Oxidative stress-related biomarkers in saliva and gingival crevicular fluid associated with chronic periodontitis: A systematic review and meta-analysis

AIM

Oxidative stress (OS) biomarkers have been detected in saliva and gingival crevicular fluid (GCF) during chronic periodontitis (CP) progression; however, the relationship between OS biomarkers and CP progression remains elusive. The purpose of this meta-analysis is to investigate the relationship between local OS biomarkers and CP.

METHODS

This review was conducted through a systematic search from three databases. Studies on CP participants were included as an experimental group, and studies on periodontally healthy (PH) participants were included as a control. Mean effects were expressed as standardized mean difference with their associated 95% confidence intervals.

RESULTS

From a total of 2,972 articles, 32 articles fulfilled the inclusion criteria. We found a significant decrease of total antioxidant capacity and a significant increase of malondialdehyde (MDA), nitric oxide, total oxidant status (TOS), and 8-hydroxy-deoxyguanosine levels in the saliva of CP patients. Moreover, we also found an elevation of MDA level in GCF of CP group when compared with the PH group. There were no significant differences of salivary and GCF superoxide dismutase levels, salivary glutathione peroxidase level, and GCF TOS level between two groups. However, a high heterogeneity was observed among evaluated studies.

CONCLUSIONS

Despite the limitations of this study, the result of our meta-analysis supported the rationale that there was a direct link between CP and OS-related biomarkers' levels in the local site, indicating the important role of OS in the onset and development of CP.

The effects of statins on dental and oral health: a review of preclinical and clinical studies

The statin family of drugs are safe and effective therapeutic agents for the treatment of arteriosclerotic cardiovascular disease (CVD). Due to a wide range of health benefits in addition to their cholesterol lowering properties, statins have recently attracted significant attention as a new treatment strategy for several conditions, which are not directly related to normalizing a lipid profile and preventing CVD. Statins exert a variety of beneficial effects on different aspects of oral health, which includes their positive effects on bone metabolism, their anti-inflammatory and antioxidant properties, and their potential effects on epithelization and wound healing. Additionally, they possess antimicrobial, antiviral, and fungicidal properties, which makes this class of drugs attractive to the field of periodontal diseases and oral and dental health. However, to the best of our knowledge, there has been no comprehensive study to date, which has investigated the effects of statin drugs on different aspects of dental and oral health. Therefore, the primary objective of this paper was to review the effect of statins on dental and oral health. Results of our extensive review have indicated that statins possess remarkable and promising effects on several aspects of dental and oral health including chronic periodontitis, alveolar bone loss due to either extraction or chronic periodontitis, osseointegration of implants, dental pulp cells, orthodontic tooth movement, and orthodontic relapse, tissue healing (wound/bone healing), salivary gland function, and finally, anti-cancer effects. Hence, statins can be considered as novel, safe, inexpensive, and widely-accessible therapeutic agents to improve different aspects of dental and oral health.

An injectable in situ gel with cubic and hexagonal nanostructures for local treatment of chronic periodontitis

Periodontitis is a chronic bacterial infection, and its effective treatment is dependent on the retention of antibiotics of effective concentrations at the periodontal pockets. In this study, a solution-gel based inverse lyotropic liquid crystalline (LLC) system was explored to deliver metronidazole to the periodontal pockets for local treatment of periodontitis. It was found that the metronidazole-loaded LLC precursor spontaneously transformed into gel in the presence of water in the oral cavity. The low viscosity of the precursor would allow its penetration to the rather difficult to reach infection sites, while the adhesiveness and crystalline nanostructures (inverse bicontinuous cubic Pn3m phase and inverse hexagonal phase) of the formed gel would permit its firm adhesion to the periodontal pockets. The LLC system provided sustained drug release over one week in vitro. Results from in vivo study using a rabbit periodontitis model showed that the LLC system was able to maintain the metronidazole concentrations in the periodontal pockets above the minimum inhibition concentration for over 10 days without detectable drug concentration in the blood. Owing to the spontaneous solution-gel transition in the periodontal pockets and unique liquid crystalline nanostructures, the LLC in situ gel provided effective treatment of periodontitis for a prolonged period of time with reduced systematic side effects, compared to metronidazole suspension which was effective for 24 h with detectable metronidazole concentrations in the blood after 6 h.

Comparative Analysis of Calcium-Binding Myeloid-Related Protein-8/14 in Saliva and Serum of Patients With Periodontitis and Healthy Individuals

BACKGROUND

This study aims to investigate calcium-binding myeloid-related protein (MRP)-8/14 in the saliva and serum of individuals with periodontitis and periodontally healthy individuals for the assessment of its role in the pathogenesis and clinical diagnosis of periodontitis.

METHODS

This cross-sectional study includes 56 patients with periodontitis and 44 periodontally healthy individuals. Saliva and serum were collected for the detection of MRP-8/14 and calcium levels. Periodontopathic bacteria were determined by polymerase chain reaction in saliva. Correlations between salivary and serum MRP-8/14 levels and clinical parameters, bacteria, and calcium were analyzed with Pearson correlation in a multiple regression model. MRP-8/14 levels were documented with receiver operating characteristic (ROC) curves.

RESULTS

Compared with healthy individuals, MRP-8/14 levels were significantly higher in both the saliva and serum of patients with periodontitis, but calcium was increased only in saliva. A high diagnostic potential of salivary MRP-8/14 was detected for periodontitis (ROC = 0.86). Salivary MRP-8/14 levels correlated significantly with the presence of the periodontopathogen Treponema denticola, as well as with the clinical parameters of periodontitis.

CONCLUSION

MRP-8/14 in saliva might be a potential diagnostic parameter for periodontal disease.

Amnion membrane as a novel barrier in the treatment of intrabony defects: a controlled clinical trial

PURPOSE

The purpose of this 6-month randomized, controlled, blinded, clinical trial was to evaluate and compare the efficacy of amnion membrane (AM) with deproteinized bovine bone mineral (BBM) and a collagen membrane (CM) with BBM in guided tissue regeneration (GTR) for the treatment of intrabony periodontal defects.

MATERIALS AND METHODS

Ten chronic periodontitis patients with bilateral intrabony defects with radiographic evidence of intrabony component ≥ 4 mm and probing pocket depths (PPDs) ≥ 6 mm were treated with AM+BBM, and the control group was managed with CM+BBM. Periodontal clinical parameters were recorded at baseline and at 6 months after treatment.

RESULTS

PPD, clinical attachment level (CAL), and probing bone (PB) showed significant improvements after 6 months in both the test and control groups. Gingival recession showed a significant increase in the control group but not in the test group. The changes in mean PPD, PB, and CAL preoperatively and postoperatively between the groups were not significant. There was no significant relationship between the depth of the baseline bony defect and CAL gain.

CONCLUSION

Both AM and CM in conjunction with BBM provided improvement of clinical periodontal parameters. AM did not induce significant gingival recession and is suggested as a new barrier membrane in GTR treatment.

Inflammatory Status and Glycemic Control Level of Patients with Type 2 Diabetes and Periodontitis: A Randomized Clinical Trial

Background: Based on the holistic approach to prevention diabetic disease, the role of periodontal inflammation in type 2 diabetes mellitus (T2DM) is under intensive scrutiny. Data from clinical trials have shown benefit from a periodontal therapy in providing patients with type 2 diabetes improvement despite relatively disappointing long-terms response rates. The aim of this study was to investigate the short-term glycemic control level and systemic inflammatory status after periodontal therapy. Methods: This was a randomized trial with a 6-months follow-up. Participants aged 56.4 ± 7.9 years with diagnosed type 2 diabetes and periodontitis were enrolled. Among the 187 type 2 diabetic patients, 93 were randomly assigned to receive non-surgical periodontal treatment immediately and 94 to receive the delayed treatment. Within and between groups comparison was done during the study period, and the differences between groups were assessed. Results: The difference between HbA1c values at baseline (Mdn = 7.7) and 6 months after non-surgical periodontal treatment (Mdn = 7.2) was statistically significant, U = 3174.5, p = 0.012, r = 0.187. However, although technically a positive correlation, the relationship between the glycated hemoglobin value and periodontal variables was weak. The differences between both the groups over 6 months were not statistically considerable, failing to reach statistical significance. At 6 months the difference between groups about the C-reactive protein (CRP) levels was statistically significant, U=1839.5, p = 0, r = 0.472, with a lower concentration for the intervention group. Furthermore, the intervention group showed a statistically significant difference between baseline and 6 months evaluation (U = 2606.5, p = 0, r = 0.308). Conclusions: The periodontal intervention potentially may allow individuals with type 2 diabetes to improve glycemic control and CRP concentrations, and diabetes alters the periodontal status.

Salivary Microbiota and Host-Inflammatory Responses in Periodontitis Affected Individuals With and Without Rheumatoid Arthritis

Objectives

Periodontitis and rheumatoid arthritis (RA) are two widespread chronic inflammatory diseases with a previously suggested association. The objective of the current study was to compare the oral microbial composition and host´s inflammatory mediator profile of saliva samples obtained from subjects with periodontitis, with and without RA, as well as to predict biomarkers, of bacterial pathogens and/or inflammatory mediators, for classification of samples associated with periodontitis and RA.

Methods

Salivary samples were obtained from 53 patients with periodontitis and RA and 48 non-RA with chronic periodontitis. The microbial composition was identified using 16S rRNA gene sequencing and compared across periodontitis patients with and without RA. Levels of inflammatory mediators were determined using a multiplex bead assay, compared between the groups and correlated to the microbial profile. The achieved data was analysed using PCoA, DESeq2 and two machine learning algorithms, OPLS-DA and sPLS-DA.

Results

Differential abundance DESeq2 analyses showed that the four most highly enriched (log2 FC >20) amplicon sequence variants (ASVs) in the non-RA periodontitis group included Alloprevotella sp., Prevotella sp., Haemophilus sp., and Actinomyces sp. whereas Granulicatella sp., Veillonella sp., Megasphaera sp., and Fusobacterium nucleatum were the most highly enriched ASVs (log2 FC >20) in the RA group. OPLS-DA with log2 FC analyses demonstrated that the top ASVs with the highest importance included Vampirovibrio sp. having a positive correlation with non-RA group, and seven ASVs belonging to Sphingomonas insulae, Sphingobium sp., Novosphingobium aromaticivorans, Delftia acidovorans, Aquabacterium spp. and Sphingomonas echinoides with a positive correlation with RA group. Among the detected inflammatory mediators in saliva samples, TWEAK/TNFSF12, IL-35, IFN-α2, pentraxin-3, gp130/sIL6Rb, sIL-6Ra, IL-19 and sTNF-R1 were found to be significantly increased in patients with periodontitis and RA compared to non-RA group with periodontitis. Moreover, correlations between ASVs and inflammatory mediators using sPLS-DA analysis revealed that TWEAK/TNFSF12, pentraxin-3 and IL-19 were positively correlated with the ASVs Sphingobium sp., Acidovorax delafieldii, Novosphingobium sp., and Aquabacterium sp.

Conclusion

Our results suggest that the combination of microbes and host inflammatory mediators could be more efficient to be used as a predictable biomarker associated with periodontitis and RA, as compared to microbes and inflammatory mediators alone.

Association between Periodontal Disease and Cognitive Impairment in Adults

INTRODUCTION

Periodontitis is a severe oral infection that can contribute to systemic inflammation. A large body of evidence suggests a role for systemic inflammation in the initiation of neurodegenerative disease. This systematic review synthesized data from observational studies to investigate the association between periodontitis and neuroinflammation in adults.

METHODS AND MATERIALS

A systematic literature search of PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) was performed for studies published from the date of inception up to September 2021. Search terms for the exposure "oral disease" and outcome "dementia", "neuroinflammation" and "cognitive decline" were used. Study selection and data extraction were independently undertaken by two reviewers. The final eligible articles were included only if the exposure is periodontitis and the outcome is cognitive impairment or dementia or a topic related to this condition, and if the study was conducted in an adult population. The quality and risk of bias were assessed by Newcastle Ottawa Scale (NOS). Qualitative synthesis was used to narratively synthesize the results. Six cohort studies, three cross-sectional studies, and two case-control studies met the inclusion criteria. These eleven studies were only narratively synthesized. Meta-analysis was not performed due to the methodological heterogeneity of the studies.

RESULTS

The results of included studies show that chronic periodontitis patients with at least eight years of exposure are at higher risk of developing cognitive decline and dementia. Oral health measures such as gingival inflammation, attachment loss, probing depth, bleeding on probing, and alveolar bone loss are associated with cognitive impairment. The reduction of epidermal growth factor (EGF), interleukin 8 (IL-8), interferon γ-induced protein 10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) in addition to over expression of interleukin 1-β (IL-1β) are significant in patients suffering from cognitive decline with pre-existing severe periodontitis.

CONCLUSIONS

All the included studies show evidence of an association between periodontitis and cognitive impairment or dementia and Alzheimer's disease pathology. Nonetheless, the mechanisms responsible for the association between periodontitis and dementia are still unclear and warrant further investigation.

Investigation of molecular biomarker candidates for diagnosis and prognosis of chronic periodontitis by bioinformatics analysis of pooled microarray gene expression datasets in Gene Expression Omnibus (GEO)

BACKGROUND

Chronic periodontitis (CP) is a multifactorial inflammatory disease. For the diagnosis of CP, it is necessary to investigate molecular biomarkers and the biological pathway of CP. Although analysis of mRNA expression profiling with microarray is useful to elucidate pathological mechanisms of multifactorial diseases, it is expensive. Therefore, we utilized pooled microarray gene expression data on the basis of data sharing to reduce hybridization costs and compensate for insufficient mRNA sampling. The aim of the present study was to identify molecular biomarker candidates and biological pathways of CP using pooled datasets in the Gene Expression Omnibus (GEO) database.

METHODS

Three pooled transcriptomic datasets (GSE10334, GSE16134, and GSE23586) of gingival tissue with CP in the GEO database were analyzed for differentially expressed genes (DEGs) using GEO2R, functional analysis and biological pathways with the Database of Annotation Visualization and Integrated Discovery database, Protein-Protein Interaction (PPI) network and hub gene with the Search Tool for the Retrieval of Interaction Genes database, and biomarker candidates for diagnosis and prognosis and upstream regulators of dominant biomarker candidates with the Ingenuity Pathway Analysis database.

RESULTS

We shared pooled microarray datasets in the GEO database. One hundred and twenty-three common DEGs were found in gingival tissue with CP, including 81 upregulated genes and 42 downregulated genes. Upregulated genes in Gene Ontology were significantly enriched in immune responses, and those in the Kyoto Encyclopedia of Genes and Genomes pathway were significantly enriched in the cytokine-cytokine receptor interaction pathway, cell adhesion molecules, and hematopoietic cell lineage. From the PPI network, the 12 nodes with the highest degree were screened as hub genes. Additionally, six biomarker candidates for CP diagnosis and prognosis were screened.

CONCLUSIONS

We identified several potential biomarkers for CP diagnosis and prognosis (e.g., CSF3, CXCL12, IL1B, MS4A1, PECAM1, and TAGLN) and upstream regulators of biomarker candidates for CP diagnosis (TNF and TGF2). We also confirmed key genes of CP pathogenesis such as CD19, IL8, CD79A, FCGR3B, SELL, CSF3, IL1B, FCGR2B, CXCL12, C3, CD53, and IL10RA. To our knowledge, this is the first report to reveal associations of CD53, CD79A, MS4A1, PECAM1, and TAGLN with CP.

Unique etiologic, demographic, and pathologic characteristics of localized aggressive periodontitis support classification as a distinct subcategory of periodontitis

BACKGROUND

Localized aggressive periodontitis (LAgP) occurs in 2% of African-American adolescents but only 0.15% of white adolescents. First molars and incisors are affected by rapid onset and progression.

METHODS

This nonsystematic critical review evaluated published data for LAgP and chronic periodontitis (CP), focusing on potential differences in epidemiology, microbiology, immunology, genetics, and response to therapy.

RESULTS

LAgP differs from CP by localization to incisors and first molars, early onset and rapid progression in adolescents and young adults, and a 10-fold higher prevalence in populations of African or Middle Eastern origin, often with strong familial aggregation. The bacterium Aggregatibacter actinomycetemcomitans and hyperresponsive neutrophils are frequently observed. Antibiotic and nonsurgical therapies are highly effective.

CONCLUSIONS

LAgP differs in many ways from the far more common CP that affects older adults. The substantial evidence of dissimilarities summarized in this review strongly supports the classification of LAgP as a distinct form of periodontitis.

PRACTICAL IMPLICATIONS

Classifying LAgP as a distinct subcategory of periodontitis will encourage future research and does not conflict with the newly proposed "staging and grading" system. The silent onset and rapid progression of LAgP make early diagnosis and frequent follow-up with patients essential for effective treatment.

Do patients with aggressive and chronic periodontitis exhibit specific differences in the subgingival microbial composition? A systematic review

BACKGROUND

The 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions grouped the diseases previously recognized as chronic (CP) or aggressive (AgP) periodontitis under a single category named periodontitis. The rationale for this decision was the lack of specific patterns of immune-inflammatory response or microbial profiles associated with CP or AgP. However, no previous studies have compiled the results of all studies comparing subgingival microbial data between these clinical conditions. Thus, this systematic review aimed to answer the following focused question: "Do patients with AgP periodontitis present differences in the subgingival microbiota when compared with patients with CP?"

METHODS

A systematic review was conducted according to the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to June 2019 for studies of any design (except case reports, case series, and reviews) comparing subgingival microbial data from patients with CP and AgP.

RESULTS

A total of 488 articles were identified and 56 were included. Thirteen studies found Aggregatibacter actinomycetemcomitans elevated in AgP in comparison with CP, while Fusobacterium nucleatum, Parvimonas micra, and Campylobacter rectus were elevated in AgP in a few studies. None of these species were elevated in CP. However, the number of studies not showing statistically significant differences between CP and AgP was always higher than that of studies showing differences.

CONCLUSION

These results suggested an association of A. actinomycetemcomitans with AgP, but neither this species nor the other species studied to date were unique to or could differentiate between CP and AgP (PROSPERO #CRD42016039385).

Salivary neuropeptides, stress, and periodontitis

BACKGROUND

Scientific evidence for psychologic stress as a risk factor for periodontitis is fragmentary and relies mostly on either questionnaire-based or biomarker studies. The aim of this study is to investigate brain-derived neurotrophic factor, substance P, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), calcitonin gene-related peptide, and adrenomedullin as well as cortisol in saliva and serum in periodontal health and disease combined with different aspects of stress and possible associations with clinical parameters.

METHODS

In total, 56 patients with aggressive and chronic periodontitis and 44 healthy controls were screened by enzyme-linked immunosorbent assay and mass spectrometry for presence of neuropeptides and cortisol in saliva and serum. Psychologic stress was evaluated by validated questionnaires. All substances were explored for a possible relationship to periodontitis, clinical parameters, and stress.

RESULTS

VIP and NPY showed significantly higher levels in saliva but not in serum of patients with periodontitis. These neuropeptides correlated with the extent, severity, and bleeding on probing scores in patients with periodontitis. Females had significantly lower salivary VIP levels. There were no differences among participants regarding psychologic stress.

CONCLUSION

VIP and NPY in saliva could be potential sex-specific salivary biomarkers for periodontitis regardless of psychologic stress.

Impact of diabetes on clinical periodontal outcomes following non-surgical periodontal therapy

AIM

This systematic review aimed to evaluate the impact of diabetes mellitus on clinical outcomes of non-surgical periodontal therapy.

MATERIALS AND METHODS

Searches were conducted in electronic databases to screen studies published from January 1960 to August 2018. The included studies had at least two groups of patients: chronic periodontitis only (P) or both diabetes and chronic periodontitis (DMP). Outcomes of interest included the difference between the two groups in probing depth (PD) reduction and clinical attachment level (CAL) gain following non-surgical periodontal therapy. Meta-regression was conducted to evaluate the correlation between the outcomes of interest and contributing factors.

RESULTS

A total of 12 studies with a follow-up period up to 6 months were included. There was no significant difference in PD reduction (p = 0.55) or CAL gain (p = 0.65) between the two groups. A positive association between PD reduction and baseline PD difference (p = 0.03), and a negative association between PD reduction and age (p = 0.04) were found. The level of HbA1c at baseline did not significantly affect the difference in PD reduction (p = 0.39) or CAL gain (p = 0.44) between two groups.

CONCLUSIONS

Recognizing the study's limitations, we conclude that diabetes mellitus (HbA1c ≤ 8.5%) does not appear to significantly affect short-term clinical periodontal outcomes of non-surgical periodontal treatment.

Effect of probiotics as a complement to non-surgical periodontal therapy in chronic periodontitis: a systematic review

BACKGROUND

To improve the results of the classic periodontal treatment, probiotics have been suggested recently to decrease the number of bacteria and the expression of mediators of inflammation. This systematic review aimed to assess the literature for the effectiveness of different probiotic strains as adjuvants to non-surgical periodontal therapy.

MATERIAL AND METHODS

The electronic database of MEDLINE (via Pubmed) was searched up to December 2017 for randomised clinical trials in English comparing non-surgical periodontal treatment and probiotics versus periodontal treatment and placebo. The primary outcome investigated was reduction in pocket probing depth. Secondary outcomes were bleeding on probing, plaque index reduction and bacteria counts.

RESULTS

Nine trials were included. A narrative data synthesis did not result in any major improvement of overall pocket probing depth but moderate pockets from 4 to 6 mm showed larger reductions in study groups, which could decrease the need for surgery. Sites with bleeding on probing and presence of plaque decreased after treatment. For periimplant mucositis, there was a small tendency to better results in the study group.

CONCLUSIONS

With the available data, it is concluded that probiotics may provide an additional benefit to manual debridement in chronic periodontitis. More studies are required on dose, route of administration and strains of probiotics used.

Bacterial growth stage determines the yields, protein composition, and periodontal pathogenicity of Porphyromonas gingivalis outer membrane vesicles

Introduction

P. gingivalis (W83), as the keystone pathogen in chronic periodontitis, has been found to be tightly bound to systemic diseases. Outer membrane vesicles (OMVs) produced by P. gingivalis (W83) are thought to serve key functions in bacterial virulence and pathogenicity. This study aims to comprehend the biological functions of P. gingivalis OMVs isolated from different growth stages by comparing their physicochemical properties and pathogenicity.

Methods

Protein composition was analyzed via isotope-labeled relative and absolute quantification (iTRAQ). Macrophage polarization and the expression of IL-6 and IL-1β were detected. The proliferation, migration, osteogenic differentiation, and IL-1b/NLRP3 expression of periodontal ligament stem cells (PDLSCs) were evaluated. P. gingivalis/P. gingivalis OMVs-induced periodontal models were also constructed in Sprague Dawley rats.

Results

The protein composition of P. gingivalis OMVs isolated from different growth stages demonstrated obvious differences ranging from 25 KDa to 75 KDa. In the results of flow cytometry, we found that in vitro experiments the M1 subtype of macrophages was more abundant in the late-log OMVs and stationary OMVs groups which boosted the production of inflammatory cytokines more than pre-log OMVs. Compared to pre-log OMVs, late-log OMVs and stationary OMVs had more pronounced inhibitory effects on proliferation, migration, and early osteogenesis of PDLSCs. The NLRP3 inflammasome was activated to a larger extent in the stationary OMVs group. Micro-computed tomography (Micro CT), hematoxylin-eosin staining (HE), and tartrate acid phosphatase (TRAP) results showed that the periodontal damage in the stationary OMVs group was worse than that in the pre-log OMVs and late-log OMVs group, but almost equal to that in the positive control group (P. gingivalis).

Discussion

In general, both in vivo and in vitro experiments showed that late-log OMVs and stationary OMVs have more significant pathogenicity in periodontal disease.

Adjunctive use of InGaAsP and Er,Cr:YSGG lasers in nonsurgical periodontal therapy: a randomized controlled clinical study

OBJECTIVE

To evaluate clinically and microbiologically the outcomes following the combined application of InGaAsP diode laser and Er,Cr:YSGG laser for nonsurgical treatment of chronic periodontitis (ChP).

METHOD AND MATERIALS

Forty-two patients (age 45.31 ± 9.78 years, 22 female, 23 smokers) with ChP were randomly treated with subgingival debridement (SD) by means of ultrasonic and hand instruments (control group, n = 21) or with InGaAsP followed 1 week later by InGaAsP + SD + Er,Cr:YSGG (test group, n = 21). In the test group, a second laser treatment was performed for all residual sites (bleeding sites with probing depth [PD] ≥ 4 mm) 2 months after the first laser therapy. At baseline and 6 months after therapy, periodontal clinical and microbiologic parameters were evaluated.

RESULTS

Six months after therapy, statistically significant clinical and microbiologic improvements (PD reduction, clinical attachment level [CAL] gain, quantitative reduction of periopathogens) were observed in both groups compared to baseline. However, the use of InGaAsP followed by SD and the adjunctive use of an Er,Cr:YSGG laser, yielded statistically significantly higher clinical (PD, CAL, bleeding on probing, number of sites with PD ≥ 5 mm, PD ≥ 6 mm, PD ≥ 7 mm) and microbiologic (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum) improvements (P < .05) compared to SD alone.

CONCLUSIONS

In patients with ChP, the adjunctive use of InGaAsP and Er,Cr:YSGG to SD may additionally improve the clinical and microbiologic parameters obtained with SD alone, thus representing a valuable approach in nonsurgical periodontal therapy.

MicroRNA-155 (miR-155) as an accurate biomarker of periodontal status and coronary heart disease severity: a case-control study

BACKGROUND

Increasing evidence supports associations between periodontal disease and coronary heart disease (CHD). This case-control study evaluated whether inflammatory regulator, microRNA-155 (miR-155), could be utilised as a biomarker of periodontitis and/or CHD.

METHODS

Of 120 participants, 30 patients had clinically healthy periodontium (controls, C), 30 patients had generalized periodontitis (P), 30 patients had CHD and clinically healthy periodontium (AS-C); and 30 patients had CHD with generalized periodontitis (AS-P). Patient demographic and periodontal characteristics (plaque index, bleeding on probing, probing pocket depth and clinical attachment loss), were collected. Patient whole blood and saliva levels of miR-155 and pro-inflammatory cytokine (interleukin-1β), were quantified by quantitative real time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). One-way ANOVA with post-hoc Tukey test was used to determine differences among the four groups. Chi Square test was used for participant gender comparisons. Pearson correlation tests and multiple linear regression analyses were used to assess associations between the demographic and clinical variables analysed, versus IL-1β and miR-155 levels. miR-155 and IL-1β accuracy in differentiating healthy versus other patient groups were analysed using receiver operating characteristic (ROC) curves, by calculating area under the curve (AUC) values and sensitivity and specificity cut-off points using Youden's index. Statistical tests of sensitivity and specificity were conducted using the McNemar test.

RESULTS

Whole blood miR-155 levels were elevated in periodontitis/non-periodontitis patients with CHD (AS-P, AS-C), and periodontitis patients alone (P) (p < 0.001). Receiver operating characteristic (ROC) and area under the curve (AUC) analyses confirmed miR-155 accuracy in discriminating P, AS-C and AS-P groups (AUC 0.6861-0.9944, p < 0.0001-0.05), coupled with high sensitivity (76.7-100.0%), specificity (53.3-96.7%) and cut-off points (> 0.955- > 2.915 a.u.; p < 0.0001). miR-155 levels further distinguished between CHD (AS-C, AS-P) and periodontitis (P) patients (AUC ≥ 0.8378, sensitivity ≥ 88.7%, specificity ≥ 73.3%, cut-off > 2.82 a.u; p < 0.0001), and between AS-C and AS-P patients (AUC 0.7578, sensitivity 80.0%, specificity 50.0%, cut-off > 7.065 a.u; p < 0.001). Subsequent analyses identified positive correlations between miR-155 and the various patient demographics, salivary interleukin-1β and periodontal parameters assessed.

CONCLUSIONS

This study advocates miR-155 as an accurate diagnostic/prognostic biomarker of periodontitis and/or CHD severity, thereby improving detection and treatment for both conditions.

Impact of Severe Chronic Periodontitis on Oral Health-related Quality of Life

PURPOSE

To assess the impact of extent and severity of chronic periodontitis (CP) on oral health-related quality of life (OHRQoL).

MATERIALS AND METHODS

A cross-sectional comparative study was performed on subjects from multiple dental centres in Malaysia using a questionnaire covering sociodemographics, OHRQoL using the Malaysian Oral Health Impact Profile questionnaire, OHIP-14(M) and self-reported symptoms. Participants with severe CP were age-and gender-matched with periodontally healthy/mild periodontitis (HMP) participants based on inclusion and exclusion criteria. Full mouth periodontal examination was performed on participants. Outcome measures were OHIP-14(M) prevalence of impact and severity of impact scores.

RESULTS

One hundred and thirty (130) participants comprising 65 severe CP and 65 HMP participants were included in the study. Prevalence of impact on OHRQoL was significantly higher in the severe CP than HMP group, with an odds ratio of 3. Mean OHIP-14(M) score was significantly higher in the severe CP (18.26 ± 10.22) compared to HMP (11.28± 8.09) group. The dimensions of psychological discomfort and functional limitation, and factors such as 'discomfort due to food stuck' and 'felt shy' were impacted more in severe CP compared to HMP group (p < 0.05). When compared with the HMP group, generalised severe CP participants showed higher prevalence of impact on OHRQoL [OR=5] (p < 0.05) compared to localised severe CP [OR=2] (p = 0.05). Participants who had experienced self-reported symptoms had statistically significant impacts on OHRQoL.

CONCLUSIONS

Severe CP had a greater impact on OHRQoL compared to HMP. Impacts were mainly for functional limitation and psychological discomfort dimensions. When considering extent of disease, the impact on OHRQoL was mostly in generalised severe CP subgroup.

Impaired function of epithelial plakophilin-2 is associated with periodontal disease

BACKGROUND AND OBJECTIVES

Plakophilin-2 (PKP2) is an intracellular desmosomal anchoring protein that has been implicated in a genome-wide association study, in which genetic variants of PKP2 are associated with Porphyromonas gingivalis (P.gingivalis) -dominant periodontal dysbiosis. In this study, we compared the ex vivo PKP2 expression in periodontitis gingival biopsies to periodontitis-free subjects and assessed the in vitro role of PKP2 in gingival epithelial barrier function and the mechanism by which P.gingivalis modulates PKP2 expression.

MATERIAL AND METHODS

Using reverse transcription quantitative real-time PCR (RT-qPCR), we determined PKP2 mRNA expression levels in gingival biopsies collected from 11 periodontally healthy, 10 experimental gingivitis, and 10 chronic periodontitis subjects. PKP2 protein expression in gingival biopsies was detected by immunohistochemistry. We then challenged primary gingival epithelial cells with bacteria including P.gingivalis, Campylobacter rectus, and various Toll-like receptor agonists. Western blot and immunofluorescence staining were used to detect protein expression. Inhibitors blocking proteases pathways were tested for P.gingivalis-mediated PKP2 protein degradations. We also knocked down endogenous epithelial PKP2 using lentiviral short-hairpin RNA (shRNA) and evaluated cell proliferation, spreading, and barrier function.

RESULTS

Periodontitis gingival biopsies had approximately twofold less PKP2 mRNA than did healthy controls (p < .05). PKP2 protein was predominantly expressed in gingival epithelium. In primary gingival epithelial cells, P.gingivalis challenge increased PKP2 mRNA levels, while protein expression decreased, which suggests that P.gingivalis has a protein degradation mechanism. Cysteine proteases inhibitors greatly attenuated P.gingivalis-mediated PKP2 protein degradation. Epithelial cells with deficient PKP2 exhibited inhibited cell proliferation and spreading and failed to form monolayers. Finally, P.gingivalis impaired gingival epithelial barrier function.

CONCLUSIONS

PKP2 appears to be critical in maintaining gingival epithelial barrier function and is susceptible to degradation by cysteine proteases produced by P.gingivalis. Our findings have identified a mechanism by which P.gingivalis impairs epithelial barrier function by promoting PKP2 degradation.

Influence of physical activity on periodontal health in patients with type 2 diabetes mellitus. A blinded, randomized, controlled trial

OBJECTIVES

The aim was to investigate the effect of physical activity on periodontal health and HbA1c levels in patients with type 2 diabetes mellitus (T2DM) over a period of 6 months.

MATERIALS AND METHODS

Thirty-seven patients with non-insulin-dependent T2DM were included in the study. The intervention group (n=20) performed physical activity over a period of 6 months. The control group (n=17) did not receive any intervention. Baseline and final examinations included dental parameters and concentrations of glycosylated hemoglobin (HbA1c) and high-sensitivity C-reactive protein (hsCRP).

RESULTS

Physical activity showed a positive effect on periodontal health. Both the BOP (p= 0.005) and the severity of periodontitis (p= 0.001) were significantly reduced in the intervention group compared to the control group. Furthermore, HbA1c levels were reduced (p= 0.010) significantly in the intervention group while hsCRP levels significantly increased in the control group (p= 0.04).

CONCLUSIONS

Within the limitations of this randomized, controlled trial, physical activity over a period of 6 months is a health-promoting measure for patients with T2DM and improves both periodontal health and HbA1c concentrations.

Interleukin-35 pathobiology in periodontal disease: a systematic scoping review

BACKGROUND

Interleukin (IL)-35 is a novel anti-inflammatory cytokine that is produced by regulatory T cells. IL-35 mediates immunological functions and plays a protective role in several diseases such as asthma and rheumatoid arthritis. However, the role of IL-35 in gingivitis and periodontitis remains unclear. The aim of this study was to systematically review the literature and collecting the available evidence regarding the role of IL-35 in pathogenesis of periodontal disease.

METHODS

A systematic search of electronic databases including MEDLINE, Google Scholar, Cochrane Library, Web of Science, and Scopus was conducted in November 2020 to identify studies addressing the Interleukin-35 pathobiology in periodontal disease. The identified studies were subjected to pre-identified inclusion criteria. The retrived papers were assessed by the authours independently and consensus was reached in cases where disagreement occurred. Articles written in languages other than English, case reports, letters to editors, conference abstracts, theses, and dissertations were excluded from the review.

RESULTS

A total of 176 possibly relevant articles were identified through the search strategy. Finally, 15 papers which met the criteria of eligibility were included in this review by consensus. The included articles were classified based on their design and level of evidence.Three subclinical study, ten cross sectional investigation and two randomized clinical trials constituted the final set of studies in this review. At preclinical level, Il-35 showed inhibitory characteristics regarding alveolar bone resorption of animal periodontitis models. The results of observatory human studies confirmed the presence of high levels of IL-35 in saliva, GCF, serum, and gingival biopsies of patients suffering from inflammatory periodontal disease. Moreover, two included clinical trials showed that non-surgical periodontal therapy could downregulate IL-35 production in chronic periodontitis patients.

CONCLUSION

Interleukin-35 has an undeniable role in pathobiology of inflammatory periodontal disease. Further well-controlled studies are needed to better elucidate the functional pattern of IL-35 in pathogeneisis of gingival and periodontal disease.

Effects of adjunctive light-activated disinfection and probiotics on clinical and microbiological parameters in periodontal treatment: a randomized, controlled, clinical pilot study

Objectives

The aim of this pilot study was to evaluate the clinical and microbiological outcomes of light-activated disinfection (LAD) alone or combined with probiotics as an adjunct to non-surgical periodontal treatment.

Materials and methods

In this single-blinded, randomized, controlled clinical pilot study, 48 patients (28 females and 20 males) with untreated periodontitis (stages II and III, grade B) were included. Using a parallel-group design, patients were randomly assigned into 3 groups to receive subgingival debridement (SD) alone (group 1, n = 16), SD with LAD (group 2, n = 16), or SD with LAD plus probiotic treatment (group 3, n = 16). Probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), gingiva-index simplified (GIs), plaque-control record (PCR), and subgingival microbiological samples were analyzed at baseline, 3 months, and 6 months of follow-up.

Results

All treatment modalities demonstrated clinical improvements in PPD and CAL at 6 months compared to baseline but without a statistical significant difference between the groups. The combination of SD + LAD + probiotic treatment (group 3) demonstrated significantly greater reductions in BOP, GIs, and red complex bacteria P. gingivalis and T. forsythia compared with other groups at 6 months (p < 0.05).

Conclusions

A single application of LAD as an adjunct to SD provided no additional clinical and microbiological benefits compared to SD alone. The combination of SD + LAD + probiotic treatment in group 3 led to further improvements of the inflammatory parameters.

Clinical relevance

The additional use of probiotics in periodontal treatment can be a useful approach to support inflammation and infection control of periodontal tissues. Further studies are necessary to determine the extent of added benefit for this treatment approach.

Detection of Treponema denticola in Chronic Periodontitis by Quantitative Real-Time Polymerase Chain Reaction

Chronic periodontitis constitutes a significant public health issue, particularly in China. Treponema denticola is one of the bacterial species critically involved in the development of this disease. Therefore, an effort was made in this study to design a technique for isolation of DNA from gingival fluid and detection of T. denticola genes by PCR methodology. For this purpose, samples were collected from 30 patients with severe periodontitis and 20 patients with mild periodontitis. A group of 50 healthy individuals served as a control. Following the isolation of DNA from the gingival fluid by magnetic microbeads, the material was analyzed for the presence of 16S rRNA by conventional and quantitative real-time PCR protocols. This newly developed methodology identified the presence of T. denticola in all samples from periodontitis patients. Quantitative analysis of copy numbers demonstrated that the bacterial count was highest in the severe periodontitis group and intermediate in the mild periodontitis group. The smallest number of bacteria were present in healthy controls. Besides being rapid, accurate and specific, the proposed method eliminates the need for anaerobic bacterial cultures, making it applicable in a typical clinical setting.

The correlation between pancreatic dysfunction markers and selected indices of periodontitis

BACKGROUND

Periodontitis is a major risk factor of systemic diseases with inflammatory etiology. Numerous studies have established the connection between periodontal condition and diabetes, but there are no reports in the literature on the relationship between periodontitis and other pancreas conditions. The activity of pancreatic enzymes is an important parameter of pancreatic damage, and is also a diagnostic marker of acute and chronic pancreatitis, and the bleeding index determines the periodontitis activity. To date, the periodontal status in both of the above-mentioned conditions has not been examined.

OBJECTIVES

The objective of the study was to provide a clinical evaluation of oral cavity hygiene and the condition of periodontal tissues in patients diagnosed with pancreatic adenocarcinoma or chronic pancreatitis and in the control group, and to assess the correlation between the activity of periodontitis and the concentration of glycated hemoglobin HbA1c, lipase activity and pancreatic amylase in serum from the examined groups.

MATERIAL AND METHODS

The serum activity levels of amylase, lipase and HbA1c concentration were correlated with periodontitis activity markers in patients diagnosed with chronic pancreatitis (n = 41), pancreatic cancer (n = 29) and in the control group (n = 50).

RESULTS

In the group with chronic pancreatitis, we have found a positive association between the bleeding on probing (BOP) and the amylase activity (r = 0.64) as well as the lipase (r = 0.62; p < 0.05). The patients diagnosed with pancreatic cancer evinced a higher value of the inflammatory response index, namely 1.51, than the other studied groups (H = 24.94; p = 0.01). Patients diagnosed with chronic pancreatitis evinced the highest periodontitis activity indices: BOP: 62.53% (H = 61.31; p = 0.01) and probing depth (PD): 4.14 ±0.89 mm (H = 22.43; p < 0.0001).

CONCLUSIONS

The study showed that periodontitis in patients with pancreatic cancer is independent of the state of oral hygiene. In the group of patients with chronic pancreatitis, the observed positive correlation between the bleeding index and the enzyme activity suggests interaction between the examined diseases.