Trends of endodontic and periapical status in adult Danish populations from 1997 to 2009: A repeated cross-sectional study.

AIM: To compare the endodontic and periapical status of two similar adult Danish populations examined in 1997-1998 and 2007-2009, respectively. METHODOLOGY: Two populations from Aarhus County, Denmark (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 1997-1998 (C1: 16 018 teeth) and 398 individuals in 2007-2009 (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 = .003), (teeth; C1: 26.0, C2: 26.8; p < .001). The prevalence of root filled teeth was lower in C2 than C1 (C1: 51.8%, C2: 45.0%; p = .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 = .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 = .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 ≤ .0007). CONCLUSIONS: Two similar general Danish populations examined, respectively, in 1997-1998 and 2007-2009, 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.

Quality aspects of ex vivo root canal treatments done by undergraduate dental students using four different endodontic treatment systems.

OBJECTIVE: To evaluate factors associated with treatment quality of ex vivo root canal treatments performed by undergraduate dental students using different endodontic treatment systems. MATERIAL AND METHODS: Four students performed root canal treatment on 80 extracted human teeth using four endodontic treatment systems in designated treatment order following a Latin square design. Lateral seal and length of root canal fillings was radiographically assessed; for lateral seal, a graded visual scale was used. Treatment time was measured separately for access preparation, biomechanical root canal preparation, obturation and for the total procedure. Mishaps were registered. An ANOVA mirroring the Latin square design was performed. RESULTS: Use of machine-driven nickel-titanium systems resulted in overall better quality scores for lateral seal than use of the manual stainless-steel system. Among systems with machine-driven files, scores did not significantly differ. Use of machine-driven instruments resulted in shorter treatment time than manual instrumentation. Machine-driven systems with few files achieved shorter treatment times. With increasing number of treatments, root canal-filling quality increased, treatment time decreased; a learning curve was plotted. No root canal shaping file separated. CONCLUSIONS: The use of endodontic treatment systems with machine-driven files led to higher quality lateral seal compared to the manual system. The three contemporary machine-driven systems delivered comparable results regarding quality of root canal fillings; they were safe to use and provided a more efficient workflow than the manual technique. Increasing experience had a positive impact on the quality of root canal fillings while treatment time decreased.