Fatigue Evaluation of a New Two-Piece Dental Implant, Having a Replaceable Titanium Sleeve

2020 ◽  
Author(s):  
Chaushu Liat ◽  
Chaushu Gavriel

Abstract A new two-piece dental implant, having a replaceable thin titanium sleeve in its 5mm crestal part was designed. The use of a sleeve of near 0.2mm thickness reduces implant diameter by 0.4mm. Narrower diameter implants may increase the likelihood of component fracture in dental implant systems. 14 two-piece dental implants, with 25° abutment angle were subjected to a dynamic fatigue test according to DIN EN ISO 14801. The highest load at which a runout (non-failure) occurred at 5x106 cycles, amounted to 575 N. According to DIN EN ISO 14801, this load level was confirmed with n=3 samples. The Wöhler curve was determined. Accordingly, the runout at 106 cycles can be anticipated as 625N. The new two-piece Implant B™ design using a 0.2 mm sleeve is compatible with the DIN EN ISO 14801 standard for dimensions of 4.2mm diameter and 13mm length. It withstands dynamic fatigue test at least as good as any other standard endosseous implant.

2015 ◽  
Vol 27 (04) ◽  
pp. 1550037 ◽  
Author(s):  
G. Uzcátegui ◽  
E. Dávila ◽  
M. Cerrolaza

Objective: To propose a methodology based on virtual simulation to assist in the design proposals of dental implants. Methods: The finite element method (FEM) was used to analyze the biomechanical dental implant system behavior, determining von Mises stress distribution induced by functional loads, varying parameter as load direction and geometric characteristic of the implant (taper, length, abutment angulation, thread pitch and width pitch). A final design was obtained by considering the parameters that showed improved performance. The estimated lifetime of the final design was calculated by reproducing in a virtual way the experimental fatigue test required by the ISO:14801 standards. Results: For all the studied cases, the maximum stresses were obtained in the connecting screw under oblique loads (OLs). The estimated lifetime for this critical part is at least 5 × 106 cycles, which meets the requirement of the ISO:14801. In bone tissue, the largest stresses were concentrated in cortical bone, in the zone surrounding the implant, in good agreement with previous reports. Conclusions: A dental implant design was obtained and validated through a simple and efficient methodology based on the application of numerical methods and computer simulations.


2021 ◽  
Vol 30 ◽  
pp. 81-86
Author(s):  
Luboš Řehounek ◽  
Aleš Jíra ◽  
Gabriela Javorská ◽  
Daniel Bodlák

Most modern dental implants differentiate in regard to the fixation of the abutment into two main categories - the external or internal hexagon or octagon. We performed mechanical tests according to the ČSN EN ISO 14801 standard on a dental implant variant using the external hex. We found that failure of all implant specimens occured below the screw head. To improve the current geometry, we performed numerical analysis of an alternative variant (internal hex) and compared it with analysis of the current geometry (external hex). It was found that the stress distribution of the variant with internal hex is preferable to the old variant. Although extreme values of shear stress in the corresponding plane of loading are higher, they do not concentrate below the screw head, where the screw itself is thinner and more prone to breaking. Therefore, it seems that the new variant of the dental implant is stronger, which is still to be proven by mechanical tests.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 744 ◽  
Author(s):  
Mikel Armentia ◽  
Mikel Abasolo ◽  
Ibai Coria ◽  
Joseba Albizuri

Fatigue is the most common mechanical failure type in dental implants. ISO 14801 standardizes fatigue testing of dental implants, providing the load-life curve which is most useful for comparing the fatigue behavior of different dental implant designs. Based on it, many works were published in the dental implant literature, comparing different materials, component geometries, connection types, surface treatments, etc. These works are useful for clinicians in order to identify the best options available in the market. The present work is intended not for clinicians but for dental implant manufacturers, developing a design tool that combines Finite Element Analysis, fatigue formulation and ISO 14801 experimental tests. For that purpose, 46 experimental tests were performed on BTI INTERNA® IIPSCA4513 implants joined with INPPTU44 abutments by means of INTTUH prosthetic screws under three different tightening torque magnitudes. Then, the load case was reproduced in a FE model from where the nominal stress state in the fatigue critical section was worked out. Finally, Walker criterion was used to represent accurately the effects of mean stress and predict fatigue life of the studied dental implant assembly, which can be extended to most of the products of BTI manufacturer. By means of this tool, dental implant manufacturers will be able to identify the critical design and assembly parameters in terms of fatigue behavior, evaluate their influence in preliminary design stages and consequently design dental implants with significantly better fatigue response which in turn will reduce future clinical incidences.


Author(s):  
А.С. Рыбалко ◽  
А.С. Григорьян ◽  
А.А. Орлов

Цель исследования состояла в разработке неинвазивного метода диагностики состояния тканей периимплантационной зоны после постановки дентальных имплантатов, а также прогноза течения послеоперационного периода и ранней диагностики послеоперационных осложнений, таких, как мукозит и периимплантит, при одноэтапном методе дентальной имплантации. Методы. В исследовании представлена цитологическая характеристика отпечатков из области контакта имплантата с десной, в которых оценивали состояние эпителиальных клеток при различных проявлениях цитопатологии. Определяли индекс деструкции (ИД) и воспалительно-деструктивный индекс (ВДИ) в клетках воспалительного инфильтрата, которые сопоставляли с клинической картиной течения послеоперационного периода. Сроки забора цитологического материала 1, 5, 15, 25, 30, 60, 120 дней после постановки имплантатов. Количество исследованных цитограмм - 442 от 11 пациентов (по 1-2 имплантата). Общий массив использованных для вычисления интегральных показателей составил »2550. Результаты. Было установлено, что в сроки 1-5 дней после постановки дентальных имплантатов происходит резкое повышение показателей ИД (до 7500 ± 15) и ВДИ (до 80 ± 20), что отражает процесс развития в области имплантатов острых воспалительных реакций. В отдаленные сроки наблюдений отмечалось 2 варианта развития событий. Первый из них характеризовался сохранением во все сроки высоких показателей ИД и ВДИ. Для второго варианта динамики показателей было характерно их падение, что соответствовало развитию процесса остеоинтеграции дентальных имплантатов. The objectives of the investigation were to develop protocols evaluating the validity and effectiveness of the cytological method for diagnosis and prognosis of tissue conditions adjacent to a dental implant. Methods. This study examined the cytological characteristics of imprints of the gingiva-implant contact area, a. the correlation of quantitative ratios of epithelial cells either with or without hystopathological manifestations (an index of destruction, ID); b. ratio of cells of the inflammatory infiltrate (an inflammatory and destructive index, IDI); these data were researched in relation with dynamics of the clinical pictures during a postoperative period.The cytological material was obtained 1, 5, 15, 25, 30, 60, 120 days after dental implantation. Totally 442 cytogramme from 11 patients (1-2 implant per a patient) were assayed. The data array for computation of integrated indicators was composed of ca. 2550 data points. Results. A significant increase of ID (7500 ± 15) and IDI (80 ± 20) indicators, which reflects the development of acute inflammatory reactions in tissues neighboring an implant, was observed within 1-5 days following the insertion of dental implants. Long-term observations revealed two scenarios. The first scenario was characterized by the retention of high levels of ID and IDI over the period of observations. The second scenario featured the reduction of ID and IDI indices, which corresponded to the development of the osseointegration of dental implants.


2011 ◽  
pp. 96-103
Author(s):  
Quang Hai Nguyen ◽  
Toai Nguyen

1. Background: Loss of permanent teeth is very common, affected chewing function, speech and aesthetics; restoration of missing teeth with dental implant has several advantages, but we need thoroughly study the clinical and X ray features at the position at missing teeth, then to select the type of implant and make the best plan for the dental implant patients. 2. Materials and method: Cross-section descriptive study. From January 2009 to November 2010, study with 56 patients with 102 implants of MIS and Megagen systems at the Faculty of Odonto-Stomatology, Hue College of Medicine and Pharmacy and Vietnam-Cuba Hospital in Ha Noi. 3. Results: Distributed equally in male and female, common ages 40 – 59 (55,4%), the majority of missing teeth occurs in the lower jaw (63,8%) and especially, the teeth 36 and 46 (25,4%). The majority of missing teeth due to dental caries, dental pulp and apical diseases (64,7%) of the molar teeth (51,9%); the most position of missing tooth have enough bone for dental implants (87,3%), time of tooth loss and bone status in the position of tooth loss are related to each other (p < 0,01). Diameter and length of implant usually used 4.0 – 6.0 mm (63,7%) and 8.5 – 13.0 mm (83,3%). 4. Conclusion: Clinical and X ray features of edentulous patients has an important role in determining the type of implants and treatment planning of dental implants. Key words: Loss of permanent teeth, X ray and clinical features, Dental implant.


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.


2013 ◽  
Vol 70 (6) ◽  
pp. 586-594 ◽  
Author(s):  
Zoran Vlahovic ◽  
Branko Mihailovic ◽  
Zoran Lazic ◽  
Mileta Golubovic

Background/Aim. Flapless implant surgery has become very important issue during recent years, mostly thanks to computerization of dentistry and software planning of dental implants placements. The aim of this study was to compare flap and flapless surgical techniques for implant placement through radiographic and radiofrequency analyses. Methods. The experiment was made in five domestic pigs. Nine weeks following domestic pigs teeth extraction, implants were placed, on the right side using surgical technique flap, and flapless on the left side. Digital dental Xrays were applied to determine primary dental implant stability quality (ISQ). At certain intervals, not later than three months, the experimental animals were sacrificed, and just before it, control X-rays were applied to measure dental implants stability. Results. Radiographic analysis showed that peri-implant bone resorption in the first 4 weeks following placement implants with flap and flapless surgical techniques was negligible. After the 3 months, mean value of peri-implant bone resorption of the implants placed using flap technique was 1.86 mm, and of those placed using flapless technique was 1.13 mm. In relation to the primary dental implant stability in the first and second week there was an expected decrease in ISQ values, but it was less expressed in the dental implants placed using the flapless technique. In the third week the ISQ values were increased in the dental implants placed by using both techniques, but the increase in flapless implant placement was higher (7.4 ISQ) than in flap implant placement (1.5 ISQ). The upward trend continued in a 4- week period, and after 3 months the dental implant stability values in the implants placed using flap technique were higher than the primary stability for 7.1 ISQ, and in the implants placed using flapless technique were higher comparing to the primary stability for 10.1 ISQ units. Conclusion. Based on the results of radiographic and resonance frequency analyses it can be concluded that the flapless technique in surgical implants placemat, leads to better results.


Ceramics ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 568-577 ◽  
Author(s):  
Frigan ◽  
Chevalier ◽  
Zhang ◽  
Spies

The market share of zirconia (ZrO2) dental implants is steadily increasing. This material comprises a polymorphous character with three temperature-dependent crystalline structures, namely monoclinic (m), tetragonal (t) and cubic (c) phases. Special attention is given to the tetragonal phase when maintained in a metastable state at room temperature. Metastable tetragonal grains allow for the beneficial phenomenon of Phase Transformation Toughening (PTT), resulting in a high fracture resistance, but may lead to an undesired surface transformation to the monoclinic phase in a humid environment (low-temperature degradation, LTD, often referred to as ‘ageing’). Today, the clinical safety of zirconia dental implants by means of long-term stability is being addressed by two international ISO standards. These standards impose different experimental setups concerning the dynamic fatigue resistance of the final product (ISO 14801) or the ageing behavior of a standardized sample (ISO 13356) separately. However, when evaluating zirconia dental implants pre-clinically, oral environmental conditions should be simulated to the extent possible by combining a hydrothermal treatment and dynamic fatigue. For failure analysis, phase transformation might be quantified by non-destructive techniques, such as X-Ray Diffraction (XRD) or Raman spectroscopy, whereas Scanning Electron Microscopy (SEM) of cross-sections or Focused Ion Beam (FIB) sections might be used for visualization of the monoclinic layer growth in depth. Finally, a minimum load should be defined for static loading to fracture. The purpose of this communication is to contribute to the current discussion on how to optimize the aforementioned standards in order to guarantee clinical safety for the patients.


2017 ◽  
Vol 907 ◽  
pp. 104-118
Author(s):  
Maria Stoicănescu ◽  
Eliza Buzamet ◽  
Dragos Vladimir Budei ◽  
Valentin Craciun ◽  
Roxana Budei ◽  
...  

Dental implants are becoming increasingly used in current dental practice. This increased demand has motivated manufacturers to develop varieties of product through design, but also looking for new materials used to improve surface characteristics in order to obtain a better osseointegration. But the increase in the use of implants goes to a consequent increase in the number of failures. These failures are caused either by treatment complications (peri-implantitis), by fatigue breakage under mechanical over-stress, by defective raw material, or due to errors during the insertion procedures. Although they are rare, these complications are serious in dentistry. Before to market a dental implant to clinical practitioners, the product is validated among other determinations in number of biocompatibility research. Raw material issues, details about its structure and properties are less published by the scientific literature, but all this are subject of a carefully analysis of the producers. Breaking of dental implants during surgical procedures, during the prosthetic procedures or during use (chewing, bruxism, accidents, etc.), is the second most common cause of loss of an implant after consecutive peri-implantitis rejection. Although the frequency of this type of failure for a dental implant is much smaller than those caused by the peri-implantitis, a detailed study of broken implants can explain possible causes. The use of scanning electron microscopy (SEM) in the study of the cleave areas explain the production mechanism of cleavages, starting from micro-fissures in the alloy used for the production of dental implants. These micro-fissures in weak areas of the implant (anti-rotational corners of the polygons, etc.) could generate a serious risk of cleavage first time when a higher force is applied.


Sign in / Sign up

Export Citation Format

Share Document