Harder and Stiffer Bone Osseointegrated to Roughened Titanium

2006 ◽  
Vol 85 (6) ◽  
pp. 560-565 ◽  
Author(s):  
F. Butz ◽  
H. Aita ◽  
C.J. Wang ◽  
T. Ogawa

Mechanisms underlying the beneficial anchorage of roughened titanium implants have not been identified. We hypothesized that the implant surface roughness alters intrinsic biomechanical properties of bone integrated to titanium. Nano-indentation performed on two- and four-week post-implantation bone specimens of rats revealed that bone integrated to acid-etched titanium was approximately 3 times harder than that integrated to the machined titanium, both at the osseointegration interface and at the inner area of the peri-implant bone. The hardness of the acid-etched surface-associated bone was equivalent to that of untreated cortical bone at week 4, while the bone hardness around the machined surface was equivalent to that of the untreated trabecular bone. The elastic modulus of the integrated bone was 1.5 to 2.5 times greater around the acid-etched surface than around the machined surface. Analysis of the data suggests that the implant surface roughness affects the biomechanical quality of osseo-integrated bone, and that the bone integrated to the acid-etched surface is harder and stiffer than the bone integrated to the machined surface.

2012 ◽  
Vol 529-530 ◽  
pp. 559-564 ◽  
Author(s):  
Akihiro Furuhashi ◽  
Yasunori Ayukawa ◽  
Ikiru Atsuta ◽  
Yunia Dwi Rakhmatia ◽  
Noriyuki Yasunami ◽  
...  

At the neck area of dental implant surface, machined surface (Ms) has been employed to avoid surface contamination. Recently, implants which have roughened surface texture (Rs) at their neck are also available. However, from the viewpoint of soft tissue integration, it remains to be elucidated whether or not surface topography affects the soft tissue attachment around implants. The aim of the present study was to clarify the influence of surface topography on peri-implant soft tissue integration. First, surface roughness of both surfaces was measured. Second, protein adsorption capability on both surfaces was examined. Then, as the rat implant model, titanium implants with each surface were inserted into the maxillae. Horseradish peroxidase (HRP) tracer was applied 4 weeks post implantation to the gingival sulci of implants or natural teeth (NT) to investigate the sealing capability of periodontal/peri-implant soft tissue. Collagen density was also observed by fluorescent staining. As a result, surface roughness (Sa) of Ms and Rs was 0.16 µm and 0.25 µm, respectively. Protein adsorption capability on both surface showed no significant differences. In the NT group of the rat implant model, presence of HRP was restricted only in the coronal portion of epithelium. In both implant groups, in contrast, more invasion of HRP was observed in the soft tissue around implants. Especially in the Ms group, more HRP was observed in the deeper area compared with Rs group. Stronger expression of collagen was observed around Rs compared to Ms at the connective tissue-implant interface. It could be speculated that, with dense collagen, Rs implants showed stronger soft tissue integration compared with Ms implants, but the integration is not as strong as NT’s.


Author(s):  
Tribeni Roy ◽  
Anuj Sharma ◽  
Prabhat Ranjan ◽  
R. Balasubramaniam

Abstract Electrical discharge machined surfaces inherently possess recast layer on the surface with heat affected zone (HAZ) beneath it and these have a detrimental effect on the mechanical properties viz. hardness, elastic modulus, etc. It is very difficult to experimentally characterise each machined surface. Therefore, an attempt is made in this study to numerically calculate the mechanical properties of the parent material, HAZ and the recast layer on a hemispherical protruded micro feature fabricated by reverse micro EDM (RMEDM). In the 1st stage, nano indentation was performed to experimentally determine the load-displacement plots, elastic modulus and hardness of the parent material, HAZ and the recast layer. In the 2nd stage, FEA simulation was carried out to mimic the nano indentation process and determine the load-displacement plots for all the three cases viz. parent material, recast layer and HAZ. Results demonstrated that the load'displacement plots obtained from numerical model in each case was in good agreement with that of the experimental curves. Based on simulated load-displacement plots, hardness was also calculated for parent material, HAZ and the recast layer. A maximum of 11% error was observed between simulated values of hardness and experimentally determined values.


Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.


Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 840 ◽  
Author(s):  
José Henrique de Lima Cavalcanti ◽  
Patrícia Matos ◽  
Cresus Vinícius Depes de Gouvêa ◽  
Waldimir Carvalho ◽  
José Luis Calvo-Guirado ◽  
...  

Manipulation of implant surface characteristics constitutes a promising strategy for improving cell growth and tissue response on a variety of materials with different surface topographies. Mesenchymal progenitor cells with a capacity to respond to titanium surface stimuli and differentiate into osteoblasts were used to perform comparative tests between two different implant topographies, including their functional interaction with pre-osteoblasts directly seeded onto the implants. Functional analysis of nanostructured implant surfaces was performed by in vitro assay analysis. The machined surface of titanium implants (mach group) was used as a control and compared with a nanoparticle HA activated surface implant (nano group), developed by the deposition of pure crystalline hydroxyapatite. Cell culture on the nano group surface resulted in higher cell adhesion and cultured osteoblast viability compared with the mach group. Scanning electron microscope (SEM) images revealed a stable interaction, indicated by the presence of focal cell adhesion formation. These results together with positive mineralization assays showed the nano group to be an excellent scaffold for bone-implant integration.


2010 ◽  
Vol 36 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Susana d'Avila ◽  
Leonardo Delfino dos Reis ◽  
Adriano Piattelli ◽  
Kelly C. S. Aguiar ◽  
Marcelo de Faveri ◽  
...  

Abstract Smoking has adverse effects on peri-implant bone healing and can cause bone loss around successfully integrated implants placed on type IV bone. This study evaluated the influence of implant surface topography of microimplants retrieved from posterior maxilla of smokers after 2 months of unloaded healing. Seven partially edentulous patients received 2 microimplants (machined and sandblasted acid-etched surface) each during conventional implant surgery. Histometric evaluation showed that the mean bone to implant contact was 10.40 ± 14.16% and 22.19 ± 14.68% to machined and sandblasted acid-etched surfaces, respectively (P < .001). These data suggest that the sandblasted acid-etched surface presented better results than the machined surface after a short healing time in smokers.


2007 ◽  
Vol 33 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Sauro Grassi ◽  
Adriano Piattelli ◽  
Daniel S. Ferrari ◽  
Luciene C. Figueiredo ◽  
Magda Feres ◽  
...  

Abstract The aim of this preliminary study was to evaluate the influence of a sandblasted acid-etched surface on bone-implant contact percentage (BIC%) as well as the bone density in the threads area (BD%) in type 4 bone after 2 months of unloaded healing. Five subjects (mean age = 42.6 years) received 2 microimplants each during conventional implant surgery in the posterior maxilla. The microimplants with commercially pure titanium surface (machined) and sandblasted acid-etched surface served as the control and test surfaces, respectively. After a healing period of 2 months, the microimplants and the surrounding tissue were removed and prepared for ground sectioning and histomorphometric analysis. One microimplant with a machined surface was found to be clinically unstable at the time of retrieval. Histometric evaluation indicated mean BIC% was 20.66 ± 14.54% and 40.08 ± 9.89% for machined and sandblasted acid-etched surfaces, respectively (P = .03). The BD% was 26.33 ± 19.92% for machined surface and 54.84 ± 22.77% for sandblasted acid-etched surface (P = .015). Within the limits of this study, the data suggest that the sandblasted acid-etched implant surface presented a higher percentage of bone-implant contact compared with machined surfaces, under unloaded conditions in posterior maxilla after a healing period of 2 months.


2007 ◽  
Vol 361-363 ◽  
pp. 849-852 ◽  
Author(s):  
Y. Herr ◽  
J.A. Woo ◽  
Y.H. Kwon ◽  
J.B. Park ◽  
S.J. Heo ◽  
...  

The increased surface roughness of dental implants has shown enhanced integration of bone tissues to implant surfaces, but may be predisposed to an increased risk of pathogenic bacterial infection and contamination with bacterial products. Tetracycline-HCl (Tc) treatment has been regarded as a practical and effective chemical modality for decontamination and detoxification of contaminated implant surfaces. The purpose of this study was to examine if Tc treatment alters the microstructures of the modified surface of dental implants. For this purpose, dental implants with pure titanium machined surface (MS), sandblasted, large grit, acid-etched surface (SLAS), or anodized surface (AS) were used. The surface of dental implants was rubbed for 30, 60, 90, 120, or 150 sec with sponge pellets soaked in Tc solution (50mg/ml) and in distilled water for 0 and 150 sec as the control group. The specimens were then routinely processed for scanning electron microscopy. The results show that Tc treatment did not change the surface of MS, SLAS, and AS.


2021 ◽  
Author(s):  

The turning of caprolon with the use of cutting fluid is investigated. It is established that when turning with a simultaneous supply of a water emulsion of a water repellent to the cutting zone, the water absorption of caprolon decreases and the quality of the machined surface increases. Keywords: caprolon, turning, water absorption, water repellent emulsion, surface roughness, chip formation. [email protected]


2017 ◽  
Vol 261 ◽  
pp. 215-220
Author(s):  
Martin Novák ◽  
Natasa Naprstkova

Machining of tool steels is often an important used technology. Products made from these materials are often used in mechanical engineering, and quality of workpiece surface roughness after machining respective grinding is one of the important parameters that to us speak about the quality of the machining process. The paper deals with the influence of cutting conditions when grinding bearing steel 100Cr (EN ISO) on machined surface roughness. This steel belongs to a group of bearing steels.


2008 ◽  
Vol 47-50 ◽  
pp. 467-470 ◽  
Author(s):  
Yeon Wook Kim

The osseointegration capability of titanium dental implants is related to their chemical composition and surface roughness. In this study, the combination of grit-blasting and micro-arc oxidation had been used for producing the improved implant surfaces. The ceramic particles were projected to titanium dental implants through a nozzle at high velocity by means of compressed air to get high surface roughness. Then the surface of titanium implants was modified by micro-arc oxidation treatment. The current density, frequency and duty were 50-300 mA/cm2, 100 Hz, and 50%, respectively. A porous TiO2 layer was formed on the surface after the oxidation treatment. The surface structure of oxidized implants exhibited nanometer-sized pores with an average diameter of 0.2 µm. The TiO2 passive layer of the implant surface can attribute to the excellent biocompatibility. The high roughness (Ra=0.182 µm) formed by grit-blasting maximizes the interlocking between mineralized bone and the surface of the implant. Surface roughness in the manometer range formed by micro-arc oxidation treatment would play an important role in the adsorption of proteins, adhesion of osteoblastic cell and thus the rate of osseointegration.


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