Comparison of culture and real-time PCR for detection and quantification of five putative periodontopathogenic bacteria in subgingival plaque samples

Real-Time PCR Method as Diagnostic Tool for Detection of Periodontal Pathogens in Patients with Periodontitis

The most common type of periodontal disease is chronic periodontitis, an inflammatory condition caused by pathogenic bacteria in subgingival plaque. The aim of our study was the development of a real-time PCR test as a diagnostic tool for the detection and differentiation of five periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola, in patients with periodontitis. We compared the results of our in-house method with the micro-IDent® semiquantitative commercially available test based on the PCR hybridization method. DNA was isolated from subgingival plaque samples taken from 50 patients and then analyzed by both methods. Comparing the results of the two methods, they show a specificity of 100% for all bacteria. The sensitivity for A. actinomycetemcomitans was 97.5%, for P. gingivalis 96.88%, and for P. intermedia 95.24%. The sensitivity for Tannerella forsythia and T. denticola was 100%. The Spearman correlation factor of two different measurements was 0.976 for A. actinomycetemcomitans, 0.967 for P. gingivalis, 0.949 for P. intermedia, 0.966 for Tannerella forsythia, and 0.917 for T. denticola. In conclusion, the in-house real-time PCR method developed in our laboratory can provide information about relative amount of five bacterial species present in subgingival plaque in patients with periodontitis. It is likely that such a test could be used in dental diagnostics in assessing the efficacy of any treatment to reduce the bacterial burden.

A Fluorogenic DNAzyme for A Thermally Stable Protein Biomarker from Fusobacterium nucleatum, a Human Bacterial Pathogen

Fusobacterium nucleatum has been correlated to many poor human conditions including oral infections, adverse pregnancies and cancer, and thus molecular tools capable of detecting this human pathogen can be used to develop diagnostic tests for them. Using a new selection method targeting thermally stable proteins without a counter-selection step, we derived an fluorogenic RNA-cleaving DNAzyme, named RFD-FN1, that can be activated by a thermally stable protein target that is unique to F. nucleatum subspecies. High thermal stability of protein targets is a very desirable attribute for DNAzyme-based biosensing directly with biological samples because nucleases found inherently in these samples can be heat-inactivated. We further demonstrate that RFD-FN1 can function as a fluorescent sensor in both human saliva and human stool samples. The discovery of RFD-FN1 paired with a highly thermal stable protein target presents opportunities for developing simpler diagnostic tests for this important pathogen.

Efficacy of Bioceramic and Calcium Hydroxide-Based Root Canal Sealers against Pathogenic Endodontic Biofilms: An In vitro Study

Background

Complete eradication of root canal pathogens cannot be predictably achieved by chemomechanical preparation and root canal disinfection. Therefore, an obturation material that has superior antimicrobial activity and sealing ability is required to inactivate residual microbes and prevent them from reentering the root canal system. Recently developed bioceramic root canal sealers are hydraulic cement which form calcium hydroxide during the hydration process. Like calcium hydroxide sealers, they exert an antimicrobial effect by releasing hydroxyl ions and increasing the pH.

Objective

The objective of this study was to evaluate and compare the antimicrobial activity of a calcium hydroxide-based sealer and two bioceramic sealers against Porphyromonas gingivalis, Enterococcus faecalis, and Candida albicans biofilms.

Materials and Methods

The sealers were dissolved in sterile saline to obtain supernatants. Biofilm formation assays, colony counting, and real-time polymerase chain reaction (PCR) were performed to evaluate the antimicrobial activity of each supernatant. The data were analyzed using one-way analysis of variance.

Results

All sealers exerted effects against all three microbial biofilms. The biofilm formation assays showed that the bioceramic sealers were more effective against P. gingivalis and E. faecalis biofilms. In contrast, colony counting and real-time PCR showed that the calcium hydroxide sealer was significantly more effective than the bioceramic sealers. All tests showed that the calcium hydroxide sealer was more effective against C. albicans, with the colony count and real-time PCR results showing statistically significant differences.

Conclusion

The calcium hydroxide-based sealer was more effective than the bioceramic sealers in eradicating pathogenic root canal biofilms.

Influence of Anti-Infective Periodontal Therapy on Subgingival Microbiota Evaluated by Chair-Side Test Compared to qPCR—A Clinical Follow-Up Study

A chair-side test (CST) for five periodontal pathogens (Aggregatibacter actinomycetemcomitans, A.a.; Porphyromonas gingivalis, P.g.; Prevotella intermedia, P.i.; Treponema denticola, T.d.; Tannerella forsythia, T.f.) was compared with qPCR in a previous clinical study on 100 periodontitis patients at first diagnosis (T0). Following non-surgical treatment alone (SRP) or in combination with systemic or local antibiotics, 74 patients (57.4 ± 13.5 years) were again tested at the same sites from 14 to 24 months after T0. Bacterial elimination (%; compared to T0) was determined for each single species and compared between both test systems. In all patients, all five pathogens could not be fully eliminated regardless of therapy or test method. Tested with CST, the mean elimination ranged from 90% for SRP + Amoxicillin/Metronidazole to 59.13% for SRP only. The corresponding qPCR values were 30% and 29.6%. Only A.a. was eradicated in 100% by SRP + Amoxicillin/Metronidazole tested by CST, and it was 80% when qPCR was the test method. CST agreed with qPCR in 98.7% in the detection of A.a., and 74.3%, 78.4%, 73.0%, and 48.7% for P.g., P.i., T.d., and T.f., respectively. Neither conventional treatment nor the additional use of antibiotics—even with the correct indication—could completely eradicate the tested pathogens or prevent pocket reinfection.

In Vitro Antibacterial Activity of Myrtus communis L. and Marrubium vulgare L. Leaves against Aggregatibacter actinomycetemcomitans and Eikenella corrodens

Materials and Methods

Clinical strains of Aggregatibacter actinomycetemcomitans and Eikenella corrodens and two reference strains of A. actinomycetemcomitans were tested. The antibacterial activity of each studied plant extract was evaluated using agar diffusion and broth microdilution assays.

Results

Both aqueous and methanolic extracts of M. communis exhibited high antibacterial activity against periodontal pathogens as compared to M. vulgare extracts. At concentrations of 2.5-0.32 mg/disc, inhibition zones of the methanolic extract of M. communis ranged from 19.66 ± 0.57 to 12.33 ± 0.57 mm. The methanolic extract of M. vulgare showed at concentrations of 5-0.63 mg/disc inhibition zones ranging from 15.66 ± 0.57 to 12 ± 0.00 mm. Its aqueous extract at concentration of 0.63 mg/disc showed no antimicrobial activity against the clinical and reference strain of A. actinomycetemcomitans. Conclusion. This study showed that methanolic and aqueous extracts of M. communis and M. vulgare have in vitro an antibacterial activity against periodontal pathogens. They could be use as ingredients of an oral antimicrobial agent for prevention or treatment of periodontal diseases. Further research on isolating the compounds from these plant extracts and their toxicity effect could be conducted.

Bacterial composition of subgingival plaque in crowded and noncrowded teeth

INTRODUCTION

Patients with dental crowding, even with good oral hygiene, may show increased bacterial presence in the crowded area. This study aimed to determine the microbial composition of subgingival plaque in crowded and noncrowded dental regions.

METHODS

Forty dental students with anterior dental crowding, who were aware of correct brushing techniques and oral hygiene, were enrolled in this study. After orthodontic records were taken and the periodontal examination was performed, subgingival plaque samples were collected from the crowded (experimental) and noncrowded regions (control) of each patient. Colony counting was performed for Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), and streptococcus species.

RESULTS

The mean amount of Aa and Pg colonies was significantly higher in crowded areas (P <0.0001), but there was no significant difference between streptococcus species colonization and crowding. Aa and Pg colonization had a significant direct relation with the amount of crowding. (P <0.0001).

CONCLUSIONS

Crowded dental areas, even with good oral hygiene, are more suitable environments for Aa and Pg colonization.

Clinico-microbiological Efficacy of Indocyanine Green as a Novel Photosensitizer for Photodynamic Therapy among Patients with Chronic Periodontitis: A Split-mouth Randomized Controlled Clinical Trial

Objective:

Conventional nonsurgical periodontal therapy, i.e., scaling and root planing (SRP), is not sufficient to completely eradicate the microorganisms present in dental plaque biofilm due to the incapability of instruments to reach the inaccessible areas of a tooth with anatomical variations. Hence, to increase the effectiveness of SRP, many adjunctive treatment strategies are proposed, including photodynamic therapy (PDT). Therefore, the purpose of this study was to determine the clinical and microbiological efficacy of PDT using Indocyanine green (ICG) as a novel photosensitizer for the treatment of chronic periodontitis.

Materials and Methods:

Twenty individuals who fulfilled the eligibility criteria were enrolled for this randomized controlled clinical trial using split-mouth design. Treatment sites from each individual were randomly allocated into two groups: SRP was done for the sites of the control group and an additional session of PDT using ICG was performed for the sites of the test group. Subgingival plaque samples were collected from both the sites and sent for quantitative analysis of Treponema denticola, Porphyromonas gingivalis, and Tannerella forsythia using real-time polymerase chain reaction (RT-PCR) technique. Probing pocket depth (PD), clinical attachment loss (CAL), and count of all the three microorganisms were assessed at baseline and after 3 months.

Results:

After 3 months, PD and CAL showed statistically significant improvement in the test sites (P < 0.001) compared to the control sites. However, the differences in the microbiological parameters were statistically nonsignificant between the groups.

Conclusion:

ICG as a photosensitizer may enhance the outcomes of SRP and can be used for PDT for the nonsurgical management of periodontal diseases.

Comparison of irrigation protocols for the internal decontamination of dental implants-results of in vitro and in vivo studies

OBJECTIVES

Previous investigations have shown a progressive bacterial colonization of the internal cavities of two-piece dental implants with possible implications for peri-implant bone loss. The aim of the study was to compare different irrigation protocols for the internal decontamination of implants in vitro and in vivo.

MATERIALS AND METHODS

In the in vitro part, 80 samples were obtained 24 h after inoculation with an aliquot of subgingival bacteria from 40 implants as follows: before and after either cleaning with a brush and an irrigation solution (irrigation-brush-irrigation: test) or repeated irrigation alone (irrigation-irrigation: control). In the clinical study, 40 samples from twenty partially edentulous patients contributing each with one implant were collected after removal of abutment and suprastructure with sterile paper points immediately before and after decontamination and subsequently analyzed for total bacterial counts (TBC) by real-time-PCR. Irrigation solutions were chlorhexidine (0.2% (CHX)), H₂ O₂ (10%), alcohol (70%, (ALC)), and NaCl (0.9%). Differences in proportional reduction of TBC between the four irrigation solutions were analyzed.

RESULTS

Irrigation with H₂ O₂ showed the highest effect in both parts of the study (relative TBC reduction in vitro: H₂ O₂ : 87.1%, CHX: 56.9%, ALC: 43.7%, NaCl: 42.7%; in vivo: H₂ O₂ : 51.4%, ALC: 30.4%, NaCl: 26.3%, CHX: 7.1%). The additional use of a brush showed no beneficial effect (p = 0.088). Overall, H₂ O₂ was superior to all other irrigation solutions with regard to relative TBC reduction.

CONCLUSIONS

The present results indicate the potential of an irrigation protocol that includes a 10% H₂ O₂ solution for the internal decontamination of implants. (ClinicalTrials.gov NCT01917305).

A View on Polymerase Chain Reaction as an Outstanding Molecular Diagnostic Technique in Periodontology

Objectives

This study presents a discussion on the fundamentals of polymerase chain reaction (PCR) and its use as a diagnostic tool in periodontology.

Materials and Methods

A computer-aided as well as hand-made search in PubMed and Scopus indexed journals (relevant to the topic) was done by keywords of molecular technique in periodontology, PCR, applications of PCR, and PCR in periodontics. Only the papers in the English language and outlining PCR and its association with periodontology were collected and utilized to provide a succinct review. There was no limitation for publication time.

Results

The results of our search showed that PCR has turned into a standard in diagnosis in the field of periodontology. A variety of researches has demonstrated that its sensitive, and specific characteristics make it a quick and effective technique of recognition, identification, and quantification of microorganisms. Identification of various immunoinflammatory markers at the mRNA expression level as well as ascertaining gene-related polymorphisms can also be performed.

Conclusions

The mechanisms of periodontal disease can further become clarified using PCR. Clinical Relevance. PCR as a diagnostic method can play a main part in the validation of the clinical diagnosis of periodontal disease indicating the reason, pathogenesis, clinical steps, progress, and prognosis of the disease.

Efficacy of salivary versus subgingival bacterial sampling for the detection and quantification of periodontal pathogens

Purpose

The aim of this study was to investigate the efficacy and validity of subgingival bacterial sampling using a retraction cord, and to evaluate how well this sampling method reflected changes in periodontal conditions after periodontal therapy.

Methods

Based on clinical examinations, 87 subjects were divided into a healthy group (n=40) and a periodontitis group (n=47). Clinical measurements were obtained from all subjects including periodontal probing depth (PD), bleeding on probing (BOP), clinical attachment loss (CAL), and the plaque index. Saliva and gingival crevicular fluid (GCF) as a subgingival bacterial sample were sampled before and 3 months after periodontal therapy. The salivary and subgingival bacterial samples were analyzed by reverse-transcription polymerase chain reaction to quantify the following 11 periodontal pathogens: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythus (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Pavimonas micra (Pm), Campylobacter rectus (Cr), Prevotella nigrescens (Pn), Eikenella corrodens (Ec), and Eubacterium nodatum (En).

Results

Non-surgical periodontal therapy resulted in significant decreases in PD (P<0.01), CAL (P<0.01), and BOP (P<0.05) after 3 months. Four species (Pg, Tf, Pi, and Pm) were significantly more abundant in both types of samples in the periodontitis group than in the healthy group. After periodontal therapy, Cr was the only bacterium that showed a statistically significant decrease in saliva, whereas statistically significant decreases in Cr, Pg, and Pn were found in GCF.

Conclusions

Salivary and subgingival bacterial sampling with a gingival retraction cord were found to be equivalent in terms of their accuracy for differentiating periodontitis, but GCF reflected changes in bacterial abundance after periodontal therapy more sensitively than saliva.

Anti-Early Stage of Bacterial Recolonization Effect of Curcuma longa Extract as Photodynamic Adjunctive Treatment

Objective

To evaluate the amount of Fusobacterium nucleatum (F. nucleatum) and Prevotella intermedia (P. intermedia) on subgingival recolonized plaque after mechanical debridement and photodynamic treatment by using blue light-emitting diodes (LEDs) in combination with topical Curcuma longa gel extract.

Methods

A total of 12 subjects with stage III grade B periodontitis were recruited for the study. Maxillary posterior teeth with periodontal pocket >4 mm were selected. These teeth were examined for periodontal clinical data at baseline and at 1, 2, 4, and 6 weeks after treatment. All remaining teeth were treated by scaling and root planing (SRP). Then, the teeth were bilaterally divided using randomized split-mouth design with and without photodynamic adjunctive therapy (PDT). Samples of the subgingival microbiota were obtained in each visit. All samples were analyzed by multicolor TaqMan real-time polymerase chain reaction (PCR) for the presence of target bacteria.

Results

Throughout the six-week follow-up, long-term improvement of probing depth and bleeding on probing was revealed on the PDT group. The number of subgingival F. nucleatum and P. intermedia also significantly reduced, compared to the baseline. There was a statistically significant recolonization in F. nucleatum and P. intermedia number after 2 and 4 weeks of conventional SRP, respectively. Our quantitative PCR method showed no significant recolonization of those subgingival bacteria on PDT sites throughout the 6-week study duration.

Conclusion

The results showed that adjunctive photodynamic treatment by using blue LEDs in combination with topical Curcuma longa gel extract was effective to alter the recolonization patterns of F. nucleatum and P. intermedia after conventional debridement.

Short-term variation in the subgingival microbiota in two groups of patients treated with clear aligners and vestibular fixed appliances: A longitudinal study

OBJECTIVE

To evaluate the subgingival microbiological changes during the first six months of therapy with clear aligners (CAs) and fixed appliances (FAs). The null hypothesis was that there would be no microbiological differences between the two.

SETTING/SAMPLE

Two groups of patients to be treated, respectively, with CAs (14 patients; 9 females and 5 males; mean age 21 years ± 0.25) and FAs (13 patients; 8 females and 5 males; mean 14 years ± 0.75) were consecutively recruited.

MATERIALS AND METHODS

Subgingival microbiological samples were obtained at the right upper central incisor and right first molar at four different time points: before appliance fitting (T0), and at 1 month (T1), 3 months (T3) and 6 months (T6) thereafter. Total bacterial load (TBL) and counts of the bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Campylobacter rectus, Treponema denticola and Tannerella forsythia were determined using real-time PCR.

RESULTS

Total bacterial load did not vary in the CA group, while a significant increase was detected after 3 and 6 months of treatment in the FA group. Unlike red complex species, C rectus and F nucleatum were often detected: levels remained stable in the CA group but increased progressively in the FA group.

CONCLUSION

The type of orthodontic appliance influences the subgingival microbiota. TBL increased in the FA group but not in the CA group, although the levels of the individual periodontal pathogenic bacteria species did not significantly increase during the observation period.

Sequencing of Porphyromonas gingivalis from saliva in patients with periodontitis and type 2 diabetes mellitus

Background

Porphyromonas gingivalis is a major periodontal pathogen. Saliva is the most easy, non-invasive microbiological sample for detection of periodontal pathogens.

Aim and Objectives

A prospective study on 37 diabetic patients was grouped into well-controlled diabetes with/without periodontitis and uncontrolled diabetic with periodontitis. PCR and sequencing of P. gingivalis was performed in saliva samples.

Materials and Methods

DNA was extracted from saliva using Triton X-100 and 16s rRNA gene (404 bp) was amplified by polymerase chain reaction. DNA sequencing was performed for two samples.

Results

P. gingivalis was detected in 27.03% (n = 10), of which 30% (n = 9) were diabetic with periodontal disease and 14.3% (n = 1) were diabetic without periodontal disease. The percentage of poor oral hygiene was 50% and 20% in uncontrolled and controlled glycaemic patients, respectively. DNA sequencing of two samples showed 100% identity with the sequences in the GenBank database (Gen Bank accession no: KX640913-KX640914).

Conclusion

Type 2 diabetes mellitus and periodontitis are interlinked. Early detection of P. gingivalis and appropriate treatment with doxycycline will also assist in controlling the glycaemic status.

Among Live and Dead Bacteria, the Optimization of Sample Collection and Processing Remains Essential in Recovering Gut Microbiota Components

The human gut microbiota plays an important role in human health. Accessing and culturing the gut microbes remains critical in microbiology. The culturomics approach, combined with sequencing strategies, provides new insights in the study of gut microbiota components. However, we are still far from having described all the microbes. Many factors are involved in recovering as much bacteria as possible. One of the most important factors is sample preparation and conservation. The aim of the present work was to evaluate three different types of stool sample conditioning by mainly studying the effect of atmospheric oxygen on bacterial viability and culturability. Quantitative analysis of fecal samples from eight different healthy individuals was carried out using a culture-independent method (flow cytometry) and a culture-dependent method (plating technique). We found that the cultured bacteria reached a 50% yield when the samples were exposed to oxygen for 120 min without any protectant medium, while the percentage of culturability increased to 67% in the presence of antioxidants. More importantly, when samples were exposed to oxygen for less than 2 min, combined with the work under the anaerobic chamber, no discordance was found between the two counting techniques and the culturability increased to 87%. Our study confirmed the importance of sample conditioning to preserve the bacterial viability in samples, especially for oxygen-sensitive intestinal bacteria.

Microbiological Response to Periodontal Therapy: A Retrospective Study

BACKGROUND

Periodontitis is a multifactorial infection caused by a complex of pathogenic bacterial species that induce the destruction of periodontal structures.

OBJECTIVE

The aim of this study is to evaluate the presence and bacterial load of six periodontal pathogens bacteria, measured at initial visit and after osseous surgery in patients affected by chronic periodontitis and treated between 2005 and 2007.

METHODS

This cohort study was carried out on a sample of 38 consecutive patients affected by severe chronic periodontitis, diagnosed at baseline on the basis of probing depths equal to 6.68 ± 1.47 mm. On each subject, a microbiological test was performed before periodontal initial therapy and after osseous surgery (one year later). Five compromised teeth were chosen for each patient (the same teeth, before and after surgery), for a total of 190 teeth. Real-time PCR based analysis computed total bacterial load of the samples and quantified six periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum and Prevotella intermedia. Data collection was made consulting medical charts.

RESULTS

Pocket probing depth reduction after surgery was 4.50 ± 1.54 mm (p=0.0001). The mean number of sites with bleeding at baseline was 2.08 ± 1.17 and 0.58 ± 1.00 after surgery (p=0.001). The mean number of sites with suppuration at baseline was 0.26 ± 0.86 and 0 after surgery (p=0.02). Cell count of each pathogen and total cell count were significantly higher at baseline than after surgery. Almost all bacteria presented a mean percentage reduction equal to that of the total count, except for Aa and Pi, which seemed to show a greater resistance. The difference of bacterial load, both before and after surgery, between smokers and non-smokers was not statistically significant (p<0.05). A statistically significant correlation was detected between pocket probing depth variation and bleeding on probing variation before and after the surgery, controlling for age (r=0.6, p=0.001). No significant correlations were observed between pocket probing depth and bacterial loads, except for Pg (r=0.5, p=0.001), Tf (r=0.6, p=0.001) and Td (r=0.4, p=0.02).

CONCLUSIONS

Reduction of presence and bacterial load of the examined periodontal pathogens bacteria after osseous surgery, along with periodontal pocket reduction, appeared to be essential to achieve and maintain periodontal stability over years.

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children

Oral biofilm and its molecular analysis provide a basis for investigating various dental research and clinical questions. Knowledge of biofilm composition leads to a better understanding of cariogenic and periopathogenic mechanisms. Microbial changes taking place in the oral cavity during childhood are of interest for several reasons. The evolution of the child oral microbiota and shifts in its composition need to be analyzed further to understand and possibly prevent the onset of disease. At the same time, advanced knowledge of the natural composition of oral biofilm is needed. Early stages of caries-free permanent dentition with healthy gums provide a widely unaffected subgingival habitat that can serve as an in situ baseline for studying features of oral health and disease. Analysis of children's oral biofilm during different stages in life is thus an important theme in the field. Modern molecular analysis methods can provide comprehensive information about the bacterial diversity of such biofilms. To enable microbiota data comparison, it is important to standardize each step in the procedure for molecular data generation. This procedure spans from clinical sampling, Next Generation Sequencing (NGS), bioinformatic data processing, to taxonomic interpretation. One of the most critical factors here is biofilm sampling. Sampling in children is even more challenging in particular due to limited space in subgingival areas. We thus focus on the use of paper points for subgingival sampling. This article provides a detailed protocol for oral biofilm sampling of the subgingival sulcus, the mucosa, and saliva in children.

Quantification by qPCR of Pathobionts in Chronic Periodontitis: Development of Predictive Models of Disease Severity at Site-Specific Level

Currently, there is little evidence available on the development of predictive models for the diagnosis or prognosis of chronic periodontitis based on the qPCR quantification of subgingival pathobionts. Our objectives were to: (1) analyze and internally validate pathobiont-based models that could be used to distinguish different periodontal conditions at site-specific level within the same patient with chronic periodontitis; (2) develop nomograms derived from predictive models. Subgingival plaque samples were obtained from control and periodontal sites (probing pocket depth and clinical attachment loss <4 mm and >4 mm, respectively) from 40 patients with moderate-severe generalized chronic periodontitis. The samples were analyzed by qPCR using TaqMan probes and specific primers to determine the concentrations of Actinobacillus actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Parvimonas micra (Pm), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and Treponema denticola (Td). The pathobiont-based models were obtained using multivariate binary logistic regression. The best models were selected according to specified criteria. The discrimination was assessed using receiver operating characteristic curves and numerous classification measures were thus obtained. The nomograms were built based on the best predictive models. Eight bacterial cluster-based models showed an area under the curve (AUC) ≥0.760 and a sensitivity and specificity ≥75.0%. The PiTfFn cluster showed an AUC of 0.773 (sensitivity and specificity = 75.0%). When Pm and AaPm were incorporated in the TdPiTfFn cluster, we detected the two best predictive models with an AUC of 0.788 and 0.789, respectively (sensitivity and specificity = 77.5%). The TdPiTfAa cluster had an AUC of 0.785 (sensitivity and specificity = 75.0%). When Pm was incorporated in this cluster, a new predictive model appeared with better AUC and specificity values (0.787 and 80.0%, respectively). Distinct clusters formed by species with different etiopathogenic role (belonging to different Socransky’s complexes) had a good predictive accuracy for distinguishing a site with periodontal destruction in a periodontal patient. The predictive clusters with the lowest number of bacteria were PiTfFn and TdPiTfAa, while TdPiTfAaFnPm had the highest number. In all the developed nomograms, high concentrations of these clusters were associated with an increased probability of having a periodontal site in a patient with chronic periodontitis.

Rapid real-time recirculating PCR using localized surface plasmon resonance (LSPR) and piezo-electric pumping

Rapid detection and characterization of pathogens in patients with bloodstream infections (BSIs) is a persistent problem for modern medicine, as current techniques are slow or provide incomplete diagnostic information. Real-time polymerase chain reaction (qPCR) allows specific detection of a wide range of targets and quantification of pathogenic burdens to aid in treatment planning. However, new technological advances are required for a rapid and multiplex implementation of qPCR in clinical applications. In this paper, the feasibility of a novel microfluidic platform for qPCR is presented, integrating highly sensitive, label-free localized surface plasmon resonance (LSPR) imaging of DNA hybridization into a recirculating chip design for real-time analysis. Single target and multiplex detection of DNA target amplification are demonstrated, with a limit of detection of 5 fg μL^-1 of E. coli DNA for single target PCR, correlating with approximately 300 bacteria per mL. The results of this study demonstrate the potential of this platform for simultaneous real-time detection of multiple target genes within 15 minutes that could provide live saving benefits in patients with BSIs.

Detection of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans after Systemic Administration of Amoxicillin Plus Metronidazole as an Adjunct to Non-surgical Periodontal Therapy: A Systematic Review and Meta-Analysis

Objective: To evaluate the variations in the detection of Porphyromonas gingivalis and/or Aggregatibacter actinomycetemcomitans before and after systemic administration of amoxicillin plus metronidazole in association with non-surgical periodontal therapy (NSPT).

Background: The adjunctive use of antibiotics has been advocated to improve the clinical outcomes of NSPT. However, no systematic review has investigated the microbiological benefit of this combination.

Materials and Methods: An electronic search was conducted up to December 2015. Randomized clinical trials comparing the number of patients testing positive for P. gingivalis and/or A. actinomycetemcomitans before and after NSPT with (test group) or without (control group) amoxicillin plus metronidazole were included. The difference between groups in the variation of positive patients was calculated using the inverse variance method with a random effects model.

Results: The frequency of patients positive for A. actinomycetemcomitans was decreased by 30% (p = 0.002) and by 25% (p = 0.01) in the test group compared to the control group at 3- and 6-month follow-up, respectively. Similar findings were observed when considering the frequency of patients positive for Porphyromonas gingivalis, with a reduction by 28% (p < 0.0001), 32% (p < 0.0001), and 34% (p = 0.03) in the test group compared to the control group at 3-, 6-, and 12-month follow-up, respectively.

Conclusion: The systemic administration of amoxicillin plus metronidazole as an adjunct to NSPT significantly decreased the number of patients positive for P. gingivalis and A. actinomycetemcomitans compared with periodontal therapy alone or with a placebo.

Accuracy of commercial kits and published primer pairs for the detection of periodontopathogens

OBJECTIVES

Despite the input of microbiome research, a group of 20 bacteria continues to be the focus of periodontal diagnostics and therapy. The aim of this study was to compare three commercial kits and laboratory-developed primer pairs for effectiveness in detecting such periodontopathogens.

MATERIALS AND METHODS

Fourteen bacterial mock communities, consisting of 16 randomly assembled bacterial strains, were used as reference standard for testing kits and primers. Extracted DNA from mock communities was analyzed by PCR in-house with specific primers and forwarded for analysis to the manufacturer's laboratory of each of the following kits: ParoCheck®Kit 20, micro-IDent®plus11, and Carpegen® Perio Diagnostik.

RESULTS

The kits accurately detected Fusobacterium nucleatum, Prevotella intermedia/Prevotella nigrescens, Parvimonas micra, Aggregatibacter actinomycetemcomitans, Campylobacter rectus/showae, Streptococcus mitis, Streptococcus mutans, and Veillonella parvula. The in-house primers for F.nucleatum were highly specific to subtypes of the respective periopathogen. Other primers repeatedly detected oral pathogens not present in the mock communities, indicating reduced specificity.

CONCLUSIONS

The commercial kits used in this study are reliable tools to support periodontal diagnostics. Whereas the detection profile of the kits is fixed at a general specificity level, the design of primers can be adjusted to differentiate between highly specific strains. In-house primers are more error-prone. Bacterial mock communities can be established as a reference standard for any similar testing.

CLINICAL RELEVANCE

The tested kits render good results with selected bacterial species. Primers appear to be less useful for routine clinical diagnostics and of limited applicability in research. Basic information about the periodontopathogens identified in this study supports clinical decision-making.

Polymerase chain reaction: A molecular diagnostic tool in periodontology

This review discusses the principles of polymerase chain reaction (PCR) and its application as a diagnostic tool in periodontology. The relevant MEDLINE and PubMed indexed journals were searched manually and electronically by typing PCR, applications of PCR, PCR in periodontics, polymorphism studies in periodontitis, and molecular techniques in periodontology. The searches were limited to articles in English language and the articles describing PCR process and its relation to periodontology were collected and used to prepare a concise review. PCR has now become a standard diagnostic and research tool in periodontology. Various studies reveal that its sensitivity and specificity allow it as a rapid, efficient method of detecting, identifying, and quantifying organism. Different immune and inflammatory markers can be identified at the mRNA expression level, and also the determination of genetic polymorphisms, thus providing the deeper insight into the mechanisms underlying the periodontal disease.

Current status and future prospects of using advanced computer-based methods to study bacterial colonial morphology

Despite the advancement of recent molecular technologies, culturing is still considered the gold standard for microbial sample analysis. Here we review three different bacterial colony-based screening modalities that provide significant information beyond the simple shape and color of the colony. The plate imaging technique provides numeration and quantitative spectral reflectance information for each colony, while Raman spectroscopic analysis of bacteria colonies relates the Raman-shifted peaks to specific chemical bonding. Finally, the elastic-light-scatter technique provides a volumetric interaction of the whole colony through laser-bacteria interactions, instantly capturing the morphological traits of the colony and allowing quantitative classifications.

Oral Microbiota, Periodontal Status, and Osteoporosis in Postmenopausal Females

BACKGROUND

Alterations in hormone levels during menopause decrease bone density and may worsen oral health, favoring the growth of periodontal pathogens, whose detection could improve the diagnosis of periodontitis. The aim of this study is to detect and quantify the main periodontal pathogens in the oral microbiota of postmenopausal females and to explore the relationship between clinical and periodontal parameters.

METHODS

This was an observational cross-sectional study of 76 postmenopausal females. Dental examinations and sampling for microbiologic evaluation were performed, and a history of osteoporosis/osteopenia was collected. Real-time polymerase chain reaction was used for detecting and quantifying Fusobacterium nucleatum (Fn), Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Campylobacter rectus (Cr), and Tannerella forsythia (Tf). The results obtained were subjected to statistical analyses. Statistical significance was defined as P <0.05.

RESULTS

Periodontitis was detected in 77.1% of females with osteoporosis/osteopenia (P >0.05). A significant correlation was found between osteoporosis and missing teeth. T. forsythia and C. rectus were detected in 100% of the samples, Fn and Pg in 98.7%, and Aa in 73.7%.

CONCLUSIONS

Osteoporosis did not influence the prevalence of periodontitis among postmenopausal females. The presence of periodontopathogenic bacteria was not sufficient to confirm disease. A preventive maintenance program for postmenopausal females, particularly osteoporotic females, who are at greater risk of tooth loss, could minimize the potential effects of bone loss on periodontal tissues.

Detection of subgingival periodontal pathogens--comparison of two sampling strategies

OBJECTIVE

The aim of the study is to compare detection frequency of periodontal pathogens in patients with aggressive/severe chronic periodontitis using pooled plaque samples from the deepest pockets per quadrant/per sextant.

METHODS

In 100 patients with aggressive/chronic periodontitis, subgingival plaque was sampled from the deepest pockets per quadrant (MT4) and per sextant (MT6). Plaque samples were taken using two sterile paper points simultaneously. One paper point from each pocket was pooled with the three other paper points of the pockets (MT4). Subsequently, the remaining four paper points were pooled with two paper points from the deepest pockets from the two remaining sextants (MT6). The content of each vial was analyzed with nucleic-acid based methods for Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Parvimonas micra, Fusobacterium nucleatum, Campylobacter rectus, Eubacterium nodatum, Eikenella corrodens, and Capnocytophaga sp.

RESULTS

The detection frequency of A. actinomycetemcomitans (MT4/MT6) at 22/24 %, T. forsythia at 93/96 %, P. gingivalis at 78/79 %, T. denticola at 88/90 %, P. intermedia at 40/46 %, P. micra at 75/79 %, F. nucleatum at both 99 %, C. rectus at 84/89 %, E. nodatum at 62/65 %, E. corrodens at 80/87 %, and Capnocytophaga sp. at 49/58 % was higher with MT6 than with MT4. None of these differences were statistically significant.

CONCLUSION

The detection frequency of the investigated periopathogens was statistically insignificant higher with the sampling method MT6 compared with MT4.

CLINICAL RELEVANCE

In daily dental practice, the plaque sampling of the deepest pockets per quadrant seems to be sufficient.

Periodontal health status in patients treated with the Invisalign(®) system and fixed orthodontic appliances: A 3 months clinical and microbiological evaluation

OBJECTIVE

The aim of this prospective study was to compare the periodontal health and the microbiological changes via real-time polymerase chain reaction (PCR) in patients treated with fixed orthodontic appliances and Invisalign(®) system (Align Technology, Santa Clara, California).

MATERIALS AND METHODS

Seventy-seven patients were enrolled in this study and divided into three groups (Invisalign(®) group, fixed orthodontic appliances group and control group). Plaque index, probing depth, bleeding on probing were assessed. Total biofilm mass and periodontal pathogens were analyzed and detected via real-time PCR. All these data were analyzed at the T0 (beginning of the treatment) T1 (1-month) and T2 (3 months); and statistically compared using the Mann-Whitney test for independent groups.

RESULTS

After 1-month and after 3 months of treatment there was only one sample with periodontopathic anaerobes found in patient treated using fixed orthodontic appliances. The Invisalign(®) group showed better results in terms of periodontal health and total biofilm mass compared to the fixed orthodontic appliance group. A statistical significant difference (P < 0.05) at the T2 in the total biofilm mass was found between the two groups.

CONCLUSION

Patients undergoing orthodontic treatment with the Invisalign(®) System show a superior periodontal health in the short-term when compared to patients in treatment with fixed orthodontic appliances. Invisalign(®) should be considered as a first treatment option in patients with risk of developing periodontal disease.

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.

Microbiologic Observations After Four Treatment Strategies Among Patients With Periodontitis Maintaining a High Standard of Oral Hygiene: Secondary Analysis of a Randomized Controlled Clinical Trial

BACKGROUND

The benefit of full-mouth disinfection (FDIS) over traditional scaling and root planing (SRP), with or without adjunctive metronidazole, when treating chronic destructive periodontitis remains equivocal, as does the long-term association between clinical and microbiologic outcomes after such strategies. The aim of this study is to examine the relationship between clinical and microbiologic outcomes of four different treatment strategies for chronic destructive periodontitis among patients who maintain excellent oral hygiene and low gingival bleeding scores.

METHODS

One hundred eighty-four patients with periodontitis and capable of maintaining a high standard of oral hygiene were randomly allocated to one of four treatment groups: 1) FDIS + metronidazole; 2) FDIS + placebo; 3) SRP + metronidazole; and 4) SRP + placebo. Recordings of plaque, bleeding on probing, probing depth (PD), and clinical attachment level were carried out in four sites per tooth at baseline, 3 and 12 months after treatment. Before treatment, pooled subgingival samples were obtained from the five deepest pockets, which were sampled again 3 and 12 months after treatment. Microbiologic assessments of eight putative periodontal pathogens were performed using the checkerboard DNA-DNA hybridization method.

RESULTS

Levels of bacterial species were already relatively low at baseline. The only microbial factor statistically significantly associated with the clinical outcomes of treatment after 12 months was the association between reductions of Tannerella forsythia and being free from PD ≥5 mm.

CONCLUSION

In this clinical trial, the only microbial factor associated with the clinical outcomes after 12 months was a statistically significant association between the reductions of T. forsythia and being free from PD ≥5 mm.

Comparison of viable plate count, turbidity measurement and real-time PCR for quantification of Porphyromonas gingivalis

The viable plate count (VPC) is considered as the reference method for bacterial enumeration in periodontal microbiology but shows some important limitations for anaerobic bacteria. As anaerobes such as Porphyromonas gingivalis are difficult to culture, VPC becomes time-consuming and less sensitive. Hence, efficient normalization of experimental data to bacterial cell count requires alternative rapid and reliable quantification methods. This study compared the performance of VPC with that of turbidity measurement and real-time PCR (qPCR) in an experimental context using highly concentrated bacterial suspensions. Our TaqMan-based qPCR assay for P. gingivalis 16S rRNA proved to be sensitive and specific. Turbidity measurements offer a fast method to assess P. gingivalis growth, but suffer from high variability and a limited dynamic range. VPC was very time-consuming and less repeatable than qPCR. Our study concludes that qPCR provides the most rapid and precise approach for P. gingivalis quantification. Although our data were gathered in a specific research context, we believe that our conclusions on the inferior performance of VPC and turbidity measurements in comparison to qPCR can be extended to other research and clinical settings and even to other difficult-to-culture micro-organisms.

SIGNIFICANCE AND IMPACT OF THE STUDY

Various clinical and research settings require fast and reliable quantification of bacterial suspensions. The viable plate count method (VPC) is generally seen as 'the gold standard' for bacterial enumeration. However, VPC-based quantification of anaerobes such as Porphyromonas gingivalis is time-consuming due to their stringent growth requirements and shows poor repeatability. Comparison of VPC, turbidity measurement and TaqMan-based qPCR demonstrated that qPCR possesses important advantages regarding speed, accuracy and repeatability.

Real-time PCR quantification of six periodontal pathogens in saliva samples from healthy young adults

OBJECTIVE

The use of saliva as a diagnostic fluid for the evaluation of periodontal health has gained attention recently. Most published real-time PCR assays focused on quantification of bacteria in subgingival plaque, not in saliva. The aims of this study were to develop a real-time PCR assay for quantification of six periodontal pathogens in saliva and to establish a relationship between the amount of DNA (fg) and colony-forming unit (CFU).

MATERIALS AND METHODS

TaqMan primers/probe sets were used for the detection of Aggregatibacter actinomycetemcomitans (Aa), Eikenella corrodens (Ec), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and total bacteria. Six periodontal pathogens and total bacteria in saliva from 24 periodontally healthy individuals were determined. The relationship between the amount of DNA (fg) and CFU was established by measuring the concentrations of extracted bacterial DNA and CFU per milliliter of bacteria on agar plates.

RESULTS

Fn, Ec, and Pi were detected in all saliva samples, while 58.5, 45.8, and 33.3% were detected for Tf, Pg, and Aa, respectively. Numbers of Ec and Fn in saliva were highly correlated (R(2) = 0.93, P < 0.01). The values of DNA (fg) per CFU ranged from 64 for Ec to 121 for Pg.

CONCLUSION

The real-time PCR assay in combination with the relationship between DNA (fg) and CFU can be used to quantitate periodontal pathogens in saliva and estimate the number of live bacteria (CFU).

CLINICAL RELEVANCE

This real-time PCR assay in combination with the relationship between DNA (fg) and CFU has the potential to be an adjunct in evaluation of periodontal health status.

Comparison of culture and polymerase chain reaction techniques in the identification of Tannerella forsythia in periodontal health and disease, an in vitro study

Background and Objectives:

Various bacterial species from subgingival biofilm have demonstrated aetiological relevance in the initiation and progression of periodontitis. The aim of this study was to detect the presence of Tannerella forsythia (Tf) in subgingival plaque of periodontally healthy subjects and chronic periodontitis patients by using both culture and PCR technique and compare the two techniques.

Materials and Methods:

Pooled subgingival plaque samples were taken using sterile curettes from predetermined sites in 50 periodontally healthy subjects and from 50 periodontitis subjects. Samples were analyzed for the presence of T. forsythia using both techniques. Statistical analysis of the results was done using Chi-square test, sensitivity, and specificity tests.

Results:

Both techniques could detect T. forsythia in subgingival plaque samples from healthy and periodontitis subjects. Periodontally healthy individuals and individuals with chronic periodontitis using the culture technique showed the presence of T. forsythia in 14 and 34%, respectively. PCR technique showed the presence of T. forsythia in 20% healthy and 40% chronic periodontitis patients. T. forsythia detection in the periodontitis group was statistically significantly higher when compared to the healthy group by both culture and PCR technique (P = 0.019 and P = 0.029). PCR demonstrated high sensitivity and low specificity when compared to the culture technique.

Conclusion:

The results indicated that T. forsythia was more prevalent in periodontitis patients when compared with healthy subjects. The PCR was found to be more sensitive than culture technique for detection of T. forsythia from the subgingival plaque samples.

Evaluation of periodontal pathogens of the mandibular third molar pericoronitis by using real time PCR

OBJECTIVES

The aim of this study was to investigate the mandibular third molar pericoronitis flora by using real-time polymerase chain reaction (PCR).

MATERIALS AND METHODS

The quantitative values of Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi) and Tannerella forsythia (Tf) were evaluated in comparison with the healthy third molar flora by using real time PCR.

RESULTS

Aa, Cr, Pg, and Pi were not statistically significant but numerically higher than the pericoronitis group. In contrast to samples from control subjects, statistically significant higher numbers of Tf were detected in samples from pericoronitis patients. The study revealed the strong relation between risk of pericoronitis and the presence of Tf. Individuals who have Tf in their samples present with an almost eight times relative risk of pericoronitis as the individuals with an absence of Tf in their samples.

CONCLUSION

Tf plays an important role in the development of clinical symptoms related to pericoronitis.

Periodontal bacteria in the genital tract: are they related to adverse pregnancy outcome?

One of the most important factors implicated in preterm birth (PTB) is acute genitourinary tract infection. The bacteria causing chronic periodontal inflammation include Gram-negative rods and anaerobes similar to those found in women with bacterial vaginosis. The aim of this prospective study is to investigate the relationship between oral and vaginal microflora and preterm low birth weight. Real-time polymerase chain reaction was used to detect both the presence and level of six periodontitis-related species: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Fusobacterium nucleatum ssp(Fn), and Prevotella intermedia (Pi) for both oral samples of subgingival plaque and cervical samples, obtained from 80 patients, during gynaecological examinations. The more representative oral pathogen (less than 60 percent) species in oral samples of preterm and term group were Tf, Td, and Fn. 24.4 percent of pregnant women presented periodontal pathogens in vaginal swab; the most representative species with a percentage over 0.1 percent of total bacteria in genital tract of preterm group were Tf, Td, and Piwith a positive correlation (less than 0.5). The presence of the bacterium T. denticolain the vagina, regardless of the amount, adversely affects preterm delivery.

Microbiological assessment of the implant-abutment interface in different connections: cross-sectional study after 5 years of functional loading

OBJECTIVE

To evaluate the bacterial microflora present inside the implant connection and in the peri-implant sulcus fluid of healthy implants, and to analyze the relationships between these harboring sites for four different implant systems after at least 5 years of functional loading.

MATERIALS AND METHODS

A cross-sectional study was performed involving 40 patients treated with metal-ceramic cemented bridges supported by at least two healthy implants functionally loaded for 5 years. Four different implant-abutment connections were studied: external hexagon (control group), double internal hexagon (test group 1), internal hexagon with external collar (test group 2), and conical connection (test group 3). Samples for microbiological analysis were obtained from three types of sites: peri-implant sulci, connections' inside and abutments surface and, as control, gingival sulci of neighboring teeth. Quantitative real-time PCR was carried out for Total Bacterial Count and for 10 microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, and Candida albicans. The response variables were percentage of positive sites and absolute bacterial load. The relations of the response variables with the type of connection and of sampling site were assessed using generalized estimating equations.

RESULTS

Regarding the analysis of positivity to bacteria in the peri-implant sulcus no significant differences were observed. Analyzing the connection's inside, none of the connection designs had the capacity to prevent microbiological leakage through the implant/abutment microgap. Test group 3 presented the lowest mean values for red complex bacteria and control group the highest, although differences were non-significant. Statistical significance was only reached for Treponema denticola in the bacterial load analysis inside the connection. Test groups 1 and 2 yielded lower values for orange complex bacteria but only for Peptostreptococos micros the differences resulted significant. Test groups 2 and 3 had significantly lower total bacterial counts in the peri-implant sulcus and inside the connection.

CONCLUSIONS

Outcomes suggested that all the analyzed connections resulted contaminated after 5 years of functional loading. However, the connection design might influence bacterial activity levels qualitatively and quantitatively, especially inside the implant connection.

Effectiveness of an alcohol-free essential oil-containing mouthwash in institutionalised elders receiving long-term care: a feasibility study

OBJECTIVES

To conduct a feasibility study on investigating the effectiveness of an alcohol-free essential oil mouthwash (AF-EOMW) to reduce plaque accumulation and oral pathogen levels in institutionalised elders receiving long-term care and to obtain preliminary results.

BACKGROUND

Although simple, cost-effective strategies to improve oral hygiene in seniors such as the use of mouthwashes have been shown to reduce the risks of respiratory diseases, little information is available on the feasibility of implementing these measures.

METHODS

Twenty-five elderly participants with significant loss of autonomy were initially recruited and divided into two groups. A test group rinsed with an AF-EOMW twice a day, and a control group rinsed with tap water. Data on demographic characteristics, dental history and tobacco use were collected from a questionnaire. Problems encountered during recruitment and data collection were documented. Plaque index, denture cleanliness and salivary levels of several pathogens were measured at three time points: baseline (T0 ), day 22 (T1 ) and day 45 (T2 ).

RESULTS

Eighteen participants completed the study. Several problems were encountered during recruitment and execution of the study protocol. No significant differences in clinical or microbiological measures were found between the test group and controls at three time points (p > 0.05).

CONCLUSION

This pilot study shows that, if sufficient logistical and financial resources are available, it is feasible to conduct randomised clinical trials in a seniors' facility. The use of an AF-EOMW to improve oral hygiene in seniors was not found to be superior to tap water. However, larger controlled clinical studies are needed to confirm these results.

Quantification of periodontal pathogens in vascular, blood, and subgingival samples from patients with peripheral arterial disease or abdominal aortic aneurysms

BACKGROUND

The aim of this investigation is to quantify periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, and Tannerella forsythia) in vascular, blood, and subgingival samples. As a secondary objective, two molecular bacterial identification methods (nested polymerase chain reaction [PCR] and quantitative PCR [qPCR]) are compared.

METHODS

Seventy consecutive patients provided a vascular lesion, a blood sample, and 36 subgingival samples. Bacterial DNA was extracted, and qPCR was used to determine the prevalence and amounts of the target pathogens in each sample. Nested PCR was performed only in the samples from vascular lesions. Periodontal examination was performed in 42 patients. Mann-Whitney U or χ(2) tests were used to compare microbiologic results according to periodontal diagnosis.

RESULTS

All targeted periodontal pathogens (A. actinomycetemcomitans, P. gingivalis, T. forsythia, or C. rectus) were detected in subgingival samples, with a prevalence rate of 72.2%, 47.2%, 74.3%, and 82.9%, respectively. In 7.1% and 11.4% of vascular and blood samples, bacterial DNA was detected. One patient was positive for A. actinomycetemcomitans in the three types of samples. No differences were found in the levels of targeted bacteria when comparing patients with and without periodontitis. Prevalence rates obtained with nested PCR were significantly higher than those obtained with qPCR.

CONCLUSIONS

The presence of A. actinomycetemcomitans was demonstrated in vascular, blood, and subgingival samples in one of 36 patients. These results, although with a very low frequency, may support the hypothesis of a translocation of periodontal pathogens from subgingival microbiota to the bloodstream and then to atheromatous plaques in carotid or other peripheral arteries. Nested PCR is not an adequate method for identifying DNA of periodontal pathogens in low quantities because of the high number of false-negative results.