Smoking and periodontal disease. A review of the literature

Screening of heat-killed lactic acid bacteria based on inhibitory activity against oral bacteria and effects of oral administration of heat-killed Ligilactobacillus salivarius CP3365 on periodontal health in healthy participants: a double-blinded, randomized, placebo-controlled trial

Objectives

The aims of this study were to select heat-killed lactic acid bacteria (HKL) with antibiotic activity and investigate the efficacy of this bacteria in maintaining periodontal parameters in healthy participants.

Materials and methods

An in vitro evaluation was conducted to assess the inhibitory efficacy of lactic acid bacteria against Porphyromonas gingivalis and Fusobacterium nucleatum subsp. nucleatum. The effects of HKL administration on various parameters (plaque control record, bleeding on probing, and probing pocket depth) were assessed in a randomized, placebo-controlled trial. Participants in the test and placebo groups (n = 32) consumed oral tablets containing placebo or HKL daily for 8 weeks. Oral bacteria in supra-plaque and saliva were identified using 16S rRNA gene community profiling analysis.

Results

Heat-killed Ligilactobacillus salivarius CP3365 significantly (p < 0.05) decreased the viability of oral bacteria and was selected for clinical trials. Administration of HKL CP3365 significantly (p < 0.05) inhibited increases in each parameter. No changes in the relative abundance of P. gingivalis or F. nucleatum subsp. nucleatum were detected by HKL CP3365, but the relative abundance of oral bacteria (genera Porphyromonas, Fusobacterium, and Haemophilus) was significantly (p < 0.05) decreased.

Conclusion

HKL CP3365 effectively inhibited oral bacteria growth and was useful for maintaining periodontal health.

Clinical Trial Registration

[https://www.umin.ac.jp/ctr/index.htm], identifier [UMIN000045656].

Gingival Crevicular Fluid and Salivary Periostin Levels in Non-Smoker Subjects With Chronic and Aggressive Periodontitis : Periostin Levels in Chronic and Aggressive Periodontitis

Periostin, an extracellular matrix protein functioning as an important structural mediator and adhesion molecule, has been shown to be an important regulator of connective tissue integrity. This study aimed to evaluate the levels of periostin in chronic periodontitis (CP) and aggressive periodontitis (AgP) compared to non-periodontitis (NP). Individuals were submitted to gingival crevicular fluid (GCF) and saliva sampling. Periodontal examination consisted of plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL) measurements. Assays for periostin were performed by an enzyme-linked immunosorbent assay. Periodontitis patients presented more severe clinical indices compared to the NP group (p < 0.001). The mean GCF level of periostin was lowest in the AgP group as compared to the other groups and was lower in the CP group as compared to the NP group (p < 0.001). Increased levels of periostin were observed in the saliva of patients with AgP as compared to the CP and NP groups (p < 0.05). There was a negative relationship between GCF periostin levels and clinical parameters (p < 0.01), whereas a positive correlation was observed between salivary periostin levels and full-mouth GI and CAL scores (p < 0.01). To our knowledge, this is the first report investigating periostin levels in GCF and saliva in aggressive periodontitis. The results suggest that subjects with CP and AgP exhibit a different periostin profile. Periostin in GCF may have a protective role against periodontal disease. Furthermore, salivary periostin concentrations may have a promising diagnostic potential for the aggressive forms of periodontal disease.

Acute periodontal lesions

This review provides updates on acute conditions affecting the periodontal tissues, including abscesses in the periodontium, necrotizing periodontal diseases and other acute conditions that cause gingival lesions with acute presentation, such as infectious processes not associated with oral bacterial biofilms, mucocutaneous disorders and traumatic and allergic lesions. A periodontal abscess is clinically important because it is a relatively frequent dental emergency, it can compromise the periodontal prognosis of the affected tooth and bacteria within the abscess can spread and cause infections in other body sites. Different types of abscesses have been identified, mainly classified by their etiology, and there are clear differences between those affecting a pre-existing periodontal pocket and those affecting healthy sites. Therapy for this acute condition consists of drainage and tissue debridement, while an evaluation of the need for systemic antimicrobial therapy will be made for each case, based on local and systemic factors. The definitive treatment of the pre-existing condition should be accomplished after the acute phase is controlled. Necrotizing periodontal diseases present three typical clinical features: papilla necrosis, gingival bleeding and pain. Although the prevalence of these diseases is not high, their importance is clear because they represent the most severe conditions associated with the dental biofilm, with very rapid tissue destruction. In addition to bacteria, the etiology of necrotizing periodontal disease includes numerous factors that alter the host response and predispose to these diseases, namely HIV infection, malnutrition, stress or tobacco smoking. The treatment consists of superficial debridement, careful mechanical oral hygiene, rinsing with chlorhexidine and daily re-evaluation. Systemic antimicrobials may be used adjunctively in severe cases or in nonresponding conditions, being the first option metronidazole. Once the acute disease is under control, definitive treatment should be provided, including appropriate therapy for the pre-existing gingivitis or periodontitis. Among other acute conditions affecting the periodontal tissues, but not caused by the microorganisms present in oral biofilms, infectious diseases, mucocutaneous diseases and traumatic or allergic lesions can be listed. In most cases, the gingival involvement is not severe; however, these conditions are common and may prompt an emergency dental visit. These conditions may have the appearance of an erythematous lesion, which is sometimes erosive. Erosive lesions may be the direct result of trauma or a consequence of the breaking of vesicles and bullae. A proper differential diagnosis is important for adequate management of the case.

Effects of Areca Nut Extracts on Phagocytosis of Actinobacillus actinomycete mcomitans ATCC 33384 by Neutrophils in Patients with Chronic Periondontitis

BACKGROUND & OBJECTIVE

A higher prevalence of periodontal disease among areca nut chewers than non chewers has been demonstrated. Neutrophils, the first line of defence mechanism against microbial infection play an important role in maintaining the periodontal health. In this context our aim was to evaluate the effects of areca nut extracts on phagocytic activity by neutrophils isolated from gingival crevicular washing of healthy subjects and patients with chronic periodontitis.

MATERIAL AND METHODS

Sample size consisted of a total of 60 subjects which were divided into two groups of 30 each. Group I consisted healthy subjects and Group II consisted clinically diagnosed cases of chronic periodontitis. Neutrophils isolated from gingival crevicular washings of both groups were treated with aqueous extracts of ripe areca nut (rANE) and tender areca nut (tANE) and examined for their effect on cellular viability of neutrophils using typan blue exclusion assay. The possible/ ableffects on the phagocytic activity of neutrophils against a periodontal pathogen Aggregatibacter actinomycetemcomitans(ATCC 33384) was determined by using microscopic method.

RESULTS

Both rANE and tANE affected the phagocytic activity by neutrophils in healthy and patients with chronic periodontitis. Ripe areca nut extract has altered the neutrophil functions more than tender areca nut in both the groups. There was no difference seen in the cell viability of neutrophils when treated with rANE and tANE in both the groups (p> 0.05).

CONCLUSION

Both ripe and tender arecanut extract affected the neutrophil function in healthy and patients with chronic periodontitis. Ripe arecanut extract significantly altered the neutrophils functions more than tender areca nut extract. Thus, alterations in these functions of neutrophils may lead to signs of clinical diseases associated with areca chewing.

The up-regulation of heme oxygenase-1 expression in human gingival fibroblasts stimulated with nicotine

BACKGROUND

Cigarette smoking is a major risk factor in the development and further progression of periodontal diseases. Heme oxygenase-1 (HO-1) is known as a stress-inducible protein and functions as an antioxidant enzyme. There is limited information on the expression of HO-1 in smoking-associated periodontal disease.

OBJECTIVES

The aim of the present study was to investigate the effects of nicotine on the expression of HO-1 protein in cultured human gingival fibroblasts in vitro and further to compare HO-1 expression in gingival tissues obtained from cigarette smokers and non-smokers in vivo.

METHODS

Western blot assay was used to investigate the effects on human gingival fibroblasts exposed to nicotine. In addition, antioxidants catalase, superoxide dismutase (SOD), and N-acetyl-l-cysteine (NAC) were added to test how they modulated the effects on nicotine-induced HO-1 expression. Gingival biopsies taken from the flap surgery of 20 male patients with periodontal disease (10 cigarette smokers and 10 non-smokers) were examined by immunohistochemistry.

RESULTS

The exposure of quiescent human gingival fibroblasts to 10 mm nicotine resulted in the induction of HO-1 protein expression in a time-dependent manner (p < 0.05). The addition of glutathione (GSH) precursor NAC inhibited the nicotine-induced HO-1 protein expression (p < 0.05). However, SOD and catalase did not decrease the nicotine-induced HO-1 protein expression (p > 0.05). The results from immunohistochemistry demonstrated that HO-1 expression was significantly higher in cigarette smokers (p < 0.05). HO-1 was noted in the basal layers of epithelium, inflammatory cells, and fibroblasts in specimens from cigarette smoking.

CONCLUSIONS

Taken together, these results suggest that HO-1 expression is significantly up-regulated in gingival tissues from cigarette smokers, and nicotine may, among other constituents, be responsible for the enhanced HO-1 expression in vivo. The regulation of HO-1 expression induced by nicotine is critically dependent on the intracellular GSH concentration.

Effects of periodontitis and smoking on the microbiota of oral mucous membranes and saliva in systemically healthy subjects

BACKGROUND/AIM

To examine the differences in the proportions of 40 bacterial species in samples from eight oral soft-tissue surfaces and saliva in systemically healthy adult subjects with and without periodontitis and in smokers and nonsmokers.

METHODS

Saliva and microbial samples were taken from eight oral soft-tissue surfaces in 229 systemically healthy subjects stratified by periodontal and smoking status. Subjects included 84 periodontally healthy and 145 periodontitis individuals. Of these, there were 182 nonsmokers and 47 smokers. Soft-tissue samples were taken using a "buccal brush" and saliva was taken by expectoration. All samples were individually evaluated for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The percentage of total DNA probe count was determined for each species at each sample location and averaged across subjects. The significance of differences among the proportions of the 40 test species at different sample locations was sought in these populations using the Kruskall-Wallis test and adjusted for multiple comparisons.

RESULTS

When stratified for periodontal status or smoking status, microbial profiles at most sites did not differ significantly. Generally, periodontal pathogens were found at higher levels on the soft tissues of periodontitis subjects than in periodontally healthy subjects, and at higher levels in smokers than nonsmokers. Few significant differences were found, although trends in the populations were noted.

CONCLUSIONS

Small differences in the proportions of bacterial species were observed on soft tissues and in saliva comparing periodontally healthy and periodontitis subjects. Somewhat greater differences between smokers and nonsmokers were found; however, these were not statistically significant.

Interleukin 1 and receptor antagonist levels in gingival crevicular fluid in heavy smokers versus non-smokers

BACKGROUND/AIMS

This study aimed to investigate the concentration of the cytokine interleukin (IL)-1beta and its receptor antagonist IL-1ra in gingival crevicular fluid (GCF) in patients with adult periodontitis who were heavy smokers compared with non-smokers.

METHOD

GCF samples were collected from two groups of subjects: smokers and non-smokers. Thirty-nine GCF samples were harvested from 13 subjects with moderate to severe adult periodontitis who were heavy smokers. A further 30 GCF samples were harvested from 10 subjects with moderate to severe adult periodontitis who were non-smokers. Subjects were selected from both genders and none had any relevant systemic illness, were pregnant, had recent medication or had received any periodontal therapy in the preceding 3 months. One deep bleeding site, one deep non-bleeding site and one healthy site were investigated in each subject. Clinical measurements were recorded for each site, after obtaining a GCF sample using a Periopaper strip. IL-1beta and IL-1ra were quantified using new commercially available ELISA kits (Quantikine), and could be detected in all samples.

RESULTS

For smokers, the mean concentrations for IL-1beta were 2714.5 (SD 4416.2) pg/ micro L for healthy sites, 37.0 (SD 57.2) pg/ micro L for non-bleeding periodontitis sites and 24.5 (SD 29.2) pg/ micro L for bleeding periodontitis sites. The concentrations of IL-1beta for non-smokers for the same category of sites were 393.8 (SD 867.1), 74.2 (SD 107.0) and 73.1 (SD 61.0) pg/ micro L, respectively. The mean concentrations of IL-1ra for smokers were 5.8 x 10(5) (SD 9.7) pg/ micro L for healthy sites, 2.2 x 10(5) (SD 0.15) pg/ micro L for deep non-bleeding sites and 0.19 x 10(5) (SD 0.07) pg/ micro L for deep bleeding sites. The concentrations for non-smokers were: 4.1 x 10(10) (SD 3.8), 18.1 x 10(5) (SD 20.4) and 3.2 x 10(5) (SD 2.3) pg/ micro L, respectively. Significance levels of P < 0.05 were found for comparisons of healthy vs. deep bleeding and deep non-bleeding sites for IL-1beta and IL-1ra in smokers, before adjustments for multiple testing. However, none of these comparisons reached statistical significance following adjustments for multiple testing. P < 0.05 for the correlation between IL-1beta and IL-1ra at healthy sites in smokers only. Differences in GCF concentrations for IL-1beta in smokers vs. non-smokers were significant for deep bleeding sites only (P < 0.05), the mean concentration of IL-1beta being lower in GCF from smokers vs. non-smokers. All differences in GCF concentrations of IL-1ra reached statistical significance for smokers vs. non-smokers. The mean concentrations of IL-1ra in GCF were lower in smokers compared with non-smokers for all categories of sites.

CONCLUSIONS

A decreased concentration of IL-1beta and also IL-1ra was found in GCF from periodontitis sites compared to healthy sites in smokers and in non-smokers, although this did not reach statistical significance following adjustments for multiple testing. For comparisons between heavy smokers and non-smokers, statistically significant differences were found in the GCF concentrations of IL-1beta from deep bleeding sites only. Statistically significant differences were found in the IL-1ra concentrations for smokers vs. non-smokers for all categories of sites.

Enhanced Escherichia coli invasion of human brain microvascular endothelial cells is associated with alternations in cytoskeleton induced by nicotine

Although epidemiological studies have shown that exposure to tobacco smoking significantly increases the risk of bacterial meningitis, heretofore the pathogenic effects of smoking on this disease have been poorly understood. In order to dissect this issue, we have investigated the effects of nicotine, the major component of tobacco, on E. coli invasion of human brain microvascular endothelial cells (HBMEC). Our studies showed that E. coli invasion of HBMEC was significantly enhanced by nicotine in a dose-dependent manner. The nicotine-mediated enhancement was associated with actin cytoskeleton rearrangement and morphological changes in the eukaryotic host cell that are essential for bacterial entry. The recombinant IbeA protein and alpha-bungarotoxin (a nicotinic acetylcholine receptor antagonist) were able to efficiently block the nicotine-mediated cellular effects, suggesting the involvement of the IbeA and nicotinic receptors. Blocking of phosphatidylinositol 3-kinase (PI3K) by LY294002 abolished the entry of E. coli in HBMECs treated with nicotine in a dose-dependent manner. Inhibition of PI3K was associated with decreased phosphorylation of Akt and actin cytoskeletal rearrangement. In contrast to PI3K, blockage of Rho kinase (ROCK) by Y27632 upregulated both nicotine- and E. coli-mediated cellular responses. Thus, this study provides experimental evidence for the first time that the major component of tobacco, nicotine, enhances meningitic E. coli invasion of HBMEC through modulation of cytoskeleton.

Influence of smoking on marginal bone loss and tooth loss--a prospective study over 20 years

AIMS

The aim was to investigate the influence of smoking on longitudinal marginal bone loss and tooth loss in a prospective study over 20 years. In addition, the effect of cessation of smoking on bone loss and the interaction between smoking, plaque and marginal bone loss were evaluated.

MATERIAL AND METHODS

A total of 507 dentate individuals from an epidemiological study were examined in 1970 and 1990. The clinical investigation included registration of number of remaining teeth and presence of plaque. The marginal bone level was determined by assessments on the proximal surfaces on the radiographs from 1970 and 1990. The marginal bone loss was defined as the difference in marginal bone level over 20 years. The subjects were interviewed about smoking habits. Stepwise multiple regression analyses were adopted to calculate the influence of the independent variables on longitudinal marginal bone loss and tooth loss.

RESULTS

In 1970, 50.7% of the subjects were smokers, while the corresponding relative frequency in 1990 had decreased to 31.0%. Smoking was significantly correlated to an increased marginal bone loss over 20 years. Individuals who stopped smoking between 1970 and 1990 lost significantly less marginal bone during this period than those who declared that they smoked during the 20-year period. Smoking was not found to be significantly correlated to tooth loss over 20 years.

CONCLUSIONS

The results support the hypothesis that smoking is a significant risk factor of periodontal disease.

Inhibition of salivary enzymes by cigarette smoke and the protective role of glutathione

Tobacco smoke is involved in the pathogenesis of several diseases regarding different body systems, mainly cardiovascular and respiratory in addition to its local toxic effect in the oral cavity. The noxious effects of smoke compounds justify the high incidence of periodontal diseases, caries, and neoplastic diseases of oral tissues in smokers. Some toxic components of tobacco smoke, unsaturated and saturated aldehydes, could interact with thiol rich compounds, leading to structural and functional modification of these molecules. Previous papers have demonstrated an in vitro significant decrease of some enzymatic activities, both in plasma and in saliva, following external addition of aldehydes or exposure to cigarette smoke (CS). Furthermore, the same studies underlined the protective effect exerted by the addition of glutathione (GSH) against the damaging role of smoke aldehydes. In this study some salivary enzymes (lactic dehydrogenase [LDH], aspartate aminotransferase [AST] and amylase), and total GSH were measured in 20 volunteers smokers, before and just after smoking a single cigarette. All enzymatic activities showed a significant inhibition following a single cigarette, probably due to the interaction between smoke aldehydes and -SH groups of the enzyme molecules. Moreover, the percentage of the enzymatic inhibition showed a negative correlation with the basal level of salivary GSH. Our results emphasize that not only one cigarette is sufficient to impair the salivary enzymatic activities but also strengthen the proposed protective role of GSH against the noxious biochemical effects of CS.

Oral nitric oxide during plaque deposition

BACKGROUND

Nitric oxide (NO) is one of the most powerful antibacterial compounds. We investigated if NO oral production increases during dental plaque deposition.

MATERIALS AND METHODS

Oral NO and salivary nitrite were measured in 31 healthy subjects - 11 smokers and 20 nonsmokers - with natural healthy teeth, in the morning after tooth cleaning (baseline), after withdrawal of oral hygiene for 24 h and again after tooth cleaning.

RESULTS

NO and nitrite were significantly higher during plaque deposition than with clean teeth: mean NO values +/- SEM were 44.3 +/- 4.9 parts per billion (ppb) at baseline, 58.8 +/- 3.7 ppb with plaque and 43.6 +/- 3.7 ppb after tooth cleaning, P < 0.05; nitrite values were 32.9 +/- 5.5 microm at baseline, 66.4 +/- 8.2 with plaque and 37.5 +/- 5.5 after tooth cleaning, P < 0.01. During plaque deposition, oral NO was significantly directly related to salivary nitrite (r = 0.497, P = 0.002) and so were their respective changes after tooth cleaning (r = 0.577, P < 0.001). Smokers had significantly lower oral NO than nonsmokers, with both clean and dirty teeth (P < 0.001), and higher bacteria counts in the plaque (38.6 +/- 11.5 vs. 19.9 +/- 2.3, P = 0.046).

CONCLUSIONS

Oral NO production increases during de novo deposition of dental plaque. NO might be an early host defence mechanism against bacterial proliferation in the plaque. Such a mechanism is inhibited by cigarette smoking.

Effect of nicotine on fibroblast beta 1 integrin expression and distribution in vitro

BACKGROUND

Integrins are a family of transmembrane cell surface glycoproteins, and those with the beta 1-subunit function in both cell-to-cell and cell-to-substrate adhesion. The purpose of this study was to determine nicotine's effect on the expression and distribution of the beta 1 integrin subunit on the human gingival fibroblast cell surface.

METHODS

Pure nicotine was diluted in medium to the following concentrations: 0 (control), 0.025, 0.05, 0.1, 0.2, and 0.4 microM. Human gingival fibroblasts (HFG) were grown for 24 hours in each concentration and fluorescein-labeled with a mouse monoclonal anti-human beta 1 antibody and secondarily incubated with a urease-labeled anti-mouse IgG antibody. After a final wash, the cells were incubated with urea/bromcresol blue substrate for 15 minutes at 37 degrees C and measured in a microplate reader at 570 nm.

RESULTS

The integrin beta 1-subunit was detected on the HGF surface membrane by fluorescence labeling, and cell-enzyme-linked immunosorbent assay testing demonstrated its decreased expression with increasing nicotine concentrations that were statistically different at the concentrations of 0.2 and 0.4 microM versus controls (P < 0.05).

CONCLUSIONS

Nicotine concentrations of 0.2 and 0.4 microM significantly decrease beta 1 integrin expression in human gingival fibroblasts that may affect cell-cell and cell-substratum adhesion during wound healing.

Cigarette smoking, salivary/gingival crevicular fluid cotinine and periodontal status. A 10-year longitudinal study

BACKGROUND, AIMS

The primary purpose of this study was to determine the association of salivary and gingival crevicular fluid (GCF) cotinine levels with periodontal disease status in smokers and non-smokers.

METHODS

147 male smokers and 30 male non-smokers were included in the current longitudinal study. The 177 individuals were part of a group of 200 subjects (89%) seen 10 years previously for a baseline survey. Oral hygiene indices, probing depth and attachment loss were recorded. Salivary and GCF cotinine levels of 58 smokers were determined by means of ELISA.

RESULTS

Results indicated that no significant difference was found in subjects who smoked, when compared to subjects who did not smoke with respect to plaque accumulation and calculus deposits. Smokers, however, had fewer gingival bleeding sites. Cigarette smoking was associated with a greater increase in probing depth and attachment loss, as well as greater tooth loss at an earlier age. There was greater tooth loss in smokers than non-smokers (p < 0.001). 11 smokers became edentulous, while only 1 non-smoker lost all his teeth within 10 years. The degree of periodontal tissue breakdown was different in each age group with greater periodontal deterioration as age increased. All smokers had detectable salivary and GCF cotinine. Mean GCF cotinine was about 4x higher than mean salivary cotinine levels. Individuals who smoked > or = 20 pack years when compared to <20 pack years, had significantly higher saliva and GCF cotinine levels (p < or = 0.05).

CONCLUSION

Neither salivary cotinine nor GCF cotinine was significantly correlated with probing depth, attachment loss and tooth loss (p > 0.05).

Effects of smoking on periodontal health: a review

Cigarette smoking is a risk factor for several diseases, and recent evidence strongly suggests an adverse effect on periodontal health. Nevertheless, the nature of the relationship between smoking and periodontal disease is not clear. Smoking causes defects in neutrophil function, impairs inflammatory and immune responses to periodontal pathogens, and exerts both systemic and local effects. Smoking is associated with an increased rate of periodontal disease in terms of alveolar bone loss and attachment loss, as well as pocket formation. Nicotine, the major component of cigarette smoke, may weaken host defenses to the bacterial invasion induced by plaque.

Sudden infant death syndrome: a toxic response

Causes of sudden infant death syndrome (SIDS) remain elusive. Much of the current literature points to an infectious cause with a role for proinflammatory cytokines and septic shock in stimulating an overwhelming response in an infant. This article reviews the literature and possible causes of this devastating condition.

Effects of nicotine on the strength of attachment of gingival fibroblasts to glass and non-diseased human root surfaces

BACKGROUND

The aim of this study was to evaluate the effect of nicotine on the strength of attachment of human gingival fibroblast cells to glass and non-diseased human root surfaces.

METHODS

Human gingival fibroblast cells (HGF) were trypsinized, suspended in RPMI 1640 medium, and incubated with autoclaved human root and glass sections and nicotine (NIC) concentrations of 0 (control), 25, 50, and 100 ng/ml for 1 week. HGF attached and grew on glass and root surfaces for 4 weeks at all NIC concentrations. HGF cultures were subjected to a rotary shaker machine for 30 minutes to test the strength of attachment of these cells at 100, 150, and 200 rpm. The root and glass sections were examined at 48 hours by light microscopy.

RESULTS

Control groups exhibited a monolayer of long, spindle-shaped fibroblasts with a parallel alignment and minimal overlapping. With a concentration of NIC of 50 or 100 ng/ml as well as with increasing "speeds," the number of cells attached to these surfaces decreased dramatically. When 200 rpm was used for both groups at all NIC concentrations, very few HGF remained attached to these surfaces.

CONCLUSIONS

This study showed that the nature of cell attachment to either glass or root surfaces is altered by nicotine, and marked detachment was noted when nicotine exposure was coupled with vigorous agitation at different rpm. Marked detachment noted in all specimens at 200 rpm indicates that this speed is excessive for use in subsequent experimentation.

Effect of aqueous extract of cigarette smoke on peripheral blood polymorphonuclear leukocytes chemiluminescence

Cigarette smoke induces a vast cohort of deleterious effects on biological structures. In the present paper, the effect of aqueous extract of cigarette smoke on the activity of polymorphonuclear leukocytes was studied. Although the aqueous extract of cigarette smoke inhibits the luminol oxidation catalysed by horseradish peroxidase, it strongly interacts with polymorphonuclear leukocytes and inhibits their phorbol-induced chemiluminescence in the presence of either luminol or lucigenin. The results indicate that at least some of the components of the aqueous extract of cigarette smoke may strongly interfere with polymorphonuclear cells, contributing to the deleterious effects of smoke products.

The prevalence of pathogenic periodontal microflora in healthy young adult smokers

BACKGROUND

Smoking is a major risk factor in periodontitis, although the mechanisms of its effects are not well understood. The overall goal of this clinical study was to determine if smoking enhances the colonization of the oral cavity by pathogenic bacteria in a periodontitis-free population. The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, Bacteroides forsythus, and Treponema denticola was investigated in 25 smokers and 25 non-smokers by using DNA probes.

METHODS

The subjects were 21 to 35 years of age with a healthy periodontium or slight gingivitis and were systemically healthy. The test group included subjects who had a minimum of a 1.5 pack-year history of smoking, while the control subjects never smoked. Subgingival plaque samples were taken by paper point following the assessment of multiple clinical parameters.

RESULTS

This investigation showed: 1) no statistically significant differences were noted in any clinical parameter measured between the groups; 2) of the 8 subjects who were infected by at least 1 tested pathogen, seven were smokers (P= 0.02); 3) infected smokers had a 15.7+/-3.5 pack-year history and smoked a mean of 27+/-5 cigarettes/day versus 4.4+/-0.8 pack years and 15+/-1 cigarettes/day for the non-infected smokers (P = 0.0001 and P = 0.004); and 4) smokers were 18 times more likely to exhibit the presence of pathogens than non-smokers.

CONCLUSIONS

These data indicate that the prevalence of colonization of the sulcus by pathogenic bacterial species in periodontitis-free individuals is related to the quantity and duration of cigarette smoking.

Increased salivary acetaldehyde levels in heavy drinkers and smokers: a microbiological approach to oral cavity cancer

The pathogenetic mechanisms behind alcohol-associated carcinogenesis in the upper digestive tract remain unclear, as alcohol is not carcinogenic. However, there is increasing evidence that a major part of the tumour-promoting action of alcohol might be mediated via its first, toxic and carcinogenic metabolite acetaldehyde. Acetaldehyde is produced from ethanol in the epithelia by mucosal alcohol dehydrogenases, but much higher levels derive from microbial oxidation of ethanol by the oral microflora. In this study we investigated factors that might alter the composition and quantities of the oral microflora and, consequently, influence microbial acetaldehyde production. Information about dental health, smoking habits, alcohol consumption and other factors was obtained by a questionnaire from 326 volunteers with varying social backgrounds and health status, e.g. oral cavity malignancy. Paraffin-induced saliva was collected and the microbial production of acetaldehyde from ethanol was measured. Smoking and heavy drinking were the strongest factors increasing microbial acetaldehyde production. Whether poor dental status may alter local acetaldehyde production from ethanol remained unanswered. Bacterial analysis revealed that mainly gram-positive aerobic bacteria and yeasts were associated with higher acetaldehyde production. Increased local microbial salivary acetaldehyde production due to ethanol among smokers and heavy drinkers could be a biological explanation for the observed synergistic carcinogenic action of alcohol and smoking on upper gastrointestinal tract cancer. It offers a new microbiological approach to ethanol-associated carcinogenesis at these anatomic sites.

Possible potentiation of toxins from Prevotella intermedia, Prevotella nigrescens, and Porphyromonas gingivalis by cotinine

BACKGROUND

Smoking is a recognized risk factor for the initiation and progression of periodontitis. However, the mechanism by which smoking induces its negative effects on the periodontium is not clear. This study aimed to test the hypothesis that synergy may occur between cotinine and bacterial products isolated from 3 putative periodontopathogens.

METHODS

A chick embryo toxin assay was used to investigate bacterial toxins (cell-free extracellular toxins and cell-free cell lysates) from 5 species with and without cotinine. A total of 9 putative periodontopathogens (3 species) and 2 non-oral controls (2 species) were studied. The periodontal species were: Prevotella intermedia (n = 4), Prevotella nigrescens (n = 4), and Porphyromonas gingivalis (n = 1). The control species tested were: Staphylococcus aureus (n = 1) and Escherichia coli (n = 1).

RESULTS

The toxicity kill was significantly greater than expected by simple addition alone (P <0.05, Fisher's exact test) between cotinine (800 ng/ml) and 1) the cell-free extracellular toxins of P. nigrescens MH1 and 2) the cell-free cell lysates of P. intermedia MH2. Synergy occurred with cotinine plus the cell-free extracellular toxins in all but 3 periodontal isolates, and the cell-free cell lysates in all but 2 periodontal isolates. Cotinine significantly (P <0.05, Fisher's exact test) enhanced the effects of cell-free extracellular toxins and cell lysates from one control species (E. coli), but not the other (S. aureus).

CONCLUSIONS

These findings indicate that synergy in an in vitro assay can occur between cotinine and toxins from putative periodontopathogens. This may be one important mechanism by which smoking increases the severity of periodontitis.

Animal models used to test the interactions between infectious agents and products of cigarette smoked implicated in sudden infant death syndrome

Animal test systems are reviewed that have relevance to sudden infant death syndrome (SIDS) are reviewed. These test interactions between infectious agents (or their toxins) and products of cigarette smoke. Infectious agents implicated in SIDS include members of the enterobacteria and clostridia, Staphylococcus aureus and Streptococcus pyogenes. Smoking is thought to be the single most preventable cause of SIDS. Tobacco smoke contains many extremely toxic products including cyanide and nicotine. Many animal test systems are available to examine the potency of bacterial toxins and smoke-derived components. These include mice, hamsters, rats and chick embryos. Such systems reveal synergy between bacterial toxins, especially endotoxin and superantigens. They have also demonstrated potentiation of low levels of bacterial toxin by low levels of both nicotine and its primary metabolite, cotinine. These findings suggest a possible causal explanation for the fact that passive exposure to cigarette smoke is a risk factor in sudden infant death syndrome.

Effect of smoking one cigarette on antioxidant metabolites in the saliva of healthy smokers

Concentrations of glutathione, uric acid and total antioxidant activity, expressed as Trolox (a water-soluble vitamin E analogue) equivalent, were measured in the saliva of healthy non-smokers and smokers before and just after smoking a single cigarette. There was no statistically significant difference between smokers and non-smokers in uric acid concentrations and total radical-trapping antioxidant capacity, but glutathione concentrations were significantly (p < 0.05) higher in smokers. Smoking of a single cigarette induced a significant reduction in glutathione concentration (p < 0.05). Salivary antioxidant power may affect individual sensitivity toward tobacco stress.

Drugs and oral disorders

This chapter affirms that drugs and medicaments may have a profound effect on the periodontal structures. In some instances, such as drug-induced melanosis, the effect may be insignificant to the health of the patient. In other circumstances, drug-induced disorders may initiate painful, destructive disease processes that will not be successfully managed unless the causal role of drugs is recognized and altered. Finally, the clinician must remain aware of the contribution of drug-induced xerostomia and smoking to increased susceptibility to dental and periodontal diseases.

Cigarette smoking and periodontal diseases: etiology and management of disease

Cigarette smoking has long been suspected to be associated with a variety of oral conditions including periodontal diseases. Experimental evidence accumulated over the last 2 decades has indicated that cigarette smoking is probably a true risk factor for periodontitis. This environmental exposure has been associated with 2- to 3-fold increases in the odds of developing clinically detectable periodontitis. Smokers have both increased prevalence and more severe extent of periodontal disease, as well as higher prevalence of tooth loss and edentulism, compared to non-smokers. The greater severity of periodontal destruction may be partly accounted for by the reported increases in the rate of periodontal disease progression. The noxious effect of smoking has been shown to be dose dependent and to be particularly marked in younger individuals; in these subjects, up to 51% of the observed risk of periodontitis was associated with smoking. Much of the literature has also indicated that smokers affected with periodontitis respond less favorably to both non-surgical, surgical, and regenerative periodontal treatments. The success rate of dental implants has also been shown to be compromised in smokers. Furthermore, longterm studies have pointed out that smoking was associated with recurrence of periodontitis during periodontal maintenance; the effect appeared to be dose dependent, with heavy smokers (> 10 cigarettes/day) presenting with higher levels of disease progression. The indication that previous smokers have lower levels of risk for periodontitis compared to current smokers is considered to be the strongest available evidence that smoking cessation will result in improved periodontal health and that smoking cessation counseling should be an integral part of periodontal therapy and prevention. So far, however, no randomized controlled clinical trial establishing the effect of smoking cessation and/or reduction on the periodontal outcomes has been reported. Given the present state of uncertainty about the periodontal benefits, but in light of the established general health gains for the patient that could be derived from a smoking cessation program, practitioners are incorporating smoking cessation counseling as an integral part of periodontal therapy. Furthermore, smoking status represents a key parameter to assess the periodontal risk of an individual subject and therefore to make evidence-based clinical decisions.

Distribution of metallothionein in cigarette smokers and non-smokers in advanced periodontitis patients

This study evaluated the effect of smoking on periodontal tissue in periodontal patients. Gingival biopsies were taken from the flap during periodontal surgery of 33 male patients with advanced periodontal disease (22 cigarette smokers; 11 non-smokers). Frozen sections were made immediately and used for hematoxylin-eosin and Giemsa staining, and for detection of metallothionein (MT), a free radical scavenger. The expression and distribution of MT in these sections was studied using monoclonal antibody and immunohistochemical staining. The smokers had a large number of infiltrate cells in the gingival epithelium compared with non-smokers. Moreover, samples from the smokers showed high levels of MT in the prickle cell layer of the epithelium. In the non-smokers, basal and prickle cell layers of the gingival epithelium also showed detectable MT. Smokers, however, had a higher metallothionein-positive cell ratio in the prickle cell layer as compared to non-smokers. This increased level of MT in smokers may reflect an attempt to defend against free radicals in the gingiva of smokers. These results suggest that inflammation is much greater in periodontal tissues of cigarette smoking periodontal patients than in non-smoking periodontal patients, and that the defense against free radicals is heightened in smokers' gingiva.

Possible lethal enhancement of toxins from putative periodontopathogens by nicotine: implications for periodontal disease

AIM

To test the hypothesis that lethal synergy in the chick embryo model may occur between nicotine and bacterial products (cell-free extracellular toxins and cell lysates) of five putative periodontopathogens.

METHODS

The lethality of cell-free extracellular toxins and cell lysates of five periodontal species was assessed with or without nicotine in the chick embryo assay system. Ten putative periodontopathogens (five species) were studied: Prevotella intermedia (n = 5), Porphyromonas gingivalis (n = 1), Porphyromonas asaccharolytica (n = 1), Fusobacterium nucleatum (n = 2), and Fusobacterium necrophorum (n = 1).

RESULTS

Simultaneous testing of cell-free extracellular toxins from isolates W50, PS2, PS3, PS4, and PS5 and nicotine resulted in a percentage kill significantly greater than expected (Fisher's Exact test). Simultaneous testing of cell lysates from isolates W50, PS2, and PS5 and nicotine resulted in a percentage kill significantly greater than expected (Fisher's Exact test).

CONCLUSIONS

Lethal synergy in the chick embryo model may occur between nicotine and toxins from putative periodontopathogens (both cell-free extracellular toxins and cell lysates). This may be an important mechanism by which smoking increases the severity of periodontal disease.

The relationship between life-events and periodontitis. A case-control study

This case-control study (n = 100 dental patients, matched for age and sex) investigated the role of life-events in periodontitis. Data collected included life events, tobacco use, oral health behaviours and socio-demographics. The results of conditional simple logistic regression analysis showed that periodontitis was associated with the negative impact of life-events (p < 0.01), the number of negative life-events (p < 0.05), high levels of dental plaque (p < 0.01), tobacco smoking (p < 0.01) and being unemployed (p < 0.05). These associations remained statistically significant after adjusting for oral health behaviour and socio-demographic variables, but not tobacco smoking (p > 0.05). Marital status became statistically significant after adjusting for the other variables (p < 0.05). A model is suggested to explain the pathways through which life events may affect periodontal health. It was concluded that psychosocial factors and oral health risk behaviours cluster together as important determinants of periodontitis.

Periodontal diagnosis in treated periodontitis. Why, when and how to use clinical parameters

The objective of clinical periodontal diagnosis in maintenance patients is to monitor the risk for periodontal disease progression. Risk for progression should be continuously monitored at the patient, tooth and site level at each recall appointment. At the patient level, the significance of systemic diseases, cigarette smoking, compliance with the recall program, loss of support in relation to the patient's age, full mouth plaque and/or bleeding scores, and prevalence of residual pockets are of key importance. At the tooth and tooth-site levels, residual periodontal support, inflammatory parameters and their persistence, presence of ecological niches with difficult access such as furcations, and presence of iatrogenic factors have to be put into proportion with the patient's overall risk profile. The information gathered by clinical monitoring and continuous multilevel risk assessment facilitates an immediate appreciation of the periodontal health status of an individual and the possible risk for further infection and/or disease progression in the dentition and at a particular tooth or site.

Serum cotinine levels, smoking, and periodontal attachment loss

Cigarette smoking and tobacco use have been the subjects of numerous studies for many years. Smoking has also been associated with periodontal disease. However, no relationship between a reliable biochemical marker and increased severity of the periodontal condition has yet been described. It was thus the aim of this study to apply the measurement of cotinine, the major metabolite of nicotine, as a quantitative method to assess levels of smoking, and to correlate serum levels of cotinine with severity of periodontal disease. The degree of association between smoking and periodontal attachment loss was investigated in a study including 79 patients 25 to 64 years old suffering from periodontitis. Patients were examined and the following parameters recorded: Gingival Assessment (GA), Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Bone Crest Height (BCH). In addition, self-reported histories of tobacco use as well as blood samples for quantitative analysis of serum levels of cotinine were taken. The serum samples were analyzed for cotinine content by means of a competitive-inhibition ELISA technique. The differences in mean cotinine levels were statistically significant (p = 0.0001) between smokers and non-smokers, showing no overlap between the groups. Severity of periodontal attachment loss was positively correlated with serum levels of cotinine for both measures of periodontal disease (CAL p = 0.005; BCH p = 0.008). Results from the present study indicate that serum cotinine levels used as a biochemical marker of smoking status are correlated with severity of periodontal attachment loss.

Long-term stability of clinical attachment following guided tissue regeneration and conventional therapy

44 patients (34% smokers) presenting with severe periodontitis were treated with full mouth root planing (RPL). In each patient, 1 intrabony defect was treated with guided tissue regeneration (GTR). After 1 year of monthly prophylaxis, full mouth plaque (FMPS) and bleeding (FMBS) scores were 8.3 +/- 4.1% and 5.6 +/- 3.8%. At 1 year, the GTR treated sites were matched, in each patient, with 1 RPL site, in terms of probing attachment level (PAL 6.8 +/- 2.4 mm GTR, and 6.5 +/- 2.3 mm RPL). At this point, 24 patients took part in a supportive periodontal care program. 20 patients did not participate, and received only sporadic care by general dentists. At 5 years, all patients were reexamined. FMPS was 10.5 +/- 6.8% and FMBS 7.7 +/- 6.4%. A significant PAL loss was observed in both sites (1.2 +/- 1.4 mm GTR, 1.3 +/- 1.3 mm RPL, p < 0.0001) between 1 and 5 years. Differences in PAL loss between GTR and RPL sites were not statistically significant. Only a minority of sites (34%), however, lost PAL, while 66% remained stable. 75% of the matched sites (GTR and RPL) within the same patients were concordant in terms of PAL stability. The 23 patients in which both sites remained stable, had good oral hygiene, complied with the recall system, and did not smoke. The 10 patients in which both sites lost PAL showed deteriorating oral hygiene, did not comply with the recall system, and smoked. PAL loss in the GTR and/or RPL sites was consistently observed in patients (losers) showing PAL loss in other teeth. Losers had, in general, negative subjects characteristics, and showed a higher prevalence of tooth loss.

IN CONCLUSION

(i) GTR and RPL sites showed comparable susceptibility to periodontal breakdown; (ii) stability of outcomes was consistently associated with good oral hygiene, compliance with a supportive periodontal care program, and no cigarette smoking.

Psychosocial factors in inflammatory periodontal diseases. A review

Reviewing the literature concerning the possible rôle of psychosocial factors in the aetiology of inflammatory periodontal diseases, it may be concluded that there is evidence which strongly suggests that emotional stress is one of the predisposing factors to ANUG. On the other hand, it is not clear that the scientific evidence is sufficient to substantiate the hypothesis that psychosocial factors are of aetiological importance in periodontitis. The proposed mechanisms which may mediate the putative relationship between psychosocial conditions and inflammatory periodontal diseases remain to be tested. However, psychoneuroimmunologic studies make lowered host resistance especially interesting as a possible mechanism. Although available studies do not definitively support causal relationships, they suggest that psychosocial factors may be involved in the aetiology of inflammatory periodontal diseases, which, in turn, would relate to clinical management of these conditions.

Effect of cigarette smoking on periodontal healing following GTR in infrabony defects. A preliminary retrospective study

This retrospective study examined the effect of cigarette smoking on the healing response following guided tissue regeneration (GTR) in deep infrabony defects. 71 defects in 51 patients underwent GTR with teflon membranes. 20 patients (32 defects) smoked more than 10 cigarettes per day, while 31 patients (39 defects) did not smoke. Clinical measurements were available at baseline, at membrane removal and at the 1-year follow-up. The oral hygiene of both groups was good, but smokers had significantly higher full-mouth plaque scores. No significant differences were observed between smokers and non-smokers in terms of % of tissue gained at membrane removal. At the 1-year follow-up, however, smokers gained significantly less probing attachment level than non-smokers (2.1 +/- 1.2 mm compared with 5.2 +/- 1.9 mm). A multivariate model, correcting for the oral hygiene level of the patients and the depth of the infrabony component, indicated that smoking was in itself a significant factor in determining the clinical outcome. A risk-assessment analysis indicated that smokers had a significantly greater risk than non-smokers to display a reduced probing attachment level gain following GTR. It is concluded that cigarette smoking is associated with a reduced healing response after GTR treatment, and may be responsible, at least in part, for the observed results.

Tetracycline-loaded fibers as adjunctive treatment in periodontal disease

Fiber placed in periodontal pockets to deliver tetracycline continuously for 10 days was effective in reducing pocket depth and bleeding on probing when used as an adjunct to scaling and root planing. In this study, the combined therapy was valuable in treating adult patients who had refractory disease sites.

Smoke signals: an alert for oral disease

Since the early 1600s, questions have been raised about the ill effects of smoking. Tobacco has long been linked to oral cancer and leukoplakia, but research in the last 20 years suggests an association with other oral diseases as well. Studies concerning the effects of smoking on the periodontal diseases--and the mechanisms involved--are reviewed.

The effect of smoking on the response to periodontal therapy

This study evaluated the effect of smoking on the clinical response to non-surgical and surgical periodontal therapy. 74 adult subjects with moderate to advanced periodontitis were treated according to a split-mouth design involving the following treatment modalities: coronal scaling, root planing, modified Widman surgery, and flap with osseous resectional surgery. Clinical parameters assessed included probing depth, probing attachment level, horizontal attachment level in furcation sites, recession, presence of supragingival plaque and bleeding on probing. Data were collected: initially, 4 weeks following phase-I therapy, 10 weeks following phase-II therapy and on a yearly basis during 6 years of maintenance care. Data analysis demonstrated that smokers exhibited significantly less reduction of probing depth and less gain of probing attachment level when compared to non-smokers immediately following active therapy and during each of the 6 years of maintenance (p < 0.05). A greater loss of horizontal attachment level was evident in smokers at each yearly exam during maintenance therapy (p < 0.05). There were no differences between groups in recession changes. In general, these findings were true for the outcomes following all 4 modalities of therapy and were most pronounced in the deepest probing depth category (> or = 7 mm). Statistical analysis showed a tendency for smokers to have slightly more supragingival plaque and bleeding on probing. In summary, smokers responded less favorably than non-smokers to periodontal therapy which included 3-month maintenance follow-up.

Association between cigarette smoking, bacterial pathogens, and periodontal status

The purposes of this study were to determine if: 1) an association exists between cigarette smoking and signs of periodontal disease after controlling for the confounding variables of age, sex, plaque, and calculus; 2) the prevalence of 5 bacteria commonly associated with periodontal disease differs between smokers and non-smokers; and 3) the presence of any of these bacteria or smoking are associated with a mean proximal posterior probing depth > or = 3.5 mm. Plaque, calculus, gingivitis, and probing depth were measured at the proximal surfaces of all teeth in one randomly selected posterior dental sextant in 615 adults. Subgingival plaque was sampled from the same sites and assayed for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Eikenella corrodens, and Fusobacterium nucleatum. A subsample of non-smokers (n = 126), who were similar to smokers (n = 63) with respect to age, sex, plaque, and calculus, was randomly drawn from the original sample. These two groups were then compared on the basis of clinical and microbial parameters. The results indicated that the odds of having a mean probing depth > or = 3.5 mm were 5 times greater for smokers than the non-smoker subsample (odds ratio = 5.3; 95% CI = 2.0 to 13.8). No statistically significant difference in the prevalence of any of the bacteria was found between smokers and the non-smoker subsample. Based on logistic regression analyses of each of the 5 bacteria and smoking, mean probing depth > or = 3.5 mm was significantly associated with the presence of A. actinomycetemcomitans, P. intermedia, E. corrodens, and smoking (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Occurrence of periopathogens in smoker and non-smoker patients

The aim of the present study was to elucidate the interrelationship between cigarette smoking and the occurrence of periopathogens, i.e., Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius. The study was based on 145 patients with clinically severe periodontitis, 52 men (age range 32-73 years) and 93 women (age range 32-74 years). 83 patients were smokers (> or = 15 cigarettes/day) and 62 non-smokers. Bacterial samples were collected from one site with a probing depth > or = 6 mm for each individual. There were no statistically significant differences in bacterial counts between smokers and non-smokers (p > 0.05). The relative frequencies of smokers and non-smokers positive for A. actinomycetemcomitans were 31% and 31%, for B. gingivalis 42% and 44%, and for B. intermedius 65% and 53%, respectively. The differences between smoking groups were not statistically significant (p > 0.05). The occurrence in different combinations of these bacteria was also determined. There were no statistically significant differences between smoking and combinations of periopathogens (p > 0.05). The results suggest that smoker and non-smoker patients do not differ with regard to occurrence, relative frequency or different combinations of A. actinomycetemcomitans, B. gingivalis and B. intermedius.

Risk indicators for periodontitis in a military treatment population

The association between the periodontal diagnosis and a variety of subject characteristics was studied in a group of 1,783 patients examined at a large military dental clinic. In order of importance, age greater than 30, smoking, male sex, and Filipino racial background were all found to be statistically significant risk indicators for the presence of moderate or advanced periodontitis. A logistic regression equation serving as a predictive model employing these four variables was presented. The strong association found between smoking and advanced periodontitis is consistent with the hypothesis that smoking has cumulative detrimental effects on periodontal health. While these and other risk indicators are neither causative, diagnostic, nor prognostic, they may be helpful in alerting the clinician to more carefully evaluate other clinical signs or laboratory findings of disease.

Observations and concepts of the oral health consequences of tobacco use of Finnish periodontists and dentists

The observations of Finnish periodontists and other dentists, and their concepts of the oral health consequences of tobacco use as well as their counseling on tobacco use, were surveyed from November 1987 to January 1988. A questionnaire was mailed to all 61 Finnish periodontists and to 535 other dentists; 37 periodontists (61%) and 432 of the other dentists (80%) responded. The periodontists enquired about and advised on smoking significantly more frequently than did the other dentists; 71% of the periodontists often or always enquired about, and 62% advised their patients on smoking. 31% of all dentists had patients who were users of smokeless tobacco, and 62% of those dentists had often or always advised the users to quit. Nearly all dentists had seen some tobacco-caused effects. Periodontists reported more frequently than the other dentists that they had observed more periodontitis, impaired healing of periodontitis and more changes in the oral mucosa in smokers compared with non-smokers. The majority of those who had seen users of smokeless tobacco had noticed changes in the oral mucosa and in the color of the gingiva. The majority of all dentists believed that heavy smoking may impair the host response in the periodontium, with periodontists believing in this more strongly than other dentists.

Effects of topical and systemic nicotine on gingival blood flow in dogs

It has been suggested that due to its vasoconstrictive action, nicotine may have a deleterious effect on the periodontium. This study examined the effects of topical and systemic nicotine administration on gingival blood flow. Eighteen young adult dogs were divided into three groups receiving the following treatments for 28 days; topical nicotine in orabase, systemic nicotine via osmotic mini-pumps, and topical orabase or systemic saline via osmotic mini-pumps. Blood flow to the gingiva was measured (at days 0 and 28) by the radiolabeled microsphere method. Blood flow was consistently increased from day 0 to day 28 in the nicotine-treated animals. Comparison of days 0 and 28 blood-flow values demonstrated a statistically significant change (p less than 0.05) in the anterior regions of the topical-nicotine group as compared with the control group. The increased flow may be a reflection of the mode of nicotine delivery and timing of the blood-flow determination procedures.

Periodontal healing after impacted lower third molar surgery in adolescents and adults. A prospective study

The effects of impacted lower 3rd molar surgery on periodontal tissues in the adjacent 2nd molar area have been investigated in a prospective study comprising 176 cases from 2 age groups: less than or equal to 20 years (n = 93) and greater than or equal to 30 years (n = 83), respectively. The preoperative and 1-year postoperative examinations included both clinical and radiographic variables. All patients were subjected to a standardized surgical procedure and optimal plaque control pre-, intra- and postoperatively. Early removal of impacted lower 3rd molars with large angulation and close positional relationship to the adjacent 2nd molar proved to have a beneficial effect on periodontal health.

Oral hygiene compliance and gingivitis expression in cigarette smokers

The compliance with an oral hygiene intervention program and its effect on oral cleanliness and gingivitis was studied in smokers and non-smokers. The study group represented patients with regular dental attendance. It comprised 68 patients 21-60 yr of age, including 28 habitual smokers. The program included toothbrushing with an electric toothbrush for 12 months. Oral cleanliness was evaluated according to a percentage plaque index and gingivitis according to the percentage of bleeding sites. The compliance with the oral hygiene program was very high among smokers and non-smokers. Plaque index at baseline was very similar in smokers and non-smokers and remained so during the course of the investigation. Following the introduction of the oral hygiene program, plaque index decreased in both groups, and there were no statistically significant differences between the two groups. In spite of the similarity in plaque index, gingival bleeding was significantly lower in smokers than non-smokers. The results suggest that smokers and non-smokers do not differ with respect to habitual oral hygiene or compliance with hygiene programs. In smokers, however, the clinical gingivitis expression in response to plaque is suppressed.