The use of screwless Morse taper implant−abutment connections (IAC) might facilitate the clinician’s work by eliminating the mechanical complications associated with the retention screw. The aim of this study is to evaluate the effect of artificial chewing on the long-term stability of screwless Morse taper IACs. Thirty-two implant abutments restored with an upper central incisor zirconia crown were used and divided into four groups according to the implant−abutment assembling manner (C1,H: screw retained (20 Ncm); C2: tapped; or C3: torqued (20 Ncm; the screws were removed before the dynamic loading)). All specimens were subjected to a cyclic loading (98 N) for 10 million chewing cycles. The survived samples were exposed to a pull-off force until failure/disassembling of the connection. All the samples revealed a 100% survival. Regarding the pull-off test, the screw-retained internal hexagonal IAC revealed significantly higher resistance to failure/disassembling (769.6 N) than screwless conical IACs (171.6 N−246 N) (p < 0.0001). The retention forces in the Morse taper groups were not significantly different (p > 0.05). The screw-retained hexagonal IAC showed the highest retention stability. The screw preload/retention in the conical IAC was lost over time in the group where the screws were kept in place during loading. Nevertheless, the screwless Morse taper IACs were stable for an extended service time and might represent a valid form of treatment for single-tooth replacement.
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http://dx.doi.org/10.3390/ma15093381 | DOI Listing |
Arch Orthop Trauma Surg
January 2025
Division of Orthopaedics and Traumatology, Cantonal Hospital Winterthur, Winterthur, Switzerland.
Total hip arthroplasty (THA) is a very successful operation. Once the problem of implant fixation was solved with the use of bone cement, the next development steps focused on improving the bearing. Weber, a Swiss surgeon, introduced the first modular heads in THA.
View Article and Find Full Text PDFJ Adv Prosthodont
December 2024
Department Prosthetic Dental Sciences, College of Dentistry, Jouf University, Jouf, Saudia Arabia.
Purpose: This study assessed the microgap width and adhesion of three bacterial species in four dental implants with different interlocks under four screwing torques.
Materials And Methods: Ten samples of four implant systems with various interlockings, including full-hexagonal (FHI), cylindrical-conical trilobe-index (TLI), Morse-taper with octagon terminal index (OI), and hexagonal interlock (slip-fit) (HI-SF), were used. The abutments were screwed to the fixtures under torques of 10, 20, 30, and 40 Ncm.
Braz Oral Res
December 2024
Universidade Federal de Uberlândia - UFU, School of Dentistry, Department of Periodontology and Implantology, Uberlândia, MG, Brazil.
The purpose of this study was to evaluate the effect of a single dose of ionizing radiation (30 Gy) on the osseointegration of implants in the rabbit tibia. Twenty rabbits received two dental Morse-tapered junction implants and one implant in each tibia. The animals were randomly divided into two groups (n=10), non-irradiated (NoIr) and irradiated (Ir), wherein the Ir group received a single dose of 30 Gy radiation 2 weeks after implant installation.
View Article and Find Full Text PDFJ Prosthet Dent
December 2024
Professor, School of Dentistry, University of Ribeirão Preto (UNAERP), Ribeirão Preto, Brazil. Electronic address:
Statement Of Problem: The biomechanical stability of the implant-prosthesis assembly and its maintenance under function is a determining factor in the success of implant prosthesis rehabilitation, but studies of different angular tapers are lacking.
Purpose: The purpose of this in vitro study was to evaluate the axial displacement and torque loss of prosthetic abutments with Morse-type connections of different angular tapers after thermomechanical cycling by using microcomputed tomography (µCT) and a digital torque wrench.
Material And Methods: Eighteen Ø3.
J Funct Biomater
June 2024
Department of Implantology, Bioface/Postgrados en Odontología/Universidad Catolica de Murcia, 11100 Montevideo, Uruguay.
The present study evaluated the mechanical behavior of five designs of Morse taper (MT) connections with and without the application of loads. For this, the detorque of the fixing screw and the traction force required to disconnect the abutment from the implant were assessed. A total of 100 sets of implants/abutments (IAs) with MT-type connections were used, comprising five groups ( = 20/group): (1) Group Imp 11.
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