Search Results (57)

Aim: This study aimed to evaluate and compare the surface properties, roughness, skewness, and wettability of three CAD/CAM-processed ceramic materials: zirconia-reinforced lithium silicate (Celtra Duo), feldspathic ceramic (CEREC Blocs), and lithium disilicate (CEREC Tessera). Materials and Methods: Thirty specimens (10 per group) were fabricated (10 × 10 × 2 mm) using the CEREC Omnicam AC system with the MC XL milling unit and SpeedFire furnace. Surface characterization included computed tomography (CT) for dimensional accuracy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) for microstructure and composition, profilometry for roughness parameters (Ra, Rq, Rsk), and contact angle measurements with water, ethylene glycol, and diiodomethane for wettability. Statistical analysis was performed using ANOVA (p < 0.05). Results: No dimensional or compositional changes occurred after processing. Mean Ra values were 2.8647 µm for lithium disilicate, 1.9715 µm for zirconia-reinforced lithium silicate, and 1.9148 µm for feldspathic ceramic. All materials exhibited negative skewness, with zirconia-reinforced lithium silicate showing the smoothest morphology. Contact angle results indicated greater hydrophilicity for lithium disilicate (31.41°), followed by feldspathic ceramic (38.31°) and zirconia-reinforced lithium silicate (42.48°). Conclusions: Zirconia-reinforced lithium silicate demonstrated a favorable combination of surface topography, roughness, and wettability, suggesting superior long-term clinical performance. Full article

Introduction: Nutrition literacy has garnered growing research attention worldwide, yet only a few instruments have been developed to specifically measure this construct among adolescents. Accordingly, the present research sought to examine the validity and reliability of the Adolescent Nutrition Literacy Scale (ANLS) within a group of Lebanese adolescents. Methods: A cross-sectional study was carried out from December 2022 to March 2023, targeting a nationally representative sample. Results: Fit indices of the three-factor structure were good. Internal reliability was adequate for the following three subscales: Functional Nutrition Literacy (FNL) (ω = 0.88/α = 0.88), Interactive Nutrition Literacy (INL) (ω = 0.87/α = 0.86) and Critical Nutrition Literacy (CNL) (ω = 0.89/α = 0.89). Invariance was established across genders at configural, metric, and scalar levels. A significantly higher mean FNL and INL scores were found in males compared to females, with no significant difference between the two genders in terms of CNL. Higher FNL, but not CNL and INL scores were significantly associated with lower child food security. Conclusions: The Arabic ANLS has exhibited robust psychometric reliability, validity, and cost-effectiveness as a tool for assessing nutrition literacy. By utilizing the Arabic version of the ANLS, we can more efficiently and accurately assess the nutritional literacy of adolescents. Full article

Background: The increasing adoption of digital workflows in implant dentistry necessitates rigorous assessment of intraoral scanning, particularly for complex full-arch rehabilitations like All-on-Four prostheses, where posterior implant angulation may impact the accuracy of optical data acquisition. Objectives: This in vitro study aimed to assess the accuracy of digital intraoral scanners in scanning All-on-Four implant models with different posterior implant angulations. Methods: Two epoxy resin All-on-Four implant models were fabricated with two posterior implant angulations (30-degree and 45-degree). Both models were digitized to obtain control datasets using a Smart Optics reference scanner (REF). Four intraoral scanners were comparatively assessed: Cerec Omnicam AC (OMN), Trios 4 (TRI), Cerec Primescan AC (PRI), and Medit i700 (MED), with nine scans per each scanner (n = 9). All STL files were exported and analyzed using Geomagic Control X with root mean square (RMS) values computed for trueness and precision assessments. Results: The comparison between IOS types in terms of trueness revealed that with 30° angulation, the MED group showed the statistically significant least deviation (p = 402). With 45° angulation, both PRI and OMN scanners showed the statistically significant highest deviation values (p = 0.047 and 0.007, respectively). MED again showed the statistically significant least deviation (p = 402). For precision evaluation in 30° angulation models, PRI and OMN scanners showed the statistically significant least deviation values (p = 402 and <0.001, respectively). While, in 45° angulation models, no statistically significant inter-scanner differences were observed. Conclusions: While MED, PRI, and OMN scanners demonstrated clinical validity for 30° angled posterior implants, only the MED system achieved sufficient accuracy for 45° tilt. These findings emphasize the critical relationship between scanner selection and extreme implant angulations in full-arch digital workflows. Full article

The aim was to assess the blending effect of universal-shade resin-based composites (RBCs) (Omnichroma—OC; Clearfil Majesty Universal–CM; Venus Pearl—V; Transcend—T) used for repair for lithium disilicate blocks. Fifteen parallelepiped-shaped (10.5 × 10.5 × 3 mm) specimens with four cavities (3 mm in diameter and 2 mm in depth) were designed from lithium disilicate CAD/CAM blocks (CEREC Tessera HT A3) and milled. Specimens were then randomly divided into five groups based on the five resin composite materials for cavity restoration (n = 12): Group 1, control group (F); Group 2 (T); Group 3 (OC); Group 4 (V); and Group 5 (CM). After surface conditioning, composite resins were applied to the ceramic surface. Color measurements were taken with a colorimeter in the center of the resin restoration and on the CAD/CAM block. Tristimulus values were converted to CIELab color coordinates and color differences were expressed in ΔE₀₀ units using the CIEDE-2000 formula. F showed significantly better color matching (ΔE₀₀ = 2.51 ± 0.64) in comparison to single-shade RBCs except T (ΔE₀₀ = 2.55 ± 0.64). All groups exceeded perceptibility and acceptability thresholds. The control group presented higher color matching than the single shade universal composites except for Transcend. Full article

Purpose Maintaining the surface quality of ceramic restorations after clinical adjustments is critical for both aesthetic outcomes and long-term oral health, yet the optimal approach to restoring gloss and smoothness remains unclear. The purpose of this study is to investigate the effect of different surface finishing and grinding procedures on the surface gloss and roughness of three different monolithic lithium disilicate ceramics and one monolithic ultra-translucent zirconia ceramic. Materials and Methods A total of 104 specimens (1.5 × 12 × 14 mm) were prepared from four ceramic materials: LiSi CEREC Tessera (CT), GC Initial LiSi (LS), IPS e.max CAD (EC), and zirconia disc (KATANA UTML (KAT)). Each was divided into two subgroups based on surface finishing (mechanical polishing or glazing; n = 10). Gloss and surface roughness were measured using a glossmeter and a profilometer, respectively. One specimen per subgroup was analyzed under SEM at ×1000 magnification. Results Gloss and roughness values were analyzed with the two-way robust ANOVA test and multiple comparisons were made with Bonferroni correction. The significance level was set at p < 0.05. Mechanical polishing, glazing, and repolishing increased the gloss values of the materials, with the KAT group achieving the highest gloss in the repolishing groups. The lowest gloss values were observed in the grinding groups. Additionally, these surface treatments reduced the roughness of the surface of all the materials. Conclusions Surface finishing procedures significantly influenced the gloss and roughness of monolithic lithium disilicate and zirconia ceramics. Mechanical polishing systems performed similarly or better than glazing. However, selecting an appropriate polishing system for each material is essential. Full article

Objective: The purpose of this investigation was to assess and compare the internal adaptation of different distinct CAD (Computer-aided design)/CAM (Computer-aided manufacturing) endocrown materials: feldspathic porcelain, indirect composite, hybrid ceramic, reinforced lithium disilicate, and lithium disilicate, utilizing microcomputed tomography. Methods: Standardized endocrown restorations were fabricated for mandibular first molar models. A total of seventy-five restorations were evenly allocated into five groups (n = 15 each): Group I (Cerec Blocks), Group II (Lava Ultimate), Group III (PICN Vita Enamic), Group IV (Celtra Duo), and Group V (Cerec Tessera). The restorations were bonded using PANAVIA V5 adhesive resin cement. To evaluate internal adaptations within the restorations, three distinct locations were selected for the acquisition of high-resolution micro-CT scans: the margin, the axial wall, and the pulpal floor. Data were analyzed using SPSS. To identify statistically significant differences among groups, a two-way ANOVA was conducted, followed by post hoc Tukey tests. Results: The statistical analysis did not reveal significant differences in internal gap measurements across the various material groups (p = 0.055). However, significant variations were observed within individual material groups (p < 0.001) at distinct locations, with the most pronounced discrepancies in thickness evident at the pulpal floor. Conclusion: While no significant differences were observed in internal adaptations among the various endocrown materials, substantial intra-group variability, particularly in terms of pulpal floor thickness, was evident. Since the study maintained a consistent preparation design across all groups, the observed variations in internal adaptation are likely attributed to differences in material behavior rather than changes in preparation geometry. Full article

Introduction: In orthodontics, determining the parameters of tooth size and dental arch and conducting Bolton analysis is crucial for diagnosis, treatment planning, and patient outcomes. This study evaluates the accuracy and reliability of measuring dental-arch dimensions on digital models created using the CEREC Primescan intraoral scanner, compared to measurements taken from plaster models. Methods: The study included two types of dental models (plaster and intraoral scan) from sixty-three subjects. Impressions were taken to create plaster models, and the subjects’ mouths were scanned with the CEREC Primescan system (Dentsply Sirona, Charlotte, NC) to create digital models. Intra-arch measurements included tooth heights and widths, overjet, and overbite. The arch width and depth were examined at the first permanent upper or lower molar. The paired t-test and Bland–Altman plot were used to determine the accuracy, while intra-rater and inter-rater correlation coefficient values were calculated to assess the reliability of measurements from the intraoral scan compared to those from the plaster model. Results: For tooth heights, there was a statistically significant difference in only one measurement (tooth 34) between the plaster and digital models, with an average difference of 0.01 mm. For tooth widths, there was a statistically significant difference in only one measurement (tooth 15) with an average difference of 0.03 mm. The Bland–Altman plots of almost all of measurements of tooth heights and widths showed that differences between the two models were within the limits of agreement. The inter- and intra-rater correlation coefficient values for measurements on the digital model were found to be statistically insignificant. Conclusion: Measuring dental dimensions on digital models obtained through the Primescan intraoral digital system yielded similar results to those obtained from plaster models and showed excellent reliability, indicating its potential application in clinical practice. Full article

The Impostor Phenomenon (IP) is a widespread psychological phenomenon impacting the personal and professional experiences of individuals. This study aims to examine the impact of the IP on employee well-being, performance, and job satisfaction within Higher Education Institutions (HEIs) in Lebanon. Moreover, this study explores if these effects vary depending on individuals’ personality types, such as introverted or extroverted, and if perceived organizational support (POS) plays a moderating role in these relationships. The research employed a mono-method quantitative approach to collect data from a sample of 155 faculty and staff employees using an online structured survey. Data were statistically analyzed using SPSS software. The findings obtained indicate that higher impostorism levels were linked to lower employee well-being, job satisfaction, and self-assessed job performance. Introverts showed a negative association between impostorism and well-being, while extroverts had significant negative associations with both job satisfaction and performance. POS only moderately influenced the association between impostorism and job satisfaction. The significance of the IP’s impacts on employee outcomes among different personality types is emphasized in this study. Furthermore, the moderating role played by POS highlighted the importance of organizational efforts in addressing employees’ experiences. This study provided insights to Human Resources (HR) professionals in Lebanon’s Higher Education Institutions to develop targeted interventions addressing IP experiences and personality types and promoting mental wellness and better job satisfaction and performance, and thus better organizational outcomes. Full article

Background/Objectives: Aesthetics is a challenging aspect to restore for both dentists and dental technicians. One of the characteristics of aesthetic restoration is the shade. The purpose of the study is to assess the accuracy of the shade selection feature of intraoral scanners (CEREC Omnican, 3Shape TRIOS) in comparison with an already established method—the VITA Easyshade V spectrophotometer (VE)—and test if there is any significant difference between the three devices. Methods: To conduct this in vitro study, the VITA Classical shade guide was used. The intraoral scanners would not be able to scan the VITA Classical as it is, hence, a study model (SM) was fabricated. To be able to test the accuracy of the intraoral scanners (IOSs) in detecting the dental color, a spectrophotometer had to be included in the study, as it was shown that it is the most accurate instrument for this purpose. Therefore, for the current study, the VITA Easyshade V spectrophotometer (VITA Zahnfabrik, Bad Sackingen, Germany) was selected. Results: The accuracy of the three devices when measuring the shade of the study model was calculated as a percentage. When comparing the primary results of the VE and the results obtained by the Omnicam and TRIOS, the latter is the most accurate (26.67%), whereas the other two scored 20%. The study also revealed the limitations of the instrumental devices that were used. Conclusions: First, both the VE and IOSs obtained unexpectedly low accuracy results. Possibly, the material VC is made of influenced the final accuracy values, but in practice, on a daily basis, dental materials represent a factor that cannot really be controlled. Full article

Background/Objectives: This study aimed to investigate the microtensile bond strength (µTBS) of composite-based (Cerasmart), polymer-infiltrated (Vita Enamic), and feldspathic (Cerec) CAD/CAM blocks luted to dentin using a dual-cure resin cement (LinkForce), as well as micro-hybrid (G-aenial) and flowable composites (G-aenial Universal Flo), and evaluate the microhardness (HV) of luting materials through the CAD/CAM blocks. Methods: Cerasmart, Enamic, and Cerec were luted to dentin using three luting materials; LinkForce, G-aenial, and Universal Flo (n = 5). For HV, 117 disk-shaped specimens from LinkForce, G-aenial, and Universal Flo (n = 13) were polymerized through 3 mm thick CAD/CAM. Thirty-nine light-cured specimens without CAD/CAM were used as control. Following 24 h storage, the µTBS and HV were evaluated. Data were analyzed using the two-way ANOVA and post hoc Tukey tests (p < 0.05). Results: The µTBS to dentin and HV were significantly influenced by the type of luting material and CAD/CAM material. With all the CAD/CAM materials, LinkForce and Universal Flo exhibited a significantly similar µTBS to that of dentin (p > 0.05). Compared with the control group, all the HV values of the luting materials decreased significantly (p < 0.05). Conclusions: Heavily filled flowable composites exhibit a bonding effectiveness similar to that of dual-cure resin cements. All the luting materials showed similar HV when polymerized through the polymer-infiltrated CAD/CAM material. Full article

The aim of this study was to the evaluate volumetric and linear adaptation of an indirect adhesive restoration, comparing a novel chairside 3D printer to conventional milling techniques. An intact upper premolar was selected, prepared for an overlay restoration, and replicated. A standardized overlay restoration was designed with CAD software (Cerec inLab CAD SW 4.5.2, Dentsply Sirona, Charlotte, NC, USA), maintaining equal morphology for each sample. Restorations were produced with three CAM processes: chairside 3D printer (D-FAB, DWS, Thiene, Italy), chairside milling unit (Cerec MCXL, Dentsply Sirona, Charlotte, NC, USA), and an industrial milling machine serving as control (Micro 5x, Aman Girrbach, Mäder, Austria). Once cemented, specimens were scanned using micro-computed tomography to assess volumetric, internal, and external adaptation. Data were statistically analyzed with ANOVA and post hoc Bonferroni tests. CAM technique significantly affected volumetric adaptation (p < 0.001), with the chairside 3D printer performing the best and chairside milling unit the worst. Concerning internal adaptation, the chairside milling unit performed significantly worse than the other groups (p < 0.001). No significant differences were reported for external adaptation (p > 0.05). In conclusion, CAM technique influenced volumetric and internal adaptation, with the 3D printer showing optimal volumetric adaptation and chairside milling poor internal adaptation. Full article

To assess the biomechanical behaviors of endodontically treated molars (ETMs) restored with endocrowns composed of different materials, forty mandibular molars were assigned to five groups (n = 8 each). Untreated molars constituted the control group (group C); the rest of the teeth that underwent root canal therapy were restored with endocrowns composed of polycrystalline ceramics (ST zirconia^®, UPCERA) in group ZR, lithium disilicate glass ceramics (UP.CAD^®, UPCERA) in group LD, resin-based nanoceramics (Hyramic^®, UPCERA) in group NC, and feldspathic ceramics (CEREC Blocs^®, Sirona) in group FC. All teeth were axially loaded until fracture. The process was recorded using a high-speed camera system, and fractographic analysis was conducted. The results showed that fracture loads did not significantly differ among groups C, LD, and NC; the loads were significantly lower than the load in group ZR but higher than the load in group FC. The mean time from the initial crack to complete tooth fracture varied. Group C had the longest time, followed by group NC; groups ZR, LD, and FC had the shortest time. Similar failure patterns were observed in groups ZR and LD, which were more regular than the pattern in group NC; group FC exhibited the roughest fracture surfaces. Fracture resistance testing combined with a high-speed camera system and fractographic analysis provides a promising modality for studying the biomechanical behaviors of restored teeth. Endocrowns composed of lithium disilicate glass ceramics or resin-based nanoceramics offer alternative restorations for ETMs with extensive coronal loss. Full article

This study aimed to evaluate the marginal and internal adaptation of CAD/CAM crowns milled using two different milling protocols (fine or extra-fine) within a 4-axis milling machine. The crowns were fabricated from lithium disilicate ceramic (IPS e.max CAD) and resin composite (Tetric CAD), assessing their fit in various regions. The crowns (N = 40, n = 10) were milled from lithium disilicate and resin composite using a CEREC Primemill unit. Four groups were formed based on the material and milling protocol: EFLD (extra-fine lithium disilicate), FLD (fine lithium disilicate), EFRC (extra-fine resin composite), and FRC (fine resin composite). The crowns were measured using the replica technique, evaluating internal and marginal adaptation in 18 measuring points per specimen. Data were statistically analyzed using ANOVA and Tukey’s test. Resin composite crowns demonstrated a significantly better internal fit compared to lithium disilicate (p < 0.001). Marginal and internal measurements for resin composites were consistently smaller across regions compared to lithium disilicate. No significant differences were found between milling protocols except for the axial wall region (p = 0.001), where extra-fine milling resulted in smaller values. Resin composite crowns exhibited superior internal fit compared to lithium disilicate, regardless of milling protocol. Both the fine and extra-fine milling protocols had minimal impact on adaptation, except at the axial wall region, with both protocols promoting adequate results overall. Full article

Objectives: The objective of this study was to compare the trueness and precision of three intraoral scanners (IOSs) for the digitization of dentate and edentulous maxillectomy and mandibulectomy defects in artificial models. Methods: Four representative defect models—a dentate and an edentulous maxillectomy model and a dentate and an edentulous mandibulectomy model—were used for digital scanning. After a reference scan of each model, they were scanned with three IOSs: CEREC AC Omnicam, True Definition, and cara TRIOS 3. For comparison, five conventional impressions with a polysiloxane material were taken and digitized with a laboratory scanner. The obtained data were evaluated with three-dimensional (3D) inspection software and superimposed with the reference scan data by using a best-fit algorithm. The mean absolute 3D deviations of the IOS compared to the reference data (trueness) and when comparing the datasets within the IOS (precision) were analyzed. Linear mixed models and multiple pairwise comparisons were used for statistical analyses. Results: The overall comparison of the four evaluated procedures for data acquisition showed a significant difference in trueness (p < 0.0001) and precision (p < 0.0001). The average mean trueness of the IOSs ranged from 32.17 to 204.43 µm, compared to 32.07 to 64.85 µm for conventional impressions. Here, the conventional impression and cara TRIOS 3 performed the most precisely with no significant difference. CEREC AC Omnicam achieved the worst precision. Conclusions: Using a suitable intraoral scanner, defective jaws even without teeth could be captured in satisfying accuracy. This shows the possibility to use an intraoral scanner for maxillofacial defect patients and gives a vision of using digital technology in maxillofacial prosthetics. Full article

The Pendjari Biosphere Reserve is one of the protected areas of Benin where biodiversity conservation policies intertwine with the economic development of local populations. It is located in the Atacora region in northern Benin, which has a high prevalence of poverty and food insecurity among households. Agriculture and livestock farming are the primary activities of the local communities in the villages surrounding the reserve. However, wild animals sometimes cause damage to people’s fields or livestock. To deal with the damage caused by wild animals, local populations have developed several mitigation measures that may not be effective, leading them into a vulnerable situation. Vulnerability is often associated with the impacts of natural disasters and their management, anticipation, and recovery. In the context of human–wildlife conflict, vulnerability refers to the level of risk farmers face from issues such as crop raiding, livestock depredation, and human injury caused by wildlife, as well as farmers’ ability to cope with such damage. To assess the vulnerability of households, we used the Livelihood Vulnerability Index (LVI). Data were collected from July to December 2019 through questionnaires and interviews. We surveyed 320 households to collect data on their socio-demographics, livelihoods, social networks, natural capital, food and water security, and the incidence and severity of human–wildlife conflicts. The results showed that farmers around the Pendjari Biosphere Reserve are highly sensitive to human–wildlife conflicts, with a low adaptive capacity, revealing their vulnerability. More precisely, farmers are vulnerable in terms of major components of the LVI such as water, food, social networks, and livelihoods. Conservation policies are expected to pay more attention to local populations’ vulnerability to human–wildlife conflicts in order to improve their tolerance towards wildlife and guarantee the success of conservation efforts. Full article