BackgroundEpidemiological studies of non-carious cervical lesions (NCCLs) are being conducted in all geographical regions, which is completely justified, considering the high frequency of these lesions and possible consequences. Data obtained from such studies are of great importance because, beside describing the extent and degree of lesions, they can also point to specific etiological factors. The purpose of this study was to analyze the frequency and distribution of NCCLs among the patients of Faculty of Dentistry in Pancevo, Serbia, and to investigate the impact of certain etiological factors on the frequency of NCCLs.Material and MethodsThe study included 394 patients, who were clinically examined for the presence of NCCLs and interviewed about potential etiological factors using specially designed questionnaire. Saliva samples were analyzed for 30 patients with multiple NCCLs (≥3) and 30 patients without signs of cervical lesions and restorations. Subject – level logistic regression was used to analyze the association of potential etiological factors and presence of NCCLs and Wilcoxon test for the quantity and quality of saliva.ResultsNCCLs were diagnosed at 68.5% from total number of respondents, 15% from all present teeth were affected. The highest prevalence was recorded on premolars. Presence of lesions significantly increased with age. Frequent consumption of citrus fruit was associated with the presence of NCCLs. Significantly lower frequency of NCCLs was recorded among subjects who frequently chew gums. Significantly lower pH values of unstimulated and stimulated saliva were recorded in the group of patients with multiple NCCLs compared to control group.ConclusionsThis study showed high frequency of NCCLs among subjects of different age. Premolars were the most frequently affected. Age, frequent consumption of citrus fruit and lower salivary pH value were associated with an increased occurrence of NCCLs. Chewing gums habit was associated with an decreased occurrence of NCCLs. Key words:NCCL, abrasion, erosion, abfraction, saliva.

Background/Aim. Apical extrusion of material is considered as one of the very important factor for endodontic treatment success. Microorganisms, necrotic tissue, filling material and irrigants, which can be extruded apically during endodontic retreatment, may jeopardize the success of the therapy. The aim of this in vitro study was to quantitatively evaluate the amount of apically extruded debris during endodontic retreatment of teeth obturated with two different materials, using one hand and three rotary instrumentation techniques. Methods. Ninety-six extracted single-rooted teeth were endodontically treated and enlarged to size 40 using BioRaCe system, and then randomly divided into 8 groups of 12 specimens each. Half of the specimens were obturated with gutta-percha and AH Plus® sealer and another half with RealSeal SE system, using lateral condensation technique. Retreatment was performed using: Hedström files; ProFile rotary files; ProTaper Retreatment system and D-RaCe system. Apically extruded debris was collected in pre-weighed Eppendorf tubes and evaluated using an electronic microbalance. Data were analyzed statistically using t-test and analysis of variance. Results. In the AH Plus/gutta-percha group, all tested rotary instruments gave significantly less extruded debris compared with Hedström files (p < 0.05). In theRe-alSeal group, there was significant difference between D-RaCe and Hedström instruments (p < 0.05). Conclusion. All retreatment techniques resulted in apical extrusion. D-RaCe system produced significantly less extruded debris compared to hand files. No significant difference was found when comparing two instruments specially designed for retreatment: D-RaCe and ProTaper systems.

The COVID-19 pandemic has drastically changed the routine way of life, having consequences in many segments of life, including dental practice and education. The aim of this study was to evaluate the frequency of probable bruxism in a sample of dental students in Serbia and to estimate the potential association between psychological factors related to the COVID-19 pandemic and the presence of bruxism. A cross-sectional study included 178 dental students in Serbia, who were interviewed using a specially-designed self-administered online questionnaire, which consisted of three sections, and after that, a clinical examination for the presence of bruxism symptoms in the oral cavity. Psychological status was evaluated using the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Fear of COVID-19 Scale (FCV-19S). Saliva samples were taken to analyze salivary cortisol levels. The prevalence of probable bruxism was 34.8%. Respondents with probable bruxism had significantly higher DASS-21 and FCV-19S scores and mean values of salivary cortisol compared to non-bruxers. A history of COVID-19 infection, high stress, and fear of COVID-19 scores were associated with the presence of probable bruxism. The findings suggest that the COVID-19 pandemic has had a great psychological impact and impact on the presence and worsening of bruxism symptoms in a sample of dental students in Serbia.

The aim of this study was to determine the impact of oral health on adolescent quality of life and to compare the results obtained using standard statistical methods and artificial intelligence algorithms. In order to measure the impact of oral health on adolescent quality of life, a validated Serbian version of the Oral Impacts on Daily Performance (OIDP) scale was used. The total sample comprised 374 respondents. The obtained results were processed using standard statistical methods and machine learning, i.e., artificial intelligence algorithms—singular value decomposition. OIDP score was dichotomized into two categories depending on whether the respondents had or did not have oral or teeth problems affecting their life quality. Human intuition and machine algorithms came to the same conclusion on how the respondents should be divided. As such, method quality and the need to perform analyses of this type in dentistry studies were demonstrated. Using artificial intelligence algorithms, the respondents can be clustered into characteristic groups that allow the discovery of details not possible with the intuitive division of respondents by gender.

According to correlations between lead concentration and the number of extracted teeth, number of carious lesions and non-carious lesions found in the patients living in Pancevo, one possible cause of tooth loss and hard dental tissue damage could be a long-term environmental exposure to lead.