Root filled teeth in two parallel Danish cohorts: A repeated longitudinal cohort study

Abstract

Aim The aim of the study was to compare the frequency of root filled teeth and quality of root fillings (RFs) in two parallel, Danish cohorts each examined over 10 years and to evaluate factors associated with apical periodontitis (AP) and extraction of root filled teeth. Methodology Two randomly selected cohorts (C1, C2) from Aarhus (age: 20–64 years) were followed for approximately 10 years, with full‐mouth radiographic surveys performed at 5‐year intervals (C1: 1997–2003–2008; C2: 2009–2014–2019). Frequency of root filled teeth, quality of RFs and coronal restorations, periapical status and tooth extraction were registered. Logistic regression analyses compared C1 with C2 for baseline and follow‐up periods and assessed variables associated with AP (PAI‐based) and extraction of root filled teeth. Results C1 included 330 and C2, 170 individuals, mean age 42.9 and 47.3 years, respectively, who attended all three radiographic examinations. The relative frequency of root filled teeth was lower in C2 than C1 at baseline (C1: 4.7%, C2: 3.6%; p < .001) and after 10 years (C1: 5.7%, C2: 4.2%; p < .001). The relative frequency of new RFs was lower in C2 than in C1 (p = .02). C2 had fewer short/long RFs at baseline than C1; quality of new RFs or coronal restorations was similar in C1 and C2. The risk of tooth extraction (p = .93) and risk of AP (p = .37) at 10‐year follow‐up was similar between the two cohorts. For both C1 and C2, root filled teeth with AP at baseline had increased risk of having AP (p < .001) or having been extracted (p < .001) at follow‐up. Risk of extraction was higher for root filled premolars (p = .01) and molars (p = .01) than anteriors. Risk of AP at follow‐up was higher for root filled molars (p < .001). Furthermore, inadequate quality of RFs (p = .02) and coronal restorations (p = .04) increased the risk of AP at follow‐up in C1 and C2. Conclusions The frequency of root filled teeth and new RFs decreased and little to no change in new RFs' quality, AP, or tooth extraction was seen over time (1997–2019). Root filled molars and teeth with AP at baseline had increased risk of AP and extraction.

Longitudinal study of endodontic and periapical status of an adult Danish population examined in 2009, 2014, and 2019: a repeated cohort study

“…the descriptive analyses of individuals participating in the first, second, and third examinations indicated that the selection caused by drop-out during follow-up did not introduce serious bias for main findings regarding teeth with aP, root filled teeth, and tooth extractions in c1 and c2. a comparison of individuals, who participated in all three examinations, with those, who did not, showed that the individuals, who did not participate in all three examinations, were younger; but no differences in the number of root filled teeth per person and the proportion of root filled teeth with aP were found [12]. thus, the results based on individuals from c1 and c2, who participated in all three examinations, seem relevant.…”

“…in addition, the use of several observers necessitated a thorough calibration of the observers. this has been described and discussed in detail in previous articles [11,12].…”

“…the change from conventional radiography to digital radiography. to ensure comparability of conventional radiographs from the early examinations, all traditional radiographic images were scanned in the highest possible resolution and assessed on a computer screen so that viewing conditions were as similar as possible to the digital images, which were obtained from the more recent examinations [12]. in addition, the use of several observers necessitated a thorough calibration of the observers.…”

“…another, and perhaps more important change occurring during the observation period of the present study, was the global financial crises (2007)(2008)(2009), which almost coincided with the first examination of c2. according to statistic Denmark, the general use of dental services decreased during this and the subsequent period [12]. it indicates that the focus on oral health care was closely related to the economic situation.…”

“…Overall, the study showed that individuals in c2 had fewer root filled teeth than in c1, however, the periapical status of root filled teeth did not differ between the cohorts. c2 has also been reexamined after 5 years and again after 10 years and a repeated longitudinal cohort study of the root filled teeth in the two study populations has recently been published [12].…”