Experimental Gingivitis Research Articles

Label-Free Quantitative Proteomics Reveals Differentially Regulated Proteins in Experimental Gingivitis

We investigated the sequential protein expression in gingival crevicular fluid samples during the induction (I) and resolution (R) of experimental gingivitis. Periodontally and systemically healthy volunteers (n = 20) participated in a three-week experimental gingivitis protocol, followed by debridement and two weeks of regular plaque control. Gingival crevicular fluid (GCF) samples were collected at baseline, Day 7, 14, and 21 (induction; I-phase), and at Day 21, 25, 30, and 35 (resolution; R-phase). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for label-free quantitative proteomics was applied. A total of 287 proteins were identified including 254 human, 14 bacterial, 12 fungal, and 7 yeast proteins. Ontology analysis revealed proteins primarily involved in cytoskeletal rearrangements, immune response, antimicrobial function, protein degradation, and DNA binding. There was considerable variation in the number of proteins identified, both among subjects and within subjects across time points. After pooling of samples between subjects at each time point, the levels of 59 proteins in the I-phase and 73 proteins in the R-phase were quantified longitudinally. Our data demonstrate that LC-MS/MS label-free quantitative proteomics is valuable in the assessment of the protein content of the GCF and can facilitate a better understanding of the molecular mechanisms involved in the induction and resolution of plaque-induced gingival inflammation in humans.

Effect of probiotic lozenges on inflammatory reactions and oral biofilm during experimental gingivitis

Aim. Probiotic bacteria have been introduced for prevention and treatment of periodontal diseases. The aim was to assess if daily oral administration of probiotic bacteria could influence the inflammatory response and the composition of supragingival plaque in an experimental gingivitis model. Materials and methods. Eighteen healthy female adults volunteered after informed consent. A double-blind randomized placebo-controlled cross-over design was used. The buccal surface of first molars was used as experimental sites. A mouth-guard covering the first premolar to second molar was used when brushing, preventing accidental cleaning during 3 weeks of plaque accumulation. Lozenges containing L. reuteri (ATCC55730 and ATCC PTA5289) or placebo were taken twice a day. During the run-in and washout periods, professional tooth cleaning was performed 5 days/week. At baseline and follow-up, plaque index, gingival index and bleeding on probing were recorded. Samples of gingival crevicular fluid (GCF) were analysed for concentration of seven inflammatory mediators. Bacterial samples were processed with checkerboard DNA/DNA-hybridization. Results. All subjects presented a local plaque accumulation and developed manifest gingivitis at the test sites during the intervention periods. The volume of GCF increased in both groups but was statistically significant only in the placebo group (p < 0.05). The concentrations of IL1-β and IL-18 increased significantly (p < 0.05), while IL-8 and MIP1-β decreased (p < 0.05). No differences were displayed between test and placebo. Likewise, the microbial composition did not differ between the groups. Conclusion. Daily intake of probiotic lozenges did not seem to significantly affect the plaque accumulation, inflammatory reaction or the composition of the biofilm during experimental gingivitis.

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.

Host–Bacterial Interactions During Induction and Resolution of Experimental Gingivitis in Current Smokers

Changes in clinical profiles, microbial succession, and immune mediator fluctuations have all been separately examined during onset and resolution of experimental gingivitis in smokers. However, because both the bacterial challenge and the host response contribute to periodontal disease, the purpose of this investigation is to simultaneously examine clinical, bacterial, and immune changes that occur during the onset and resolution of disease in smokers. Experimental gingivitis was induced in 15 smokers for 21 days, followed by treatment with a sonic toothbrush for 21 days. Marginal and subgingival plaque and gingival crevicular fluid samples were collected at baseline; after 7, 14, and 21 days of undisturbed plaque formation; and 21 days after reinstitution of brushing. 16S cloning and sequencing was used for bacterial quantification, and multiplexed bead-based flow cytometry was used to quantify the levels of 27 immune mediators. Onset of clinical gingivitis was preceded by significant changes in the marginal and subgingival biofilms, with a decrease in the abundance of early colonizers, namely, Streptococcus, Veillonella, and Pseudomonas, and an increase in levels of periodontopathogens, such as Treponema, Selenomonas, Parvimonas, Dialister, and Campylobacter. This was accompanied by a decrease in anti-inflammatory, chemokine, and T-helper 2 (Th2) responses and altered Th1/Th2 ratios. Although the bacterial communities continued to shift in the same direction after onset of clinical gingivitis and returned to baseline levels after resolution of disease, the anti-inflammatory, chemokine, and Th2 profiles demonstrated an increase from day 14 that continued even after clinical health was evident. Both marginal and subgingival biofilms in smokers are characterized by early acquisition of pathogenic organisms, which elicit a sustained host response that persists even after removal of the bacterial challenge.

Effect of cetylpyridinium chloride with xylitol on the formation of biofilm and development of gingivitis

Aim: To assess the effect of the combination of cetylpyridinium chloride and xylitol on the formation of dental biofilm and development of experimental gingivitis. Methods: A crossover, double-blind, placebo-controlled study was conducted and divided into two phases of 21 days each with a time interval of 10 days between them. A modified experimental gingivitis model was used and 31 volunteers were randomly divided into 2 groups. The volunteers performed daily mouthwashes twice a day with the test solution containing cetylpyridinium combined with xylitol or a placebo solution. On day 0 and day 21 of each phase the Plaque Index (PI) and Gingival Index (GI) of each volunteer were measured. During this phase, the volunteers brushed their teeth with standard toothbrushes and dentifrice, protecting the third quadrant with a toothshield. After brushing, the toothshield was removed and the mouthwash was used. Results: The PI values observed in the Test Group at baseline and on day 21 were 0 (0.00 – 0.03) and 0 (0.22-0.48) respectively, and in Control Group 0 (0.00 – 0.03) and 1 (0.45 – 0.81) (inter-group analysis - McNemar test, p 0.05). Conclusions: The test solution had a positive effect on dental biofilm control. However, it was not capable of preventing the development of experimental gingivitis.

The relationship between two kinds of human herpesviruses and experimental gingivitis

To investigate human cytomegalovirus (HCMV) and Epstein-Barr virus-type 1 (EBV-1) in GCF and saliva during experimental gingivitis in Chinese young subjects and to evaluate the effect of the virus in the initial stage of gingival inflammation. GCF of 14 and 45 and saliva without stimulating in 11 Chinese young males with healthy gingiva were collected at baseline (day 0), day 7, 14 and 21 after stopping oral hygiene and day7 after reestablishing oral hygiene (day 28). DNA of HCMV and EBV-1 were detected by nested-polymerase chain reaction (n-PCR) at the times mentioned above. HCMV was detected in GCF of 4 subjects at baseline, 4 subjects at day 7, 3 subjects at day 14 and 2 subjects at day 21 while the subjects were different. At day 28 HCMV could not be detected. EBV-1 was not detectable in GCF during the experimental gingivitis. HCMV was detected in saliva in 4 subjects and EBV-1 was in 3 subjects. And there is no relationship between the detection of the herpesviruses and the clinical parameters as well. We suggest that HCMV and EBV-1 are not the important factors during the initial stage of gingival inflammation.

Microvascular regulatory role and increased expression of vascular endothelial growth factor receptor type 2 in experimental gingivitis

The aim of the present study was to investigate the possible microvascular regulatory role of vascular endothelial growth factor receptor type 2 (VEGFR2) in experimental gingivitis in rats. Our previous results demonstrated that functionally active VEGFR2s are located in the venules of rat gingiva. While there is no remarkable endogenous gingival VEGF production under normal circumstances, exogenous VEGF, via VEGFR2, shows venodilatory effects. We assumed that VEGF plays an important role in vasoregulatory processes (vasodilation, increased permeability, angiogenesis) of gingival inflammation. Gingivitis was induced by placing ligatures and composite material around and between the lower incisors of anesthetized Wistar rats next to the gingival margin. Seven days later, VEGFR2 antagonist (ZM323881), was dripped upon the labial gingiva next to the lower incisors. Diameter changes of the selected gingival venules were measured by vital microscopy. Animals with healthy gingiva served as controls. Venule diameter changes were compared to the baseline and to control groups (no ligature). Immunohistochemical and Western blot analysis for VEGFR2 were utilized. After 15, 30 and 60 min of local application of ZM323881, there was a significant venoconstriction in the inflamed gingiva compared to the baseline, while no change was recorded in controls. Endothelium, smooth muscle cells and pericytes of the gingivitis group showed increased VEGFR2 expression. Our findings suggest that there is an increased VEGF production in gingivitis, which may play an important role in vasodilation of rat gingival venules.

A Comparative Study of Fluoride Containing Chlorhexidine and Non-Chlorhexidine Mouthrinses in a Teenage Group

Aim: The study was planned to assess the effect of a mouthrinse containing Chlorhexidine (CHX) and amine/stannous fluoride (AmF) on plaque accumulation, gingivitis and salivary fluoride levels in comparison with two mouthrinses containing either essential oils (EO) or cetylpyridinium chloride (CPC) with sodium fluoride (NaF) in a teenage group.&#x0D; Methodology: For this study 82 healthy teenage between 13 and 16 years were recruited for participation. The experimental gingivitis model consisted of a 2-weeks recruitment phase, followed by a 6-day rinsing period with one of the 4 mouthrinse formulations was used for the study. At the end of the pre-phase period and the rinsing period (Day-0/Day-6), gingival index (GI), plaque index (PI) and salivary fluoride levels were recorded. The statistical analyses were performed using Wilcoxon sign test and the dependent t test.&#x0D; Results: A reduction in plaque re-growth was seen for the CHX+AmF formulation rinse, although there were no significant differences among all groups (p&gt;0,001). During the experimental periods, the gingivitis indices increased significantly for all formulations (p&lt;0,001), except for the CHX+AmF formulation. The CHX+AmF formulation scored higher levels of salivary fluoride at the end of the rinsing period (p&gt;0,001).&#x0D; Conclusion: It reveals that the adjunctive use of AmF containing CHX mouthrinses to mechanical oral hygiene should be recommended for teenage at risk groups. &#x0D; How to cite this article: Atabek D, Alaçam A, Çakılcı B, Berkkan A. A Comparative Study of Fluoride Containing Chlorhexidine and Non-Chlorhexidine Mouthrinses in a Teenage Group. Int Dent Res 2012;1:1-7.&#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Pellicle and early dental plaque in periodontitis patients before and after surgical pocket elimination

Objective. Gingival inflammation may affect the composition of the dental pellicle and initial acquisition of bacteria, which in turn could affect the healing of the periodontal pocket. The aim of this study was to examine the dental pellicle and early supragingival biofilms in periodontitis patients with an established subgingival infiltrate before and after surgical pocket elimination. Materials and methods. Eleven patients with remaining pockets were selected. Samples were taken before and after surgical pocket elimination and after subsequent experimental gingivitis. Pellicle proteins were analyzed by SDS-PAGE, immunoblotting and image analysis and 4-h supragingival plaque by culturing. Results. The inflammatory status affected to a greater extent the concentration of plasma proteins than salivary proteins in the dental pellicle. The highest plasma protein concentrations were observed at remaining periodontal pockets where also the highest bacterial counts were found. The TVC was reduced on the gingival tooth surfaces (p < 0.05) after pocket elimination and increased slightly during experimental gingivitis. The finding of streptococci was highest on the incisal tooth surfaces and increased after surgery. Gram-negative anaerobes were sparse but seen more often before than after pocket elimination and on gingival than on incisal surfaces. Conclusions. This study suggests that increased amounts of plasma proteins in the pellicle formed in the presence of remaining periodontal pockets may foster the acquisition of bacteria, including proteolytic Gram-negative species. This, in turn, results in an increased de novo plaque formation rate.

Mapping biological to clinical phenotypes during the development (21 days) and resolution (21 days) of experimental gingivitis

To characterize and map temporal changes in the biological and clinical phenotype during a 21-day experimental gingivitis study. Experimental gingivitis was induced over 21 days in healthy human volunteers (n = 56), after which normal brushing was resumed (resolution phase). Gingival and plaque indices were assessed. Gingival crevicular fluid was collected from four paired test and contra-lateral control sites in each volunteer during induction (Days 0, 7, 14 and 21) and resolution (Days 28 and 42) of experimental gingivitis. Fluid volumes were measured and a single analyte was quantified from each site-specific, 30s sample. Data were evaluated by analysis of repeated measurements and paired sample tests. Clinical indices and gingival crevicular fluid volumes at test sites increased from Day 0, peaking at Day 21 (test/control differences all p < 0.0001) and decreased back to control levels by Day 28. Levels of four inflammatory markers showed similar patterns, with significant differences between test and control apparent at Day 7 (substance P, cathepsin G, interleukin-1β, elastase: all p < 0.03) and peaking at Day 21 (all p < 0.002). Levels of α-1-antitrypsin showed no pattern. Levels of substance P, cathepsin G, interleukin-1β and neutrophil elastase act as objective biomarkers of gingival inflammation induction and resolution that typically precede phenotypical changes.

Microbiological profile and calprotectin expression in naturally occurring and experimentally induced gingivitis

This study was performed to evaluate the microbiological profile and the calprotectin expression in gingival crevicular fluid (GCF) in spontaneous and experimentally induced gingival inflammation. Thirty-seven periodontally healthy subjects were evaluated in real life conditions (N-O gingivitis) as well as after 21days of experimental gingivitis trial (E-I gingivitis). During the experimental gingivitis trial, in one maxillary quadrant (test quadrant), gingival inflammation was induced by oral hygiene abstention, while in the contralateral (control) quadrant, oral hygiene was routinely continued. The results of the study showed that (1) the microbiological profile of quadrants where gingival inflammation was experimentally induced (i.e., E-I test quadrants) differed significantly from that of either quadrants where gingival inflammation was controlled by proper plaque control (i.e., E-I control quadrants) or quadrants with N-O gingivitis, and (2) GCF calprotectin was significantly higher at E-I test quadrants compared to either E-I control quadrants or quadrants with N-O gingivitis. A positive intrasubject correlation was found between GCF concentration of calprotectin at sites presenting N-O and E-I gingivitis. N-O and E-I gingivitis showed a different microbiological profile of the subgingival environment. GCF calprotectin is a reliable marker of gingival inflammation, and its concentration in N-O gingivitis is correlated with its expression in E-I gingivitis. The modality of plaque accumulation seems to affect the subgingival microbiological profile associated with a gingivitis condition. Calprotectin levels in GCF may be regarded as a promising marker of the individual susceptibility to develop gingival inflammation in response to experimentally induced plaque accumulation.

Reversibility of experimental peri‐implant mucositis compared with experimental gingivitis in humans

To monitor clinical, microbiological and host-derived alterations occurring around teeth and titanium implants during the development of experimental gingivitis/mucositis and their respective healing sequence in humans. Fifteen subjects with healthy or treated periodontal conditions and restored with dental implants underwent an experimental 3-week period of undisturbed plaque accumulation in the mandible. Subsequently, a 3-week period with optimal plaque control was instituted. At Days 0, 7, 14, 21, 28, 35 and 42, the presence/absence of plaque deposits around teeth and implants was assessed, (plaque index [PlI]) and the gingival/mucosal conditions were evaluated (gingival index[GI]). Subgingival/submucosal plaque samples and gingival/mucosal crevicular fluid (CF) samples were collected from two pre-determined sites around each experimental unit. CF samples were analyzed for matrix-metalloproteinase-8 (MMP-8) and interleukin-1beta (IL-1β). Microbial samples were analyzed using DNA-DNA hybridization for 40 species. During 3 weeks of plaque accumulation, the median PlI and GI increased significantly at implants and teeth. Implant sites yielded a greater increase in the median GI compared with tooth sites. Over the 6-week experimental period, the CF levels of MMP-8 were statistically significantly higher at implants compared with teeth (P<0.05). The CF IL-1β levels did not differ statistically significantly between teeth and implants (P>0.05). No differences in the total DNA counts between implant and tooth sites were found at any time points. No differences in the detection frequency were found for putative periodontal pathogens between implant and tooth sites. Peri-implant soft tissues developed a stronger inflammatory response to experimental plaque accumulation when compared with that of their gingival counterparts. Experimental gingivitis and peri-implant mucositis were reversible at the biomarker level. Clinically, however, 3 weeks of resumed plaque control did not yield pre-experimental levels of gingival and peri-implant mucosal health indicating that longer healing periods are needed.

Comparative efficacy of two daily use mouthrinses: randomized clinical trial using an experimental gingivitis model

Two antimicrobial agents, a fixed combination of essential oils (EOs) and 0.07% cetylpyridinium chloride (CPC) are found in commercially available mouthrinses, Listerine® Antiseptic and Crest® Pro HealthTM, respectively. Both mouthrinses have been shown to control dental plaque and gingivitis in short and longer term studies. The aim of this study was to determine the comparative effectiveness of these two mouthrinses using a 2-week experimental gingivitis model. Qualified subjects were randomly assigned to one of three mouthrinse groups: a fixed combination of EOs, 0.07% CPC, or negative control (C) rinse. Following baseline clinical assessments and a dental prophylaxis, subjects began a two-week period in which they rinsed twice daily with their assigned rinse and abstained from any mechanical oral hygiene procedures or other oral care products. Subjects were reassessed at the end of the two-week period. One hundred and forty-seven subjects were randomized and 142 completed this study. After two weeks use, the EOs rinse was superior (p < 0.011) to the CPC rinse in inhibiting the development of gingivitis, plaque, and bleeding, with 9.4% and 6.6% reductions compared to CPC for gingivitis and plaque, respectively. Both rinses were superior to the negative control rinse (p < 0.001). This study demonstrates that the essential oil-containing mouthrinse has superior antiplaque/antigingivitis effectiveness compared to the 0.07% CPC-containing mouthrinse without mechanical oral hygiene influence.

Multiple Hypothesis Testing for Experimental Gingivitis Based on Wilcoxon Signed Rank Statistics

Dental research often involves repeated multivariate outcomes on a small number of subjects for which there is interest in identifying outcomes that exhibit change in their levels over time as well as to characterize the nature of that change. In particular, periodontal research often involves the analysis of molecular mediators of inflammation for which multivariate parametric methods are highly sensitive to outliers and deviations from Gaussian assumptions. In such settings, nonparametric methods may be favored over parametric ones. Additionally, there is a need for statistical methods that control an overall error rate for multiple hypothesis testing. We review univariate and multivariate nonparametric hypothesis tests and apply them to longitudinal data to assess changes over time in 31 biomarkers measured from the gingival crevicular fluid in 22 subjects whereby gingivitis was induced by temporarily withholding tooth brushing. To identify biomarkers that can be induced to change, multivariate Wilcoxon signed rank tests for a set of four summary measures based upon area under the curve are applied for each biomarker and compared to their univariate counterparts. Multiple hypothesis testing methods with choice of control of the false discovery rate or strong control of the family-wise error rate are examined.

Gingival tissue transcriptomes in experimental gingivitis

We investigated the sequential gene expression in the gingiva during the induction and resolution of experimental gingivitis. Twenty periodontally and systemically healthy non-smoking volunteers participated in a 3-week experimental gingivitis protocol, followed by debridement and 2-week regular plaque control. We recorded clinical indices and harvested gingival tissue samples from four interproximal palatal sites in half of the participants at baseline, Day 7, Day 14 and Day 21 (the "induction phase"), and at Day 21, Day 25, Day 30 and Day 35 in the other half (the "resolution phase"). RNA was extracted, amplified, reversed transcribed, amplified, labelled and hybridized using Affymetrix Human Genome U133Plus2.0 microarrays. Paired t-tests compared gene expression changes between consecutive time points. Gene ontology analyses summarized the expression patterns into biologically relevant categories. The median gingival index was 0 at baseline, 2 at Day 21 and 1 at Day 35. Differential gene regulation peaked during the third week of induction and the first 4 days of resolution. Leucocyte transmigration, cell adhesion and antigen processing/presentation were the top differentially regulated pathways. Transcriptomic studies enhance our understanding of the pathobiology of the reversible inflammatory gingival lesion and provide a detailed account of the dynamic tissue responses during the induction and resolution of experimental gingivitis.

Endotoxemia and the host systemic response during experimental gingivitis

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

Experimental gingivitis in overweight subjects Clinical and Microbiological study

Background:Obesity is a complex multifactorial chronic diseasethat affecting the host immunity which may stimulate a hyperinflammatory response in periodontal disease.Aims of the study is to determine and compare the gingival clinical parameters between Obese, pre-obese, and normal weight. Along with estimating the effect of overweight on healing process of experimental gingivitis, also to determine and compare the microbiological findings between Obese, pre-obese, and normal weight. Materials and Methods: Our study dealing with experimental gingivitis using the clinical parameters (plaque index and gingival index), existent bacterial flora, oral hygiene improvement on normal weight, pre-obese, and obese subjects showing healthy systemic condition, using the body mass index (BMI) and inter parametric comparison on 30 individuals, male with no previous medical history, age ranged from 20-30years old,10 of them are obese, 10 are within overweight(pre-obese) and the other 10 are within normal weight.Dental plaque samples were taken from each subjects when the gingiva reaches inflammation (Mean GI≥1). Results: The G.I .parameter showed a significant higher score of inflammation on the pre-obese and obese samples during the initiation of the disease (P≤0.002), and also showed a prolonged improvement response after the recovery of the oral hygiene control (P≤0.001).The bacterial findings showed an equal percent of streptococci and staphylococci but with predominance on other species in normal weight subjects. The pre-obese showed an increase percent of klebsiella .The obese subjects showed insignificant differences and almost equal percent of streptococci, staphylococci and pseudomonades with undetectable number of klebseila. Conclusion: This study found that Obesity is an active risk factor for gingival and periodontal disease, and it’s playing a role in elevating body response to dental plaque with increasing the healing period.

Multiple Hypothesis Testing for Experimental Gingivitis Based on Wilcoxon Signed Rank Statistics

Multiple Hypothesis Testing for Experimental Gingivitis Based on Wilcoxon Signed Rank Statistics

Interferon‐gamma promoter hypomethylation and increased expression in chronic periodontitis

The goal of this investigation was to determine whether epigenetic modifications in the IFNG promoter are associated with an increase of IFNG transcription in different stages of periodontal diseases. DNA was extracted from gingival biopsy samples collected from 47 total sites from 47 different subjects: 23 periodontally healthy sites, 12 experimentally induced gingivitis sites and 12 chronic periodontitis sites. Levels of DNA methylation within the IFNG promoter containing six CpG dinucleotides were determined using pyrosequencing technology. Interferon gamma mRNA expression was analysed by quantitative polymerase chain reactions using isolated RNA from part of the biological samples mentioned above. The methylation level of all six analysed CpG sites within the IFNG promoter region in the periodontitis biopsies {52% [interquartile range, IQR (43.8%, 63%)]} was significantly lower than periodontally healthy samples {62% [IQR (51.3%, 74%)], p=0.007} and gingivitis biopsies {63% [IQR (55%, 74%)], p=0.02}. The transcriptional level of IFNG in periodontitis biopsies was 1.96-fold and significantly higher than tissues with periodontal health (p=0.04). Although the mRNA level from experimental gingivitis samples exhibited an 8.5-fold increase as compared with periodontally healthy samples, no significant methylation difference was observed in experimental gingivitis sample. A hypomethylation profile within IFNG promoter region is related to an increase of IFNG transcription present in the chronic periodontitis biopsies, while such an increase of IFNG in experimentally induced gingivitis seems independent of promoter methylation alteration.

Clinical and antibacterial effect of an anti-inflammatory toothpaste formulation with Scutellaria baicalensis extract on experimental gingivitis

It was the aim of the study to evaluate the clinical and antibacterial effect of a dentifrice containing an anti-inflammatory plant extract (SB) versus a placebo (PLA) using an experimental gingivitis model. Forty subjects (20 per group) discontinued all oral hygiene measures for four teeth for a period of 21days using a shield (to generate a possible gingivitis) while they could brush the other teeth normally. After brushing, the shield was removed and teeth were treated with the randomly assigned toothpaste slurry for 1min. Löe and Silness gingival index (GI), Silness and Löe plaque index (PI), and biofilm vitality (VF%) were assessed at days0, 14, and 21, respectively. Subjects of the PLA group developed a GI of 0.82 ± 0.342 (day14) and 1.585 ± 0.218 (day21), while the data of the SB group were significantly reduced (0.355 ± 0.243 and 0.934 ± 0.342, p < 0.001). While PI was significantly reduced at all follow-up appointments, reductions in VF reached the level of significance only at day21. The results suggest that the new toothpaste formulation was able to significantly reduce the extent of gingivitis, plaque development, and vital flora.