assessment with curettes.

Patients with deep periodontal pockets were treated with either Vector System (TG) or manual instruments (CG). Clinical assessments by supragingival plaque (PL+), gingival index (GI), bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL) and subgingival plaque collection for microbiological analysis were made prior to and after treatment. Multiplex Polymerase Chain Reaction was used to determine the presence of Actinobacillus actinomycetemcomitans, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola. GI, PD, CAL and the number of BOP+ sites underwent a significant reduction over time in both groups. When compared to baseline, the pair-wise analyses showed significantly lower PD and CAL at 6 months in the CG and significant reductions in the GI, PD, CAL and a number of BOP+ sites at 3 and 6 months in the TG. For microbiological results, significant reductions were seen for C. rectus and R. gingivalis in the CG and for T. forsythensis, E. corrodens and T. denticola in the TG. The total bacterial count underwent a reduction in both groups. Both ultrasonic and manual debridement are equally effective in non-surgical periodontal therapy of severe periodontitis in terms of clinical and microbiological effects.

[Critical assessment of microbiological diagnostics in periodontal diseases with special focus on Porphyromonas gingivalis]. / Kritische Beurteilung mikrobiologischer Diagnostik bei marginaler Parodontitis unter besonderer Berüchsichtigung von Porphyomonas gingivalis.

Periodontitis is caused by an opportunistic infection with pathogenic microorganisms of the oral biofilm. In this paper, we discuss the usefulness of microbial diagnostics with respect to the differential diagnosis or the treatment approaches of periodontal diseases. Several diagnostic techniques, based on morphological, enzymatic, cultural, genetic or antigenetic properties have been established to analyze the microbial flora. Among the bacterial species some virulent genotypes of P. gingivalis play an important role in the etiology of periodontitis. Expression of fimbriae or different proteases have been identified as potential virulence factors of this gram negative anaerobic rod. To date a characterization of virulence of specific strains or a correlation between expression of different virulence factors and distinct periodontal conditions, however, is missing. Therefore, the importance of a routine identification of P. gingivalis still needs further evaluation.

A rapid DNA probe test compared to culture methods for identification of subgingival plaque bacteria.

There has been a significant amount of interest in developing a more rapid and cost-effective test to identify bacterial pathogens in plaque. DNA probe technology may meet both these objectives, it is more rapid and cost-effective when compared to culture methods. The purpose of this study was to compare an automated DNA probe test with classical culture methods for identifying Bacteroides forsythus and Porphyromonas gingivalis in subgingival plaque of patients with adult periodontitis. Subgingival plaque samples were collected from sites with moderate to severe periodontitis and divided into two aliquots for analysis by either DNA probe or culture methods. When the DNA probe method was compared with the culture method (gold standard), the sensitivity and specificity for B. forsythus were 92.0% (SE = 3.4%) and 50.5% (SE = 7.8%), respectively; for P. gingivalis they were 52.2% (SE = 8.7%) and 74.7% (SE = 5.9%), respectively. Detection of B. forsythus and P. gingivalis by DNA probe correlated with probing depth (P = 0.01 for B. forsythus and P = 0.03 for P. gingivalis). It was concluded the DNA probe test was comparable to culture methods in detecting B. forsythus. In addition, when compared to the culture method, a better correlation was obtained with DNA probe detection of B. forsythus or P. gingivalis and clinical parameters.

Microbiological markers for prediction and assessment of treatment outcome following non-surgical periodontal therapy.

BACKGROUND: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus are considered major putative periodontal pathogens. However, it remains unclear what combinations or what levels of these bacteria influence treatment outcome. The purpose of the present study was to establish useful pathogenic markers for prediction and assessment of treatment outcome following scaling and root planing (SRP). METHODS: A total of 1,149 sites in 104 chronic periodontitis patients were clinically examined at baseline. Three months after SRP, 606 sites in 56 of these patients were reexamined. Subgingival plaque samples taken from the examined sites at baseline and 3 months were analyzed for the detection and quantification of A. actinomycetemcomitans, P. gingivalis, and B. forsythus using a colorimetric polymerase chain reaction technique. RESULTS: At baseline, high levels and a combination of P. gingivalis and B. forsythus were frequently detected in diseased sites (74%). SRP reduced the levels and the coexistence of P. gingivalis and B. forsythus (from 75% to 43%). However, in treated sites where there was less reduction of probing depth (<2 mm), or where bleeding on probing (BOP) or suppuration was detected, residual coexistence of P. gingivalis and B. forsythus and a high level of P. gingivalis after SRP were significantly more frequent. Furthermore, SRP did not improve BOP at sites exhibiting initially high levels of A. actinomycetemcomitans. CONCLUSIONS: These results suggest that the combination of P. gingivalis and B. forsythus, as well as the level of P. gingivalis, is useful in assessing treatment outcome. Furthermore, the high level of A. actinomycetemcomitans before SRP is a possible valuable predictor of treatment outcome.