Destructive effects of smoking on molecular and genetic factors of periodontal disease

Effects of tobacco smoke on the expression of virulence genes in Escherichia coli

It is widely acknowledged that smoking exacerbates the severity of infectious diseases. A presumed mechanism involves the damage inflicted by tobacco smoke on the organs of host organisms. In this study, an alternative hypothesis was explored: smoking enhances the virulence of bacteria. This possibility was investigated using Escherichia coli as the model bacteria and Drosophila as the host organism. Our inquiry focused on the potential gene expression changes in E. coli subsequent to exposure to tobacco smoke extracts. Analysis of the transcription promoter activity of genes encoding proteins within the E. coli two-component system, a regulatory machinery governing gene expression, revealed the suppression of thirteen out of 23 promoters in response to tobacco smoke extracts. Subsequently, Drosophila was infected with E. coli exposed to tobacco smoke extracts or left untreated. Interestingly, there were no significant differences observed in the survival periods of Drosophila following infection with E. coli, whether treated or untreated with tobacco smoke extracts. Contrary to the initial hypothesis, the findings suggest that while tobacco smoke extracts alter gene expression in E. coli, these changes do not appear to impact bacterial virulence. Although this study has illuminated the influence of tobacco smoke extracts on the gene expression of E. coli, further analyses are necessary to elucidate the implications of these changes. Nevertheless, the results imply that smoking affects not only host organisms but may also exert influence on invading bacteria.

Salivary IL-17 and IL-10 as Potential Diagnostic Biomarkers of Different Stages of Periodontitis in Smoker and Nonsmoker Patients

OBJECTIVES

 The gold standard in the field of periodontal research currently is to find a valid biomarker that can reliably be used for diagnosing periodontal diseases. Given the limitations of the current diagnostic tools that stall to predict susceptible individuals and determine whether active tissue destruction is occurring, there is an increased urge to develop alternative diagnostic techniques that would compensate for the problems inherited in these available methods, such as measuring levels of biomarkers present in oral fluids such as saliva; so the aim of this study was to determine the diagnostic potential of interleukin-17 (IL-17) and IL-10 to differentiate periodontal health from smoker and nonsmoker periodontitis, and to differentiate among different stages (severities) of periodontitis.

MATERIALS AND METHODS

 An observational case-control study was performed on 175 systemically healthy participants grouped into healthy as controls and periodontitis as cases. Periodontitis cases were divided according to the severity into stages I, II, and III, and each of the stages was further subdivided into smokers and nonsmokers patients. Unstimulated saliva samples were collected, clinical parameters were recorded, and salivary levels were assayed using enzyme-linked immunosorbent assay.

RESULTS

 Elevated levels of IL-17 and IL-10 were associated with stage I and II compared with the healthy controls. However, a significant decrease in stage III was observed compared with the control group for both biomarkers.

CONCLUSION

 Salivary IL-17 and IL-10 might be useful for distinguishing periodontal health from periodontitis; however, further research is needed to substantiate their use as potential biomarkers for the diagnosis of periodontitis.

Soluble Receptor Activator of Nuclear Factor Ligand and Osteoprotegerin Levels in Gingival Crevicular Fluid among Cigarette Smokers and Non-smokers with and without Periodontitis

AIM

This study aimed to measure and compare the levels of soluble receptor activator of nuclear factor ligand (RANKL) and osteoprotegerin (OPG) in the gingival crevicular fluid (GCF), as well as their ratio, in smokers and nonsmokers with periodontitis.

MATERIALS AND METHODS

Gingival crevicular fluid samples were collected using PerioPaper strips, from 150 individuals, who were categorized into three groups: current smokers with periodontitis stage III grades C and B (n = 50), nonsmokers with periodontitis stages I and II grade A (n = 50), and control healthy individuals (n = 50). The concentrations (pg/mL) of sRANKL and OPG in the GCF were measured by enzyme-linked immunesorbent assays (ELISA).

RESULT

The smokers' group exhibited the highest sRANKL (pg/mL) concentration as a subsequent lead to a higher sRANKL/OPG ratio. The healthy control group exhibited higher OPG and lower sRANKL concentration, subsequently, the sRANKL/OPG ratio was reduced compared with the other study groups. However, there was no statistical significance of sRANKL and its relative ratio between periodontitis stage III grades C and B, periodontitis stages I and II grade A, and healthy control individuals. There was a statistically significant positive moderate correlation between smoking duration (years) and the sRANKL (pg/mL) concentration and a statistically significant negative moderate correlation between OPG (pg/mL) concentration and cigarettes smoked per day.

CONCLUSION

As a result, compared to the other research groups, smokers with periodontitis stage III grades C and B had greater GCF concentrations of sRANKL, lower OPG, and a higher sRANKL/OPG ratio. The difference in OPG (pg/mL) level was statistically significant. However, there was no statistically significant difference in sRANKL (pg/mL) or its relative ratio, sRANKL/OPG, across the groups.

CLINICAL SIGNIFICANCE

A characteristic that sets periodontitis apart is alveolar bone loss. Resorption is induced by RANKL and inhibited by OPG, resulting in a relative ratio. In light of this, the levels of RANKL and OPG may be helpful indicators for monitoring the activity of periodontal disease in both smokers and nonsmokers with and without periodontitis.

The effect of different cigarette smoking levels on gingival crevicular fluid volume and periodontal clinical parameters in Saudi Arabia

Introduction

Periodontal disease is a chronic inflammatory condition of the periodontium. It is the main cause of tooth loss and is considered one of the biggest threats to the oral cavity. Tobacco smoking has long been associated with increased risk for periodontal, peri-implant, and other medical diseases.

Objective

To evaluate the effect of smoking and its level on periodontal clinical parameters (probing depth (PD), plaque index (PI), gingival index (GI), clinical attachment level (CAL), bleeding on probing (BOP), and the volume of gingival crevicular fluid (GCF)) in healthy and chronic periodontitis individuals.

Material and Method

A total of 160 participants were recruited in the present study, who were equally divided into the following five groups: healthy controls (C), healthy smokers (HS), nonsmokers with periodontitis (PNS), light smokers with periodontitis (PLS), and heavy smokers with periodontitis (PHS). GCF volume and periodontal clinical parameters (PD, PI, GI, CAL, and BOP) were assessed for each participant and compared between the study groups.

Result

There was a statistically significant difference in PD, PI, GI, CAL, and BOP between healthy and periodontitis patients (p < 0.001). The mean PI, PD, and CAL were considerably higher in heavy smokers than light smokers and non-smokers (P < 0.001). In contrast, the mean GI and BOP were significantly lower in heavy smokers than in light smokers and non-smokers. There was a statistically significant difference in GCF between healthy and periodontitis patients (p < 0.001). The mean GCF readings were higher in heavy smokers than light smokers or non-smokers (P < 0.001).

Conclusion

The present study confirms the influence of smoking on periodontal clinical parameters. Smoking was associated with increased PD, PI, CAL, and GCF readings; however, GI and BOP were decreased in smokers. The number of cigarettes played a key role in the volume of GCF and periodontal clinical parameters.

Effect of Smoking Exposure on Nonsurgical Periodontal Therapy: 1-Year Follow-up

This study investigated the influence of different levels of exposure to smoking on periodontal healing for 12 mo after nonsurgical periodontal therapy and supportive periodontal care every third month. Eighty smokers willing to quit smoking and with periodontitis were included. Participants were offered an individualized voluntary smoking cessation program. Data collection included questionnaires and a full-mouth periodontal examination. Group-based trajectory modeling was used to model smoking trajectories over the follow-up. The effect of smoking trajectory on periodontal parameters over time was estimated with mixed effects modeling. Three smoking patterns were identified: light smokers/quitters (n = 46), moderate smokers (n = 17), and heavy smokers (n = 17). For the periodontal data, the first factor, moderate periodontitis, included the number of sites with clinical attachment levels (CALs) of 4, 5, 6, and 7 mm; periodontal pocket depths (PPDs) of 4, 5, and 6 mm; and bleeding on probing. The second factor, severe periodontitis, consisted of the number of sites with a CAL ≥8 mm and PPD ≥7 mm. Heavy smokers commenced with a higher average CAL of 1.1 mm and 10 more sites with severe periodontitis than light smokers/quitters. While light smokers/quitters and moderate smokers obtained an average improvement of 0.6-mm PPD and 0.7-mm CAL, respectively, heavy smokers experienced 0.5-mm attachment loss. Heavy smokers had only a 50% reduction in the number of sites with moderate periodontitis when compared with light smokers/quitters and moderate smokers. While most participants benefited from nonsurgical periodontal therapy with results affected in a dose-response manner, the therapy had no effect on severe periodontitis among heavy smokers. Smoking cessation should be part of periodontal therapy; otherwise, limited benefits would be observed among heavy smokers, hindering the effect of treatment.

Clinical and Biochemical Effects of Smoking on Non-Surgical Periodontal Treatment in Grade III Stage C Periodontitis Patients

Objective: The purpose of this study was to evaluate the effect of smoking on clinical parameters and the serum and saliva levels of RANKL, OPG, and IL-34 in periodontitis stage III grade C (III-C) patients after non-surgical periodontal treatment (NSPT). Methods: A total of 60 subjects, 40 periodontitis-III-C patients (20 smokers and 20 non-smokers) and 20 non-smoker periodontally healthy individuals, were included. All clinical periodontal parameters were recorded, and unstimulated saliva and serum samples were collected from all patients at baseline, but at 1 and 3 months only from periodontitis patients (N=40). Saliva and serum levels of RANKL, OPG, and IL-34 were analyzed by ELISA. Results: At baseline only whole mouth probing depth (PD) and percent of sites with PD>5mm were higher in smokers than non-smoker periodontitis patients (p

Free haem levels in gingival crevicular fluid and their relationship to periodontal clinical parameters, smoking and subgingival microbial composition

Background and Objectives:

Periodontitis caused by multifactorial polymicrobial infection results in a destructive inflammatory process and loss of tooth supporting tissues. Many putative bacterial virulence factors that cause host destruction are regulated by iron and haem. Therefore, this study investigated the free haem levels in the gingival crevicular fluid (GCF) at periodontitis sites in smokers and nonsmokers and their relationship to subgingival microbial composition.

Materials and Methods:

A cross-sectional study was carried out on 78 patients with a split-mouth design who were divided into Group I A – periodontally healthy sites and Group I B – periodontally diseased sites in nonsmokers with chronic periodontitis and Group II A – periodontally healthy sites and Group II B – periodontally diseased sites in smokers. Clinical parameters recorded included a plaque and gingival index, papillary bleeding index, pocket probing depth, and clinical attachment level. The collected GCF samples were subjected to Biovision™ Hemin Colorimetric Assay Kit and subgingival plaque samples to BANA™ test.

Results:

Increased GCF free haem concentration and positive BANA sites were seen at periodontitis sites compared to healthy sites, in both smokers and nonsmokers group. However, no difference was found in GCF free haem levels between smokers and nonsmokers, but it was statistically significant with respect to BANA-positive sites.

Conclusion:

Thus, this study concludes that the higher concentration of GCF free haem at diseased sites indicates that it could be used as a potential biomarker to determine active periodontal sites, also smoking and BANA results did not influence the biomarker levels.

Behavioral risk factors and periodontal disease in Malang, Indonesia

OBJECTIVE

This study aimed to analyze the relationship of behavioral risk factors for periodontal disease among 19-64 age group in Malang City.

METHOD

A non-experimental quantitative analytic with a cross sectional study approach was used in this study. The respondents were 331 patients who visited the dental clinics of the Health Centers in Malang City. A cluster random sampling technique was used in this study. The instrument used was questionnaire. The data analysis was done through multivariate analyses use logistic-regression.

RESULTS

The Wald test results on logistic-regression models showed there is no significant effect of smoking habits and consumption patterns on periodontal disease. There is a significant effect of systemic disease on periodontal disease with a significance value of 0.000 (p<0.05).

CONCLUSIONS

There was a significant relationship and effect between systemic disease and periodontal disease in this study.

Relationship between the prevalence of oral human papillomavirus DNA and periodontal disease (Review)

Human papillomavirus (HPV) is a small DNA virus that infects the basal keratinocytes of squamous epithelium in the skin, and in the oral and genital mucosa. Smoking and sexual behavior have been recognized as significant risk factors for oral HPV infection. In the present review, the findings of recent studies of oral HPV infection in relation to periodontitis are discussed, as well as periodontopathic bacteria and periodontal herpes virus. Previous research suggests that HPV localizes to the inflammatory periodontal tissue. Inflammatory periodontal pockets may thus act as a reservoir for HPV. The interactions between HPV and periodontopathic bacteria remain unclear, but it is hypothesized that oral HPV infection may be related to a characteristic oral microbiome. Smoking is associated with HPV and periodontitis, as smoking induces destruction of periodontal tissue and suppresses the host defense, allowing HPV to infect periodontal tissue. Carcinogenic HPV and periodontitis may lead to the development of oral cavity cancer. However, oral HPV E6/E7 expression (transcriptionally active HPV) has not yet been fully investigated in patients with periodontitis. Collectively, the evidence suggests that oral HPV prevalence may be associated with periodontitis. The effect of clinical factors (age, sex, smoking, immunosuppressive condition and vaccination) on oral HPV DNA prevalence should be considered when clarifying the relationship between oral HPV and periodontitis. Additionally, the sampling method should be carefully chosen to directly detect HPV DNA in periodontal tissues.

Peri-implant soft tissue inflammatory parameters and crestal bone loss among waterpipe (narghile) smokers and never-smokers with and without type 2 diabetes mellitus

BACKGROUND

Peri-implant soft tissue inflammatory parameters and crestal bone loss (CBL) among waterpipe smokers (WS) with and without type 2 diabetes mellitus (T2DM) remains uninvestigated. The aim of the present study was to assess peri-implant soft tissue inflammatory parameters and CBL among WS and never smokers (NS) with and without T2DM.

METHODS

Demographic data and information regarding duration of implants in function, daily frequency of smoking, duration and treatment of T2DM, and daily toothbrushing was collected using a questionnaire. Peri-implant plaque index (PI), bleeding on probing (BOP), probing depth (PD) ≥4 mm, CBL, and hemoglobin A1c (HbA1c) levels were assessed in all individuals. Level of significance was set at 5%.

RESULTS

Seventy-nine male individuals (39 patients with T2DM [20 WS and 19 NS] and 40 systemically healthy individuals [21 WS smokers and 19 NS]) were included. The mean age was comparable among individuals in all groups. The mean HbA1c levels were significantly higher among patients with T2DM compared to controls (P < 0.01). Peri-implant PI, BOP, PD, and CBL were comparable among WS and NS with T2DM. Among patients without T2DM, PI (P < 0.05), PD ≥4 mm (P < 0.05) and mesial and distal CBL (P < 0.05) were significantly higher in WS than NS. Among individuals without T2DM, BOP was significantly higher among NS (P < 0.05) than WS. In patients with T2DM, BOP was comparable among WS and NS.

CONCLUSIONS

Peri-implant soft tissue inflammatory parameters and CBL were comparable among WS and NS with T2DM. Among individuals without T2DM, these parameters were worse among WS than NS.

Predicting doxorubicin drug delivery by single-walled carbon nanotube through cell membrane in the absence and presence of nicotine molecules: a molecular dynamics simulation study

In order to study the interaction of the anticancer agent Doxorubicin with the single-walled carbon nanotubes with different diameters as drug delivery systems, the molecular dynamics (MD) simulations have been used. Also, for design and development of intracellular Doxorubicin drug delivery systems, a series of steered MD simulations are applied to explore the possibility of encapsulated Doxorubicin-carbon nanotube penetration through a lipid bilayer in presence and absence of Nicotine molecules at different pulling rates. Our simulation results showed that in spite of the adsorption of drug molecules on the outer sidewall of the nanotubes, the spontaneous localization of one Doxorubicin molecule into the cavity of the nanovectors with larger diameters is observed. It is found that the presence of Nicotine molecules in extracellular medium increases the required force for pulling nanotube-encapsulated drug as well as the required time for penetration process, especially at higher velocity. Also, the entering process of the Nicotine molecules into the carbon nanotube causes that the encapsulated drug molecule is fully released in the hydrophobic phase of the lipid bilayer.Communicated by Ramaswamy H. Sarma.

Smoking and periodontal microorganisms

Resolution of dysbiosis following treatment for periodontal disease and tobacco dependence has been reported in longitudinal intervention studies. In the present report, we evaluated the biological findings regarding the effect of smoking on the periodontal microbiome. A standardized electronic search was conducted using MEDLINE; overall, 1099 papers were extracted. Studies that addressed the relationship between tobacco and periodontal pathogens were included. Finally, 42 papers were deemed appropriate for the present review. Functional changes in periodontal pathogens exposed to nicotine and cigarette smoke extract support the clinical findings regarding dysbiosis of the subgingival microbiome. Dysbiosis of the periodontal microbiome was presented in smokers regardless of their periodontal condition (healthy, gingivitis, or periodontitis) and remained significant only in smokers even after the resolution of experimentally-induced gingivitis and following reduction of clinical signs of periodontitis with non-surgical periodontal treatment and over 3 months post-therapy. Based on these findings, smoking cessation in periodontitis patients is beneficial for promoting a health-compatible subgingival microbial community. To maximize the benefits of these interventions in dental settings, further studies on periodontal microbiome are needed to elucidate the impact of tobacco intervention on preventing recurrence of periodontal destruction in the susceptible subjects.

Influence of Cigarette Smoke Inhalation on an Autogenous Onlay Bone Graft Area in Rats with Estrogen Deficiency: A Histomorphometric and Immunohistochemistry Study

PURPOSE

The present study aimed to evaluate the influence of cigarette smoke inhalation on an autogenous onlay bone graft area, either covered with a collagen membrane or not, in healthy and estrogen-deficient rats through histomorphometry and immunohistochemistry.

MATERIALS AND METHODS

Sixty female rats (Wistar), weighing 250-300 g, were randomly divided and allocated into groups (either exposed to cigarette smoke inhalation or not, ovariectomized and SHAM). After 15 days, the test group underwent cigarette smoke inhalation. Sixty days after exposition, autogenous bone grafting was only performed on all right hemimandibles, and the left ones underwent autogenous onlay bone grafting with the collagen membrane (BioGide^®). The graft was harvested from the parietal bone and attached to the animals' jaws (right and left). They were euthanized at 21, 45, and 60 days after grafting. Histological measurements and immunohistochemical analyses were performed, and results were submitted to a statistical analysis.

RESULTS

The addition of a collagen membrane to the bone graft proved more efficient in preserving graft area if compared to the graft area without a collagen membrane and the one associated with cigarette smoke inhalation at 21 (p = 0.0381) and 60 days (p = 0.0192), respectively. Cigarette smoke inhalation combined with ovariectomy promoted a significant reduction of the autogenous graft area at 21 and 60 days. At 45 days, no statistically significant results were observed. In the immunohistochemical analysis, the ovariectomized and smoking subgroups, combined or not with collagen membrane, received moderate and intense immunolabeling at 21 days for Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL) (p = 0.0017 and p = 0.0381, respectively). For Osteoprotegerin (OPG), intense immunolabeling was observed in most subgroups under analysis at 60 days.

CONCLUSION

Smoking inhalation promoted resorption on the autogenous onlay bone graft, mainly when associated with ovariectomy. Furthermore, when associated with the collagen membrane, a lower resorption rate was observed if compared to the absence of the membrane.

Microbiological and biochemical findings in relation to clinical periodontal status in active smokers, non-smokers and passive smokers

INTRODUCTION

Cigarette users are more susceptible than non-smokers to periodontitis, a bacterial-induced, inflammation-driven, destructive disease of the supporting tissues of the teeth. We hypothesized that clinical periodontal findings and microbiological and/or inflammatory marker levels would be intermediate in those exposed to environmental tobacco smoke compared to active smokers and non-smokers.

METHODS

Sixty individuals were recruited from a University periodontal clinic and assigned as non-smokers, active smokers or passive-smokers according to their self reports. Clinical periodontal measurements, comprising plaque index, probing depth (PD), clinical attachment level (CAL) and bleeding on probing, were recorded at six sites per tooth. Cotinine levels were determined in whole saliva samples by EIA. Treponema denticola and Porphyromonas gingivalis infection was determined by PCR, while matrix metalloproteinase-8 (MMP-8) and interleukin-8 (IL-8) concentrations were determined by ELISA.

RESULTS

Study groups were subsequently reassigned in accordance with the cotinine data. The smoker group exhibited higher mean PD and CAL values compared to the non-smoker group (p<0.05). Passive-smokers exhibited PD and CAL values smaller than those of the active smokers and greater than those of the non-smokers, but the differences were not statistically significant. PD and CAL values correlated with cotinine concentrations (p<0.05). P. gingivalis infection was noted in most subjects, irrespective of smoking status. T. denticola infection was noted in 4/23 (17.4%) smokers, 0/16 (0%) environmentally-exposed recruits and 2/21 (9.5%) non-smokers. Salivary MMP-8 and IL-8 levels were lower in smokers compared to both non-smokers and passive-smokers but the differences were not significant (all p>0.05).

CONCLUSIONS

The present clinical periodontal findings provide further support for a negative, dose-related effect of tobacco exposure on periodontal health. The tendency for a more prevalent detection of T. denticola and for a suppressed inflammatory response observed in the smokers may partly explain the increased susceptibility to periodontal tissue destruction, but needs to be verified in larger scale studies.

The effect of nonsurgical periodontal treatment on gingival crevicular fluid stress hormone levels: A prospective study

OBJECTIVES

The purpose of this prospective study was to investigate the effect of nonsurgical periodontal treatment (PT) on anxiety/depression scale scores and on gingival crevicular fluid (GCF) cortisol (COR) and dehydroepiandrosterone (DHEA) levels.

METHODS

Fifty-five participants with generalized chronic periodontitis (GCP group, n: 21), with localized chronic periodontitis (LCP group, n: 19) and with gingivitis or healthy (control group, n: 15) subjects were treated and followed up for 6 months. Clinical periodontal parameters include plaque index, gingival index, bleeding on probing, probing depth and attachment level; psychosocial measurements include Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI 1-2) psychometric instruments; hormone levels in GCF including COR and DHEA were evaluated.

RESULTS

All clinical parameters were significantly decreased (except attachment loss) after PT (p < 0.05). No significant differences were observed between the two groups for STAI-1-2 and BDI scores, either at baseline or at 6 months (p > 0.05). COR levels were statistically lower following PT in GCP and LCP groups when compared to the baseline levels (p < 0.05). DHEA values at baseline and 6 months did not show significant differences.

CONCLUSION

Within the limits of the study, decreased GCF COR and unchanged GCF DHEA levels were determined in nonsurgically treated patients regardless of the extent and severity of periodontitis.

The dynamics of smoking-related disturbed methylation: a two time-point study of methylation change in smokers, non-smokers and former smokers

Background

The evidence for epigenome-wide associations between smoking and DNA methylation continues to grow through cross-sectional studies. However, few large-scale investigations have explored the associations using observations for individuals at multiple time-points. Here, through the use of the Illumina 450K BeadChip and data collected at two time-points separated by approximately 7 years, we investigate changes in methylation over time associated with quitting smoking or remaining a former smoker, and those associated with continued smoking.

Results

Our results indicate that after quitting smoking the most rapid reversion of altered methylation occurs within the first two decades, with reversion rates related to the initial differences in methylation. For 52 CpG sites, the change in methylation from baseline to follow-up is significantly different for former smokers relative to the change for never smokers (lowest p-value 3.61 x 10^-39 for cg26703534, gene AHRR). Most of these sites’ respective regions have been previously implicated in smoking-associated diseases. Despite the early rapid change, dynamism of methylation appears greater in former smokers vs never smokers even four decades after cessation. Furthermore, our study reveals the heterogeneous effect of continued smoking: the methylation levels of some loci further diverge between smokers and non-smokers, while others re-approach. Though intensity of smoking habit appears more significant than duration, results remain inconclusive.

Conclusions

This study improves the understanding of the dynamic link between cigarette smoking and methylation, revealing the continued fluctuation of methylation levels decades after smoking cessation and demonstrating that continuing smoking can have an array of effects. The results can facilitate insights into the molecular mechanisms behind smoking-induced disturbed methylation, improving the possibility for development of biomarkers of past smoking behavior and increasing the understanding of the molecular path from exposure to disease.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4198-0) contains supplementary material, which is available to authorized users.

Comparative systems toxicology analysis of cigarette smoke and aerosol from a candidate modified risk tobacco product in organotypic human gingival epithelial cultures: A 3-day repeated exposure study

Smoking is one of the major lifestyle-related risk factors for periodontal diseases. Modified risk tobacco products (MRTP) offer a promising alternative in the harm reduction strategy for adult smokers unable to quit. Using a systems toxicology approach, we investigated and compared the exposure effects of a reference cigarette (3R4F) and a heat-not-burn technology-based candidate MRTP, the Tobacco Heating System (THS) 2.2. Human gingival epithelial organotypic cultures were repeatedly exposed (3 days) for 28 min at two matching concentrations of cigarette smoke (CS) or THS2.2 aerosol. Results showed only minor histopathological alterations and minimal cytotoxicity upon THS2.2 aerosol exposure compared to CS (1% for THS2.2 aerosol vs. 30% for CS, at the high concentration). Among the 14 proinflammatory mediators analyzed, only 5 exhibited significant alterations with THS2.2 exposure compared with 11 upon CS exposure. Transcriptomic and metabolomic analysis indicated a general reduction of the impact in THS2.2 aerosol-exposed samples with respect to CS (∼79% lower biological impact for the high THS2.2 aerosol concentration compared to CS, and 13 metabolites significantly perturbed for THS2.2 vs. 181 for CS). This study indicates that exposure to THS2.2 aerosol had a lower impact on the pathophysiology of human gingival organotypic cultures than CS.

Relationship between salivary stress biomarker levels and cigarette smoking in healthy young adults: an exploratory analysis

Background

This study investigated the relationships among salivary stress biomarkers, cigarette smoking, and mood states.

Methods

The study population comprised 49 healthy sixth-year dental students at Fukuoka Dental College (39 men, 10 women; age, 23–31 years). Lifetime exposure to smoking was calculated using the Brinkman index (BI). Resting saliva samples were collected, and concentrations of cortisol, secretory immunoglobulin A (SIgA), interleukin (IL)-1β, interleukin-6, and tumor necrosis factor (TNF)-α were determined. Mood states (tension-anxiety, depression-dejection, anger-hostility, fatigue, confusion, and vigor) over the previous week were assessed using the Profile of Mood States - Brief Japanese Version.

Results

Salivary IL-1β levels were significantly higher in smokers than non-smokers (P = 0.044), regardless of the BI or mood state. A significant positive correlation was evident between the TNF-α level and the BI (P = 0.036), and the SIgA level was positively correlated with the BI (P = 0.067) but did not reach statistical significance. In terms of mood states, higher fatigue scores and lower vigor scores were observed in smokers. The TNF-α level and vigor score were negatively correlated (r = –0.229, P = 0.135), but the correlation did not reach statistical significance. However, the SIgA level and fatigue score were significantly positively correlated (r = 0.410, P = 0.005).

Conclusions

The TNF-α and SIgA levels were both positively correlated with the BI. Furthermore, the TNF-α level was negatively correlated with the vigor score, whereas the SIgA level was positively correlated with the fatigue score. Thus, salivary levels of TNF-α and SIgA may be used as biomarkers of mood states in healthy young smokers.

Influence of interventional nonsurgical periodontal treatment on levels of salivary and serum nitric oxide in smokers and nonsmokers with chronic periodontitis

Background and Objective

Nitric oxide (NO) is a widespread signaling molecule which is known to influence varied biological processes. However, an uncontrolled high level of NO accelerates tissue destruction. The pathogenesis of periodontal disease is also affected by smoking which alters the inflammatory response. The present study was thus performed to assess the effect of nonsurgical periodontal treatment on salivary and serum NO levels in smokers and nonsmokers with chronic periodontitis.

Materials and Methods

Forty patients with chronic periodontitis, including 20 nonsmokers and equal number of smokers participated in the present study. Probing depth, clinical attachment level, plaque index, gingival index were assessed, serum and saliva samples were obtained from the patients at baseline and after Phase I therapy at 6 weeks to estimate NO by Griess colorimetric reaction.

Results

Smokers showed higher serum and saliva NO levels 30.3 ± 3.28 and 50.4 ± 4.07 μM as compared to nonsmokers 20.05 ± 2.42 μM and 37.5 ± 2.95 μM, respectively, at baseline. After Phase I therapy, both the groups exhibited significant improvement in clinical parameters and reduction in serum and saliva NO levels; however, reduction was higher in nonsmokers.

Conclusion

More destructive expression of periodontal disease in smokers causes an increase in the concentrations of NO and less reduction after Phase I therapy as compared to nonsmokers with chronic periodontitis. Hence, NO levels in saliva and serum could be used as indicators of periodontal inflammatory condition.

Periodontal Inflammatory Conditions Among Smokers and Never-Smokers With and Without Type 2 Diabetes Mellitus

BACKGROUND

There is a dearth of studies regarding the influence of cigarette smoking on periodontal inflammatory conditions among patients with type 2 diabetes mellitus (T2DM). The aim of the present study is to assess periodontal inflammatory conditions among smokers and never-smokers with and without T2DM.

METHODS

One hundred individuals (50 patients with T2DM [25 smokers and 25 never-smokers] and 50 controls [25 smokers and 25 never-smokers]) were included. Information regarding age, sex, duration and daily frequency of smoking, duration and treatment of diabetes, and oral hygiene was recorded using a questionnaire. Periodontal parameters (plaque index [PI], bleeding on probing [BOP], probing depth [PD], clinical attachment loss [AL], and marginal bone loss [MBL]) were measured. Hemoglobin A1c (HbA1c) levels were also recorded.

RESULTS

Mean age, monthly income status, and education levels were comparable among smokers and never-smokers with and without T2DM. Mean HbA1c levels were significantly higher among patients with T2DM (8.2% ± 0.1%) compared with controls (4.4% ± 0.3%) (P <0.05). Smokers in the control group were smoking significantly greater numbers of cigarettes (15.5 ± 2.5 cigarettes daily) compared with smokers with T2DM (6.2 ± 2.1 cigarettes daily) (P <0.05). Periodontal parameters were comparable among smokers and never-smokers with T2DM. Among controls, periodontal parameters (PI [P <0.05], AL [P <0.05], PD ≥4 mm [P <0.05], and MBL [P <0.05]) were significantly higher in smokers than never-smokers. Never-smokers with T2DM had worse periodontal status than smokers and never-smokers in the control group (P <0.05).

CONCLUSIONS

Periodontal inflammatory conditions are comparable among smokers and never-smokers with T2DM. Among controls, periodontal inflammation is worse among smokers than never-smokers.

Resistance to cigarette smoke is increased in periodontal ligament cells by attachment to collagen and fibronectin

BACKGROUND

The toxic effects of cigarette smoke often presents in smokers as increased incidence and severity of periodontal disease. These patients demonstrate symptomatic inflammation, increased probing depth, and tooth loss likely attributable to the direct effects of cigarette smoke on periodontal ligament (PDL) fibroblasts. The goal of this in vitro study is to investigate the direct effects of smoking on PDL fibroblasts, focusing on cell-extracellular matrix (ECM) interactions and cell survival.

METHODS

PDL cells were plated for various times on tissue culture plastic, PDL-derived ECMs, collagen Type I, or fibronectin. Cells were exposed to various concentrations of cigarette smoke extract (CSE) at different times during the cell attachment process. Subsequently, cell survival was quantified using calcein-acetoxymethyl ester compound and a fluorescent plate reader.

RESULTS

After exposure to CSE, PDL cell survival increased with increased cell attachment time to plastic. These observations were independent of soluble factors present in PDL cell-conditioned media. PDL-derived ECMs and collagen Type I-pretreated plates promoted increased cell survival after 1 day of cell attachment. Fibronectin-pretreated plates demonstrated increased cell survival after 3 days of cell attachment.

CONCLUSIONS

Cell-ECM interactions increase survival of PDL cells exposed to CSE. It is suggested that the increased survival is attributable to PDL cells altering their ECM, potentially by depositing collagen and fibronectin. This may imply that cells embedded in an ECM would be more resistant to the toxic effects of cigarette smoke, leading to increased cell death near the exposed edges of a wound.

Polymorphisms in Glutathione S-Transferase M1, T1, and P1 in Patients with Chronic Periodontitis: A Pilot Study

Background. Although the direct cause of chronic periodontitis is bacterial infection, the progression of this disease depends on genetic and environmental factors, and smoking is a known risk factor in the development and severity of the disease. An individual's susceptibility may be influenced by polymorphisms in the glutathione S-transferase genes. These genes encode enzymes that metabolize xenobiotic compounds. The aim of this study was to determine the frequency of GSTM1, GSTT1, and GSTP1 polymorphisms in Mexicans with chronic periodontitis. Methods. 60 Mexicans with chronic periodontitis (30 smokers and 30 nonsmokers) were studied. A peripheral blood sample was taken for subsequent DNA extraction. The genetic material was PCR-amplified followed by restriction fragment length polymorphism with the aim of identifying GST polymorphisms. Results. Polymorphisms in the GSTT1 and GSTP1 genes were not significantly different between the smokers and nonsmokers. However, there were significant differences (P = 0.05) between groups in polymorphisms in the GSTM1 gene. The patients with chronic periodontitis have a higher frequency of null and mutant polymorphisms in GSTM1, GSTT1, and GSTP1 compared with historical data from a healthy Mexican population. Conclusions. The presence of these polymorphisms may be a risk factor for the development of chronic periodontitis.

[Association between periodontal pockets and health-related behaviors of workers]

OBJECTIVE

Periodontal disease is a chronic disease caused by bacterial infection, and frequently develops in adulthood. As the disease is closely related to lifestyle, it is important to clarify its relationship with health-related behaviors to provide effective health instructions targeting its prevention. In this study, we focused on periodontal pockets with advanced periodontal disease to clarify the health-related behaviors associated with the presence or absence of periodontal pockets.

METHODS

The subjects were 3,142 employees (male: N=2,429, female: N=713; 42.4 ± 10.5 years, Range 20-59 years) of one company, which had provided all employees with an oral health program in 2002. Participants with a Community Periodontal Index code of ≤2 and ≥3 were classified as those without and with periodontal pockets, respectively. To clarify the health-related behaviors associated with the presence or absence of periodontal pockets, we conducted multivariate logistic regression analysis, with presence/absence of periodontal pockets as the dependent variable, and items of health-related behavior investigated in 2002 as independent variables, and calculated the odds ratios (OR) and 95% confidence intervals (95%CI) adjusted for sex, age group and occupation.

RESULTS

The factor most strongly correlated with the presence of periodontal pockets was non-use of dental floss (OR=1.95 (95%CI: 1.57-2.41)), followed by smoking (OR=1.71 (95%CI: 1.44-2.03)), and tooth-brushing habits (≤once a day: OR=1.33 (95%CI: 1.10-1.61)).

CONCLUSIONS

Our results suggest that, to promote oral health program at the worksite, it is important to provide health education and instructions to encourage the use of dental floss, a daily tooth-brushing habit, and smoking cessation.

Determination of levels of nitric oxide in smoker and nonsmoker patients with chronic periodontitis

Purpose

Cigarette smoking is a major risk factor in periodontal diseases. The pathogenesis of periodontal diseases may be affected by alterations of the inflammatory response by smoke. Nitric oxide (NO) is a gaseous, colorless, highly reactive, short-lived free radical with a pivotal role in the regulation of various physiological and pathological mechanisms in the body. It is important in host defense and homeostasis, on the one hand, whereas, on the other hand, it modulates the inflammatory response in periodontitis, leading to harmful effects. The aim of this study was to assess the levels of NO in both the serum and saliva of smokers and nonsmokers having chronic periodontitis and to compare them with periodontally healthy controls.

Methods

Sixty subjects participated in the study and were divided into three groups: group I, healthy nonsmoking subjects; group II, nonsmoking patients with chronic periodontitis; group III, smoking patients with chronic periodontitis. Each group consisted of twenty subjects. The biochemical estimation of NO in the collected serum and in the saliva was performed using the Griess colorimetric reaction.

Results

The results showed that the mean value of the salivary and serum NO was greater in group II than in group I, and also greater in group III than in group II.

Conclusions

NO appears to play an important and rather complex role in the immuno-inflammatory process and in the remodeling and maintenance of osseous structures. It is therefore logical that modulation of this mediator has potential for the treatment of a number of inflammatory conditions including periodontal disease.

Menthol-enhanced cytotoxicity of cigarette smoke demonstrated in two bioassay models

Background

Cigarette smoke is harmful to human health at both cellular and genetic levels. Recently, a unique bioassay for smoke cytotoxicity using air pollution-sensitive plant cells (tobacco) has been proposed.

Methods

Model plant cells (tobacco Bel-W3 cells) and human cells (alveolar epithelial A549 cells) suspended in fresh culture media were exposed to cigarette smoke sampled after lighting the tip of cigarettes (with vs. without menthol capsules) which were attached to a glass pipe connected to the cell-containing plastic tubes. Control cultures were also assessed.

Results

After exposing tobacco plant cells to cigarette smoke, cell death occurred in a dose-dependent manner. Cell death was significantly enhanced by mentholated smoke, while menthol alone was shown to be inert suggesting that menthol synergistically contributes to the enhancement of cell death, initiated by smoke-associated compounds. The enhanced toxicity of mentholated smoke was confirmed in human alveolar epithelial A549 cells.

Conclusions

Cigarette smoke cytotoxicity leading to cell death assessed in plant and human model cells was enhanced by menthol. Further research into these findings is encouraged.

Comparison of relative TLR-2 and TLR-4 expression level of disease and healthy gingival tissue of smoking and non-smoking patients and periodontally healthy control patients

BACKGROUND

Toll-like receptors are a family of sensor proteins that induce the inflammatory diseases in context of microbial infection. The role of these proteins in periodontal disease and their interaction with smoking status are yet to be investigated. The aim of the present study was to evaluate the effect of smoking on gene expression of toll like receptor 2 (TLR-2) and toll-like receptor 4 (TLR-4) in patients with periodontitis.

METHODS

RNAs were extracted from gingival biopsies of healthy sites (no bleeding on probing and pocket depth ≤3 mm) as well as diseased sites (with bleeding on probing and pocket depth ≥5 mm) of 20 smoker and 17 non-smoker subjects with chronic periodontitis. Gingival biopsies from eight periodontally healthy, never-smoker subjects served as control. Real-time PCR was carried out to evaluate the relative quantities of TLR-2 and TLR-4 mRNA concentrations.

RESULTS

Regardless of smoking status, the relative expression levels of TLR-2 and TLR-4 were significantly greater (about 3 fold) at diseased sites compared to healthy sites of patients with periodontitis and healthy controls (p < 0.05). In sites with periodontitis, smoking caused an increase of about 6.5 fold in mRNA levels of TLR-4 in gingival tissue (p < 0.05).

CONCLUSIONS

Although periodontitis might significantly increase TLR-2 and TLR-4 gene expression in gingival tissues, smoking habit in periodontitis subjects could selectively potentiate TLR-4 gene expression.

Cognitive function and number of teeth in a community-dwelling population in Japan

BACKGROUND

It has been reported that oral health is poor in elderly populations and is associated with poor cognition and dementia. The objective of this study was to examine the association between tooth loss and cognitive function in a community-dwelling population in Japan.

METHODS

We examined the association between tooth loss and cognitive function in 462 Japanese community-dwelling individuals. The Mini-Mental State Examination (MMSE) was employed to measure global cognitive status. A multiple logistic regression analysis, with both crude and adjusted conditions for confounding factors, was used to assess the relationship between poor cognition and the number of remaining teeth.

RESULTS

The overall prevalence of poor cognition (MMSE ≤ 23) in this study population was 5.6%. Subjects with poor cognition were significantly older, less educated, scored lower in intellectual activity, and had fewer remaining teeth than those with normal cognition. According to the multiple logistic regression analysis, a lower number of teeth (0-10) was found to be a significant independent risk factor (OR = 20.21, 95% confidence interval = 2.20 to 185.47) of cognitive impairment.

CONCLUSIONS

This cross-sectional study on a Japanese community-dwelling population revealed relationships between tooth loss and cognitive function. However, the interpretation of our results was hampered by a lack of data, including socioeconomic status and longitudinal observations. Future research exploring tooth loss and cognitive function is warranted.

The role of tobacco use on dental care and oral disease severity within community dental clinics in Japan

Background

To examine facilitators of dental smoking intervention practices in Japan, where smokeless tobacco is rarely used, we evaluated the characteristics of dental care for smokers.

Methods

Community dentists volunteered to record the treated disease or encounter with patients that was principally responsible for their dental care on the survey day. Patients were classified into groups receiving gingival/periodontal treatment (GPT), caries/endodontic treatment (CET), prosthetic treatment (PRT), periodical check-up/orthodontic treatment (POT), or other encounters/treatments. Potential effect of dentist clustering was adjusted by incorporating the complex survey design into the analysis.

Results

Data of 2835 current smokers (CS) and 6850 non-smokers (NS) from 753 clinics were analysed. Distribution of treatments significantly differed between CS and NS (P = 0.001). In ad hoc multiple comparisons for each treatment, CS were significantly higher than NS for CET (47.1% vs. 43.6%, P = 0.002), and lower for POT (1.6% vs. 2.7%, P = 0.001), whereas GPT and PRT proportions were equivalent by smoking. When stage of disease progression was compared in the GPT subpopulation, CS were more likely received treatment for advanced stage disease than NS in the age groups of 40–59 years (24.9% vs. 15.3%, P = 0.001) and more than 60 years (40.8% vs. 22.1%, P < 0.001). However, the difference was less apparent in the entire population (9.7% vs. 6.0%), and CS were not predominant among patients receiving GPT for advanced stage disease (37.6%).

Conclusions

The association of smoking with type of dental care of CET and GPT severity would warrant the need for dental professionals to engage their patients smoking within clinical practice. The detrimental effects of smoking in dental care for smokers, as evidenced by the distribution of treatment and encounter and stage of treated disease, may not be clearly realized by dental professionals, unless the smoking status of all patients is identified.

Is there a positive effect of smoking cessation on periodontal health? A systematic review

BACKGROUND

Although the detrimental effects of tobacco on the periodontal tissues have been reported extensively, little is known about the potential beneficial effect of smoking cessation on periodontal health. The aim of this systematic review is to evaluate the effect of smoking cessation on periodontitis progression and response to periodontal therapy.

METHODS

Two independent reviewers completed the review process through title (n = 118), abstract (n = 24), and whole-paper selection (n = 5). Sources include Medline and EMBASE databases (up to December 2012) and a reference list of selected studies. Prospective studies comparing progression rates of periodontitis between smokers and quitters and clinical trials evaluating the effect of smoking-cessation programs, alone or in combination with periodontal treatment, were included. At least 1 year of follow-up was required for inclusion.

RESULTS

Of 331 potentially relevant publications, five studies fulfilled the inclusion criteria. Because of heterogeneity of the studies, a meta-analysis could not be performed. One study reported that the progression of clinical attachment loss (AL) ≥3 mm during a 6-year period was approximately three times higher among smokers than quitters (P <0.001). Two studies (10 and 20 years of follow-up) observed a decrease in radiographic bone loss of ≈30% among quitters when compared with smokers. Among individuals receiving non-surgical periodontal treatment, quitters were more likely to have periodontal probing depth reductions (P <0.05) than non-quitters/oscillators. No differences in AL were observed.

CONCLUSION

Based on the limited available evidence, smoking cessation seems to have a positive influence on periodontitis occurrence and periodontal healing.

Periodontal disease in habitual cigarette smokers and nonsmokers with and without prediabetes

INTRODUCTION

: Prediabetes and habitual cigarette smoking are significant risk factors contributing to periodontal disease. The aim was to assess the clinical and radiological markers of periodontal disease in habitual cigarette smokers and nonsmokers with and without prediabetes.

METHODS

Sixty-eight individuals with prediabetes (test group; 34 smokers and 34 nonsmokers) and 68 medically healthy individuals (control group; 34 smokers and 34 nonsmokers) were included. Sociodemographic information, duration of smoking habit and number of cigarettes smoked daily were recorded through a questionnaire. Fasting blood glucose levels and periodontal inflammatory conditions (plaque index [PI], bleeding on probing [BOP] and probing pocket depth [PPD] of 4 to <6 mm and ≥6 mm) were recorded. In both groups, marginal bone loss (MBL) was measured on digital panoramic radiographs.

RESULTS

Cigarette smokers and nonsmokers in the test group had significantly higher fasting blood glucose level when compared with cigarette smokers in the control group (P < 0.001). In the test group, there was no significant difference in PI, BOP, PPD (4 to <6 mm and ≥6 mm) and MBL among cigarette smokers and nonsmokers. Cigarette smokers in the control group had significantly higher PI (P < 0.001), PPD (4 to <6 mm; P < 0.001), PPD ≥6 mm (P < 0.01) and MBL (P < 0.05) than nonsmokers. BOP was significantly reduced in smokers when compared with nonsmokers in the control group (P < 0.001).

CONCLUSIONS

Cigarette smokers without prediabetes exhibit significantly severe periodontal disease than nonsmokers. In subjects with prediabetes, the severity of periodontal disease seems to be over shadowed by the hyperglycemic state, obscuring the effect of habitual smoking.

Active and passive smoking and prevalence of periodontal disease in young Japanese women

BACKGROUND AND OBJECTIVE

Studies reporting on the association between smoking and periodontal disease have mostly focused on active smoking. The purpose of this study was to examine the relationships between active smoking and exposure to second-hand smoke at home and at work and the prevalence of periodontal disease among young Japanese women.

MATERIAL AND METHODS

Study subjects were 1167 postpartum women with a mean age of 31.5 years. Information on smoking and potential confounding factors was obtained through a self-administered questionnaire. Partial-mouth recording was used to determine probing pocket depth at six sites per tooth for six teeth in the mouth. Periodontal disease was defined as positive if a woman had at least one tooth with a probing pocket depth of 3.5 mm or deeper. Adjustment was made for age, region of residence, household income, education, toothbrushing frequency and use of an interdental brush.

RESULTS

Compared with never smoking, ever smoking was independently positively associated with the prevalence of periodontal disease: the adjusted odds ratio was 1.56 (95% confidence interval: 1.02-2.36). There was a marginally significant positive dose-response relationship between pack-years of smoking and the prevalence of periodontal disease (p for linear trend = 0.08). No material associations were observed between second-hand smoke exposure at home or at work and periodontal disease.

CONCLUSION

Our findings suggest that active smoking, but not passive smoking, might be associated with an increased prevalence of periodontal disease among young women in Japan.

Assessment of some biochemical oxidative stress markers in male smokers with chronic periodontitis

The present study aims to assess and compare the biochemical oxidative stress markers in male smokers and non-smokers with chronic periodontitis. One hundred thirty-four male chronic periodontitis patients and 64 apparently healthy male volunteers were recruited for the study. The periodontal status was evaluated by measuring gingival index, plaque index, papillary bleeding index and clinical attachment loss using UNC-15 probe. The biochemical markers estimated were total antioxidant capacity, RBC-superoxide dismutase, glutathione peroxidase, vitamin C, malondialdehyde and C-reactive protein. The obtained results indicate higher oxidative stress in chronic periodontitis. Smokers with chronic periodontitis show significantly higher periodontal clinical parameters and relatively higher systemic oxidative stress. Vitamin C estimation may be an important biochemical parameter in conjunction with clinical parameters for diagnosis of chronic periodontitis in smokers.

Clinical profile of orofacial infections: an experience from two primary care dental practices

Objectives: Orofacial infections are common reasons for dental consultations worldwide. However, there is scarcity of data on clinico-epidemiological profiles reported from primary care dental practices. To address this issue, a study was done to characterize the clinical pattern, age groups affected and sex predilection of orofacial infections in the primary care dental practice. Study design: Clinical data was evaluated from random electronic files of patients for whom antimicrobials were prescribed at two Dental Practices in UK between January 2009 and December 2010. Results: 200 case records were studied. 104 (52%) cases were females. Mean age was 37.2 (+/-15.1) years. 107 (53.5%) cases belonged to age group 21-40 years. Posterior teeth were involved in 112 (56%) cases. Types of disease were as follows: dentoalveolar abscess 63(31.5%), pulpitis 27(13.5%), apical periodontitis 21(10.5%), pericoronitis 21(10.5%), dry socket 13(6.5%), periodontitis 9(4.5%) infected root stump 5(2.5%), facial swelling 5(2.5%) and infections unspecified 36(18%) cases. Conclusions: Orofacial infections affect both sexes equally. 21-40 years is the commonest age-group affected. Dentoalveolar abscess is the commonest infection followed by unspecified infections and pulpitis.

Key words:Orofacial infections, primary care dental practice, dentoalveolar abscess and pulpitis.

Salivary immunoglobulin classes in Nigerians with periodontitis

AIM

To provide information on the usefulness of salivary immunoglobulin classes in the diagnosis of periodontitis.

MATERIALS AND METHODS

About 5 ml of unstimulated saliva was collected from 25 newly diagnosed subjects with periodontitis and 21 sex/age-matched apparently healthy individuals into plain sample bottles. The samples were collected between 9 am and 11 am at least, 1 hour after eating or washing of mouth and levels of salivary immunoglobulin classes (IgA, IgG, IgE and IgM) were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Only the mean level of IgA was significantly raised (p = 0.05) in the saliva of periodontitis patients compared with controls. The mean levels of IgG, IgM and IgE were not significantly elevated in patients with periodontitis, when compared with controls (p > 0.05).

CONCLUSION

This study showed that elevated salivary levels of IgA could be used as a screening tool for periodontitis.

CLINICAL SIGNIFICANCE

Identification of patients at risk and the diagnosis of active phases of periodontal disease remains a challenge due to lack of laboratory test routinely employed in the diagnosis and monitoring of patients with periodontal disease. This study showed that elevated salivary levels of immunoglobulin classes especially, IgA could be used as a screening tool for periodontitis.

Anabolic Actions of the Regenerative Agent Enamel Matrix Derivative (EMD) in Oral Periosteal Fibroblasts and MG 63 Osteoblasts, Modulation by Nicotine and Glutathione in a Redox Environment

Our study seeks to explore anabolic effects of a periodontal regenerative agent enamel matrix derivative (EMD). Its modulation by nicotine and the anti-oxidant glutathione (GSH) are investigated in human periosteal fibroblasts (HPF) and MG63 osteoblasts. Androgen biomarkers of oxidative stress and healing, resulting from radiolabeled androgen substrates are assayed. This in vitro model simulates a redox environment relevant to the periodontal lesion. It aims to confirm the hypothesis that EMD is an effective regenerative agent in a typically redox environment of the periodontal lesion. Monolayer cultures of MG63 osteoblasts and HPF established in culture medium are incubated with androgen substrates, and optimal concentrations of EMD, nicotine and GSH, alone and in combination. EMD significantly enhances yields of 5α-dihydrotestosterone (DHT) an effective bioactive metabolite, alone and in combination with GSH, to overcome oxidative effects of nicotine across cultures. The ‘in vitro’ findings of this study could be extrapolated to “in vivo” applications of EMD as an adjunctive regenerative therapeutic agent in an environment of chronic inflammation and oxidative stress. Increased yields of DHT implicated in matrix synthesis and direct antioxidant capacity, confirm the potential applications for enamel matrix derivative in periodontal regenerative procedures.

Lethal impacts of cigarette smoke in cultured tobacco cells

Background

In order to understand and generalize the toxic mechanism of cigarette smoke in living cells, comparison of the data between animal systems and other biological system such as microbial and plant systems is highly beneficial.

Objective

By employing the tobacco cells as model materials for cigarette smoke toxicity assay, the impacts of the combustion by-products such as nitrogen oxides could be highlighted as the toxic impacts of the plant-derived endogenous chemicals could be excluded in the plant cells.

Methods

Cigarette smoke-induced cell death was assessed in tobacco cell suspension cultures in the presence and absence of pharmacological inhibitors.

Results

Cigarette smoke was effective in induction of cell death. The smoke-induced cell death could be partially prevented by addition of nitric oxide (NO) scavenger, suggesting the role for NO as the cell death mediator. Addition of NO donor to tobacco cells also resulted in development of partial cell death further confirming the role of NO as cell death mediator. Members of reactive oxygen species and calcium ion were shown to be protecting the cells from the toxic action of smoke-derived NO.

The effect of smoking on the mRNA expression of MMPs and TIMP-1 in untreated chronic periodontitis patients: a cross-sectional study

BACKGROUND AND OBJECTIVE

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important for extracellular matrix. Expression of MMPs has been evaluated in gingiva without studying smoking. The aim of this study was to explore the effect of smoking on mRNA expression of MMP-1, -3, -8, -9 and -13 and TIMP-1 in untreated chronic periodontitis and in periodontal health.

MATERIAL AND METHODS

Gingival samples were harvested from 30 subjects with untreated chronic periodontitis (15 nonsmokers and 15 smokers) and 30 periodontally healthy subjects (15 nonsmokers and 15 smokers). Full-mouth plaque score, gingival index, bleeding on probing, probing depth and clinical attachment level were recorded. Total RNA was isolated, and the mRNA expression of MMPs and TIMP-1 was assessed by RT-PCR.

RESULTS

Periodontitis groups were comparable in clinical measurements. Nonsmoker subjects with periodontitis had statistically significantly higher MMP-1, lower MMP-9 and TIMP-1 expression and higher MMP-1/TIMP-1 ratio than smokers; and higher MMP-8 expression and MMP-8/TIMP-1 and MMP-1/TIMP-1 ratios than healthy nonsmokers. Healthy nonsmokers had statistically significantly higher MMP-13 expression than healthy smokers. Smoker periodontitis and healthy subjects had similar expression levels of MMPs and TIMP-1 and MMPs/TIMP-1 ratios. There was correlation among the MMPs only for smoker periodontitis subjects. Expression of MMP-13 was correlated with mean clinical attachment level.

CONCLUSION

Within its limits, this study demonstrated that smoking affected mRNA expression of MMPs and TIMP-1, MMPs/TIMP-1 ratios and relationships among MMPs in untreated chronic periodontitis and expression of MMPs in health. In the absence of smoking, chronic periodontitis affected expression of MMPs and MMPs/TIMP-1 ratios.

Causal assessment of smoking and tooth loss: a systematic review of observational studies

BACKGROUND

Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies.

METHODS

Relevant literature was searched and screened, and the methodological quality was assessed. Information on the strength of the association between smoking and tooth loss, the dose-response relationship and natural experimental data was collected and evaluated with respect to consistency and study design.

RESULTS

Our literature search yielded 496 citations, and 6 cross-sectional and 2 cohort high-quality studies examining 58,755 subjects in four countries. All studies reported significant associations, although the strength of the association was usually moderate. Four studies reported dose-response relationships between exposure to smoking and the risk of developing tooth loss. A decrease in the risk of tooth loss for former smokers was evident in six studies. Interpretation of evidence for each element was consistent, despite some shortcomings regarding study type and population.

CONCLUSIONS

Based on the consistent evidence found with the existing biological plausibility, a causal association between smoking and tooth loss is highly likely. Further studies using a cohort design and different populations are necessary to confirm this association.