1. Studies on dental diseases among 35-year-olds in Oslo, Norway, 1973-2003. Trends and determinants
Rasa Skudutyte-Rysstad
Department of Cariology and Gerodontology
Faculty of Dentistry, University of Oslo

2. Contents Background for the project General aims Material
Papers I-IV (specific aims, methods and findings)
Conclusions

3. The Oslo studies
Repetitive cross-sectional studies performed among 35-year-olds in Oslo in 1973¹, 1984² and 1993³
Have described changes in dental caries, endodontic and periodontal conditions
(¹Hansen 1976, ²Bjertness et al.1986, ³Berset et al.1996)

4. Aims of the study
To investigate dental health among 35-year-olds in Oslo in 2003 and to assess possible changes in a 30-year perspective
To assess determinants associated with differences in dental health in 2003

5. Material Data collected in 2003
Both published and unpublished data available from investigations

6. Material
Random samples of 35-year-olds born in 1938, 1949, 1958 and 1968
Invitation letter with general information about the survey
Clinical and radiographic examination and questionnaire

7. Material ( )
Year of study
Number
examined
Response rate
1973
117
66%
1984
156
80%
1993
121
68%
2003
149
64%

8. Non-response in 2003
Of in total 83 non-responders, 56 (68%) were contacted and 44 (53%) telephone interviewed
Main reasons for non-response
Males (N=20): lack of time (60%) and lack of interest (30%)
Females (N=36): pregnancy/maternity (31%), lack of time (31%) and dental fear (11%)

9. Paper I
Changes in caries experience among 35-year-old Oslo citizens,

10. Paper I. Aims
To describe caries experience among 35- year-olds in 2003
To assess changes in caries experience from 1973 to 2003

11. Paper I. Methods
DMFS/T based on clinical and radiographical caries registration
Clinically the WHO criteria, 28 teeth
Supplemented by caries registration from BW radiographs

12. Changes in the mean DMFS scores, 1973-2003
68.2
26.1
Changes in caries experience during the 30 year period are presented as the mean values of DMFS (at the surface level). The first substantial decline in the total caries experience was observed in 1993 and it continued to The mean DMFS decreased to 26,1 in 2003 compared to 68,2 in 1973, which is a 62% reduction during this 30 year period.
When looking at the distribution of the separate DMF index components , there was a significant decrease in the mean DS and MS scores and a slight increase in FS scores. In 1993 the mean numbers of DS, MS and FS were significantly reduced compared to In 2003 the decrease in the total caries experience was mainly due to FS score, since no significant differences in the mean number of DS and FS compared to 1993 were observed.

13. Cumulative % of participants according to the DS scores, 1973-2003
In this figure cumulative percentage distributions for carious surfaces or DS scores are presented. Cumulative percentage distributions indicate percentage of people who responded with the particular score or less. In there was 5% of individuals with DS =0 (no caries registered), compared to 54% in Only during the last decade from 1993 to 2003, the proportion with DS=0 increased from 41% to 54%.
If we look at the other end of the curve or those who presented with highest DS scores, in 2003 there was 5% who had DS score of 4 ore more, compared to 73% in 1973.

14. Cumulative % of participants according to the FS scores, 1973-2003
Cumulative percentage distributions for filled surfaces indicate that the whole distribution curve has moved to the left. Still, there were very few individuals who had no fillings at all.

15. A 35-year-old in 1973 and 2003
1973
DMFS=68
2003
DMFS=26

16. Paper II
Endodontic status amongst 35- year-old Oslo citizens and changes over a 30-year period

17. Paper II. Aims To describe endodontic status in 2003
To investigate possible changes in endodontic status in a 30-year perspective

18. Paper II. Methods Prevalence of root filled teeth
Prevalence of apical periodontitis
Prevalence of root filled teeth with apical periodontitis

19. Paper II. Methods Technical quality of root fillings
Distance to the radiographic apex
1-2 mm versus under/overfilling
Complete/ incomplete seal

20. Paper II. Methods OPG and periapical radiographs
PAI index (Ørstavik et al. 1986)

21. Prevalence of root filled teeth and apical periodontitis, 1973-2003
Forekomsten av rotfylte tenner og tenner med apikal periodontitt gikk ned i 1993, men forble uforandret i 2003

22. Root filled teeth with apical periodontitis

23. Quality of root fillings 1984-2003

24. Paper III
Trends in periodontal health among 35-year-olds in Oslo,

25. Paper III. Aim
To describe trends in periodontal health and oral hygiene from 1973 to 2003

26. Paper III. Methods
Community Periodontal Index for Treatment Needs (CPITN), data
Assessment of radiographic bone loss
The Simplified Oral Hygiene Index (OHI-S) (Greene & Vermillion 1964)

27. Paper III. Methods
Community Periodontal Index for Treatment Needs (CPITN)
Registrations are based on index teeth
Score 0: healthy
Score 1: bleeding gingiva on gentle probing
Score 2: presence of calculus
Score 3: 4-5 mm periodontal pockets
Score 4: ≥6 mm periodontal pockets

28. Paper III. Methods OPG available from 71-97% of participants
Radiographic bone loss was assessed from OPG by modified Schei (1959) technique (bone height was measured in relation to the radiographic root length)
Participants were categorized according to the highest bone loss score recorded at one or more sites

29. Periodontal conditions by the highest CPITN score per person, 1984-2003

30. Distribution of participants (%) according to the level of radiographic bone loss, 1973-2003
1984
1993
2003

31. Cumulative % of participants according to the Simplified Oral Hygiene Index (OHI-S) scores,

32. Paper IV
Dental health and disease determinants among 35-year- olds in Oslo, Norway

33. Paper IV. Aims
To identify non-biological determinants associated with the number of sound teeth (ST) and the presence of decayed surfaces (DS) among 35-year-old Oslo citizens.

34. Paper IV. Material and methods
Data from 2003 study
year-olds
Questionnaire and clinical/radiographic examination

35. Paper IV. Methods

36. Paper IV. Methods Dependent variables: ST and D3S≥2
Linear (ST) and logistic (D3S≥2) regression analyses taking into account the hierarchical relationships between the independent variables

37. Factors associated with the number of sound teeth (ST)
Variable
Block I
Block II
Beta
P value
Marital status: single versus married/partner
0.245
0.004
0.251
0.001
Region of birth: non-Western versus other
0.388
0.000
0.381
Education: university versus other
0.149
0.093
0.181
0.028
Family income: low versus medium/high
0.968
Dental anxiety score: high versus low
-0.093
0.237
Last dental visit: >1 year ago versus other
0.059
0.455
Model summary
Adj.R2=0.172
Adj.R2=0.173

38. Background factors associated with the presence of D3S≥2
Variable
Block I
Odds ratio
95% CI
Region of birth: non-Western versus other
1.9
(0.6; 6.7)
Education: university versus other
0.8
(0.3; 2.1)
Family income: low versus medium/high
2.7
(0.9; 8.1)
Dental anxiety score: high versus low
2.4
(0.7; 8.6)

39. Factors associated with the presence of D3S≥2
Variable
Block I
Block II
Odds ratio
95% CI
Family income: low versus medium/high
4.5
(1.9; 10.2)
2.1
(0.8; 5.8)
Tooth brushing frequency: more than once a day versus other
0.6
(0.2; 1.6)
Dental visits: irregular versus regular
4.1
(1.5; 11.4)
Last dental visit: >1 year ago versus other
1.0
(0.4; 2.6)
Smoking (reference: non-smoker)
Smoker
Former smoker
2.8
(1.6; 12.6)
(1.0; 8.2)
Model summary
Nagelkerke R2 =0.151
Nagelkerke R2 =0.317

40. Paper IV. Results
Higher numbers of sound teeth were associated with having university education, being single and being born in the non-Western country.
Low family income, smoking and irregular dental visits were associated with presence of untreated decay.

41. Conclusions
The results of the present thesis indicate positive development in dental health among young urban adults in Norway.
The results indicate a considerable decrease in caries among 35-year-olds in Oslo from 1973 to 2003.

42. Conclusions
Prevalence of root filled teeth and teeth with apical periodontitis decreased in 1993 compared to 1973 and No further changes were observed in 2003.
A gradual increase in root filled teeth with apical periodontitis from 1973 to 2003 was observed.

43. Conclusions
The results indicate improvement in periodontal conditions and oral hygiene during the period

44. Conclusions
Socio-demographic determinants were associated with numbers of sound teeth.
Both socio-demographic and behavioral variables were associated with presence of decayed surfaces.

45. Studies on dental diseases among 35-year-olds in Oslo, Norway, 1973-2003. Trends and determinants
Rasa Skudutyte-Rysstad
Department of Cariology and Gerodontology
Faculty of Dentistry, University of Oslo