Subantimicrobial-Dose Doxycycline and Cytokine-Chemokine Levels in Gingival Crevicular Fluid

Effects of Coriander on the Repair Process of Experimentally-induced Periodontitis in Rats

The aim of this study was to evaluate the effects of Coriandrum sativum L. (CSL) seed extract on gingival levels of antioxidant enzymes, pro-inflammatory cytokines and on alveolar bone and attachment levels after experimental periodontitis induction in rats and compare it with low-dose doxycycline (LDD). Forty adult male Wistar Albino rats were divided randomly into 5 groups as follows: 1 = periodontally healthy (control); 2 = periodontitis; 3 = periodontitis + CSL (32 mg/kg); 4 = periodontitis + CSL (200 mg/kg); and 5 = periodontitis + LDD (6 mg/kg). Gingival superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated by enzyme-linked immunosorbent assay. The presence of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1βeta (IL-1β) immunoreactivity was detected immunohistochemically. Alveolar bone area in the furcation space (ABA), alveolar bone loss (ABL), and attachment loss (AL) were evaluated histomorphometrically. The SOD level was lower in group 5 than in groups 2, 3, and 4. The IL-1β level was highest in group 4. The TNF-α level was statistically higher in groups 2 and 4 than in groups 1, 3, and 5. The IL-6 level was highest in group 4. Its level was higher in groups 2 and 3 than in group 5. ABA was less in groups 2, 3, and 4 compared to groups 1 and 5. ABL was less in group 5 than in groups 2, 3, and 4. AL was greater in group 4 than in group 5. The use of 200 mg/kg CSL showed a pro-inflammatory effect and IL-1β and TNF-α levels decreased after 32 mg/kg CSL application in the treatment of periodontitis.

Changes in the level of cytokines in the saliva of hypertensive patients with chronic periodontitis after scaling and root planning

INTRODUCTION

Cytokines have a key role in the pathogenesis of both hypertension and periodontitis. Salivary diagnosis is a promising field with numerous clinical applications. Since limited studies have been carried out on how salivary inflammatory cytokines can be determined and how well periodontal disease and hypertension might react to scaling and root planning (SRP). The goal of this study was to identify the pattern of changes in salivary inflammatory cytokines in chronic periodontitis subjects with hypertension after nonsurgical periodontal therapy.

METHODS

It included observational trial recruited 94 chronic periodontitis patients, 44 of whom had hypertension. All subjects have undergone non- surgical periodontal treatment. The clinical periodontal parameters included gingival index (GI), plaque index (PI), and probing of pocket depth (PPD). Unstimulated saliva was collected to determine the inflammatory biomarkers (using a commercial Elisa kit) both before and after SRP RESULTS: In comparison to non-hypertensive participants, the periodontal PPD was significantly higher in hypertensive subjects. All clinical parameters in the first examination, except for PI, were significantly higher in hypertensive than in non-hypertensive subjects. Plaque Index, GI, and PPD parameters at first visit and after finishing treatment positively correlated with salivary IL-1β, excluding pretreatment GI. The current results demonstrate the presence of a positive correlation between diastolic blood pressure and TNF (r = 0.330 and P = 0.029). All patients enrolled in this study showed a significant increase in the salivary levels of IL-4 after SRP.

CONCLUSIONS

The current study offer important and valuable information concerning the practical application of pro-inflammatory and anti-inflammatory cytokines as useful biomarkers and indicators for determining the outcome of SRP and progression of chronic periodontitis in patients with hypertension.

Non-Invasive Physical Plasma Reduces the Inflammatory Response in Microbially Prestimulated Human Gingival Fibroblasts

Non-invasive physical plasma (NIPP), an electrically conductive gas, is playing an increasingly important role in medicine due to its antimicrobial and regenerative properties. However, NIPP is not yet well established in dentistry, although it has promising potential, especially for periodontological applications. The aim of the present study was to investigate the effect of NIPP on a commercially available human gingival fibroblast (HGF) cell line and primary HGFs in the presence of periodontitis-associated bacteria. First, primary HGFs from eight patients were characterised by immunofluorescence, and cell numbers were examined by an automatic cell counter over 5 days. Then, HGFs that were preincubated with Fusobacterium nucleatum (F.n.) were treated with NIPP. Afterwards, the IL-6 and IL-8 levels in the cell supernatants were determined by ELISA. In HGFs, F.n. caused a significant increase in IL-6 and IL-8, and this F.n.-induced upregulation of both cytokines was counteracted by NIPP, suggesting a beneficial effect of physical plasma on periodontal cells in a microbial environment. The application of NIPP in periodontal therapy could therefore represent a novel and promising strategy and deserves further investigation.

Periodontal therapy for primary or secondary prevention of cardiovascular disease in people with periodontitis

BACKGROUND

There may be an association between periodontitis and cardiovascular disease (CVD); however, the evidence so far has been uncertain about whether periodontal therapy can help prevent CVD in people diagnosed with chronic periodontitis. This is the third update of a review originally published in 2014, and most recently updated in 2019. Although there is a new multidimensional staging and grading system for periodontitis, we have retained the label 'chronic periodontitis' in this version of the review since available studies are based on the previous classification system.

OBJECTIVES

To investigate the effects of periodontal therapy for primary or secondary prevention of CVD in people with chronic periodontitis.

SEARCH METHODS

An information specialist searched five bibliographic databases up to 17 November 2021 and additional search methods were used to identify published, unpublished, and ongoing studies. We also searched the Chinese BioMedical Literature Database, the China National Knowledge Infrastructure, the VIP database, and Sciencepaper Online to March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared active periodontal therapy to no periodontal treatment or a different periodontal treatment. We included studies of participants with a diagnosis of chronic periodontitis, either with CVD (secondary prevention studies) or without CVD (primary prevention studies).

DATA COLLECTION AND ANALYSIS

Two review authors carried out the study identification, data extraction, and 'Risk of bias' assessment independently and in duplicate. They resolved any discrepancies by discussion, or with a third review author. We adopted a formal pilot-tested data extraction form, and used the Cochrane tool to assess the risk of bias in the studies. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

There are no new completed RCTs on this topic since we published our last update in 2019. We included two RCTs in the review. One study focused on the primary prevention of CVD, and the other addressed secondary prevention. We evaluated both as being at high risk of bias. Our primary outcomes of interest were death (all-cause and CVD-related) and all cardiovascular events, measured at one-year follow-up or longer. For primary prevention of CVD in participants with periodontitis and metabolic syndrome, one study (165 participants) provided very low-certainty evidence. There was only one death in the study; we were unable to determine whether scaling and root planning plus amoxicillin and metronidazole could reduce incidence of all-cause death (Peto odds ratio (OR) 7.48, 95% confidence interval (CI) 0.15 to 376.98), or all CVD-related death (Peto OR 7.48, 95% CI 0.15 to 376.98). We could not exclude the possibility that scaling and root planning plus amoxicillin and metronidazole could increase cardiovascular events (Peto OR 7.77, 95% CI 1.07 to 56.1) compared with supragingival scaling measured at 12-month follow-up. For secondary prevention of CVD, one pilot study randomised 303 participants to receive scaling and root planning plus oral hygiene instruction (periodontal treatment) or oral hygiene instruction plus a copy of radiographs and recommendation to follow-up with a dentist (community care). As cardiovascular events had been measured for different time periods of between 6 and 25 months, and only 37 participants were available with at least one-year follow-up, we did not consider the data to be sufficiently robust for inclusion in this review. The study did not evaluate all-cause death and all CVD-related death. We are unable to draw any conclusions about the effects of periodontal therapy on secondary prevention of CVD.

AUTHORS' CONCLUSIONS

For primary prevention of cardiovascular disease (CVD) in people diagnosed with periodontitis and metabolic syndrome, very low-certainty evidence was inconclusive about the effects of scaling and root planning plus antibiotics compared to supragingival scaling. There is no reliable evidence available regarding secondary prevention of CVD in people diagnosed with chronic periodontitis and CVD. Further trials are needed to reach conclusions about whether treatment for periodontal disease can help prevent occurrence or recurrence of CVD.

Modulating the Immune Response in Periodontitis

Periodontitis is a chronic inflammatory condition initiated by the accumulation of bacterial biofilm. It is highly prevalent and when left untreated can lead to tooth loss. The presence of bacterial biofilm is essential for the initiation of the inflammatory response but is not the sole initiator. Currently it is unknown which mechanisms drive the dysbiosis of the bacterial biofilm leading to the dysregulation of the inflammatory response. Other players in this equation include environmental, systemic, and genetic factors which can play a role in exacerbating the inflammatory response. Treatment of periodontal disease consists of removal of the bacterial biofilm with the goal of resolving the inflammatory response; however, this does not occur in every case. Understanding the way the inflammatory response does not return to a state of homeostasis has led investigators to consider both systemic and local pharmacological interventions. Nonetheless, a better understanding of the impact that genetics and environmental factors may have on the inflammatory response could be key to helping identify how inflammation can be modulated therefore stopping the destruction of the periodontium. In this article, we will explore the current evidence associating the microbial dysbiosis and the dysregulation of the immune response, potential mechanisms or pathways that may be targeted for the modulation of the inflammatory response, and discuss the advantages and drawbacks associated with local and systemic inflammatory modulation in the management of periodontal disease. This information will be valuable for those interested in understanding potential adjunct methods for managing periodontal diseases, but not limited to, dental professionals, clinical researchers and the public at large.

Central Regulatory Role of Cytokines in Periodontitis and Targeting Options

BACKGROUND

Periodontitis is an immune-inflammatory disease that leads to the progressive destruction of bone and connective tissue in the periodontal area. The cytokine network plays a primary role in tissue homeostasis, the recruitment of immune cells to control the pathogenic impact and the regulation of osteoclastic function, thus modulating the intensity and duration of the immune response. This review provides an update on the main cytokines implicated in the pathogenesis and progression of periodontitis and their targeting potential in order to enrich current treatment options.

METHODS

A structured search of bibliographic databases (PubMed, MEDLINE, Scopus) was performed for peer-reviewed cytokine studies focused on periodontitis the last ten years. A qualitative content analysis was performed in screened papers and a critical discussion of main findings is provided.

RESULTS

An altered cytokine profile has been detected in periodontitis patients and the interplay of pro-inflammatory and/or anti-inflammatory cytokines has been associated with disease pathogenesis. Among the most prominent pro-inflammatory cytokines, TNF-α, IL-1β, IL-17, IL-6 and the chemokines CXCL-6, CXCL-8 are overexpressed in periodontitis patients and correlate with disease progression. On the other hand, the anti-inflammatory IL-4 and IL- 11 levels are reduced while IL-12 and IFN-γ expression play a dual role in periodontal disease. Current periodontitis treatment strategies include selective antibiotics, antimicrobial photodynamic therapy and probiotics, which can modulate the cytokine network and when applied in combination with specific anti-cytokine agents can exert additional beneficial effects.

CONCLUSION

It is evident that cytokines play a central regulatory role in the inflammatory process and immune cell response that underlies bone destruction in periodontitis. Specific cytokine targeting should be considered as a complementary therapeutic scheme to current periodontal management.

The adjunctive use of host modulators in non-surgical periodontal therapy. A systematic review of randomized, placebo-controlled clinical studies

BACKGROUND

Considering the role of the inflammatory host response in the pathogenesis of periodontitis, different host modulators have been proposed to enhance the outcomes of non-surgical periodontal therapy (NSPT), but their efficacy has not been fully clarified.

OBJECTIVES

This systematic review investigated the efficacy of host modulators combined with NSPT in reducing probing pocket depth (PPD) in periodontitis patients.

MATERIALS AND METHODS

Placebo-controlled RCTs with ≥6 months follow-up were searched. Meta-analysis was conducted when ≥5 studies using the same host modulator were identified.

RESULTS

Fifty eight studies met the inclusion criteria. After 6 months, local administration of 1.2% statin gels as adjuncts to NSPT significantly improved PPD reduction (1.83 mm) in infrabony defects and systemic administration of sub-antimicrobial dose doxycycline (SDD) in addition to NSPT improved PPD reduction of deep pockets. Administration of probiotics conferred limited clinical benefits. Local bisphosphonate and metformin gels showed potential for clinical use in infrabony defects, which needs to be confirmed.

CONCLUSIONS

Local delivery of statins in infrabony defects and systemic SDD for deep pockets may confer additional clinical benefits to NSPT. Their long-term effectiveness and safety need to be confirmed in independent multi-centred studies. Further studies are needed to confirm the benefit of other host modulators.

Evaluation of periodontal status and cytokine/chemokine profile of GCF in patients with severe congenital neutropenia

Severe congenital neutropenia (SCN) is a primary immunodeficiency characterized by defect in neutrophil count. Increased risk of infections in addition to periodontal problems, such as ulcerations of oral mucosa, gingival inflammation, and rapid loss of attachment are common in the course of the disease. The aim of the present study is to define the causal relationship between the severity of periodontal inflammation and severe congenital neutropenia through identification of cytokine profile in gingival crevicular fluid (GCF). A case-control study was performed in patients diagnosed with SCN and healthy controls. Demographic data, the molecular defect, laboratory work-up were gathered from the hospital registry. Periodontal indices were recorded and GCF samples were analyzed using multiplex analysis for the simultaneous measurements of the particular cytokines and chemokines. The present study included 14 patients and 22 control subjects. Both groups were comparable in terms of age and sex. Severity of gingival inflammation measured by the criteria of Löe was higher in the SCN cases (p < 0.05). Moreover, GCF levels of IFN-α, TNF-α, IL-10, IL-13, IL-15, IL-17, IL-2, IL-7, IL-33, IP-10, MIG, MIP-1β were significantly higher in the controls. Decreased cytokine secretion seems to correlate with the decrease in neutrophil counts. The severity of gingival inflammation in SCN patients may be due to the bacterial overgrowth and the change in the content of the oral flora due to the decreased neutrophil counts. Therefore, regular periodontal examinations, the motivation of oral hygiene as well as the compliance with therapy in SCN patients contribute to the periodontal health.

Expression of inflammatory biomarkers and growth factors in gingival crevicular fluid at different healing intervals following non-surgical periodontal treatment: A systematic review

BACKGROUND

Non-surgical periodontal treatment (NSPT) is widely employed for the treatment of periodontal disease and yields significant clinical improvements. Gingival crevicular fluid (GCF) can be used to profile health and disease, and recent technological advances, such as multiplex bead immunoassays, are promising in identifying a wider array of GCF factors with the ultimate aim to predict the treatment response.

OBJECTIVE

The aim of this systematic review was to compare the expression of GCF markers using multiplex bead immunoassays before treatment and during early, average, or late healing period, following non-surgical periodontal treatment (NSPT).

METHODS

An electronic literature search was conducted by two independent examiners (VK and NC) in MEDLINE, EMBASE, OpenGrey, LILACS, and Cochrane Library up to January 2020. The PICO question formulated was as follows: "In patients with periodontal disease, does the expression of gingival crevicular fluid (GCF) markers detected using multiplex bead immunoassay differ at baseline compared with early (≤30 days), average (6-8 weeks), or late (≥3 months) healing after intervention?"

RESULTS

A total of 366 publications were obtained and reviewed for eligibility for inclusion. Of these, 12 publications fulfilled the inclusion criteria and were included in the present review. Data for a total of 31 different GCF markers were extracted and summarized for early, average, or late healing after NSPT. Early healing following NSPT (≤ 30 days) indicated an increase in IL-1β, TNFα, and IL-10. At the average healing period (6-8 weeks), IL-1β, IL-1α, IL-6, TNF-α, IFN-γ, GM-CSF, MCP-1, and MIP-1α were all reduced, compared to their respective baseline values. Three months after NSPT, IL-1β, IL-4, IL-6, IL-10, TNF-α, and IFN-γ were detected at reduced levels, compared to pre-treatment levels. Overall, the changes following treatment indicated a reduction of inflammation present at baseline.

CONCLUSION

Following non-surgical periodontal treatment, an upregulation of inflammation markers is noted early post-operatively and a subsequent reduction of their levels three months following treatment. The investigation of levels of GCF markers associated with inflammation and regeneration, especially using multiplex bead immunoassay technologies, is a valuable tool to better understand the processes associated with healing following periodontal treatment.

Mechanical Debridement with Antibiotics in the Treatment of Chronic Periodontitis: Effect on Systemic Biomarkers-A Systematic Review

In this systematic review, we assessed the effectiveness of systemic antibiotics as an adjunctive therapy to mechanical debridement in improving inflammatory systemic biomarkers, as compared to mechanical debridement alone, among adults with chronic periodontitis. We searched relevant electronic databases for eligible randomized controlled trials. Two review authors independently screened, extracted data, and assessed risk of bias. We conducted meta-analysis, assessed heterogeneity, and assessed certainty of evidence using GRADEPro software. We included 19 studies (n = 1350 participants), representing 18 randomized controlled trials and found very little or no impact of antibiotics on inflammatory biomarkers. A meta-analysis of eight studies demonstrated a mean reduction of 0.26 mm in the periodontal pockets at three months (mean difference [MD] −0.26, 95%CI: −0.36 to −0.17, n = 372 participants, moderate certainty of evidence) in favor of the antibiotics. However, results from five studies reporting clinical attachment level (mm) yielded little or no difference at three months (MD −0.16, 95% CI: −0.35 to 0.03, n = 217 participants) between antibiotic and placebo groups. There is little or no evidence that adjunctive systemic antibiotics therapy improves inflammatory systemic biomarkers, compared to mechanical debridement alone, among adults with chronic periodontitis.

Effect of scaling and root planing on the expression of anti-inflammatory cytokines (IL-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid of electronic cigarette users and non-smokers with moderate chronic periodontitis

Purpose

The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and non-smokers with moderate chronic periodontitis (CP).

Methods

Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P<0.05 was considered to indicate statistical significance.

Results

Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and non-smokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups (P<0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers (P<0.05) than in electronic cigarette users at the 3-month follow-up.

Conclusions

Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.

Periodontal therapeutics: Current host-modulation agents and future directions

With the recognition in the 1960s and 1970s of the periodontopathic importance of the microbial biofilm and its specific anaerobic microorganisms, periodontitis was treated as an infectious disease (more recently, as a dysbiosis). Subsequently, in the 1980s, host-response mechanisms were identified as the mediators of the destruction of the collagen-rich periodontal tissues (gingiva, periodontal ligament, alveolar bone), and the periodontopathogens were now regarded as the "trigger" of the inflammatory/collagenolytic response that characterizes actively destructive periodontitis. Also at this time a new pharmacologic strategy emerged, entitled "host-modulation therapy", based on 2 major findings: (1) that the ability of tetracycline antibiotics to inhibit periodontal breakdown was due (in large part) to their previously unrecognized ability to inhibit the host-derived matrix metalloproteinases (notably, the collagenases, gelatinases, macrophage metalloelastase), and by mechanisms unrelated to the antimicrobial properties of these medications; and (2) that nonsteroidal anti-inflammatory drugs, such as flurbiprofen, again by nonantimicrobial mechanisms, could reduce the severity of periodontitis (however, the adverse effects of long-term therapy precluded their development as safe and effective host-modulatory agents). Additional mechanistic studies resulted in the development of novel nonantimicrobial formulations (Periostat® [now generic] and Oracea®) and compositions of tetracyclines (notably chemically modified tetracycline-3) as host-modulator drugs for periodontitis, arthritis, cardiovascular and pulmonary diseases, cancer, and, more recently, for local and systemic bone loss in postmenopausal women. Identification of the cation-binding active site in the tetraphenolic chemically modified tetracycline molecules drove the development of a new category of matrix metalloproteinase-inhibitor compounds, with a similar active site, the biphenolic chemically modified curcumins. A lead compound, chemically modified curcumin 2.24, has demonstrated safety and efficacy in vitro, in cell culture, and in vivo in mouse, rat, rabbit, and dog models of disease. In conclusion, novel host-modulation compounds have shown significant promise as adjuncts to traditional local therapy in the clinical management of periodontal disease; appear to reduce systemic complications of this all-too-common "inflammatory/collagenolytic" disease; and Oracea® is now commonly prescribed for inflammatory dermatologic diseases.

Periodontal therapy for primary or secondary prevention of cardiovascular disease in people with periodontitis

BACKGROUND

There may be an association between periodontitis and cardiovascular disease (CVD); however, the evidence so far has been uncertain about whether periodontal therapy can help prevent CVD in people diagnosed with chronic periodontitis. This is the second update of a review originally published in 2014, and first updated in 2017. Although there is a new multidimensional staging and grading system for periodontitis, we have retained the label 'chronic periodontitis' in this version of the review since available studies are based on the previous classification system.

OBJECTIVES

To investigate the effects of periodontal therapy for primary or secondary prevention of CVD in people with chronic periodontitis.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the Cochrane Oral Health's Trials Register, CENTRAL, MEDLINE, Embase, and CINAHL, two trials registries, and the grey literature to September 2019. We placed no restrictions on the language or date of publication. We also searched the Chinese BioMedical Literature Database, the China National Knowledge Infrastructure, the VIP database, and Sciencepaper Online to August 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared active periodontal therapy to no periodontal treatment or a different periodontal treatment. We included studies of participants with a diagnosis of chronic periodontitis, either with CVD (secondary prevention studies) or without CVD (primary prevention studies).

DATA COLLECTION AND ANALYSIS

Two review authors carried out the study identification, data extraction, and 'Risk of bias' assessment independently and in duplicate. They resolved any discrepancies by discussion, or with a third review author. We adopted a formal pilot-tested data extraction form, and used the Cochrane tool to assess the risk of bias in the studies. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

We included two RCTs in the review. One study focused on the primary prevention of CVD, and the other addressed secondary prevention. We evaluated both as being at high risk of bias. Our primary outcomes of interest were death (all-cause and CVD-related) and all cardiovascular events, measured at one-year follow-up or longer. For primary prevention of CVD in participants with periodontitis and metabolic syndrome, one study (165 participants) provided very low-certainty evidence. There was only one death in the study; we were unable to determine whether scaling and root planning plus amoxicillin and metronidazole could reduce incidence of all-cause death (Peto odds ratio (OR) 7.48, 95% confidence interval (CI) 0.15 to 376.98), or all CVD-related death (Peto OR 7.48, 95% CI 0.15 to 376.98). We could not exclude the possibility that scaling and root planning plus amoxicillin and metronidazole could increase cardiovascular events (Peto OR 7.77, 95% CI 1.07 to 56.1) compared with supragingival scaling measured at 12-month follow-up. For secondary prevention of CVD, one pilot study randomised 303 participants to receive scaling and root planning plus oral hygiene instruction (periodontal treatment) or oral hygiene instruction plus a copy of radiographs and recommendation to follow-up with a dentist (community care). As cardiovascular events had been measured for different time periods of between 6 and 25 months, and only 37 participants were available with at least one-year follow-up, we did not consider the data to be sufficiently robust for inclusion in this review. The study did not evaluate all-cause death and all CVD-related death. We are unable to draw any conclusions about the effects of periodontal therapy on secondary prevention of CVD.

AUTHORS' CONCLUSIONS

For primary prevention of cardiovascular disease (CVD) in people diagnosed with periodontitis and metabolic syndrome, very low-certainty evidence was inconclusive about the effects of scaling and root planning plus antibiotics compared to supragingival scaling. There is no reliable evidence available regarding secondary prevention of CVD in people diagnosed with chronic periodontitis and CVD. Further trials are needed to reach conclusions about whether treatment for periodontal disease can help prevent occurrence or recurrence of CVD.

Adjunctive Effects of a Sub-Antimicrobial Dose of Doxycycline on Clinical Parameters and Potential Biomarkers of Periodontal Tissue Catabolism

Objectives: The aim of the present randomized, double-blind, placebo-controlled, parallel-arm study was to examine the effectiveness of a sub-antimicrobial dose of doxycycline (SDD) in combination with nonsurgical periodontal therapy, compared to nonsurgical periodontal therapy alone, on potential gingival crevicular fluid (GCF) biomarkers of periodontal tissue catabolism related to the clinical outcomes over a 12-month period. Materials and Methods: GCF was collected and clinical parameters were recorded from 30 periodontitis patients randomized either to an SDD or placebo group. The SDD group received SDD (20 mg) b.i.d for 3 months plus scaling and root planing (SRP), while the placebo group was given placebo capsules b.i.d for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. At each visit, clinical parameters and GCF sampling were repeated. Matrix metalloproteinase (MMP)-8, MMP-9, MMP-13, myeloperoxidase (MPO), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase-5 (TRAP-5) were determined by IFMA and ELISA. Results: Significant improvements were observed in all clinical parameters in both groups over 12 months (p < 0.0125) while the SDD group showed significantly better reduction in gingival index (GI) and pocket depth and a gain in clinical attachment compared to the placebo group (p < 0.05). GCF MMP-8 and OPG levels significantly reduced in the SDD group compared to baseline (p < 0.05). GCF MMP-9 significantly decreased in both groups compared to baseline (p < 0.05). GCF MPO significantly decreased at 3 and 9 months in the SDD group, while it significantly decreased at 6 months in the placebo group (p < 0.05). TRAP and MMP-13 could be detected in none of the samples. Conclusions: The present results indicate that three months of adjunctive usage of SDD to nonsurgical periodontal therapy compared to nonsurgical periodontal therapy alone in periodontitis patients results in further improvement of clinical periodontal parameters and GCF markers of periodontal tissue breakdown over a 12-month period. Beneficial effects of adjunctive SDD therapy is likely to be related to the reduced levels of two major periodontitis-associated MMPs, MMP-8 and -9, and their potential oxidative activator MPO.

The anti-inflammatory effect of locally delivered nano-doxycycline gel in therapy of chronic periodontitis

BACKGROUND AND OBJECTIVE

To date, various drugs as host modulating agents had been suggested as adjunctive treatment modality in the therapy of chronic periodontal disease. In this study, the anti-inflammatory effect of subgingivally delivered nanostructured doxycycline gel (nDOX) was evaluated and compared to conventional doxycycline gel (DOX) used as adjunct to scaling and root planning (SRP) in the treatment of moderate chronic periodontitis to reduce probing pocket depth.

MATERIAL AND METHODS

Nanostructured doxycycline gel (nDOX) was prepared using spray-drying technique with chitosan (CH) as a matrix polymer, followed by dispersion in polyvinyl alcohol (PVA). The deepest periodontal pocket in 45 patients suffering from moderate chronic periodontitis was selected. The patients were divided into three groups following scaling and root planning (SRP); group I: SRP + nDOX, group II: SRP + DOX and group III: SRP + placeboCH. Plaque Index (PI), Gingival Index (GI), pocket depth (PD) and clinical attachment level(CAL), as well as ginigival crevicular fluid levels of (GCF) IL-6 and TNF-α were assessed at baseline, 1 and 3 months following local drug application.

RESULTS

Group I showed significant reduction in probing depth and attachment gain compared with group II and III at one and three months period. The inflammatory mediators levels were significantly reduced in all treatment groups at one-month period. Except for group I, the reduced values were observed at three-month period.

CONCLUSION

The results suggest that treatment with nDOX gel as an adjunct to SRP had anti-inflammatory effect by improving both clinical parameters and inflammatory markers up to three months period.

Periodontal therapy for the management of cardiovascular disease in patients with chronic periodontitis

BACKGROUND

There is an association between chronic periodontitis and cardiovascular disease (CVD). However, it is not known whether periodontal therapy could prevent or manage CVD in patients with chronic periodontitis.

OBJECTIVES

The objective of this systematic review was to investigate the effects of periodontal therapy in preventing the occurrence of, and management or recurrence of, CVD in patients with chronic periodontitis.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 31 August 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 7), MEDLINE Ovid (1946 to 31 August 2017), Embase Ovid (1980 to 31 August 2017) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL EBSCO) (1937 to 31 August 2017) . The US National Institutes of Health Trials Registry (ClinicalTrials.gov), the World Health Organization International Clinical Trials Registry Platform and Open Grey were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.We also searched the Chinese BioMedical Literature Database (1978 to 27 August 2017), the China National Knowledge Infrastructure (1994 to 27 August 2017), the VIP database (1989 to 27 August 2017) and Sciencepaper Online (2003 to 27 August 2017).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs were considered eligible. Studies were selected if they included patients with a diagnosis of chronic periodontitis and previous CVD (secondary prevention studies) or no CVD (primary prevention studies); patients in the intervention group received active periodontal therapy compared to maintenance therapy, no periodontal treatment or another kind of periodontal treatment in the control group.

DATA COLLECTION AND ANALYSIS

Two review authors carried out the study identification, data extraction and risk of bias assessment independently and in duplicate. Any discrepancies between the two authors were resolved by discussion or with a third review author. A formal pilot-tested data extraction form was adopted for the data extraction, and the Cochrane tool for risk of bias assessment was used for the critical appraisal of the literature.

MAIN RESULTS

No studies were identified that assessed primary prevention of CVD in people with periodontitis. One study involving 303 participants with ≥ 50% blockage of one coronary artery or a coronary event within three years, but not the three months prior, was included. The study was at high risk of bias due to deviation from the protocol treatment allocation and lack of follow-up data. The trial compared scaling and root planing (SRP) with community care for a follow-up period of six to 25 months. No data on deaths (all-cause or CVD-related) were reported. There was insufficient evidence to determine the effect of SRP and community care in reducing the risk of CVD recurrence in patients with chronic periodontitis (risk ratio (RR) 0.72; 95% confidence interval (CI) 0.23 to 2.22; very low quality evidence). The effects of SRP compared with community care on high-sensitivity C-reactive protein (hs-CRP) (mean difference (MD) 0.62; -1.45 to 2.69), the number of patients with high hs-CRP (RR 0.77; 95% CI 0.32 to 1.85) and adverse events (RR 9.06; 95% CI 0.49 to 166.82) were also not statistically significant. The study did not assess modifiable cardiovascular risk factors, other blood test results, heart function parameters or revascularisation procedures.

AUTHORS' CONCLUSIONS

We found very low quality evidence that was insufficient to support or refute whether periodontal therapy can prevent the recurrence of CVD in the long term in patients with chronic periodontitis. No evidence on primary prevention was found.

Commentary: Targeting Underlying Biologic Mechanisms in Selecting Adjunctive Therapies to Improve Periodontal Treatment in Smokers: A Commentary

Despite well-established evidence that cigarette smoking is the largest modifiable risk factor for periodontal disease and has many deleterious health effects, treatment of periodontal disease in smokers remains a challenge of periodontal therapy. A recent meta-analysis revealed that adjunctive use of local delivery of antimicrobials, but not systemic antibiotic usage, with non-surgical periodontal therapy resulted in improvement in clinical periodontal parameters. Further evaluation of the current literature reveals that host modulation therapy may also result in clinical benefit in smokers. These findings may be tied to the underlying pathophysiology of periodontal disease progression in smokers and suggest that focused therapies that target known mechanisms of action are critical to the success of proposed treatments.

Is caffeic acid phenethyl ester more protective than doxycycline in experimental periodontitis?

BACKGROUND AND OBJECTIVES

Host modulation therapies (anti-inflammatory drugs, bone-stimulating agents, anti-proteinase etc.) target the inhibition or stabilization of tissue breakdown. The aim of the present study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) and/or low dose doxycycline (LDD) administrations on alveolar bone loss (ABL), serum cytokines and gingival apoptosis, as well as the levels of oxidants and anti-oxidants in rats with ligature-induced periodontitis.

MATERIAL AND METHODS

The animals were randomly divided into five groups: Group C (periodontally healthy), Group PC (Periodontitis+CAPE), Group PD (Periodontitis+LDD), Group PCD (Periodontitis+CAPE+LDD), Group P (Periodontitis). Experimental periodontitis was induced for 14days. Levels of ABL, and the serum cytokines, interleukin (IL)-1 β, IL-6, tumor necrosis factor-α (TNF-α) and IL-10 were assessed as were the levels of the oxidants and anti-oxidants, malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GSH-Px), and levels of gingival apoptosis.

RESULTS

The lowest ABL levels was evident in the PC group, among the experimental groups. There was also less inflammatory infiltration in the PC group than the PD group. IL-1β, IL-6, and IL-10 were lower in the PC group and higher in the P group in comparison to the levels in the other experiment groups. TNF-α levels in the PD group were higher than levels in the PC and PCD groups. The PC and PCD groups did not differ from the C group in regard to MDA levels. The highest GSH-Px level was found in the PC group. Gingival apoptosis in the PC group was not only lower than the PD and PCD groups, but also lower than in the C group.

CONCLUSION

The present study suggests that CAPE has more anti-inflammatory, anti-oxidant and anti-apoptotic effects than LDD, with no additive benefits of a CAPE+LDD combination being evident in rats with periodontitis.

Systematic review and meta-analysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing with or without adjuncts

BACKGROUND

Conduct a systematic review and meta-analysis on nonsurgical treatment of patients with chronic periodontitis by means of scaling and root planing (SRP) with or without adjuncts.

METHODS

A panel of experts convened by the American Dental Association Council on Scientific Affairs conducted a search of PubMed (MEDLINE) and Embase for randomized controlled trials of SRP with or without the use of adjuncts with clinical attachment level (CAL) outcomes in trials at least 6 months in duration and published in English through July 2014. The authors assessed individual study bias by using the Cochrane Risk of Bias Tool and conducted meta-analyses to obtain the summary effect estimates and their precision and to assess heterogeneity. The authors used funnel plots and Egger tests to assess publication bias when there were more than 10 studies. The authors used a modified version of the US Preventive Services Task Force methods to assess the overall level of certainty in the evidence.

RESULTS

The panel included 72 articles on the effectiveness of SRP with or without the following: systemic antimicrobials, a systemic host modulator (subantimicrobial-dose doxycycline), locally delivered antimicrobials (chlorhexidine chips, doxycycline hyclate gel, and minocycline microspheres), and a variety of nonsurgical lasers (photodynamic therapy with a diode laser, a diode laser, neodymium:yttrium-aluminum-garnet lasers, and erbium lasers).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

With a moderate level of certainty, the panel found approximately a 0.5-millimeter average improvement in CAL with SRP. Combinations of SRP with assorted adjuncts resulted in a range of average CAL improvements between 0.2 and 0.6 mm over SRP alone. The panel judged the following 4 adjunctive therapies as beneficial with a moderate level of certainty: systemic subantimicrobial-dose doxycycline, systemic antimicrobials, chlorhexidine chips, and photodynamic therapy with a diode laser. There was a low level of certainty in the benefits of the other included adjunctive therapies. The panel provides clinical recommendations in the associated clinical practice guideline.

Identification of Gingival Crevicular Fluid Sampling, Analytical Methods, and Oral Biomarkers for the Diagnosis and Monitoring of Periodontal Diseases: A Systematic Review

Background. Several studies in the last decades have focused on finding a precise method for the diagnosis of periodontal disease in its early stages. Aim. To evaluate from current scientific literature the most common and precise method for gingival crevicular fluid (GCF) sample collection, biomarker analytical methods, and the variability of biomarker quantification, even when using the same analytical technique. Methodology. An electronic search was conducted on in vivo studies that presented clinical data on techniques used for GCF collection and biomarker analysis. Results. The results showed that 71.1%, 24.7%, and 4.1% of the studies used absorption, microcapillary, and washing techniques, respectively, in their gingival crevicular fluid collection. 73.1% of the researchers analyzed their samples by using enzyme-linked immunosorbent assay (ELISA). 22.6%, 19.5%, and 18.5% of the researchers included interleukin-1 beta (IL-1β), matrix metalloproteinase-8 (MMP-8), and tumor necrosis factor-alpha (TNF-α), respectively, in their studies as biomarkers for periodontal disease. Conclusion. IL-1β can be considered among the most common biomarkers that give precise results and can be used as an indicator of periodontal disease progression. Furthermore, paper strips are the most convenient and accurate method for gingival crevicular fluid collection, while enzyme-linked immunosorbent assay can be considered the most conventional method for the diagnosis of biofluids.

Downregulation of Proteinase-Activated Receptor-2, Interleukin-17, and Other Proinflammatory Genes by Subantimicrobial Doxycycline Dose in a Rat Periodontitis Model

BACKGROUND

Subantimicrobial dose doxycycline (SDD) has been used as an adjunct in periodontal treatment because of its matrix metalloproteinase inhibition properties. Although the benefits of SDD therapy, such as improvement in the parameters of periodontal probing depth and clinical attachment level, have been proven in multiple clinical studies, the comprehension of other biologic mechanisms of action on periodontitis remains poorly investigated. Therefore, this animal-model study evaluated the effects of SDD monotherapy on the expressions of the following key proinflammatory genes: proteinase-activated receptor-2 (PAR2), tumor necrosis factor (TNF)-α, interleukin (IL)-17, and IL-1β.

METHODS

Male Wistar rats were assigned randomly to the following: 1) control group: no ligature-induced periodontitis and no treatment; 2) ligature group: ligature-induced periodontitis and placebo treatment; and 3) ligature + doxycycline group: ligature-induced periodontitis and SDD treatment. After the experimental time, animals were sacrificed, and reverse transcription-polymerase chain reaction was performed to analyze the mRNA expression of IL-1β, IL-17, TNF-α, and PAR2 in gingival tissue samples. Histologic analyses were performed on the furcation region and mesial gingiva of mandibular first molars to measure periodontal bone loss and collagen content.

RESULTS

SDD administration significantly downregulated PAR2, IL-17, TNF-α, and IL-1β mRNA expressions (P <0.05). In addition, SDD treatment was accompanied by lower rates of alveolar bone loss (P <0.05) and maintenance of the amount of gingival collagen fibers.

CONCLUSION

These findings reveal new perspectives regarding SDD efficacy because it can be partially related to proinflammatory gene expression modulation, even considering PAR2 and IL-17, which has not been investigated thus far.

Crevicular fluid levels of interleukin-8, interleukin-17 and soluble intercellular adhesion molecule-1 after regenerative periodontal therapy

Objective:

The aim of this study is to evaluate the influence of regenerative periodontal therapy on clinical parameters and interleukin-8 (IL-8), IL-17 and soluble intercellular adhesion molecule-1 (sICAM-1) levels in gingival crevicular fluid (GCF) of subjects with chronic periodontitis (CP).

Materials and Methods:

Fifteen patients received demineralized freeze-dried bone allograft (DFDBA) surgically to the site of infrabony defect. Clinical periodontal indices were recorded, and GCF samples were collected at baseline and at the 6^th and the 9^th month after the surgery.

Results:

Except plaque index, all clinical parameters improved following surgery (P < 0.05). The volume of GCF diminished from baseline to follow-up periods (P < 0.05). However, no effect was observed on the total amount of IL-8, IL-17 and sICAM-1 in GCF.

Conclusion:

DFDBA improved clinical outcome in CP subjects and was effective on decreasing the volume of GCF, but no effect was determined on IL-8, IL-17 and sICAM-1. Findings did not indicate a direct relationship between biochemical parameters and periodontal healing after demineralized freeze-dried bone grafting.

Impact of metronidazole and amoxicillin combination on matrix metalloproteinases-1 and tissue inhibitors of matrix metalloproteinases balance in generalized aggressive periodontitis

OBJECTIVE

Generalized aggressive periodontitis (GAgP) is a complex periodontal disease affecting the entire dentition with a rapid destruction of the periodontium and resulting in loss of teeth. We hypothesized that better clinical healing of adjunctive use of amoxicillin plus metronidazole combination may be related to the effect of this combination therapy to restore imbalance between matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) which is associated with connective tissue and alveolar bone destruction in patients with GAgP.

MATERIALS AND METHODS

Twenty-eight subjects diagnosed with GAgP were recruited. Patients were randomly assigned to test or control groups. MMP-1/TIMP-1 ratio was compared between groups receiving scaling and root planning (SRP) alone (control) or in combination with amoxicillin plus metronidazole (test). Clinical periodontal variables were measured. Gingival crevicular fluid samples were obtained and analyzed for MMP-1 and TIMP-1. Measurements were taken at baseline and repeated at 3 and 6 months after therapy.

RESULTS

Total MMP-1 levels were significantly decreased in both groups (P < 0.05) at 3 and 6 months. MMP-1 concentration levels showed a similar pattern to MMP-1 total levels decreasing significantly at 3 months (P < 0.05). TIMP-1 concentration levels increased in the test group throughout the study period, while the difference did not reach statistical significance (P > 0.05). TIMP-1/MMP-1 balance was restored in test group at 6 months significantly better than the control group (P < 0.05).

CONCLUSION

The results of this study suggest that metronidazole and amoxicillin combination as an adjunct to SRP results in better clinical healing through restoring TIMP-1/MMP-1 balance.

Efficacy of Subantimicrobial Dose Doxycycline for Moderate-to-Severe and Active Graves' Orbitopathy

Aim. To study the efficacy and safety of subantimicrobial dose (SD) doxycycline(50 mg/d) in patients with active and moderate-to-severe Graves' orbitopathy (GO). Methods. Thirteen patients with active and moderate-to-severe GO received once daily oral doxycycline (50 mg/d) for 12 wk. Treatment response at 24 wk was used as the primary outcome, measured by a composite of improvement in Clinical Activity Score (CAS), diplopia, motility, soft tissue swelling, proptosis, and eyelid aperture. Secondary outcome was the change of quality of life score (QoL, including visual functioning subscale and appearance subscale). Adverse events were also recorded. Results. Overall improvement was noted in eight out of 13 patients (61.5%, 95% CI 31.6%-86.1%). Both CAS and soft tissue swelling significantly ameliorated in eight patients at 24 wk. Five patients (38.5%) had improvement in ocular motility of ≥8 degrees. Eyelid aperture (46.2%) also decreased remarkably. For QoL, a significant improvement in appearance subscale (P = 0.008) was noted during the study, whereas no difference was observed in visual functioning subscale (P = 0.21). Two patients reported mild stomachache at 12 wk. Conclusions. SD doxycycline appears to be effective and safe for the treatment of active and moderate-to-severe GO. It might serve as a new promising therapeutic strategy for GO. This trial is registered with NCT01727973.

Non-surgical periodontal therapy with systemic antibiotics in patients with untreated chronic periodontitis: a systematic review and meta-analysis

OBJECTIVE

The purpose of this meta-analysis is to evaluate the effectiveness of different systemic antibiotics in combination with scaling and root planing (SRP) when compared to SRP alone in patients with untreated chronic periodontitis.

BACKGROUND

Although chronic periodontitis is mostly treated without adjunctive systemic antibiotics, some recent meta-analyses have shown clinical benefit for some systemic antibiotics when used as an adjunct to SRP. However, there is a wide variety of systemic antibiotic regimens used today. It remains unclear if the selected type of systemic antibiotic influences the magnitude of clinical benefit.

MATERIAL AND METHODS

The MEDLINE-PubMed database was searched from their earliest records through May 16, 2013. Several journals were hand searched and some authors were contacted for additional information. Outcome measures analysed were mean bleeding on probing change, mean clinical attachment level gain and mean probing pocket depth reduction. Extracted data were pooled using a random effect model. Weighted mean differences were calculated and heterogeneity was assessed.

RESULTS

The search yielded 281 abstracts. Ultimately, 95 studies were selected, describing 43 studies meeting the eligibility criteria. Systemic antibiotics showed a significant (p < 0.05) additional pocket depth reduction for moderate (at 3 mo 0.27 mm ± 0.09, at 6 mo 0.23 mm ± 0.10 and at 12 mo 0.25 mm ± 0.27) and deep pockets (at 3 mo 0.62 mm ± 0.17, at 6 mo 0.58 mm ± 0.16 and at 12 mo 0.74 mm ± 0.30). Statistically, no specific type of antibiotic was superior over another. However, when analysing the clinical data for initially moderate pockets or deep pockets, some trends became apparent.

CONCLUSION

Systemic antibiotics combined with SRP offer additional clinical improvements compared to SRP alone. Although there were no statistically significant differences, there was a trend that for initially moderate and deep pockets, metronidazole or metronidazole combined with amoxicillin, resulted in clinical improvements that were more pronounced over doxycycline or azithromycin. Additionally, there was a trend that the magnitude of the clinical benefit became smaller over time (1 year).

Periodontal therapy for the management of cardiovascular disease in patients with chronic periodontitis

BACKGROUND

There is an association between chronic periodontitis and cardiovascular disease (CVD). However, it is not known whether periodontal therapy could prevent or manage CVD in patients with chronic periodontitis.

OBJECTIVES

The objective of this systematic review was to investigate the effects of periodontal therapy in preventing the occurrence of, and management or recurrence of, CVD in patients with chronic periodontitis.

SEARCH METHODS

The electronic databases that were searched were the Cochrane Oral Health Group's Trials Register (to 7 April 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 3), MEDLINE via OVID (1946 to 7 April 2014), EMBASE via OVID (1980 to 7 April 2014), CINAHL via EBSCO (1937 to 7 April 2014), OpenGrey (to 7 April 2014), the Chinese BioMedical Literature Database (1978 to April 2014), the China National Knowledge Infrastructure (1994 to April 2014) and the VIP database (1989 to April 2014). We searched the US National Institutes of Health Trials Register, the World Health Organization (WHO) Clinical Trials Registry Platform and Sciencepaper Online for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs were considered eligible. Studies were selected if they included patients with a diagnosis of chronic periodontitis and previous CVD (secondary prevention studies) or no CVD (primary prevention studies); patients in the intervention group received active periodontal therapy compared to maintenance therapy, no periodontal treatment or another kind of periodontal treatment in the control group.

DATA COLLECTION AND ANALYSIS

Two review authors carried out the study identification, data extraction and risk of bias assessment independently and in duplicate. Any discrepancies between the two authors were resolved by discussion or with a third review author. A formal pilot-tested data extraction form was adopted for the data extraction, and the Cochrane Collaboration's tool for risk of bias assessment was used for the critical appraisal of the literature.

MAIN RESULTS

No studies were identified that assessed primary prevention of CVD in people with periodontitis. One study involving 303 participants with ≥ 50% blockage of one coronary artery or a coronary event within three years, but not the three months prior, was included. The study was at high risk of bias due to deviation from the protocol treatment allocation and lack of follow-up data. The trial compared scaling and root planing (SRP) with community care for a follow-up period of six to 25 months. No data on deaths (all-cause or CVD-related) were reported. There was insufficient evidence to determine the effect of SRP and community care in reducing the risk of CVD recurrence in patients with chronic periodontitis (risk ratio (RR) 0.72; 95% confidence interval (CI) 0.23 to 2.22; very low quality evidence). The effects of SRP compared with community care on high-sensitivity C-reactive protein (hs-CRP) (mean difference (MD) 0.62; -1.45 to 2.69), the number of patients with high hs-CRP (RR 0.77; 95% CI 0.32 to 1.85) and adverse events (RR 9.06; 95% CI 0.49 to 166.82) were also not statistically significant. The study did not assess modifiable cardiovascular risk factors, other blood test results, heart function parameters or revascularisation procedures.

AUTHORS' CONCLUSIONS

We found very low quality evidence that was insufficient to support or refute whether periodontal therapy can prevent the recurrence of CVD in the long term in patients with chronic periodontitis. No evidence on primary prevention was found.

Anti-inflammatory Actions of Adjunctive Tetracyclines and Other Agents in Periodontitis and Associated Comorbidities

The non-antimicrobial properties of tetracyclines such as anti-inflammatory, proanabolic and anti-catabolic actions make them effective pharmaceuticals for the adjunctive management of chronic inflammatory diseases. An over-exuberant inflammatory response to an antigenic trigger in periodontitis and other chronic inflammatory diseases could contribute to an autoimmune element in disease progression. Their adjunctive use in managing periodontitis could have beneficial effects in curbing excessive inflammatory loading from commonly associated comorbidities such as CHD, DM and arthritis. Actions of tetracyclines and their derivatives include interactions with MMPs, tissue inhibitors of MMPs, growth factors and cytokines. They affect the sequence of inflammation with implications on immunomodulation, cell proliferation and angiogenesis; these actions enhance their scope, in treating a range of disease entities. Non-antimicrobial chemically modified tetracyclines (CMTs) sustain their diverse actions in organ systems which include anti-inflammatory, anti-apoptotic, anti-proteolytic actions, inhibition of angiogenesis and tumor metastasis. A spectrum of biological actions in dermatitis, periodontitis, atherosclerosis, diabetes, arthritis, inflammatory bowel disease, malignancy and prevention of bone resorption is particularly relevant to minocycline. Experimental models of ischemia indicate their specific beneficial effects. Parallel molecules with similar functions, improved Zn binding and solubility have been developed for reducing excessive MMP activity. Curbing excessive MMP activity is particularly relevant to periodontitis, and comorbidities addressed here, where specificity is paramount. Unique actions of tetracyclines in a milieu of excessive inflammatory stimuli make them effective therapeutic adjuncts in the management of chronic inflammatory disorders. These beneficial actions of tetracyclines are relevant to the adjunctive management of periodontitis subjects presenting with commonly prevalent comorbidities addressed here.

Efficacy of subantimicrobial-dose doxycycline against nitrosative stress in chronic periodontitis

AIM

To evaluate the effectiveness of subantimicrobial-dose doxycycline (SDD) as an adjunct to scaling and root planing (SRP) treatment against the nitrosative stress of moderate to advanced chronic periodontitis.

METHODS

Adults with untreated chronic periodontitis (n=174) were randomly administered SRP+SDD (n=87) (20 mg of doxycycline twice daily) or SRP+placebo (n=87) treatment for 3 months. At baseline and after 3 months, the probing depths (PD), bleeding on probing (BOP) and clinical attachment level (CAL) were measured, and a gingivomucosal biopsy was collected to assay the induction of nitric oxide synthase (iNOS) and 3-nitrotyrosine (3NT), and blood was collected to assay for total nitrites and nitrates (NO(x)) and 3NT.

RESULTS

Compared to baseline, at the completion of treatment, significant decreases in the levels of tissue iNOS and 3NT and serum NO(x) and 3NT were observed in both groups. SRP+SDD yielded a greater reduction in the gingivomucosal and serum nitrosative stress markers than did SRP+placebo. PD, BOP, and CAL reduction were correlated with the nitrosative stress parameters.

CONCLUSION

On a short-term basis, SDD therapy may be used as an adjunct to SRP treatment against nitrosative stress in moderate to advanced chronic periodontitis.

Non-antibacterial tetracycline formulations: clinical applications in dentistry and medicine

In 1983, it was first reported that tetracyclines (TCs) can modulate the host response, including (but not limited to) inhibition of pathologic matrix metalloproteinase (MMP) activity, and by mechanisms unrelated to the antibacterial properties of these drugs. Soon thereafter, strategies were developed to generate non-antibacterial formulations (subantimicrobial-dose doxycycline; SDD) and compositions (chemically modified tetracyclines; CMTs) of TCs as host-modulating drugs to treat periodontal and other inflammatory diseases. This review focuses on the history and rationale for the development of: (a) SDD which led to two government-approved medications, one for periodontitis and the other for acne/rosacea and (b) CMTs, which led to the identification of the active site of the drugs responsible for MMP inhibition and to studies demonstrating evidence of efficacy of the most potent of these, CMT-3, as an anti-angiogenesis agent in patients with the cancer, Kaposi's sarcoma, and as a potential treatment for a fatal lung disease (acute respiratory distress syndrome; ARDS). In addition, this review discusses a number of clinical studies, some up to 2 years' duration, demonstrating evidence of safety and efficacy of SDD formulations in humans with oral inflammatory diseases (periodontitis, pemphigoid) as well as medical diseases, including rheumatoid arthritis, post-menopausal osteopenia, type II diabetes, cardiovascular diseases, and a rare and fatal lung disease, lymphangioleiomyomatosis.

Rheumatoid arthritis and periodontitis - inflammatory and infectious connections. Review of the literature

An association between oral disease/periodontitis and rheumatoid arthritis (RA) has been considered since the early 1820s. The early treatment was tooth eradication. Epidemiological studies suggest that the prevalence of RA and periodontitis may be similar and about 5% of the population are aged 50 years or older. RA is considered as an autoimmune disease whereas periodontitis has an infectious etiology with a complex inflammatory response. Both diseases are chronic and may present with bursts of disease activity. Association studies have suggested odds ratios of having RA and periodontitis varying from 1.8:1 (95% CI: 1.0–3.2, NS) to 8:1 (95% CI: 2.9–22.1, p<0.001). Genetic factors are driving the host responses in both RA and periodontitis. Tumor necrosis factor-α, a proinflammatory cytokine, regulates a cascade of inflammatory events in both RA and periodontitis. Porphyromonas gingivalis is a common pathogen in periodontal infection. P. gingivalis has also been identified in synovial fluid. The specific abilities of P. gingivalis to citrullinate host peptides by proteolytic cleavage at Arg-X peptide bonds by arginine gingipains can induce autoimmune responses in RA through development of anticyclic citrullinated peptide antibodies. In addition, P. gingivalis carries heat shock proteins (HSPs) that may also trigger autoimmune responses in subjects with RA. Data suggest that periodontal therapies combined with routine RA treatments further improve RA status.

Effects of periodontal therapy on GCF cytokines in generalized aggressive periodontitis subjects

AIM

To examine changes in levels of gingival crevicular fluid (GCF) cytokines, after periodontal therapy of generalized aggressive periodontitis (GAgP).

MATERIALS AND METHODS

Twenty-five periodontally healthy and 24 GAgP subjects had periodontal clinical parameters measured and gingival crevicular fluid (GCF) samples collected from up to 14 sites/subject. GCF samples were analysed using multiplex bead immunoassay for: GM-CSF, IFN-γ, IL-10, IL-1β, IL-2, IL-6 and TNF-α. Aggressive periodontitis subjects were randomly assigned to either scaling and root planing (SRP) alone or SRP plus systemic amoxicillin (500 mg) and metronidazole (400 mg) 3 times a day for 14 days. Clinical parameters and GCF cytokines were re-measured 6 months after treatment. Differences over time were analysed using the Wilcoxon test and between groups using the Mann-Whitney test.

RESULTS

Significant reductions in GCF GM-CSF, IL-1β and the ratio IL-1β/IL-10 and increases in GCF IL-6 were detected after therapy. The mean change in GCF cytokines did not differ significantly between groups.

CONCLUSIONS

Periodontal therapy improved GCF cytokine profiles by lowering IL-1β and increasing IL-10 levels. The reduction in GCF GM-CSF after therapy implicates this cytokine in the pathogenesis of GAgP. There was no difference between therapies in changes of GCF cytokines.

Effects of low-dose doxycycline on cytokine secretion in human monocytes stimulated with Aggregatibacter actinomycetemcomitans

Doxycycline is an antibiotic used in the treatment of a variety of inflammatory conditions, including periodontitis. Apart from its antimicrobial properties, this drug also has independent anti-inflammatory effects at sub-antimicrobial doses. The present study aimed to investigate the effects of low-doses of doxycycline (LDD) on cytokine production by human monocytic cells challenged with the periodontal pathogen Aggregatibacter actinomycetemcomitans, for up to 6 h. The simultaneous regulation of 12 cytokines were measured by a Human Cytokine Array Kit. To validate the array findings, selected cytokines were also measured by enzyme-linked immunosorbant assay (ELISA). A. actinomycetemcomitans stimulated the production of tumor necrosis factor (TNF)-α, interleukin (IL)-1α, IL-1β, IL-6 and IL-8 by the cells after 6 h of challenge, and doxycycline significantly inhibited this effect. The kinetics of this regulation demonstrated an early (within 2 h) and significant (P<0.05) inhibition of pro-inflammatory cytokines, with a mild (0.5-fold) up-regulation of the anti-inflammatory cytokine IL-10. The results indicate that LDD acts as an anti-inflammatory agent in human monocytic cells stimulated with A. actinomycetemcomitans. This model provides clear evidence that some of the clinically proven benefits of LDD may be related to its ability to regulate inflammatory mediator release by monocytic cells. This property may contribute to the clinically proven benefits of this antibiotic as an adjunctive treatment for periodontitis.

Long-term efficacy of subantimicrobial-dose doxycycline as an adjunctive treatment to scaling and root planing: a systematic review and meta-analysis

BACKGROUND

Subantimicrobial-dose doxycycline (SDD) is widely used as an adjunctive treatment to scaling and root planing (SRP), but its long-term effectiveness remains controversial. The purpose of this systematic review was to assess the actual evidence of the effectiveness of SRP + SDD compared to SRP + placebo in the treatment of chronic periodontitis.

METHODS

A literature search of electronic databases was performed for articles published through November 1, 2010. Several dental journals were screened during the manual search, and authors were contacted for missing information. The systematic review and meta-analysis were conducted according to the Quality of Reporting of Meta-Analyses statement and recommendations of the Cochrane Collaboration. The methodologic quality of the studies was determined via a Consolidated Standards of Reporting Trials-based assessment. Clinical attachment levels, probing depths, plaque and gingival indices, and gingival crevicular fluid levels were compared between baseline and the end of follow-up. Data were extracted and pooled using a random-effect model. The weighted mean difference was reported with the 95% confidence interval. Heterogeneity was assessed using the χ(2)-based Q-statistic method and I(2) measurement. P <0.05 was considered statistically significant.

RESULTS

After applying inclusion and exclusion criteria, three randomized placebo-controlled clinical trials were entered into the meta-analysis. These studies had similar treatment designs, SDD dosage regimens (20 mg twice daily for 3 months), and post-treatment follow-up lengths (9 months). Significant differences were observed for all investigated clinical parameters in favor of the SRP + SDD group.

CONCLUSION

The meta-analysis results seemed to support the long-term effectiveness of adjunctive SDD therapy; however, future studies are needed to confirm these findings.