University of Oulu

Similä, T., Virtanen, J.I. Association between smoking intensity and duration and tooth loss among Finnish middle-aged adults: The Northern Finland Birth Cohort 1966 Project. BMC Public Health 15, 1141 (2015).

Association between smoking intensity and duration and tooth loss among Finnish middle-aged adults : the Northern Finland Birth Cohort 1966 Project

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Author: Similä, Toni1,2,3; Virtanen, Jorma I.1,2,3
Organizations: 1Research Unit of Oral Health Sciences, Faculty of Medicine, University of Oulu, P.O. Box 5281, Oulu, FIN-90014, Finland
2Medical Research Center Oulu, Oulu, Finland
3Oulu University Hospital, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.5 MB)
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Language: English
Published: Springer Nature, 2015
Publish Date: 2020-05-20


Background: Smoking is a risk factor for oral diseases and tooth loss. Our aim was to analyze the association between smoking intensity and duration and tooth loss among middle-aged Finnish adults who have enjoyed access to subsidized dental care since childhood.

Methods: This study was based on the Northern Finland Birth Cohort 1966 (NFBC1966) Project, a representative sample of Finnish 46-year-olds. Altogether 1946 46-year-olds participated in a survey and comprehensive clinical oral examinations. We measured smoking exposure in pack-years (intensity) and years of smoking (duration) combined with recent smoking status (current, former, occasional or never). We used negative binomial regression models to estimate the unadjusted and adjusted relative risks (RR) with corresponding 95 % confidence intervals (CI) for tooth loss as an outcome. Gender, education, tooth brushing frequency, dental plaque, diabetes and alcohol use served as explanatory variables for the adjusted models.

Results: Smoking intensity associated with tooth loss in an exposure-dependent manner: those with a high number of pack-years had a significantly greater probability of tooth loss than never smokers: 11–20 pack-years (RR = 1.55, 95 % CI = 1.15–2.08) and 21 or more pack-years (RR = 1.78, 95 % CI = 1.36–2.33). Smoking duration also associated with tooth loss: those who had smoked for several years had a significantly higher probability of tooth loss than never smokers: 21–30 years of smoking (RR = 1.66, 95 % CI = 1.29–2.12) and 31 or more years of smoking (RR = 1.72, 95 % CI = 1.20–2.45).

Conclusions: We found a clear intensity- and duration-dependent relation between smoking and tooth loss among adults with access to subsidized dental care and in good oral health.

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Series: BMC public health
ISSN: 1471-2458
ISSN-E: 1471-2458
ISSN-L: 1471-2458
Volume: 15
Article number: 1141
DOI: 10.1186/s12889-015-2450-6
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
Funding: NFBC1966 received financial support from University of Oulu Grant no. 24000692, Oulu University Hospital Grant no. 24301140, ERDF European Regional Development Fund Grant no. 539/2010 A31592.
Copyright information: © 2015 Similä and Virtanen. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.