LAUSR

AIM This study aimed to identify the factors influencing the changes in the number of teeth present, and the number of healthy or filled surfaces between two time-points. MATERIALS AND METHODS Repeated cross-sectional data from population-based studies, i.e., the German Oral Health Studies (DMS-III vs DMS-V), the Studies of Health in Pomerania (SHIP-START-0 vs. SHIP-TREND-0), and the Jönköping study (2003 vs. 2013), were analysed. Oaxaca decomposition models were constructed for the outcomes (number of teeth, number of healthy surfaces and number of filled surfaces). RESULTS The number of teeth increased between examinations [DMS: +2.26 (adults), +4.92 (seniors), SHIP: +1.67, Jönköping: +0.96]. Improvements in education and dental awareness brought a positive change in all outcomes. An increase in powered toothbrushing and interdental cleaning showed a great impact in DMS (adults: +0.25 tooth, +0.78 healthy surface, +0.38 filled surface; seniors: +1.19 teeth, 5.79 healthy surfaces, +0.48 filled surface). Interdental cleaning decreased by 4% between SHIP-START-0 and SHIP-TREND-0, which negatively affected the outcomes. CONCLUSION From this study, it can be concluded that education may be the most important factor having a direct and indirect effect on the outcomes. However, for better oral health, powered toothbrushing and interdental cleaning should not be neglected.