Biomechanical considerations on tooth-implant supported fixed partial dentures (original) (raw)
Journal of Oral Implantology, 2019
This study analyzed the biomechanical behavior of rigid and nonrigid tooth-implant supported fixed partial dentures. Different implants were used to observe the load distribution over teeth, implants, and adjacent bone using three-dimensional finite element analysis. A simulation of tooth loss of the first and second right molars was created with an implant placed in the second right molar and a prepared tooth with simulated periodontal ligament (PDL) in the second right premolar. Configurations of two types of implants and their respective abutments—external hexagon (EX) and Morse taper (MT)—were transformed into a 3D format. Metal-ceramic fixed partial dentures were constructed with rigid and nonrigid connections. Mesh generation and data processing were performed on the 3D finite element analysis (FEA) results. Static loading of 50 N (premolar) and 100 N (implant) were applied. When an EX implant was used, with a rigid or nonrigid connection, there was intrusion of the tooth in t...
Bone's responses to different designs of implant-supported fixed partial dentures
Biomechanics and modeling in mechanobiology, 2014
This paper explores the biomechanics and associated bone remodeling responses of two different abutment configurations, namely implant-implant-supported versus tooth-implant-supported fixed partial dentures. Two 3D finite element analysis models are created based upon computerized tomography data. The strain energy density induced by occlusal loading is used as a mechanical stimulus for driving the bone remodeling. To measure osseointegration and stability during healing, a resonance frequency analysis is conducted. At the second premolar peri-implant region, overloading resorption around the neck of implant is identified in both the models over the first 12 months. Stress-shielding around the edentulous region is also observed in both the models with a greater resorption rate found in the implant-implant case. The remodeling and resonance frequency analyses reveal that the tooth-implant scheme offers a higher degree of osseointegration. The remodeling procedure is expected to provi...
Useful Facts Concerning Implant-Assisted Removable Partial Dentures
Removable Partial Dentures, 2016
Objectives: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. Materials and Methods: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. Results: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant intercanine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). Conclusion: Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, 2020
The aim of this finite element study was to analyze effect of supporting implants inclination on stress distribution in the bone for a four-unit fixed partial denture. A three-dimensional finite element model of mandibular molar section of the bone to receive implants was constructed. Three implant-supported fixed partial dentures, with null, moderate and wide tilting, of 0°, 15° and 30° implant inclinations, respectively, were modeled. A mechanical load of 10 MPa was applied in coronal–apical direction on bridge framework at the regions of crowns positions. The finite element analysis was performed, and von Mises stress levels were calculated. Peak stress concentration in the cortical bone was observed mostly around the implant necks, in inter-implants line. There was favorable stress distribution during loading, with peak stress being 90.04 MPa for 0°, which decreased to 54.33 MPa for 15° and 46.36 MPa for 30° inclination. The supporting implants inclination in fixed partial dentu...
Mechanical behaviour of dental implants
Procedia structural integrity, 2016
Dental implants are majority made of titanium, since this material promotes a stable and functional connection between the bone and the surface of the implant. Efforts produced during the chewing cycles may interfere with this union, affecting the process of osseointegration and eventually compromising the stability of the implant. Given the difficulty in working with bone in vivo, in the present study two implant systems were inserted in polymer samples, known as Sawbones, which simulate the structure of trabecular bone. On the experimental side, the performance of the implants was evaluated through fatigue tests. The qualitative analysis of the damage in the structure of the samples was performed using scanning electron microscope images. The study was complemented with the determination and comparison of stress fields and deformations at the Sawbone-implant interface using an analytical model of indentation and the finite element method. The experimental results showed that the performance of the Morse taper implant is greater than the external hexagonal implant when both are tested cyclically in samples of different densities. It was proven that the diameter, length, density and type of implantabutment interface are design variables that affect the behavior of the implants. The numerical results of indentation model are very similar to those obtained by the analytical model. The results of the penetration FEM model have the same tendency as the experimental values and the FEM models and analytical indentation with increasing density of the polymer foam. It can be concluded that, as in foams, the increase of the bone density will induce an increased stability to the implants
Biomechanical Analysis of Implant Treatment for Fully Edentulous Maxillas
Journal of Biomechanical Science and Engineering, 2010
Three-dimensional maxillary bone models of a male and a female patient were constructed using their CT-images. The distributions of Young's modulus were estimated from their bone mineral density distributions. Total six implants were embedded into each of the maxillary models. Finite element analysis of the maxilla models was then performed in order to assess the concentrations of strain energy density especially in the vicinities of the embedded implants. It was found that in both models, strain energy density was concentrated especially around the right-molar implant, suggesting outbreak of damage and subsequent absorption of bone tissue in this region. The female model with smaller size and lower bone density exhibited much higher localized concentration of strain energy density than the male model. Therefore, a modified placement of the right-molar implant was then introduced into the female model and such high concentration was effectively reduced by using the inclined and longer implant. It is thus concluded that this kind of three-dimensional modeling can clinically be used to predict the optimal implant treatment for each of dental patients.
Principles of biomechanics in oral implantology
Medicine and Pharmacy Reports, 2019
Background and aims. The principles of biomechanics comprise all the interactions between the body (tissues) and the forces acting upon it (directly or via different medical devices). Besides the mechanical aspects, the tissues response is also studied. Understanding and applying these principles is vital for the researchers in the field of oral implantology, but they must be equally known by the practitioners. From the planning stages to the final prosthetic restoration, they are involved in each and every aspect. Ignoring them inevitably leads to failure. Methods. The first part of this paper includes a review of our current research in oral implantology (mechanical, digital and biological testing), while the second part includes a review of the available literature on certain biomechanical aspects and their implications in everyday practice. Results. Our research opens new study directions and provides increased chances of success for dental implant therapy. The practical aspects of our findings, combined with the available literature (from the basic principles described more than 40 years ago to the most recent studies and technologies) can serve as a guide to practitioners for increasing their success rate. Conclusion. While no therapy is without failure risk, a good understanding of the biomechanics involved in oral implantology can lead to higher success rates in implant supported prosthetic restorations.
Journal of Clinical and Experimental Dentistry
Background: The fixed tooth-implant connection remains a controversial issue. This private practice-based retrospective study aimed to evaluate the clinical outcomes of a contemporary fixed partial denture (FPD) design for connecting natural teeth and implants (TI-FPD), over an 11.8 years observation period. Material and Methods: The data of 91 partially edentulous patients (44 males and 47 females, mean age of 47.7 years) treated with a newly designed TI-FPD retained on 1 implant and 1 natural tooth were analyzed retrospectively. Teeth were covered with electroformed copings and a CAD/CAM made bridge was fixed over the abutments with provisional cement. Two different implant systems were used: Camlog (N=22; anterior areas) and Straumann tissue level (N=69; posterior areas). Results: The survival rate for both implants and teeth was 100%. 19/21 (90%, 95%CI 82-95%), 16/21 (66%, 95%CI 66-84%), and 16/21 (66%, 95%CI 66-84%) patients were free of biological complications after 5 years, 10 years, and 15 years post-loading, respectively. 23/35 (90%, 95%CI 54-74%), 21/35 (61%, 95%CI 50-70%), and 21/35 (61%, 95%CI 50-70%) were free of technical complications following 5 years, 10 years, and 15 years post loading, respectively. Conclusions: Despite limitations of the study, the findings demonstrated that the use of a recently designed TI-FPD could be used for the tooth-implant connection in cases of partial edentulism and this may widen the treatment modalities by reducing the cost and need for extensive bone tissue augmentations. Further controlled longitudinal studies with larger patient groups are needed.
Non-linear 3D finite element analysis of full-arch implant-supported fixed dentures
Materials Science and Engineering: C, 2014
Despite the necessity for faster clinical protocols for immediate loading of implant-supported dentures, there is a lack of biomechanical studies to confirm the rigid splinting effectiveness. We compared the stress in mandibular full-arch implant-supported fixed dentures under immediate loading through three-dimensional finite element analysis. Edentulous human mandible models were restored with a 4-implant fixed denture. Implants were splinted with a metallic framework and submitted to conventional loading (group A-control), with acrylic resin and submitted to immediate loading (group B), with a metallic framework and submitted to immediate loading (group C), and with acrylic resin and a prefabricated distal bar and submitted to immediate loading (group D). Models were supported by masticatory muscles. A 100-N oblique load was applied on the first molar. Group A presented the lowest stress and implant displacement values, whereas group D showed the highest values. In bone, groups under immediate loading exhibited the highest stress, whereas the group experiencing conventional loading showed an approximately 50% reduction. All groups submitted to immediate loading presented similar stress values in peri-implant bone. The loading protocol influenced the stress and implant displacement, but the design of the fixed denture did not affect the stress in the peri-implant bone. Rigid splinting of implants submitted to immediate loading is not essential for treatment success.
Journal of Contemporary Dentistry, 2011
Aim To evaluate the stress distribution and displacement of the denture base in a three dimensional finite element edentulous mandibular model with varied implant positions. Objectives 1)To evaluate the stresses induced by implants placed in the anterior region of the edentulous mandible. 2)To evaluate the stresses induced by implants placed in the anterior and posterior region of the edentulous mandible. 3)To compare the stresses induced by implants placed in the anterior and posterior region of the edentulous mandible. 4)To evaluate the displacement of the denture base with implants placed in the anterior and posterior region of the edentulous mandible.5)To compare the displacement of the denture base with implants placed in the anterior and posterior region of the edentulous mandible. Materials and Methods The materials used were Nobel Biocare Mk III long implants 3.75×13mm and short 5.0×7.0 implants, with O-ball head attachment. ANSYS: Version 8.0 software was used to create a t...
Tooth-implant Connection: A Literature Review
World Journal of Dentistry, 2012
The aim of this review is to summarize and discuss the available information concerning the connection between the tooth and implant in a fixed partial denture.
The role of biomechanics in oral implantology
Journal of Biomedical Materials Research, 1974
This paper begins with a brief historical review of the field of biomechanics applied to oral implantology. Based on the current status of development, a set of generalized biomechanical requirements are presented covering analytical, experimental and clinical considerations. The current biomechanics status and requirements are then used to derive a three part role for the biomechanics of oral implantology. The expected benefits to be gained from implementing this role are outlined.
Biomechanical considerations in implant prosthodontics
The Journal of Prosthetic Dentistry, 1983
I mplants can provide the partially edentulous patient with favorable support for a fixed prosthesis. To successfully design a prosthesis supported by an implant abutment(s), the dentist must consider the same biomechanical principles that are applied to fixed prosthodontics. l-3 Span deflection and the Class I lever, two biomechanical principles that apply to the selection and placement of implants as well as the design of a fixed prosthesis, will be considered.
The objective of the present study was to assess the influence of various clinically relevant scenarios on the strain distribution in the biomechanical surrounding of five different dental implant macrogeometries. The biomechanical environment surrounding an implant, i.e., the cortical and trabecular bone, was modeled along with the implant. These models included two different values of the study parameters including loading conditions, trabecular bone elastic modulus, cortical/trabecular bone thickness ratio, and bone loss for five implant designs. Finite element analysis was conducted on the models and strain in the bones surrounding the implant was calculated. Bone volumes having strains in four different windows of 0 -200 , 200-1000 , 1000-3000 , and Ͼ3000 were measured and the effect of each biomechanical variable and their twoway interactions were statistically analyzed using the analysis of variance method. This study showed that all the parameters included in this study had an effect on the volume of bones in all strain windows, except the implant design, which affected only the 0 -200 and Ͼ3000 windows. The two-way interaction results showed that interactions existed between implant design and bone loss, and loading condition, bone loss in the 200-1000 window, and between implant design and loading condition in the 0 -200 window. Within the limitations of the present methodology, it can be concluded that although some unfavorable clinical scenarios demonstrated a higher volume of bone in deleterious strain levels, a tendency toward the biomechanical equilibrium was evidenced regardless of the implant design.
The structure of dental implant is very important to its service life. In order to investigate the effect of the biomechanical properties of anchored dental implant on the osseointegration strength and secondary stability of dental implant, a dental implant model was established based on the three-dimensional structure of human oral cavity, craniomaxillofacial region. Static analysis of dental implant under static load was carried out by using ANSYS finite element analysis software. The results show that the anchorage structure dental implants have better biomechanical compatibility than the traditional standard dental implants, and can improve the strength of the bone-bonding interface. At the same time, the side of the anchorage structure can share the stress of the alveolar bone-implant interface and reduce the risk of unintentional bone-implant damage, so as to ensure the secondary stability of the dental implant, and can better limit the degree of freedom of movement of the dental implant, indirectly promote the restoration of bone-implant injury by reducing the fretting of the dental implant.