scholarly journals Proposal for a New Bioactive Kinetic Screw in an Implant, Using a Numerical Model

2022 ◽  
Vol 12 (2) ◽  
pp. 779
Author(s):  
Carlos Aurelio Andreucci ◽  
Abdullah Alshaya ◽  
Elza M. M. Fonseca ◽  
Renato N. Jorge

A new biomechanism, Bioactive Kinetic Screw (BKS) for screws and bone implants created by the first author, is presented using a bone dental implant screw, in which the bone particles, blood, cells, and protein molecules removed during bone drilling are used as a homogeneous autogenous transplant in the same implant site, aiming to obtain primary and secondary bone stability, simplifying the surgical procedure, and improving the healing process. The new BKS is based on complex geometry. In this work, we describe the growth factor (GF) delivery properties and the in situ optimization of the use of the GF in the fixation of bone screws through a dental implant. To describe the drilling process, an explicit dynamic numerical model was created, where the results show a significant impact of the drilling process on the bone material. The simulation demonstrates that the space occupied by the screw causes stress and deformation in the bone during the perforation and removal of the particulate bone, resulting in the accumulation of material removed within the implant screw, filling the limit hole of the drill grooves present on the new BKS.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
George Deryabin ◽  
Simonas Grybauskas

Abstract Background The purpose of this study was to analyze medium-to-long-term implant success and survival rates, and lower lip sensory disturbance after placement of dental implants with simultaneous inferior alveolar nerve (IAN) repositioning. Methods Fifteen patients (3 men, 12 women) treated in two centers were included in this retrospective study. The ages of the participants ranged from 19 to 68. A total of 48 dental implants were placed in 23 posterior mandibular segments simultaneously with IAN transposition or lateralization. The residual bone above the IAN ranged from 0.5 to 7.0 mm. Crestal bone changes were measured using cone beam computed tomography (CBCT) images. Disturbance of the IAN was evaluated subjectively using a modified questionnaire. Results The healing process was uneventful in fourteen patients. In one patient, spontaneous fracture of the operated mandible occurred on tenth day after the surgery. The implant in the fracture line was removed at the time of open reduction and fixation. One more implant was lost after 5 years of loading. Therefore, the overall dental implant survival rate was 95.8%, whereas all implants in function were judged as successful after a follow-up period of 1 to 10 years. Transient neurosensory disturbances (ND) were observed in all patients who underwent IAN lateralization and IAN transposition. At follow-up times of 3 years, 5 years, and 10 years, weak hypoesthesia remained in two subjects treated with IAN transposition. None of the patients developed neuropathic pain after the procedure. Conclusions Within the limitations of this study, we conclude that reconstruction of severely resorbed mandibles with dental implants in conjunction with IAN repositioning is an effective and reliable technique. Although neurosensory disturbances are the most common complication after surgery, they tend to resolve over time. Advanced surgical skills are required to perform this technique.


Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.


Author(s):  
Reza Harirforoush ◽  
Siamak Arzanpour

This paper investigates primary stability of dental implant that indicates the process of bone-implant integration. This integration is known to happen at the boundary of the bone and dental implant contact surface. The resonance frequency of dental implant is used as the parameter for this investigation due to its high sensitivity to boundary condition variations. In this study, resonance frequency analysis (RFA) of the jaw-implant structure is carried out using finite element modeling. The FEM analyses are conducted in ANSYS modal analysis simulation environment. The FEM model of the structure includes titanium implant, Cancellous and cortical bone. Different implant-bone interface conditions are studied for this investigation. Various boundary conditions were studied to identify natural frequencies of jaw-implant structure. Our analysis shows that the resonance frequency of the implant increases during the healing period and reaches a plateau when the implant-bone interface was fully integrated. The results show that RFA could be suggested as a non-invasive, reliable and accurate diagnostic method for early assessment of the healing stages.


Author(s):  
Lebogang Lebea ◽  
Harry M Ngwangwa ◽  
Dawood Desai ◽  
Fuluphelo Nemavhola

The initial stability after implantology is paramount to the survival of the dental implant and the surface roughness of the implant plays a vital role in this regard. The characterisation of surface topography is a complicated branch of metrology, with a huge range of parameters available. Each parameter contributes significantly towards the survival and mechanical properties of 3D-printed specimens. The purpose of this paper is to experimentally investigate the effect of surface roughness of 3D-printed dental implants and 3D-printed dogbone tensile samples under areal height (Ra) parameters, amplitude parameters (average of ordinates), skewness (Rsk) parameters and mechanical properties. During the experiment, roughness values were analysed and the results showed that the skewness parameter demonstrated a minimum value of 0.596%. The 3D-printed dental implant recorded Ra with a 3.4 mm diameter at 43.23% and the 3D-printed dental implant with a 4.3 mm diameter at 26.18%. Samples with a complex geometry exhibited a higher roughness surface, which was the greatest difficulty of additive manufacturing when evaluating surface finish. The results show that when the ultimate tensile stress (UTS) decreases from 968.35 MPa to 955.25 MPa, Ra increases by 1.4% and when UTS increases to 961.18 MPa, Ra increases by 0.6%. When the cycle decreases from 262142 to 137433, Ra shows that less than a 90.74% increase in cycle is obtained. For 3D-printed dental implants, the higher the surface roughness, the lower the mechanical properties, ultimately leading to decreased implant life and poor performance.


Author(s):  
Marcin Kozłowski

Current standards and glass codes of design practice require that glazing used in architectural applications has to be resistant to, in addition to typical loads, also accidental events, in particular human impact, without showing damage that is disproportionate to the original cause. A case study was performed of an indoor glass lantern in a public building made from slender two-side supported glass panels with a complex geometry (36 ventilation holes). The paper provides structural assessments and results of in-situ experiments including static loading and soft body impact. Results from numerical simulations of impact loading on the glass panels complementing the experimental results are also presented.


2021 ◽  
Vol 11 (Suppl. 1) ◽  
pp. 299-302
Author(s):  
Utku Nezih Yılmaz ◽  
Fatma Eriş Derkuş

Aim: Today, dental implant applications have become the most preferred option in the treatment of tooth deficiencies. Long-term successful results in dental implant applications depend largely on the volume and quality of the hard and soft tissues in the relevant region. Insufficient soft tissues and alveolar crest resorption complicate implant applications. Grafts and additional surgical procedures are required to compensate for resorption and to provide bone augmentation. Shell technique, one of the augmentation methods used in the treatment of alveolar bone defects, is an important procedure for guided bone regeneration. The purpose of this case report is to describe the treatment of vertical and horizontal bone loss with the Shell technique using allogeneic cortical grafts. Methodology: A 58-year-old female patient without any systemic disease was admitted to our clinic with the complaint of tooth loss in the right posterior mandibular region. In the intraoral and radiological examinations, it was determined that the bone volume in the relevant region was not sufficient for dental implant. Two-stage surgical treatment was planned for the patient. First, vertical and horizontal bone defects were augmented with allogeneic cortical graft application under local anesthesia. After the healing process, dental implants were placed in the sufficient volume of the alveolar bone and the patient's treatment was completed. Conclusion: Allogeneic grafts in the treatment of alveolar crest defects; it is a good alternative to autogenous bone grafts,there is no need for a second surgical field and the resulting reduction in morbidity.   How to cite this article: Eriş Derkuş F, Yılmaz UN. Current approach to bone augmentation with allogeneic cortical graft: A case report. Int Dent Res 2021;11(Suppl.1):299-302. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.44     Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.


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