The intent of the KAP (knowledge, attitude, practices) survey is to collect information about a specific target group related to their knowledge, what they consider to be known, and what they do about a particular topic. The aim of this study was to identify the level of importance of oral health, especially the level of knowledge, attitude and practices of rural patients around Cluj-Napoca, Romania. Material and methods: A questionnaire consisting of five parts was used, trying to assess the self-perception of oral health, knowledge and attitude towards oral health, dental hygiene practices and eating habits. A clinical examination was also performed in order to identify the number of missing teeth, the caries and the presence of calculus. Results: The study revealed that most patients have an average and good self-perception of oral health, although three-quarters of them have calculus deposits, and about half of them have more than three carious lesions and at least one extracted tooth. There is also a discrepancy between declared knowledge of oral health, eating habits and dental practices. Conclusions: The basic knowledge of rural patients about oral health can be considered satisfactory, but the practices, unfortunately, do not reflect this knowledge.

Background and Objectives: This numerical analysis investigated the biomechanical behavior of the mandibular bone as a structure subjected to 0.5 N of orthodontic force during periodontal breakdown. Additionally, the suitability of the five most used failure criteria (Von Mises (VM), Tresca (T), maximum principal (S1), minimum principal (S3), and hydrostatic pressure (HP)) for the study of bone was assessed, and a single criterion was identified for the study of teeth and the surrounding periodontium (by performing correlations with other FEA studies). Materials and Methods: The finite element analysis (FEA) employed 405 simulations over eighty-one mandibular models with variable levels of bone loss (0–8 mm) and five orthodontic movements (intrusion, extrusion, tipping, rotation, and translation). For the numerical analysis of bone, the ductile failure criteria are suitable (T and VM are adequate for the study of bone), with Tresca being more suited. S1, S3, and HP criteria, due to their distinctive design dedicated to brittle materials and liquids/gas, only occasionally correctly described the bone stress distribution. Results: Only T and VM displayed a coherent and correlated gradual stress increase pattern for all five movements and levels of the periodontal breakdown. The quantitative values provided by T and VM were the highest (for each movement and level of bone loss) among all five criteria. The MHP (maximum physiological hydrostatic pressure) was exceeded in all simulations since the mandibular bone is anatomically less vascularized, and the ischemic risks are reduced. Only T and VM displayed a correlated (both qualitative and quantitative) stress increase for all five movements. Both T and VM displayed rotation and translation, closely followed by tipping, as stressful movements, while intrusion and extrusion were less stressful for the mandibular bone. Conclusions: Based on correlations with earlier numerical studies on the same models and boundary conditions, T seems better suited as a single unitary failure criterion for the study of teeth and the surrounding periodontium.

Herein, the finite elements analysis (FEA) numerical study investigated the absorption–dissipation ability of dental tissues under orthodontic forces, during orthodontic movements and the periodontal breakdown process. Additionally, we investigated the correctness of FEA boundary assumptions up to 2.4 N of loads. Eighty-one models of the second lower premolar were subjected to 810 FEA numerical simulations using Tresca failure criterion under 0.6 N, 1.2 N, and 2.4 N and five movements: intrusion, extrusion, rotation, tipping, and translation. The results showed that both coronal dentine and enamel components had comparable high absorption–dissipation abilities, allowing for only a limited fraction of stresses to reach the circulatory sensitive tissues. Isotropy, linear elasticity, and homogeneity are correct when Tresca is employed up to 2.4 N. Forces of 0.6 N, 1.2 N, and 2.4 N displayed similar qualitative results for all movements and bone levels, while quantitative results doubled for 1.2 N and quadrupled for 2.4 N when compared with 0.6 N. FEA simulations showed 0.6–1.2 N to be safe for application in intact periodontium, while for reduced periodontium more than 0.6 N are prone to resorptive and ischemic risks. For reducing these risks, after 4 mm of bone loss, 0.2–0.6 N are recommended. Rotation and translation were the most stressful followed by tipping.

Background: Adhesion within endodontic obturation material and root canal walls improves the efficacy of the endodontic treatment by establishing a barrier that inhibits reinfection and entombs residual bacteria. This study evaluates the push-out bond strength (POBS) of calcium silicate sealers compared to an epoxy-resin-based sealer. Methods: A total of 36 extracted mono-radicular teeth were prepared with Pro Taper Ultimate and irrigated with 5.25% sodium hypochlorite and 17% EDTA. The specimens were randomly split into three groups (n = 12) according to the endodontic sealer and filling technique used as follows: Ah Plus with the continuous wave condensation technique (CWC), Ah Bioceramic (Ah Bio) with the single-cone technique, and Total Fill Hi-Flow (FKG Hi-Flow) with the CWC technique. The material was allowed to set for 4 weeks, and afterwards, the roots were placed in acrylic resin and sectioned into 1 mm transverse slices. A POBS test was conducted using a universal testing machine, and the mode of bond failure was assessed at 4× magnification using a stereomicroscope. Six specimens from each group were selected for SEM-EDX examination to evaluate dentinal tubule penetration. The data were analysed using analysis of variance and Tukey and Bonferroni post hoc tests. Results: The POBS tests revealed higher values for Ah Plus in comparison to both calcium silicate sealers (p < 0.001), while FKG Hi-Flow showed superior results to Ah Bio (p < 0.001). The cohesive mode of failure was prevalent in all three groups. Conclusions: In conclusion, the resin-based sealer showed higher bond strength and better dentinal tubule penetration than the two calcium silicate sealers tested, while FKG Hi-Flow outperformed AH Bio.

This study assessed the stress distribution (in eighty-one 3D models of the second lower premolar) in a stainless-steel bracket and enamel crown under 0.5 N of intrusion, extrusion, rotation, translation, and tipping during a horizontal periodontal breakdown of 0–8 mm. The FEA simulations (totaling 405) employed five failure criteria and assessed the adequacy and accuracy of Von Mises (VM), Tresca (T), Maximum Principal (S1), Minimum Principal (S3), and Hydrostatic Pressure. T and VM criteria showed no change in stress display areas during the periodontal breakdown, seeming to be more correct and adequate than the other three (with unusual stress displays). Both VM and T (found to be more adequate) generated maximum stress areas on the attachment side and the entire base of the bracket, confirming the non-homogenous stress distribution areas and the risks of bond failure. Rotation, translation, and tipping were the most stressful movements and showed slightly lower quantitative values for 8 mm bone loss when compared with the intact periodontium, while intrusion and extrusion showed the opposite behavior (slight increase). Periodontal breakdown did not influence the stress display in the bracket and its surrounding enamel area during the five orthodontic movements.

This finite elements analysis (FEA) assessed the accuracy of maximum shear stress criteria (Tresca) in the study of orthodontic internal surface resorption and the absorption–dissipation ability of dental tissues. The present study was conducted over eighty-one models totaling 324 simulations with various bone loss levels (0–8 mm), where 0.6 N and 1.2 N were applied in the intrusion, extrusion, rotation, tipping, and translation movements. Tresca criteria displayed localized high-stress areas prone to resorption for all situations, better visible in the dentine component. The internal resorptive risks are less than external ones, seeming to increase with the progression of the periodontal breakdown, especially after 4 mm. The internal and external surface high-stress areas are strictly correlated. The qualitative stress display for both forces was almost similar. The rotation and tipping displayed the highest resorptive risks for the pulp chamber, decreasing with bone loss. The resorptive risks seem to increase along with the progression of periodontal breakdown if the same applied force is kept. The dentine resemblance to ductile based on its high absorption–dissipation ability seems correct. Tresca seems to supply a better predictability of the prone-to-resorption areas than the other failure criteria.