title: Cigarette smoking and alveolar bone in young adults: a study using digitized radiographs.
abstract: BACKGROUND
  Evidence indicates that cigarette smoking is one of the most significant risk factors for periodontal diseases; however, there have been few radiographic prospective studies of alveolar bone in young populations. The purpose of this study was to evaluate the effect of smoking on alveolar bone in young adults.
  
  
  METHODS
  Eighty-one dental students (mean age: 20.5 years), considered not to have periodontitis according to clinical criteria, participated in this study. Forty-two subjects were smokers (mean consumption was 14.1 cigarettes/day for > or =2 years), and 39 subjects had never smoked. A parallel-arm prospective design was used. All subjects took part in a dental hygiene program (DHP) that included oral hygiene instructions, mechanical debridement, and polishing. The following clinical variables were measured before and after the DHP: plaque index (PI), gingival crevicular fluid (GCF) flow rate, gingival index (GI), probing depth, and clinical attachment level (CAL). Standardized posterior vertical bitewing radiographs were taken and digitized preexperimentally and on days 180, 365, and 545. The following analyses were performed: bone height measurement (BHM), computer-assisted densitometric image analysis (CADIA), and qualitative analysis of digital subtraction radiography (DSR). Repeated-measures multiple-way analysis of variance (ANOVA) was performed between the groups, and one-way ANOVA was performed within the groups.
  
  
  RESULTS
  The mean PI and GI were significantly greater in the smokers (P <0.01). The mean GCF flow rate was significantly lower in the smokers (P <0.01). CAL and the number of sites with recession were significantly greater in the smokers (P <0.001). The BHM indicated a significantly lower mean alveolar bone height in the smokers (P <0.01). The smokers showed significantly lower CADIA values, which indicated a lower bone density on days 0 (P <0.05), 180, 365, and 545 (P <0.01). CADIA values decreased during the study in the smokers, with significant differences on day 545 (P <0.05). The smokers had a significantly higher mean percentage of sites that had decreased density, as assessed by DSR (P <0.001). In the smokers, the mean percentage of sites with decreased density, as assessed by DSR, had increased significantly by days 365 (P <0.05) and 545 (P <0.01).
  
  
  CONCLUSIONS
  Smoking produces an adverse effect on clinical periodontal variables and alveolar bone height and density, acting as a potential risk factor for alveolar bone loss, even at an early age with low tobacco consumption. It is very important to inform young smokers about the risk of this habit in relation to periodontal health.
authors.affiliation: Department of Research, Graduate School Foundation, Resistencia, Chaco, Argentina. gmrosa@gigared.com
authors.forename: Guillermo M
authors.initials: GM
authors.lastname: Rosa
authors.forename: Gabriela Q
authors.initials: GQ
authors.lastname: Lucas
authors.forename: Oscar N
authors.initials: ON
authors.lastname: Lucas
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging* / Q000209:etiology*; D000704:Analysis of Variance; D015519:Bone Density; D016022:Case-Control Studies; D003774:Dental Plaque Index; D005260:Female; D006801:Humans; D008297:Male; D009910:Oral Hygiene / Q000193:education; D010512:Periodontal Index; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D016300:Radiography, Bitewing; D019252:Radiography, Dental, Digital; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013382:Subtraction Technique