Toll-like receptor-4 activation by subgingival biofilm and periodontal treatment response

OBJECTIVES

This study aims to investigate longitudinally the activation of Toll-like receptor-4 (TLR-4) by subgingival biofilm samples before and after nonsurgical periodontal therapy (NSPT).

MATERIALS AND METHODS

Forty periodontitis patients received NSPT and were reviewed 3 and 6 months post-treatment. Subgingival biofilm was sampled from 4 teeth per patient, at baseline and each follow-up time point. TLR-4 activation was determined using the HEK-BLUE™/hTLR4 system. Changes in TLR-4 activation and probing pocket depths (PPDs) were evaluated using generalised linear models, and the association between TLR-4 activation and pocket reduction (defined as 6-month PPDs ≤ 3mm) was determined using generalised estimating equations.

RESULTS

At 6 months, the mean TLR-4 activation by subgingival biofilm samples was significantly reduced from 11.2AU (95%CI 7.1AU, 15.4AU) to 3.6AU (95%CI 2.3AU, 4.8AU, p < 0.001), paralleling significant reductions in mean PPDs at sampled sites. The response to NSPT was associated with longitudinal TLR-4 activation profiles, with significantly higher TLR-4 activation by subgingival biofilm obtained from sites that did not achieve pocket reduction, compared to sites at which pocket reduction was achieved.

CONCLUSIONS

The activation of TLR-4 by subgingival biofilm samples was reduced after NSPT, and this reduction was significantly associated with the clinical improvements (PPD reductions) at sampled sites.

CLINICAL RELEVANCE

This study demonstrated an association between the longitudinal profile of TLR-4 activation by subgingival biofilm and periodontal treatment response. Longitudinal monitoring of TLR-4 activation by subgingival biofilm may potentially identify non-responsive sites, enabling targeted additional treatment.

Effect of oral health intervention on cognitive decline in community-dwelling older adults: A randomized controlled trial

PURPOSE

The incidence of dementia is rapidly increasing worldwide, especially in developed countries. Little is known regarding the effectiveness of dental intervention to prevent dementia or a decline in cognitive functions among community-dwelling older adults, but a few studies have reported a correlation between the lack of regular dental checkups and dementia. For that reason, this study aimed to investigate the effects of oral health intervention on cognitive functions in community-dwelling subjects with a mild cognitive decline via a randomized controlled trial.

PATIENTS AND METHODS

Fifty-five community-dwelling older adults with a Mini-Mental State Examination score of ≥21 to ≤26 who had not visited a dental clinic in the previous year were randomized to an intervention group (n = 28) or a control group (n = 29). The intervention group received monthly oral health intervention by dental hygienists for 8 months while the control group did not. Data on demographics, cognitive function and oral parameters were collected before and after the intervention.

RESULTS

Twenty-five subjects in the intervention group (mean age 77.0 years) and 25 in the control group (mean age 72.8 years) completed the study. Significant improvements were observed in the Trail Making Test (TMT)-A, TMT-B, bleeding on probing rate, oral diadochokinesis, tongue pressure and chewing ability in the intervention group (P < 0.05). There were also significant interactions between the TMT-A and TMT-B scores, oral diadochokinesis, tongue pressure and chewing ability (P < 0.05).

CONCLUSION

Oral health intervention by dental hygienists may be effective for improving the oral health and executive function of cognitive function assessed via TMT.

Periodontopathogens: a new view. Systematic review. Part 2

Relevance. The modern view of periodontitis as a dysbiotic disease that occurs as a result of changes in the microbial composition of the subgingival region is considered in a systematic review.

Purpose. To study a new paradigm of development of generalized periodontitis.

Materials and methods. Randomized controlled trials (RCTS) were selected for the study, including cluster RCTS, controlled (non-randomized) microbiological and clinical studies of the oral microbiome in adult patients with generalized periodontitis over the past 10 years.

Results. The transition from a symbiotic microflora to a dysbiotic pathogenic community triggers the host's inflammatory response, which contributes to the development of periodontal diseases. Modern ideas about periodontal pathogenic bacteria dictate new requirements for the treatment of periodontal diseases. The second part of the review examines the microbial profiles of periodontal disease in various nosological forms, the mechanisms of the immune response and approaches to the treatment of periodontal disease from the perspective of biofilm infection.

Conclusions. As follows from modern literature periodontitis is to a certain extent caused by the transition from a harmonious symbiotic bacterial community to a dysbiotic one. Recent scientific studies have shown that not single microorganism is not able to cause disease but the microbial community as a whole leads to the development of pathology.

Periodontopathogens: a new view. Systematic review. Part 1

Relevance. The modern view of periodontitis as a dysbiotic disease that occurs as a result of changes in the microbial composition of the subgingival region is considered in a systematic review.

Purpose. To study a new paradigm of development of generalized periodontitis.

Materials and methods. Randomized controlled trials (RCTS) were selected for the study, including cluster RCTS, controlled (non-randomized) microbiological and clinical studies of the oral microbiome in adult patients with generalized periodontitis over the past 10 years.

Results. The development of periodontal dysbiosis occurs over a period of time, which slowly turns the symbiotic association of the host and microbe into a pathogenic one. This review examines the current paradigm of periodontitis progression, which calls into question the traditional concept of a disease induced by several particular periodontal pathogens belonging to the red complex.

Conclusions. As follows from modern literature periodontitis is to a certain extent caused by the transition from a harmonious symbiotic bacterial community to a dysbiotic one. Recent scientific studies have shown that not single microorganism is not able to cause disease but the microbial community as a whole leads to the development of pathology. 

Impact of non-surgical periodontal therapy on serum Resistin and periodontal pathogen in periodontitis patients with obesity

BACKGROUND

Non-surgical periodontal therapy (NSPT) known as gold standard treatment in managing periodontitis. The aim of this study was to investigate the response of NSPT in periodontitis subjects who were obese. Clinical parameters of periodontitis, changes in serum resistin and periodontal pathogens in subgingival plaque were compared before and after NSPT in periodontitis subjects who were obese and with normal weight.

METHODS

A total of 48 periodontitis subjects (obese, n = 18; normal weight, n = 30) were recruited (hereafter will be referred as participants) to participate into a prospective, before and after clinical trial. Obesity status is defined by body mass index (BMI) criteria (obese: ≥30 kg/ m2; normal weight < 25 kg/m2). Visible Plaque Index (VPI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD) and Clinical Attachment Loss (CAL) were recorded; and serum and plaque were collected at baseline and following 12 weeks post-NSPT. Serum resistin level was analyzed using enzyme-linked immune-sorbant assay (ELISA), while detection of periodontal pathogens in dental plaque were carried out using real time PCR (qPCR).

RESULTS

Following NSPT, means VPI and GBI showed significant improvement between obese and normal weight groups (p <  0.05), but no difference in means PPD and CAL was observed between groups. Obesity remained as a predictor for VPI and GBI after adjusting for smoking habit. No significant difference was observed in serum resistin level and mean counts for P. gingivalis, T. forsythia, and P. intermedia between obese and normal weight groups following NSPT.

CONCLUSIONS

Regardless of obesity status, NSPT has a significant impact on VPI and GBI in periodontitis subjects. However, the impact of NSPT towards serum resistin and periodontal pathogens was non-significant in those with periodontitis.

TRIAL REGISTRATION

This study followed the Consolidation Standards of Reporting Trials Statement and retrospectively registered on 26/11/2015 at clinicaltrials.gov (No. NCT02618486).