Objectives: Mechanical properties are cardinal for the long-term clinical success of laminate veneer restorations but the selection of new restorative materials should ideally be based on clinical evidence, therefore, in vitro testing of dental materials is a good alternative to evaluate their properties and understand their behavior so this study aimed to compare and evaluate the effect of two different thicknesses and yttria percentage on the fracture resistance of laminate veneer zirconia restorations.
Materials And Methods: Forty laminate veneer restoration prepared from partial sintering zirconia of 3Y (yttria), 5Y (yttria), combined 3Y&5Y (yttria), and lithium disilicate. Specimens were assigned into four main groups according to their percentage of yttria content (n = 10) and subgrouped into two thicknesses (0.5 mm thickness and 0.3 mm thickness) (n = 5) as follows: Group I, II, III, and IV (Group I for lithium disilicate (control), Group II for 3Y zirconia, Group III for 5Y zirconia, and Group IV for combined 3Y&5Y zirconia), each of them subdivided according to their thickness into two subgroups (n = 5 for each one) and resistance to fracture for each restoration was evaluated using a universal testing machine. Data were analyzed using a one-way analysis of variance and Duncan's tests at a 5% level of significance.
Results: The thickness of laminate veneer restoration significantly affects the fracture resistance value of all type of laminate veneers restorations (fracture resistance mean value was highest for 0.5 mm thickness and lower for 0.3 mm thickness restorations) and yttria percentage significantly affect fracture resistance value of zirconia laminate veneer restorations (fracture resistance mean value was highest for 0.5 mm thickness of 3Y zirconia [865 N] and combined 3Y&5Y zirconia [846 N]).
Conclusions: Reducing the thickness of laminate zirconia veneer restorations to 0.3 mm reduces its fracture resistance and increasing yttria percentage had an adverse effect on fracture resistance of zirconia laminate veneer restorations.
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http://dx.doi.org/10.1002/cre2.658 | DOI Listing |
J Prosthodont
January 2025
The Office of Assistant Dean for Research, School of Dental Medicine, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico.
Purpose: This study aimed to evaluate and compare the fracture resistance of long-span fixed provisional restorations fabricated using milling, three-dimensional (3D) printing, and conventional methods.
Materials And Methods: Sixty specimens were prepared, divided into four groups of 15 each, corresponding to four fabrication methods: computer-aided design and computer-aided manufacturing (CAD-CAM) milled provisional resins, 3D-printed provisional resins, 3D-printed permanent resins, and conventional bis-acryl restorations reinforced with wire. The specimens underwent a three-point bending test using a universal testing machine to measure fracture resistance, quantified as maximum force (in Newtons).
Bone
January 2025
The School of Public Health, North China University of Science and Technology, Tangshan, Hebei, China. Electronic address:
Objective: To investigate the association between the cumulative exposure to triglyceride-glucose index (cumTyG index) and fragility fractures in the general population.
Methods: This prospective cohort study analyzed active and retired employees of Kailuan Group who participated in three consecutive health examinations in 2006, 2008 and 2010, and were followed up until 31st December 2022. The cohort comprised 55,824 participants who met the inclusion and exclusion criteria and were grouped using the cumTyG index quartiles.
JMIR Rehabil Assist Technol
January 2025
Department of Occupational Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada.
Background: Forearm, wrist, and hand impairments affect many individuals and impose a significant economic burden on health care systems. The FEPSim (flexion, extension, pronation, and supination) is designed for hand and wrist rehabilitation. It could become part of the standard care for upper extremity rehabilitation, aiming to improve range of motion, dexterity, and strength during therapeutic activities.
View Article and Find Full Text PDFJ Am Acad Orthop Surg
January 2025
From the Department of Orthopaedics (A. Mo and F. Mo), Medstar Georgetown University Hospital, Washington, DC, and the Department of Orthopaedic Surgery (S. Lockey), University of Virginia, Charlottesville, VA.
The posterior ligamentous complex (PLC) provides critical structural support in the thoracolumbar spine. Its role in resisting progressive flexion is particularly important at the thoracolumbar junction due to the transition from the rigid thoracic spine to the more mobile lumbar region. Each component of the PLC contains anatomic features that contribute to both the structure and function of the PLC as a whole.
View Article and Find Full Text PDFJ Dent Sci
January 2025
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing, China.
Background/purpose: It remains unclear how the thickness and number of pulp-chamber lateral walls (PCLWs) affects fracture resistance in endocrown-restored teeth.
Materials And Methods: 64 mandibular molars were collected and randomly divided into eight groups (n = 8). In group C (control group), the teeth were untreated.
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