General Health

How Does Smoking affect Periodontal Health?

Periodontitis is an array of inflammatory diseases affecting the periodontium, i.e., tissues supporting and lining the radical portion of teeth. It is a chronic inflammatory disease caused by gram-negative anaerobic bacteria present in the dental biofilm which irrevocably impairs the periodontium.

Periodontitis results in a continuous release of bacterial and inflammatory cytokines into saliva and to a certain degree into blood. These periodontal pathogens and inflammatory markers travel via saliva and blood from the affected tissues to distant sites thus affecting systemic healthy. The etiology of active periodontal disease considers three factors: A susceptible host, the presence of pathogenic species, and the absence of “beneficial bacteria”. Potential risk factors for periodontitis include smoking, diabetes, socioeconomic status, behaviour and stress.

Smoking and Gingivitis

Smoking and its clinical manifestations on periodontium is evident. However, paradoxically, smokers show reduced signs of inflammation in response to dental plaque than non-smokers, particularly in relation to gingival bleeding on probing and oedema. This could be due to altered caliber of the blood vessels perfusing the gingival tissues caused by cotinine, a nicotine metabolic by-product. Cotinine has a peripheral constrictive action on gingival vessels that reduces gingival clinical signs of bleeding, redness and oedema. Chang et al. have demonstrated altered Cox-2 mRNA expression in gingival fibroblasts in response to nicotine.

Smoking and Periodontitis

The relationship between smoking and periodontal health was investigated as early as the middle of the nineteenth century. More recently, several epidemiological, clinical and in vitro studies have emerged that prove that smoking adversely effects periodontal health. Studies indicate that smokers exhibit

  • increased bleeding on probing,
  • higher calculus and plaque deposits,
  • increased clinical attachment loss,
  • gingival recession and tooth mobility

All of these occur independent of age, gender and systemic condition.

Radiographic investigation of older adult population showed that the prevalence of molar furcation defects among cigarette smokers was twice of as compared to the group of non-smokers. Krall et al. concluded that men who smoke cigars or pipes were at increased risk of experiencing tooth loss. Cigar smokers also were at a higher risk of tolerating alveolar bone loss. These elevations in risk were similar in magnitude to those observed in cigarette smokers.

Further considering the region affected most, clinical investigations reveals that cigarette smokers with aggressive or early onset periodontitis have more extensive periodontal destruction in the maxillary region. In a Brazillian study, scientist showed that group of smokers had higher alveolar bone resorption than non-smokers, especially in the incisors region. They also confirmed that cigarette consumption affects maxillary region more than the lower jaw and the anterior region.

Smoking and Oral Microflora

Smoking affects the development of periodontitis both directly and indirectly. One of the suggestions is that the periodontal microflora is modified by smoking which in turn affects the periodontal development. Smokers present decreased oxygen tension in periodontal pockets, which favours anaerobic colonization. In vitro exposure of bacteria to cigarette smoking results in a marked decrease in viable bacterial population. Smokers were 2.3 times more likely to harbour T. forsythia, a periodontal pathogen than former smokers or non-smokers.

Current smokers displayed an increased risk of harbouring T. denticola in periodontal pockets. They also harbour other bacterial populations like A. actinomycetemcomitans, P. gingivalis, P. intermedia, E. corrodens and F. nucleatum. They also have an increased risk of having a mean pocket depth of ≥3.5 mm.

Haffajee and Socransky investigated the relationship between cigarette smoking and subgingival microbiota using checkerboard DNA hybridization. They concluded that the major difference between smokers and non-smokers was in the prevalence of species. This means that the periodontal pathogens colonized a larger proportion of sites, rather than counts.

Smoking and Periodontal Therapy

Using tobacco majorly influences periodontal therapy. Reduced clinical benefits in smokers following non-surgical periodontal therapy has been a consistent finding across many studies. The suggested mechanisms for this finding include inflammatory, immunological, microbiological and wound-healing phenomena. Preber and Bergstrom reported that smokers did not respond to non-surgical therapy as much as non-smokers.

Many studies have also noted that the effect of smoking on implant survival is more pronounced in areas of loose trabecular bone. Type II diabetes mellitus may have an adverse effect on implant survival rates which again as mentioned above is linked to both smoking and periodontal destruction. A history of treated periodontitis does not appear to adversely affect implant survival rates but it may negatively affect implant success rates, particularly over longer periods. Well-evaluated markers of collagen turnover, such as the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) are used to investigate changes in bone breakdown and bone turnover.

Smoking Cessation and Periodontitis

Studies suggest that tooth loss risk does decline after smoking cessation but the risk remains elevated in relation to non-smokers for at least 9-10 years. This is due to irreversible alveolar bone loss. So one might expect the cumulative damage to the bone tissue by cigarettes to be permanent.

Doctors also assume that as time elapses, these other risk factors become more important and begins to obscure the differences due to smoking history. Smokers who quit appear to be more health conscious than those who continue to smoke, and they make physician visits and use health screening programs at rates comparable to those of non-smokers.


Removing exposure to smoke reduces the likelihood of periodontal disease from becoming widespread. Hence, smoking is the most important risk factor for periodontitis.


Dr Shilpa Subramanian

Dr. Shilpa Subramanian is a Periodontist and currently manages Global Pharmacovigilance Operations at Indegene Pvt Ltd. She is passionate about staying ahead of the curve in clinical and non-clinical advances in the field of pharma and healthcare.

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