Sinikka Salo

Data mining of clinical oral health documents for analysis of the longevity of different restorative materials in Finland

Evidence-based dentistry has shown that different restorative materials have different survival times. Our primary hypothesis is that this should be revealed from normal dental records by the use of data mining technique and a practice-based dentistry approach analysed in a scientifically sound way. Dental records from 1626 patients and altogether 19,892 restorations in three Finnish age cohorts were analysed. Survival curves (Kaplan-Meier) were drawn for each of the restorative materials. Median survival times for amalgam and resin-based composites were more than 15 years in older cohorts. More than 60% of silicate cement restorations were replaced within 5 years, and more than 50% of glass ionomers within 7 years. There was a significant reduction in the longevity of amalgams in the 1980 cohort. Data mining of digital oral heath documents would be a useful tool to analyse survival curves of new restorative materials in a practice-based manner in real-life conditions.

Practice-based study of the cost-effectiveness of fissure sealants in Finland

OBJECTIVE To retrospectively analyze the cost-effectiveness of sealant treatment in two health centers with different caries preventive strategies in Finland using a practice-based research protocol. MATERIALS AND METHODS The data of digital dental records were data-mined and analyzed retrospectively in the health center in Kemi where the preventive strategy was sealing selectively only high-caries risk patients, and in Vantaa where all patients were routinely sealed. Risk group determination in Kemi was based on the presence of Streptococcus mutans in dental plaque. Supervised use of xylitol was an additional caries preventive measure in Kemi. The subjects were divided into all-sealed and non-sealed groups in the beginning of the follow-up according to the sealant treatment status of their first permanent molars. The mean cumulative cost of restorations and sealing treatment was counted in children at 12 years of age. RESULTS Sealing of risk children in Kemi resulted in a total cost of 185euro per child whereas the respective cost of routinely sealed children in Vantaa was 235euro. The cost of restorations was 76euro in Kemi and 150euro in 5 years in Vantaa. Risk determination and the use of xylitol did not affect significantly the total treatment cost in Kemi. CONCLUSION The significant reduction in the cost of dental treatment can be achieved by leaving non-risk subjects unsealed and sealing only high-caries risk individuals.

A practice-based study of the variation of diagnostics of dental caries in new and old patients of different ages.

Data mining of digital dental records provides possibilities for analysing the variation between dentists when diagnosing caries. A total of 71,317 male and 82,302 female subjects visited the health centres in Vantaa and Kemi during the ‘digital era’ (1994–2005). As subjects were classified as ‘new patients’ at the first examination, all re-examinations of the same subjects thereafter by the same dentist produced ‘old patients’. A mean number of decayed surfaces (DS) was counted as a function of the age of the subject during the follow-up. The significance of the difference between old and new patients was determined by the Mann-Whitney test for each age cohort at the cross sections, and for the whole follow-up. Caries was seen to affect new patients more than the old ones in both health centres after the age of 20 years. The mean DS values were the same, reaching about 1 for new and old patients at the age of 15 years. The mean DS had a peak for new patients in both health centres at the age of 25 years and another peak around 45–50 years in Kemi. With a few exceptions there was a significant difference between the DS values of new and old patients at most cross sections and for the whole follow-up time. Evidently dentists examine new patients more carefully than their old patients. After the age of 18 years patients may have changed their dentists because they have finished the free-of-charge treatment period.

Computed online determination of life-long mean index values for carious, extracted, and/or filled permanent teeth

Objective. The purpose of this study was to develop and test a data-mining system for the online determination of mean DS, M, and FS or DMFS values per subject at different ages from electronic patient records at two health centers to see if there are north–south differences in oral health in Finland. Material and methods. The mean index values were determined at two health centers using the codes of dental charts and progress notes of electronic dental records during the digital era of more than 10 years in a total of 153,619 subjects of all ages. Extracted teeth, as well as sound, carious, and restored tooth surfaces, were recorded from the dental charts. Treatments were then additionally registered from progress notes of the records when performed. Results. The cumulative DS and FS values were similar in subjects under the age of 20 years at both health centers. In adults, caries was more abundant in northern Finland, where there was a higher number of restored surfaces (>40) registered, compared to only 30 in southern Finland at the age of 40 years. A high increase in the number of extractions began at age 45 in the north compared to age 70 in the south. These changes were clearly reflected in the DMFS index. Conclusions. Online determination of health parameters is a feasible methodology. The results revealed that north–south regional differences in dental health still occur in adults in Finland, but not in subjects younger than 20 years of age.

International study & promotion of osteoporosis prevention with Finnish bone exercise monitor in Sendai city, Japan

Under the project launched by Finland and City of Sendai, Japan, we started an international study of osteoporosis prevention with high-impact exercise scaled with accelerometer-based physical activity monitor, Bone Exercise Monitor (BEM). Following to the previous study in Finland, a randomized controlled study was done in Japan for 91 premenopausal women. Based on the joint study an exercise protocol with BEM will be developed. The purpose is to promote prevention of osteoporosis with exercise and thus improve QOL of older adults. I. BACKGROUND GEING is known as a big challenge for the society of most long-living nation Japan. However, it should be discussed and given solutions over the national boarders. When an advanced technology is developed, it is recommended to be shared by multinational collaboration. With this consequence, Sendai City of Japan and Republic of Finland launched a project named Sendai-Finland Wellbeing Center (S-FWBC) (Fig.1). In the project we emphasize the dignity, autonomy and activity of senior citizens (1), (2), (3). The ultimate goal of the project is to improve quality of life (QOL) of senior citizens supported by collaboration of academia, government, and industry. Fig. 1. A view of Finnish Wellbeing Center in Sendai, Japan. Research and Development Unit (left) and Care Unit (right)