Notes

Sexual intercourse Variations in your Association Involving Infection and Event-Free Survival inside Individuals Using Cardiovascular Failure.
OBJECTIVE To evaluate the cyclic contact fatigue resistance and failure mode of ceramics for monolithic and multilayer restorations. METHODS Ceramic structures (10 mm × 1.8 mm) were fabricated as follows (n = 28) (1) CAD-on- trilayer structure composed of Y-TZP (yttria stabilized tetragonal zirconia polycrystal- IPS e.max ZirCAD) infrastructure, fusion glass-ceramic (IPS e.max CAD Crystall/Connect) and lithium disilicate-based glass-ceramic (IPS e.max CAD); (2) ZFC- bilayer structure composed of Y-TZP infrastructure veneered by a fluorapatite glass-ceramic (IPS e.max Ceram); (3) LDC- monolithic lithium-disilicate glass-ceramic (IPS e.max CAD); and (4) YZW- monolithic Y-TZP (Zenostar Zr Translucent). All ceramics structures were bonded to a dentin analog substrate (G10). Specimens were submitted to cyclic contact fatigue test in a pneumatic cycling machine with 80 N load and 2 Hz frequency in distilled water at 37 °C. Test was interrupted after 104, 105, 5 × 105 and 106 cycles and the presence or absence of failure was recorded. Fatigue data were analyzed using Kaplan-Meier (log rank) and Holm-Sidak tests (α = 0.05). SL327 The relationship between the type of crack leading to failure and the experimental group was analyzed using chi-square test (α = 0.05). RESULTS There was no statistical difference between CAD-on and YZW groups (p = 0.516), which presented the highest survival rates after cyclic loading, followed by ZFC and LDC groups (p less then 0.01). There was a significant relationship between type of crack and experimental group (p less then 0.001). LDC specimens showed the greatest frequency of radial cracks, while cone cracks were more prevalent for ZFC and CAD-on specimens. SIGNIFICANCE Monolithic Y-TZP (YZW) showed similar fatigue resistance to CAD-on multilayer specimens, but different failure mode. Monolithic lithium disilicate glass-ceramic (LDC) and Y-TZP conventionally veneered by glass-ceramic (ZFC) showed lower survival time under fatigue. STATEMENT OF PROBLEM Limited information is available regarding the fabrication of tooth-supported interim single crowns (SCs) with either a digital or a conventional workflow. PURPOSE The purpose of this randomized clinical trial was to compare the time efficiency and fit of interim crowns fabricated by using either a digital or a conventional workflow. MATERIAL AND METHODS Forty participants in need of posterior tooth-supported SCs were enrolled and randomly allocated to either the digital or conventional group. In the digital group, the interim SCs were fabricated by using digital sextant scans and computer-aided design and computer-aided manufacturing (CAD-CAM) technology without definitive casts. The conventional group included conventional impressions and direct fabrication of the interim restorations intraorally. Five experienced and 5 less experienced clinicians were randomly assigned to fabricate the interim SCs. The total fabrication time (laboratory and clinical) was recorded for time efficiency. Ts significantly better than that of the less-experienced clinicians. CONCLUSIONS The interim SCs fabricated with a digital workflow required a shorter fabrication time and resulted in better fit than those fabricated with a conventional workflow, especially for less-experienced clinicians. Tightening torques are often specified in implant dentistry, including for surgical procedures, testing implant stability, and attaching prosthetic components when screws are used. The mechanical torque limiting devices (MTLDs) commonly used are typically either a toggle-type or beam-type. The International Organization for Standardization (ISO) 6789 recommends MTLDs should be periodically tested to confirm the validity of their readings, and, where necessary, recalibrated if possible or replaced. The verification of the toggle-type MLTD has been previously published. This article describes a straightforward, in-office technique to verify a beam-type MTLD. STATEMENT OF PROBLEM The mechanical behavior of ceramic endocrowns is unclear. PURPOSE The purpose of this in vitro and 3-dimensional finite element analysis (3D-FEA) study was to evaluate the mechanical behavior of endodontically treated teeth restored with ceramic endocrowns made by using different computer-aided design and computer-aided manufacturing (CAD-CAM) systems. MATERIAL AND METHODS Sixty mandibular human molars were endodontically treated, prepared for endocrowns, and divided into 4 groups (n=15) according to the following various ceramic systems leucite-based glass ceramic (LC group), lithium disilicate-based glass ceramic (LD group), glass ceramic based on zirconia-reinforced lithium silicate (LSZ group), and monolithic zirconia (ZR group). After adhesive bonding, the specimens were subjected to thermomechanical loading and then to fracture resistance testing in a universal testing machine. The failure mode of the specimens was qualitatively evaluated. Three-dimensional FEA was performed to evaluate the stress distribution in each group. Data were analyzed by using a 1-way ANOVA and the Tukey HSD test (α=.05). RESULTS Statistically significant differences among the groups were observed (P less then .05). The outcomes of the LC, LD, and LSZ groups were similar (1178 N, 1935 N, and 1859 N) but different from those of the ZR group (6333 N). The LC and LD groups had a higher ratio of restorable failures, while LSZ and ZR had more nonrestorable failures. Fractographic analysis indicated a regular failure pattern in the ZR group and irregular failure patterns in the other groups. Three-dimensional FEA revealed similar values and stress pattern distributions among the groups. CONCLUSIONS The mechanical performance of monolithic zirconia was better than that of the other ceramic endocrowns considered in this research; however, monolithic zirconia presented a higher rate of catastrophic tooth structure failure. The mitochondrial network structure dynamically adapts to cellular metabolic challenges. Mitochondrial depolarisation, particularly, induces fragmentation of the network. This fragmentation may be a result of either a direct regulation of the mitochondrial fusion machinery by transmembrane potential or an indirect effect of metabolic remodelling. Activities of ATP synthase and adenine nucleotide translocator (ANT) link the mitochondrial transmembrane potential with the cytosolic NTP/NDP ratio. Given that mitochondrial fusion requires cytosolic GTP, a decrease in the NTP/NDP ratio might also account for protonophore-induced mitochondrial fragmentation. For evaluating the contributions of direct and indirect mechanisms to mitochondrial remodelling, we assessed the morphology of the mitochondrial network in yeast cells with inhibited ANT. We showed that the repression of AAC2 (PET9), a major ANT gene in yeast, increases mitochondrial transmembrane potential. However, the mitochondrial network in this strain was fragmented.
Homepage: https://www.selleckchem.com/products/SL327.html