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

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

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)

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

Material Data collected in 2003 Both published and unpublished data available from 1973-1993 investigations

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

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

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%)

Paper I Changes in caries experience among 35-year-old Oslo citizens, 1973-2003

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

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

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 2003. 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 1973-84, 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 1984. 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.

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 1973 there was 5% of individuals with DS =0 (no caries registered), compared to 54% in 2003. 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.

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.

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

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

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

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

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

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

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

Root filled teeth with apical periodontitis

Quality of root fillings 1984-2003

Paper III Trends in periodontal health among 35-year-olds in Oslo, 1973-2003

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

Paper III. Methods Community Periodontal Index for Treatment Needs (CPITN), 1984-2003 data Assessment of radiographic bone loss The Simplified Oral Hygiene Index (OHI-S) (Greene & Vermillion 1964)

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

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

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

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

Cumulative % of participants according to the Simplified Oral Hygiene Index (OHI-S) scores, 1973-2003

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

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.

Paper IV. Material and methods Data from 2003 study 149 35-year-olds Questionnaire and clinical/radiographic examination

Paper IV. Methods

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

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

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)

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

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.

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.

Conclusions Prevalence of root filled teeth and teeth with apical periodontitis decreased in 1993 compared to 1973 and 1984. No further changes were observed in 2003. A gradual increase in root filled teeth with apical periodontitis from 1973 to 2003 was observed.

Conclusions The results indicate improvement in periodontal conditions and oral hygiene during the period 1973-2003.

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

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