Search Results (26)

Objectives: To compare fracture toughness (FT), work of fracture (WOF) and Vickers hardness (HV) of four 3D-printed denture base resins—including two novel formulations—and one conventional cold-cured polymethylmethacrylate (PMMA) resin. Methods: 3D-printed specimens (Freeprint denture (FD)/denture impact (FDI), DETAX GmbH and V-Print dentbase/dentbase 2.0, VOCO GmbH) were fabricated at 90° layer orientation (n = 40/group) and notched according to ISO 20795-1. FT and WOF were measured via single-edge notched bend testing after seven-day water storage at 37 °C. HV was determined on fractured shards using 3 N load. Data were analyzed with Welch-ANOVA/Dunnett-T3 or ANOVA/Tukey (α = 0.05). Results: The conventional PMMA showed the highest FT and WOF, followed by the novel formulations of the 3D-printed groups VD2 and FDI. Lowest FT and WOF values were measured for VD and FD. HV was highest for the conventional PMMA, followed by the primary formulations FD and VD. Lowest hardness was measured for the novel formulations FDI and VD2. Conclusions: The formulations of the novel 3D-printed materials (FDI and VD2) exhibited markedly greater FT and WOF than their respective predecessors, although this improvement was accompanied by a decrease in hardness. Nevertheless, none of the 3D-printed materials fulfilled the ISO standard criteria for enhanced FT. Full article

Objective: This retrospective study aimed to evaluate the two-year clinical performance of ultra-thin, no-prep Prettau^® Skin zirconia veneers placed in the anterior region of the maxilla and mandible. Materials and Methods: This single-cohort retrospective series did not include a conventional control group. A total of 201 veneers (Prettau^® Skin, 5Y-TZP zirconia) were placed in the anterior maxilla and mandible. Veneers were air-abraded with 50 µm Al₂O₃ (0.25 MPa, ~10 mm, 20 s) and bonded using an MDP-containing adhesive (Tokuyama Bond, Tokuyama Dental, Japan) and dual-cure resin cement (Estecem II, Tokuyama Dental, Japan) following enamel etching with 37% H₃PO₄ (Etching Gel, Cerkamed, Poland). Clinical performance was assessed using the modified FDI criteria after two years. Results: At 24 months, no debonding events were recorded. The survival rate was 99.5% (95% CI: 97.3–99.9). Fracture rate was 0.5% (95% CI: 0.1–2.8). Most veneers received “very good” scores for surface luster (81.6%, 95% CI: 75.6–86.4), color match (96.0%, 95% CI: 92.0–98.0), marginal adaptation (84.1%, 95% CI: 78.3–88.6), and anatomical form (100%, 95% CI: 98.1–100). Periodontal response was rated as “very good” or “good” in 90.0% (95% CI: 85.4–93.4) of cases. Patient satisfaction remained consistently high (100%, 95% CI: 98.1–100). Conclusions: Ultra-thin, no-prep Prettau^® Skin zirconia veneers show favorable short-term clinical outcomes, offering excellent esthetic results, mechanical stability, and biological compatibility. These findings support their use as a minimally invasive option in anterior restorative dentistry. However, further long-term studies are needed to confirm their durability and compare outcomes with conventional veneer techniques. Full article

Objective: The aim of this study was to evaluate and compare the clinical behavior of indirect onlays/overlays made of lithium disilicate and composite resin and to investigate risk factors associated with restoration failures. Methods: 112 indirect partial coverage posterior restorations (onlays and overlays) placed in 51 adult patients between January 2014 and December 2020 were examined. The restorations were evaluated using selected FDI criteria (color match, surface gloss, anatomic form, fracture of restorative material, tooth cracks and fractures, marginal discoloration, marginal integrity and recurrence of initial pathology). The survival of the restorations was analyzed using Kaplan–Meier method. Risk factors (type of restoration, type of tooth, tooth vitality, smoking) were investigated using Cox regression analysis. Risk estimation was conducted for each evaluated criterion (p < 0.05). Results: For composite restorations, the estimated survival rate was 94.2% after 5 years, dropping to 74.3% in 7.9 years and continued falling to less than 60% after 8.2 years. On the contrary, for lithium disilicate restorations the estimated survival rate was 90.9% after 5 years, dropped to 85.2% after 5.5 years remaining stable thereafter. Lithium disilicate onlays demonstrated significantly better performance than lithium disilicate overlays. Cox regression analysis did not reveal any significant association between the survival of the indirect partial restorations and restoration material, tooth type, restoration type and history of endodontic treatment. However, smoking was found to be a statistically significant risk factor (p < 0.05). Conclusions: Lithium disilicate and composite indirect restorations exhibited comparable survival rates at the early observation period. However, lithium disilicate partial coverage restorations demonstrated more favorable clinical behavior compared to composite in the long term, with statistical significance observed in ceramic vs. composite onlays. Full article

Background/Objectives: Self-adhesive flowable resins (SAFR) entered the market, eliminating the adhesive system application due to their self-adhesive technology. Guided by the PICO framework (Population, Intervention, Comparison, Outcome), the aim was to conduct a systematic review of clinical studies to compare the clinical performance of Self Adhesive Flowable Resin (SAFRs) with conventional flowable resins used for direct restorations. Methods: The protocol of this systematic review was registered in the International Prospective Register of Systematic Reviews (CRD42023394297) and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. Five databases (PubMed, Embase, Web of Science, Scopus, and Cochrane Library) were searched from inception to July 2025. Nine randomized clinical trials were included, totaling 493 restorations in 232 patients. Clinical performance was assessed using USPHS or FDI criteria, with follow-up periods ranging from 6 months to 5 years. Data were pooled using a random-effects meta-analysis to calculate risk differences (RD) and 95% confidence intervals (CI) for marginal adaptation, retention, marginal staining, post-operative sensitivity, color stability, surface roughness, secondary caries, and anatomical form. Results: Meta-analysis showed no significant differences between SAFRs and CFRCs for in terms of: marginal adaptation (RD = 0.01; 95% CI: −0.02 to 0.04; p = 0.53; I² = 0%), retention (RD = 0.00; 95% CI: −0.02 to 0.03; p = 0.81; I² = 0%), marginal staining (RD = 0.01; 95% CI: −0.01 to 0.02; p = 0.51; I² = 0%), and post-operative sensitivity (RD = −0.01; 95% CI: −0.03 to 0.02; p = 0.62; I² = 0%). The certainty of the evidence for all outcomes was rated as moderate to high according to the GRADE assessment. Conclusions: SAFR restorations demonstrated comparable clinical performance to conventional resins; however, heterogeneity in follow-up duration and the scarcity of long-term data (>5 years) warrant caution. Full article

In this paper, we introduce a health parameter and estimation algorithm to assess the severity of stator turn-to-turn/inter-turn short-circuit (TTSC) faults in wound-rotor synchronous generators (WRSG). Our methodology establishes criteria for evaluating the severity of stator TTSC faults in WRSG and provides a specific solution for estimating both the severity of these faults and the resultant power loss. Our assessment methodology directly reflects the intrinsic impact of stator TTSC faults on the WRSG, offering enhanced efficiency, accuracy, and resilience to interference compared with traditional methods in estimating and gauging the TTSC severity. First, we demonstrate that it is impossible to determine the two fault parameters of the WRSG stator TTSC faults solely based on the voltage and current measurements. Subsequently, we introduce a novel health parameter for the WRSG stator TTSC faults and show that for a given generator and load, the dynamics of voltage and current during these faults as well as the resulting power loss are determined by this health parameter. We then detail the characteristics of the proposed health parameter and criteria for evaluating the severity of the WRSG stator TTSC faults. Furthermore, we present an estimation algorithm that is capable of accurately estimating the health parameter and power loss, demonstrating its minimal estimation error. Finally, we provide a comprehensive set of simulation results, including Monte Carlo results, to validate our proposed methodology and illustrate that our approach offers significant improvements in terms of the efficiency, accuracy, and robustness of the WRSG stator TTSC fault detection and isolation (FDI) over conventional methods. Full article

Background and objective: The aim of this randomized split-mouth study-controlled clinical trial was to compare the 2-year clinical performance of resin composite restorations placed at non-caries cervical lesions (NCCL) with one-step self-etch, total-etch, and selective enamel etch and self-etch adhesive techniques. Materials and methods: Thirty-two patients received three resin composite restorations each at NCCLs (Tetric EvoCeram/Ivoclar/Vivadent), bonded with a total-etch adhesive agent (ExciTE F/Ivoclar/Vivadent) and a self-etch (AdheSE One F/Ivoclar/Vivadent) without and with selective enamel etching. All restorations were evaluated by two examiners at baseline, 6-, 12-, 18-, and 24-months with FDI clinical criteria (post-operation regarding retention, caries occurrence, marginal adaptation, and marginal staining). A logistic regression analysis, a Cohen’s kappa statistic, a multifactorial analysis, and X² were performed with generalized estimating equations. Results: After 2 years, the retention rate was 86.8% for total etch, 92.26% for self-etch, and 93.63% for selective enamel etching and self-etch. No caries was detected on the restorations. Concerning marginal adaptation, the clinically perfect restorations were 26.9% for the total-etch technique, 16% for self-etch, and 25.9% for selective enamel etch and self-etch. The logistic regression model revealed that only time reduced the probability of perfect marginal adaptation. Conclusions: All three adhesive strategies provided restorations with no significant differences in the retention rate or marginal adaptation, whereas the total etch yielded better performance for marginal staining. All restorations were assessed as clinically acceptable after 2 years. Full article

Enamel hypoplasia (EH) is a qualitative defect, and it can have a significant impact on oral health. The aim of this study was to evaluate the prevalence of enamel hypoplasia in urban area in Albania. Methodology: In total, 234 children of both sexes aged 8–12 years old were randomly selected in five schools in Tirana, Albania. They underwent an intra-oral examination. Diagnostic criteria were in accordance with a European meeting on MIH held in Athens, 2003, and the FDI. Medical history was retrieved using questionnaires, and data obtained from clinical examination were recorded. Results: The prevalence of enamel hypoplasia was 12.8%. The most commonly occurring enamel hypoplasia was the mild type (58.62%). The mandibular first molar showed the highest prevalence of enamel hypoplasia (19.5%), and the maxillary canines and premolars were the least affected (2.3%). In this study, medical story did not have a significant effect on enamel hypoplasia. Conclusions: The prevalence of enamel hypoplasia remains high at 12.8%. Interestingly, the features of enamel hypoplasia were consistent across both sexes, with no correlation found between them. The predominant occurrence of mild enamel hypoplasia underscores the importance of implementing oral hygiene strategies in schools to mitigate its progression. Full article

The effectiveness of a universal adhesive applied in three application modes for the preparation of Class V composite restorations was evaluated both clinically and by quantitative marginal analysis (QMA) over 36 months. In 50 patients, three (n = 21) or four (n = 29) non-carious cervical lesions (NCCL) were restored with Venus^® Diamond Flow (Kulzer GmbH, Hanau, Germany). The adhesive iBond^® Universal (iBU, Kulzer, Germany) was used in self-etch (SE), etch-and-rinse (ER), or selective-enamel-etch mode (SEE). The etch-and-rinse adhesive OptiBond^TM FL served as a control (OFL, Kerr GmbH, Herzogenrath, Germany). The restorations were clinically assessed (FDI criteria) at 14 days (BL), 6, 12, 24, and 36 months. Additionally, QMA was conducted on all restorations of 11 randomly selected patients. FDI criteria and marginal gap and perfect margin were compared between and within groups and recalls using McNemar, Wilcoxon, or Mann–Whitney U-tests (α = 0.05). Starting with 12 months, cumulative failure rates were lower in iBU-SE (0.0%, p = 0.016) and iBU-ER groups (2.1%, p = 0.07) compared to OFL (16.7%). At two years, iBU-SEE also showed fewer failures (0.0% SEE vs. 34.6% OFL, p = 0.016), as did iBU-SE compared to iBU-ER after 36 months (2.2 and 19.6%, p = 0.039). From BL, the iBU-SEE group always had the fewest marginal gaps and the highest percentage of perfect margins. From BL, iBU-SEE (0%, p = 0.008) and iBU-ER (0.2%, p = 0.027) showed significantly fewer marginal gaps compared to OFL (2.5%) and more perfect margins were found with iBU-SEE starting at 6 months (p = 0.054). The SEE and ER modes ensured the most excellent marginal quality, with differences from the control appearing earlier with QMA than clinically. In restoring NCCls, iBU showed superior clinical performance over OFL, especially in modes SE and SEE. Full article

The purpose of this observational follow-up clinical study was to observe the quality of posterior composite restorations more than 23 years after application. A total of 22 patients, 13 male and 9 female (mean age 66.1 years, range 50–84), with a total of 42 restorations attended the first and second follow-up examinations. The restorations were examined by one operator using modified FDI criteria. Statistical analysis was performed with the Wilcoxon Mann–Whitney U test and Wilcoxon exact matched-pairs test with a significance level of p = 0.05. Bonferroni–Holm with an adjusted significance level of alpha = 0.05 was applied. With the exception of approximal anatomical form, significantly worse scores were seen for six out of seven criteria at the second follow-up evaluation. There was no significant difference in the first and second follow-up evaluations in the grades of the restorations with regard to having been placed in the maxilla or mandible, as well as for one-surface or multiple-surface restorations. The approximal anatomical form showed significantly worse grades at the second follow-up when having been placed in molars. In conclusion, the study results show that significant differences regarding FDI criteria in posterior composite restorations occur after more than 23 years of service. Further studies with extended follow-up time and at regular and short time intervals are recommended. Full article

Background: The goal of materials should be early caries detection, removal of carious lesions, and reduction of dentin hypersensitivity. Thus, the study aims to determine the efficacy of a bioactive caries detecting dye (BCD) for the diagnosing and mechanical removal of occlusal and proximal dental caries. Methods: Patients with occlusal (A1, A2) and proximal carious lesions (B1, B2) were treated with the rotary technique and BCD solution on 120 teeth (n = 60 for each). Group 1: Excavation was performed using diamond points. Group 2: 0.5 mL of BCD solution was scrubbed for 20 sec and excavation was performed with a sharp spoon excavator. Post-excavation cavity volume analysis was performed using a 3D scanner. The time required, VAS for pain, VAS for facial expression, and sound eye motor scoring were scored during excavation. Post-restoration evaluation was performed at 3, 6, and 12 months (FDI criteria). Results: The chi-square test revealed that the A1 (197.90 30.97 s) and B1 (273.06 69.95 s) had significantly less mean procedural time than the A2 (292.13 44.87 s) and B2 (411.86 88.34 s). BCD (A2, B2) group showed good patient acceptance, less pain during caries excavation VAS (p = 0.001, FACE (p = 0.001), and SEM (p < 0.001) analysis than the rotary group. There was a statistically insignificant difference between groups immediately (p = 0.235), (p = 0.475) and after 24 h (p = 0.561), (p = 0.688). Color score, hardness of excavated surface, and caries removal score for occlusal and proximal groups showed insignificant differences between the groups. BCD group showed significantly less mean caries excavated volume for the occlusal group (p = 0.003) as compared to the proximal group (p = 0.417) evaluated by 3D scanner. Evaluation of restoration after 3-, 6-, and 12 months intervals (Occlusal caries group (p = 0.247), (p = 0.330), and (0.489) and Proximal caries group (p = 0.299), (p = 0.594), and (0.494)) was acceptable for both the groups. Conclusion: BCD helps in identification of dental caries clinically, radiographically, and in effective removal of denatured teeth with less pain or sensitivity. Full article

Foreign investment is one of the driving forces of a country’s economy. The global foreign direct investment (FDI) flows in 2020 amounted to USD 1 trillion, but FDI distribution varies from country to country. Here, the questions arise as to what determines the choice of foreign investors, what the countries can do/are doing to attract FDI, and which Baltic states are the most attractive for FDI. Based on the scientific literature analysis, the definitions of FDI and the attractiveness for FDI, as referred to in the empirical study, are reviewed; the factors affecting FDI are singled out, and the methods/models that are applicable for assessing FDI are investigated. The major purpose of the article is to assess the attractiveness of the Baltic states for foreign direct investment. Research methods: comparative analysis of the concepts and methods available in the scientific literature, secondary data analysis, statistical data processing, and multi-criteria evaluation methods. The results of the assessment of the attractiveness of the Baltic states for foreign direct investment that were determined by applying the TOPSIS multi-criteria evaluation method helped to determine a country’s position in relation to its neighbors and revealed the criteria that weaken or strengthen this position. The results of the research can help the leaders of the states to select the relevant measures to improve their state’s FDI attractiveness in relation to other states. Full article

The effectiveness of a universal adhesive applied in different application modes for the preparation of Class V composite restorations was evaluated both clinically and by quantitative marginal analysis (QMA). In each of the 22 patients, four non-carious cervical lesions (NCCL) were restored with Filtek^™ Supreme XTE (3M). The adhesive Scotchbond^™ Universal (SBU, 3M) was applied in self-etch (SE), selective-enamel-etch (SEE) or etch-and-rinse (ER) modes. The etch-and-rinse adhesive OptiBond^™ FL (OFL, Kerr) served as a control. The restorations were clinically evaluated (FDI criteria) after 14 days (BL), 6, 12, 24, and 36 months. Additionally, QMA was conducted on all restorations of 11 randomly selected patients. The FDI criteria and marginal gap were statistically compared between the groups at each recall as well as for the time periods between recalls. The cumulative failure rate was non-significantly higher in the OFL group when compared to all of the SBU groups. Marginal adaptation in the OFL and SBU-SE/ER groups was significantly decreased (BL-36 m, p: 0.004) in comparison to the SBU-SEE group (BL-36 m, p: 0.063). More marginal gaps were found in the OFL group than in the SBU-SEE (BL to 36 m, p: 0.063–0.003) and SBU-ER (24/36 m, p: 0.066/0.005) groups as well as in the SBU-SE group when compared to the SBU-SEE (12–36 m, p_i ≤ 0.016) and SBU-ER (24/36 m, p: 0.055/0.001) groups. SBU-SEE performed most effectively. The clinical evaluation and QMA corresponded, yet QMA detected group differences earliest after 6 months and is thus a valuable extension to clinical evaluations. Full article

Conservative dentistry in primary dentition aims to remove and repair existing carious lesions and to prevent secondary caries up until exfoliation of the primary tooth happens, in order to maintain the important role in terms of the space maintenance and guidance for eruption that deciduous teeth have. Many different materials are used, and some of them, recently commercialized, show bioactive properties able to prevent secondary caries. This trial’s primary focus is to evaluate the biological, functional, and aesthetic characteristics of Cention-N alkasite material compared to glass ionomer cement (GIC) through the use of standardized FDI criteria for direct restorations. A blinded, split-mouth study was designed for this purpose, including 112 deciduous molars in 45 children showing class II caries restored with either GIC or alkasite material. The data from this study indicates that the Cention-N alkasite material showed equal performance compared with Fuji IX GIC after one year. A thorough evaluation of exfoliated teeth restored with this material will provide long-term data and an evaluation on infiltration rates. Full article

Restorative procedures for caries affecting primary molars are a daily challenge for pediatric dentistry, and one of the main factors influencing the results of these restorative procedures is the choice of dental material used: bioactive materials were recently introduced, combining the strength of composites and the benefits of glass ionomers. The present study’s objective is to clinically evaluate the aesthetic, functional and biological properties of Activa™ Bioactive composite in approximal and occlusal carious lesions for 1 year using the FDI criteria for evaluating direct dental restorations. Forty-five children with occlusal or approximal caries in first or second primary molars were included in the study: the cavities were then randomized to be restored with either Activa BioActive or SDR Bulk-fill and evaluated over time according to Federation Dentaire Internationale (FDI) criteria. Results showed that Activa BioActive composite has similar performance over time compared to Bulk-fill composite, for both functional and aesthetic properties. Thus, within the limitations of this study, including the short follow-up period, it can be concluded that bioactive materials might be the material of choice to restore primary molars. A longer follow-up period is desirable to confirm these findings. Full article

The purpose of this study was to evaluate the clinical outcome of feldspathic ceramic laminate veneers over a 7-year period using minimally invasive techniques, such as vertical preparation (without prosthetic finish line), or no preparation (no-prep). A total of 170 feldspathic ceramic veneers were cemented in the anterior region, including 70 maxillary and 100 mandibular veneers, after special conditioning of the teeth and restorations. The veneers were evaluated using the FDI World Dental Federation criteria evaluation kit after recalling all the patients between February and June 2021. In total, 14 feldspathic veneers failed and were replaced with lithium disilicate because of core fracture, and 10 cases of chipping occurred on the ceramic surface and were polished. The overall survival rate was 91.77% for up to 7 years of function, with a failure rate of 8.23%. In this retrospective survival analysis, the failures, including the fracture of veneers and dental hard tissue, occurred both in prep and no-prep teeth. No failures were observed in veneers with a maximum thickness of 0.5 mm compared to those with a maximum thickness of 1 mm, 1.5 mm, 2 mm, and 2.5 mm. Full article