Quality of Endodontic Treatment and Prevalence of Apical Radiolucencies in a Bulgarian Subpopulation: a CBCT Analysis.

INTRODUCTION: The advent of Cone Beam Computed Tomography (CBCT) in endodontics has enhanced the diagnosis of periapical radiolucencies and the assessment of endodontically treated teeth. AIM: The purpose of this study was to assess the prevalence of periapical radiolucencies in a Bulgarian subpopulation and the quality of previous endodontic treatment using CBCT scans. MATERIALS AND METHODS: This study included 2795 roots from 160 Large FOV CBCT which were evaluated by two independent examiners using two scoring systems: CBCT-PAI and PESS. RESULTS: The inter-examiner agreement spanned from strong to almost perfect (0.892 and 0.983). The prevalence of periapical lesions according to the two scoring systems was 23.1% and 12.9 %, respectively. The prevalence of endodontically treated teeth was high (34.1%). Sixty-five percent of them presented with signs of periapical radiolucencies, while only 1.4% of all non-treated roots had a periapical lesion. A significant association between periapical disease, poor quality of the root canal filling and inadequate coronal seal was found (p<0.001). CONCLUSIONS: The prevalence of periapical disease in endodontically-treated teeth in the Bulgarian subpopulation was high. Poor qual-ity of the root canal filling and inadequate coronal seal were assessed as prognostic determinants of treatment failure. CBCT techniques can augment conventional diagnostic techniques in the field of endodontics.

Effect of ageing and endodontic treatment on the thermal stability of human dentin.

BACKGROUND: Human dentin is a highly calcified tissue of mesenchymal origin with a heterogeneous structure. Its morphology is constantly remodelled throughout the life span of the tooth, as well as under the influence of external stimuli. OBJECTIVE: The aim of the present study was to obtain information about the thermal changes in the crown and root dentin specimens of vital and devitalized teeth. METHODS: The investigated samples were divided into 6 groups, depending on the patients' age and dentin location (crown, root). An additional group of endodontically treated teeth was created. The methods of choice were were combined thermal analysis (DTA-TG(DTG)-MS and gas chromatography-mass spectrometry. RESULTS: After heating up to 1200 °C, endo- and exothermal effects were observed. The effects' dynamic was the same for all samples. The differences were in the samples' weight after the experiment, with root dentin showing the greatest mass loss percentage. CONCLUSIONS: The observed mass loss differences could be attributed to the presence of impurities in the dentin, as well as alterations in the collagen matrix. Ageing and endodontic treatment could catalyse the accumulation of such changes and affect the microstructure of the mineralized tissue.

Clinical Assessment of Endodontically Treated Teeth, Restored with or without Radicular Posts.

BACKGROUND: The reduced fracture resistance in endodontically treated teeth requires the use of radicular posts, with their advantages and disadvantages. AIM: To evaluate the clinical performance of teeth restored with or without radicular posts at 6 and 12 months. MATERIALS AND METHODS: The study included 22 patients who received endodontic therapy on premolars with a loss of one or two proximal walls. The premolars were divided into groups according to the restoration method: metal post group (MP), fiber post group (FP), and no post group (NP). For the NP group, a dentinal core of fiber-reinforced composite was used. The McNemar test, marginal homogeneity test and Kruskal-Wallis test were used in the statistical analysis. At the 6 and 12 month recall, both the direct composite restorations and the integrity of the post systems were assessed. RESULTS: At 6-month recall assessment, there was no statistically significant difference in the categories of 'appropriate colour', 'secondary caries' and 'obturation integrity'. That was not the case with 'marginal discoloration', 'marginal adaptation', 'proximal contact' and 'surface smoothness'. The recall at 12 months showed a continuation of this tendency, with significant decrease in the category of 'adequate colour'. Assessment of post longevity at the two recalls did not show any significant changes. The teeth restored without a post showed survival rates comparable to that of teeth restored with a post for the 12-month period of observation. CONCLUSIONS: There were no failures of the different posts used. The observed changes were attributed to the progressive deterioration of the composite restorations.