LAUSR

AIM To compare the endodontic and periapical status of two similar adult Danish populations examined in 1997-98 and 2007-09, respectively. METHODOLOGY Two populations from Aarhus County (age-range: 20-64 years) were randomly selected using the Danish Civil Registration System. Full-mouth intraoral radiographs (14 periapical, 2 bitewing) of 616 individuals in 1997-98 (C1: 16,018 teeth) and 398 individuals in 2007-09 (C2: 10,668 teeth) were taken to ascertain the number of teeth, presence of root fillings (RFs), and apical periodontitis (AP) using the Periapical Index (PAI). T-tests with unequal variances were used to assess differences between C1 and C2 with respect to age and the number of teeth. Multivariable and multinomial logistic regression analyses were used to assess the effect of cohort, age, and tooth type on the prevalence and relative frequency of RFs and AP. RESULTS Mean age and mean number of teeth were higher in C2 than C1 (age; C1: 42.3 years, C2: 44.6 years; p=0.003), (teeth; C1: 26.0, C2: 26.8; p<0.001). The prevalence of root filled teeth was lower in C2 than C1 (C1: 51.8%, C2: 45.0%; p=0.03); however, the prevalence of AP was similar (C1: 42.0%, C2: 45.0%). The relative frequency of root filled teeth was lower in C2 than C1 (C1: 4.8%, C2: 3.6%; p=0.004), although the individuals were older in C2. The relative frequency of AP was similar in the two cohorts (C1: 3.3%, C2: 3.6%; p=0.42). The relative frequency of AP in non-root filled teeth doubled from 0.9% in C1 to 1.8% in C2. C2 had higher PAI scores than C1 for root filled and non-root filled teeth, despite age-correction (p≤0.0007). CONCLUSIONS Two similar general Danish populations examined, respectively, in 1997-98 and 2007-09, were associated with a decreasing trend in the prevalence and relative frequency of RFs over the decade. There was no difference in relative frequency of AP in root filled teeth, but an increase in relative frequency of AP in non-root filled teeth. Further population-based studies including analysis of non-root filled teeth using the full-scale PAI and quality assessment of restorations are recommended.