Mechanical properties of ion-releasing restorative materials.

PURPOSE: To evaluate and compare the laboratory compressive strength (CS), flexural strength (FS), and diametral tensile strength (DTS) of Cention Forte and three bulk fill restorative materials. METHODS: A total of 168 specimens were prepared following the manufacturers' instructions and standards for testing CS, FS, and DTS. Mechanical properties of Cention Forte (LC-Cent) were compared to three commercial bulk-fill materials for posterior restorations: Fuji IX Extra (Fuji), Tetric PowerFill (TPF), and Equia Forte HT (Equia). The tests were performed 24 hours after storage in distilled water on a universal testing machine at a crosshead speed of 0.75 mm/minute. Strength values (MPa) were calculated and statistically analyzed by one-way ANOVA and Tukey's post hoc test (P< 0.05). RESULTS: Analysis showed significant differences between tested materials for CS, FS, and DTS (P= 0.0001). LC-Cent showed the highest mean value for FS (112.8 MPa) with a significant difference compared to Fuji and Equia. DTS (49.2 MPa) of LC-Cent was significantly higher than all tested materials. TPF showed the highest mean value (180 MPa) for CS but without significant difference compared to LC-Cent. CLINICAL SIGNIFICANCE: Ion-releasing material Cention Forte, according to obtained results, may serve as a viable alternative for posterior restorations compared to conventional bulk-fill restorative materials.

Probable Bruxism and Psychological Issues among Dental Students in Serbia during the COVID-19 Pandemic.

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.

Analysis of the Impact of Oral Health on Adolescent Quality of Life Using Standard Statistical Methods and Artificial Intelligence Algorithms.

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.

Epidemiological investigation of non-carious cervical lesions and possible etiological factors.

BACKGROUND: Epidemiological 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 METHODS: The 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. RESULTS: NCCLs 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. CONCLUSIONS: This 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.

Environmental lead pollution and its possible influence on tooth loss and hard dental tissue lesions.

BACKGROUND/AIM: Environmental lead (Pb) pollution is a global problem. Hard dental tissue is capable of accumulating lead and other hard metals from the environment. The aim of this study was to investigate any correlation between the concentration of lead in teeth extracted from inhabitants of Pancevo and Belgrade, Serbia, belonging to different age groups and occurrence of tooth loss, caries and non-carious lesions. METHODS: A total of 160 volunteers were chosen consecutively from Pancevo (the experimental group) and Belgrade (the control group) and divided into 5 age subgroups of 32 subjects each. Clinical examination consisted of caries and hard dental tissue diagnostics. The Decayed Missing Filled Teeth (DMFT) Index and Significant Caries Index were calculated. Extracted teeth were freed of any organic residue by UV digestion and subjected to voltammetric analysis for the content of lead. RESULTS: The average DMFT scores in Pancevo (20.41) were higher than in Belgrade (16.52); in the patients aged 31-40 and 41-50 years the difference was significant (p < 0.05) and highly significant in the patients aged 51-60 (23.69 vs 18.5, p < 0.01). Non-carious lesions were diagnosed in 71 (44%) patients from Pancevo and 39 (24%) patients from Belgrade. The concentrations of Pb in extracted teeth in all the groups from Pancevo were statistically significantly (p < 0.05) higher than in all the groups from Belgrade. In the patients from Pancevo correlations between Pb concentration in extracted teeth and the number of extracted teeth, the number of carious lesions and the number of non-carious lesions showed a statistical significance (p < 0.001, p < 0.01 andp < 0.001, respectively). CONCLUSION: 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.