Background: For implant-supported hybrid prostheses, high mastication forces and reduced acrylic resin thickness over a metal substructure often cause failures arising from tooth or resin fractures. To assay fracture resistance of artificial teeth and resin in implant-supported hybrid prostheses in relation to the titanium structure and retention design supporting teeth.
Material And Methods: 40 specimens bearing incisors were divided into four groups according to the titanium structure supporting the teeth and the type of load force applied: Group I (Control; n=10): Application of static loading to ten incisors set over a metal structure with internal retention. Group II (Control; n=10): Application of static loading to ten incisors set over a metal structure with external retention. The remaining study specimens (n=20) were subjected to 120,000 masticatory and thermal cycles in a chewing simulator. Afterwards, static loading was applied until the point of fracture using an Instron machine. Group III (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with internal retention. Group IV (Study; n=10): Application of dynamic and static loading to ten incisors set over a metal structure with external retention. Data obtained for the four groups was analyzed and compared, determining the type of fracture (cohesive or adhesive) using a reflected light microscope.
Results: Statistical analysis confirmed that there were significant differences in fracture resistance between the four groups. External retention was found to have more fracture resistance than the internal retention.
Conclusions: Hybrid prostheses with titanium substructures and external retention obtained significantly better results than samples with internal retention.
Key Words: Chewing simulator, thermocycler, fatigue, implant-supported hybrid prosthesis, acrylic teeth, fracture, metal structure design.
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http://dx.doi.org/10.4317/jced.52228 | DOI Listing |
Comput Methods Biomech Biomed Engin
January 2025
Department of Mathematics, National Institute of Technology Uttarakhand, Srinagar, India.
As humans age, they experience deformity and a decrease in their bone strength, such brittleness in the bones ultimately lead to bone fracture. Magnetic field exposure combined with physical exercise may be useful in mitigating age-related bone loss by improving the canalicular fluid motion within the bone's lacuno-canalicular system (LCS). Nevertheless, an adequate amount of fluid induced shear stress is necessary for the bone mechano-transduction and solute transport in the case of brittle bone diseases.
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Vehicle Safety Institute, Graz University of Technology, Inffeldgasse 13/6, 8010 Graz, Austria.
This work deals with the strain-rate dependent characterization of paper under uniaxial tension at high strain-rates. Experiments were performed involving a Split Hopkinson bar for high strain-rate testing, comparing the results with conventional quasi-static tests. Tests were conducted in a strain-rate range between 0.
View Article and Find Full Text PDFBMC Oral Health
January 2025
Department of Prosthetic Dentistry, Biomaterials Division, Faculty of Dentistry, King Salman International University, El Tur, South Sinai, Egypt.
Purpose: Investigating high performance thermoplastic polymers as substitutes to titanium alloy, in fabrication of implants and attachments to support mandibular overdenture, aiming to overcome stress shielding effect of titanium alloy implants. AIM OF STUDY: Assessment of stress distribution in polymeric prosthetic components and bone around polymeric implants, in case of implant-supported mandibular overdenture.
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Acta Bioeng Biomech
June 2024
1School of Health Science and Engineering, University of Shanghai for Science and Technology, Shanghai, China.
: Brain tissue immersed in cerebrospinal fluid often exhibits complex mechanical behaviour, especially the nonlinear stress- strain and rate-dependent responses. Despite extensive research into its material properties, the impact of solution environments on the mechanical behaviour of brain tissue remains limited. This knowledge gap affects the biofidelity of head modelling.
View Article and Find Full Text PDFJ Dent Sci
January 2025
Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and National University Hospital, Taipei, Taiwan.
Background/purpose: Dental implants can restore both function and aesthetics in edentulous areas. However, the absence of cushioning mechanical behavior in implants may limit their clinical performance and reduce the long-term survival rates. This study aimed to establish an implant cushion mechanism that mimicked the natural periodontal ligament, utilizing the properties of composite hydrogels.
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