Interleukin-1 beta levels in gingival crevicular fluid and serum under naturally occurring and experimentally induced gingivitis

Salivary levels of catalase, total antioxidant capacity and interleukin-1β and oral health-related quality of life after matcha and green tea consumption for patients with gingivitis: A randomized clinical trial

OBJECTIVES

To evaluate the changes in salivary levels of catalase (CAT), total antioxidant capacity (TAC) and IL-1β (primary outcomes) as well as gingival health and oral health-related quality of life (OHRQOL) 1 month after the consumption of matcha and green tea in adult patients with gingivitis.

METHODS

This study was a parallel randomized clinical trial. Forty gingivitis adult patients were randomly assigned to drink either matcha or green tea cup twice daily for a duration of 1 month. They were asked to keep their habitual oral hygiene measures. Plaque index (PI) and bleeding on probing (BOP) were recorded. In addition, saliva was collected at baseline and 1 month after tea consumption. Salivary levels of CAT, TAC and IL-1β were determined by ELISA. Each participant was asked to fill OHIP-14 questionnaire before and after tea consumption.

RESULTS

Following tea intake, 40.6% of the study sample had healthy gingiva. Both groups similarly showed reductions in PI (0.32 ± 0.11-0.22 ± 0.08) and BOP (0.24 ± 0.08-0.13 ± 0.07) scores after tea consumption. There was a significant difference between mean TAC before and after matcha tea consumption only. Non-significant reductions in salivary levels of CAT and IL-1β were detected after tea consumption. OHRQOL of participants was improved after tea, both types, consumption.

CONCLUSION

Despite study limitations, daily consumption of matcha and green tea might be beneficial as they potentially enhance OHRQOL of individuals with gingivitis and reduce the extent of gingivitis despite non-significant changes in salivary antioxidants and IL-1β levels.

Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health

BACKGROUND

The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings.

METHODS

The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test.

RESULTS

Our findings showed that EG had a greater gingival index than NG and was healthy (p < 0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p < 0.001), CCL3 (p < 0.05), and IL-1B (p < 0.001) than NG. In contrast, NG had increased levels of MIF (p < 0.05), Fractalkine (p < 0.001), angiogenin (p < 0.05), C3a (p < 0.001), BMP-2 (p < 0.001), OPN (p < 0.05), RANKL (p < 0.001), and MMP-13 (p < 0.001) than EG.

CONCLUSIONS

Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

The Correlation between Periodontal Parameters and Cell-Free DNA in the Gingival Crevicular Fluid, Saliva, and Plasma in Chinese Patients: A Cross-Sectional Study

Purpose: To investigate the correlation between periodontal parameters and cell-free DNA (cfDNA) concentrations in gingival crevicular fluid (GCF), saliva, and plasma. Methods: Full mouth periodontal parameters, including probing depth (PD), bleeding on probing (BOP), and plaque index (PI) were recorded from 25 healthy volunteers, 31 patients with untreated gingivitis, and 25 patients with untreated periodontitis. GCF, saliva, and plasma samples were collected from all subjects. Extraction and quantification assays were undertaken to determine cfDNA concentrations of each sample. Results: GCF and salivary cfDNA levels were increased with aggravation of periodontal inflammation (GCF p < 0.0001; saliva p < 0.001). Plasma cfDNA concentrations in patients with periodontitis were significantly higher than those in healthy volunteers and patients with gingivitis. GCF and salivary cfDNA were positively correlated with mean PD, max PD, BOP, and mean PI (p < 0.0001), whereas plasma cfDNA was not correlated with BOP (p = 0.099). Conclusion: GCF, saliva, and plasma concentrations of cfDNA were significantly elevated in patients with periodontal disease. There were also positive correlations between cfDNA levels in GCF and saliva and periodontal parameters.

Human Umbilical Cord Mesenchymal Stem Cells: Current Literature and Role in Periodontal Regeneration

Periodontal disease can cause irreversible damage to tooth-supporting tissues such as the root cementum, periodontal ligament, and alveolar bone, eventually leading to tooth loss. While standard periodontal treatments are usually helpful in reducing disease progression, they cannot repair or replace lost periodontal tissue. Periodontal regeneration has been demonstrated to be beneficial in treating intraosseous and furcation defects to varied degrees. Cell-based treatment for periodontal regeneration will become more efficient and predictable as tissue engineering and progenitor cell biology advance, surpassing the limitations of present therapeutic techniques. Stem cells are undifferentiated cells with the ability to self-renew and differentiate into several cell types when stimulated. Mesenchymal stem cells (MSCs) have been tested for periodontal regeneration in vitro and in humans, with promising results. Human umbilical cord mesenchymal stem cells (UC-MSCs) possess a great regenerative and therapeutic potential. Their added benefits comprise ease of collection, endless source of stem cells, less immunorejection, and affordability. Further, their collection does not include the concerns associated with human embryonic stem cells. The purpose of this review is to address the most recent findings about periodontal regenerative mechanisms, different stem cells accessible for periodontal regeneration, and UC-MSCs and their involvement in periodontal regeneration.

Association of the Unstimulated Whole Salivary Cytokine IL-1β Levels with Initial, Moderate and Severe Periodontitis. A Case Control Study

Periodontitis (P) is a highly prevalent inflammatory disease of the oral cavity. The objective of the study was to evaluate the stages of pro-inflammatory cytokine IL-1β in initial, moderate and severe periodontitis. One hundred and twenty two patients were included in the study. Periodontitis subjects had at least 20 natural teeth and ≥8 sites with pocket depths of >4 mm and clinical attachment loss (CAL). A questionnaire was used with respect to the socio demographic parameters which included age, gender, ethnicity, education, marital, residence and occupation. To categorize the severity of the disease, teeth were assessed for, Plaque index (PI), Bleeding on probing (BOP), CAL, missing tooth, tooth mobility and bone loss. Unstimulated whole saliva (UWS) was collected and Interleukin-1β (IL-1β) cytokine levels were analyzed using enzyme linked immunosorbent assay with microplate reader at 450 nm. Clinical parameters and salivary cytokine concentrations were assessed using one-way analysis of variance, whereas a correlation of cases with gender and severity of periodontitis was evaluated using chi-square test. Fifty-nine patients were healthy controls and 63 were periodontitis patients Thirty two percent (n = 20) had initial periodontitis, 40% (n = 25) suffered from moderate and 29% (n = 18) had severe periodontitis. Periodontitis subgroups were significantly different with regards to age and gender (p < 0.001). The mean PPD and CAL among the periodontitis patients (PPD, 3.52 ± 1.25 mm; CAL, 4.04 ± 1.64 mm) were significantly compromised (p < 0.05) compared to healthy controls (PPD, 1.52 ± 0.73 mm; CAL, 0.08 ± 0.28 mm). Increased levels of IL-1β were associated with high CAL and PPD findings. UWS IL-1β levels were higher in periodontitis patients compared to healthy individuals. In addition, cases of severe periodontitis showed significantly higher UWS IL-1β levels compared to initial and moderate periodontitis patients. Comparative levels of salivary IL-1β can be potentially used as a diagnostic tool for periodontitis identification and disease progression along with clinical parameters.

Human variation in gingival inflammation

Oral commensal bacteria actively participate with gingival tissue to maintain healthy neutrophil surveillance and normal tissue and bone turnover processes. Disruption of this homeostatic host-bacteria relationship occurs during experimental gingivitis studies where it has been clearly established that increases in the bacterial burden increase gingival inflammation. Here, we show that experimental gingivitis resulted in three unique clinical inflammatory phenotypes (high, low, and slow) and reveal that interleukin-1β, a reported major gingivitis-associated inflammatory mediator, was not associated with clinical gingival inflammation in the slow response group. In addition, significantly higher levels of Streptococcus spp. were also unique to this group. The low clinical response group was characterized by low concentrations of host mediators, despite similar bacterial accumulation and compositional characteristics as the high clinical response group. Neutrophil and bone activation modulators were down-regulated in all response groups, revealing novel tissue and bone protective responses during gingival inflammation. These alterations in chemokine and microbial composition responses during experimental gingivitis reveal a previously uncharacterized variation in the human host response to a disruption in gingival homeostasis. Understanding this human variation in gingival inflammation may facilitate the identification of periodontitis-susceptible individuals. Overall, this study underscores the variability in host responses in the human population arising from variations in host immune profiles (low responders) and microbial community maturation (slow responders) that may impact clinical outcomes in terms of destructive inflammation.

Optimal frequency of tooth brushing in mechanically ventilated adults: Study protocol for a randomized controlled trial

The optimal frequency of tooth brushing in the critically ill has not been experimentally determined. For mechanically ventilated patients, optimal frequency of tooth brushing is an important unresolved issue as there is little evidence to judge the benefits or associated risks of tooth brushing. Given this knowledge gap, the project's overall goal is to determine the optimal frequency of tooth brushing (once, twice, or three times daily) for mechanically ventilated adults. A prospective, randomized, experimental design is used. Specifically, 345 subjects, with 207 expected to complete the study, are randomly assigned within 36 hr of intubation to one of three groups (once, twice, or three times tooth brushing daily). Tooth brushing with a soft compact-head toothbrush takes approximately 2 min. Dental plaque assessment, gingival crevicular fluid (GCF) determination for IL-1β, and data regarding healthcare-acquired infection (HAI) and clinical status are collected at baseline and daily in-hospital. The clinical impact of daily frequency of tooth brushing in relation to extent of dental plaque and inflammation reflected by GCF analysis will be compared by the three treatment arms. In addition, evaluation of safety for HAIs will be compared based on calculation of the number needed to harm. The trial will empirically determine the optimal frequency of tooth brushing in mechanically ventilated adults, balancing benefits and risks. This contribution is significant because it will have immediate impact on bedside nursing practice, and is a final component necessary for specific evidence-based guidelines for the common nursing intervention of oral care in mechanically ventilated adults.

Salivary cytokine levels in early gingival inflammation

Salivary protein levels have been studied in periodontitis. However, there is lack of information on salivary cytokine levels in early gingival inflammation. The aim of this study was to determine salivary levels of vascular endothelial growth factor (VEGF), interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1, IL-1β, and IL-1 receptor antagonist (IL-1Ra) in gingival inflammation. Twenty-eight systemically and orally healthy nonsmokers abstained from oral hygiene protocols for 10 days. After that, self-performed cleaning was resumed for 14 days. Plaque and gingival indexes were measured, and saliva samples were collected at days 1, 4, 7, 10, and 24. Salivary cytokines were detected with Luminex®-xMAP™. Salivary IL-1β, IL-1Ra, and VEGF levels decreased after 10 days' development of experimental gingivitis and reached baseline levels at the end of the 2-week resolution period. Salivary IL-8 levels decreased and remained low during development and resolution of experimental gingivitis. Initial inflammation in gingival tissues is associated with a decrease in inflammatory cytokines in saliva. Further studies are needed to evaluate if inflammatory cytokines bind to their functional receptors within the gingival tissue during early gingivitis, which may limits their spillover to the gingival crevice and ultimately saliva.

Association of interleukin-1 gene variations with moderate to severe chronic periodontitis in multiple ethnicities

Background and Objective

Genetic markers associated with disease are often non-functional and generally tag one or more functional “causative” variants in linkage disequilibrium. Markers may not show tight linkage to the causative variants across multiple ethnicities due to evolutionary divergence, and therefore may not be informative across different population groups. Validated markers of disease suggest causative variants exist in the gene and, if the causative variants can be identified, it is reasonable to hypothesize that such variants will be informative across diverse populations. The aim of this study was to test that hypothesis using functional Interleukin-1 (IL-1) gene variations across multiple ethnic populations to replace the non-functional markers originally associated with chronic adult periodontitis in Caucasians.

Material and Methods

Adult chronic periodontitis cases and controls from four ethnic groups (Caucasians, African Americans, Hispanics and Asians) were recruited in the USA, Chile and China. Genotypes of IL1B gene single nucleotide polymorphisms (SNPs), including three functional SNPs (rs16944, rs1143623, rs4848306) in the promoter and one intronic SNP (rs1143633), were determined using a single base extension method or TaqMan 5′ nuclease assay. Logistic regression and other statistical analyses were used to examine the association between moderate to severe periodontitis and IL1B gene variations, including SNPs, haplotypes and composite genotypes. Genotype patterns associated with disease in the discovery study were then evaluated in independent validation studies.

Results

Significant associations were identified in the discovery study, consisting of Caucasians and African Americans, between moderate to severe adult chronic periodontitis and functional variations in the IL1B gene, including a pattern of four IL1B SNPs (OR = 1.87, p < 0.0001). The association between the disease and this IL1B composite genotype pattern was validated in two additional studies consisting of Hispanics (OR = 1.95, p = 0.04) or Asians (OR = 3.27, p = 0.01). A meta-analysis of the three populations supported the association between the IL-1 genotype pattern and moderate to severe periodontitis (OR 1.95; p < 0.001). Our analysis also demonstrated that IL1B gene variations had added value to conventional risk factors in predicting chronic periodontitis.

Conclusion

This study validated the influence of IL-1 genetic factors on the severity of chronic periodontitis in four different ethnicities.

Salivary and crevicular fluid interleukins in gingivitis

INTRODUCTION

Gingivitis is a frequent inflammatory process of the gum tissue that is mainly caused by the accumulation of plaque. The immune response against inflammatory processes is regulated in part by cytokines.

AIMS

Given that a continuous inflammation exists in gingivitis, it would be logical to assume that the interleukins will be altered locally in those patients. Therefore, the aim of this review was to check whether there is evidence that the interleukins can be used as diagnostic markers of inflammation levels in patients with gingivitis.

MATERIALS AND METHODS

A bibliographical search was undertaken using the key words interleukin and gingivitis in Pubmed, Cochrane, Scopus and Embase. Only those articles published over the last 10 years that were systematic reviews, case-controls or cohort studies in which interleukins in saliva and/or crevicular fluid was investigated in patients with gingivitis were selected.

RESULTS

Finally 15 articles were selected, all of them being case-control studies. The interleukins analyzed in the reviewed articles were: IL-1β, IL-8, IL-18, IL-11, IL-12, TNFα, IL-4, IL-17, IL-1α and IL-6. The most commonly studied interleukin is IL-1β and most authors agree that it is higher in the saliva and/or crevicular fluid of patients with gingivitis. Therefore, it could be used as a diagnostic marker of the degree of inflammation in gingivitis. Moreover, as far as the other interleukins studied are concerned, there is no clear consensus among the authors.

CONCLUSION

There is sufficient evidence to suggest that IL-1β in saliva and/or crevicular fluid can be used as a marker of the degree of inflammation in gingivitis. Key words:Interleukins, gingivitis, saliva, crevicular fluid.

Salivary biomarkers associated with gingivitis and response to therapy

BACKGROUND

Salivary biomarkers are potentially important for determining the presence, risk, and progression of periodontal disease. However, clinical translation of biomarker technology from lab to chairside requires studies that identify biomarkers associated with the transitional phase between health and periodontal disease (i.e., gingivitis).

METHODS

Eighty participants (40 with gingivitis, 40 healthy) provided saliva at baseline and 7 to 30 days later. An additional sample was collected from gingivitis participants 10 to 30 days after dental prophylaxis. Clinical parameters of gingival disease were recorded at baseline and the final visit. Salivary concentrations of interleukin (IL)-1β, IL-6, matrix metalloproteinase (MMP)-8, macrophage inflammatory protein (MIP)-1α, and prostaglandin E2 (PGE2) were measured.

RESULTS

Clinical features of health and gingivitis were stable at both baseline visits. Participants with gingivitis demonstrated significantly higher bleeding on probing (BOP), plaque index (PI), and gingival index (GI) (P ≤0.002) and a significant drop in BOP, PI, and GI post-treatment (P ≤0.001). Concentrations of MIP-1α and PGE2 were significantly higher (2.8 times) in the gingivitis group than the healthy group (P ≤0.02). After dental prophylaxis, mean biomarker concentrations did not decrease significantly from baseline in the gingivitis group, although concentrations of IL-1β, IL-6, and MMP-8 approached healthy levels, whereas MIP-1α and PGE2 concentrations remained significantly higher than in the healthy group (P ≤0.04). Odds ratio analyses showed that PGE2 concentrations, alone and in combination with MIP-1α, readily discriminated gingivitis from health.

CONCLUSIONS

Salivary PGE2 and MIP-1α discriminate gingivitis from health, and patients with gingivitis who return to clinical health continue to produce inflammatory mediators for weeks after dental prophylaxis.

Local and systemic inflammatory responses to experimentally induced gingivitis

This study profiled the local and systemic inflammatory responses to experimentally induced gingivitis. Eight females participated in a 21-day experimental gingivitis model followed by a 14-day resolution phase. Bleeding on probing and plaque index scores were assessed before, during, and after resolution of gingival inflammation, and samples of saliva, GCF, and plasma were collected. Samples were assessed for biomarkers of inflammation using the BioPlex platform and ELISA. There were no significant changes in GCF levels of cytokines during the experimental phase; however, individual variability in cytokine profiles was noted. During resolution, mean GCF levels of IL-2, IL-6, and TNF-α decreased and were significantly lower than baseline levels (P = 0.003, P = 0.025, and P = 0.007, resp.). Furthermore, changes in GCF levels of IL-2, IL-6, and TNF-α during resolution correlated with changes in plaque index scores (r = 0.88, P = 0.004; r = 0.72, P = 0.042; r = 0.79, P = 0.019, resp.). Plasma levels of sICAM-1 increased significantly during the experimental phase (P = 0.002) and remained elevated and significantly higher than baseline levels during resolution (P < 0.001). These results support the concept that gingivitis adds to the systemic inflammatory burden of an individual.

The potential association between gingival crevicular fluid inflammatory mediators and adverse pregnancy outcomes: a systematic review

OBJECTIVES

The association between periodontal disease and adverse pregnancy outcomes (APO), primarily preterm birth (PTB), is still controversially discussed in the literature. Therefore, the aim of the present systematic review was to analyze the existing literature on the potential association between inflammatory mediators detected in gingival crevicular fluid (GCF) and APO.

MATERIALS AND METHODS

MEDLINE (PubMed) and EMBASE databases were searched for entries up to April 2012 and studies were selected by two independent reviewers.

RESULTS

The majority of the eight studies included confirmed a positive association between GCF mediators, such as interleukin-1β, prostaglandin E2, and tumor necrosis factor-alpha, and APO. Due to the heterogeneity and variability of the available studies, no meta-analysis could be performed.

CONCLUSIONS

A positive association between GCF inflammatory mediator levels and APO/PTB might be present but the results need to be considered with great caution because of the heterogeneity and variability among the studies. Further studies with an adequate number of patients allowing for an appropriate analysis are warranted to definitely confirm this association.

CLINICAL RELEVANCE

The present findings suggest that an association between GCF inflammatory mediator levels and APO might exist.

Endotoxemia and the host systemic response during experimental gingivitis

AIM

To assess endotoxemia episodes and subsequent changes in serum inflammatory biomarkers using the experimental gingivitis model.

MATERIALS AND METHODS

Data from 50 healthy black and white adult males and females were compared for serum concentrations of endotoxin, and serum biomarkers [neutrophil oxidative activity, interleukin (IL)-1β, IL-6, IL-8, C-reactive protein (CRP), and fibrinogen] at baseline, at 3 weeks of experimental gingivitis, and after 2 weeks of recovery. Means were compared using repeated measures analysis of variance.

RESULTS

Endotoxemia was reported in 56% of the serum samples at 3 weeks of induced gingivitis. At 2 weeks of recovery, endotoxin levels decreased to levels similar to those reported at baseline. Neutrophil oxidative activity increased significantly following 3 weeks of gingivitis versus baseline (p<0.05). In the endotoxin-negative group this increase was associated with the black subjects whereas in the endotoxin-positive group change in neutrophil activity was driven by the female subpopulation. Serum cytokines, CRP, and fibrinogen levels did not change during the study.

CONCLUSIONS

Experimental gingivitis was associated with endotoxemia and hyperactivity of circulating neutrophils, but not with changes in systemic levels of cytokines and acute-phase proteins. This may be attributed to the mild nature and the short duration of the induced gingivitis.