Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space.

Science.gov (United States)

Yuan, Fusong; Zheng, Jianqiao; Sun, Yuchun; Wang, Yong; Lyu, Peijun

2017-06-01

The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space. The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve. Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p heat generated in the pulp cavity was lower than the threshold for dental pulp damage. These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.

Synthesis and ultrastructure of plate-like apatite single crystals as a model for tooth enamel

International Nuclear Information System (INIS)

Zhuang, Zhi; Yoshimura, Hideyuki; Aizawa, Mamoru

2013-01-01

Hydroxyapatite (HAp) is an inorganic constituent compound of human bones and teeth, with superior biocompatibility and bioactivity characteristics. Its crystal structure is hexagonal, characterized by a(b)- and c-planes. In vertebrate long bones, HAp crystals have a c-axis orientation, while in tooth enamel, they have an a(b)-axis orientation. Many methods can be used to synthesize c-axis oriented HAp single crystals; however, to the best of our knowledge, there have been no reports on a synthesis method for a(b)-axis oriented HAp single crystals. In this study, we successfully synthesized plate-like HAp crystals at the air–liquid interface of a starting solution via an enzyme reaction of urea with urease. Crystal phase analysis and ultrastructure observations were carried out, and the results indicated that the particles were single crystals, with almost the same a(b)-axis orientation as tooth enamel. It is hoped that by utilizing their unique surface charge and atomic arrangement, the resulting particles can be used as a high-performance biomaterial, capable of adsorbing bio-related substances and a model for tooth enamel. - Highlights: ► Synthesis of plate-like hydroxyapatite crystals at air–liquid interface ► Ultrastructural analysis of plate-like hydroxyapatite crystals ► Plate-like hydroxyapatite single crystals with a high a(b)-axis orientation ► Plate-like hydroxyapatite single crystals as a model for tooth enamel

Synthesis and ultrastructure of plate-like apatite single crystals as a model for tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Zhi, E-mail: zhuang@meiji.ac.jp [Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Yoshimura, Hideyuki, E-mail: hyoshi@isc.meiji.ac.jp [Department of Physics, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Aizawa, Mamoru, E-mail: mamorua@isc.meiji.ac.jp [Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan)

2013-07-01

Hydroxyapatite (HAp) is an inorganic constituent compound of human bones and teeth, with superior biocompatibility and bioactivity characteristics. Its crystal structure is hexagonal, characterized by a(b)- and c-planes. In vertebrate long bones, HAp crystals have a c-axis orientation, while in tooth enamel, they have an a(b)-axis orientation. Many methods can be used to synthesize c-axis oriented HAp single crystals; however, to the best of our knowledge, there have been no reports on a synthesis method for a(b)-axis oriented HAp single crystals. In this study, we successfully synthesized plate-like HAp crystals at the air–liquid interface of a starting solution via an enzyme reaction of urea with urease. Crystal phase analysis and ultrastructure observations were carried out, and the results indicated that the particles were single crystals, with almost the same a(b)-axis orientation as tooth enamel. It is hoped that by utilizing their unique surface charge and atomic arrangement, the resulting particles can be used as a high-performance biomaterial, capable of adsorbing bio-related substances and a model for tooth enamel. - Highlights: ► Synthesis of plate-like hydroxyapatite crystals at air–liquid interface ► Ultrastructural analysis of plate-like hydroxyapatite crystals ► Plate-like hydroxyapatite single crystals with a high a(b)-axis orientation ► Plate-like hydroxyapatite single crystals as a model for tooth enamel.

Pulmonary emboli from blood-biomaterial interaction

International Nuclear Information System (INIS)

Coleman, J.E.; Ramberg, K.; McEnroe, C.S.; Connolly, R.J.; Callow, A.D.

1988-01-01

The problem of surface thrombosis and subsequent embolization remains entrenched as a yet incompletely surmounted barrier to the development of truly satisfactory intravascular prosthetic devices. A baboon ex vivo shunt was used to determine the interaction of Indium-111 platelets and potential biomaterials. The uptake of Indium-111 platelets was monitored continuously by gamma camera scanning. Several of the materials tested demonstrated a saw-toothed pattern of platelet activity, with accumulation followed by rapid decline. Neither PTFE nor Dacron exhibited this pattern. Post shunt scans of the animals' chests showed discrete foci of platelet activity in the lungs, corresponding to each embolic event noted on the material's scan. In conclusion, the search for a smooth surface as a blood material interface may produce a material which accumulates and then sloughs significant platelet aggregates. It is crucial that these materials be subjected to vigorous testing to determine their safety prior to initiation of clinical trials

Preventing tissue fibrosis by local biomaterials interfacing of specific cryptic extracellular matrix information

Science.gov (United States)

Horejs, Christine-Maria; St-Pierre, Jean-Philippe; Ojala, Juha R. M.; Steele, Joseph A. M.; da Silva, Patricia Barros; Rynne-Vidal, Angela; Maynard, Stephanie A.; Hansel, Catherine S.; Rodríguez-Fernández, Clara; Mazo, Manuel M.; You, Amanda Y. F.; Wang, Alex J.; von Erlach, Thomas; Tryggvason, Karl; López-Cabrera, Manuel; Stevens, Molly M.

2017-01-01

Matrix metalloproteinases (MMPs) contribute to the breakdown of tissue structures such as the basement membrane, promoting tissue fibrosis. Here we developed an electrospun membrane biofunctionalized with a fragment of the laminin β1-chain to modulate the expression of MMP2 in this context. We demonstrate that interfacing of the β1-fragment with the mesothelium of the peritoneal membrane via a biomaterial abrogates the release of active MMP2 in response to transforming growth factor β1 and rescues tissue integrity ex vivo and in vivo in a mouse model of peritoneal fibrosis. Importantly, our data demonstrate that the membrane inhibits MMP2 expression. Changes in the expression of epithelial-to-mesenchymal transition (EMT)-related molecules further point towards a contribution of the modulation of EMT. Biomaterial-based presentation of regulatory basement membrane signals directly addresses limitations of current therapeutic approaches by enabling a localized and specific method to counteract MMP2 release applicable to a broad range of therapeutic targets. PMID:28593951

Preventing tissue fibrosis by local biomaterials interfacing of specific cryptic extracellular matrix information

Science.gov (United States)

Horejs, Christine-Maria; St-Pierre, Jean-Philippe; Ojala, Juha R. M.; Steele, Joseph A. M.; da Silva, Patricia Barros; Rynne-Vidal, Angela; Maynard, Stephanie A.; Hansel, Catherine S.; Rodríguez-Fernández, Clara; Mazo, Manuel M.; You, Amanda Y. F.; Wang, Alex J.; von Erlach, Thomas; Tryggvason, Karl; López-Cabrera, Manuel; Stevens, Molly M.

2017-06-01

Matrix metalloproteinases (MMPs) contribute to the breakdown of tissue structures such as the basement membrane, promoting tissue fibrosis. Here we developed an electrospun membrane biofunctionalized with a fragment of the laminin β1-chain to modulate the expression of MMP2 in this context. We demonstrate that interfacing of the β1-fragment with the mesothelium of the peritoneal membrane via a biomaterial abrogates the release of active MMP2 in response to transforming growth factor β1 and rescues tissue integrity ex vivo and in vivo in a mouse model of peritoneal fibrosis. Importantly, our data demonstrate that the membrane inhibits MMP2 expression. Changes in the expression of epithelial-to-mesenchymal transition (EMT)-related molecules further point towards a contribution of the modulation of EMT. Biomaterial-based presentation of regulatory basement membrane signals directly addresses limitations of current therapeutic approaches by enabling a localized and specific method to counteract MMP2 release applicable to a broad range of therapeutic targets.

[Biomaterials in bone repair].

Science.gov (United States)

Puska, Mervi; Aho, Allan J; Vallittu, Pekka K

2013-01-01

In orthopedics, traumatology, and craniofacial surgery, biomaterials should meet the clinical demands of bone that include shape, size and anatomical location of the defect, as well as the physiological load-bearing stresses. Biomaterials are metals, ceramics, plastics or materials of biological origin. In the treatment of large defects, metallic endoprostheses or bone grafts are employed, whereas ceramics in the case of small defects. Plastics are employed on the artificial joint surfaces, in the treatment of vertebral compression fractures, and as biodegradable screws and plates. Porosity, bioactivity, and identical biomechanics to bone are fundamental for achieving a durable, well-bonded, interface between biomaterial and bone. In the case of severe bone treatments, biomaterials should also imply an option to add biologically active substances.

Confocal microscopic observation of structural changes in glass-ionomer cements and tooth interfaces.

Science.gov (United States)

Watson, T F; Pagliari, D; Sidhu, S K; Naasan, M A

1998-03-01

This study aimed to develop techniques to allow dynamic imaging of a cavity before, during and after placement of glass-ionomer restorative materials. Cavities were cut in recently extracted third molars and the teeth longitudinally sectioned. Each hemisected tooth surface was placed in green modelling compound at 90 to the optical axis of the microscope. The cavity surface was imaged using a video rate confocal microscope in conjunction with an internally focusable microscope objective. The sample on the stage was pushed up to the objective lens which 'clamped' the cover glass onto it. Water, glycerine or oil was placed below the coverglass, with oil above. Internal tooth structures were imaged by changing the internal focus of the objective. The restorative material was then placed into the cavity. Video images were stored either onto video tape or digitally, using a frame grabber, computer and mass memory storage. Software controls produced time-lapse recordings of the interface over time. Preliminary experiments have examined the placement and early maturation of conventional glass-ionomer cements and a syringeable resin-modified glass-ionomer cement. Initial contact of the cement matrix and glass particles was visible as the plastic material rolled past the enamel and dentine, before making a bond. Evidence for water movement from the dentine into the cement has also been seen. After curing, the early dimensional changes in the cements due to water flux were apparent using the time-lapse facility. This new technique enables examination of developing tooth/restoration interfaces and the tracking of movement in materials.

Biomaterials for Tissue Engineering

Science.gov (United States)

Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

2013-01-01

Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

Tooth wear and wear investigations in dentistry.

Science.gov (United States)

Lee, A; He, L H; Lyons, K; Swain, M V

2012-03-01

Tooth wear has been recognised as a major problem in dentistry. Epidemiological studies have reported an increasing prevalence of tooth wear and general dental practitioners see a greater number of patients seeking treatment with worn dentition. Although the dental literature contains numerous publications related to management and rehabilitation of tooth wear of varying aetiologies, our understanding of the aetiology and pathogenesis of tooth wear is still limited. The wear behaviour of dental biomaterials has also been extensively researched to improve our understanding of the underlying mechanisms and for the development of restorative materials with good wear resistance. The complex nature of tooth wear indicates challenges for conducting in vitro and in vivo wear investigations and a clear correlation between in vitro and in vivo data has not been established. The objective was to critically review the peer reviewed English-language literature pertaining to prevalence and aetiology of tooth wear and wear investigations in dentistry identified through a Medline search engine combined with hand-searching of the relevant literature, covering the period between 1960 and 2011. © 2011 Blackwell Publishing Ltd.

An Overview of Biomaterials in Periodontology and Implant Dentistry

Directory of Open Access Journals (Sweden)

Young-Dan Cho

2017-01-01

Full Text Available Material is a crucial factor for the restoration of the tooth or periodontal structure in dentistry. Various biomaterials have been developed and clinically applied for improved periodontal tissue regeneration and osseointegration, especially in periodontology and dental implantology. Furthermore, the biomimetic approach has been the subject of active research in recent years. In this review, the most widely studied biomaterials (bone graft material, barrier membrane, and growth or differentiation factors and biomimetic approaches to obtain optimal tissue regeneration by making the environment almost similar to that of the extracellular matrix are discussed and specifically highlighted.

Lock-in thermography, penetrant inspection, and scanning electron microscopy for quantitative evaluation of open micro-cracks at the tooth-restoration interface

Science.gov (United States)

Streza, M.; Hodisan, I.; Prejmerean, C.; Boue, C.; Tessier, Gilles

2015-03-01

The evaluation of a dental restoration in a non-invasive way is of paramount importance in clinical practice. The aim of this study was to assess the minimum detectable open crack at the cavity-restorative material interface by the lock-in thermography technique, at laser intensities which are safe for living teeth. For the analysis of the interface, 18 box-type class V standardized cavities were prepared on the facial and oral surfaces of each tooth, with coronal margins in enamel and apical margins in dentine. The preparations were restored with the Giomer Beautifil (Shofu) in combination with three different adhesive systems. Three specimens were randomly selected from each experimental group and each slice has been analysed by visible, infrared (IR), and scanning electron microscopy (SEM). Lock-in thermography showed the most promising results in detecting both marginal and internal defects. The proposed procedure leads to a diagnosis of micro-leakages having openings of 1 µm, which is close to the diffraction limit of the IR camera. Clinical use of a thermographic camera in assessing the marginal integrity of a restoration becomes possible. The method overcomes some drawbacks of standard SEM or dye penetration testing. The results support the use of an IR camera in dentistry, for the diagnosis of micro-gaps at bio-interfaces.

Preparation and mechanical property of polymer-based biomaterials

International Nuclear Information System (INIS)

Zhang, P; Chen, G; Zheng, X F

2010-01-01

The porous polymer-based biomaterial has been synthesized from PLGA, dioxane and tricalcium phosphate (TCP) by low-temperature deposition process. The deformation behaviours and fracture mechanism of polymer-based biomaterials were investigated using the compression test and the finite element (FE) simulation. The results show that the stress-strain curve of compression process includes linear elastic stage I, platform stage II and densification stage III, and the fracture mechanism can be considered as brittle fracture.

Ultrasensitive and Highly Stable Resistive Pressure Sensors with Biomaterial-Incorporated Interfacial Layers for Wearable Health-Monitoring and Human-Machine Interfaces.

Science.gov (United States)

Chang, Hochan; Kim, Sungwoong; Jin, Sumin; Lee, Seung-Woo; Yang, Gil-Tae; Lee, Ki-Young; Yi, Hyunjung

2018-01-10

Flexible piezoresistive sensors have huge potential for health monitoring, human-machine interfaces, prosthetic limbs, and intelligent robotics. A variety of nanomaterials and structural schemes have been proposed for realizing ultrasensitive flexible piezoresistive sensors. However, despite the success of recent efforts, high sensitivity within narrower pressure ranges and/or the challenging adhesion and stability issues still potentially limit their broad applications. Herein, we introduce a biomaterial-based scheme for the development of flexible pressure sensors that are ultrasensitive (resistance change by 5 orders) over a broad pressure range of 0.1-100 kPa, promptly responsive (20 ms), and yet highly stable. We show that employing biomaterial-incorporated conductive networks of single-walled carbon nanotubes as interfacial layers of contact-based resistive pressure sensors significantly enhances piezoresistive response via effective modulation of the interlayer resistance and provides stable interfaces for the pressure sensors. The developed flexible sensor is capable of real-time monitoring of wrist pulse waves under external medium pressure levels and providing pressure profiles applied by a thumb and a forefinger during object manipulation at a low voltage (1 V) and power consumption (<12 μW). This work provides a new insight into the material candidates and approaches for the development of wearable health-monitoring and human-machine interfaces.

Preparation of hybrid biomaterials for bone tissue engineering

Directory of Open Access Journals (Sweden)

Vilma Conceição Costa

2007-03-01

Full Text Available Tissue engineering has evolved from the use of biomaterials for bone substitution that fulfill the clinical demands of biocompatibility, biodegradability, non-immunogeneity, structural strength and porosity. Porous scaffolds have been developed in many forms and materials, but few reached the need of adequate physical, biological and mechanical properties. In the present paper we report the preparation of hybrid porous polyvinyl alcohol (PVA/bioactive glass through the sol-gel route, using partially and fully hydrolyzed polyvinyl alcohol, and perform structural characterization. Hybrids containing PVA and bioactive glass with composition 58SiO2-33CaO-9P2O5 were synthesized by foaming a mixture of polymer solution and bioactive glass sol-gel precursor solution. Sol-gel solution was prepared from mixing tetraethoxysilane (TEOS, triethylphosphate (TEP, and calcium chloride as chemical precursors. The hybrid composites obtained after aging and drying at low temperature were chemically and morphologically characterized through infrared spectroscopy and scanning electron microscopy. The degree of hydrolysis of PVA, concentration of PVA solution and different PVA-bioglass composition ratios affect the synthesis procedure. Synthesis parameters must be very well combined in order to allow foaming and gelation. The hybrid scaffolds obtained exhibited macroporous structure with pore size varying from 50 to 600 µm.

Longevity of anterior resin-bonded bridges: survival rates of two tooth preparation designs.

Science.gov (United States)

Abuzar, M; Locke, J; Burt, G; Clausen, G; Escobar, K

2018-04-16

Significant developments have occurred in the design of resin-bonded bridges (RBB) over the past two decades. They are commonly used as an alternative treatment option for a single missing tooth. The longevity of these bridges needs to be further investigated to evaluate long-term outcomes for this option to remain relevant. A cohort of patients who received anterior resin-bonded bridges (ARBB) over two decades was studied retrospectively. Longevity of 206 ARBB was assessed using Kaplan-Meier probability estimates. The two modified tooth preparation designs investigated were: (A) mesial and distal vertical grooves only; and (B) one proximal groove adjacent to the pontic and two palatal grooves. Age and gender of the patient cohort were also recorded. Overall survival rate of ARBB was 98% at 5 years, 97.2% at 10 years, and 95.1% from 12 years till 21 years. Survival curves showed minor differences when compared for the two designs, age groups and gender of ARBB recipients. Differences in the proportion of surviving bridges for design A (95.96%) and design B (98.13%) were not statistically significant (Fisher's exact test). Anterior RBB with described tooth preparation designs demonstrate a high survival rate. © 2018 Australian Dental Association.

3D quantification of clinical marginal and internal gap of porcelain laminate veneers with minimal and without tooth preparation and 2-year clinical evaluation.

Science.gov (United States)

Karagözoğlu, İrem; Toksavul, Suna; Toman, Muhittin

2016-01-01

The aims of this clinical study were to compare internal three-dimensional (3D) adaptation of porcelain laminate veneers (PLV) with minimal tooth preparation and without tooth preparation (prepless) and to evaluate the clinical outcomes at baseline and following 6, 12, and 24 months after luting. Thirty-one prepless PLV and 31 PLV with minimal tooth preparation were fabricated using lithium disilicate glass-ceramic material and placed in 12 patients (8 women, 4 men; 18 to 40 years old). All PLV were luted with an adhesive luting system (Variolink veneer). A silicone replica was obtained to measure internal adaptation of each PLV using a low viscosity polyvinyl siloxane impression material just before luting. Silicone replicas were scanned in x-ray micro computerized tomography (micro CT). Clinical evaluations took place at baseline (2 days after luting) and following 6, 12, and 24 months after luting. Marginal integrity, marginal discoloration, secondary caries, tooth sensitivity, and fracture were evaluated following FDI criteria. Replica scores were analyzed using Mann-Whitney U and Student's t test (α = .05). Kaplan-Meier statistical analysis was done for the survival rate of PLV. FDI criteria scores were analyzed using Pearson's chi-square test (α = .05). The median marginal gaps for PLV-without-tooth-preparation and PLV-with-minimal-tooth-preparation groups were 100 μm and 140 μm respectively. There was a statistically significant difference between the two groups with respect to marginal gap (P = .04). The mean internal adaptation for the PLV-without-tooth-preparation group was 217.17 ± 54.72 μm, and was 170.67 ± 46.54 μm for the PLV-with-minimaltooth- preparation group. There was a statistically significant difference between the two groups (P = .001). Based on FDI criteria, 100% of the PLV were rated satisfactory during the 2-year period. In this in-vivo study, mean and median values of marginal gap and internal adaptation for PLV with minimal tooth

Advanced biomaterials and their potential applications in the treatment of periodontal disease.

Science.gov (United States)

Chen, Xi; Wu, Guofeng; Feng, Zhihong; Dong, Yan; Zhou, Wei; Li, Bei; Bai, Shizhu; Zhao, Yimin

2016-08-01

Periodontal disease is considered as a widespread infectious disease and the most common cause of tooth loss in adults. Attempts for developing periodontal disease treatment strategies, including drug delivery and regeneration approaches, provide a useful experimental model for the evaluation of future periodontal therapies. Recently, emerging advanced biomaterials including hydrogels, films, micro/nanofibers and particles, hold great potential to be utilized as cell/drug carriers for local drug delivery and biomimetic scaffolds for future regeneration therapies. In this review, first, we describe the pathogenesis of periodontal disease, including plaque formation, immune response and inflammatory reactions caused by bacteria. Second, periodontal therapy and an overview of current biomaterials in periodontal regenerative medicine have been discussed. Third, the roles of state-of-the-art biomaterials, including hydrogels, films, micro/nanofibers and micro/nanoparticles, developed for periodontal disease treatment and periodontal tissue regeneration, and their fabrication methods, have been presented. Finally, biological properties, including biocompatibility, biodegradability and immunogenicity of the biomaterials, together with their current applications strategies are given. Conclusive remarks and future perspectives for such advanced biomaterials are discussed.

Biomimetic approaches with smart interfaces for bone regeneration.

Science.gov (United States)

Sailaja, G S; Ramesh, P; Vellappally, Sajith; Anil, Sukumaran; Varma, H K

2016-11-05

A 'smart tissue interface' is a host tissue-biomaterial interface capable of triggering favourable biochemical events inspired by stimuli responsive mechanisms. In other words, biomaterial surface is instrumental in dictating the interface functionality. This review aims to investigate the fundamental and favourable requirements of a 'smart tissue interface' that can positively influence the degree of healing and promote bone tissue regeneration. A biomaterial surface when interacts synergistically with the dynamic extracellular matrix, the healing process become accelerated through development of a smart interface. The interface functionality relies equally on bound functional groups and conjugated molecules belonging to the biomaterial and the biological milieu it interacts with. The essential conditions for such a special biomimetic environment are discussed. We highlight the impending prospects of smart interfaces and trying to relate the design approaches as well as critical factors that determine species-specific functionality with special reference to bone tissue regeneration.

β-pyrophosphate: A potential biomaterial for dental applications

OpenAIRE

Anastasiou, AD; Strafford, S; Posada-Estefan, O; Thomson, CL; Hussaein, SA; Edwards, TJ; Malinowski, M; Hondow, N; Metzger, NK; Brown, CTA; Routledge, MN; Brown, AP; Duggal, MS; Jha, A

2017-01-01

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluat...

β-pyrophosphate : a potential biomaterial for dental applications

OpenAIRE

Anastasiou, A. D.; Strafford, S.; Posada-Estefan, O.; Thomson, C. L.; Hussaein, S. A.; Edwards, T. J.; Malinowski, M.; Hondow, N.; Metzger, N. K.; Brown, C. T. A.; Routledge, M. N.; Brown, A. P.; Duggal, M. S.; Jha, A.

2017-01-01

The authors acknowledge support from the sponsors of this work; the EPSRC LUMIN (EP/K020234/1) and EU-Marie-Curie-IAPP LUSTRE (324538) projects. Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral trans...

Advances and perspectives in tooth tissue engineering.

Science.gov (United States)

Monteiro, Nelson; Yelick, Pamela C

2017-09-01

Bio-engineered teeth that can grow and remodel in a manner similar to that of natural teeth have the potential to serve as permanent replacements to the currently used prosthetic teeth, such as dental implants. A major challenge in designing functional bio-engineered teeth is to mimic both the structural and anisotropic mechanical characteristics of the native tooth. Therefore, the field of dental and whole tooth regeneration has advanced towards the molecular and nanoscale design of bio-active, biomimetic systems, using biomaterials, drug delivery systems and stem cells. The focus of this review is to discuss recent advances in tooth tissue engineering, using biomimetic scaffolds that provide proper architectural cues, exhibit the capacity to support dental stem cell proliferation and differentiation and sequester and release bio-active agents, such as growth factors and nucleic acids, in a spatiotemporal controlled manner. Although many in vitro and in vivo studies on tooth regeneration appear promising, before tooth tissue engineering becomes a reality for humans, additional research is needed to perfect methods that use adult human dental stem cells, as opposed to embryonic dental stem cells, and to devise the means to generate bio-engineered teeth of predetermined size and shape. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Novel hydroxyapatite biomaterial covalently linked to raloxifene.

Science.gov (United States)

Meme, L; Santarelli, A; Marzo, G; Emanuelli, M; Nocini, P F; Bertossi, D; Putignano, A; Dioguardi, M; Lo Muzio, L; Bambini, F

2014-01-01

Since raloxifene, a drug used in osteoporosis therapy, inhibits osteoclast, but not osteoblast functions, it has been suggested to improve recovery during implant surgery. The present paper describes an effective method to link raloxifene, through a covalent bond, to a nano-Hydroxyapatite-based biomaterial by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by Infra Red-Fourier Transformed (IR-FT) spectroscopy and Scanning Electron Microscope (SEM). To evaluate the safety of this modified new material, the vitality of osteoblast-like cells cultured with the new biomaterial was then investigated. Raloxifene-conjugated HAbiomaterial has been shown to be a safe material easy to obtain which could be an interesting starting point for the use of a new functional biomaterial suitable in bone regeneration procedures.

Applying thermosettable zwitterionic copolymers as general fouling-resistant and thermal-tolerant biomaterial interfaces.

Science.gov (United States)

Chou, Ying-Nien; Chang, Yung; Wen, Ten-Chin

2015-05-20

We introduced a thermosettable zwitterionic copolymer to design a high temperature tolerance biomaterial as a general antifouling polymer interface. The original synthetic fouling-resistant copolymer, poly(vinylpyrrolidone)-co-poly(sulfobetaine methacrylate) (poly(VP-co-SBMA)), is both thermal-tolerant and fouling-resistant, and the antifouling stability of copolymer coated interfaces can be effectively controlled by regulating the VP/SBMA composition ratio. We studied poly(VP-co-SBMA) copolymer gels and networks with a focus on their general resistance to protein, cell, and bacterial bioadhesion, as influenced by the thermosetting process. Interestingly, we found that the shape of the poly(VP-co-SBMA) copolymer material can be set at a high annealing temperature of 200 °C while maintaining good antifouling properties. However, while the zwitterionic PSBMA polymer gels were bioinert as expected, control of the fouling resistance of the PSBMA polymer networks was lost in the high temperature annealing process. A poly(VP-co-SBMA) copolymer network composed of PSBMA segments at 32 mol % showed reduced fibrinogen adsorption, tissue cell adhesion, and bacterial attachment, but a relatively higher PSBMA content of 61 mol % was required to optimize resistance to platelet adhesion and erythrocyte attachment to confer hemocompatibility to human blood. We suggest that poly(VP-co-SBMA) copolymers capable of retaining stable fouling resistance after high temperature shaping have a potential application as thermosettable materials in a bioinert interface for medical devices, such as the thermosettable coating on a stainless steel blood-compatible metal stent investigated in this study.

Plant Products for Innovative Biomaterials in Dentistry

Directory of Open Access Journals (Sweden)

Elena M. Varoni

2012-07-01

Full Text Available Dental biomaterials and natural products represent two of the main growing research fields, revealing plant-derived compounds may play a role not only as nutraceuticals in affecting oral health, but also in improving physico-chemical properties of biomaterials used in dentistry. Therefore, our aim was to collect all available data concerning the utilization of plant polysaccharides, proteins and extracts rich in bioactive phytochemicals in enhancing performance of dental biomaterials. Although compelling evidences are suggestive of a great potential of plant products in promoting material-tissue/cell interface, to date, only few authors have investigated their use in development of innovative dental biomaterials. A small number of studies have reported plant extract-based titanium implant coatings and periodontal regenerative materials. To the best of our knowledge, this review is the first to deal with this topic, highlighting a general lack of research findings in an interesting field which still needs to be investigated.

Marine Structural Biomaterials in Medical Biomimicry.

Science.gov (United States)

Green, David W; Lee, Jong-Min; Jung, Han-Sung

2015-10-01

Marine biomaterials display properties, behaviors, and functions that have not been artificially matched in relation to their hierarchical construction, crack-stopping properties, growth adaptation, and energy efficiency. The discovery and understanding of such features that are characteristic of natural biomaterials can be used to manufacture more energy-efficient and lightweight materials. However, a more detailed understanding of the design of natural biomaterials with good performance and the mechanism of their design is required. Far-reaching biomolecular characterization of biomaterials and biostructures from the ocean world is possible with sophisticated analytical methods, such as whole-genome RNA-seq, and de novo transcriptome sequencing and mass spectrophotometry-based sequencing. In combination with detailed material characterization, the elements in newly discovered biomaterials and their properties can be reconstituted into biomimetic or bio-inspired materials. A major aim of harnessing marine biomaterials is their translation into biomimetic counterparts. To achieve full translation, the genome, proteome, and hierarchical material characteristics, and their profiles in space and time, have to be associated to allow for smooth biomimetic translation. In this article, we highlight the novel science of marine biomimicry from a materials perspective. We focus on areas of material design and fabrication that have excelled in marine biological models, such as embedded interfaces, chiral organization, and the use of specialized composite material-on-material designs. Our emphasis is primarily on key materials with high value in healthcare in which we evaluate their future prospects. Marine biomaterials are among the most exquisite and powerful aspects in materials science today.

Biomaterials surface science

CERN Document Server

Taubert, Andreas; Rodriguez-Cabello, José Carlos

2013-01-01

The book provides an overview of the highly interdisciplinary field of surface science in the context of biological and biomedical applications. The covered topics range from micro- and nanostructuring for imparting functionality in a top-down manner to the bottom-up fabrication of gradient surfaces by self-assembly, from interfaces between biomaterials and living matter to smart, stimuli-responsive surfaces, and from cell and surface mechanics to the elucidation of cell-chip interactions in biomedical devices.

Age-related changes in the tooth-bone interface area of acrodont dentition in the chameleon.

Science.gov (United States)

Dosedělová, Hana; Štěpánková, Kateřina; Zikmund, Tomáš; Lesot, Herve; Kaiser, Jozef; Novotný, Karel; Štembírek, Jan; Knotek, Zdeněk; Zahradníček, Oldřich; Buchtová, Marcela

2016-09-01

Chameleon teeth develop as individual structures at a distance from the developing jaw bone during the pre-hatching period and also partially during the post-hatching period. However, in the adult, all teeth are fused together and tightly attached to the jaw bone by mineralized attachment tissue to form one functional unit. Tooth to bone as well as tooth to tooth attachments are so firm that if injury to the oral cavity occurs, several neighbouring teeth and pieces of jaw can be broken off. We analysed age-related changes in chameleon acrodont dentition, where ankylosis represents a physiological condition, whereas in mammals, ankylosis only occurs in a pathological context. The changes in hard-tissue morphology and mineral composition leading to this fusion were analysed. For this purpose, the lower jaws of chameleons were investigated using X-ray micro-computed tomography, laser-induced breakdown spectroscopy and microprobe analysis. For a long time, the dental pulp cavity remained connected with neighbouring teeth and also to the underlying bone marrow cavity. Then, a progressive filling of the dental pulp cavity by a mineralized matrix occurred, and a complex network of non-mineralized channels remained. The size of these unmineralized channels progressively decreased until they completely disappeared, and the dental pulp cavity was filled by a mineralized matrix over time. Moreover, the distribution of calcium, phosphorus and magnesium showed distinct patterns in the different regions of the tooth-bone interface, with a significant progression of mineralization in dentin as well as in the supporting bone. In conclusion, tooth-bone fusion in chameleons results from an enhanced production of mineralized tissue during post-hatching development. Uncovering the developmental processes underlying these outcomes and performing comparative studies is necessary to better understand physiological ankylosis; for that purpose, the chameleon can serve as a useful model

The dynamics of a non-equilibrium bubble near bio-materials

International Nuclear Information System (INIS)

Ohl, S W; Klaseboer, E; Khoo, B C

2009-01-01

In many medical treatments oscillating (non-equilibrium) bubbles appear. They can be the result of high-intensity-focused ultrasound, laser treatments or shock wave lithotripsy for example. The physics of such oscillating bubbles is often not very well understood. This is especially so if the bubbles are oscillating near (soft) bio-materials. It is well known that bubbles oscillating near (hard) materials have a tendency to form a high speed jet directed towards the material during the collapse phase of the bubble. It is equally well studied that bubbles near a free interface (air) tend to collapse with a jet directed away from this interface. If the interface is neither 'free' nor 'hard', such as often occurs in bio-materials, the resulting flow physics can be very complex. Yet, in many bio-applications, it is crucial to know in which direction the jet will go (if there is a jet at all). Some applications require a jet towards the tissue, for example to destroy it. For other applications, damage due to impacting jets is to be prevented at all cost. This paper tries to address some of the physics involved in these treatments by using a numerical method, the boundary element method (BEM), to study the dynamics of such bubbles near several bio-materials. In the present work, the behaviour of a bubble placed in a water-like medium near various bio-materials (modelled as elastic fluids) is investigated. It is found that its behaviour depends on the material properties (Young's modulus, Poisson ratio and density) of the bio-material. For soft bio-materials (fat, skin, brain and muscle), the bubble tends to split into smaller bubbles. In certain cases, the resulting bubbles develop opposing jets. For hard bio-materials (cornea, cartilage and bone), the bubble collapses towards the interface with high speed jets (between 100 and about 250 m s -1 ). A summary graph is provided identifying the combined effects of the dimensionless elasticity (κ) and density ratio (α) of

Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications.

Science.gov (United States)

Verma, Mahesh; Kumari, Pooja; Gupta, Rekha; Gill, Shubhra; Gupta, Ankur

2015-01-01

Erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser has been successfully used in the ablation of dental hard and soft tissues. It has been reported that this system is also useful for preparing tooth surfaces and etching, but no consensus exist in the literature regarding the advantage of lasers over conventional tooth preparation technique. Labial surfaces of 25 extracted human maxillary central incisors were divided into two halves. Right half was prepared with diamond bur and left half with Er, Cr; YSGG laser and a reduction of 0.3-0.5 mm was carried out. Topography of prepared surfaces of five teeth were examined under scanning electron microscope (SEM). The remaining samples were divided into 4 groups of 10 specimens each based on the surface treatment received: One group was acid etched and other was nonetched. Composite resin cylinders were bonded on prepared surfaces and shear bond strength was assessed using a universal testing machine. The SEM observation revealed that the laser prepared surfaces were clean, highly irregular and devoid of a smear layer. Bur prepared surfaces were relatively smooth but covered with smear layer. Highest bond strength was shown by laser prepared acid etched group, followed by bur prepared the acid etched group. The bur prepared nonacid etched group showed least bond strength. Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

Numerical Modeling of Porous Structure of Biomaterial and Fluid Flowing Through Biomaterial

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

A Cellular Automata model of simulating body fluid flowing into porous bioceramic implants generated with stochastic methods is described, of which main parameters and evolvement rule are determined in terms of flow behavior of body fluid in porous biomaterials. The model is implemented by GUI( Graphical User Interface) program in MATLAB, and the results of numerical modeling show that the body fluid percolation is related to the size of pores and porosity.

Biological biomaterials

Energy Technology Data Exchange (ETDEWEB)

Jorge-Herrero, E. [Servicio de Cirugia Experimental. Clinica Puerta de Hierro, Madrid (Spain)

1997-05-01

There are a number of situations in which substances of biological origin are employed as biomaterials. Most of them are macromolecules derived from isolated connective tissue or the connective tissue itself in membrane form, in both cases, the tissue can be used in its natural form or be chemically treated. In other cases, certain blood vessels can be chemically pretreated and used as vascular prostheses. Proteins such as albumin, collagen and fibrinogen are employed to coat vascular prostheses. Certain polysaccharides have also been tested for use in controlled drug release systems. Likewise, a number of tissues, such as dura mater, bovine pericardium, procine valves and human valves, are used in the preparation of cardiac prostheses. We also use veins from animals or humans in arterial replacement. In none of these cases are the tissues employed dissimilar to the native tissues as they have been chemically modified, becoming a new bio material with different physical and biochemical properties. In short, we find that natural products are being utilized as biomaterials and must be considered as such; thus, it is necessary to study both their chemicobiological and physicomechanical properties. In the present report, we review the current applications, problems and future prospects of some of these biological biomaterials. (Author) 84 refs.

Calcium-based biomaterials for diagnosis, treatment, and theranostics.

Science.gov (United States)

Qi, Chao; Lin, Jing; Fu, Lian-Hua; Huang, Peng

2018-01-22

Calcium-based (CaXs) biomaterials including calcium phosphates, calcium carbonates, calcium silicate and calcium fluoride have been widely utilized in the biomedical field owing to their excellent biocompatibility and biodegradability. In recent years, CaXs biomaterials have been strategically integrated with imaging contrast agents and therapeutic agents for various molecular imaging modalities including fluorescence imaging, magnetic resonance imaging, ultrasound imaging or multimodal imaging, as well as for various therapeutic approaches including chemotherapy, gene therapy, hyperthermia therapy, photodynamic therapy, radiation therapy, or combination therapy, even imaging-guided therapy. Compared with other inorganic biomaterials such as silica-, carbon-, and gold-based biomaterials, CaXs biomaterials can dissolve into nontoxic ions and participate in the normal metabolism of organisms. Thus, they offer safer clinical solutions for disease theranostics. This review focuses on the state-of-the-art progress in CaXs biomaterials, which covers from their categories, characteristics and preparation methods to their bioapplications including diagnosis, treatment, and theranostics. Moreover, the current trends and key problems as well as the future prospects and challenges of CaXs biomaterials are also discussed at the end.

PIXE study of the kinetics of biomaterials ossification

Science.gov (United States)

Weber, G.; Robaye, G.; Braye, F.; Oudadesse, H.; Irigaray, J. L.

1994-05-01

Biomaterials are frequently implanted in bones. This implantation is followed by a phenomenon of ossification. The purpose of this work was to study the time evolution of the gradient of characteristic atomic element's concentrations in the bone, the implant and the bone-implant interface. We have studied two types of neutral biomaterials: pure synthetic hydroxyapatite and porite's asteroid coral. The animal implantations have been made on sheep of the same age and sex having received the same basic diet. The implantations have been made in the cortical femur. On both sides of the implant, at the same distance, two screws were placed to allow further determination of the position of the implant. The PIXE method is particularly suitable here because of the possibility to analyze directly the samples without any preparation and to choose easily the dimensions of beam used for the gradient study. The X-rays have been detected with an ultra LEGe instead of the usual Si(Li) device to avoid the Si escape peak associated with the K α X-ray of calcium, the major constituent of bone. This peak is particularly disturbing here because its energy corresponds to the K α line of phosphorus, an important constituent of bone. The results of these determinations are presented and discussed.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation

Directory of Open Access Journals (Sweden)

Niranjan Joshi

2013-01-01

Objective: The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. Materials and Methods: For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. Results: The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. Conclusion: The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications

Directory of Open Access Journals (Sweden)

Mahesh Verma

2015-01-01

Conclusions: Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

Epi-detected quadruple-modal nonlinear optical microscopy for label-free imaging of the tooth

Energy Technology Data Exchange (ETDEWEB)

Wang, Zi; Zheng, Wei; Huang, Zhiwei, E-mail: biehzw@nus.edu.sg [Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117576 (Singapore); Stephen Hsu, Chin-Ying [Department of Dentistry, Faculty of Dentistry, National University of Singapore and National University Health System, Singapore 119083 (Singapore)

2015-01-19

We present an epi-detected quadruple-modal nonlinear optical microscopic imaging technique (i.e., coherent anti-Stokes Raman scattering (CARS), second-harmonic generation (SHG), third-harmonic generation (THG), and two-photon excited fluorescence (TPEF)) based on a picosecond (ps) laser-pumped optical parametric oscillator system for label-free imaging of the tooth. We demonstrate that high contrast ps-CARS images covering both the fingerprint (500–1800 cm{sup −1}) and high-wavenumber (2500–3800 cm{sup −1}) regions can be acquired to uncover the distributions of mineral and organic biomaterials in the tooth, while high quality TPEF, SHG, and THG images of the tooth can also be acquired under ps laser excitation without damaging the samples. The quadruple-modal nonlinear microscopic images (CARS/SHG/THG/TPEF) acquired provide better understanding of morphological structures and biochemical/biomolecular distributions in the dentin, enamel, and the dentin-enamel junction of the tooth without labeling, facilitating optical diagnosis and characterization of the tooth in dentistry.

Biomaterials

NARCIS (Netherlands)

Van Mourik, P.; Van Dam, J.; Picken, S.J.; Ursem, B.

2013-01-01

The metabolic pathways of living organisms produce biomaterials. Hence, in principle biomaterials are fully sustainable. This does not mean that their processing and application have no impact on the environment, e.g. the recycling of natural rubber remains a problem. Biomaterials are applied in a

Fracture toughness of zirconia ceramic crowns made by feather-edge tooth preparation design

Directory of Open Access Journals (Sweden)

Mirković Nemanja

2012-01-01

Full Text Available Background/Aim. Fracture toughness determines functional crown strenght and prevents damages on ceramics during mastication. There is a lack of relevant literature data about fracture toughness of crowns made by feather-edge preparation. Mechanical testing of ceramic samples is supposed to show if feather-edge tooth preparation is a successful method for making ceramic crowns without any risk of reduction of their mechanical properties. This research was done to establish effects of feather-edge tooth preparation on fracture toughness of single zirconia ceramic crowns. Methods. The research was performed as an experimental study. Sixty (60 ceramic crowns were made on non-carious extracted human premolars. Thirty (30 crowns were made on the basis of feather-edge preparation (experimental group I. The group II included 30 crowns made on 1 mm rounded shoulder. Crowns fabrication was executed on a copy mill production system “Zirkonzahn” (Zirkonzahn GMBH, Gais, Germany. The spherical compression test was used to determine fracture toughness, using 6 mm diameter ceramic ball. Fracture load for damaging ceramic crown was recorded on a universal testing machine - Zwick, type 1464, with the speed of 0.05 mm/min. Results. The results of this research introduced significant differences between fracture toughness of ceramic samples in every examined group. However, fracture toughness of crowns from both group was above 2 000 N, what was double beyond a recommended value. The mean value of fracture toughness in the feather-edge group was 2 090 N, and in shoulder group it was 2 214 N. Conclusion. This research showed a high fracture toughness of zirconia crowns made on feather-edge preparation. The examined crowns showed a fracture resistance at a sufficient distance in relation to the minimum values of functional loads. Further research of functional loads of these crown is necessary, as well as research of marginal adaptation of cemented crowns and

Wettability and surface free energy of polarised ceramic biomaterials

International Nuclear Information System (INIS)

Nakamura, Miho; Hori, Naoko; Namba, Saki; Yamashita, Kimihiro; Toyama, Takeshi; Nishimiya, Nobuyuki

2015-01-01

The surface modification of ceramic biomaterials used for medical devices is expected to improve osteoconductivity through control of the interfaces between the materials and living tissues. Polarisation treatment induced surface charges on hydroxyapatite, β-tricalcium phosphate, carbonate-substituted hydroxyapatite and yttria-stabilized zirconia regardless of the differences in the carrier ions participating in the polarisation. Characterization of the surfaces revealed that the wettability of the polarised ceramic biomaterials was improved through the increase in the surface free energies compared with conventional ceramic surfaces. (note)

Clay-Enriched Silk Biomaterials for Bone Formation

Science.gov (United States)

Mieszawska, Aneta J.; Llamas, Jabier Gallego; Vaiana, Christopher A.; Kadakia, Madhavi P.; Naik, Rajesh R.; Kaplan, David L.

2011-01-01

The formation of silk protein/clay composite biomaterials for bone tissue formation is described. Silk fibroin serves as an organic scaffolding material offering mechanical stability suitable for bone specific uses. Clay montmorillonite (Cloisite ® Na+) and sodium silicate are sources of osteoinductive silica-rich inorganic species, analogous to bioactive bioglass-like bone repair biomaterial systems. Different clay particle-silk composite biomaterial films were compared to silk films doped with sodium silicate as controls for support of human bone marrow derived mesenchymal stem cells (hMSCs) in osteogenic culture. The cells adhered and proliferated on the silk/clay composites over two weeks. Quantitative real-time RT-PCR analysis revealed increased transcript levels for alkaline phosphatase (ALP), bone sialoprotein (BSP), and collagen type 1 (Col I) osteogenic markers in the cells cultured on the silk/clay films in comparison to the controls. Early evidence for bone formation based on collagen deposition at the cell-biomaterial interface was also found, with more collagen observed for the silk films with higher contents of clay particles. The data suggest that the silk/clay composite systems may be useful for further study toward bone regenerative needs. PMID:21549864

Biocompatibility and Toxicity of Nano biomaterials 2014

International Nuclear Information System (INIS)

Li, X.; Lee, S.Ch.; Zhang, Sh.; Akasaka, T.

2014-01-01

It is well known that nano materials have developed rapidly over the past few decades. Based on their unique physicochemical properties and special mechanical properties, nano materials have provided application possibility in many different fields. Currently, as nano biomaterials, they are widely used in various biomedical applications, such as drug delivery systems, tissue engineering, dental/bone implant, and biosensors. For example, nano biomaterials have been used in tissue engineering because of their satisfactory bioactivity, high mechanical properties, and large surface area to adsorb specific proteins. Many kinds of nano biomaterials are used to prepare composite scaffolds to get better biocompatibility and higher ability in repairing specific tissues. Several antibacterial metallic nano biomaterials are used to coat implant surfaces to improve the speed of healing fractures. In addition, lots of nano biomaterials have the potential to break the limitations of the traditional delivery systems. They can load larger amount of drugs and provide stable drug release for long time at the targeted sites, such as tumors. Moreover, they can combine with polymers to furnish simultaneous drug delivery systems with the controllable release rate. Besides these applications, more and more nano biomaterials show great potential to be applied as highly sensitive biosensors because they have higher ability in loading firmly or interacting completely with recognition aptamers.

Comparative study to evaluate the accuracy of polyether occlusal bite registration material and occlusal registration wax as a guide for occlusal reduction during tooth preparation.

Science.gov (United States)

Joshi, Niranjan; Shetty, Sridhar N; Prasad, Krishna D

2013-01-01

The use of different materials and techniques has been studied to decide the safest quantum of reduction of the occlusal surfaces. However, these methods provide limited information as to the actual amount of reduction with limitations in accuracy, accessibility and complexity. The objective of this study was to compare and evaluate the reliability of the most commonly used occlusal registration wax that with polyether bite registration material as a guide for occlusal reduction required during tooth preparations. For the purpose of this study, 25 abutment teeth requiring tooth preparation for fixed prosthesis were selected and tooth preparations carried out. Modeling wax strips of specific dimensions were placed onto the cast of prepared tooth, which was mounted on maximum intercuspation on the articulator and the articulator was closed. The thickness of the wax registration was measured at three zones namely two functional cusps and central fossa. Similar measurements were made using the polyether bite registration material and prosthesis at the same zones. The data was tabulated and was subjected to statistical analysis using anova test and Tukey honestly significant difference test. The differences in thickness between wax record and prosthesis by 0.1346 mm, whereas the difference between polyether and prosthesis was 0.02 mm with a P value of 0.042, which is statistically significant. This means that the wax record was 8.25% larger than the prosthesis while polyether was just 1.27% larger than the prosthesis. The clinical significance of the above analysis is that Ramitec polyether bite registration material is most suitable material when compared with commonly used modeling wax during the tooth preparation.

Conducting polymer-based multilayer films for instructive biomaterial coatings

OpenAIRE

Hardy, John G; Li, Hetian; Chow, Jacqueline K; Geissler, Sydney A; McElroy, Austin B; Nguy, Lindsey; Hernandez, Derek S; Schmidt, Christine E

2015-01-01

Aim: To demonstrate the design, fabrication and testing of conformable conducting biomaterials that encourage cell alignment. Materials & methods: Thin conducting composite biomaterials based on multilayer films of poly (3,4-ethylenedioxythiophene) derivatives, chitosan and gelatin were prepared in a layer-by-layer fashion. Fibroblasts were observed with fluorescence microscopy and their alignment (relative to the dipping direction and direction of electrical current passed through the films)...

Engineering Musculoskeletal Tissue Interfaces

Directory of Open Access Journals (Sweden)

Ece Bayrak

2018-04-01

Full Text Available Tissue engineering aims to bring together biomaterials, cells, and signaling molecules within properly designed microenvironments in order to create viable treatment options for the lost or malfunctioning tissues. Design and production of scaffolds and cell-laden grafts that mimic the complex structural and functional features of tissues are among the most important elements of tissue engineering strategy. Although all tissues have their own complex structure, an even more complex case in terms of engineering a proper carrier material is encountered at the tissue interfaces, where two distinct tissues come together. The interfaces in the body can be examined in four categories; cartilage-bone and ligament-bone interfaces at the knee and the spine, tendon-bone interfaces at the shoulder and the feet, and muscle-tendon interface at the skeletal system. These interfaces are seen mainly at the soft-to-hard tissue transitions and they are especially susceptible to injury and tear due to the biomechanical inconsistency between these tissues where high strain fields are present. Therefore, engineering the musculoskeletal tissue interfaces remain a challenge. This review focuses on recent advancements in strategies for musculoskeletal interface engineering using different biomaterial-based platforms and surface modification techniques.

The interface between blood preparation and use in Uganda

NARCIS (Netherlands)

Kajja, I.; Bimenya, G.; Smit Sibinga, Cornelis

Background and Objectives The interface between preparation and use of blood impacts directly on the outcome of hemotherapy. The present study explores the knowledge and opinions of key players at, practical realities at, and quality improvement strategies of this interface. Materials and Methods We

Facile design of biomaterials by 'click' chemistry

DEFF Research Database (Denmark)

Hvilsted, Søren

2012-01-01

The advent of the so‐called ‘click chemistry’ a decade ago has significantly improved the chemical toolbox for producing novel biomaterials. This review focuses primarily on the application of Cu(I)‐catalysed azide–alkyne 1,3‐cycloadditon in the preparation of numerous, diverse biomaterials...... chemistry is elaborated. The present state of creating functional and biologically active surfaces by click chemistry is presented. Finally, conducting surfaces based on an azide‐functionalized polymer with prospective biological sensor potential are introduced. Copyright © 2012 Society of Chemical Industry...

Engineering of biomaterials

CERN Document Server

dos Santos, Venina; Savaris, Michele

2017-01-01

This book focuses on biomaterials of different forms used for medical implants. The authors introduce the characteristics and properties of biomaterials and then dedicate special chapters to metallic, ceramic, polymeric and composite biomaterials. Case studies on sterilization methods by biomaterials are also presented. Finally, the authors describe the degradation and effects of biomaterials in living tissue.

Characterization of biomaterials

CERN Document Server

Jaffe, M; Tolias, P; Arinzeh, T

2012-01-01

Biomaterials and medical devices must be rigorously tested in the laboratory before they can be implanted. Testing requires the right analytical techniques. Characterization of biomaterials reviews the latest methods for analyzing the structure, properties and behaviour of biomaterials. Beginning with an introduction to microscopy techniques for analyzing the phase nature and morphology of biomaterials, Characterization of biomaterials goes on to discuss scattering techniques for structural analysis, quantitative assays for measuring cell adhesion, motility and differentiation, and the evaluation of cell infiltration and tissue formation using bioreactors. Further topics considered include studying molecular-scale protein-surface interactions in biomaterials, analysis of the cellular genome and abnormalities, and the use of microarrays to measure cellular changes induced by biomaterials. Finally, the book concludes by outlining standards and methods for assessing the safety and biocompatibility of biomaterial...

Host response to biomaterials the impact of host response on biomaterial selection

CERN Document Server

Badylak, Stephen F

2015-01-01

Host Response to Biomaterials: The Impact of Host Response on Biomaterial Selection explains the various categories of biomaterials and their significance for clinical applications, focusing on the host response to each biomaterial. It is one of the first books to connect immunology and biomaterials with regard to host response. The text also explores the role of the immune system in host response, and covers the regulatory environment for biomaterials, along with the benefits of synthetic versus natural biomaterials, and the transition from simple to complex biomaterial solutions. Fiel

Biomaterials

CERN Document Server

Migonney , Véronique

2014-01-01

Discovered in the 20th century, biomaterials have contributed to many of the incredible scientific and technological advancements made in recent decades. This book introduces and details the tenets of biomaterials, their relevance in a various fields, practical applications of their products, and potential advancements of the years to come. A comprehensive resource, the text covers the reasons that certain properties of biomaterials contribute to specific applications, and students and researchers will appreciate this exhaustive textbook.

Parallel post-space preparation in different tooth types ex vivo : deviation from the canal centre and remaining dentine thickness

NARCIS (Netherlands)

Huysmans, M. C. D. N. J. M.; Klein, M. H. J.; Kok, G. F.; Whitworth, J. M.

2007-01-01

Aim To determine the deviation of parallel-sided twist-drills during post-channel preparation and relate this to tooth type and position. Methodology Human teeth with single root canals were selected: maxillary second premolars (group i); maxillary lateral incisors (group ii); mandibular canines

Morphology of resin-dentin interfaces after Er,Cr:YSGG laser and acid etching preparation and application of different bonding systems.

Science.gov (United States)

Beer, Franziska; Buchmair, Alfred; Körpert, Wolfram; Marvastian, Leila; Wernisch, Johann; Moritz, Andreas

2012-07-01

The goal of this study was to show the modifications in the ultrastructure of the dentin surface morphology following different surface treatments. The stability of the adhesive compound with dentin after laser preparation compared with conventional preparation using different bonding agents was evaluated. An Er,Cr:YSGG laser and 36% phosphoric acid in combination with various bonding systems were used. A total of 100 caries-free human third molars were used in this study. Immediately after surgical removal teeth were cut using a band saw and 1-mm thick dentin slices were created starting at a distance of 4 mm from the cusp plane to ensure complete removal of the enamel. The discs were polished with silicon carbide paper into rectangular shapes to a size of 6 × 4 mm (±0,2 mm).The discs as well as the remaining teeth stumps were stored in 0.9% NaCl at room temperature. The specimens were divided into three main groups (group I laser group, group II etch group, group III laser and etch group) and each group was subdivided into three subgroups which were allocated to the different bonding systems (subgroup A Excite, subgroup B Scotchbond, subgroup C Syntac). Each disc and the corresponding tooth stump were treated in the same way. After preparation the bonding composite material was applied according to the manufacturers' guidelines in a hollow tube of 2 mm diameter to the disc as well as to the corresponding tooth stump. Shear bond strength testing and environmental scanning electron microscopy were used to assess the morphology and stability of the resin-dentin interface. The self-etching bonding system showed the highest and the most constant shear values in all three main groups, thus enabling etching with phosphoric acid after laser preparation to be avoided. Thus we conclude that laser preparation creates a surface texture that allows prediction of the quality of the restoration without the risk of negative influences during the following treatment steps. This

β-pyrophosphate: A potential biomaterial for dental applications

Energy Technology Data Exchange (ETDEWEB)

Anastasiou, A.D., E-mail: a.anastasiou@leeds.ac.uk [School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Strafford, S. [Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT (United Kingdom); Posada-Estefan, O. [Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, LS2 9JT (United Kingdom); Thomson, C.L. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Hussain, S.A. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Cambridge Graphene Centre, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Edwards, T.J. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Malinowski, M. [Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT (United Kingdom); Hondow, N. [School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Metzger, N.K.; Brown, C.T.A. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Routledge, M.N. [Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, LS2 9JT (United Kingdom); Brown, A.P. [School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom); Duggal, M.S. [Leeds Dental School, Worsley Building, University of Leeds, Leeds LS2 9JT (United Kingdom); Jha, A. [School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

2017-06-01

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000 °C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel. - Highlights: • A novel procedure for the restoration of dental enamel is introduced. • Fe-doped ß-pyrophosphate is evaluated as potential biomaterial for enamel restoration. • Fe-doped ß-pyrophosphate found to have the same hardness as natural enamel and dramatically lower wear rate. • Cytotoxicity and genotoxicity tests suggest that Fe-doped ß-pyrophosphate is safe for dental applications.

β-pyrophosphate: A potential biomaterial for dental applications

International Nuclear Information System (INIS)

Anastasiou, A.D.; Strafford, S.; Posada-Estefan, O.; Thomson, C.L.; Hussain, S.A.; Edwards, T.J.; Malinowski, M.; Hondow, N.; Metzger, N.K.; Brown, C.T.A.; Routledge, M.N.; Brown, A.P.; Duggal, M.S.; Jha, A.

2017-01-01

Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000 °C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel. - Highlights: • A novel procedure for the restoration of dental enamel is introduced. • Fe-doped ß-pyrophosphate is evaluated as potential biomaterial for enamel restoration. • Fe-doped ß-pyrophosphate found to have the same hardness as natural enamel and dramatically lower wear rate. • Cytotoxicity and genotoxicity tests suggest that Fe-doped ß-pyrophosphate is safe for dental applications.

Biomaterials and host versus graft response: A short review

Science.gov (United States)

Velnar, Tomaz; Bunc, Gorazd; Klobucar, Robert; Gradisnik, Lidija

2016-01-01

Biomaterials and biotechnology are increasing becoming an important area in modern medicine. The main aim in this area is the development of materials, which are biocompatible to normal tissue. Tissue-implant interactions with molecular, biological and cellular characteristics at the implant-tissue interface are important for the use and development of implants. Implantation may cause an inflammatory and immune response in tissue, foreign body reaction, systemic toxicity and imminent infection. Tissue-implant interactions determine the implant life-period. The aims of the study are to consider the biological response to implants. Biomaterials and host reactions to implants and their mechanisms are also briefly discussed. PMID:26894284

Nanotechnology in medicine: nanofilm biomaterials.

Science.gov (United States)

Van Tassel, Paul R

2013-12-13

By interrogating nature at the length scale of important biological molecules (proteins, DNA), nanotechnology offers great promise to biomedicine. We review here our recent work on nanofilm biomaterials: "nanoscopically" thin, functional, polymer-based films serving as biocompatible interfaces. In one thrust, films containing carbon nanotubes are shown to be highly antimicrobial and, thus, to be promising as biomedical device materials inherently resistive to microbial infection. In another thrust, strategies are developed toward films of independently controllable bioactivity and mechanical rigidity - two key variables governing typical biological responses.

[An in vitro study of the fracture strength of tooth preparations for Empress 2 veneers and crowns and mandibular incisors restored with Empress 2 veneers and crowns].

Science.gov (United States)

Wei, Xue; Li, Yan

2009-12-01

To compare the fracture resistance of mandibular incisors' preparations for veneers and crowns, mandibular incisors restored with Empress 2 veneers and crowns. 50 human mandibular incisors were randomly divided into five groups. Each group consisted of ten teeth and the treatment obtained as follows: A, tooth preparations for veneers; B, tooth preparations for crowns; C, teeth restored with veneers; D, teeth restored with crowns; E, untreated group. The teeth received standardized preparation and the restorations were manufactured with Empress 2 system and cemented with resin luting agent. The fracture resistances of teeth were measured by Instron universal testing machine and statistically analyzed with one-way ANOVA. The fracture resistances of A, B, C, D, E were (576.11 +/- 91.53), (204.13 +/- 85.88), (451.50 +/- 116.81), (386.16 +/- 117.75) and (566.05 +/- 121.37) N, respectively. The statistical analysis demonstrated significant differences between five groups. There were no significant differences between group A and E, group C and D. Tooth preparations for veneers did not significantly reduce the fracture resistance of mandibular incisor. The fracture resistance of teeth restored with Empress 2 veneers and crowns did not significantly differ from each other.

Impact of Digital Tooth Preparation Evaluation Technology on Preclinical Dental Students' Technical and Self-Evaluation Skills.

Science.gov (United States)

Gratton, David G; Kwon, So Ran; Blanchette, Derek; Aquilino, Steven A

2016-01-01

The aim of this study was to evaluate the effect of digital tooth preparation imaging and evaluation technology on dental students' technical abilities, self-evaluation skills, and the assessment of their simulated clinical work. A total of 80 second-year students at one U.S. dental school were assigned to one of three groups: control (n=40), E4D Compare (n=20), and Sirona prepCheck (n=20). Students in the control group were taught by traditional teaching methodologies, and the technology-assisted groups received both traditional training and supplementary feedback from the corresponding digital system. Three outcomes were measured: faculty technical score, self-evaluation score, and E4D Compare scores at 0.30 mm tolerance. Correlations were determined between the groups' scores from visual assessment and self-evaluation and between the visual assessment and digital scores. The results showed that the visual assessment and self-evaluation scores did not differ among groups (p>0.05). Overall, correlations between visual and digital assessment scores were modest though statistically significant (5% level of significance). These results suggest that the use of digital tooth preparation evaluation technology did not impact the students' prosthodontic technical and self-evaluation skills. Visual scores given by faculty and digital assessment scores correlated moderately in only two instances.

Stress distribution difference between Lava Ultimate full crowns and IPS e.max CAD full crowns on a natural tooth and on tooth-shaped implant abutments.

Science.gov (United States)

Krejci, Ivo; Daher, René

2017-04-01

The goal of this short communication is to present finite element analysis comparison of the stress distribution between CAD/CAM full crowns made of Lava Ultimate and of IPS e.max CAD, adhesively luted to natural teeth and to implant abutments with the shape of natural teeth. Six 3D models were prepared using a 3D content-creating software, based on a micro-CT scan of a human mandibular molar. The geometry of the full crown and of the abutment was the same for all models representing Lava Ultimate full crowns (L) and IPS e.max CAD full crowns (E) on three different abutments: prepared natural tooth (n), titanium abutment (t) and zirconia abutment (z). A static load of 400 N was applied on the vestibular and lingual cusps, and fixtures were applied to the base of the models. After running the static linear analysis, the post-processing data we analyzed. The stress values at the interface between the crown and the abutment of the Lt and Lz groups were significantly higher than the stress values at the same interface of all the other models. The high stress concentration in the adhesive at the interface between the crown and the abutment of the Lava Ultimate group on implants might be one of the factors contributing to the reported debondings of crowns.

Tooth structure and fracture strength of cavities

DEFF Research Database (Denmark)

Mondelli, José; Sene, Fábio; Ramos, Renata Pereira

2007-01-01

This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities......) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using...... mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50...

Magnetic nanofilms of nickel prepared at the liquid-liquid interface

International Nuclear Information System (INIS)

Varghese, Neenu; Rao, C.N.R.

2011-01-01

Highlights: → Formation of nickel thinfims at the organic-aqueous interface at room temperature. → Thickness of nanofilm is ∼20 nm. → Ni nanofilms exhibit superparamagnetic behavior. → Thicker Ni films are obtained at a higher temperature (60 o C). -- Abstract: Thin films of metallic nickel with a thickness of the order of 20 nm have been prepared at the organic-aqueous interface at room temperature by the reaction of nickel cupferronate [Ni(C 6 H 5 N 2 O 2 ) 2 ] in toluene medium and sodium borohydride (NaBH 4 ) in aqueous medium. The films were characterized with transmission electron microscopy, scanning electron microscopy and atomic force microscopy. Thicker Ni films could be prepared by carrying out the reaction at the interface at 60 o C. The Ni nanofilms exhibit superparamagnetic behavior.

MO-FG-BRA-05: Next Generation Radiotherapy Biomaterials Loaded With Gold Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Cifter, G; Ngwa, W [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Univ Massachusetts Lowell, Lowell, MA (United States); Sajo, E [Univ Massachusetts Lowell, Lowell, MA (United States); Korideck, H; Cormack, R; Makrigiorgos, G [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Kumar, R [Dana Farber Cancer Institute, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA (United States); Northeastern University, Boston, MA (United States); Sridhar, S [Northeastern University, Boston, MA (United States)

2015-06-15

Purpose: It has been proposed that routinely used inert radiotherapy (RT) biomaterials (e.g. fiducials, spacers) can be upgraded to smarter ones by coating/loading them with radiosensitizing gold nanoparticles (GNPs), for sustained in-situ release after implantation to enhance RT. In this work, we developed prototypes of such RT biomaterials and investigated the sustained release of GNPs from the biomaterials as a function of design parameters. Methods: Prototype smart biomaterials were produced by incorporating the GNPs in poly(D,L-lactide-co-glycolide) (PLGA) polymer millirods during the gel phase of production. For comparison, commercially available spacers were also coated with a polymer film loaded with fluorescent GNP. Optical/spectroscopy methods were used to monitor in vitro release of GNPs over time as a function of different design parameters: polymer weighting, type, and initial (loading) GNP concentrations. Inductively coupled plasma mass spectrometry was employed to verify GNP release. Results: Results showed that gold nanoparticles could be successfully loaded in the new RT biomaterial prototypes. Burst release of GNPs could be achieved within 1 to 25 days depending on the preparation approach. Burst release was followed by sustained release profile over time. The amount of released GNP increased with increasing loading concentration as expected. The release profiles could also be customized as a function of polymer weighting, or preparation approaches. Conclusion: Considered together, our results highlight potential for the development of next generation RT biomaterials loaded with GNPs customizable to different RT schedules. Such biomaterials could be employed as needed instead of currently used inert spacers/fiducials at no additional inconvenience to patients, to enhance RT.

MO-FG-BRA-05: Next Generation Radiotherapy Biomaterials Loaded With Gold Nanoparticles

International Nuclear Information System (INIS)

Cifter, G; Ngwa, W; Sajo, E; Korideck, H; Cormack, R; Makrigiorgos, G; Kumar, R; Sridhar, S

2015-01-01

Purpose: It has been proposed that routinely used inert radiotherapy (RT) biomaterials (e.g. fiducials, spacers) can be upgraded to smarter ones by coating/loading them with radiosensitizing gold nanoparticles (GNPs), for sustained in-situ release after implantation to enhance RT. In this work, we developed prototypes of such RT biomaterials and investigated the sustained release of GNPs from the biomaterials as a function of design parameters. Methods: Prototype smart biomaterials were produced by incorporating the GNPs in poly(D,L-lactide-co-glycolide) (PLGA) polymer millirods during the gel phase of production. For comparison, commercially available spacers were also coated with a polymer film loaded with fluorescent GNP. Optical/spectroscopy methods were used to monitor in vitro release of GNPs over time as a function of different design parameters: polymer weighting, type, and initial (loading) GNP concentrations. Inductively coupled plasma mass spectrometry was employed to verify GNP release. Results: Results showed that gold nanoparticles could be successfully loaded in the new RT biomaterial prototypes. Burst release of GNPs could be achieved within 1 to 25 days depending on the preparation approach. Burst release was followed by sustained release profile over time. The amount of released GNP increased with increasing loading concentration as expected. The release profiles could also be customized as a function of polymer weighting, or preparation approaches. Conclusion: Considered together, our results highlight potential for the development of next generation RT biomaterials loaded with GNPs customizable to different RT schedules. Such biomaterials could be employed as needed instead of currently used inert spacers/fiducials at no additional inconvenience to patients, to enhance RT

Graded/Gradient Porous Biomaterials

Directory of Open Access Journals (Sweden)

Xigeng Miao

2009-12-01

Full Text Available Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young’s moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering.

ISS protocol for EPR tooth dosimetry

International Nuclear Information System (INIS)

Onori, S.; Aragno, D.; Fattibene, P.; Petetti, E.; Pressello, M.C.

2000-01-01

The accuracy in Electron Paramagnetic Resonance (EPR) dose reconstruction with tooth enamel is affected by sample preparation, dosimetric signal amplitude evaluation and unknown dose estimate. Worldwide efforts in the field of EPR dose reconstruction with tooth enamel are focused on the optimization of the three mentioned steps in dose assessment. In the present work, the protocol implemented at ISS in the framework of the European Community Nuclear Fission Safety project 'Dose Reconstruction' is presented. A combined mechanical-chemical procedure for ground enamel sample preparation is used. The signal intensity evaluation is carried out with powder spectra simulation program. Finally, the unknown dose is evaluated individually for each sample with the additive dose method. The unknown dose is obtained by subtracting a mean native dose from the back-extrapolated dose. As an example of the capability of the ISS protocol in unknown dose evaluation, the results obtained in the framework of the 2nd International Intercomparison on EPR tooth enamel dosimetry are reported

Macrophages, Foreign Body Giant Cells and Their Response to Implantable Biomaterials

Directory of Open Access Journals (Sweden)

Zeeshan Sheikh

2015-08-01

Full Text Available All biomaterials, when implanted in vivo, elicit cellular and tissue responses. These responses include the inflammatory and wound healing responses, foreign body reactions, and fibrous encapsulation of the implanted materials. Macrophages are myeloid immune cells that are tactically situated throughout the tissues, where they ingest and degrade dead cells and foreign materials in addition to orchestrating inflammatory processes. Macrophages and their fused morphologic variants, the multinucleated giant cells, which include the foreign body giant cells (FBGCs are the dominant early responders to biomaterial implantation and remain at biomaterial-tissue interfaces for the lifetime of the device. An essential aspect of macrophage function in the body is to mediate degradation of bio-resorbable materials including bone through extracellular degradation and phagocytosis. Biomaterial surface properties play a crucial role in modulating the foreign body reaction in the first couple of weeks following implantation. The foreign body reaction may impact biocompatibility of implantation devices and may considerably impact short- and long-term success in tissue engineering and regenerative medicine, necessitating a clear understanding of the foreign body reaction to different implantation materials. The focus of this review article is on the interactions of macrophages and foreign body giant cells with biomaterial surfaces, and the physical, chemical and morphological characteristics of biomaterial surfaces that play a role in regulating the foreign body response. Events in the foreign body response include protein adsorption, adhesion of monocytes/macrophages, fusion to form FBGCs, and the consequent modification of the biomaterial surface. The effect of physico-chemical cues on macrophages is not well known and there is a complex interplay between biomaterial properties and those that result from interactions with the local environment. By having a

Encapsulation of biomaterials in porous glass-like matrices prepared via an aqueous colloidal sol-gel process

Science.gov (United States)

Liu, Dean-Mo; Chen, I-Wei

2001-01-01

The present invention provides a process for the encapsulation of biologically important proteins into transparent, porous silica matrices by an alcohol-free, aqueous, colloidal sol-gel process, and to the biological materials encapsulated thereby. The process is exemplified by studies involving encapsulated cytochrome c, catalase, myoglobin, and hemoglobin, although non-proteinaceous biomaterials, such as active DNA or RNA fragments, cells or even tissues, may also be encapsulated in accordance with the present methods. Conformation, and hence activity of the biomaterial, is successfully retained after encapsulation as demonstrated by optical characterization of the molecules, even after long-term storage. The retained conformation of the biomaterial is strongly correlated to both the rate of gelation and the subsequent drying speed of the encapsulatng matrix. Moreover, in accordance with this process, gelation is accelerated by the use of a higher colloidal solid concentration and a lower synthesis pH than conventional methods, thereby enhancing structural stability and retained conformation of the biomaterials. Thus, the invention also provides a remarkable improvement in retaining the biological activity of the encapsulated biomaterial, as compared with those involved in conventional alkoxide-based processes. It further provides new methods for the quantitative and qualitative detection of test substances that are reactive to, or catalyzed by, the active, encapsulated biological materials.

Biomaterials for MEMS

CERN Document Server

Chiao, Mu

2011-01-01

This book serves as a guide for practicing engineers, researchers, and students interested in MEMS devices that use biomaterials and biomedical applications. It is also suitable for engineers and researchers interested in MEMS and its applications but who do not have the necessary background in biomaterials.Biomaterials for MEMS highlights important features and issues of biomaterials that have been used in MEMS and biomedical areas. Hence this book is an essential guide for MEMS engineers or researchers who are trained in engineering institutes that do not provide the background or knowledge

Biomaterials. The Behavior of Stainless Steel as a Biomaterial

Directory of Open Access Journals (Sweden)

Sanda VISAN

2011-06-01

Full Text Available The biomaterials belong to the broad range of biocompatible chemical substances (sometimes even an element, which can be used for a period of time to treat or replace a tissue, organ or function of the human body. These materials bring many advantages in the diagnosis, prevention and medical therapy, reducing downtime for patients, restoring their biological functions, improving hospital management. The market in Romania sells a wide range of biomaterials for dental, cardiovascular medicine, renal, etc. Scientific research contributes to the discovery of new biomaterials or testing known biomaterials, for finding new applications. The paper exemplifies this contribution by presenting the testing of passive stainless steel behaviour in albumin solution using technique of cyclic voltammetry. It was shown that passivation contribute to increased stability of stainless steel implants to corrosive body fluids.

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Advancing biomaterials of human origin for tissue engineering

Science.gov (United States)

Chen, Fa-Ming; Liu, Xiaohua

2015-01-01

Biomaterials have played an increasingly prominent role in the success of biomedical devices and in the development of tissue engineering, which seeks to unlock the regenerative potential innate to human tissues/organs in a state of deterioration and to restore or reestablish normal bodily function. Advances in our understanding of regenerative biomaterials and their roles in new tissue formation can potentially open a new frontier in the fast-growing field of regenerative medicine. Taking inspiration from the role and multi-component construction of native extracellular matrices (ECMs) for cell accommodation, the synthetic biomaterials produced today routinely incorporate biologically active components to define an artificial in vivo milieu with complex and dynamic interactions that foster and regulate stem cells, similar to the events occurring in a natural cellular microenvironment. The range and degree of biomaterial sophistication have also dramatically increased as more knowledge has accumulated through materials science, matrix biology and tissue engineering. However, achieving clinical translation and commercial success requires regenerative biomaterials to be not only efficacious and safe but also cost-effective and convenient for use and production. Utilizing biomaterials of human origin as building blocks for therapeutic purposes has provided a facilitated approach that closely mimics the critical aspects of natural tissue with regard to its physical and chemical properties for the orchestration of wound healing and tissue regeneration. In addition to directly using tissue transfers and transplants for repair, new applications of human-derived biomaterials are now focusing on the use of naturally occurring biomacromolecules, decellularized ECM scaffolds and autologous preparations rich in growth factors/non-expanded stem cells to either target acceleration/magnification of the body's own repair capacity or use nature's paradigms to create new tissues for

Biomaterials for cardiac regeneration

CERN Document Server

Ruel, Marc

2015-01-01

This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

Suitability of Different Natural and Synthetic Biomaterials for Dental Pulp Tissue Engineering.

Science.gov (United States)

Galler, Kerstin M; Brandl, Ferdinand P; Kirchhof, Susanne; Widbiller, Matthias; Eidt, Andreas; Buchalla, Wolfgang; Göpferich, Achim; Schmalz, Gottfried

2018-02-01

Dental pulp tissue engineering is possible after insertion of pulpal stem cells combined with a scaffold into empty root canals. Commonly used biomaterials are collagen or poly(lactic) acid, which are either difficult to modify or to insert into such a narrow space. New hydrogel scaffolds with bioactive, specifically tailored functions could optimize the conditions for this approach. Different synthetic and natural hydrogels were tested for their suitability to engineer dental pulp. Two functionalized modifications of polyethylene glycol were developed in this study and compared to a self-assembling peptide, as well as to collagen and fibrin. Cell viability of dental pulp stem cells in test materials was assessed over two weeks. Cells in selected test materials laden with dentin-derived growth factors were inserted into human tooth roots and implanted subcutaneously into immunocompromised mice. In vitro cell culture exhibited distinct differences between scaffold types, where viability was significantly higher in natural compared to synthetic materials. In vivo experiments showed considerable differences regarding scaffold degradation, soft tissue formation, vascularization, and odontoblast-like cell differentiation. Fibrin appeared most suitable to enable generation of a pulp-like tissue and differentiation of cells into odontoblasts at the cell-dentin interface. In conclusion, natural materials, especially fibrin, proved to be superior compared to synthetic scaffolds regarding cell viability and dental pulp-like tissue formation.

Dependencies of the radiation sensitivity of human tooth enamel in EPR dosimetry

International Nuclear Information System (INIS)

Wieser, A.; El-Faramawy, N.; Meckbach, R.

2001-01-01

The EPR dose response of tooth enamel was determined for human molars collected in Egypt. The influence of age, gender and residence of the tooth donors as well as tooth position and sample preparation on EPR sensitivity and its variability over the enamel samples was investigated. The EPR sensitivity and its variability were found to depend only on the sample preparation procedure. The variability in EPR sensitivity of enamel from Egyptian teeth was maximally 10% and the mean sensitivity was in good agreement with that of German teeth

Efficacy of tooth whitening with different calcium phosphate-based formulations.

Science.gov (United States)

Jin, Jian; Xu, Xiaohui; Lai, Guangyun; Kunzelmann, Karl-Heinz

2013-08-01

The aim of this in-vitro study was to evaluate the efficacy of tooth whitening using different calcium phosphate-based formulations. Teeth were treated with three different hydroxyapatite preparations at different concentrations and with two control preparations; each tooth was treated a total of three times. After application of the last material, hydrodynamic shear force was applied to mimic mechanical loading. After each treatment, tooth color was measured using a dental spectrophotometer, and the mean changes in L*a*b* values between different measurements were expressed as ∆E. The results indicated significant differences between the materials, but neither dose- nor time-dependent associations were found. The suspension containing tricalcium phosphate (10 wt%) showed the most obvious color change (∆E = 2.20 ± 0.90), while the suspension containing zinc-carbonate-apatite (20 wt%) showed the least obvious color change (∆E = 0.91 ± 0.50). Calcium phosphate-based formulations that can adhere to the enamel surface and contribute to tooth whitening have promising tooth-whitening potential. © 2013 Eur J Oral Sci.

Smart Radiation Therapy Biomaterials.

Science.gov (United States)

Ngwa, Wilfred; Boateng, Francis; Kumar, Rajiv; Irvine, Darrell J; Formenti, Silvia; Ngoma, Twalib; Herskind, Carsten; Veldwijk, Marlon R; Hildenbrand, Georg Lars; Hausmann, Michael; Wenz, Frederik; Hesser, Juergen

2017-03-01

Radiation therapy (RT) is a crucial component of cancer care, used in the treatment of over 50% of cancer patients. Patients undergoing image guided RT or brachytherapy routinely have inert RT biomaterials implanted into their tumors. The single function of these RT biomaterials is to ensure geometric accuracy during treatment. Recent studies have proposed that the inert biomaterials could be upgraded to "smart" RT biomaterials, designed to do more than 1 function. Such smart biomaterials include next-generation fiducial markers, brachytherapy spacers, and balloon applicators, designed to respond to stimuli and perform additional desirable functions like controlled delivery of therapy-enhancing payloads directly into the tumor subvolume while minimizing normal tissue toxicities. More broadly, smart RT biomaterials may include functionalized nanoparticles that can be activated to boost RT efficacy. This work reviews the rationale for smart RT biomaterials, the state of the art in this emerging cross-disciplinary research area, challenges and opportunities for further research and development, and a purview of potential clinical applications. Applications covered include using smart RT biomaterials for boosting cancer therapy with minimal side effects, combining RT with immunotherapy or chemotherapy, reducing treatment time or health care costs, and other incipient applications. Copyright © 2016 Elsevier Inc. All rights reserved.

The development of peptide-based interfacial biomaterials for generating biological functionality on the surface of bioinert materials.

Science.gov (United States)

Meyers, Steven R; Khoo, Xiaojuan; Huang, Xin; Walsh, Elisabeth B; Grinstaff, Mark W; Kenan, Daniel J

2009-01-01

Biomaterials used in implants have traditionally been selected based on their mechanical properties, chemical stability, and biocompatibility. However, the durability and clinical efficacy of implantable biomedical devices remain limited in part due to the absence of appropriate biological interactions at the implant interface and the lack of integration into adjacent tissues. Herein, we describe a robust peptide-based coating technology capable of modifying the surface of existing biomaterials and medical devices through the non-covalent binding of modular biofunctional peptides. These peptides contain at least one material binding sequence and at least one biologically active sequence and thus are termed, "Interfacial Biomaterials" (IFBMs). IFBMs can simultaneously bind the biomaterial surface while endowing it with desired biological functionalities at the interface between the material and biological realms. We demonstrate the capabilities of model IFBMs to convert native polystyrene, a bioinert surface, into a bioactive surface that can support a range of cell activities. We further distinguish between simple cell attachment with insufficient integrin interactions, which in some cases can adversely impact downstream biology, versus biologically appropriate adhesion, cell spreading, and cell survival mediated by IFBMs. Moreover, we show that we can use the coating technology to create spatially resolved patterns of fluorophores and cells on substrates and that these patterns retain their borders in culture.

A preliminary report on histological outcome of pulpotomy with endodontic biomaterials vs calcium hydroxide.

Science.gov (United States)

Nosrat, Ali; Peimani, Ali; Asgary, Saeed

2013-11-01

The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.

Adhesive interfaces of enamel and dentin prepared by air-abrasion at different distances

International Nuclear Information System (INIS)

Chinelatti, Michelle Alexandra; Andreolli do Amaral, Thais Helena; Borsatto, Maria Cristina; Palma-Dibb, Regina Guenka; Corona, Silmara Aparecida Milori

2007-01-01

The purpose of this study was to analyse, by scanning electron microscopy (SEM), the morphology of enamel and dentin/adhesive interfaces in cavities prepared by air-abrasion at different working distances. Thirty sound third human molars were selected and, on both their buccal and lingual surfaces, class V cavities were prepared by air-abrasion, at 2-, 4-, 6-, 8- and 10-mm working distances, or high-speed bur (control group). After preparation, all cavities were etched with 35% phosphoric acid gel and restored with Single Bond/Filtek Z-250. Buccal and lingual surfaces were separated and restorations sectioned in a buccolingual direction, providing two sections of each cavity, which were analysed by scanning electron microscopy. It was observed that the distances of 6 and 8 mm promoted more homogeneous dentin/adhesive interfaces, with tags formation, and more uniform for enamel, which were similar to the control group. It may be concluded that the air-abrasion working distance can influence the morphology of enamel and dentin/adhesive interfaces, and the intermediate distances provided better adhesive interfaces

An introduction to biomaterials

CERN Document Server

Hollinger, Jeffrey O

2011-01-01

Consensus Definitions, Fundamental Concepts, and a Standardized Approach to Applied Biomaterials Sciences, J.O. HollingerBiology, Biomechanics, Biomaterial Interactions: Wound Healing BiologyCutaneous Wound Pathobiology: Raison d'etre for Tissue Engineering, L.K. Macri and R.A.F. ClarkOsseous Wound Healing, A. Nawab, M. Wong, D. Kwak, L. Schutte, A. Sharma, and J.O. HollingerBiology, Biomechanics, Biomaterial Interactions: Cellular MechanicsCell and Tissue Mechanobiology, W. Guo, P. Alvarez, and Y. WangBiology, Biomechanics, Biomaterial Interactions: Materials-Host InteractionsCell-Material In

Integrated micro/nanoengineered functional biomaterials for cell mechanics and mechanobiology: a materials perspective.

Science.gov (United States)

Shao, Yue; Fu, Jianping

2014-03-12

The rapid development of micro/nanoengineered functional biomaterials in the last two decades has empowered materials scientists and bioengineers to precisely control different aspects of the in vitro cell microenvironment. Following a philosophy of reductionism, many studies using synthetic functional biomaterials have revealed instructive roles of individual extracellular biophysical and biochemical cues in regulating cellular behaviors. Development of integrated micro/nanoengineered functional biomaterials to study complex and emergent biological phenomena has also thrived rapidly in recent years, revealing adaptive and integrated cellular behaviors closely relevant to human physiological and pathological conditions. Working at the interface between materials science and engineering, biology, and medicine, we are now at the beginning of a great exploration using micro/nanoengineered functional biomaterials for both fundamental biology study and clinical and biomedical applications such as regenerative medicine and drug screening. In this review, an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions is presented and they are highlighted them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. The recent exciting trend where micro/nanoengineered biomaterials are integrated into miniaturized biological and biomimetic systems for dynamic multiparametric microenvironmental control of emergent and integrated cellular behaviors is also discussed. The impact of integrated micro/nanoengineered functional biomaterials for future in vitro studies of regenerative medicine, cell biology, as well as human development and disease models are discussed. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endodontic Treatment of an Anomalous Anterior Tooth with the Aid of a 3-dimensional Printed Physical Tooth Model.

Science.gov (United States)

Byun, Chanhee; Kim, Changhwan; Cho, Seungryong; Baek, Seung Hoon; Kim, Gyutae; Kim, Sahng G; Kim, Sun-Young

2015-06-01

Endodontic treatment of tooth formation anomalies is a challenge to clinicians and as such requires a complete understanding of the aberrant root canal anatomy followed by careful root canal disinfection and obturation. Here, we report the use of a 3-dimensional (3D) printed physical tooth model including internal root canal structures for the endodontic treatment of a challenging tooth anomaly. A 12-year-old boy was referred for endodontic treatment of tooth #8. The tooth showed class II mobility with swelling and a sinus tract in the buccal mucosa and periapical radiolucency. The tooth presented a very narrow structure between the crown and root by distal concavity and a severely dilacerated root. Moreover, a perforation site with bleeding and another ditching site were identified around the cervical area in the access cavity. A translucent physical tooth model carrying the information on internal root canal structures was built through a 3-step process: data acquisition by cone-beam computed tomographic scanning, virtual modeling by image processing, and manufacturing by 3D printing. A custom-made guide jig was then fabricated to achieve a safe and precise working path to the root canal. Endodontic procedures including access cavity preparation were performed using the physical tooth model and the guide jig. At the 7-month follow-up, the endodontically treated tooth showed complete periapical healing with no clinical signs and symptoms. This case report describes a novel method of endodontic treatment of an anomalous maxillary central incisor with the aid of a physical tooth model and a custom-made guide jig via 3D printing technique. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A model of growth restraints to explain the development and evolution of tooth shapes in mammals.

Science.gov (United States)

Osborn, Jeffrey W

2008-12-07

The problem investigated here is control of the development of tooth shape. Cells at the growing soft tissue interface between the ectoderm and mesoderm in a tooth anlage are observed to buckle and fold into a template for the shape of the tooth crown. The final shape is created by enamel secreted onto the folds. The pattern in which the folds develop is generally explained as a response to the pattern in which genes are locally expressed at the interface. This congruence leaves the problem of control unanswered because it does not explain how either pattern is controlled. Obviously, cells are subject to Newton's laws of motion so that mechanical forces and constraints must ultimately cause the movements of cells during tooth morphogenesis. A computer model is used to test the hypothesis that directional resistances to growth of the epithelial part of the interface could account for the shape into which the interface folds. The model starts with a single epithelial cell whose growth is constrained by 4 constant directional resistances (anterior, posterior, medial and lateral). The constraints force the growing epithelium to buckle and fold. By entering into the model different values for these constraints the modeled epithelium is induced to buckle and fold into the different shapes associated with the evolution of a human upper molar from that of a reptilian ancestor. The patterns and sizes of cusps and the sequences in which they develop are all correctly reproduced. The model predicts the changes in the 4 directional constraints necessary to develop and evolve from one tooth shape into another. I conclude more generally expressed genes that control directional resistances to growth, not locally expressed genes, may provide the information for the shape into which a tooth develops.

FUNCTIONAL BIOMATERIALS: Design of Novel Biomaterials

Science.gov (United States)

Sakiyama-Elbert, Se; Hubbell, Ja

2001-08-01

The field of biomaterials has recently been focused on the design of intelligent materials. Toward this goal, materials have been developed that can provide specific bioactive signals to control the biological environment around them during the process of materials integration and wound healing. In addition, materials have been developed that can respond to changes in their environment, such as a change in pH or cell-associated enzymatic activity. In designing such novel biomaterials, researchers have sought not merely to create bio-inert materials, but rather materials that can respond to the cellular environment around them to improve device integration and tissue regeneration.

Platelet-rich fibrin-mediated revitalization of immature necrotic tooth

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Navin Mishra

2013-01-01

Full Text Available Contemporary studies have shown that the regeneration of tissues and root elongation is possible in necrotic immature permanent teeth. The purpose of this case report is to add a new vista in regenerative endodontic therapy by using platelet rich fibrin for revitalization of immature non vital tooth. An 11year old boy with the history of trauma was diagnosed with the pulpal necrosis and symptomatic apical periodontitis in tooth #21. Intra oral periapical radiograph showed open apex and associated immature supernumerary tooth with respect to tooth #21. Access preparation and minimal instrumentation was done to remove necrotic debris under copious irrigation with 2.5% sodium hypochlorite. Triple antibiotic paste was packed in the canal for four weeks. During second visit, 5 mL of whole blood was drawn from the medial cubital vein of the patient and blood was then subjected to centrifugation at 2400 rpm for 12 minutes for the preparation of Platelet rich fibrin (PRF utilizing Choukroun′s method. Triple antibiotic paste was removed and canal was dried. PRF clot was pushed to the apical region of tooth #21 using hand pluggers. Three milimetres of Mineral trioxide (MTA was placed in cervical part of the root canal and permanent restoration was done three days later. Clinical examination at 6 and 12 months revealed no sensitivity to percussion and palpation in tooth #21and it responded positively to both electric pulp and cold tests. Radiographic examination showed resolution of periapical rarefaction, further root development and apical closure of the tooth #21 and its associated supernumerary tooth. On the basis of successful outcome of the present case it can be stated that PRF clot may serve as a scaffold for regeneration of necrotic immature teeth.

Tooth wear

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Tušek Ivan

2014-01-01

surfaces. Attrition of teeth (attritio dentium represents teeth wear during mastication, friction on the tooth or teeth during parafunctional mandibular movements (bruxism, but without the abrasive effect. Dental erosion (erosio dentium or corrosive wear is a progressive, irreversible loss of dental hard tissue resulting from the effect of acids and /or chelation in the mouth, but without the participation of bacteria. Acids, of either exogenous or endogenous origin (peptic ulcer, gastritis, or bulimia, anoreksia nervosa, that come into the mouth can lead to different clinical manifestations of erosion depending on the time of exposure, the microstructure of teeth, buffering capacity, the amount of saliva and other factors. The changes are visible on the palatal surfaces of upper anterior teeth and, in severe cases, the lingual surfaces of posterior teeth. Occupational dental erosion occurs during exposure to industrial gases that contain hydrochloric or sulfuric acids, as well as the acids used in galvanizing and manufacture of battery and weapons. Due to the multifactorial nature of erosive tooth wear preventive measures must be applied taking into account chemical and biological factors as well as the patient's behavior associated with the etiology and pathogenesis of erosion. It is recommended to consume food and drinks that stimulate the secretion of large amounts of saliva base; to use neutral or alkaline mouthwash, and to chew sugar-free gum; to apply adequate oral hygiene (soft brushes, non-abrasive tooth paste, proper washing technique and not to consume aciding food and carbonated soft drinks and fizzy drinks in a great amount and frequently. It is necessary to apply preparations with high content of fluoride, and lubricant of tooth wear (powder CaF, CaF mixture and olive oil, and asset-based titanium tetrafluoride and casein-calcium phosphate. Commercial tooth paste that contains CPP-ACP (casein phosphopeptide-amorphous calcium phosphate and calcium phosphate

Quantitative assessment of the enamel machinability in tooth preparation with dental diamond burs.

Science.gov (United States)

Song, Xiao-Fei; Jin, Chen-Xin; Yin, Ling

2015-01-01

Enamel cutting using dental handpieces is a critical process in tooth preparation for dental restorations and treatment but the machinability of enamel is poorly understood. This paper reports on the first quantitative assessment of the enamel machinability using computer-assisted numerical control, high-speed data acquisition, and force sensing systems. The enamel machinability in terms of cutting forces, force ratio, cutting torque, cutting speed and specific cutting energy were characterized in relation to enamel surface orientation, specific material removal rate and diamond bur grit size. The results show that enamel surface orientation, specific material removal rate and diamond bur grit size critically affected the enamel cutting capability. Cutting buccal/lingual surfaces resulted in significantly higher tangential and normal forces, torques and specific energy (pmachinability for clinical dental practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biomaterials for artificial organs

CERN Document Server

Lysaght, Michael J

2010-01-01

The worldwide demand for organ transplants far exceeds available donor organs. Consequently some patients die whilst waiting for a transplant. Synthetic alternatives are therefore imperative to improve the quality of, and in some cases, save people's lives. Advances in biomaterials have generated a range of materials and devices for use either outside the body or through implantation to replace or assist functions which may have been lost through disease or injury. Biomaterials for artificial organs reviews the latest developments in biomaterials and investigates how they can be used to improve the quality and efficiency of artificial organs. Part one discusses commodity biomaterials including membranes for oxygenators and plasmafilters, titanium and cobalt chromium alloys for hips and knees, polymeric joint-bearing surfaces for total joint replacements, biomaterials for pacemakers, defibrillators and neurostimulators and mechanical and bioprosthetic heart valves. Part two goes on to investigate advanced and ...

Biomaterials and their applications

CERN Document Server

Reza Rezaie, Hamid; Öchsner, Andreas

2015-01-01

This short book presents an overview of different types of biomaterial such as bio ceramics, bio polymers, metals and bio composites, while especially focusing on nano biomaterials and their applications in different tissues. It provides a compact introduction to nano materials for drug delivery systems, tissue engineering and implants, while also reviewing essential trends in the biomaterial field over the last few decades and the latest developments.

Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

International Nuclear Information System (INIS)

Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

2010-01-01

Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

Biomaterials based on photosynthetic membranes as potential sensors for herbicides.

Science.gov (United States)

Ventrella, Andrea; Catucci, Lucia; Placido, Tiziana; Longobardi, Francesco; Agostiano, Angela

2011-08-15

In this study, ultrathin film multilayers of Photosystem II-enriched photosynthetic membranes (BBY) were prepared and immobilized on quartz substrates by means of a Layer by Layer procedure exploiting electrostatic interactions with poly(ethylenimine) as polyelectrolyte. The biomaterials thus obtained were characterized by means of optical techniques and Atomic Force Microscopy, highlighting the fact that the Layer by Layer approach allowed the BBYs to be immobilized with satisfactory results. The activity of these hybrid materials was evaluated by means of optical assays based on the Hill Reaction, indicating that the biosamples, which preserved about 65% of their original activity even ten weeks after preparation, were both stable and active. Furthermore, an investigation of the biochips' sensitivity to the herbicide terbutryn, as a model analyte, gave interesting results: inhibition of photosynthetic activity was observed at terbutryn concentrations higher than 10(-7)M, thus evidencing the potential of such biomaterials in the environmental biosensor field. Copyright © 2011 Elsevier B.V. All rights reserved.

Chicken eggshells (Gallus gallus domesticus) as carbonate calcium source for biomaterials production

International Nuclear Information System (INIS)

Junior, E.A. de O.; Bastos, J.S.B.; Silva, R.C. de S.; Macedo, H.R.A.; Macedo, M. O.C.; Bradim, A.S.

2016-01-01

The eggshells present high levels of calcium carbonate. Calcium carbonate obtained from eggshells has been used in the production of biomaterials with applications in bone regeneration, since it is biocompatible. In this work, calcium carbonate was obtained from eggshells to prepare a composite biomaterial. The presence of calcium carbonate bands was observed through spectrometry in the infrared region. Scanning electron microscopy showed the presence of calcium carbonate particles with different sizes and shapes. Carbonate predominance in the form of calcite was also observed through the X-ray diffraction

Biomaterials and their applications

Science.gov (United States)

Sharma, Anu; Sharma, Gayatri

2018-05-01

There is a growing demand for novel biomaterials for the replacement and repairing of soft and hard tissues such as bones, cartilage and blood vessels, decaying teeth, arthritic hips, injured tissues or even entire organs. The main aim of biomaterial research is to find the appropriate combination of chemical and physical properties matched with tissues replaced in the host. It improves the quality of life. On increasing number of people each year with increasing demands on these materials with higher expectations related to quality of life arising from an aging population. Now a day there is an ever-increasing search for novel biomaterials as the material requirements for complex biomedical devices increases with time. Many materials such as metals, ceramics, polymers, and glasses are being investigated as biomaterials. They are very useful in various fields due to their excellent bioactivity and biocompatibility. This paper includes various eco-friendly biomaterials and their application in various fields.

Evaluation of pH at the Bacteria–Dental Cement Interface

Science.gov (United States)

Mayanagi, G.; Igarashi, K.; Washio, J.; Nakajo, K.; Domon-Tawaraya, H.; Takahashi, N.

2011-01-01

Physiochemical assessment of the parasite-biomaterial interface is essential in the development of new biomaterials. The purpose of this study was to develop a method to evaluate pH at the bacteria-dental cement interface and to demonstrate physiochemical interaction at the interface. The experimental apparatus with a well (4.0 mm in diameter and 2.0 mm deep) was made of polymethyl methacrylate with dental cement or polymethyl methacrylate (control) at the bottom. Three representative dental cements (glass-ionomer, zinc phosphate, and zinc oxide-eugenol cements) were used. Each specimen was immersed in 2 mM potassium phosphate buffer for 10 min, 24 hrs, 1 wk, or 4 wks. The well was packed with Streptococcus mutans NCTC 10449, and a miniature pH electrode was placed at the interface between bacterial cells and dental cement. The pH was monitored after the addition of 1% glucose, and the fluoride contained in the cells was quantified. Glass-ionomer cement inhibited the bacteria-induced pH fall significantly compared with polymethyl methacrylate (control) at the interface (10 min, 5.16 ± 0.19 vs. 4.50 ± 0.07; 24 hrs, 5.20 ± 0.07 vs. 4.59 ± 0.11; 1 wk, 5.34 ± 0.14 vs. 4.57 ± 0.11; and 4 wks, 4.95 ± 0.27 vs. 4.40 ± 0.14), probably due to the fluoride released from the cement. This method could be useful for the assessment of pH at the parasite-biomaterial interface. PMID:21933936

Biofilm and Dental Biomaterials

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Marit Øilo

2015-05-01

Full Text Available All treatment involving the use of biomaterials in the body can affect the host in positive or negative ways. The microbiological environment in the oral cavity is affected by the composition and shape of the biomaterials used for oral restorations. This may impair the patients’ oral health and sometimes their general health as well. Many factors determine the composition of the microbiota and the formation of biofilm in relation to biomaterials such as, surface roughness, surface energy and chemical composition, This paper aims to give an overview of the scientific literature regarding the association between the chemical, mechanical and physical properties of dental biomaterials and oral biofilm formation, with emphasis on current research and future perspectives.

Tooth Retained Implant: No More an Oxymoron

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Divya Bhat

2011-03-01

Full Text Available Introduction: Periodontally af-fected teeth are treated in one of the two ways. (1 Tooth retention after periodontal surgery, in which the degree of regeneration achieved is unpredictable. (2 Tooth extrac-tion and implant placement. Implants have an osseointegrated surface which does not provide adequate shock absorption. Regeneration can be achieved by resecting the crown of the affected tooth and submerging the root. This technique has not had a clinical application so far as the tooth becomes difficult to restore. Placing an implant within the root can make the retained root restorable. At the same time, as the implant is placed within the root surface it achieves a periodontal integration which dampens occlusal forces better than osseointegration. Therefore, such a “tooth retained implant” may serve as an additional treatment option with significant benefits over tooth retention and implant placement alone. The hypothesis: Implants placed within retained roots have shown cementum deposition and attachment of periodontal ligament fibers over their surface. This periodontal attachment may be able to dam-pen forces better than in an osseointegrated implant. Moreover, since an implant is being placed, the crown of the tooth can be resected and submerged. This prevents epithelial migration, allows for the periodontal ligament cells to populate the wound and favors regeneration.Evaluation of the hypothesis: The technique of placing implants within cavities prepared in the root and then submerging them are simple for any practitioner placing implants routinely.

Mechanics of additively manufactured biomaterials.

Science.gov (United States)

Zadpoor, Amir A

2017-06-01

Additive manufacturing (3D printing) has found many applications in healthcare including fabrication of biomaterials as well as bioprinting of tissues and organs. Additively manufactured (AM) biomaterials may possess arbitrarily complex micro-architectures that give rise to novel mechanical, physical, and biological properties. The mechanical behavior of such porous biomaterials including their quasi-static mechanical properties and fatigue resistance is not yet well understood. It is particularly important to understand the relationship between the designed micro-architecture (topology) and the resulting mechanical properties. The current special issue is dedicated to understanding the mechanical behavior of AM biomaterials. Although various types of AM biomaterials are represented in the special issue, the primary focus is on AM porous metallic biomaterials. As a prelude to this special issue, this editorial reviews some of the latest findings in the mechanical behavior of AM porous metallic biomaterials so as to describe the current state-of-the-art and set the stage for the other studies appearing in the issue. Some areas that are important for future research are also briefly mentioned. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

International Nuclear Information System (INIS)

Khan, Rao F.H.

2003-01-01

This thesis deals with the advancements made in the field of Electron Paramagnetic Resonance (EPR) for biophysical dosimetry with tooth enamel for accident, emergency, and retrospective radiation dose reconstruction. A methodology has been developed to measure retrospective radiation exposures in human tooth enamel. This entails novel sample preparation procedures with minimum mechanical treatment to reduce the preparation induced uncertainties, establish optimum measurement conditions inside the EPR cavity, post-process the measured spectrum with functional simulation of dosimetric and other interfering signals, and reconstruct dose. By using this technique, retrospective gamma exposures as low as 80±30 mGy have been successfully deciphered. The notion of dose modifier was introduced in EPR biodosimetry for low dose measurements. It has been demonstrated that by using the modified zero added dose (MZAD) technique for low radiation exposures, doses in 100 mGy ranges can be easily reconstructed in teeth that were previously thought useless for EPR dosimetry. Also, the use of a dose modifier makes robust dose reconstruction possible for higher radiation exposures. The EPR dosimetry technique was also developed for tooth samples extracted from rodents, which represent small tooth sizing. EPR doses in the molars, extracted from the mice irradiated with whole body exposures, were reassessed and shown to be correct within the experimental uncertainty. The sensitivity of human tooth enamel for neutron irradiation, obtained from the 3 MV McMaster K.N. Van de Graaff accelerator, was also studied. For the first time this work has shown that the neutron sensitivity of the tooth enamel is approximately 1/10th of the equivalent gamma sensitivity. Parametric studies for neutron dose rate and neutron energy within the available range of the accelerator, showed no impact on the sensitivity of the tooth enamel. Therefore, tooth enamel can be used as a dosimeter for both neutrons

Bioresorption and degradation of biomaterials.

Science.gov (United States)

Das, Debarun; Zhang, Ziyang; Winkler, Thomas; Mour, Meenakshi; Gunter, Christina; Morlock, Michael; Machens, Hans-Gunther; Schilling, Arndt F

2012-01-01

The human body is a composite structure, completely constructed of biodegradable materials. This allows the cells of the body to remove and replace old or defective tissue with new material. Consequently, artificial resorbable biomaterials have been developed for application in regenerative medicine. We discuss here advantages and disadvantages of these bioresorbable materials for medical applications and give an overview of typically used metals, ceramics and polymers. Methods for the quantification of bioresorption in vitro and in vivo are described. The next challenge will be to better understand the interface between cell and material and to use this knowledge for the design of “intelligent” materials that can instruct the cells to build specific tissue geometries and degrade in the process.

Biomaterials modification by ion beam

International Nuclear Information System (INIS)

Zhang Tonghe; Yi Zhongzhen; Zhang Xu; Wu Yuguang

2001-01-01

Ion beam technology is one of best ways for the modification of biomaterials. The results of ion beam modification of biomaterials are given. The method and results of improved biocompatibility are indicated by ion beam technology. The future development of ion beam modification of biomaterials is discussed

Inorganic biomaterials structure, properties and applications

CERN Document Server

Zhang, Xiang C

2014-01-01

This book provides a practical guide to the use and applications of inorganic biomaterials. It begins by introducing the concept of inorganic biomaterials, which includes bioceramics and bioglass. This concept is further extended to hybrid biomaterials consisting of inorganic and organic materials to mimic natural biomaterials. The book goes on to provide the reader with information on biocompatibility, bioactivity and bioresorbability. The concept of the latter is important because of the increasing role resorbable biomaterials are playing in implant applications. The book also introduces a n

The interface between blood preparation and use in Uganda.

Science.gov (United States)

Kajja, I; Bimenya, G; Smit Sibinga, C

2010-04-01

The interface between preparation and use of blood impacts directly on the outcome of hemotherapy. The present study explores the knowledge and opinions of key players at, practical realities at, and quality improvement strategies of this interface. We surveyed clinicians (n = 81) and blood bank staff (n = 25) to assess their knowledge on key issues in their counterparts' working domains, the turnaround time on effecting a blood order from a hospital transfusion laboratory and strategies to improve communication of blood needs to blood banks. Out of 81 clinicians, 20 knew the four available blood products while only 17 knew the three uses of these products. Twenty-three blood bank staff reported the patient's condition as the main factor on which blood orders are based. Forty-four (54.3%) clinicians reported reception of a blood product within an hour of placing the order. Addressing infrastructure and human resource were some of the strategies suggested to improve this step of the transfusion chain. The knowledge of staff at the extreme ends of the clinical interface in their counterparts' working domain is far from adequate. However, they have well formed opinions on strategies to improve this interface.

Plasma assisted surface treatments of biomaterials.

Science.gov (United States)

Minati, L; Migliaresi, C; Lunelli, L; Viero, G; Dalla Serra, M; Speranza, G

2017-10-01

The biocompatibility of an implant depends upon the material it is composed of, in addition to the prosthetic device's morphology, mechanical and surface properties. Properties as porosity and pore size should allow, when required, cells penetration and proliferation. Stiffness and strength, that depend on the bulk characteristics of the material, should match the mechanical requirements of the prosthetic applications. Surface properties should allow integration in the surrounding tissues by activating proper communication pathways with the surrounding cells. Bulk and surface properties are not interconnected, and for instance a bone prosthesis could possess the necessary stiffness and strength for the application omitting out prerequisite surface properties essential for the osteointegration. In this case, surface treatment is mandatory and can be accomplished using various techniques such as applying coatings to the prosthesis, ion beams, chemical grafting or modification, low temperature plasma, or a combination of the aforementioned. Low temperature plasma-based techniques have gained increasing consensus for the surface modification of biomaterials for being effective and competitive compared to other ways to introduce surface functionalities. In this paper we review plasma processing techniques and describe potentialities and applications of plasma to tailor the interface of biomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

Understanding biomaterial-tissue interface quality: combined in vitro evaluation

Science.gov (United States)

Gasik, Michael

2017-12-01

One of the greatest challenges in the development of new medical products and devices remains in providing maximal patient safety, efficacy and suitability for the purpose. A 'good quality' of the tissue-implant interface is one of the most critical factors for the success of the implant integration. In this paper this challenge is being discussed from the point of view of basic stimuli combination to experimental testing. The focus is in particular on bacterial effects on tissue-implant interaction (for different materials). The demonstration of the experimental evaluation of the tissue-implant interface is for dental abutment with mucosal contact. This shows that testing of the interface quality could be the most relevant in controlled conditions, which mimic as possible the clinical applications, but consider variables being under the control of the evaluator.

Biomaterials for tissue engineering: summary

Science.gov (United States)

Christenson, L.; Mikos, A. G.; Gibbons, D. F.; Picciolo, G. L.; McIntire, L. V. (Principal Investigator)

1997-01-01

This article summarizes presentations and discussion at the workshop "Enabling Biomaterial Technology for Tissue Engineering," which was held during the Fifth World Biomaterials Congress in May 1996. Presentations covered the areas of material substrate architecture, barrier effects, and cellular response, including analysis of biomaterials challenges involved in producing specific tissue-engineered products.

Heat Transfer Behavior across the Dentino-Enamel Junction in the Human Tooth.

Directory of Open Access Journals (Sweden)

Lin Niu

Full Text Available During eating, the teeth usually endure the sharply temperature changes because of different foods. It is of importance to investigate the heat transfer and heat dissipation behavior of the dentino-enamel junction (DEJ of human tooth since dentine and enamel have different thermophysical properties. The spatial and temporal temperature distributions on the enamel, dentine, and pulpal chamber of both the human tooth and its discontinuous boundaries, were measured using infrared thermography using a stepped temperature increase on the outer boundary of enamel crowns. The thermal diffusivities for enamel and dentine were deduced from the time dependent temperature change at the enamel and dentine layers. The thermal conductivities for enamel and dentine were calculated to be 0.81 Wm-1K-1 and 0.48 Wm-1K-1 respectively. The observed temperature discontinuities across the interfaces between enamel, dentine and pulp-chamber layers were due to the difference of thermal conductivities at interfaces rather than to the phase transformation. The temperature gradient distributes continuously across the enamel and dentine layers and their junction below a temperature of 42°C, whilst a negative thermal resistance is observed at interfaces above 42°C. These results suggest that the microstructure of the dentin-enamel junction (DEJ junction play an important role in tooth heat transfer and protects the pulp from heat damage.

Biomaterials a basic introduction

CERN Document Server

Chen, Qizhi

2014-01-01

Part IBiomaterials ScienceBiomaterials Science and EngineeringLearning ObjectivesMaterials Science and EngineeringMultilevels of Structure and Categorization of MaterialsFour Categories of MaterialsDefinitions of Biomaterials, Biomedical Materials, and Biological MaterialsBiocompatibilityChapter HighlightsActivitiesSimple Questions in ClassProblems and ExercisesBibliographyToxicity and CorrosionLearning ObjectivesElements in the BodyBiological Roles and Toxicities of Trace ElementsSelection of Metallic Elements in Medical-Grade AlloysCorrosion of MetalsEnvironment inside the BodyMinimization of Toxicity of Metal ImplantsChapter HighlightsLaboratory Practice 1Simple Questions in ClassProblems and ExercisesAdvanced Topic: Biological Roles of Alloying ElementsBibliographyMechanical Properties of BiomaterialsLearning ObjectivesRole of Implant BiomaterialsMechanical Properties of General ImportanceHardnessElasticity: Resilience and StrechabilityMechanical Properties Terms Used in the Medical CommunityFailureEssent...

Biomaterials Made from Coiled-Coil Peptides.

Science.gov (United States)

Conticello, Vincent; Hughes, Spencer; Modlin, Charles

The development of biomaterials designed for specific applications is an important objective in personalized medicine. While the breadth and prominence of biomaterials have increased exponentially over the past decades, critical challenges remain to be addressed, particularly in the development of biomaterials that exhibit highly specific functions. These functional properties are often encoded within the molecular structure of the component molecules. Proteins, as a consequence of their structural specificity, represent useful substrates for the construction of functional biomaterials through rational design. This chapter provides an in-depth survey of biomaterials constructed from coiled-coils, one of the best-understood protein structural motifs. We discuss the utility of this structurally diverse and functionally tunable class of proteins for the creation of novel biomaterials. This discussion illustrates the progress that has been made in the development of coiled-coil biomaterials by showcasing studies that bridge the gap between the academic science and potential technological impact.

TEM specimen preparation of semiconductor-PMMA-metal interfaces

International Nuclear Information System (INIS)

Thangadurai, P.; Lumelsky, Yulia; Silverstein, Michael S.; Kaplan, Wayne D.

2008-01-01

Transmission electron microscopy (TEM) cross-section specimens of PMMA in contact with gold and Si were prepared by focused ion beam (FIB) and compared with plan-view PMMA specimens prepared by a dip-coating technique. The specimens were characterized by TEM and electron energy loss spectroscopy (EELS). In the cross-section specimens, the thin films of PMMA were located in a Si-PMMA-Au multilayer. Different thicknesses of PMMA films were spin-coated on the Si substrates. The thickness of the TEM specimens prepared by FIB was estimated using EELS to be 0.65 of the plasmon mean-free-path. Along the PMMA-Au interface, Au particle diffusion into the PMMA was observed, and the size of the Au particles was in the range of 2-4 nm. Dip-coating of PMMA directly on Cu TEM grids resulted in thin specimens with a granular morphology, with a thickness of 0.58 of the plasmon mean-free-path. The dip-coated specimens were free from ion milling induced artifacts, and thus serve as control specimens for comparison with the cross-sectioned specimens prepared by FIB

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

Directory of Open Access Journals (Sweden)

Sang-Mi Yun

2012-02-01

Full Text Available Objectives The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10. Each experimental group was restored with Caviton (GC, Spacer (Vericom, IRM (Dentsply-Caulk, or Fuji II(GC. Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiple-comparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM. Results There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Measurement of total occlusal convergence of 3 different tooth preparations in 4 different planes by dental students.

Science.gov (United States)

Yoon, Stephan S; Cheong, Chan; Preisser, John; Jun, Sangho; Chang, Brian M; Wright, Robert F

2014-08-01

Total occlusal convergence of crown preparation is an important didactic and clinical concept in dental education. The purpose of this study was to compare the discrepancy between the total occlusal convergence of dental students' typodont crown preparations and the ideal range (4 to 10 degrees) in 3 different regions of the mouth and in 4 different planes of the teeth. The dental students of the Class of 2012 at Harvard School of Dental Medicine were asked to prepare typodont teeth for crowns on 3 different teeth, the maxillary left central incisor (ceramic), mandibular left first molar (complete metal), and mandibular left first premolar (metal ceramic), during their third year preclinical summative examination and the Comprehensive Clinical Examination in their fourth year. Eighteen students prepared 3 teeth in their third and fourth years, whereas 19 students participated only in their fourth year, for a total of 55 sets of 3 teeth. By using custom fit die bases to reproduce the position, a novel procedure of measuring each tooth was accomplished in 4 different planes: the faciolingual, mesiodistal, mesiofacial-distolingual, and mesiolingual-distofacial. The total occlusal convergence of each image was measured with a computer screen protractor. The gingival 2 mm of the axial wall was used to determine the taper of each wall. Linear mixed model analysis was used to estimate and compare the total occlusal convergences of different teeth and planes (α=.05). Bonferroni corrections were used to adjust for post hoc multiple comparisons. The mean total occlusal convergence varied by tooth and plane (2-way interaction; Pplanes; the model-predicted 99% CIs for the total occlusal convergence were as follows: faciolingual (12.7, 19.4), mesiodistal (14.0, 19.3), mesiofacial-distolingual (13,4, 19.4), and mesiolingual-distofacial (13.7, 19.1). For the central incisor, 99% CIs for the total occlusal convergence were (15.9, 24.4) for the faciolingual measurement, providing

Bioactive Polymeric Composites for Tooth Mineral Regeneration: Physicochemical and Cellular Aspects

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Skrtic, Drago; Antonucci, Joseph M.

2011-01-01

Our studies of amorphous calcium phosphate (ACP)-based dental materials are focused on the design of bioactive, non-degradable, biocompatible, polymeric composites derived from acrylic monomer systems and ACP by photochemical or chemically activated polymerization. Their intended uses include remineralizing bases/liners, orthodontic adhesives and/or endodontic sealers. The bioactivity of these materials originates from the propensity of ACP, once exposed to oral fluids, to release Ca and PO4 ions (building blocks of tooth and bone mineral) in a sustained manner while spontaneously converting to thermodynamically stable apatite. As a result of ACP's bioactivity, local Ca- and PO4-enriched environments are created with supersaturation conditions favorable for the regeneration of tooth mineral lost to decay or wear. Besides its applicative purpose, our research also seeks to expand the fundamental knowledge base of structure-composition-property relationships existing in these complex systems and identify the mechanisms that govern filler/polymer and composite/tooth interfacial phenomena. In addition to an extensive physicochemical evaluation, we also assess the leachability of the unreacted monomers and in vitro cellular responses to these types of dental materials. The systematic physicochemical and cellular assessments presented in this study typically provide model materials suitable for further animal and/or clinical testing. In addition to their potential dental clinical value, these studies suggest the future development of calcium phosphate-based biomaterials based on composite materials derived from biodegradable polymers and ACP, and designed primarily for general bone tissue regeneration. PMID:22102967

Biomaterials Evaluation: Conceptual Refinements and Practical Reforms.

Science.gov (United States)

Masaeli, Reza; Zandsalimi, Kavosh; Tayebi, Lobat

2018-01-01

Regarding the widespread and ever-increasing applications of biomaterials in different medical fields, their accurate assessment is of great importance. Hence the safety and efficacy of biomaterials is confirmed only through the evaluation process, the way it is done has direct effects on public health. Although every biomaterial undergoes rigorous premarket evaluation, the regulatory agencies receive a considerable number of complications and adverse event reports annually. The main factors that challenge the process of biomaterials evaluation are dissimilar regulations, asynchrony of biomaterials evaluation and biomaterials development, inherent biases of postmarketing data, and cost and timing issues. Several pieces of evidence indicate that current medical device regulations need to be improved so that they can be used more effectively in the evaluation of biomaterials. This article provides suggested conceptual refinements and practical reforms to increase the efficiency and effectiveness of the existing regulations. The main focus of the article is on strategies for evaluating biomaterials in US, and then in EU.

Assessment of residual coronal tooth structure postendodontic cavity preparation using digital dental impressions and micro-computed tomography.

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Al-Nuaimi, Nassr; Patel, Shanon; Foschi, Federico; Mannocci, Francesco; Austin, Rupert S

To evaluate the in vitro accuracy of digital impressions for three-dimensional (3D) volumetric measurement of residual coronal tooth structure postendodontic cavity preparation, with reference to micro-computed tomography (μCT). Quantification of the accuracy and precision of the intraoral digital scanner (3M True Definition Scanner - IOS) was performed using a metrology gauge block and a profilometric calibration model. Thirty-four human extracted molars with endodontic access cavities were scanned using both intraoral scanning (test scanner) in high-resolution mode, and µCT (reference scanner: GE Locus SP μCT scanner) in high- (HiResCT) and low- (LoResCT) resolution modes. Comparisons of volumetric accuracy and 3D profilometric deviations were performed using surface metrology software. One-way repeated measures analysis of variance (ANOVA), in combination with the Bonferroni post hoc test, was implemented to compare the differences in volume measurements between scanning methods. Digital scanning revealed smaller volume measurements by 1.36% and 0.68% compared to HiResCT and LoResCT, respectively. There was a statistically significant difference in the volumetric measurements obtained from the IOS scanner and both HiResCT and LoResCT scans (P digital scanner was able to reliably measure the extra- and intracoronal aspect of the endodontically accessed tooth.

Autogenous tooth transplantation for replacing a lost tooth: case reports

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Ji-Youn Kang

2013-02-01

Full Text Available The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

Comparison of Amount of Primary Tooth Reduction Required for Anterior and Posterior Zirconia and Stainless Steel Crowns.

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Clark, Larkin; Wells, Martha H; Harris, Edward F; Lou, Jennifer

2016-01-01

To determine if aggressiveness of primary tooth preparation varied among different brands of zirconia and stainless steel (SSC) crowns. One hundred primary typodont teeth were divided into five groups (10 posterior and 10 anterior) and assigned to: Cheng Crowns (CC); EZ Pedo (EZP); Kinder Krowns (KKZ); NuSmile (NSZ); and SSC. Teeth were prepared, and assigned crowns were fitted. Teeth were weighed prior to and after preparation. Weight changes served as a surrogate measure of tooth reduction. Analysis of variance showed a significant difference in tooth reduction among brand/type for both the anterior and posterior. Tukey's honest significant difference test (HSD), when applied to anterior data, revealed that SSCs required significantly less tooth removal compared to the composite of the four zirconia brands, which showed no significant difference among them. Tukey's HSD test, applied to posterior data, revealed that CC required significantly greater removal of crown structure, while EZP, KKZ, and NSZ were statistically equivalent, and SSCs required significantly less removal. Zirconia crowns required more tooth reduction than stainless steel crowns for primary anterior and posterior teeth. Tooth reduction for anterior zirconia crowns was equivalent among brands. For posterior teeth, reduction for three brands (EZ Pedo, Kinder Krowns, NuSmile) did not differ, while Cheng Crowns required more reduction.

Bone substitute biomaterials

CERN Document Server

Mallick, K

2014-01-01

Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

Viscoelasticity of biomaterials

International Nuclear Information System (INIS)

Glasser, W.G.; Hatakeyama, H.

1992-01-01

Viscoelasticity of Biomaterials is divided into three sections. The first offers a materials design lesson on the architectural arrangement of biopolymers in collagen. Included also are reviews on solution properties of polysacchardies, chiral and liquid crystalline solution characteristics of cellulose derivatives, and viscoelastic properties of wood and wood fiber reinforced thermoplastics. The second section, Biogels and Gelation, discusses the molecular arrangements of highly hydrated biomaterials such as mucus, gums, skinlike tissue, and silk fibroin. The physical effects that result from the transition from a liquid to a solid state are the subject of the third section, which focuses on relaxation phenomena. Gel formation, the conformation of domain structures, and motional aspects of complex biomaterials are described in terms of recent experimental advances in various fields. A relevant chapter on the effects of ionizing radiation on connective tissue is abstracted separately

In vivo biocompatibility of new nano-calcium-deficient hydroxyapatite/poly-amino acid complex biomaterials

Science.gov (United States)

Dai, Zhenyu; Li, Yue; Lu, Weizhong; Jiang, Dianming; Li, Hong; Yan, Yonggang; Lv, Guoyu; Yang, Aiping

2015-01-01

Objective To evaluate the compatibility of novel nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) complex biomaterials with muscle and bone tissue in an in vivo model. Methods Thirty-two New Zealand white rabbits were used in this study. Biomaterials were surgically implanted into each rabbit in the back erector spinae and in tibia with induced defect. Polyethylene was implanted into rabbits in the control group and n-CDHA/PAA into those of the experimental group. Animals were examined at four different points in time: 2 weeks, 4 weeks, 12 weeks, and 24 weeks after surgery. They were euthanized after embolization. Back erector spinae muscles with the surgical implants were examined after hematoxylin and eosin (HE) staining at these points in time. Tibia bones with the surgical implants were examined by X-ray and scanning electron microscopy (SEM) at these points in time to evaluate the interface of the bone with the implanted biomaterials. Bone tissues were sectioned and subjected to HE, Masson, and toluidine blue staining. Results HE staining of back erector spinae muscles at 4 weeks, 12 weeks, and 24 weeks after implantation of either n-CDHA/PAA or polyethylene showed disappearance of inflammation and normal arrangement in the peripheral tissue of implant biomaterials; no abnormal staining was observed. At 2 weeks after implantation, X-ray imaging of bone tissue samples in both experimental and control groups showed that the peripheral tissues of the implanted biomaterials were continuous and lacked bone osteolysis, absorption, necrosis, or osteomyelitis. The connection between implanted biomaterials and bone tissue was tight. The results of HE, Masson, toluidine blue staining and SEM confirmed that the implanted biomaterials were closely connected to the bone defect and that no rejection had taken place. The n-CDHA/PAA biomaterials induced differentiation of a large number of chondrocytes. New bone trabecula began to form at 4 weeks after

In vivo biocompatibility of new nano-calcium-deficient hydroxyapatite/poly-amino acid complex biomaterials.

Science.gov (United States)

Dai, Zhenyu; Li, Yue; Lu, Weizhong; Jiang, Dianming; Li, Hong; Yan, Yonggang; Lv, Guoyu; Yang, Aiping

2015-01-01

To evaluate the compatibility of novel nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA) complex biomaterials with muscle and bone tissue in an in vivo model. Thirty-two New Zealand white rabbits were used in this study. Biomaterials were surgically implanted into each rabbit in the back erector spinae and in tibia with induced defect. Polyethylene was implanted into rabbits in the control group and n-CDHA/PAA into those of the experimental group. Animals were examined at four different points in time: 2 weeks, 4 weeks, 12 weeks, and 24 weeks after surgery. They were euthanized after embolization. Back erector spinae muscles with the surgical implants were examined after hematoxylin and eosin (HE) staining at these points in time. Tibia bones with the surgical implants were examined by X-ray and scanning electron microscopy (SEM) at these points in time to evaluate the interface of the bone with the implanted biomaterials. Bone tissues were sectioned and subjected to HE, Masson, and toluidine blue staining. HE staining of back erector spinae muscles at 4 weeks, 12 weeks, and 24 weeks after implantation of either n-CDHA/PAA or polyethylene showed disappearance of inflammation and normal arrangement in the peripheral tissue of implant biomaterials; no abnormal staining was observed. At 2 weeks after implantation, X-ray imaging of bone tissue samples in both experimental and control groups showed that the peripheral tissues of the implanted biomaterials were continuous and lacked bone osteolysis, absorption, necrosis, or osteomyelitis. The connection between implanted biomaterials and bone tissue was tight. The results of HE, Masson, toluidine blue staining and SEM confirmed that the implanted biomaterials were closely connected to the bone defect and that no rejection had taken place. The n-CDHA/PAA biomaterials induced differentiation of a large number of chondrocytes. New bone trabecula began to form at 4 weeks after implanting n

Geographic Variations in the EPR Spectrum of Tooth Enamel

International Nuclear Information System (INIS)

Romanyukha, A.A.; Hayes, R.B.; Haskell, E.H.; Kenner, G.H.

1999-01-01

The presence of stable radiation-induced radicals in the mineral component of tooth enamel allows use of this material as a biological dosemeter. Estimation of the dose absorbed in tooth enamel can be done by EPR. Generally, for the purpose of dose reconstruction, the EPR spectrum of tooth enamel is interpreted in terms of two main components. The first is a broad background signal often called the native signal centered at a g value of 2.0045. The origin of this signal is not precisely known. The second main component in the tooth enamel spectrum is purely radiation induced and can be used for retrospective dosimetry. Internal structure of the native signal and variations of its amplitude and linewidth were investigated for the samples prepared from modern teeth obtained from different geographic locations (USA and Russia). Possible reasons for the variations observed are discussed as are the potential effects of the variations on the reliability of dose estimation. (author)

Treatment of Necrotic Calcified Tooth Using Intentional Replantation Procedure

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Nima Moradi Majd

2014-01-01

Full Text Available Introduction. If the teeth are impacted by a chronic irritant, the pulp space possibly will undergo calcific changes that may impede access opening during root canal treatment. In such cases that conventional endodontic treatment is impossible or impractical, intentional replantation may be considered as a last solution to preserve the tooth. Methods. After failing to perform conventional root canal therapy for a necrotic calcified right mandibular second premolar, the tooth was gently extracted. The root apex was resected and the root end cavity was prepared and filled with calcium enriched mixture (CEM cement. Then, the extracted tooth was replanted in its original position. Results. After a year the tooth was asymptomatic, and the size of periapical radiolucency was remarkably reduced and no clinical sign of ankylosis was observed. Conclusion. Intentional replantation of the necrotic calcified teeth could be considered as an alternative to teeth extraction, especially for the single-rooted teeth and when nonsurgical and surgical endodontic procedures seem impossible.

New method of synthesis and in vitro studies of a porous biomaterial

International Nuclear Information System (INIS)

Wers, E.; Lefeuvre, B.; Pellen-Mussi, P.; Novella, A.; Oudadesse, H.

2016-01-01

Biomaterials for bone reconstruction represent a widely studied area. In this paper, a new method of synthesis of a porous glass–ceramic obtained by thermal treatment is presented. The prepared biomaterial was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and induced couple plasma-optical emission spectroscopy (ICP-OES), mercury porosimetry and by the Archimedes method. In vitro evaluations in a simulated body fluid (SBF) and in contact with SaOS_2 human osteoblasts were also carried out. The porous glass–ceramic is composed of a total porous network of 60% suitable for body fluid and cell infiltration, with pore sizes varying from 60 nm to 143 μm. The presence of two crystalline phases decreases the kinetic of bioactivity compared to an amorphous biomaterial (bioactive glass). A hydroxyapatite layer appears from 15 days of immersion on the surface and inside the pores, showing a biodegradation and a bioactivity in four steps. Cytotoxicity assessments present an increase of the cellular viability after 72 h proving the non-cytotoxic effect of the glass–ceramic. Thus, the results of these different studies indicate that the porous biomaterial may have a potential application for the bone regeneration. This paper also presents the novelty of this method. It is a rapid synthesis which combines simplicity and low cost. This represents an advantage for an eventual industrialization. - Highlights: • The new method of synthesis of a porous glass–ceramic is reproducible. • The porous glass–ceramic possesses a total porosity of 60%. • The biomaterial shows a bioactivity in four steps with hydroxyapatite formation. • 82% of cellular viability is observed on the surface of the biomaterial.

New method of synthesis and in vitro studies of a porous biomaterial

Energy Technology Data Exchange (ETDEWEB)

Wers, E., E-mail: wers.eric@hotmail.com [Equipe Chimie du Solide et Matériaux, UMR CNRS 6226, Sciences Chimiques de Rennes, Université de Rennes 1, Université Européenne de Bretagne, 263 avenue du Général Leclerc, 35042 Rennes Cedex (France); Lefeuvre, B. [Equipe Chimie du Solide et Matériaux, UMR CNRS 6226, Sciences Chimiques de Rennes, Université de Rennes 1, Université Européenne de Bretagne, 263 avenue du Général Leclerc, 35042 Rennes Cedex (France); Pellen-Mussi, P.; Novella, A. [Equipe Chimie du Solide et Matériaux, UMR CNRS 6226, Sciences Chimiques de Rennes, Université de Rennes 1, Université Européenne de Bretagne, 2 avenue du Professeur Léon Bernard, 35042 Rennes Cedex (France); Oudadesse, H. [Equipe Chimie du Solide et Matériaux, UMR CNRS 6226, Sciences Chimiques de Rennes, Université de Rennes 1, Université Européenne de Bretagne, 263 avenue du Général Leclerc, 35042 Rennes Cedex (France)

2016-04-01

Biomaterials for bone reconstruction represent a widely studied area. In this paper, a new method of synthesis of a porous glass–ceramic obtained by thermal treatment is presented. The prepared biomaterial was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and induced couple plasma-optical emission spectroscopy (ICP-OES), mercury porosimetry and by the Archimedes method. In vitro evaluations in a simulated body fluid (SBF) and in contact with SaOS{sub 2} human osteoblasts were also carried out. The porous glass–ceramic is composed of a total porous network of 60% suitable for body fluid and cell infiltration, with pore sizes varying from 60 nm to 143 μm. The presence of two crystalline phases decreases the kinetic of bioactivity compared to an amorphous biomaterial (bioactive glass). A hydroxyapatite layer appears from 15 days of immersion on the surface and inside the pores, showing a biodegradation and a bioactivity in four steps. Cytotoxicity assessments present an increase of the cellular viability after 72 h proving the non-cytotoxic effect of the glass–ceramic. Thus, the results of these different studies indicate that the porous biomaterial may have a potential application for the bone regeneration. This paper also presents the novelty of this method. It is a rapid synthesis which combines simplicity and low cost. This represents an advantage for an eventual industrialization. - Highlights: • The new method of synthesis of a porous glass–ceramic is reproducible. • The porous glass–ceramic possesses a total porosity of 60%. • The biomaterial shows a bioactivity in four steps with hydroxyapatite formation. • 82% of cellular viability is observed on the surface of the biomaterial.

On the nature of biomaterials.

Science.gov (United States)

Williams, David F

2009-10-01

The situations in which biomaterials are currently used are vastly different to those of just a decade ago. Although implantable medical devices are still immensely important, medical technologies now encompass a range of drug and gene delivery systems, tissue engineering and cell therapies, organ printing and cell patterning, nanotechnology based imaging and diagnostic systems and microelectronic devices. These technologies still encompass metals, ceramics and synthetic polymers, but also biopolymers, self assembled systems, nanoparticles, carbon nanotubes and quantum dots. These changes imply that our original concepts of biomaterials and our expectations of their performance also have to change. This Leading Opinion Paper addresses these issues. It concludes that many substances which hitherto we may not have thought of as biomaterials should now be considered as such so that, alongside the traditional structural biomaterials, we have substances that have been engineered to perform functions within health care where their performance is directly controlled by interactions with tissues and tissue components. These include engineered tissues, cells, organs and even viruses. This essay develops the arguments for a radically different definition of a biomaterial.

Autogenous tooth transplantation: an alternative to replace extracted tooth

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David B. Kamadjaja

2015-09-01

Full Text Available Background: The gold standard treatment to replace missing tooth is dental implants, however, in certain cases, such as in young patients its placement is contraindicated. Autogenous tooth transplantation, which has been widely done in Scandinavian countries for many years, may become a good alternative to overcome this problem. Purpose: This article attempted to provide information about the indication, treatment planning, surgical technique and the successful result of autogenous tooth transplantation. Case: A fifteen year old male patient presented with large caries and periapical disease of his lower left first molar, which was partially erupted and the roots was not fully formed in radiograph. Case management: Autogenous tooth transplantation procedure was performed consisting of extraction of #36, odontectomy of #38 followed by its implantation to socket #36 and fixation of the transplanted tooth to the adjacent teeth. Post operative evaluation was done on regular basis within 18 months period. There was no complaint, the tooth was clinically stable and no evidence of periodontal problem. Serial radiographs showed healing of alveolar bone and periodontal tissue, and the complete root formation was evident by 18 months post operatively. Conclusion: Autogenous tooth transplantation is a potential alternative to replace extracted tooth. Provided that the case be properly planned and operation carefully performed, successful result of this treatment can be achieved.

High and low torque handpieces: cutting dynamics, enamel cracking and tooth temperature.

Science.gov (United States)

Watson, T F; Flanagan, D; Stone, D G

2000-06-24

The aim of these experiments was to compare the cutting dynamics of high-speed high-torque (speed-increasing) and high-speed low-torque (air-turbine) handpieces and evaluate the effect of handpiece torque and bur type on sub-surface enamel cracking. Temperature changes were also recorded in teeth during cavity preparation with high and low torque handpieces with diamond and tungsten carbide (TC) burs. The null hypothesis of this study was that high torque handpieces cause more damage to tooth structure during cutting and lead to a rise in temperature within the pulp-chamber. Images of the dynamic interactions between burs and enamel were recorded at video rate using a confocal microscope. Central incisors were mounted on a specially made servomotor driven stage for cutting with a type 57 TC bur. The two handpiece types were used with simultaneous recording of cutting load and rate. Sub-surface enamel cracking caused by the use of diamond and TC burs with high and low torque was also examined. Lower third molars were sectioned horizontally to remove the cusp tips and then the two remaining crowns cemented together with cyanoacrylate adhesive, by their flat surfaces. Axial surfaces of the crowns were then prepared with the burs and handpieces. The teeth were then separated and the original sectioned surface examined for any cracks using a confocal microscope. Heat generation was measured using thermocouples placed into the pulp chambers of extracted premolars, with diamond and TC burs/high-low torque handpiece variables, when cutting occlusal and cervical cavities. When lightly loaded the two handpiece types performed similarly. However, marked differences in cutting mechanisms were noted when increased forces were applied to the handpieces with, generally, an increase in cutting rate. The air turbine could not cope with steady heavy loads, tending to stall. 'Rippling' was seen in the interface as this stall developed, coinciding with the bur 'clearing' itself. No

Silk-based biomaterials.

Science.gov (United States)

Altman, Gregory H; Diaz, Frank; Jakuba, Caroline; Calabro, Tara; Horan, Rebecca L; Chen, Jingsong; Lu, Helen; Richmond, John; Kaplan, David L

2003-02-01

Silk from the silkworm, Bombyx mori, has been used as biomedical suture material for centuries. The unique mechanical properties of these fibers provided important clinical repair options for many applications. During the past 20 years, some biocompatibility problems have been reported for silkworm silk; however, contamination from residual sericin (glue-like proteins) was the likely cause. More recent studies with well-defined silkworm silk fibers and films suggest that the core silk fibroin fibers exhibit comparable biocompatibility in vitro and in vivo with other commonly used biomaterials such as polylactic acid and collagen. Furthermore, the unique mechanical properties of the silk fibers, the diversity of side chain chemistries for 'decoration' with growth and adhesion factors, and the ability to genetically tailor the protein provide additional rationale for the exploration of this family of fibrous proteins for biomaterial applications. For example, in designing scaffolds for tissue engineering these properties are particularly relevant and recent results with bone and ligament formation in vitro support the potential role for this biomaterial in future applications. To date, studies with silks to address biomaterial and matrix scaffold needs have focused on silkworm silk. With the diversity of silk-like fibrous proteins from spiders and insects, a range of native or bioengineered variants can be expected for application to a diverse set of clinical needs.

Fracture toughness of dentin/resin-composite adhesive interfaces.

Science.gov (United States)

Tam, L E; Pilliar, R M

1993-05-01

The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37 degrees C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.

A review of organic and inorganic biomaterials for neural interfaces.

Science.gov (United States)

Fattahi, Pouria; Yang, Guang; Kim, Gloria; Abidian, Mohammad Reza

2014-03-26

Recent advances in nanotechnology have generated wide interest in applying nanomaterials for neural prostheses. An ideal neural interface should create seamless integration into the nervous system and performs reliably for long periods of time. As a result, many nanoscale materials not originally developed for neural interfaces become attractive candidates to detect neural signals and stimulate neurons. In this comprehensive review, an overview of state-of-the-art microelectrode technologies provided fi rst, with focus on the material properties of these microdevices. The advancements in electro active nanomaterials are then reviewed, including conducting polymers, carbon nanotubes, graphene, silicon nanowires, and hybrid organic-inorganic nanomaterials, for neural recording, stimulation, and growth. Finally, technical and scientific challenges are discussed regarding biocompatibility, mechanical mismatch, and electrical properties faced by these nanomaterials for the development of long-lasting functional neural interfaces.

Cell reactions with biomaterials: the microscopies

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Curtis A. S.G.

2001-01-01

Full Text Available The methods and results of optical microscopy that can be used to observe cell reactions to biomaterials are Interference Reflection Microscopy (IRM, Total Internal Reflection Fluorescence Microscopy (TIRFM, Surface Plasmon Resonance Microscopy (SPRM and Forster Resonance Energy Transfer Microscopy (FRETM and Standing Wave Fluorescence Microscopy. The last three are new developments, which have not yet been fully perfected. TIRFM and SPRM are evanescent wave methods. The physics of these methods depend upon optical phenomena at interfaces. All these methods give information on the dimensions of the gap between cell and the substratum to which it is adhering and thus are especially suited to work with biomaterials. IRM and FRETM can be used on opaque surfaces though image interpretation is especially difficult for IRM on a reflecting opaque surface. These methods are compared with several electron microscopical methods for studying cell adhesion to substrata. These methods all yield fairly consistent results and show that the cell to substratum distance on many materials is in the range 5 to 30 nm. The area of contact relative to the total projected area of the cell may vary from a few per cent to close to 100% depending on the cell type and substratum. These methods show that those discrete contact areas well known as focal contacts are frequently present. The results of FRETM suggest that the separation from the substratum even in a focal contact is about 5 nm.

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur.

Science.gov (United States)

Liu, Min; Reed, David A; Cecchini, Giancarlo M; Lu, Xuanyu; Ganjawalla, Karan; Gonzales, Carol S; Monahan, Richard; Luan, Xianghong; Diekwisch, Thomas G H

2016-01-01

Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here, we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids vs. snakes: (i) the orientation of replacement teeth compared to the major tooth axis, (ii) the occurrence of resorption pits, and (iii) the mode of tooth implantation/attachment to the tooth bearing element (TBE). The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as Heloderma. In

Varanoid Tooth Eruption and Implantation Modes in a Late Cretaceous Mosasaur

Directory of Open Access Journals (Sweden)

Min eLiu

2016-05-01

Full Text Available Erupting teeth are some of the oldest witnesses of developmental processes in the vertebrate fossil record and provide an important resource for vertebrate cladistics. Here we have examined a mosasaur jaw fragment from central Texas using ultrathin ground section histology and 3D tomographic imaging to assess features critical for the cladistic placement of mosasaurs among varanoids versus snakes: (i the orientation of replacement teeth compared to the major tooth axis, (ii the occurrence of resorption pits, and (iii the mode of tooth implantation/attachment to the tooth bearing element. The replacement tooth studied here developed in an inclined position slightly distal of the deciduous parent tooth, similar to another varanoid squamate, the Gila monster Heloderma suspectum. Ground sections and tomographs also demonstrated that the replacement tooth attachment apparatus was entirely intact and that there was no evidence of mechanical deformation. Sections and tomographs further illustrated that the replacement tooth was located within a bony crypt and the inclination of the crypt matched the inclination of the replacement tooth. These preparations also revealed the presence of a resorption pit within the boundaries of the deciduous tooth that surrounded the developing replacement tooth. This finding suggests that developing mosasaur teeth developed within the walls of resorption pits similar to varanoid tooth germs and unlike developing snake teeth which are surrounded by fibrous connective tissue integuments. Finally, mosasaurs featured pseudo-thecodont tooth implantation with teeth anchored within a socket of mineralized tissue by means of a mineralized periodontal ligament. Together, these data indicate that the moderate inclination of the erupting mosasaur tooth studied here is neither a result of postmortem displacement nor a character representative of snakes, but rather a shared character between Mosasaurs and other varanoids such as

Biomaterials: An Introduction for Librarians.

Science.gov (United States)

Bush, Renee B.

1996-01-01

Contains an overview of biomaterials, an interdisciplinary field in which research combines medicine, biological sciences, physical sciences, and engineering. Biomaterials are substances which improve quality of life by augmenting or replacing bodily tissues or functions. Highlights problems associated with collection development and literature…

Effect of rotary cutting instruments on the resin-tooth interfacial ultra structure: An in vivo study.

Science.gov (United States)

Sherawat, Sudhir; Tewari, Sanjay; Duhan, Jigyasa; Gupta, Alpa; Singla, Rakesh

2014-12-01

To evaluate the effect of cutting teeth with different types of burs at various speeds on surface topography of tooth surface and interfacial gap formation at resin-tooth interface. The human molars were divided into seven groups: Diamond bur in airrotor (DA) & micromotor (DM), crosscut carbide bur in airrotor (CCA) & micromotor (CCM), plain carbide bur in airrotor (CA) & micromotor (CM) and #600-grit silicon carbide paper (SiC). In five samples from each group Class II box-only cavities were restored. The occlusal surface of four teeth per group was flattened. Two out of four teeth were acid etched. Teeth were subjected for scanning electron microscopy (SEM). Interfacial gap was observed in all groups with no significant difference. SEM observations revealed CA, CCA & DA were coarser than CM, CCM, DM and SiC. SEM of etched tooth surfaces revealed complete removal of amorphous smear layer in CA & CM, partial removal in CCA, CCM, DA & DM and no removal in SiC. Selecting an appropriate bur and its speed may not play an important role in bonding in terms of interfacial gap formation. Variable changes were observed in surface topography with different burs before and after acid etching. Key words:Surface topography, resin-tooth interface, interfacial gap, bonding.

Camel molar tooth enamel response to gamma rays using EPR spectroscopy.

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El-Faramawy, N A; El-Somany, I; Mansour, A; Maghraby, A M; Eissa, H; Wieser, A

2018-03-01

Tooth enamel samples from molar teeth of camel were prepared using a combined procedure of mechanical and chemical tooth treatment. Based on electron paramagnetic resonance (EPR) spectroscopy, the dose response of tooth enamel samples was examined and compared to that of human enamel. The EPR dose response of the tooth enamel samples was obtained through irradiation to gamma doses from 1 Gy up to 100 kGy. It was found that the radiation-induced EPR signal increased linearly with gamma dose for all studied tooth enamel samples, up to about 15 kGy. At higher doses, the dose response curve leveled off. The results revealed that the location of the native signal of camel tooth enamel was similar to that of enamel from human molars at 2.00644, but different from that of enamel from cows and goats. In addition, the peak-to-peak width (ΔH pp ) for human and camel molar teeth was similar. It was also found that the response of camel enamel to gamma radiation was 36% lower than that of human enamel. In conclusion, the results indicate the suitability of camel teeth for retrospective gamma dosimetry.

Camel molar tooth enamel response to gamma rays using EPR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

El-Faramawy, N.A.; El-Somany, I. [Ain Shams University, Physics Department, Faculty of Science, Cairo (Egypt); Mansour, A. [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt); Maghraby, A.M.; Eissa, H. [National Institute of Standards (NIS), Ionizing Radiation Metrology Laboratory, Giza (Egypt); Wieser, A. [Helmholtz Zentrum Muenchen-German Research Center for Environmental Health, Department of Radiation Sciences, Institute of Radiation Protection, Neuherberg (Germany)

2018-03-15

Tooth enamel samples from molar teeth of camel were prepared using a combined procedure of mechanical and chemical tooth treatment. Based on electron paramagnetic resonance (EPR) spectroscopy, the dose response of tooth enamel samples was examined and compared to that of human enamel. The EPR dose response of the tooth enamel samples was obtained through irradiation to gamma doses from 1 Gy up to 100 kGy. It was found that the radiation-induced EPR signal increased linearly with gamma dose for all studied tooth enamel samples, up to about 15 kGy. At higher doses, the dose response curve leveled off. The results revealed that the location of the native signal of camel tooth enamel was similar to that of enamel from human molars at 2.00644, but different from that of enamel from cows and goats. In addition, the peak-to-peak width (ΔH{sub pp}) for human and camel molar teeth was similar. It was also found that the response of camel enamel to gamma radiation was 36% lower than that of human enamel. In conclusion, the results indicate the suitability of camel teeth for retrospective gamma dosimetry. (orig.)

Tangible User Interfaces and Contrasting Cases as a Preparation for Future Learning

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Schneider, Bertrand; Blikstein, Paulo

2018-04-01

In this paper, we describe an experiment that compared the use of a Tangible User Interface (physical objects augmented with digital information) and a set of Contrasting Cases as a preparation for future learning. We carried out an experiment (N = 40) with a 2 × 2 design: the first factor compared traditional instruction ("Tell & Practice") with a constructivist activity designed using the Preparation for Future Learning framework (PFL). The second factor contrasted state-of-the-art PFL learning activity (i.e., students studying Contrasting Cases) with an interactive tabletop featuring digitally enhanced manipulatives. In agreement with prior work, we found that dyads of students who followed the PFL activity achieved significantly higher learning gains compared to their peers who followed a traditional "Tell & Practice" instruction (large effect size). A similar effect was found in favor of the interactive tabletop compared to the Contrasting Cases (small-to-moderate effect size). We discuss implications for designing socio-constructivist activities using new computer interfaces.

Biomaterial applications in neural therapy and repair

Institute of Scientific and Technical Information of China (English)

Harmanvir Ghuman; Michel Modo

2017-01-01

The use of biomaterials,such as hydrogels,as a scaffold to deliver cells and drugs is becoming increasingly common to treat neurological conditions,including stroke.With a limited intrinsic ability to regenerate after injury,innovative tissue engineering strategies have shown the potential of biomaterials in facilitating neural tissue regeneration and functional recovery.Using biomaterials can not only promote the survival and integration of transplanted cells in the existing circuitry,but also support controlled site specific delivery of therapeutic drugs.This review aims to provide the reader an understanding of the brain tissue microenvironment after injury,biomaterial criteria that support tissue repair,commonly used natural and synthetic biomaterials,benefits of incorporating cells and neurotrophic factors,as well as the potential of endogenous neurogenesis in repairing the injured brain.

Dose response of hydrazine - Deproteinated tooth enamel under blue light stimulation

International Nuclear Information System (INIS)

Yuece, Ulkue Rabia; Meric, Niyazi; Atakol, Orhan; Yasar, Fusun

2010-01-01

The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested.

Dose response of hydrazine - Deproteinated tooth enamel under blue light stimulation

Energy Technology Data Exchange (ETDEWEB)

Yuece, Ulkue Rabia, E-mail: ulkuyuce@hotmail.co [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Meric, Niyazi, E-mail: meric@ankara.edu.t [Ankara University, Faculty of Engineering, Department of Engineering Physics, 06100, Tandogan - Ankara (Turkey); Atakol, Orhan, E-mail: atakol@science.ankara.edu.t [Ankara University, Science Faculty, Department of Chemistry, 06100, Tandogan - Ankara (Turkey); Yasar, Fusun, E-mail: ab121310@adalet.gov.t [Council of Forensic Medicine, Ankara Branch, Ankara (Turkey)

2010-08-15

The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested.

Smart biomaterials

CERN Document Server

Ebara, Mitsuhiro; Narain, Ravin; Idota, Naokazu; Kim, Young-Jin; Hoffman, John M; Uto, Koichiro; Aoyagi, Takao

2014-01-01

This book surveys smart biomaterials, exploring the properties, mechanics and characterization of hydrogels, particles, assemblies, surfaces, fibers and conjugates. Reviews applications such as drug delivery, tissue engineering, bioseparation and more.

Biomaterials in myocardial tissue engineering

Science.gov (United States)

Reis, Lewis A.; Chiu, Loraine L. Y.; Feric, Nicole; Fu, Lara; Radisic, Milica

2016-01-01

Cardiovascular disease is the leading cause of death in the developed world, and as such there is a pressing need for treatment options. Cardiac tissue engineering emerged from the need to develop alternate sources and methods of replacing tissue damaged by cardiovascular diseases, as the ultimate treatment option for many who suffer from end-stage heart failure is a heart transplant. In this review we focus on biomaterial approaches to augment injured or impaired myocardium with specific emphasis on: the design criteria for these biomaterials; the types of scaffolds—composed of natural or synthetic biomaterials, or decellularized extracellular matrix—that have been used to develop cardiac patches and tissue models; methods to vascularize scaffolds and engineered tissue, and finally injectable biomaterials (hydrogels)designed for endogenous repair, exogenous repair or as bulking agents to maintain ventricular geometry post-infarct. The challenges facing the field and obstacles that must be overcome to develop truly clinically viable cardiac therapies are also discussed. PMID:25066525

3D Biomaterial Microarrays for Regenerative Medicine

DEFF Research Database (Denmark)

Gaharwar, Akhilesh K.; Arpanaei, Ayyoob; Andresen, Thomas Lars

2015-01-01

Three dimensional (3D) biomaterial microarrays hold enormous promise for regenerative medicine because of their ability to accelerate the design and fabrication of biomimetic materials. Such tissue-like biomaterials can provide an appropriate microenvironment for stimulating and controlling stem...... for tissue engineering and drug screening applications....... cell differentiation into tissue-specifi c lineages. The use of 3D biomaterial microarrays can, if optimized correctly, result in a more than 1000-fold reduction in biomaterials and cells consumption when engineering optimal materials combinations, which makes these miniaturized systems very attractive...

2010 Panel on the Biomaterials Grand Challenges

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Reichert, William “Monty”; Ratner, Buddy D.; Anderson, James; Coury, Art; Hoffman, Allan S.; Laurencin, Cato T.; Tirrell, David

2014-01-01

In 2009, the National Academy for Engineering issued the Grand Challenges for Engineering in the 21st Century comprised of 14 technical challenges that must be addressed to build a healthy, profitable, sustainable, and secure global community (http://www.engineeringchallenges.org). Although crucial, none of the NEA Grand Challenges adequately addressed the challenges that face the biomaterials community. In response to the NAE Grand Challenges, Monty Reichert of Duke University organized a panel entitled Grand Challenges in Biomaterials at the at the 2010 Society for Biomaterials Annual Meeting in Seattle. Six members of the National Academies—Buddy Ratner, James Anderson, Allan Hoffman, Art Coury, Cato Laurencin, and David Tirrell—were asked to propose a grand challenge to the audience that, if met, would significantly impact the future of biomaterials and medical devices. Successfully meeting these challenges will speed the 60-plus year transition from commodity, off-the-shelf biomaterials to bioengineered chemistries, and biomaterial devices that will significantly advance our ability to address patient needs and also to create new market opportunities. PMID:21171147

Biomaterials for tissue engineering applications.

Science.gov (United States)

Keane, Timothy J; Badylak, Stephen F

2014-06-01

With advancements in biological and engineering sciences, the definition of an ideal biomaterial has evolved over the past 50 years from a substance that is inert to one that has select bioinductive properties and integrates well with adjacent host tissue. Biomaterials are a fundamental component of tissue engineering, which aims to replace diseased, damaged, or missing tissue with reconstructed functional tissue. Most biomaterials are less than satisfactory for pediatric patients because the scaffold must adapt to the growth and development of the surrounding tissues and organs over time. The pediatric community, therefore, provides a distinct challenge for the tissue engineering community. Copyright © 2014. Published by Elsevier Inc.

Electrophoretic deposition of biomaterials

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Boccaccini, A. R.; Keim, S.; Ma, R.; Li, Y.; Zhitomirsky, I.

2010-01-01

Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields. PMID:20504802

Current concepts of regenerative biomaterials in implant dentistry

Directory of Open Access Journals (Sweden)

Annapurna Ahuja

2015-01-01

Full Text Available The primary objective of any implant system is to achieve firm fixation to the bone and this could be influenced by biomechanical as well as biomaterial selection. An array of materials is used in the replacement of missing teeth through implantation. The appropriate selection of biomaterials directly influences the clinical success and longevity of implants. Thus the clinician needs to have adequate knowledge of the various biomaterials and their properties for their judicious selection and application in his/her clinical practice. The recent materials such as bioceramics and composite biomaterials that are under consideration and investigation have a promising future. For optimal performance, implant biomaterials should have suitable mechanical strength, biocompatibility, and structural biostability in the physiological environment. This article reviews the various implant biomaterials and their ease of use in implant dentistry.

Biomaterials and medical devices a perspective from an emerging country

CERN Document Server

Hermawan, Hendra

2016-01-01

This book presents an introduction to biomaterials with the focus on the current development and future direction of biomaterials and medical devices research and development in Indonesia. It is the first biomaterials book written by selected academic and clinical experts experts on biomaterials and medical devices from various institutions and industries in Indonesia. It serves as a reference source for researchers starting new projects, for companies developing and marketing products and for governments setting new policies. Chapter one covers the fundamentals of biomaterials, types of biomaterials, their structures and properties and the relationship between them. Chapter two discusses unconventional processing of biomaterials including nano-hybrid organic-inorganic biomaterials. Chapter three addresses biocompatibility issues including in vitro cytotoxicity, genotoxicity, in vitro cell models, biocompatibility data and its related failure. Chapter four describes degradable biomaterial for medical implants...

Biomaterials for intervertebral disc regeneration and repair.

Science.gov (United States)

Bowles, Robert D; Setton, Lori A

2017-06-01

The intervertebral disc contributes to motion, weight bearing, and flexibility of the spine, but is susceptible to damage and morphological changes that contribute to pathology with age and injury. Engineering strategies that rely upon synthetic materials or composite implants that do not interface with the biological components of the disc have not met with widespread use or desirable outcomes in the treatment of intervertebral disc pathology. Here we review bioengineering advances to treat disc disorders, using cell-supplemented materials, or acellular, biologically based materials, that provide opportunity for cell-material interactions and remodeling in the treatment of intervertebral disc disorders. While a field still in early development, bioengineering-based strategies employing novel biomaterials are emerging as promising alternatives for clinical treatment of intervertebral disc disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tooth anatomy

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... whole tooth. This area is known as the "pulp" of the tooth. The jawbone is attached to ... JC, eds. Robbins and Cotran Pathologic Basis of Disease . 9th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ...

Advanced biomaterials and biodevices

CERN Document Server

Tiwari, Ashutosh

2014-01-01

Biomaterials are the fastest-growing emerging field of  biodevices. Design and development of biomaterials play a significant role in the diagnosis, treatment, and prevention of diseases. Recently, a variety of scaffolds/carriers have been evaluated for tissue regeneration, drug delivery, sensing and imaging.  Liposomes and microspheres have been developed for sustained delivery. Several anti-cancer drugs have been successfully formulated using biomaterial. The targeting of drugs to certain physiological sites has emerged as a promising tool in the treatment with improved drug bioavailability and reduction of dosing frequency. Biodevices-based targeting of drugs may improve the therapeutic success by limiting the adverse drug effects and resulting in more patient compliance and attaining a higher adherence level. Advanced biodevices hold merit as a drug carrier with high carrier capacity, feasibility of incorporation of both hydrophilic and hydrophobic substances, high stability, as well as the feasibility...

Can dead man tooth do tell tales? Tooth prints in forensic identification.

Science.gov (United States)

Christopher, Vineetha; Murthy, Sarvani; Ashwinirani, S R; Prasad, Kulkarni; Girish, Suragimath; Vinit, Shashikanth Patil

2017-01-01

We know that teeth trouble us a lot when we are alive, but they last longer for thousands of years even after we are dead. Teeth being the strongest and resistant structure are the most significant tool in forensic investigations. Patterns of enamel rod end on the tooth surface are known as tooth prints. This study is aimed to know whether these tooth prints can become a forensic tool in personal identification such as finger prints. A study has been targeted toward the same. In the present in-vivo study, acetate peel technique has been used to obtain the replica of enamel rod end patterns. Tooth prints of upper first premolars were recorded from 80 individuals after acid etching using cellulose acetate strips. Then, digital images of the tooth prints obtained at two different intervals were subjected to biometric conversion using Verifinger standard software development kit version 6.5 software followed by the use of Automated Fingerprint Identification System (AFIS) software for comparison of the tooth prints. Similarly, each individual's finger prints were also recorded and were subjected to the same software. Further, recordings of AFIS scores obtained from images were statistically analyzed using Cronbach's test. We observed that comparing two tooth prints taken from an individual at two intervals exhibited similarity in many cases, with wavy pattern tooth print being the predominant type. However, the same prints showed dissimilarity when compared with other individuals. We also found that most of the individuals with whorl pattern finger print showed wavy pattern tooth print and few loop type fingerprints showed linear pattern of tooth prints. Further more experiments on both tooth prints and finger prints are required in establishing an individual's identity.

Contamination of tooth-colored mineral trioxide aggregate used as a root-end filling material: a bacterial leakage study.

Science.gov (United States)

Montellano, Angela M; Schwartz, Scott A; Beeson, Thomas J

2006-05-01

This experiment investigated the ability of tooth-colored mineral trioxide aggregate (MTA) to maintain an apical seal in the presence of bacteria when contaminated with blood, saline or saliva. Ninety extracted human teeth with single canals were randomly placed into six groups of 15. Canals were prepared to size 50. The apical 3 mm of each root was removed and 3 mm root-end preparations were made with a #329 bur. Root-end preparations in groups 1 through 3 were filled with MTA after contamination with blood, saline, or saliva, respectively. In group 4, uncontaminated root-end preparations were filled with MTA. Groups 5 and 6 served as negative and positive controls. A tube/tooth assembly was utilized to suspend each root end in Trypticase Soy Broth (TSB). The access chambers were filled with Staphylococcus epidermidis. Positive growth over thirty days was demonstrated by turbidity of the TSB. Vitek analysis was used to confirm the presence of S. epidermidis in the positive samples. Data evaluation consisted of a chi(2) analysis (p < 0.05). Although all experimental groups demonstrated leakage, tooth-colored MTA contaminated with saliva (group 3) leaked significantly more than the uncontaminated tooth-colored MTA (group 4) (p = 0.028).

The case study of biomaterials and biominerals

Science.gov (United States)

Del Hoyo Martínez, Carmen

2013-04-01

The teaching of biomaterials as case study by on-line platform , susceptible to develop both individually and in groups, got different objectives proposed by the European Higher Education System, among which include: participate actively in the teaching-learning process by students, interpreting situations, adapt processes and solutions. It also improves oral and written communication, analytical skills and synthesis and also the ability to think critically. Biomaterials have their origin in biominerals. These are solid inorganic compounds of defined structure, consisting of molecular control mechanisms that operate in biological systems. Its main functions are: structural support, a reservoir of essential elements, sensors, mechanical protection and storage of toxic elements. Following the demand of materials compatible with certain functional systems of our body, developed biomaterials. Always meet the condition of biocompatibility. Should be tolerated by the body and do not provoke rejection. This involves a comprehensive study of physiological conditions and the anatomy of the body where a biomaterial has to be implemented. The possibility of generating new materials from biominerals has a major impact in medicine and other fields could reach as geology, construction, crystallography, etc. While the study of these issues is in its infancy today, can be viewed as an impact on the art and future technology. Planning case study that students would prepare its report for discussion in subgroups. Occurs then the pooling of individual analysis, joint case discussion and adoption by the subgroup of a consensual solution to the problem. The teacher as facilitator and coordinator of the final case analysis, sharing leads to group-wide class and said the unanimous decision reached by the students and gives his opinion on the resolution of the case. REFERENCES D.P. Ausubel. Psicología Educativa. Un punto de vista cognoscitivo. Trillas. Ed. 1983. E.W. Eisner. Procesos

Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target?

Science.gov (United States)

SPENCER, Paulette; Jonggu PARK, Qiang YE; MISRA, Anil; BOHATY, Brenda S.; SINGH, Viraj; PARTHASARATHY, Ranga; SENE, Fábio; de Paiva GONÇALVES, Sérgio Eduardo; LAURENCE, Jennifer

2013-01-01

Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface. PMID:24855586

Bioinspired phospholipid polymer biomaterials for making high performance artificial organs

Directory of Open Access Journals (Sweden)

K Ishihara

2000-01-01

Full Text Available Novel polymer biomaterials, which can be used in contact with blood, are prepared with strong inspiration from the surface structure of biomembrane. That is, the polymers with a phospholipid polar group in the side chain, 2-methacrylooyloxyethyl phosphorylcholine (MPC polymers were synthesized. The MPC polymers can inhibit surface-induced clot formation effectively, when they are in contact with blood even in the absence of an anticoagulant. This phenomenon was due to the reduction of plasma protein and suppression of denaturation of adsorbed proteins, that is the MPC polymers interact with blood components very mildly. As the molecular structure of the MPC polymer was easily designed by changing the monomer units and their composition, it could be applied to surface modification of artificial organs and biomedical devices for improving blood and tissue compatibility. Thus, the MPC polymers are useful polymer biomaterials for manufacturing high performance artificial organs and biomedical devices to provide safe medical treatments.

Supracolloidal Assemblies as Sacrificial Templates for Porous Silk-Based Biomaterials

Directory of Open Access Journals (Sweden)

John G. Hardy

2015-08-01

Full Text Available Tissues in the body are hierarchically structured composite materials with tissue-specific properties. Urea self-assembles via hydrogen bonding interactions into crystalline supracolloidal assemblies that can be used to impart macroscopic pores to polymer-based tissue scaffolds. In this communication, we explain the solvent interactions governing the solubility of urea and thereby the scope of compatible polymers. We also highlight the role of solvent interactions on the morphology of the resulting supracolloidal crystals. We elucidate the role of polymer-urea interactions on the morphology of the pores in the resulting biomaterials. Finally, we demonstrate that it is possible to use our urea templating methodology to prepare Bombyx mori silk protein-based biomaterials with pores that human dermal fibroblasts respond to by aligning with the long axis of the pores. This methodology has potential for application in a variety of different tissue engineering niches in which cell alignment is observed, including skin, bone, muscle and nerve.

Preparation of ZnO/Ag nanocomposite and coating on polymers for anti-infection biomaterial application.

Science.gov (United States)

Sadeghi, Babak

2014-01-24

ZnO/Ag nanocomposites coated with polyvinyl chloride (PVC) were prepared by chemical reduction method, for anti-infection biomaterial application. There is a growing interest in attempts in using biomolecular as the templates to grow inorganic nanocomposites in controlled morphology and structure. By optimizing the experiment conditions, we successfully fabricated high yield of ZnO/Ag nanocomposite with full coverage of high-density polyvinyl chloride (PVC) coating. More importantly, ZnO/Ag nanocomposites were shown to significantly inhibit the growth of Staphylococcus aureus in solution. It was further shown that ZnO/Ag nanocomposites induced thiol depletion that caused death of S. aureus. The coatings were fully characterized using techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Most importantly, compared to uncoated metals, the coatings on PVC promoted healthy antibacterial activity. Importantly, compared to ZnO-Ag -uncoated PVC, the ZnO/Ag nanocomposites coated was approximately triplet more effective in preventing bacteria attachment. The result of Thermal Gravimetric Analysis (TGA) indicates that, the ZnO/Ag nanocomposites are chemically stable in the temperature range from 50 to 900°C. This result, for the first time, demonstrates the potential of using ZnO/Ag nanocomposites as a coating material for numerous anti-bacterial applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Leveraging advances in biology to design biomaterials

Science.gov (United States)

Darnell, Max; Mooney, David J.

2017-12-01

Biomaterials have dramatically increased in functionality and complexity, allowing unprecedented control over the cells that interact with them. From these engineering advances arises the prospect of improved biomaterial-based therapies, yet practical constraints favour simplicity. Tools from the biology community are enabling high-resolution and high-throughput bioassays that, if incorporated into a biomaterial design framework, could help achieve unprecedented functionality while minimizing the complexity of designs by identifying the most important material parameters and biological outputs. However, to avoid data explosions and to effectively match the information content of an assay with the goal of the experiment, material screens and bioassays must be arranged in specific ways. By borrowing methods to design experiments and workflows from the bioprocess engineering community, we outline a framework for the incorporation of next-generation bioassays into biomaterials design to effectively optimize function while minimizing complexity. This framework can inspire biomaterials designs that maximize functionality and translatability.

Biomaterials for mediation of chemical and biological warfare agents.

Science.gov (United States)

Russell, Alan J; Berberich, Jason A; Drevon, Geraldine F; Koepsel, Richard R

2003-01-01

Recent events have emphasized the threat from chemical and biological warfare agents. Within the efforts to counter this threat, the biocatalytic destruction and sensing of chemical and biological weapons has become an important area of focus. The specificity and high catalytic rates of biological catalysts make them appropriate for decommissioning nerve agent stockpiles, counteracting nerve agent attacks, and remediation of organophosphate spills. A number of materials have been prepared containing enzymes for the destruction of and protection against organophosphate nerve agents and biological warfare agents. This review discusses the major chemical and biological warfare agents, decontamination methods, and biomaterials that have potential for the preparation of decontamination wipes, gas filters, column packings, protective wear, and self-decontaminating paints and coatings.

Designing Biomaterials for 3D Printing.

Science.gov (United States)

Guvendiren, Murat; Molde, Joseph; Soares, Rosane M D; Kohn, Joachim

2016-10-10

Three-dimensional (3D) printing is becoming an increasingly common technique to fabricate scaffolds and devices for tissue engineering applications. This is due to the potential of 3D printing to provide patient-specific designs, high structural complexity, rapid on-demand fabrication at a low-cost. One of the major bottlenecks that limits the widespread acceptance of 3D printing in biomanufacturing is the lack of diversity in "biomaterial inks". Printability of a biomaterial is determined by the printing technique. Although a wide range of biomaterial inks including polymers, ceramics, hydrogels and composites have been developed, the field is still struggling with processing of these materials into self-supporting devices with tunable mechanics, degradation, and bioactivity. This review aims to highlight the past and recent advances in biomaterial ink development and design considerations moving forward. A brief overview of 3D printing technologies focusing on ink design parameters is also included.

Tooth erosion awareness in a Brazilian dental school.

Science.gov (United States)

Hermont, Ana Paula; Oliveira, Patricia A D; Auad, Sheyla M

2011-12-01

The aim of this cross-sectional study was to assess awareness and attitudes related to tooth erosion among dental students, patients, and faculty members in a Brazilian dental school. Data were collected by means of a self-applied questionnaire that was distributed among 298 participants. The response rate was 89.6 percent. Chi-square and Fisher's exact tests were used for statistical analysis (perosion (72.9 percent), with lower percentages among the patients (perosion (p=0.004). Almost 30 percent of the students did not know if they had had a patient with erosion, and 73.1 percent reported they were not advised by their clinical supervisor to examine their patients for tooth erosion (p=0.138). Concerning the faculty, 23.6 percent of them along with 61.5 percent of the students did not feel prepared to diagnose the condition (perosion (89.6 percent). Knowledge about tooth erosion was not as widely evident as it should be in this sample, suggesting the need for better understanding and communication in this important area of oral health care.

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

Science.gov (United States)

Shi, Xinchang

2017-01-01

Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy dispersive spectrometer (EDS). The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1) Zn2+ absorbed on the surface of HA crystal and (2) Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM) results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization. PMID:29159178

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

Directory of Open Access Journals (Sweden)

Yi Li

2017-01-01

Full Text Available Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, and energy dispersive spectrometer (EDS. The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1 Zn2+ absorbed on the surface of HA crystal and (2 Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization.

EPR dosimetry with tooth enamel: A review

International Nuclear Information System (INIS)

Fattibene, Paola; Callens, Freddy

2010-01-01

When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed.

Polymer Brush Coatings Regulating Cell Behavior: Passive Interfaces Turn Into Active

NARCIS (Netherlands)

Moroni, Lorenzo; Klein Gunnewiek, Michel; Benetti, Edmondo Maria

2014-01-01

Material technology platforms able to modulate the communication with cells at the interface of biomaterials are being increasingly experimented on. Progress in the fabrication of supports is simultaneously introducing new surface modification strategies aimed at turning these supports from passive

Natural Tooth Pontic: An Instant Esthetic Option for Periodontally Compromised Teeth—A Case Series

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Rishi Raj

2016-01-01

Full Text Available Sudden tooth loss in the esthetic zone of the maxillary or mandibular anterior region can be due to trauma, periodontal disease, or endodontic failure. The treatment options for replacing the missing tooth can vary between removable prosthesis, tooth-supported prosthesis, and implant-supported prosthesis. Irrespective of the final treatment, the first line of management would be to provisionally restore the patient’s esthetic appearance at the earliest, while functionally stabilizing the compromised arch. Using the patient’s own natural tooth as a pontic offers the benefits of being the right size, shape, and color and provides exact repositioning in its original intraoral three-dimensional position. Additionally, using the patient’s platelet concentrate (platelet rich fibrin facilitates early wound healing and preservation of alveolar ridge shape following tooth extraction. The abutment teeth can also be preserved with minimal or no preparation, thus keeping the technique reversible, and can be completed at the chair side thereby avoiding laboratory costs. This helps the patient better tolerate the effect of tooth loss psychologically. The article describes a successful, immediate, and viable technique for rehabilitation of three different patients requiring replacement of a single periodontally compromised tooth in an esthetic region.

Creating biomaterials with spatially organized functionality.

Science.gov (United States)

Chow, Lesley W; Fischer, Jacob F

2016-05-01

Biomaterials for tissue engineering provide scaffolds to support cells and guide tissue regeneration. Despite significant advances in biomaterials design and fabrication techniques, engineered tissue constructs remain functionally inferior to native tissues. This is largely due to the inability to recreate the complex and dynamic hierarchical organization of the extracellular matrix components, which is intimately linked to a tissue's biological function. This review discusses current state-of-the-art strategies to control the spatial presentation of physical and biochemical cues within a biomaterial to recapitulate native tissue organization and function. © 2016 by the Society for Experimental Biology and Medicine.

Bioinspired surface functionalization of metallic biomaterials.

Science.gov (United States)

Su, Yingchao; Luo, Cheng; Zhang, Zhihui; Hermawan, Hendra; Zhu, Donghui; Huang, Jubin; Liang, Yunhong; Li, Guangyu; Ren, Luquan

2018-01-01

Metallic biomaterials are widely used for clinical applications because of their excellent mechanical properties and good durability. In order to provide essential biofunctionalities, surface functionalization is of particular interest and requirement in the development of high-performance metallic implants. Inspired by the functional surface of natural biological systems, many new designs and conceptions have recently emerged to create multifunctional surfaces with great potential for biomedical applications. This review firstly introduces the metallic biomaterials, important surface properties, and then elaborates some strategies on achieving the bioinspired surface functionalization for metallic biomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relationship between microhardness and fluorine contents on tooth enamel determined by PIGE analysis

International Nuclear Information System (INIS)

Ma, D.S.; Paik, D.I.; Park, D.Y.; Moon, H.S.; Chang, Y.I.; Kim, J.B.

1997-01-01

The remineralization effect of fluoride has been measured by surface microhardness on tooth enamel. The purpose of this study was to investigate the relationship between microhardness and fluorine concentration on tooth enamel. Twelve sound bovine enamel specimens were prepared and immersed in 0.05% NaF solution for 1, 3, 6, 24 and 36 hours, respectively. The concentration of fluorine in specimens were measured by PIGE analysis and surface microhardness of each specimen was measured by surface microhardness tester. Fluorine concentration was increased by immersing time. There was no change in microhardness of each specimen by fluorine content. The results of this study suggest that there was no relationship between the fluorine concentration and surface microhardness in sound tooth enamel. PIGE analysis can be used effectively to assess the remineralization effect of fluorine content in tooth enamel. (author)

Biomaterials with persistent growth factor gradients in vivo accelerate vascularized tissue formation.

Science.gov (United States)

Akar, Banu; Jiang, Bin; Somo, Sami I; Appel, Alyssa A; Larson, Jeffery C; Tichauer, Kenneth M; Brey, Eric M

2015-12-01

Gradients of soluble factors play an important role in many biological processes, including blood vessel assembly. Gradients can be studied in detail in vitro, but methods that enable the study of spatially distributed soluble factors and multi-cellular processes in vivo are limited. Here, we report on a method for the generation of persistent in vivo gradients of growth factors in a three-dimensional (3D) biomaterial system. Fibrin loaded porous poly (ethylene glycol) (PEG) scaffolds were generated using a particulate leaching method. Platelet derived growth factor BB (PDGF-BB) was encapsulated into poly (lactic-co-glycolic acid) (PLGA) microspheres which were placed distal to the tissue-material interface. PLGA provides sustained release of PDGF-BB and its diffusion through the porous structure results in gradient formation. Gradients within the scaffold were confirmed in vivo using near-infrared fluorescence imaging and gradients were present for more than 3 weeks. The diffusion of PDGF-BB was modeled and verified with in vivo imaging findings. The depth of tissue invasion and density of blood vessels formed in response to the biomaterial increased with magnitude of the gradient. This biomaterial system allows for generation of sustained growth factor gradients for the study of tissue response to gradients in vivo. Published by Elsevier Ltd.

In vivo biocompatibility of new nano-calcium-deficient hydroxyapatite/poly-amino acid complex biomaterials

Directory of Open Access Journals (Sweden)

Dai ZY

2015-10-01

Full Text Available Zhenyu Dai,1,2,* Yue Li,3,* Weizhong Lu,2,* Dianming Jiang,4 Hong Li,1 Yonggang Yan,1 Guoyu Lv,1 Aiping Yang1 1College of Physical Science and Technology, Sichuan University, Chengdu, 2Department of Orthopedics, Chongqing Hospital of Traditional Chinese Medicine, 3Department of Clinical Laboratory, the Second Affiliated Hospital, 4Department of Orthopedics, the First Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China *These authors contributed equally to this work Objective: To evaluate the compatibility of novel nano-calcium-deficient hydroxyapatite/poly-amino acid (n-CDHA/PAA complex biomaterials with muscle and bone tissue in an in vivo model.Methods: Thirty-two New Zealand white rabbits were used in this study. Biomaterials were surgically implanted into each rabbit in the back erector spinae and in tibia with induced defect. Polyethylene was implanted into rabbits in the control group and n-CDHA/PAA into those of the experimental group. Animals were examined at four different points in time: 2 weeks, 4 weeks, 12 weeks, and 24 weeks after surgery. They were euthanized after embolization. Back erector spinae muscles with the surgical implants were examined after hematoxylin and eosin (HE staining at these points in time. Tibia bones with the surgical implants were examined by X-ray and scanning electron microscopy (SEM at these points in time to evaluate the interface of the bone with the implanted biomaterials. Bone tissues were sectioned and subjected to HE, Masson, and toluidine blue staining.Results: HE staining of back erector spinae muscles at 4 weeks, 12 weeks, and 24 weeks after implantation of either n-CDHA/PAA or polyethylene showed disappearance of inflammation and normal arrangement in the peripheral tissue of implant biomaterials; no abnormal staining was observed. At 2 weeks after implantation, X-ray imaging of bone tissue samples in both experimental and control groups showed that

The challenges of treating a fused tooth

OpenAIRE

Baratto-Filho, Flares; Leonardi, Denise Piotto; Crozeta, Bruno Monguilhott; Baratto, Samantha Pugsley; Campos, Edson Alves; Tomazinho, Flavia Sens Fagundes; Deliberador, Tatiana Miranda

2012-01-01

This paper describes and discusses the multidisciplinary treatment involving a permanent maxillary lateral incisor fused to a supernumerary tooth, both presenting pulp necrosis and periapical lesion. A 15-year-old male patient sought treatment complaining of pain, swelling and mobility on the maxillary right lateral incisor. After clinical and radiographic examination, root canal preparation was performed according to the crown-down technique and a calcium hydroxide dressing was placed for 15...

Biomaterials in light amplification

Science.gov (United States)

Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

2017-03-01

Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

From supramolecular polymers to multi-component biomaterials.

Science.gov (United States)

Goor, Olga J G M; Hendrikse, Simone I S; Dankers, Patricia Y W; Meijer, E W

2017-10-30

The most striking and general property of the biological fibrous architectures in the extracellular matrix (ECM) is the strong and directional interaction between biologically active protein subunits. These fibers display rich dynamic behavior without losing their architectural integrity. The complexity of the ECM taking care of many essential properties has inspired synthetic chemists to mimic these properties in artificial one-dimensional fibrous structures with the aim to arrive at multi-component biomaterials. Due to the dynamic character required for interaction with natural tissue, supramolecular biomaterials are promising candidates for regenerative medicine. Depending on the application area, and thereby the design criteria of these multi-component fibrous biomaterials, they are used as elastomeric materials or hydrogel systems. Elastomeric materials are designed to have load bearing properties whereas hydrogels are proposed to support in vitro cell culture. Although the chemical structures and systems designed and studied today are rather simple compared to the complexity of the ECM, the first examples of these functional supramolecular biomaterials reaching the clinic have been reported. The basic concept of many of these supramolecular biomaterials is based on their ability to adapt to cell behavior as a result of dynamic non-covalent interactions. In this review, we show the translation of one-dimensional supramolecular polymers into multi-component functional biomaterials for regenerative medicine applications.

Metallic Biomaterials: Current Challenges and Opportunities

Directory of Open Access Journals (Sweden)

Karthika Prasad

2017-07-01

Full Text Available Metallic biomaterials are engineered systems designed to provide internal support to biological tissues and they are being used largely in joint replacements, dental implants, orthopaedic fixations and stents. Higher biomaterial usage is associated with an increased incidence of implant-related complications due to poor implant integration, inflammation, mechanical instability, necrosis and infections, and associated prolonged patient care, pain and loss of function. In this review, we will briefly explore major representatives of metallic biomaterials along with the key existing and emerging strategies for surface and bulk modification used to improve biointegration, mechanical strength and flexibility of biometals, and discuss their compatibility with the concept of 3D printing.

Evaluation of autogenous tooth transplantation for replacement of the missing or unrestorable mandibular molar tooth

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Wahiduj Jaman

2017-06-01

Full Text Available This study was undertaken to evaluate the functional and occlusal stability of autogenous tooth transplantation. A total of 30 patients were included. Among them, 21 participants received transplanted first molar and the remaining 9 received transplanted second molar. In all the cases, donor tooth were third molar. In each participant, extraction of un-restorable first or second molar tooth was performed which was then replaced by atrumatic extracted third molar tooth. Each third molar tooth was placed in the recipient extracted socket, followed by the evaluation of the occlusion and then stabilized with arch bar and ligature wire. Clinical follow-up evaluation was performed at 15 days, 3 and 12 months in respect to occlusal stability, tooth mobility and periodontal status. It was found that 23 transplanted tooth were successful and the remaining 7 tooth need long-term observation for the final outcome, which was statistically significant. It can be concluded that the autogenous tooth transplantation can replace missing tooth to ensure the preservation of function, aesthetic and to prevent bone resorption of the missing area of the jaw, which can lead to exceptional esthetic and functional outcome.

Polymeric biomaterials structure and function, v.1

CERN Document Server

Dumitriu, Severian

2013-01-01

Biomaterials have had a major impact on the practice of contemporary medicine and patient care. Growing into a major interdisciplinary effort involving chemists, biologists, engineers, and physicians, biomaterials development has enabled the creation of high-quality devices, implants, and drug carriers with greater biocompatibility and biofunctionality. The fast-paced research and increasing interest in finding new and improved biocompatible or biodegradable polymers has provided a wealth of new information, transforming this edition of Polymeric Biomaterials into a two-volume set. This volume

Assessment of performance parameters for EPR dosimetry with tooth enamel

International Nuclear Information System (INIS)

Wieser, A.; Fattibene, P.; Shishkina, E.A.; Ivanov, D.V.; De Coste, V.; Guettler, A.; Onori, S.

2008-01-01

In the framework of a comparison between three laboratories, electron paramagnetic resonance (EPR) signal-to-dose response curves were measured for sets of 30 tooth enamel samples and the variance of EPR measurements in dependence on absorbed dose was evaluated, in nine combinations of laboratory of sample preparation and EPR evaluation, respectively. As a test for benchmarking of EPR evaluation, the parameters 'critical dose' and 'limit of detection' were proposed as performance parameters following definitions from chemical-metrology, and a model function was suggested for analytical formulation of the dependence of the variance of EPR measurement on absorbed dose. First estimates of limits of detection by weighted and unweighted fitting resulted in the range 101-552 and 67-561 mGy, respectively, and were generally larger with weighted than with unweighted fitting. Indication was found for the influence of methodology of sample preparation and applied EPR measurement parameters on performance of EPR dosimetry with tooth enamel

Methodic of the gamma-rays absorbed dose measurements on tooth enamel

International Nuclear Information System (INIS)

Linev, S.V.; Muravskij, V.A.; Mashevskij, A.A.; Ugolev, I.I.

1997-01-01

The analysis of the metrological aspects of the tooth enamel ESR dosimetry has been done. The sample preparation and measurement methods have been elaborated. The methods have passed metrological certification. The methods include tabletting of the mixture of tooth enamel powder and MnO paramagnetic centres concentration additional standard, two loops of additional irradiation of samples by 1 Gy dose and ESR-spectra measurements, calculation of absorbed dose by maximum likelihood algorithm. The algorithm of dose calculation uses enamel spectrum model with axial anisotropic spin-Hamiltonian based on 126 spectra of enamel samples. The algorithm takes into account spectra of the empty cavity, the tube for a sample, the glue and MnO standard. Certificated ESR-station is based on the ESR-analyser PS-100X. ESR-station provides tooth enamel absorbed dose measurements from 0.05 to 0.25 Gy with error 35%, and from 0.25 to 3 Gy with error 20%. The set of tooth enamel absorbed dose standard samples has been created and certificated for the purposes of ESR-station testing and certification. The set consists of 12 tabletted samples of tooth enamel irradiated by doses from 0.05 to 4 Gy. (authors). 7 refs., 1 tab., 2 figs

Mathematical description of tooth flank surface of globoidal worm gear with straight axial tooth profile

Science.gov (United States)

Połowniak, Piotr; Sobolak, Mariusz

2017-12-01

In this article, a mathematical description of tooth flank surface of the globoidal worm and worm wheel generated by the hourglass worm hob with straight tooth axial profile is presented. The kinematic system of globoidal worm gear is shown. The equation of globoid helix and tooth axial profile of worm is derived to determine worm tooth surface. Based on the equation of meshing the contact lines are obtained. The mathematical description of globoidal worm wheel tooth flank is performed on the basis of contact lines and generating the tooth side by the extreme cutting edge of worm hob. The presented mathematical model of tooth flank of TA worm and worm wheel can be used e.g. to analyse the contact pattern of the gear.

Recent advances in engineering of tooth and tooth structures using postnatal dental cells

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Masaki J. Honda

2010-02-01

This review focuses on the performance of postnatal and adult dental cells that have been used for generating teeth. Their ability to contribute to tooth development was assessed in the omentum or in the tooth socket. Adult dental cells were limited in their potential owing to various parameters. From these results described, new approaches for regenerated teeth are proposed in this review. One strategy to replace teeth is tooth root engineering using tissue from postnatal teeth. Since the enamel organ epithelium disappears after tooth maturation, the epithelial rest cells of Malassez were evaluated to determine their capacity to generate enamel. From these results, it is suggested that erupted mature teeth have cell sources with the capacity to produce tooth root. The development of biological approaches for tooth root regeneration using postnatal dental cells is promising and remains one of the greatest challenges in the dental field in the years to come.

Biomaterials science an introduction to materials in medicine

CERN Document Server

Ratner, Buddy D; Lemons, Jack E; Yaszemski, Michael J; Yaszemski, Michael

2004-01-01

The second edition of this bestselling title provides the most up-to-date comprehensive review of all aspects of biomaterials science by providing a balanced, insightful approach to learning biomaterials. This reference integrates a historical perspective of materials engineering principles with biological interactions of biomaterials. Also provided within are regulatory and ethical issues in addition to future directions of the field, and a state-of-the-art update of medical and biotechnological applications. All aspects of biomaterials science are thoroughly addressed, from tissue engineering to cochlear prostheses and drug delivery systems. Over 80 contributors from academia, government and industry detail the principles of cell biology, immunology, and pathology. Focus within pertains to the clinical uses of biomaterials as components in implants, devices, and artificial organs. This reference also touches upon their uses in biotechnology as well as the characterization of the physical, chemical, biochemi...

Tooth - abnormal colors

Science.gov (United States)

... medlineplus.gov/ency/article/003065.htm Tooth - abnormal colors To use the sharing features on this page, please enable JavaScript. Abnormal tooth color is any color other than white to yellowish- ...

Wear Characteristics of Metallic Biomaterials: A Review

Science.gov (United States)

Hussein, Mohamed A.; Mohammed, Abdul Samad; Al-Aqeeli, Naser

2015-01-01

Metals are extensively used in a variety of applications in the medical field for internal support and biological tissue replacements, such as joint replacements, dental roots, orthopedic fixation, and stents. The metals and alloys that are primarily used in biomedical applications are stainless steels, Co alloys, and Ti alloys. The service period of a metallic biomaterial is determined by its abrasion and wear resistance. A reduction in the wear resistance of the implant results in the release of incompatible metal ions into the body that loosen the implant. In addition, several reactions may occur because of the deposition of wear debris in tissue. Therefore, developing biomaterials with high wear resistance is critical to ensuring a long life for the biomaterial. The aim of this work is to review the current state of knowledge of the wear of metallic biomaterials and how wear is affected by the material properties and conditions in terms of the type of alloys developed and fabrication processes. We also present a brief evaluation of various experimental test techniques and wear characterization techniques that are used to determine the tribological performance of metallic biomaterials.

Manufacturing Cell Therapies Using Engineered Biomaterials.

Science.gov (United States)

Abdeen, Amr A; Saha, Krishanu

2017-10-01

Emerging manufacturing processes to generate regenerative advanced therapies can involve extensive genomic and/or epigenomic manipulation of autologous or allogeneic cells. These cell engineering processes need to be carefully controlled and standardized to maximize safety and efficacy in clinical trials. Engineered biomaterials with smart and tunable properties offer an intriguing tool to provide or deliver cues to retain stemness, direct differentiation, promote reprogramming, manipulate the genome, or select functional phenotypes. This review discusses the use of engineered biomaterials to control human cell manufacturing. Future work exploiting engineered biomaterials has the potential to generate manufacturing processes that produce standardized cells with well-defined critical quality attributes appropriate for clinical testing. Copyright © 2017 Elsevier Ltd. All rights reserved.

To reduce the maximum stress and the stress shielding effect around a dental implant-bone interface using radial functionally graded biomaterials.

Science.gov (United States)

Asgharzadeh Shirazi, H; Ayatollahi, M R; Asnafi, A

2017-05-01

In a dental implant system, the value of stress and its distribution plays a pivotal role on the strength, durability and life of the implant-bone system. A typical implant consists of a Titanium core and a thin layer of biocompatible material such as the hydroxyapatite. This coating has a wide range of clinical applications in orthopedics and dentistry due to its biocompatibility and bioactivity characteristics. Low bonding strength and sudden variation of mechanical properties between the coating and the metallic layers are the main disadvantages of such common implants. To overcome these problems, a radial distributed functionally graded biomaterial (FGBM) was proposed in this paper and the effect of material property on the stress distribution around the dental implant-bone interface was studied. A three-dimensional finite element simulation was used to illustrate how the use of radial FGBM dental implant can reduce the maximum von Mises stress and, also the stress shielding effect in both the cortical and cancellous bones. The results, of course, give anybody an idea about optimized behaviors that can be achieved using such materials. The finite element solver was validated by familiar methods and the results were compared to previous works in the literature.

Properties and clinical relevance of osteoinductive biomaterials

NARCIS (Netherlands)

Habibovic, Pamela

2005-01-01

This thesis had two main goals: (¿) to investigate parameters influencing osteoinductive potential of biomaterials in order to unravel the mechanism underlying osteoinduction and (¿¿) to investigate performance of osteoinductive biomaterials orthotopically in order to get insight into their clinical

Additively manufactured metallic porous biomaterials based on minimal surfaces

DEFF Research Database (Denmark)

Bobbert, F. S. L.; Lietaert, K.; Eftekhari, Ali Akbar

2017-01-01

Porous biomaterials that simultaneously mimic the topological, mechanical, and mass transport properties of bone are in great demand but are rarely found in the literature. In this study, we rationally designed and additively manufactured (AM) porous metallic biomaterials based on four different...... of bone properties is feasible, biomaterials that could simultaneously mimic all or most of the relevant bone properties are rare. We used rational design and additive manufacturing to develop porous metallic biomaterials that exhibit an interesting combination of topological, mechanical, and mass...

Mechanics of Biological Tissues and Biomaterials: Current Trends

OpenAIRE

Amir A. Zadpoor

2015-01-01

Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address variou...

Inspiration and application in the evolution of biomaterials

OpenAIRE

Huebsch, Nathaniel; Mooney, David J.

2009-01-01

Biomaterials, traditionally defined as materials used in medical devices, have been used since antiquity, but recently their degree of sophistication has increased significantly. Biomaterials made today are routinely information rich and incorporate biologically active components derived from nature. In the future, biomaterials will assume an even greater role in medicine and will find use in a wide variety of non-medical applications through biologically inspired design and incorporation of ...

Inspiration and application in the evolution of biomaterials.

Science.gov (United States)

Huebsch, Nathaniel; Mooney, David J

2009-11-26

Biomaterials, traditionally defined as materials used in medical devices, have been used since antiquity, but recently their degree of sophistication has increased significantly. Biomaterials made today are routinely information rich and incorporate biologically active components derived from nature. In the future, biomaterials will assume an even greater role in medicine and will find use in a wide variety of non-medical applications through biologically inspired design and incorporation of dynamic behaviour.

Analysis of the interface zone between the glass ionomer and enamel and dentin of primary molars

Directory of Open Access Journals (Sweden)

Petrović Bojan B.

2008-01-01

Full Text Available Restoring carious teeth is one of the major dental treatment needs of young children. Conventional glassionomer materials are frequently used as filling materials in contemporary pediatric dentistry. The objective of this study was to evaluate the restorative and prophylactic efficacy of the newly marketed glass ionomer, Fuji Triage (GC, Tokyo, Japan, through morphological analysis of the interface zone between the material and the enamel and the dentin of primary molars and to determine the extent of the ion exchange at the interface zone. The sample consisted of 5 extracted intact first primary molars in which glassionomer had been used as filling material after standard class I cavity preparation. The material was placed according to the manufacturer's instructions and teeth were placed into dionised water prior to experiment. Six sections of each tooth had been examined using scanning electron microscopic and electron dispersive spectroscopic techniques (SEM/EDS. The parameters for evaluation included: morphological characteristics of the interface zone and the extent of the ion exchange between the material and the tooth structures Results were statistically analyzed using descriptive statistical methods. SEM/EDS analysis revealed the presence of the chemical bonding between the glass ionomer and the enamel and dentin, 5 and 15 μm in width, respectively. Ion exchange has not been detected in the enamel at the EDS sensitivity level. Strontium and fluor penetration has been detected in dentin. The ion exchange and chemical bonding formation justify the usage of the conventional glass ionomer materials for restorative procedures in primary molars.

Evolving the use of peptides as biomaterials components

Science.gov (United States)

Collier, Joel H.; Segura, Tatiana

2012-01-01

This manuscript is part of a debate on the statement that “the use of short synthetic adhesion peptides, like RGD, is the best approach in the design of biomaterials that guide cell behavior for regenerative medicine and tissue engineering”. We take the position that although there are some acknowledged disadvantages of using short peptide ligands within biomaterials, it is not necessary to discard the notion of using peptides within biomaterials entirely, but rather to reinvent and evolve their use. Peptides possess advantageous chemical definition, access to non-native chemistries, amenability to de novo design, and applicability within parallel approaches. Biomaterials development programs that require such aspects may benefit from a peptide-based strategy. PMID:21515167

Prosthetic clone and natural human tooth comparison by speckle interferometry

Science.gov (United States)

Slangen, Pierre; Corn, Stephane; Fages, Michel; Raynal, Jacques; Cuisinier, Frederic J. G.

2010-09-01

transducers to perform "4-buckets" phase shifting leading to phase variations during the compression test. In-plane displacement fields from speckle interferometry already showed very interesting data concerning the mechanical behaviour of teeth: the dentine-enamel junction (DEJ) and the glue junction have been shown including their interfacing function. Mechanical action of the tooth surrounding medium will also be discussed.

Applications of Biomaterials in Corneal Endothelial Tissue Engineering.

Science.gov (United States)

Wang, Tsung-Jen; Wang, I-Jong; Hu, Fung-Rong; Young, Tai-Horng

2016-11-01

When corneal endothelial cells (CECs) are diseased or injured, corneal endothelium can be surgically removed and tissue from a deceased donor can replace the original endothelium. Recent major innovations in corneal endothelial transplantation include replacement of diseased corneal endothelium with a thin lamellar posterior donor comprising a tissue-engineered endothelium carried or cultured on a thin substratum with an organized monolayer of cells. Repairing CECs is challenging because they have restricted proliferative ability in vivo. CECs can be cultivated in vitro and seeded successfully onto natural tissue materials or synthetic polymeric materials as grafts for transplantation. The optimal biomaterials for substrata of CEC growth are being investigated. Establishing a CEC culture system by tissue engineering might require multiple biomaterials to create a new scaffold that overcomes the disadvantages of single biomaterials. Chitosan and polycaprolactone are biodegradable biomaterials approved by the Food and Drug Administration that have superior biological, degradable, and mechanical properties for culturing substratum. We successfully hybridized chitosan and polycaprolactone into blended membranes, and demonstrated that CECs proliferated, developed normal morphology, and maintained their physiological phenotypes. The interaction between cells and biomaterials is important in tissue engineering of CECs. We are still optimizing culture methods for the maintenance and differentiation of CECs on biomaterials.

Collagen based Biomaterials from CLRI: An Inspiration from the ...

Indian Academy of Sciences (India)

Collagen-based Smart Biomaterials · Smart materials: As smart people see them · Some Biomaterials based on Collagen in Human Health care · Questions of Value to this presentation ... Collagen based biomaterials · COLLAGEN IN VISION CARE · Slide 57 · Bandage lens: A smart device · Work at CLRI: In summary.

Chitin fulfilling a biomaterials promise

CERN Document Server

Khor, Eugene

2001-01-01

The second edition of Chitin underscores the important factors for standardizing chitin processing and characterization. It captures the essential interplay between chitin's assets and limitations as a biomaterial, placing the past promises of chitin in perspective, addressing its present realities and offering insight into what is required to realize chitin's destiny (including its derivative, chitosan) as a biomaterial of the twenty-first century. This book is an ideal guide for both industrialists and researchers with a vested interest in commercializing chitin.An upd

[Cartilage tissue reconstruction by the polymer biomaterials--early macroscopic and histological results].

Science.gov (United States)

Scierski, Wojciech; Polok, Aleksandra; Namysłowski, Grzegorz; Nozyński, Jerzy; Turecka, Lucyna; Urbaniec, Natalia; Pamuła, Elzbieta

2009-09-01

The surgical treatment of large cartilage defects in the region of head and neck is often impossible because of the atrophy of surrounding tissues and lack of suitable material for reconstruction. In the surgical treatment many of methods and reconstructive materials have been used. For many years the suitable synthetic material for the cartilage defects reconstruction has been searched for. Was to evaluate two different biomaterials with proper mechanical and biological features for the cartilage replacement. Two type of biomaterials in this study were used: resorbable polymer - poly(L-lactide-co-glycolide) (PLG) acting as a supportive matrix. A thin layer of sodium hyaluronate (Hyal) was also deposited on the surface as well in the pore walls of PLG scaffolds in order to provide biologically active molecules promoting differentiation and regeneration of the tissue. The studies were performed on the 50 animals--rabbits divided into 2 groups. The animals were operated in the general anaesthesia. The incision was done along the edge of the rabbit's auricle. Perichondrium and cartilage of the auricle on the surface 4 x 3 cm were prepared. Subperichondrically 1 x 1 cm fragment of the cartilage was removed by the scissors. This fragment was then replaced by the biomaterials: PLG in first group of 25 rabbits and PLG-Hyal in second group 25 rabbits. The tissues were sutured with polyglycolide Safil 3-0. The animals obtained Enrofloxacin for three days after the operation. Then 1, 4 and 12 weeks after the surgery the animals were painlessly euthanized by an overdose of Morbital. Implants and surrounding tissues were excised and observed macroscopically and using an optical microscope. In all the observation periods we observed proper macroscopic healing process of biomaterials. We didn't stated strong inflammatory process and necrosis around the implanted biomaterials. The histological and macroscopic examinations indicated that both materials developed in this study have

Biomaterials and therapeutic applications

Science.gov (United States)

Ferraro, Angelo

2016-03-01

A number of organic and inorganic, synthetic or natural derived materials have been classified as not harmful for the human body and are appropriate for medical applications. These materials are usually named biomaterials since they are suitable for introduction into living human tissues of prosthesis, as well as for drug delivery, diagnosis, therapies, tissue regeneration and many other clinical applications. Recently, nanomaterials and bioabsorbable polymers have greatly enlarged the fields of application of biomaterials attracting much more the attention of the biomedical community. In this review paper I am going to discuss the most recent advances in the use of magnetic nanoparticles and biodegradable materials as new biomedical tools.

The Third International Intercomparison on EPR Tooth Dosimetry: Part 2, final analysis

International Nuclear Information System (INIS)

Wieser, A.; Debuyst, R.; Fattibene, P.; Meghzifene, A.; Onori, S.; Bayankin, S. N.; Brik, A.; Bugay, A.; Chumak, V.; Ciesielski, B.; Hoshi, M.; Imata, H.; Ivannikov, A.; Ivanov, D.; Junczewska, M.; Miyazawa, C.; Penkowski, M.; Pivovarov, S.; Romanyukha, A.; Romanyukha, L.; Schauer, D.; Scherbina, O.; Schultka, K.; Sholom, S.; Skvortsov, V.; Stepanenko, V.; Thomas, J. A.; Tielewuhan, E.; Toyoda, S.; Trompier, F.

2006-01-01

The objective of the Third International Intercomparison on EPR Tooth Dosimetry was to evaluate laboratories performing tooth enamel dosimetry <300 mGy. Final analysis of results included a correlation analysis between features of laboratory dose reconstruction protocols and dosimetry performance. Applicability of electron paramagnetic resonance (EPR) tooth dosimetry at low dose was shown at two applied dose levels of 79 and 176 mGy. Most (9 of 12) laboratories reported the dose to be within 50 mGy of the delivered dose of 79 mGy, and 10 of 12 laboratories reported the dose to be within 100 mGy of the delivered dose of 176 mGy. At the high-dose tested (704 mGy) agreement within 25% of the delivered dose was found in 10 laboratories. Features of EPR dose reconstruction protocols that affect dosimetry performance were found to be magnetic field modulation amplitude in EPR spectrum recording, EPR signal model in spectrum deconvolution and duration of latency period for tooth enamel samples after preparation. (authors)

Telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement.

Science.gov (United States)

Mladenović, Dragan; Tosić, Goran; Zivković, Dusan; Djindjić, Natasa; Mladenović, Lidija; Mladenović, Sanja; Marković, Ivana

2013-09-01

In the management of edentulous spaces, there is a permanent need of a dentist-prosthetician in charge to consult other specialists. Modern telemedicine, based on powerful computer and telecomunication systems, offers an adequate answer to these challenges, being able to transfer and obtain clinical data and consultation information over large distances. Using smartphone or a computer, the teleconsultant acces the system, downloads and review the data and photographs and gave suggestions. The system then enables direct, real time contact with the consultant, chat, or directs them to contact each other by phone. We presented telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement in 3 cases with different teleconsultation requirements: the first case for prosthetic rehabilitation of his upper teeth, the second one for prosthetic management of his partial edentulousness and "a growth on his gums" in the vestibular region of the frontal teeth and the third one for prosthetic management of total edentulousness of her upper jaw. We used the system of telemedicine in dentistry, established at the Faculty of Medicine in Kosovska Mitrovica. The operation was based on the computer application system XPA3 Online, computer networking and mobile smartphone network. All consultations were succefull with no need for further procedures in regional center. The use of a mobile smartphone has brought about the mobility and availability of teleconsultant specialists in an extent never seen before. Prostheticians are thus able to offer better service to their patients and improve the quality of management of partially or totally edentulous patients, especially in rural areas.

Heterogeneity of Scaffold Biomaterials in Tissue Engineering

Directory of Open Access Journals (Sweden)

Lauren Edgar

2016-05-01

Full Text Available Tissue engineering (TE offers a potential solution for the shortage of transplantable organs and the need for novel methods of tissue repair. Methods of TE have advanced significantly in recent years, but there are challenges to using engineered tissues and organs including but not limited to: biocompatibility, immunogenicity, biodegradation, and toxicity. Analysis of biomaterials used as scaffolds may, however, elucidate how TE can be enhanced. Ideally, biomaterials should closely mimic the characteristics of desired organ, their function and their in vivo environments. A review of biomaterials used in TE highlighted natural polymers, synthetic polymers, and decellularized organs as sources of scaffolding. Studies of discarded organs supported that decellularization offers a remedy to reducing waste of donor organs, but does not yet provide an effective solution to organ demand because it has shown varied success in vivo depending on organ complexity and physiological requirements. Review of polymer-based scaffolds revealed that a composite scaffold formed by copolymerization is more effective than single polymer scaffolds because it allows copolymers to offset disadvantages a single polymer may possess. Selection of biomaterials for use in TE is essential for transplant success. There is not, however, a singular biomaterial that is universally optimal.

Mechanics of Biological Tissues and Biomaterials: Current Trends

Directory of Open Access Journals (Sweden)

Amir A. Zadpoor

2015-07-01

Full Text Available Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address various topics within the general theme of “mechanics of biomaterials”. This editorial aims to present the context within which the studies of this Special Issue could be better understood. I, therefore, try to identify some of the most important research trends in the study of the mechanical behavior of biological tissues and biomaterials.

Innate Immunity and Biomaterials at the Nexus: Friends or Foes.

Science.gov (United States)

Christo, Susan N; Diener, Kerrilyn R; Bachhuka, Akash; Vasilev, Krasimir; Hayball, John D

2015-01-01

Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical "antigen." In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a "combined" immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

Innate Immunity and Biomaterials at the Nexus: Friends or Foes

Directory of Open Access Journals (Sweden)

Susan N. Christo

2015-01-01

Full Text Available Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

A new approach to the rationale discovery of polymeric biomaterials

Science.gov (United States)

Kohn, Joachim; Welsh, William J.; Knight, Doyle

2007-01-01

This paper attempts to illustrate both the need for new approaches to biomaterials discovery as well as the significant promise inherent in the use of combinatorial and computational design strategies. The key observation of this Leading Opinion Paper is that the biomaterials community has been slow to embrace advanced biomaterials discovery tools such as combinatorial methods, high throughput experimentation, and computational modeling in spite of the significant promise shown by these discovery tools in materials science, medicinal chemistry and the pharmaceutical industry. It seems that the complexity of living cells and their interactions with biomaterials has been a conceptual as well as a practical barrier to the use of advanced discovery tools in biomaterials science. However, with the continued increase in computer power, the goal of predicting the biological response of cells in contact with biomaterials surfaces is within reach. Once combinatorial synthesis, high throughput experimentation, and computational modeling are integrated into the biomaterials discovery process, a significant acceleration is possible in the pace of development of improved medical implants, tissue regeneration scaffolds, and gene/drug delivery systems. PMID:17644176

Biomimetic approaches to modulate cellular adhesion in biomaterials: A review.

Science.gov (United States)

Rahmany, Maria B; Van Dyke, Mark

2013-03-01

Natural extracellular matrix (ECM) proteins possess critical biological characteristics that provide a platform for cellular adhesion and activation of highly regulated signaling pathways. However, ECM-based biomaterials can have several limitations, including poor mechanical properties and risk of immunogenicity. Synthetic biomaterials alleviate the risks associated with natural biomaterials but often lack the robust biological activity necessary to direct cell function beyond initial adhesion. A thorough understanding of receptor-mediated cellular adhesion to the ECM and subsequent signaling activation has facilitated development of techniques that functionalize inert biomaterials to provide a biologically active surface. Here we review a range of approaches used to modify biomaterial surfaces for optimal receptor-mediated cell interactions, as well as provide insights into specific mechanisms of downstream signaling activation. In addition to a brief overview of integrin receptor-mediated cell function, so-called "biomimetic" techniques reviewed here include (i) surface modification of biomaterials with bioadhesive ECM macromolecules or specific binding motifs, (ii) nanoscale patterning of the materials and (iii) the use of "natural-like" biomaterials. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Examination of the foreign body response to biomaterials by nonlinear intravital microscopy.

Science.gov (United States)

Dondossola, Eleonora; Holzapfel, Boris M; Alexander, Stephanie; Filippini, Stefano; Hutmacher, Dietmar W; Friedl, Peter

2016-01-01

Implanted biomaterials often fail because they elicit a foreign body response (FBR) and concomitant fibrotic encapsulation. To design clinically relevant interference approaches, it is crucial to first examine the FBR mechanisms. Here, we report the development and validation of infrared-excited nonlinear microscopy to resolve the three-dimensional (3D) organization and fate of 3D-electrospun scaffolds implanted deep into the skin of mice, and the following step-wise FBR process. We observed that immigrating myeloid cells (predominantly macrophages of the M1 type) engaged and became immobilized along the scaffold/tissue interface, before forming multinucleated giant cells. Both macrophages and giant cells locally produced vascular endothelial growth factor (VEGF), which initiated and maintained an immature neovessel network, followed by formation of a dense collagen capsule 2-4 weeks post-implantation. Elimination of the macrophage/giant-cell compartment by clodronate and/or neutralization of VEGF by VEGF Trap significantly diminished giant-cell accumulation, neovascularization and fibrosis. Our findings identify macrophages and giant cells as incendiaries of the fibrotic encapsulation of engrafted biomaterials via VEGF release and neovascularization, and therefore as targets for therapy.

New biomaterials obtained with ionizing radiations

International Nuclear Information System (INIS)

Gaussens, G.

1982-01-01

In present-day surgery and medicine use is increasingly made of materials foreign to the organism in order to remedy a physiological defect either temporarily or permanently. These materials, known as ''biomaterials'', take widely varying forms: plastics, metals, cements, ceramics, etc. Biomaterials can be classified in accordance with their function: (a) Devices designed to be fully implanted in the human body in order to replace an anatomical structure, either temporarily or permanently, such as articular, vascular, mammary and osteosynthetic prostheses, etc.; (b) Devices having prolonged contact with mucous tissues, such as intra-uterine devices, contact lenses, etc.; (c) Extracorporeal devices designed to treat blood such as artificial kidneys, blood oxygenators, etc.; and (d) Biomaterials can also be taken to mean chemically inert, implantable materials designed to produce a continuous discharge of substances containing pharmacologically active molecules, such as contraceptive devices or ocular devices (for treating glaucoma). The two most important criteria for a biomaterial are those of biological compatibility and biological functionality. Techniques using ionizing radiation as an energy source provide an excellent tool for synthesizing or modifying the properties of plastics. The properties of polymers can be improved, new polymers can be synthesized without chemical additives (often the cause of incompatibility with tissue or blood) and without increased temperature, and polymerization can be induced in the solid state using deep-frozen monomers. Also, radiation-induced modifications in polymers can be applied to semi-finished or finished products. Examples are also given of marketed biomaterials that have been produced using radiation chemistry techniques

A conducive bioceramic/polymer composite biomaterial for diabetic wound healing.

Science.gov (United States)

Lv, Fang; Wang, Jie; Xu, Peng; Han, Yiming; Ma, Hongshi; Xu, He; Chen, Shijie; Chang, Jiang; Ke, Qinfei; Liu, Mingyao; Yi, Zhengfang; Wu, Chengtie

2017-09-15

Diabetic wound is a common complication of diabetes. Biomaterials offer great promise in inducing tissue regeneration for chronic wound healing. Herein, we reported a conducive Poly (caprolactone) (PCL)/gelatin nanofibrous composite scaffold containing silicate-based bioceramic particles (Nagelschmidtite, NAGEL, Ca 7 P 2 Si 2 O 16 ) for diabetic wound healing. NAGEL bioceramic particles were well distributed in the inner of PCL/gelatin nanofibers via co-electrospinning process and the Si ions maintained a sustained release from the composite scaffolds during the degradation process. The nanofibrous scaffolds significantly promoted the adhesion, proliferation and migration of human umbilical vein endothelial cells (HUVECs) and human keratinocytes (HaCaTs) in vitro. The in vivo study demonstrated that the scaffolds distinctly induced the angiogenesis, collagen deposition and re-epithelialization in the wound sites of diabetic mice model, as well as inhibited inflammation reaction. The mechanism for nanofibrous composite scaffolds accelerating diabetic wound healing is related to the activation of epithelial to mesenchymal transition (EMT) and endothelial to mesenchymal transition (EndMT) pathway in vivo and in vitro. Our results suggest that the released Si ions and nanofibrous structure of scaffolds have a synergetic effect on the improved efficiency of diabetic wound healing, paving the way to design functional biomaterials for tissue engineering and wound healing applications. In order to stimulate tissue regeneration for chronic wound healing, a new kind of conducive nanofibrous composite scaffold containing silicate-based bioceramic particles (Nagelschmidtite, NAGEL, Ca 7 P 2 Si 2 O 16 ) were prepared via co-electrospinning process. Biological assessments revealed that the NAGEL bioceramic particles could active epithelial to mesenchymal transition (EMT) and endothelial to mesenchymal transition (EndMT) pathway in vitro and in vivo. The new composite scaffold

Tooth apatite as a bone substitute: an experimental study and clinical applications

International Nuclear Information System (INIS)

Eun-Seok Kim; Pill-Hoon Choung

1999-01-01

The purpose of this study is to evaluate the usefulness of calcined teeth powder as biological apatite. The animal experiment was performed in 36 rabbits aging 6 weeks and weighing 1.6 kg. In experimental group, tooth apatite powder was implanted to 10 mm bony defects in diameter made on the cranial bone of the rabbits. As control groups, synthetic porous hydroxyapatite and resorbable type calcium carbonate were implanted to the defects of same size. Each group was sacrificed in 1, 2, 4, 6, 8, 12 weeks after the surgery. Specimens were prepared for decalcified samples and observed by a light microscope. And we also performed quantitative analysis of new bone formation through image analysis using computer. In clinical applications, we used tooth apatite alone or mixed with decalcified freeze-dried bone for reconstruction of bony defects in 15 patients undergone enucleation of cyst or ameloblastoma. The obtained results were as follows; 1) The powder of the calcined teeth was called as 'tooth apatite' and it seemed to have biocompatibility in rabbits and human. 2) In group of tooth apatite, after 4 weeks of operation, new bone directly bonded to the particles was observed. And in 12 weeks of it, new bone occupied most of the bony defects. In 6 weeks, resorption of the tooth apatite particles was observed. Thus the tooth apatite was regarded as one of resorbable apatite. 3) The group of tooth apatite showed new bone formation similar to the group of porous hydroxyapatite, but they were inferior to the group of resorbable calcium carbonate. 4) In clinical application, tooth apatite had biocompatibility and new bone formation was observed without any complication except for 1 case. So we think it is a useful bone substitute with osteoconductivity

Simple direct composite resin restoration on endodontically treated tooth: A case report

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Wahyuni Suci Dwiandhany

2016-06-01

Full Text Available Endodontically treated teeth generally havegreat structure loss so that the resistance to fracture is reduced. Therefore, the post-endodontic restoration design that covers the entire cusp (full cuspal coverage is necessary to increase the resistance of teeth to fracture. The aim of this case report is to present direct onlay restoration technique using composite resin material in non-vital tooth with chronic apical periodontitis. A 74-years-old male patient came to the clinic complaining of discomfort in the lower right posterior tooth related to eating since 1 week ago. Clinical examination revealed a large amalgam restoration on the second lower right molar, the tooth is negative to pulp sensitivity test, and tender to percussion. Radiographically, the tooth showed periapical radiolucency at distal and mesial root. The diagnosis of the tooth was chronic apical periodontitis. The treatment plan is a non-vital root canal treatment with multiple visit. Root canal preparation with rotary files (ProTaper Next, Dentsply, Germany was performed on the first visit and irrigated with NaOCl. On the next visit, during subjective examination, there was no pain complaints and the percussion test was negative so the obturation with a single cone technique can be done. On the final visit, direct onlay restoration using nano-hybrid composite resin material (Polofil NHT, Voco, Germany was performed. In conclusion, after 3 months follow up, the marginal integrity of the restoration remains intact and the tooth were functioned properly.

Hydration behaviors of calcium silicate-based biomaterials.

Science.gov (United States)

Lee, Yuan-Ling; Wang, Wen-Hsi; Lin, Feng-Huie; Lin, Chun-Pin

2017-06-01

Calcium silicate (CS)-based biomaterials, such as mineral trioxide aggregate (MTA), have become the most popular and convincing material used in restorative endodontic treatments. However, the commercially available CS-based biomaterials all contain different minor additives, which may affect their hydration behaviors and material properties. The purpose of this study was to evaluate the hydration behavior of CS-based biomaterials with/without minor additives. A novel CS-based biomaterial with a simplified composition, without mineral oxides as minor additives, was produced. The characteristics of this biomaterial during hydration were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectrometry. The hydration behaviors of commercially available gray and white MTAs with mineral oxide as minor additives were also evaluated for reference. For all three test materials, the XRD analysis revealed similar diffraction patterns after hydration, but MTAs presented a significant decrease in the intensities of Bi 2 O 3 -related peaks. SEM results demonstrated similar porous microstructures with some hexagonal and facetted crystals on the outer surfaces. In addition, compared to CS with a simplified composition, the FTIR plot indicated that hydrated MTAs with mineral oxides were better for the polymerization of calcium silicate hydrate (CSH), presenting Si-O band shifting to higher wave numbers, and contained more water crystals within CSH, presenting sharper bands for O-H bending. Mineral oxides might not result in significant changes in the crystal phases or microstructures during the hydration of CS-based biomaterials, but these compounds affected the hydration behavior at the molecular level. Copyright © 2016. Published by Elsevier B.V.

Biomaterials approaches to treating implant-associated osteomyelitis.

Science.gov (United States)

Inzana, Jason A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

2016-03-01

Orthopaedic devices are the most common surgical devices associated with implant-related infections and Staphylococcus aureus (S. aureus) is the most common causative pathogen in chronic bone infections (osteomyelitis). Treatment of these chronic bone infections often involves combinations of antibiotics given systemically and locally to the affected site via a biomaterial spacer. The gold standard biomaterial for local antibiotic delivery against osteomyelitis, poly(methyl methacrylate) (PMMA) bone cement, bears many limitations. Such shortcomings include limited antibiotic release, incompatibility with many antimicrobial agents, and the need for follow-up surgeries to remove the non-biodegradable cement before surgical reconstruction of the lost bone. Therefore, extensive research pursuits are targeting alternative, biodegradable materials to replace PMMA in osteomyelitis applications. Herein, we provide an overview of the primary clinical treatment strategies and emerging biodegradable materials that may be employed for management of implant-related osteomyelitis. We performed a systematic review of experimental biomaterials systems that have been evaluated for treating established S. aureus osteomyelitis in an animal model. Many experimental biomaterials were not decisively more efficacious for infection management than PMMA when delivering the same antibiotic. However, alternative biomaterials have reduced the number of follow-up surgeries, enhanced the antimicrobial efficacy by delivering agents that are incompatible with PMMA, and regenerated bone in an infected defect. Understanding the advantages, limitations, and potential for clinical translation of each biomaterial, along with the conditions under which it was evaluated (e.g. animal model), is critical for surgeons and researchers to navigate the plethora of options for local antibiotic delivery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Free Electron Laser Induced Forward Transfer Method of Biomaterial for Marking

Science.gov (United States)

Suzuki, Kaoru

Biomaterial, such as chitosan, poly lactic acid, etc., containing fluorescence agent was deposited onto biology hard tissue, such as teeth, fingernail of dog or cat, or sapphire substrate by free electron laser induced forward transfer method for direct write marking. Spin-coated biomaterial with fluorescence agent of rhodamin-6G or zinc phthalochyamine target on sapphire plate was ablated by free electron laser (resonance absorption wavelength of biomaterial : 3380 nm). The influence of the spin-coating film-forming temperature on hardness and adhesion strength of biomaterial is particularly studied. Effect of resonance excitation of biomaterial target by turning free electron laser was discussed to damage of biomaterial, rhodamin-6G or zinc phtarochyamine for direct write marking

Study on MCP-1 related to inflammation induced by biomaterials

International Nuclear Information System (INIS)

Ding Tingting; Sun Jiao; Zhang Ping

2009-01-01

The study of inflammation is important for understanding the reaction between biomaterials and the human body, in particular, the interaction between biomaterials and immune system. In the current study, rat macrophages were induced by multiple biomaterials with different biocompatibilities, including polyvinyl chloride (PVC) containing 8% of organic tin, a positive control material with cellular toxicity. Human umbilical vein endothelial cells (ECV-304), cultured with PRMI-1640, were detached from cells cultured with the supernatant of macrophages containing TNF-α and IL-1β because of stimulation by biomaterials. The cells were then treated with different biomaterials. Then both TNF-α and IL-1β in macrophages were detected by ELISA. Levels of monocyte chemoattractant protein-1 (MCP-1) were measured by RT-PCR. The results suggested that the expression of TNF-α and IL-1β was elevated by polytetrafluoroethylene (PTFE), polylactic-co-glycolic acid (PLGA) and American NPG alloy (p < 0.001). The level of MCP-1 cultured in supernatant of macrophages was higher than in PRMI-1640 with the same biomaterials. And the exposure to PTFE, PLGA and NPG resulted in the high expression of MCP-1 (p < 0.001) following cytokine stimulation. MCP-1 was also significantly expressed in β-tricalcium phosphate (β-TCP) and calcium phosphate cement samples (CPC) (p < 0.01). Thus, TNF-α, IL-1β and MCP-1 had played an important role in the immune reaction induced by biomaterials and there was a close relationship between the expression of cytokines and biomcompatibility of biomaterials. Furthermore, these data suggested that MCP-1 was regulated by TNF-α and IL-1β, and activated by both cytokines and biomaterials. The data further suggested that the expression of MCP-1 could be used as a marker to indicate the degree of immune reaction induced by biomaterials.

Biomaterials and tissue engineering in reconstructive surgery

Indian Academy of Sciences (India)

M. Senthilkumar (Newgen Imaging) 1461 1996 Oct 15 13:05:22

functional components are not generally considered to be biomaterials since by definition they are not in ... The requirements in these cases will be varied depending upon the stress transfer system within the ... few widely used biomaterials in clinical practice but rather a whole range of metals and alloys, ceramic and ...

3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

Science.gov (United States)

Asa'ad, Farah; Giannì, Aldo Bruno; Giannobile, William V.; Rasperini, Giulio

2016-01-01

To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. PMID:27366149

3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

Directory of Open Access Journals (Sweden)

Farah Asa’ad

2016-01-01

Full Text Available To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration.

Laminin active peptide/agarose matrices as multifunctional biomaterials for tissue engineering.

Science.gov (United States)

Yamada, Yuji; Hozumi, Kentaro; Aso, Akihiro; Hotta, Atsushi; Toma, Kazunori; Katagiri, Fumihiko; Kikkawa, Yamato; Nomizu, Motoyoshi

2012-06-01

Cell adhesive peptides derived from extracellular matrix components are potential candidates to afford bio-adhesiveness to cell culture scaffolds for tissue engineering. Previously, we covalently conjugated bioactive laminin peptides to polysaccharides, such as chitosan and alginate, and demonstrated their advantages as biomaterials. Here, we prepared functional polysaccharide matrices by mixing laminin active peptides and agarose gel. Several laminin peptide/agarose matrices showed cell attachment activity. In particular, peptide AG73 (RKRLQVQLSIRT)/agarose matrices promoted strong cell attachment and the cell behavior depended on the stiffness of agarose matrices. Fibroblasts formed spheroid structures on the soft AG73/agarose matrices while the cells formed a monolayer with elongated morphologies on the stiff matrices. On the stiff AG73/agarose matrices, neuronal cells extended neuritic processes and endothelial cells formed capillary-like networks. In addition, salivary gland cells formed acini-like structures on the soft matrices. These results suggest that the peptide/agarose matrices are useful for both two- and three-dimensional cell culture systems as a multifunctional biomaterial for tissue engineering. Copyright © 2012 Elsevier Ltd. All rights reserved.

PHOTOGRAMMETRY-BASED AUTOMATED MEASUREMENTS FOR TOOTH SHAPE AND OCCLUSION ANALYSIS

Directory of Open Access Journals (Sweden)

V. A. Knyaz

2016-06-01

Full Text Available Tooth measurements (odontometry are performed for various scientific and practical applications, including dentistry. Present-day techniques are being increasingly based on 3D model use that provides wider prospects in comparison to measurements on real objects: teeth or their plaster copies. The main advantages emerge through application of new measurement methods which provide the needed degree of non-invasiveness, precision, convenience and details. Tooth measurements have been always regarded as a time-consuming research, even more so with use of new methods due to their wider opportunities. This is where automation becomes essential for further development and implication of measurement techniques. In our research automation in obtaining 3D models and automation of measurements provided essential data that was analysed to suggest recommendations for tooth preparation – one of the most responsible clinical procedures in prosthetic dentistry – within a comparatively short period of time. The original photogrammetric 3D reconstruction system allows to generate 3D models of dental arches, reproduce their closure, or occlusion, and to perform a set of standard measurement in automated mode.

Photogrammetry-Based Automated Measurements for Tooth Shape and Occlusion Analysis

Science.gov (United States)

Knyaz, V. A.; Gaboutchian, A. V.

2016-06-01

Tooth measurements (odontometry) are performed for various scientific and practical applications, including dentistry. Present-day techniques are being increasingly based on 3D model use that provides wider prospects in comparison to measurements on real objects: teeth or their plaster copies. The main advantages emerge through application of new measurement methods which provide the needed degree of non-invasiveness, precision, convenience and details. Tooth measurements have been always regarded as a time-consuming research, even more so with use of new methods due to their wider opportunities. This is where automation becomes essential for further development and implication of measurement techniques. In our research automation in obtaining 3D models and automation of measurements provided essential data that was analysed to suggest recommendations for tooth preparation - one of the most responsible clinical procedures in prosthetic dentistry - within a comparatively short period of time. The original photogrammetric 3D reconstruction system allows to generate 3D models of dental arches, reproduce their closure, or occlusion, and to perform a set of standard measurement in automated mode.

Orthodontic Tooth Movement: A Historic Prospective.

Science.gov (United States)

Will, Leslie A

2016-01-01

The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement. In this theory, fluid from the vasculature, lymphatic system and intercellular spaces responds to the forces of tooth movement, damping the force and limiting movement. Bien and Baumrind expanded on this theory with their own studies in the 1960s. It is clear that both the pressure-tension and fluid flow concepts have merit, but considerable work needs to be done to ascertain the details so that tooth movement can be managed and controlled. © 2016 S. Karger AG, Basel.

Mechanically-competent and cytocompatible polycaprolactone-borophosphosilicate hybrid biomaterials.

Science.gov (United States)

Mondal, Dibakar; Dixon, S Jeffrey; Mequanint, Kibret; Rizkalla, Amin S

2017-11-01

Organic-inorganic class II hybrid materials have domain sizes at the molecular level and chemical bonding between the organic and inorganic phases. We have previously reported the synthesis of class II hybrid biomaterials from alkoxysilane-functionalized polycaprolactone (PCL) and borophosphosilicate (B 2 O 3 -P 2 O 5 -SiO 2 ) glass (BPSG) through a non-aqueous sol-gel process. In the present study, the mechanical properties and degradability of these PCL/BPSG hybrid biomaterials were studied and compared to those of their conventional composite counterparts. The compressive strength, modulus and toughness of the hybrid biomaterials were significantly greater compared to the conventional composites, likely due to the covalent bonding between the organic and inorganic phases. A hybrid biomaterial (50wt% PCL and 50wt% BPSG) exhibited compressive strength, modulus and toughness values of 32.2 ± 3.5MPa, 573 ± 85MPa and 1.54 ± 0.03MPa, respectively; whereas the values for composite of similar composition were 18.8 ± 1.6MPa, 275 ± 28MPa and 0.76 ± 0.03MPa, respectively. Degradation in phosphate-buffered saline was slower for hybrid biomaterials compared to their composite counterparts. Thus, these hybrid materials possess superior mechanical properties and more controlled degradation characteristics compared to their corresponding conventional composites. To assess in vitro cytocompatibility, MC3T3-E1 pre-osteoblastic cells were seeded onto the surfaces of hybrid biomaterials and polycaprolactone (control). Compared to polycaprolactone, cells on the hybrid material displayed enhanced spreading, focal adhesion formation, and cell number, consistent with excellent cytocompatibility. Thus, based on their mechanical properties, degradability and cytocompatibility, these novel biomaterials have potential for use as scaffolds in bone tissue engineering and related applications. Copyright © 2017. Published by Elsevier Ltd.

Biomaterials and mesenchymal stem cells for regenerative medicine.

Science.gov (United States)

Zippel, Nina; Schulze, Margit; Tobiasch, Edda

2010-01-01

The reconstruction of hard and soft tissues is a major challenge in regenerative medicine, since diseases or traumas are causing increasing numbers of tissue defects due to the aging of the population. Modern tissue engineering is increasingly using three-dimensional structured biomaterials in combination with stem cells as cell source, since mature cells are often not available in sufficient amounts or quality. Biomaterial scaffolds are developed that not only serve as cell carriers providing mechanical support, but actively influence cellular responses including cell attachment and proliferation. Chemical modifications such as the incorporation of chemotactic factors or cell adhesion molecules are examined for their ability to enhance tissue development successfully. E.g. growth factors have been investigated extensively as substances able to support cell growth, differentiation and angiogenesis. Thus, continuously new patents and studies are published, which are investigating the advantages and disadvantages of different biomaterials or cell types for the regeneration of specific tissues. This review focuses on biomaterials, including natural and synthetic polymers, ceramics and corresponding composites used as scaffold materials to support cell proliferation and differentiation for hard and soft tissues regeneration. In addition, the local delivery of drugs by scaffold biomaterials is discussed.

Rectocele repair using biomaterial augmentation: current documentation and clinical experience.

Science.gov (United States)

Altman, Daniel; Mellgren, Anders; Zetterström, Jan

2005-11-01

Although the etiology of rectocele remains debated, surgical innovations are currently promoted to improve anatomic outcome while avoiding dyspareunia and alleviating rectal emptying difficulties following rectocele surgery. Use of biomaterials in rectocele repair has become widespread in a short time, but the clinical documentation of their effectiveness and complications is limited. Medline and the Cochrane database were searched electronically from 1964 to May 2005 using the Pubmed and Ovid search engines. All English language publications including any of the search terms "rectocele," "implant," "mesh," "biomaterial," "prolapse," "synthetical," "pelvic floor," "biological," and "compatibility" were reviewed. This review outlines the basic principles for use of biomaterials in pelvic reconstructive surgery and provides a condensation of peer-reviewed articles describing clinical use of biomaterials in rectocele surgery. Historical and new concepts in rectocele surgery are discussed. Factors of importance for human in vivo biomaterial compatibility are presented together with current knowledge from clinical studies. Potential risks and problems associated with the use of biomaterials in rectocele and pelvic reconstructive surgery in general are described. Although use of biomaterials in rectocele and other pelvic organ prolapse surgery offers exciting possibilities, it raises treatment costs and may be associated with unknown and potentially severe complications at short and long term. Clinical benefits are currently unknown and need to be proven in clinical studies. Obstetricians & Gynecologists, Family Physicians After completion of this article, the reader should be able to explain that the objective of surgical treatment is to improve anatomic outcome and alleviate rectal emptying difficulties, describe the efficacy of biomaterials in rectocele repair, and summarize the potential risks and problems associated with use of biomaterials in rectocele and pelvic

Molecular Characterization of Macrophage-Biomaterial Interactions

OpenAIRE

Moore, Laura Beth; Kyriakides, Themis R.

2015-01-01

Implantation of biomaterials in vascularized tissues elicits the sequential engagement of molecular and cellular elements that constitute the foreign body response. Initial events include the non-specific adsorption of proteins to the biomaterial surface that render it adhesive for cells such as neutrophils and macrophages. The latter undergo unique activation and in some cases undergo cell-cell fusion to form foreign body giant cells that contribute to implant damage and fibrotic encapsulati...

Medical applications for biomaterials in Bolivia

CERN Document Server

Arias, Susan

2015-01-01

This book investigates the potential medical benefits natural biomaterials can offer in developing countries by analyzing the case of Bolivia. The book explores the medical and health related applications of Bolivian commodities: quinoa, barley, sugarcane, corn, sorghum and sunflower seeds. This book helps readers better understand some of the key health concerns facing countries like Bolivia and how naturally derived biomaterials and therapeutics could help substantially alleviate many of their problems.

Special Issue “Biomaterials and Bioprinting”

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Chee Kai Chua

2016-09-01

Full Text Available The emergence of bioprinting in recent years represents a marvellous advancement in 3D printing technology. It expands the range of 3D printable materials from the world of non-living materials into the world of living materials. Biomaterials play an important role in this paradigm shift. This Special Issue focuses on biomaterials and bioprinting and contains eight articles covering a number of recent topics in this emerging area.

Bone regeneration with biomaterials and active molecules delivery.

Science.gov (United States)

D' Este, Matteo; Eglin, David; Alini, Mauro; Kyllonen, Laura

2015-01-01

The combination of biomaterials and drug delivery strategies is a promising avenue towards improved synthetic bone substitutes. With the delivery of active species biomaterials can be provided with the bioactivity they still lack for improved bone regeneration. Recently, a lot of research efforts have been put towards this direction. Biomaterials for bone regeneration have been supplemented with small or biological molecules for improved osteoprogenitor cell recruitment, osteoinductivity, anabolic or angiogenic response, regulation of bone metabolism and others. The scope of this review is to summarize the most recent results in this field.

Radiation techniques in the formulation of synthetic biomaterials

International Nuclear Information System (INIS)

Kaetsu, Isao

1992-01-01

This chapter reviews the uses of various radiation techniques, such as radiation polymerization, grafting, and crosslinking, for the formulation of synthetic biomaterials. The biomaterials are divided into four categories: Biocompatible polymers, immobilized proteins, immobilized cells, and drug delivery systems. The recent achievements in each category are described, and the contributions of novel radiation techniques to this field are discussed. Work on drug delivery systemsis also reviewed, and the status of the practical applications of drug delivery systems for therapy is summarized. Future trends in the field of radiation-synthesized biomaterials are indicated. (orig.)

Mechanics of Biological Tissues and Biomaterials: Current Trends (editorial)

OpenAIRE

Zadpoor, A.A.

2015-01-01

Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the development of novel biomaterials for new fields of application, along with the emergence of advanced computational techniques. The current Special Issue is a collection of studies that address variou...

Telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement

Directory of Open Access Journals (Sweden)

Mladenović Dragan

2013-01-01

Full Text Available Introduction. In the management of edentulous spaces, there is a permanent need of a dentist-prosthetician in charge to consult other specialists. Modern telemedicine, based on powerful computer and telecomunication systems, offers an adequate answer to these challenges, being able to transfer and obtain clinical data and consultation information over large distances. Using smartphone or a computer, the teleconsultant acces the system, downloads and review the data and photographs and gave suggestions. The system then enables direct, real time contact with the consultant, chat, or directs them to contact each other by phone. Case report. We presented telemedicine consulting in the patient preparation and planning of prosthetic tooth replacement in 3 cases with different teleconsultation requirements: the first case for prosthetic rehabilitation of his upper teeth, the second one for prosthetic management of his partial edentulousness and “a growth on his gums” in the vestibular region of the frontal teeth and the third one for prosthetic management of total edentulousness of her upper jaw. We used the system of telemedicine in dentistry, established at the Faculty of Medicine in Kosovska Mitrovica. The operation was based on the computer application system XPA3 Online, computer networking and mobile smartphone network. All consultations were succefull with no need for further procedures in regional center. Conclusion. The use of a mobile smartphone has brought about the mobility and availability of teleconsultant specialists in an extent never seen before. Prostheticians are thus able to offer better service to their patients and improve the quality of management of partially or totally edentulous patients, especially in rural areas.

Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

Energy Technology Data Exchange (ETDEWEB)

Hou Aiqin, E-mail: aiqinhou@dhu.edu.c [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Chen Huawei [National Engineering Research Center for Dyeing and Finishing of Textiles, Donghua University, 3H, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China)

2010-03-15

The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

Preparation and characterization of silk/silica hybrid biomaterials by sol-gel crosslinking process

International Nuclear Information System (INIS)

Hou Aiqin; Chen Huawei

2010-01-01

The silk/silica hybrid biomaterials are synthesized by sol-gel crosslinking process. The chemical and morphological structures of silk/silica hybrids are investigated with micro-FT-IR spectra, X-ray diffraction, SEM, AFM, and DSC. The results show that the crosslinking reactions among inorganic nano-particles, fibroin and 2,4,6-tri[(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) take place during sol-gel process. The silk/silica hybrids form new molecular structures containing not only organic fibroin but also inorganic nano-silica particles. The inorganic particles are bounded to the fibroin through covalent bonds. The silk/silica hybrids can form excellent film with very even nanometer particles. The thermal properties of organic/inorganic hybrid are improved.

The pathology of the foreign body reaction against biomaterials.

Science.gov (United States)

Klopfleisch, R; Jung, F

2017-03-01

The healing process after implantation of biomaterials involves the interaction of many contributing factors. Besides their in vivo functionality, biomaterials also require characteristics that allow their integration into the designated tissue without eliciting an overshooting foreign body reaction (FBR). The targeted design of biomaterials with these features, thus, needs understanding of the molecular mechanisms of the FBR. Much effort has been put into research on the interaction of engineered materials and the host tissue. This elucidated many aspects of the five FBR phases, that is protein adsorption, acute inflammation, chronic inflammation, foreign body giant cell formation, and fibrous capsule formation. However, in practice, it is still difficult to predict the response against a newly designed biomaterial purely based on the knowledge of its physical-chemical surface features. This insufficient knowledge leads to a high number of factors potentially influencing the FBR, which have to be analyzed in complex animal experiments including appropriate data-based sample sizes. This review is focused on the current knowledge on the general mechanisms of the FBR against biomaterials and the influence of biomaterial surface topography and chemical and physical features on the quality and quantity of the reaction. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 927-940, 2017. © 2016 Wiley Periodicals, Inc.

Oligoaniline-based conductive biomaterials for tissue engineering.

Science.gov (United States)

Zarrintaj, Payam; Bakhshandeh, Behnaz; Saeb, Mohammad Reza; Sefat, Farshid; Rezaeian, Iraj; Ganjali, Mohammad Reza; Ramakrishna, Seeram; Mozafari, Masoud

2018-05-01

The science and engineering of biomaterials have improved the human life expectancy. Tissue engineering is one of the nascent strategies with an aim to fulfill this target. Tissue engineering scaffolds are one of the most significant aspects of the recent tissue repair strategies; hence, it is imperative to design biomimetic substrates with suitable features. Conductive substrates can ameliorate the cellular activity through enhancement of cellular signaling. Biocompatible polymers with conductivity can mimic the cells' niche in an appropriate manner. Bioconductive polymers based on aniline oligomers can potentially actualize this purpose because of their unique and tailoring properties. The aniline oligomers can be positioned within the molecular structure of other polymers, thus painter acting with the side groups of the main polymer or acting as a comonomer in their backbone. The conductivity of oligoaniline-based conductive biomaterials can be tailored to mimic the electrical and mechanical properties of targeted tissues/organs. These bioconductive substrates can be designed with high mechanical strength for hard tissues such as the bone and with high elasticity to be used for the cardiac tissue or can be synthesized in the form of injectable hydrogels, particles, and nanofibers for noninvasive implantation; these structures can be used for applications such as drug/gene delivery and extracellular biomimetic structures. It is expected that with progress in the fields of biomaterials and tissue engineering, more innovative constructs will be proposed in the near future. This review discusses the recent advancements in the use of oligoaniline-based conductive biomaterials for tissue engineering and regenerative medicine applications. The tissue engineering applications of aniline oligomers and their derivatives have recently attracted an increasing interest due to their electroactive and biodegradable properties. However, no reports have systematically reviewed

Biomaterials innovation bundling technologies and life

CERN Document Server

Styhre, A

2014-01-01

Rapid advances in the life sciences means that there is now a far more detailed understanding of biological systems on the cellular, molecular and genetic levels. Sited at the intersection between the life sciences, the engineering sciences and the design sciences, innovations in the biomaterials industry are expected to garner increasing attention and play a key role in future development. This book examines the biomaterials innovations taking place in corporations and in academic research settings today.

XPS - an essential tool in biomaterial research

International Nuclear Information System (INIS)

StJohn, H.A.W.; Greisser, H.J.

1999-01-01

Full text: Increased life expectancy has markedly enhanced the need for biomedical devices to combat life-threatening conditions (e.g., pacemakers, artificial blood vessels) or improve the quality of life (e.g., intraocular lenses, artificial ligaments, contact lenses). While the biomedical device industry has delivered remarkable benefits, many existing and emerging needs and applications are not adequately met with existing synthetic materials. Depending on the application, a biomaterial needs to meet a number of requirements to be 'biocompatible', such as appropriate mechanical properties, transparency, resistance to enzymatic degradation, and appropriate biological responses by the host environment. Surface science and surface analysis plays a key role in understanding and optimizing the molecular interfacial interactions between synthetic materials surfaces and biological media which lead to biological responses to implants. Many biological molecules such as proteins and lipids have surfactant activity and respond to interfaces on contact. Thus, an important part of achieving 'biocompatibility' is to produce an appropriate surface chemical composition that avoids undesirable biological consequences triggered by biological molecules recognizing a 'foreign' material interface. XPS surface analysis has proved uniquely suitable for studying several aspects of biomaterials. In order to interpret biological responses in terms of surface chemistry, it is essential that the surface be well characterized. However, for polymers this can be quite a challenge due to the inherent mobility of polymer chains. For instance, polyurethanes present a surface chemistry that differs from the 'bulk' chemistry. It is often desirable to utilize a bulk material with desirable bulk properties and improve its biocompatibility by the application of a surface modification or a thin coating. XPS has been used to verify the intended coating chemistry and the uniformity of thin coatings. On

XPS - an essential tool in biomaterial research

Energy Technology Data Exchange (ETDEWEB)

StJohn, H.A.W.; Greisser, H.J. [Commonwealth Scientific and Industrial Research Organization (CSIRO), Clayton, VIC (Australia). Molecular Science

1999-12-01

Full text: Increased life expectancy has markedly enhanced the need for biomedical devices to combat life-threatening conditions (e.g., pacemakers, artificial blood vessels) or improve the quality of life (e.g., intraocular lenses, artificial ligaments, contact lenses). While the biomedical device industry has delivered remarkable benefits, many existing and emerging needs and applications are not adequately met with existing synthetic materials. Depending on the application, a biomaterial needs to meet a number of requirements to be `biocompatible`, such as appropriate mechanical properties, transparency, resistance to enzymatic degradation, and appropriate biological responses by the host environment. Surface science and surface analysis plays a key role in understanding and optimizing the molecular interfacial interactions between synthetic materials surfaces and biological media which lead to biological responses to implants. Many biological molecules such as proteins and lipids have surfactant activity and respond to interfaces on contact. Thus, an important part of achieving `biocompatibility` is to produce an appropriate surface chemical composition that avoids undesirable biological consequences triggered by biological molecules recognizing a `foreign` material interface. XPS surface analysis has proved uniquely suitable for studying several aspects of biomaterials. In order to interpret biological responses in terms of surface chemistry, it is essential that the surface be well characterized. However, for polymers this can be quite a challenge due to the inherent mobility of polymer chains. For instance, polyurethanes present a surface chemistry that differs from the `bulk` chemistry. It is often desirable to utilize a bulk material with desirable bulk properties and improve its biocompatibility by the application of a surface modification or a thin coating. XPS has been used to verify the intended coating chemistry and the uniformity of thin coatings. On

Integrin-directed modulation of macrophage responses to biomaterials.

Science.gov (United States)

Zaveri, Toral D; Lewis, Jamal S; Dolgova, Natalia V; Clare-Salzler, Michael J; Keselowsky, Benjamin G

2014-04-01

Macrophages are the primary mediator of chronic inflammatory responses to implanted biomaterials, in cases when the material is either in particulate or bulk form. Chronic inflammation limits the performance and functional life of numerous implanted medical devices, and modulating macrophage interactions with biomaterials to mitigate this response would be beneficial. The integrin family of cell surface receptors mediates cell adhesion through binding to adhesive proteins nonspecifically adsorbed onto biomaterial surfaces. In this work, the roles of integrin Mac-1 (αMβ2) and RGD-binding integrins were investigated using model systems for both particulate and bulk biomaterials. Specifically, the macrophage functions of phagocytosis and inflammatory cytokine secretion in response to a model particulate material, polystyrene microparticles were investigated. Opsonizing proteins modulated microparticle uptake, and integrin Mac-1 and RGD-binding integrins were found to control microparticle uptake in an opsonin-dependent manner. The presence of adsorbed endotoxin did not affect microparticle uptake levels, but was required for the production of inflammatory cytokines in response to microparticles. Furthermore, it was demonstrated that integrin Mac-1 and RGD-binding integrins influence the in vivo foreign body response to a bulk biomaterial, subcutaneously implanted polyethylene terephthalate. A thinner foreign body capsule was formed when integrin Mac-1 was absent (~30% thinner) or when RGD-binding integrins were blocked by controlled release of a blocking peptide (~45% thinner). These findings indicate integrin Mac-1 and RGD-binding integrins are involved and may serve as therapeutic targets to mitigate macrophage inflammatory responses to both particulate and bulk biomaterials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Materiomics for Oral Disease Diagnostics and Personal Health Monitoring: Designer Biomaterials for the Next Generation Biomarkers

Science.gov (United States)

Zhang, Wenjun; Wang, Ming L.; Khalili, Sammy

2016-01-01

Abstract We live in exciting times for a new generation of biomarkers being enabled by advances in the design and use of biomaterials for medical and clinical applications, from nano- to macro-materials, and protein to tissue. Key challenges arise, however, due to both scientific complexity and compatibility of the interface of biology and engineered materials. The linking of mechanisms across scales by using a materials science approach to provide structure–process–property relations characterizes the emerging field of ‘materiomics,’ which offers enormous promise to provide the hitherto missing tools for biomaterial development for clinical diagnostics and the next generation biomarker applications towards personal health monitoring. Put in other words, the emerging field of materiomics represents an essentially systematic approach to the investigation of biological material systems, integrating natural functions and processes with traditional materials science perspectives. Here we outline how materiomics provides a game-changing technology platform for disruptive innovation in biomaterial science to enable the design of tailored and functional biomaterials—particularly, the design and screening of DNA aptamers for targeting biomarkers related to oral diseases and oral health monitoring. Rigorous and complementary computational modeling and experimental techniques will provide an efficient means to develop new clinical technologies in silico, greatly accelerating the translation of materiomics-driven oral health diagnostics from concept to practice in the clinic. PMID:26760957

[Assessment of tooth bleaching efficacy with spectrophotometer].

Science.gov (United States)

Zhu, Wenhao; Liu, Chang; Pan, Jie

2014-06-01

To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

Giant panda׳s tooth enamel: Structure, mechanical behavior and toughening mechanisms under indentation.

Science.gov (United States)

Weng, Z Y; Liu, Z Q; Ritchie, R O; Jiao, D; Li, D S; Wu, H L; Deng, L H; Zhang, Z F

2016-12-01

The giant panda׳s teeth possess remarkable load-bearing capacity and damage resistance for masticating bamboos. In this study, the hierarchical structure and mechanical behavior of the giant panda׳s tooth enamel were investigated under indentation. The effects of loading orientation and location on mechanical properties of the enamel were clarified and the evolution of damage in the enamel under increasing load evaluated. The nature of the damage, both at and beneath the indentation surfaces, and the underlying toughening mechanisms were explored. Indentation cracks invariably were seen to propagate along the internal interfaces, specifically the sheaths between enamel rods, and multiple extrinsic toughening mechanisms, e.g., crack deflection/twisting and uncracked-ligament bridging, were active to shield the tips of cracks from the applied stress. The giant panda׳s tooth enamel is analogous to human enamel in its mechanical properties, yet it has superior hardness and Young׳s modulus but inferior toughness as compared to the bamboo that pandas primarily feed on, highlighting the critical roles of the integration of underlying tissues in the entire tooth and the highly hydrated state of bamboo foods. Our objective is that this study can aid the understanding of the structure-mechanical property relations in the tooth enamel of mammals and further provide some insight on the food habits of the giant pandas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Asymmetric interfaces in Fe/Ag and Ag/Fe bilayers prepared by molecular beam evaporation

Energy Technology Data Exchange (ETDEWEB)

Tunyogi, A. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)]. E-mail: tunyogi@rmki.kfki.hu; Paszti, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Osvath, Z. [MTA Research Institute for Technical Physics and Materials Science, P.O. Box 49, H-1525 Budapest (Hungary); Tancziko, F. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Major, M. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary); Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics, P.O. Box 49, H-1525 Budapest (Hungary)

2006-08-15

Single layers of Fe and Ag, as well as Fe/Ag (iron deposited first) and Ag/Fe bilayers were prepared by molecular beam evaporation onto Si. The samples were investigated with backscattering spectrometry (BS) and atomic force microscopy (AFM). BS spectra of Fe/Ag and Ag/Fe indicate a significant difference at the interface. In the case of Fe/Ag the Ag peak has a long tail at the interface, while for Ag/Fe the interface is abrupt. The tail in the Fe/Ag spectrum is too large to be caused by double or plural scattering. According to AFM, the effect of surface roughness is also negligible. In spite of the fact that Fe and Ag are completely immiscible in equilibrium, this tail, however, suggests that some Ag is located in the Fe layer. After annealing, both samples show mixing between the two layers; this is much larger again for Fe/Ag.

Applications of biomaterials in corneal wound healing

Directory of Open Access Journals (Sweden)

I-Lun Tsai

2015-04-01

Full Text Available Disease affecting the cornea is a common cause of blindness worldwide. To date, the amniotic membrane (AM is the most widely used clinical method for cornea regeneration. However, donor-dependent differences in the AM may result in variable clinical outcomes. To overcome this issue, biomaterials are currently under investigation for corneal regeneration in vitro and in vivo. In this article, we highlight the recent advances in hydrogels, bioengineered prosthetic devices, contact lenses, and drug delivery systems for corneal regeneration. In clinical studies, the therapeutic effects of biomaterials, including fibrin and collagen-based hydrogels and silicone contact lenses, have been demonstrated in damaged cornea. The combination of cells and biomaterials may provide potential treatment in corneal wound healing in the future.

Immediate natural tooth pontic: A viable yet temporary prosthetic solution: A patient reported outcome

Directory of Open Access Journals (Sweden)

Sudhir Bhandari

2012-01-01

Conclusion: The concept of immediate pontic placement is surely a viable treatment option and promises an excellent transient esthetic solution for a lost tooth as well as enables good preparation of the extraction site for future prosthetic replacement.

Atmospheric-pressure-plasma-enhanced fabrication of nonfouling nanocoatings for 316 stainless steel biomaterial interfaces

Science.gov (United States)

Huang, Chun; Lin, Jin-He; Li, Chi-Heng; Yu, I.-Chun; Chen, Ting-Lun

2018-03-01

Atmospheric-pressure plasma, which was generated with electrical RF power, was fed to a tetramethyldisiloxane/argon gas mixture to prepare bioinert organosilicon coatings for 316 stainless steel. The surface characteristics of atmospheric-pressure-plasma-deposited nanocoatings were evaluated as a function of RF plasma power, precursor gas flow, and plasma working distance. After surface deposition, the chemical features, elemental compositions, and surface morphologies of the organosilicon nanocoatings were examined. It was found that RF plasma power and plasma working distance are the essential factors that affect the formation of plasma-deposited nanocoatings. Fourier transform infrared spectroscopy spectra indicate that the atmospheric-pressure-plasma-deposited nanocoatings formed showed inorganic features. Atomic force microscopy analysis showed the surface roughness variation of the plasma-deposited nanocoating at different RF plasma powers and plasma working distances during surface treatment. From these surface analyses, it was found that the plasma-deposited organosilicon nanocoatings under specific operational conditions have relatively hydrophobic and inorganic characteristics, which are essential for producing an anti-biofouling interface on 316 stainless steel. The experimental results also show that atmospheric-pressure-plasma-deposited nanocoatings have potential use as a cell-resistant layer on 316 stainless steel.

Overview of Tooth Disorders

Science.gov (United States)

... teeth using a thin resin cement. Bleaching, or tooth whitening, is a process used by dentists to lighten ... following? Damage to only the hard outer surface (enamel) of the tooth An incomplete fracture of a ...

Current Strategies in Cardiovascular Biomaterial Functionalization

Directory of Open Access Journals (Sweden)

Karla Lehle

2010-01-01

Full Text Available Prevention of the coagulation cascade and platelet activation is the foremost demand for biomaterials in contact with blood. In this review we describe the underlying mechanisms of these processes and offer the current state of antithrombotic strategies. We give an overview of methods to prevent protein and platelet adhesion, as well as techniques to immobilize biochemically active molecules on biomaterial surfaces. Finally, recent strategies in biofunctionalization by endothelial cell seeding as well as their possible clinical applications are discussed.

Novel Biomaterials Used in Medical 3D Printing Techniques

Directory of Open Access Journals (Sweden)

Karthik Tappa

2018-02-01

Full Text Available The success of an implant depends on the type of biomaterial used for its fabrication. An ideal implant material should be biocompatible, inert, mechanically durable, and easily moldable. The ability to build patient specific implants incorporated with bioactive drugs, cells, and proteins has made 3D printing technology revolutionary in medical and pharmaceutical fields. A vast variety of biomaterials are currently being used in medical 3D printing, including metals, ceramics, polymers, and composites. With continuous research and progress in biomaterials used in 3D printing, there has been a rapid growth in applications of 3D printing in manufacturing customized implants, prostheses, drug delivery devices, and 3D scaffolds for tissue engineering and regenerative medicine. The current review focuses on the novel biomaterials used in variety of 3D printing technologies for clinical applications. Most common types of medical 3D printing technologies, including fused deposition modeling, extrusion based bioprinting, inkjet, and polyjet printing techniques, their clinical applications, different types of biomaterials currently used by researchers, and key limitations are discussed in detail.

Novel Biomaterials Used in Medical 3D Printing Techniques.

Science.gov (United States)

Tappa, Karthik; Jammalamadaka, Udayabhanu

2018-02-07

The success of an implant depends on the type of biomaterial used for its fabrication. An ideal implant material should be biocompatible, inert, mechanically durable, and easily moldable. The ability to build patient specific implants incorporated with bioactive drugs, cells, and proteins has made 3D printing technology revolutionary in medical and pharmaceutical fields. A vast variety of biomaterials are currently being used in medical 3D printing, including metals, ceramics, polymers, and composites. With continuous research and progress in biomaterials used in 3D printing, there has been a rapid growth in applications of 3D printing in manufacturing customized implants, prostheses, drug delivery devices, and 3D scaffolds for tissue engineering and regenerative medicine. The current review focuses on the novel biomaterials used in variety of 3D printing technologies for clinical applications. Most common types of medical 3D printing technologies, including fused deposition modeling, extrusion based bioprinting, inkjet, and polyjet printing techniques, their clinical applications, different types of biomaterials currently used by researchers, and key limitations are discussed in detail.

[Materials/Biomaterials in Clinical Practice - a Short Review and Current Trends].

Science.gov (United States)

Bolle, T; Meyer, F; Walcher, F; Lohmann, C; Jockenhövel, S; Gries, T; Hoffmann, W

2017-04-01

Biomaterials play a major role in interventional medicine and surgery. However, the development of biomaterials is still in its early phases in spite of the huge progress made within the last decades. On the one hand, this is because our knowledge of the molecular and cellular processes associated with biomaterials is still increasing exponentially. On the other hand, a wide variety of advanced materials with highly interesting properties is being developed currently. This review provides a short introduction into the variety of materials in use as well as their application in interventional medicine and surgery. Also the importance of biomaterials for tissue engineering in the field of regenerative medicine and the functionalisation of biomaterials, including sterilisation methods are discussed. For the future, an even broader interdisciplinary scientific collaboration is necessary in order to develop novel biomaterials and facilitate their translation into clinical practice. Georg Thieme Verlag KG Stuttgart · New York.

Biomaterials and bone mechanotransduction

Science.gov (United States)

Sikavitsas, V. I.; Temenoff, J. S.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

2001-01-01

Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

Osteoinductive biomaterials: current knowledge of properties, experimental models and biological mechanisms

NARCIS (Netherlands)

Barradas, A.M.C.; Yuan, Huipin; van Blitterswijk, Clemens; Habibovic, Pamela

2010-01-01

In the past thirty years, a number of biomaterials have shown the ability to induce bone formation when implanted at heterotopic sites, an ability known as osteoinduction. Such biomaterials – osteoinductive biomaterials – hold great potential for the development of new therapies in bone

Dental Caries (Tooth Decay)

Science.gov (United States)

... Materials Contact Us Home Research Data & Statistics Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Dental Caries (Tooth Decay)

Science.gov (United States)

... Contact Us Home Research Data & Statistics Share Dental Caries (Tooth Decay) Dental caries (tooth decay) remains the most prevalent chronic disease ... adults, even though it is largely preventable. Although caries has significantly decreased for most Americans over the ...

Evaluation of protein immobilization capacity on various carbon nanotube embedded hydrogel biomaterials

Energy Technology Data Exchange (ETDEWEB)

Derkus, Burak, E-mail: burakderkus@gmail.com; Emregul, Kaan Cebesoy; Emregul, Emel

2015-11-01

This study investigates effective immobilization of proteins, an important procedure in many fields of bioengineering and medicine, using various biomaterials. Gelatin, alginate and chitosan were chosen as polymeric carriers, and applied in both their composites and nanocomposite forms in combination with carbon nanotubes (CNTs). The prepared nano/composite structures were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TG) and contact angle analysis (CA). Electrochemical impedance spectroscopy analysis revealed gelatin composites in general to exhibit better immobilization performance relative to the native gelatin which can be attributed to enhanced film morphologies of the composite structures. Moreover, superior immobilization efficiencies were obtained with the addition of carbon nanotubes, due to their conducting and surface enhancement features, especially in the gelatin–chitosan structures due to the presence of structural active groups. - Highlights: • Various nanocomposite biomaterials were developed for efficient immobilization of proteins. • CNTs enhance the immobilization efficiency owing to their conducting and surface enhancement features. • Gelatin–chitosan–CNTs structure is promising immobilization matrix thanks to its effective CNTs binding capacity.

Analysis of the Osteogenic Effects of Biomaterials Using Numerical Simulation.

Science.gov (United States)

Wang, Lan; Zhang, Jie; Zhang, Wen; Yang, Hui-Lin; Luo, Zong-Ping

2017-01-01

We describe the development of an optimization algorithm for determining the effects of different properties of implanted biomaterials on bone growth, based on the finite element method and bone self-optimization theory. The rate of osteogenesis and the bone density distribution of the implanted biomaterials were quantitatively analyzed. Using the proposed algorithm, a femur with implanted biodegradable biomaterials was simulated, and the osteogenic effects of different materials were measured. Simulation experiments mainly considered variations in the elastic modulus (20-3000 MPa) and degradation period (10, 20, and 30 days) for the implanted biodegradable biomaterials. Based on our algorithm, the osteogenic effects of the materials were optimal when the elastic modulus was 1000 MPa and the degradation period was 20 days. The simulation results for the metaphyseal bone of the left femur were compared with micro-CT images from rats with defective femurs, which demonstrated the effectiveness of the algorithm. The proposed method was effective for optimization of the bone structure and is expected to have applications in matching appropriate bones and biomaterials. These results provide important insights into the development of implanted biomaterials for both clinical medicine and materials science.

Analysis of the Osteogenic Effects of Biomaterials Using Numerical Simulation

Science.gov (United States)

Zhang, Jie; Zhang, Wen; Yang, Hui-Lin

2017-01-01

We describe the development of an optimization algorithm for determining the effects of different properties of implanted biomaterials on bone growth, based on the finite element method and bone self-optimization theory. The rate of osteogenesis and the bone density distribution of the implanted biomaterials were quantitatively analyzed. Using the proposed algorithm, a femur with implanted biodegradable biomaterials was simulated, and the osteogenic effects of different materials were measured. Simulation experiments mainly considered variations in the elastic modulus (20–3000 MPa) and degradation period (10, 20, and 30 days) for the implanted biodegradable biomaterials. Based on our algorithm, the osteogenic effects of the materials were optimal when the elastic modulus was 1000 MPa and the degradation period was 20 days. The simulation results for the metaphyseal bone of the left femur were compared with micro-CT images from rats with defective femurs, which demonstrated the effectiveness of the algorithm. The proposed method was effective for optimization of the bone structure and is expected to have applications in matching appropriate bones and biomaterials. These results provide important insights into the development of implanted biomaterials for both clinical medicine and materials science. PMID:28116309

Thromboelastometric and platelet responses to silk biomaterials.

Science.gov (United States)

Kundu, Banani; Schlimp, Christoph J; Nürnberger, Sylvia; Redl, Heinz; Kundu, S C

2014-05-13

Silkworm's silk is natural biopolymer with unique properties including mechanical robustness, all aqueous base processing and ease in fabrication into different multifunctional templates. Additionally, the nonmulberry silks have cell adhesion promoting tri-peptide (RGD) sequences, which make it an immensely potential platform for regenerative medicine. The compatibility of nonmulberry silk with human blood is still elusive; thereby, restricts its further application as implants. The present study, therefore, evaluate the haematocompatibility of silk biomaterials in terms of platelet interaction after exposure to nonmulberry silk of Antheraea mylitta using thromboelastometry (ROTEM). The mulberry silk of Bombyx mori and clinically used Uni-Graft W biomaterial serve as references. Shortened clotting time, clot formation times as well as enhanced clot strength indicate the platelet mediated activation of blood coagulation cascade by tested biomaterials; which is comparable to controls.

Innate Immunity and Biomaterials at the Nexus: Friends or Foes

OpenAIRE

Christo, Susan N.; Diener, Kerrilyn R.; Bachhuka, Akash; Vasilev, Krasimir; Hayball, John D.

2015-01-01

Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestati...

The influence of biomaterials on endothelial cell thrombogenicity

Science.gov (United States)

McGuigan, Alison P.; Sefton, Michael V.

2007-01-01

Driven by tissue engineering and regenerative medicine, endothelial cells are being used in combination with biomaterials in a number of applications for the purpose of improving blood compatibility and host integration. Endothelialized vascular grafts are beginning to be used clinically with some success in some centers, while endothelial seeding is being explored as a means of creating a vasculature within engineered tissues. The underlying assumption of this strategy is that when cultured on artificial biomaterials, a confluent layer of endothelial cells maintain their non-thrombogenic phenotype. In this review the existing knowledge base of endothelial cell thrombogenicity cultured on a number of different biomaterials is summarized. The importance of selecting appropriate endpoint measures that are most reflective of overall surface thrombogenicity is the focus of this review. Endothelial cells inhibit thrombosis through three interconnected regulatory systems (1) the coagulation cascade (2) the cellular components of the blood such as leukocytes and platelets and (3) the complement cascade, and also through effects on fibrinolysis and vascular tone, the latter which influences blood flow. Thus, in order to demonstrate the thromobgenic benefit of seeding a biomaterial with EC, the conditions under which EC surfaces are more likely to exhibit lower thrombogenicity than unseeded biomaterial surfaces need to be consistent with the experimental context. The endpoints selected should be appropriate for the dominant thrombotic process that occurs under the given experimental conditions. PMID:17316788

Fluoridation and tooth wear in Irish adults.

LENUS (Irish Health Repository)

Burke, F M

2010-10-01

The aim of this study was to determine the prevalence of tooth wear in adults in Ireland and its relationship with water fluoridation. The National Survey of Adult Oral Health was conducted in 2000\\/2001. Tooth wear was determined using a partial mouth examination assessing the upper and lower anterior teeth. A total of 2456 subjects were examined. In this survey, increasing levels and severity of tooth wear were associated with ageing. Men were more affected by tooth wear and were more likely to be affected by severe tooth wear than women. It was found that age, and gender were significant predictors of tooth wear (P < 0.01). Overall, there was no significant relationship between fluoridation and tooth wear in this study.

Injectable silk-based biomaterials for cervical tissue augmentation: an in vitro study.

Science.gov (United States)

Brown, Joseph E; Partlow, Benjamin P; Berman, Alison M; House, Michael D; Kaplan, David L

2016-01-01

Cerclage therapy is an important treatment option for preterm birth prevention. Several patient populations benefit from cerclage therapy including patients with a classic history of cervical insufficiency; patients who present with advanced cervical dilation prior to viability; and patients with a history of preterm birth and cervical shortening. Although cerclage is an effective treatment option in some patients, it can be associated with limited efficacy and procedure complications. Development of an alternative to cerclage therapy would be an important clinical development. Here we report on an injectable, silk protein-based biomaterial for cervical tissue augmentation. The rationale for the development of an injectable biomaterial is to restore the native properties of cervical tissue. While cerclage provides support to the tissue, it does not address excessive tissue softening, which is a central feature of the pathogenesis of cervical insufficiency. Silk protein-based hydrogels, which are biocompatible and naturally degrade in vivo, are suggested as a platform for restoring the native properties of cervical tissue and improving cervical function. We sought to study the properties of an injectable, silk-based biomaterial for potential use as an alternative treatment for cervical insufficiency. These biomaterials were evaluated for mechanical tunability, biocompatibility, facile injection, and in vitro degradation. Silk protein solutions were cross-linked by an enzyme catalyzed reaction to form elastic biomaterials. Biomaterials were formulated to match the native physical properties of cervical tissue during pregnancy. The cell compatibility of the materials was assessed in vitro using cervical fibroblasts, and biodegradation was evaluated using concentrated protease solution. Tissue augmentation or bulking was demonstrated using human cervical tissue from nonpregnant hysterectomy specimens. Mechanical compression tests measured the tissue stiffness as a

Soft contact lens biomaterials from bioinspired phospholipid polymers.

Science.gov (United States)

Goda, Tatsuro; Ishihara, Kazuhiko

2006-03-01

Soft contact lens (SCL) biomaterials originated from the discovery of a poly(2-hydroxyethyl methacrylate) (poly[HEMA])-based hydrogel in 1960. Incorporation of hydrophilic polymers into poly(HEMA) hydrogels was performed in the 1970-1980s, which brought an increase in the equilibrium water content, leading to an enhancement of the oxygen permeability. Nowadays, the poly(HEMA)-based hydrogels have been applied in disposable SCL. At the same time, high oxygen-permeable silicone hydrogels were produced, which made it possible to continually wear SCL. Recently, numerous trials for improving the water wettability of silicone hydrogels have been performed. However, little attention has been paid to improving their anti-biofouling properties and biocompatibility. Since biomimetic phospholipid polymers possess excellent anti-biofouling properties and biocompatibility they have the potential to play a valuable role in the surface modification of the silicone hydrogel. The representative phospholipid polymers containing a 2-methacryloyloxyethyl phosphorylcholine (MPC) unit suppressed nonspecific protein adsorption, increased cell compatibility and contributed to blood compatible biomaterials. The MPC polymer coating on the silicone hydrogel improved its water wettability and biocompatibility, while maintaining high oxygen permeability compared with the original silicone hydrogel. Furthermore, the newly prepared phospholipid-type intermolecular crosslinker made it possible to synthesize a 100% phospholipid polymer hydrogel that can enhance the anti-biofouling properties and biocompatibility. In this review, the authors discuss how polymer hydrogels should be designed in order to obtain a biocompatible SCL and future perspectives.

Biocompatibility of Subcutaneously Implanted Plant-Derived Cellulose Biomaterials.

Science.gov (United States)

Modulevsky, Daniel J; Cuerrier, Charles M; Pelling, Andrew E

2016-01-01

There is intense interest in developing novel biomaterials which support the invasion and proliferation of living cells for potential applications in tissue engineering and regenerative medicine. Decellularization of existing tissues have formed the basis of one major approach to producing 3D scaffolds for such purposes. In this study, we utilize the native hypanthium tissue of apples and a simple preparation methodology to create implantable cellulose scaffolds. To examine biocompatibility, scaffolds were subcutaneously implanted in wild-type, immunocompetent mice (males and females; 6-9 weeks old). Following the implantation, the scaffolds were resected at 1, 4 and 8 weeks and processed for histological analysis (H&E, Masson's Trichrome, anti-CD31 and anti-CD45 antibodies). Histological analysis revealed a characteristic foreign body response to the scaffold 1 week post-implantation. However, the immune response was observed to gradually disappear by 8 weeks post-implantation. By 8 weeks, there was no immune response in the surrounding dermis tissue and active fibroblast migration within the cellulose scaffold was observed. This was concomitant with the deposition of a new collagen extracellular matrix. Furthermore, active blood vessel formation within the scaffold was observed throughout the period of study indicating the pro-angiogenic properties of the native scaffolds. Finally, while the scaffolds retain much of their original shape they do undergo a slow deformation over the 8-week length of the study. Taken together, our results demonstrate that native cellulose scaffolds are biocompatible and exhibit promising potential as a surgical biomaterial.

Challenges in reconstructing an isolated anterior tooth with a metal-free crown

Directory of Open Access Journals (Sweden)

Max Doria Costa

2013-01-01

Full Text Available Introduction: Currently, new esthetic treatments are available to the dentist due to the advent of ceramic-ceramic prostheses. A new option has become part of daily clinical practice, with the promise of esthetic optimization through the elimination of metal in prosthetic crowns. The translucence of these new systems allows the transmission of light through the tooth structure, minimizing gingival darkness and producing a vibrant and natural appearance. Case Report: The patient, 30 years old, female, showed with a fractured tooth crown at the cervical level in the right lateral incisive. It was observed that the tooth had prior adequate endodontic treatment. A metal-free restorative system was selected. A plaster model was obtained for subsequent tooth preparative scanning and manufacture of ceramic framework. After receiving the framework, adjustments were made and the color choice of covering ceramic, following the protocol of choice for a chroma suboptimal aiming further characterization. After the ceramics application, adjustments in shape, texture, and occlusion were made. The crown was characterized by exterior paint, getting a favorable result, restoring esthetics and function. Discussion : The metal-free systems are a viable alternative to the restorative treatment when esthetics is desired, allowing a natural and harmonious smile, combined with the reliability of the restorative material.

Investigation of EPR signals on tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Pavlenko, A; Mironova-Ulmane, N; Polakov, M; Riekstina, D [Institute of Solid State Physics, University of Latvia, Riga (Latvia)

2007-12-15

Calcified tissues are involved in continues metabolic process in human organism exchanging a number of chemical elements with environment. The rate of biochemical reactions is tissue dependent and the slowest one at the tooth enamel, the most mineralized tissue of human organism. The long time stability and unique chemical composition make tooth enamel suitable for number of application. The assessment of individual radiation dose by Electron Paramagnetic Resonance (EPR) and evaluations of elemental composition by Instrumentation Neutron Activation Analysis (INAA) are the well known procedures where properties of tooth enamel intensively used. The current work is focused on investigation of EPR signals and determination of chemical composition on several teeth samples having different origin. The EPR spectra and INAA element content of milk tooth, caries tooth, and paradantose tooth have been compared to each other. The results showed that the intensity of EPR signal is much higher for the caries tooth than the for paradantose tooth that is in agreement with depleted Ca content.

A newer simultaneous space creation, eruption, and adjacent root control spring for the management of impacted tooth

Directory of Open Access Journals (Sweden)

Dipti Shastri

2014-01-01

Full Text Available Usually, treatment of impaction includes: Welcome preparation (to create space, surgical exposure and attachment to the impacted tooth and the orthodontic guidance for the eruption of the impacted tooth. Sometimes, due to deficiency of space, creation of space for impacted tooth requires first, and space regaining efforts may require the distal movement of posterior teeth and or mesial movement of anterior teeth in the arch, but it may create some problems. To overcome the unwanted problem in this clinical situation and to reduce overall treatment duration of the patient, we have developed the Simultaneous space creation, Eruption and Adjacent root control spring to control crown as well as root movement.

Designer biomaterials for mechanobiology

Science.gov (United States)

Li, Linqing; Eyckmans, Jeroen; Chen, Christopher S.

2017-12-01

Biomaterials engineered with specific bioactive ligands, tunable mechanical properties and complex architecture have emerged as powerful tools to probe cell sensing and response to physical properties of their material surroundings, and ultimately provide designer approaches to control cell function.

Tooth whitening: what we now know.

Science.gov (United States)

Carey, Clifton M

2014-06-01

Current research about tooth whitening shows that it is safe and effective when manufacturer's protocol is followed, yet there are risks of which the profession and users should be aware. This update provides a summary of current research and assessment of the safety and efficacy of tooth whitening regimens. Tooth whitening has become one of the most frequently requested dental procedures by the public. The public has come to demand whiter, more perfect smiles and in response many choices for tooth whitening have been made available. These include home-based products such as toothpastes, gels, and films, as well as in-office based systems where products containing highly concentrated bleaching agents are applied under professional supervision. The profession and public have been aware of certain risks related to tooth whitening such as increased tooth sensitivity and gingival irritation. New research has shown that there are other risks such as tooth surface roughening and softening, increased potential for demineralization, degradation of dental restorations, and unacceptable color change of dental restorations. The new research is also focused on optimizing whitening procedures to reduce tooth sensitivity and to increase the persistence of the whitening. Current reports in the literature are reviewed that are related to the use of peroxide based whitening methods. These reports include in vitro studies for method optimization and mechanism as well as clinical studies on effects of various whitening regimens. When manufacturer's instructions are followed, hydrogen peroxide and carbamide peroxide based tooth whitening is safe and effective. Patients should be informed of the risks associated with tooth whitening and instructed on identification of adverse occurrences so that they may seek professional help as needed. Copyright © 2014 Elsevier Inc. All rights reserved.

PEEK Biomaterials in Trauma, Orthopedic, and Spinal Implants

Science.gov (United States)

Kurtz, S. M.; Devine, J. N.

2007-01-01

Since the 1980s, polyaryletherketones (PAEKs) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. We have synthesized the extensive polymer science literature as it relates to structure, mechanical properties, and chemical resistance of PAEK biomaterials. With this foundation, one can more readily appreciate why this family of polymers will be inherently strong, inert, and biocompatible. Due to its relative inertness, PEEK biomaterials are an attractive platform upon which to develop novel bioactive materials, and some steps have already been taken in that direction, with the blending of HA and TCP into sintered PEEK. However, to date, blended HA-PEEK composites have involved a trade-off in mechanical properties in exchange for their increased bioactivity. PEEK has had the greatest clinical impact in the field of spine implant design, and PEEK is now broadly accepted as a radiolucent alternative to metallic biomaterials in the spine community. For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature. PMID:17686513

Biomaterials in Artificial Organs.

Science.gov (United States)

Kambic, Helen E.; And Others

1986-01-01

Biomaterials are substances or combinations of substances that can be used in a system that treats, augments, or replaces any tissue, organ, or body function. The nature and role of these substances, particularly in the cadiovascular system, are discussed. (JN)

Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

Science.gov (United States)

Green, David W.; Lee, Jung-Seok; Jung, Han-Sung

2016-01-01

The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a “water-tight” barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell–cell connections, cell–matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis. PMID:26903872

Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

Directory of Open Access Journals (Sweden)

David William Green

2016-02-01

Full Text Available The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a water-tight barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachement complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement.. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organising cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

Science.gov (United States)

Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2016-08-01

Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

Enamel thickness after preparation of tooth for porcelain laminate.

Science.gov (United States)

Pahlevan, Ayoub; Mirzaee, Mansoreh; Yassine, Esmaeil; Ranjbar Omrany, Ladan; Hasani Tabatabaee, Masumeh; Kermanshah, Hamid; Arami, Sakineh; Abbasi, Mehdy

2014-07-01

In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers. Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope. Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05). The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

Enamel thickness after preparation of tooth for porcelain laminate.

Directory of Open Access Journals (Sweden)

Ayoub Pahlevan

2014-08-01

Full Text Available In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope.Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05.The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

Recent Advances in Biomaterials for 3D Printing and Tissue Engineering.

Science.gov (United States)

Jammalamadaka, Udayabhanu; Tappa, Karthik

2018-03-01

Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology. Many researchers have developed novel biomaterials and compositions to enable their use in 3D printing methods. The advantages of fabricating scaffolds using 3D printing are numerous, including the ability to create complex geometries, porosities, co-culture of multiple cells, and incorporate growth factors. In this review, recently-developed biomaterials for different tissues are discussed. Biomaterials used in 3D printing are categorized into ceramics, polymers, and composites. Due to the nature of 3D printing methods, most of the ceramics are combined with polymers to enhance their printability. Polymer-based biomaterials are 3D printed mostly using extrusion-based printing and have a broader range of applications in regenerative medicine. The goal of tissue engineering is to fabricate functional and viable organs and, to achieve this, multiple biomaterials and fabrication methods need to be researched.

Evolution of high tooth replacement rates in sauropod dinosaurs.

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D'Emic, Michael D; Whitlock, John A; Smith, Kathlyn M; Fisher, Daniel C; Wilson, Jeffrey A

2013-01-01

Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs.

Evolution of high tooth replacement rates in sauropod dinosaurs.

Directory of Open Access Journals (Sweden)

Michael D D'Emic

Full Text Available BACKGROUND: Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. METHODOLOGY/PRINCIPAL FINDINGS: We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days. Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. CONCLUSIONS/SIGNIFICANCE: Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size, and derived titanosaurs and

Mechanics of Biological Tissues and Biomaterials : Current Trends (editorial)

NARCIS (Netherlands)

Zadpoor, A.A.

2015-01-01

Investigation of the mechanical behavior of biological tissues and biomaterials has been an active area of research for several decades. However, in recent years, the enthusiasm in understanding the mechanical behavior of biological tissues and biomaterials has increased significantly due to the

Combined osteoplasty of metaepiphysial defects in total knee arthroplasty with osteoplastic biomaterial

Directory of Open Access Journals (Sweden)

Gavrilov М.А.

2012-12-01

Full Text Available The research goal is to study the results of osteoplastic biomaterials application to reach the improvement of primary and long-term secondary stability of fixation. Materials and methods: 62 patients with bone defect of metaepiphy-sis of type 2 according to AORI have been included into the research. Total knee arthroplasty with osteoplasty of the defect has been carried out in all the patients. In the basic group (n=32 combined osteoplasty has been used, and in comparison group (n=30 cement osteoplasty has been applied. In cases with total arthroplasty in the basic group modifying standard resections, structural autograft of laminar form has been received simultaneously. After preparing the floor of the defect its plasty has been carried out: in the basic group the defect has been filled with osteoconductive biomaterial, and in the comparison group — with polymethylmethacrylate to restore the anatomical configuration of condyles. Besides, before cement fixation of the prosthesis in the basic group the received autograft has been put on the restored implant plateau. Results: Assessing the results during the period from 2 to 4 years objective criteria have included the data of X-ray imaging, biomechanical research and WOMAC test. In the postoperative period significant differences have not been revealed. In the follow-up period in the group with application of the combined osteoplasty joint remodulation of autograft and osteoplastic biomaterial with regenerative restoration of bone tissue of the implant plateau has been observed. Conclusion: The described technique may reduce the relative risk of revision arthroplasty.

Biocomposites and hybrid biomaterials based on calcium orthophosphates

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Dorozhkin, Sergey V.

2011-01-01

The state-of-the-art of biocomposites and hybrid biomaterials based on calcium orthophosphates that are suitable for biomedical applications is presented in this review. Since these types of biomaterials offer many significant and exciting possibilities for hard tissue regeneration, this subject belongs to a rapidly expanding area of biomedical research. Through successful combinations of the desired properties of matrix materials with those of fillers (in such systems, calcium orthophosphates might play either role), innovative bone graft biomaterials can be designed. Various types of biocomposites and hybrid biomaterials based on calcium orthophosphates, either those already in use or being investigated for biomedical applications, are extensively discussed. Many different formulations, in terms of the material constituents, fabrication technologies, structural and bioactive properties as well as both in vitro and in vivo characteristics, have already been proposed. Among the others, the nanostructurally controlled biocomposites, those containing nanodimensional compounds, biomimetically fabricated formulations with collagen, chitin and/or gelatin as well as various functionally graded structures seem to be the most promising candidates for clinical applications. The specific advantages of using biocomposites and hybrid biomaterials based on calcium orthophosphates in the selected applications are highlighted. As the way from the laboratory to the hospital is a long one, and the prospective biomedical candidates have to meet many different necessities, this review also examines the critical issues and scientific challenges that require further research and development. PMID:23507726

Hot topics in biomaterials

CERN Document Server

Alton, Eric W; Griesenbach, Uta

2014-01-01

The expert coverage of the eight chapters in this book reflects the diverse nature of the field of biomaterials science and encompasses contributions from a wide range of fields, highlighting key classes of novel materials and exploring the underlying science and potential applications.

Macrophage reaction against biomaterials in the mouse model - Phenotypes, functions and markers.

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Klopfleisch, R

2016-10-01

The foreign body reaction (FBR) is a response of the host tissue against more or less degradation-resistant foreign macromolecular material. The reaction is divided into five different phases which involve most aspects of the innate and the adaptive immune system: protein adsorption, acute and chronic inflammation, foreign body giant cell formation and fibrosis. It is long known, that macrophages play a central role in all of these phases except for protein adsorption. Initially it was believed that the macrophage driven FBR has a complete negative effect on biocompatibility. Recent progress in biomaterial and macrophage research however describe macrophages as more than pure antigen phagocytosing and presenting cells and thus pro-inflammatory cells involved in biomaterial encapsulation and failure. Quite contrary, both, pro-inflammatory M1 macrophages, the diverse regulatory M2 macrophage subtypes and even foreign body giant cells (FBGC) are after necessary for integration of non-degradable biomaterials and degradation and replacement of degradable biomaterials. This review gives a comprehensive overview on the taxonomy of the currently known macrophage subtypes. Their diverging functions, metabolism and markers are summarized and the relevance of this more diverse macrophage picture for the design of biomaterials is shortly discussed. The view on role of macrophages in the foreign body reaction against biomaterials is rapidly changing. Despite the initial idea that macrophage are mainly involved in undesired degradation and biomaterial rejection it becomes now clear that they are nevertheless necessary for proper integration of non-degradable biomaterials and degradation of placeholder, degradable biomaterials. As a pathologist I experienced a lack on a good summary on the current taxonomy, functions and phenotypes of macrophages in my recent projects on the biocompatibility of biomaterials in the mouse model. The submitted review therefore intends to gives a

Neural engineering from advanced biomaterials to 3D fabrication techniques

CERN Document Server

Kaplan, David

2016-01-01

This book covers the principles of advanced 3D fabrication techniques, stem cells and biomaterials for neural engineering. Renowned contributors cover topics such as neural tissue regeneration, peripheral and central nervous system repair, brain-machine interfaces and in vitro nervous system modeling. Within these areas, focus remains on exciting and emerging technologies such as highly developed neuroprostheses and the communication channels between the brain and prostheses, enabling technologies that are beneficial for development of therapeutic interventions, advanced fabrication techniques such as 3D bioprinting, photolithography, microfluidics, and subtractive fabrication, and the engineering of implantable neural grafts. There is a strong focus on stem cells and 3D bioprinting technologies throughout the book, including working with embryonic, fetal, neonatal, and adult stem cells and a variety of sophisticated 3D bioprinting methods for neural engineering applications. There is also a strong focus on b...

Handheld skin printer: in situ formation of planar biomaterials and tissues.

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Hakimi, Navid; Cheng, Richard; Leng, Lian; Sotoudehfar, Mohammad; Ba, Phoenix Qing; Bakhtyar, Nazihah; Amini-Nik, Saeid; Jeschke, Marc G; Günther, Axel

2018-05-15

We present a handheld skin printer that enables the in situ formation of biomaterial and skin tissue sheets of different homogeneous and architected compositions. When manually positioned above a target surface, the compact instrument (weight <0.8 kg) conformally deposits a biomaterial or tissue sheet from a microfluidic cartridge. Consistent sheet formation is achieved by coordinating the flow rates at which bioink and cross-linker solution are delivered, with the speed at which a pair of rollers actively translate the cartridge along the surface. We demonstrate compatibility with dermal and epidermal cells embedded in ionically cross-linkable biomaterials (e.g., alginate), and enzymatically cross-linkable proteins (e.g., fibrin), as well as their mixtures with collagen type I and hyaluronic acid. Upon rapid crosslinking, biomaterial and skin cell-laden sheets of consistent thickness, width and composition were obtained. Sheets deposited onto horizontal, agarose-coated surfaces were used for physical and in vitro characterization. Proof-of-principle demonstrations for the in situ formation of biomaterial sheets in murine and porcine excisional wound models illustrate the capacity of depositing onto inclined and compliant wound surfaces that are subject to respiratory motion. We expect the presented work will enable the in situ delivery of a wide range of different cells, biomaterials, and tissue adhesives, as well as the in situ fabrication of spatially organized biomaterials, tissues, and biohybrid structures.

1-Dimensional Analysis of Ultrasound at Closed Interface of Solid

International Nuclear Information System (INIS)

Yamawaki, H

2014-01-01

As a first step to investigate mechanism of nonlinear ultrasonic generation at closed cracks, computer simulation for ultrasonic propagation in 1 -dimensional solid including closed interface was examined using Improved-FDM. Fundamental calculation model which described interaction between open / closure motion of the interface and ultrasonic stress was developed. In the model, compression stress is distributed over the entire solid, as motive force for closure of the interface. The interface is exhibited by the small region, and its open / closure are determined using calculated strain of the region. As a result, motion of the interface causing generation of saw-tooth like displacement waveform was observed. Amplitude modulation of displacement waveform was also observed, and it indicated possibility that small fluctuation of open / closure timing caused the modulation of the amplitude

Silk film biomaterials for ocular surface repair

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Lawrence, Brian David

Current biomaterial approaches for repairing the cornea's ocular surface upon injury are partially effective due to inherent material limitations. As a result there is a need to expand the biomaterial options available for use in the eye, which in turn will help to expand new clinical innovations and technology development. The studies illustrated here are a collection of work to further characterize silk film biomaterials for use on the ocular surface. Silk films were produced from regenerated fibroin protein solution derived from the Bombyx mori silkworm cocoon. Methods of silk film processing and production were developed to produce consistent biomaterials for in vitro and in vivo evaluation. A wide range of experiments was undertaken that spanned from in vitro silk film material characterization to in vivo evaluation. It was found that a variety of silk film properties could be controlled through a water-annealing process. Silk films were then generated that could be use in vitro to produce stratified corneal epithelial cell sheets comparable to tissue grown on the clinical standard substrate of amniotic membrane. This understanding was translated to produce a silk film design that enhanced corneal healing in vivo on a rabbit injury model. Further work produced silk films with varying surface topographies that were used as a simplified analog to the corneal basement membrane surface in vitro. These studies demonstrated that silk film surface topography is capable of directing corneal epithelial cell attachment, growth, and migration response. Most notably epithelial tissue development was controllably directed by the presence of the silk surface topography through increasing cell sheet migration efficiency at the individual cellular level. Taken together, the presented findings represent a comprehensive characterization of silk film biomaterials for use in ocular surface reconstruction, and indicate their utility as a potential material choice in the

Mineralization behavior and interface properties of BG-PVA/bone composite implants in simulated body fluid

Energy Technology Data Exchange (ETDEWEB)

Ma Yanxuan; Zheng Yudong; Huang Xiaoshan; Xi Tingfei; Han Dongfei [School of Materials Science and Engineering, Beijing University of Science and Technology, Beijing 100083 (China); Lin Xiaodan [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Song Wenhui, E-mail: zhengyudong@mater.ustb.edu.c, E-mail: wenhui.song@brunel.ac.u [Wolfson Center for Materials Processing, School of Engineering and Design, Brunel University, West London, UB8 3PH (United Kingdom)

2010-04-15

Due to the non-bioactivity and poor conjunction performance of present cartilage prostheses, the main work here is to develop the bioactive glass-polyvinyl alcohol hydrogel articular cartilage/bone (BG-PVA/bone) composite implants. The essential criterion for a biomaterial to bond with living bone is well-matched mechanical properties as well as biocompatibility and bioactivity. In vitro studies on the formation of a surface layer of carbonate hydroxyl apatite (HCA) and the corresponding variation of the properties of biomaterials are imperative for their clinical application. In this paper, the mineralization behavior and variation of the interface properties of BG-PVA/bone composites were studied in vitro by using simulated body fluid (SBF). The mineralization and HCA layer formed on the interface between the BG-PVA hydrogel and bone in SBF could provide the composites with bioactivity and firmer combination. The compression property, shear strength and interface morphology of BG-PVA/bone composite implants varying with the immersion time in SBF were characterized. Also, the influence laws of the immersion time, content of BG in the composites and aperture of bones to the mineralization behavior and interface properties were investigated. The good mineralization behavior and enhanced conjunction performance of BG-PVA/bone composites demonstrated that this kind of composite implant might be more appropriate cartilage replacements.

Mineralization behavior and interface properties of BG-PVA/bone composite implants in simulated body fluid.

Science.gov (United States)

Ma, Yanxuan; Zheng, Yudong; Huang, Xiaoshan; Xi, Tingfei; Lin, Xiaodan; Han, Dongfei; Song, Wenhui

2010-04-01

Due to the non-bioactivity and poor conjunction performance of present cartilage prostheses, the main work here is to develop the bioactive glass-polyvinyl alcohol hydrogel articular cartilage/bone (BG-PVA/bone) composite implants. The essential criterion for a biomaterial to bond with living bone is well-matched mechanical properties as well as biocompatibility and bioactivity. In vitro studies on the formation of a surface layer of carbonate hydroxyl apatite (HCA) and the corresponding variation of the properties of biomaterials are imperative for their clinical application. In this paper, the mineralization behavior and variation of the interface properties of BG-PVA/bone composites were studied in vitro by using simulated body fluid (SBF). The mineralization and HCA layer formed on the interface between the BG-PVA hydrogel and bone in SBF could provide the composites with bioactivity and firmer combination. The compression property, shear strength and interface morphology of BG-PVA/bone composite implants varying with the immersion time in SBF were characterized. Also, the influence laws of the immersion time, content of BG in the composites and aperture of bones to the mineralization behavior and interface properties were investigated. The good mineralization behavior and enhanced conjunction performance of BG-PVA/bone composites demonstrated that this kind of composite implant might be more appropriate cartilage replacements.

Engineering Biomaterials to Integrate and Heal: The Biocompatibility Paradigm Shifts

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Bryers, James D.; Giachelli, Cecilia M.; Ratner, Buddy D.

2012-01-01

This article focuses on one of the major failure routes of implanted medical devices, the foreign body reaction (FBR)—that is, the phagocytic attack and encapsulation by the body of the so-called “biocompatible” biomaterials comprising the devices. We then review strategies currently under development that might lead to biomaterial constructs that will harmoniously heal and integrate into the body. We discuss in detail emerging strategies to inhibit the FBR by engineering biomaterials that elicit more biologically pertinent responses. PMID:22592568

Biomaterials with Antibacterial and Osteoinductive Properties to Repair Infected Bone Defects.

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Lu, Haiping; Liu, Yi; Guo, Jing; Wu, Huiling; Wang, Jingxiao; Wu, Gang

2016-03-03

The repair of infected bone defects is still challenging in the fields of orthopedics, oral implantology and maxillofacial surgery. In these cases, the self-healing capacity of bone tissue can be significantly compromised by the large size of bone defects and the potential/active bacterial activity. Infected bone defects are conventionally treated by a systemic/local administration of antibiotics to control infection and a subsequent implantation of bone grafts, such as autografts and allografts. However, these treatment options are time-consuming and usually yield less optimal efficacy. To approach these problems, novel biomaterials with both antibacterial and osteoinductive properties have been developed. The antibacterial property can be conferred by antibiotics and other novel antibacterial biomaterials, such as silver nanoparticles. Bone morphogenetic proteins are used to functionalize the biomaterials with a potent osteoinductive property. By manipulating the carrying modes and release kinetics, these biomaterials are optimized to maximize their antibacterial and osteoinductive functions with minimized cytotoxicity. The findings, in the past decade, have shown a very promising application potential of the novel biomaterials with the dual functions in treating infected bone defects. In this review, we will summarize the current knowledge of novel biomaterials with both antibacterial and osteoinductive properties.

Recent Advances in Biomaterials for 3D Printing and Tissue Engineering

Directory of Open Access Journals (Sweden)

Udayabhanu Jammalamadaka

2018-03-01

Full Text Available Three-dimensional printing has significant potential as a fabrication method in creating scaffolds for tissue engineering. The applications of 3D printing in the field of regenerative medicine and tissue engineering are limited by the variety of biomaterials that can be used in this technology. Many researchers have developed novel biomaterials and compositions to enable their use in 3D printing methods. The advantages of fabricating scaffolds using 3D printing are numerous, including the ability to create complex geometries, porosities, co-culture of multiple cells, and incorporate growth factors. In this review, recently-developed biomaterials for different tissues are discussed. Biomaterials used in 3D printing are categorized into ceramics, polymers, and composites. Due to the nature of 3D printing methods, most of the ceramics are combined with polymers to enhance their printability. Polymer-based biomaterials are 3D printed mostly using extrusion-based printing and have a broader range of applications in regenerative medicine. The goal of tissue engineering is to fabricate functional and viable organs and, to achieve this, multiple biomaterials and fabrication methods need to be researched.

Determining the direction of tooth grinding: an in vitro study.

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ten Berge, F; te Poel, J; Ranjitkar, S; Kaidonis, J A; Lobbezoo, F; Hughes, T E; Townsend, G C

2012-08-01

The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable. © 2012 Blackwell Publishing Ltd.

Primary culprit for tooth loss!!

OpenAIRE

Nuvvula, Sailavanya; Chava, Vijay Kumar; Nuvvula, Sivakumar

2016-01-01

Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A quest...

Specific material effects of wear-particle-induced inflammation and osteolysis at the bone–implant interface: A rat model

Directory of Open Access Journals (Sweden)

Lisa K. Longhofer

2017-01-01

Conclusion: Different biomaterials in particulate form exert different forms of adverse effects in terms of the amount of osteolysis and inflammatory reactions on bone tissue at the bone–implant interface. It provides information for engineering more appropriate materials for arthroplasty components.

Gradient biomaterials and their influences on cell migration

Science.gov (United States)

Wu, Jindan; Mao, Zhengwei; Tan, Huaping; Han, Lulu; Ren, Tanchen; Gao, Changyou

2012-01-01

Cell migration participates in a variety of physiological and pathological processes such as embryonic development, cancer metastasis, blood vessel formation and remoulding, tissue regeneration, immune surveillance and inflammation. The cells specifically migrate to destiny sites induced by the gradually varying concentration (gradient) of soluble signal factors and the ligands bound with the extracellular matrix in the body during a wound healing process. Therefore, regulation of the cell migration behaviours is of paramount importance in regenerative medicine. One important way is to create a microenvironment that mimics the in vivo cellular and tissue complexity by incorporating physical, chemical and biological signal gradients into engineered biomaterials. In this review, the gradients existing in vivo and their influences on cell migration are briefly described. Recent developments in the fabrication of gradient biomaterials for controlling cellular behaviours, especially the cell migration, are summarized, highlighting the importance of the intrinsic driving mechanism for tissue regeneration and the design principle of complicated and advanced tissue regenerative materials. The potential uses of the gradient biomaterials in regenerative medicine are introduced. The current and future trends in gradient biomaterials and programmed cell migration in terms of the long-term goals of tissue regeneration are prospected. PMID:23741610

Multidisciplinary Management of Complicated Crown-Root Fracture of an Anterior Tooth Undergoing Apexification

Directory of Open Access Journals (Sweden)

Merve Mese

2015-01-01

Full Text Available The purpose of this case report was to present the multidisciplinary management of a subgingival crown-root fracture of a patient undergoing apexification treatment. A 12-year-old male patient was referred to the pediatric dentistry clinic with an extensive tooth fracture of the right permanent maxillary lateral incisor. Clinical and radiographic examinations revealed the presence of a complicated crown-root fracture, which had elongated to the buccal subgingival area. The dental history disclosed that the apexification procedure had been started to be performed after his first trauma experience and he had neglected his appointment. The coronal fragment was gently extracted; endodontic treatment was performed; flap surgery was performed to make the fracture line visible. The coronal fragment was reattached to the root fragment with a dual-cure luting composite. A fiber post was stabilized and the access cavity of the tooth was restored with composite resin. At the end of the 24th month, the tooth was asymptomatic, functionally, esthetically acceptable and had no periapical pathology. It is important for the patients undergoing apexification treatment to keep their appointments because of the fracture risk. Restoration of the fractured tooth by preparing retention grooves and a bonding fiber-reinforced post are effective and necessary approaches for successful management.

Interface-Limited Spherulitic Growth of Hydroxyapatite/Chondroitin Sulfate Composite Enamel-like Films

Science.gov (United States)

Ma, Guobin; Xu, Yifei; Wang, Xiyan; Wang, Mu

2012-02-01

Understanding and mimicking the growth of hard tissues such as tooth enamel may lead to innovative approaches toward engineering novel functional materials and providing new therapeutics. Up to now, in vitro growth of enamel-like materials is still a great challenge, and the microscopic formation mechanisms are far from well understood. Here we report synthesis of large-scale hydroxyapatite (HAP) and chondroitin sulfate (ChS) composite films by an efficient solution-air interface growth method. The products have the characteristic hierarchical prism structures of enamel and the mechanical properties comparable to dentin. We demonstrate that the films are assembled by spherulites nucleated at the solution surface. The growth of the spherulites is limited by the interfaces between them as well as between the solution and air, leading to the ordered prism structure. The results are beneficial for a clearer understanding of the fundamentals of tooth enamel formation.

Biomaterials based strategies for rotator cuff repair.

Science.gov (United States)

Zhao, Song; Su, Wei; Shah, Vishva; Hobson, Divia; Yildirimer, Lara; Yeung, Kelvin W K; Zhao, Jinzhong; Cui, Wenguo; Zhao, Xin

2017-09-01

Tearing of the rotator cuff commonly occurs as among one of the most frequently experienced tendon disorders. While treatment typically involves surgical repair, failure rates to achieve or sustain healing range from 20 to 90%. The insufficient capacity to recover damaged tendon to heal to the bone, especially at the enthesis, is primarily responsible for the failure rates reported. Various types of biomaterials with special structures have been developed to improve tendon-bone healing and tendon regeneration, and have received considerable attention for replacement, reconstruction, or reinforcement of tendon defects. In this review, we first give a brief introduction of the anatomy of the rotator cuff and then discuss various design strategies to augment rotator cuff repair. Furthermore, we highlight current biomaterials used for repair and their clinical applications as well as the limitations in the literature. We conclude this article with challenges and future directions in designing more advanced biomaterials for augmentation of rotator cuff repair. Copyright © 2017 Elsevier B.V. All rights reserved.

Preparation of designed poly(D,L-lactide)/nanosized hydroxyapatite composite structures by stereolithography

NARCIS (Netherlands)

Ronca, A.; Ambrosio, L.; Grijpma, D. W.

The preparation of scaffolds to facilitate the replacement of damaged tissues and organs by means of tissue engineering has been much investigated. The key properties of the biomaterials used to prepare such scaffolds include biodegradability, biocompatibility and a well-defined three-dimensional

Preparation of designed poly(d,l-lactide)/nanosized hydroxyapatite composite structures by stereolithography

NARCIS (Netherlands)

Ronca, A.; Ambrosio, L.; Grijpma, Dirk W.

2013-01-01

The preparation of scaffolds to facilitate the replacement of damaged tissues and organs by means of tissue engineering has been much investigated. The key properties of the biomaterials used to prepare such scaffolds include biodegradability, biocompatibility and a well-defined three-dimensional

Atypical Odontalgia (Phantom Tooth Pain)

Science.gov (United States)

... atypical facial pain, phantom tooth pain, or neuropathic orofacial pain, is characterized by chronic pain in a tooth ... such as a specialist in oral medicine or orofacial pain. The information contained in this monograph is for ...

3D printing of biomaterials with mussel-inspired nanostructures for tumor therapy and tissue regeneration.

Science.gov (United States)

Ma, Hongshi; Luo, Jian; Sun, Zhe; Xia, Lunguo; Shi, Mengchao; Liu, Mingyao; Chang, Jiang; Wu, Chengtie

2016-12-01

Primary bone cancer brings patients great sufferings. To deal with the bone defects resulted from cancer surgery, biomaterials with good bone-forming ability are necessary to repair bone defects. Meanwhile, in order to prevent possible tumor recurrence, it is essential that the remaining tumor cells around bone defects are completely killed. However, there are few biomaterials with the ability of both cancer therapy and bone regeneration until now. Here, we fabricated a 3D-printed bioceramic scaffold with a uniformly self-assembled Ca-P/polydopamine nanolayer surface. Taking advantage of biocompatibility, biodegradability and the excellent photothermal effect of polydopamine, the bifunctional scaffolds with mussel-inspired nanostructures could be used as a satisfactory and controllable photothermal agent, which effectively induced tumor cell death in vitro, and significantly inhibited tumor growth in mice. In addition, owing to the nanostructured surface, the prepared polydopamine-modified bioceramic scaffolds could support the attachment and proliferation of rabbit bone mesenchymal stem cells (rBMSCs), and significantly promoted the formation of new bone tissues in rabbit bone defects even under photothermal treatment. Therefore, the mussel-inspired nanostructures in 3D-printed bioceramic exhibited a remarkable capability for both cancer therapy and bone regeneration, offering a promising strategy to construct bifunctional biomaterials which could be widely used for therapy of tumor-induced tissue defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tooth breakage in patients injected with 224Ra

International Nuclear Information System (INIS)

Sonnabend, E.; Spiess, H.; Mays, C.W.

1986-01-01

Tooth breakage has been common among the 224 Ra patients, especially those injected as teenagers. The fracture of 1 or more teeth was reported by 26% (8/31) of boys and 23% (7/30) of girls injected with 224 Ra at 16-20 years of age. Combining results from all age groups, the incidence of tooth fractures increased significantly with dose (P=0.01). Unlike the normal loss of permanent teeth by periodontal disease, in which the entire tooth is lost, the tooth loss following 224 Ra injection was primarily from tooth resorption near the gum line causing the tooth crowns to break off easily. Eventually the tooth roots may either become incorporated into the jawbone or are resorbed and replaced with bone. These tooth fractures resembled those observed in the U.S. radium dial painters and in dogs injected with bone-seeking α-emitters. (orig.)

Biocompatibility of Subcutaneously Implanted Plant-Derived Cellulose Biomaterials

Science.gov (United States)

Pelling, Andrew E.

2016-01-01

There is intense interest in developing novel biomaterials which support the invasion and proliferation of living cells for potential applications in tissue engineering and regenerative medicine. Decellularization of existing tissues have formed the basis of one major approach to producing 3D scaffolds for such purposes. In this study, we utilize the native hypanthium tissue of apples and a simple preparation methodology to create implantable cellulose scaffolds. To examine biocompatibility, scaffolds were subcutaneously implanted in wild-type, immunocompetent mice (males and females; 6–9 weeks old). Following the implantation, the scaffolds were resected at 1, 4 and 8 weeks and processed for histological analysis (H&E, Masson’s Trichrome, anti-CD31 and anti-CD45 antibodies). Histological analysis revealed a characteristic foreign body response to the scaffold 1 week post-implantation. However, the immune response was observed to gradually disappear by 8 weeks post-implantation. By 8 weeks, there was no immune response in the surrounding dermis tissue and active fibroblast migration within the cellulose scaffold was observed. This was concomitant with the deposition of a new collagen extracellular matrix. Furthermore, active blood vessel formation within the scaffold was observed throughout the period of study indicating the pro-angiogenic properties of the native scaffolds. Finally, while the scaffolds retain much of their original shape they do undergo a slow deformation over the 8-week length of the study. Taken together, our results demonstrate that native cellulose scaffolds are biocompatible and exhibit promising potential as a surgical biomaterial. PMID:27328066

Regulatory affairs for biomaterials and medical devices

CERN Document Server

Amato, Stephen F; Amato, B

2015-01-01

All biomaterials and medical devices are subject to a long list of regulatory practises and policies which must be adhered to in order to receive clearance. This book provides readers with information on the systems in place in the USA and the rest of the world. Chapters focus on a series of procedures and policies including topics such as commercialization, clinical development, general good practise manufacturing and post market surveillance.Addresses global regulations and regulatory issues surrounding biomaterials and medical devicesEspecially useful for smaller co

Engineering mechanical gradients in next generation biomaterials - Lessons learned from medical textile design.

Science.gov (United States)

Ng, Joanna L; Collins, Ciara E; Knothe Tate, Melissa L

2017-07-01

facilitate transport of molecules and cells during tissue genesis within tissue defects (surgical membranes). External and internal biomaterial membranes prescribe boundary conditions for treatment of medical disorders, from oedema to tissue defects. Studies are needed to guide the design of next generation biomaterials and devices that incorporate gradient engineering approaches, which offer great potential to enhance function in a dynamic and physiological context. Mechanical gradients intrinsic to currently implemented biomaterials such as medical textiles and surgical interface membranes are poorly understood. Here we characterise quantitatively the mechanics of textile and nonwoven biomaterial membranes for external and internal use. The lack of seamless gradients in compression medical textiles contrasts with the graded mechanical effects achieved by elastomeric exercise bands, which are designed to deliver controlled, incremental increases in loading to facilitate healing as injured tissues return to normal structure and function. Engineering textiles with a prescient choice of fibre composition/size, type of knit/weave and inlay fibres, and weave density/anisotropy will enable creation of fabrics that can deliver spatially and temporally controlled mechanical gradients to maintain force balances at tissue boundaries, e.g. to treat oedema or tissue defects. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Design and development of reactive injectable and settable polymeric biomaterials.

Science.gov (United States)

Page, Jonathan M; Harmata, Andrew J; Guelcher, Scott A

2013-12-01

Injectable and settable biomaterials are a growing class of therapeutic technologies within the field of regenerative medicine. These materials offer advantages compared to prefabricated implants because of their ability to be utilized as part of noninvasive surgical procedures, fill complex defect shapes, cure in situ, and incorporate cells and other active biologics. However, there are significant technical barriers to clinical translation of injectable and settable biomaterials, such as achieving clinically relevant handling properties and benign reaction conditions. This review focuses on the engineering challenges associated with the design and development of injectable and chemically settable polymeric biomaterials. Additionally, specific examples of the diverse chemistries utilized to overcome these challenges are covered. The future translation of injectable and settable biomaterials is anticipated to improve patient outcomes for a number of clinical conditions. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

Autotransplantation donor tooth site harvesting using piezosurgery

OpenAIRE

Ylikontiola, Leena P.; S?ndor, George K.

2016-01-01

Abstract Background: The harvesting of a tooth as a candidate for tooth autotransplantation requires that the delicate dental tissues around the tooth be minimally traumatized. This is especially so for the periradicular tissues of the tooth root and the follicular tissues surrounding the crown. The aim of this report is to describe the use of piezosurgery as an attempt at morbidity reduction in the harvesting of teeth for autotransplantation. Methods: A piezosurgical handpiece and its ...

Biomaterials with Antibacterial and Osteoinductive Properties to Repair Infected Bone Defects

Directory of Open Access Journals (Sweden)

Haiping Lu

2016-03-01

Full Text Available The repair of infected bone defects is still challenging in the fields of orthopedics, oral implantology and maxillofacial surgery. In these cases, the self-healing capacity of bone tissue can be significantly compromised by the large size of bone defects and the potential/active bacterial activity. Infected bone defects are conventionally treated by a systemic/local administration of antibiotics to control infection and a subsequent implantation of bone grafts, such as autografts and allografts. However, these treatment options are time-consuming and usually yield less optimal efficacy. To approach these problems, novel biomaterials with both antibacterial and osteoinductive properties have been developed. The antibacterial property can be conferred by antibiotics and other novel antibacterial biomaterials, such as silver nanoparticles. Bone morphogenetic proteins are used to functionalize the biomaterials with a potent osteoinductive property. By manipulating the carrying modes and release kinetics, these biomaterials are optimized to maximize their antibacterial and osteoinductive functions with minimized cytotoxicity. The findings, in the past decade, have shown a very promising application potential of the novel biomaterials with the dual functions in treating infected bone defects. In this review, we will summarize the current knowledge of novel biomaterials with both antibacterial and osteoinductive properties.

Proteomic analysis of human tooth pulp: proteomics of human tooth.

Science.gov (United States)

Eckhardt, Adam; Jágr, Michal; Pataridis, Statis; Mikšík, Ivan

2014-12-01

The unique pulp-dentin complex demonstrates strong regenerative potential, which enables it to respond to disease and traumatic injury. Identifying the proteins of the pulp-dentin complex is crucial to understanding the mechanisms of regeneration, tissue calcification, defense processes, and the reparation of dentin by dental pulp. The lack of knowledge of these proteins limits the development of more efficient therapies. The proteomic profile of human tooth pulp was investigated and compared with the proteome of human dentin and blood. The samples of tooth pulp were obtained from 5 sound permanent human third molars of 5 adults (n = 5). The extracted proteins were separated by 2-dimensional gel electrophoresis, analyzed by nano-liquid chromatography tandem mass spectrometry, and identified by correlating mass spectra to the proteomic databases. A total of 342 proteins were identified with high confidence, and 2 proteins were detected for the first time in an actual human sample. The identified tooth pulp proteins have a variety of functions: structural, catalytic, transporter, protease activity, immune response, and many others. In a comparison with dentin and blood plasma, 140 (pulp/dentin) shared proteins were identified, 37 of which were not observed in plasma. It can be suggested that they might participate in the unique pulp-dentin complex. This proteomic investigation of human tooth pulp, together with the previously published study of human dentin, is one of the most comprehensive proteome lists of human teeth to date. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Fibrin glue mixed with platelet-rich fibrin as a scaffold seeded with dental bud cells for tooth regeneration.

Science.gov (United States)

Yang, Kai-Chiang; Wang, Chun-Hao; Chang, Hao-Hueng; Chan, Wing P; Chi, Chau-Hwa; Kuo, Tzong-Fu

2012-11-01

Odontogenesis is a complex process with a series of epithelial-mesenchymal interactions and odontogenic molecular cascades. In tissue engineering of teeth from stem cells, platelet-rich fibrin (PRF), which is rich in growth factors and cytokines, may improve regeneration. Accordingly, PRF was added into fibrin glue to enrich the microenvironment with growth factors. Unerupted second molar tooth buds were harvested from miniature swine and cultured in vitro for 3 weeks to obtain dental bud cells (DBCs). Whole blood was collected for the preparation of PRF and fibrin glue before surgery. DBCs were suspended in fibrin glue and then enclosed with PRF, and the DBC-fibrin glue-PRF composite was autografted back into the original alveolar sockets. Radiographic and histological examinations were used to identify the regenerated tooth structure 36 weeks after implantation. Immunohistochemical staining was used to detect proteins specific to tooth regeneration. One pig developed a complete tooth with crown, root, pulp, enamel, dentin, odontoblast, cementum, blood vessels, and periodontal ligaments in indiscriminate shape. Another animal had an unerupted tooth that expressed cytokeratin 14, dentin matrix protein-1, vascular endothelial growth factor, and osteopontin. This study demonstrated, using autogenic cell transplantation in a porcine model, that DBCs seeded into fibrin glue-PRF could regenerate a complete tooth. Copyright © 2011 John Wiley & Sons, Ltd.

Effective atomic numbers (Z_e_f_f) of based calcium phosphate biomaterials: a comparative study

International Nuclear Information System (INIS)

Fernandes Zenobio, Madelon Aparecida; Gonçalves Zenobio, Elton; Silva, Teógenes Augusto da; Socorro Nogueira, Maria do

2016-01-01

This study determined the interaction of radiation parameters of four biomaterials as attenuators to measure the transmitted X-rays spectra, the mass attenuation coefficient and the effective atomic number by spectrometric system comprising the CdTe detector. The biomaterial BioOss"® presented smaller mean energy than the other biomaterials. The μ/ρ and Z_e_f_f of the biomaterials showed their dependence on photon energy. The data obtained from analytical methods of x-ray spectra, µ/ρ and Z_e_f_f_, using biomaterials as attenuators, demonstrated that these materials could be used as substitutes for dentin, enamel and bone. Further, they are determinants for the characterization of the radiation in tissues or equivalent materials. - Highlights: • Measure of the transmitted x-rays spectra using based calcium phosphate biomaterials as attenuators. • Determination effective atomic number using four dental biomaterials. • Determination of the mass attenuation coefficient (µ/ρ) of the biomaterials samples calculated by the WinXCOM software. • Determination of the chemical composition of calcium phosphate biomaterials.

Test Tube Tooth: The Next Big Thing.

Science.gov (United States)

Yadav, Preeti; Tahir, Mohammed; Yadav, Harsh; Sureka, Rakshit; Garg, Aarti

2016-06-01

Unlike some vertebrates and fishes, humans do not have the capacity for tooth regeneration after the loss of permanent teeth. Although artificial replacement with removable dentures, fixed prosthesis and implants is possible through advances in the field of prosthetic dentistry, it would be ideal to recreate a third set of natural teeth to replace lost dentition. For many years now, researchers in the field of tissue engineering have been trying to bioengineer dental tissues as well as whole teeth. In order to attain a whole tooth through dental engineering, that has the same or nearly same biological, mechanical and physical properties of a natural tooth, it's necessary to deal with all the cells and tissues which are concerned with the formation, maintenance and repair of the tooth. In this article we review the steps involved in odontogenesis or organogenesis of a tooth and progress in the bioengineering of a whole tooth.

Design Concept of Dialyzer Biomaterials: How to Find Biocompatible Polymers Based on the Biointerfacial Water Structure.

Science.gov (United States)

Tanaka, Masaru

2017-01-01

Although various types of materials have been used widely in dialyzers, most biomaterials lack the desired functional properties to interface with blood and have not been engineered for optimum performance. Therefore, there is increasing demand to develop novel materials to address such problems in the dialysis arena. Numerous parameters of polymeric biomaterials can affect biocompatibility in a controlled manner. The mechanisms responsible for the biocompatibility of polymers at the molecular level have not been clearly demonstrated, although many theoretical and experimental efforts have been made to try and understand them. Moreover, water interactions have been recognized as fundamental for the blood response to contact with polymers. We have proposed the 'intermediate water' concept and hypothesized that intermediate water, which prevents the proteins and blood cells from directly contacting the polymer surface, or nonfreezing water on the polymer surface, plays an important role in the biocompatibility of polymers. This chapter provides an overview of the recent experimental progress of biocompatible polymers measured by thermal, spectroscopic, and surface force techniques. Additionally, it highlights recent developments in the use of biocompatible polymeric biomaterials for dialyzers and provides an overview of the progress made in the design of multifunctional biomedical polymers by controlling the biointerfacial water structure through precision polymer synthesis. Key Messages: Intermediate water was found only in hydrated biopolymers (proteins, polysaccharides, and nucleic acids, DNA and RNA) and hydrated biocompatible synthetic polymers. Intermediate water could be one of the main screening factors for the design of appropriate dialyzer materials. © 2017 S. Karger AG, Basel.

Semi-confined compression of microfabricated polymerized biomaterial constructs

International Nuclear Information System (INIS)

Moraes, Christopher; Likhitpanichkul, Morakot; Simmons, Craig A; Sun, Yu; Zhao, Ruogang

2011-01-01

Mechanical forces are critical parameters in engineering functional tissue because of their established influence on cellular behaviour. However, identifying ideal combinations of mechanical, biomaterial and chemical stimuli to obtain a desired cellular response requires high-throughput screening technologies, which may be realized through microfabricated systems. This paper reports on the development and characterization of a MEMS device for semi-confined biomaterial compression. An array of these devices would enable studies involving mechanical deformation of three-dimensional biomaterials, an important parameter in creating physiologically relevant microenvironments in vitro. The described device has the ability to simultaneously apply a range of compressive mechanical stimuli to multiple polymerized hydrogel microconstructs. Local micromechanical strains generated within the semi-confined hydrogel cylinders are characterized and compared with those produced in current micro- and macroscale technologies. In contrast to previous work generating unconfined compression in microfabricated devices, the semi-confined compression model used in this work generates uniform regions of strain within the central portion of each hydrogel, demonstrated here to range from 20% to 45% across the array. The uniform strains achieved simplify experimental analysis and improve the utility of the compression platform. Furthermore, the system is compatible with a wide variety of polymerizable biomaterials, enhancing device versatility and usability in tissue engineering and fundamental cell biology studies

Research in Biomaterials and Tissue Engineering: Achievements and perspectives.

Science.gov (United States)

Ventre, Maurizio; Causa, Filippo; Netti, Paolo A; Pietrabissa, Riccardo

2015-01-01

Research on biomaterials and related subjects has been active in Italy. Starting from the very first examples of biomaterials and biomedical devices, Italian researchers have always provided valuable scientific contributions. This trend has steadily increased. To provide a rough estimate of this, it is sufficient to search PubMed, a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics, with the keywords "biomaterials" or "tissue engineering" and sort the results by affiliation. Again, even though this is a crude estimate, the results speak for themselves, as Italy is the third European country, in terms of publications, with an astonishing 3,700 products in the last decade.

Immune responses to implants - a review of the implications for the design of immunomodulatory biomaterials.

Science.gov (United States)

Franz, Sandra; Rammelt, Stefan; Scharnweber, Dieter; Simon, Jan C

2011-10-01

A key for long-term survival and function of biomaterials is that they do not elicit a detrimental immune response. As biomaterials can have profound impacts on the host immune response the concept emerged to design biomaterials that are able to trigger desired immunological outcomes and thus support the healing process. However, engineering such biomaterials requires an in-depth understanding of the host inflammatory and wound healing response to implanted materials. One focus of this review is to outline the up-to-date knowledge on immune responses to biomaterials. Understanding the complex interactions of host response and material implants reveals the need for and also the potential of "immunomodulating" biomaterials. Based on this knowledge, we discuss strategies of triggering appropriate immune responses by functional biomaterials and highlight recent approaches of biomaterials that mimic the physiological extracellular matrix and modify cellular immune responses. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Use of Tooth Particles as a Biomaterial in Post-Extraction Sockets. Experimental Study in Dogs.

Science.gov (United States)

Calvo-Guirado, José Luis; Maté-Sánchez de Val, José Eduardo; Ramos-Oltra, María Luisa; Pérez-Albacete Martínez, Carlos; Ramírez-Fernández, María Piedad; Maiquez-Gosálvez, Manuel; Gehrke, Sergio A; Fernández-Domínguez, Manuel; Romanos, Georgios E; Delgado-Ruiz, Rafael Arcesio

2018-05-06

Objectives : The objective of this study was to evaluate new bone formation derived from freshly crushed extracted teeth, grafted immediately in post-extraction sites in an animal model, compared with sites without graft filling, evaluated at 30 and 90 days. Material and Methods : The bilateral premolars P2, P3, P4 and the first mandibular molar were extracted atraumatically from six Beagle dogs. The clean, dry teeth were ground immediately using the Smart Dentin Grinder. The tooth particles obtained were subsequently sieved through a special sorting filter into two compartments; the upper container isolating particles over 1200 μm, the lower container isolated particles over 300 μm. The crushed teeth were grafted into the post-extraction sockets at P3, P4 and M1 (test group) (larger and smaller post-extraction alveoli), while P2 sites were left unfilled and acted as a control group. Tissue healing and bone formation were evaluated by histological and histomorphometric analysis after 30 and 90 days. Results : At 30 days, test site bone formation was greater in the test group than the control group ( p socket preservation.

Thermal induced EPR signals in tooth enamel

International Nuclear Information System (INIS)

Fattibene, P.; Aragno, D.; Onori, S.; Pressello, M.C.

2000-01-01

Electron paramagnetic resonance (EPR) spectroscopy was used to detect the effects of temperature on powdered human tooth enamel, not irradiated in the laboratory. Samples were heated at temperature between 350 and 450, at 600 and at 1000 deg. C, for different heating times, between 6 min and 39 h. Changes in the EPR spectra were detected, with the formation of new signals. Possible correlation between the changes in EPR spectra and modifications in the enamel and in the mineral phase of bone detected with other techniques is discussed. The implications for dosimetric applications of signals induced by overheating due to mechanical friction during sample preparation are underlined

Microscale architecture in biomaterial scaffolds for spatial control of neural cell behavior

Science.gov (United States)

Meco, Edi; Lampe, Kyle J.

2018-02-01

Biomaterial scaffolds mimic aspects of the native central nervous system (CNS) extracellular matrix (ECM) and have been extensively utilized to influence neural cell (NC) behavior in in vitro and in vivo settings. These biomimetic scaffolds support NC cultures, can direct the differentiation of NCs, and have recapitulated some native NC behavior in an in vitro setting. However, NC transplant therapies and treatments used in animal models of CNS disease and injury have not fully restored functionality. The observed lack of functional recovery occurs despite improvements in transplanted NC viability when incorporating biomaterial scaffolds and the potential of NC to replace damaged native cells. The behavior of NCs within biomaterial scaffolds must be directed in order to improve the efficacy of transplant therapies and treatments. Biomaterial scaffold topography and imbedded bioactive cues, designed at the microscale level, can alter NC phenotype, direct migration, and differentiation. Microscale patterning in biomaterial scaffolds for spatial control of NC behavior has enhanced the capabilities of in vitro models to capture properties of the native CNS tissue ECM. Patterning techniques such as lithography, electrospinning and 3D bioprinting can be employed to design the microscale architecture of biomaterial scaffolds. Here, the progress and challenges of the prevalent biomaterial patterning techniques of lithography, electrospinning, and 3D bioprinting are reported. This review analyzes NC behavioral response to specific microscale topographical patterns and spatially organized bioactive cues.

The Effect of Biomaterials Used for Tissue Regeneration Purposes on Polarization of Macrophages

NARCIS (Netherlands)

G.S.A. ter Hoeve-Boersema (Simone); N. Grotenhuis (Nienke); Y. Bayon (Yves); J.F. Lange (Johan); Y.M. Bastiaansen-Jenniskens (Yvonne)

2016-01-01

textabstractActivation of macrophages is critical in the acute phase of wound healing after implantation of surgical biomaterials. To understand the response of macrophages, they are often cultured in vitro on biomaterials. Since a wide range of biomaterials is currently used in the clinics, we

A three-dimensional topology optimization model for tooth-root morphology.

Science.gov (United States)

Seitz, K-F; Grabe, J; Köhne, T

2018-02-01

To obtain the root of a lower incisor through structural optimization, we used two methods: optimization with Solid Isotropic Material with Penalization (SIMP) and Soft-Kill Option (SKO). The optimization was carried out in combination with a finite element analysis in Abaqus/Standard. The model geometry was based on cone-beam tomography scans of 10 adult males with healthy bone-tooth interface. Our results demonstrate that the optimization method using SIMP for minimum compliance could not adequately predict the actual root shape. The SKO method, however, provided optimization results that were comparable to the natural root form and is therefore suitable to set up the basic topology of a dental root.

Interactions of Bacteria and Amoebae with Ocular Biomaterials

OpenAIRE

John, Thomas

1991-01-01

The use of biomaterials in periocular and intraocular sites has resulted in some ocular inflammations and infections which can result in vision-threatening ocular disease. This review addresses bacterial interactions with, and adherence to ocular biomaterials such as soft contact lenses, surgical suture materials, and intraocular lenses. In addition, adherence of Acanthamoeba to soft contact lenses is described, and the role of these lenses in the development of Acanthamoeba keratitis is disc...

Advancing biomaterials of human origin for tissue engineering

OpenAIRE

Chen, Fa-Ming; Liu, Xiaohua

2015-01-01

Biomaterials have played an increasingly prominent role in the success of biomedical devices and in the development of tissue engineering, which seeks to unlock the regenerative potential innate to human tissues/organs in a state of deterioration and to restore or reestablish normal bodily function. Advances in our understanding of regenerative biomaterials and their roles in new tissue formation can potentially open a new frontier in the fast-growing field of regenerative medicine. Taking in...

Hydroxyapatite coating on damaged tooth surfaces by immersion

International Nuclear Information System (INIS)

Lim, Byoung-Ki; Ryu, Su-Chak; Sun, Fangfang; Koh, Kwangnak; Han, Dong-Wook; Lee, Jaebeom

2009-01-01

Hydroxyapatite (HAp) was coated on scratched areas of a human tooth and HAp disks by the immersion method in a HAp colloidal solution (≤20 μm of average diameter dispersed in DI water). The surface morphologies of the scratched area after immersion for 1-3 months were investigated showing that the damaged surfaces were remarkably recovered. Then, the mechanical property and chemical stability of the HAp coating layers on both specimens were determined via the Vickers hardness test and concentration measurement of extracted Ca 2+ ions, respectively, after strong acidic treatment. The cellular behavior of mouse calvaria-derived pre-osteoblastic cells (MC3T3-E1) was also examined on the HAp layers regenerated on micro-scratched HAp disks for the purpose of their potential applications on maxillofacial bone conservation and reconstruction for prosthetic dentistry, and artificial disk preparation of a vertebral column. The notable loss of Ca 2+ ions under a highly acidic condition was not observed in the layers coated by HAp adsorption, indicating that the coating surface was well adhered with the original surfaces of the respective specimen. Moreover, the HAp adsorption did not adversely affect the adhesion, growth and proliferation of MC3T3-E1 cells on the coated HAp layers for up to 21 days. These results suggest that the HAp coating on the scratched areas of the tooth would be effectively applicable for the development of long-term prevention of micro-cleavage and tooth health supporters to reduce discoloration and further maxillofacial and orthopedic applications.

A review of the clinical implications of anti-infective biomaterials and infection-resistant surfaces.

Science.gov (United States)

Campoccia, Davide; Montanaro, Lucio; Arciola, Carla Renata

2013-11-01

Infection is currently regarded as the most severe and devastating complication associated to the use of biomaterials. The important social, clinical and economic impacts of implant-related infections are promoting the efforts to obviate these severe diseases. In this context, the development of anti-infective biomaterials and of infection-resistant surfaces is being regarded as the main strategy to prevent the establishment of implant colonisation and biofilm formation by bacteria. In this review, the attention is focused on the biomaterial-associated infections, from which the need for anti-infective biomaterials originates. Biomaterial-associated infections differ markedly for epidemiology, aetiology and severity, depending mainly on the anatomic site, on the time of biomaterial application, and on the depth of the tissues harbouring the prosthesis. Here, the diversity and complexity of the different scenarios where medical devices are currently utilised are explored, providing an overview of the emblematic applicative fields and of the requirements for anti-infective biomaterials. © 2013 Elsevier Ltd. All rights reserved.

Molecular Characterization of Macrophage-Biomaterial Interactions.

Science.gov (United States)

Moore, Laura Beth; Kyriakides, Themis R

2015-01-01

Implantation of biomaterials in vascularized tissues elicits the sequential engagement of molecular and cellular elements that constitute the foreign body response. Initial events include the non-specific adsorption of proteins to the biomaterial surface that render it adhesive for cells such as neutrophils and macrophages. The latter undergo unique activation and in some cases undergo cell-cell fusion to form foreign body giant cells that contribute to implant damage and fibrotic encapsulation. In this review, we discuss the molecular events that contribute to macrophage activation and fusion with a focus on the role of the inflammasome, signaling pathways such as JAK/STAT and NF-κB, and the putative involvement of micro RNAs in the regulation of these processes.

Treatment Outcomes of Full Pulpotomy as an Alternative to Tooth Extraction in Molars with Hyperplastic/Irreversible Pulpitis: A Case Report

Science.gov (United States)

Asgary, Saeed; Verma, Prashant; Nosrat, Ali

2017-01-01

Root canal therapy (RCT) is a common and successful treatment for irreversible pulpitis due to carious pulp exposure in mature permanent teeth. However, it is often an expensive procedure, may require multiple appointments, and requires a high level of training and clinical skill, specifically in molars. Uninsured patients, low-income patients, and patients with limited access to specialist care often elect for extraction of restorable teeth with irreversible pulpitis. There is a need for an alternative affordable treatment option to preserve their teeth and maintain chewing function. A case of pulpotomy using calcium-enriched mixture (CEM) cement in two maxillary molars (#14 and 15) in a healthy 36-year-old patient is presented. Both teeth were diagnosed with symptomatic hyperplastic/irreversible pulpitis. Patient did not have dental insurance, was unable to afford RCT, and refused to extract the teeth. CEM pulpotomy and amalgam build-ups were done as an alternative to extraction. At 2-year recall, both teeth were functional with no signs/symptoms of inflammation/infection. Periapical radiographs and 3D images showed normal PDL around all roots. Pulpotomy with CEM biomaterial might be a viable alternative to tooth extraction for mature permanent teeth with hyperplastic/irreversible pulpitis, and can result in long-term tooth retention and improved oral health. PMID:28512498

Influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions.

Science.gov (United States)

Carbajal Mejía, Jeison B; Wakabayashi, Kazumichi; Nakamura, Takashi; Yatani, Hirofumi

2017-09-01

Direct (intraoral) and indirect (desktop) digital scanning can record abutment tooth preparations despite their geometry. However, little peer-reviewed information is available regarding the influence of abutment tooth geometry on the accuracy of digital methods of obtaining dental impressions. The purpose of this in vitro study was to evaluate the influence of abutment tooth geometry on the accuracy of conventional and digital methods of obtaining dental impressions in terms of trueness and precision. Crown preparations with known total occlusal convergence (TOC) angles (-8, -6, -4, 0, 4, 8, 12, 16, and 22 degrees) were digitally created from a maxillary left central incisor and printed in acrylic resin. Each of these 9 reference models was scanned with a highly accurate reference scanner and saved in standard tessellation language (STL) format. Then, 5 conventional polyvinyl siloxane (PVS) impressions were made from each reference model, which was poured with Type IV dental stone scanned using both the reference scanner (group PVS) and the desktop scanner and exported as STL files. Additionally, direct digital impressions (intraoral group) of the reference models were made, and the STL files were exported. The STL files from the impressions obtained were compared with the original geometry of the reference model (trueness) and within each test group (precision). Data were analyzed using 2-way ANOVA with the post hoc least significant difference test (α=.05). Overall trueness values were 19.1 μm (intraoral scanner group), 23.5 μm (desktop group), and 26.2 μm (PVS group), whereas overall precision values were 11.9 μm (intraoral), 18.0 μm (PVS), and 20.7 μm (desktop). Simple main effects analysis showed that impressions made with the intraoral scanner were significantly more accurate than those of the PVS and desktop groups when the TOC angle was less than 8 degrees (Pimpression and the TOC angle on the precision of single-tooth dental impressions (F=2

Invasive Intraneural Interfaces: Foreign Body Reaction Issues

Science.gov (United States)

Lotti, Fiorenza; Ranieri, Federico; Vadalà, Gianluca; Zollo, Loredana; Di Pino, Giovanni

2017-01-01

Intraneural interfaces are stimulation/registration devices designed to couple the peripheral nervous system (PNS) with the environment. Over the last years, their use has increased in a wide range of applications, such as the control of a new generation of neural-interfaced prostheses. At present, the success of this technology is limited by an electrical impedance increase, due to an inflammatory response called foreign body reaction (FBR), which leads to the formation of a fibrotic tissue around the interface, eventually causing an inefficient transduction of the electrical signal. Based on recent developments in biomaterials and inflammatory/fibrotic pathologies, we explore and select the biological solutions that might be adopted in the neural interfaces FBR context: modifications of the interface surface, such as organic and synthetic coatings; the use of specific drugs or molecular biology tools to target the microenvironment around the interface; the development of bio-engineered-scaffold to reduce immune response and promote interface-tissue integration. By linking what we believe are the major crucial steps of the FBR process with related solutions, we point out the main issues that future research has to focus on: biocompatibility without losing signal conduction properties, good reproducible in vitro/in vivo models, drugs exhaustion and undesired side effects. The underlined pros and cons of proposed solutions show clearly the importance of a better understanding of all the molecular and cellular pathways involved and the need of a multi-target action based on a bio-engineered combination approach. PMID:28932181

Novel biomaterials: plasma-enabled nanostructures and functions

International Nuclear Information System (INIS)

Levchenko, Igor; Ostrikov, Kostya; Keidar, Michael; Cvelbar, Uroš; Mariotti, Davide; Mai-Prochnow, Anne; Fang, Jinghua

2016-01-01

Material processing techniques utilizing low-temperature plasmas as the main process tool feature many unique capabilities for the fabrication of various nanostructured materials. As compared with the neutral-gas based techniques and methods, the plasma-based approaches offer higher levels of energy and flux controllability, often leading to higher quality of the fabricated nanomaterials and sometimes to the synthesis of the hierarchical materials with interesting properties. Among others, nanoscale biomaterials attract significant attention due to their special properties towards the biological materials (proteins, enzymes), living cells and tissues. This review briefly examines various approaches based on the use of low-temperature plasma environments to fabricate nanoscale biomaterials exhibiting high biological activity, biological inertness for drug delivery system, and other features of the biomaterials make them highly attractive. In particular, we briefly discuss the plasma-assisted fabrication of gold and silicon nanoparticles for bio-applications; carbon nanoparticles for bioimaging and cancer therapy; carbon nanotube-based platforms for enzyme production and bacteria growth control, and other applications of low-temperature plasmas in the production of biologically-active materials. (topical review)

Advances in biomaterials for preventing tissue adhesion.

Science.gov (United States)

Wu, Wei; Cheng, Ruoyu; das Neves, José; Tang, Jincheng; Xiao, Junyuan; Ni, Qing; Liu, Xinnong; Pan, Guoqing; Li, Dechun; Cui, Wenguo; Sarmento, Bruno

2017-09-10

Adhesion is one of the most common postsurgical complications, occurring simultaneously as the damaged tissue heals. Accompanied by symptoms such as inflammation, pain and even dyskinesia in particular circumstances, tissue adhesion has substantially compromised the quality of life of patients. Instead of passive treatment, which involves high cost and prolonged hospital stay, active intervention to prevent the adhesion from happening has been accepted as the optimized strategy against this complication. Herein, this paper will cover not only the mechanism of adhesion forming, but also the biomaterials and medicines used in its prevention. Apart from acting as a direct barrier, biomaterials also show promising anti-adhesive bioactivity though their intrinsic physical and chemical are still not completely unveiled. Considering the diversity of human tissue organization, it is imperative that various biomaterials in combination with specific medicine could be tuned to fit the microenvironment of targeted tissues. With the illustration of different adhesion mechanism and solutions, we hope this review can become a beacon and further inspires the development of anti-adhesion biomedicines. Copyright © 2017 Elsevier B.V. All rights reserved.

Resin-bonded restorations: a strategy for managing anterior tooth loss in adolescence.

Science.gov (United States)

Zitzmann, Nicola U; Özcan, Mutlu; Scherrer, Susanne S; Bühler, Julia M; Weiger, Roland; Krastl, Gabriel

2015-04-01

In children or adolescents with anterior tooth loss, space closure with the patient's own teeth should be considered as the first choice to avoid lifelong restorative needs. Thorough diagnostics and treatment planning are required when autotransplantation or orthodontic space closure is considered. If these options are not indicated and a single tooth implant restoration is considered, implant placement should be postponed until adulthood, particularly in young women and in patients with hyperdivergent skeletal growth pattern. A ceramic resin-bonded fixed dental prosthesis with 1 retainer is an excellent treatment solution for the interim period; it may also serve as a long-term restoration, providing that sound enamel structure is present, sufficient framework dimensions have been provided, adhesive cementation techniques have been meticulously applied, and functional contacts of the cantilever pontic avoided. In contrast, a resin-bonded fixed dental prosthesis with a metal framework and retentive preparation is indicated if the palatal enamel structure is compromised, interocclusal clearance is limited, splinting (such as after orthodontic treatment) is required, or more than 1 tooth has to be replaced. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Multiphoton microscopy imaging of developing tooth germs

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Pei-Yu Pan

2014-01-01

Conclusion: In this study, a novel multiphoton microscopy database of images from developing tooth germs in mice was set up. We confirmed that multiphoton laser microscopy is a powerful tool for investigating the development of tooth germ and is worthy for further application in the study of tooth regeneration.

A Radiographic Study of Fused and Geminated Tooth

Energy Technology Data Exchange (ETDEWEB)

Park, Chul Jae; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyunhee University, Seoul (Korea, Republic of)

1990-02-15

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

A Radiographic Study of Fused and Geminated Tooth

International Nuclear Information System (INIS)

Park, Chul Jae; Lee, Sang Rae

1990-01-01

The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

Low-temperature plasma techniques in surface modification of biomaterials

International Nuclear Information System (INIS)

Feng Xiangfen; Xie Hankun; Zhang Jing

2002-01-01

Since synthetic polymers usually can not meet the biocompatibility and bio-functional demands of the human body, surface treatment is a prerequisite for them to be used as biomaterials. A very effective surface modification method, plasma treatment, is introduced. By immobilizing the bio-active molecules with low temperature plasma, polymer surfaces can be modified to fully satisfy the requirements of biomaterials

Bio-Functional Design, Application and Trends in Metallic Biomaterials

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Ke Yang

2017-12-01

Full Text Available Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1 mechanical properties that mimic the host tissues; (2 sufficient bioactivities to form bio-bonding between implants and surrounding tissues; and (3 a degradation rate that matches tissue regeneration and biodegradability. This article reviews the development of metal implants and their applications in biomedical engineering. Development trends and future perspectives of metallic biomaterials are also discussed.

Bio-Functional Design, Application and Trends in Metallic Biomaterials.

Science.gov (United States)

Yang, Ke; Zhou, Changchun; Fan, Hongsong; Fan, Yujiang; Jiang, Qing; Song, Ping; Fan, Hongyuan; Chen, Yu; Zhang, Xingdong

2017-12-22

Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1) mechanical properties that mimic the host tissues; (2) sufficient bioactivities to form bio-bonding between implants and surrounding tissues; and (3) a degradation rate that matches tissue regeneration and biodegradability. This article reviews the development of metal implants and their applications in biomedical engineering. Development trends and future perspectives of metallic biomaterials are also discussed.

Harnessing the potential of biomaterials for brain repair after stroke

Science.gov (United States)

Tuladhar, Anup; Payne, Samantha L.; Shoichet, Molly S.

2018-03-01

Stroke is a devastating disease for which no clinical treatment exists to regenerate lost tissue. Strategies for brain repair in animal models of stroke include the delivery of drug or cell-based therapeutics; however, the complex anatomy and functional organization of the brain presents many challenges. Biomaterials may alleviate some of these challenges by providing a scaffold, localizing the therapy to the site of action, and/or modulating cues to brain cells. Here, the challenges associated with delivery of therapeutics to the brain and the biomaterial strategies used to overcome these challenges are described. For example, innovative hydrogel delivery systems have been designed to provide sustained trophic factor delivery for endogenous repair and to support transplanted cell survival and integration. Novel treatments, such as electrical stimulation of transplanted cells and the delivery of factors for the direct reprogramming of astrocytes into neurons, may be further enhanced by biomaterial delivery systems. Ultimately, improved clinical translation will be achieved by combining clinically relevant therapies with biomaterials strategies.

In silico design of anti-atherogenic biomaterials.

Science.gov (United States)

Lewis, Daniel R; Kholodovych, Vladyslav; Tomasini, Michael D; Abdelhamid, Dalia; Petersen, Latrisha K; Welsh, William J; Uhrich, Kathryn E; Moghe, Prabhas V

2013-10-01

Atherogenesis, the uncontrolled deposition of modified lipoproteins in inflamed arteries, serves as a focal trigger of cardiovascular disease (CVD). Polymeric biomaterials have been envisioned to counteract atherogenesis based on their ability to repress scavenger mediated uptake of oxidized lipoprotein (oxLDL) in macrophages. Following the conceptualization in our laboratories of a new library of amphiphilic macromolecules (AMs), assembled from sugar backbones, aliphatic chains and poly(ethylene glycol) tails, a more rational approach is necessary to parse the diverse features such as charge, hydrophobicity, sugar composition and stereochemistry. In this study, we advance a computational biomaterials design approach to screen and elucidate anti-atherogenic biomaterials with high efficacy. AMs were quantified in terms of not only 1D (molecular formula) and 2D (molecular connectivity) descriptors, but also new 3D (molecular geometry) descriptors of AMs modeled by coarse-grained molecular dynamics (MD) followed by all-atom MD simulations. Quantitative structure-activity relationship (QSAR) models for anti-atherogenic activity were then constructed by screening a total of 1164 descriptors against the corresponding, experimentally measured potency of AM inhibition of oxLDL uptake in human monocyte-derived macrophages. Five key descriptors were identified to provide a strong linear correlation between the predicted and observed anti-atherogenic activity values, and were then used to correctly forecast the efficacy of three newly designed AMs. Thus, a new ligand-based drug design framework was successfully adapted to computationally screen and design biomaterials with cardiovascular therapeutic properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

Maggot excretions inhibit biofilm formation on biomaterials.

Science.gov (United States)

Cazander, Gwendolyn; van de Veerdonk, Mariëlle C; Vandenbroucke-Grauls, Christina M J E; Schreurs, Marco W J; Jukema, Gerrolt N

2010-10-01

Biofilm-associated infections in trauma surgery are difficult to treat with conventional therapies. Therefore, it is important to develop new treatment modalities. Maggots in captured bags, which are permeable for larval excretions/secretions, aid in healing severe, infected wounds, suspect for biofilm formation. Therefore we presumed maggot excretions/secretions would reduce biofilm formation. We studied biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella oxytoca, Enterococcus faecalis, and Enterobacter cloacae on polyethylene, titanium, and stainless steel. We compared the quantities of biofilm formation between the bacterial species on the various biomaterials and the quantity of biofilm formation after various incubation times. Maggot excretions/secretions were added to existing biofilms to examine their effect. Comb-like models of the biomaterials, made to fit in a 96-well microtiter plate, were incubated with bacterial suspension. The formed biofilms were stained in crystal violet, which was eluted in ethanol. The optical density (at 595 nm) of the eluate was determined to quantify biofilm formation. Maggot excretions/secretions were pipetted in different concentrations to (nonstained) 7-day-old biofilms, incubated 24 hours, and finally measured. The strongest biofilms were formed by S. aureus and S. epidermidis on polyethylene and the weakest on titanium. The highest quantity of biofilm formation was reached within 7 days for both bacteria. The presence of excretions/secretions reduced biofilm formation on all biomaterials. A maximum of 92% of biofilm reduction was measured. Our observations suggest maggot excretions/secretions decrease biofilm formation and could provide a new treatment for biofilm formation on infected biomaterials.

Assessment of crown angulations, crown inclinations, and tooth size discrepancies in a South Indian population

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Geeta Maruti Doodamani

2011-01-01

Full Text Available Aims and Objective: The aim of this study was to assess crown angulations, crown inclinations, and tooth size discrepancy in a sample population from Davangere, South India. Materials and Methods: One hundred adults (50 male and 50 female of age 18-30 years, with Angle′s class I ideal occlusion and balanced profiles, were selected for the study. Study models were prepared and crown angulations and crown inclinations were measured using a customized protractor device. Bolton′s analysis was used to measure the tooth size discrepancies. Results: Maxillary and mandibular teeth had less crown angulations. Maxillary and mandibular incisors and maxillary molars showed increased crown inclinations, whereas mandibular molars and premolars had less crown inclinations than the original Andrews sample. The mean maxillary and mandibular tooth size ratios, overall and anterior, were similar to Bolton′s ratios. Conclusions: The finding of this study indicates that there are possible racial and ethnic factors contributing to variations in crown angulations and crown inclinations.

Analysis of tooth tissues using Raman spectroscopy

International Nuclear Information System (INIS)

Timchenko, E.V.; Timchenko, P.E.; Kulabukhova, A.Yu.; Volova, L.T.; Rosenbaum, A.Yu.

2016-01-01

The results of experimental studies of healthy tooth tissue and tooth tissues during caries disease are presented. Features of Raman spectrum of tooth tissues during caries disease are obtained: the main changes are detected at wavenumbers 956 cm -1 .1069 cm -1 . corresponding to phosphates. and 1241 cm -1 . 1660 cm -1 . corresponding to collagen III and collagen I. respectively. Were introduced criteria allowing to detect caries and to identify weakening of tooth tissues. preceding the caries. The reliability of research results is confirmed by scanning electron microscopy. (paper)

A preliminary study of local administration of dexamethasone after tooth extraction: Better preservation of residual alveolar ridge?

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Poštić Srđan D.

2014-01-01

Full Text Available Background/Aim. It is important that the height of the edentulous alveolar ridge after tooth extraction remains at a reasonable acceptable level for as long as possible. The aim of this study was to report preliminary results of the clinical effect of local oral submucous administration of dexamethasone after tooth extractions in order to prepare alveolar supporting tissues for acceptance of removable dentures. Methods. In a total of 15 patients (11 partially and 4 completely edentulous the quantity of 0.25 mL to 0.5 mL of dexamethasone was injected bucally and orally in the region of the tooth socket after complicated extractions. Results. Healing of extraction wounds was uneventful in all the patients, without pain or local inflammation. Conclusion. Dexamethasone can be locally applied to oral tissues to prevent post-extraction inflammation and extensive resorption of the residual alveolar ridge. The obtained results are promising for patients undergoing classic prosthodontic rehabilitation soon after tooth extraction, demonstrating that there are no adverse effects after local oral corticosteroids administration. [Projekat Ministarstva nauke Republike Srbije, br. 175021

Microscale Architecture in Biomaterial Scaffolds for Spatial Control of Neural Cell Behavior

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Edi Meco

2018-02-01

Full Text Available Biomaterial scaffolds mimic aspects of the native central nervous system (CNS extracellular matrix (ECM and have been extensively utilized to influence neural cell (NC behavior in in vitro and in vivo settings. These biomimetic scaffolds support NC cultures, can direct the differentiation of NCs, and have recapitulated some native NC behavior in an in vitro setting. However, NC transplant therapies and treatments used in animal models of CNS disease and injury have not fully restored functionality. The observed lack of functional recovery occurs despite improvements in transplanted NC viability when incorporating biomaterial scaffolds and the potential of NC to replace damaged native cells. The behavior of NCs within biomaterial scaffolds must be directed in order to improve the efficacy of transplant therapies and treatments. Biomaterial scaffold topography and imbedded bioactive cues, designed at the microscale level, can alter NC phenotype, direct migration, and differentiation. Microscale patterning in biomaterial scaffolds for spatial control of NC behavior has enhanced the capabilities of in vitro models to capture properties of the native CNS tissue ECM. Patterning techniques such as lithography, electrospinning and three-dimensional (3D bioprinting can be employed to design the microscale architecture of biomaterial scaffolds. Here, the progress and challenges of the prevalent biomaterial patterning techniques of lithography, electrospinning, and 3D bioprinting are reported. This review analyzes NC behavioral response to specific microscale topographical patterns and spatially organized bioactive cues.

Primary culprit for tooth loss!!

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Sailavanya Nuvvula

2016-01-01

Full Text Available Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A questionnaire containing 10 items was distributed to the dental practitioners, which included age, gender, no of teeth indicated for extraction, the reason for extraction, and the periodontal parameters that are involved with the extracted tooth and were requested to complete the form on every extraction they were to undertake. the study form was collected at the end of the study period and data was subjected to statistical analysis. Results: A total of 502 patients were enrolled during the study period, and a total of 1055 teeth were extracted for several reasons. we found that 51.14%extractions are due to dental caries in case of 20-30years age groups, which is more when compared to tooth loss due to periodontal diseases in this age group. whereas in case of >40years of age group periodontal diseases account for 54.11%, and dental caries accounts for only 29.11%. Showing more teeth were lost due to periodontal disease. Conclusion: therefore we concluded that, caries is the dominant reason for extraction in patients with 20–30 years of age while periodontal disease accounts for the majority of tooth extraction in patients older than 40 years.

Sustainable Biomaterials: Current Trends, Challenges and Applications.

Science.gov (United States)

Kumar Gupta, Girish; De, Sudipta; Franco, Ana; Balu, Alina Mariana; Luque, Rafael

2015-12-30

Biomaterials and sustainable resources are two complementary terms supporting the development of new sustainable emerging processes. In this context, many interdisciplinary approaches including biomass waste valorization and proper usage of green technologies, etc., were brought forward to tackle future challenges pertaining to declining fossil resources, energy conservation, and related environmental issues. The implementation of these approaches impels its potential effect on the economy of particular countries and also reduces unnecessary overburden on the environment. This contribution aims to provide an overview of some of the most recent trends, challenges, and applications in the field of biomaterials derived from sustainable resources.

Sustainable Biomaterials: Current Trends, Challenges and Applications

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Girish Kumar Gupta

2015-12-01

Full Text Available Biomaterials and sustainable resources are two complementary terms supporting the development of new sustainable emerging processes. In this context, many interdisciplinary approaches including biomass waste valorization and proper usage of green technologies, etc., were brought forward to tackle future challenges pertaining to declining fossil resources, energy conservation, and related environmental issues. The implementation of these approaches impels its potential effect on the economy of particular countries and also reduces unnecessary overburden on the environment. This contribution aims to provide an overview of some of the most recent trends, challenges, and applications in the field of biomaterials derived from sustainable resources.

Microarrays for the evaluation of cell-biomaterial surface interactions

Science.gov (United States)

Thissen, H.; Johnson, G.; McFarland, G.; Verbiest, B. C. H.; Gengenbach, T.; Voelcker, N. H.

2007-01-01

The evaluation of cell-material surface interactions is important for the design of novel biomaterials which are used in a variety of biomedical applications. While traditional in vitro test methods have routinely used samples of relatively large size, microarrays representing different biomaterials offer many advantages, including high throughput and reduced sample handling. Here, we describe the simultaneous cell-based testing of matrices of polymeric biomaterials, arrayed on glass slides with a low cell-attachment background coating. Arrays were constructed using a microarray robot at 6 fold redundancy with solid pins having a diameter of 375 μm. Printed solutions contained at least one monomer, an initiator and a bifunctional crosslinker. After subsequent UV polymerisation, the arrays were washed and characterised by X-ray photoelectron spectroscopy. Cell culture experiments were carried out over 24 hours using HeLa cells. After labelling with CellTracker ® Green for the final hour of incubation and subsequent fixation, the arrays were scanned. In addition, individual spots were also viewed by fluorescence microscopy. The evaluation of cell-surface interactions in high-throughput assays as demonstrated here is a key enabling technology for the effective development of future biomaterials.

Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

Science.gov (United States)

2009-01-01

Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves. PMID:19939265

A 5-year prospective study of single-tooth replacements supported by the Astra Tech implant: a pilot study

DEFF Research Database (Denmark)

Gotfredsen, Klaus

2004-01-01

BACKGROUND: Implant-supported single-tooth replacements are an increasingly used method to replace teeth, especially in young patients. Therefore, long-term validation of different treatment modalities with different implant systems is of great importance. PURPOSE: The aim of the present study...... was to make a biologic, technical, and aesthetic evaluation of single-tooth replacement supported by the Astra Tech implant (Astra Tech AB, Mölndal, Sweden) during a 5-year period. MATERIALS AND METHODS: Twenty patients were divided into two consecutively treated groups. In group A the implants were placed...... "early" in the extraction sockets, and standard single-tooth abutments were used. In group B the implants were placed "delayed," and preparable abutments were used. Clinical examinations including registration of plaque, bleeding, crown lengths, soft tissue marginal level, papilla height, complications...

Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study.

LENUS (Irish Health Repository)

Harding, M A

2010-03-01

To determine the prevalence of tooth wear in the permanent dentition of a sample of 12-year-old school children and establish whether an association exists between tooth wear recorded now and tooth wear recorded in their primary dentition at age five.

Ultrafast dynamics of solvation and charge transfer in a DNA-based biomaterial.

Science.gov (United States)

Choudhury, Susobhan; Batabyal, Subrata; Mondol, Tanumoy; Sao, Dilip; Lemmens, Peter; Pal, Samir Kumar

2014-05-01

Charge migration along DNA molecules is a key factor for DNA-based devices in optoelectronics and biotechnology. The association of a significant amount of water molecules in DNA-based materials for the intactness of the DNA structure and their dynamic role in the charge-transfer (CT) dynamics is less documented in contemporary literature. In the present study, we have used a genomic DNA-cetyltrimethyl ammonium chloride (CTMA) complex, a technological important biomaterial, and Hoechest 33258 (H258), a well-known DNA minor groove binder, as fluorogenic probe for the dynamic solvation studies. The CT dynamics of CdSe/ZnS quantum dots (QDs; 5.2 nm) embedded in the as-prepared and swollen biomaterial have also been studied and correlated with that of the timescale of solvation. We have extended our studies on the temperature-dependent CT dynamics of QDs in a nanoenvironment of an anionic, sodium bis(2-ethylhexyl)sulfosuccinate reverse micelle (AOT RMs), whereby the number of water molecules and their dynamics can be tuned in a controlled manner. A direct correlation of the dynamics of solvation and that of the CT in the nanoenvironments clearly suggests that the hydration barrier within the Arrhenius framework essentially dictates the charge-transfer dynamics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Systematic Study on Tooth Enamel Microstructures of Lambdopsalis bulla (Multituberculate, Mammalia)--Implications for Multituberculate Biology and Phylogeny.

Science.gov (United States)

Mao, Fangyuan; Wang, Yuanqing; Meng, Jin

2015-01-01

Tooth enamel microstructure is a reliable and widely used indicator of dietary interpretations and data for phylogenetic reconstruction, if all levels of variability are investigated. It is usually difficult to have a thorough examination at all levels of enamel structures for any mammals, especially for the early mammals, which are commonly represented by sparse specimens. Because of the random preservation of specimens, enamel microstructures from different teeth in various species are often compared. There are few examples that convincingly show intraspecific variation of tooth enamel microstructure in full dentition of a species, including multituberculates. Here we present a systematic survey of tooth enamel microstructures of Lambdopsalis bulla, a taeniolabidoid multituberculate from the Late Paleocene Nomogen Formation, Inner Mongolia. We examined enamel structures at all hierarchical levels. The samples are treated differently in section orientations and acid preparation and examined using different imaging methods. The results show that, except for preparation artifacts, the crystallites, enamel types, Schmelzmuster and dentition types of Lambdopsalis are relatively consistent in all permanent teeth, but the prism type, including the prism shape, size and density, may vary in different portions of a single tooth or among different teeth of an individual animal. The most common Schmelzmuster of the permanent teeth in Lambdopsalis is a combination of radial enamel in the inner and middle layers, aprismatic enamel in the outer layer, and irregular decussations in tooth crown area with great curvature. The prism seam is another comparably stable characteristic that may be a useful feature for multituberculate taxonomy. The systematic documentation of enamel structures in Lambdopsalis may be generalized for the enamel microstructure study, and thus for taxonomy and phylogenetic reconstruction, of multituberculates and even informative for the enamel study of

A Systematic Study on Tooth Enamel Microstructures of Lambdopsalis bulla (Multituberculate, Mammalia) - Implications for Multituberculate Biology and Phylogeny

Science.gov (United States)

Mao, Fangyuan; Wang, Yuanqing; Meng, Jin

2015-01-01

Tooth enamel microstructure is a reliable and widely used indicator of dietary interpretations and data for phylogenetic reconstruction, if all levels of variability are investigated. It is usually difficult to have a thorough examination at all levels of enamel structures for any mammals, especially for the early mammals, which are commonly represented by sparse specimens. Because of the random preservation of specimens, enamel microstructures from different teeth in various species are often compared. There are few examples that convincingly show intraspecific variation of tooth enamel microstructure in full dentition of a species, including multituberculates. Here we present a systematic survey of tooth enamel microstructures of Lambdopsalis bulla, a taeniolabidoid multituberculate from the Late Paleocene Nomogen Formation, Inner Mongolia. We examined enamel structures at all hierarchical levels. The samples are treated differently in section orientations and acid preparation and examined using different imaging methods. The results show that, except for preparation artifacts, the crystallites, enamel types, Schmelzmuster and dentition types of Lambdopsalis are relatively consistent in all permanent teeth, but the prism type, including the prism shape, size and density, may vary in different portions of a single tooth or among different teeth of an individual animal. The most common Schmelzmuster of the permanent teeth in Lambdopsalis is a combination of radial enamel in the inner and middle layers, aprismatic enamel in the outer layer, and irregular decussations in tooth crown area with great curvature. The prism seam is another comparably stable characteristic that may be a useful feature for multituberculate taxonomy. The systematic documentation of enamel structures in Lambdopsalis may be generalized for the enamel microstructure study, and thus for taxonomy and phylogenetic reconstruction, of multituberculates and even informative for the enamel study of

Update on biomaterials for prevention of epidural adhesion after lumbar laminectomy

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Huailan Wang

2018-04-01

Full Text Available Summary: Lumbar laminectomy often results in failed back surgery syndrome. Most scholars support the three-dimensional theory of adhesion: Fibrosis surrounding the epidural tissues is based on the injured sacrospinalis behind, fibrous rings and posterior longitudinal ligaments. Approaches including using the minimally invasive technique, drugs, biomaterial and nonbiomaterial barriers to prevent the postoperative epidural adhesion were intensively investigated. Nevertheless, the results are far from satisfactory. Our review is based on various implant biomaterials that are used in clinical applications or are under study. We show the advantages and disadvantages of each method. The summary will help us to figure out ideas towards new techniques.The translational potential of this article: This review summarises recent biomaterials-related clinical and basic research that focuses on prevention of epidural adhesion after lumbar laminectomy. We also propose a novel possible translational method where a soft scaffold acts as a physical barrier in the early stage, engineered adipose tissue acts as a biobarrier in the later stage in the application of biomaterials and adipose-derived mesenchymal stem cells are used for prevention of epidural adhesion. Keywords: Adhesion, Biomaterials, Fibrosis, Implant, Laminectomy

Surface modification of biomaterials and biomedical devices using additive manufacturing.

Science.gov (United States)

Bose, Susmita; Robertson, Samuel Ford; Bandyopadhyay, Amit

2018-01-15

The demand for synthetic biomaterials in medical devices, pharmaceutical products and, tissue replacement applications are growing steadily due to aging population worldwide. The use for patient matched devices is also increasing due to availability and integration of new technologies. Applications of additive manufacturing (AM) or 3D printing (3DP) in biomaterials have also increased significantly over the past decade towards traditional as well as innovative next generation Class I, II and III devices. In this review, we have focused our attention towards the use of AM in surface modified biomaterials to enhance their in vitro and in vivo performances. Specifically, we have discussed the use of AM to deliberately modify the surfaces of different classes of biomaterials with spatial specificity in a single manufacturing process as well as commented on the future outlook towards surface modification using AM. It is widely understood that the success of implanted medical devices depends largely on favorable material-tissue interactions. Additive manufacturing has gained traction as a viable and unique approach to engineered biomaterials, for both bulk and surface properties that improve implant outcomes. This review explores how additive manufacturing techniques have been and can be used to augment the surfaces of biomedical devices for direct clinical applications. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Multiscale mechanics of hierarchical structure/property relationships in calcified tissues and tissue/material interfaces

International Nuclear Information System (INIS)

Katz, J. Lawrence; Misra, Anil; Spencer, Paulette; Wang, Yong; Bumrerraj, Sauwanan; Nomura, Tsutomu; Eppell, Steven J.; Tabib-Azar, Massood

2007-01-01

This paper presents a review plus new data that describes the role hierarchical nanostructural properties play in developing an understanding of the effect of scale on the material properties (chemical, elastic and electrical) of calcified tissues as well as the interfaces that form between such tissues and biomaterials. Both nanostructural and microstructural properties will be considered starting with the size and shape of the apatitic mineralites in both young and mature bovine bone. Microstructural properties for human dentin and cortical and trabecular bone will be considered. These separate sets of data will be combined mathematically to advance the effects of scale on the modeling of these tissues and the tissue/biomaterial interfaces as hierarchical material/structural composites. Interfacial structure and properties to be considered in greatest detail will be that of the dentin/adhesive (d/a) interface, which presents a clear example of examining all three material properties, (chemical, elastic and electrical). In this case, finite element modeling (FEA) was based on the actual measured values of the structure and elastic properties of the materials comprising the d/a interface; this combination provides insight into factors and mechanisms that contribute to premature failure of dental composite fillings. At present, there are more elastic property data obtained by microstructural measurements, especially high frequency ultrasonic wave propagation (UWP) and scanning acoustic microscopy (SAM) techniques. However, atomic force microscopy (AFM) and nanoindentation (NI) of cortical and trabecular bone and the dentin-enamel junction (DEJ) among others have become available allowing correlation of the nanostructural level measurements with those made on the microstructural level

Evaluating tooth restorations: micro-computed tomography in practical training for students in dentistry

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Deyhle, Hans; Schmidli, Fredy; Krastl, Gabriel; Müller, Bert

2010-09-01

Direct composite fillings belong to widespread tooth restoration techniques in dental medicine. The procedure consists of successive steps, which include etching of the prepared tooth surface, bonding and placement of composite in incrementally built up layers. Durability and lifespan of the composite inlays strongly depend on the accurate completion of the individual steps to be also realized by students in dental medicine. Improper handling or nonconformity in the bonding procedure often lead to air enclosures (bubbles) as well as to significant gaps between the composite layers or at the margins of the restoration. Traditionally one analyzes the quality of the restoration cutting the tooth in an arbitrarily selected plane and inspecting this plane by conventional optical microscopy. Although the precision of this established method is satisfactory, it is restricted to the selected two-dimensional plane. Rather simple micro computed tomography (μCT) systems, such as SkyScan 1174™, allows for the non-destructive three-dimensional imaging of restored teeth ex vivo and virtually cutting the tomographic data in any desired direction, offering a powerful tool for inspection of the restored tooth with micrometer resolution before cutting and thus also to select a two-dimensional plane with potential defects. In order to study the influence of the individual steps on the resulted tooth restoration, direct composite fillings were placed in mod cavities of extracted teeth. After etching, an adhesive was applied in half of the specimens. From the tomographic datasets, it becomes clear that gaps occur more frequently when bonding is omitted. The visualization of air enclosures offers to determine the probability to find a micrometer-sized defect using an arbitrarily selected cutting plane for inspection.

Comparison of the buccolingual inclination in alveolar bone and tooth using dental CBCT

International Nuclear Information System (INIS)

Kim, Sung Eun; Kim, Jin Soo; Kim, Jae Duk

2008-01-01

It is important to determine the bucco-lingual inclination of implants on radiographs before the implant surgery. The purpose of this study was to compare the buccolingual inclination in alveolar bone and the tooth with dental cone beam CT and to prepare the standard for the buccolingual inclination of implant. Axial, panoramic, and buccolingually sectioned images of 80 implant cases with stent including straight marker using CB Mercuray TM (Hitachi, Japan) were evaluated. The comparison of the buccolingual inclination of remained alveolar bone with the tooth and the marker on buccolingually sectioned views was performed statistically. The average buccolingual inclination of remained alveolar bone and tooth was 82.8 ± 4.6 .deg. C and 85.8 ± 4.7 .deg. C (p 0.05, r=0.12) at the 2nd premolar area in upper jaw. The average buccolingual inclination of remained alveolar bone and tooth was 81.3 ± 8.3 .deg. C and 87.5 ± 6.3 .deg. C (p>0.05, r=0.85) at the lower 2nd premolar area and 94.3 ± 6.6 .deg. C and 93.3 ± 7.2 .deg. C respectively (p>0.05, r=0.91) at the 1st molar area in lower jaw. The inclinations of markers were very different from those of remained bone at the most of areas except the upper 2nd premolar area (r=0.79). We recommend dental CBCT analysis for determining the buccolingual inclination of dental implant, because of significant difference, in average, between the buccolingual inclination of remained alveolar bone and tooth.

Predoctoral Curriculum Guidelines for Biomaterials.

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Journal of Dental Education, 1986

1986-01-01

The American Association of Dental Schools' predoctoral guidelines for biomaterials curricula includes notes on interrelationships between this and other fields, a curriculum overview, primary educational goals, prerequisites, a core content outline, specific behavioral objectives for each content area, and information on sequencing, faculty and…

Accelerated tooth eruption in children with diabetes mellitus.

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Lal, Shantanu; Cheng, Bin; Kaplan, Selma; Softness, Barney; Greenberg, Ellen; Goland, Robin S; Lalla, Evanthia; Lamster, Ira B

2008-05-01

The objective of this study was to evaluate tooth eruption in 6- to 14-year-old children with diabetes mellitus. Tooth eruption status was assessed for 270 children with diabetes and 320 control children without diabetes. Data on important diabetes-related variables were collected. Analyses were performed using logistic regression models. Children with diabetes exhibited accelerated tooth eruption in the late mixed dentition period (10-14 years of age) compared to healthy children. For both case patients and control subjects the odds of a tooth being in an advanced eruptive stage were significantly higher among girls than boys. There was also a trend associating gingival inflammation with expedited tooth eruption in both groups. No association was found between the odds of a tooth being in an advanced stage of eruption and hemoglobin A(1c) or duration of diabetes. Patients with higher body mass index percentile demonstrated statistically higher odds for accelerated tooth eruption, but the association was not clinically significant. Children with diabetes exhibit accelerated tooth eruption. Future studies need to ascertain the role of such aberrations in dental development and complications such as malocclusion, impaired oral hygiene, and periodontal disease. The standards of care for children with diabetes should include screening and referral programs aimed at oral health promotion and disease prevention.

Studying the glial cell response to biomaterials and surface topography for improving the neural electrode interface

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Ereifej, Evon S.

Neural electrode devices hold great promise to help people with the restoration of lost functions, however, research is lacking in the biomaterial design of a stable, long-term device. Current devices lack long term functionality, most have been found unable to record neural activity within weeks after implantation due to the development of glial scar tissue (Polikov et al., 2006; Zhong and Bellamkonda, 2008). The long-term effect of chronically implanted electrodes is the formation of a glial scar made up of reactive astrocytes and the matrix proteins they generate (Polikov et al., 2005; Seil and Webster, 2008). Scarring is initiated when a device is inserted into brain tissue and is associated with an inflammatory response. Activated astrocytes are hypertrophic, hyperplastic, have an upregulation of intermediate filaments GFAP and vimentin expression, and filament formation (Buffo et al., 2010; Gervasi et al., 2008). Current approaches towards inhibiting the initiation of glial scarring range from altering the geometry, roughness, size, shape and materials of the device (Grill et al., 2009; Kotov et al., 2009; Kotzar et al., 2002; Szarowski et al., 2003). Literature has shown that surface topography modifications can alter cell alignment, adhesion, proliferation, migration, and gene expression (Agnew et al., 1983; Cogan et al., 2005; Cogan et al., 2006; Merrill et al., 2005). Thus, the goals of the presented work are to study the cellular response to biomaterials used in neural electrode fabrication and assess surface topography effects on minimizing astrogliosis. Initially, to examine astrocyte response to various materials used in neural electrode fabrication, astrocytes were cultured on platinum, silicon, PMMA, and SU-8 surfaces, with polystyrene as the control surface. Cell proliferation, viability, morphology and gene expression was measured for seven days in vitro. Results determined the cellular characteristics, reactions and growth rates of astrocytes

Biomaterials trigger endothelial cell activation when co-incubated with human whole blood.

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Herklotz, Manuela; Hanke, Jasmin; Hänsel, Stefanie; Drichel, Juliane; Marx, Monique; Maitz, Manfred F; Werner, Carsten

2016-10-01

Endothelial cell activation resulting from biomaterial contact or biomaterial-induced blood activation may in turn also affect hemostasis and inflammatory processes in the blood. Current in vitro hemocompatibility assays typically ignore these modulating effects of the endothelium. This study describes a co-incubation system of human whole blood, biomaterial and endothelial cells (ECs) that was developed to overcome this limitation. First, human endothelial cells were characterized in terms of their expression of coagulation- and inflammation-relevant markers in response to various activators. Subsequently, their capacity to regulate hemostasis as well as complement and granulocyte activation was monitored in a hemocompatibility assay. After blood contact, quiescent ECs exhibited anticoagulant and anti-inflammatory properties. When they were co-incubated with surfaces exhibiting pro-coagulant or pro-inflammatory characteristics, the ECs down-regulated coagulation but not complement or leukocyte activation. Analysis of intracellular levels of the endothelial activation markers E-selectin and tissue factor showed that co-incubation with model surfaces and blood significantly increased the activation state of ECs. Finally, the coagulation- and inflammation-modulating properties of the ECs were tested after blood/biomaterial exposure. Pre-activation of ECs by biomaterials in the blood induced a pro-coagulant and pro-inflammatory state of the ECs, wherein the pro-coagulant response was higher for biomaterial/blood pre-activated ECs than for TNF-α-pre-activated cells. This work provides evidence that biomaterials, even without directly contacting the endothelium, affect the endothelial activation state with and have consequences for plasmatic and cellular reactions in the blood. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trends in prosthetic biomaterials in implant dentistry

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Saranjit Singh Bhasin

2015-01-01

Full Text Available The most important criterion for the success of dental implants is the selection of a suitable implant biomaterial. To improve the biologic performance of an implant, it is necessary to select a material that does not elicit any negative biological response and at the same time maintains adequate function. It is mandatory for a dentist to have a comprehensive knowledge of various biomaterials used for dental implants. The material of choice for fabrication of the dental implant till date is titanium. With the advancements in the field of implants, zirconia seems to be propitious in the future. However, more advanced in vitro and in vivo studies are required before reaching any such conclusion. To increase the success of zirconia implants, care should be taken to reduce the incidence of mechanical failures. Such failures can be taken care of by having a thorough technical knowledge of implant designing and manufacturing defects. This article attempts to compare the advantages and disadvantages of various dental implant biomaterials. Focus is placed on the recent advances in this field with the recently introduced zirconia and its comparison to conventional titanium.

Bio-Functional Design, Application and Trends in Metallic Biomaterials

OpenAIRE

Ke Yang; Changchun Zhou; Hongsong Fan; Yujiang Fan; Qing Jiang; Ping Song; Hongyuan Fan; Yu Chen; Xingdong Zhang

2017-01-01

Introduction of metals as biomaterials has been known for a long time. In the early development, sufficient strength and suitable mechanical properties were the main considerations for metal implants. With the development of new generations of biomaterials, the concepts of bioactive and biodegradable materials were proposed. Biological function design is very import for metal implants in biomedical applications. Three crucial design criteria are summarized for developing metal implants: (1) m...

Current and future biocompatibility aspects of biomaterials for hip prosthesis

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Amit Aherwar

2015-12-01

Full Text Available The field of biomaterials has turn into an electrifying area because these materials improve the quality and longevity of human life. The first and foremost necessity for the selection of the biomaterial is the acceptability by human body. However, the materials used in hip implants are designed to sustain the load bearing function of human bones for the start of the patient’s life. The most common classes of biomaterials used are metals, polymers, ceramics, composites and apatite. These five classes are used individually or in combination with other materials to form most of the implantation devices in recent years. Numerous current and promising new biomaterials i.e. metallic, ceramic, polymeric and composite are discussed to highlight their merits and their frailties in terms of mechanical and metallurgical properties in this review. It is concluded that current materials have their confines and there is a need for more refined multi-functional materials to be developed in order to match the biocompatibility, metallurgical and mechanical complexity of the hip prosthesis.

Self-assembly of protein-based biomaterials initiated by titania nanotubes.

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Forstater, Jacob H; Kleinhammes, Alfred; Wu, Yue

2013-12-03

Protein-based biomaterials are a promising strategy for creating robust highly selective biocatalysts. The assembled biomaterials must sufficiently retain the near-native structure of proteins and provide molecular access to catalytically active sites. These requirements often exclude the use of conventional assembly techniques, which rely on covalent cross-linking of proteins or entrapment within a scaffold. Here we demonstrate that titania nanotubes can initiate and template the self-assembly of enzymes, such as ribonuclease A, while maintaining their catalytic activity. Initially, the enzymes form multilayer thick ellipsoidal aggregates centered on the nanotube surface; subsequently, these nanosized entities assemble into a micrometer-sized enzyme material that has enhanced enzymatic activity and contains as little as 0.1 wt % TiO2 nanotubes. This phenomenon is uniquely associated with the active anatase (001)-like surface of titania nanotubes and does not occur on other anatase nanomaterials, which contain significantly fewer undercoordinated Ti surface sites. These findings present a nanotechnology-enabled mechanism of biomaterial growth and open a new route for creating stable protein-based biomaterials and biocatalysts without the need for chemical modification.

A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication.

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Dejak, Beata; Młotkowski, Andrzej

2015-03-01

Polymerization shrinkage of composites is one of the main causes of leakage around dental restorations. Despite the large numbers of studies there is no consensus, what kind of teeth reconstruction--direct or indirect composite restorations are the most beneficial and the most durable. The aim was to compare equivalent stresses and contact adhesive stresses in molar teeth with class II MOD cavities, which were restored with inlays and direct restorations (taking into account polymerization shrinkage of composite resin) during simulated mastication. The study was conducted using the finite elements method with the application of contact elements. Three 3D models of first molars were created: model A was an intact tooth; model B--a tooth with a composite inlay, and model C--a tooth with a direct composite restoration. Polymerization linear shrinkage 0.7% of a direct composite restoration and resin luting cement was simulated (load 1). A computer simulation of mastication was performed (load 2). In these 2 situations, equivalent stresses according to the modified von Mises criterion (mvM) in the materials of mandibular first molar models with different restorations were calculated and compared. Contact stresses in the luting cement-tooth tissue adhesive interface around the restorations were also assessed and analyzed. Equivalent stresses in a tooth with a direct composite restoration (the entire volume of which was affected by polymerization shrinkage) were many times higher than in the tooth restored with a composite inlay (where shrinkage was present only in a thin layer of the luting cement). In dentin and enamel the stress values were 8-14 times higher, and were 13 times higher in the direct restoration than in the inlay. Likewise, contact stresses in the adhesive bond around the direct restoration were 6.5-7.7 times higher compared to an extraorally cured restoration. In the masticatory simulation, shear contact stresses in the adhesive bond around the direct

Biologically Based Restorative Management of Tooth Wear

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Martin G. D. Kelleher

2012-01-01

Full Text Available The prevalence and severity of tooth wear is increasing in industrialised nations. Yet, there is no high-level evidence to support or refute any therapeutic intervention. In the absence of such evidence, many currently prevailing management strategies for tooth wear may be failing in their duty of care to first and foremost improve the oral health of patients with this disease. This paper promotes biologically sound approaches to the management of tooth wear on the basis of current best evidence of the aetiology and clinical features of this disease. The relative risks and benefits of the varying approaches to managing tooth wear are discussed with reference to long-term follow-up studies. Using reference to ethical standards such as “The Daughter Test”, this paper presents case reports of patients with moderate-to-severe levels of tooth wear managed in line with these biologically sound principles.

Role of biomaterials in neurorestoration after spinal cord injuries

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Ioana Stanescu

2016-05-01

Full Text Available Despite advances in knowledge and technology SCI remains one of the most severe and disabling disorders affecting young people. Spinal cord lesions result in permanent loss of motor, sensory and autonomic functions, causing an enormous impact on patient’s personal, social, familial and professional life. There is currently no effective treatment available to improve severe neurologic deficits and to decrease disability. Tissue-engineering techniques have developed a variety of scaffolds, made by biomaterials, used alone, incapsulated with cells or embedded with molecules, which are delivered to lesion site to achieve neural regeneration. Biomaterials may provide structural support and/or serve as a delivery vehicle for factors to arrest growth inhibition and promote axonal growth. Biomaterials acts like cell-carriers for the injury site, but also as reservoirs for growth factors or biomolecules. Hydrogels are a promising therapeutical strategy in spinal cord repair. Nano-fibers provide a three-dimensional network, which mimic closely the native extracellular matrix, thus offering a better support for cell attachment and proliferation than traditional micro-structure. New strategies like pharmacologic treatments, cell therapies, gene therapies and biomaterial tissue engineering should combine to increase their synergistic effect and to obtain the expected functional recovery in spinal cord injured patients

[Modern biomaterials as hemostatic dressings in kidney nephron sparing surgery (NSS)--murine model. A preliminary report].

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Nowacki, Maciej; Jundziłł, Arkadiusz; Bieniek, Miłosz; Kowalczyk, Tomasz; Kloskowski, Tomasz; Drewa, Tomasz

2012-01-01

sacrificed for comparison of hemostatic dressings function. Used biomaterials fulfilled their role as a hameostatic dresings. The material (Type I) was convenient and good for suturing. Haemostatic action times were as follows: (Type I) - 30 seconds. (Type III) - 50 seconds. In the control group were also observed, a proper hemostatic function after 30 seconds. In sectional observation was also found in 3 kidneys section preparation samples, a local tumor recurrence and metastasis to the other tissues of the abdomen. The tested biomaterials fulfill their hemostatic effect on kidney after NSS, without any significant difference acording to a standard hemostatic dressing used clinically. This data may be a potential factor for use in further studies to determine their continued relevance in the prevention of local tumor recurrence after nephron sparing surgery.

Tooth loss prevalence among cardiac males and females

International Nuclear Information System (INIS)

Bokhari, S.A.H.; Khan, A.A.; Butt, A.K.

2007-01-01

Objective of study was to observe differences of tooth loss prevalence in males and females with Cardiac diseases Poor oral health, tooth loss and periodontal diseases have been reported to be associated with coronary heart diseases. Studies report gender differences in prevalence of cardiac diseases and tooth loss. This paper presents gender differences of tooth loss in cardiac patients of a cardiac hospital of Lahore, Pakistan. Methodology: Age matched Cardiac males and females attending OPD of the Punjab Institute of Cardiology (PIC), Lahore were included in the study. Personal and health-related information were questioned and noted. Oral examination was performed for recording of missing teeth. 1200 CHD study subjects with age-range of 30 to 80 years were enrolled for study. 1045 age matched, 766 (73.30%) males and 279 (26.70%) females were examined for tooth loss. 852 (81.53%) genders had at least one tooth missing. 599 (78.19) males and 253 (90.68%) females were observed with mean tooth loss of 7.5 (SD 8.720) and 11.15 (SD 10.375)respectively statistical association among them was also significant (P= 0.000) with OR of 2.339. More subjects (76.29%) showed a loss of 1-15 teeth that I was also significant among males and females. Tooth loss was significant in age groups of 41-50 years (P=0.001) and 51-60 years (P=0.000) Gender differences of tooth loss prevalence among CHD Subjects were significant with more risk for males as compared to females. (author)

Functional constraints on tooth morphology in carnivorous mammals

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Smits Peter D

2012-08-01

Full Text Available Abstract Background The range of potential morphologies resulting from evolution is limited by complex interacting processes, ranging from development to function. Quantifying these interactions is important for understanding adaptation and convergent evolution. Using three-dimensional reconstructions of carnivoran and dasyuromorph tooth rows, we compared statistical models of the relationship between tooth row shape and the opposing tooth row, a static feature, as well as measures of mandibular motion during chewing (occlusion, which are kinetic features. This is a new approach to quantifying functional integration because we use measures of movement and displacement, such as the amount the mandible translates laterally during occlusion, as opposed to conventional morphological measures, such as mandible length and geometric landmarks. By sampling two distantly related groups of ecologically similar mammals, we study carnivorous mammals in general rather than a specific group of mammals. Results Statistical model comparisons demonstrate that the best performing models always include some measure of mandibular motion, indicating that functional and statistical models of tooth shape as purely a function of the opposing tooth row are too simple and that increased model complexity provides a better understanding of tooth form. The predictors of the best performing models always included the opposing tooth row shape and a relative linear measure of mandibular motion. Conclusions Our results provide quantitative support of long-standing hypotheses of tooth row shape as being influenced by mandibular motion in addition to the opposing tooth row. Additionally, this study illustrates the utility and necessity of including kinetic features in analyses of morphological integration.

Photon absorption of calcium phosphate-based dental biomaterials

International Nuclear Information System (INIS)

Singh, V. P.; Badiger, N. M.; Tekin, H. O.; Kara, U.; Vega C, H. R.; Fernandes Z, M. A.

2017-10-01

Effective atomic number and mass energy absorption buildup factors for four calcium phosphate-based biomaterials used in dental treatments were calculated for 0.015 to 15 MeV photons. The mass energy absorption coefficients were calculated for 0.5 to 40 mean free paths of photons. In the energy region important for dental radiology the Zeff for all studied biomaterials are larger in comparison to larger energies. In x-rays for dental radiology and the energy absorption buildup factors are low, however CbMDI bio material shows a resonance at 80 keV. (Author)

Use of ultrasound Doppler to determine tooth vitality in a discolored tooth after traumatic injury: its prospects and limitations

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Yong-Wook Cho

2014-02-01

Full Text Available When a tooth shows discoloration and does not respond to the cold test or electric pulp test (EPT after a traumatic injury, its diagnosis can be even more difficult due to the lack of proper diagnostic methods to evaluate its vitality. In these case reports, we hope to demonstrate that ultrasound Doppler might be successfully used to evaluate the vitality of the tooth after trauma, and help reduce unnecessary endodontic treatments. In all three of the present cases, the teeth were discolored after traumatic injuries and showed negative responses to the cold test and EPT. However, they showed distinctive vital reactions in the ultrasound Doppler test during the whole observation period. In the first case, the tooth color returned to normal, and the tooth showed a positive response to the cold test and EPT at 10 wk after the injury. In the second case, the tooth color had returned to its normal shade at 10 wk after the traumatic injury but remained insensitive to the cold test and EPT. In the third case, the discoloration was successfully treated with vital tooth bleaching.

Nanoporous biomaterials for uremic toxin adsorption in artificial kidney systems: A review.

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Cheah, Wee-Keat; Ishikawa, Kunio; Othman, Radzali; Yeoh, Fei-Yee

2017-07-01

Hemodialysis, one of the earliest artificial kidney systems, removes uremic toxins via diffusion through a semipermeable porous membrane into the dialysate fluid. Miniaturization of the present hemodialysis system into a portable and wearable device to maintain continuous removal of uremic toxins would require that the amount of dialysate used within a closed-system is greatly reduced. Diffused uremic toxins within a closed-system dialysate need to be removed to maintain the optimum concentration gradient for continuous uremic toxin removal by the dialyzer. In this dialysate regenerative system, adsorption of uremic toxins by nanoporous biomaterials is essential. Throughout the years of artificial kidney development, activated carbon has been identified as a potential adsorbent for uremic toxins. Adsorption of uremic toxins necessitates nanoporous biomaterials, especially activated carbon. Nanoporous biomaterials are also utilized in hemoperfusion for uremic toxin removal. Further miniaturization of artificial kidney system and improvements on uremic toxin adsorption capacity would require high performance nanoporous biomaterials which possess not only higher surface area, controlled pore size, but also designed architecture or structure and surface functional groups. This article reviews on various nanoporous biomaterials used in current artificial kidney systems and several emerging nanoporous biomaterials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1232-1240, 2017. © 2016 Wiley Periodicals, Inc.

Surface Reconstruction for Preparation of Plasmonic Au/TiO₂ Nanoparticle with Perfect Hetero Interface and Improved Photocatalytic Capacity.

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Yuan, Guoqiu; Ping, Chen; Zhao, Qin; Cao, Min; Jin, Yonglong; Ge, Cunwang

2018-07-01

The photocatalytic activity of plasmonic Au/TiO2 nanoparticles (NPs) is dependent on distances between Au and TiO2. The preparation of plasmonic NPs is still a challenge because of an inherent lattice mismatch on heterogeneous interfaces. The combination between Au and TiO2 NPs often exhibits physical adsorption, which affect block the electron transferring process by photo-induction from TiO2 to Au NPs and weaken the photocatalytic activity. In this work an approach for preparing plasmonic Au/TiO2 NPs with perfect hetero-interface was proposed based on reconstruction of anatase TiO2 with (101) surface and in-situ reduction of Au NPs. Under UV-irradiation, anatase TiO2 NPs with a high percentage of (001) facets in formaldehyde solution undergo photochemical reactions to reconstruct the (101) surface of TiO2 and simultaneously allow polyformaldehyde to absorb on the same surface. Thus, Au(OH)-4 ions could be adsorbed on the (101) surfaces of TiO2 through electrostatic adsorption and reduced to form nano-Au in situ after recrystallization at 180 °C. The high-resolution transmission electron microscopy (HRTEM) images showed clear nanoscale lattice transition on heterogeneous interfaces of Au/TiO2 NPs. The surface structure of TiO2 NPs and the growth mechanism of Au/TiO2 NPs were evaluated with HRTEM, X-ray photoelectron spectra (XPS) and Fourier transform infrared spectroscopy (FTIR). It was demonstrated that the as-prepared plasmonic Au/TiO2 NPs had higher photocatalytic activity and corrosion resistance in comparison with primary TiO2 NPs by photo-electrochemical measurements. The reinforcing mechanism could be interpreted with Mott-Schottky analysis in terms of quantum mechanics. Our study implied that the reconstruction based synthesis may open up more opportunities to obtain lattice-mismatch nanomaterials for photocatalysis.

Novel Biomaterials Used in Medical 3D Printing Techniques

OpenAIRE

Karthik Tappa; Udayabhanu Jammalamadaka

2018-01-01

The success of an implant depends on the type of biomaterial used for its fabrication. An ideal implant material should be biocompatible, inert, mechanically durable, and easily moldable. The ability to build patient specific implants incorporated with bioactive drugs, cells, and proteins has made 3D printing technology revolutionary in medical and pharmaceutical fields. A vast variety of biomaterials are currently being used in medical 3D printing, including metals, ceramics, polymers, and c...

Autogenous Transplantation for Replacing a Hopeless Tooth.

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Zakershahrak, Mehrsa; Moshari, Amirabbas; Vatanpour, Mehdi; Khalilak, Zohreh; Jalali Ara, Afsoon

2017-01-01

Autogenous tooth transplantation (ATT) is a simple and reasonable choice for replacing the missing teeth when a proper donor tooth is available. This report presents a case of successful ATT of a maxillary right third molar for replacement of mandibular right second molar with a concomitant endodontic-periodontal disease. The mandibular second molar was believed to be hopeless due to a severe damage to coronal tooth structure, inappropriate root canal treatment and apical radiolucency. After extraction of mandibular second molar and maxillary third molar (the donor), the tooth was re-implanted into the extracted socket of second molar site. Root canal therapy was then performed. After 3 years, clinical and radiographic examinations revealed satisfying results, with no signs and symptoms. The patient is asymptomatic and the transplanted tooth is still functional with no signs of marginal periodontal pathosis. Radiographies showed bone regeneration in the site of previous extensive periapical lesion, normal periodontal ligament with no signs of root resorption.

Development of biomaterial scaffold for nerve tissue engineering: Biomaterial mediated neural regeneration

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Sethuraman Swaminathan

2009-11-01

Full Text Available Abstract Neural tissue repair and regeneration strategies have received a great deal of attention because it directly affects the quality of the patient's life. There are many scientific challenges to regenerate nerve while using conventional autologous nerve grafts and from the newly developed therapeutic strategies for the reconstruction of damaged nerves. Recent advancements in nerve regeneration have involved the application of tissue engineering principles and this has evolved a new perspective to neural therapy. The success of neural tissue engineering is mainly based on the regulation of cell behavior and tissue progression through the development of a synthetic scaffold that is analogous to the natural extracellular matrix and can support three-dimensional cell cultures. As the natural extracellular matrix provides an ideal environment for topographical, electrical and chemical cues to the adhesion and proliferation of neural cells, there exists a need to develop a synthetic scaffold that would be biocompatible, immunologically inert, conducting, biodegradable, and infection-resistant biomaterial to support neurite outgrowth. This review outlines the rationale for effective neural tissue engineering through the use of suitable biomaterials and scaffolding techniques for fabrication of a construct that would allow the neurons to adhere, proliferate and eventually form nerves.

A novel method for improving chest tube insertion skills among medical interns. Using biomaterial-covered mannequin

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Ozgur Tatli

2017-10-01

Full Text Available Objectives: To develop a low-cost biomaterial-covered chest tube simulation model and assess its possible usefulness for developing the chest tube insertion skills among medical interns. Methods: This mannequin-based interventional study was performed in a University hospital setting. We included 63 physicians performing emergency medicine internship at the Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, between January 2015 and March 2015. A dummy was prepared for training simulation using a display mannequin. Medical interns received instruction concerning pneumothorax and the chest tube procedure. A total of 63 medical interns participating in this interventional study were asked to insert a chest tube in a biomaterial-covered mannequin. A senior trainee scored their performance using a check list and the mean of the total scores was calculated (21 items; total score, 42. Results: The mean procedural score was 40.9 ± 1.3 of a possible 42. The maximum score of 42 was achieved by 39.7% of the medical interns, while another 33.3% achieved a score of 41. Of the participants, 85% succeeded in inserting the tube via an appropriate technique, achieving a score of 40 or more. Conclusion: Our results indicated that this model could be useful for effective training of medical interns for chest tube insertion, which is an important skill in emergency medicine. This biomaterial-covered model is inexpensive and its use can potentially be widened to improve training methods without significant financial demand.

A novel method for improving chest tube insertion skills among medical interns. Using biomaterial-covered mannequin.

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Tatli, Ozgur; Turkmen, Suha; Imamoglu, Melih; Karaca, Yunus; Cicek, Mustafa; Yadigaroglu, Metin; Bayrak, Selen T; Asik, Olgun; Topbas, Murat; Turedi, Suleyman

2017-10-01

To develop a low-cost biomaterial-covered chest tube simulation model and assess its possible usefulness for developing the chest tube insertion skills among medical interns. Methods: This mannequin-based interventional study was performed in a University hospital setting. We included 63 physicians performing emergency medicine internship at the Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey, between January 2015 and March 2015. A dummy was prepared for training simulation using a display mannequin. Medical interns received instruction concerning pneumothorax and the chest tube procedure. A total of 63 medical interns participating in this interventional study were asked to insert a chest tube in a biomaterial-covered mannequin. A senior trainee scored their performance using a check list and the mean of the total scores was calculated (21 items; total score, 42). Results: The mean procedural score was 40.9 ± 1.3 of a possible 42. The maximum score of 42 was achieved by 39.7% of the medical interns, while another 33.3% achieved a score of 41. Of the participants, 85% succeeded in inserting the tube via an appropriate technique, achieving a score of 40 or more. Conclusion: Our results indicated that this model could be useful for effective training of medical interns for chest tube insertion, which is an important skill in emergency medicine. This biomaterial-covered model is inexpensive and its use can potentially be widened to improve training methods without significant financial demand.

Predicting biomaterial property-dendritic cell phenotype relationships from the multivariate analysis of responses to polymethacrylates

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Kou, Peng Meng; Pallassana, Narayanan; Bowden, Rebeca; Cunningham, Barry; Joy, Abraham; Kohn, Joachim; Babensee, Julia E.

2011-01-01

Dendritic cells (DCs) play a critical role in orchestrating the host responses to a wide variety of foreign antigens and are essential in maintaining immune tolerance. Distinct biomaterials have been shown to differentially affect the phenotype of DCs, which suggested that biomaterials may be used to modulate immune response towards the biologic component in combination products. The elucidation of biomaterial property-DC phenotype relationships is expected to inform rational design of immuno-modulatory biomaterials. In this study, DC response to a set of 12 polymethacrylates (pMAs) was assessed in terms of surface marker expression and cytokine profile. Principal component analysis (PCA) determined that surface carbon correlated with enhanced DC maturation, while surface oxygen was associated with an immature DC phenotype. Partial square linear regression, a multivariate modeling approach, was implemented and successfully predicted biomaterial-induced DC phenotype in terms of surface marker expression from biomaterial properties with R2prediction = 0.76. Furthermore, prediction of DC phenotype was effective based on only theoretical chemical composition of the bulk polymers with R2prediction = 0.80. These results demonstrated that immune cell response can be predicted from biomaterial properties, and computational models will expedite future biomaterial design and selection. PMID:22136715

Biomaterials for Local, Controlled Drug Delivery to the Injured Spinal Cord

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Alexis M. Ziemba

2017-05-01

Full Text Available Affecting approximately 17,000 new people each year, spinal cord injury (SCI is a devastating injury that leads to permanent paraplegia or tetraplegia. Current pharmacological approaches are limited in their ability to ameliorate this injury pathophysiology, as many are not delivered locally, for a sustained duration, or at the correct injury time point. With this review, we aim to communicate the importance of combinatorial biomaterial and pharmacological approaches that target certain aspects of the dynamically changing pathophysiology of SCI. After reviewing the pathophysiology timeline, we present experimental biomaterial approaches to provide local sustained doses of drug. In this review, we present studies using a variety of biomaterials, including hydrogels, particles, and fibers/conduits for drug delivery. Subsequently, we discuss how each may be manipulated to optimize drug release during a specific time frame following SCI. Developing polymer biomaterials that can effectively release drug to target specific aspects of SCI pathophysiology will result in more efficacious approaches leading to better regeneration and recovery following SCI.

Design, clinical translation and immunological response of biomaterials in regenerative medicine

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Sadtler, Kaitlyn; Singh, Anirudha; Wolf, Matthew T.; Wang, Xiaokun; Pardoll, Drew M.; Elisseeff, Jennifer H.

2016-07-01

The field of regenerative medicine aims to replace tissues lost as a consequence of disease, trauma or congenital abnormalities. Biomaterials serve as scaffolds for regenerative medicine to deliver cells, provide biological signals and physical support, and mobilize endogenous cells to repair tissues. Sophisticated chemistries are used to synthesize materials that mimic and modulate native tissue microenvironments, to replace form and to elucidate structure-function relationships of cell-material interactions. The therapeutic relevance of these biomaterial properties can only be studied after clinical translation, whereby key parameters for efficacy can be defined and then used for future design. In this Review, we present the development and translation of biomaterials for two tissue engineering targets, cartilage and cornea, both of which lack the ability to self-repair. Finally, looking to the future, we discuss the role of the immune system in regeneration and the potential for biomaterial scaffolds to modulate immune signalling to create a pro-regenerative environment.

21 CFR 872.3580 - Preformed gold denture tooth.

Science.gov (United States)

2010-04-01

... tooth in a fixed or removable partial denture. (b) Classification. Class I (general controls). The... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Preformed gold denture tooth. 872.3580 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3580 Preformed gold denture tooth. (a...

Highly effective Cu/Zn-carbon micro/nanofiber-polymer nanocomposite-based wound dressing biomaterial against the P. aeruginosa multi- and extensively drug-resistant strains.

Science.gov (United States)

Ashfaq, Mohammad; Verma, Nishith; Khan, Suphiya

2017-08-01

Pseudomonas aeruginosa (P. aeruginosa) is the most prevalent bacteria in the infections caused by burn, surgery, and traumatic injuries. Emergence of the P. aeruginosa bacterial resistance against various clinical drugs for wound treatment is the major concern nowadays. The present study describes the synthesis of the polyvinyl alcohol (PVA) and cellulose acetate phthalate (CAP) polymeric composite film (~0.2mm thickness) reinforced with the Cu/Zn bimetal-dispersed activated carbon micro/nanofiber (ACF/CNF), as a wound dressing material. The focus is on determining the efficacy of the prepared biomaterial against the multi and extensively drug-resistant P. aeruginosa strains isolated from the burning, surgical, and traumatic injury-wounds. The primary synthesis steps for the biomaterial include the mixing of a blend of CAP powder and the asymmetrically distributed Cu/Zn bimetals in ACF/CNF, into the polymerization reaction mixture of PVA. Biochemical tests showed that the prepared composite material significantly enhanced the in-vitro blood clotting rate, platelet aggregation, and macrophage cell proliferation, indicating the suitability of the material as a fast wound healer. The antibacterial tests performed against the P. aeruginosa strains showed that the material effectively suppressed the bacterial growth, with the bimetal nanoparticles dispersed in the material serving as an antibacterial agent. The PVA/CAP polymer composite served as an encapsulating agent providing a slow release of the nanoparticles, besides increasing the hemostatic properties of the biomaterial. The ACF/CNF served as a support to the dispersed bimetal nanoparticles, which also provided a mechanical and thermal stability to the material. Experimentally demonstrated to be biocompatible, the prepared metal-carbon-polymer nanocomposite in this study is an effective dressing material for the P. aeruginosa-infected wounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Macrophage phagocytic activity toward adhering staphylococci on cationic and patterned hydrogel coatings versus common biomaterials

NARCIS (Netherlands)

Da Silva Domingues, Joana; Roest, Steven; Wang, Yi; van der Mei, Henny C.; Libera, Matthew; van Kooten, Theo G.; Busscher, Henk J.

Biomaterial-associated-infection causes failure of biomaterial implants. Many new biomaterials have been evaluated for their ability to inhibit bacterial colonization and stimulate tissue-cell-integration, but neglect the role of immune cells. This paper compares macrophage phagocytosis of adhering

Biomaterials in Cardiovascular Research: Applications and Clinical Implications

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Saravana Kumar Jaganathan

2014-01-01

Full Text Available Cardiovascular biomaterials (CB dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs, is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of CB.

Titanium biomaterials with complex surfaces induced aberrant peripheral circadian rhythms in bone marrow mesenchymal stromal cells.

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Hassan, Nathaniel; McCarville, Kirstin; Morinaga, Kenzo; Mengatto, Cristiane M; Langfelder, Peter; Hokugo, Akishige; Tahara, Yu; Colwell, Christopher S; Nishimura, Ichiro

2017-01-01

Circadian rhythms maintain a high level of homeostasis through internal feed-forward and -backward regulation by core molecules. In this study, we report the highly unusual peripheral circadian rhythm of bone marrow mesenchymal stromal cells (BMSCs) induced by titanium-based biomaterials with complex surface modifications (Ti biomaterial) commonly used for dental and orthopedic implants. When cultured on Ti biomaterials, human BMSCs suppressed circadian PER1 expression patterns, while NPAS2 was uniquely upregulated. The Ti biomaterials, which reduced Per1 expression and upregulated Npas2, were further examined with BMSCs harvested from Per1::luc transgenic rats. Next, we addressed the regulatory relationship between Per1 and Npas2 using BMSCs from Npas2 knockout mice. The Npas2 knockout mutation did not rescue the Ti biomaterial-induced Per1 suppression and did not affect Per2, Per3, Bmal1 and Clock expression, suggesting that the Ti biomaterial-induced Npas2 overexpression was likely an independent phenomenon. Previously, vitamin D deficiency was reported to interfere with Ti biomaterial osseointegration. The present study demonstrated that vitamin D supplementation significantly increased Per1::luc expression in BMSCs, though the presence of Ti biomaterials only moderately affected the suppressed Per1::luc expression. Available in vivo microarray data from femurs exposed to Ti biomaterials in vitamin D-deficient rats were evaluated by weighted gene co-expression network analysis. A large co-expression network containing Npas2, Bmal1, and Vdr was observed to form with the Ti biomaterials, which was disintegrated by vitamin D deficiency. Thus, the aberrant BMSC peripheral circadian rhythm may be essential for the integration of Ti biomaterials into bone.

Impact of Ellagic Acid in Bone Formation after Tooth Extraction: An Experimental Study on Diabetic Rats

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Mazen M. Jamil Al-Obaidi

2014-01-01

Full Text Available Objectives. To estimate the impact of ellagic acid (EA towards healing tooth socket in diabetic animals, after tooth extraction. Methods. Twenty-four Sprague Dawley male rats weighing 250–300 g were selected for this study. All animals were intraperitoneally injected with 45 mg/kg (b.w. of freshly prepared streptozotocin (STZ, to induce diabetic mellitus. Then, the animals were anesthetized, and the upper left central incisor was extracted and the whole extracted sockets were filled with Rosuvastatin (RSV. The rats were separated into three groups, comprising 8 rats each. The first group was considered as normal control group and orally treated with normal saline. The second group was regarded as diabetic control group and orally treated with normal saline, whereas the third group comprised diabetic rats, administrated with EA (50 mg/kg orally. The maxilla tissue stained by eosin and hematoxylin (H&E was used for histological examinations and immunohistochemical technique. Fibroblast growth factor (FGF-2 and alkaline phosphatase (ALP were used to evaluate the healing process in the extracted tooth socket by immunohistochemistry test. Results. The reactions of immunohistochemistry for FGF-2 and ALP presented stronger expression, predominantly in EA treated diabetic rat, than the untreated diabetic rat. Conclusion. These findings suggest that the administration of EA combined with RSV may have accelerated the healing process of the tooth socket of diabetic rats, after tooth extraction.

[Gelatin/alginate hydrogel scaffolds prepared by 3D bioprinting promotes cell adhesion and proliferation of human dental pulp cells in vitro].

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Yu, Hai-Yue; Ma, Dan-Dan; Wu, Bu-Ling

2017-05-20

To evaluate the cytotoxicity of gelatin/alginate hydrogel scaffolds prepared by 3D bioprinting in human dental pulp cells (HDPCs) and compare the cell adhesion and proliferation of the cells seeded in the biomaterial using two different methods. HDPCs isolated by tissue block culture and enzyme digestion were cultured and passaged. Gelatin/alginate hydrogel scaffolds were printed using a bioplotter, and the cytotoxicity of the aqueous extracts of the scaffold material was tested in the third passage of HDPCs using cell counting kit-8. Scanning electron microscopy and trypan blue were used to assess the adhesion and proliferation of the cells seeded in the scaffold material at a low or high concentration. The aqueous extract of the scaffolds at different concentrations showed no obvious cytotoxicity and promoted the proliferation of HDPCs. The scaffolds had a good biocompatibility and HDPCs seeded in the scaffold showed good cell growth. Cell seeding at a high concentration in the scaffold better promoted the adhesion of HDPCs and resulted in a greater cell number on the scaffold surface compared with low-concentration cell seeding after a 5-day culture (Palginate hydrogel scaffolds prepared by 3D bioprinting has a good biocompatibility and promotes the proliferation of HDPCs, and can be used as a scaffold material for tooth regeneration. Cell seeding at a high concentration can better promote cell adhesion to the scaffold material.

A review of the biomaterials technologies for infection-resistant surfaces.

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Campoccia, Davide; Montanaro, Lucio; Arciola, Carla Renata

2013-11-01

Anti-infective biomaterials need to be tailored according to the specific clinical application. All their properties have to be tuned to achieve the best anti-infective performance together with safe biocompatibility and appropriate tissue interactions. Innovative technologies are developing new biomaterials and surfaces endowed with anti-infective properties, relying either on antifouling, or bactericidal, or antibiofilm activities. This review aims at thoroughly surveying the numerous classes of antibacterial biomaterials and the underlying strategies behind them. Bacteria repelling and antiadhesive surfaces, materials with intrinsic antibacterial properties, antibacterial coatings, nanostructured materials, and molecules interfering with bacterial biofilm are considered. Among the new strategies, the use of phages or of antisense peptide nucleic acids are discussed, as well as the possibility to modulate the local immune response by active cytokines. Overall, there is a wealth of technical solutions to contrast the establishment of an implant infection. Many of them exhibit a great potential in preclinical models. The lack of well-structured prospective multicenter clinical trials hinders the achievement of conclusive data on the efficacy and comparative performance of anti-infective biomaterials. © 2013 Elsevier Ltd. All rights reserved.

Biomaterial associated impairment of local neutrophil function.

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Kaplan, S S; Basford, R E; Kormos, R L; Hardesty, R L; Simmons, R L; Mora, E M; Cardona, M; Griffith, B L

1990-01-01

The effect of biomaterials on neutrophil function was studied in vitro to determine if these materials activated neutrophils and to determine the subsequent response of these neutrophils to further stimulation. Two biomaterials--polyurethane, a commonly used substance, and Velcro pile (used in the Jarvik 7 heart)--were evaluated. Two control substances, polyethylene and serum-coated polystyrene, were used for comparison. Neutrophil superoxide release was measured following incubation with these materials for 10, 30, and 120 min in the absence of additional stimulation and after stimulation with formylmethionylleucylphenylalanine (fMLP) or phorbol myristate acetate (PMA). The authors observed that the incubation of neutrophils on both polyurethane and Velcro resulted in substantially increased superoxide release that was greater after the 10 min than after the 30 or 120 min association. These activated neutrophils exhibited a poor additional response to fMLP but responded well to PMA. The effect of implantation of the Novacor left ventricular assist device on peripheral blood neutrophil function was also evaluated. The peripheral blood neutrophils exhibited normal superoxide release and chemotaxis. These studies suggest that biomaterials may have a profound local effect on neutrophils, which may predispose the patient to periprosthetic infection, but that the reactivity of circulating neutrophils is unimpaired.

Bone bonding at natural and biomaterial surfaces.

Science.gov (United States)

Davies, John E

2007-12-01

Bone bonding is occurring in each of us and all other terrestrial vertebrates throughout life at bony remodeling sites. The surface created by the bone-resorbing osteoclast provides a three-dimensionally complex surface with which the cement line, the first matrix elaborated during de novo bone formation, interdigitates and is interlocked. The structure and composition of this interfacial bony matrix has been conserved during evolution across species; and we have known for over a decade that this interfacial matrix can be recapitulated at a biomaterial surface implanted in bone, given appropriate healing conditions. No evidence has emerged to suggest that bone bonding to artificial materials is any different from this natural biological process. Given this understanding it is now possible to explain why bone-bonding biomaterials are not restricted to the calcium-phosphate-based bioactive materials as was once thought. Indeed, in the absence of surface porosity, calcium phosphate biomaterials are not bone bonding. On the contrary, non-bonding materials can be rendered bone bonding by modifying their surface topography. This paper argues that the driving force for bone bonding is bone formation by contact osteogenesis, but that this has to occur on a sufficiently stable recipient surface which has micron-scale surface topography with undercuts in the sub-micron scale-range.

21 CFR 872.5525 - Preformed tooth positioner.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5525 Preformed tooth positioner. (a) Identification. A preformed tooth positioner is a plastic device that is an impression of a perfected bite...

The use of CD47-modified biomaterials to mitigate the immune response.

Science.gov (United States)

Tengood, Jillian E; Levy, Robert J; Stachelek, Stanley J

2016-05-01

Addressing the aberrant interactions between immune cells and biomaterials represents an unmet need in biomaterial research. Although progress has been made in the development of bioinert coatings, identifying and targeting relevant cellular and molecular pathways can provide additional therapeutic strategies to address this major healthcare concern. To that end, we describe the immune inhibitory motif, receptor-ligand pairing of signal regulatory protein alpha and its cognate ligand CD47 as a potential signaling pathway to enhance biocompatibility. The goals of this article are to detail the known roles of CD47-signal regulatory protein alpha signal transduction pathway and to describe how immobilized CD47 can be used to mitigate the immune response to biomaterials. Current applications of CD47-modified biomaterials will also be discussed herein. © 2016 by the Society for Experimental Biology and Medicine.

Remineralising efficacy of tooth mousse plus (ACP CCPF) on radiated tooth

International Nuclear Information System (INIS)

Priya; Hegde, Mithra N.; Hegde, Nidarsh D.; Suchetha Kumari, N.; Sanjeev, Ganesh

2016-01-01

Dental complication is the common problem faced all over the world. Subjects with poor oral hygiene and patients undergoing radiotherapy for oral cancers are developing signs of decalcification of enamel, lesions and Caries. A well designed treatment is necessary to safeguard the tooth enamel surface before and after radiation, only then the caries on the enamel surface can be arrested by re-hardening it and ultimately converting them to the normal healthy condition. To determine the Annealing effect of radiated tooth by testing maximum micro hardness of the teeth before and after 30 days of radiation by the application of Remineralising agents. In our study, we collected 30 intact caries free human molar teeth and were sectioned mesio-distally

Cell-biomaterial mechanical interaction in the framework of tissue engineering: insights, computational modeling and perspectives.

Science.gov (United States)

Sanz-Herrera, Jose A; Reina-Romo, Esther

2011-01-01

Tissue engineering is an emerging field of research which combines the use of cell-seeded biomaterials both in vitro and/or in vivo with the aim of promoting new tissue formation or regeneration. In this context, how cells colonize and interact with the biomaterial is critical in order to get a functional tissue engineering product. Cell-biomaterial interaction is referred to here as the phenomenon involved in adherent cells attachment to the biomaterial surface, and their related cell functions such as growth, differentiation, migration or apoptosis. This process is inherently complex in nature involving many physico-chemical events which take place at different scales ranging from molecular to cell body (organelle) levels. Moreover, it has been demonstrated that the mechanical environment at the cell-biomaterial location may play an important role in the subsequent cell function, which remains to be elucidated. In this paper, the state-of-the-art research in the physics and mechanics of cell-biomaterial interaction is reviewed with an emphasis on focal adhesions. The paper is focused on the different models developed at different scales available to simulate certain features of cell-biomaterial interaction. A proper understanding of cell-biomaterial interaction, as well as the development of predictive models in this sense, may add some light in tissue engineering and regenerative medicine fields.

Influence of interface preparation on minority carrier lifetime for low bandgap tandem solar cell materials

Energy Technology Data Exchange (ETDEWEB)

Szabo, Nadine; Sagol, B. Erol; Seidel, Ulf; Schwarzburg, Klaus; Hannappel, Thomas [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

2010-07-01

III-V semiconductor compounds grown by MOVPE are implemented in todays state-of-the-art third generation multi-junction solar cells. The current record multi junction solar cell grown on germanium, having Ge, Ga(In)As and GaInP as subcells, reached a record efficiency of 41.6%. The efficiency of these multi junction solar cells could be significantly increased, if its low bandgap Ge subcell would be replaced by a more efficient tandem. For this purpose the low bandgap materials InGaAs and InGaAsP are suitable. The bandgap composition of these materials allows a better yield of the solar spectrum. Based on InGaAs/InGaAsP absorber materials we have developed a low bandgap tandem solar cell with optimized bandgaps. Results of time resolved photoluminescence (TRPL) for the IR-bandgap compounds InGaAsP (1.03 eV)/InGaAs (0.73 eV) are presented. The lifetime of minority carriers is one of the most important properties of solar cell absorber materials. We show on the example of the low band gap tandem cell how the choice of the materials, the quality of the bulk, the optimization of the band gap energies and the preparation of the critical interfaces are essential to build a high efficiency solar cell. The quality of the bulk and the preparation of the critical interfaces are essential for the growth of the double heterostructure (DHS).

Parameters affecting tooth loss during periodontal maintenance in a Greek population.

Science.gov (United States)

Tsami, Alexandra; Pepelassi, Eudoxie; Kodovazenitis, George; Komboli, Mado

2009-09-01

Investigators have evaluated predictive parameters of tooth loss during the maintenance phase (MP). The authors conducted a retrospective study to evaluate the rate of tooth loss and to explore the parameters that affect tooth loss during MP in a Greek population. A periodontist administered periodontal treatment and maintenance care to 280 participants with severe periodontitis for a mean period +/- standard deviation of 10.84 +/- 2.13 years. The periodontist recorded the following parameters for each participant: oral hygiene index level, simplified gingival index level, clinical attachment level, probing depth measurements, initial tooth prognosis, smoking status, tooth loss during active periodontal treatment and MP, and compliance with suggested maintenance visits. The authors found that total tooth loss during active treatment (n = 1,427) was greater than during MP (n = 918) and was associated with the initial tooth prognosis, tooth type group, participants' compliance with suggested maintenance visits, smoking status and acceptability of the quality of tooth restorations. Most of the teeth extracted during maintenance had an initial guarded prognosis (n = 612). Participants whose compliance was erratic had a greater risk of undergoing tooth extraction than did participants whose compliance was complete. Participants' initial tooth prognosis, tooth type, compliance with suggested maintenance visits and smoking status affected tooth loss during MP. Initial guarded prognosis and erratic compliance increased the risk of undergoing tooth extraction during maintenance. Determining predictive parameters for disease progression and tooth loss provides critical information to clinicians so that they can develop and implement rational treatment planning.

Incorporation of Biomaterials in Multicellular Aggregates Modulates Pluripotent Stem Cell Differentiation

Science.gov (United States)

Bratt-Leal, Andrés M.; Carpenedo, Richard L.; Ungrin, Mark; Zandstra, Peter W.; McDevitt, Todd C.

2010-01-01

Biomaterials are increasingly being used to engineer the biochemical and biophysical properties of the extracellular stem cell microenvironment in order to tailor niche characteristics and direct cell phenotype. To date, stem cell-biomaterial interactions have largely been studied by introducing stem cells into artificial environments, such as 2D cell culture on biomaterial surfaces, encapsulation of cell suspensions within hydrogel materials, or cell seeding on 3D polymeric scaffolds. In this study, microparticles fabricated from different materials, such as agarose, PLGA and gelatin, were stably integrated, in a dose-dependent manner, within aggregates of pluripotent stem cells (PSCs) prior to differentiation as a means to directly examine stem cell-biomaterial interactions in 3D. Interestingly, the presence of the materials within the stem cell aggregates differentially modulated the gene and protein expression patterns of several differentiation markers without adversely affecting cell viability. Microparticle incorporation within 3D stem cell aggregates can control the spatial presentation of extracellular environmental cues (i.e. soluble factors, extracellular matrix and intercellular adhesion molecules) as a means to direct the differentiation of stem cells for tissue engineering and regenerative medicine applications. In addition, these results suggest that the physical presence of microparticles within stem cell aggregates does not compromise PSC differentiation, but in fact the choice of biomaterials can impact the propensity of stem cells to adopt particular differentiated cell phenotypes. PMID:20864164

In vitro evaluation of three different biomaterials as scaffolds for canine mesenchymal stem cells

Directory of Open Access Journals (Sweden)

Oduvaldo Câmara Marques Pereira-Junior

2013-05-01

Full Text Available PURPOSE: To evaluate in vitro ability the of three different biomaterials - purified hydroxyapatite, demineralized bone matrix and castor oil-based polyurethane - as biocompatible 3D scaffolds for canine bone marrow mesenchymal stem cell (MSC intending bone tissue engineering. METHODS: MSCs were isolated from canine bone marrow, characterized and cultivated for seven days with the biomaterials. Cell proliferation and adhesion to the biomaterial surface were evaluated by scanning electron microscopy while differentiation into osteogenic lineage was evaluated by Alizarin Red staining and Sp7/Osterix surface antibody marker. RESULTS: The biomaterials allowed cellular growth, attachment and proliferation. Osteogenic differentiation occurred in the presence of hydroxyapatite, and matrix deposition commenced in the presence of the castor oil-based polyurethane. CONCLUSION: All the tested biomaterials may be used as mesenchymal stem cell scaffolds in cell-based orthopedic reconstructive therapy.

Assessment of angiogenic properties of biomaterials using the chicken embryo chorioallantoic membrane assay

International Nuclear Information System (INIS)

Azzarello, Joseph; Ihnat, Michael A; Kropp, Bradley P; Warnke, Linda A; Lin, H.-K.

2007-01-01

The angiogenic potential of a biomaterial is a critical factor for successful graft intake in tissue engineering. We developed a modified, rapid and reproducible chicken embryo chorioallantoic membrane (CAM) assay to evaluate the ability of biomaterials in inducing blood vessel density. Five biomaterials including one-layer porcine small intestinal submucosa (SIS), two-layer SIS, four-layer vacuum pressed (VP) SIS, polyglycolic acid (PGA) and PGA modified with poly(lactic-co-glycolic acid) (PLGA) were analyzed. A circular section (1.2 mm diameter) of each biomaterial was placed near a group of blood vessels in the CAM. Blood vessels around the biomaterials were captured with black and white images at 96 h post implantation; and the images were subjected to densitometry evaluation. One-layer SIS induced a significant increase in blood vessel density as compared to the cellulose nitrate negative control, and had the greatest increase in blood vessel density as compared to four-layer VP SIS, PGA, or PLGA modified PGA. Although two-layer SIS has enhanced physical structure for surgical manipulation, its induction in blood vessel density was significantly lower than the one-layer SIS. Stripping the SIS proteins or incubating one-layer SIS with neutralizing antibodies against basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) resulted in decreased angiogenesis. Consistent with results obtained from bladder augmentation animal models, these results confirmed that angiogenic growth factors were present in SIS and affected the angiogenic potential of biomaterials. These data also demonstrated that the CAM assay can be used to ascertain methodically the angiogenic potential of biomaterials

The application of radiation technology in the field of medical biomaterials

International Nuclear Information System (INIS)

Jin Huanyu; An Yan; Yin Hua

2011-01-01

The radiation technology has been applied extensively in the fields of biological engineering, tissue engineering, medical industry and so on. It also plays an important role in the sterilization and modification of biomaterials. This work reviews the development of irradiation technology and absorbed doses for the sterilization and modification of medical biomaterials. (authors)

Diversification and enrichment of clinical biomaterials inspired by Darwinian evolution.

Science.gov (United States)

Green, D W; Watson, G S; Watson, J A; Lee, D-J; Lee, J-M; Jung, H-S

2016-09-15

Regenerative medicine and biomaterials design are driven by biomimicry. There is the essential requirement to emulate human cell, tissue, organ and physiological complexity to ensure long-lasting clinical success. Biomimicry projects for biomaterials innovation can be re-invigorated with evolutionary insights and perspectives, since Darwinian evolution is the original dynamic process for biological organisation and complexity. Many existing human inspired regenerative biomaterials (defined as a nature generated, nature derived and nature mimicking structure, produced within a biological system, which can deputise for, or replace human tissues for which it closely matches) are without important elements of biological complexity such as, hierarchy and autonomous actions. It is possible to engineer these essential elements into clinical biomaterials via bioinspired implementation of concepts, processes and mechanisms played out during Darwinian evolution; mechanisms such as, directed, computational, accelerated evolutions and artificial selection contrived in the laboratory. These dynamos for innovation can be used during biomaterials fabrication, but also to choose optimal designs in the regeneration process. Further evolutionary information can help at the design stage; gleaned from the historical evolution of material adaptations compared across phylogenies to changes in their environment and habitats. Taken together, harnessing evolutionary mechanisms and evolutionary pathways, leading to ideal adaptations, will eventually provide a new class of Darwinian and evolutionary biomaterials. This will provide bioengineers with a more diversified and more efficient innovation tool for biomaterial design, synthesis and function than currently achieved with synthetic materials chemistry programmes and rational based materials design approach, which require reasoned logic. It will also inject further creativity, diversity and richness into the biomedical technologies that

Chicken eggshells (Gallus gallus domesticus) as carbonate calcium source for biomaterials production; Casca de ovo de galinha caipira (gallus gallus domesticus), como fonte de carbonato de calcio para producao de biomateriais

Energy Technology Data Exchange (ETDEWEB)

Junior, E.A. de O.; Bastos, J.S.B.; Silva, R.C. de S.; Macedo, H.R.A.; Macedo, M. O.C.; Bradim, A.S., E-mail: angelcassiasasilva@gmail.com [Instituto Federal de Educacao, Ciencia e Tecnologia do Piaui (FIPI), PI (Brazil)

2016-07-01

The eggshells present high levels of calcium carbonate. Calcium carbonate obtained from eggshells has been used in the production of biomaterials with applications in bone regeneration, since it is biocompatible. In this work, calcium carbonate was obtained from eggshells to prepare a composite biomaterial. The presence of calcium carbonate bands was observed through spectrometry in the infrared region. Scanning electron microscopy showed the presence of calcium carbonate particles with different sizes and shapes. Carbonate predominance in the form of calcite was also observed through the X-ray diffraction.

Variables affecting orthodontic tooth movement with clear aligners.

Science.gov (United States)

Chisari, Justin R; McGorray, Susan P; Nair, Madhu; Wheeler, Timothy T

2014-04-01

In this study, we examined the impacts of age, sex, root length, bone levels, and bone quality on orthodontic tooth movement. Clear aligners were programmed to move 1 central incisor 1 mm over the course of 8 weeks. Thirty subjects, ages 19 to 64, were enrolled, and measurements were made on digital models (percentage of tooth movement goal achieved). Morphometric features and bone quality were assessed with cone-beam computed tomography. Data from this study were combined with data from 2 similar studies to increase the power for some analyses. The mean percentage of tooth movement goal achieved was 57% overall. Linear regression modeling indicated a cubic relationship between age and tooth movement, with a decreasing rate of movement from ages 18 to 35 years, a slightly increasing rate from ages 35 to 50, and a decreasing rate from ages 50 to 70. The final decreasing trend was not apparent for women. As would be expected, the correlation was significant between the percentage of the goal achieved and the cone-beam computed tomography superimposed linear measures of tooth movement. A significant negative correlation was found between tooth movement and the measurement apex to the center of rotation, but bone quality, as measured by fractal dimension, was not correlated with movement. The relationship between age and tooth movement is complex and might differ for male and female patients. Limited correlations with cone-beam computed tomography morphology and rate of tooth movement were detected. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Autotransplantation of Premolars With a 3-Dimensional Printed Titanium Replica of the Donor Tooth Functioning as a Surgical Guide: Proof of Concept.

Science.gov (United States)

Verweij, Jop P; Moin, David Anssari; Mensink, Gertjan; Nijkamp, Peter; Wismeijer, Daniel; van Merkesteyn, J P Richard

2016-06-01

Autotransplantation of premolars is a good treatment option for young patients who have missing teeth. This study evaluated the use of a preoperatively 3-dimensional (3D)-printed replica of the donor tooth that functions as a surgical guide during autotransplantation. Five consecutive procedures were prospectively observed. Transplantations of maxillary premolars with optimal root development were included in this study. A 3D-printed replica of the donor tooth was used to prepare a precisely fitting new alveolus at the recipient site before extracting the donor tooth. Procedure time, extra-alveolar time, and number of attempts needed to achieve a good fit of the donor tooth in the new alveolus were recorded. For each transplantation procedure, the surgical time was shorter than 30 minutes. An immediate good fit of the donor tooth in the new alveolus was achieved with an extra-alveolar time shorter than 1 minute for all transplantations. These results show that the extra-alveolar time is very short when the surgical guide is used; therefore, the chance of iatrogenic damage to the donor tooth is minimized. The use of a replica of the donor tooth makes the autotransplantation procedure easier for the surgeon and facilitates optimal placement of the transplant. Copyright © 2016 The American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Tooth resorption in cats: contribution of vitamin D and inflammation

NARCIS (Netherlands)

Vrieling, H.E.

2010-01-01

Tooth resorption in cats Tooth resorption affecting several teeth is a painful disease with a prevalence of up to 75% in household cats and is often accompanied by periodontitis. Tooth resorption is caused by an increased number and activity of tooth-resorbing odontoclasts, cells that share

Tooth fractures in canine clinical practice

International Nuclear Information System (INIS)

Capik, I.; Ledecky, V.; Sevcik, A.

2001-01-01

Tooth fractures constitute a considerable fraction of all tooth diseases. Out of the 5,370 dogs treated during four years, 492 were presented with dental problems and 28.3 % of the latter were treated for tooth fractures. Canines were the most frequently affected teeth (38.8 %), followed by premolars (33.1 %), incisors (25.9 %), and molars (2.2 %), 55.4 % of the patients with canine and incisor fractures being large breed dogs. Fractures of premolars (mostly of 108, 208) were divided evenly irrespective of breed or body size. Nonsurgical endodontic treatment yielded good therapeutic results in most cases, but repeated treatment was necessary in some patients

Simulation of Protein and Peptide-Based Biomaterials

National Research Council Canada - National Science Library

Daggett, Valerie

2002-01-01

The overall goal of the proposed research is to pursue realistic molecular modeling studies of the stability, dynamics, structure, function, and folding of proteins and protein-based biomaterials in solution...

Computational prediction of the fatigue behavior of additively manufactured porous metallic biomaterials

NARCIS (Netherlands)

Hedayati, R.; Hosseini-Toudeshky, H; Sadighi, M.; Mohammadi-Aghdam, M; Zadpoor, A.A.

2016-01-01

The mechanical behavior of additively manufactured porous biomaterials has recently received increasing attention. While there is a relatively large body of data available on the static mechanical properties of such biomaterials, their fatigue behavior is not yet well-understood. That is partly

Open focused microwave-assisted sample preparation for rapid total and mercury species determination in environmental solid samples

OpenAIRE

Tseng, C. M.; Garraud, H.; Amouroux, D.; Donard, O. F. X.; de Diego, A.

1998-01-01

This paper describes rapid, simple microwave-assisted leaching/ digestion procedures for total and mercury species determination in sediment samples and biomaterials. An open focused microwave system allowed the sample preparation time to be dramatically reduced to only 24 min when a power of 40-80 W was applied. Quantitative leaching of methylmercury from sediments by HNO3 solution and complete dissolution of biomaterials by an alkaline solution, such as 25% TMAH solution, were obtained. Met...

Repair of dense connective tissues via biomaterial-mediated matrix reprogramming of the wound interface.

Science.gov (United States)

Qu, Feini; Pintauro, Michael P; Haughan, Joanne E; Henning, Elizabeth A; Esterhai, John L; Schaer, Thomas P; Mauck, Robert L; Fisher, Matthew B

2015-01-01

Repair of dense connective tissues in adults is limited by their intrinsic hypocellularity and is exacerbated by a dense extracellular matrix (ECM) that impedes cellular migration to and local proliferation at the wound site. Conversely, healing in fetal tissues occurs due in part to an environment conducive to cell mobility and division. Here, we investigated whether the application of a degradative enzyme, collagenase, could reprogram the adult wound margin to a more fetal-like state, and thus abrogate the biophysical impediments that hinder migration and proliferation. We tested this concept using the knee meniscus, a commonly injured structure for which few regenerative approaches exist. To focus delivery and degradation to the wound interface, we developed a system in which collagenase was stored inside poly(ethylene oxide) (PEO) electrospun nanofibers and released upon hydration. Through a series of in vitro and in vivo studies, our findings show that partial digestion of the wound interface improves repair by creating a more compliant and porous microenvironment that expedites cell migration to and/or proliferation at the wound margin. This innovative approach of targeted manipulation of the wound interface, focused on removing the naturally occurring barriers to adult tissue repair, may find widespread application in the treatment of injuries to a variety of dense connective tissues. Copyright © 2014 Elsevier Ltd. All rights reserved.

In-vitro responses of T lymphocytes to poly(butylene succinate) based biomaterials.

Science.gov (United States)

Toso, Montree; Patntirapong, Somying; Janvikul, Wanida; Singhatanadgit, Weerachai

2017-04-01

Polybutylene succinate (PBSu) and PBSu/β-tricalcium phosphate (TCP) composites are biocompatible and good candidates as bone graft materials. However, little is known about the responses of T lymphocytes to these biomaterials, which play an important role in the success of bone grafting. Activated T lymphocytes were cultured onto 32 mm diameter films (PBSu/TCP films), that had previously been placed in 6-well culture plates, for 8, 24 and 72 hours. A plastic-well culture plate was used as a control surface. The effects of PBSu-based biomaterials on T lymphocytes were examined by the using flow cytometry and reverse-transcription polymerase chain reaction. These biomaterials were non-toxic to T lymphocytes, allowing their normal DNA synthesis and activation. All materials induced only transient activation of T lymphocytes, which existed no longer than 72 hours. Proportions of four main CD4/CD8 T lymphocyte subpopulations were not affected by these biomaterials. Moreover, PBSu and PBSu/TCP significantly suppressed the expression of IL-1β and IL-6 genes by 15-35% and 21-26%, respectively. In contrast, a PBSu/TCP composite (at PBSu:TCP=60:40) significantly stimulated the expression of IL-10 and IL-13 genes by 17% and 19%, respectively. PBSu and PBSu/TCP composites were non-toxic to T lymphocytes and did not induce unfavorable responses of T lymphocytes. The tested biomaterials down-regulated key proinflammatory cytokine genes and up-regulated anti-inflammatory cytokine genes in T lymphocytes. These suggest that the biomaterials studied are good candidates as bone graft materials.

Age-related changes of dental pulp tissue after experimental tooth movement in rats

Directory of Open Access Journals (Sweden)

Martina Von Böhl

2016-01-01

Full Text Available It is generally accepted that the effect of orthodontic tooth movement on the dental pulp in adolescents is reversible and that it has no long-lasting effect on pulpal physiology. However, it is not clear yet if the same conclusion is also valid for adult subjects. Thus, in two groups of rats, aged 6 and 40 weeks respectively, 3 molars at one side of the maxilla were moved together in a mesial direction with a standardized orthodontic appliance delivering a force of 10 cN. The contralateral side served as a control. Parasagittal histological sections were prepared after tooth movement for 1, 2, 4, 8, and 12 weeks. The pulp tissue was characterized for the different groups, with special emphasis on cell density, inflammatory cells, vascularity, and odontoblasts. Dimensions of dentin and the pulpal horns was determined and related with the duration of orthodontic force application and age ware evaluated. We found that neither in young nor in adult rats, force application led to long-lasting or irreversible changes in pulpal tissues. Dimensional variables showed significant age-related changes. In conclusion, orthodontic tooth movement per se has no long-lasting or irreversible effect on pulpal tissues, neither in the young nor in the adult animals.

Radiochemical studies on corrosion products of oral biomaterials

International Nuclear Information System (INIS)

Madbouly, H.A.Abdallah

1998-01-01

The work given in this thesis deals with a radioactive tracer study of the sorption of the corrosion products of dental amalgams and antimony on human teeth, porcelain and acrylic materials, used as dental restorative material. Sorption was investigated in presence of water and liquids commonly intaken by man; namely tea with or without sugar, soluble coffee ( Nescaffee) with or without sugar and/or milk, red tea (karkadeh or hibiscus) with or without sugar and chicken soup. The radioactive isotopes of Ag, Sn, Zn (amalgam components) and antimony were prepared by their irradiation in the nuclear reactor; 110m Ag, 113 Sn, 65 Zn and 124 Sb were thereby produced. The percent uptake of each studied element was evaluated from the depletion of radioactivity of the corresponding radioactive tracer in the given medium containing a tooth (human or artificial)

Tooth cusp sharpness as a dietary correlate in great apes.

Science.gov (United States)

Berthaume, Michael A

2014-02-01

Mammalian molars have undergone heavy scrutiny to determine correlates between morphology and diet. Here, the relationship between one aspect of occlusal morphology, tooth cusp radius of curvature (RoC), and two broad dietary categories, folivory and frugivory, is analyzed in apes. The author hypothesizes that there is a relationship between tooth cusp RoC and diet, and that folivores have sharper teeth than frugivores, and further test the correlation between tooth cusp RoC and tooth cusp size. Eight measures of tooth cusp RoC (two RoCs per cusp) were taken from 53 M(2) s from four species and subspecies of frugivorous apes (Pongo pygmaeus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, and Gorilla gorilla gorilla) and two subspecies of folivorous apes (Gorilla beringei beringei, and Gorilla beringei graueri). Phylogenetically corrected ANOVAs were run on the full dataset and several subsets of the full dataset, revealing that, when buccolingual RoCs are taken into account, tooth cusp RoCs can successfully differentiate folivores and frugivores. PCAs revealed that folivores consistently had duller teeth than frugivores. In addition, a weak, statistically significant positive correlation exists between tooth cusp size and tooth cusp RoC. The author hypothesizes differences in tooth cusp RoC are correlated with wear rates, where, per vertical unit of wear, duller cusps will have a longer length of exposed enamel ridge than sharper cusps. More data need to be gathered to determine if the correlation between tooth cusp RoC and tooth cusp size holds true when small primates are considered. Copyright © 2013 Wiley Periodicals, Inc.

Engineering Biomaterials to Influence Oligodendroglial Growth, Maturation, and Myelin Production.

Science.gov (United States)

Russell, Lauren N; Lampe, Kyle J

2016-01-01

Millions of people suffer from damage or disease to the nervous system that results in a loss of myelin, such as through a spinal cord injury or multiple sclerosis. Diminished myelin levels lead to further cell death in which unmyelinated neurons die. In the central nervous system, a loss of myelin is especially detrimental because of its poor ability to regenerate. Cell therapies such as stem or precursor cell injection have been investigated as stem cells are able to grow and differentiate into the damaged cells; however, stem cell injection alone has been unsuccessful in many areas of neural regeneration. Therefore, researchers have begun exploring combined therapies with biomaterials that promote cell growth and differentiation while localizing cells in the injured area. The regrowth of myelinating oligodendrocytes from neural stem cells through a biomaterials approach may prove to be a beneficial strategy following the onset of demyelination. This article reviews recent advancements in biomaterial strategies for the differentiation of neural stem cells into oligodendrocytes, and presents new data indicating appropriate properties for oligodendrocyte precursor cell growth. In some cases, an increase in oligodendrocyte differentiation alongside neurons is further highlighted for functional improvements where the biomaterial was then tested for increased myelination both in vitro and in vivo. © 2016 S. Karger AG, Basel.

Life of a Tooth: A Visual Timeline

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Full Text Available ... Dentist Your Family's Oral Health About the AGD Dental care and oral health information you need from ... Menstrual Calendar for Tooth Extraction Learn what those dental words mean. The Life of a Tooth Home | ...

Is gingival recession a consequence of an orthodontic tooth size and/or tooth position discrepancy? "A paradigm shift".

Science.gov (United States)

Richman, Colin

2011-01-01

Gingival recession (GR) is a commonly observed dental lesion. The underlying etiology has not been clearly identified, although several theories have been suggested. Tooth crowding or tooth malalignment is also frequently observed, with both conditions appearing to be more prevalent in developed countries with heterogeneous populations. A total of 25 consecutively treated patients representing 72 teeth and demonstrating facial clinical GR of > 3 mm were examined clinically, photographically, and with 3-dimensional radiology using conebeam computed tomography. All examined teeth presented with normal interproximal probing depths and attachment levels (teeth demonstrating > 3 mm of GR presented with significantly prominent facial tooth contours and associated alveolar bone dehiscences. Most involved teeth presented with their root structures extending beyond the facial alveolar bony housing (fenestrations). This represents a discrepancy between tooth size and alveolar bone dimensions in the buccolingual, axial, and sagittal orientation. Fewer involved teeth were malpositioned toward the buccal aspect. Both conditions were associated with facial alveolar bone dehiscences and associated GR. This study suggests tooth volume and/or tooth position within the alveolar bony housing strongly correlate with GR. All nonperiodontitis-involved teeth with GR were associated with either wider teeth or facially aligned teeth. However, it is emphasized that all facially aligned teeth, or "larger" teeth, do not necessarily present with GR. Based on these findings, the radiographic-supporting bone index is proposed. This index should facilitate appropriate evaluation of the alveolar bone supporting the mucogingival complex, both on the facial and lingual aspect of teeth. Further investigations are needed to support these preliminary data.

Gastroesophageal Reflux Disease and Tooth Erosion

Directory of Open Access Journals (Sweden)

Sarbin Ranjitkar

2012-01-01

Full Text Available The increasing prevalence of gastroesophageal reflux disease (GERD in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

Tooth positioners and their effects on treatment outcome.

Science.gov (United States)

Pravindevaprasad, A; Therese, Beena Agnes

2013-07-01

Malocclusion can also be corrected by means of clear removable appliances called as "tooth positioners" or "aligners". A tooth positioner is used to control settling and to minimize or eliminate relapse of the teeth after an orthodontic treatment. In this article, a complete review of the objectives, course of treatment, fabrication, and the materials used for fabrication of tooth positioners along with their importance and disadvantages were discussed. Tooth positioners did improve the overall orthodontic treatment outcome as quantified by the ABO (American Board of orthodontics) objective scoring method. But once the initial occlusal contact was achieved, the vertical movement of teeth was found to be inhibited.

The 4th international comparison on EPR dosimetry with tooth enamel

Energy Technology Data Exchange (ETDEWEB)

Fattibene, P., E-mail: paola.fattibene@iss.it [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Wieser, A. [Helmholtz Zentrum Muenchen, Neuherberg D-85764 (Germany); Adolfsson, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Benevides, L.A. [Naval Dosimetry Center, Bethesda MD 20889-5600 (United States); Brai, M. [University of Palermo, I-90128 Palermo (Italy); Callens, F. [Ghent University, B-9000 Gent (Belgium); Chumak, V. [Research Center for Radiation Medicine AMS, 04050 Kiev (Ukraine); Ciesielski, B. [Medical University of Gdansk, 80-211 Gdansk (Poland); Della Monaca, S. [Istituto Superiore di Sanita, Department of Technology and Health, Viale Regina Elena 299, I-00162 Rome (Italy); Regina Elena Institute, I-00144 Rome (Italy); Emerich, K. [Medical University of Gdansk, 80-211 Gdansk (Poland); Department of Paediatric Dentistry, 80-208 Gdansk (Poland); Gustafsson, H. [Linkoeping University, SE-58185 Linkoeping (Sweden); Hirai, Y. [Radiation Effects Research Foundation, Minami-ku, Hiroshima 732-0815 (Japan); Hoshi, M. [Hiroshima University, Minami-ku, Hiroshima 734-8553 (Japan); Israelsson, A. [Linkoeping University, SE-58185 Linkoeping (Sweden); Ivannikov, A. [Medical Radiological Research Center, Obninsk, Kaluga region (Russian Federation); Ivanov, D. [Institute of Metal Physics, Yekaterinburg 620041 (Russian Federation); Kaminska, J. [Medical University of Gdansk, 80-211 Gdansk (Poland); Ke, Wu [Beijing Institute of Radiation Medicine, Beijing 100850 (China); Lund, E. [Linkoeping University, SE-58185 Linkoeping (Sweden); Marrale, M. [University of Palermo, I-90128 Palermo (Italy)

2011-09-15

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum Muenchen. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers.

Tooth-marked small theropod bone: an extremely rare trace

DEFF Research Database (Denmark)

Jacobsen, Aase Roland

2001-01-01

Tooth-marked dinosaur bones provide insight into feeding behaviours and biting strategies of theropod dinosaurs. The majority of theropod tooth marks reported to date have been found on herbivorous dinosaur bones, although some tyrannosaurid bones with tooth marks have also been reported. In 1988...

Association between Severity of Tooth Wear and Dentinal Hypersensitivity

Directory of Open Access Journals (Sweden)

Ashok Ayer

2016-11-01

Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

Orientation and deformation of mineral crystals in tooth surfaces.

Science.gov (United States)

Fujisaki, Kazuhiro; Todoh, Masahiro; Niida, Atsushi; Shibuya, Ryota; Kitami, Shunsuke; Tadano, Shigeru

2012-06-01

Tooth enamel is the hardest material in the human body, and it is mainly composed of hydroxyapatite (HAp)-like mineral particles. As HAp has a hexagonal crystal structure, X-ray diffraction methods can be used to analyze the crystal structure of HAp in teeth. Here, the X-ray diffraction method was applied to the surface of tooth enamel to measure the orientation and strain of the HAp crystals. The c-axis of the hexagonal crystal structure of HAp was oriented to the surface perpendicular to the tooth enamel covering the tooth surface. Thus, the strain of HAp at the surface of teeth was measured by X-ray diffraction from the (004) lattice planes aligned along the c-axis. The X-ray strain measurements were conducted on tooth specimens with intact surfaces under loading. Highly accurate strain measurements of the surface of tooth specimens were performed by precise positioning of the X-ray irradiation area during loading. The strains of the (004) lattice plane were measured at several positions on the surface of the specimens under compression along the tooth axis. The strains were obtained as tensile strains at the labial side of incisor tooth specimens. In posterior teeth, the strains were different at different measurement positions, varying from tensile to compressive types. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tooth Matrix Analysis for Biomonitoring of Organic Chemical Exposure: Current Status, Challenges, and Opportunities

Science.gov (United States)

Andra, Syam S.; Austin, Christine; Arora, Manish

2015-01-01

Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers to

Life of a Tooth: A Visual Timeline

Medline Plus

Full Text Available ... Child First See a Dentist? The History of Dental Advances Why is Oral Health Important for Men? What is Baby Bottle Tooth Decay? Learn what those dental words mean. The Life of a Tooth Home | ...

Evaluation of new injection and cavity preparation model in local anesthesia teaching

NARCIS (Netherlands)

Yekta, S.S.; Lampert, F.; Kazemi, S.; Kazemi, R.; Brand, H.S.; Baart, J.A.; Mazandarani, M.

2013-01-01

The aim of this study was to evaluate a recently developed preclinical injection and cavity preparation model in local anesthesia. Thirty-three dental students administered an inferior alveolar nerve block injection in the model, followed by preparation on a tooth. The injection was evaluated by

Inhibitory effect of interferon-γ on experimental tooth movement in mice.

Science.gov (United States)

Kohara, Haruka; Kitaura, Hideki; Yoshimatsu, Masako; Fujimura, Yuji; Morita, Yukiko; Eguchi, Toshiko; Yoshida, Noriaki

2012-09-01

The aim of this study was to investigate the effects of interferon (IFN)-γ on experimental tooth movement in mice using a murine experimental tooth movement model. An Ni-Ti closed-coil spring was inserted between the upper-anterior alveolar bones and the upper-left first molars in mice. We evaluated the relationship between local Ifn-γ mRNA levels and orthodontic tooth movement. In other experiments, IFN-γ was injected adjacent to each first molar every other day during tooth movement. After 12 days, the amount of tooth movement was measured. Tartrate-resistant acid phosphatase (TRAP)-positive cells at the pressure side of each experimental tooth were counted as osteoclasts. Local Ifn-γ mRNA expression increased with orthodontic tooth movement. The number of TRAP-positive cells increased on the pressure side of the first molar. In contrast, the degree of tooth movement and the number of TRAP-positive cells on the pressure side in IFN-γ-injected mice were less than those of control mice. IFN-γ was induced in experimental tooth movement, and could inhibit mechanical force-loaded osteoclastogenesis and tooth movement. These results suggest that IFN-γ might be useful in controlling orthodontic tooth movement because of its inhibitory action on excessive osteoclastogenesis during this movement.

Tooth bleaching and young adults in Nigeria: knowledge, experiences and intention.

Science.gov (United States)

Azodo, C C; Ogbomo, A C; Agbor, M A

2012-12-01

To assess the knowledge, experiences and intention to have tooth bleaching among young adults studying in a Nigerian University. A cross-section of part-time undergraduate students of University of Benin, Benin City, Nigeria were studied in 2010 using a self-administered questionnaire. About three-quarters 289 (72.4%) of the respondents reported awareness of at least one cause of tooth discoloration. A total of 143 (35.8%) of the respondents have heard of tooth bleaching with main sources of information being friends/relatives, dentists and the internet. One-third 132 (33.1%) of the respondents correctly identified that the aim of tooth bleaching was to make the teeth whiter. The respondents that had correct knowledge about mechanism, duration and complications of tooth bleaching were 51 (12.8%), 25 (6.3%) and 35 (8.8%) respectively. The major perceived benefits of tooth bleaching reported by the respondents were self confidence boost 152 (38.1%) and improvement of one's beauty 107 (26.8%). Out of the 68 (17.0%) respondents that have attempted tooth bleaching, 36 (52.9%) used tooth whitening toothpaste. Out of the 151 (37.8%) respondents that expressed intention of having tooth bleaching procedure, 32 (21.2%) would pursue the course, no matter the cost. In the studied population, knowledge of tooth discoloration was high, awareness and experiences of tooth bleaching were low but significant number expressed intention of having tooth bleaching. It is important that dentists increase oral health information particularly tooth bleaching information accessibility to the young adult population to improve the knowledge and prevent adverse effects.

Dental histology of Coelophysis bauri and the evolution of tooth attachment tissues in early dinosaurs.

Science.gov (United States)

Fong, Raymond K M; LeBlanc, Aaron R H; Berman, David S; Reisz, Robert R

2016-07-01

Studies of dinosaur teeth have focused primarily on external crown morphology and thus, use shed or in situ tooth crowns, and are limited to the enamel and dentine dental tissues. As a result, the full suites of periodontal tissues that attach teeth to the jaws remain poorly documented, particularly in early dinosaurs. These tissues are an integral part of the tooth and thus essential to a more complete understanding of dental anatomy, development, and evolution in dinosaurs. To identify the tooth attachment tissues in early dinosaurs, histological thin sections were prepared from the maxilla and dentary of a partial skull of the early theropod Coelophysis bauri from the Upper Triassic (Rhaetian- 209-201 Ma) Whitaker Quarry, New Mexico, USA. As one of the phylogenetically and geologically oldest dinosaurs, it is an ideal candidate for examining dental tissues near the base of the dinosaurian clade. The teeth of C. bauri exhibited a fibrous tooth attachment in which the teeth possessed five tissues: enamel, dentine, cementum, periodontal ligament (PDL), and alveolar bone. Our findings, coupled with those of more recent studies of ornithischian teeth, indicate that a tripartite periodontium, similar to that of crocodilians and mammals, is the plesiomorphic condition for dinosaurs. The occurrence of a tripartite periodontium in dinosaurs adds to the growing consensus that the presence of these tissues is the plesiomorphic condition for the major amniote clades. Furthermore, this study establishes the relative timing of tissue development and growth directions of periodontal tissues and provides the first comparative framework for future studies of dinosaur periodontal development, tooth replacement, and histology. J. Morphol. 277:916-924, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Application of biomaterials to advance induced pluripotent stem cell research and therapy

Science.gov (United States)

Tong, Zhixiang; Solanki, Aniruddh; Hamilos, Allison; Levy, Oren; Wen, Kendall; Yin, Xiaolei; Karp, Jeffrey M

2015-01-01

Derived from any somatic cell type and possessing unlimited self-renewal and differentiation potential, induced pluripotent stem cells (iPSCs) are poised to revolutionize stem cell biology and regenerative medicine research, bringing unprecedented opportunities for treating debilitating human diseases. To overcome the limitations associated with safety, efficiency, and scalability of traditional iPSC derivation, expansion, and differentiation protocols, biomaterials have recently been considered. Beyond addressing these limitations, the integration of biomaterials with existing iPSC culture platforms could offer additional opportunities to better probe the biology and control the behavior of iPSCs or their progeny in vitro and in vivo. Herein, we discuss the impact of biomaterials on the iPSC field, from derivation to tissue regeneration and modeling. Although still exploratory, we envision the emerging combination of biomaterials and iPSCs will be critical in the successful application of iPSCs and their progeny for research and clinical translation. PMID:25766254