http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Sun, 16 Jun 2013 12:51:12 +0000 http://www.hindawi.com/isrn/biomaterials/2013/783873/ This study was conducted to characterize titanium (Ti) metal surfaces modified by polishing, coating with titanium nitride, coating with titanium oxide, sandblasting with alumina (Al2O3) particles and coating with titanium oxide, coating with titanium plasma spray (TPS); and to evaluate the effect of surface roughness and crystalline structure on adhesion of human fetal osteoblast cells (CRL-11372) in vitro after 24 hours. Surface topography and roughness were examined by scanning electron microscopy (SEM) and a noncontacting optical profilometer, respectively. The crystalline structures of the coatings were characterized by X-ray diffraction (XRD). CRL-11372 cells were incubated at these surfaces for 24 h and were evaluated for their mean total cell counts and cell viabilities. Cell morphologies were examined qualitatively by SEM images. Glass discs served as control group (CG) for the cell culture experiments. Surfaces at the Group TPS had the highest and values. Highest mean total cell counts were found for the CG. SC (sandblasted and TiO2 coated) surfaces had shown sparsely oriented CRL-11372 cells while other surfaces and CG showed confluency. Surfaces displayed diverse crystalline structures. Crystalline structures led to different cellular adhesion responses among the groups regardless of the surface roughness values. Sinem Yeniyol, Nilüfer Bölükbaşı, Ayhan Bilir, Ali Fuat Çakır, Mefail Yeniyol, and Tayfun Ozdemir Copyright © 2013 Sinem Yeniyol et al. All rights reserved. Thu, 06 Jun 2013 13:31:42 +0000 http://www.hindawi.com/isrn/biomaterials/2013/627367/ Wound healing is a staged process which involves the activity of leukocytes and platelets. For this process to work efficiently, the platelets play a vital role. The growth factors present in platelets are important to guide the regenerating cells to the area of healing. Platelet-rich-fibrin (PRF) is one such material that holds on to these growth factors enmeshed in the fibrin network resulting in their sustained release over a period of time that can accelerate the wound healing process. With this knowledge, research has been carried out for a past few years for the clinical application of PRF. Various platelet concentrates have been studied including the platelet-rich-plasma (PRP). However, the short duration of cytokine release and its poor mechanical properties have resulted in the search of a new material with adequate properties for clinical application and ease of preparation. PRF has found a place in the regenerative field owing to its advantages over PRP. This review focuses on the properties and various applications of PRF in the clinical practice. Sujeet Vinayak Khiste and Ritam Naik Tari Copyright © 2013 Sujeet Vinayak Khiste and Ritam Naik Tari. All rights reserved. Tue, 09 Apr 2013 10:42:47 +0000 http://www.hindawi.com/isrn/biomaterials/2013/253761/ For adult Indian premolar teeth, we report for the first time ever the simultaneous evaluations of nanohardness, Young's modulus, and fracture toughness of the enamel nanocomposite. The nanohardness and Young's moduli were evaluated from near the beginning of the middle enamel region to within 10 μm of the dentino-enamel junction (DEJ) and in the dentin region using the nanoindentation technique. The fracture toughness from near the middle of the enamel region to near the DEJ zone was measured using the microindentation technique. The deformation was studied using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM). The relative differences in the extents of biomineralization in the enamel and dentin regions were studied by the energy dispersive X-ray (EDS) technique. The variations of the toughness of the enamel as a function of the toughness of the protein matrix phase have been analyzed which showed that the predicted value of the toughness of the protein present in the nanocomposite was comparable to that of other bioproteins reported in the literature. Further, the work of fracture estimated from the measured value of toughness of the enamel nanocomposite agreed well with the experimental data reported in the literature. Nilormi Biswas, Arjun Dey, Saugata Kundu, Himel Chakraborty, and Anoop K. Mukhopadhyay Copyright © 2013 Nilormi Biswas et al. All rights reserved. Tue, 12 Mar 2013 13:02:48 +0000 http://www.hindawi.com/isrn/biomaterials/2013/728791/ Prosthetic heart valves are commonly used in the treatment of valvular heart disease. Mechanical valves are more durable than the bioprosthetic valves; however, the need for long-term anticoagulant therapy renders them unsuitable for some patient groups. In this paper we discuss the different types and models of bioprosthesis, and in particular, pericardial bioprosthesis. We also discuss the preimplantation preparation processes, as well as their postimplantation changes and modes of failure. Pooja Singhal, Adriana Luk, and Jagdish Butany Copyright © 2013 Pooja Singhal et al. All rights reserved. Tue, 01 Jan 2013 09:22:35 +0000 http://www.hindawi.com/isrn/biomaterials/2013/205601/ Several techniques have been described to modify the surface of titanium to make it more bioactive. Heat treatment (HT) and sodium hydroxide treatment (NaOH) have been used and can change the crystallinity and surface chemistry of titanium implants. However, no studies have systemically focused on comparing these different methods and their effect on the bioactivity of Ti. Therefore, in this study, Ti substrates were systematically treated using HT, NaOH, and a combination of HT and NaOH. The Ti plates were heat treated at various temperatures, and the plates were subjected to HT followed by soaking in NaOH or first soaked in NaOH and then heat treated. The morphology, crystallinity, hardness, water contact angle, and surface energy of the samples were analyzed as well as the bioactivity after immersion in PBS. Morphology and crystallinity changed with increasing temperature. The difference was most pronounced for the 800°C treated samples. The water contact angle decreased, and the surface energy increased with increasing temperature and was highest for 800°C. The rutile surface showed faster hydroxyapatite formation. NaOH treatment of the HT Ti samples increased the surface energy and improved its bioactivity further. Also, HT of NaOH samples improved the bioactivity compared to only HT. Carl Lindahl, Håkan Engqvist, and Wei Xia Copyright © 2012 Carl Lindahl et al. All rights reserved. Wed, 12 Dec 2012 14:52:08 +0000 http://www.hindawi.com/isrn/biomaterials/2013/649163/ Goniopora was hydrothermally converted to coralline hydroxyapatite (CHA) and incorporated with Sr (Sr-CHA). The pore size of Goniopora was in the range of 40–300 μm with a porosity of about 68%. Surface morphologies of the coral were modified to flake-like hydroxyapatite structures on CHA and the addition of Sr detected on Sr-CHA as confirmed by SEM and EDX. As the first report of incorporating Sr into coral, about 6%–14% Sr was detected on Sr-CHA. The compressive strengths of CHA and Sr-CHA were not compromised due to the hydrothermal treatments. Sr-CHA was studied in vitro using MC3T3-E1 cells and in vivo with an ovariectomized rat model. The proliferation of MC3T3-E1 cells was significantly promoted by Sr-CHA as compared to CHA. Moreover, higher scaffold volume retention (+40%) was reported on the micro-CT analysis of the Sr-CHA scaffold. The results suggest that the incorporation of Sr in CHA can further enhance the osteoconductivity and osteoinductivity of corals. Strontium has been suggested to stimulate bone growth and inhibit bone resorption. In this study, we have successfully incorporated Sr into CHA with the natural porous structure remained and explored the idea of Sr-CHA as a potential scaffolding material for bone regeneration. Waiching Liu, Ting Wang, Yuhui Shen, Haobo Pan, Songlin Peng, and William W. Lu Copyright © 2012 Waiching Liu et al. All rights reserved. Tue, 27 Nov 2012 08:17:22 +0000 http://www.hindawi.com/isrn/biomaterials/2013/545791/ Human tooth enamel is a natural nanocomposite with a hierarchical structural architecture that spans from macroscale to nanoscale. Thus it offers the unique opportunity to study the physics of deformation at the nanoscale in a controlled manner using the novel nanoindentation technique. In spite of the wealth of literature, however, the information about the effect of loading rate on the nanoindentation behavior of human tooth enamel is far from being significant. Therefore, the major objective of the present work was to study the loading rate effect on nanoindentation behavior of enamel with a view to improve our understanding that could be used for development of better bioinspired synthetic structures for functional as well as biomedical utilities. The nanoindentation experiments were conducted at loading rates in the range of to   at peak load of   at room temperature with a Berkovich tip on the longitudinal section from a freshly extracted premolar tooth enamel surface from a 65-year-old Indian male. To the best of our knowledge here we report for the first time the experimental observation of the increase in intrinsic resistance against contact-induced deformation at the nanoscale with the loading rate applied to the enamel surface. The results were explained by considering the microstructural details and the shear stress underneath the nanoindenter. Nilormi Biswas, Arjun Dey, and Anoop Kumar Mukhopadhyay Copyright © 2013 Nilormi Biswas et al. All rights reserved. Mon, 26 Nov 2012 15:26:49 +0000 http://www.hindawi.com/isrn/biomaterials/2013/750720/ Three-dimensional printing (3DP) has been employed to fabricate scaffolds with advantages of fully controlled geometries and reproducibility. In this study, the scaffold structure design was established through investigating the minimum feature size and powder size distribution. It was then fabricated from the 3DP plaster-based powders (CaSO4·1/2H2O). Scaffolds produced from this material demonstrated low mechanical properties and a rapid degradation rate. This study investigated the effects of heat treatment on the mechanical and in vitro degradation properties of the CaSO4 scaffolds. The occurrence of dehydration during the heating cycle offered moderate improvements in the mechanical and degradation properties. By using a heat treatment protocol of 200°C for 30 min, compressive strength increased from 0.36 ± 0.13 MPa (pre-heat-treated) to 2.49 ± 0.42 MPa (heat-treated). Heat-treated scaffolds retained their structure and compressive properties for up to two days in a tris-buffered solution, while untreated scaffolds completely disintegrated within a few minutes. Despite the moderate improvements observed in this study, the heat-treated CaSO4 scaffolds did not demonstrate mechanical and degradation properties commensurate with the requirements for bone-tissue-engineering applications. Zuoxin Zhou, Christina A. Mitchell, Fraser J. Buchanan, and Nicholas J. Dunne Copyright © 2013 Zuoxin Zhou et al. All rights reserved. Sun, 21 Oct 2012 07:53:34 +0000 http://www.hindawi.com/isrn/biomaterials/2013/921645/ Connecting teeth to osseointegrated implants presents a biomechanical challenge. This is due to the implant being rigidly fixed to the bone and the tooth being attached to the bone with a periodontal ligament. In order to overcome this problem, various connection types such as rigid and nonrigid have been proposed. However, the mechanism of attachment and the perceived problem of the differential support provided by the implant and the tooth have been discussed by many authors, and the ideal connection type is still controversial. The aim of this study was to carry out a review of all available literature addressing the tooth-implant connection and evidence-based understanding of the management of tooth-implant-retained restorations. Serhat Ramoglu, Simge Tasar, Selim Gunsoy, Oguz Ozan, and Gokce Meric Copyright © 2013 Serhat Ramoglu et al. All rights reserved. Thu, 13 Sep 2012 13:46:27 +0000 http://www.hindawi.com/isrn/biomaterials/2013/629807/ A chitosan-carrageenan polyelectrolyte complex (PEC) was prepared by salt induced impeding of polyplex formation method and was encapsulated with bovine serum albumin (BSA) to study the potential to be tailored to the pH responsive oral delivery of protein drugs. The FTIR spectra showed the successful formation of the PEC under the experimental condition. The release kinetics of BSA from the PEC was studied in the simulated gastrointestinal fluids with and without digestive enzymes. The prepared PEC showed the nature of pH-sensitivity. A typical controlled release of BSA from the PEC (180 μg of BSA from 3 mg of PEC) was obtained in the simulated intestinal fluid (SIF, pH 7.5), which was due to the significant swelling and disintegration of PEC, but little amount of BSA was released (11 μg of BSA from 3 mg of PEC) in the simulated gastric fluid (SGF, pH 1.2), confirming acidic stability of the prepared PEC. The presence of digestive enzymes was found not to affect the response of PEC to ambient pH value, but to speed up the release of BSA from carriers. Cunben Li, San Hein, and Kean Wang Copyright © 2013 Cunben Li et al. All rights reserved.