A retrospective repeated cross sectional study assessing changes in the prevalence of apical periodontitis associated with the endodontic status and DMFT scores of patients in two adult cohorts (2008/2009 and 2018/2019) attending a UK dental hospital.

Aim: To compare the prevalence of apical periodontitis (AP), endodontic treatments, quality of endodontic treatments and their association with apical radiolucencies and DMFT scores, in patients attending a British National Health Service (NHS) Hospital in 2008-2009 (Cohort 1/C1) and 2018-2019 (Cohort 2/C2). Methodology Randomly selected panoramic radiographs of 980 patients, evenly distributed into two cohorts: C1 (2008-2009) and C2 (2018-2019), were retrospectively analysed. Patient demographics, number of teeth, presence and quality of endodontic treatments, apical radiolucencies in treated and untreated teeth, endodontic treatment quality, apical periodontitis prevalence by tooth type and DMFT scores were compared. Results: C1 had significantly higher DMFT scores (p<0.001), but similar numbers of teeth to C2. Patients with apical periodontitis had higher DMFT scores and lower number of molars (p<0.001). Similar percentages of untreated teeth had apical periodontitis in C1 (3.4%) and C2 (2.9%) but at a patient level, C2 had significantly fewer endodontic treatments (48.2% vs 41.2%; p=0.015), less apical disease (51%, vs 44%; p=0.04) and fewer endodontically treated teeth (5.5% vs 4.2%; p=0.007). The percentage of endodontically treated teeth with apical periodontitis was similar (29.3%, vs 27.9%). C2 patients had less unsatisfactorily obturated teeth (63.7% vs 57.6%) which was short of significance (p=0.072). C2 had fewer endodontically treated anterior teeth (p<0.001) but a higher proportion of endodontically treated molars (20.2%, vs 28.7%; p=0.003). A close to significant improvement in the quality of molars’ root canal treatments in C2 was noted (well-obturated teeth C1: 23.48%, c2: 35.11%; p=0.061). Conclusion A reduction of caries and endodontic disease burden and a slight improvement in the quality of endodontic treatments in the 2018/2019 cohort was observed. This was not accompanied by increased tooth retention.