Persistence of Porphyromonas gingivalis is a negative predictor in patients with moderate to severe periodontitis after nonsurgical periodontal therapy

Microbial biomarkers as a predictor of periodontal treatment response: A systematic review

To evaluate the prognostic accuracy of microbial biomarkers and their associations with the response to active periodontal treatment (APT) and supportive periodontal therapy (SPT). Microbial dysbiosis plays a crucial role in the disease processes of periodontitis. Biomarkers based on microbial composition may offer additional prognostic value, supplementing the limitations of current clinical parameters. While these microbial biomarkers have been clinically evaluated, there is a lack of consensus regarding their prognostic accuracy. A structured search strategy was applied to MEDLINE (PubMed), Cochrane Library, and Embase on 1/11/2022 to identify relevant publications. Prospective clinical studies involving either APT or SPT, with at least 3-month follow-up were included. There were no restrictions on the type of microbial compositional analysis. 1918 unique records were retrieved, and 13 studies (comprising 943 adult patients) were included. Heterogeneity of the studies precluded a meta-analysis, and none of the included studies had performed the sequence analysis of the periodontal microbiome. Seven and six studies reported on response to APT and SPT, respectively. The prognostic accuracy of the microbial biomarkers for APT and SPT was examined in only two and four studies, respectively. Microbial biomarkers had limited predictive accuracy for APT and inconsistent associations for different species across studies. For SPT, elevated abundance of periodontal pathogens at the start of SPT was predictive of subsequent periodontal progression. Similarly, persistent high pathogen loads were consistently associated with progressive periodontitis, defined as an increased pocket probing depth or clinical attachment loss. While there was insufficient evidence to support the clinical use of microbial biomarkers as prognostic tools for active periodontal treatment outcomes, biomarkers that quantify periodontal pathogen loads may offer prognostic value for predicting progressive periodontitis in the subsequent supportive periodontal therapy phase. Additional research will be required to translate information regarding subgingival biofilm composition and phenotype into clinically relevant prognostic tools.

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.

Microcirculation and somatosensory profiling of patients with periodontitis: a preliminary case control report

OBJECTIVES

The purpose of this preliminary study was to explore blood microcirculation and somatosensory profiles in periodontitis patients before and after non-surgical periodontal therapy.

MATERIALS AND METHODS

Twenty patients (10 men and 10 women, 20 to 30 years old) and 20 age- and gender-matched healthy controls were included. Non-surgical periodontal therapy was performed for all patients. Clinical examination including pocket probing depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP) were performed at baseline (BL), 1 week (1W), and 4 weeks (4W) after non-surgical periodontal therapy on 6 sites of tooth 32 and 42. Laser Doppler flowmetry (LDF) and quantitative sensory testing (QST) were applied at the attached gingiva of tooth 32 and 42 at BL, 1W, and 4W after non-surgical periodontal therapy. Data were analyzed with a two-way mixed-model of ANOVA.

RESULTS

The PPD, CAL and BOP significantly improved after non-surgical periodontal therapy (p < 0.001). Periodontitis patients demonstrated a higher tissue microvascular blood cell concentration (p = 0.015) and a significant gain in thermal (p = 0.037) and mechanical (p = 0.003) somatosensory function compared to controls. After non-surgical periodontal therapy, the flux (p = 0.002) and speed (p = 0.008) of blood flow decreased significantly and thermal (p = 0.029) and mechanical (p < 0.001) somatosensory function were reversed.

CONCLUSION

Gingival microcirculation and somatosensory function seem impaired in patients with periodontitis and are reversed following non-surgical periodontal therapy.

CLINICAL RELEVANCE

LDF and QST may be appropriate tools to further characterize gingival inflammation and treatment responses in periodontitis.

Full-mouth disinfection effects on gingival fluid calprotectin, osteocalcin, and N-telopeptide of Type I collagen in severe periodontitis

BACKGROUND

To compare the effects of full-mouth disinfection (FMD) and full-mouth ultrasonic debridement (FMUD) on clinical, microbiological and biochemical parameters with conventional quadrant-wise scaling and root planning (Q-SRP) in severe chronic periodontitis.

METHODS

In the present prospective randomized controlled clinical trial with three parallel arms (#NCT04038801), 60 chronic periodontitis patients were randomly assigned to three study groups by a consecutive number in ascending order: FMD (n = 20), FMUD (n = 20), and Q-SRP (n = 20). All measurements and treatments were performed by the same investigator. At baseline, gingival crevicular fluid (GCF) and subgingival plaque were collected and clinical periodontal parameters were recorded. Ultrasonic debridement was completed within 24 hours in FMD and FMUD groups. Chlorhexidine gluconate was used for FMD. Q-SRP was performed by hand instruments per quadrant at 1-week-intervals. Clinical measurements and sampling were repeated at 1, 3, and 6 months after treatment. Real-time PCR was used for quantitative analysis of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and total bacteria count. GCF Calprotectin, osteocalcin, and N-telopeptide of type I collagen (NTx) levels were analyzed by ELISA. The changes of GCF biomarker levels after treatment between groups were the primary outcomes.

RESULTS

No harm was observed. All treatment strategies resulted in significant improvements in all clinical parameters (P < 0.05), with no significant differences between study groups at all time-points (P ˃ 0.05). Aggregatibacter actinomycetemcomitans was significantly decreased in FMD compared to FMUD and Q-SRP at 6 months (P < 0.05). Although GCF NTx total amounts increased in all groups during the study period, this increase was less prominent in full-mouth groups at three time points after treatment (P < 0.05).

CONCLUSIONS

Present results represent the short-term effects. Full-mouth treatment approaches offered limited beneficial effects on microbiological and biochemical parameters over quadrant-wise approach. All three treatment strategies can be recommended in the management of severe chronic periodontitis.

Professional tooth cleaning prior to non-surgical periodontal therapy: A randomized clinical trial

BACKGROUND

This study was aimed to investigate if professional oral prophylaxis before scaling and root planing (SRP) has an effect on the outcome of non-surgical periodontal treatment in patients with chronic periodontitis.

METHODS

Fifty-two individuals with chronic periodontitis receiving non-surgical periodontal therapy by SRP with (test) and without (control) two appointments of professional tooth cleaning but with motivation and instruction were monitored for clinical variables, four selected microorganisms and two biomarkers at baseline, before SRP as well as 3 and 6 months after SRP. Statistical analysis included non-parametric tests for intra- and intergroup comparisons.

RESULTS

Probing depth (PD), attachment level, bleeding on probing (BOP), and interproximal plaque index (API) were significantly improved in both groups 3 and 6 months after SRP. PD, BOP, API, and the number of sites with PD ≥5 mm were significantly lower in the test group than in the control group at the appointment immediately before SRP. Tannerella forsythia was significantly reduced in both groups at 3 and 6 months, Porphyromonas gingivalis only in the test group. Interleukin-1β was significantly reduced in the control group 3 and 6 months after SRP, matrix metalloproteinase-8 level decreased in the test group 3 months after SRP. There was no significant difference of any clinical and non-clinical variable between both groups at 3 and 6 months after SRP.

CONCLUSIONS

Professional tooth cleaning before the SRP does not improve the clinical results of the SRP. It has no obvious long-lasting effects on major periodontopathogens in the subgingival biofilm as well as on biomarkers in the gingival crevicular fluid after SRP.

Comparison of clinical parameters, microbiological effects and calprotectin counts in gingival crevicular fluid between Er: YAG laser and conventional periodontal therapies: A split-mouth, single-blinded, randomized controlled trial

BACKGROUND

The erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser is thought to be the most promising laser for periodontal treatment; however, its application is still under consideration. The aim of this study was to compare Er:YAG laser monotherapy with conventional scaling and root planing (SRP) for chronic periodontitis using clinical parameters, the detection rate of periodontal pathogens, and the calprotectin level in gingival crevicular fluid.

METHODS

Twenty-seven participants with moderate-to-advanced chronic periodontitis were included. In a split-mouth design, the 2 half-mouths of each participant were randomly assigned to Er:YAG laser or SRP (combination of ultrasonic and manual instruments) treatment. Clinical parameters were recorded at baseline, 6 weeks, and 3 and 6 months after treatment. At the same time points, gingival crevicular fluid was collected to analyze the detection rate of 6 periodontal pathogens by polymerase chain reaction and the levels of calprotectin by enzyme-linked immunosorbent assay.

RESULTS

Both treatment groups showed significant reductions in probing depth (PD), bleeding index (BI), and clinical attachment level (CAL) from baseline to 6 months. For sites with 4 mm ≤ PD ≤ 6 mm at baseline, SRP resulted in a greater reduction in PD and CAL than Er:YAG laser treatment, and the difference remained at 6 months post-treatment (P = .01 and P < .01, respectively). For sites with PD ≥7 mm at baseline, the clinical parameters showed similar results between the 2 groups. SRP resulted in a lower detection rate of Porphyromonas gingivalis at 6 months post-treatment. The levels of calprotectin were significantly decreased from baseline to 6 months in both groups, without a significant difference between the groups.

CONCLUSION

For mild pockets, conventional SRP may still be the preferred choice. For deep pockets, Er:YAG laser treatment could be an effective alternative. Studies are needed to explore more advanced instruments and new application methods for the Er:YAG laser for periodontal treatment in deep pockets.