Background Crown-to-implant ratio and crown height space, associated with the use of short implants, have been related with marginal bone loss. However, it is unclear which of the two entities would play the most important role on the bone remodelling process. Using a finite element analysis, the present work aims to help clarifying how those two factors contribute for the stress generation at the marginal bone level. A numerical model (reference model), with a crown-to-implant ratio of 4, was double validated and submitted to a numerical calculation. Then, it was modified in two different ways: (a) by decreasing the prosthetic height obtaining crown-to-implant ratios of 3, 2.5 and 2 and (b) by increasing the implants length obtaining a crown-to-implant ratio of 2.08. The new models were also submitted to numerical calculations. Results The reference model showed a marginal bone stress of 96.9 MPa. The increase in the implants’ length did not show statistically significant differences in the marginal bone stress (p-value = 0.2364). The decrease in the prosthetic height was accompanied with a statistically significant decrease in the marginal bone stresses (p-value = 2.2e− 16). Conclusions The results represent a paradigm change as the crown height space appears to be more responsible for marginal bone stress than the high crown-to-implant ratios or the implants’ length. New prosthetic designs should be attempted to decrease the stress generated at the marginal bone level.
A protocol to perform a prosthetically driven minimally invasive zygomatic osteotomy, named zygoma anatomy-guided approach (ZAGA) is introduced. The ZAGA method aims at promoting a patient-specific therapy by adapting the osteotomy type to the patient's anatomy. In most cases, this method avoids the opening of a window or slot into the lateral wall of the maxillary sinus before implant placement. Instead, a mucoperiosteal flap, including the posterior maxillary wall and the superior zygomatic rim, is raised to allow visual control of the complete surgical field. The surgical management of the implant site is guided by the anatomy of the patient according to specific prosthetic, bio-mechanic, and anatomic criteria. The ZAGA Concept represents the logical evolution of the extra-sinus technique and ZAGA classification previously described by Aparicio. The results of using the combination of the ZAGA Concept together with the new ZAGA implant designs consistently show less traumatic osteotomy; better implant stability; improved bone to implant contact, and bone sealing around the implant neck. Additionally, the rate of late complications such as oral–sinus communication or soft tissue recession dramatically decreases when compared to the original technique.
Objectives: This research intended to develop and validate a digital model that could be used to study the stresses and strains created in the different components involved in oral fixed rehabilitations with short implants. The validated model was then used to simulate a clinical-like situation.Methods: A digital model was created considering the posterior areas of the mandible. Its materialization obtained ten specimens of the experimental prototype. Seven of them were static compressive tested until failure and, for the other three, the tests were progressively interrupted, to allow the establishment of a damage sequence. On the numerical model a finite element analysis was performed with Abaqus software, under similar conditions to the experimental situation. Results:The stress pattern on the FEA and the failure location on the static test were similar.The sequence in which each part reached the yield strength was the same as that observed on the interrupted static test (resin, prosthetic framework, implants and implant screws, in this order). Due to these results, the model was considered valid. A clinical-like simulation with the validated model showed that buccal cortical bone, around the implants platform, is the weakest part of such a rehabilitation.Conclusions: This research allowed the development and validation of a computer-aided design model that can be used to study an oral fixed rehabilitation supported by short im- Conclusões: Esta investigação permitiu o desenvolvimento e a validação de um modelo que permite o estudo de reabilitações fixas sobre implantes curtos. Clinicamente é importante realçar que o osso cortical é a zona que apresenta tensões e deformações mais elevadas.
Study Design: This is an in vitro study composed by a fatigue test followed by an optical microscopy analysis.Background: Dynamic abutments concept, recently introduced on screw-retained implant dental prosthesis, consists on the screw channel customization according to the individual needs of each rehabilitation. Geometry and tightening torque differences advise the assessment of their mechanical performance.Objectives: Clarify whether the combination of dynamic and conventional abutments in a three-unit implant-fixed prosthesis, has detrimental effects either on the mechanical performance under cyclic loading or on the implant-abutment microgap dimensions.Methods: The fatigue test was performed in agreement with the ISO standard 14801.Than on the samples that resisted 5 million cycles, the implant-abutment microgap was measured on dynamic and conventional abutments using optical microscopy. Two unloaded samples were used as control group.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.