This in-vitro study compared the marginal and internal fit and also the microleakage of zirconia infrastructures (Procera All-Zircon, Cercon Smart Ceramics) in contrast to heat-pressed ones (Empress 2).Thirty maxillary premolars (n=30) were divided into three groups (n=10) and prepared with individual chamfer preparations by using the silicone index method. Plaster dies of 10 individual preparations were allocated to each coping fabrication method of computer-aided design and computer-aided manufacturing (Procera), computer-aided manufacturing (Cercon) and heat pressing (Empress 2) as the control. All the specimens were kept in distilled water at room temperature for four weeks after cementation with dual-curing resin cement (Variolink II, Ivoclar-Vivadent). They were then thermocycled between 5°C to 55°C for 5000 cycles with a 20-second dwell time and immersed in 0.5% basic fuchsin for 48 hours. The cemented specimens were separated into two halves vertically in the midvestibulo-palatal direction. The specimens were examined under a computer-aided stereomicroscope to evaluate both the internal and marginal fit. Marginal and internal gap widths were measured at 100× magnification. The specimens were evaluated for microleakage under a stereomicroscope at 100 × magnification. Selected specimens from each group were also examined using a scanning electron microscope. Fitting accuracy data were analyzed statistically with the Welch test and the Post-hoc Dunnett C-test (p<0.05). The microleakage data were analyzed with the Kruskal-Wallis test. Special software (SPSS/PC+ Version 10.0, SPSS, Chicago, IL, USA) was used for statistical evaluations.Differences between the marginal and internal fitting accuracy of the tested non-veneered infrastructures were found to be statistically significant (p<0.05). However, there were no significant differences in microleakage among the groups (p=0.273).
This study investigated the C. albicans adhesion to cold-and heat-polymerized soft lining materials that were initially incubated in two different artificial body fluids, namely saliva and nasal secretion, and examined the surface roughness the materials (cold and heat polymerized soft liner) tested in vitro. Cold (Visco Gel) and heat-polymerized (Molloplast B) soft liner specimens (N=32, n=8 per group) (10×10×1.5 mm) were randomly produced to express the relationship between surface roughness and contamination, and influence of body fluids, and incubated in 1.5 ml contaminated solutions for 2 h. After fixation, all of materials were evaluated under optical microscope (×400) and SEM. Surface roughness measurements were examined with profilometre for each material. Data were analyzed using two-way ANOVA, Tukey's HSD and Dunnett T3 tests (α=0.05). Material type (p<0.05) and contamination media (p<0.05) showed a significant influence on the C. albicans adherence. The surface roughness of cold polymerized soft liner (Visco Gel) was significantly higher than heat-polymerized soft liner (Molloplast B) (p<0.05).
A 24-year-old man with a bilateral cleft lip and palate was treated by a multidisciplinary team composed of an orthodontist, plastic surgeon, and prosthodontist with assistance from an engineer. Before treatment, clinical photographs, dental casts, lateral and posteroanterior cephalograms, periapical and panoramic radiographs, and three-dimensional computed tomography (3D CT) images were obtained. He presented with a narrow and retrognathic maxilla with a 23-mm anterior open bite. Following maxillary expansion with rapid palatal expansion, a Le Fort I maxillary osteotomy was performed, and an internal distractor was placed. After a 5-day latency period, internal maxillary distraction was performed at a rate of 1 mm/day achieved by two activations per day. Cephalometric analysis showed a 7-mm maxillary advancement. Mandibular bilateral sagittal split osteotomy was also performed to close the open bite following maxillary distraction and a 3-month stabilization period. Finally, the treatment was completed with prosthetic rehabilitation. The changes in speech production were evaluated using an automatic speech recognition system.
Objective: Aim of this study was to evaluate possible effects of saliva and nasal secretion on some physical properties, such as sorption, solubility, surface hardness and colour change on four different resin-based materials over a certain time period. Materials and Methods: A total of 128 disc-shaped specimens with a diameter of 50mm and thickness of 0.5mm were tested to evaluate sorption and solubility (ISO-1567). The specimens were stored in different solutions prior to testing. Surface hardness measurements were performed by using a Vickers hardness testing machine. A total of 20 cylindershaped test specimens with a diameter of 13 mm and thickness of 1 mm were prepared to evaluate colour change (ΔE). Analysis of variance was used to determine significant differences among groups. Paired t and Tukey Post-Hoc tests were performed to investigate significant differences among subgroups at all time intervals (p<0.05). Results: It was found that while the percentage absorption value at T7(7 days) of the auto-polymerizing (A) groups storaged in artificial saliva + nasal secretion were the highest (0.057±0.119), the percentage absorption value at T15(15 days) of the D groups storaged in artificial nasal secretion were the lowest (0.013±0.09). Besides, it was found that the percentage solubility value at T30(30 days) of visible ligth-cusing resin (VLC) groups storaged in artificial nasal secretion were the highest (0.016±0.003), and the percentage solubility value at T1(1 day) of the D groups storaged in distilled water were the lowest (0.01±0.02). While the highest hardness value was of T0(Dry) in group heat-polymerizing (H) (36.19±1.35), the lowest hardness value was of T0 in group D (9.83±2.48). When E values analysed for each group, VLC group showed the highest values (23.78±5.05) (p<0.05), group D showed the lowest values (9.06±2.82) in time (between the T0 and T30). Conclusion: The new polyamide resin was observed to show better physical properties when compared with other materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.