Subgingival microbial changes in Down Syndrome adults with periodontitis after chlorhexidine adjunct non-surgical therapy and monthly recalls-A 12-month case series study

OBJECTIVES

Down Syndrome (DS) adults are at risk for periodontitis. Previous reports indicated difficulties in periodontopathogen reduction or eradication in DS individuals after periodontal treatment. This case series follows the subgingival microbial changes in adult DS individuals with periodontitis who received chlorhexidine adjunct non-surgical therapy plus 12-month recalls.

METHODS

Twenty periodontitis DS participants (7 females; 25.5 ± 5.6 years of age; 3 with generalized periodontitis) partook in a study involving non-surgical mechanical periodontal therapy, twice daily chlorhexidine gel toothbrushing, chlorhexidine mouthwash, and monthly recalls. The subgingival microbiota profile was followed at baseline, 6-, and 12-months post-operation.

RESULTS

Desulfobulbus, Saccharibacteria (TM7), Tannerella, and Porphyromonas were the major subgingival genera in this DS cohort. Favorable chlorhexidine adjunct non-surgical treatment outcomes were observed, with the relative abundance of Desulfobulbus sp. HMT 041, Saccharibacteria (TM7) [G-1] bacterium HMT 346 or 349, and Tannerella forsythia significantly reduced at the end of the study, but no significant reduction of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans could be observed. Relative abundance of Desulfobulbus sp. HMT 041 and T. forsythia were also found to be significantly associated with plaque, bleeding on probing, and probing pocket depth (PPD, in mm) at a site level, while the relative abundance of Halomonas pacifica was negatively associated with PPD.

CONCLUSIONS

Successful chlorhexidine adjunct non-surgical treatment with hygiene care was accompanied by a subgingival microbial shift involving certain periodontopathogenic species, except P. gingivalis and A. actinomycetemcomitans. Further investigations are required to clarify the mechanism underpinning the unchanged relative abundance of the above two pathogens despite favorable clinical responses.

CLINICAL SIGNIFICANCE

DS adults face challenges achieving optimal home care or hygiene for periodontal healing and disease prevention. Chemical adjunct mechanical periodontal therapy plus regular recalls appeared promising clinically and microbiologically, with subgingival periodontopathogenic species reduction. The persistence of A. actinomycetemcomitans and P. gingivalis in subgingival niches post-treatment warrants further investigation.

Heterogeneity of Size and Toxin Distribution in Aggregatibacter actinomycetemcomitans Outer Membrane Vesicles

Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of A. actinomycetemcomitans most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs). We previously observed that the highly leukotoxic A. actinomycetemcomitans strain JP2 produces two populations of OMVs: a highly abundant population of small (<100 nm) OMVs and a less abundant population of large (>300 nm) OMVs. Here, we have developed a protocol to isolate the OMVs produced during each specific phase of growth and used this to demonstrate that small OMVs are produced throughout growth and lack LtxA, while large OMVs are produced only during the exponential phase and are enriched with LtxA. Our results indicate that surface-associated DNA drives the selective sorting of LtxA into large OMVs. This study provides valuable insights into the observed heterogeneity of A. actinomycetemcomitans vesicles and emphasizes the importance of understanding these variations in the context of bacterial pathogenesis.

Periodontal Health in Children with Juvenile idiopathic arthritis

AIM

To investigate gingival inflammation and prevalence of four specific periodontal associated pathogens in Juvenile idiopathic arthritis (JIA) in relation to orofacial pain, jaw function and systemic inflammatory activity in JIA.

METHODS

Forty-five children with JIA and 16 healthy children as controls, were enrolled. Subjects were examined and classified according to the diagnostic criteria for temporomandibular disorders (DC/TMD). Pain, pain-related disability and jaw function were also assessed. A clinical periodontal examination was performed. Subgingival plaque samples were collected and analyzed for semiquantitative levels of the following periodontal pathogens; Aggregatibacter actinomycetemcomintans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola.

CONCLUSION

This study suggests that the periodontal disease-associated bacteria P. gingivalis and T. forsythia do not contribute to neither periodontal disease, systemic inflammatory activity nor orofacial pain and jaw dysfunction, including TMJ arthritis, in JIA patients in Sweden.

Glucose-6-Phosphatase-Dehydrogenase activity as modulative association between Parkinson's disease and periodontitis

The association between periodontitis (PD) and Parkinson's disease (PK) is discussed due to the inflammatory component of neurodegenerative processes. PK severity and affected areas were determined using the following neuropsychological tests: Unified Parkinson's Disease Rating Score (UPDRS) and Hoehn and Yahr; non-motoric symptoms by Non-Motor Symptoms Scale (NMSS), and cognitive involvement by Mini-Mental State Examination (MMSE). Neuroinflammation and the resulting Glucose-6-Phosphatase-Dehydrogenase (G6PD) dysfunction are part of the pathophysiology of PK. This study aimed to evaluate these associations in periodontal inflammation. Clinical data and saliva-, serum-, and RNA-biobank samples of 50 well-characterized diametric patients with PK and five age- and sex-matched neurologically healthy participants were analyzed for G6PD function, periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, and Filifactor alocis), monocyte chemoattractant protein (MCP) 1, and interleukin (IL) 1-beta. Regression analysis was used to identify associations between clinical and behavioral data, and t-tests were used to compare health and disease. Compared with PK, no pathogens and lower inflammatory markers (p < 0.001) were detectible in healthy saliva and serum, PK-severity/UPDRS interrelated with the occurrence of Prevotella intermedia in serum as well as IL1-beta levels in serum and saliva (p = 0.006, 0.019, 0.034), Hoehn and Yahr correlated with Porphyromonas gingivalis, Prevotella intermedia, RNA IL1-beta regulation, serum, and saliva IL1-beta levels, with p-values of 0.038, 0.011, 0.008, <0.001, and 0.010, while MMSE was associated with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, serum MCP 1 levels, RNA IL1-beta regulation and G6PD serum activity (p = 0.036, 0.003, 0.045, <0.001, and 0.021). Cognitive and motor skills seem to be important as representative tests are associated with periodontal pathogens and oral/general inflammation, wherein G6PD-saliva dysfunction might be involved.

Clinical trial registration

https://www.bfarm.de/DE/Das-BfArM/Aufgaben/Deutsches-Register-Klinischer-Studien/_node.html, identifier DRKS00005388.

Aggregatibacter Actinomycetemcomitans With Periodontitis and Rheumatoid Arthritis

OBJECTIVE

The aim of this work was to explore the association between Aggregatibacter actinomycetemcomitans (A actinomycetemcomitans) infection and disease activity amongst those with rheumatoid arthritis (RA) with or without periodontitis (PD) in a Chinese population.

METHODS

A case-control study was conducted from November 2017 to March 2019. The correlation coefficients between A actinomycetemcomitans positivity and RA-related examination indicators as well as periodontal examination parameters were calculated by using the Spearman correlation analysis.

RESULTS

A total of 115 patients with RA were recruited: 67 patients with RA only and 48 with RA + PD. The percentage of A actinomycetemcomitans positivity was significantly higher in the RA + PD group compared with the RA-only group (P = .007 for positive percentage; P = .020 for percentage of A actinomycetemcomitans positivity in the total oral microbiome). Furthermore, RA-related measures such as Disease Activity Score 28, rheumatoid factor, anticyclic citrullinated peptide, and anticitrullinated protein antibodies were all positively correlated with the percentage of A actinomycetemcomitans positivity (P range: .002∼.041). In addition, significant correlations were observed amongst A actinomycetemcomitans positivity and probing pocket depth (P = .027) and gingival index (P = .043), whereas null correlations were found amongst the percentage of A actinomycetemcomitans positivity and plaque index (P = .344), clinical attachment loss (P = .217), and bleeding on probing (P = .710).

CONCLUSIONS

A actinomycetemcomitans infection may be related to the development of PD amongst patients with RA.

Herpesvirus-Bacteria pathogenic interaction in juvenile (aggressive) periodontitis. A novel etiologic concept of the disease

Localized juvenile (aggressive) periodontitis starts at puberty in otherwise healthy individuals and involves the proximal surfaces of permanent incisors and first molars. The disease destroys a sizeable amount of periodontal bone within a few months despite minimal dental plaque and gingival tissue inflammation. Cytomegalovirus and Epstein-Barr virus, as well as the two main periodontopathic bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, are linked to juvenile periodontitis. Juvenile periodontitis-affected teeth show cementum hypoplasia. We hypothesize that an active herpesvirus infection, at the time of root formation, hampers cementum formation and, at puberty, herpesvirus reactivation triggers an upgrowth of bacterial pathogens which produce rapid periodontal destruction on teeth with a defective periodontium. A pathogenic interaction between active herpesviruses and bacterial pathogens can potentially explain the etiology and incisor-first molar destructive pattern of juvenile periodontitis. Effective treatment of juvenile periodontitis may target the herpesvirus-bacteria co-infection.

Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay

AIM

The study aims is to evaluate the antibacterial effect of vitamin D3 against the red complex bacteria, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia in chronic periodontitis patients.

MATERIALS AND METHODS

The study comprised 98 participants with chronic periodontitis. All clinical parameters including plaque index (PI), gingival bleeding index (GBI), probing pocket depth (PPD), clinical attachment level (CAL), and a microbiological assay of P. gingivalis, T. denticola, T. forsythia were assessed at the baseline. All study participants who underwent scaling and root planning were divided into two groups, A and B, each with 49 patients and only group B patients were advised to take vitamin D supplementation of 60,000 IU granules, once daily for 2 months. All the patients of both the groups were recalled at the end of 2nd month and all the clinical and microbiological parameters were reassessed.

RESULTS

After two months, there was a reduction in all the clinical markers in both groups, but the group B patients showed more improvement following non-surgical treatment vitamin D intake. There was also a statistical reduction in P. gingivalis, T. denticola, and T. forsythia following administration of vitamin D in group B patients compared to group A.

CONCLUSION

These discoveries proposed that vitamin D has a superb antimicrobial impact against red complex periodontal microbes and might be considered a promising compound in the counteraction of periodontal disease.

CLINICAL SIGNIFICANCE

Vitamin D is considered to possess anti-inflammatory and antimicrobial activity, which may help to delay the progression of periodontitis. So, vitamin D3 can be used as a potential supplement that could be employed to stop the advancement of periodontal disease. How to cite this article: Govindharajulu R, Syed NK, Sukumaran B, et al. Assessment of the Antibacterial Effect of Vitamin D3 against Red Complex Periodontal Pathogens: A Microbiological Assay. J Contemp Dent Pract 2024;25(2):114-117.

Comparative study of the effect of different exposure parameters of 635nm diode laser and toluidine blue O in eliminating Aggregatibacter actinomycetemcomitans biofilm from titanium implant surfaces

BACKGROUND

The aim of this study was to investigate the effects of antimicrobial photodynamic therapy (PDT) using 635 nm diode laser irradiation with an energy density of 6 to 30 J/cm2 and toluidine blue O (TBO) as a photosensitizer on the viability of Aggregatibacter actinomycetemcomitans attached to the surface of titanium implants.

MATERIALS AND METHODS

Titanium implants contaminated with A. actinomycetemcomitans were treated with TBO alone or in combination with different exposure parameters (light doses of 6 - 30 J/cm2 at 635 nm) and 0.2 % chlorhexidine (CHX). After treatment, colony forming units (CFUs)/ml were determined to assess PDT efficacy. The structure of the biofilm of A. actinomycetemcomitans was analyzed by field emission scanning electron microscopy (FESEM).

RESULTS

Under optimal conditions, the colony count was reduced by ∼90 %. Treatment with CHX was somewhat more effective (colony formation was reduced by ∼95 %), but this agent has adverse effects that can be avoided with PDT.

CONCLUSION

This study confirms the efficacy of PDT against A. actinomycetemcomitans depending on the light dose. Treatment with TBO + 635 nm diode laser has an effect that may be equivalent to that of CHX, but perhaps with fewer adverse effects.

Effect of antibacterial photodynamic therapy with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans

BACKGROUND

This study aimed to assess the effect of antibacterial photodynamic therapy (aPDT) with chitosan nanoparticles on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in the culture medium.

MATERIALS AND METHODS

In this in vitro, experimental study, chitosan nanoparticles (CHNPs) containing indocyanine green (ICG) were first synthesized and characterized. A. actinomycetemcomitans was cultured on trypticase soy agar. The culture media containing A. actinomycetemcomitans were randomly subjected to the following six decontamination protocols: negative control subjected to sterile phosphate buffered saline (PBS) for 5 min, positive control exposed to 0.2 % chlorhexidine (CHX) for 5 min, exposure to 0.25 mg/mL ICG in the dark at 37 °C for 5 min, aPDT with 0.25 mg/mL ICG and diode laser (808 nm, 250 mW, 14.94 J/cm2, 30 s, 1 mm distance, 8 mm tip diameter), exposure to CHNPs containing 0.25 mg/mL ICG in the dark at 37 °C for 5 min, and aPDT with CHNPs containing 0.25 mg/mL ICG and diode laser. The number of colonies was counted, and analyzed by one-way ANOVA and Tamhane test (alpha=0.050).

RESULTS

Antimicrobial PDT with CHNPs, and CHX groups comparably showed the highest decontamination efficacy (P = 0.000).

CONCLUSION

The results showed optimal efficacy of aPDT with CHNPs containing 0.25 mg/mL ICG and 808 nm diode laser for reduction of A. actinomycetemcomitans colony count. Thus, aPDT appears to be as effective as CHX, but with fewer adverse effects.

Systemic ciprofloxacin treatment of multidrug-resistant Aggregatibacter actinomycetemcomitans in severe periodontitis

An adult periodontitis patient treated with mechanical/surgical therapy experienced gingival necrosis and granulomas post-treatment. Aggregatibacter actinomycetemcomitans, a tissue-invasive pathogen, was recovered and multidrug-resistant but susceptible to ciprofloxacin. Systemic ciprofloxacin eliminated A. actinomycetemcomitans with marked clinical improvement. Ciprofloxacin may be prescribed for A. actinomycetemcomitans periodontal infection unresponsive to the common amoxicillin-metronidazole treatment.

Evaluation of the effect of photodynamic therapy with Curcumin and Riboflavin on implant surface contaminated with Aggregatibacter actinomycetemcomitans

BACKGROUND

Peri-implantitis is a destructive inflammatory disease affecting both hard and soft tissues of the osseointegrated implant and causing bone loss and envelope surrounding the implant. The study aimed at evaluating the effect of Photodynamic therapy with Curcumin and Riboflavin on the level of decontamination of implant surface impregnated with Aggregatibacter actinomycetemcomitans (A.a) biofilm.

MATERIALS AND METHODS

In this experimental and laboratory study, 42 implants (4.3 mm in diameter and 8 mm in length) were infected with A.a. bacterial suspension. Then, the implants carrying A.a biofilm were randomly divided into seven groups (n = 6). The groups included: 1- a negative control group (without treatment), 2- a positive control group of Chlorhexidine 0.12 %, 3- a Curcumin (5 mg/ ml) group, 4- a Riboflavin (0.5 %) group, 5- an LED irradiation group (390-480 nm), 6- a photodynamic therapy with Curcumin group, and 7- a photodynamic therapy with Riboflavin group. Then, the implants were sonicated and the amount of CFU/mL of each sample was calculated. One-way ANOVA and Tamhane tests were used to analyze the data.

RESULTS

The lowest mean number of colonies of A.a (CFU/ mL) were seen in the following groups, respectively: the positive control group of Chlorhexidine 0.12 %, the photodynamic therapy with Curcumin group, the photodynamic therapy with Riboflavin group, the Curcumin (5 mg/ ml) group, the Riboflavin (0.5 %) group, the LED radiation group, and the negative control group. The use of photodynamic therapy with Curcumin significantly reduced the number of colonies of A.a (CFU/ mL) in comparison with the photodynamic therapy with Riboflavin group (p = 0.004), the Riboflavin group (p = 0.045), the LED radiation group (p = 0.012), and the negative control group (p = 0.007).

CONCLUSION

aPDT with Curcumin and LED can reduce A.a biofilm on implant surfaces and can be used as a safe and non-invasive disinfection method to reduce A.a biofilm on implant surfaces.

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.

Efficacy of hypochlorous acid as an alternative oral antimicrobial agent on human gingival fibroblasts, Aggregatibacter actinomycetemcomitans, and Candida albicans biofilms in vitro

This study compared the cytotoxicity and antimicrobial activity of hypochlorous acid (HOCl) at 50 ppm and 200 ppm and 0.2% chlorhexidine (CHX) at various time intervals, in vitro. Cell viability and cytotoxicity of human gingival fibroblasts (HGF) were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and the lactate dehydrogenase assay. Antimicrobial effects on Aggregatibacter actinomycetemcomitans and Candida albicans were determined using the time-kill method. All solutions exhibited a significant impact on HGFs in a dose- and time-dependent manner. 50 ppm HOCl demonstrated the highest cell viability, followed by 200 ppm HOCl. Both HOCl solutions were less cytotoxic to HGFs than 0.2% CHX. 50 ppm and 200 ppm HOCl demonstrated stronger efficiencies than CHX against A. actinomycetemcomitans and C. albicans. The data suggest that HOCl solutions have potential as an alternative antiseptic to CHX due to their lower cytotoxicity and superior antimicrobial activity, but optimal dosage of HOCl requires further investigations.

Evaluation of the antibacterial activity of cinnamon essential oil and its individual compounds on Aggregatibacter actinomycetemcomitans isolated from black extrinsic tooth stain: an in vitro study

AIM

Black extrinsic tooth stain (BETS) is a health challenge that commonly affects children. Aggregatibacter actinomycetemcomitans (Aa) presents in higher prevalence within the polymicrobial community of BETS. In this study, the anti-planktonic and anti-sessile activities of cinnamon essential oil (CEO) and its individual compounds against Aa were evaluated. The preventive effect of CEO and its active substances on BETS formation was also studied in vitro.

METHODS

Aa was isolated from a preschool child with BETS and was identified based on the morphological characteristics, MALDI-TOF mass spectroscopy and 16S rRNA sequencing. The effect of CEO and its individual compounds on the growth kinetics of planktonic and sessile Aa cells as well as their antibacterial efficacy and their rate of bacterial killing were examined. The preventive effect of CEO and its active substances on the formation of BETS was evaluated using an ex vivo model. The data were analysed using one-way analysis of variance (ANOVA) and the significance level was set at p < 0.05.

RESULTS

Out of eight individual compounds of CEO, only eugenol, cinnamaldehyde and α-methyl cinnamaldehyde showed anti-Aa activities. The values of the minimum inhibitory concentrations (MICs) were in the following order: CEO (421.5 mg/ml) > α-methyl cinnamaldehyde (26.37 mg/ml) > cinnamaldehyde (0.209 mg/ml) > eugenol (0.052 mg/ml). CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde, respectively, exhibited two-, four-, four- and eightfold increase of sessile MIC compared to their planktonic MIC. The growth kinetics of both planktonic and sessile Aa in the presence of CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde revealed a complete inhibition at the MICs and 5.3%-37.4% biofilm inhibition at sub-MICs. The time-killing study demonstrated that CEO, eugenol and cinnamaldehyde were capable of reducing the survival rate of both planktonic and sessile Aa cells after 15-20 and 25-30 min, respectively. However, α-methyl cinnamaldehyde showed a superior anti-planktonic to anti-biofilm activity. The daily incorporation of CEO, eugenol and cinnamaldehyde at their MICs for 14 days totally prevented the formation of BETS in the ex vivo model; however, in the case of α-methyl cinnamaldehyde, BETS was visually detectable after 10 days.

CONCLUSION

CEO and its individual compounds have marked antibacterial activity against Aa. The effective results against planktonic and sessile Aa within reasonable time indicate that they can be used to prevent BETS.

Antibiotic resistance in periodontitis patients: A systematic scoping review of randomized clinical trials

OBJECTIVES

The objective of the study was to evaluate the prevalence and proportions of antibiotic-resistant species in periodontitis patients.

METHODS

A systematic scoping review of randomized clinical trials (RCTs) was conducted using the PRISMA extension for scoping reviews involving different databases. MeSH terms and keywords were provided to examine only RCTs with antibiotic-resistant results that included at least 3 months of follow-up of systematically healthy patients diagnosed with periodontitis and treated with systemic or local antibiotics adjunctive to subgingival debridement. RCTs that managed participants surgically, duplicate publications, and investigations implemented on animals were discarded.

RESULTS

Six RCTs were chosen. These studies included 465 patients. Most investigations observed that while Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Porphyromonas gingivalis had low resistance to amoxicillin, microorganisms in many sites showed resistance to tetracycline, metronidazole, and azithromycin pretreatment. A. actinomycetemcomitans showed high resistance to tetracycline pre- and post-therapy. The proportion of antibiotic-resistant samples augmented rapidly after the prescription of antibiotics in all test groups. The percentage of antibiotic-resistant microorganisms decreased over time; at the end of the follow-up period, resistance levels were close to baseline levels.

CONCLUSIONS

Adjunctive local and systemic antibiotic treatment temporarily increased the antibiotic resistance of subgingival microorganisms; nonetheless, many bacteria remained susceptible to antibiotics during their administration.

The effect of antimicrobial photodynamic therapy on periodontal disease and glycemic control in patients with type 2 diabetes mellitus

OBJECTIVES

This study is aimed at determining the effect of concomitant antimicrobial photodynamic therapy (aPTD) on periodontal disease and glycaemic control in patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Twenty-four patients with T2DM were enrolled in the study. Periodontal clinical parameters were assessed by measuring probing pocket depth (PPD), clinical attachment loss (CAL), gingival recession (GR), full-mouth bleeding score (FMBS), full-mouth plaque score (FMPS), and full-mouth sulcus bleeding score (FMSBS). Glycated haemoglobin A1c (HbA1c) was measured. To determine the presence of the following periodontal pathogenic bacteria, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, subgingival plaque samples were taken from two periodontal pockets per jaw with the greatest PPD using paper tips. Patients were randomly divided into the test and control group. In the test group, full-mouth disinfection was performed in combination with aPTD. In the control group, only full-mouth disinfection was performed.

RESULTS

The results showed an improvement in periodontal clinical parameters in both groups. The difference between the groups in favour of the test group was statistically significant for BOP. The HbA1c level decreased in both groups. The difference was not statistically significant. The results of the microbiological analysis suggest that the presence of periodontal pathogenic bacteria is lower with additional antimicrobial photodynamic therapy with statistically significant difference for T. forsythia.

CONCLUSIONS

Additional aPDT causes a significant reduction in BoP in the proportion of positive sites for periodontal pathogens.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT05816941.

CLINICAL RELEVANCE

aPTD is a noninvasive adjunctive therapy that can positively influence the periodontal treatment outcome.

Aggregatibacter actinomycetemcomitans cytolethal distending toxin modulates host phagocytic function

Cytolethal distending toxins (Cdt) are a family of toxins produced by several human pathogens which infect mucocutaneous tissue and induce inflammatory disease. Human macrophages exposed to Aggregatibacter actinomycetemcomitans (Aa) Cdt respond through canonical and non-canonical inflammasome activation to stimulate cytokine release. The inflammatory response is dependent on PI3K signaling blockade via the toxin's phosphatidylinositol-3,4,5-triphosphate (PIP3) phosphatase activity; converting PIP3 to phosphatidylinsoitol-3,4-diphosphate (PI3,4P2) thereby depleting PIP3 pools. Phosphoinositides, also play a critical role in phagosome trafficking, serving as binding domains for effector proteins during phagosome maturation and subsequent fusion with lysosomes. We now demonstrate that AaCdt manipulates the phosphoinositide (PI) pools of phagosome membranes and alters Rab5 association. Exposure of macrophages to AaCdt slowed phagosome maturation and decreased phago-lysosome formation, thereby compromising macrophage phagocytic function. Moreover, macrophages exposed to Cdt showed decreased bactericidal capacity leading to increase in Aggregatibacter actinomycetemcomitans survival. Thus, Cdt may contribute to increased susceptibility to bacterial infection. These studies uncover an underexplored aspect of Cdt function and provide new insight into the virulence potential of Cdt in mediating the pathogenesis of disease caused by Cdt-producing organisms such as Aa.

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

OBJECTIVES

Culturable and unculturable microorganisms have been associated with periodontitis. Their differential proportions and composition have not been evaluated by their severity and complexity defined by stages in the 2018 AAP-EEP classification.

METHODS

One hundred eighty subgingival biofilm samples were collected in Spain and Colombia from subjects categorized as health/gingivitis: periodontitis stages I/II periodontitis stages III/IV. Target culturable microorganisms (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Eubacterium nodatum) and target unculturable microorganisms (Filifactor alocis, Eubacterium saphenum, Eubacterium brachy, Desulfobulbus oralis) were evaluated by quantitative PCR analysis. In addition, their differences and association with periodontal status were analyzed by ANCOVA and logistic regression models once adjusted to age, current smoking, and country.

RESULTS

P. gingivalis was significantly associated with periodontitis stages I/II, OR 2.44 (CI 95% 1.08-5.47) and stages III/V, OR 6.43 (CI 95% 2.43-16.9). T forsythia, OR 7.53 (CI 95% 2.07-27.4); D. oralis, OR 5.99 (CI 95% 2.71-13.23); F. alocis, OR 10.9 (CI 95% 4.56-23.2); E. brachy, 3.57 (CI 95% 1.40-9.11); and E. saphenum, 4.85 (CI 95% 1.99-11.7) were significantly associated only with stages III/IV periodontitis. P. gingivalis evidenced significant differences with the increase in the severity of the periodontal lesion: 2.97 colony forming unit (CFU)/μL (CI 95% 2.32-3.54) health/gingivitis, and 4.66 CFU/μL (CI 95% 4.03-5.30) and 5.90 CFU/μL (CI 95% 5.20-6.48) in stages I/II and III/IV respectively (p < 0.0001). Unculturable microorganisms only evidenced differences in concentration in stages III/IV compared with health-gingivitis (p ≤ 0.001).

CONCLUSION

Culturable and unculturable are strongly associated with stages III/IV periodontitis. Classic culturable microorganisms are more sensitive to differentiate between stages of periodontitis in the quantitative analysis.

CLINICAL RELEVANCE

Future interventional studies of periodontal disease should include Filifactor alocis, Eubacterium saphenum, Eubacterium brachy, and Desulfobulbus oralis as possible markers of therapy response and as indicators of progressive disease.

Aggressive pulmonary destructive lesion caused by aggregatibacter actinomycetemcomitans: a pediatric case report in Saudi Arabia

BACKGROUND

This study aimed to describe invasive pneumonia with rib destruction caused by Aggregatibacter (Actinobacillus) actinomycetemcomitans that mimicked malignancy and tuberculosis of the chest on initial presentation.

CASE PRESENTATION

We reported a case of A. actinomycetemcomitans pneumonia with rib destruction and reviewed similar published pediatric cases. It was noted in this case that Aggregatibacter (Actinobacillus) actinomycetemcomitans is a fastidious, slow-growing organism that caused pneumonia and rib destruction. It needed a long duration of therapy to eradicate the organism.

CONCLUSIONS

Aggregatibacter (Actinobacillus) actinomycetemcomitans, a fastidious gram-negative bacillus that is part of the oral flora, is frequently found in human periodontal cultures and is an important pathogen causing various invasive infections. Pneumonia caused by A. actinomycetemcomitans is rare and treatment protocols are not well established.

Bacterial Leakage Evaluation Through DNA-DNA Checkerboard Hybridization Technique in Morse Taper Implant-Abutment Connections: An In Vitro Study

Purpose: The objective of this in vitro study was to evaluate the activity of local gel containing metronidazole (MN) in the leakage area, which was analyzed by the DNA-DNA checkerboard hybridization method. Materials and Methods: Thirty-six sets of Morse taper/mini-pillar implants were used in this study. These implants were equally divided into the following three groups: MN gel (test group), no MN gel (negative test group), and no gel (control). The gel was prepared with metronidazole (15%). Unstimulated saliva samples were collected, transferred to a Falcon tube, and stored at 37°C. The sets were partially immersed in microtubes containing 300 μL of saliva and were incubated at 37°C ± 1°C for 7 days. Microbial infiltration was evaluated (37 bacterial species and 5 species of Candida). The results were analyzed with Wald-Type, ANOVA, and multiple comparisons analysis between groups. Results: After comparing the quantity of microorganisms, both gel-treated groups (no MN gel and MN gel) had more significant microorganism presence than the control group (P < .001), and no significant result was found between the no MN gel and MN gel groups (P > .05). Regarding the bacteria found, the most common were Aggregatibacter actinomycetemcomitans, Prevotella melaninogenica, Bacteroides fragilis, and Candida tropicalis. Conclusion: Within the limitations of this study, it was concluded that the gel containing metronidazole used in this study was not effective in preventing the infiltration of microorganisms through the Morse taper implant-abutment interface.

Differential Virulence of Aggregatibacter actinomycetemcomitans Serotypes Explained by Exoproteome Heterogeneity

Aggregatibacter actinomycetemcomitans (Aa) is a Gram-negative bacterial pathogen associated with periodontitis and nonoral diseases like rheumatoid arthritis and Alzheimer´s disease. Aa isolates with the serotypes a, b, and c are globally most prevalent. Importantly, isolates displaying these serotypes have different clinical presentations. While serotype b isolates are predominant in severe periodontitis, serotypes a and c are generally encountered in mild periodontitis or healthy individuals. It is currently unknown how these differences are reflected in the overall secretion of virulence factors. Therefore, this study was aimed at a comparative analysis of exoproteomes from different clinical Aa isolates with serotypes a, b, or c by mass spectrometry, and a subsequent correlation of the recorded exoproteome profiles with virulence. Overall, we identified 425 extracellular proteins. Significant differences in the exoproteome composition of isolates with different serotypes were observed in terms of protein identification and abundance. In particular, serotype a isolates presented more extracellular proteins than serotype b or c isolates. These differences are mirrored in their virulence in infection models based on human salivary gland epithelial cells and neutrophils. Remarkably, serotype a isolates displayed stronger adhesive capabilities and induced more lysis of epithelial cells and neutrophils than serotype b or c isolates. Conversely, serotype c isolates showed relatively low leukotoxicity, while provoking NETosis to similar extents as serotype a and b isolates. Altogether, we conclude that the differential virulence presentation by Aa isolates with the dominant serotypes a, b, or c can be explained by their exoproteome heterogeneity. IMPORTANCE Periodontitis is an inflammatory disease that causes progressive destruction of alveolar bone and supporting tissues around the teeth, ultimately resulting in tooth loss. The bacterium Aggregatibacter actinomycetemcomitans (Aa) is a prevalent causative agent of periodontitis, but this oral pathogen is also associated with serious extraoral diseases like rheumatoid arthritis and Alzheimer's disease. Clinical Aa isolates are usually distinguished by serotyping, because of known serotype-specific differences in virulence. Aa with serotype b is associated with aggressive forms of periodontitis, while isolates with serotypes a or c are usually encountered in cases of mild periodontitis or healthy individuals. The molecular basis for these differences in virulence was so far unknown. In the present study, we pinpoint serotype-specific differences in virulence factor production by clinical Aa isolates. We consider these findings important, because they provide new leads for future preventive or therapeutic approaches to fight periodontitis and associated morbidities.

Quantitative Analysis of Periodontal Pathogens Using Real-Time Polymerase Chain Reaction (PCR)

The quantitative polymerase chain reaction (qPCR) is a variant of PCR aimed to detect and quantify a targeted DNA molecule. This is made through the addition of probes labeled with fluorescent molecules that emit fluorescence within each amplification cycle, resulting in fluorescence values proportional to the amount of accumulated PCR product. This chapter presents the detailed procedures for quantification of different periodontal pathogens (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Campylobacter rectus, Streptococcus oralis, and Fusobacterium spp.) using qPCR. It also includes the description of the most frequent problems encountered, how to solve them, and recommendations to minimize the risks for laboratory staff handling oral samples. In addition, a detailed protocol for multiplex qPCR to detect and quantify Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia is also included.

Comparative evaluation of the antibacterial activity of red diode laser therapy and 0.2% chlorhexidine against Aggregatibacter actinomycetemcomitans on implant healing abutments: An ex vivo study

Aims

The intraoral microbiota has a high potential to undergo dysbiosis, causing inflammatory changes with respect to the tissues surrounding either a natural tooth or an implant. Thus, the longevity of implant prosthesis depends on a thorough implant decontamination protocol. Among all the techniques available for doing so, laser is garnering increasing popularity, owing to minimal bleeding, high efficiency, and faster healing. However, limited literature exists regarding the superiority of lasers over chlorhexidine (CHX), the indisputable gold standard antibacterial chemical agent. The aim of this study was to compare the percentage of bacterial reduction of Aggregatibacter actinomycetemcomitans from implant healing abutments post red diode laser therapy versus 0.2% CHX treatment.

Settings and Design

The current study had an ex vivo, observational, case-control design.

Materials and Methods

Patients reporting for the second stage of the implant surgery were taken as the source of data and the healing abutments, the clinical samples. Eleven patients were chosen with one intraoral implant serving as the test site for laser treatment and another, the control site for CHX treatment. Microbiological analysis was performed via quantitative real time polymerase chain reaction to compare the bacterial reduction percentage after each treatment.

Statistical Analysis Used

Repeated measures ANOVA and independent sample t test were used.

Results

The mean bacterial viability of the test group (laser) was 1.2%-1.6%, and 0.6%-1.4% for the control group (CHX). The former caused a mean bacterial reduction of 96.1% while the latter, 96.3%. Both the treatments caused a highly statistically significant reduction of viable bacterial counts (P = 0.001). However, when compared, there was no statistically significant difference in the bacterial reduction, when compared in between the two (P = 0.902).

Conclusion

Laser treatment is at par with chemical implant surface decontamination. It can help bypass the complications of CHX and revolutionize the protocols for implant surface decontamination.

Oral and throat microbiological changes after orthodontic debonding

As already known, orthodontic treatment presents a factor of plaque retention, promoting an increase of bacterial growth in the oral cavity. Nevertheless, after orthodontic debonding an alteration of the previous microbiological status may occur. The present study was designed to assess variations among six bacterial species in the oral cavity and the status of oral health after orthodontic debonding. At the end of the fixed orthodontic treatment, 30 patients were divided into three groups based on the type of retention: I - 10 patients were treated with upper and lower fixed retention devices, II - 10 with upper and lower removable retention devices, and III - 10 with lower fixed and upper removable retention devices. To assess the alterations of oral microbiota after orthodontic debonding, two salivary swabs were collected for each individual: the first immediately after debonding (T0) and the other one 6 weeks later (T1). Six species, the ones most correlated with the development of caries and periodontal disease, were selected for microbiological analysis with Real-time PCR: Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum. Furthermore, in order to correlate the microbiological outcomes with the clinical condition, oral health indexes at T0 and T1 were assessed for all patients. Six weeks after debonding, the salivary levels of the bacteria investigated tend to decrease and the values of the oral health indexes tend to improve with all types of treatment considered (p<.05). Salivary bacteria levels and oral health are similarly influenced by fixed and/or removable orthodontic retentions.

Antibiotic Resistance in Patients with Peri-Implantitis: A Systematic Scoping Review

The implementation of adjunctive antibiotics has been recommended for the therapy of peri-implantitis (PI). In this review, antibiotic resistance patterns in PI patients were assessed. A systematic scoping review of observational studies and trials was established in conjunction with the PRISMA extension for scoping reviews. The SCOPUS, PubMed/MEDLINE, EMBASE, SCIELO, Web of Science, and LILACS databases were reviewed along with the gray literature. The primary electronic examination produced 139 investigations. Finally, four observational studies met the selection criteria. These studies evaluated 214 implants in 168 patients. Porphyromonas gingivalis and Fusobacterium nucleatum mainly presented high resistance to tetracycline, metronidazole, and erythromycin in PI patients. Similarly, Aggregatibacter&nbsp;actinomycetemcomitans was also highly resistant to clindamycin and doxycycline. Other microorganisms such as Tannerella forsythia, Parvimonas micra, and Prevotella intermedia/nigrescens also presented significant levels of resistance to other antibiotics including amoxicillin, azithromycin, and moxifloxacin. However, most microorganisms did not show resistance to the combination amoxicillin metronidazole. Although the management of adjunctive antimicrobials in the therapy of PI is controversial, in this review, the resistance of relevant microorganisms to antibiotics used to treat PI, and usually prescribed in dentistry, was observed. Clinicians should consider the antibiotic resistance demonstrated in the treatment of PI patients and its public health consequences.