scholarly journals Assessment of Mechanical Stability and Safety for Fully Edentulous Maxilla with Dental Implants

2010 ◽  
Vol 4 (7) ◽  
pp. 953-962 ◽  
Author(s):  
Takaaki ARAHIRA ◽  
Mitsugu TODO ◽  
Yasuyuki MATSUSHITA ◽  
Kiyoshi KOYANO
2011 ◽  
Vol 2 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Himanshu Arora ◽  
Anil Nafria ◽  
Anup Kanase

ABSTRACT Development of an optimal interface between bone and orthopedic or dental implants has taken place for many years. In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation. For this reason the use of animal models is often an essential step in the testing of orthopedic and dental implants prior to clinical use in humans. This review discusses the reasons, the importance, and the research carried out in rabbits in our quest to develop a dental implant ideally suited for human bone.


Author(s):  
T. J. Sego ◽  
Yung-Ting Hsu ◽  
Tien-Min Gabriel Chu ◽  
Andres Tovar

Short dental implants are commonly recommended to be implemented with small crown-to-implant (C/I) ratios due to their mechanical stability — decreasing C/I ratios cause less deformation in skeletal tissue under occlusal force. However, the long-term stability of short implants with high C/I ratios remains a controversial issue due to biomechanical complications. This study evaluates the strain distribution and functional implications in an implant-supported crown with various C/I ratios using a high-fidelity, nonlinear finite-element model. Several clinical scenarios are simulated by loading implants with various implant lengths (IL) and crown heights (CH). Strain distribution and maximum equivalent strain are analyzed to evaluate the effects and significance of CH, IL, and the C/I ratio. The study shows underloading for certain implant configurations with high C/I ratio. Increasing IL and decreasing C/I in moderation demonstrates a positive effect in long-term stability.


Folia Medica ◽  
2020 ◽  
Vol 62 (3) ◽  
pp. 563-571
Author(s):  
Vasilena Ivanova ◽  
Ivan Chenchev ◽  
Stefan Zlatev ◽  
Dimitar Atanasov

Introduction: Sufficient bone volume, as well as the bone quality characteristics are necessary prerequisites to ensure optimal mechanical stability of the implants and subsequent osseointegration. Aim: The aim of the present study was to assess the correlation between bone density values obtained by cone-beam computed tomography (CBCT), the primary stability of dental implants and the histomorphometric analysis of bone quality. Materials and methods: Following tooth extraction, socket preservation with frieze-dried bone allograft or protein-rich fibrin (PRF) was performed on 30 patients with 30 maxillary teeth in the region from second premolar to second premolar. Four months after the procedure, CBCT was used to assess the bone density (Hounsfield units) in the area of extraction. Thirty bone samples were harvested from implant sites using a trephine drill. They were analyzed with Image J software. Immediately after placing the implant, the implant stability quotient was measured using the Osstell Idx device. Results: The results revealed significant correlations between bone density and primary stability along the vestibulo-oral (r=0.392, p=0.032) and mesiodistal axes (r=0.407, p=0.026). Bone density also correlated strongly with the percentage of newly formed bone (r=0.776, p<0.001). Conclusion: Bone quality, in terms of bone density measured in CBCT and new bone formation are correlated to the primary stability of the dental implants and vice versa.


Author(s):  
Manjeet Kumar ◽  
Rajesh Kumar ◽  
Sandeep Kumar ◽  
Chander Prakash

The demand for the orthopedic and dental implants has increased sharply in last decade due to physical traumas and age-related deficiencies. The material used for orthopedic and dental implants should be biocompatible to ensure the adaptability of the implant in the human body. The mechanical stability of implants is dependent on mechanical properties and surface characteristics essential to ensure corrosion and wear resistance. The requirement of mechanical properties also differs substantially from load-bearing to non-load-bearing implants. There are many problems arising due to lack of sufficient biocompatibility, like infection, poor osseointegration, and excessive foreign body response. Fatigue failure, stress shielding, and bone resorption are some major problems associated with lack of mechanical stability. Numerous conventional materials, coatings, and nanomaterials have been used to enhance the implant stability.


Author(s):  
Manjeet Kumar ◽  
Rajesh Kumar ◽  
Sandeep Kumar ◽  
Chander Prakash

The demand for the orthopedic and dental implants has increased sharply in last decade due to physical traumas and age-related deficiencies. The material used for orthopedic and dental implants should be biocompatible to ensure the adaptability of the implant in the human body. The mechanical stability of implants is dependent on mechanical properties and surface characteristics essential to ensure corrosion and wear resistance. The requirement of mechanical properties also differs substantially from load-bearing to non-load-bearing implants. There are many problems arising due to lack of sufficient biocompatibility, like infection, poor osseointegration, and excessive foreign body response. Fatigue failure, stress shielding, and bone resorption are some major problems associated with lack of mechanical stability. Numerous conventional materials, coatings, and nanomaterials have been used to enhance the implant stability.


2013 ◽  
Vol 5 (2) ◽  
pp. 34-37
Author(s):  
K.T. ROOPA ◽  
K. RAKSHA ◽  
SAGAR SHAH

ABSTRACT With the introduction ofbiocompatible materials like titanium and other bio ceramics and added advantages of preservation of tooth structure, implants have created a new era in dentistry as treatment option for missing teeth. Earlier short coming oflack of bonding with bone are overcome by osseointegration property of titanium and zirconia implants. This osseointegration rate of titanium dental implants is related to surface composition, surface roughness and hydrophilicity which increase the mechanical stability of implants. The present review throws some light on various methods employed for surface modifications. AIM & OBJECTIVE Aim of this paper is to discuss various surface treatment methods of Implants and its effect on osseointegration. CONCLUSION There are various surface modified implants available. Studies have proven that these implants show better osseointegration compared to machined implants.


Author(s):  
W.K. Lo ◽  
J.C.H. Spence

An improved design for a combination Scanning Tunnelling Microscope/TEM specimen holder is presented. It is based on earlier versions which have been used to test the usefulness of such a device. As with the earlier versions, this holder is meant to replace the standard double-tilt specimen holder of an unmodified Philips 400T TEM. It allows the sample to be imaged simultaneously by both the STM and the TEM when the TEM is operated in the reflection mode (see figure 1).The resolution of a STM is determined by its tip radii as well as its stability. This places strict limitations on the mechanical stability of the tip with respect to the sample. In this STM the piezoelectric tube scanner is rigidly mounted inside the endcap of the STM holder. The tip coarse approach to the sample (z-direction) is provided by an Inchworm which is located outside the TEM vacuum.


Author(s):  
Oliver C. Wells ◽  
Mark E. Welland

Scanning tunneling microscopes (STM) exist in two versions. In both of these, a pointed metal tip is scanned in close proximity to the specimen surface by means of three piezos. The distance of the tip from the sample is controlled by a feedback system to give a constant tunneling current between the tip and the sample. In the low-end STM, the system has a mechanical stability and a noise level to give a vertical resolution of between 0.1 nm and 1.0 nm. The atomic resolution STM can show individual atoms on the surface of the specimen.A low-end STM has been put into the specimen chamber of a scanning electron microscope (SEM). The first objective was to investigate technological problems such as surface profiling. The second objective was for exploratory studies. This second objective has already been achieved by showing that the STM can be used to study trapping sites in SiO2.


Author(s):  
Debby A. Jennings ◽  
Michael J. Morykwas ◽  
Louis C. Argenta

Grafts of cultured allogenic or autogenic keratlnocytes have proven to be an effective treatment of chronic wounds and burns. This study utilized a collagen substrate for keratinocyte and fibroblast attachment. The substrate provided mechanical stability and augmented graft manipulation onto the wound bed. Graft integrity was confirmed by light and transmission electron microscopy.Bovine Type I dermal collagen sheets (100 μm thick) were crosslinked with 254 nm UV light (13.5 Joules/cm2) to improve mechanical properties and reduce degradation. A single cell suspension of third passage neonatal foreskin fibroblasts were plated onto the collagen. Five days later, a single cell suspension of first passage neonatal foreskin keratinocytes were plated on the opposite side of the collagen. The grafts were cultured for one month.The grafts were fixed in phosphate buffered 4% formaldehyde/1% glutaraldehyde for 24 hours. Graft pieces were then washed in 0.13 M phosphate buffer, post-fixed in 1% osmium tetroxide, dehydrated, and embedded in Polybed 812.


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