Relationship of smoking and smoking cessation with oral health status in Japanese men

Impact of Smoking Cessation on Periodontal Tissues

There is cumulative evidence supporting the negative effects of smoking on periodontal tissues. Smoking cessation can be successfully accomplished through specific programs, including behaviour modification and medications, and has been suggested as a suitable way to reduce the risk of several diseases, including periodontitis. The aim of this review is to provide a concise overview of the current knowledge about the impact of smoking cessation on periodontal tissues and therapy, with data from studies published in the last 15 years. Literature was searched using Medline database from 2005 up to and including September 2020 using medical subject heading (MeSH) terms and other search terms, restricted to the English language. Studies were evaluated and summarised in a narrative review format. Results demonstrated that there is convincing evidence to support the benefits of tobacco cessation in reducing the risk of periodontitis and tooth loss. In addition, the harmful effects of smoking on periodontal tissues seem to be assuaged as the number of years since quitting increases. The existing current evidence, even limited, also shows that smoking cessation may result in additional benefits to the outcome of nonsurgical periodontal treatment. Periodontal care providers should not only check their patient's smoking habit for estimating risk of disease progression and predictability of periodontal therapy, but they should also help smokers improve their oral and systemic health by providing efficient and personalised tobacco‐cessation counselling and treatment.

Effect of Switching to the Tobacco Heating System Versus Continued Cigarette Smoking on Chronic Generalized Periodontitis Treatment Outcome: Protocol for a Randomized Controlled Multicenter Study

BACKGROUND

Smoking is a significant risk factor for periodontal disease and tooth loss, as shown in several clinical studies comparing smokers and nonsmokers. Although only a few longitudinal studies have assessed the outcome of periodontal disease after smoking cessation, they indicated that recovery after nonsurgical treatment was more successful in those who had quit smoking. As part of tobacco harm reduction strategies, substituting cigarettes with alternative, less harmful tobacco products is an approach complementary to cessation for smokers who would otherwise continue to smoke. The Tobacco Heating System (THS), developed by Philip Morris International (commercialized as IQOS), is part of the heat-not-burn product category. The IQOS device electrically heats tobacco instead of burning it, at much lower temperatures than cigarettes, thereby producing substantially lower levels of harmful and potentially harmful constituents, while providing the nicotine, taste, ritual, and a sensory experience that closely parallel those of cigarettes. Phillip Morris International has published the results from a broad clinical assessment program, which was established to scientifically substantiate the harm reduction potential of the THS among adult healthy smokers switching to the THS. The program is now progressing toward including adult smokers with smoking-related diseases.

OBJECTIVE

The goal of this study is to demonstrate favorable changes of periodontal endpoints in response to mechanical periodontal therapy in patients with generalized chronic periodontitis who completely switched to THS use compared with continued cigarette smoking.

METHODS

This is a randomized controlled two-arm parallel-group multicenter Japanese study conducted in patients with chronic generalized periodontitis who switch from cigarettes to THS compared with smokers continuing to smoke cigarettes for 6 months. The patients were treated with mechanical periodontal therapy as per standard of care in Japan. The primary objective of the study is to demonstrate the beneficial effect of switching to THS use compared with continued cigarette smoking on pocket depth (PD) reduction in all sites with an initial PD≥4 mm. The secondary objectives include evaluation of other periodontal parameters (eg, clinical attachment level or gingival inflammation) and overall oral health status upon switching to THS. Safety was monitored throughout the study.

RESULTS

In total, 172 subjects were randomized to the cigarette (n=86) or THS (n=86) groups, and all 172 completed the study. The conduct phase of the study is completed, while data cleaning and analyses are ongoing.

CONCLUSIONS

This study is the first to test a heat-not-burn tobacco product in smokers with an already established disease. The results should further strengthen the evidence that switching to THS can significantly reduce the risk of smoking-related diseases if favorable changes in the evolution of chronic generalized periodontitis after mechanical therapy are found when compared with continued cigarette smoking.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03364751; https://clinicaltrials.gov/ct2/show/NCT03364751.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/15350.

NETs Are Double-Edged Swords with the Potential to Aggravate or Resolve Periodontal Inflammation

Periodontitis is a general term for diseases characterised by inflammatory destruction of tooth-supporting tissues, gradual destruction of the marginal periodontal ligament and resorption of alveolar bone. Early-onset periodontitis is due to disturbed neutrophil extracellular trap (NET) formation and clearance. Indeed, mutations that inactivate the cysteine proteases cathepsin C result in the massive periodontal damage seen in patients with deficient NET formation. In contrast, exaggerated NET formation due to polymorphonuclear neutrophil (PMN) hyper-responsiveness drives the pathology of late-onset periodontitis by damaging and ulcerating the gingival epithelium and retarding epithelial healing. Despite the gingival regeneration, periodontitis progression ends with almost complete loss of the periodontal ligament and subsequent tooth loss. Thus, NETs help to maintain periodontal health, and their dysregulation, either insufficiency or surplus, causes heavy periodontal pathology and edentulism.

Effect of smoking on patient-reported postoperative complications following minor oral surgical procedures

Objective

This study evaluated the effect of smoking on patient-reported postoperative complications after minor oral surgical procedures by comparing the post-extraction symptoms between smokers and nonsmokers.

Materials and methods

Patients undergoing minor oral surgical procedures were recruited and followed up prospectively on the first, second, seventh, and twenty-first days after simple dental extractions.

Results

A total of 85 patients completed the study. Postoperative pain, measured with a visual analog scale, was consistently higher among smokers than nonsmokers (P < 0.0001). Patient-reported experience of bleeding events was significantly less among nonsmokers (P = 0.009) only on the first postoperative day. Facial swelling was more common in smokers than in nonsmokers (P = 0.04) on the second postoperative day. Postoperative infection was reported more by smokers than nonsmokers (P > 0.05). Trismus did not vary with time according to smoking status. On the 21st postoperative day, there were no statistically significant differences in postoperative complications between the groups.

Conclusions

The patient-reported pain score was consistently higher among smokers. The study’s findings suggested that initial differences in patient-reported complications between smokers and nonsmokers undergoing minor oral surgical procedures diminished after a week.

Effect of smoking cessation on tooth loss: a systematic review with meta-analysis

BACKGROUND

Smoking is a major risk factor for periodontitis and tooth loss. Smoking cessation has a positive impact in periodontal treatment. However, so far, no systematic review has evaluated the effect of smoking cessation on tooth loss. Therefore, this review aimed to evaluate if smoking cessation reduces the risk of tooth loss.

METHODS

Observational (cross-sectional and longitudinal) studies that investigated the association between smoking cessation and tooth loss were included. MEDLINE, EMBASE and LILACS databases were searched for articles published up to November 2018. Pooled results for subgroups of current and former smokers were compared in meta-analysis. Meta-regression was used to test the influence of smoking status on estimates and explore the heterogeneity.

RESULTS

Of 230 potentially relevant publications, 21 studies were included in the qualitative review and 12 in the quantitative analysis. Meta-analysis of cross-sectional studies did not show any differences between former and current smokers in the chance of losing 1 or more teeth (OR = 1.00; 95% CI = 0.80 to 1.24, I² = 80%), losing more than 8 teeth (OR = 1.02; 95% CI = 0.78 to 1.32, I² = 0%) or being edentulous (OR = 1.37; 95% CI = 0.94 to 1.99, I² = 98%). Meta-analysis from longitudinal studies showed that, when compared to never smokers, former smokers presented no increased risk of tooth loss (RR = 1.15; 95% CI = 0.98 to 1.35, I² = 76%), while current smokers presented an increased risk of tooth loss (RR = 2.60; 95% CI = 2.29 to 2.96, I² = 61%). Meta-regression showed that, among former smokers, the time of cessation was the variable that better explained heterogeneity (approximately 60%).

CONCLUSIONS

Risk for tooth loss in former smokers is comparable to that of never smokers. Moreover, former smokers have a reduced risk of tooth loss, when compared to current smokers.

Effect of tobacco on periodontal disease and oral cancer

INTRODUCTION

Periodontal disease and oral cancer are common health hazards. Epidemiological investigations show that smoking, periodontal disease and oral cancer are closely related. Tobacco is one of the major risk factors for periodontitis and oral cancer.

METHODS

A systematic literature review was performed. To identify relevant studies, the following online databases were searched using specific keywords: PubMed, Web of Science and CNKI.

RESULTS

Tobacco not only possesses an addictive effect, but it aggravates periodontal disease by promoting the invasion of pathogenic bacteria, inhibiting autoimmune defense, aggravating the inflammatory reaction, and aggravating the loss of alveolar bone. According to current evidence, tobacco significantly aggravates the development and progression of periodontal disease and oral cancer, and periodontal disease may be related to the prevalence of oral cancer.

CONCLUSIONS

Clinicians should strongly recommend that smokers undertake a strategy to stop smoking to avoid the exacerbation of nicotine-related periodontal disease and to reduce the incidence of oral cancer.

Resveratrol attenuates oxidative stress during experimental periodontitis in rats exposed to cigarette smoke inhalation

OBJECTIVES

This study aimed at investigating the effect of the systemic administration of resveratrol (RESV) on oxidative stress during experimental periodontitis in rats subjected to cigarette smoke inhalation.

MATERIAL AND METHODS

Experimental periodontitis (EP) was induced in 26 male Wistar rats by the insertion of a ligature around one of the first mandibular and maxillary molars. The animals were assigned randomly to the following groups: cigarette smoke inhalation (CSI; 3 times/d, 8 minutes/d) + resveratrol (10 mg/Kg), that is, SMK + RESV (n = 13) and cigarette smoke inhalation + placebo, that is, SMK + PLAC (n = 13). The substances were administered daily for 30 days (19 days prior and 11 days following EP induction), and then, the animals were euthanized. The maxillary specimens were processed for morphometric analysis of bone loss, and the tissue surrounding the first maxillary molars was collected for mRNA quantification of Sirtuin 1 (SIRT1) by real-time PCR. The gingival tissues surrounding the mandibular first molars were collected for quantification of superoxide dismutase 1 (SOD1) and nicotinamide adenine dinucleotide phosphatase oxidase (NADPH) using an ELISA assay.

RESULTS

Reduced bone loss was demonstrated in animals in the SMK + RESV group as compared to those in the SMK + PLAC (P < 0.05) group on the basis of morphometric analysis. Resveratrol promoted higher levels of SIRT and SOD (P < 0.05) as well as reduced levels of NADPH oxidase (P < 0.05) were found in tissues derived from animals in the SMK + RESV group when compared to those in the SMK + PLAC group.

CONCLUSION

Resveratrol is an efficient therapeutic agent that reduces exacerbation of bone loss found in animals with EP that were also exposed to smoke. The results suggest that its effects could be mediated, at least in part, by its antioxidant and anti-inflammatory properties which attenuate the effects of oxidative stress on EP in the presence of cigarette smoke.

Life quality improvement in hoarse patients with early glottic cancer after transoral laser microsurgery

BACKGROUND

The purpose of this study was to evaluate the recovery kinetics of voice and quality of life (QOL) over time in patients with early glottic cancer who underwent transoral laser microsurgery (TLM).

METHODS

A prospective cohort study was conducted in which acoustic and aerodynamic voice assessments and QOL analyses were done using health-related questionnaires (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30-questions [EORTC-QLQ-C30] and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Head and Neck 35-questions [EORTC-QLQ-H&N35]) were administered at designated times.

RESULTS

Most voice laboratory parameters worsened during the first month, then recovered to baseline after 6 months. The QLQ-H&N35 speech subscale was significantly improved. Among the voice laboratory parameters, pretreatment harmonics-to-noise ratio was an independent predictor (P = .041) for improvement on the speech subscale at the endpoint.

CONCLUSION

Despite an initial deterioration of voice and QOL in the first month, patients who underwent TLM recovered to a plateau since the sixth month and then to better than preoperative status afterward. A greater improvement in QOL was seen in patients with poorer baseline voice quality.

Long-term effects of smoking on tooth loss after cessation among middle-aged Finnish adults: the Northern Finland Birth Cohort 1966 Study

Background

Despite smoking cessation efforts, cigarette smoking remains a serious general and oral health problem. We aimed to investigate the putative benefits of smoking cessation on dentition and to analyse whether the time elapsed since smoking cessation associated positively with the remaining number of teeth.

Methods

This cross-sectional study analyses data from the 46-year follow-up of the Northern Finland Birth Cohort Study 1966 (NFBC1966). A total of 5 540 subjects participated in this cross-sectional study, which utilises both clinical dental examinations and mailed questionnaires. We used the following information on smoking: status (current, former, never), years of smoking (current, former) and years elapsed since smoking cessation (former). Self-reported and clinically measured number of teeth (including third molars) served as alternative outcomes. We used binary logistic regression models to analyse the dichotomised number of teeth (‘0–27’, ’28–32’) and then calculated unadjusted and adjusted odds ratios (OR) with 95 % confidence intervals (CI) for the smoking variables (never smoker as the reference). Gender, education, tooth brushing frequency, diabetes and alcohol use served as confounders for the adjusted models.

Results

Ten years or more of smoking associated with tooth loss; this effect was the strongest among men who reported having an ongoing smoking habit (self-reported outcome: adjusted OR = 1.74, CI = 1.40–2.16) and the weakest among women classified as former smokers (self-reported outcome: adjusted OR = 1.27, CI = 1.00–1.62).

Conclusions

This study shows that smoking has long-term effects on tooth loss even after cessation. The findings support smoking cessation efforts to reduce oral health risks.

The association of active and secondhand smoking with oral health in adults: Japan public health center-based study

Background

Smoking is one of the major risk factors for oral diseases, and many studies have found that active smoking is closely associated with the prevalence or severity of periodontal disease and fewer remaining teeth. In contrast to the established association between active smoking and oral health, there have been very few studies investigating the effects of secondhand smoking on oral health, and whether secondhand smoking deteriorates oral health has not been fully clarified. The purpose of the present study was to examine whether active and secondhand smoking were associated with the prevalence of severe periodontal disease and number of teeth among Japanese adults.

Methods

Subjects were 1,164 dentate adults aged 55–75 years as of May 2005 who participated in both the Japan Public Health Center-Based Study Cohort I in 1990 and a dental survey in 2005. The dental survey was implemented in the Yokote health center jurisdiction, Akita Prefecture. Participating subjects completed a self-administered questionnaire and a clinical oral examination. The association of smoking status with prevalence of periodontal disease was analyzed using a logistic regression, and with number of teeth or functional tooth units of natural teeth (n-FTUs) using a generalized linear model.

Results

After adjusting for age, education level, history of diabetes, BMI, alcohol consumption, perceived mental stress, presence of a family dentist, and oral hygiene, the odds ratio (OR) of risk for periodontal disease in male subjects was significantly increased in non-smokers with secondhand smoking only at home (OR = 3.14, 95 % CI: 1.08−9.12, p = 0.036), non-smokers with secondhand smoking both at home and other places (OR = 3.61, 95 % CI: 1.33−9.81, p = 0.012) and current smokers (OR = 3.31, 95 % CI: 1.54−7.08, p = 0.002), compared to non-smokers without secondhand smoking. Further in men, current smokers had significantly fewer numbers of teeth (19.7 ± 6.82) and n-FTUs (4.92 ± 4.12) than non-smokers without secondhand smoking (22.2 ± 6.92, p = 0.014 and 6.56 ± 4.18, p = 0.007). Such significant relationships of smoking status with periodontal disease and dentition were not observed in women.

Conclusions

The present study indicates that active smoking as well as secondhand smoking may have harmful effects on periodontal health in men. Therefore, it is imperative for health and oral health professionals to enlighten people about the negative influence of smoking, not only on their own health but also on others’ health.

Current perspective of the impact of smoking on the progression and treatment of periodontitis

This literature review provides an overview of the current scenario regarding the impact of smoking on the progression and treatment of periodontitis; clinical, microbiological and immunological data from studies from our and other groups are presented. In general, preclinical and clinical data are unanimous in demonstrating that smokers present increased susceptibility, greater severity and faster progression of periodontal disease compared with nonsmokers. The evidence further demonstrates that smokers lose more teeth and have a less favorable response to therapy than do nonsmokers. Although it is well established that smoking significantly impacts on the onset, progression and outcome of periodontal disease, the mechanisms involved remain unclear. More importantly, some of the reported deleterious effects of smoking on periodontal tissues have been reported to be reversible upon participation in smoking-cessation programs. Therefore, clinicians should strongly advise smokers to enroll in cessation strategies, even temporarily, in order to improve the overall outcome.

Is frequency of tooth brushing a risk factor for periodontitis? A systematic review and meta-analysis

OBJECTIVES

The epidemiology of periodontitis regarding oral-hygiene practices particularly the frequency of tooth brushing has been the subject of relatively few dedicated studies. This paper provides a systematic review of available relevant epidemiological studies and a meta-analysis of the effect of tooth brushing frequency on periodontitis. To review and to quantify the risk for periodontitis associated with frequency of tooth brushing.

METHODS

Systematic literature search was conducted in nine online resources (PUBMED, ISI and 7 additional databases). Related and cross-referencing publications were reviewed. Papers published until end of March 2013 reporting associations between tooth brushing frequency and periodontitis were considered. A meta-analysis was performed to quantify this association.

RESULTS

Fourteen studies were identified. The test of heterogeneity for cross-sectional studies was not significant (P = 0.31). A fixed-effects model yielded a significant overall odds ratio estimate of 1.41 (95%CI: 1.25-1.58, P < 0.0001) for infrequent compared to frequent tooth brushing. For all fourteen studies, there was a slight indication for heterogeneity (I² = 48%, P = 0.02) and the corresponding result with a random-effects model was 1.44 (95%CI: 1.21-1.71, P < 0.0001).

CONCLUSIONS

There are relatively few studies evaluating the association between tooth brushing frequency and periodontitis. A clear effect was observed, indicating that infrequent tooth brushing was associated with severe forms of periodontal disease. Further epidemiological studies are needed to precisely estimate the effect of key risk factors for periodontitis and their interaction effects.

Risk factors associated with the longevity of multi-rooted teeth. Long-term outcomes after active and supportive periodontal therapy

AIM

To investigate risk factors for the loss of multi-rooted teeth (MRT) in subjects treated for periodontitis and enrolled in supportive periodontal therapy (SPT).

MATERIAL AND METHODS

A total of 172 subjects were examined before (T0) and after active periodontal therapy (APT)(T1) and following a mean of 11.5 ± 5.2 (SD) years of SPT (T2). The association of risk factors with loss of MRT was analysed with multilevel logistic regression. The tooth was the unit of analysis.

RESULTS

Furcation involvement (FI) = 1 before APT was not a risk factor for tooth loss compared with FI = 0 (p = 0.37). Between T0 and T2, MRT with FI = 2 (OR: 2.92, 95% CI: 1.68, 5.06, p = 0.0001) and FI = 3 (OR: 6.85, 95% CI: 3.40, 13.83, p < 0.0001) were at a significantly higher risk to be lost compared with those with FI = 0. During SPT, smokers lost significantly more MRT compared with non-smokers (OR: 2.37, 95% CI: 1.05, 5.35, p = 0.04). Non-smoking and compliant subjects with FI = 0/1 at T1 lost significantly less MRT during SPT compared with non-compliant smokers with FI = 2 (OR: 10.11, 95% CI: 2.91, 35.11, p < 0.0001) and FI = 3 (OR: 17.18, 95% CI: 4.98, 59.28, p < 0.0001) respectively.

CONCLUSIONS

FI = 1 was not a risk factor for tooth loss compared with FI = 0. FI = 2/3, smoking and lack of compliance with regular SPT represented risk factors for the loss of MRT in subjects treated for periodontitis.

Salivary cotinine concentrations and prevalence of periodontal disease in young Japanese women: the Kyushu Okinawa maternal and child health study

BACKGROUND

The authors investigated the relationship between objectively assessed tobacco smoke exposure and periodontal disease.

METHODS

This cross-sectional study included 1,103 women with a mean age of 31.5 years. Information on potential confounding factors was obtained through a self-administered questionnaire. Periodontal disease was defined as positive if a woman had at least one tooth with a probing depth of ≥ 3.5 mm. Exposure to tobacco smoke was determined based on salivary cotinine concentration. Adjustment was made for age, region of residence, household income, education, toothbrushing frequency, and use of an interdental brush.

RESULTS

The prevalence of periodontal disease was 11.3%. Salivary cotinine concentration was independently positively associated with the prevalence of periodontal disease: the adjusted odds ratio for every 1-unit (ng/mL) increase in salivary cotinine was 1.004 (95% confidence interval: 1.000 to 1.007).

CONCLUSION

Salivary cotinine concentrations were positively associated with the prevalence of periodontal disease among young women.

Factors related to tooth loss among community-dwelling middle-aged and elderly Japanese men

Background

Using data from a large-scale community-based Japanese population, we attempted to identify factors associated with tooth loss in middle-aged and elderly men.

Methods

A total of 8352 men aged 40 to 79 years who lived in the north of the main island of Japan and underwent health checkups were enrolled between 2002 and 2005. Number of teeth was assessed by the question, “How many teeth do you have (0, 1–9, 10–19, or ≥20)?”. On the basis of the answer to this question, participants were classified into 2 groups (≤19 teeth or ≥20 teeth). Using multivariate logistic regression, factors related to having 19 or fewer teeth were estimated.

Results

The numbers (percentages) of participants who had 0, 1 to 9, 10 to 19, and 20 or more teeth were 1764 (21.1%), 1779 (21.3%), 1836 (22.0%), and 2973 (35.6%), respectively. Among the participants overall and those aged 65 to 79 years, having 19 or fewer teeth was significantly associated with older age, smoking status (current smoking and ex-smoking), and low education level. In addition, men with 19 or fewer teeth were more likely to have a low body mass index and low serum albumin level and less likely to be current alcohol drinkers. Among men aged 40 to 64 years, but not men aged 65 to 79 years, those with 19 or fewer teeth were more likely to have a low serum high-density lipoprotein cholesterol level and high glycosylated hemoglobin (HbA1c) level.

Conclusions

Smoking, low education level, and poor nutritional status were associated with tooth loss among middle-aged and elderly Japanese men.

Smoking increases risk of tooth loss: A meta-analysis of the literature

AIM: To quantitatively evaluate the impact of smoking on tooth loss.

METHODS: We performed a PubMed search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using meta-regression models.

RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73 (95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers (1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers (2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.

CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.

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.

Dental caries in relation to smoking and the use of Swedish snus: epidemiological studies covering 20 years (1983-2003)

OBJECTIVE

The aim of this study was to evaluate some intra-oral caries-associated variables and tobacco use on dental caries.

MATERIALS AND METHODS

The participants were randomly recruited from three cross-sectional studies in Jönköping, Sweden, in 1983, 1993 and 2003. Each study consisted of 130 individuals in each of the 20, 30, 40, 50, 60 and 70-year age groups. Of these, 550, 552 and 523 dentate individuals attended respective year of examination. They were all examined both clinically and radiographically. A questionnaire was completed in conjunction with the examination. In the studies, 345 were smokers, 104 snus users and 1142 non-tobacco users, in total 1591 individuals.

RESULTS

In 1983 and 1993, there were no significant differences in mean DFS between non-users and smokers, but a statistically significantly higher mean DFS in comparison with snus users. In 2003, there was no statistically significant difference in mean DFS between the groups. Multiple regressions showed that, after adjusting for age, gender and socio-demographic variables, there was a statistically significant association between DFS and smoking in 1983 (smoking excluded in favour of lactobacilli when further analysed) and DFS and plaque index (PLI) in 1993. In 2003, there was no association, apart from buffer capacity (Power rising) between DFS and the examined intra-oral caries-associated variables and tobacco use.

CONCLUSIONS

The results of these epidemiological studies, performed in 1993 and 2003, indicate that daily smoking or snus use does not increase the risk of dental caries.

Factors associated with self-reported number of teeth in a large national cohort of Thai adults

BACKGROUND

Oral health in later life results from individual's lifelong accumulation of experiences at the personal, community and societal levels. There is little information relating the oral health outcomes to risk factors in Asian middle-income settings such as Thailand today.

METHODS

Data derived from a cohort of 87,134 adults enrolled in Sukhothai Thammathirat Open University who completed self-administered questionnaires in 2005. Cohort members are aged between 15 and 87 years and resided throughout Thailand. This is a large study of self-reported number of teeth among Thai adults. Bivariate and multivariate logistic regressions were used to analyse factors associated with self-reported number of teeth.

RESULTS

After adjusting for covariates, being female (OR = 1.28), older age (OR = 10.6), having low income (OR = 1.45), having lower education (OR = 1.33), and being a lifetime urban resident (OR = 1.37) were statistically associated (p < 0.0001) with having less than 20 teeth. In addition, daily soft drink consumptions (OR = 1.41), current regular smoking (OR = 1.39), a history of not being breastfed as a child (OR = 1.34), and mother's lack of education (OR = 1.20) contributed significantly to self-reported number of teeth in fully adjusted analyses.

CONCLUSIONS

This study addresses the gap in knowledge on factors associated with self-reported number of teeth. The promotion of healthy childhoods and adult lifestyles are important public health interventions to increase tooth retention in middle and older age.

Dental health behaviors, dentition, and mortality in the elderly: the leisure world cohort study

In the last decade the effect of oral health on the general health and mortality of elderly people has attracted attention. We explored the association of dental health behaviors and dentition on all-cause mortality in 5611 older adults followed from 1992 to 2009 (median = 9 years) and calculated risk estimates using Cox regression analysis in men and women separately. Toothbrushing at night before bed, using dental floss everyday, and visiting the dentist were significant risk factors for longevity. Never brushing at night increased risk 20-35% compared with brushing everyday. Never flossing increased risk 30% compared with flossing everyday. Not seeing a dentist within the last 12 months increased risk 30-50% compared with seeing a dentist two or more times. Mortality also increased with increasing number of missing teeth. Edentulous individuals (even with dentures) had a 30% higher risk of death compared with those with 20+ teeth. Oral health behaviors help maintain natural, healthy and functional teeth but also appear to promote survival in older adults.

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.