Personalized antibiotic selection in periodontal treatment improves clinical and microbiological outputs

Introduction

Periodontitis is a biofilm-mediated disease that is usually treated by non-surgical biofilm elimination with or without antibiotics. Antibiotic treatment in periodontal patients is typically selected empirically or using qPCR or DNA hybridization methods. These approaches are directed towards establishing the levels of different periodontal pathogens in periodontal pockets to infer the antibiotic treatment. However, current methods are costly and do not consider the antibiotic susceptibility of the whole subgingival biofilm.

Methods

In the current manuscript, we have developed a method to culture subgingival samples ex vivo in a fast, label-free impedance-based system where biofilm growth is monitored in real-time under exposure to different antibiotics, producing results in 4 hours. To test its efficacy, we performed a double-blind, randomized clinical trial where patients were treated with an antibiotic either selected by the hybridization method (n=32) or by the one with the best effect in the ex vivo growth system (n=32).

Results

Antibiotic selection was different in over 80% of the cases. Clinical parameters such as periodontal pocket depth, attachment level, and bleeding upon probing improved in both groups. However, dental plaque was significantly reduced only in the group where antibiotics were selected according to the ex vivo growth. In addition, 16S rRNA sequencing showed a larger reduction in periodontal pathogens and a larger increase in health-associated bacteria in the ex vivo growth group.

Discussion

The results of clinical and microbiological parameters, together with the reduced cost and low analysis time, support the use of the impedance system for improved individualized antibiotic selection.

The effect of Nigella sativa extracts against Porphyromonas gingivalis isolated from periodontitis patients

OBJECTIVE

Periodontitis is an inflammatory condition that results in pocket formation, gingival recession, and tooth loss by gradually destroying the periodontium. An alternate therapeutic approach that can address these problems is required due to the prohibitive cost of periodontal therapy, unfavorable antibiotic side effects, the advent of novel bacterial strains, and the resistance of those strains. The primary goal of our study was to assess Nigella sativa's (N. sativa) antibacterial effectiveness against Porphyromonas gingivalis (P. gingivalis) utilizing seed extract.

PATIENTS AND METHODS

Six individuals with periodontitis, both male and female, between the ages of 30 and 50, were enrolled in the study. Each patient's medical and dental histories were documented. Then, anaerobic procedures were conducted in the microbiology lab to find P. gingivalis development. The specimens were all then cultured.

RESULTS

At 12.5 mg/ml concentration, P. gingivalis did not show any zone of inhibition (ZOI). However, N. sativa, at a concentration of 25 mg/ml, demonstrated a ZOI of 6.2 mm against P. gingivalis. Similarly, at 50 mg/ml, it showed a ZOI of 8.4 mm. Tetracycline as a positive control demonstrated a ZOI of 14.1 mm against P. gingivalis. Although N. sativa samples had somewhat less antibacterial activity than tetracycline samples, it was discovered that N. sativa had noticeable antibacterial activity against P. gingivalis.

CONCLUSIONS

This study's findings suggest that N. sativa can be utilized against periodontitis as an adjunct to scaling since it has high antibacterial action against P. gingivalis.

Antineoplastic therapy in childhood cancer patients presents a negative impact in the periodontal tissues: a cohort study

OBJECTIVES

To investigate the effect of antineoplastic therapy (AT) in the periodontal tissues of childhood cancer (CC) patients.

MATERIALS AND METHODS

Seventy-two individuals were divided into CC (n=36) and healthy individuals (control group-CG, n=36). Demographics, hygiene habits, CC type, and AT were collected. Salivary flow and the presence and concentration of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Fusobacterium nucleatum were analyzed. Clinical evaluation included plaque (PI) and gingival indexes (GI), periodontal probing depth (PPD), and clinical attachment level (CAL). Patients were classified into periodontal health, gingivitis, or periodontitis. Descriptive statistics, T test, Mann-Whitney test, chi-square, Fisher's exact test, and two-way analysis of variance were used (p<0.05).

RESULTS

The mean age of the patients was similar (CC 12.0±3.9 years and CG 12.0±4.0 years). In the CC group, all patients underwent chemotherapy and nine radiotherapy. Color/race, income, and family education showed significant differences between groups. There was no difference between groups in salivary flow. Higher levels of Fusobacterium nucleatum were seen in CC (p=0.02). Significant difference between groups was found for PI (CC: 30.5%, CG: 22.6%), GI (CC: 28.8%, CG: 17.3%), PPD (CC: 1.77 mm, CG: 1.61 mm), and CAL (CC: 1.77 mm, CG: 1.57 mm), periodontal health (CC: 3, CG: 7), gingivitis (CC: 16, CG: 24), or periodontitis (CC: 17, CG: 5).

CONCLUSION

AT in CC patients presents a negative impact in the periodontal and microbiological parameters.

CLINICAL RELEVANCE

Childhood cancer individuals showed worse periodontal parameters and higher levels of Fusobacterium nucleatum in the saliva when compared to healthy individuals.

Microbiota present in combined endodontic-periodontal diseases and its risks for endocarditis

INTRODUCTION

Infective endocarditis (IE) is an inflammatory disease usually caused by bacteria that enter the bloodstream and establish infections in the inner linings or valves of the heart, including blood vessels. Despite the availability of modern antimicrobial and surgical treatments, IE continues to cause substantial morbidity and mortality. Oral microbiota is considered one of the most significant risk factors for IE. The objective of this study was to evaluate the microbiota present in root canal (RC) and periodontal pocket (PP) clinical samples in cases with combined endo-periodontal lesions (EPL) to detect species related to IE using NGS.

METHODS

Microbial samples were collected from 15 RCs and their associated PPs, also from 05 RCs with vital pulp tissues (negative control, NC). Genomic studies associated with bioinformatics, combined with structuring of a database (genetic sequences of bacteria reported for infective endocarditis), allowed for the assessment of the microbial community at both sites. Functional prediction was conducted using PICRUSt2.

RESULTS

Parvimonas, Streptococcus, and Enterococcus were the major genera detected in the RCs and PPs. A total of 79, 96, and 11 species were identified in the RCs, PPs, and NCs, respectively. From them, a total of 34 species from RCs, 53 from PPs, and 2 from NCs were related to IE. Functional inference demonstrated that CR and PP microbiological profiles may not be the only risk factors for IE but may also be associated with systemic diseases, including myocarditis, human cytomegalovirus infection, bacterial invasion of epithelial cells, Huntington's disease, amyotrophic lateral sclerosis, and hypertrophic cardiomyopathy. Additionally, it was possible to predict antimicrobial resistance variants for broad-spectrum drugs, including ampicillin, tetracycline, and macrolides.

CONCLUSION

Microorganisms present in the combined EPL may not be the only risk factor for IE but also for systemic diseases. Antimicrobial resistance variants for broad-spectrum drugs were inferred based on PICRUSt-2. State-of-the-art sequencing combined with bioinformatics has proven to be a powerful tool for conducting studies on microbial communities and could considerably assist in the diagnosis of serious infections.

CLINICAL RELEVANCE

Few studies have investigated the microbiota in teeth compromised by combined endo-periodontal lesions (EPL), but none have correlated the microbiological findings to any systemic condition, particularly IE, using NGS techniques. In such cases, the presence of apical periodontitis and periodontal disease can increase IE risk in susceptible patients.

Nanomaterials: an intra-periodontal pocket drug-delivery system for periodontitis

Periodontitis is a microbiological condition that affects the tissues supporting the teeth. The fundamental to effective periodontal therapy is choosing the suitable antimicrobial and anti-inflammatory agent, together with the proper route of drug administration and delivery system. Intra-periodontal pocket approach with nano drug-delivery systems (NDDS) such as polymeric nanoparticles, gold nanoparticles, silica nanoparticles, magnetic nanoparticles, liposomes, polymersomes, exosomes, nano micelles, niosome, solid lipid nanoparticles, nano lipid carriers, nanocomposites, nanogels, nanofibers, scaffolds, dendrimers, quantum dots, etc., will be appropriate route of drug administration and delivery system. This NDDS delivers the drugs at the site of infection to inhibit growth and promote tissue regeneration. The present review focused on providing comprehensive information on the NDDS for periodontitis, which enhanced therapeutic outcomes via intra-periodontal pocket delivery.

A Placebo-Controlled Trial to Evaluate Two Locally Delivered Antibiotic Gels (Piperacillin Plus Tazobactam vs. Doxycycline) in Stage III-IV Periodontitis Patients

Background and objectives: this study aims to evaluate the clinical and microbiological effects of a single subgingival administration of a locally delivered antibiotic gel containing piperacillin plus tazobactam and compare it with a slow-release doxycycline (14%) gel and a placebo gel, following subgingival instrumentation (SI) in patients with severe periodontitis. Materials and methods: sixty-four patients diagnosed with stage III-IV periodontitis were enrolled, were randomly assigned into three groups, and were treated additionally with a single subgingival administration of piperacillin plus tazobactam gel (group A); doxycycline gel (group B); and placebo gel (group C). The primary outcome variable was the change in mean probing pocket depth (PPD) 6 months after the intervention. Secondary outcome variables were changes in mean full-mouth bleeding score (FMBS); full-mouth plaque score (FMPS); overall bleeding index (BOP); pocket closure; and clinical attachment level (CAL), along with changes in the numbers of five keystone bacteria: Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Tannerella forsythia (T.f.), and Treponema denticola (T.d.). Intergroup and intragroup differences were evaluated at 3 and 6 months. Results: at baseline, the three groups were comparable. An improvement in clinical parameters such as PPD, CAL, and BOP between groups was observed at 3 and 6 months, but without statistical significance (p > 0.05). At 6 months, the intragroup analysis showed a significant reduction in clinical parameters. Even though the piperacillin plus tazobactam group showed slightly higher PPD reduction, this was not statistically significant when compared to both control groups. Conclusions: The groups had similar results, and subgingival instrumentation can be executed without adjunctive antimicrobials, reducing the costs for the patient and the working time/load of the professional.

Effect of supragingival air polishing on subgingival periodontitis microbiota

Background

Supragingival air polishing of teeth effectively removes dental plaque and extrinsic stain on coronal tooth surfaces, but its impact on specific periodontal pathogens in adjacent subgingival biofilms is not known. This study assessed the microbiological effect of supragingival air polishing on the subgingival microbiota of individuals with severe periodontitis.

Methods

Supragingival air polishing with a sodium bicarbonatebased powder was performed on 15 adult test subjects, with the nozzle of the air polishing device aimed apically at a 45° angle onto tooth surfaces immediately coronal to the entrance of periodontal pockets. Supragingival prophylaxis paste polishing, using a slow-speed handpiece, was carried out on 13 adult control subjects. Subgingival specimens were collected from a single 5 mm to 7 mm periodontal pocket with bleeding on probing in each of the study participants before and immediately after supragingival polishing procedures. Viable bacterial counts and selected putative periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Fusobacterium nucleatum, Parvimonas micra, Campylobacter species) were quantified by microbial culture, and motile morphotypes (spirochetes and motile rods) by phase-contrast microscopy.

Results

Statistically significant decreases were detected after supragingival air polishing in total viable counts (84.9% decrease), in P. intermedia/nigrescens, F. nucleatum, Campylobacter species, total proportions of red/orange complex periodontal pathogens (82.3% decrease), and in motile morphotypes (85.3% decrease). No statistically significant subgingival microbiological changes occurred with supragingival prophylaxis paste polishing.

Conclusion

Supragingival air polishing of teeth, but not supragingival prophylaxis paste polishing, may serve as a useful therapeutic adjunct to disrupt and help remove pathogenic biofilms in deep periodontal pockets.

Correlation of marker periodontopathogenic bacteria with the immune component sCD14 secretion level in inflammatory periodontal diseases

Lipopolysaccharide of the cell wall of gram-negative bacteria is a highly active biological substance: its interaction with toll-like receptors-4 (TLR-4) of myeloid cells leads to the activation of a cascade of inflammatory reactions, which is accompanied by the release of the soluble CD14 receptor (sCD14), which can be considered not only as a marker of cell activation by endotoxin, but also as a marker of microbial translocation. The aim of the work was to assess the prognostic significance of the sCD14 level in the samples of the periodontal pocket in inflammatory periodontal diseases and the relationship of its secretion with marker periodontopathogens. For the study, washes were obtained from the periodontal pocket (88 samples in total) from patients with chronic periodontitis and intact periodontium. The sCD14 content was determined by ELISA; during real-time PCR, the marker periodontopathogens Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, Porphyromonas gingivalis, Prevotella intermedia, and Candida albicans were isolated. The study revealed differences in the level of sCD14 secretion by groups: in chronic periodontitis, its content was 8,5 times higher than in the control group and amounted to 17,2±4,06 ng/ml (p=0,006). The frequency of detecting genes of periodontal pathogenic bacteria was 89,3% in patients with periodontitis and 31,25% in the group with intact periodontium. An interesting dependence of the detection of periodontal pathogenic bacteria in the group of patients with chronic periodontitis was established depending on the content of sCD14. Thus, at high concentrations of soluble coreceptor, a greater number of periodontopathogenic bacteria of the I and II orders were released. Thus, in inflammatory periodontal diseases, the processes of sCD14 synthesis change, which is probably due to the colonization of periodontal pathogenic bacteria and the action of their toxins and aggression factors. The relationship of marker periodontopathogens with the level of secretion of the immune component sCD14 and its effect on the structure of the periodontal index reflect shifts in the processes of reparative regeneration of the oral mucosa and the regulation of local immunity in response to microbial invasion.

Clinical and microbiological effects of a single application of sodium hypochlorite gel during subgingival re-instrumentation: a triple-blind randomized placebo-controlled clinical trial

OBJECTIVES

The aim of this study is to assess the clinical and microbiological effects of a single subgingival administration of sodium hypochlorite gel (NaOCl) and compare it with 1% chlorhexidine (CHX) gel and a placebo gel following mechanical re-instrumentation during supportive periodontal therapy (SPT).

MATERIALS AND METHODS

Sixty-two patients who had been treated for stage III-IV periodontitis and enrolled in SPT were included in the study based on following criteria: (1) active periodontal therapy completed at least 6 months before enrollment in the study, (2) presence of at least 4 non-adjacent sites with probing pocket depths (PPDs) ≥ 4 mm with bleeding on probing (BOP), or presence of 5-8 mm PPDs with or without BOP. All sites presenting PPD ≥ 4 mm and BOP at baseline and 3-, 6-, and 9-month follow-up timepoints were subgingivally re-instrumented with ultrasounds. Selected patients were randomly assigned into three groups and treated additionally with a single subgingival administration of NaOCl gel (group A); 1% CHX gel (group B); and placebo gel (group C). Main outcome variable was pocket closure at 12 months. Secondary outcome variables were changes in mean PPD, BOP, and clinical attachment level (CAL) along with changes in the numbers of the following five keystone bacterial pathogens: Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Tannerella forsythia (T.f.), and Treponema denticola (T.d.).

RESULTS

At 12 months, pocket closure was obtained in 77.5% in the NaOCl treated sites. The reduction in PPD was higher with CHX than with NaOCl, although a statistically significant adjunctive effect for NaOCl (P = 0.028) was only observed in comparison with placebo only. Mean CAL improved in all groups and at all timepoints, compared to the baseline (P < 0.05). However, after 6 months, CAL gain was statistically significantly higher in the NaOCl treated group than following application of CHX (P = 0.0026).

CONCLUSION

In SPT patients, a single adjunctive use of a NaOCl gel may provide benefits in controlling inflammation and residual pockets.

TRIAL REGISTRATION

ISRCTN Registry of Clinical Trials (ISRCTN11387188).

CLINICAL RELEVANCE

A baseline single application of NaOCl gel in conjunction with mechanical debridement may achieve substantial pocket closure in patients enrolled in SPT; treatment time, cost, and applicability considerations should be taken into account when selecting this therapy.

A novel in vitro periodontal pocket model to evaluate the effect of root surface instrumentation on biofilm-epithelial cell interactions

Objective

To develop a novel in vitro periodontal pocket model for evaluating the effect of two different root surface instrumentation modalities on biofilm-epithelial cell interactions.

Materials and methods

An artificial periodontal pocket model was created using an impression material. Dentin discs were prepared and incubated for 3.5 days with a biofilm consisting of 12 bacterial strains. Then, the discs were inserted into the pocket model and instrumented for 10 s or 10 strokes either with ultrasonics (US) or hand instruments (HI). Subsequently, a glass slide coated with epithelial cells was placed in close vicinity to the discs. After incubation of the pocket model in a 5% CO2 atmosphere for 6 h, residual bacteria of the biofilm as well as bacteria adhering to or invaded into epithelial cells were determined using colony-forming unit (cfu) counts and real-time PCR. Further, as a parameter of the pro-inflammatory cell response, interleukin (IL)-8 expression was determined by ELISA.

Results

Compared to untreated control, HI reduced the cfu counts by 0.63 log10 (not significant) and US by 1.78 log10 (p = 0.005) with a significant difference between the treatment modalities favoring US (p = 0.048). By trend, lower detection levels of Tannerella forsythia were detected in the US group compared to HI. Concerning the interaction with epithelial cells, half of the control and the HI samples showed epithelial cells with attaching or invading bacteria, while US displayed bacteria only in two out of eight samples. In addition, US resulted in significantly lower IL-8 secretion by epithelial cells compared to the untreated control. Between HI and controls, no statistically significant difference in IL-8 secretion was found.

Conclusion

This newly developed in vitro model revealed in terms of biofilm-epithelial cell interaction after root surface instrumentation that compared to hand curettes, ultrasonic instrumentation appeared to be more effective in removing bacterial biofilm and in decreasing the inflammatory response of epithelium to biofilm.

Clinical relevance

Ultrasonic instrumentation might be more advantageous to reduce cellular inflammatory response than hand instruments.

[The assessment of a role of muramyl peptides in the treatment of patients with aggressive form of periodontitis]

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 (hnp_1-3) 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 hnp_1-3 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 hnp_1-3, 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 hnp_1-3 in patients with an aggressive form of periodontitis.

Role of the Filifactor alocis Hypothetical Protein FA519 in Oxidative Stress Resistance

In the periodontal pocket, there is a direct correlation between environmental conditions, the dynamic oral microbial flora, and disease. The relative abundance of several newly recognized microbial species in the oral microenvironment has raised questions on their impact on disease development. One such organism, Filifactor alocis, is significant to the pathogenic biofilm structure. Moreover, its pathogenic characteristics are highlighted by its ability to survive in the oxidative-stress microenvironment of the periodontal pocket and alter the microbial community dynamics. There is a gap in our understanding of its mechanism(s) of oxidative stress resistance and impact on pathogenicity. Several proteins, including HMPRFF0389-00519 (FA519), were observed in high abundance in F. alocis during coinfection of epithelial cells with Porphyromonas gingivalis W83. Bioinformatics analysis shows that FA519 contains a "Cys-X-X-Cys zinc ribbon domain" which could be involved in DNA binding and oxidative stress resistance. We have characterized FA519 to elucidate its roles in the oxidative stress resistance and virulence of F. alocis. Compared to the wild-type strain, the F. alocis isogenic gene deletion mutant, FLL1013 (ΔFA519::ermF), showed significantly reduced sensitivity to hydrogen peroxide and nitric oxide-induced stress. The ability to form biofilm and adhere to and invade gingival epithelial cells was also reduced in the isogenic mutant. The recombinant FA519 protein was shown to protect DNA from Fenton-mediated damage with an intrinsic ability to reduce hydrogen peroxide and disulfide bonds. Collectively, these results suggest that FA519 is involved in oxidative stress resistance and can modulate important virulence attributes in F. alocis. IMPORTANCE Filifactor alocis is an emerging member of the periodontal community and is now proposed to be a diagnostic indicator of periodontal disease. However, due to the lack of genetic tools available to study this organism, not much is known about its virulence attributes. The mechanism(s) of oxidative stress resistance in F. alocis is unknown. Therefore, identifying the adaptive mechanisms utilized by F. alocis to survive in the oxidative stress environment of the periodontal pocket would lead to understanding its virulence regulation, which could help develop novel therapeutic treatments to combat the effects of periodontal disease. This study is focused on the characterization of FA519, a hypothetical protein in F. alocis, as a multifunctional protein that plays an important role in the reactive oxygen species-detoxification pathway. Collectively, our results suggest that FA519 is involved in oxidative stress resistance and can modulate important virulence attributes in F. alocis.

Neutrophils Orchestrate the Periodontal Pocket

The subgingival biofilm attached to tooth surfaces triggers and maintains periodontitis. Previously, late-onset periodontitis has been considered a consequence of dysbiosis and a resultant polymicrobial disruption of host homeostasis. However, a multitude of studies did not show "healthy" oral microbiota pattern, but a high diversity depending on culture, diets, regional differences, age, social state etc. These findings relativise the aetiological role of the dysbiosis in periodontitis. Furthermore, many late-onset periodontitis traits cannot be explained by dysbiosis; e.g. age-relatedness, attenuation by anti-ageing therapy, neutrophil hyper-responsiveness, and microbiota shifting by dysregulated immunity, yet point to the crucial role of dysregulated immunity and neutrophils in particular. Furthermore, patients with neutropenia and neutrophil defects inevitably develop early-onset periodontitis. Intra-gingivally injecting lipopolysaccharide (LPS) alone causes an exaggerated neutrophil response sufficient to precipitate experimental periodontitis. Vice versa to the surplus of LPS, the increased neutrophil responsiveness characteristic for late-onset periodontitis can effectuate gingiva damage likewise. The exaggerated neutrophil extracellular trap (NET) response in late-onset periodontitis is blameable for damage of gingival barrier, its penetration by bacteria and pathogen-associated molecular patterns (PAMPs) as well as stimulation of Th17 cells, resulting in further neutrophil activation. This identifies the dysregulated immunity as the main contributor to periodontal disease.

Taxonomic and Gene Category Analyses of Subgingival Plaques from a Group of Japanese Individuals with and without Periodontitis

Periodontitis is an inflammation of tooth-supporting tissues, which is caused by bacteria in the subgingival plaque (biofilm) and the host immune response. Traditionally, subgingival pathogens have been investigated using methods such as culturing, DNA probes, or PCR. The development of next-generation sequencing made it possible to investigate the whole microbiome in the subgingival plaque. Previous studies have implicated dysbiosis of the subgingival microbiome in the etiology of periodontitis. However, details are still lacking. In this study, we conducted a metagenomic analysis of subgingival plaque samples from a group of Japanese individuals with and without periodontitis. In the taxonomic composition analysis, genus Bacteroides and Mycobacterium demonstrated significantly different compositions between healthy sites and sites with periodontal pockets. The results from the relative abundance of functional gene categories, carbohydrate metabolism, glycan biosynthesis and metabolism, amino acid metabolism, replication and repair showed significant differences between healthy sites and sites with periodontal pockets. These results provide important insights into the shift in the taxonomic and functional gene category abundance caused by dysbiosis, which occurs during the progression of periodontal disease.

Characterization of the Treponema denticola Virulence Factor Dentilisin

Treponema denticola is a potent periodontal pathogen that forms a red complex with Porphyromonas gingivalis and Tannerella forsythia. It has many virulence factors, yet there are only a few reports detailing these factors. Among them, dentilisin is a well-documented surface protease. Dentilisin is reported to be involved in nutrient uptake, bacterial coaggregation, complement activation, evasion of the host immune system, inhibition of the hemostasis system, and cell invasion as a result of its action, in addition to its original proteolysis function. Therefore, characterization of dentilisin, and clarifying the relationship between T. denticola and the onset of periodontal disease will be important to better understanding this disease. In this chapter, we explain the methods for analysis of dentilisin activity and pathogenicity.

Effects of Short-Chain Fatty Acids on Human Oral Epithelial Cells and the Potential Impact on Periodontal Disease: A Systematic Review of In Vitro Studies

Short-chain fatty acids (SCFA), bacterial metabolites released from dental biofilm, are supposed to target the oral epithelium. There is, however, no consensus on how SCFA affect the oral epithelial cells. The objective of the present study was to systematically review the available in vitro evidence of the impact of SCFA on human oral epithelial cells in the context of periodontal disease. A comprehensive electronic search using five databases along with a grey literature search was performed. In vitro studies that evaluated the effects of SCFA on human oral epithelial cells were eligible for inclusion. Risk of bias was assessed by the University of Bristol's tool for assessing risk of bias in cell culture studies. Certainty in cumulative evidence was evaluated using GRADE criteria (grading of recommendations assessment, development, and evaluation). Of 3591 records identified, 10 were eligible for inclusion. A meta-analysis was not possible due to the heterogeneity between the studies. The risk of bias across the studies was considered "serious" due to the presence of methodological biases. Despite these limitations, this review showed that SCFA negatively affect the viability of oral epithelial cells by activating a series of cellular events that includes apoptosis, autophagy, and pyroptosis. SCFA impair the integrity and presumably the transmigration of leucocytes through the epithelial layer by changing junctional and adhesion protein expression, respectively. SCFA also affect the expression of chemokines and cytokines in oral epithelial cells. Future research needs to identify the underlying signaling cascades and to translate the in vitro findings into preclinical models.

Development of Oral Care Chip, a novel device for quantitative detection of the oral microbiota associated with periodontal disease

Periodontal disease, the most prevalent infectious disease in the world, is caused by biofilms formed in periodontal pockets. No specific bacterial species that can cause periodontitis alone has been found in any study to date. Several periodontopathic bacteria are associated with the progress of periodontal disease. Consequently, it is hypothesized that dysbiosis of subgingival microbiota may be a cause of periodontal disease. This study aimed to investigate the relationship between the subgingival microbiota and the clinical status of periodontal pockets in a quantitative and clinically applicable way with the newly developed Oral Care Chip. The Oral Care Chip is a DNA microarray tool with improved quantitative performance, that can be used in combination with competitive PCR to quantitatively detect 17 species of subgingival bacteria. Cluster analysis based on the similarity of each bacterial quantity was performed on 204 subgingival plaque samples collected from periodontitis patients and healthy volunteers. A significant difference in the number of total bacteria, Treponema denticola, Campylobacter rectus, Fusobacterium nucleatum, and Streptococcus intermedia bacteria in any combination of the three clusters indicated that these bacteria gradually increased in number from the stage before the pocket depth deepened. Conversely, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Streptococcus constellatus, which had significant differences only in limited clusters, were thought to increase in number as the pocket depth deepened, after periodontal pocket formation. Furthermore, in clusters where healthy or mild periodontal disease sites were classified, there was no statistically significant difference in pocket depth, but the number of bacteria gradually increased from the stage before the pocket depth increased. This means that quantitative changes in these bacteria can be a predictor of the progress of periodontal tissue destruction, and this novel microbiological test using the Oral Care Chip could be effective at detecting dysbiosis.

[Creation of a molecular genetic test system for early diagnosis and evaluation of the effectiveness of treatment of inflammatory periodontal diseases.]

Inflammatory periodontal diseases represent a serious dental and general medical problem due to the high prevalence among the adult population, the presence of clinical forms leading to the destruction of the dentition and tooth loss, insufficient treatment effectiveness and the frequency of relapse, including in connection with the formation of biofilms. A molecular genetic test system has been developed to evaluate the content of periodontopathogenic microorganisms Porphyromonas gingivalis, Treponema denticola, Streptococcus oralis, Streptococcus sanguis and Streptococcus sobrinus in the contents of periodontal pockets. The analytical characteristics of the test system were determined, and testing was carried out on clinical samples of patients with chronic generalized periodontitis of moderate severity. The constructed diagnostic kit allowed us to conduct a comparative analysis of the effectiveness of various types of treatment of inflammatory periodontal diseases based on quantitative data on the content of bacteria in the contents of periodontal pockets.

Microbiological study of the subgingival biofilm in HIV+/HAART patients at a specialized dental service

The aim of this study was to describe the microbiological profile of HIV patients under highly active antiretroviral treatment (HAART). This crosssectional study comprised 32 HIV patients with periodontal disease (PD) who had been under HAART for more than 6 months. Information about the patients' medical history was obtained from clinical records. Clinical dental examination was performed by a calibrated researcher using standard dental instruments to determine probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). A total 4,765 periodontal sites were evaluated, 125 of which were also studied microbiologically. Subgingival biofilm samples were obtained using sterile paper points; one set was used for microbiological culture studies and the other for endpoint PCR. Statistical analysis was performed using KruskalWallis and posthoc DunnBonferroni contrast tests. All participants were on HAART at the time of the study, and 90.6% had a viral load below 50 copies / mm3. Prevalence of periodontally active sites was low in the study population. Microbiological studies: Black pigmented anaerobic bacteria and fusiform CFU counts were significantly higher in samples from sites with BOP and PD ≥4mm (p 0.020 and p 0.005, respectively). Molecular Assays: Detection of Porphyromonas gingivalis (p 0.002), Tannerella forsythia (p 0.023) and Treponema denticola (p 0.015) was significantly more frequent at sites with BOP and PD ≥4mm. Conclusions: The patients living with HIV/AIDS under HAART studied here had low prevalence of clinical periodontal disease signs. However, significant detection of P. gingivalis, T. denticola, and T. forsythia in periodontal active sites, and the involvement of these microorganisms as potential HIV reactivators, show the importance of creating awareness among dental health professionals of the need for close dental and periodontal monitoring in HIV patients.

Comparison of the clinical and microbiological effects of antibiotic therapy in periodontal pockets following laser treatment: An in vivo study

BACKGROUND

Laser technology in periodontal therapy could help in reducing total bacterial count.

OBJECTIVES

The aim of this study was to evaluate the effects of pocket debridement using an erbium-doped yttrium aluminium garnet laser (Er:YAG laser - ERL), scaling and root planing (SRP) with photodynamic therapy (PDT), or SRP alone. Teeth vitality and soft tissue carbonization were also assessed.

MATERIAL AND METHODS

This study included 1,169 single-rooted teeth from 84 patients divided into 3 groups (n = 28). The G1 group had ERL with 40 mJ of energy, a frequency of 40 Hz and a fluence of 63.66 J/cm2. The G2 group had SRP + PDT (635 nm diode laser, 12 J of energy and irradiation time of 30 s) and a Toluidine Blue photosensitizer (PS) (application time of 60 s). The G3 group was administered SRP alone. In the 42 subjects (G1: n = 11, G2: n = 14 and G3: n = 17) with high amounts of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Treponema denticola (Td) and Tannerella forsythia (Tf), additional 1-week antibiotic treatments with clindamycin or amoxicillin + clavulanic acid - in doses of 600 mg/day or 1000 mg/day, respectively - were prescribed 3 months after the therapy. Microbiological and clinical analyses of the probing depth (PD), recession (RC), plaque index (PI), bleeding on probing (BOP), and attachment loss (AT) were performed at baseline and at the follow-up of 3 months, 3 months and 1 week, and 6 months.

RESULTS

Plaque index decreased in G1 after 3 months, 3 months and 1 week, and 6 months (p < 0.05) and was lower in G1 vs G2 after 3 months (p < 0.05). The reduction in BOP in G1 after 3 months and 1 week was higher in comparison with G2 or G3 (p < 0.02). Probing depth decreased in all groups (p < 0.05). We found a reduction in the percentage of sites with some bacteria after 3 months - Prevotella intermedia (Pi) (G1 and G2), Capnocytophaga gingivalis (Cg) and Eubacterium nucleatum (En) (G3), and after 3 months and 1 week with En, Td, Tf (G1, G2 and G3), Pi (G1 and G2), Aa, Peptostreptococcus micros (Pm), and Cg (G3), and with Pi (G1 and G2), Tf (G2), Pg, En (G2 and G3), and Pm (G3) after 6 months (p < 0.05). We observed no signs of carbonization or teeth injury.

CONCLUSIONS

Scaling and root planing + PDT and ERL may be an alternative therapy for chronic periodontitis.

Association Between Clinical and Microbiologic Cluster Profiles and Peri-implantitis

PURPOSE

The correlation between associated local factors and peri-implantitis remains unknown. The aim of this study was to investigate the association between the clinical and microbiologic profiles and peri-implantitis to eventually categorize different groups of this disease.

MATERIALS AND METHODS

Subjects with at least one implant presenting signs of peri-implantitis were selected. The clinical, radiographic, occlusal, and microbiologic profiles of these infected implants were collected. Cases were classified into five peri-implantitis groups according to potential disease-triggering factors: surgically, prosthetically, biomechanically, purely plaque-associated, and a combination of them. Generalized estimating equations models were used to study differences among the potential risk factors. Cluster analyses were applied to investigate the correlation between clinical and microbiologic profiles and diseased implant samples.

RESULTS

Overall, 110 diseased and 121 healthy implants were included. The biomechanically associated group showed higher levels of microbiologic contamination inside the connection; however, the plaque-associated group had a higher level of microbial variety in the peri-implant sulcus. Cluster analyses demonstrated a significant ability to predict the associated factor of peri-implantitis. Moreover, radiographic marginal bone loss and implant width demonstrated the largest influence on the model.

CONCLUSION

While peri-implantitis represents a plaque-induced inflammatory condition, certain local factors might be associated with this biologic complication, as they imply plaque retention. Therefore, disease classification could be further implemented with the associated surgical, prosthetic, and biomechanical factors to better target the etiology.

The subgingival periodontal microbiota of the aging mouth

Different mechanisms have been hypothesized to explain the increase in prevalence and severity of periodontitis in older adults, including shifts in the periodontal microbiota. However, the actual impact of aging on the composition of subgingival biofilms remains unclear. In the present article, we provide an overview of the composition of the subgingival biofilm in older adults and the potential effects of age on the oral microbiome. In particular, this review covers the following topics: (i) the oral microbiota of an aging mouth; (ii) the effects of age and time on the human oral microbiome; (iii) the potential impact of inflammaging and immunosenescence in the host-oral microbiota interactions; and (iv) the relationship of the aging oral microbiota and Alzheimer's disease. Finally, we present analyses of data compiled from large clinical studies that evaluated the subgingival microbiota of periodontally healthy subjects and patients with periodontitis from a wide age spectrum (20-83 years of age).

Zinc plus octenidine: a new formulation for treating periodontal pathogens. A single blind study

Periodontal treatment has the aim to reduce oral infection, and prevent the progression of the disease. The potential benefits of new chemical devices for periodontal therapy, include improved patient compliance, an easier access to periodontal pocket and a lower dosage of antimicrobial agent. The objective of this study was to explore the efficacy of a chemical device containing zinc and octenidine in the treatment of chronic periodontitis in adult patients. Ten patients with a diagnosis of chronic periodontitis (20 localized chronic periodontitis sites) in the age group of 35 to 55 were selected. None of these patients received any surgical or non-surgical periodontal therapy and demonstrated radiographic evidence of moderate bone loss. The chemical device zinc plus octenedine was used by each patient after daily oral hygiene. Microbial analysis were analyzed at baseline and on the 15th day. After the treatment, a remarkable decrease in bacteria amount, both for some species and for the total count was observed in the study group. Specifically T. Forsythia and T. Denticola were eradicated whereas Total Bacteria Loading and Fusobacterium Nucleatum showed a reduction of 38&#x0025; and 55&#x0025;, respectively. Our study demonstrated the efficacy of the new chemical device containing zinc and octenidine in a sustained release drug delivery system in the management of moderate to severe chronic periodontitis.

The periodontal pocket: pathogenesis, histopathology and consequences

The conversion of junctional epithelium to pocket epithelium is regarded as a hallmark in the development of periodontitis. Knowledge of factors contributing to the initiation and progression of pocket formation is important and may result in the development of better preventive measures and improve healing outcomes after therapeutic interventions. The periodontal pocket is a pathologically deepened gingival sulcus. In healthy periodontal conditions, the defense mechanisms are generally sufficient to control the constant microbiological challenge through a normally functioning junctional epithelium and the concentrated powerful mass of inflammatory and immune cells and macromolecules transmigrating through this epithelium. In contrast, destruction of the structural integrity of the junctional epithelium, which includes disruption of cell-to-cell contacts and detachment from the tooth surface, consequently leading to pocket formation, disequilibrates this delicate defense system. Deepening of the pocket apically, and also horizontal expansion of the biofilm on the tooth root, puts this system to a grueling test. There is no more this powerful concentration of defense cells and macromolecules that are discharged at the sulcus bottom and that face a relatively small biofilm surface in the gingival sulcus. In a pocket situation, the defense cells and the macromolecules are directly discharged into the periodontal pocket and the majority of epithelial cells directly face the biofilm. The thinning of the epithelium and its ulceration increase the chance for invasion of microorganisms and their products into the soft connective tissue and this aggravates the situation. Depending on the severity and duration of disease, a vicious circle may develop in the pocket environment, which is difficult or impossible to break without therapeutic intervention.

Microbial colonization of the periodontal pocket and its significance for periodontal therapy

The aim of this paper was to evaluate strategies for periodontal therapy from the perspective of periodontal disease being a consequence of microbial colonization of the periodontal pocket environment. In classic bacterial infections the diversity of the microbiota decreases as the disease develops. In most cases of periodontitis, however, the diversity of the flora increases. Most incriminating bacteria are thought to harm tissues significantly only if present in high numbers over prolonged periods of time. Clinical trials have repeatedly demonstrated that scaling and root planing, a procedure that aims to remove subgingival bacterial deposits by scraping on the tooth surface within the periodontal pocket, is effective. At present, for the therapy of any form of periodontal disease, there exists no protocol with proven superiority, in terms of efficiency or effectiveness, over scaling and root planing plus systemic amoxicillin and metronidazole. Some exponents advocate rationing these drugs for patients with a specific microbial profile. However, the evidence for any benefit of bacteriology-assisted clinical protocols is unsatisfactory. Treated sites are subject to recolonization with a microbiota similar to that present before therapy. The degree and speed of recolonization depends on the treatment protocol, the distribution patterns of periodontal microorganisms elsewhere in the oral cavity and the quality of the patient's oral hygiene. To limit the use of antibiotics and to avoid accumulation of harmful effects by repeated therapy, further efforts must be made to optimize procedures addressing the microbial colonization and recolonization of the periodontal pocket.

The periodontal pocket

Periodontal disease is synonymous with the presence of periodontal pockets, and very often the clinical success of periodontal therapy is based on periodontal pocket depth reduction. Therefore, in the fields of periodontology and implant dentistry, significant research effort has been placed on the etiopathogenesis, diagnosis and treatment of periodontal/peri-implant disease and as a consequence on pocket pathology. In this volume of Periodontology 2000, the in-depth reviews include topics ranging from preclinical models, anatomy and structure of tissues, and molecular and bacterial components, to treatments of pockets around teeth and implants. These reviews aim to provide the readers with current and future perspectives on the different areas of research into the periodontal pocket.

Microbial profile comparisons of saliva, pooled and site-specific subgingival samples in periodontitis patients

Objectives

The purpose of this study was to compare microbial profiles of saliva, pooled and site-specific subgingival samples in patients with periodontitis. We tested the hypotheses that saliva can be an alternative to pooled subgingival samples, when screening for presence of periopathogens.

Design

Site specific subgingival plaque samples (n = 54), pooled subgingival plaque samples (n = 18) and stimulated saliva samples (n = 18) were collected from 18 patients with generalized chronic periodontitis. Subgingival and salivary microbiotas were characterized by means of HOMINGS (Human Oral Microbe Identification using Next Generation Sequencing) and microbial community profiles were compared using Spearman rank correlation coefficient.

Results

Pronounced intraindividual differences were recorded in site-specific microbial profiles, and site-specific information was in general not reflected by pooled subgingival samples. Presence of Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Filifactor alocis, Tannerella forsythia and Parvimona micra in site-specific subgingival samples were detected in saliva with an AUC of 0.79 (sensitivity: 0.61, specificity: 0.94), compared to an AUC of 0.76 (sensitivity: 0.56, specificity: 0.94) in pooled subgingival samples.

Conclusions

Site-specific presence of periodontal pathogens was detected with comparable accuracy in stimulated saliva samples and pooled subgingival plaque samples. Consequently, saliva may be a reasonable surrogate for pooled subgingival samples when screening for presence of periopathogens. Future large-scale studies are needed to confirm findings from this study.

Periodontal microbioma and rheumatoid arthritis: The role of Porhyromonas gingivalis

Rheumatoid Arthritis is a disease, which can be described as an autoimmune response after molecular mimicry caused by infective agents. The current study aims at evaluating the correlation between Rhematoid Arthritis (RA) and Periodontal Disease (PD), with special attention to the microbioma detected in the gums. Thirty-four patients with RD were recruited into the current study. Among rheumatic parameters, Rheumatoid Factor (RF), anti-citrullinated protein antibody (CCP), HLA-BDR1 and DAS28 were collected. A dental clinician evaluated the periodontal screening record (PSR). Afterwards, 1 paper cone was inserted for 30 seconds into the gingival sulcus then sent to the laboratory for evaluation. Quantitative PCR of 16S rRNA genes was performed with the hydrolysis probes method to identify and evaluate the amount Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Fusobacterium nucleatum and Campylobacter rectus. There were no statistical differences in the composition of oral microbioma between PSR groups. There were no statistical significant differences between bacterial loads and serum values. On the contrary, a positive correlation was found between the presence of Porphyromonas gingivalis in periodontal pockets on one side and RF and CCP on the other. Therefore, the presence of Porhyromonas gingivalis in periodontal pockets is associated to RA inflammatory indices.

[The characteristics of microbiota of periodontal recesses in smoking patients with chronic generalized periodontitis]

The clinical examination of 36 tobacco smokers with chronic generalized periodontitis of light, average and severe degree was carried out. The examination established poor hygienic condition of oral cavity, less expressed inflammatory reaction of tissues of periodont and predominance of occurrences of destruction of alveolar portion of bone as compared with the group of 59 non-smoking patients with chronic generalized periodontitis of light, average and severe degree. The study demonstrated higher rate of detection of T. forsythia in smokers as compared with non-smoking patients at all stages of of development of chronic generalized periodontitis. Under light stage of chronic generalized periodontitis increasing of rate of detection of T. forsythia more than twice was registered. P.gigngivalis and P.intermedia were detected in smoking patients with light stage of chronic generalized periodontitis either in the same values or more rarely as compared with non-smokers. In the group of smokers with average stage of chronic generalized periodontitis increasing of rate of occurrence of association of T. forsythia-P. gigngivalis-P. intermedia occurred more than five times in comparison with non-smokers. The obtained results indicate on relationship between alterations of microbiota and aggressive development of chronic generalized periodontitis in smoking patients and on development in periodontal recesses of smokers of favorable conditions for growth of T. forsythia. The presence of T. forsythia is a significant factor of development of destructive processes in tissues of periodont.

Helicobacter pylori in periodontal pockets and saliva: a possible role in gastric infection relapses

It has been a long time since the scientific community started to speculate upon the presence of Helicobacter pylori (HP) in periodontal pockets as an extra-gastric reservoir responsible for gastric relapses after eradication therapy. The aim of this study is to evaluate the presence of oral HP in a group of patients who underwent examination for gastric infection. Sixty patients were enrolled in the current study, subdivided into two groups: 30 patients with a positive result for HP gastric infection with C-Breath Test Urea examination, and 30 patients with a negative result for HP gastric infection. Crevicular fluid and salivary samples were collected in a sterile tube and then sent to the laboratory for evaluation. Specimens were processed to quantify the levels of HP and bacterial load by real time PCR technique. Even though there was no statistically significant difference among the two groups (A vs B) with regard to the total amount of HP in saliva or in periodontal tissues, this study demonstrates that the oral cavity is an extra-gastric reservoir of HP when it is affected by periodontal disease, and that periodontal disease is correlated to gastric HP infection.

Comparative molecular analysis of bacterial species associated with periodontal disease

Periodontal disease is an inflammatory disorder affecting the supporting teeth structures, including gingiva, periodontal ligament and alveolar bone, causing loss of connective tissue, reabsorption of alveolar bone and formation of periodontal pockets. The aim of this study is to find a correlation between bacterial growth and periodontal disease. Fifty-seven patients aged between 21 and 65 years, median age 46 years, were enrolled. According to gingival pocket depth, ranging from 3 to 7 mm, patients were divided into two groups: the first (30 patients, 53%) with deep pockets ³ 5 mm and the second (27 patients, 47%) less than 5 mm. The samples taken were processed for microbiological analysis by absolute quantitative real-time Taq-Man technique. Patients affected by periodontal disease were 32 (56%) and patients with gingival bleeding were 35 (61%). This data showed that the presence, the type and the bacterial load in gingival pockets were strongly correlated with gingival depth, periodontal disease and gingival bleeding. Quantitative microbiological analysis is a key point to improve patient compliance, allowing to choose the specific antibiotic treatment. avoiding antibiotic resistance and ensuring the successful outcome of therapy for periodontal disease.

Microbiologic and Clinical Findings of Implants in Healthy Condition and with Peri-Implantitis

PURPOSE

To compare implants in healthy conditions and implants with peri-implantitis with regard to their clinical parameters and the microbiologic composition at the peri-implant sulcus, inside the implant connection, and the gingival sulcus of neighboring teeth.

MATERIALS AND METHODS

A cross-sectional study was performed including consecutive patients with implants in healthy conditions and with peri-implantitis. Clinical parameters for which patients were screened included bleeding on probing, pocket depth, and plaque index at six sites. Samples for microbiologic analysis were obtained from three locations: the peri-implant sulcus, inside the implant connection, and the gingival sulcus of neighboring teeth. Quantitative real-time polymerase chain reaction (PCR) was carried out for total counts of 10 microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromona gingivalis, Tanerella forsythia, Tanerella denticola, Prevotela intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, and Candida albicans. The response variables were the percentage of positive sites and total bacterial counts.

RESULTS

One hundred twenty-two implants in 57 patients were analyzed in the healthy group and 113 implants in 53 patients in the peri-implantitis group. Differences between the groups were statistically significant for bruxism, probing pocket depth, bleeding on probing, and radiographic bone level. Orange complex species (P intermedia, P micros, F nucleatum) were the most prevalent in the three types of sites for both groups, and prevalence values were higher in the peri-implantitis group. Differences in prevalence between groups were more marked inside the connection than in the peri-implant sulcus. Absolute loads of most microbes and total bacterial counts were higher for the peri-implantitis group in the three locations. Again, differences were bigger inside the connection than at the peri-implant sulcus. Significant interactions were found for prevalence and absolute microbial loads between groups and locations, and for the interaction of group × location.

CONCLUSION

Clinical and microbiologic differences were observed between healthy subjects and those with peri-implantitis. Microbiologic differences between groups were more marked inside the connection than in the peri-implant sulcus. The potential role of the implant connection as a microbial reservoir for peri-implant diseases and in the outcome of their treatment should be confirmed with further studies.

Assessment of the quantity of microorganisms associated with bronchiectasis in saliva, sputum and nasal lavage after periodontal treatment: a study protocol of a randomised controlled trial

INTRODUCTION

The association between periodontal disease (PD) and chronic obstructive pulmonary disease (COPD) has been widely studied, with aspiration of periodontal pathogens being one of the most accepted causal mechanisms for pulmonary exacerbation. Periodontal treatment (PT) was associated with a decrease in these exacerbations. Bronchiectasis is a pulmonary disease that has many similarities to COPD; however, there are no studies correlating this condition to PD thus far. This study will evaluate if PT reduces proinflammatory cytokines in serum and saliva, as well as halitosis and the amount of microorganisms associated with exacerbation of bronchiectasis in saliva, sputum and nasal lavage 3 months after PT.

METHODS AND ANALYSIS

A total of 182 patients with PD and bronchiectasis will be randomly allocated to group 1 (positive control; scaling and root planing (SRP)+oral hygiene (OH)) or group 2 (experimental; SRP+photodynamic therapy+OH). After 3 months, samples of saliva, nasal lavage and sputum will be collected to determine the level of Pseudomonas aeruginosa, Staphylococcus aureus and Porphyromonas gingivalis by quantitative PCR. This protocol will determine the efficacy of PT in reducing the most likely niches of bronchiectasis exacerbation by comparing pre- and post-treatment microbiology samples. Furthermore, there will be assessment of oral halitosis and verification of inflammatory cytokines in serum and saliva.

ETHICS AND DISSEMINATION

This protocol has been approved by the Research Ethics Committee of Universidade Nove de Julho. Data will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT02514226.

Oxygen high level laser therapy is efficient in treatment of chronic periodontitis: a clinical and microbiological study using PCR analysis

In periodontology, lasers have been suggested for the photodynamic therapy (PDT). Such therapy can be defined as the inactivation of cells, microorganisms or molecules induced by light and not by heat. The aim of our study is to assess the effect of Oxygen high-level laser therapy (OHLLT) in removing all bacterial deposits on root or implant surface by means of mechanical instrumentation and laser irradiation. OHLLT has two effects on targeted bacteria and tissues, decontamination and biostimulation. A total of 33 patients were randomly selected with a diagnosis of chronic periodontitis. The patients enrolled were 16 females and 17 males, six smokers and 4 diabetic patients. For each patient a periodontal charting was performed, assessing probing depth, plaque index and bleeding on probing at baseline and after 6 months. Microbiological analysis were performed with PCR Real Time, using paper tips to withdraw gingival fluid in periodontal pockets before and after treatment, at baseline and after 6 months. All patients were treated with OHLLT at baseline, after 1 week, after 2 weeks and every month for 6 months. After 6 months, all periodontal pockets were treated successfully, without complications and no significant differences in results. All clinical parameters showed an improvement, with a decrease both of plaque index (average decrease of 75%), bleeding on probing (average decrease of 62%) and probing depth (average decrease of 1.8 mm). After the treatment, a remarkable decrease in bacteria amount, both for each species and for total bacteria was observed except for Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis demonstrating that this laser protocol is effective on periodontitis treatment. OHLLT is efficient in treatment of chronic periodontitis as demonstrated by clinical and microbiological parameters, going beyond the traditional periodontal therapy.

Microbiological Distribution of Six Periodontal Pathogens Between Untreated Italian and Dutch Periodontal Patients

PURPOSE

To compare prevalence and microbial load of six periodontal pathogens between Italian and Dutch patients affected by chronic periodontitis, using oligonucleotide probe technology.

MATERIALS AND METHODS

Subgingival plaque samples data from 352 Italians and 115 Dutch periodontal patients were analysed and compared. Bleeding on probing, suppuration, probing pocket depth, clinical attachment level, age, gender, ethnicities and smoking habits were recorded. Presence and level of bacterial species were determined by realtime polymerase chain reaction under the identical microbiological protocol. Statistical analysis was performed using the chi-square test, Mann-Whitney U-test and binary unconditional logistic regression (α = 0.05).

RESULTS

Between populations, only Treponema denticola and Porphyromonas gingivalis differed significantly, being more prevalent in the Italian group (p = 0.0001). Except for Tannerella forsythia, all bacterial loads differed significantly: Treponema denticola (p = 0.0001) and Prevotella intermedia (p = 0.001) were higher in Italians, while Porphyromonas gingivalis (p = 0.001), Fusobacterium nucleatum (p = 0.03) and Aggregatibacter actinomycetemcomitans (p = 0.001) were higher in Dutch patients.

CONCLUSIONS

Significant differences in prevalence and bacterial load of periodontal pathogens exist between Italian and Dutch patients affected by chronic periodontitis. The microbiological profile, and particularly the bacterial load of pathogens, varied significantly between populations.

[Sensitivity of microbial associations of periodontal lesions to antibacterial agents]

The aim of the study was the development of approaches to improve the effectiveness of antibiotic therapy in dental practice on the basis of determining the sensitivity of pathogenic microorganisms to antibiotics of different groups.

MATERIAL AND METHODS

The study included determination of the sensitivity of the microbial complexes from wound exudate of periodontal pocket and apical abscess to macrolides, quinolones, penicillins, lincosamides and 5-nitroimidazole. A survey of dentists and dental clinics patients to identify the cause and frequency of use of antibiotics and to identify possible adverse reactions was also conducted.

RESULTS

Dentists prefer macrolide antibiotics, protected penicillins, and fluoroquinolone combined with 5-nitroimidazole. All patients have taken antibiotics themselves at least once a year. Microbial complexes in patients with acute and exacerbated apical periodontitis in 79% of cases are susceptible to amoxicillin/clavulanic acid, to azithromycin - 52%, lincomycin - 36%, 5-nitroimidazole - 68%, ciprofloxacin - 73.7%. In patients with apical abscess high rates of resistance of microbial complexes to all types of antibiotics was revealed (33% for lincomycin 76,1% for ciprofloxacin, 28,6% for 5-nitroimidazole). Patients with moderate to severe periodontitis in 90.5% are sensitive to amoxicillin/clavulanic acid and azithromycin, in 62.4% to lincomycin. Sensitivity to ciprofloxacin was detected in 85.7% of patients, in 14.3% - moderate resistance.

Elevated Matrix Metalloproteinase Levels in Bronchi Infected with Periodontopathogenic Bacteria

Objectives

To determine whether bronchial colonisations/infections with periodontopathogenic bacteria are associated with elevated inflammatory markers such as MMPs, interleukins and Tumor necrosis factor alpha in the bronchial fluid.

Methods

Periodontal status was assessed in consecutive outpatients planned for elective bronchoscopies, and PCR for periodontopathogenic bacteria was performed from a protected specimen brush sample taken from the bronchial mucosa. Additionally, MMPs, interleukins and Tumor necrosis factor alpha were measured in the bronchial fluid.

Results

Out of the four species assessed, one species was found in 13 of 91 (14%) patients, and two in 12 (13%), three in 13 (14%) and all four in 1 (1%) patient, respectively. In multiple linear regression models the presence of Treponema denticola showed a consistent pattern of positive effects in bronchial fluid (Bonferroni adjusted p-values) on the levels of MMP9 (p adj.: 0.028) and MMP12 (p adj.: 0.029). Active smoking was independently associated with increased levels of aMMP8 (p adj.: 0.005) and MMP9 (p adj.: 0.009). Levels of IL-1 ß, IL-8 and Tumor necrosis factor alpha measured in the bronchial fluid were not affected by the presence of periodontopathogenic bacteria.

Conclusions

Bronchial colonisation/infection with Treponema denticola and smoking are independently associated with elevated MMPs (MMP9/MMP12 and MMP8/MMP9, respectively) in the bronchial fluid.

[THE MOLECULAR GENETIC CHARACTERISTIC OF SPECIES CONTENT OF SALIVA AND GINGIVAL RECESS UNDER PERIODONTITIS]

The examination was carried out of samplings of 110 patients with periodontitis (observation group) and 60 patients without pathology of periodont (comparison group). The polymerase chain reaction was used to analyze samples of saliva and contents of periodontal recesses for detecting species-specific DNA fragments of Porphymmonas gigngivalis, Streptococcus macacae, S. mutans, S. oralis, S. salivarius, S. sangis, S. sobrinus, Treponema denticola. In patients with periodontitis S. mutans, S. oralis S. sobrinus were reliably more often detected in the content of periodontal recesses and S. mutans, S. sobrinus i in saliva. In the observation group the rate of detection of association S. mutans--S. oralis--S. sangis--S. sobrinus was significantly exceeded (up to 15.6%, X2 = 9.1, p = 0.004). In ten days of effective treatment of periodontitis reliable decreastng of rate of detection of S. wasoralis, S. sobrinus was observed in contents of periodontal recesses but not in of saliva. The detection of S.sobrinus using technique of polymerase chain reaction in contents of periodontal recesses and/or saliva of patients with periodontitis has a diagnostic value. The detection of S.sobrinus in contents of periodontal recesses is significant both in monoculture and in association S. mutans--S. oralis--S. sangis--S.sobrinus. The absence of S. sobrinus in contents of periodontal recesses testifies effectiveness of treatment of main disease (periodontitis).

Microbiomes of Endodontic-Periodontal Lesions before and after Chemomechanical Preparation

INTRODUCTION

This study was conducted to evaluate the microbiomes of endodontic-periodontal lesions before and after chemomechanical preparation (CMP).

METHODS

Clinical samples were taken from 15 root canals (RCs) with necrotic pulp tissues and from their associated periodontal pockets (PPs) (n = 15) of teeth with endodontic-periodontal lesions before and after CMP. The Human Oral Microbe Identification using Next Generation Sequencing (NGS) protocol and viable culture were used to analyze samples from RCs and PPs. The Mann-Whitney U test and Benjamini-Hochberg corrections were performed to correlate the clinical and radiographic findings with microbial findings (P < .05).

RESULTS

Bacteria were detected in 100% of the samples in both sites (15/15) using NGS. Firmicutes was the most predominant phylum in both sites using both methods. The most frequently detected species in the RCs before and after CMP using NGS were Enterococcus faecalis, Parvimonas micra, Mogibacterium timidum, Filifactor alocis, and Fretibacterium fastidiosum. The species most frequently detected in the PPs before and after CMP using NGS were P. micra, E. faecalis, Streptococcus constellatus, Eubacterium brachy, Tannerella forsythia, and F. alocis. Associations were found between periapical lesions ≤ 2 mm and Desulfobulbus sp oral taxon 041 and with periodontal pockets ≥ 6 mm and Dialister invisius and Peptostreptococcus stomatis (all P < .05, found in the RCs before CMP).

CONCLUSIONS

It is concluded that the microbial community present in combined endodontic-periodontal lesions is complex and more diverse than previously reported. It is important to note that bacteria do survive in some root canals after CMP. Finally, the similarity between the microbiota of both sites, before and after CMP, suggests there may be a pathway of infection between the pulp and periodontium.

A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts

BACKGROUND AND AIM

There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts.

MATERIAL AND METHODS

Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD.

RESULTS

After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts.

CONCLUSION

The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and results in a smooth surface with nearly no residual biofilm that promotes the reattachment of PDL fibroblasts.

Mechanistic analysis of PLGA/HPMC-based in-situ forming implants for periodontitis treatment

In-situ forming implant formulations based on poly(lactic-co-glycolic acid) (PLGA), acetyltributyl citrate (ATBC), minocycline HCl, N-methyl pyrrolidone (NMP) and optionally hydroxypropyl methylcellulose (HPMC) were prepared and thoroughly characterized in vitro. This includes electron paramagnetic resonance (EPR), nuclear magnetic resonance ((1)H NMR), mass change and drug release measurements under different conditions, optical microscopy, size exclusion chromatography (SEC) as well as antibacterial activity tests using gingival crevicular fluid samples from periodontal pockets of periodontitis patients. Based on these results, deeper insight into the physico-chemical phenomena involved in implant formation and the control of drug release could be gained. For instance, the effects of adding HPMC to the formulations, resulting in improved implant adherence and reduced swelling, could be explained. Importantly, the in-situ formed implants effectively hindered the growth of bacteria present in the patients' periodontal pockets. Interestingly, the systems were more effectively hindering the growth of pathogenic bacterial strains (e.g., Fusobacterium nucleatum) than that of strains with a lower pathogenic potential (e.g., Streptococcus salivarius). In vivo, such a preferential action against the pathogenic bacteria can be expected to give a chance to the healthy flora to re-colonize the periodontal pockets.

The effect of metronidazole on the presence of P. gingivalis and T. forsythia at 3 and 12 months after different periodontal treatment strategies evaluated in a randomized, clinical trial

OBJECTIVE

The benefit of full-mouth disinfection (FDIS) over traditional scaling and root planing (SRP) in the treatment of chronic, destructive periodontitis remains equivocal and it is not known whether the use of adjunctive antibiotics may enhance the effect of FDIS. Therefore, the aim of this study was to evaluate the effect of conventional SRP completed over 21 days or 1-day FDIS, with or without systemically delivered adjunctive metronidazole (MET) on the presence of P. gingivalis and T. forsythia after 3 and 12 months.

MATERIALS AND METHODS

One hundred and eighty-four patients with moderate-to-severe periodontitis were randomly allocated to one of four treatment groups; (1) FDIS+MET; (2) FDIS+placebo; (3) SRP+MET; (4) SRP+placebo. Prior to treatment, pooled subgingival samples were obtained from the five deepest pockets. The same sites were sampled again 3 and 12 months after treatment. All samples were analyzed for P. gingivalis and T. forsythia by PCR, whereas A. actinomycetemcomitans and other bacteria were identified by culture techniques.

RESULTS

At baseline, 47% of the samples were positive for P. gingivalis, while almost all samples were positive for T. forsythia. The occurrence of P. gingivalis and T. forsythia was significantly reduced at 3 and 12 months after treatment in the FDIS+MET group, but not in the other treatment groups.

CONCLUSION

FDIS+MET had a significant effect in patients with P. gingivalis and T. forsythia, resulting in a significant reduction in number of patients where these micro-organisms could be detected at 3 and 12 months post-therapy.

Subgingival Microbial and Inflammatory Cell Morphotypes Associated with Chronic Periodontitis Progression in Treated Adults

OBJECTIVE

In a secondary data analysis, this pilot study evaluated the relationship between subgingival biofilm morphotypes and chronic periodontitis progression in treated adults.

METHODS

Periodontal parameters in 47 adults with chronic periodontitis were assessed by a calibrated examiner at baseline and a mean 4.5 years after a non-surgical periodontal therapy regimen. Microbial and inflammatory cell morphotypes in subgingival biofilm specimens from each patient were evaluated with phase-contrast microscopy at baseline, and at post-treatment intervals. Chronic periodontitis progression in patients was defined as ≥ 2 teeth exhibiting ≥ 3 mm interproximal clinical periodontal attachment loss from baseline evaluations. Bivariate and odds ratio analysis assessed baseline and post-treatment variables relative to chronic periodontitis progression.

RESULTS

Eight (17%) patients had chronic periodontitis progression. No baseline clinical, radiographic or microbiological variables, and no post-treatment clinical variables demonstrated statistically significant relationships with chronic periodontitis progression. Elevated post-treatment counts of subgingival spirochetes, medium to large-sized motile rods, and crevicular leukocytes, both alone and concurrently, appeared more frequently in patients experiencing chronic periodontitis progression. A post-treatment occurrence of high concurrent counts of subgingival spirochetes and crevicular leukocytes exhibited the strongest association with chronic periodontitis progression (odds ratio = 10.1; 95% Cl = 2.2, 45.4; p = 0.004), which was greater than with either morphotype alone.

CONCLUSIONS

Joint morphotype analysis of subgingival spirochetes and crevicular leukocytes, as simplified biomarkers of pathogenic biofilm infection and host inflammatory responses in periodontal pockets, may be diagnostically useful in assessing risk of progressive disease in treated chronic periodontitis patients.

[Clinical and putative periodontal pathogens' features of different sites with probing depth reduction after non-surgical periodontal treatment of patients with aggressive periodontitis]

OBJECTIVE

To evaluate the differences of clinical parameters and putative periodontal pathogens in sites of different probing depth (PD) reduction after non-surgical periodontal treatment in patients with aggressive periodontitis (AgP).

METHODS

Clinical examinations including plaque index, probing depth (PD), attachment level (AL) and bleeding index (BI), and full-mouth periapical photographs were collected from 20 patients with AgP. All the patients received non-surgical periodontal treatment, including oral hygiene instruction, supra-gingival scaling, subgingival scaling and root planing (SRP) and were followed up for 6 months post-therapy. Gingival crevicular fluids (GCF) were collected at 1 site in each quadrant before and at the end of 6 months post-therapy. Six kinds of putative periodontal pathogens and 6 kinds of short chain fatty acids (SCFAs) were detected in the GCF samples.

RESULTS

The baseline clinical parameters of PD, AL and BI, the baseline concentration of succinic acid, acetic acid, propionic acid and butyric acid, and the prevalence of Treponema denticola were significantly higher in sites with PD reduction more than 2 mm sites compared with PD reduction no more than 2 mm sites [(7.7 ± 1.2) mm vs. (5.1 ± 1.8) mm, (6.3 ± 1.9) mm vs. (4.5 ± 2.2) mm, 3.8 ± 0.4 vs. 3.3 ± 0.8, 1.66 mmol/L vs. 1.10 mmol/L, 31.67 mmol/L vs.17.78 mmol/L, 3.31 mmol/L vs.1.95 mmol/L, 84.6% vs. 56.1%, P<0.05]. However, there were no significant differences in the clinical parameters, the 6 kinds of putative periodontal pathogen detection and SCFAs concentration between the 2 groups at the end of 6 months post-treatment. In sites with PD>5 mm at the end of 6 months post-therapy, all were found with red complex bacteria infection.

CONCLUSION

The baseline clinical parameters are important factors in predicting PD reduction after non-surgical periodontal treatment in patients with AgP. In sites with deep pockets after non-surgical periodontal treatment, the active control of red complex bacteria is recommended.

How do peri-implant mucositis and gingivitis respond to supragingival biofilm control - an intra-individual longitudinal cohort study

PURPOSE

This single-arm study to compare the gingival with peri-implant mucosal inflammatory response to a mechanical supragingival-supramucosal biofilm control program.

MATERIALS AND METHODS

Twenty-two participants (55.7 ± 11.2 years) with both gingivitis and periimplant mucositis were examined at days 0, 30 and 390 (full mouth/6 sites per tooth/implant [TTH/IMPL]) for visible plaque (VPI), gingival bleeding (GBI), modified plaque (mPlI) and bleeding indexes (mBI), probing depth (PD) and bleeding on probing (BOP). The biofilm control was carried out weekly in the first month and every 3 months thereafter. An intention-to-treat analysis was performed (drop-out rate = 8) and linear models were used against comparisons in order to look at the clustering of TTH/IMPL by each individual.

RESULTS

VPI/mPlI and GBI/mBI reduced from day 0 onwards. Intra-group reductions (P < 0.05) were observed at day 30. PD values (in mm) were higher (P < 0.001) for IMPL than for TTH [mean difference (95% CI) at day 0: -1.10 (-1.58 to -0.63); day 30: -0.88 (-1.28 to -0.48); and day 390: -0.60 (-0.84 to -0.33)], where both groups showed reductions (P < 0.05) throughout the study. BOP was greater (P = 0.00001) for IMPL at baseline [mean difference (95% CI): -0.24 (-0.31 to -0.17)] but reduced (P = 0.00001) and showed similar levels to TTH from day 30 onwards. With regard to sites with the greatest PD, BOP reduced (P < 0.05) in both IMPL and TTH, with greater PD reductions observed for IMPL (P = 0.00001).

CONCLUSIONS

The supragingival-supramucosal biofilm control benefited both teeth and implants.

Occurrence of socransky red complex in pregnant women with and without periodontal disease

PURPOSE

To verify the presence of Socransky Red Complex (Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia) and P. intermedia using polymerase chain reaction (PCR) in periodontally healthy pregnant women and pregnant women with periodontal disease, as well as its relation to arterial blood pressure and capillary glycaemia.

MATERIALS AND METHODS

This case control study included 86 pregnant women, including 50 pregnant women with healthy periodontium, 27 with gingivitis and 9 with periodontitis. Arterial blood pressure and glycaemia were evaluated and recorded. Clinical specimens from the gingival crevice or periodontal pockets were gathered with sterile absorbent paper cones. DNA extraction was accomplished using the Easy-DNA Kit test and the presence of bacteria was detected by PCR with primers and specific probes for each microorganism.

RESULTS

The arterial pressure of all pregnant women was found to be within normal levels and 51% presented with hyperglycaemia, these two variables were not associated with periodontal conditions and/or presence of microorganisms. Socransky Red Complex was not present in pregnant women with healthy periodontium; however, it was present in pregnant women with gingivitis (3.7%) and in a higher percentage of pregnant women with periodontitis (33.3%).

CONCLUSION

Socransky Red Complex was found only in cases of periodontal diseases and is not related to blood pressure and/or high levels of blood glucose.

[Features of adhesion of anaerobic periodontopathogenic bacteria and Candida albicans fungi to experimental samples of basis dental plastic depending on surface roughness and polishing method]

AIM

Study the main surface parameters of milled polyacrylic materials using atomic force microscopy and primary microbial adhesion of periodontopathogenic group bacteria and Candida albicans fungi taking into consideration the method of sample polishing.

MATERIALS AND METHODS

Studied samples: mill-treated without polishing (control); ergobox polished; polished in dental laboratory conditions; polished by a rubber brush in dentists' office. Microbial strains belonging to periodontopathogenic species (clinical isolates) that had been isolated from periodontal pockets of periodontitis patients: Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus sanguis, C. albicans fungi were used for modelling experiments of primary adhesion of microbes to the material samples.

RESULTS

S. sanguis had the highest degree of adhesion to polymer after milling, P. gingivalis, C. albicans--medium, F. nucleatum--low. A significant reduction of adhesion is observed during polishing in dental laboratory conditions or ergobox, less significant--during polishing in dental office.

CONCLUSION

The data obtained allow to make a conclusion that the samples from polymer materials for preparation of prosthesis basis have varying degree of intensity of microbial adhesion of members of periodontopathogenic microflora and C. albicans fungi that depends on the polishing method, that accordingly determined the differences in colonization resistance against formation of microbial biofilm during polymer use in clinical conditions. . ,

Microbial diversity similarities in periodontal pockets and atheromatous plaques of cardiovascular disease patients

Background and Objective

The immune and infectious alterations occurring in periodontitis have been shown to alter the development and severity of cardiovascular disease. One of these relationships is the translocation of oral bacteria to atheroma plaques, thereby promoting plaque development. Thus, the aim of this study was to assess, by 16s cloning and sequencing, the microbial diversity of the subgingival environment and atheroma plaques of patients concomitantly suffering from periodontitis and obstructive coronary artery atherosclerosis (OCAA).

Methods

Subgingival biofilm and coronary balloons used in percutaneous transluminal coronary angioplasty were collected from 18 subjects presenting with generalized moderate to severe periodontitis and OCAA. DNA was extracted and the gene 16S was amplified, cloned and sequenced.

Results

Significant differences in microbial diversity were observed between both environments. While subgingival samples mostly contained the phylum Firmicutes, in coronary balloons, Proteobacteria (p<0.05) was predominant. In addition, the most commonly detected genera in coronary balloons were Acinetobacter, Alloprevotella, Pseudomonas, Enterobacter, Sphingomonas and Moraxella, while in subgingival samples Porphyromonas, Filifactor, Veillonella, Aggregatibacter and Treponema (p<0.05) were found. Interestingly, 17 identical phylotypes were found in atheroma and subgingival samples, indicating possible bacterial translocation between periodontal pockets and coronary arteries.

Conclusion

Periodontal pockets and atheromatous plaques of cardiovascular disease patients can present similarities in the microbial diversity.

Metronidazole alone or with amoxicillin as adjuncts to non-surgical treatment of chronic periodontitis: a secondary analysis of microbiological results from a randomized clinical trial

AIM

To evaluate the changes occurring in the subgingival microbial profile of subjects with generalized chronic periodontitis (ChP) treated by scaling and root planing (SRP) alone or with metronidazole (MTZ) or MTZ + amoxicillin(AMX). A secondary aim was to examine a possible added effect of chlorhexidine(CHX) to these therapies.

METHODS

One hundred and eighteen subjects were randomly assigned to receive SRP-only or with MTZ [400 mg/thrice a day (TID)] or MTZ + AMX (500 mg/TID) for 14 days. Half of the subjects in each group rinsed with 0.12% CHX twice a day (BID) for 2 months. Nine subgingival plaque samples/subject were analysed by checkerboard DNA–DNA hybridization for 40 bacterial species at baseline, 3, 6 and 12 months post-therapy.

RESULTS

At 12 months, the antibiotic-treated groups harboured lower mean counts and proportions of key periodontal pathogens than the SRP group (p < 0.05). These benefits were observed at initially deep and shallow sites. Initial reductions in periodontal pathogens obtained with SRP partially rebound after 12 months. CHX rinsing enhanced the microbiological effects of the MTZ + AMX treatment in shallow sites.

CONCLUSION

The adjunctive use of MTZ and MTZ + AMX results in a greater reduction in the levels of periodontal pathogens in generalized ChP subjects compared to SRP alone.

Recovery of putative periodontal pathogens from curette sampling at different depths of periodontal lesions: an in vivo cross-sectional clinical study

OBJECTIVE

The aim of this study was to evaluate the effect of the depth of curette sample collection from periodontal lesions on the recovery of putative periodontal pathogens using real-time polymerase chain reaction (PCR).

METHODS

Twenty-two periodontal pockets 6 to 8 mm deep with bleeding on probing at a single-rooted tooth were sampled, yielding 66 separate samples. Curette samples were obtained at three different levels of the periodontal lesion (orifice, shallow--2 mm into the pocket; or base of lesion), and processed using PCR to identify 10 periodontal pathogens. The chi-square procedure was used to determine whether probe depth affected the distribution of bacterial counts observed. A repeated measures analysis of variance tested the hypotheses related to level of probe and microorganism on mean rank of bacterial counts.

RESULTS

The effect of probe level on mean bacterial counts depends on the type of microorganism. Likewise, the effect of microorganism type on mean bacterial counts significantly depends on probe level, where sampling from 2 mm into the periodontal pocket was found to yield significantly higher results than sampling from the orifice. Overall mean counts of pathogenic microorganisms were found to differ significantly across the three probe depths. The microorganisms differed in their observed levels over all three probe levels. Further analysis found several significant differences that characterize the nature of the interaction between probe level and microorganism type.

CONCLUSION

There is significant difference in the amount of putative periodontal pathogens at varying depths of the pocket when sampled with a periodontal curette.