Objectives: To evaluate and compare fracture resistance, translucency, and color reproducibility, as well as the effect of aging on the fracture load and color stability of novel monolithic CAD/CAM ceramics.
Materials And Methods: One hundred crowns of uniform thickness were milled from five ceramic blocks (n = 20): partially crystallized lithium disilicate (PLD) and fully crystallized lithium disilicate (FLD), lithium metasilicate (LMS), 4Y-TZP (SMZ), and 5Y-TZP (UMZ) monolithic zirconia. PLD crowns were glazed, LMS was fired, and FLD was polished. SMZ and UMZ crowns were sintered and polished. Crowns were adhesively cemented to epoxy dies. Half of the crowns (n = 10) were subjected to 1.200.000 load cycles with thermal cycling. Color space values L, a, b defined by the Commission Internationale de l´Eclairage (CIELAB) were measured before and after aging, and (∆E) was calculated. Both aged and non-aged specimens were loaded until fracture in a universal testing machine and the fracture load was recorded. X-ray diffraction (XRD) and scanning electron microscope (SEM) fractographic analysis were carried out on fractured fragments of representative samples. For translucency and color reproducibility, 50 rectangular-shaped specimens were fabricated and processed as described previously. Color values were measured over black and white backgrounds, and the translucency parameter (TP) was computed. Using the shade verification mode, (∆E) to shade A3 was calculated. Data were statistically analyzed using one-way and two-way ANOVA, and t-test.
Results: Aging did not affect fracture resistance significantly (p > 0.05). The highest mean fracture load was obtained for the SMZ and UMZ. A significant color change was observed after aging in all groups. The highest TP was noted for FLD. SMZ and UMZ had the best shade match.
Conclusions: Zirconia showed higher fracture resistance and color stability than lithium silicate ceramics. Lithium silicate ceramics were more translucent. The experimental FLD demonstrated high translucency.
Clinical Relevance: Tested ceramics showed sufficient stability to withstand masticatory forces. Characterization of final restorations might be mandatory for better color match.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10264477 | PMC |
http://dx.doi.org/10.1007/s00784-022-04833-y | DOI Listing |
Environ Monit Assess
January 2025
Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa.
Due to incessant contamination of the groundwater system near the dumpsite in southwestern Nigeria Basement Complex, this study seeks to evaluate the impact of the Odogbo dumpsite on the local groundwater system by integrating geophysical and geochemical methodologies. Aeromagnetic data covering the study area was acquired, processed, and enhanced to delineate basement features that could potentially be passing plumes to the groundwater system. Concurrently, geoelectric methods using 2-D dipole-dipole imaging and vertical electrical sounding (VES) were utilized to characterize the vulnerability indices of the lithologies underlying the dumpsite.
View Article and Find Full Text PDFJ Med Case Rep
January 2025
Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden.
Background: Congenital insensitivity to pain with anhidrosis is a rare but devastating hereditary disease. Congenital insensitivity to pain with anhidrosis is caused by a mutation in the neurotrophic receptor tyrosine kinase 1 gene (NRTK1). The condition is characterized by multiple injuries, recurrent infections, and mental retardation.
View Article and Find Full Text PDFGraefes Arch Clin Exp Ophthalmol
January 2025
Department of Oculoplastic, Orbital & Lacrimal Surgery, Aichi Medical University Hospital, 1-1 Yazako-Karimata, Nagakute, Aichi, 480-1195, Japan.
Purpose: To define the anatomical variance between orbital floor and medial orbital wall blowout fractures, and its change with age.
Methods: This was a retrospective, observational study analyzing data from 557 patients with isolated blowout fractures of the orbital floor or medial orbital wall. Axial and quasi-sagittal CT images were analyzed to compare radiologic data on orbital wall morphology between fracture site groups and among age groups.
Can Vet J
January 2025
Veterinary Clinical Sciences Department, College of Veterinary Medicine, University of Minnesota, 1352 Boyd Avenue, St. Paul, Minnesota 55108, USA.
A 6-year-old Labrador retriever dog with a history of pneumonia was presented because of an acute onset of dull mentation and coughing. Diagnostic imaging and cytology revealed a pneumothorax, pneumomediastinum, and pleural effusion, consistent with pyothorax. The dog underwent exploratory sternotomy for lung lobectomy of the right cranial and middle lung lobes.
View Article and Find Full Text PDFAdv Mater
January 2025
Key Laboratory of Advanced Materials Technologies, International (HongKong Macao and Taiwan) Joint Laboratory on Advanced Materials Technologies, College of Materials Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China.
Hydrogels have received great attention due to their molecular designability and wide application range. However, they are prone to freeze at low temperatures due to the existence of mass water molecules, which can damage their flexibility and transparency, greatly limiting their use in cold environments. Although adding cryoprotectants can reduce the freezing point of hydrogels, it may also deteriorate the mechanical properties and face the risk of cryoprotectant leakage.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!