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Szabó ÁL, Matusovits D, Slyteen H, Lakatos ÉI, Baráth Z. Biomechanical Effects of Different Load Cases with an Implant-Supported Full Bridge on Four Implants in an Edentulous Mandible: A Three-Dimensional Finite Element Analysis (3D-FEA). Dent J (Basel) 2023; 11:261. [PMID: 37999025 PMCID: PMC10670282 DOI: 10.3390/dj11110261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/29/2023] [Accepted: 11/03/2023] [Indexed: 11/25/2023] Open
Abstract
The long-term success and predictability of implant-supported restorations largely depends on the biomechanical forces (stresses) acting on implants and the surrounding alveolar bone in the mandible. The aim of our study was to investigate the biomechanical behavior of an edentulous mandible with an implant-supported full bridge on four implants under simulated masticatory forces, in the context of different loading schemes, using a three-dimensional finite element analysis (3D-FEA). A patient-specific 3D finite element model was constructed using pre- and post-implantation computer tomography (CT) images of a patient undergoing implant treatment. Simplified masticatory forces set at 300 N were exerted vertically on the denture in four different simulated load cases (LC1-LC4). Two sets of simulations for different implants and denture materials (S1: titanium and titanium; S2: titanium and cobalt-chromium, respectively) were made. Stress outputs were taken as maximum (Pmax) and minimum principal stress (Pmin) and equivalent stress (Peqv) values. The highest peak Pmax values were observed for LC2 (where the modelled masticatory force excluded the cantilevers of the denture extending behind the terminal implants), both regarding the cortical bone (S1 Pmax: 89.57 MPa, S2 Pmax: 102.98 MPa) and trabecular bone (S1 Pmax: 3.03 MPa, S2 Pmax: 2.62 MPa). Overall, LC1-where masticatory forces covered the entire mesio-distal surface of the denture, including the cantilever-was the most advantageous. Peak Pmax values in the cortical bone and the trabecular bone were 14.97-15.87% and 87.96-94.54% higher in the case of S2, respectively. To ensure the long-term maintenance and longevity of treatment for implant-supported restorations in the mandible, efforts to establish the stresses of the surrounding bone in the physiological range, with the most even stress distribution possible, have paramount importance.
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Affiliation(s)
- Árpád László Szabó
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary; (Á.L.S.); (D.M.)
| | - Danica Matusovits
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary; (Á.L.S.); (D.M.)
| | - Haydar Slyteen
- Department of Structural Mechanics, Faculty of Civil Engineering, University of Technology and Economics, Budapest, Műegyetem rkp. 3., 1111 Budapest, Hungary; (H.S.); (É.I.L.)
| | - Éva Ilona Lakatos
- Department of Structural Mechanics, Faculty of Civil Engineering, University of Technology and Economics, Budapest, Műegyetem rkp. 3., 1111 Budapest, Hungary; (H.S.); (É.I.L.)
| | - Zoltán Baráth
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66., 6720 Szeged, Hungary; (Á.L.S.); (D.M.)
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Körtvélyessy G, Szabó ÁL, Pelsőczi-Kovács I, Tarjányi T, Tóth Z, Kárpáti K, Matusovits D, Hangyási BD, Baráth Z. Different Conical Angle Connection of Implant and Abutment Behavior: A Static and Dynamic Load Test and Finite Element Analysis Study. Materials (Basel) 2023; 16:1988. [PMID: 36903102 PMCID: PMC10004464 DOI: 10.3390/ma16051988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/23/2023] [Accepted: 02/26/2023] [Indexed: 06/18/2023]
Abstract
Dental implants are artificial dental roots anchoring prosthetic restorations to replace natural teeth. Dental implant systems may have different tapered conical connections. Our research focused on the mechanical examination of implant-superstructure connections. Thirty-five samples with 5 different cone angles (24°, 35°, 55°, 75°, and 90°) were tested for static and dynamic loads, carried out by a mechanical fatigue testing machine. Fixing screws were fixed with a torque of 35 Ncm before measurements. For static loading, samples were loaded with a force of 500 N in 20 s. For dynamic loading, the samples were loaded for 15,000 cycles with a force of 250 ± 150 N. In both cases, the compression resulting from load and reverse torque was examined. At the highest compression load of the static tests, a significant difference (p = 0.021) was found for each cone angle group. Following dynamic loading, significant differences (p < 0.001) for the reverse torques of the fixing screw were also shown. Static and dynamic results showed a similar trend: under the same loading conditions, changing the cone angle-which determines the relationship between the implant and the abutment-had led to significant differences in the loosening of the fixing screw. In conclusion, the greater the angle of the implant-superstructure connection, the smaller the screw loosening due to loading, which may have considerable effects on the long-term, safe operation of the dental prosthesis.
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Affiliation(s)
- Győző Körtvélyessy
- Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Árpád László Szabó
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - István Pelsőczi-Kovács
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Tamás Tarjányi
- Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Zsolt Tóth
- Department of Medical Physics and Informatics, Albert Szent-Györgyi Medical School, Faculty of Science and Informatics, University of Szeged, Korányi fasor 9, H-6720 Szeged, Hungary
| | - Krisztina Kárpáti
- Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Danica Matusovits
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Botond Dávid Hangyási
- Department of Periodontology, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
| | - Zoltán Baráth
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 64-66, H-6720 Szeged, Hungary
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Szabó ÁL, Nagy ÁL, Lászlófy C, Gajdács M, Bencsik P, Kárpáti K, Baráth Z. Distally Tilted Implants According to the All-on-Four ® Treatment Concept for the Rehabilitation of Complete Edentulism: A 3.5-Year Retrospective Radiographic Study of Clinical Outcomes and Marginal Bone Level Changes. Dent J (Basel) 2022; 10:dj10050082. [PMID: 35621535 PMCID: PMC9140184 DOI: 10.3390/dj10050082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/13/2022] [Accepted: 05/09/2022] [Indexed: 11/16/2022] Open
Abstract
Bone grafting procedures during the use of dental implants may be avoided by the use of tilted implants in the maxilla and the mandible; advantages of angled implants are associated with the extension of the distal cantilever, leading to better implant survival rates. However, the bending effect on the single tilting implants may increase the marginal bone stress. The purpose of the present study was to retrospectively assess the clinical success and proximal bone loss rate following the implantation of distally tilted implants according to the All-on-Four™ prosthetic concept—based on radiographic findings—in a single-center experience, in addition to the assessment of the outcomes in the context of various clinico-epidemiological correlates. During the study period, n = 36 patients (24 males and 12 females) with complete records of periapical radiographs, received a full-arch fixed bridge supported by two axial and two distal tilted implants; overall n = 144 and n = 144 implants (Nobel B) were place in the maxilla and mandibles of patients, respectively. Mean age of patients at the time of fixture installation was 58.75 ± 13.71 years; n =11 patients presented with relevant underlying conditions/habits. To assess peri-implant bone-level changes, matched and calibrated orthopantomogram (OPT) images were taken at follow-ups after 1.5 years, 2.5 years, and 3.5 years post-restoration, and marginal bone levels were assessed on the mesio- (MA) and disto-approximal (DA) aspects. All implants were successful, resulting in a 100% overall survival rate. The radiographic mean bone loss levels at baseline (mean ± SEM) were 0.181 ± 0.011 mm and 0.178 ± 0.017 mm in the maxilla and mandible, respectively, while by the 3.5-year mark, bone loss was 0.770 ± 0.029 mm and 0.713 ± 0.026 mm in the maxilla and mandible (p > 0.05), respectively; bone-level changes were significant over time (p = 0.035 and p = 0.033). Peri-implant bone loss was more aggressive around titled distal implants versus mesial actual position implants. The effect of smoking and other underlying conditions showed significantly higher (p < 0.05) bone resorption levels when assessed on an individual implant-level, while during patient-level analysis, only a tendency was shown for higher bone loss rates for both MA and DA implants (p > 0.05). Within its limitations, our study has concluded that the use of All-on-Four™ prosthetic concept for total arch rehabilitation yields higher bone loss in association with tilted implants and, in some cases, on the MA surfaces at vertically positioned implants after >40 months in function.
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Affiliation(s)
- Árpád László Szabó
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos körút 62-64, 6720 Szeged, Hungary; (Á.L.S.); (Á.L.N.)
- Oral Centrum Dental Ltd., Angyalka u. 1/A, 2030 Érd, Hungary
| | - Ádám László Nagy
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos körút 62-64, 6720 Szeged, Hungary; (Á.L.S.); (Á.L.N.)
| | - Csaba Lászlófy
- Sanoral Healthcare Ltd., Ó utca 6, 1066 Budapest, Hungary;
| | - Márió Gajdács
- Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, Tisza Lajos krt. 63., 6720 Szeged, Hungary;
| | - Péter Bencsik
- Department of Pharmacology and Pharmacotherapy, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 12, 6721 Szeged, Hungary;
| | - Krisztina Kárpáti
- Department of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, University of Szeged, Tisza Lajos körút 62-64, 6720 Szeged, Hungary;
| | - Zoltán Baráth
- Department of Prosthodontics, Faculty of Dentistry, University of Szeged, Tisza Lajos körút 62-64, 6720 Szeged, Hungary; (Á.L.S.); (Á.L.N.)
- Correspondence: or ; Tel.: +36-62-545-297
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