Purpose: To investigate retention and stability characteristics of soft-liner and clip attachments used for bar/implant-assisted mandibular overdentures.
Materials And Methods: Two implants were placed in an edentulous mandibular model. According to the type of bar, presence of cantilevers, and type of attachments, eight groups were tested: (1) Dolder bar with cantilevers and three titanium clips (DCC), (2) Dolder bar with cantilevers and resilient liner attachments (DLC), (3) Dolder bar without cantilevers and one titanium clip (DCWC), (4) Dolder bar without cantilevers and resilient liner attachments (DLWC), (5) Hader bar with cantilevers and three plastic clips (HCC), (6) Hader bar with cantilevers and resilient liner attachments (HLC), (7) Hader bar without cantilevers and one plastic clip (HCWC), and (8) Hader bar without cantilever and resilient liner (HLWC). Axial (retention) and nonaxial (stability during anterior, posterior, and lateral dislodging) forces were evaluated initially and after 540 times of prosthesis insertion and withdrawal.
Results: The highest retention and stability forces were observed with HCC, and the lowest forces were recorded with DLWC. The lowest retention and stability after wear was noted with DCWC and HCWC. For the majority of groups, the highest forces were noted with posterior dislodgment, and the lowest forces were observed with lateral dislodgment. The largest retention loss was recorded with DCC and HCC, and the lowest retention loss was noted with HLWC. DLC and HLC showed retention gain.
Conclusion: Hader bar with clips and cantilever extensions achieved the highest retention and stability forces after wear simulation, while bars without cantilevers and clips showed the lowest forces. For cantilevered Dolder and Hader bars, clip attachments showed increased retention loss, while soft-liner attachments showed retention gain.
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http://dx.doi.org/10.11607/jomi.8862 | DOI Listing |
J Dent
November 2024
Department of Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Brazil; College of Dentistry, University of Illinois Chicago (UIC), Chicago, USA.
Biomimetics (Basel)
August 2024
Department of Aerospace Engineering, Toronto Metropolitan University (Formerly Ryerson University), Toronto, ON M5B 2K3, Canada.
Innovative designs such as morphing wings and terrain adaptive landing systems are examples of biomimicry and innovations inspired by nature, which are actively being investigated by aerospace designers. Morphing wing designs based on Variable Geometry Truss Manipulators (VGTMs) and articulated helicopter robotic landing gear (RLG) have drawn a great deal of attention from industry. Compliant mechanisms have become increasingly popular due to their advantages over conventional rigid-body systems, and the research team led by the second author at Toronto Metropolitan University (TMU) has set their long-term goal to be exploiting these systems in the above aerospace applications.
View Article and Find Full Text PDFJ Dent
August 2024
Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR. Electronic address:
Objectives: To evaluate the longevity of cantilevered zirconia-based resin-bonded fixed partial dentures (RBFPDs) in replacing missing posterior teeth, as well as the quality of life and patient satisfaction experienced by those receiving zirconia RBFPDs.
Methods: A prospective single-arm uncontrolled clinical trial was conducted to replace one or more missing premolars or molars with a span of 5 to 8 mm using cantilevered zirconia RBFPDs. Thirty-six participants with 40 prostheses were recruited and underwent a 3-year clinical evaluation.
Sci Rep
June 2024
Department of Mathematics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu, 632 014, India.
In recent years, many researchers have made a continuous effort to develop new and efficient meta-heuristic algorithms to address complex problems. Hence, in this study, a novel human-based meta-heuristic algorithm, namely, the learning cooking algorithm (LCA), is proposed that mimics the cooking learning activity of humans in order to solve challenging problems. The LCA strategy is primarily motivated by observing how mothers and children prepare food.
View Article and Find Full Text PDFSci Rep
April 2024
Operations Research Department, Faculty of Graduate Studies for Statistical Research, Cairo University, Giza, 12613, Egypt.
This study presents an advanced metaheuristic approach termed the Enhanced Gorilla Troops Optimizer (EGTO), which builds upon the Marine Predators Algorithm (MPA) to enhance the search capabilities of the Gorilla Troops Optimizer (GTO). Like numerous other metaheuristic algorithms, the GTO encounters difficulties in preserving convergence accuracy and stability, notably when tackling intricate and adaptable optimization problems, especially when compared to more advanced optimization techniques. Addressing these challenges and aiming for improved performance, this paper proposes the EGTO, integrating high and low-velocity ratios inspired by the MPA.
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