WorldWideScience

Sample records for bioengineered tooth replacement

  1. Replacing a Missing Tooth

    Science.gov (United States)

    ... the extra bulk and removable nature of the partial denture and report that it feels unnatural. This type of prosthesis is best as a temporary replacement as described above. The second option in a patient without a bone graft is a fixed bridge. The missing tooth is restored with an ...

  2. Immediate total tooth replacement.

    Science.gov (United States)

    Garber, D A; Salama, M A; Salama, H

    2001-03-01

    Successful implant placement at the time of extraction has been documented. Implant placement at the time of extraction was initially performed as a two-stage procedure often with barrier membranes and sophisticated second-stage surgical uncoverings. The authors describe the next generation of this technique, including atraumatic tooth removal with simultaneous root form, implant placement, and temporization at one appointment. This technique of "Immediate Total Tooth Replacement" allows for the maintenance of the bony housing and soft-tissue form that existed before extraction, while at the same time establishing a root form anchor in the bone for an esthetic restoration. PMID:11913258

  3. Biology of tooth replacement in amniotes

    Institute of Scientific and Technical Information of China (English)

    John A Whitlock; Joy M Richman

    2013-01-01

    Tooth replacement is a common trait to most vertebrates, including mammals. Mammals, however, have lost the capacity for continuous tooth renewal seen in most other vertebrates, and typically have only 1–2 generations of teeth. Here, we review the mechanisms of tooth replacement in reptiles and mammals, and discuss in detail the current and historical theories on control of timing and pattern of tooth replacement and development.

  4. 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

  5. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    OpenAIRE

    Banerjee Nandini; Singh Sushma

    2013-01-01

    A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness a...

  6. Update on Renal Replacement Therapy: Implantable Artificial Devices and Bioengineered Organs.

    Science.gov (United States)

    Attanasio, Chiara; Latancia, Marcela T; Otterbein, Leo E; Netti, Paolo A

    2016-08-01

    Recent advances in the fields of artificial organs and regenerative medicine are now joining forces in the areas of organ transplantation and bioengineering to solve continued challenges for patients with end-stage renal disease. The waiting lists for those needing a transplant continue to exceed demand. Dialysis, while effective, brings different challenges, including quality of life and susceptibility to infection. Unfortunately, the majority of research outputs are far from delivering satisfactory solutions. Current efforts are focused on providing a self-standing device able to recapitulate kidney function. In this review, we focus on two remarkable innovations that may offer significant clinical impact in the field of renal replacement therapy: the implantable artificial renal assist device (RAD) and the transplantable bioengineered kidney. The artificial RAD strategy utilizes micromachining techniques to fabricate a biohybrid system able to mimic renal morphology and function. The current trend in kidney bioengineering exploits the structure of the native organ to produce a kidney that is ready to be transplanted. Although these two systems stem from different technological approaches, they are both designed to be implantable, long lasting, and free standing to allow patients with kidney failure to be autonomous. However, for both of them, there are relevant issues that must be addressed before translation into clinical use and these are discussed in this review. PMID:26905099

  7. Contemporary management of tooth replacement in the traumatized dentition

    Science.gov (United States)

    Alani, Aws; Austin, Rupert; Djemal, Serpil

    2012-01-01

    Dental trauma can result in tooth loss despite best efforts at retaining and maintaining compromised teeth (Dent Traumatol, 24, 2008, 379). Upper anterior teeth are more likely to suffer from trauma, and their loss can result in significant aesthetic and functional problems that can be difficult to manage (Endod Dent Traumatol, 9, 1993, 61; Int Dent J 59, 2009, 127). Indeed, teeth of poor prognosis may not only present with compromised structure but trauma may also result in damage to the support tissues. Injury to the periodontium and alveolus can have repercussions on subsequent restorative procedures (Fig. 19). Where teeth are identified as having a hopeless prognosis either soon after the incident or at delayed presentation; planning for eventual tooth loss and replacement can begin at the early stages. With advances in both adhesive and osseointegration technologies, there are now a variety of options for the restoration of edentate spaces subsequent to dental trauma. This review aims to identify key challenges in the provision of tooth replacement in the traumatized dentition and outline contemporary methods in treatment delivery. PMID:22494549

  8. DENTAL IMPLANTS: AS AN ALTERNATIVE FOR TOOTH REPLACEMENT

    Directory of Open Access Journals (Sweden)

    Banerjee Nandini

    2013-08-01

    Full Text Available A dental implant is an artificial tooth that replaces a tooth that has been taken out. Implants are natural-looking, can provide support for dentures and do not affect the teeth bordering them. They are as stable as your real teeth and protect you from the loss of jawbone, which occurs when you lose teeth. Endosseous dental implants have revolutionized the fields of implants and periodontics. During the last decade, a great deal of information has been generated concerning the effectiveness and predictability of endosseous implants. Implant placement is a viable option in the treatment of partial and full edentulism and has become an integral facet of periodontal therapy. The available implants are remarkably successful. This review discusses the different aspects of dental implant including its advantages over the contemporary removable implants, its procedure in detail and the financial outlook of the same. The review also has a small consideration on minidental implant.

  9. Single-tooth replacement: factors affecting different prosthetic treatment modalities

    Directory of Open Access Journals (Sweden)

    Al-Quran Firas A

    2011-12-01

    Full Text Available Abstract Background The choice between several treatment options for replacing a single missing tooth is influenced by clinical, dentist- and patient-immanent factors. This study aimed to determine the patient factors that would affect the treatment decision to replace a single missing tooth and to assess the satisfaction with several options. Method 200 volunteers involved (121 females and 79 males divided into four groups, Group A: consisted of patients with conventional fixed partial dentures or patients with resin bonded fixed partial dentures. Group B: consisted of patients who received removable partial dentures while Group C: consisted of patients who received a single implant supported crown, and a control group D: consisted of patients who received no treatment. Data were collected using a questionnaire. Results The highest percentage of males within groups (58% was within the removable prostheses category. The majority of the subjects in the study reported that the main reason for replacing a missing tooth was for esthetic and function. Most important factor affecting the choice between treatment modalities was damaging the neighboring teeth. Pain, post operative sensitivity and dental phobia were important factors in choosing the prosthesis type and affected the control group patients not to have any treatment. The highest satisfaction percentage among groups studied was recorded for dental implants then FPD groups, while the least percentage were in both the control and RPD groups, for all aspects of function, esthetic and speech efficiency. Conclusions The final choice between FPD, RPD and implant depended on several factors which affected the decision making; among these is cost and patients' awareness of the different treatment options.

  10. Tooth replacement of tigerfish Hydrocynus vittatus from the Kruger National Park

    OpenAIRE

    1996-01-01

    Evidence of tooth replacement was observed in 14 tigerfish which had been caught during the period 1991 - 1993 in the Olifants and Letaba rivers in the Kruger National Park. Replacement of teeth is a quick process (3-5 days) and first replacement of adult coni- cal dentition takes place at six to seven months post hatch, at a body length of 100 mm (FL). Swollen gums are evident prior to tooth replacement and newly erupted teeth are loosely embedded in the gums. Tooth replacement occurs in bot...

  11. Autogenous transplantation of mandibular third molar to replace tooth with vertical root fracture

    OpenAIRE

    Asgary, Saeed

    2009-01-01

    Autogenous tooth transplantation (ATT) can be considered when there is a hopeless molar tooth and suitable donor present. This report presents an unconventional case of successful ATT of a third molar replacing the adjacent fractured second molar in a 33 year old woman. This wisdom tooth had completely developed roots. Root-end filling with Calcium Enriched Mixture (CEM) cement was performed in the third molar. The second molar was extracted non-traumatically without any bone removal; the wis...

  12. Tooth replacement of tigerfish Hydrocynus vittatus from the Kruger National Park

    Directory of Open Access Journals (Sweden)

    C.L. Gagiano

    1996-01-01

    Full Text Available Evidence of tooth replacement was observed in 14 tigerfish which had been caught during the period 1991 - 1993 in the Olifants and Letaba rivers in the Kruger National Park. Replacement of teeth is a quick process (3-5 days and first replacement of adult coni- cal dentition takes place at six to seven months post hatch, at a body length of 100 mm (FL. Swollen gums are evident prior to tooth replacement and newly erupted teeth are loosely embedded in the gums. Tooth replacement occurs in both the upper and lower jaws simultaneously. It was observed in the laboratory that the feeding behaviour was affected when adult conical dentition was replaced in @ 287 mm (FL specimens.

  13. Autocrine and paracrine Shh signaling are necessary for tooth morphogenesis, but not tooth replacement in snakes and lizards (Squamata).

    Science.gov (United States)

    Handrigan, Gregory R; Richman, Joy M

    2010-01-01

    Here we study the role of Shh signaling in tooth morphogenesis and successional tooth initiation in snakes and lizards (Squamata). By characterizing the expression of Shh pathway receptor Ptc1 in the developing dentitions of three species (Eublepharis macularius, Python regius, and Pogona vitticeps) and by performing gain- and loss-of-function experiments, we demonstrate that Shh signaling is active in the squamate tooth bud and is required for its normal morphogenesis. Shh apparently mediates tooth morphogenesis by separate paracrine- and autocrine-mediated functions. According to this model, paracrine Shh signaling induces cell proliferation in the cervical loop, outer enamel epithelium, and dental papilla. Autocrine signaling within the stellate reticulum instead appears to regulate cell survival. By treating squamate dental explants with Hh antagonist cyclopamine, we induced tooth phenotypes that closely resemble the morphological and differentiation defects of vestigial, first-generation teeth in the bearded dragon P. vitticeps. Our finding that these vestigial teeth are deficient in epithelial Shh signaling further corroborates that Shh is needed for the normal development of teeth in snakes and lizards. Finally, in this study, we definitively refute a role for Shh signaling in successional dental lamina formation and conclude that other pathways regulate tooth replacement in squamates. PMID:19850027

  14. Beta-Catenin and Plakoglobin Expression during Zebrafish Tooth Development and Replacement.

    Science.gov (United States)

    Verstraeten, Barbara; van Hengel, Jolanda; Huysseune, Ann

    2016-01-01

    We analyzed the protein distribution of two cadherin-associated molecules, plakoglobin and β-catenin, during the different stages of tooth development and tooth replacement in zebrafish. Plakoglobin was detected at the plasma membrane already at the onset of tooth development in the epithelial cells of the tooth. This pattern remained unaltered during further tooth development. The mesenchymal cells only showed plakoglobin from cytodifferentiation onwards. Plakoglobin 1a morpholino-injected embryos showed normal tooth development with proper initiation and differentiation. Although plakoglobin is clearly present during normal odontogenesis, the loss of plakoglobin 1a does not influence tooth development. β-catenin was found at the cell borders of all cells of the successional lamina but also in the nuclei of surrounding mesenchymal cells. Only membranous, not nuclear, β-catenin, was found during morphogenesis stage. However, during cytodifferentiation stage, both nuclear and membrane-bound β-catenin was detected in the layers of the enamel organ as well as in the differentiating odontoblasts. Nuclear β-catenin is an indication of an activated Wnt pathway, therefore suggesting a possible role for Wnt signalling during zebrafish tooth development and replacement. PMID:26938059

  15. Beta-Catenin and Plakoglobin Expression during Zebrafish Tooth Development and Replacement.

    Directory of Open Access Journals (Sweden)

    Barbara Verstraeten

    Full Text Available We analyzed the protein distribution of two cadherin-associated molecules, plakoglobin and β-catenin, during the different stages of tooth development and tooth replacement in zebrafish. Plakoglobin was detected at the plasma membrane already at the onset of tooth development in the epithelial cells of the tooth. This pattern remained unaltered during further tooth development. The mesenchymal cells only showed plakoglobin from cytodifferentiation onwards. Plakoglobin 1a morpholino-injected embryos showed normal tooth development with proper initiation and differentiation. Although plakoglobin is clearly present during normal odontogenesis, the loss of plakoglobin 1a does not influence tooth development. β-catenin was found at the cell borders of all cells of the successional lamina but also in the nuclei of surrounding mesenchymal cells. Only membranous, not nuclear, β-catenin, was found during morphogenesis stage. However, during cytodifferentiation stage, both nuclear and membrane-bound β-catenin was detected in the layers of the enamel organ as well as in the differentiating odontoblasts. Nuclear β-catenin is an indication of an activated Wnt pathway, therefore suggesting a possible role for Wnt signalling during zebrafish tooth development and replacement.

  16. Bio-Root and Implant-Based Restoration as a Tooth Replacement Alternative.

    Science.gov (United States)

    Gao, Z H; Hu, L; Liu, G L; Wei, F L; Liu, Y; Liu, Z H; Fan, Z P; Zhang, C M; Wang, J S; Wang, S L

    2016-06-01

    We previously reported that dental stem cell-mediated bioengineered tooth root (bio-root) regeneration could restore tooth loss in a miniature pig model. As a potential new method for tooth restoration, it is essential to compare this method with the widely used commercial dental implant-based method of tooth restoration. Tooth loss models were created by extracting mandibular incisors from miniature pigs. Allogeneic periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) were isolated and cultured. A PDLSC sheet was prepared by adding 20.0 µg/mL vitamin C to the culture medium; in addition, a hydroxyapatite tricalcium phosphate (HA/TCP)/DPSC graft was fabricated and cultured in a 3-dimensional culture system. A total of 46 bio-root implantations and 9 dental implants were inserted, and crown restorations were performed 6 mo after implantation. Histological, radiological, biomechanical, and elemental analyses were used to evaluate and compare tissue-engineered bio-roots and dental implants to the natural tooth roots. After 6 mo, both computed tomography scans and histological examinations showed that root-like structures and dentin-like tissues had formed. Three months after crown restoration, clinical assessments revealed that tooth function was equivalent in the regenerated bio-root and the dental implant. Biomechanical testing showed that the bio-roots were similar to natural tooth roots in compressive strength, modulus of elasticity, and torsional force; however, these properties were significantly higher in the dental implants. Elemental analysis revealed a higher similarity in elemental composition between bio-roots and natural tooth roots than between bio-roots and dental implants. However, the dental implant success rate was 100% (9 of 9) and the bio-root success rate was only 22% (10 of 46). Taken together, we showed that an allogeneic HA/TCP/DPSC/PDLSC sheet could successfully build a bio-root with structure and function similar to

  17. Contemporary management of tooth replacement in the traumatized dentition

    OpenAIRE

    Alani, Aws; Austin, Rupert; Djemal, Serpil

    2012-01-01

    Dental trauma can result in tooth loss despite best efforts at retaining and maintaining compromised teeth (Dent Traumatol, 24, 2008, 379). Upper anterior teeth are more likely to suffer from trauma, and their loss can result in significant aesthetic and functional problems that can be difficult to manage (Endod Dent Traumatol, 9, 1993, 61; Int Dent J 59, 2009, 127). Indeed, teeth of poor prognosis may not only present with compromised structure but trauma may also result in damage to the sup...

  18. Bioengineered Lacrimal Gland Organ Regeneration in Vivo

    Directory of Open Access Journals (Sweden)

    Masatoshi Hirayama

    2015-07-01

    Full Text Available The lacrimal gland plays an important role in maintaining a homeostatic environment for healthy ocular surfaces via tear secretion. Dry eye disease, which is caused by lacrimal gland dysfunction, is one of the most prevalent eye disorders and causes ocular discomfort, significant visual disturbances, and a reduced quality of life. Current therapies for dry eye disease, including artificial tear eye drops, are transient and palliative. The lacrimal gland, which consists of acini, ducts, and myoepithelial cells, develops from its organ germ via reciprocal epithelial-mesenchymal interactions during embryogenesis. Lacrimal tissue stem cells have been identified for use in regenerative therapeutic approaches aimed at restoring lacrimal gland functions. Fully functional organ replacement, such as for tooth and hair follicles, has also been developed via a novel three-dimensional stem cell manipulation, designated the Organ Germ Method, as a next-generation regenerative medicine. Recently, we successfully developed fully functional bioengineered lacrimal gland replacements after transplanting a bioengineered organ germ using this method. This study represented a significant advance in potential lacrimal gland organ replacement as a novel regenerative therapy for dry eye disease. In this review, we will summarize recent progress in lacrimal regeneration research and the development of bioengineered lacrimal gland organ replacement therapy.

  19. Single Tooth Replacement Using InCeram Resin Bonded Fixed Partial Denture: A Clinical Report.

    Directory of Open Access Journals (Sweden)

    Elnaz Moslehifard

    2014-02-01

    Full Text Available This clinical report describes a treatment option for replacement of a missing mandibular anterior tooth using InCeram resin bonded fixed partial denture (RBFPD. The conventional approach for replacing mandibular incisors dictates the placement of either a conventional porcelain-fused-to-metal (PFM bridge, Maryland bridge, or fiber-reinforced composite veneer bridge and several appearance-related disadvantages have been reported in the use of a prosthesis that incorporates a metal substructure. The InCeram bridge is a minimally invasive restoration and eliminates undesirable incisal graying frequently observed in metal RBFPDs. This method was successfully clinically applied to overcome shortcomings of other approaches that may require a minimal invasive technique to preserve lasting sound tooth structure.

  20. Single Anterior Tooth Replacement by a Cast Lingual Loop Connector - A Conservative Approach

    OpenAIRE

    Dandekeri, Shilpa Sudesh; Dandekeri, Savita

    2014-01-01

    One of the most challenging and complex treatment modality is replacement of single anterior tooth. This can be overcome by different treatment options such as implant-supported restorations as well as conventional porcelain-fused-to-metal and resin-bonded fixed partial dentures. Drifting of teeth into the edentulous area may reduce the available pontic space; whereas a diastema existing before an extraction may result in excessive mesiodistal dimension to the pontic space. Loop connector fix...

  1. The teamwork approach to esthetic tooth replacement with immediate implant placement and immediate temporization.

    Science.gov (United States)

    Levin, Barry P; Wilk, Brian L

    2015-10-01

    Enduring a period of edentulism between extraction and final restoration is difficult for patients- especially when it concerns the esthetic zone. The approach described demonstrates key points of consideration when replacing a maxillary anterior tooth with a dental implant using immediate implant placement, hard- and soft-tissue augmentation, and provisionalization. The authors stress adherence to patient selection and prosthetic design guidelines, and recommend the use of a digital impression technique, rather than traditional, rubber-based impressions. PMID:26448151

  2. Replacement of a single missing tooth in maxilla : factors to consider

    OpenAIRE

    Skogekker, Vegard Haug; Sørensen, Karoline; Hustad, Kyrre Aas; Skogen, Katrine Horn

    2013-01-01

    Background: In dentistry when replacing a single missing tooth in the maxilla, the choice of treatment is often between either a fixed partial denture (FPD) or a single dental implant. The challenge is to utilize relevant factors in treatment planning, achieving benefit for the patient. This article focuses on the factors that should be taken into consideration in decision-making. The investigation provides an attempted to further understand the importance of the factors studied. Method: A q...

  3. Single anterior tooth replacement by a cast lingual loop connector - a conservative approach.

    Science.gov (United States)

    Dandekeri, Shilpa Sudesh; Dandekeri, Savita

    2014-09-01

    One of the most challenging and complex treatment modality is replacement of single anterior tooth. This can be overcome by different treatment options such as implant-supported restorations as well as conventional porcelain-fused-to-metal and resin-bonded fixed partial dentures. Drifting of teeth into the edentulous area may reduce the available pontic space; whereas a diastema existing before an extraction may result in excessive mesiodistal dimension to the pontic space. Loop connector fixed partial denture (FPD) may be the simplest and best solution to maintain the diastema and provide optimum restoration of aesthetics. This article describes the procedure for the fabrication of a loop connector FPD to restore an excessively wide anterior edentulous space in a patient with existing spacing between the maxillary anterior teeth. PMID:25386535

  4. Bioengineered nanomaterials

    CERN Document Server

    Tiwari, Atul

    2013-01-01

    Many varieties of new, complex diseases are constantly being discovered, which leaves scientists with little choice but to embrace innovative methods for controlling the invasion of life-threatening problems. The use of nanotechnology has given scientists an opportunity to create nanomaterials that could help medical professionals in diagnosing and treating problems quickly and effectively. Bioengineered Nanomaterials presents in-depth information on bioengineered nanomaterials currently being developed in leading research laboratories around the world. In particular, the book focuses on nanom

  5. Dental-derived Stem Cells and whole Tooth Regeneration: an Overview

    OpenAIRE

    Dannan, Aous

    2009-01-01

    The need for new dental tissue-replacement therapies is evident in recent reports which reveal startling statistics regarding the high incidence of tooth decay and tooth loss. Recent advances in the identification and characterization of dental stem cells, and in dental tissue-engineering strategies, suggest that bioengineering approaches may successfully be used to regenerate dental tissues and whole teeth. Interest in dental tissue-regeneration applications continues to increase as clinical...

  6. 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 wa......: Implant-supported single-tooth replacement with the Astra Tech system is a reliable treatment resulting in a good 5-year prognosis and only few complications.......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...... bone adjacent to implants and neighboring teeth was less than 0.5 mm during the 5-year period, and there was no significant difference after crown placement between the treatment modality for group A and that for B. There were fewer clinical complications and repairs in group B than in group A. Soft...

  7. Single-tooth replacement by osseointegrated Astra Tech dental implants: a 2-year report

    DEFF Research Database (Denmark)

    Karlsson, U; Gotfredsen, K; Olsson, C

    1998-01-01

    This study presents the outcome of single-tooth restorations supported by Astra Tech single-tooth implants followed for 2 years. Forty-seven implants were placed in the same number of patients. Forty-three patients attended the second recall visit, and none of the evaluated implants have been...

  8. Aesthetic Alternative Using Composite Resin to Replace a Missing Tooth. A Case Report

    Directory of Open Access Journals (Sweden)

    Yuritza Hernández Núñez

    2014-06-01

    Full Text Available Patients who experience dental trauma resulting in permanent tooth loss are often prosthetically rehabilitated through any of its variants. However, it is uncommon to rehabilitate a patient using composite resin when a tooth is lost. The case of a patient who had lost a maxillary central incisor years ago and its space had been occupied by the lateral incisor is presented. The missing tooth was built up through the enlargement of the lateral incisor using the layering technique or stratification with Brilliant New Line resin. This paper aims at demonstrating a more economical and simpler alternative for restoring the aesthetics of a patient with unfavorable prognosis.

  9. The endodontically involved tooth: treat, or extract, and replace?%牙髓病患牙:治疗,拔除,种植?

    Institute of Scientific and Technical Information of China (English)

    Roger J.Smales

    2010-01-01

    @@ Introduction In recent years there has been increasing discussion and controversy regarding endodontic therapy and restoration versus tooth extraction and replacement with an osseointegrated dental implant-supported single crown[1-10].

  10. Randomized controlled trial to evaluate tooth stain reduction with nicotine replacement gum during a smoking cessation program

    LENUS (Irish Health Repository)

    Whelton, Helen

    2012-06-13

    AbstractBackgroundIn addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette® Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers.MethodsAn evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette® Freshmint Gum or Nicorette® Microtab (tablet). Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita® Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA), using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat) was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test.ResultsAt week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p = 0.005, ANCOVA). The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p = 0.015), 6 (p = 0

  11. Randomized controlled trial to evaluate tooth stain reduction with nicotine replacement gum during a smoking cessation program

    Directory of Open Access Journals (Sweden)

    Whelton Helen

    2012-06-01

    Full Text Available Abstract Background In addition to its general and periodontal health effects smoking causes tooth staining. Smoking cessation support interventions with an added stain removal or tooth whitening effect may increase motivation to quit smoking. Oral health professionals are well placed to provide smoking cessation advice and support to patients. The objective of the present study was to evaluate the effect of Nicorette® Freshmint Gum used in a smoking cessation programme administered in a dental setting, on extrinsic stain and tooth shade among smokers. Methods An evaluator-blinded, randomized, 12-week parallel-group controlled trial was conducted among 200 daily smokers motivated to quit smoking. Participants were randomised to use either the Nicorette® Freshmint Gum or Nicorette® Microtab (tablet. Tooth staining and shade were rated using the modified Lobene Stain Index and the Vita® Shade Guide at baseline, weeks 2, 6 and 12. To maintain consistency with other whitening studies, the primary end-point was the mean change in stain index between baseline and week 6. Secondary variables included changes in stain measurements and tooth shade at the other time points the number of gums or tablets used per day and throughout the trial period; and the number of cigarettes smoked per day. Treatments were compared using analysis of covariance (ANCOVA, using treatment and nicotine dependence as factors and the corresponding baseline measurement as a covariate. Each comparison (modified intention-to-treat was tested at the 0.05 level, two-sided. Within-treatment changes from baseline were compared using a paired t-test. Results At week 6, the gum-group experienced a reduction in mean stain scores whilst the tablet-group experienced an increase with mean changes of -0.14 and +0.12 respectively, (p = 0.005, ANCOVA. The change in mean tooth shade scores was statistically significantly greater in the gum-group than in the tablet group at 2 (p = 0

  12. Clinical application of single-tooth replacement with ankylos implant system

    International Nuclear Information System (INIS)

    Objective: To evaluate the clinical effects of Ankylos implant system to restore the loss of single-tooth. Methods: 90 cases with loss of single-tooth were selected and treated with routinely two-stage surgery. When the patients presented with deficient alveolar ridge, guided bone regeneration (GBR), osteotome sinus floor elevation, lateral antrostomy surgery with simultaneous placement of implant were applied. They were restored with platinum ceramic crown. All the implants were followed up, and the records were kept about stability of the implant and abutment, the status of surrounding soft tissue, sealability of implant abutment junction and the marginal bone lossing through X-ray checking,and satisfaction of the patients to mastication and aspect of the restorations. The follow-up time was 1-2.5 years. Results: Among the cases,one case had peri-implant inflammation, and one case had porcelain dropped. No loosening occurred in the other implants and abuments. Implant abutment junction was sealed well. The marginal bone loss 1 year after final restoration was less than 1 mm. Soft tissue surrounding implants was healthy. The satisfaction rate was 98.9% (89/90). According to standard of implant success, 88 cases were successful, the 2.5-year cumulative success rate was 97.8%, 2 cases failed, and the failure rate was 2.2 %. Conclusion: A satisfactory treatment effects could be gotten by using Ankylos implant system to restore the loss of single-tooth. (authors)

  13. Single tooth replacement using a ceramic resin bonded fixed partial denture: A case report

    OpenAIRE

    Kara, Haluk Baris; Aykent, Filiz

    2012-01-01

    This article describes the use of an all ceramic resin-bonded fixed partial denture as a conservative solution for the replacement of an incisor. It is a minimally invasive technique that does not discolor the abutment teeth.

  14. Integrative Bioengineering Institute

    Energy Technology Data Exchange (ETDEWEB)

    Eddington, David; Magin,L,Richard; Hetling, John; Cho, Michael

    2009-01-09

    Microfabrication enables many exciting experimental possibilities for medicine and biology that are not attainable through traditional methods. However, in order for microfabricated devices to have an impact they must not only provide a robust solution to a current unmet need, but also be simple enough to seamlessly integrate into standard protocols. Broad dissemination of bioMEMS has been stymied by the common aim of replacing established and well accepted protocols with equally or more complex devices, methods, or materials. The marriage of a complex, difficult to fabricate bioMEMS device with a highly variable biological system is rarely successful. Instead, the design philosophy of my lab aims to leverage a beneficial microscale phenomena (e.g. fast diffusion at the microscale) within a bioMEMS device and adapt to established methods (e.g. multiwell plate cell culture) and demonstrate a new paradigm for the field (adapt instead of replace). In order for the field of bioMEMS to mature beyond novel proof-of-concept demonstrations, researchers must focus on developing systems leveraging these phenomena and integrating into standard labs, which have largely been ignored. Towards this aim, the Integrative Bioengineering Institute has been established.

  15. Immediate, Non Submerged Root Analog Zirconia Implant in Single Rooted Tooth Replacement: Case Report with 2 years Follow Up.

    Science.gov (United States)

    Patankar, Amod; Kshirsagar, Rajesh; Patankar, Swapna; Pawar, Sudhir

    2016-07-01

    This report demonstrates the clinical use of a modified, truly anatomic, root analogue zirconia implant for immediate replacement of a right mandibular first premolar. A 22-year-old female patient with chronic apical periodontitis of the right mandibular first premolar was referred and the tooth was carefully extracted. A truly anatomical, root identical, roughened zirconia implant modified by macro-retentions was manufactured and placed into the extraction socket by tapping 3 days later. After 4 months a composite crown was cemented in place. No complications occurred during the healing period. A good functional and aesthetic result was achieved with minimal bone resorption and soft tissue recession at 18 months follow-up. This report describes the successful clinical use of an immediate, single stage, truly anatomical root-analogue zirconia implant for replacement of a single rooted tooth. Significant modifications such as macro-retentions yielded primary stability and excellent osseointegration. This novel approach is minimally invasive, respects the underlying anatomy and aids socket prevention. In addition the procedure saves time and cost, has good patient acceptance as there is no need for osteotomy, sinus lift or bone augmentation. PMID:27408451

  16. Bioengineering a conceptual approach

    CERN Document Server

    Pavlovic, Mirjana

    2015-01-01

    This book explores critical principles and new concepts in bioengineering, integrating the biological, physical and chemical laws and principles that provide a foundation for the field. Both biological and engineering perspectives are included, with key topics such as the physical-chemical properties of cells, tissues and organs; principles of molecules; composition and interplay in physiological scenarios; and the complex physiological functions of heart, neuronal cells, muscle cells and tissues. Chapters evaluate the emerging fields of nanotechnology, drug delivery concepts, biomaterials, and regenerative therapy. The leading individuals and events are introduced along with their critical research. Bioengineering: A Conceptual Approach is a valuable resource for professionals or researchers interested in understanding the central elements of bioengineering. Advanced-level students in biomedical engineering and computer science will also find this book valuable as a secondary textbook or reference.

  17. Methods in Bioengineering

    CERN Document Server

    Rege, Kaushal

    2009-01-01

    Filling a critical gap in the current literature, this new resource presents practical, step-by-step methods to help you synthesize, characterize, biofunctionalize and apply the nanomaterial that is most suitable for handling a given nanoscale bioengineering problem. Written and presented by leading scientists and engineers in their respective fields, the authors offer a clear and detailed understanding of how to carry out nanoparticle functionalization with biomolecules (including enzymes), nanoparticle analysis and characterization, in vitro evaluation of nanoparticles using different cell l

  18. Tooth extraction

    Science.gov (United States)

    A tooth extraction is a procedure to remove a tooth from the gum socket. It is usually done by a general ... gum. If you need a more complex tooth extraction: You will be given sedation so you are ...

  19. Bioengineering fluid mechanics

    CERN Document Server

    Hung, Tin-kan

    2013-01-01

    This book highlights the basic concepts and equations for bioengineering flow processes. Physical concepts and meanings are emphasized while rigorous derivations are simplified, making it easier for self learning on some biological and medical flow processes. The well known Bernoulli equation in hydraulics is extended for pulsating flows, peristaltic flows and cardiac pumping. The dimensional analysis, model law and dimensionless equations can be related to computational models and experimental observations. The velocity vector imaging stored in echocardiograms can be used to analyze the pumping characteristics of the ventricular contraction. New topics included oxygen transport in membrane oxygenator and micro mixing of blood flow in capillary channels.

  20. Tooth abscess

    Science.gov (United States)

    ... your teeth, mouth, and gums. You may have pain when the dentist taps the tooth. Biting or closing the mouth tightly also increases ... abscess; Dental abscess; Tooth infection; Abscess - tooth Images Tooth anatomy References Amsterdam JT. Oral Medicine. In: Marx JA, Hockberger RS, Walls RM, et ...

  1. Topics of Bioengineering in Wikipedia

    Directory of Open Access Journals (Sweden)

    Vassia Atanassova

    2009-10-01

    Full Text Available The present report aims to give a snapshot of how topics from the field of bioengineering (bioinformatics, bioprocess systems, biomedical engineering, biotechnology, etc. are currently covered in the free electronic encyclopedia Wikipedia. It also offers insights and information about what Wikipedia is, how it functions, how and when to cite Wikipedian articles, if necessary. Several external wikis, devoted to topics of bioengineering, are also listed and reviewed.

  2. Tooth anatomy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002214.htm Tooth anatomy To use the sharing features on this page, ... upper jawbone is called the maxilla. Images Tooth anatomy References Lingen MW. Head and neck. In: Kumar ...

  3. Bioengineered kidney tubules efficiently excrete uremic toxins

    Science.gov (United States)

    Jansen, J.; Fedecostante, M.; Wilmer, M. J.; Peters, J. G.; Kreuser, U. M.; van den Broek, P. H.; Mensink, R. A.; Boltje, T. J.; Stamatialis, D.; Wetzels, J. F.; van den Heuvel, L. P.; Hoenderop, J. G.; Masereeuw, R.

    2016-01-01

    The development of a biotechnological platform for the removal of waste products (e.g. uremic toxins), often bound to proteins in plasma, is a prerequisite to improve current treatment modalities for patients suffering from end stage renal disease (ESRD). Here, we present a newly designed bioengineered renal tubule capable of active uremic toxin secretion through the concerted action of essential renal transporters, viz. organic anion transporter-1 (OAT1), breast cancer resistance protein (BCRP) and multidrug resistance protein-4 (MRP4). Three-dimensional cell monolayer formation of human conditionally immortalized proximal tubule epithelial cells (ciPTEC) on biofunctionalized hollow fibers with maintained barrier function was demonstrated. Using a tailor made flow system, the secretory clearance of human serum albumin-bound uremic toxins, indoxyl sulfate and kynurenic acid, as well as albumin reabsorption across the renal tubule was confirmed. These functional bioengineered renal tubules are promising entities in renal replacement therapies and regenerative medicine, as well as in drug development programs. PMID:27242131

  4. Bioengineering-enhanced neurosurgical solutions

    OpenAIRE

    Ganau, Mario

    2016-01-01

    The advancements in basic sciences and the availability of sophisticated technological aids have led over the last few years to the rise of innovative surgical strategies, the identification of better prognostic/predictive biomolecular factors, and the development of novel drugs all meant to profoundly impact the outcome of neurosurgical patients. This thesis touches upon the window of opportunity to exploit bioengineering techniques in three subspecialties of this vast discipline: neuro-onco...

  5. Tooth Problems

    Science.gov (United States)

    ... to determine if you need to see your dentist right away. SYMPTOMS DIAGNOSIS SELF-CARE Begin Here ... You have TOOTH LOSS. DENTAL EMERGENCY See your dentist or go to the emergency room right away. ...

  6. Placement of replace select Ti-Unite-coated type implants using a combination of immediate and submerge techniques after tooth extraction

    Directory of Open Access Journals (Sweden)

    Coen Pramono D

    2006-06-01

    Full Text Available The high success rate of immediate implant placement both in the anterior and posterior regions were reported by many authors, therefore applying this techniques can be considered as a safe surgical procedure and minimizing the dental office visit for patient satisfaction. This paper reports the outcome of immediate placement of implants following extraction of anterior maxillary teeth. Combination technique of immediate and submerge implant placements including bone grafting procedure were used. Four implants with TiUnite surface type were placed immediately in two patients with the short-term result indicated that this technique may serve as a simple and safe procedure for immediate implant placement. It was concluded that immediate implant placement technique combined with TiUnite implant surface was successful in treating region directly after tooth extraction therefore this technique can be use as an alternative surgical method for dental implant rehabilitation.

  7. Medical ultrasound education for bioengineers

    Science.gov (United States)

    Vaezy, Shahram

    2005-04-01

    The widespread adoption of ultrasound technologies in medicine has necessitated the development of educational programs to address the growing demand for trained expertise in both academia and industry. The demand has been especially great in the field of therapeutic ultrasound that has experienced a significant level of research and development activities in the past decade. The applications cover a wide range including cancer treatment, hemorrhage control, cardiac ablation, gene therapy, and cosmetic surgery. A comprehensive educational program in ultrasound is well suited for bioengineering departments at colleges and universities. Our educational program for students in Bioengineering at the University of Washington includes a year-long coursework covering theory and practice of ultrasound, conducting research projects, attending and presenting at weekly seminars on literature survey, presentations at scientific meetings, and attending specialized workshops offered by various institutions for specific topics. An important aspect of this training is its multi-disciplinary approach, encompassing science, engineering, and medicine. The students are required to build teams with expertise in these disciplines. Our experience shows that these students are well prepared for careers in academia, conducting cutting edge research, as well as industry, being involved in the transformation of research end-products to commercially viable technology.

  8. Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model.

    Science.gov (United States)

    Takagi, Ryoji; Ishimaru, Junko; Sugawara, Ayaka; Toyoshima, Koh-Ei; Ishida, Kentaro; Ogawa, Miho; Sakakibara, Kei; Asakawa, Kyosuke; Kashiwakura, Akitoshi; Oshima, Masamitsu; Minamide, Ryohei; Sato, Akio; Yoshitake, Toshihiro; Takeda, Akira; Egusa, Hiroshi; Tsuji, Takashi

    2016-04-01

    The integumentary organ system is a complex system that plays important roles in waterproofing, cushioning, protecting deeper tissues, excreting waste, and thermoregulation. We developed a novel in vivo transplantation model designated as a clustering-dependent embryoid body transplantation method and generated a bioengineered three-dimensional (3D) integumentary organ system, including appendage organs such as hair follicles and sebaceous glands, from induced pluripotent stem cells. This bioengineered 3D integumentary organ system was fully functional following transplantation into nude mice and could be properly connected to surrounding host tissues, such as the epidermis, arrector pili muscles, and nerve fibers, without tumorigenesis. The bioengineered hair follicles in the 3D integumentary organ system also showed proper hair eruption and hair cycles, including the rearrangement of follicular stem cells and their niches. Potential applications of the 3D integumentary organ system include an in vitro assay system, an animal model alternative, and a bioengineered organ replacement therapy. PMID:27051874

  9. Bioengineering beige adipose tissue therapeutics

    Directory of Open Access Journals (Sweden)

    Kevin eTharp

    2015-10-01

    Full Text Available Unlocking the therapeutic potential of brown/beige adipose tissue requires technological advancements that enable the controlled expansion of this uniquely thermogenic tissue. Transplantation of brown fat in small animal model systems has confirmed the expectation that brown fat expansion could possibly provide a novel therapeutic to combat obesity and related disorders. Expansion and/or stimulation of UCP1-positive adipose tissues have repeatedly demonstrated physiologically beneficial reductions in circulating glucose and lipids. The recent discovery that brown adipose tissue-derived secreted factors positively alter whole body metabolism further expands potential benefits of brown or beige/brite adipose expansion. Unfortunately, there are no sources of transplantable brown adipose tissues for human therapeutic purposes at this time.Recent developments in bioengineering, including novel hyaluronic acid based hydrogels, have enabled non-immunogenic, functional tissue allografts that can be used to generate large quantities of UCP1-positive adipose tissue. These sophisticated tissue-engineering systems have provided the methodology to develop metabolically active brown or beige/brite adipose tissue implants with the potential to be used as a metabolic therapy. Unlike the pharmacological browning of white adipose depots, implantation of bioengineered UCP1-positive adipose tissues offers a spatially controlled therapeutic. Moving forward, new insights into the mechanisms by which extracellular cues govern stem cell differentiation and progenitor cell recruitment may enable cell-free matrix implant approaches, which generate a niche sufficient to recruit WAT derived stem cells and support their differentiation into functional beige/brite adipose tissues. This review summarizes clinically relevant discoveries in tissue-engineering and biology leading toward the recent development of beige adipose tissue implants and their potential for the metabolic

  10. Bioengineering Beige Adipose Tissue Therapeutics.

    Science.gov (United States)

    Tharp, Kevin M; Stahl, Andreas

    2015-01-01

    Unlocking the therapeutic potential of brown/beige adipose tissue requires technological advancements that enable the controlled expansion of this uniquely thermogenic tissue. Transplantation of brown fat in small animal model systems has confirmed the expectation that brown fat expansion could possibly provide a novel therapeutic to combat obesity and related disorders. Expansion and/or stimulation of uncoupling protein-1 (UCP1)-positive adipose tissues have repeatedly demonstrated physiologically beneficial reductions in circulating glucose and lipids. The recent discovery that brown adipose tissue (BAT)-derived secreted factors positively alter whole body metabolism further expands potential benefits of brown or beige/brite adipose expansion. Unfortunately, there are no sources of transplantable BATs for human therapeutic purposes at this time. Recent developments in bioengineering, including novel hyaluronic acid-based hydrogels, have enabled non-immunogenic, functional tissue allografts that can be used to generate large quantities of UCP1-positive adipose tissue. These sophisticated tissue-engineering systems have provided the methodology to develop metabolically active brown or beige/brite adipose tissue implants with the potential to be used as a metabolic therapy. Unlike the pharmacological browning of white adipose depots, implantation of bioengineered UCP1-positive adipose tissues offers a spatially controlled therapeutic. Moving forward, new insights into the mechanisms by which extracellular cues govern stem-cell differentiation and progenitor cell recruitment may enable cell-free matrix implant approaches, which generate a niche sufficient to recruit white adipose tissue-derived stem cells and support their differentiation into functional beige/brite adipose tissues. This review summarizes clinically relevant discoveries in tissue-engineering and biology leading toward the recent development of biomaterial supported beige adipose tissue implants and

  11. Bioengineering functional human sphincteric and non-sphincteric gastrointestinal smooth muscle constructs.

    Science.gov (United States)

    Rego, Stephen L; Zakhem, Elie; Orlando, Giuseppe; Bitar, Khalil N

    2016-04-15

    Digestion and motility of luminal content through the gastrointestinal (GI) tract are achieved by cooperation between distinct cell types. Much of the 3 dimensional (3D) in vitro modeling used to study the GI physiology and disease focus solely on epithelial cells and not smooth muscle cells (SMCs). SMCs of the gut function either to propel and mix luminal contents (phasic; non-sphincteric) or to act as barriers to prevent the movement of luminal materials (tonic; sphincteric). Motility disorders including pyloric stenosis and chronic intestinal pseudoobstruction (CIPO) affect sphincteric and non-sphincteric SMCs, respectively. Bioengineering offers a useful tool to develop functional GI tissue mimics that possess similar characteristics to native tissue. The objective of this study was to bioengineer 3D human pyloric sphincter and small intestinal (SI) constructs in vitro that recapitulate the contractile phenotypes of sphincteric and non-sphincteric human GI SMCs. Bioengineered 3D human pylorus and circular SI SMC constructs were developed and displayed a contractile phenotype. Constructs composed of human pylorus SMCs displayed tonic SMC characteristics, including generation of basal tone, at higher levels than SI SMC constructs which is similar to what is seen in native tissue. Both constructs contracted in response to potassium chloride (KCl) and acetylcholine (ACh) and relaxed in response to vasoactive intestinal peptide (VIP). These studies provide the first bioengineered human pylorus constructs that maintain a sphincteric phenotype. These bioengineered constructs provide appropriate models to study motility disorders of the gut or replacement tissues for various GI organs. PMID:26314281

  12. Mesenchymal Stem Cells and Tooth Engineering

    Institute of Scientific and Technical Information of China (English)

    Li Peng; Ling Ye; Xue-dong Zhou

    2009-01-01

    Tooth loss compromises human oral health. Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss problems, they are thought to have safety and usage time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells (MSCs) are multipotent stem cells which can differentiate into a variety of cell types. The potential MSCs for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth (SHEDs), adult dental pulp stem cells (DPSCs), stem cells from the apical part of the papilla (SCAPs), stem cells from the dental follicle (DFSCs), periodontal ligament stem cells (PDLSCs) and bone marrow derived mesenchymal stem cells (BMSCs). This review outlines the recent progress in the mesenchymal stem cells used in tooth regeneration.

  13. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic

    OpenAIRE

    K. Pavan Kumar; Surya Kumari Nujella; S. Sujatha Gopal; K. Karthik Roy

    2016-01-01

    For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge w...

  14. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic.

    Science.gov (United States)

    Kumar, K Pavan; Nujella, Surya Kumari; Gopal, S Sujatha; Roy, K Karthik

    2016-01-01

    For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge was intact with good esthetics and no problem was reported. PMID:27195156

  15. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic

    Science.gov (United States)

    Kumar, K. Pavan; Nujella, Surya Kumari; Gopal, S. Sujatha

    2016-01-01

    For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge was intact with good esthetics and no problem was reported. PMID:27195156

  16. Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

    Science.gov (United States)

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2014-09-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis. PMID:25183915

  17. FGF-9 accelerates epithelial invagination for ectodermal organogenesis in real time bioengineered organ manipulation

    Directory of Open Access Journals (Sweden)

    Tai Yun-Yuan

    2012-11-01

    Full Text Available Abstract Background Epithelial invagination is important for initiation of ectodermal organogenesis. Although many factors regulate ectodermal organogenesis, there is not any report about their functions in real-time study. Electric cell-substrate impedance sensing (ECIS, a non-invasive, real-time surveillance system, had been used to detect changes in organ cell layer thickness through quantitative monitoring of the impedance of a cell-to-microelectrode interface over time. It was shown to be a good method for identifying significant real-time changes of cells. The purpose of this study is to establish a combined bioengineered organ-ECIS model for investigating the real time effects of fibroblast growth factor-9 (FGF-9 on epithelial invagination in bioengineered ectodermal organs. We dissected epithelial and mesenchymal cells from stage E14.5 murine molar tooth germs and identified the real-time effects of FGF-9 on epithelial-mesenchymal interactions using this combined bioengineered organ-ECIS model. Results Measurement of bioengineered ectodermal organ thickness showed that Fibroblast growth factor-9 (FGF-9 accelerates epithelial invagination in reaggregated mesenchymal cell layer within 3 days. Gene expression analysis revealed that FGF-9 stimulates and sustains early Ameloblastin and Amelogenin expression during odontogenesis. Conclusions This is the first real-time study to show that, FGF-9 plays an important role in epithelial invagination and initiates ectodermal organogenesis. Based on these findings, we suggest FGF-9 can be applied for further study in ectodermal organ regeneration, and we also proposed that the ‘FGF-BMP balancing system’ is important for manipulating the morphogenesis of ectodermal organs. The combined bioengineered organ-ECIS model is a promising method for ectodermal organ engineering and regeneration research.

  18. The Status of Fluid Mechanics in Bioengineering Curricula.

    Science.gov (United States)

    Miller, Gerald E.; Hyman, William A.

    1981-01-01

    Describes the status of fluid mechanics courses in bioengineering curricula. A survey of institutions offering bioengineering degrees indicates that over half do not require fluid mechanics courses. Suggests increasing number of mechanics courses to increase the quality of bioengineering students and to prepare students for graduate work and more…

  19. Potential feasibility of dental stem cells for regenerative therapies: stem cell transplantation and whole-tooth engineering.

    Science.gov (United States)

    Nakahara, Taka

    2011-07-01

    Multipotent mesenchymal stem cells from bone marrow are expected to be a somatic stem cell source for the development of new cell-based therapy in regenerative medicine. However, dental clinicians are unlikely to carry out autologous cell/tissue collection from patients (i.e., marrow aspiration) as a routine procedure in their clinics; hence, the utilization of bone marrow stem cells seems impractical in the dental field. Dental tissues harvested from extracted human teeth are well known to contain highly proliferative and multipotent stem cell compartments and are considered to be an alternative autologous cell source in cell-based medicine. This article provides a short overview of the ongoing studies for the potential application of dental stem cells and suggests the utilization of 2 concepts in future regenerative medicine: (1) dental stem cell-based therapy for hepatic and other systemic diseases and (2) tooth replacement therapy using the bioengineered human whole tooth, called the "test-tube dental implant." Regenerative therapies will bring new insights and benefits to the fields of clinical medicine and dentistry. PMID:21805289

  20. Addressing endotoxin issues in bioengineered heparin.

    Science.gov (United States)

    Suwan, Jiraporn; Torelli, Amanda; Onishi, Akihiro; Dordick, Jonathan S; Linhardt, Robert J

    2012-01-01

    Heparin is a widely used clinical anticoagulant that is prepared from pig intestine. A contamination of heparin in 2008 has led to a reexamination of animal-derived pharmaceuticals. A bioengineered heparin prepared by bacterial fermentation and chemical and enzymatic processing is currently under development. This study examines the challenges of reducing or removing endotoxins associated with this process that are necessary to proceed with preclinical in vivo evaluation of bioengineered heparin. The current process is assessed for endotoxin levels, and strategies are examined for endotoxin removal from polysaccharides and enzymes involved in this process. PMID:23586950

  1. Soil bioengineering application and practices in Nepal.

    Science.gov (United States)

    Dhital, Yam Prasad; Kayastha, Rijan Bhakta; Shi, Jiancheng

    2013-02-01

    The small mountainous country Nepal is situated in the central part of the Himalayas. Its climate varies from tropical in the south to arctic in the north; and natural vegetation follows the pattern of climate and altitude. Water-induced disaster problems including soil erosion, debris flow, landslides and flooding are common due to the unstable landscape. Soil erosion is the most important driving force for the degradation of upland and mountain ecosystems. Soil bioengineering has been used in Nepal for nearly 30 years to deal with erosion problems on slopes, in high way construction and riverbank stabilization. The main soil bioengineering techniques used in Nepal are brush layering, palisades, live check dams, fascines and vegetative stone pitching. This study is based on the geology, climate and vegetation of Nepal and briefly summarizes the application of soil bioengineering on slopes and stream banks, with especial attention to the role of vegetation on slope and stream bank stabilization. Furthermore, this paper addresses the role of community participation and responsibility for successful application of vegetation-based techniques in management, maintenance and utility aspects for the future. In recent years, soil bioengineering techniques are extensively used due to their cost-effectiveness, using locally available materials and low-cost labour in comparison to more elaborate civil engineering works. However, scientific implementation and record-keeping and evaluation of the work are indeed essential. PMID:23263565

  2. The regulation of tooth morphogenesis is associated with epithelial cell proliferation and the expression of Sonic hedgehog through epithelial-mesenchymal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Kentaro; Murofushi, Mayumi [Faculty of Industrial Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Nakao, Kazuhisa; Morita, Ritsuko [Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Ogawa, Miho [Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Organ Technologies Inc., Tokyo 101-0048 (Japan); Tsuji, Takashi, E-mail: t-tsuji@rs.noda.tus.ac.jp [Faculty of Industrial Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Research Institute for Science and Technology, Tokyo University of Science, Chiba 278-8510 (Japan); Organ Technologies Inc., Tokyo 101-0048 (Japan)

    2011-02-18

    Research highlights: {yields} Bioengineered teeth regulated the contact area of epithelium and mesenchyme. {yields} The crown width is regulated by the contact area of the epithelium and mesenchyme. {yields} This regulation is associated with cell proliferation and Sonic hedgehog expression. {yields} The cusp number is correlated with the crown width of the bioengineered tooth. {yields} Cell proliferation and Shh expression areas regulate the tooth morphogenesis. -- Abstract: Ectodermal organs, such as the tooth, salivary gland, hair, and mammary gland, develop through reciprocal epithelial-mesenchymal interactions. Tooth morphologies are defined by the crown width and tooth length (macro-morphologies), and by the number and locations of the cusp and roots (micro-morphologies). In our current study, we report that the crown width of a bioengineered molar tooth, which was reconstructed using dissociated epithelial and mesenchymal cells via an organ germ method, can be regulated by the contact area between epithelial and mesenchymal cell layers. We further show that this is associated with cell proliferation and Sonic hedgehog (Shh) expression in the inner enamel epithelium after the germ stage has formed a secondary enamel knot. We also demonstrate that the cusp number is significantly correlated with the crown width of the bioengineered tooth. These findings suggest that the tooth micro-morphology, i.e. the cusp formation, is regulated after the tooth width, or macro-morphology, is determined. These findings also suggest that the spatiotemporal patterning of cell proliferation and the Shh expression areas in the epithelium regulate the crown width and cusp formation of the developing tooth.

  3. Bio-engineering in the Baltic Sea

    DEFF Research Database (Denmark)

    Zandersen, Marianne

    2011-01-01

    Bio-engineering in the Baltic Sea – value of water quality improvements & risk perceptions Dr. Marianne Zandersen1 Department of Environmental Science, Aarhus University Abstract The Baltic Sea is heavily eutrofied and the trend has gone from bad to worse. The hypoxic zone has increased about 4...... Baltic Sea, the prevalence of oxygen depleted areas has not decreased. Two pilot projects in Sweden and Finland investigate the effects of oxygenation pumping in coastal and deepwater areas (PROPPEN and BOX projects, respectively). Oxygenation pumping moves oxygen rich water from the higher levels of the...... water column to the bottom waters/deepwater. The expected effects include a slowing down of the sediment release from the bottom and improvement of the possibilities for aerobic bacterial decomposition and over time for the establishment of fauna. The projects test a bio-engineered approach to speeding...

  4. Immediate Esthetic Rehabilitation of Periodontally Compromised Anterior Tooth Using Natural Tooth as Pontic

    Directory of Open Access Journals (Sweden)

    K. Pavan Kumar

    2016-01-01

    Full Text Available For patients who require removal of anterior teeth and their replacement various treatment modalities are available. With advancement in technology and availability of glass/polyethylene fibres, use of natural tooth as pontic with fibre reinforced composite restorations offers the promising results. The present case report describes management of periodontally compromised mandibular anterior tooth using natural tooth pontic with fibre reinforcement. A 1-year follow-up showed that the bridge was intact with good esthetics and no problem was reported.

  5. 78 FR 9066 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2013-02-07

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... of Biomedical Imaging and Bioengineering, National Institutes of Health, 6707 Democracy...

  6. 77 FR 13347 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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    2012-03-06

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... Committee: National Institute of Biomedical Imaging and Bioengineering Special Emphasis Panel;...

  7. 77 FR 71605 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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    2012-12-03

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... Biomedical Imaging and Bioengineering Special Emphasis Panel; MSM Program Review. Date: February 26,...

  8. 77 FR 50516 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2012-08-21

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special...., Scientific Review Officer, National Institute of Biomedical Imaging, And Bioengineering, National...

  9. 78 FR 3009 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2013-01-15

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... Biomedical Imaging and Bioengineering, National Institutes of Health, 6707 Democracy Boulevard, Suite...

  10. 78 FR 46995 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2013-08-02

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  11. 78 FR 76632 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2013-12-18

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  13. 78 FR 31953 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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  14. 78 FR 3903 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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  15. 78 FR 66373 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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  16. 76 FR 58023 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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    2011-09-19

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  17. 77 FR 2987 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2012-01-20

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  18. 76 FR 53690 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2011-08-29

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  19. 77 FR 74675 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

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  20. 76 FR 572 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2011-01-05

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  1. Decellularization for whole organ bioengineering

    International Nuclear Information System (INIS)

    Organ transplantation in an orthotopic location is the current treatment for end-stage organ failure. However, the need for transplantable organs far exceeds the number of available donor organs. As a result, new options, such as tissue engineering and regenerative medicine, have been explored to achieve functional organ replacement. Although there have been many advances in the laboratory leading to the reconstruction of tissue and organ structures in vitro, these efforts have fallen short of producing organs that contain intact vascular networks capable of nutrient and gas exchange and are suitable for transplantation. Recently, advances in whole organ decellularization techniques have enabled the fabrication of scaffolds for engineering new organs. These scaffolds, consisting of naturally-derived extracellular matrix (ECM), provide biological signals and maintain tissue microarchitecture, including intact vascular systems that could integrate into the recipient's circulatory system. The decellularization techniques have led to the development of scaffolds for multiple organs, including the heart, liver, lung and kidney. While the experimental studies involving the use of decellularized organ scaffolds are encouraging, the translation of whole organ engineering into the clinic is still distant. This paper reviews recently described techniques used to decellularize whole organs such as the heart, lung, liver and kidney and describes possible methods for using these matrices for whole organ engineering. (paper)

  2. Exogenous FGF8 rescues development of mouse diastemal vestigial tooth ex vivo

    OpenAIRE

    Li, Lu; Yuan, Guohua; Liu, Chao; Zhang, Lu; Zhang, Yanding; Chen, Yiping; Chen, Zhi

    2011-01-01

    Regression of vestigial tooth buds results in the formation of the toothless diastema, a unique feature of the mouse dentition. Revitalization of the diastemal vestigial tooth bud provides an excellent model for studying tooth regeneration and replacement. It was shown previously that suppression of FGF signaling in the diastema is a causative of vestigial tooth bud regression. In this study, we report that application of exogenous FGF8 to the mouse embryonic diastemal region rescues diastema...

  3. Immune tolerance of mice allogenic tooth transplantation induced by immature dendritic cells

    OpenAIRE

    Li, Wenying; Deng, Feng; WANG Yu; Ma, Ce; Wang, Yurong

    2015-01-01

    As a common procedure in dentistry for replacing a missing tooth, allogenic tooth transplantation has encountered many difficulties in the clinical application because of immunological rejection. It is hypothesized that immature dendritic cell injection might be a potential alternative method to avoid or alleviate immunological rejection in allogenic tooth transplantation. To test this hypothesis, a mouse model of allogenic and autogeneic tooth transplantation was to established test the immu...

  4. The Randomized Shortened Dental Arch Study: Tooth Loss

    OpenAIRE

    Walter, M H; Weber, A; Marré, B; Gitt, I.; Gerß, J.; Hannak, W.; Hartmann, S.; Heydecke, G; Huppertz, J.; Jahn, F; Ludwig, A.; Mundt, T.; Kern, M; Klein, V; Pospiech, P.

    2010-01-01

    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA ...

  5. Broken or knocked out tooth

    Science.gov (United States)

    Teeth - broken; Tooth - knocked out ... dentist right away. If your tooth is badly broken, your nerve endings may be exposed. You will ... emergency visit for a simple chip or a broken tooth that is not causing you discomfort. You ...

  6. 7th WACBE World Congress on Bioengineering 2015

    CERN Document Server

    Lim, Chwee

    2015-01-01

    This volume publishes the proceedings of the WACBE World Congress on Bioengineering 2015 (WACBE 2015), which was be held in Singapore, from 6 to 8 July 2015. The World Association for Chinese Biomedical Engineers (WACBE) organizes this World Congress biannually. Our past congresses have brought together many biomedical engineers from over the world to share their experiences and views on the future development of biomedical engineering. The 7th WACBE World Congress on Bioengineering 2015 in Singapore continued to offer such a networking platform for all biomedical engineers. Hosted by the Biomedical Engineering Society (Singapore) and the Department of Biomedical Engineering, National University of Singapore, the congress covered all related areas in bioengineering.

  7. Welcome to Bioengineering: A New Open-Access Journal

    Directory of Open Access Journals (Sweden)

    Anthony Guiseppi-Elie

    2013-12-01

    Full Text Available It is my great pleasure to welcome you to a new open access journal, Bioengineering, which represents a scope that fits squarely with the core expertise and growing ambitions and interests of bioengineers globally. Of particular interest are the transdisciplinary and translational research represented by the activities within centers and institutes where the biological sciences and engineering disciplines cohabit seamlessly for a focus on solutions to global challenges in human, veterinary and ecological health, bioenergy, bioprocess and sustainability. Bioengineering emphasizes the publication of novel and high quality peer reviewed articles via an open access platform. The scope includes: [...

  8. New Biosorbent Materials: Selectivity and Bioengineering Insights

    Directory of Open Access Journals (Sweden)

    George Z. Kyzas

    2014-05-01

    Full Text Available Many researchers have studied the biosorption of different pollutants. However, a quite limited number of works focus on selectivity, which may be characterized as specific property for each biosorbent. Two main criteria need to be adopted for the selection and synthesis of modern biosorbents, such as their rebinding capacity and selectivity for only one target, molecule, ion, etc. Selective biosorption could be achieved using in synthesis an innovative technique termed molecular imprinting; the idea applied through specific polymers (Molecular Imprinted Polymers (MIPs was used in many fields, mainly analytical. In the present work, also isotherm and kinetic models were reviewed highlighting some crucial parameters, which possibly affect selectivity. A critical analysis of the biosorption insights for biosorbents, mostly selective, describes their characteristics, advantages and limitations, and discusses various bioengineering mechanisms involved.

  9. Defining Hair Follicles in the Age of Stem Cell Bioengineering

    OpenAIRE

    Chuong, Cheng-Ming; Cotsarelis, George; Stenn, Kurt

    2007-01-01

    One challenge faced by stem cell biologists is the bioengineering of an organ. Ehama et al. (2007, this issue) used cells derived from human and rodent epidermis and dermal papilla to reconstitute hair-follicle mini-organs. Some result in hair follicles; others are hair follicle–like. The challenge calls for the development of a set of criteria to define a hair follicle so that bioengineered products in the future can be evaluated.

  10. Wood-soil interactions in soil bioengineering slope stabilization works

    OpenAIRE

    Moscatelli MC; Romagnoli M; Cenfi S; Lagomarsino A; Di Tizio A; Spina S; Grego S

    2009-01-01

    In this work we propose the use of soil quality indicators with the aim of assessing the environmental impact of soil bioengineering works. This study was carried out in central Italy where soil bioengineering slope stabilization works were established using chestnut wood. In particular the goal of this study was to determine the occurrence of a wood-effect, that is changes of soil properties due to the presence of decomposing logs in two sites characterized by different time span since works...

  11. Overview of Tooth Disorders

    Science.gov (United States)

    ... bands and wires or appliances Cap Crown Cavities Caries Cleaning Prophylaxis Eye teeth Canines or cuspids Filling ... Abnormal tooth enamel may be due to a diet containing insufficient vitamin D. Abnormal enamel may also ...

  12. Stem cell-based biological tooth repair and regeneration

    OpenAIRE

    Volponi, Ana Angelova; Pang, Yvonne; Sharpe, Paul T.

    2010-01-01

    Teeth exhibit limited repair in response to damage, and dental pulp stem cells probably provide a source of cells to replace those damaged and to facilitate repair. Stem cells in other parts of the tooth, such as the periodontal ligament and growing roots, play more dynamic roles in tooth function and development. Dental stem cells can be obtained with ease, making them an attractive source of autologous stem cells for use in restoring vital pulp tissue removed because of infection, in regene...

  13. Fractional calculus in bioengineering, part 3.

    Science.gov (United States)

    Magin, Richard L

    2004-01-01

    Fractional calculus (integral and differential operations of noninteger order) is not often used to model biological systems. Although the basic mathematical ideas were developed long ago by the mathematicians Leibniz (1695), Liouville (1834), Riemann (1892), and others and brought to the attention of the engineering world by Oliver Heaviside in the 1890s, it was not until 1974 that the first book on the topic was published by Oldham and Spanier. Recent monographs and symposia proceedings have highlighted the application of fractional calculus in physics, continuum mechanics, signal processing, and electromagnetics, but with few examples of applications in bioengineering. This is surprising because the methods of fractional calculus, when defined as a Laplace or Fourier convolution product, are suitable for solving many problems in biomedical research. For example, early studies by Cole (1933) and Hodgkin (1946) of the electrical properties of nerve cell membranes and the propagation of electrical signals are well characterized by differential equations of fractional order. The solution involves a generalization of the exponential function to the Mittag-Leffler function, which provides a better fit to the observed cell membrane data. A parallel application of fractional derivatives to viscoelastic materials establishes, in a natural way, hereditary integrals and the power law (Nutting/Scott Blair) stress-strain relationship for modeling biomaterials. In this review, I will introduce the idea of fractional operations by following the original approach of Heaviside, demonstrate the basic operations of fractional calculus on well-behaved functions (step, ramp, pulse, sinusoid) of engineering interest, and give specific examples from electrochemistry, physics, bioengineering, and biophysics. The fractional derivative accurately describes natural phenomena that occur in such common engineering problems as heat transfer, electrode/electrolyte behavior, and sub

  14. Bioengineering virus-like particles as vaccines.

    Science.gov (United States)

    Lua, Linda H L; Connors, Natalie K; Sainsbury, Frank; Chuan, Yap P; Wibowo, Nani; Middelberg, Anton P J

    2014-03-01

    Virus-like particle (VLP) technology seeks to harness the optimally tuned immunostimulatory properties of natural viruses while omitting the infectious trait. VLPs that assemble from a single protein have been shown to be safe and highly efficacious in humans, and highly profitable. VLPs emerging from basic research possess varying levels of complexity and comprise single or multiple proteins, with or without a lipid membrane. Complex VLP assembly is traditionally orchestrated within cells using black-box approaches, which are appropriate when knowledge and control over assembly are limited. Recovery challenges including those of adherent and intracellular contaminants must then be addressed. Recent commercial VLPs variously incorporate steps that include VLP in vitro assembly to address these problems robustly, but at the expense of process complexity. Increasing research activity and translation opportunity necessitate bioengineering advances and new bioprocessing modalities for efficient and cost-effective production of VLPs. Emerging approaches are necessarily multi-scale and multi-disciplinary, encompassing diverse fields from computational design of molecules to new macro-scale purification materials. In this review, we highlight historical and emerging VLP vaccine approaches. We overview approaches that seek to specifically engineer a desirable immune response through modular VLP design, and those that seek to improve bioprocess efficiency through inhibition of intracellular assembly to allow optimal use of existing purification technologies prior to cell-free VLP assembly. Greater understanding of VLP assembly and increased interdisciplinary activity will see enormous progress in VLP technology over the coming decade, driven by clear translational opportunity. PMID:24347238

  15. 75 FR 57969 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2010-09-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  16. 76 FR 370 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2011-01-04

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... Person: Manana Sukhareva, Ph.D., Scientific Review Officer, National Institute of Biomedical Imaging...

  17. 77 FR 2737 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2012-01-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  18. 75 FR 6039 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2010-02-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  19. 75 FR 35820 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

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    2010-06-23

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special..., ARRA Related Biomedical Research and Research Support Awards, National Institutes of Health, HHS)...

  20. 76 FR 62814 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2011-10-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  1. 77 FR 3480 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2012-01-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  2. 78 FR 6126 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting.

    Science.gov (United States)

    2013-01-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  3. 76 FR 5593 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2011-02-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  4. 77 FR 58146 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2012-09-19

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special...: John K. Hayes, Ph.D., Scientific Review Officer, National Institute of Biomedical Imaging...

  5. 78 FR 37557 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meetings

    Science.gov (United States)

    2013-06-21

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special...: Ruth Grossman, DDS, Scientific Review Officer, National Institute of Biomedical Imaging...

  6. 77 FR 37684 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2012-06-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering...

  7. Factors associated with tooth loss and prosthodontic status among Sudanese adults.

    Science.gov (United States)

    Khalifa, Nadia; Allen, Patrick F; Abu-bakr, Neamat H; Abdel-Rahman, Manar E

    2012-01-01

    A study was conducted to determine the degree of tooth loss, factors influencing tooth loss, and the extent of prosthodontic rehabilitation in Sudanese adults (≥ 16 years old) attending outpatient clinics in Khartoum State. Pearson and multivariate analyses were used to examine the relationships between tooth loss and specific characteristics determined through interviews and clinical examinations. The mean number of missing teeth was 3.6 (SD, 4.9) and the prevalence of edentulism was 0.1%. The prevalence of tooth loss (missing at least one tooth) was 78%; 66.9% of tooth loss was due to caries, and 11.2% was attributable to other reasons. Prosthetic replacement of missing teeth was evident in 3%, whereas a need for prosthetic replacement was evident in 57%. Having rate of dental consultation. Tooth loss due to other reasons was associated with age, tribe, education, periodontal pocketing, tobacco use, tooth wear, and prosthetic status. The results of the present study indicated that the major cause of tooth loss was dental caries, thus emphasizing the importance of a public prevention-based healthcare program. Replacement of missing teeth was uncommon in the study subjects, which may reflect lack of access to this type of oral healthcare. PMID:23221155

  8. Glycan bioengineering in immunogen design for tumor T antigen immunotargeting

    DEFF Research Database (Denmark)

    Sendra, Victor G; Zlocowski, Natacha; Ditamo, Yanina;

    2009-01-01

    Bioengineering of Galbeta3GalNAcalpha, known as Thomsen-Friedenreich disaccharide (TFD), is studied to promote glycan immunogenicity and immunotargeting to tumor T antigen (Galbeta3GalNAcalpha-O-Ser/Thr). Theoretical studies on disaccharide conformations by energy minimization of structures using...... MM2 energy function showed that pentalysine (Lys5) linker and benzyl (Bzl) residue enhance TFD rigidity of the glycosidic bond. Antibodies raised against BzlalphaTFD-Lys5 immunogen recognize tumor T antigen. Competitive assays confirm that TFD-related structures are the main glycan epitope...... bioengineered glycoconjugate inhibited CT26 tumor cell proliferation and reduced tumor growth in an in vivo mouse model. These results show that TFD bioengineering is a useful immunogenic strategy with potential application in cancer therapy. The same approach can be extended to other glycan immunogens for...

  9. Tooth patterning and evolution.

    Science.gov (United States)

    Salazar-Ciudad, Isaac

    2012-12-01

    Teeth are a good system for studying development and evolution. Tooth development is largely independent of the rest of the body and teeth can be grown in culture to attain almost normal morphology. Their development is not affected by the patterns of movement or sensorial perception in the embryo. Teeth are hard and easily preserved. Thus, there is plenty of easily accessible information about the patterns of morphological variation occurring between and within species. This review summarises recent work and describes how tooth development can be understood as the coupling between a reaction-diffusion system and differential growth produced by diffusible growth factors: which growth factors are involved, how they affect each other's expression and how they affect the spatial patterns of proliferation that lead to final morphology. There are some aspects of tooth development, however, that do not conform to some common assumptions in many reaction-diffusion models. Those are discussed here since they provide clues about how reaction-diffusion systems may work in actual developmental systems. Mathematical models implementing what we know about tooth development are discussed. PMID:23266218

  10. 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

  11. 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

    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

  12. The future of starch bioengineering: GM microorganisms or GM plants?

    DEFF Research Database (Denmark)

    Hebelstrup, Kim; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots...... concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However, in some situations, GM crops for starch bioengineering without deleterious effects have been achieved....

  13. Signals and systems for bioengineers a Matlab-based introduction

    CERN Document Server

    Semmlow, John

    2011-01-01

    This book guides the reader through the electrical engineering principles that can be applied to biological systems and are therefore important to biomedical studies. The basic engineering concepts that underlie biomedical systems, medical devices, biocontrol, and biosignal analysis are explained in detail.This textbook is perfect for the one-semester bioengineering course usually offered in conjunction with a laboratory on signals and measurements which presents the fundamentals of systems and signal analysis. The target course occupies a pivotal position in the bioengineering curricu

  14. Application of Induced Pluripotent Stem Cells Reprogrammed from Dental Pulp Cells: a Novel Approach for Tooth Regeneration

    Directory of Open Access Journals (Sweden)

    Xiaoyan Zhou

    2011-03-01

    Full Text Available Introduction: Candidate human dental stem/progenitor cells have been isolated and charac-terized from dental tissues and shown to hold the capability to differentiate into tooth-generating cells. However, ad-vances in engineering a whole tooth by these stem cells are hindered by various factors, such as the poor availability of human primitive tooth bud stem cells, difficulties in isolating and purifying dental mesenchymal stem cells and ethical controversies when using embryonic oral epithelium. As a result it is meaningful to find other autologous dental cells for the purpose of reconstructing a tooth.The hypothesis: Previous studies demonstrated that somatic cells can be reprogrammed into induced pluripotent stem cells by ex-ogenous expression Oct-4 and Sox-2. On the basis of these findings we can reasonably hypothesize that when transfected with specific transcription factors Oct-4 and Sox-2, dental pulp cells, the main cell in pulp, could also be reprogrammed into induced pluripotent stem cells, which are considered to be of best potential to regenerate a whole tooth. Evaluation of the hypothesis: After transfection with Oct-4 and Sox-2 into human dental pulp cells, the positive colonies are isolated and then identified according to the characteristics of iPS cells. These cells are further investigated the capability in differentiating into ameloblasts and odontoblasts and finally seeded onto the sur-face of a tooth-shaped biodegradable polymer scaffold to detect the ability of constructing a bioengineered tooth.

  15. 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.

  16. A Comparison between Osteotomy and Corticotomy-Assisted Tooth Movement.

    Science.gov (United States)

    Yen, Stephen L-K

    2016-01-01

    Osteotomies and corticotomies used in combination with orthodontic tooth movement can activate different bone responses that may be exploited to accelerate tooth movement. Segmental osteotomies around dental roots can create a tooth-bearing transport disk that may be distracted and positioned with orthodontic appliances and archwires. In difficult craniofacial repairs, alveolar segments can be guided into position with archwires and orthodontic mechanics. The corticotomy extending into the marrow space can activate bone injury repair mechanisms that accelerate bone turnover as the alveolar bone surrounding the dental roots transitions from a demineralization phase to a fibrous replacement phase and, finally, a mineralization phase. The controlled demineralization and replacement of alveolar bone provides a window of opportunity for roots to move though less dense bone prior to remineralization. Although the corticotomies and osteotomies are minor surgeries compared to orthognathic surgery, the goal of future research is to produce similar bone responses by using smaller surgeries or by eliminating the surgeries altogether. PMID:26599126

  17. The randomized shortened dental arch study: tooth loss.

    Science.gov (United States)

    Walter, M H; Weber, A; Marré, B; Gitt, I; Gerss, J; Hannak, W; Hartmann, S; Heydecke, G; Huppertz, J; Jahn, F; Ludwig, A; Mundt, T; Kern, M; Klein, V; Pospiech, P; Stumbaum, M; Wolfart, S; Wöstmann, B; Busche, E; Böning, K; Luthardt, R G

    2010-08-01

    The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant. PMID:20400723

  18. Combined implant-residual tooth supported prosthesis after tooth hemisection: A finite element analysis.

    Science.gov (United States)

    He, Yun; Hasan, Istabrak; Keilig, Ludger; Chen, Junliang; Pan, Qing; Huang, Yue; Bourauel, Christoph

    2016-07-01

    Tooth hemisection preserves partial tooth structure and reduces the resorption of alveolar bone. The aim of this study was to analyze the feasibility of preserving a molar after hemisection and inserting a dental implant with different prosthetic superstructures by means of finite element analysis. First, the distance between the root of the mandibular second premolar and the distal root of the first molar were measured in 80 cone beam computed tomography (CBCT) data sets. Based on these data, the lower right posterior jaw segment was reconstructed and the geometries of the appropriate implant were imported. Four models were created: (1) Hemi-1: An implant (3.7×9mm) replaced the mesial root of the molar, and a single crown was placed on the implant and residual tooth. (2) Hemi-2: Two separate crowns were generated for the implant and the residual tooth. (3) Single: An implant (5.5×9mm) with crown replaced the whole molar. (4) FPD: A 3-unit fixed partial denture combined the distal residual part of the molar and premolar. The results indicated that stresses in the cortical bone and strains in the majority region of the spongious bone were below the physiological upper limits. There were higher stresses in implant with the Hemi-1 and Single models, which had the same maximum values of 45.0MPa. The FPD models represented the higher values of stresses in the teeth and strains in PDL compared to other models. From a biomechanical point of view, it can be concluded that a combination of an implant and residual molar after tooth hemisection is an acceptable treatment option. PMID:26851558

  19. The Replacement of Missing Teeth

    OpenAIRE

    Zarb, George A.

    1988-01-01

    Dentists have used a great deal of ingenuity in replacing lost teeth. Until recently, however, it was not possible to duplicate the natural situation and attach tooth-root analogues to the host bone. Osseointegration allows such an attachment, in which threaded unalloyed titanium implants are placed in the bone by means of a meticulous surgical procedure. The documented successful use of this process has already altered profoundly the predicament of the edentulous patient. The application of ...

  20. Hip Replacement

    Science.gov (United States)

    Hip replacement is surgery for people with severe hip damage. The most common cause of damage is ... therapy, pain medicines, and exercise haven't helped, hip replacement surgery might be an option for you. ...

  1. Whole-organ bioengineering: current tales of modern alchemy.

    Science.gov (United States)

    Moran, Emma C; Dhal, Abritee; Vyas, Dipen; Lanas, Angel; Soker, Shay; Baptista, Pedro M

    2014-04-01

    End-stage organ disease affects millions of people around the world, to whom organ transplantation is the only definitive cure available. However, persistent organ shortage and the resulting widespread transplant backlog are part of a disturbing reality and a common burden felt by thousands of patients on waiting lists in almost every country where organ transplants are performed. Several alternatives and potential solutions to this problem have been sought in past decades, but one seems particularly promising now: whole-organ bioengineering. This review describes briefly the evolution of organ transplantation and the development of decellularized organ scaffolds and their application to organ bioengineering. This modern alchemy of generating whole-organ scaffolds and recellularizing them with multiple cell types in perfusion bioreactors is paving the way for a new revolution in transplantation medicine. Furthermore, although the first generation of bioengineered organs still lacks true clinical value, it has created a number of novel tissue and organ model platforms with direct application in other areas of science (eg, developmental biology and stem cell biology, drug discovery, physiology and metabolism). In this review, we describe the current status and numerous applications of whole-organ bioengineering, focusing also on the multiple challenges that researchers have to overcome to translate these novel technologies fully into transplantation medicine. PMID:24486135

  2. Combining bioengineering and plant conservation on a Mediterranean islet

    Directory of Open Access Journals (Sweden)

    La Mantia T

    2012-12-01

    Full Text Available This paper reports the results of a bioengineering intervention within the Mediterranean Basin carried out at Lampedusa Island (Strait of Sicily on the “Spiaggia dei Conigli”, the only sand shore of all Sicilian territory where the sea turtle Caretta caretta lays its eggs every year. The erosion of the steep slope over the beach itself caused sensitive changes in the grain size of shore’s sediment and reduced the area of the beach with fine sand suitable for C. caretta oviposition. In order to reduce surface water flow and to stop erosion, several bioengineering options were adopted using only native plant species to preserve local botanical heritage and to prevent the local extinction of some species. One year after interventions, average plant establishment was about 90% and many species which were severely endangered before the action (i.e., Jacobaea maritima (L. Pelser & Meijden subsp. bicolor (Willd. B. Nord. & Greuter and Limoniastrum monopetalum (L. Boiss. are now at low risk. Micropropagation and inoculation with beneficial root microbial symbionts were successfully applied to selected species. Regular demographic and phytosociological monitoring on permanent plot areas enabled to quantify the effect of bioengineering techniques on plant percentage cover and plant survival. The combination of bioengineering, biotechnology, and agronomic practices applied on plants appears to be effective in increasing plant cover and preserving several locally endangered plant species. Results presented here suggest that erosion can be controlled without moving large quantities of soil and without planting tree species.

  3. Glycan bioengineering in immunogen design for tumor T antigen immunotargeting.

    Science.gov (United States)

    Sendra, Victor G; Zlocowski, Natacha; Ditamo, Yanina; Copioli, Silvina; Tarp, Mads P; Bennett, Eric P; Clausen, Henrik; Roth, German A; Nores, Gustavo A; Irazoqui, Fernando J

    2009-10-01

    Bioengineering of Galbeta3GalNAcalpha, known as Thomsen-Friedenreich disaccharide (TFD), is studied to promote glycan immunogenicity and immunotargeting to tumor T antigen (Galbeta3GalNAcalpha-O-Ser/Thr). Theoretical studies on disaccharide conformations by energy minimization of structures using MM2 energy function showed that pentalysine (Lys5) linker and benzyl (Bzl) residue enhance TFD rigidity of the glycosidic bond. Antibodies raised against BzlalphaTFD-Lys5 immunogen recognize tumor T antigen. Competitive assays confirm that TFD-related structures are the main glycan epitope. Antibodies produced by glycan bioengineering recognize HT29, T47D, MCF7, and CT26 epithelial tumor cells. Epithelial tumor cell adhesion to T antigen-binding lectins and endothelial cells was lower in the presence of antibodies raised against the engineered immunogen. The immune response directed to the bioengineered glycoconjugate inhibited CT26 tumor cell proliferation and reduced tumor growth in an in vivo mouse model. These results show that TFD bioengineering is a useful immunogenic strategy with potential application in cancer therapy. The same approach can be extended to other glycan immunogens for immunotargeting purposes. PMID:19726087

  4. Bioengineering: A Perfect Amalgamation of Life Science and Engineering

    OpenAIRE

    Batchala Bharghava

    2015-01-01

    Bioengineering is the amalgamation of the biology, physics and engineering techniques to solve medical and associated problems. It is advanced stage in engineering field and great revolution in life science. It is also a branch of genetic engineering which helps to make a regenerative medicine.

  5. Saw-tooth cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Karatza Ageliki A

    2009-12-01

    Full Text Available Abstract We present an unusual case of cardiomyopathy in a two month old male infant with a grade-I systolic murmur. Echocardiographic examination disclosed left ventricular (LV, dysplasia with saw-tooth like inwards myocardial projections extending from the lateral walls towards the LV cavity. There was mild LV systolic dysfunction with apical hypokinesia. Cardiovascular magnetic resonance demonstrated in detail these cross bridging muscular projections originating from the inferior interventricular septum and lateral LV wall, along with areas of hypokinesis at the LV septum and apex in a noncoronary distribution, without any late gadolinium enhancement. We have termed this condition saw-tooth cardiomyopathy because of the very characteristic appearance.

  6. The Rachitic Tooth

    OpenAIRE

    Foster, Brian L.; Nociti, Francisco H.; Somerman, Martha J

    2013-01-01

    Teeth are mineralized organs composed of three unique hard tissues, enamel, dentin, and cementum, and supported by the surrounding alveolar bone. Although odontogenesis differs from osteogenesis in several respects, tooth mineralization is susceptible to similar developmental failures as bone. Here we discuss conditions fitting under the umbrella of rickets, which traditionally referred to skeletal disease associated with vitamin D deficiency but has been more recently expanded to include new...

  7. Saw-tooth cardiomyopathy

    OpenAIRE

    Karatza Ageliki A; Danias Peter G; Davlouros Periklis A; Kiaffas Maria G; Alexopoulos Dimitrios

    2009-01-01

    Abstract We present an unusual case of cardiomyopathy in a two month old male infant with a grade-I systolic murmur. Echocardiographic examination disclosed left ventricular (LV), dysplasia with saw-tooth like inwards myocardial projections extending from the lateral walls towards the LV cavity. There was mild LV systolic dysfunction with apical hypokinesia. Cardiovascular magnetic resonance demonstrated in detail these cross bridging muscular projections originating from the inferior interve...

  8. Dental Pulp Stem Cells as a multifaceted tool for bioengineering and the regeneration of craniomaxillofacial tissues

    Directory of Open Access Journals (Sweden)

    Maitane eAurrekoetxea

    2015-10-01

    Full Text Available Dental pulp stem cells, or DPSC, are neural crest-derived cells with an outstanding capacity to differentiate along multiple cell lineages of interest for cell therapy. In particular, highly efficient osteo/dentinogenic differentiation of DPSC can be achieved using simple in vitro protocols, making these cells a very attractive and promising tool for the future treatment of dental and periodontal diseases. Among craniomaxillofacial organs, the tooth and salivary gland are two such cases in which complete regeneration by tissue engineering using DPSC appears to be possible, as research over the last decade has made substantial progress in experimental models of partial or total regeneration of both organs, by cell recombination technology. Moreover, DPSC seem to be a particularly good choice for the regeneration of nerve tissues, including injured or transected cranial nerves. In this context, the oral cavity appears to be an excellent testing ground for new regenerative therapies using DPSC. However, many issues and challenges need yet to be addressed before these cells can be employed in clinical therapy. In this review, we point out some important aspects on the biology of DPSC with regard to their use for the reconstruction of different craniomaxillofacial tissues and organs, with special emphasis on cranial bones, nerves, teeth, and salivary glands. We suggest new ideas and strategies to fully exploit the capacities of DPSC for bioengineering of the aforementioned tissues.

  9. Dental pulp stem cells as a multifaceted tool for bioengineering and the regeneration of craniomaxillofacial tissues.

    Science.gov (United States)

    Aurrekoetxea, Maitane; Garcia-Gallastegui, Patricia; Irastorza, Igor; Luzuriaga, Jon; Uribe-Etxebarria, Verónica; Unda, Fernando; Ibarretxe, Gaskon

    2015-01-01

    Dental pulp stem cells, or DPSC, are neural crest-derived cells with an outstanding capacity to differentiate along multiple cell lineages of interest for cell therapy. In particular, highly efficient osteo/dentinogenic differentiation of DPSC can be achieved using simple in vitro protocols, making these cells a very attractive and promising tool for the future treatment of dental and periodontal diseases. Among craniomaxillofacial organs, the tooth and salivary gland are two such cases in which complete regeneration by tissue engineering using DPSC appears to be possible, as research over the last decade has made substantial progress in experimental models of partial or total regeneration of both organs, by cell recombination technology. Moreover, DPSC seem to be a particularly good choice for the regeneration of nerve tissues, including injured or transected cranial nerves. In this context, the oral cavity appears to be an excellent testing ground for new regenerative therapies using DPSC. However, many issues and challenges need yet to be addressed before these cells can be employed in clinical therapy. In this review, we point out some important aspects on the biology of DPSC with regard to their use for the reconstruction of different craniomaxillofacial tissues and organs, with special emphasis on cranial bones, nerves, teeth, and salivary glands. We suggest new ideas and strategies to fully exploit the capacities of DPSC for bioengineering of the aforementioned tissues. PMID:26528190

  10. Clinical measurement of tooth wear: tooth Wear Indices

    OpenAIRE

    López Frías, J.; Castellanos Cosano, Lizett; Martín González, Jenifer; Llamas Carreras, José María; Segura-Egea, Juan J.

    2012-01-01

    Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification corresponds to a different process with specific clinical features. Classifications made so far have no accurate prevalence data because the indexes do not necessarily measure a specific etiology, or because the study populations can be diverse in age and characteristics. Tooth wears (attrition, erosion and abrasion) is perceived internationally as a growing problem. However, th...

  11. Human tooth bank: sociocultural profile of a group of donors

    Directory of Open Access Journals (Sweden)

    Mariane Moreira Poletto

    2010-04-01

    Full Text Available Objective: To survey the sociocultural profile of a specific group of individuals who donated teeth to the Human Tooth Bank of Positivo University, Curitiba, Paraná, Brazil. Methods: The research consisted of a questionnaire containing the following information about: Patient’s age, sex, occupation, education, reason for tooth loss and intention to replace the missing tooth by means of prosthesis or implant. The questionnaire was filled out by 50 patients after having the extraction procedure performed and donating the dental organ. The data were compiled and analyzed by means of descriptive and multivariate statistics. Results: The sociocultural profile of the donor was basically composed of individuals in the age group between 30 and 50 years, with educational level ranging from zero to nine or more years of formal schooling. Caries disease was the most frequent reason for tooth loss (36%, followed by periodontal disease (34%. Of the donors analyzed, more than half did not intend to replace the tooth. Furthermore, according to the multivariate analysis, the most relevant factors for assessing the profile of donors were the variables age, orthodontic indication, caries and periodontal disease. Conclusion: This information was shown to be relevant for structuring the oral health care services, as well as in the strategy for obtaining teeth from the Public Health Units.

  12. Bioengineering of Dental Tissues: Bibliometric Analysis 2000-2011.

    Directory of Open Access Journals (Sweden)

    Sebastián Zamorano

    2014-03-01

    Full Text Available ABSTRACT Introduction: There has been a noticeable increase in experimental use and therapies based on stem cells over recent years. Nevertheless, there is a lack of information about this progress in the dental field, which makes it difficult to trace development and design policies. The purpose of this study, as a first approach to the subject, is to determine a bibliometric profile for the investigation related to bioengineering of dental tissue at a worldwide scale, based on the MEDLINE database, for the period 2000-2011.Methodology: A bibliometric study was carried out. Every article indexed in the MEDLINE database and associated with the terms “stem cells” and “tooth regeneration” for the period 2000-2011 was included. The analyzed variables were publishing date, country of origin, language and publication type (original or review, journal, author, associated university and tissue source (human or animal. Results: For the entire period included in the study, 257 articles were found. Of these, 149 corresponded to original works published in English; 5 in other languages; 92 comprised literature reviews in English, 9 in other languages and 2 publications were included in the “others” category. The countries with the highest research productivity were the United States (24.51%, Japan (20.62% and China (17.90%, while Brazil (3.9% was the only Latin-American country found in the list. Animal tissues were used in 59.09% of them. The most productive authors were Ueda M (17 and Jin Y (11, whereas Fourth Military University (13, University of Tokyo (12 and Capital Medical University (10 had the largest number of publications.Conclusion: The United States, Japan and China concentrate about two thirds of the production. Latin-America was represented only by Brazil. RESUMEN Introducción: El creciente uso experimental de células madres y el perfeccionamiento de las terapias con estas es un hecho notorio en los últimos años. Sin embargo

  13. Delayed Tooth Replantation after Traumatic Avulsion: A Case Report

    OpenAIRE

    Khalilak, Zohreh; Shikholislami, Mahshid; Mohajeri, Ladan

    2008-01-01

    Avulsion is a serious injury which causes damage to dental and supportive tissues, ranging from 1-16 % among dental injuries and it mostly occurs in maxillary incisors. This report presents a case of replantation of a traumatically avulsed central incisor. The left central incisor of an 8 year-old boy with open apex was avulsed and was left in unclean and dry conditions. Tooth was replaced after 270 min and splinted. After 24 hours, tooth was treated endodontically. The calcium hydroxide past...

  14. Directed Replacement

    CERN Document Server

    Karttunen, L

    1996-01-01

    This paper introduces to the finite-state calculus a family of directed replace operators. In contrast to the simple replace expression, UPPER -> LOWER, defined in Karttunen (ACL-95), the new directed version, UPPER @-> LOWER, yields an unambiguous transducer if the lower language consists of a single string. It transduces the input string from left to right, making only the longest possible replacement at each point. A new type of replacement expression, UPPER @-> PREFIX ... SUFFIX, yields a transducer that inserts text around strings that are instances of UPPER. The symbol ... denotes the matching part of the input which itself remains unchanged. PREFIX and SUFFIX are regular expressions describing the insertions. Expressions of the type UPPER @-> PREFIX ... SUFFIX may be used to compose a deterministic parser for a ``local grammar'' in the sense of Gross (1989). Other useful applications of directed replacement include tokenization and filtering of text streams.

  15. Bioengineering of Dental Tissues: Bibliometric Analysis 2000-2011.

    OpenAIRE

    Sebastián Zamorano; Lissete Guzmán; Flavio Zamorano

    2014-01-01

    ABSTRACT Introduction: There has been a noticeable increase in experimental use and therapies based on stem cells over recent years. Nevertheless, there is a lack of information about this progress in the dental field, which makes it difficult to trace development and design policies. The purpose of this study, as a first approach to the subject, is to determine a bibliometric profile for the investigation related to bioengineering of dental tissue at a worldwide scale, based on the MEDLINE ...

  16. Bioengineering Heart Muscle: A Paradigm for Regenerative Medicine

    OpenAIRE

    Vunjak-Novakovic, Gordana; Lui, Kathy O; Tandon, Nina; Chien, Kenneth R.

    2011-01-01

    The idea of extending the lifetime of our organs is as old as humankind, fueled by major advances in organ transplantation, novel drugs, and medical devices. However, true regeneration of human tissue has becoming increasingly plausible only in recent years. The human heart has always been a focus of such efforts, given its notorious inability to repair itself following injury or disease. We discuss here the emerging bioengineering approaches to regeneration of heart muscle as a paradigm for ...

  17. Current Bioengineering Methods for Whole Kidney Regeneration

    Directory of Open Access Journals (Sweden)

    Shuichiro Yamanaka

    2015-01-01

    Full Text Available Kidney regeneration is likely to provide an inexhaustible source of tissues and organs for immunosuppression-free transplantation. It is currently garnering considerable attention and might replace kidney dialysis as the ultimate therapeutic strategy for renal failure. However, anatomical complications make kidney regeneration difficult. Here, we review recent advances in the field of kidney regeneration, including (i the directed differentiation of induced pluripotent stem cells/embryonic stem cells into kidney cells; (ii blastocyst decomplementation; (iii use of a decellularized cadaveric scaffold; (iv embryonic organ transplantation; and (v use of a nephrogenic niche for growing xenoembryos for de novo kidney regeneration from stem cells. All these approaches represent potentially promising therapeutic strategies for the treatment of patients with chronic kidney disease. Although many obstacles to kidney regeneration remain, we hope that innovative strategies and reliable research will ultimately allow the restoration of renal function in patients with end-stage kidney disease.

  18. A Brief History of the Bioengineering Institute of California and the UC System-wide Symposia

    OpenAIRE

    Chien, Shu

    2011-01-01

    The plan to establish a Multicampus Research Unit (MRU) on Bioengineering in the University of California (UC) System started in August 1999. The cooperative efforts of the UC campuses led to the formal establishment of the Bioengineering Institute of California (BIC) in October 2003. Three years prior to the BIC establishment, the System-wide Annual Bioengineering Symposium was started at UC Davis. The Symposia were then hosted sequentially by UC Santa Barbara, UC Berkeley, UCSD, UC Santa Cr...

  19. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  20. Tooth fragment reattachment technique on a pluri traumatized tooth

    OpenAIRE

    Giuseppe Lo Giudice; Frank Lipari; Angelo Lizio; Gabriel Cervino; Marco Cicciù

    2012-01-01

    This case report describes and analyses a tooth fragment reattachment technique used to resolve crown fractures of the anterior teeth. This treatment allows a conservative approach to traumatic coronal lesions offering a better possibility of maintaining aesthetics and function. The authors have illustrated here a clinical case of a fractured incisor. This case is characterized by several traumas on the same tooth that required different therapeutic solutions. We used an easy and ultra-conser...

  1. Tooth fragment reattachment technique on a pluri traumatized tooth

    Directory of Open Access Journals (Sweden)

    Giuseppe Lo Giudice

    2012-01-01

    Full Text Available This case report describes and analyses a tooth fragment reattachment technique used to resolve crown fractures of the anterior teeth. This treatment allows a conservative approach to traumatic coronal lesions offering a better possibility of maintaining aesthetics and function. The authors have illustrated here a clinical case of a fractured incisor. This case is characterized by several traumas on the same tooth that required different therapeutic solutions. We used an easy and ultra-conservative technique without any tooth preparation in the first and third traumatic injuries. In the second trauma, a direct restoration of the fractured tooth was performed. The adhesive reattachment is a simple system to achieve good aesthetic and functional results.Our clinical experiences demonstrated that, when tooth and fragment margins are intact, the reattachment technique without any tooth preparation is a simple and predictable procedure. Quality of adhesion is shown by the retention of the reattached fragment in the second trauma that caused only partial enamel fractures.

  2. Periodontal Bioengineering: A Discourse in Surface Topographies, Progenitor Cells and Molecular Profiles

    Science.gov (United States)

    Dangaria, Smit J.

    2011-12-01

    Stem/progenitor cells are a population of cells capable of providing replacement cells for a given differentiated cell type. We have applied progenitor cell-based technologies to generate novel tissue-engineered implants that use biomimetic strategies with the ultimate goal of achieving full regeneration of lost periodontal tissues. Mesenchymal periodontal tissues such as cementum, alveolar bone (AB), and periodontal ligament (PDL) are neural crest-derived entities that emerge from the dental follicle (DF) at the onset of tooth root formation. Using a systems biology approach we have identified key differences between these periodontal progenitors on the basis of global gene expression profiles, gene cohort expression levels, and epigenetic modifications, in addition to differences in cellular morphologies. On an epigenetic level, DF progenitors featured high levels of the euchromatin marker H3K4me3, whereas PDL cells, AB osteoblasts, and cementoblasts contained high levels of the transcriptional repressor H3K9me3. Secondly, we have tested the influence of natural extracellular hydroxyapatite matrices on periodontal progenitor differentiation. Dimension and structure of extracellular matrix surfaces have powerful influences on cell shape, adhesion, and gene expression. Here we show that natural tooth root topographies induce integrin-mediated extracellular matrix signaling cascades in tandem with cell elongation and polarization to generate physiological periodontium-like tissues. In this study we replanted surface topography instructed periodontal ligament progenitors (PDLPs) into rat alveolar bone sockets for 8 and 16 weeks, resulting in complete attachment of tooth roots to the surrounding alveolar bone with a periodontal ligament fiber apparatus closely matching physiological controls along the entire root surface. Displacement studies and biochemical analyses confirmed that progenitor-based engineered periodontal tissues were similar to control teeth and

  3. NSAIDs in orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Muthukumar Karthi

    2012-01-01

    Full Text Available Orthodontic tooth movement is basically a biological response toward a mechanical force. The movement is induced by prolonged application of controlled mechanical forces, which create pressure and tension zones in the periodontal ligament and alveolar bone, causing remodeling of tooth sockets. Orthodontists often prescribe drugs to manage pain from force application to biologic tissues. Nonsteroidal anti-inflammatory drugs (NSAIDs are the drugs usually prescribed. NSAIDs block prostaglandin synthesis and result in slower tooth movement. Prostaglandins have been found to play a direct role in bone resorption. Aspirin, acetaminophen, ibuprofen, diclofenac, vadecoxib, and celecoxib are the commonly prescribed drugs. Acetaminophen is the drug of choice for orthodontic pain without affecting orthodontic tooth movement.

  4. Broken or knocked out tooth

    Science.gov (United States)

    Pfenninger JL, Fowlder GC. Management of dental injuries and reimplantation of an avulsed tooth. In: Pfenninger JL, Fowlder GC, eds. Pfenninger & Fowler's Procedures for Primary Care . 3rd ed. Philadelphia, PA: Elsevier Mosby; 2011:chap 81

  5. Atypical Odontalgia (Phantom Tooth Pain)

    Science.gov (United States)

    ... site where teeth have been extracted or following endodontic treatment, without an identifiable cause. Over time, the ... of dental procedure such as having a root canal or tooth extraction. On occasion, the pain can ...

  6. Post-Odontoma autotransplantation of an impacted tooth: A case report

    OpenAIRE

    Robindro Singh, Waikhom; Aheibam, Kirankumar; Nameirakpam, Anthopia

    2015-01-01

    After years of relegation by dental implants, autotransplantation has recently become more popular because of a better understanding of its science. The prognosis of autotransplantation primarily depends upon the presence of an intact alveolar bone at the transplant site and the regeneration of a functional periodontal ligament of the transplant. Replacement of an unsalvaged or a missing tooth by a natural tooth with normal periodontium within a short duration of treatment is the ultimate cha...

  7. 76 FR 5184 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2011-01-28

    ... published in the Federal Register on January 5, 2011, 76 FR 572. This Federal Register Notice has been... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, March 14, 2011, 6 p.m. to March 16, 2011, 12...

  8. 78 FR 107 - National Institute of Biomedical Imaging and Bioengineering; Notice of Closed Meeting

    Science.gov (United States)

    2013-01-02

    ... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... personal privacy. Name of Committee: National Institute of Biomedical Imaging and Bioengineering Special... Person: John K. Hayes, Ph.D., Scientific Review Officer, National Institute of Biomedical Imaging...

  9. 78 FR 78982 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2013-12-27

    ... published in the Federal Register on August 29, 2013, 78 FR 64506. The meeting notice is amended to change... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, December 11, 2013, 08:30 a.m.,...

  10. 78 FR 55268 - National Institute of Biomedical Imaging and Bioengineering Amended; Notice of Meeting

    Science.gov (United States)

    2013-09-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, November 6, 2013, 8:00 a.m. to 5:00...

  11. 78 FR 64519 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2013-10-29

    ..., which was published in the Federal Register on June 21, 2013, 78 FR 37557. The meeting notice is amended... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, October 3, 2013, 8:30 a.m. to 5:00...

  12. 78 FR 66755 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2013-11-06

    ..., which was published in the Federal Register on August 2, 2013, 78 FR 46995. The meeting notice is... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, October 10-11, 2013, 09:00 a.m.-08:00...

  13. 78 FR 64506 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2013-10-29

    ..., which was published in the Federal Register on July 26, 2013, 78 FR 45254. The meeting notice is amended... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, October 11, 2013, 10:00 a.m. to 5:00...

  14. 77 FR 25488 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2012-04-30

    ... April 2, 2012, 77 FR 19675. The meeting location has been changed to The Bolger Center, 9600 Newbridge... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... for Biomedical Imaging and Bioengineering, May 21, 2012, 9:00 a.m. to 3:00 p.m., Bethesda...

  15. 78 FR 64966 - National Institute of Biomedical Imaging and Bioengineering; Amended Notice of Meeting

    Science.gov (United States)

    2013-10-30

    ..., which was published in the Federal Register on July 18, 2013, 78 FR 42970. The meeting notice is amended... HUMAN SERVICES National Institutes of Health National Institute of Biomedical Imaging and Bioengineering... Biomedical Imaging and Bioengineering Special Emphasis Panel, October 10-11, 2013, 03:00 p.m.-06:00...

  16. Mandibular Symphyseal/Parasymphyseal Fracture with Incisor Tooth Loss: Preventing Lower Arch Constriction.

    Science.gov (United States)

    Rahpeyma, Amin; Khajehahmadi, Saeedeh; Abdollahpour, Somayeh

    2016-03-01

    Mandibular fractures are the second most common fractures of the face after the nasal bone. Mandibular symphyseal/parasymphyseal fracture comprises 15.6 to 29.3% of mandibular fractures. Tooth loss in the fracture line is a known phenomenon, but space loss has not been evaluated comprehensively in the literature. In a retrospective study, patients with mandibular symphyseal/parasymphyseal fractures, who had been treated from 2012 to 2013 in Mashhad University, Iran, Emdadi Hospital, were recalled. Patients with mandibular incisor tooth/teeth loss were included in the study. Space loss, the technique used to replace the lost tooth/teeth, upper and lower dental midline relationship, combination fracture or fractures in other facial skeleton, and type of treatment were evaluated. Of 98 patients with mandibular symphyseal/parasymphyseal fractures, 22.5% had incisor tooth/teeth loss. In this group, 73% had space loss. Only four patients had replaced the lost tooth/teeth. Dental midlines did not match each other in patients whose feature was evaluated. Open reduction and internal fixation with miniplates were used in symphyseal/parasymphyseal fractures except one. Space loss after mandibular symphyseal/parasymphyseal fracture with incisor tooth loss is a common error. The most important factor to prevent complications related to space loss following mandibular symphyseal/parasymphyseal fracture accompanying incisor tooth loss is space preservation. PMID:26889343

  17. Should bioengineering graduates seek employment in the defense industry?

    Science.gov (United States)

    Johnson, Arthur T

    2014-01-01

    They say that the difference between a mechanical engineer and a civil engineer is that the mechanical engineer develops weapons whereas a civil engineer designs targets. The implication is that some engineers are involved with building peaceful infrastructure whereas others contribute to destruction. This brings to mind the question: what is the proper role for engineers in the creation of weapons and defenses against them? In particular, should engineers specializing in biology or medicine be involved in the defense industry? After all, bioengineers are supposed to be builders or healers rather than warriors or destroyers. PMID:25264694

  18. Understanding the human machine a primer for bioengineering

    CERN Document Server

    Valentinuzzi, Max E

    2004-01-01

    This introductory book for undergraduate students poses a question: What is bioengineering all about? After offering a reference frame and defining the objectives (chapter 1), "physiology" (chapter 2) is presented as a source material followed by "signals" (chapter 3) and "signal pick up" (chapter 4). Chapter 5 deals with the biological amplifier. Reading the signal and the need for mathematical models are the subject matter, respectively, of chapters 6 and 7; they only provide guidance. The last chapter tries to look ahead. Sometimes, the subject is treated in relative depth; at times, the vi

  19. Treatment of a horizontal root-fractured tooth with decoronation procedure: case report

    Directory of Open Access Journals (Sweden)

    Selen Esin Yoldaş

    2016-05-01

    Full Text Available INTRODUCTION: Early loss of permanent anterior teeth due to trauma can cause esthetic and functional problems for young patients. In such cases, replacement of the missing tooth with traditional approaches is possible; however such approaches will reduce the chance of the patient to receive an esthetic and consistent treatment in the future. CASE REPORT: A 12-year-old male patient referred to our clinic with a history of trauma. Complicated crown fracture in tooth no.11 and horizontal root fracture in tooth no. 21 was detected. Following root canal treatment, tooth no. 11 was restored with a fiber post and a strip crown. To avoid alveolar bone loss due to early tooth extraction, decoronation procedure, an alternative approach, was applied to tooth no. 21. This procedure consisted of leaving the root fragment inside the alveolar socket following the removal of the crown. For the rehabilitation of the missing crown, a partial removable prosthesis was implemented. The patient was recalled in 6., 12. and 18. months. Within the follow-up period, no reduction in the alveolar bone level was seen. No sign of infection was evident. The remaining root fragment kept on resorbing. Tooth no. 11 remained symptom-free as well. The patient is still being followed. CONCLUSION: Decoronation is essentially a treatment choice for preventing alveolar bone loss in ankylosed teeth considered for extraction. In this case report, decoronation was shown to be a suitable alternative also for a fractured, non-ankylosed tooth.

  20. Dental patterning in the earliest sharks: Implications for tooth evolution.

    Science.gov (United States)

    Maisey, John G; Turner, Susan; Naylor, Gavin J P; Miller, Randall F

    2014-05-01

    Doliodus problematicus is the oldest known fossil shark-like fish with an almost intact dentition (Emsian, Lower Devonian, c. 397Ma). We provide a detailed description of the teeth and dentition in D. problematicus, based on tomographic analysis of NBMG 10127 (New Brunswick Museum, Canada). Comparisons with modern shark dentitions suggest that Doliodus was a ram-feeding predator with a dentition adapted to seizing and disabling prey. Doliodus provides several clues about the early evolution of the "shark-like" dentition in chondrichthyans and also raises new questions about the evolution of oral teeth in jawed vertebrates. As in modern sharks, teeth in Doliodus were replaced in a linguo-labial sequence within tooth families at fixed positions along the jaws (12-14 tooth families per jaw quadrant in NBMG 10127). Doliodus teeth were replaced much more slowly than in modern sharks. Nevertheless, its tooth formation was apparently as highly organized as in modern elasmobranchs, in which future tooth positions are indicated by synchronized expression of shh at fixed loci within the dental epithelium. Comparable dental arrays are absent in osteichthyans, placoderms, and many "acanthodians"; a "shark-like" dentition, therefore, may be a synapomorphy of chondrichthyans and gnathostomes such as Ptomacanthus. The upper anterior teeth in Doliodus were not attached to the palatoquadrates, but were instead supported by the ethmoid region of the prechordal basicranium, as in some other Paleozoic taxa (e.g., Triodus, Ptomacanthus). This suggests that the chondrichthyan dental lamina was originally associated with prechordal basicranial cartilage as well as jaw cartilage, and that the modern elasmobranch condition (in which the oral dentition is confined to the jaws) is phylogenetically advanced. Thus, oral tooth development in modern elasmobranchs does not provide a complete developmental model for chondrichthyans or gnathostomes. PMID:24347366

  1. Shoulder replacement - discharge

    Science.gov (United States)

    Total shoulder arthroplasty - discharge; Endoprosthetic shoulder replacement - discharge; Partial shoulder replacement - discharge; Partial shoulder arthroplasty - discharge; Replacement - shoulder - discharge; ...

  2. Optical fiber based imaging of bioengineered tissue construct

    Science.gov (United States)

    Sapoznik, Etai; Niu, Guoguang; Lu, Peng; Zhou, Yu; Xu, Yong; Soker, Shay

    2016-04-01

    Imaging cells and tissues through opaque and turbid media is challenging and presents a major barrier for monitoring maturation and remodeling of bioengineered tissues. The fiber optics based imaging system described here offers a new approach for fluorescent cell imaging. A micro imaging channel is embedded in a Polycaprolactone (PCL) electrospun scaffold designed for cell seeding, which allows us to use an optical fiber to locally deliver excitation laser close to the fluorescent cells. The emission is detected by an Electron Multiplying Charge Coupled Device (EMCCD) detector and image reconstruction of multiple excitation points is achieved with a working distance of several centimeters. The objective of this study is to assess the effects of system parameters on image reconstruction outcomes. Initial studies using fluorescent beads indicated that scaffold thickness had a small effect on image quality, whereas scaffold composition (collagen content), fluorophore spectra, and the reconstruction window size had a large effect. The results also suggest that a far-red fluorescent emission is preferential when using collagenous scaffolds with a thickness of up to 500 μm. Using these optimized parameters, we were able to image fluorescently labeled cells on a scaffold with a resolution of 15-20 μm, and have also measured muscle progenitor cell differentiation and scaffold surface coverage with endothelial cells. In the future, this imaging platform can be applied to other bioengineered tissues for non-invasive monitoring both in vitro and in vivo.

  3. The future of starch bioengineering: GM microorganisms or GM plants?

    Science.gov (United States)

    Hebelstrup, Kim H; Sagnelli, Domenico; Blennow, Andreas

    2015-01-01

    Plant starches regularly require extensive modification to permit subsequent applications. Such processing is usually done by the use of chemical and/or physical treatments. The use of recombinant enzymes produced by large-scale fermentation of GM microorganisms is increasingly used in starch processing and modification, sometimes as an alternative to chemical or physical treatments. However, as a means to impart the modifications as early as possible in the starch production chain, similar recombinant enzymes may also be expressed in planta in the developing starch storage organ such as in roots, tubers and cereal grains to provide a GM crop as an alternative to the use of enzymes from GM microorganisms. We here discuss these techniques in relation to important structural features and modifications of starches such as: starch phosphorylation, starch hydrolysis, chain transfer/branching and novel concepts of hybrid starch-based polysaccharides. In planta starch bioengineering is generally challenged by yield penalties and inefficient production of the desired product. However, in some situations, GM crops for starch bioengineering without deleterious effects have been achieved. PMID:25954284

  4. PREFACE: XVII Congress of Bioengineering and VI Clinical Engineering Conference

    Science.gov (United States)

    Rocha, Darío

    2011-09-01

    SABI 2009 was the XVII Biennial Congress of the Argentinean Bioengineering Society (SABI - www.sabi.org.ar), celebrated along with the VI Clinical Engineering Conference. It took place in Rosario, the second city of Argentina, located on the west bank of the Paraná, one of the world's most important rivers. This city, with its 150 year history and one million inhabitants, is characterized by a strong enterprising spirit. It is the agroindustrial leader of Argentina, with cereal ports recognized to be among the most active in the world, and its cereal stock exchange competes with Chicago's in international cereal pricing. Demographically Rosario presents a European profile, and there are seven national and private higher level universities in the area. SABI 2009 was the first time the Congress was celebrated in Rosario. Usually the Congress is organized by the Bioengineering Society in cooperation with a university with an undergraduate program, which Rosario lacks. To meet the needs of this exceptional case, a young local institution was asked to coordinate the Congress, the Rosario Technological Center (www.polotecnologico.net). This organization gathers together around 100 companies that produce technology, with a large number focused on IT, but those focused on biotechnology also stand out. The Center is also integrated with relevant public and government bodies. Traditionally, bioengineering has been related to human health applications, with less emphasis on applications significant to agrotechnology, an area in which Rosario is growing as an economic force. In order to address this oversight, the Congress formulated its main goals for integrating and synergizing bioengineering and biotechnology, particularly bioengineering and agrotechnology. This initiative has produced promising results. The importance of the Congress was reflected in the high number of participants - including researchers, professionals and students - from abroad, with participants from

  5. Tooth polishing: The current status

    Directory of Open Access Journals (Sweden)

    Madhuri Alankar Sawai

    2015-01-01

    Full Text Available Healthy teeth and gums make a person feel confident and fit. As people go about their daily routines and with different eating and drinking habits, the tooth enamel turns yellowish or gets stained. Polishing traditionally has been associated with the prophylaxis procedure in most dental practices, which patients know and expect. However, with overzealous use of polishing procedure, there is wearing of the superficial tooth structure. This would lead to more accumulation of local deposits. Also, it takes a long time for the formation of the fluoride-rich layer of the tooth again. Hence, now-a-days, polishing is not advised as a part of routine oral prophylaxis procedure but is done selectively based on the patients′ need. The article here, gives an insight on the different aspects of the polishing process along with the different methods and agents used for the same.

  6. Primary culprit for tooth loss!!

    Science.gov (United States)

    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 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. PMID:27143841

  7. Design and nondestructive imaging of a bioengineered vascular graft endothelium

    Science.gov (United States)

    Whited, Bryce Matthew

    Cardiovascular disease is currently the leading cause of death in the U.S. that frequently requires bypass surgery using vascular grafts for treatment. Current limitations with fully synthetic grafts have led researchers to bioengineered alternatives that consist of a combination of vascular scaffolds and cells. A major challenge in creating a functional bioengineered vascular graft is development of a confluent endothelium on the lumen that is able to resist detachment under physiologic fluid flow. In addition, methodologies used to assess the growth and maturation of the endothelium in a noninvasive and dynamic manner are severely lacking. Therefore, the overall goal of this research is to advance the field of vascular tissue engineering by 1) creating methodologies to enhance EC adherence to a vascular graft and 2) development of a noninvasive and real-time imaging system capable of assessing the graft endothelium. To achieve these objectives, three separate studies were performed. In the first study, electrospun scaffold fiber diameter and alignment were systematically varied to determine their effect on endothelial cell (EC) morphology and adherence under fluid flow. ECs on uniaxially aligned nanofibers displayed elongated and aligned morphologies leading to higher adherence to the scaffolds under physiologic levels of fluid flow as compared to those on randomly oriented scaffolds. In the second study, a fiber optic based (FOB) imaging system was developed to image fluorescent ECs through a thick electrospun scaffold. Results demonstrated that the FOB imaging system was able to accurately visualize fluorescent ECs in a noninvasive manner through the thick and highly opaque scaffold. In the final study, the FOB imaging system was used to noninvasively quantify vascular graft endothelialization, EC detachment, and apoptosis through the vessel wall with greater imaging penetration depth than two-photon microscopy. Additionally, the FOB method was capable of

  8. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and...... secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014...

  9. 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. PMID:26599117

  10. Dynamic, nondestructive imaging of a bioengineered vascular graft endothelium.

    Directory of Open Access Journals (Sweden)

    Bryce M Whited

    Full Text Available Bioengineering of vascular grafts holds great potential to address the shortcomings associated with autologous and conventional synthetic vascular grafts used for small diameter grafting procedures. Lumen endothelialization of bioengineered vascular grafts is essential to provide an antithrombogenic graft surface to ensure long-term patency after implantation. Conventional methods used to assess endothelialization in vitro typically involve periodic harvesting of the graft for histological sectioning and staining of the lumen. Endpoint testing methods such as these are effective but do not provide real-time information of endothelial cells in their intact microenvironment, rather only a single time point measurement of endothelium development. Therefore, nondestructive methods are needed to provide dynamic information of graft endothelialization and endothelium maturation in vitro. To address this need, we have developed a nondestructive fiber optic based (FOB imaging method that is capable of dynamic assessment of graft endothelialization without disturbing the graft housed in a bioreactor. In this study we demonstrate the capability of the FOB imaging method to quantify electrospun vascular graft endothelialization, EC detachment, and apoptosis in a nondestructive manner. The electrospun scaffold fiber diameter of the graft lumen was systematically varied and the FOB imaging system was used to noninvasively quantify the affect of topography on graft endothelialization over a 7-day period. Additionally, results demonstrated that the FOB imaging method had a greater imaging penetration depth than that of two-photon microscopy. This imaging method is a powerful tool to optimize vascular grafts and bioreactor conditions in vitro, and can be further adapted to monitor endothelium maturation and response to fluid flow bioreactor preconditioning.

  11. Tooth Avulsion in the School Setting

    Science.gov (United States)

    Krause-Parello, Cheryl A.

    2005-01-01

    Tooth avulsions occur when a tooth is displaced from its socket. Tooth avulsions are common dental injuries that may occur before, during, or after school. Therefore, it is essential that school nurses be well prepared to intervene when such a dental emergency arises. It is also imperative that school nurses and school personnel are fully equipped…

  12. 21 CFR 872.3920 - Porcelain tooth.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Porcelain tooth. 872.3920 Section 872.3920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3920 Porcelain tooth. (a) Identification. A porcelain tooth is a prefabricated device made of...

  13. Charcot-Marie-Tooth Disease

    Science.gov (United States)

    Charcot-Marie-Tooth disease (CMT) is a group of genetic nerve disorders. It is named after the three doctors who first identified it. ... a nerve biopsy. There is no cure. The disease can be so mild you don't realize ...

  14. Successful immediate autotransplantation of tooth with incomplete root formation: case report.

    Science.gov (United States)

    Kumar, Rahul; Khambete, Neha; Priya, Ekta

    2013-05-01

    This case report presents successful immediate mandibular third molar autotransplantation to replace the nonrestorable mandibular first molar. In this case, after the extraction of the nonrestorable tooth, the donor molar with incomplete root formation was autotransplanted into the recipient site after the atraumatic extraction. A long-term follow-up of 2 years revealed that the tooth was fixed in its socket without residual inflammation, masticatory function was satisfactory and without discomfort; the tooth was not mobile, no pathologic condition was apparent radiographically, the lamina dura appeared normal and the tooth showed radiographic evidence of root growth, and pulpal regeneration and the depth of the pocket, gingival contour, and gingival color were all normal. The purpose of this case report is to demonstrate the clinical application of autotransplantation as a future option of permanent restoration without implants, orthodontic space closure, or partial denture. PMID:22762917

  15. Formative Assessment and Professional Training: Reflections from a Mathematics course in Bioengineering

    Science.gov (United States)

    Carrere, C.; Milesi, S.; Lapyckyj, I.; Ravera, E.; Escher, L.; Miyara, A.; Pita, G.; Añino, M.

    2016-04-01

    Bioengineering is currently considered an interdisciplinary professional field which provides solutions to different problems arising in the area of health care. Its strategic importance is widely acknowledged since its developments and proposals could help diminish the level of technological dependence in the sector. The fast pace of innovation in the area of biomedical technology gives rise to permanent reflection on the learning goals and teaching strategies proposed by educators in the different training stages of a bioengineer. In this context, learning assessment appears as a controversial issue which needs to be debated and rethought. This paper describes the reflections of teachers of a Mathematics course within a Bioengineering program around the question, What approach to assessment favors the student’s participation, autonomy and training as a future bioengineer? The investigation was carried out in the framework of a Participatory Research Action project and helped us to redesign assessment activities from a different perspective.

  16. Angiogenesis enhances factor IX delivery and persistence from retrievable human bioengineered muscle implants

    OpenAIRE

    Thorrez, Lieven; Vandenburgh, Herman; Callewaert, Nico; Mertens, Nico; Shansky, Janet; Wang, Lin; Arnout, Jozef; Collen, Desire; Chuah, Marinee; VandenDriessche, Thierry

    2006-01-01

    Human muscle progenitor cells transduced with lentiviral vectors secreted high levels of blood clotting factor IX (FIX). When bioengineered into postmitotic myofibers as human bioartificial muscles (HBAMs) and subcutaneously implanted into immunodeficient mice, they secreted FIX into the circulation for >3 months. The HBAM-derived FIX was biologically active, consistent with the cells' ability to conduct the necessary posttranslational modifications. These bioengineered muscle implants are re...

  17. Engineering excellence in breakthrough biomedical technologies: bioengineering at the University of California, Riverside.

    Science.gov (United States)

    Schultz, Jane S; Rodgers, V G J

    2012-07-01

    The Department of Bioengineering at the University of California, Riverside (UCR), was established in 2006 and is the youngest department in the Bourns College of Engineering. It is an interdisciplinary research engine that builds strength from highly recognized experts in biochemistry, biophysics, biology, and engineering, focusing on common critical themes. The range of faculty research interests is notable for its diversity, from the basic cell biology through cell function to the physiology of the whole organism, each directed at breakthroughs in biomedical devices for measurement and therapy. The department forges future leaders in bioengineering, mirroring the field in being energetic, interdisciplinary, and fast moving at the frontiers of biomedical discoveries. Our educational programs combine a solid foundation in bio logical sciences and engineering, diverse communication skills, and training in the most advanced quantitative bioengineering research. Bioengineering at UCR also includes the Bioengineering Interdepartmental Graduate (BIG) program. With its slogan Start-Grow-Be-BIG, it is already recognized for its many accomplishments, including being third in the nation in 2011 for bioengineering students receiving National Science Foundation graduate research fellowships as well as being one of the most ethnically inclusive programs in the nation. PMID:22850835

  18. 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.

  19. Proteomic Analysis of Human Tooth Pulp: Proteomics of Human Tooth

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

    Roč. 40, č. 12 (2014), s. 1961-1966. ISSN 0099-2399 R&D Projects: GA ČR(CZ) GA13-17224S; GA ČR(CZ) GAP206/12/0453; GA MZd(CZ) NT14324 Institutional support: RVO:67985823 Keywords : dentin * human pulp * tandem mass spectrometry * tooth proteome * 2-dimensional gel electrophoresis Subject RIV: FF - HEENT, Dentistry Impact factor: 3.375, year: 2014

  20. PREFACE: XVII Congress of Bioengineering and VI Clinical Engineering Conference

    Science.gov (United States)

    Rocha, Darío

    2011-09-01

    SABI 2009 was the XVII Biennial Congress of the Argentinean Bioengineering Society (SABI - www.sabi.org.ar), celebrated along with the VI Clinical Engineering Conference. It took place in Rosario, the second city of Argentina, located on the west bank of the Paraná, one of the world's most important rivers. This city, with its 150 year history and one million inhabitants, is characterized by a strong enterprising spirit. It is the agroindustrial leader of Argentina, with cereal ports recognized to be among the most active in the world, and its cereal stock exchange competes with Chicago's in international cereal pricing. Demographically Rosario presents a European profile, and there are seven national and private higher level universities in the area. SABI 2009 was the first time the Congress was celebrated in Rosario. Usually the Congress is organized by the Bioengineering Society in cooperation with a university with an undergraduate program, which Rosario lacks. To meet the needs of this exceptional case, a young local institution was asked to coordinate the Congress, the Rosario Technological Center (www.polotecnologico.net). This organization gathers together around 100 companies that produce technology, with a large number focused on IT, but those focused on biotechnology also stand out. The Center is also integrated with relevant public and government bodies. Traditionally, bioengineering has been related to human health applications, with less emphasis on applications significant to agrotechnology, an area in which Rosario is growing as an economic force. In order to address this oversight, the Congress formulated its main goals for integrating and synergizing bioengineering and biotechnology, particularly bioengineering and agrotechnology. This initiative has produced promising results. The importance of the Congress was reflected in the high number of participants - including researchers, professionals and students - from abroad, with participants from

  1. Stress analysis of the radial head replacement in an elbow articulation

    Czech Academy of Sciences Publication Activity Database

    Hlavoň, Pavel; Fuis, Vladimír; Návrat, Tomáš; Florian, Z.

    Bangkok, Thailand : Biomedical Engineering Society, Singapore and World Association for Chinese Biomedical Engineers, 2007, P23-P23. ISBN 978-81-904262-8-2. - (Program and Abstracts of World Congress on Bioengineering). [WACBE 2007. Bangkok (TH), 09.07.2007-11.07.2007] R&D Projects: GA ČR GA101/05/0136 Institutional research plan: CEZ:AV0Z20760514 Keywords : radial head replacement * elbow joint * stress analysis Subject RIV: BO - Biophysics

  2. Conservative Approach for Restoring Posterior Missing Tooth with Fiber Reinforcement Materials: Four Clinical Reports

    OpenAIRE

    Karaarslan, Emine Sirin; Ertas, Ertan; Ozsevik, Semih; Usumez, Aslihan

    2011-01-01

    Adhesively luted, fiber-reinforced, composite-inlay, retained fixed-partial dentures can be a clinical alternative for the replacement of missing posterior teeth in selective situations. This type of restoration allows for satisfactory esthetics and reduced tooth preparation compared to a conventional, fixed-partial denture. This clinical report describes the use of a fiber-reinforced, composite-inlay, retained fixed-partial denture as a conservative alternative for the replacement of missing...

  3. Optical spectroscopy and tooth decay

    Science.gov (United States)

    Misra, P.; De, T.; Singh, R.

    2005-11-01

    Optical spectroscopy in the ultraviolet, visible and mid-infrared spectral regions has been used to discriminate between healthy and diseased teeth of patients in the age range 15-75 years. Spectral scans of absorbance versus wavenumber and fluorescence intensity versus wavelength have been recorded and investigated for caries and periodontal disease. Such optical diagnostics can prove very useful in the early detection and treatment of tooth decay.

  4. Charcot-Marie-Tooth disease.

    LENUS (Irish Health Repository)

    Reilly, Mary M

    2011-03-01

    Charcot-Marie-Tooth (CMT) disease is the commonest inherited neuromuscular disorder affecting at least 1 in 2,500. Over the last two decades, there have been rapid advances in understanding the molecular basis for many forms of CMT with more than 30 causative genes now described. This has made obtaining an accurate genetic diagnosis possible but at times challenging for clinicians. This review aims to provide a simple, pragmatic approach to diagnosing CMT from a clinician\\'s perspective.

  5. Mechanical modelling of tooth wear.

    Science.gov (United States)

    Karme, Aleksis; Rannikko, Janina; Kallonen, Aki; Clauss, Marcus; Fortelius, Mikael

    2016-07-01

    Different diets wear teeth in different ways and generate distinguishable wear and microwear patterns that have long been the basis of palaeodiet reconstructions. Little experimental research has been performed to study them together. Here, we show that an artificial mechanical masticator, a chewing machine, occluding real horse teeth in continuous simulated chewing (of 100 000 chewing cycles) is capable of replicating microscopic wear features and gross wear on teeth that resemble wear in specimens collected from nature. Simulating pure attrition (chewing without food) and four plant material diets of different abrasives content (at n = 5 tooth pairs per group), we detected differences in microscopic wear features by stereomicroscopy of the chewing surface in the number and quality of pits and scratches that were not always as expected. Using computed tomography scanning in one tooth per diet, absolute wear was quantified as the mean height change after the simulated chewing. Absolute wear increased with diet abrasiveness, originating from phytoliths and grit. In combination, our findings highlight that differences in actual dental tissue loss can occur at similar microwear patterns, cautioning against a direct transformation of microwear results into predictions about diet or tooth wear rate. PMID:27411727

  6. Life cycle performances of log wood applied for soil bioengineering constructions

    Science.gov (United States)

    Kalny, Gerda; Strauss-Sieberth, Alexandra; Strauss, Alfred; Rauch, Hans Peter

    2016-04-01

    Nowadays there is a high demand on engineering solutions considering not only technical aspects but also ecological and aesthetic values. Soil bioengineering is a construction technique that uses biological components for hydraulic and civil engineering solutions. Soil bioengineering solutions are based on the application of living plants and other auxiliary materials including among others log wood. This kind of construction material supports the soil bioengineering system as long as the plants as living construction material overtake the stability function. Therefore it is important to know about the durability and the degradation process of the wooden logs to retain the integral performance of a soil bio engineering system. These aspects will be considered within the framework of the interdisciplinary research project „ELWIRA Plants, wood, steel and concrete - life cycle performances as construction materials". Therefore field investigations on soil bioengineering construction material, specifically European Larch wood logs, of different soil bioengineering structures at the river Wien have been conducted. The drilling resistance as a parameter for particular material characteristics of selected logs was measured and analysed. The drilling resistance was measured with a Rinntech Resistograph instrument at different positions of the wooden logs, all surrounded with three different backfills: Fully surrounded with air, with earth contact on one side and near the water surface in wet-dry conditions. The age of the used logs ranges from one year old up to 20 year old. Results show progress of the drilling resistance throughout the whole cross section as an indicator to assess soil bioengineering construction material. Logs surrounded by air showed a higher drilling resistance than logs with earth contact and the ones exposed to wet-dry conditions. Hence the functional capability of wooden logs were analysed and discussed in terms of different levels of degradation

  7. Application of AMOR in Craniofacial Rabbit Bone Bioengineering

    Directory of Open Access Journals (Sweden)

    Marcelo Freire

    2015-01-01

    Full Text Available Endogenous molecular and cellular mediators modulate tissue repair and regeneration. We have recently described antibody mediated osseous regeneration (AMOR as a novel strategy for bioengineering bone in rat calvarial defect. This entails application of anti-BMP-2 antibodies capable of in vivo capturing of endogenous osteogenic BMPs (BMP-2, BMP-4, and BMP-7. The present study sought to investigate the feasibility of AMOR in other animal models. To that end, we examined the efficacy of a panel of anti-BMP-2 monoclonal antibodies (mAbs and a polyclonal Ab immobilized on absorbable collagen sponge (ACS to mediate bone regeneration within rabbit calvarial critical size defects. After 6 weeks, de novo bone formation was demonstrated by micro-CT imaging, histology, and histomorphometric analysis. Only certain anti-BMP-2 mAb clones mediated significant in vivo bone regeneration, suggesting that the epitopes with which anti-BMP-2 mAbs react are critical to AMOR. Increased localization of BMP-2 protein and expression of osteocalcin were observed within defects, suggesting accumulation of endogenous BMP-2 and/or increased de novo expression of BMP-2 protein within sites undergoing bone repair by AMOR. Considering the ultimate objective of translation of this therapeutic strategy in humans, preclinical studies will be necessary to demonstrate the feasibility of AMOR in progressively larger animal models.

  8. Bioengineering case studies sustainable stream bank and slope stabilization

    CERN Document Server

    Goldsmith, Wendi; McCullah, John

    2014-01-01

    This unique volume describes and evaluates 30 projects from across the United States where bio-stabilization was employed to address a detrimental naturally occurring process or byproduct of the built environment. Bio-stabilization (or soil bioengineering) refers to the use of plant materials, primarily live cuttings, arranged in the ground in different arrays to reinforce soils and protect upland slopes and/or stream banks against surficial erosion and shallow slope failures. Examples included in the collection represent different regions of the country and their specific conditions and challenges. Each project is illustrated with a number of distinctive photographs to support the reader's understanding and showcase the wide scope of projects and techniques presented. This book also: ·         Presents a range of well-documented case studies on key techniques and best practices for bio-stabilization projects ·         Emphasizes evaluation and comparison of different techniques and challeng...

  9. The role of coccolithophore calcification in bioengineering their environment.

    Science.gov (United States)

    Flynn, Kevin J; Clark, Darren R; Wheeler, Glen

    2016-06-29

    Coccolithophorids are enigmatic plankton that produce calcium carbonate coccoliths, which over geological time have buried atmospheric CO2 into limestone, changing both the atmosphere and geology of the Earth. However, the role of coccoliths for the proliferation of these organisms remains unclear; suggestions include roles in anti-predation, enhanced photosynthesis and sun-screening. Here we test the hypothesis that calcification stabilizes the pH of the seawater proximate to the organisms, providing a level of acidification countering the detrimental basification that occurs during net photosynthesis. Such bioengineering provides a more stable pH environment for growth and fits the empirical evidence for changes in rates of calcification under different environmental conditions. Under this scenario, simulations suggest that the optimal production ratio of inorganic to organic particulate C (PIC : POCprod) will be lower (by approx. 20%) with ocean acidification and that overproduction of coccoliths in a future acidified ocean, where pH buffering is weaker, presents a risk to calcifying cells. PMID:27358373

  10. Bioengineered models of solid human tumors for cancer research

    Science.gov (United States)

    Marturano-Kruik, Alessandro; Villasante, Aranzazu; Vunjak-Novakovic, Gordana

    2016-01-01

    Summary The lack of controllable in vitro models that can recapitulate the features of solid tumors such as Ewing’s sarcoma limits our understanding of the tumor initiation and progression and impedes the development of new therapies. Cancer research still relies of the use of simple cell culture, tumor spheroids, and small animals. Tissue-engineered tumor models are now being grown in vitro to mimic the actual tumors in patients. Recently, we have established a new protocol for bioengineering the Ewing’s sarcoma, by infusing tumor cell aggregates into the human bone engineered from the patient’s mesenchymal stem cells. The bone niche allows crosstalk between the tumor cells, osteoblasts and supporting cells of the bone, extracellular matrix and the tissue microenvironment. The bioreactor platform used in these experiments also allows the implementation of physiologically relevant mechanical signals. Here, we describe a method to build an in vitro model of Ewing’s sarcoma that mimics the key properties of the native tumor and provides the tissue context and physical regulatory signals. PMID:27115504

  11. The role of coccolithophore calcification in bioengineering their environment

    Science.gov (United States)

    Clark, Darren R.; Wheeler, Glen

    2016-01-01

    Coccolithophorids are enigmatic plankton that produce calcium carbonate coccoliths, which over geological time have buried atmospheric CO2 into limestone, changing both the atmosphere and geology of the Earth. However, the role of coccoliths for the proliferation of these organisms remains unclear; suggestions include roles in anti-predation, enhanced photosynthesis and sun-screening. Here we test the hypothesis that calcification stabilizes the pH of the seawater proximate to the organisms, providing a level of acidification countering the detrimental basification that occurs during net photosynthesis. Such bioengineering provides a more stable pH environment for growth and fits the empirical evidence for changes in rates of calcification under different environmental conditions. Under this scenario, simulations suggest that the optimal production ratio of inorganic to organic particulate C (PIC : POCprod) will be lower (by approx. 20%) with ocean acidification and that overproduction of coccoliths in a future acidified ocean, where pH buffering is weaker, presents a risk to calcifying cells. PMID:27358373

  12. A brief history of the Bioengineering Institute of California and the UC System-wide Symposia.

    Science.gov (United States)

    Chien, Shu

    2011-04-01

    The plan to establish a Multicampus Research Unit (MRU) on Bioengineering in the University of California (UC) System started in August 1999. The cooperative efforts of the UC campuses led to the formal establishment of the Bioengineering Institute of California (BIC) in October 2003. Three years prior to the BIC establishment, the System-wide Annual Bioengineering Symposium was started at UC Davis. The Symposia were then hosted sequentially by UC Santa Barbara, UC Berkeley, UCSD, UC Santa Cruz, UC Irvine, UCSF, UCLA, and UC Riverside, with the completion of the first cycle of a decade in the newest campus of UC Merced in 2009. The second cycle began in 2010 with the Symposium returning again to UC Davis. Each campus hosted a wonderful Symposium, with the active participation of students and faculty from all campuses, with the motto of "Ten campuses united as one, learning and growing together." These Symposia have contributed significantly to the collaborative research and training of students and young scientists in bioengineering, as well as fruitful interactions with industry and government agencies, which have provided strong support for these valuable meetings. The BIC will endeavor to further enhance these efforts by fostering research collaborations and joint education and training activities, with the ultimate goal of advancing bioengineering for the improvement of human health and wellbeing. PMID:21384235

  13. Tooth use in Aboriginal Australia

    Directory of Open Access Journals (Sweden)

    Anna Clement

    2008-09-01

    Full Text Available The study of dental casts taken from living people avoids the ethical problems of research into human remains, while providing valuable information about diet and life styles. This article describes a study of tooth wear in dental casts of three different groups of Australian Aborigines. The authors describe their methods of recording and report differential patterns of wear in the different groups. Preliminary interpretation relates the wear patterns both to diet and to the use of teeth as tools in a range of cultural activities, results which are potentially relevant to other groups of hunter-gatherers, past and present.

  14. Deep tissue injury from a bioengineering point of view.

    Science.gov (United States)

    Gefen, Amit

    2009-04-01

    The phrasing of the National Pressure Ulcer Advisory Panel's (NPUAP) definition of deep tissue injury (DTI) was based on case reports, clinical observations, and experience. Although etiological studies of DTI, primarily related to characterizing biomechanical factors affecting onset and progression, support and strengthen parts of the NPUAP's definition, some recent findings suggest a need to re-evaluate the wording and perhaps refine future definitions of DTI. Application of existing bioengineering research to underlying biological, physical, biomechanical, and biochemical mechanisms involved in the definition of DTI suggests the following: 1) changes in skin color - ie, deviation of the local skin color from the surroundings - may indicate a DTI might be present, but color is not useful for quantifying the severity of injury; 2) the pressure and/or shear definition is inaccurate because it creates an artificial distinction between pressure and shear, which are physically coupled, and because it ignores tensional loads; 3) palpating tissue firmness at the wound site provides limited assessment information because tissue firmness will depend on the point in time along the course of DTI development. Damaged tissues might appear stiffer than surrounding tissues if examined when muscle tissue is locally contracted due to local rigor mortis but at a later stage damage might manifest as tissues that are softer than their surroundings when digestive enzymes start decomposing necrotic tissues; 4) skin temperature changes near the DTI site may reflect inflammatory response, causing local heating, or ischemic perfusion, causing local cooling; and 5) rapid deterioration of DTI is likely occurring due to muscle tissue stiffening at the rigor mortis phase; stiffened tissues abnormally deform adjacent tissues and this effect is amplified if muscles are atrophied. The application of interdisciplinary research may help clinicians and researchers move from evolving jargons

  15. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... trial. This calcar mill has a single cutting tooth, and we use it on a reamer, so ... if I use the wrong type of cutting tooth. I think it’s critically important, because this thing ...

  16. [Tooth erosion - a multidisciplinary approach].

    Science.gov (United States)

    Strużycka, Izabela; Rusyan, Ewa; Bogusławska-Kapała, Agnieszka

    2016-02-01

    During the last decades, an increasingly greater interest in dental erosion has been observed in clinical dental practice, in dental public health and in dental research because prevalence of erosive tooth wear is still increasing especially in young age group of population. Erosive tooth wear is a multifactorial etiology process characterized by progressive loss of hard dental tissue. It is defined as the exogenous and/or endogenous acids dissolution of the dental tissue, without bacterial involvement. In the development of dental erosive wear, interactions are required which include chemical, biological, behavioral, diet, time, socioeconomic, knowledge, education, and general health factors. Examples of risk groups could be patients with eating disorders, like anorexia nervosa or bulimia nervosa, gastroesophageal reflux disease, chronic alcohol abuse or dependence. Special nutrition habits groups with high consumption of soft or sport drinks, special diets like vegetarian, vegan or raw food diet, the regular intake of drugs, medications and food supplements can also increase the risk for dental erosion. Comprehensive knowledge of the different risk and protective factors is a perquisite for initiating adequate preventive measures. PMID:27000809

  17. Joint Replacement Surgery

    Science.gov (United States)

    ... a Clinical Trial Journal Articles Arthritis July 2014 Joint Replacement Surgery: Health Information Basics for You and Your Family What Is Joint Replacement Surgery? Joint replacement surgery is removing a ...

  18. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Disorder What is Baby Bottle Tooth Decay? Men: Looking for a Better Job? Start by Visiting the Dentist When Should My Child First See a Dentist? Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | ...

  19. Addressing Tooth Decay in Head Start Children

    Science.gov (United States)

    Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

    2012-01-01

    Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

  20. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Quick Reference Learn more Nutrition - Adults What is Dental Amalgam (Silver Filling)? Are You Biting Off More Than You Can Chew? What is Baby Bottle Tooth Decay? Men: Looking for a Better Job? Start by Visiting the Dentist Is My Child at Risk for Early Childhood ... The Life of a Tooth games ...

  1. Life of a Tooth: A Visual Timeline

    Science.gov (United States)

    ... Quick Reference Learn more Nutrition - Adults What is Dental Amalgam (Silver Filling)? Are You Biting Off More Than You Can Chew? What is Baby Bottle Tooth Decay? Men: Looking for a Better Job? Start by Visiting the Dentist Is My Child at Risk for Early Childhood ... The Life of a Tooth games ...

  2. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Decay? Check Menstrual Calendar for Tooth Extraction The History of Dental Advances Men: Looking for a Better Job? Start by Visiting the Dentist Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a ...

  3. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health What is Baby Bottle Tooth Decay? Is My ... for Early Childhood Tooth Decay? Why is Oral Health Important for Men? When Should My Child First ...

  4. An Effective Numerical Method and Its Utilization to Solution of Fractional Models Used in Bioengineering Applications

    Directory of Open Access Journals (Sweden)

    Petráš Ivo

    2011-01-01

    Full Text Available This paper deals with the fractional-order linear and nonlinear models used in bioengineering applications and an effective method for their numerical solution. The proposed method is based on the power series expansion of a generating function. Numerical solution is in the form of the difference equation, which can be simply applied in the Matlab/Simulink to simulate the dynamics of system. Several illustrative examples are presented, which can be widely used in bioengineering as well as in the other disciplines, where the fractional calculus is often used.

  5. Post-Odontoma autotransplantation of an impacted tooth: A case report.

    Science.gov (United States)

    Robindro Singh, Waikhom; Aheibam, Kirankumar; Nameirakpam, Anthopia

    2015-01-01

    After years of relegation by dental implants, autotransplantation has recently become more popular because of a better understanding of its science. The prognosis of autotransplantation primarily depends upon the presence of an intact alveolar bone at the transplant site and the regeneration of a functional periodontal ligament of the transplant. Replacement of an unsalvaged or a missing tooth by a natural tooth with normal periodontium within a short duration of treatment is the ultimate challenge of autotransplantation. Meanwhile, Platelet Rich Fibrin (PRF) is popular as a biomaterial which helps in the regeneration of bone and periodontal tissues. To improve the prognosis, and also shorten the treatment time in a rare case of autotransplantation of an impacted tooth in a post-odontoma site, we did a two-stage surgical procedure aided by synthetic bone granules (Biograft) and PRF. The clinical and radiological findings at 6 months follow-up showed good result and promise. PMID:26258027

  6. Anterior fixed interim prosthesis with natural tooth crown as pontic subsequent to replantation failure

    Directory of Open Access Journals (Sweden)

    Sivakumar Nuvvula

    2011-01-01

    Full Text Available Facial trauma resulting in tooth avulsion results in problems of physical and emotional nature for the patient and a challenge for the dentist. Avulsion accounts for 0.5-16% of traumatic injuries in the permanent dentition that can occur at any age and is most common in the young permanent dentition. As an emergency procedure, it is advisable to replant a traumatically avulsed tooth, but unfortunately long-term success is rather low. After unsuccessful replantation and subsequent extraction, it is prudent to replace the lost tooth to avoid aesthetic, masticatory, and psychological difficulties and also to prevent arch length discrepancy with various alternatives are available for the same. We presented a method for management of one of the two replanted teeth that showed failure, using the natural crown as pontic in a fixed semi-permanent bridge until a more definitive prosthesis can be fabricated at a later age for better patient compliance.

  7. Replacement of missing teeth with fiber-reinforced composite FPDs: clinical protocol

    OpenAIRE

    Bouillaguet, Serge; Schütt, Andrea; Marin, Isabelle; Etechami, Leila; Di Salvo, Giancarlo; Krejci, Ivo

    2003-01-01

    The concept of minimally invasive preparation protocols has resulted in reduced loss of critical tooth structures and maintenance of optimal strength, form, and aesthetics. While various treatment options have been described for single-tooth replacement, fiber-reinforced composite (FRC) fixed partial dentures (FPDs) provide a viable treatment alternative with proven mechanical properties, aesthetics, and function. This article presents several clinical scenarios in which minimally invasive ad...

  8. Bio-Engineering High Performance Microbial Strains for MEOR

    Energy Technology Data Exchange (ETDEWEB)

    Xiangdong Fang; Qinghong Wang; Patrick Shuler

    2007-12-30

    The main objectives of this three-year research project are: (1) to employ the latest advances in genetics and bioengineering, especially Directed Protein Evolution technology, to improve the effectiveness of the microbial enhanced oil recovery (MEOR) process. (2) to improve the surfactant activity and the thermal stability of bio-surfactant systems for MEOR; and (3) to develop improved laboratory methods and tools that screen quickly candidate bio-systems for EOR. Biosurfactants have been receiving increasing attention as Enhanced Oil Recovery (EOR) agents because of their unique properties (i.e., mild production conditions, lower toxicity, and higher biodegradability) compared to their synthetic chemical counterparts. Rhamnolipid as a potent natural biosurfactant has a wide range of potential applications, including EOR and bioremediation. During the three-year of the project period, we have successfully cloned the genes involved in the rhamnolipid bio-synthesis. And by using the Transposon containing Rhamnosyltransferase gene rhlAB, we engineered the new mutant strains P. aeruginosa PEER02 and E. coli TnERAB so they can produce rhamnolipid biosurfactans. We were able to produce rhamnolipds in both P. aeroginosa PAO1-RhlA- strain and P. fluorescens ATCC15453 strain, with the increase of 55 to 175 fold in rhamnolipid production comparing with wild type bacteria strain. We have also completed the first round direct evolution studies using Error-prone PCR technique and have constructed the library of RhlAB-containing Transposon to express mutant gene in heterologous hosts. Several methods, such as colorimetric agar plate assay, colorimetric spectrophotometer assay, bioactive assay and oil spreading assay have been established to detect and screen rhamnolipid production. Our engineered P. aeruginosa PEER02 strain can produce rhamnolipids with different carbon sources as substrate. Interfacial tension analysis (IFT) showed that different rhamnolipids from different

  9. Kidney transplantation, bioengineering and regeneration: an originally immunology-based discipline destined to transition towards ad hoc organ manufacturing and repair.

    Science.gov (United States)

    Rogers, Jeffrey; Katari, Ravi; Gifford, Sheyna; Tamburrini, Riccardo; Edgar, Lauren; Voigt, Marcia R; Murphy, Sean V; Igel, Daniel; Mancone, Sara; Callese, Tyler; Colucci, Nicola; Mirzazadeh, Majid; Peloso, Andrea; Zambon, Joao Paulo; Farney, Alan C; Stratta, Robert J; Orlando, Giuseppe

    2016-02-01

    Kidney transplantation (KT), as a modality of renal replacement therapy (RRT), has been shown to be both economically and functionally superior to dialysis for the treatment of end-stage renal disease (ESRD). Progress in KT is limited by two major barriers: a) a chronic and burgeoning shortage of transplantable organs and b) the need for chronic immunosuppression following transplantation. Although ground-breaking advances in transplant immunology have improved patient survival and graft durability, a new pathway of innovation is needed in order to overcome current obstacles. Regenerative medicine (RM) holds the potential to shift the paradigm in RRT, through organ bioengineering. Manufactured organs represent a potentially inexhaustible source of transplantable grafts that would bypass the need for immunosuppressive drugs by using autologous cells to repopulate extracellular matrix (ECM) scaffolds. This overview discusses the current status of renal transplantation while reviewing the most promising innovations in RM therapy as applied to RRT. PMID:26634874

  10. Mechanism of human tooth eruption

    DEFF Research Database (Denmark)

    Kjær, Inger

    2014-01-01

    Human eruption is a unique developmental process in the organism. The aetiology or the mechanism behind eruption has never been fully understood and the scientific literature in the field is extremely sparse. Human and animal tissues provide different possibilities for eruption analyses, briefly......, and the ability of the periodontal ligament to adapt to eruptive movements. Animal studies and studies on normal and pathological eruption in humans can support and explain different aspects in the new theory. The eruption mechanism still needs elucidation and the paper recommends that future research...... discussed in the introduction. Human studies, mainly clinical and radiological, have focused on normal eruption and gender differences. Why a tooth begins eruption and what enables it to move eruptively and later to end these eruptive movements is not known. Pathological eruption courses contribute to...

  11. [Tracheal replacement grafts: current options].

    Science.gov (United States)

    Dulguerov, Pavel; Soccal, Paola M; Bouayed, Salim; Huber, Olivier; Pittet, Brigitte

    2011-10-01

    A critical review of publications on tracheal reconstruction is presented. The extent of the resection defect in terms of horizontal circumference or longitudinal extension determines the difficulty of the reconstruction. To allow a valid comparison, a classification of tracheal defects is proposed. The reconstruction materials can be subdivided into synthetic grafts, autografts, allografts, and bioengineering constructs. Reconstruction of tracheal defects greater than half of the tracheal length was not possible until recently. Numerous publications on animal experimental techniques, and rare human case reports show few successful outcomes. During the last five years, new reconstructive options have emerged: autograft of composite flaps mimicking tracheal architecture and bioengineered tracheal constructs. PMID:22046681

  12. The pattern of histogenesis and growth of tooth plates in larval stages of extant lungfish.

    Science.gov (United States)

    Smith, M M

    1985-06-01

    Comparison of new data obtained in this study on Protopterus aethiopicus with that published on Protopterus aethiopicus and Neoceratodus forsteri has confirmed the suggestion that the pattern of histogenesis of tooth plates in the early larval stages is very similar in the two genera. These similarities are more apparent both when a common terminology is adopted, based on a topogenic classification, and when the fundamental assumption is made that a single morphogenetic system operates for all odontodes. The model to explain the structure of all vertebrate dentitions with separate teeth in single or multiple tooth rows has been found to apply to dipnoan dentitions with fused teeth in a composite tooth plate. In this model, the epithelial invagination surrounding the margins of the tooth plate represents the dental lamina and, where this is in contact with mesenchymal cells, cell clusters (protogerms) arise. From these protogerms new odontodes (teeth) may develop if factors to inhibit differentiation are not present. Sites for initiation of odontodes become restricted to the labial margins of existing ridges on the tooth plate. Experimental studies on mammalian tooth germs are discussed and a model proposed for control of odontogenesis and histogenesis in dipnoan dentitions. Patterns of growth of hypermineralised petrodentine have been analysed and shown to depend initially on the arrangement of odontodes, and subsequently upon the ability of special cells in the pulp to generate new and wider layers of petrodentine. The initial pattern of petrodentine depends upon the position of odontodes in the forming ridges of the tooth plate. Subsequent patterns of petrodentine depend upon the extent of replacement growth beneath the tritural surface. Specialised cells, petroblasts, secrete the petrodentine within a shell of dentine. These cells differentiate from cells of the dental papilla after odontoblasts have begun to form dentine. They are regarded as a unique type of

  13. Associations between smoking and tooth loss according to reason for tooth loss

    Science.gov (United States)

    Mai, Xiaodan; Wactawski-Wende, Jean; Hovey, Kathleen M.; LaMonte, Michael J.; Chen, Chaoru; Tezal, Mine; Genco, Robert J.

    2013-01-01

    Background Smoking is associated with tooth loss. However, smoking's relationship to the specific reason for tooth loss in postmenopausal women is unknown. Methods Postmenopausal women (n = 1,106) who joined a Women's Health Initiative ancillary study (The Buffalo OsteoPerio Study) underwent oral examinations for assessment of the number of missing teeth, as well as the self-reported reasons for tooth loss. The authors obtained information about smoking status via a self-administered questionnaire. The authors calculated odds ratios (ORs) and 95 percent confidence intervals (CIs) by means of logistic regression to assess smoking's association with overall tooth loss, as well as with tooth loss due to periodontal disease (PD) and with tooth loss due to caries. Results After adjusting for age, education, income, body mass index (BMI), history of diabetes diagnosis, calcium supplement use and dental visit frequency, the authors found that heavy smokers (≥ 26 pack-years) were significantly more likely to report having experienced tooth loss compared with never smokers (OR = 1.82; 95 percent CI, 1.10-3.00). Smoking status, packs smoked per day, years of smoking, pack-years and years since quitting smoking were significantly associated with tooth loss due to PD. For pack-years, the association for heavy smokers compared with that for never smokers was OR = 6.83 (95 percent CI, 3.40-13.72). The study results showed no significant associations between smoking and tooth loss due to caries. Conclusions and Practical Implications Smoking may be a major factor in tooth loss due to PD. However, smoking appears to be a less important factor in tooth loss due to caries. Further study is needed to explore the etiologies by which smoking is associated with different types of tooth loss. Dentists should counsel their patients about the impact of smoking on oral health, including the risk of tooth loss due to PD. PMID:23449901

  14. Treatment of root surface in delayed tooth replantation: a review of literature.

    Science.gov (United States)

    Panzarini, Sônia Regina; Gulinelli, Jéssica Lemos; Poi, Wilson Roberto; Sonoda, Celso Koogi; Pedrini, Denise; Brandini, Daniela Atili

    2008-06-01

    The time elapsed between a trauma and tooth replantation usually ranges from 1 to 4 h. The chances of root surface damage are higher when tooth replantation is not performed immediately or if the avulsed tooth is not stored in an adequate medium. This invariably leads to necrosis of pulp tissue, periodontal ligament cells and cementum, thus increasing the possibility of root resorption, which is the main cause of loss of replanted teeth. This paper presents a comprehensive review of literature on root surface treatments performed in cases of delayed tooth replantation with necrotic cemental periodontal ligament. Journal articles retrieved from PubMed/MedLine, Bireme and Scielo databases were reviewed. It was observed that, when there are no periodontal ligament remnants and contamination is under control, replacement resorption and ankylosis are the best results and that, although these events will end up leading to tooth loss, this will happen slowly with no loss of the alveolar ridge height, which is important for future prosthesis planning. PMID:18410388

  15. Effects of carbonated soft drink consumption on orthodontic tooth movements in rats.

    Directory of Open Access Journals (Sweden)

    Hossein Agha Aghili

    2014-04-01

    Full Text Available The aim of this animal study was to evaluate the possible effects of Carbonated Soft Drink consumption on the rate of orthodontic tooth movement in rats.Thirty-six adult male Sprague-Dawley rats were randomly divided into two experimental groups and one control group. In the experimental groups (A&B, the water in the dietary regimen was replaced with soft drinks (Fanta® in group A and Cola® in group B two weeks before placement of orthodontic appliances. Then 5-mm nickel-titanium closed-coil springs were placed between the maxillary right first molars and first incisors under general anesthesia. This regimen continued for two weeks more and animals drank soft drink ad libitum. At the end of the experimental period, the rats were sacrificed, and interproximal tooth movements were measured.The mean amounts of tooth movement were 0.19mm in group A, 0.22mm in group B and 0.37mm in group C. Statistical analysis with analysis of variance (ANOVA test showed significant differences between all groups. The least movement occurred in group A that had received Fanta® drink.CSDs consumption decreases the rate of orthodontic tooth movement. The role of soft drinks in decreasing tooth movement might be related to its effects on bone metabolism.

  16. An Introductory Course in Bioengineering and Biotechnology for Chemical Engineering Sophomores

    Science.gov (United States)

    O'Connor, Kim C.

    2007-01-01

    Advances in the biological sciences necessitate the training of chemical engineers to translate these fundamental discoveries into applications that will benefit society. Accordingly, Tulane University revised its core chemical engineering curriculum in 2005 to include a new introductory course in bioengineering and biotechnology for sophomores.…

  17. Simulation of a Congress at the Chair of Biology II in Bioengineering

    International Nuclear Information System (INIS)

    This work has been developed in the Chair of Biology II, the curricular contents of which correspond to Human Anatomy. This subject is taught in the second semester of the second year of studies in Bioengineering. Our main objective is that the students attending the course may integrate the syllabus contents of Anatomy with those of other subjects in the career. Ever since 1998 we have organized a congress named Congreso Intracatedra de BiologIa II (Intra Chair Congress on Biology II). This is the last assignment in the semester and is compulsory for regular students of the subject. It consists in simulating a scientific congress with international characteristics. The guidelines for the congress are made known to the students at the beginning of the semester. In groups of up to three members, the students must undertake a work that relates aspects of Anatomy with Bioengineering. Students are expected to investigate on diagnostic and/or therapeutic technology in order to write a paper that must be accepted in advance of the event. The presentation of the work must be made through PowerPoint. The originality of the research work done and the wide range of topics selected are surprising. Problems are tackled from the standpoints both of the various medical fields and of bioengineering despite the fact that they are just students of the second year in Bioengineering

  18. Simulation of a Congress at the Chair of Biology II in Bioengineering

    Science.gov (United States)

    Naranjo, A. V.; Reznichenco, V.; López, N.; Hernández, R.; Bajinay, S.

    2007-11-01

    This work has been developed in the Chair of Biology II, the curricular contents of which correspond to Human Anatomy. This subject is taught in the second semester of the second year of studies in Bioengineering. Our main objective is that the students attending the course may integrate the syllabus contents of Anatomy with those of other subjects in the career. Ever since 1998 we have organized a congress named Congreso Intracátedra de Biología II (Intra Chair Congress on Biology II). This is the last assignment in the semester and is compulsory for regular students of the subject. It consists in simulating a scientific congress with international characteristics. The guidelines for the congress are made known to the students at the beginning of the semester. In groups of up to three members, the students must undertake a work that relates aspects of Anatomy with Bioengineering. Students are expected to investigate on diagnostic and/or therapeutic technology in order to write a paper that must be accepted in advance of the event. The presentation of the work must be made through PowerPoint. The originality of the research work done and the wide range of topics selected are surprising. Problems are tackled from the standpoints both of the various medical fields and of bioengineering despite the fact that they are just students of the second year in Bioengineering.

  19. Tooth fractures in canine clinical practice

    International Nuclear Information System (INIS)

    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

  20. Conceptional Considerations to Energy Balance and Global Warming Potential of Soil Bioengineering Structures

    Science.gov (United States)

    von der Thannen, Magdalena; Paratscha, Roman; Smutny, Roman; Lampalzer, Thomas; Strauss, Alfred; Rauch, Hans Peter

    2016-04-01

    Nowadays there is a high demand on engineering solutions considering not only technical aspects but also ecological and aesthetic values. In this context soil bioengineering techniques are often used as standalone solutions or in combination with conventional engineering structures. It is a construction technique that uses biological components for hydraulic and civil engineering solutions. In general it pursues the same objectives as conventional civil engineering structures. Currently the used assessment methods for soil bioengineering structures are referencing technically, ecologically and socio-economically. In a modern engineering approach additionally, environmental impacts and potential added values should be considered. The research project E-Protect aims at developing Environmental Life Cycle Assessment (LCA) models for this special field of alpine protective constructions. Both, the Cumulative Energy Demand (CED) and the Global Warming Potential (GWP) should be considered in an Environmental LCA over the whole life cycle of an engineering structure. The life cycle itself can be divided into three phases: the construction phase, the use phase and the end of life phase. The paper represents a concept to apply an Environmental LCA model for soil bioengineering structures. Beside the construction phase of these structures particular attention will be given to the use phase. It is not only important in terms of engineering effects but also plays an important role for positive carbon footprint due to the growing plants of soil bioengineering structures in contrast to conventional structures. Innovative Environmental LCA models will be applied to soil bioengineering structures which provide a new transparency for the responsible planners and stakeholders, by pointing out the total consumption of resources in all construction phases and components.

  1. Impacted supernumerary tooth in coronoid process: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Se; Lee, Je Ho; Park, Hyok; Jung, Ho Gul; Kim, Kee Deog [Yonsei University College of Dentistry, Seoul (Korea, Republic of)

    2010-06-15

    Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.

  2. Genetics And Tooth Anomalies - An Update

    Directory of Open Access Journals (Sweden)

    Aswathy Brahmanandan

    2013-01-01

    Full Text Available Tooth development like the development of all epithelial appendages is regulated by inductive tissue interactions between epithelium and mesenchyme. Numerous genes interact, either act in conjunction or antagonize each other in odontogenesis. A number of different mesenchymal molecules and their receptors act as mediators in epithelial mesenchymal interactions. Several genes linked with early tooth positioning and developments belong to signaling pathways and have morphogenesis regulatory functions in morphogenesis of other organs. Their mutations often show pleiotropic effects beyond dental morphogenesis. In contrast, certain genes involved in enamel and dentin structures are highly specific for tooth. Mutations in these genes have been identified as causes of Amelogenesis Imperfecta (AI, Dentinogenesis Imperfecta (DI, Dentin Dysplasia (DD and anomalies in tooth number. This article focuses on genetic basis of inherited non-syndromic teeth disorders.

  3. Robust tooth surface reconstruction by iterative deformation.

    Science.gov (United States)

    Jiang, Xiaotong; Dai, Ning; Cheng, Xiaosheng; Wang, Jun; Peng, Qingjin; Liu, Hao; Cheng, Cheng

    2016-01-01

    Digital design technologies have been applied extensively in dental medicine, especially in the field of dental restoration. The all-ceramic crown is an important restoration type of dental CAD systems. This paper presents a robust tooth surface reconstruction algorithm for all-ceramic crown design. The algorithm involves three necessary steps: standard tooth initial positioning and division; salient feature point extraction using Morse theory; and standard tooth deformation using iterative Laplacian Surface Editing and mesh stitching. This algorithm can retain the morphological features of the tooth surface well. It is robust and suitable for almost all types of teeth, including incisor, canine, premolar, and molar. Moreover, it allows dental technicians to use their own preferred library teeth for reconstruction. The algorithm has been successfully integrated in our Dental CAD system, more than 1000 clinical cases have been tested to demonstrate the robustness and effectiveness of the proposed algorithm. PMID:26638148

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Wednesday, June 08, ... Orofacial Pain? Temporomandibular Joint Disorder Learn what those dental words mean. The Life of a Tooth games ...

  5. The Replace Operator

    CERN Document Server

    Karttunen, L

    1995-01-01

    This paper introduces to the calculus of regular expressions a replace operator, ->, and defines a set of replacement expressions that concisely encode several alternate variations of the operation. The basic case is unconditional obligatory replacement: UPPER -> LOWER Conditional versions of replacement, such as, UPPER -> LOWER || LEFT _ RIGHT constrain the operation by left and right contexts. UPPER, LOWER, LEFT, and RIGHT may be regular expressions of any complexity. Replace expressions denote regular relations. The replace operator is defined in terms of other regular expression operators using techniques introduced by Ronald M. Kaplan and Martin Kay in "Regular Models of Phonological Rule Systems" (Computational Linguistics 20:3 331-378. 1994).

  6. Tooth Preparation and Pulpal Response: Literature Review

    OpenAIRE

    ACAR, Dr. Özlem; ERKUT, Doç. Dr. Selim

    2013-01-01

    Pulp tissue reaction to tooth preparation for direct or indirect restorations is one of the major concerns in fixed prosthodontics. Although the sensitivity of dentine to a variety of stimuli is difficult to correlate with morphological and functional observations, hydrodynamic theory was used to explain dental pain mechanism. External stimuli (e.g., thermal, mechanical and dental restorative processes) applied to human tooth cause either an inward (toward the pulp chamber) or outward (away f...

  7. Tooth wear: the view of the anthropologist

    OpenAIRE

    John A. Kaidonis

    2007-01-01

    Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental ar...

  8. Dielectric response of the human tooth dentine

    Energy Technology Data Exchange (ETDEWEB)

    Leskovec, J. [Dental Clinic, Faculty of Medicine, University of Ljubljana, Hrvatski trg 6, 1104 Ljubljana (Slovenia); Filipic, C. [Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana (Slovenia); Levstik, A. [Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana (Slovenia)]. E-mail: adrijan.levstik@ijs.si

    2005-07-15

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters -bar {sub v0} and {sigma}{sub v}, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy.

  9. Dielectric response of the human tooth dentine

    International Nuclear Information System (INIS)

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters -bar v0 and σv, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy

  10. Genetics And Tooth Anomalies - An Update

    OpenAIRE

    Aswathy Brahmanandan; Ahmed Hasan Farooqi T; Deepa.M.S; Aswathy Raj R

    2013-01-01

    Tooth development like the development of all epithelial appendages is regulated by inductive tissue interactions between epithelium and mesenchyme. Numerous genes interact, either act in conjunction or antagonize each other in odontogenesis. A number of different mesenchymal molecules and their receptors act as mediators in epithelial mesenchymal interactions. Several genes linked with early tooth positioning and developments belong to signaling pathways and have morphogenesis regulatory f...

  11. Fus Expression Patterns in Developing Tooth

    OpenAIRE

    Kim, Eun-Jung; Lee, Jong-Min; Jung, Han-Sung

    2013-01-01

    Recently, the RNA/DNA-binding protein FUS, Fused in sarcoma, was shown to play a role in growth, differentiation, and morphogenesis in vertebrates. Because little is known about Fus, we investigated its expression pattern in murine tooth development. In situ hybridization of mouse mandibles at specific developmental stages was performed with a DIG-labeled RNA probe. During early tooth development, Fus was detected in the dental epithelium and dental mesenchyme at 11 days postcoitum (dpc) and ...

  12. Computer simulation of gear tooth manufacturing processes

    Science.gov (United States)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  13. Dielectric response of the human tooth dentine

    Science.gov (United States)

    Leskovec, J.; Filipič, C.; Levstik, A.

    2005-07-01

    Dielectric properties of tooth dentine can be well described by the model which was developed for the dielectric response to hydrating porous cement paste. It is shown that the normalized dielectric constant and the normalized specific conductivity are proportional to the model parameters ɛ and σv, indicating the deposition of AgCl in the dentine tubules during the duration of the precipitation. The fractal dimension of the tooth dentine was determined by dielectric spectroscopy.

  14. Treatment imprudence leading to missed tooth fragment

    OpenAIRE

    Barua, Pranamee; Chaudhary, Seema; Kaur, Harsimran; Mallikarjuna, Rachappa

    2013-01-01

    Traumatic dental injuries (TDI) represent one of the most common oral health problems in children and adolescents. Dental trauma requires a special consideration when it accompanies soft tissue lacerations. Tooth fragments occasionally penetrate into soft tissues and may cause severe complications. This article describes the case of a 12-year-old girl with a fractured tooth fragment embedded in the lower lip for 4 months, which went unnoticed at her primary health centre. This report highligh...

  15. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series To use the sharing features on ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  16. Shoulder Joint Replacement

    Science.gov (United States)

    ... en because of implant loosening, wear, infection, and dislocation. When this occurs, a second joint replacement surgery — called a revision surgery — may be necessary. Is Shoulder Joint Replacement for You? The decision to have ...

  17. Elbow replacement - discharge

    Science.gov (United States)

    Total elbow arthroplasty - discharge; Endoprosthetic elbow replacement - discharge ... You had surgery to replace your elbow joint with artificial joint parts (prosthetics). The surgeon made a cut (incision) in the back of your upper or lower arm and ...

  18. Tooth-colored CAD/CAM monolithic restorations.

    Science.gov (United States)

    Reich, S

    2015-01-01

    A monolithic restoration (also known as a full contour restoration) is one that is manufactured from a single material for the fully anatomic replacement of lost tooth structure. Additional staining (followed by glaze firing if ceramic materials are used) may be performed to enhance the appearance of the restoration. For decades, monolithic restoration has been the standard for inlay and partial crown restorations manufactured by both pressing and computer-aided design and manufacturing (CAD/CAM) techniques. A limited selection of monolithic materials is now available for dental crown and bridge restorations. The IDS (2015) provided an opportunity to learn about and evaluate current trends in this field. In addition to new developments, established materials are also mentioned in this article to complete the picture. In line with the strategic focus of the IJCD, the focus here is naturally on CAD/CAM materials. PMID:26110926

  19. Comparative evaluation of soft tissue characteristics around implant and tooth

    Directory of Open Access Journals (Sweden)

    Paknejad M.

    2008-12-01

    Full Text Available "nBackground and Aim: Soft tissue condition around dental implant is an essential part for long term healthy and esthetic outcome. The aim of this study was to compare soft tissue dimensions between implant supported single  tooth replacement and the contra-lateral natural tooth. "nMaterials and Methods: This retrospective study was performed on dentate patients treated with anterior single  tooth implant at least 1 year ago. Of twenty eight, fourteen patients had been treated with one stasge method and others with two stage method. Biologic width (BW, papilla index (PI, and mucosal thickness (MT were evaluated around implants and contra-lateral teeth clinically and compared with each other. The Wilcoxon test, Mann-Whitney test, and Student pair t-test were used to assess the differences between one stasge and two stage implants, and implant and tooth groups. "nResults: The mean BW around one stasge implants, two stage implants, and contra-lateral teeth were 1.42±0.48 mm, 1.67±0.48 mm, and 1.47±0.60 mm, respectively. The mean PI adjacent to one stasge implants, Two stage implants, and contra-lateral teeth were 2.50±0.52, 2.53±0.55, and 2.72±0.47, correspondingly. The mean MT around one stasge implants, two stage implants, and contra-lateral teeth were 3.10±0.48, 3.09±0.75, and 2.57±0.88, respectively. There was no statistically significant difference among one stasge implants, two stage implants, and contra-lateral teeth with regard to measured variables. "nConclusion: Based on the results of this investigation, in standard condition, it seems that there is no noticeable difference in indicators of; biologic width, papilla index, and mucosal thickness around one stasge implants, two stage implants, and contra-lateral teeth.

  20. Adhesion of Dental Materials to Tooth Structure

    Science.gov (United States)

    Mitra, Sumita B.

    2000-03-01

    The understanding and proper application of the principles of adhesion has brought forth a new paradigm in the realm of esthetic dentistry. Modern restorative tooth procedures can now conserve the remaining tooth-structure and also provide for the strengthening of the tooth. Adhesive restorative techniques call for the application and curing of the dental adhesive at the interface between the tooth tissue and the filling material. Hence the success of the restoration depends largely on the integrity of this interface. The mechanism of adhesion of the bonding materials to the dental hard tissue will be discussed in this paper. There are four main steps that occur during the application of the dental adhesive to the oral hard tissues: 1) The first step is the creation of a microstructure in the tooth enamel or dentin by means of an acidic material. This can be through the application of a separate etchant or can be accomplished in situ by the adhesive/primer. This agent has to be effective in removing or modifying the proteinaceous “smear” layer, which would otherwise act as a weak boundary layer on the surface to be bonded. 2) The primer/adhesive must then be able to wet and penetrate the microstructure created in the tooth. Since the surface energies of etched enamel and that of etched dentin are different finding one material to prime both types of dental tissues can be quite challenging. 3) The ionomer types of materials, particularly those that are carboxylate ion-containing, can chemically bond with the calcium ions of the hydroxyapatite mineral. 4) Polymerization in situ allows for micromechanical interlocking of the adhesive. The importance of having the right mechanical properties of the cured adhesive layer and its role in absorbing and dissipating stresses encountered by a restored tooth will also be discussed.

  1. Environmental Life Cycle Assessment Model for Soil Bioengineering Measures on Infrastructure Slopes

    Science.gov (United States)

    Hoerbinger, Stephan; Obriejetan, Michael

    2015-04-01

    Soil bioengineering techniques can be a helpful instrument for civil engineers taking into account not only technical but also ecological, socio-economic and sustainability aspects. Environmental Life Cycle Assessment (LCA) models can serve as supplementary evaluation methods to economic analyses, taking into account the resource demand and environmental burdens of engineering structures. The presented LCA model includes the functional grade of structures in addition to environmental aspects. When using vegetation as living construction material, several factors have to be considered. There is the provision of ecosystem services of plants, such as the stabilization of the slope through its root-system, CO2 sequestration through biomass production et cetera. However, it must be noted that vegetation can cause security issues on infrastructure facilities and entail costs through the necessity of maintenance works. For this reason, it is necessary to already define the target systems during the planning phase of a soil bioengineering structure. In this way, necessary measures can be adapted in all life cycles of a structure. The objective of the presented LCA model is to serve as a basis for the definition of target systems. In the designed LCA model the soil bioengineering structures are divided into four life phases; construction phase, operational phase, end of life phase and subsequent use phase. A main objective of the LCA model is the understanding of the "Cumulative Energy Demand" (CED) and "Global Warming Potential" (GWP) of soil bioengineering structures during all life cycle phases. Additionally, the biomass production and the CO2 sequestration potential of the used plants are regarded as well as the functional integrity of the soil bioengineering system. In the life phase of soil bioengineering structures, a major part of the energy input is required during the construction phase. This is mainly due to the cumulative energy demand of the inert materials

  2. Kidney bioengineering in regenerative medicine: An emerging therapy for kidney disease.

    Science.gov (United States)

    Lin, Yi-Qian; Wang, Li-Ren; Pan, Liang-Liang; Wang, Hui; Zhu, Gui-Qi; Liu, Wen-Yue; Wang, Jiang-Tao; Braddock, Martin; Zheng, Ming-Hua

    2016-02-01

    The prevalence of end-stage renal disease is emerging as a serious worldwide public health problem because of the shortage of donor organs and the need to take lifelong immunosuppressive medication in patients who receive a transplanted kidney. Recently, tissue bioengineering of decellularization and recellularization scaffolds has emerged as a novel strategy for organ regeneration, and we review the critical technologies supporting these methods. We present a summary of factors associated with experimental protocols that may shed light on the future development of kidney bioengineering and we discuss the cell sources and bioreactor techniques applied to the recellularization process. Finally, we review some artificial renal engineering technologies and their future prospects, such as kidney on a chip and the application of three-dimensional and four-dimensional printing in kidney tissue engineering. PMID:26596504

  3. History of bioengineering techniques for erosion control in rivers in Western Europe.

    Science.gov (United States)

    Evette, Andre; Labonne, Sophie; Rey, Freddy; Liebault, Frederic; Jancke, Oliver; Girel, Jacky

    2009-06-01

    Living plants have been used for a very long time throughout the world in structures against soil erosion, as traces have been found dating back to the first century BC. Widely practiced in Western Europe during the eighteenth and nineteenth centuries, bioengineering was somewhat abandoned in the middle of the twentieth century, before seeing a resurgence in recent times. Based on an extensive bibliography, this article examines the different forms of bioengineering techniques used in the past to manage rivers and riverbanks, mainly in Europe. We compare techniques using living material according to their strength of protection against erosion. Many techniques are described, both singly and in combination, ranging from tree planting or sowing seeds on riverbanks to dams made of fascine or wattle fences. The recent appearance of new materials has led to the development of new techniques, associated with an evolution in the perception of riverbanks. PMID:19238480

  4. Suitability of soil bioengineering techniques in Central America: a case study in Nicaragua

    Directory of Open Access Journals (Sweden)

    A. Petrone

    2008-02-01

    Full Text Available In the last few years "D. I. A. F." (Department of Agriculture and Forestry Engineering of Florence University, has been testing the effectiveness of Soil Bio-Engineering techniques in Central America. The focus of the present study was to find out which native plants were most suited for soil bio-engineering purposes, particularly in the realization of riverbank protection. Furthermore, we have also been aiming at economic efficiency. In the context of sustainable watershed management, these techniques seem to be appropriate, especially in underdeveloped countries. Concerning the plants to be used, we considered three native species, Gliricidia Sepium, Cordia dentata and Jatropha curcas, to be appropriate for this type of work. Economically speaking, the low cost of such interventions in underdeveloped countries, has been shown by the construction of riverbank protection using vegetated crib-walls in Nicaragua.

  5. Bioengineered probiotics as a new hope for health and diseases: an overview of potential and prospects.

    Science.gov (United States)

    Kumar, Manoj; Yadav, Ashok Kumar; Verma, Vinod; Singh, Birbal; Mal, Gorakh; Nagpal, Ravinder; Hemalatha, Rajkumar

    2016-04-01

    Despite the use of microorganisms as therapeutics for over a century, the scientific and clinical admiration of their potential is a recent phenomenon. Genome sequencing and genetic engineering has enabled researchers to develop novel strategies, such as bioengineered probiotics or pharmabiotics, which may become a therapeutic strategy. Bioengineered probiotics with multiple immunogenic or antagonistic properties could be a viable option to improve human health. The bacteria are tailored to deliver drugs, therapeutic proteins or gene therapy vectors with precision and a higher degree of site specificity than conventional drug administration regimes. This article provides an overview of methodological concepts, thereby encouraging research and interest in this topic, with the ultimate goal of using designer probiotics as therapeutics in clinical practice. PMID:27070955

  6. Controlled Deposition of HAp Mimicking Tooth Enamel

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Chemical compositions and microsturcture of mature human tooth enamel were investigated by XRD , FTIR and SEM to further understand the characteristics of tooth enamel. In order to obtain apatite crystals chemically and structurally similar to those in tooth enamel, biomimetic way was employed. Selfassembled monolyers terminated with-SO3 H groups were used as deposition substrates and 1.5 SBF ( the concentrations of Ca2+ and PO43- ions 1.5 times than those in simulated body fluid ) with and without 5 ppm F- were used as soaking medium. The XRD and FTIR results showed that both the deposited fluoride-substituted hydroxyapatite( F-HAp ) crystals in 1.5 SBF with F- and hydroxyapatite ( HAp ) crystals in 1.5 SBF were carbonate-containing, mimicking human tooth enamel in chemical compositions. The SEM photos showed that needle-like F-HAp crystals bad large aspect ratios and grew in bundles, which were similar to the crystals in human tooth enamel.The results provide available information on dental restoration.

  7. JRRD Then & Now: Commentary on bioengineering of wheelchairs: The past 50 years

    OpenAIRE

    Rory A. Cooper, PhD

    2013-01-01

    It was a pleasure to become reacquainted with the landmark article “Bioengineering methods of wheelchair evaluation” by Peizer et al. from the 1964 Bulletin of Prosthetics Research. As is to be expected, in some areas, there have been tremendous advances since the article was written and, in others, our understanding remains limited. Probably the three most profound aspects of the Peizer et al. article are that (1) much of the wheelchair engineering research at the time could be summarized in...

  8. Restoration of active gully systems following the implementation of bioengineering techniques.

    Science.gov (United States)

    Borja, Pablo; Vanacker, Veerle; Govers, Gerard

    2015-04-01

    Intensive land use in the central parts of the Andean basin has led to widespread land degradation. The formation of badlands dates back from the 1950s and 1960s. Several studies indicate that human activities have accelerated mountain erosion rates by up to 100 times. In this study, we have evaluated the effects of bio-engineering works aiming to stabilize degraded catchments. Five micro-catchments (0.2 up to 5 ha) have been selected within a 3 km2 area in the lower part of the Loreto catchment (Southern Ecuadorian Andes). The five micro-catchments differ in vegetation cover and implementation of bio-engineering works. The experimental design consisted of three micro-catchments: (1) DI with conservation works, (2) DF with reforestation by Eucalyptus sp and (3) DT with no conservation works. Two micro-catchments have been monitored in an agricultural area: with (AI) and without (AT) bio-engineering works in the active gullies. Small checkdams were constructed in the gully floors of two of the micro-catchments in the badland area (DI) and the agricultural area (AI). The checkdams are made of wood and tires. Water flow has been measured in every micro-catchment, while sediment traps were constructed to monitor sediment transport. Results show that bio-engineering techniques are effective to stabilize active gullies. Deposition of sediments in manmade dams is strongly dependent on previous rainfall events, as well as gully channel slope, and its vegetation cover. From the experimental data, an I30 max threshold value was determined. Above this threshold value, all micro-catchments are actively contributing sediment to the main river system. The checkdams built with wood and tires have an efficiency of 70%, and were shown to be very effective to stabilize active gullies in bad lands through significant reduction (about 62%) of the amount of sediment exported from the micro-catchments. Key words: degraded soils, erosion, sediment, restoration, reforestation

  9. Levels of Functional Equivalence in Reverse Bioengineering: The Darwinian Turing Test for Artificial Life

    OpenAIRE

    Harnad, Stevan

    1994-01-01

    Both Artificial Life and Artificial Mind are branches of what Dennett has called "reverse engineering": Ordinary engineering attempts to build systems to meet certain functional specifications, reverse bioengineering attempts to understand how systems that have already been built by the Blind Watchmaker work. Computational modelling (virtual life) can capture the formal principles of life, perhaps predict and explain it completely, but it can no more be alive than a virtual forest fi...

  10. Then & Now: Reflections on "Bioengineering evaluation and field test of the Stand-Alone Therapeutic Aid"

    OpenAIRE

    Ronald J. Triolo, PhD

    2013-01-01

    Our thinking and approachto research and assistivetechnologies have evolvedsignificantly since the publication 50years ago of “Bioengineering evaluationand field test of the Stand-AloneTherapeutic Aid.” The most strikingchange is in the value placed on basicdiscovery and knowledge generation,in addition to device developmentand verification testing. This evolutionfrom a “Consumer Reports” mentality,where assistive technologies arefield tested, to prospective, controlledtrials of fundamental c...

  11. Bioengineering dermo-epidermal skin grafts with blood and lymphatic capillaries

    OpenAIRE

    Marino, Daniela; Luginbühl, Joachim; Scola, Simonetta; Meuli, Martin; Reichmann, Ernst

    2014-01-01

    The first bioengineered, autologous, dermo-epidermal skin grafts are presently undergoing clinical trials; hence, it is reasonable to envisage the next clinical step at the forefront of plastic and burn surgery, which is the generation of autologous skin grafts that contain vascular plexuses, preformed in vitro. As the importance of the blood, and particularly the lymphatic vascular system, is increasingly recognized, it is attractive to engineer both human blood and lymphatic vessels in one ...

  12. Conscience dilemma: to become a bioengineer or to survive as a biologist.

    Science.gov (United States)

    Selimoglu, Sureyya Mert

    2014-01-01

    Bioengineering is the consideration of biological problems from modern engineering, therefore money-oriented, perspective. Today, grant-giving bodies always favor bioengineering projects rather than pure biology projects (like those in ecology, entomology, etc.). Therefore, today's biologist is forced to be on the horns of a dilemma. They have to either submit a very powerful and valid reason for the proposal of their project, or change the project to one having a potential of money-based outcome. On the other hand, because of dealing with the living components of nature, conducting a research in pure biology is like a kind of worship. For this reason, from a believer scientist's view, a deviation (in terms of research) from biology to bioengineering can be considered like committing a sin. Unfortunately, today's wild capitalism has been bringing new sinners day by day, and this system will continue for the foreseeable future unless grant-giving bodies comprehend the real importance of pure biology. PMID:25936219

  13. Tooth number, World War II, nuns, and the real fountain of youth.

    Science.gov (United States)

    Warpeha, Walter S

    2014-01-01

    A new appreciation for the direct relationship of mouth health to systemic health is forcing re-evaluation of previous concepts of oral health strategies. Although a person shows adaptation to loss of some permanent teeth, it appears a threshold of 10 functional pairs or 20 teeth have linkage to a number of disabling diseases of aging. The Shortened Dental Arch concept has limitations for sustainability and leaves little functional cushion. Nevertheless, when teeth are lost leaving fewer than 20, systemic disease and mortality risk increase significantly. Several theories try to explain the phenomenon. An unusually credible study, however, changes the metric to fewer teeth, nine or less, before a cognitive decline is noted. Due to a standardized high level of prosthodontic treatment in that study, some of the deleterious health effects of tooth loss appear to be mitigated. The importance of these findings has implications for tooth replacement strategies. Recognizing the huge biologic and psychological cost of tooth loss, a renewed emphasis to maintain natural teeth is indicated. When fewer than 20 teeth are viable, well-made prosthodontics, including maxillary complete denture or a mandibular partial or overdenture, both tooth- and implant-supported, could be remunerative therapies. PMID:24683924

  14. Tooth-germ damage by ionizing radiation

    International Nuclear Information System (INIS)

    Experiments on animals (four-week-old dogs) were conducted in an investigation made to study the possibility of dose-dependent tooth-germ damage produced by ionizing radiation. The individual doses were 50 R and 200 R, respectively, and they were administered once to three times at weekly intervals. Hyperemia and edemata could be observed on tooth-germ pulps from 150 R onward. Both of these conditions became more acute as the radiation dose increased (from 150 R to 600 R). Possible damage to both the dentin and enamel is pointed out. (author)

  15. Clinical Evaluation of Reasons for Replacement of Amalgam Restorations in Patients Referring to a Dental School in Iran

    OpenAIRE

    Pouralibaba, Firoz; Joulaei, Mohammad; Kashefimehr, Atabak; Pakdel, Farzaneh; Jamali, Zahra; Esmaeili, Ali

    2010-01-01

    Background and aims The present study evaluated the most common reasons for replacing amalgam restorations in a university clinic. Materials and methods A total of 217 restorations which needed to be replaced were clinically and radiographically evaluated in a period of 4 months. The frequencies of reasons for replacing amalgam restorations were calculated: The assessed items included recurrent caries, tooth structure fracture (functional or non-functional cusps), amalgam bulk fracture, amalg...

  16. Seal Out Tooth Decay: A Fact Sheet for Parents

    Science.gov (United States)

    ... Institute of Dental and Craniofacial Research Seal Out Tooth Decay A Fact Sheet for Parents What are dental ... important reason for getting sealants is to avoid tooth decay. • Fluoride in toothpaste and in drinking water protects ...

  17. Laser bioengineering of glass-titanium implants surface

    Science.gov (United States)

    Lusquiños, F.; Arias-González, F.; Penide, J.; del Val, J.; Comesaña, R.; Quintero, F.; Riveiro, A.; Boutinguiza, M.; Pascual, M. J.; Durán, A.; Pou, J.

    2013-11-01

    Osseointegration is the mean challenge when surgical treatments fight against load-bearing bone diseases. Absolute bone replacement by a synthetic implant has to be completed not only from the mechanics point of view, but also from a biological approach. Suitable strength, resilience and stress distribution of titanium alloy implants are spoiled by the lack of optimal biological characteristics. The inert quality of extra low interstitial titanium alloy, which make it the most attractive metallic alloy for biomedical applications, oppose to an ideal surface with bone cell affinity, and capable to stimulate bone attachment bone growth. Diverse laser treatments have been proven as effective tools to modify surface properties, such as wettability in contact to physiological fluids, or osteoblast guided and slightly enhanced attachment. The laser surface cladding can go beyond by providing titanium alloy surfaces with osteoconduction and osteoinduction properties. In this research work, the laser radiation is used to produce bioactive glass coatings on Ti6Al4V alloy substrates. Specific silicate bioactive glass compositions has been investigated to achieve suitable surface tension and viscosity temperature behavior during processing, and to provide with the required release of bone growth gene up regulation agents in the course of resorption mediated by physiological fluids. The produced coatings and interfaces, the surface osteoconduction properties, and the chemical species release in simulated physiological fluid were characterized by scanning electron microscopy (SEM), hot stage microscopy (HSM), X-ray diffraction (XRD), X ray fluorescence (XRF), and Fourier transform infrared spectroscopy (FTIR).

  18. Effect of partial replacement of sugar with stevia on the quality of kulfi

    OpenAIRE

    Giri, Apurba; Rao, H. G. Ramachandra; V., Ramesh

    2012-01-01

    Stevia is a natural sweetener obtained from the leaf of Stevia rebaudiana plant. Its refined extract powder is 130–300 times sweeter than sucrose. Besides, it prevents diabetes, decreases weight, prevents tooth decay, increases digestion etc. Dietetic kulfi was produced, in which 50, 60 and 70% sugar was replaced with 0.05, 0.06 and 0.07% refined stevia extract powder respectively. At higher levels of sugar replacement there was a significant decrease in specific gravity, melting rate, carboh...

  19. Hyaluronan in human deciduous tooth germs in the bell stage. Histochemistry and immunohistochemistry

    DEFF Research Database (Denmark)

    Matthiessen, Martin Ebbe; Garbarsch, Charly; Olsen, Birgitte Engelbrecht;

    1997-01-01

    Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry......Anatomy, development, glycosaminoglycans, hyaluronan, tooth germs, histochemistry, immunocytochemistry...

  20. The relationship between gastroesophageal reflux disease and tooth decay?

    OpenAIRE

    ÖZKAN, Buğra; FİLİK, Levent; SAĞLAM, Osman

    2014-01-01

    Backgaround and Aims: The aim of this study was to show the relationship of gastroesophageal reflux disease and tooth decay. The most common cause of tooth decay is poor oral hygiene but gastric contents may also cause poor oral hygiene and tooth decay. In this study, we hypothesized and investigated whether gastroesophageal reflux disease caused tooth decay. Materials and Methods:Sixty-five patients were studied; 30 patients had gastroesophageal reflux disease, with disease diagnosis...

  1. Ectopic located tooth which obstrcuted the maxillary sinus ostium

    OpenAIRE

    Atalay Erdogan, Banu; Paksoy, Mustafa; Sanli, Arif; Altin, Gokhan; Bekmez, Eda

    2012-01-01

    A giant mucocele secondary to obstruction of the maxillary sinus ostium with an ectopic tooth. Mucocele secondary to ectopic maxillary tooth is very rare. We present a case of giant mucocele which is caused by obstruction of the maxillary sinus ostium with an ectopic tooth. The patient presented with headache and facial asymmetry. CT of the paranasal sinuses revealed an ectopic maxillary tooth, obstructing the maxillary sinus ostium and a mucocele of the maxillary sinus that erodes bony w...

  2. Tooth width ratios in crowded and non-crowded dentitions

    OpenAIRE

    Bernabé, E.; Villanueva, KM; Flores-Mir, C

    2004-01-01

    Discrepancies in tooth width ratios could affect the excellence in the finishing of orthodontic cases. This study compares tooth width ratios in crowded and noncrowded dental arches. Tooth widths were measured from 143 dental casts (40 crowded and 33 spaced in male individuals and 43 crowded and 27 spaced in female individuals). Simultaneous crowded or spaced arches were selected. Tooth width measurements were made with a sliding caliper with a Vernier scale neared 0.1 mm. Inter- (0.990) and ...

  3. Knee joint replacement

    Science.gov (United States)

    Knee joint replacement is a surgery to replace a knee joint with a man-made joint. The artificial joint is called a prosthesis . ... cartilage and bone are removed from the knee joint. Man-made pieces are then placed in the ...

  4. Replacement nuclear steam generators

    International Nuclear Information System (INIS)

    This paper reviews past and current practices in the replacement of nuclear steam generators. Plants where steam generator replacement has occurred are reviewed to see what changes have been made, and how the evolving technology has significantly reduced outage time and man-rem exposures. Current preferences in design and material are reviewed. 3 refs., 3 tabs., 2 figs

  5. Radiation Source Replacement Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  6. The Importance of Tooth Decay Prevention in Children under Three

    Science.gov (United States)

    Milgrom, Peter; Huebner, Colleen; Chi, Donald

    2010-01-01

    Tooth decay and tooth loss was once the norm but public health interventions have led to major improvements for most people. Nevertheless, not all children have benefited. Dental disease in young children is unacceptably high. Tooth decay is preventable. Early childhood educators are often the first to notice the problem. Professional…

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | Reprints and Permissions | Privacy Statement | Terms and Conditions © 1996-2016 Academy of General Dentistry. All Rights Reserved.

  8. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Friday, July 15, 2016 About | Contact InfoBites Quick Reference ... Temporomandibular Joint Disorder Check Menstrual Calendar for Tooth Extraction Pacifiers Have Negative and Positive Effects How Do I Care for My Child's Baby Teeth? What is Orofacial ...

  9. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... InfoBites Quick Reference Learn more Sports and Oral Health Temporomandibular Joint Disorder Check Menstrual Calendar for Tooth ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  10. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Thursday, August 04, 2016 About | Contact InfoBites Quick Reference ... of Dental Advances How Do I Care for My Child's Baby Teeth? Headaches and Jaw Pain? Check Your Posture! Check Menstrual Calendar for Tooth Extraction Learn what ...

  11. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Saturday, June 04, 2016 About | Contact InfoBites Quick Reference ... Learn more Nutrition - Adults How Do I Care for My Child's Baby Teeth? What is Orofacial Pain? Pacifiers Have Negative and Positive Effects What is Baby Bottle Tooth ...

  12. EPR dosimetry with tooth enamel: A review

    International Nuclear Information System (INIS)

    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.

  13. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health What is Baby Bottle Tooth Decay? Headaches and ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  14. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health Check Menstrual Calendar for Tooth Extraction Pacifiers Have Negative and Positive Effects Why is Oral Health Important for Men? When Should My Child First ...

  15. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Monday, August 22, 2016 About | Contact InfoBites Quick Reference ... My Child's Baby Teeth? What is Orofacial Pain? Learn what those dental words mean. The Life of a Tooth ...

  16. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... a Composite Resin (White Filling)? Why is Oral Health Important for Men? How Do I Care for My Child's Baby Teeth? What is Orofacial Pain? Learn what those dental words mean. The Life of a Tooth games Home | InfoBites | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  17. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available Dental care and oral health information you need from the Academy of General Dentistry Wednesday, August 03, 2016 About | Contact InfoBites Quick Reference ... Than You Can Chew? How Do I Care for My Child's Baby Teeth? Is My Child at Risk for Early Childhood Tooth Decay? Temporomandibular Joint Disorder Learn what ...

  18. Computed tomography to quantify tooth abrasion

    Science.gov (United States)

    Kofmehl, Lukas; Schulz, Georg; Deyhle, Hans; Filippi, Andreas; Hotz, Gerhard; Berndt-Dagassan, Dorothea; Kramis, Simon; Beckmann, Felix; Müller, Bert

    2010-09-01

    Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology including root canal, dentin, and enamel volumes.

  19. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health What is a Composite Resin (White Filling)? Pacifiers ... for Early Childhood Tooth Decay? Why is Oral Health Important for Men? Learn what those dental words ...

  20. Recent Approaches in Tooth Engineering Research

    Czech Academy of Sciences Publication Activity Database

    Švandová, Eva; Veselá, Barbora; Křivánek, J.; Hampl, A.; Matalová, Eva

    2014-01-01

    Roč. 60, Suppl 1 (2014), s. 21-29. ISSN 0015-5500 R&D Projects: GA ČR GAP304/11/1418; GA MZd(CZ) NT11420 Institutional support: RVO:67985904 Keywords : engineering * tooth * stem cells * culture techniques Subject RIV: EA - Cell Biology Impact factor: 1.000, year: 2014

  1. Apoptotic cell elimination during early tooth development

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Míšek, Ivan; Chovancová, Eva

    2003-01-01

    Roč. 72, č. 7 (2003), s. 34. ISSN 0001-7213. [Congress of the European Association of Veterinary Anatomists/24./. 21.07.2002-25.07.2002, Brno] R&D Projects: GA ČR GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : tooth development Subject RIV: FF - HEENT, Dentistry

  2. Death in the life of a tooth

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Tucker, A. S.; Sharpe, P. T.

    2004-01-01

    Roč. 83, č. 1 (2004), s. 11-16. ISSN 0022-0345 R&D Projects: GA ČR GP204/02/P112 Institutional research plan: CEZ:AV0Z5045916 Keywords : apoptosis * tooth development Subject RIV: EA - Cell Biology Impact factor: 3.131, year: 2004

  3. Restoration of the endodontically treated posterior tooth

    Directory of Open Access Journals (Sweden)

    Andrea Polesel

    2014-06-01

    Results and conclusions: Direct adhesive restorations, indirect bonded restorations and traditional full crown are three therapeutic options for the single posterior endodontically treated teeth. The amount of remaining sound tooth structure is the most significant factor influencing the therapeutic approach. The clinician's operative skill is a determining aspect for long-term success of adhesive inlays.

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Quick Reference Learn more Oral Health and Overal Health How Do I Care for My Child's Baby Teeth? Temporomandibular Joint Disorder Pacifiers Have Negative and Positive Effects Check Menstrual Calendar for Tooth Extraction Why is Oral Health Important for Men? Learn what those dental words ...

  5. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health How Do I Care for My Child's Baby ... Menstrual Calendar for Tooth Extraction Why is Oral Health Important for Men? Learn what those dental words ...

  6. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health Are You Biting Off More Than You Can ... for Early Childhood Tooth Decay? Why is Oral Health Important for Men? Temporomandibular Joint Disorder Check Menstrual ...

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... InfoBites Quick Reference Learn more Sports and Oral Health How Do I Care for My Child's Baby Teeth? The History of Dental Advances Check Menstrual Calendar for Tooth Extraction What is Orofacial Pain? Pacifiers Have Negative and Positive ... | Find a Dentist | Your Family's Oral Health | Newsroom | RSS About AGD | Contact AGD | Site Map | ...

  8. Regenerative Applications Using Tooth Derived Stem Cells in Other Than Tooth Regeneration: A Literature Review

    OpenAIRE

    Yun-Jong Park; Seunghee Cha; Young-Seok Park

    2016-01-01

    Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry ha...

  9. Tooth-implant connection: a review.

    Science.gov (United States)

    Hoffmann, Oliver; Zafiropoulos, Gregory-George

    2012-04-01

    The aim of this review was to assess the long-term outcomes of restorations supported by implants and natural teeth with regard to complications associated with implants, teeth, and restorations, as well as the influence on these parameters of the connector type used. A net-based search in PubMed was combined with a manual search. Clinical studies, reviews, and biomechanical studies were included. Information on survival rate, complication rate, incidence of tooth intrusion, and, where applicable, type of connector used, was retrieved from the clinical studies. Force distribution and types of connectors used were retrieved from the biomechanical study. A summary of outcomes was retrieved from the reviews. A total of 25 articles were selected for inclusion in this review, including clinical studies (15), biomechanical studies (7), and reviews (3). Implant success rates ranged from 79.5%-100%. Tooth complications occurred in 5.4%-11.8% of cases. Complications in the suprastructure were observed in 5%-90% of cases. Tooth intrusion presented in a total of 0%-66% of all cases, more often in cases with nonrigid connection (0%-66%) than in cases with rigid connection (0%-44%). Biomechanical studies show a large difference in stress distribution and in dependence on the type of connector used, with most studies demonstrating that nonrigid connectors drastically reduce stress on the suprastructure while increasing forces on supporting teeth and implants. Long-term success rates for tooth-implant connections are lower than for solely implant-supported restorations with regard to prognosis for teeth, implants, and suprastructure. Use of rigid connectors leads to more favorable clinical outcomes in terms of long-term stability, occurrence of complications, and tooth intrusion. PMID:21091344

  10. Relative cheek-tooth size in Australopithecus.

    Science.gov (United States)

    McHenry, H M

    1984-07-01

    Until the discovery of Australopithecus afarensis, cheek-tooth megadontia was unequivocally one of the defining characteristics of the australopithecine grade in human evolution along with bipedalism and small brains. This species, however, has an average postcanine area of 757 mm2, which is more like Homo habilis (759 mm2) than A. africanus (856 mm2). But what is its relative cheek-tooth size in comparison to body size? One approach to this question is to compare postcanine tooth area to estimated body weight. By this method all Australopithecus species are megadont: they have cheek teeth 1.7 to 2.3 times larger than modern hominoids of similar body size. The series from A. afarensis to A. africanus to A. robustus to A. boisei shows strong positive allometry indicating increasing megadontia through time. The series from H. habilis to H. erectus to H. sapiens shows strong negative allometry which implies a sharp reduction in the relative size of the posterior teeth. Postcanine megadontia in Australopithecus species can also be demonstrated by comparing tooth size and body size in associated skeletons: A. afarensis (represented by A.L. 288-1) has a cheek-tooth size 2.8 times larger than expected from modern hominoids; A. africanus (Sts 7) and A. robustus (TM 1517) are over twice the expected size. The evolutionary transition from the megadont condition of Australopithecus to the trend of decreasing megadontia seen in the Homo lineage may have occurred between 3.0 and 2.5 m.y. from A. afarensis to H.habilis but other evidence indicates that it is more likely to have occurred between 2.5 to 2.0 m.y. from an A. africanus-like form to H. habilis. PMID:6433716

  11. 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. PMID:27087142

  12. 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.

  13. A TOOTH TATTOO WITH A PURPOSE: AN INNOVATIVE APPROACH

    Directory of Open Access Journals (Sweden)

    Neetu

    2014-01-01

    Full Text Available Skin is not the only place that can be decorated with a tattoo. You can decorate your tooth with amazing tattoos. Tooth tattoos and tooth jewels have become one of the hottest fashion trends , and a very popular arrival in cosmetic dentistry. But won’t it be a boon if it had some preventive or medicinal v alue. Yes tooth tattoos can act as indicators of once illness. These tiny electronic sensors can diagnose illnesses by 'tasting' your breath. This paper is an insight into how a tooth tattoos can pick up early warning signs of sickness or infection by bact eria in people's breath.

  14. Computer aided design and analysis of gear tooth geometry

    Science.gov (United States)

    Chang, S. H.; Huston, R. L.

    1987-01-01

    A simulation method for gear hobbing and shaping of straight and spiral bevel gears is presented. The method is based upon an enveloping theory for gear tooth profile generation. The procedure is applicable in the computer aided design of standard and nonstandard tooth forms. An inverse procedure for finding a conjugate gear tooth profile is presented for arbitrary cutter geometry. The kinematic relations for the tooth surfaces of straight and spiral bevel gears are proposed. The tooth surface equations for these gears are formulated in a manner suitable for their automated numerical development and solution.

  15. Hip replacement - precautions

    Science.gov (United States)

    ... Barker KL, Dewey ME, Sackley CM. Effectiveness of physiotherapy exercise following hip arthroplasty for osteoarthritis: a systematic ... to ask your doctor Hip replacement - discharge Preventing falls - what to ask your doctor Update Date 11/ ...

  16. Total Knee Replacement

    Science.gov (United States)

    ... following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other ... to the final success of your surgery. To learn more about the full value of total knee ...

  17. Hormone Replacement Therapy

    Science.gov (United States)

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  18. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series To use the sharing features ... 4 out of 4 Normal anatomy Overview The knee is a complex joint. It contains the distal ...

  19. The replacement research reactor

    International Nuclear Information System (INIS)

    As a consequences of the government decision in September 1997. ANSTO established a replacement research reactor project to manage the procurement of the replacement reactor through the necessary approval, tendering and contract management stages This paper provides an update of the status of the project including the completion of the Environmental Impact Statement. Prequalification and Public Works Committee processes. The aims of the project, management organisation, reactor type and expected capabilities are also described

  20. Transcatheter Pulmonary Valve Replacement

    OpenAIRE

    Ghawi, Hani; Kenny, Damien; Hijazi, Ziyad M.

    2012-01-01

    Transcatheter pulmonary valve replacement (tPVR) has evolved into a viable alternative to surgical conduit or bioprosthetic valve replacement. This procedure has paved the way for a more advanced approach to congenital and structural interventional cardiology. Although many successes have been noted, there are still a number of challenges with this procedure, including large delivery systems, the need for a conduit or a bioprosthetic valve as a landing zone for the valve, optimal timing of th...

  1. Soil bio-engineering for risk mitigation and environmental restoration in a humid tropical area

    Directory of Open Access Journals (Sweden)

    A. Petrone

    2009-07-01

    Full Text Available The use of soil bio-engineering techniques in developing countries is a relevant issue for disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essential for the divulgation of such techniques. The present paper is focused on this two issues related to the realization of various typologies of soil bio-engineering works in the humid tropic of Nicaragua.



    In the area of Río Blanco, located in the Department of Matagalpa, soil bio-engineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power in order to compare the Nicaraguan context with the Italian one.



    Among the used species we found that Madero negro (Gliricidia sepium and Roble macuelizo (Tabebuia rosea are adequate for soil-bioengineering measure on slopes while Helequeme (Erythrina fusca reported a successful behaviour only in the crib wall for riverbank protection.



    In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the Central American country ranges between 1.5 times (for the vegetative covering and almost 4 times (for the fascine mattress if it's used the EPP dollar exchange

  2. Assessing the transport and fate of bioengineered microorganisms in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L.W.; Palumbo, A.V.

    1985-01-01

    We review the methods currently available for quantifying the transport and fate of microbes in atmospheric and aqueous media and assess their adequacy for purposes of risk assessment. We review the literature on transport and fate of microorganisms, including studies of: (1) pathways of migration, (2) the survival of microorganisms during transport and fate. In addition, we review the transport and fate models that have been used in environmental risk assessments for radionuclides and toxic chemicals and evaluate their applicability to the problem of assessing environmental risks of bioengineered microorganisms.

  3. Assessing the transport and fate of bioengineered microorganisms in the environment

    International Nuclear Information System (INIS)

    We review the methods currently available for quantifying the transport and fate of microbes in atmospheric and aqueous media and assess their adequacy for purposes of risk assessment. We review the literature on transport and fate of microorganisms, including studies of: (1) pathways of migration, (2) the survival of microorganisms during transport and fate. In addition, we review the transport and fate models that have been used in environmental risk assessments for radionuclides and toxic chemicals and evaluate their applicability to the problem of assessing environmental risks of bioengineered microorganisms

  4. Tooth mobility changes subsequent to root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because of...... pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured with a...... Mühlemanns periodontometer and noninjured incisors served as controls. The mobility values represented the labial-lingual excursion of the root measured in μm when the tooth received a frontal and a palatal impact of 100 g force. In 18 cases of hard tissue healing (HT), a slightly increased mobility was seen...

  5. Prevention of dental anomalies in children by prosthetics defects hard tooth tissues and dentitions: the need to possibilities

    Directory of Open Access Journals (Sweden)

    Suetenkov D.Ye.

    2011-03-01

    Full Text Available This article presents the possibility of restore the function and anatomy of the tooth and replacement of defects of dentition by prosthesis in children under the removable bite as a method of prevention of dentoalveolar anomalies. Identified the need for prosthetic treatment of children and the willingness of dentists as primary health care professional to address the problems identified. A clinical analysis of complex treatment of defects in the teeth with fixed restorations

  6. Prevention of dental anomalies in children by prosthetics defects hard tooth tissues and dentitions: the need to possibilities

    OpenAIRE

    Suetenkov D.Ye.; Pudovkina Е.А.; Venatovskaya N.V.; Proshin A.G.

    2011-01-01

    This article presents the possibility of restore the function and anatomy of the tooth and replacement of defects of dentition by prosthesis in children under the removable bite as a method of prevention of dentoalveolar anomalies. Identified the need for prosthetic treatment of children and the willingness of dentists as primary health care professional to address the problems identified. A clinical analysis of complex treatment of defects in the teeth with fixed restorations

  7. Bivalent histone modifications during tooth development

    Institute of Scientific and Technical Information of China (English)

    Li-Wei Zheng; Bin-Peng Zhang; Ruo-Shi Xu; Xin Xu; Ling Ye; Xue-Dong Zhou

    2014-01-01

    Histone methylation is one of the most widely studied post-transcriptional modifications. It is thought to be an important epigenetic event that is closely associated with cell fate determination and differentiation. To explore the spatiotemporal expression of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) epigenetic marks and methylation or demethylation transferases in tooth organ development, we measured the expression of SET7, EZH2, KDM5B and JMJD3 via immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis in the first molar of BALB/c mice embryos at E13.5, E15.5, E17.5, P0 and P3, respectively. We also measured the expression of H3K4me3 and H3K27me3 with immunofluorescence staining. During murine tooth germ development, methylation or demethylation transferases were expressed in a spatial–temporal manner. The bivalent modification characterized by H3K4me3 and H3K27me3 can be found during the tooth germ development, as shown by immunofluorescence. The expression of SET7, EZH2 as methylation transferases and KDM5B and JMJD3 as demethylation transferases indicated accordingly with the expression of H3K4me3 and H3K27me3 respectively to some extent. The bivalent histone may play a critical role in tooth organ development via the regulation of cell differentiation.

  8. Tooth development in incisor region of sheep

    Czech Academy of Sciences Publication Activity Database

    Míšek, Ivan

    Olomouc: -, 2008 - (Bezdičková, M.; Molíková, R.). s. 128-128 ISBN 978-80-244-2061-5. [Morphology 2008. Lojda Symposium on Histochemistry /45./. 08.09.2008-10.09.2008, Olomouc] R&D Projects: GA ČR GC524/08/J032 Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth development * sheep Subject RIV: FF - HEENT, Dentistry

  9. Caspase-7 in molar tooth development

    Czech Academy of Sciences Publication Activity Database

    Matalová, Eva; Vanden Berghe, T.; Švandová, Eva; Vandenabeele, P.; Healy, C.; Sharpe, P. T.; Tucker, A. S.

    2012-01-01

    Roč. 57, č. 11 (2012), s. 1474-1481. ISSN 0003-9969 R&D Projects: GA AV ČR IAA600450904 Grant ostatní: GA ČR(CZ) GAP502/12/1285 Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth * apoptosis * mineralisation Subject RIV: FF - HEENT, Dentistry Impact factor: 1.549, year: 2012

  10. Enamel alteration following tooth bleaching and remineralization.

    Science.gov (United States)

    Coceska, Emilija; Gjorgievska, Elizabeta; Coleman, Nichola J; Gabric, Dragana; Slipper, Ian J; Stevanovic, Marija; Nicholson, John W

    2016-06-01

    The purpose of this study was to compare the effects of professional tooth whitening agents containing highly concentrated hydrogen peroxide (with and without laser activation), on the enamel surface; and the potential of four different toothpastes to remineralize any alterations. The study was performed on 50 human molars, divided in two groups: treated with Opalescence(®) Boost and Mirawhite(®) Laser Bleaching. Furthermore, each group was divided into five subgroups, a control one and 4 subgroups remineralized with: Mirasensitive(®) hap+, Mirawhite(®) Gelleѐ, GC Tooth Mousse™ and Mirafluor(®) C. The samples were analysed by SEM/3D-SEM-micrographs, SEM/EDX-qualitative analysis and SEM/EDX-semiquantitative analysis. The microphotographs show that both types of bleaching cause alterations: emphasized perikymata, erosions, loss of interprizmatic substance; the laser treatment is more aggressive and loss of integrity of the enamel is determined by shearing off the enamel rods. In all samples undergoing remineralization deposits were observed, those of toothpastes based on calcium phosphate technologies seem to merge with each other and cover almost the entire surface of the enamel. Loss of integrity and minerals were detected only in the line-scans of the sample remineralized with GC Tooth Mousse™. The semiquantitative EDX analysis of individual elements in the surface layer of the enamel indicates that during tooth-bleaching with HP statistically significant loss of Na and Mg occurs, whereas the bleaching in combination with a laser leads to statistically significant loss of Ca and P. The results undoubtedly confirm that teeth whitening procedures lead to enamel alterations. In this context, it must be noted that laser bleaching is more aggressive for dental substances. However, these changes are reversible and can be repaired by application of remineralization toothpastes. PMID:27197087

  11. Expression of Clock Proteins in Developing Tooth

    OpenAIRE

    Zheng, Li; Papagerakis, Silvana; Schnell, Santiago D.; Hoogerwerf, Willemijntje A; Papagerakis, Petros

    2010-01-01

    Morphological and functional changes during ameloblast and odontoblast differentiation suggest that enamel and dentin formation is under circadian control. Circadian rhythms are endogenous self-sustained oscillations with periods of 24 hours that control diverse physiological and metabolic processes. Mammalian clock genes play a key role in synchronizing circadian functions in many organs. However, close to nothing is known on clock genes expression during tooth development. In this work, we ...

  12. EPR TOOTH DOSIMETRY OF SNTS AREA INHABITANTS

    OpenAIRE

    Sholom, Sergey; Desrosiers, Marc; Bouville, André; Luckyanov, Nicholas; Chumak, Vadim; Simon, Steven L.

    2007-01-01

    The determination of external dose to teeth of inhabitants of settlements near the Semipalatinsk Nuclear Test Site (SNTS) was conducted using the EPR dosimetry technique to assess radiation doses associated with exposure to radioactive fallout from the test site. In this study, tooth doses have been reconstructed for 103 persons with all studied teeth having been formed before the first nuclear test in 1949. Doses above those received from natural background radiation, termed “accident doses”...

  13. Ectopic Premolar Tooth in the Sigmoid Notch

    Science.gov (United States)

    Akgül, H. M.; Bayrakdar, I. S.

    2016-01-01

    Impaction of a mandibular premolar is relatively uncommon. Ectopic placement is more unusual and there has been no discussion in the literature of an ectopic mandibular premolar in the coronoid process. In this case report, we present an impacted ectopic mandibular permanent premolar in the sigmoid notch (incisura mandibulae) region. Etiology of the tooth and treatment options are discussed and illustrated by Cone Beam Computed Tomography (CBCT) images.

  14. Tooth loss and obstructive sleep apnoea

    OpenAIRE

    Gai Valerio; Pera Paolo; Erovigni Francesco; Graziano Alessandra; Arienti Andrea; Brussino Luisa; Cicolin Alessandro; Bucca Caterina; Mutani Roberto; Preti Giulio; Rolla Giovanni; Carossa Stefano

    2006-01-01

    Abstract Background Complete tooth loss (edentulism) produces anatomical changes that may impair upper airway size and function. The aim of this study was to evaluate whether edentulism favours the occurrence of obstructive sleep apnoea (OSA). Methods Polysomnography was performed in 48 edentulous subjects on two consecutive nights, one slept with and the other without dentures. Upper airway size was assessed by cephalometry and by recording forced mid-inspiratory airflow rate (FIF50). Exhale...

  15. Tooth wear: the view of the anthropologist.

    Science.gov (United States)

    Kaidonis, John A

    2008-03-01

    Anthropologists have for many years considered human tooth wear a normal physiological phenomenon where teeth, although worn, remain functional throughout life. Wear was considered pathological only if pulpal exposure or premature tooth loss occurred. In addition, adaptive changes to the stomatognathic system in response to wear have been reported including continual eruption, the widening of the masticatory cycle, remodelling of the temporomandibular joint and the shortening of the dental arches from tooth migration. Comparative studies of many different species have also documented these physiological processes supporting the idea of perpetual change over time. In particular, differential wear between enamel and dentine was considered a physiological process relating to the evolution of the form and function of teeth. Although evidence of attrition and abrasion has been known to exist among hunter-gatherer populations for many thousands of years, the prevalence of erosion in such early populations seems insignificant. In particular, non-carious cervical lesions to date have not been observed within these populations and therefore should be viewed as 'modern-day' pathology. Extrapolating this anthropological perspective to the clinical setting has merits, particularly in the prevention of pre-mature unnecessary treatment. PMID:17938977

  16. Anthropology, tooth wear, and occlusion ab origine.

    Science.gov (United States)

    Young, W G

    1998-11-01

    The purpose of this essay is to emphasize that anthropology, the study of man in his environments, is a potent tool for scientific discovery and inspiration in dental science. It attempts to capture flashes of creative anthropological insight which have illuminated studies of tooth wear and occlusion in the past. While it documents contributions, understandings, and misunderstandings from Australian and New Zealand dentists, it is not a hagiography. The real saint of this essay is the Australian aborigine. For when men and women are understood in their environments, much is learned from them which challenges preconceptions of our dental science culture. The essay concludes that new, contemporary Australian culture needs to be studied by anthropological approaches if we are to understand how dental erosion is exacerbating tooth wear and damaging the occlusions of contemporary Australians. Much remains to be discovered about contemporary lifestyles, habits, and diets that lead to dental erosion, the principal cause of contemporary tooth wear in this part of the world. PMID:9823723

  17. Digital Computer Matching of Tooth Color

    Directory of Open Access Journals (Sweden)

    Won-suk Oh

    2010-06-01

    Full Text Available This study aimed to determine the validity of the digital photocolorimetric (PCM method in matching the color of human teeth. First, two Vitapan Classical shade guides, each containing 16 shade guide teeth, were visually shade matched, and digital photographs of each three pair of shade guide teeth were taken in a color matching booth. Secondly, visual shade matching of the upper central incisors of 48 subjects was performed by two prosthodontists independently in a chair, using the Vitapan Classical shade guide. The three closest shade guide teeth were visually selected and ranked in order of preference, for which digital photographs were taken under ceiling daylight-corrected fluorescent lighting. All digital images were analyzed on a computer screen using software to calculate the color difference between the reference tooth and other teeth in the same digital image. The percent color matching for the shade guide teeth and human teeth was 88% and 75%, respectively. There was no statistically significant difference in matching the tooth color between the shade guide teeth and human teeth. The digital PCM method is valid for the range of human teeth based on the Vitapan Classical shade guide. This method enhances communication with the laboratory personnel in matching the tooth color.

  18. Radiosterilization of tooth pastes EF, MB, LK

    International Nuclear Information System (INIS)

    The effect of decontaminating doses of gamma rays (60Co, 10 Kr - 1.5 Mr) on the quality and biological activity of tooth pastes is studied. The radioresistance factors D10 of the dominating microorganisms in the studied pastes, namely Bac. subtilis, Staph. epidermidis, S. lutea, Ps. aeruginosa, Pen. notatum, Pen. chrysogenum, Asp. niger, C. parapsilosis, are determined. Ps aeruginosa appears to show the highest radiosensitivity - D10 = 20 Kr. The irradiation in the range 500 Kr - 1.5 Mr reveals that Ps. aeruginosa are inactivated with doses of 750 Kr while the inactivation of sporebearing bacteria and grampositive microorganisms starts at doses above 1 Mr. The lower values of radioresistance factors observed as compared to that established by the authors for cosmetic preparations henna and starch are due to radiosensitizing of microorganisms in a medium with higher water content. The radiolytic effect of water causes changes in consistency, odour, taste and colour of the tooth pastes and for that reason the radiosterilization of tooth pastes is not recommended. A mathematical model for irradiation of products contaminated with a variety of microorganisms is developed. Bac. subtilis - the most frequent and radioresistant pollutant - is suggested as a standard in selecting the proper sterilization procedure and in checking the efficiency of irradiation. 3 tabs, 3 figs, 6 refs

  19. Effects of Carbonated Soft Drink Consumption on Orthodontic Tooth Movements in Rats

    OpenAIRE

    Hossein Agha Aghili; Seyed Mohammad Hoseini; Soghra Yassaei; Seyed Amirreza Fatahi Meybodi; Mohammad Hosein Toudeh Zaeim; Mahdjoubeh Goldani Moghadam

    2014-01-01

    Objective: The aim of this animal study was to evaluate the possible effects of Carbonated Soft Drink consumption on the rate of orthodontic tooth movement in rats. Materials and Methods: Thirty-six adult male Sprague-Dawley rats were randomly divided into two experimental groups and one control group. In the experimental groups (A&B), the water in the dietary regimen was replaced with soft drinks (Fanta® in group A and Cola® in group B) two weeks before placement of orthodontic appliances. T...

  20. Retrofitting a Crown Supporting a Removable Partial Denture Using "Biogeneric Copy" to Replicate Tooth's Preoperative Condition.

    Science.gov (United States)

    Patel, Dhaval

    2016-02-01

    When a crown that supports a removable partial denture (RPD) needs to be replaced, patients often balk at having to wait several weeks for laboratory production to be completed before receiving the new restoration. Moreover, the fit of the lab-produced unit may not always be satisfactory. CEREC® CAD/CAM technology provides a design method known as Biogenetic Copy, which allows a clinician to replicate the preexisting size, shape, and form of a tooth chairside. As this case report demonstrates, using this method to retrofit a crown under an existing RPD prosthesis can result in a predictable, accurate, durable, and esthetic same-day restorative solution. PMID:26905091

  1. Profile of prospective bioengineering students at National University of San Juan

    International Nuclear Information System (INIS)

    The low percentage of students (43 % of applicants) that passed the entrance exams for the bioengineering career at the National University of San Juan in 2007, plus the historical situation of desertion in first year (about 50%), motivated the application of a diagnostic test to prospective students of this career. The aim of this test was to obtain information about the competences acquired by students to solve problems in different contexts using basic mathematical tools, reading comprehension skills to understand texts, graphs and tables. Although this test was sat by the entire population of applicants of the current school year, only the results belonging to bioengineering students are the ones presented for the purpose of this work. However, students of other disciplines of the school of engineering also have similar problems. From the analysis of the answers to the different items, it can be observed that there are serious difficulties in the development of basic capacities to successfully take the courses of this career

  2. Profile of prospective bioengineering students at National University of San Juan

    Science.gov (United States)

    Lopez, N.; Puzzella, A.; Zabala, A.; Demartini, H.; Alborch, A.; Cabrera, L.

    2007-11-01

    The low percentage of students (43 % of applicants) that passed the entrance exams for the bioengineering career at the National University of San Juan in 2007, plus the historical situation of desertion in first year (about 50%), motivated the application of a diagnostic test to prospective students of this career. The aim of this test was to obtain information about the competences acquired by students to solve problems in different contexts using basic mathematical tools, reading comprehension skills to understand texts, graphs and tables. Although this test was sat by the entire population of applicants of the current school year, only the results belonging to bioengineering students are the ones presented for the purpose of this work. However, students of other disciplines of the school of engineering also have similar problems. From the analysis of the answers to the different items, it can be observed that there are serious difficulties in the development of basic capacities to successfully take the courses of this career.

  3. Profile of prospective bioengineering students at National University of San Juan

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, N [School of Engineering. National University of San Juan. Av. San MartIn 1109 (Oeste). CP 5400. San Juan (Argentina); Puzzella, A [School of Philosophy, Humanities and Arts. National University of San Juan. I de la Roza 230 (Oeste). CP 5400. San Juan (Argentina); Zabala, A [School of Engineering. National University of San Juan. Av. San MartIn 1109 (Oeste). CP 5400. San Juan (Argentina); Demartini, H [School of Engineering. National University of San Juan. Av. San MartIn 1109 (Oeste). CP 5400. San Juan (Argentina); Alborch, A [School of Philosophy, Humanities and Arts. National University of San Juan. I de la Roza 230 (Oeste). CP 5400. San Juan (Argentina); Cabrera, L [' Col. Central Universitario Dr. M. Moreno' Secondary School. National University of San Juan. I de la Roza 230 (Oeste). CP 5400. San Juan (Argentina)

    2007-11-15

    The low percentage of students (43 % of applicants) that passed the entrance exams for the bioengineering career at the National University of San Juan in 2007, plus the historical situation of desertion in first year (about 50%), motivated the application of a diagnostic test to prospective students of this career. The aim of this test was to obtain information about the competences acquired by students to solve problems in different contexts using basic mathematical tools, reading comprehension skills to understand texts, graphs and tables. Although this test was sat by the entire population of applicants of the current school year, only the results belonging to bioengineering students are the ones presented for the purpose of this work. However, students of other disciplines of the school of engineering also have similar problems. From the analysis of the answers to the different items, it can be observed that there are serious difficulties in the development of basic capacities to successfully take the courses of this career.

  4. Bioengineering bacteriophages to enhance the sensitivity of phage amplification-based paper fluidic detection of bacteria.

    Science.gov (United States)

    Alcaine, S D; Law, K; Ho, S; Kinchla, A J; Sela, D A; Nugen, S R

    2016-08-15

    Bacteriophage (phage) amplification is an attractive method for the detection of bacteria due to a narrow phage-host specificity, short amplification times, and the phages' ability to differentiate between viable and non-viable bacterial cells. The next step in phage-based bacteria detection is leveraging bioengineered phages to create low-cost, rapid, and easy-to-use detection platforms such as lateral flow assays. Our work establishes the proof-of-concept for the use of bioengineered T7 phage strains to increase the sensitivity of phage amplification-based lateral flow assays. We have demonstrated a greater than 10-fold increase in sensitivity using a phage-based protein reporter, maltose-binding protein, over the detection of replicated T7 phage viron itself, and a greater then 100-fold increase in sensitivity using a phage-based enzymatic reporter, alkaline phosphatase. This increase in sensitivity enabled us to detect 10(3)CFU/mL of Escherichia coli in broth after 7h, and by adding a filter concentration step, the ability to detect a regulatory relevant E. coli concentration of 100CFU/100mL in inoculated river water after 9h, where the current standard requires days for results. The combination of the paper fluidic format with phage-based detection provides a platform for the development of novel diagnostics that are sensitive, rapid, and easy to use. PMID:27031186

  5. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    shed light on this unexplored and growing managerial concern, the purpose of this explorative study is to identify operational challenges to management when product platforms are replaced. Design/methodology/approach – The study uses a longitudinal field-study approach. Two companies, Gamma and Omega......Purpose – It is argued in this article that too little is known about product platforms and how to deal with them from a manager's point of view. Specifically, little information exists regarding when old established platforms are replaced by new generations in R&D and production environments. To...... distinguishing between platform replacement “height” and “width”. Seven groups of managerial measures for dealing with the issues are recommended. Originality/value – The study aims to contribute to the existing literature by taking a managers' perspective of product platform development. Its specific...

  6. Squalicorax Chips a Tooth: A Consequence of Feeding-Related Behavior from the Lowermost Navesink Formation (Late Cretaceous: Campanian-Maastrichtian of Monmouth County, New Jersey, USA

    Directory of Open Access Journals (Sweden)

    John A. Chamberlain

    2012-05-01

    Full Text Available Chipped and broken functional teeth are common in modern sharks with serrated tooth shape. Tooth damage consists of splintering, cracking, and flaking near the cusp apex where the enameloid is broken and exposes the osteodentine and orthodentine. Such damage is generally viewed as the result of forces applied during feeding as the cusp apex impacts the skeletal anatomy of prey. Damage seen in serrated functional teeth from sharks Squalicorax kaupi [1] and Squalicorax pristodontus [1] from the late Cretaceous lowermost Navesink Formation of New Jersey resembles that occurring in modern sharks and suggests similar feeding behavior. Tumbling experiments using serrated modern and fossil functional shark teeth, including those of Squalicorax, show that teeth are polished, not cracked or broken, by post-mortem abrasion in lowermost Navesink sediment. This provides further evidence that chipped and broken Squalicorax teeth are feeding-related and not taphonomic in origin. Evolution of rapid tooth replacement in large sharks such as Squalicorax ensured maximum functionality after feeding-related tooth damage occurred. Serrated teeth and rapid tooth replacement in the large sharks of the Mesozoic and Cenozoic afforded them competitive advantages that helped them to achieve their place as apex predators in today’s ocean.

  7. 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. PMID:25702966

  8. ESR dosimetry using eggshells and tooth enamel for accidental dosimetry

    International Nuclear Information System (INIS)

    The CO2- signal of eggshells showed a good dose linearity and was appropriate in the wide dose range from 1 to 10 kGy, while ESR signal of CO2- in sea and fresh water shells were saturated at a dose od below 10 kGy. The minimum detectable dose and G-value of CO2- in eggshells were estimated 0.3 Gy and 0.28, respectively. The lifetime of CO2- in eggshells could not be determined exactly because of overlapping organic signals, however it is still sufficiently long for practical use as ESR dosimeter materials. Various bird's or reptile's eggshells would be available as natural retrospective ESR dosimeter materials after nuclear accidents. Eggshells will be useful for the food irradiation dosimetry in the dose range of about a few kGy. Tooth enamel is one of the most useful dosimeter materials in public at a accident because of its high sensitivity. ESR dosimetry will replace TLD in near future if the cost of an ESR reader is further reduced . (author)

  9. Local Synthesis and Tooth Contact Analysis of Face-Milled, Uniform Tooth Height Spiral Bevel Gears

    Science.gov (United States)

    Litvin, F. L.; Wang, A. G.

    1996-01-01

    Face-milled spiral bevel gears with uniform tooth height are considered. An approach is proposed for the design of low-noise and localized bearing contact of such gears. The approach is based on the mismatch of contacting surfaces and permits two types of bearing contact either directed longitudinally or across the surface to be obtained. Conditions to avoid undercutting were determined. A Tooth Contact Analysis (TCA) was developed. This analysis was used to determine the influence of misalignment on meshing and contact of the spiral bevel gears. A numerical example that illustrates the theory developed is provided.

  10. Using biomimetic cell wall models to identify new plant lignin bioengineering targets for improving forage and biomass utilization

    Science.gov (United States)

    Bioengineering of lignin to contain atypical components derived from other metabolic pathways is increasingly being pursued to custom design lignified cell walls that are inherently more digestible by livestock or more easily pretreated and saccharified for biofuel production. Because plants produce...

  11. Biomimetic cell wall model studies to identify new lignin bioengineering targets for improving biomass susceptibility to pretreatment and enzymatic saccharification

    Science.gov (United States)

    Increasingly, bioengineering of lignin to contain atypical building blocks from other metabolic pathways is being pursued to custom-design lignin that is easier to remove by chemical pretreatments and less inhibitory toward polysaccharide saccharification. Because plants produce such a diverse array...

  12. Identifying new lignin bioengineering targets for improving biomass and forage utilization: a review of biomimetic studies with maize cell walls

    Science.gov (United States)

    Bioengineering of lignin to contain atypical components derived from other metabolic pathways is increasingly being pursued to custom design lignified cell walls that are more readily pretreated and saccharified for biofuel production or easily digested by livestock. Because plants produce such a di...

  13. The Tooth Wear Evaluation System: development and applications

    OpenAIRE

    Wetselaar, P.

    2016-01-01

    Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues, viz., enamel and dentine. Because of its multifactorial etiology, tooth wear can manifest itself in many different representations, and therefore it can be difficult and demanding to diagnose and manage the condition. In this thesis, the development of a comprehensive modular system is described, the Tooth Wear Evaluation System (TWES). With this system, one can recognize the problem (viz., qualifying the to...

  14. Functional constraints on tooth morphology in carnivorous mammals

    OpenAIRE

    Smits Peter D; Evans Alistair R

    2012-01-01

    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 mandibu...

  15. The Association Between childhood Obesity and Tooth Eruption

    OpenAIRE

    Must, Aviva; Phillips, Sarah M.; Tybor, David J.; Lividini, Keith; Hayes, Catherine

    2012-01-01

    Obesity is a growth-promoting process as evidenced by its effect on the timing of puberty. Although studies are limited, obesity has been shown to affect the timing of tooth eruption. Both the timing and sequence of tooth eruption are important to overall oral health. The purpose of this study was to examine the association between obesity and tooth eruption. Data were combined from three consecutive cycles (2001–2006) of the National Health and Nutrition Examination Survey (NHANES) and analy...

  16. Sonosurgery for atraumatic tooth extraction: a clinical report.

    Science.gov (United States)

    Papadimitriou, Dimitrios E V; Geminiani, Alessandro; Zahavi, Thomas; Ercoli, Carlo

    2012-12-01

    The preservation of an intact labial plate during tooth extraction is a critical determinant of whether an immediate implant can be placed and is also an important predictor of the esthetic result. The purpose of this clinical report was to present a method for atraumatic tooth extraction by using an air-driven sonic instrument with specially designed inserts. This surgical technique provides the clinician with an efficient method for atraumatic tooth extraction and preservation of an intact labial plate. PMID:23217465

  17. Hair keratin mutations in tooth enamel increase dental decay risk

    OpenAIRE

    Duverger, Olivier; Ohara, Takahiro; Shaffer, John R.; Donahue, Danielle; Zerfas, Patricia; Dullnig, Andrew; Crecelius, Christopher; Beniash, Elia; Marazita, Mary L; Morasso, Maria I.

    2014-01-01

    Tooth enamel is the hardest substance in the human body and has a unique combination of hardness and fracture toughness that protects teeth from dental caries, the most common chronic disease worldwide. In addition to a high mineral content, tooth enamel comprises organic material that is important for mechanical performance and influences the initiation and progression of caries; however, the protein composition of tooth enamel has not been fully characterized. Here, we determined that epith...

  18. Protection and Reinforcement of Tooth Structures by Dental Coating Materials

    OpenAIRE

    Toru Nikaido; Rena Takahashi; Meu Ariyoshi; Junji Tagami; Alireza Sadr

    2012-01-01

    It has been proposed that a resin coating can serve as a means to protect dental structure after preparation of the tooth for indirect restorations, sealing the exposed dentin. The resin coating is applied on the cut surfaces immediately after tooth preparation and before making an impression by assembling a dentin bonding system and a flowable composite. Resin coatings minimize pulp irritation and improve the bond strength between a resin cement and tooth when bonding the restoration to toot...

  19. A theropod tooth from the Late Triassic of southern Africa

    Indian Academy of Sciences (India)

    Sanghamitra Ray; Anusuya Chinsamy

    2002-06-01

    An isolated, large recurved and finely serrated tooth found associated with the prosauropod Euskelosaurus from the Late Triassic part of the Elliot Formation is described here. It is compared to the Triassic thecodonts and carnivorous dinosaurs and its possible affinity is discussed. The tooth possibly belongs to a basal theropod and shows some features similar to the allosauroids. This tooth is of significance, as dinosaur remains except for some footprints and trackways, are poorly known in the Late Triassic horizons of southern Africa.

  20. Esthetic Management of an Anterior Avulsed Tooth: A Case Report

    OpenAIRE

    AR, Prabhakar; Sugandhan,; KB, Roopa; Gulati, Akanksha

    2009-01-01

    Avulsion and luxation account for up to 16% of all traumatic injuries in the permanent dentition and 7.2% of injuries in the primary dentition. A range of treatment options are available that can help conserve the tooth after a traumatic episode. There are, however, occasions where loss of the traumatized tooth is inevitable with special regard to avulsion injuries. replantation of teeth having doubtful long-term prognosis. Following the traumatic loss of an anterior tooth it is important tha...

  1. A TOOTH TATTOO WITH A PURPOSE: AN INNOVATIVE APPROACH

    OpenAIRE

    Neetu,; Anuroop; Prasant; Ashishkumar K; Fareedi Mukram

    2014-01-01

    Skin is not the only place that can be decorated with a tattoo. You can decorate your tooth with amazing tattoos. Tooth tattoos and tooth jewels have become one of the hottest fashion trends , and a very popular arrival in cosmetic dentistry. But won’t it be a boon if it had some preventive or medicinal v alue. Yes tooth tattoos can act as indicators of once illness. These tiny electronic sensors can diagnose illnesses by 'tasting' your breath. This paper is an i...

  2. Computer-aided design of bevel gear tooth surfaces

    Science.gov (United States)

    Shuo, Hung Chang; Huston, Ronald L.; Coy, John J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  3. Computer aided design of bevel gear tooth surfaces

    Science.gov (United States)

    Chang, S. H.; Huston, R. L.; Coy, J. J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  4. [Interproximal tooth cleansing of abutment teeth and pontic design].

    Science.gov (United States)

    Kocher, T; Plagmann, H C; Engelsmann, U; Schlüter, R

    1990-03-01

    This clinical study was an attempt to find out if a patient's home care plaque control at his or her abutment tooth is more effectively enhanced by a modified ridge lap or a hygienic pontic design. Oral hygiene was performed either with a tooth brush alone or in combination with an interdental brush. We found that the effectivity of interproximal toothcleaning was not influenced by the pontic design and that only interdental brushes permit a good plaque control at the proximal area of the abutment tooth. This implies that "self cleansing" is non-existent in these tooth areas. PMID:2257819

  5. Msx1 Mutations: How Do They Cause Tooth Agenesis?

    OpenAIRE

    Wang, Y.; Kong, H; Mues, G.; D’Souza, R.

    2011-01-01

    Mutations in the transcription factors PAX9 and MSX1 cause selective tooth agenesis in humans. In tooth bud mesenchyme of mice, both proteins are required for the expression of Bmp4, which is the key signaling factor for progression to the next step of tooth development. We have previously shown that Pax9 can transactivate a 2.4-kb Bmp4 promoter construct, and that most tooth-agenesis-causing PAX9 mutations impair DNA binding and Bmp4 promoter activation. We also found that Msx1 by itself rep...

  6. ROLE OF BACTERIA IN THE TOOTH ABSCESS: A MINI REVIEW

    OpenAIRE

    Biswajit Batabyal; Gautam kr. Kundu

    2013-01-01

    A tooth abscess or root abscess is pus enclosed in the tissues of the jaw bone at the apex of an infected tooth's root(s). Usually the abscess originates from a bacterial infection that has accumulated in the soft, often dead, pulp of the tooth. This can be caused by untreated tooth decay, cracked teeth or extensive periodontal disease. A failed root canal treatment may also create a similar abscess. Recently developed molecular methods have made it possible to characterise mixed micro flora ...

  7. Tooth-shaped plasmonic waveguide filters with nanometeric sizes

    CERN Document Server

    Lin, Xianshi; 10.1364/OL.33.002874

    2009-01-01

    A novel nanometeric plasmonic filter in a tooth-shaped Metal-Insulator-Metal waveguide is proposed and demonstrated numerically. An analytic model based on the scattering matrix method is given. The result reveals that the single tooth-shaped filter has a wavelength filtering characteristic and an ultra-compact size in the length of a few hundred nanometers, compared to grating-like SPPs filters. Both analytic and simulation results show that the wavelength of the trough of the transmission has linear and nonlinear relationships with the tooth depth and the tooth width, respectively. The waveguide filter could be utilized to develop ultra-compact photonic filters for high integration.

  8. 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...... partial skeleton of the dromaeosaurid Saurornitholestes was collected from southern Alberta, Canada, that bore marks on one dentary. The location and morphology of the tooth marks suggests that a theropod (possible a juvenile tyrannosaurid) included a Saurornitholestes in its diet....

  9. Impact of diet on tooth erosion.

    Science.gov (United States)

    Richards, Derek

    2016-06-01

    Data sourcesPubMed, Web of Science, Scopus, Science Direct, EBSHost, Scientific Electronic Library online (SciELO).Study selectionPopulation-based cross-sectional and longitudinal studies assessing tooth erosion and diet, conducted in children and adolescents between eight and 19 years reporting on the permanent dentition were considered.Data extraction and synthesisStudies were selected independently by two reviewers and standard data items extracted. Study quality was assessed using the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) statement and Newcastle-Ottawa Quality Assessment Scale (NOS). The pooled effect of dietary habits on tooth erosion occurrence was calculated using a fixed and a random model (OR and 95%CI).ResultsThirteen studies involving a total of 16,661 children were included. Eleven of the studies were cross-sectional and two longitudinal. Dietary habits data were mainly obtained from brief dietary assessments (69.2%) with food amount (weighed or estimated) and food frequency questionnaires used less commonly (15.4%). Most dietary assessments were self-administered (84.6%), assessed diet on a single occasion (61.5%) and required recalls of a week or more days or usual behaviours (46.2%). Meta-analyses were carried out for carbonated/soft drinks, sports drinks, milk-based drinks, yogurt, confectionery and snacks and acidic natural fruit drinks. Higher consumption of carbonated drinks or acid snacks/sweets and for acid fruit juices increased the odds for tooth erosion, while higher intake of milk and yogurt reduced the odds of erosion (see table).ConclusionsThe evidence indicated that some dietary habits (soft drinks, acidic snacks/sweets and acidic fruit juices) increased the odds for erosion occurrence, while milk or yogurt produced a protective effect. Methodological issues were shown to partly explain the heterogeneity of the data for some dietary products. PMID:27339233

  10. Epithelial topography for repetitive tooth formation

    Directory of Open Access Journals (Sweden)

    Marcia Gaete

    2015-12-01

    Full Text Available During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2+ cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial topography involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2+/Sox9+ cells.

  11. Forensic Identification Based on Tooth Material

    Directory of Open Access Journals (Sweden)

    Elza Ibrahim Auerkari

    2015-10-01

    Full Text Available Human teeth are the most robust and stable parts of the body, providing biological clue material for forensic purposes even when most of the oter means of identifcation have been seriously affected by adverse environmental conditions. In particular blood grouping, isozymes, serum proteins and DNA polymorhphisms can be detected from teeth that protect these identification markers in addition to the traditional dental records. While in general the value of traditional dental records in the forensic work is decreasing eg due to mproved dental care, the newer means of identification from tooth material provide considerable promise for effective identification in difficult cases.The DNA analysis from tooth material has been shown to ba a viable route in forensic analysis, when other material for such an analysis is unusable. However in most cases useful biologic material other than teeth is abailable, and then DNA analysis can be made from other tissue with less effort than by using teeth. Also, in cases with lacking other tissue, blood grouping, isozymes and serum proteins may provide cheaper inherited combinations of blood grouping, isozymes and serum proteins can be treated similary to polymorphic DNA loci as independent markers, their identification can be managed if the false positives and negatives in analysis can be minimmised, and the corresponding frequencies of occurrence are known.It was the purpose of the present work to review the methods of forensic identification from tooth material, based on analysis of blood grouping, isozymes and serum proteins. It appears that such a combined analysis provides a robust method for forensic purposes. Nevertheless, for efficient identification it is recommended that as many (multiple forensic methods as possible are combined, so that faster and cheaper methods such as imminent medical forensics are used first, and more thorough analysis is used to support and complement these methods.

  12. Comparison of the effect of thermal stresses on tooth-colored posts, cores and tooth structures by finite element analysis

    OpenAIRE

    Egilmez, Ferhan; Nalbant, Levent

    2012-01-01

    Objectives: The aims of this study were to analyze the influence of cold heat flow in all ceramic crown material, composite core, zirconium and glass fiber reinforced composite post materials, resin based luting cement and root dentin; and to compare these two tooth-colored post systems about their temperature and thermal stress distributions. Materials and Methods: A 3-dimesional finite element model of maxillary left canine tooth was constructed. All ceramic crown, composite core, tooth den...

  13. ESR dating of tooth enamel samples

    International Nuclear Information System (INIS)

    Five tooth samples from the palaeoanthropological site of Jinniushan were dated with both electron-spin-resonance (ESR) and uranium-series techniques. The ESR age of about 230 ka is in good agreement with the U-series dating result, which confirms the hypothesis of possible coexistence of Homo erect us and Homo sapiens in China. Problems in ESR dating are discussed such as: 1) inappropriate of simple exponential extrapolation for accumulated dose determination; 2)experimental measurement of alpha detection efficiency and radon emanation and 3)selection of U-uptake model

  14. Measurement of Gear Tooth Dynamic Friction

    Science.gov (United States)

    Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

    1996-01-01

    Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

  15. Evaluating the Reasons of Amalgam Restoration Replacement in Esthetic and Restorative Department of Babol Dental School in 2013-14

    OpenAIRE

    F Abolghasemzade; H. Alaghehmand; H Khadem; R Judi

    2015-01-01

    Introduction: Dental amalgam is regarded as a popular restorative material. The purpose of this study is to investigate the reasons of replacing amalgam restorations in patients referring to Babol dental school within 2013-2014. Methods: In this analytic-descriptive study, age, sex, type of occlusion DMF, existence of parafunction, as well as type of tooth, restoration class and reason of amalgam restoration replacement were recorded in patients referred to the Babol dental school during 2...

  16. Tooth Germ-Like Construct Transplantation for Whole-Tooth Regeneration: An In Vivo Study in the Miniature Pig.

    Science.gov (United States)

    Yang, Kai-Chiang; Kitamura, Yutaka; Wu, Chang-Chin; Chang, Hao-Hueng; Ling, Thai-Yen; Kuo, Tzong-Fu

    2016-04-01

    The purpose of this study was to demonstrate the feasibility of whole-tooth regeneration using a tooth germ-like construct. Dental pulp from upper incisors, canines, premolars, and molars were extracted from sexually mature miniature pigs. Pulp tissues were cultured and expanded in vitro to obtain dental pulp stem cells (DPSCs), and cells were differentiated into odontoblasts and osteoblasts. Epithelial cells were isolated from gingival epithelium. The epithelial cells, odontoblasts, and osteoblasts were seeded onto the surface, upper, and lower layers, respectively, of a bioactive scaffold. The lower first and second molar tooth germs were removed bilaterally and the layered cell/scaffold constructs were transplanted to the mandibular alveolar socket of a pig. At 13.5 months postimplantation, seven of eight pigs developed two teeth with crown, root, and pulp structures. Enamel-like tissues, dentin, cementum, odontoblasts, and periodontal tissues were found upon histological inspection. The regenerated tooth expressed dentin matrix protein-1 and osteopontin. All pigs had regenerated molar teeth regardless of the original tooth used to procure the DPSCs. Pigs that had tooth germs removed or who received empty scaffolds did not develop teeth. Although periodontal ligaments were generated, ankylosis was found in some animals. This study revealed that implantation of a tooth germ-like structure generated a complete tooth with a high success rate. The implant location may influence the morphology of the regenerated tooth. PMID:26582651

  17. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

    Science.gov (United States)

    Vandenplas, Sam; Willems, Maxime; Witten, P Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

    2016-01-01

    The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement. PMID:27049953

  18. Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

    Directory of Open Access Journals (Sweden)

    Sam Vandenplas

    Full Text Available The Atlantic salmon (Salmo salar and African bichir (Polypterus senegalus are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1 determine the localization and extent of proliferating cells in the dental epithelial layers, (2 describe cell dynamics and (3 investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks and P. senegalus (eight weeks and twelve weeks, we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement.

  19. The replacement research reactor

    International Nuclear Information System (INIS)

    The contract for the design, construction and commissioning of the Replacement Research Reactor was signed in July 2000. This was followed by the completion of the detailed design and an application for a construction licence was made in May 2001. This paper will describe the main elements of the design and their relation to the proposed applications of the reactor. The future stages in the project leading to full operation are also described

  20. Aortic valve replacement

    DEFF Research Database (Denmark)

    Kapetanakis, Emmanouil I; Athanasiou, Thanos; Mestres, Carlos A;

    2008-01-01

    BACKGROUND AND AIMS OF THE STUDY: Prompted by anecdotal evidence and observations by surgeons, an investigation was undertaken into the potential differences in implanted aortic valve prosthesis sizes, during aortic valve replacement (AVR) procedures, between northern and southern European countr...... southern European countries. Imbalances in the prevalence of rheumatic heart disease, health resource availability and variations in surgical practice throughout Europe might be possible etiological causes....

  1. Nanotechnology in joint replacement

    OpenAIRE

    Torrecillas, Ramón; J. S. MOYA; Díaz, L. A.; Bartolomé, J. F.; Fernández, Adolfo; Lopez-Esteban, S.

    2009-01-01

    This paper reviews the most relevant achievements and new developments in the field of nanomaterials and their possible impact on the fabrication of a new generation of reliable and longer lasting implants for joint replacement. Special emphasis is given to the role of nanocomposites with different microstructural designs: micro-nano composites, nano-nano composites, macro-micro-nano composites as well as bioinspired hierarchical composite materials. These nanostructured materials have opened...

  2. Renal Replacement Therapy

    OpenAIRE

    Zaccaria Ricci; Stefano Romagnoli; Claudio Ronco

    2016-01-01

    During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute...

  3. In vitro tooth whitening effect of two medicated chewing gums compared to a whitening gum and saliva

    Directory of Open Access Journals (Sweden)

    Saroea Geoffrey

    2008-08-01

    Full Text Available Abstract Background Extrinsic staining of teeth may result from the deposition of a variety of pigments into or onto the tooth surface, which originate mainly from diet or from tobacco use. More recently, clinical studies have demonstrated the efficacy of some chewing gums in removing extrinsic tooth staining. The aim of this study was to assess the effectiveness of two nicotine medicated chewing gums (A and B on stain removal in an in vitro experiment, when compared with a confectionary whitening chewing gum (C and human saliva (D. Methods Bovine incisors were stained by alternating air exposure and immersion in a broth containing natural pigments such as coffee, tea and oral microorganisms for 10 days. Stained enamel samples were exposed to saliva alone or to the test chewing gums under conditions simulating human mastication. The coloration change of the enamel samples was measured using a spectrophotometer. Measurements were obtained for each specimen (average of three absorbances using the L*a*b scale: lightness (L*, red-green (a and yellow-blue (b. Results Medicated chewing gums (A and B removed a greater amount of visible extrinsic stain, while the confectionary chewing gum with a whitening claim (C had a milder whitening effect as evaluated by quantitative and qualitative assessment. Conclusion The tested Nicotine Replacement Therapy (NRT chewing gums were more effective in the removal of the extrinsic tooth stain. This visible improvement in tooth whitening appearance could strengthen the smokers' motivation to quit smoking.

  4. Bioengineering aspects of inorganic carbon supply to mass algal cultures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, J.C.

    1980-06-01

    The work included in this report is part of an ongoing study (currently funded by the Solar Energy Research Institute - Subcontract No. XR-9-8144-1) on the inorganic carbon requirements of microalgae under mass culture conditions and covers the period June 1, 1978 through May 31, 1979. It is divided into two parts appended herein. The first part is a literature review on the inorganic carbon chemical system in relation to algal growth requirements, and the second part deals with the kinetics of inorganic carbon-limited growth of two freshwater chlorophytes including the effect of carbon limitation on cellular chemical composition. Additional experiment research covered under this contract was reported in the Proceedings of the 3rd Annual Biomass Energy Systems Conferences, pp. 25-32, Bioengineering aspects of inorganic carbon supply to mass algal cultures. Report No. SERI/TP-33-285.

  5. Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis.

    Science.gov (United States)

    Rinaldi, Roberto; Jastrzebski, Robin; Clough, Matthew T; Ralph, John; Kennema, Marco; Bruijnincx, Pieter C A; Weckhuysen, Bert M

    2016-07-11

    Lignin is an abundant biopolymer with a high carbon content and high aromaticity. Despite its potential as a raw material for the fuel and chemical industries, lignin remains the most poorly utilised of the lignocellulosic biopolymers. Effective valorisation of lignin requires careful fine-tuning of multiple "upstream" (i.e., lignin bioengineering, lignin isolation and "early-stage catalytic conversion of lignin") and "downstream" (i.e., lignin depolymerisation and upgrading) process stages, demanding input and understanding from a broad array of scientific disciplines. This review provides a "beginning-to-end" analysis of the recent advances reported in lignin valorisation. Particular emphasis is placed on the improved understanding of lignin's biosynthesis and structure, differences in structure and chemical bonding between native and technical lignins, emerging catalytic valorisation strategies, and the relationships between lignin structure and catalyst performance. PMID:27311348

  6. Cereal bioengineering: amylopectin-free and hyper-phosphorylated barley starch

    DEFF Research Database (Denmark)

    Hebelstrup, Kim; Carciofi, Massimiliano; Jensen, Susanne Langgård;

    2011-01-01

    Barley lines producing grains with either amylopectin-free or hyper-phosphorylated starches were engineered by transgenic methods. Amylopectin-free barley was generated by simultaneously silencing the three genes encoding the starch branching enzymes (SBEIIa, SBEIIb and SBEI) by a chimeric hairpin...... demonstrates for the first time a way for production of pure amylose in plants with limited yield loss. In a different barley line endosperm specific overexpression of glucan water dikinase from potato (StGWD) was conducted. The content of phosphate esters in starch from consecutive generations (T0 and T1) of...... the presence of a general mechanism in starch degradation in the plant kingdom where phosphorylation carried out by ectopic expression of StGWD tags barley starch granules for degradation by endogenous enzymes. Together this work shows two new strategies for in planta starch bioengineering of cereals...

  7. Enhancing the natural folate level in wine using bioengineering and stabilization strategies.

    Science.gov (United States)

    Liu, Yazheng; Walkey, Christopher J; Green, Timothy J; van Vuuren, Hennie J J; Kitts, David D

    2016-03-01

    Folate deficiency is linked to many diseases, some of which may have higher probability in individuals with alcohol-induced alterations in one-carbon metabolism. Our study shows that folate content in commercial wine is not related to white or red varieties, but associated with the yeast that is used to produce the wine. The stability of folate in these wines, once opened for consumption, did not correlate with total phenolic or sulfite content. In addition, we employed yeast bioengineering to fortify wine with folate. We confirmed by overexpression that FOL2 was the key gene encoding the rate-limiting step of folate biosynthesis in wine yeast. In this study, we also show that overexpression of other folate biosynthesis genes, including ABZ1, ABZ2, DFR1, FOL1 and FOL3, had no effect on folate levels in wine. Ensuring stability of the increased natural folate in all wines was achieved by the addition of ascorbate. PMID:26471523

  8. Renal Replacement Therapy.

    Science.gov (United States)

    Ricci, Zaccaria; Romagnoli, Stefano; Ronco, Claudio

    2016-01-01

    During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute kidney injury. Recent technological improvement has led to the production of safe, versatile and efficient dialysis machines. In addition, emerging evidence may allow better individualization of treatment with tailored prescription depending on the patients' clinical picture (e.g. sepsis, fluid overload, pediatric). The aim of the present review is to give a general overview of current practice in renal replacement therapies for critically ill patients. The main clinical aspects, including dose prescription, modality of dialysis delivery, anticoagulation strategies and timing will be addressed. In addition, some technical issues on physical principles governing blood purification, filters characteristics, and vascular access, will be covered. Finally, a section on current standard nomenclature of renal replacement therapy is devoted to clarify the "Tower of Babel" of critical care nephrology. PMID:26918174

  9. Root reinforcement and slope bioengineering stabilization by Spanish Broom (Spartium junceum L.

    Directory of Open Access Journals (Sweden)

    F. Giadrossich

    2009-09-01

    Full Text Available The present paper deals with the root system's characteristics of Spanish Broom (Spartium junceum L., a species whose capacity for adaptating and resisting to drought is worth investigating. In particular, the aims of the study were 1 to investigate the plant's bio-mechanical aspects and 2 to verify whether root reinforcement and the field rooting ability of stem cuttings enhance its potential for use in slope stabilization and soil bio-engineering techniques, particularly in the Mediterranean areas. Single root specimens were sampled and tested for tensile strength, obtaining classic tensile strength-diameter relationships. Analysis were performed on the root systems in order to assess root density distribution. The Root Area Ratio (RAR was analyzed by taking both direct and indirect measurements, the latter relying on image processing. The data obtained were used to analyze the stability of an artificial slope (landfill and the root reinforcement. The measurement and calculation of mean root number, mean root diameter, RAR, root cohesion and Factor of safety are presented in order to distinguish the effect of plant origin and propagation. Furthermore, tests were performed to assess the possibility of agamic propagation (survival rate of root-ball endowed plants, rooting from stem cuttings. These tests confirmed that agamic propagation is difficult, even though roots were produced from some buried stems, and for practical purposes it has been ruled out. Our results show that Spanish Broom has good bio-mechanical characteristics with regard to slope stabilization, even in critical pedoclimatic conditions and where inclinations are quite steep, and it is effective on soil depths up to about 50 cm, in agreement with other studies on Mediterranean species. It is effective in slope stabilization, but less suitable for soil bio-engineering or for triggering natural plant succession.

  10. New approaches to increase intestinal length: Methods used for intestinal regeneration and bioengineering.

    Science.gov (United States)

    Shirafkan, Ali; Montalbano, Mauro; McGuire, Joshua; Rastellini, Cristiana; Cicalese, Luca

    2016-03-24

    Inadequate absorptive surface area poses a great challenge to the patients suffering a variety of intestinal diseases causing short bowel syndrome. To date, these patients are managed with total parenteral nutrition or intestinal transplantation. However, these carry significant morbidity and mortality. Currently, by emergence of tissue engineering, anticipations to utilize an alternative method to increase the intestinal absorptive surface area are increasing. In this paper, we will review the improvements made over time in attempting elongating the intestine with surgical techniques as well as using intestinal bioengineering. Performing sequential intestinal lengthening was the preliminary method applied in humans. However, these methods did not reach widespread use and has limited outcome. Subsequent experimental methods were developed utilizing scaffolds to regenerate intestinal tissue and organoids unit from the intestinal epithelium. Stem cells also have been studied and applied in all types of tissue engineering. Biomaterials were utilized as a structural support for naive cells to produce bio-engineered tissue that can achieve a near-normal anatomical structure. A promising novel approach is the elongation of the intestine with an acellular biologic scaffold to generate a neo-formed intestinal tissue that showed, for the first time, evidence of absorption in vivo. In the large intestine, studies are more focused on regeneration and engineering of sphincters and will be briefly reviewed. From the review of the existing literature, it can be concluded that significant progress has been achieved in these experimental methods but that these now need to be fully translated into a pre-clinical and clinical experimentation to become a future viable therapeutic option. PMID:27011901

  11. Hierarchical structure and biomineralization in cricket tooth

    CERN Document Server

    Xing, Xueqing; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhongjun; Wu, Zhonghua

    2012-01-01

    Cricket is a truculent insect with stiff and sharp teeth as a fighting weapon. The structure and possible biomineralization of the cricket teeth are always interested. Synchrotron radiation X-ray fluorescence, X-ray diffraction and small angle X-ray scattering techniques were used to probe the element distribution, possible crystalline structures and size distribution of scatterers in cricket teeth. Scanning electron microscope was used to observe the nanoscaled structure. The results demonstrate that Zn is the main heavy element in cricket teeth. The surface of the cricket teeth has a crystalline compound like ZnFe2(AsO4)2(OH)2(H2O)4. While, the interior of the teeth has a crystalline compound like ZnCl2, which is from the biomineralization. The ZnCl2-like biomineral forms nanoscaled microfibrils and their axial direction points at the top of tooth cusp. The microfibrils aggregate random into intermediate filaments, forming a hierarchical structure. A sketch map of the cricket tooth cusp was proposed and a d...

  12. [Tooth regeneration in the guinea pig (Cavia porcellus)].

    Science.gov (United States)

    Stephan, F; Artis, J P; Lanot, R

    1977-01-01

    The first inferior molar has been extracted, a part of its being reimplanted or not. A new molar of normal form regenerated, apparently from the apex of the tooth germ, in all cases in which the alveolus was left free or implanted with a tooth freagment deprived of pulpa. PMID:145296

  13. 3D Simulation Modeling of the Tooth Wear Process.

    Directory of Open Access Journals (Sweden)

    Ning Dai

    Full Text Available Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation.

  14. Surgical Methods for the Acceleration of the Orthodontic Tooth Movement.

    Science.gov (United States)

    Almpani, Konstantinia; Kantarci, Alpdogan

    2016-01-01

    Surgical techniques for the acceleration of the orthodontic tooth movement have been tested for more than 100 years in clinical practice. Since original methods have been extremely invasive and have been associated with increased tooth morbidity and various other gaps, the research in this field has always followed an episodic trend. Modern approaches represent a well-refined strategy where the concept of the bony block has been abandoned and only a cortical plate around the orthodontic tooth movement has been desired. Selective alveolar decortication has been a reproducible gold standard to this end. Its proposed mechanism has been the induction of rapid orthodontic tooth movement through the involvement of the periodontal ligament. More recent techniques included further refinement of this procedure through less invasive techniques such as the use of piezoelectricity and corticision. This chapter focuses on the evolution of the surgical approaches and the mechanistic concepts underlying the biological process during the surgically accelerated orthodontic tooth movement. PMID:26599122

  15. Fiber-reinforced Composite for Chairside Replacement of Anterior Teeth: A Case Report.

    Science.gov (United States)

    Garoushi, S; Vallittu, Pk; Lassila, Lvj

    2008-01-01

    A variety of therapeutic modalities, from implant to conventional Maryland prosthesis, can be used for the replacement of a missing anterior tooth. Whenever a minimal tooth reduction is preferred, a fiber reinforced composite (FRC) prosthesis could be a good alternative to conventional prosthetic techniques, chiefly as temporary restoration before making a final decision on the treatment. The purpose of this case report is to describe the clinical procedure of fabricating anterior chairside FRC prosthesis with pre-impregnated unidirectional E-glass fibers and veneered particulate filler composite. Fiber-reinforced composite in combination with adhesive technology appears to be a promising treatment option for replacing missing teeth. However, further and long-term clinical investigation will be required to provide additional information on the survival of directly-bonded anterior fixed prosthesis made with FRC systems. PMID:21499473

  16. ESOPHAGEAL REPLACEMENT IN CHILDREN

    Directory of Open Access Journals (Sweden)

    G. Giannotti

    2012-01-01

    Full Text Available Introduction: esophageal replacement in childhood, is indicated for intractable stenosis and long-gap atresia. When it is impossible to preserve the native esophagus we must create an appropriate conduit that should allow physiological oral feeding. Patients and Methods: we present two cases. The first patient, born with long gap esophageal atresia (AE, was submitted to ligation of fistula, gastrostomy and esophagostomy. When he was 1 years old came to our observation with two derivations. The radiological examination with contrast confirmed the large gap between the two oesophageal stumps. We decided to refer the patient to esophageal substitution with isoperistaltic jejunum through the posterior mediastinum. The second patient was born with AE type III and he was submitted to ligation of fistula, primary anastomosis, and 4 additional interventions of closure of recurrent fistula, esophageal resection and anti-reflux surgery. He came to our observation when he was 6 years old. The radiography showed esophageal dysmotility and dislocation of the stomach in the chest. We decided to subject the patient to esophageal replacement with stomach in toto. Results: Both patients had a good post-operative course. They began food orally in the first case in 18th day and in the second case in 7th. At follow-up after 1 year the children ate regularly, they don’t show respiratory symptoms or gastro-oesophageal reflux and they have a good growth. Conclusions: Esophageal replacement is a complex surgical procedure, which provides various options. Only a careful preoperative evaluation allows us a choice of organ to be used as esophageal substitute. The colon is the most widely used. There are other surgical options that may offer, in skilled hands, the same guarantees. Both our cases have a good long term follow-up with regular diet and weight-height growth. Our experience confirms the validity of the 2 techniques, which include preferably the use of

  17. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    HR/SOC

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), in order to fill in a 'fiche individuelle' form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format. The French card in their possession. An A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done...

  18. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division; Cards.Service@cern.ch

    2001-01-01

    The French Ministry of Foreign Affairs is currently replacing all diplomatic cards, special cards and employment permits («attestations de fonctions») held by members of the personnel and their families. These cards are replaced by secure, computerized equivalents. The old cards may no longer be used after 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015) between 8h30 and 12h30, in order to fill in a «fiche individuelle» form, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, the French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested...

  19. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. The old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel are asked to go to the cards office (33/1-015), taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format, The French card in their possession, an A4 photocopy of the same French card, certified by the cards office as being a true copy. Those members of the personnel whose cards (and/or cards belonging to members of their families) are shortly due to expire, or have recently done so, are also requested to take these items to the c...

  20. REPLACEMENT OF FRENCH CARDS

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The French Ministry of Foreign Affairs has informed the Organization that it is shortly to replace all diplomatic cards, special cards and employment permits ('attestations de fonctions') now held by members of the personnel and their families. Between 2 July and 31 December 2001, these cards are to be replaced by secure, computerized equivalents. A 'personnel office' stamped photocopy of the old cards may continue to be used until 31 December 2001. For the purposes of the handover, members of the personnel must go personally to the cards office (33/1-015), between 8:30 and 12:30, in order to fill a 'fiche individuelle' form (in black ink only), which has to be personally signed by themselves and another separately signed by members of their family, taking the following documents for themselves and members of their families already in possession of a French card : A recent identity photograph in 4.5 cm x 3.5 cm format (signed on the back) The French card in their possession an A4 photocopy of the same Fre...

  1. Total disc replacement.

    Science.gov (United States)

    Vital, J-M; Boissière, L

    2014-02-01

    Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine. PMID:24412045

  2. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  3. Power Plant Replacement Study

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University's aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  4. The Optimum Replacement of Weapon

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao; ZHANG Jin-chun

    2002-01-01

    The theory of LCC (Life Cycle Cost) is applied in this paper. The relation between the economic life of weapon and the optimum replacement is analyzed. The method to define the optimum replacement time of weapon is discussed.

  5. When to Replace a Prosthesis

    Science.gov (United States)

    ... to Replace a Prosthesis When to Replace a Prosthesis Web Development April 21, 2015 Fact Sheet Last ... workplace, they must be accurately fit with a prosthesis that matches their own anatomy; one that is ...

  6. Laser therapy for faster orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Wasundhara A Bhad-Patil

    2014-01-01

    Full Text Available One of the major component of patient to reject orthodontic treatment is the long duration of treatment..If Low intensity laser therapy can promote wound healing by increased cell proliferation and improved micro circulation can bring about faster bone remodelling at fracture sites; then why not to use it with orthodontic forces for better results? Soft tissue laser has now become a part of essential equipment of modern dental clinics. To accelerate the physiologic tooth movement during orthodontic treatment a thorough knowledge of laser unit, mode of action and key factors to gain therapeutic effect is a must which this article illustrates .Study carried out by us did show a 30% reduction in the treatment time.

  7. Unusual intraosseous transmigration of impacted tooth

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima [Manipal College of Dental Sciences, Manipal (India)

    2012-03-15

    Transmigration of an impacted tooth through the symphyseal suture is a rare and special developmental anomaly of unknown etiology that is unique to the mandibular canine. Maxillary canine transmigration is even rarer. Transmigrated canines are particularly significant due to the aesthetic and functional importance. A maxillary lateral incisor crossing the mid-palatal suture has never been reported in the literature. The aim of this report is to present the first case of simultaneous transmigration of a lateral incisor and canine in the maxilla. The paper also reports four unusual cases of unilateral canine transmigration in the maxilla and mandible and successful eruption of one of the transmigrated mandibular canines following orthodontic traction. Etiology of transmigration and its clinical considerations are also discussed.

  8. Side effects of external tooth bleaching

    DEFF Research Database (Denmark)

    E.M., Bruzell; Pallesen, Ulla; Thoresen, N.R.;

    2013-01-01

    -office = 39.3% [n = 28]; p >0.05; 95% CI [OR]: 0.198‑1.102) whereas prevalence of gingival irritation was higher after in-office treatment (at-home = 14.0%; in-office = 35.7%; p <0.05) (mean age: 37.3 years; 73.7% women; n = 171). At the second follow-up, two and three patients reported side effects...... attributed to the bleaching treatment in the at-home and in-office groups, respectively. Predictors for side effects were tooth sensitivity, surface loss and gingivitis when observed at inclusion. Treatment-related predictors were bleaching concentration and contact between tray and gingiva. Conclusions...

  9. Dental pulp stem cells as a multifaceted tool for bioengineering and the regeneration of craniomaxillofacial tissues

    OpenAIRE

    Aurrekoetxea, Maitane; Garcia-Gallastegui, Patricia; Irastorza, Igor; Luzuriaga, Jon; Uribe-Etxebarria, Verónica; Unda, Fernando; Ibarretxe, Gaskon

    2015-01-01

    Dental pulp stem cells, or DPSC, are neural crest-derived cells with an outstanding capacity to differentiate along multiple cell lineages of interest for cell therapy. In particular, highly efficient osteo/dentinogenic differentiation of DPSC can be achieved using simple in vitro protocols, making these cells a very attractive and promising tool for the future treatment of dental and periodontal diseases. Among craniomaxillofacial organs, the tooth and salivary gland are two such cases in wh...

  10. Dental Pulp Stem Cells as a multifaceted tool for bioengineering and the regeneration of craniomaxillofacial tissues

    OpenAIRE

    Maitane eAurrekoetxea; Patricia eGarcía-Gallastegui; Igor eIrastorza; Jon eLuzuriaga; Verónica eUribe-Etxebarria; Fernando eUnda; Gaskon eIbarretxe

    2015-01-01

    Dental pulp stem cells, or DPSC, are neural crest-derived cells with an outstanding capacity to differentiate along multiple cell lineages of interest for cell therapy. In particular, highly efficient osteo/dentinogenic differentiation of DPSC can be achieved using simple in vitro protocols, making these cells a very attractive and promising tool for the future treatment of dental and periodontal diseases. Among craniomaxillofacial organs, the tooth and salivary gland are two such cases in wh...

  11. Tooth loss and obstructive sleep apnoea

    Directory of Open Access Journals (Sweden)

    Gai Valerio

    2006-01-01

    Full Text Available Abstract Background Complete tooth loss (edentulism produces anatomical changes that may impair upper airway size and function. The aim of this study was to evaluate whether edentulism favours the occurrence of obstructive sleep apnoea (OSA. Methods Polysomnography was performed in 48 edentulous subjects on two consecutive nights, one slept with and the other without dentures. Upper airway size was assessed by cephalometry and by recording forced mid-inspiratory airflow rate (FIF50. Exhaled nitric oxide (eNO and oral NO (oNO, were measured as markers of airway and oropharyngeal inflammation. Results The apnoea/hypopnoea index (AHI without dentures was significantly higher than with dentures (17·4 ± 3·6 versus 11·0 ± 2·3. p = 0·002, and was inversely related to FIF50 (p = 0·017 and directly related to eNO (p = 0·042. Sleeping with dentures, 23 subjects (48% had an AHI over 5, consistent with OSA, but sleeping without dentures the number of subjects with abnormal AHI rose to 34 (71%. At cephalometry, removing dentures produced a significant decrease in retropharyngeal space (from 1·522 ± 0·33 cm to 1·27 ± 0·42 cm, p = 0·006. Both morning eNO and oNO were higher after the night slept without dentures (eNO 46·1 ± 8·2 ppb versus 33·7 ± 6·3 ppb, p = 0·035, oNO 84·6 ± 13·7 ppb versus 59·2 ± 17·4 ppb, p = 0·001. Conclusion These findings suggest that complete tooth loss favours upper airway obstruction during sleep. This untoward effect seems to be due to decrease in retropharyngeal space and is associated with increased oral and exhaled NO concentration.

  12. Development and microstructure of tooth histotypes in the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae) and the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae).

    Science.gov (United States)

    Moyer, Joshua K; Riccio, Mark L; Bemis, William E

    2015-07-01

    Elasmobranchs exhibit two distinct arrangements of mineralized tissues in the teeth that are known as orthodont and osteodont histotypes. Traditionally, it has been said that orthodont teeth maintain a pulp cavity throughout tooth development whereas osteodont teeth are filled with osteodentine and lack a pulp cavity when fully developed. We used light microscopy, scanning electron microscopy, and high-resolution micro-computed tomography to compare the structure and development of elasmobranch teeth representing the two histotypes. As an example of the orthodont histotype, we studied teeth of the blue shark, Prionace glauca (Carcharhiniformes: Carcharhinidae). For the osteodont histotype, we studied teeth of the great white shark, Carcharodon carcharias (Lamniformes: Lamnidae). We document similarities and differences in tooth development and the microstructure of tissues in these two species and review the history of definitions and interpretations of elasmobranch tooth histotypes. We discuss a possible correlation between tooth histotype and tooth replacement and review the history of histotype differentiation in sharks. We find that contrary to a long held misconception, there is no orthodentine in the osteodont teeth of C. carcharias. PMID:25845614

  13. Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Duk; Kim, Jin Soo; You, Choong Hyun [Chosun University College of Medicine, Kwangju (Korea, Republic of)

    2005-03-15

    To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

  14. Mesiodistal tooth angulation to segmental occlusal plane in panoramic radiography

    International Nuclear Information System (INIS)

    To evaluate the stability of the segmental occlusal plane and anatomical line as the reference line for measuring the mesiodistal tooth angulation in panoramic radiography and to determine the mean angle and the range of the mesiodistal tooth angulation in Korean population with normal occlusions. Twenty nine subjects (15 men, 14 women) with normal occlusion were selected. A total of 29 panoramic radiograms were taken at normal head position and then 10 images of 5 subjects selected were repeatedly taken with repositioning 2 times at each of the head down (V-shaped occlusion) and up (horizontal occulsion) for evaluation of stability of adopted reference lines by using PM2002CC (Planmeca, Finland). The images were traced with adoption of two test reference lines and the long axes of the teeth. The mesial angles formed by each reference line and the long axes of the teeth were measured and analyzed. With anatomical reference line, the mesiodistal tooth angulations of the molars showed the significant difference by over 5 degree between the normal and each changed head position. With segmented occlusal reference line, deviations of mesiodistal tooth angulations by the two changed head positions were less than 1 degree. The means, standard deviations, and maximum and minimum values of mesiodistal tooth angulations to segmental occlusal reference line on panoramic radiography were determined. It would appear that mesiodistal tooth angulations to segmental occlusal plane as reference line in panograms are predictable as standards of normal occlusion and useful for evaluation of tooth arrangement between adjacent teeth.

  15. ClC-7 Deficiency Impairs Tooth Development and Eruption.

    Science.gov (United States)

    Wang, He; Pan, Meng; Ni, Jinwen; Zhang, Yanli; Zhang, Yutao; Gao, Shan; Liu, Jin; Wang, Zhe; Zhang, Rong; He, Huiming; Wu, Buling; Duan, Xiaohong

    2016-01-01

    CLCN7 gene encodes the voltage gated chloride channel 7 (ClC-7) in humans. The mutations in CLCN7 have been associated with osteopetrosis in connection to the abnormal osteoclasts functions. Previously, we found that some osteopetrosis patients with CLCN7 mutations suffered from impacted teeth and root dysplasia. Here we set up two in vivo models under a normal or an osteoclast-poor environment to investigate how ClC-7 affects tooth development and tooth eruption. Firstly, chitosan-Clcn7-siRNA nanoparticles were injected around the first maxillary molar germ of newborn mice and caused the delay of tooth eruption and deformed tooth with root dysplasia. Secondly, E13.5 molar germs infected with Clcn7 shRNA lentivirus were transplanted under the kidney capsule and presented the abnormal changes in dentin structure, periodontal tissue and cementum. All these teeth changes have been reported in the patients with CLCN7 mutation. In vitro studies of ameloblasts, odontoblasts and dental follicle cells (DFCs) were conducted to explore the involved mechanism. We found that Clcn7 deficiency affect the differentiation of these cells, as well as the interaction between DFCs and osteoclasts through RANKL/OPG pathway. We conclude that ClC-7 may affect tooth development by directly targeting tooth cells, and regulate tooth eruption through DFC mediated osteoclast pathway. PMID:26829236

  16. Digital modeling technology for full dental crown tooth preparation.

    Science.gov (United States)

    Dai, Ning; Zhong, Yicheng; Liu, Hao; Yuan, Fusong; Sun, Yuchun

    2016-04-01

    A dental defect is one of the most common oral diseases, and it often requires a full crown restoration. In this clinical operation, the dentist must manually prepare the affected tooth for the full crown so that it has a convergence angle between 4° and 10°, no undercuts, and uniform and even shoulder widths and depths using a high speed diamond bur in the patient׳s mouth within one hour, which is a difficult task that requires visual-manual operation. The quality of the tooth preparation has an important effect on the success rate of the subsequent prosthodontic treatment. This study involved research into digital modeling technology for full dental crown tooth preparation. First, the margin line of the tooth preparation was designed using a semi-automatic interactive process. Second, the inserting direction was automatically computed. Then, the characteristic parameters and the constraints on the tooth preparation were defined for the model. Next, the shoulder and axial surface of the tooth preparation were formed using parametric modeling. Finally, the implicit surface of a radial basis function was used to construct the tooth preparation׳s occlusal surface. The experimental results verified that the method of digital modeling for full crown preparation proposed in this study can quickly and accurately implement personalized designs of various parameters, such as the shoulder width and the convergence angle; it provides a digital design tool for full crown preparation. PMID:26945598

  17. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications. PMID:26868932

  18. Iron replacement therapy

    DEFF Research Database (Denmark)

    Nielsen, Ole Haagen; Coskun, Mehmet; Weiss, Günter

    2016-01-01

    PURPOSE OF REVIEW: Approximately, one-third of the world's population suffers from anemia, and at least half of these cases are because of iron deficiency. With the introduction of new intravenous iron preparations over the last decade, uncertainty has arisen when these compounds should be...... administered and under which circumstances oral therapy is still an appropriate and effective treatment. RECENT FINDINGS: Numerous guidelines are available, but none go into detail about therapeutic start and end points or how iron-deficiency anemia should be best treated depending on the underlying cause of...... iron deficiency or in regard to concomitant underlying or additional diseases. SUMMARY: The study points to major issues to be considered in revisions of future guidelines for the true optimal iron replacement therapy, including how to assess the need for treatment, when to start and when to stop...

  19. Multiple essential MT1-MMP functions in tooth root formation, dentinogenesis, and tooth eruption.

    Science.gov (United States)

    Xu, H; Snider, T N; Wimer, H F; Yamada, S S; Yang, T; Holmbeck, K; Foster, B L

    2016-01-01

    Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a transmembrane zinc-endopeptidase that breaks down extracellular matrix components, including several collagens, during tissue development and physiological remodeling. MT1-MMP-deficient mice (MT1-MMP(-/-)) feature severe defects in connective tissues, such as impaired growth, osteopenia, fibrosis, and conspicuous loss of molar tooth eruption and root formation. In order to define the functions of MT1-MMP during root formation and tooth eruption, we analyzed the development of teeth and surrounding tissues in the absence of MT1-MMP. In situ hybridization showed that MT1-MMP was widely expressed in cells associated with teeth and surrounding connective tissues during development. Multiple defects in dentoalveolar tissues were associated with loss of MT1-MMP. Root formation was inhibited by defective structure and function of Hertwig's epithelial root sheath (HERS). However, no defect was found in creation of the eruption pathway, suggesting that tooth eruption was hampered by lack of alveolar bone modeling/remodeling coincident with reduced periodontal ligament (PDL) formation and integration with the alveolar bone. Additionally, we identified a significant defect in dentin formation and mineralization associated with the loss of MT1-MMP. To segregate these multiple defects and trace their cellular origin, conditional ablation of MT1-MMP was performed in epithelia and mesenchyme. Mice featuring selective loss of MT1-MMP activity in the epithelium were indistinguishable from wild type mice, and importantly, featured a normal HERS structure and molar eruption. In contrast, selective knock-out of MT1-MMP in Osterix-expressing mesenchymal cells, including osteoblasts and odontoblasts, recapitulated major defects from the global knock-out including altered HERS structure, short roots, defective dentin formation and mineralization, and reduced alveolar bone formation, although molars were able to erupt. These data

  20. Functional constraints on tooth morphology in carnivorous mammals

    Directory of Open Access Journals (Sweden)

    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.

  1. Tooth loss prevalence among cardiac males and females

    International Nuclear Information System (INIS)

    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)

  2. The effect of felled tree stems as bio-engineering type rockfall protection

    Science.gov (United States)

    Bigot, Christophe; Bourrier, Franck; Berger, Frederic; Dorren, Luuk; Astrade, Laurent

    2010-05-01

    In mountainous regions forested slopes play an important protective role against rockfall. Up to now, most of the researches on rockfall protection forest have been and are focused on the dissipative effect of standing and living trees. There are hardly any studies on the protective capacity of tree stumps and lying stems against snow avalanches and rockfalls. Although, these techniques are more and more used throughout the Alps. In Austria, the felling technique Alpi has been developed, which allows a specialised lumberjack to create small rockfall barriers using one or two tree stems anchored on high tree stumps. Lying tree stems can be then used to increase efficiently the roughness of the soil and so to limit or avoid triggering and propagation falling rocks. But, due to the wood decay, the efficiency of such bio-engineering type protective works is decreasing with time. One of the questions that the forest and natural hazard managers have to answer is: what is the lifetime of such protective structures? In order to answer to this question we have developed a specific research on this thematic. The main objectives of this research program are to quantify the efficacy of these bio-engineering type rockfall fences depending on their characteristics (stump and stems density, position on the slope, tree species, etc.), and to evaluate their resistance over time. To achieve these objectives we have developed two types of experiments. The first one, performed during the summer 2009 on our experimental site test of Vaujany (France), are full scale rockfall experiments on four felled trees, which have been anchored on their stumps and are lying in an oblique direction to the slope. In total, fifty rocks (from 522 at 2242 kg) have been released one by one. For each rock, the trajectory has been filmed with high speed digital cameras. The second type of experiment is the uprooting of tree stumps (spruce, fir and beech) of different ages and diameter. To uproot the stumps

  3. Effect of Cervical Lessions on the Tooth FEM Study

    Directory of Open Access Journals (Sweden)

    Gabriela Bereşescu

    2010-12-01

    Full Text Available The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method study on the results of a mechanical analysis of the phenomena involving the tooth damaged by cervical lesions.

  4. Study on differences of radiosensitivity of human tooth enamel

    International Nuclear Information System (INIS)

    To study differences of radiosensitivity of human tooth enamel, 84 tooth enamel samples from 5 subjects were separated, and irradiated with radiation dose of 5 Gy from 60Co γ rays. After irradiation each sample was measured by ESR technique. Experimental results indicate that some difference in radiosensitivity exists for teeth from each subject (coefficients of variation of each subject range from 9.3% to 14.0%). Nevertheless, the mean values for all teeth of each subject among 5 subjects agree within the range of 325.77 to 386.80. It shows that the radiosensitivity of tooth enamel is basically uniform

  5. Tooth brushing among 11- to 15-year-olds in Denmark

    DEFF Research Database (Denmark)

    Bast, L. S.; Nordahl, H.; Christensen, L. B.;

    2015-01-01

    OBJECTIVE: Regular tooth brushing in adolescence predicts stable tooth brushing habits later in life. Differences in tooth brushing habits by ethnic background and socioeconomic position have been suggested. We investigated migration status and social class in relation to infrequent tooth brushing...

  6. Effect of partial replacement of sugar with stevia on the quality of kulfi.

    Science.gov (United States)

    Giri, Apurba; Rao, H G Ramachandra; V, Ramesh

    2014-08-01

    Stevia is a natural sweetener obtained from the leaf of Stevia rebaudiana plant. Its refined extract powder is 130-300 times sweeter than sucrose. Besides, it prevents diabetes, decreases weight, prevents tooth decay, increases digestion etc. Dietetic kulfi was produced, in which 50, 60 and 70% sugar was replaced with 0.05, 0.06 and 0.07% refined stevia extract powder respectively. At higher levels of sugar replacement there was a significant decrease in specific gravity, melting rate, carbohydrate percentage and total calorie content and a significant increase in freezing point, hardness and fat, protein, ash and moisture percentage. Kulfi prepared by replacing half the sugar content with stevia was adjudged on par with the control in sensory characteristics. Above 50% sugar replacement resulted in bitterness, lack of brownish appearance and presence of icy texture. PMID:25114356

  7. Restoration of badlands through applying bio-engineering techniques in active gully systems: Evidence from the Ecuadorian Andes

    Science.gov (United States)

    Borja, P.; Vanacker, V.; Alvarado, D.; Govers, G.

    2012-04-01

    A better insight in the processes controlling sediment generation, transport and deposition in badlands is necessary to enhance restoration of degraded soils through eco-engineering techniques. In this study, we evaluate the effect of different bio-engineering measures on soil and slope stability. Five micro-catchments (of 0.2 to 5 ha) were selected within a 3 km2 area in the lower part of the Loreto catchment (Southern Ecuadorian Andes). The micro-catchments differ only by land cover and degree of implementation of soil and water conservation measures. Bio-engineering techniques were used to construct dikes made of fascines of wooden sticks and earth-filled tires in active gully beds, where they are most efficient to reduce water and sediment transport. The experimental design consists of three micro-catchments within highly degraded lands: (DI) micro-catchment with bio-engineering measures concentrated in the active gully beds, (DF) with reforestation of Eucalyptus trees, and (DT) reference situation without any conservation measures. Two micro-catchments were monitored in agricultural lands with (AI) and without (AT) bio-engineering measures in the active gully beds. All catchments were equipped with San Dimas flumes to measure water flow, and sediment traps to monitor sediment export. In the (active) gully beds, various parameters related to gully stability (soil water content, bed elevation, vegetation cover, sedimentation/erosion) were monitored at weekly intervals. First results show that bio-engineering techniques are efficient to stabilize active gully beds through a reduction of the rapid concentration of excess rainfall and the sediment production and transfer. Fascines made of wooden sticks are far more efficient than earth-filled tires. Sediment deposition behind dikes is strongly dependent on precedent rainfall events, and the slope and vegetation cover of the gully floor. The sediment deposited facilitates colonization of the gully floor by native

  8. EFFICIENCY OF SIMPLE SUPER PHOSPHATE IN THE VETIVER GRASS DEVELOPMENT SUBJECTED TO SOIL BIOENGINEERING

    Directory of Open Access Journals (Sweden)

    RENISSON NEPONUCENO DE ARAÚJO FILHO

    2015-01-01

    Full Text Available The development of vetiver grass (Chrysopogon zizanioides L. has been evaluated under differ-ent levels of phosphorus on slopes of the right-side bank of the San Francisco River, in the municipality of Am-paro do São Francisco, SE. Techniques of soil bioengineering were used, characterized by the combination of vegetated riprap with stakes, seedlings of vetiver grass and sediment retainers. The experimental design was randomized blocks with five doses (0, 4, 8, 12, and 16 g pit-1 of simple superphosphate and five replicates. The growth of vetiver seedlings were observed in periods of 30, 60, 90, e 180 days, carrying out the following pa-rameters: number of roots, external root surface, root density, root length, root length density, root and shoot dry weight, root and shoot fresh weight, and shoot length, at each evaluation period. The phosphorus doses and periods of morphological development interacted in all variables of plant biomass mentioned above. Higher superphosphate doses than 9.0 g pit-1 did not offer advantages in terms of cost-benefit for the production of vetiver seedings.

  9. Laboratory-scale production of 13C-labeled lycopene and phytoene by bioengineered Escherichia coli.

    Science.gov (United States)

    Lu, Chi-Hua; Choi, Jin-Ho; Engelmann Moran, Nancy; Jin, Yong-Su; Erdman, John W

    2011-09-28

    Consumption of tomato products has been associated with decreased risks of chronic diseases such as cardiovascular disease and cancer, and therefore the biological functions of tomato carotenoids such as lycopene, phytoene, and phytofluene are being investigated. To study the absorption, distribution, metabolism, and excretion of these carotenoids, a bioengineered Escherichia coli model was evaluated for laboratory-scale production of stable isotope-labeled carotenoids. Carotenoid biosynthetic genes from Enterobacter agglomerans were introduced into the BL21Star(DE3) strain to yield lycopene. Over 96% of accumulated lycopene was in the all-trans form, and the molecules were highly enriched with 13C by 13C-glucose dosing. In addition, error-prone PCR was used to disrupt phytoene desaturase (crtI) function and create a phytoene-accumulating strain, which was also found to maintain the transcription of phytoene synthase (crtB). Phytoene molecules were also highly enriched with 13C when the 13C-glucose was the only carbon source. The development of this production model will provide carotenoid researchers a source of labeled tracer materials to further investigate the metabolism and biological functions of these carotenoids. PMID:21888370

  10. Study of bioengineered zebra fish olfactory receptor 131-2: receptor purification and secondary structure analysis.

    Directory of Open Access Journals (Sweden)

    Kwong-Joo Leck

    Full Text Available How fishes are able to detect trace molecules in large bodies of water is not understood. It is plausible that they use olfactory receptors to detect water-soluble compounds. How the zebra fish Danio Rerio, an organism with only 98 functional olfactory receptors, is able to selectively detect and recognize numerous compounds in water remains a puzzling phenomenon. We are interested in studying the biochemical and molecular mechanisms of olfaction in fish. Here, we report on the study of a bioengineered zebra fish olfactory receptor OR131-2, affinity-purified from a HEK293S tetracycline-inducible system. This receptor was expressed and translocated to the cell plasma membrane as revealed by confocal microscopy. Circular dichroism spectroscopy showed that the purified zebra fish receptor folded into an α-helical structure, as observed for other G-protein coupled receptors (GPCRs. Our study shows that it is possible to produce viable quantities of the zebra fish olfactory receptor. This will not only enable detailed structural and functional analyses, but also aid in the design of biosensor devices in order to detect water-soluble metabolites or its intermediates, which are associated with human health.

  11. Scorpion Toxins Specific for Potassium (K+ Channels: A Historical Overview of Peptide Bioengineering

    Directory of Open Access Journals (Sweden)

    Zachary L. Bergeron

    2012-11-01

    Full Text Available Scorpion toxins have been central to the investigation and understanding of the physiological role of potassium (K+ channels and their expansive function in membrane biophysics. As highly specific probes, toxins have revealed a great deal about channel structure and the correlation between mutations, altered regulation and a number of human pathologies. Radio- and fluorescently-labeled toxin isoforms have contributed to localization studies of channel subtypes in expressing cells, and have been further used in competitive displacement assays for the identification of additional novel ligands for use in research and medicine. Chimeric toxins have been designed from multiple peptide scaffolds to probe channel isoform specificity, while advanced epitope chimerization has aided in the development of novel molecular therapeutics. Peptide backbone cyclization has been utilized to enhance therapeutic efficiency by augmenting serum stability and toxin half-life in vivo as a number of K+-channel isoforms have been identified with essential roles in disease states ranging from HIV, T-cell mediated autoimmune disease and hypertension to various cardiac arrhythmias and Malaria. Bioengineered scorpion toxins have been monumental to the evolution of channel science, and are now serving as templates for the development of invaluable experimental molecular therapeutics.

  12. Teaching statics of fluids in bioengineering: a multidisciplinary proposal based on competences

    Science.gov (United States)

    Alborch, A.; Puzzella, A.; Lopez, N.; Cabrera, L.; Zabala, A.; Demartini, H.

    2007-11-01

    The aim of this work is to share the findings of an educational experience undertaken by first-year university students of bioengineering, oriented towards the model of Competence-based Education. Different aspects on integrative education pursued in the subject goals are explicitly focused here by designing a strategy within a contextualized and multidisciplinary approach that combines knowledge from Physics, Chemistry and Biology. The topic chosen for the work is Static of Fluids, because it allows relating pressure to its biological effects on human beings. After evaluating a pre-test, new interrelated strategies are implemented. Due to the motivation audiovisuals generate in adolescents, we start showing an argumentative film entitled 'The Big Blue', and continue with different individual and/or group activities, finishing with a post-test to assess the development of the competences proposed. Results are encouraging as regards the level of specific competences acquired and, complementarily, basic and professional competences in general. Besides, the experience met expectations as regards student motivation, interest and commitment to learning, which ensured the path taken by the academicians by means of implementing innovative strategies.

  13. Teaching statics of fluids in bioengineering: a multidisciplinary proposal based on competences

    International Nuclear Information System (INIS)

    The aim of this work is to share the findings of an educational experience undertaken by first-year university students of bioengineering, oriented towards the model of Competence-based Education. Different aspects on integrative education pursued in the subject goals are explicitly focused here by designing a strategy within a contextualized and multidisciplinary approach that combines knowledge from Physics, Chemistry and Biology. The topic chosen for the work is Static of Fluids, because it allows relating pressure to its biological effects on human beings. After evaluating a pre-test, new interrelated strategies are implemented. Due to the motivation audiovisuals generate in adolescents, we start showing an argumentative film entitled 'The Big Blue', and continue with different individual and/or group activities, finishing with a post-test to assess the development of the competences proposed. Results are encouraging as regards the level of specific competences acquired and, complementarily, basic and professional competences in general. Besides, the experience met expectations as regards student motivation, interest and commitment to learning, which ensured the path taken by the academicians by means of implementing innovative strategies

  14. Mentoring by design: integrating medical professional competencies into bioengineering and medical physics graduate training.

    Science.gov (United States)

    Woods, Kendra V; Peek, Kathryn E; Richards-Kortum, Rebecca

    2014-12-01

    Many students in bioengineering and medical physics doctoral programs plan careers in translational research. However, while such students generally have strong quantitative abilities, they often lack experience with the culture, communication norms, and practice of bedside medicine. This may limit students' ability to function as members of multidisciplinary translational research teams. To improve students' preparation for careers in cancer translational research, we developed and implemented a mentoring program that is integrated with students' doctoral studies and aims to promote competencies in communication, biomedical ethics, teamwork, altruism, multiculturalism, and accountability. Throughout the program, patient-centered approaches and professional competencies are presented as foundational to optimal clinical care and integral to translational research. Mentoring is conducted by senior biomedical faculty and administrators and includes didactic teaching, online learning, laboratory mini-courses, clinical practicums, and multidisciplinary patient planning conferences (year 1); student development and facilitation of problem-based patient cases (year 2); and individualized mentoring based on research problems and progress toward degree completion (years 3-5). Each phase includes formative and summative evaluations. Nineteen students entered the program from 2009 through 2011. On periodic anonymous surveys, the most recent in September 2013, students indicated that the program substantially improved their knowledge of cancer biology, cancer medicine, and academic medicine; that the mentors were knowledgeable, good teachers, and dedicated to students; and that the program motivated them to become well-rounded scientists and scholars. We believe this program can be modified and disseminated to other graduate research and professional health care programs. PMID:24585385

  15. Characteristics of Four Plant Species Used for Soil Bioengineering Techniques in River Bank Stabilization

    Science.gov (United States)

    Liu, Y.; Gao, J. R.; Lou, H. P.; Zhang, J. R.; Rauch, H. P.

    2010-05-01

    Use the potential values of soil bioengineering techniques are important for the wide attention river ecological restoration works in Beijing. At first, demand for basic knowledge of the technical and biological properties of plants is essential for development of such techniques. Species for each chosen plant material type should be selected with an emphasis on the following: suitability for anticipated environment conditions, reasonable availability in desired quantity and probability of successful establishment. Account on these criteria, four species which used as live staking and rooted cutting techniques were selected, namely, Salix X aureo-pendula, Salix cheilophila, Vitex negundo var. heterophylla and Amorpha fruticosa L.. And monitoring work was performed on three construction sites of Beijing. Various survival rates and morphological parameters data were collected. Concerning plants hydraulic and hydrological behavior, bending tests were used to analysis the flexibility of each plant species. The results from rate and morphological parameters monitoring show that: Salix cheilophila performed the best. Other three plants behaved satisfactorily in shoots or roots development respectively. In the bending test mornitoring, Salix cheilophila branch had the least broken number. Then were Salix X aureo-pendula and Amorpha fruticosa L.. Vitex negundo var. branch had the highest broken number, but it tolerated the highest amount of stress. All plant species should be considered in the future scientific research and construction works in Beijing. Keywords: River bank stabilization, live staking, rooted cutting

  16. Photosynthetic biomass and H2 production by green algae: from bioengineering to bioreactor scale-up.

    Science.gov (United States)

    Hankamer, Ben; Lehr, Florian; Rupprecht, Jens; Mussgnug, Jan H; Posten, Clemens; Kruse, Olaf

    2007-09-01

    The development of clean borderless fuels is of vital importance to human and environmental health and global prosperity. Currently, fuels make up approximately 67% of the global energy market (total market = 15 TW year(-1)) (Hoffert et al. 1998). In contrast, global electricity demand accounts for only 33% (Hoffert et al. 1998). Yet, despite the importance of fuels, almost all CO(2) free energy production systems under development are designed to drive electricity generation (e.g. clean-coal technology, nuclear, photovoltaic, wind, geothermal, wave and hydroelectric). In contrast, and indeed almost uniquely, biofuels also target the much larger fuel market and so in the future will play an increasingly important role in maintaining energy security (Lal 2005). Currently, the main biofuels that are at varying stages of development include bio-ethanol, liquid carbohydrates [e.g. biodiesel or biomass to liquid (BTL) products], biomethane and bio-H(2). This review is focused on placing bio-H(2) production processes into the context of the current biofuels market and summarizing advances made both at the level of bioengineering and bioreactor design. PMID:18251920

  17. Microalgal bioengineering for sustainable energy development: Recent transgenesis and metabolic engineering strategies.

    Science.gov (United States)

    Banerjee, Chiranjib; Singh, Puneet Kumar; Shukla, Pratyoosh

    2016-03-01

    Exploring the efficiency of algae to produce remarkable products can be directly benefitted by studying its mechanism at systems level. Recent advents in biotechnology like flux balance analysis (FBA), genomics and in silico proteomics minimize the wet lab exertion. It is understood that FBA predicts the metabolic products, metabolic pathways and alternative pathway to maximize the desired product, and these are key components for microalgae bio-engineering. This review encompasses recent transgenesis techniques and metabolic engineering strategies applied to different microalgae for improving different traits. Further it also throws light on RNAi and riboswitch engineering based methods which may be advantageous for high throughput microalgal research. A valid and optimally designed microalga can be developed where every engineering strategies meet each other successfully and will definitely fulfill the market needs. It is also to be noted that Omics (viz. genetic and metabolic manipulation with bioinformatics) should be integrated to develop a strain which could prove to be a futuristic solution for sustainable development for energy. PMID:26844808

  18. A novel process for obtaining pinosylvin using combinatorial bioengineering in Escherichia coli.

    Science.gov (United States)

    Liang, Jing-Long; Guo, Li-Qiong; Lin, Jun-Fang; He, Ze-Qi; Cai, Fa-Ji; Chen, Jun-Fei

    2016-06-01

    Pinosylvin as a bioactive stilbene is of great interest for food supplements and pharmaceuticals development. In comparison to conventional extraction of pinosylvin from plant sources, biosynthesis engineering of microbial cell factories is a sustainable and flexible alternative method. Current synthetic strategies often require expensive phenylpropanoic precursor and inducer, which are not available for large-scale fermentation process. In this study, three bioengineering strategies were described to the development of a simple and economical process for pinosylvin biosynthesis in Escherichia coli. Firstly, we evaluated different construct environments to give a highly efficient constitutive system for enzymes of pinosylvin pathway expression: 4-coumarate: coenzyme A ligase (4CL) and stilbene synthase (STS). Secondly, malonyl coenzyme A (malonyl-CoA) is a key precursor of pinosylvin bioproduction and at low level in E. coli cell. Thus clustered regularly interspaced short palindromic repeats interference (CRISPRi) was explored to inactivate malonyl-CoA consumption pathway to increase its availability. The resulting pinosylvin content in engineered E. coli was obtained a 1.9-fold increase depending on the repression of fabD (encoding malonyl-CoA-ACP transacylase) gene. Eventually, a phenylalanine over-producing E. coli consisting phenylalanine ammonia lyase was introduced to produce the precursor of pinosylvin, trans-cinnamic acid, the crude extraction of cultural medium was used as supplementation for pinosylvin bioproduction. Using these combinatorial processes, 47.49 mg/L pinosylvin was produced from glycerol. PMID:27116968

  19. Surface modification of electrospun PLGA scaffold with collagen for bioengineered skin substitutes.

    Science.gov (United States)

    Sadeghi, A R; Nokhasteh, S; Molavi, A M; Khorsand-Ghayeni, M; Naderi-Meshkin, H; Mahdizadeh, A

    2016-09-01

    In skin tissue engineering, surface feature of the scaffolds plays an important role in cell adhesion and proliferation. In this study, non-woven fibrous substrate based on poly (lactic-co-glycolic acid) (PLGA) (75/25) were hydrolyzed in various concentrations of NaOH (0.05N, 0.1N, 0.3N) to increase carboxyl and hydroxyl groups on the fiber surfaces. These functional groups were activated by EDC/NHS to create chemical bonding with collagen. To improve bioactivity, the activated substrates were coated with a collagen solution (2mg/ml) and cross-linking was carried out using the EDC/NHS in MES buffer. The effectiveness of the method was evaluated by contact angle measurements, porosimetry, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), tensile and degradation tests as well as in vitro cell attachment and cytotoxicity assays. Cell culture results of human dermal fibroblasts (HDF) and keratinocytes cell line (HaCat) revealed that the cells could attach to the scaffold. Further investigation with MTT assay showed that the cell proliferation of HaCat significantly increases with collagen coating. It seems that sufficient stability of collagen on the surface due to proper chemical bonding and cross-linking has increased the bioactivity of surface remarkably which can be promising for bioengineered skin applications. PMID:27207046

  20. Bioengineering of carbon fixation, biofuels, and biochemicals in cyanobacteria and plants.

    Science.gov (United States)

    Rosgaard, Lisa; de Porcellinis, Alice Jara; Jacobsen, Jacob H; Frigaard, Niels-Ulrik; Sakuragi, Yumiko

    2012-11-30

    Development of sustainable energy is a pivotal step towards solutions for today's global challenges, including mitigating the progression of climate change and reducing dependence on fossil fuels. Biofuels derived from agricultural crops have already been commercialized. However the impacts on environmental sustainability and food supply have raised ethical questions about the current practices. Cyanobacteria have attracted interest as an alternative means for sustainable energy productions. Being aquatic photoautotrophs they can be cultivated in non-arable lands and do not compete for land for food production. Their rich genetic resources offer means to engineer metabolic pathways for synthesis of valuable bio-based products. Currently the major obstacle in industrial-scale exploitation of cyanobacteria as the economically sustainable production hosts is low yields. Much effort has been made to improve the carbon fixation and manipulating the carbon allocation in cyanobacteria and their evolutionary photosynthetic relatives, algae and plants. This review aims at providing an overview of the recent progress in the bioengineering of carbon fixation and allocation in cyanobacteria; wherever relevant, the progress made in plants and algae is also discussed as an inspiration for future application in cyanobacteria. PMID:22677697

  1. Enhanced Prediction of Gear Tooth Surface Fatigue Life Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sentient will develop an enhanced prediction of gear tooth surface fatigue life with rigorous analysis of the tribological phenomena that contribute to pitting...

  2. Molar tooth sign − looking beyond the obvious

    Directory of Open Access Journals (Sweden)

    Nasreen Mahomed

    2013-08-01

    Full Text Available The molar tooth sign was initially identified in Joubert syndrome, named after Marie Joubert who first described it in 1968 as a rare autosomal recessive disorder characterised by the neuroradiological hallmark of the molar tooth sign caused by cerebellar vermian hypoplasia. Subsequently, it emerged that the molar tooth sign encompasses many syndromes that are now grouped together and termed Joubert syndrome and related disorders (JSRDs. Knowledge of the newer classification system and the subtypes is important and helps to direct and interpret imaging studies based on clinical signs so as to avoid delay in diagnosis of the hepatic oculorenal and renal subtypes of JSRDs in patients in whom the molar tooth sign is identified on brain MRI.

  3. Patient Discomfort Following Single-Tooth Implant Placement

    DEFF Research Database (Denmark)

    Spin-Neto, Rubens; Pontes, Ana Emília Farias; Wenzel, Ann;

    2014-01-01

    Aims: Evaluate postoperative discomfort (pain, bleeding and swelling) in single-tooth implant patients submitted to immediate or conventional tooth restoration together with assessment of treatment time. Methods: Twenty-four patients who received single-tooth maxillary dental implants were randomly...... assigned to an IR (Immediate Restoration) or CR (Conventional Restoration) group. In IR, an implant was inserted and a provisional tooth crown was delivered within the same session, while in CR it was delivered three months after implantation. Pain (first three days), bleeding (first day) and swelling...... (first seven days) were assessed using a questionnaire with Visual Analogue Scales (VAS). Results: Treatment time was longer for IR than for CR (57 ± 14 and 33 ± 8 min, respectively; ppain, bleeding, and swelling were low for both groups at the first postoperative day. VAS...

  4. Ectopic 3rd Molar Tooth in the Maxillary Antrum

    Directory of Open Access Journals (Sweden)

    Seidu A. Bello

    2014-01-01

    Full Text Available Location of ectopic tooth in a nondentate area like the maxillary antrum is rare. A 17-year-old boy, with one year history of recurrent right facial swelling and radiographic finding of a maxillary third molar tooth located at the posterior wall of the maxillary antrum, is presented. Under endotracheal intubation, the tooth was extracted through a Caldwell-Luc antrostomy approach and patient had an uneventful recovery and has been symptom free for eight months. Ectopic tooth in the maxillary antrum is rare and is commonest with maxillary third molar. It may be symptomless but is more commonly associated with inflammatory symptoms. The treatment of choice is surgical excision which is mostly carried out with Caldwell-Luc approach, even though endoscopic approach is being reported.

  5. Making a tooth: growth factors, transcription factors, and stem cells

    Institute of Scientific and Technical Information of China (English)

    Yah Ding ZHANG; Zhi CHEN; Yi Qiang SONG; Chao LIU; Yi Ping CHEN

    2005-01-01

    Mammalian tooth development is largely dependent on sequential and reciprocal epithelial-mesenchymal interactions.These processes involve a series of inductive and permissive interactions that result in the determination, differentiation,and organization of odontogenic tissues. Multiple signaling molecules, including BMPs, FGFs, Shh, and Wnt proteins,have been implicated in mediating these tissue interactions. Transcription factors participate in epithelial-mesenchymal interactions via linking the signaling loops between tissue layers by responding to inductive signals and regulating the expression of other signaling molecules. Adult stem cells are highly plastic and multipotent. These cells including dental pulp stem cells and bone marrow stromal cells could be reprogrammed into odontogenic fate and participated in tooth formation. Recent progress in the studies of molecular basis of tooth development, adult stem cell biology, and regeneration will provide fundamental knowledge for the realization of human tooth regeneration in the near future.

  6. Genetics Home Reference: Charcot-Marie-Tooth disease

    Science.gov (United States)

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Charcot-Marie-Tooth disease Charcot- ...

  7. Retrospective individual dosimetry using EPR of tooth enamel

    International Nuclear Information System (INIS)

    The results of joint investigations (in the framework of ECP-10 program) aimed on the improvement of the sensitivity and accuracy of the procedure of dose measurement using tooth enamel EPR spectroscopy are presented. It is shown, what the sensitivity of method may be increased using special physical-chemical procedure of the enamel samples treatment, which leads to the reducing of EPR signal of organic components in enamel. Tooth diseases may have an effect on radiation sensitivity of enamel. On the basis of statistical analysis of the results of more then 2000 tooth enamel samples measurements it was shown, what tooth enamel EPR spectroscopy gives opportunity to register contribution into total dose, which is caused by natural environmental radiation and by radioactive contamination. EPR response of enamel to ultraviolet exposure is investigated and possible influences to EPR dosimetry is discussed. The correction factors for EPR dosimetry in real radiation fields are estimated

  8. ROLE OF BACTERIA IN THE TOOTH ABSCESS: A MINI REVIEW

    Directory of Open Access Journals (Sweden)

    Biswajit Batabyal

    2013-02-01

    Full Text Available A tooth abscess or root abscess is pus enclosed in the tissues of the jaw bone at the apex of an infected tooth's root(s. Usually the abscess originates from a bacterial infection that has accumulated in the soft, often dead, pulp of the tooth. This can be caused by untreated tooth decay, cracked teeth or extensive periodontal disease. A failed root canal treatment may also create a similar abscess. Recently developed molecular methods have made it possible to characterise mixed micro flora in their entirety, including the substantial numbers of uncultivable bacteria. This paper will review the current literature regarding the molecular techniques used to identify uncultivable bacteria from dental abscess.

  9. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala O; Bardow, Allan; Hertz, Jens Michael; Nielsen, Lis A; Kreiborg, Sven

    2007-01-01

    first to elaborate on anomalies of tooth formation found in a group of hemizygous males and heterozygous females with known ED1 mutations. These tooth anomalies may be used as dental biomarkers for heterozygous females, enabling an earlier diagnosis, and therefore, better treatment and genetic...... counselling. METHODS: Anomalies of tooth formation were examined using panoramic radiographs, dental casts and oral photographs in hemizygous males and heterozygous females who were identified by molecular genetic analysis. The results were compared to existing controls and normative data. RESULTS: All......, especially in the mesiodistal dimension. CONCLUSIONS: We conclude that observed anomalies of tooth formation may be used as dental biomarkers in the clinical identification of potentially heterozygous females. Udgivelsesdato: 2007-Jan...

  10. Atraumatic surgical extrusion to improve tooth restorability: A clinical report.

    Science.gov (United States)

    Kelly, Robert D; Addison, Owen; Tomson, Phillip L; Krastl, Gabriel; Dietrich, Thomas

    2016-06-01

    This clinical report describes the use of an "atraumatic" vertical extraction system to facilitate the restorative treatment of a tooth that would otherwise be considered unrestorable because of subgingival caries. Minimally invasive surgical root extrusion was undertaken using the Benex extraction system, which can provide controlled tooth extrusion with minimal deformation of the bone socket. A carious endodontically treated mandibular premolar was extruded to provide routine restorative treatment and endodontic retreatment. PMID:26803176

  11. Inflammatory side effects associated with orthodontic tooth movement

    OpenAIRE

    Giannopoulou, Catherine

    2009-01-01

    Orthodontic tooth movement is induced my mechanical stimuli and facilitated by the remodeling of the periodontal ligament and alveolar bone. The remodeling activities and the ultimately tooth displacement are the consequence of an inflammatory process. Vascular and cellular changes were the first events to be recognized and described. With the advancement of research techniques an important number of inflammatory mediators, growth factors, neuropeptides and metabolites of arachidonic acid hav...

  12. Cell adhesion molecules during odontogenesis and tooth-related diseases

    OpenAIRE

    Heymann, Robert

    2002-01-01

    Cell adhesion molecules play essential roles in the development and disease of tooth and oral structures, as well as in the maintenance of adult tissue structure/function. It has been shown that different types of cell adhesion molecules (CAMs) play an important part in craniofacial development when ectomesenchymal cells migrate from the neural list to the primitive oral cavity, giving rise to the palatal processes and tooth germs. The role of CAMs in craniofacial developmen...

  13. Role of Homeobox Genes in Tooth Morphogenesis: A Review

    OpenAIRE

    Suryadeva, Sreevalli; Khan, Mohammadi Begum

    2015-01-01

    In oral cavity, disturbances due to genetic alterations may range from lack of tooth development to morphological defects. Due to technical advances in genetic engineering and molecular biology, valuable information regarding dentofacial growth could be studied in detailed manner. This helped us to explain the aetiology and pathogenesis of many dentofacial disorders. The success in treatment lies first in determining the aetiology of tooth anomalies and finally differentiating the effect of g...

  14. Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

    International Nuclear Information System (INIS)

    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

  15. Modification of tooth development by heat shock protein 60

    OpenAIRE

    Papp Tamás; Polyák Angéla; Papp Krisztina; Mészár Zoltán (1977-) (állatorvos); Zákány Róza (1963-) (anatómus-, kötőszövetbiológus); Mészár-Katona Éva (1986-) (Ph.D hallgató); Terdik Tünde (1969-) (analitikus); Chang, Hwa Ham; Felszeghy Szabolcs Béla (1972-) (fogorvos, anatómus, kötőszövetbiológus)

    2016-01-01

    Although several heat shock proteins have been investigated in relation to tooth development, no available information is available about the spatial and temporal expression pattern of heat shock protein 60 (Hsp 60). To characterize Hsp 60 expression in the structures of the developing tooth germ, we used Western blotting, immunohistochemistry and in situ hybridization. Hsp 60 was present in high amounts in the inner and outer enamel epithelia, enamel knot (EK) and stratum intermedium (SI). H...

  16. Treatment of Necrotic Calcified Tooth Using Intentional Replantation Procedure

    OpenAIRE

    Nima Moradi Majd; Armita Arvin; Alireza Darvish; Sareh Aflaki; Hamed Homayouni

    2014-01-01

    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 extrac...

  17. Interdisciplinary Treatment of a Fused Lower Premolar with Supernumerary Tooth

    OpenAIRE

    Gadimli, Cengiz; Sari, Zafer

    2011-01-01

    The objective of this report is to describe combined orthodontic and endodontic treatment of a fused mandibular premolar with supernumerary tooth. The patient was a 15 year old girl seeking orthodontic treatment for the correction of maxillary and mandibular crowding. Cephalometric examination revealed skeletally Class I relationship. The panoramic radiograph showed a fused tooth with two separate pulp chambers and two separate root canals connecting in apical third. After the endodontic trea...

  18. The Prevalence and Treatment Outcomes of Primary Tooth Injuries

    OpenAIRE

    Arikan, Volkan; Sari, Saziye; Sonmez, Hayriye

    2010-01-01

    Objectives: The aim of the present study was to evaluate the type and prevalence of primary tooth injuries, as well as their treatment and treatment outcomes, among children referred to the Department of Pedodontics at the Ankara University Faculty of Dentistry in Turkey. Methods: The study population consisted of patients applying to the department with a primary tooth injury over a period of 21 months. Fifty-one patients presented with trauma to 99 primary teeth. Clinical and radiographic e...

  19. Retrieval and reattachment of an elusive tooth fragment

    OpenAIRE

    Savita Sangwan; Shivani Mathur; Samir Dutta

    2011-01-01

    Traumatic dental injuries of uncomplicated nature are a common finding and upper central incisors are the most commonly affected teeth. Sometimes, the fractured fragment or the tooth gets embedded in the surrounding soft tissues and is often missed. There are few case reports regarding the retrieval and reattachment of tooth fragment. This report presents the case of an 8-year-old girl who came with the chief complaint of pain, irritation, and tingling sensation in the lower lip since one yea...

  20. Two Mathematical Models for Generation of Crowned Tooth Surface

    OpenAIRE

    Laszlo Kelemen; Jozsef Szente

    2014-01-01

    Gear couplings are mechanical components to connect shaft ends and eliminate the misalignments. The most important element of the gear coupling is the hub which is an external gear having crowned teeth. The crowned teeth on the hub are typically produced by hobbing. The resulting tooth surface depends on several parameters. It is influenced by the size of the hob and the feed. In this paper two mathematical models of the crowned tooth surface are introduced for the generation of the idealized...

  1. Prevalence and Indicators of Tooth Wear among Chinese Adults.

    Science.gov (United States)

    Wei, Zhao; Du, Yangge; Zhang, Jing; Tai, Baojun; Du, Minquan; Jiang, Han

    2016-01-01

    Numerous epidemiological studies have focused on the prevalence and related indicators of tooth wear. However, no sufficient studies have been conducted with Chinese adults. The purpose of this study was to assess the prevalence of tooth wear and identify related indicators among adults aged 36 to 74 years in Wuhan City, P.R. China. A cross-sectional and analytic study was conducted with 720 participants, aged 35-49 yrs and 50-74 yrs, in 2014. Each age group included 360 participants, of which 50% were males and 50% were females. All participants completed a questionnaire before examination. Tooth wear was assessed using the modified Basic Erosive Wear Examination (BEWE) index. The data were analyzed using the chi-square test and binary logistic regression analysis. The prevalence of tooth wear was 67.5% and 100% in the 35-49 and 50-74 age groups, respectively. The prevalence of dentin exposure was 64.7% and 98.3%, respectively. A significantly higher prevalence of tooth wear and dentin exposure was found in the 50-74 yr group than in the 35-49 yr group (p status, and unilateral chewing. The frequency of changing toothbrushes and the habit of drinking water during meals were associated with tooth wear. In addition, the usage of hard-bristle toothbrushes and consuming vitamin C and aspirin were found to be linked with dentin exposure. In conclusion, the prevalence of tooth wear and dentin exposure observed in Chinese adults was high, and the results revealed an association between tooth wear and socio-behavioral risk indicators. PMID:27583435

  2. 8th Argentinean Bioengineering Society Conference (SABI 2011) and 7th Clinical Engineering Meeting

    Science.gov (United States)

    Meschino, Gustavo Javier; Ballarin, Virginia L.

    2011-12-01

    In September 2011, the Eighteenth Edition of the Argentinean Bioengineering Society Conference (SABI 2011) and Seventh Clinical Engineering Meeting were held in Mar del Plata, Argetina. The Mar del Plata SABI Regional and the School of Engineering of the Universidad Nacional de Mar del Plata invited All bioengineers, engineers, physicists, mathematicians, biologists, physicians and health professionals working in the field of Bioengineering to participate in this event. The overall objectives of the Conference were: To provide discussion of scientific research results in Bioengineering and Clinical Engineering. To promote technological development experiences. To strengthen the institutional and scientific communication links in the area of Bioengineering, mainly between Universities of Latin America. To encourage students, teachers, researchers and professionals to establish exchanges of experiences and knowledge. To provide biomedical engineering technology solutions to the society and contributing ideas for low cost care. Conference photograph Conference photograph Conference photograph Conference photograph EXECUTIVE COMMITTEE SABI 2011 Chair Dra Virginia L Ballarin Universidad Nacional de Mar del Plata Co-Chair Dra Teresita R Cuadrado Universidad Nacional de Mar del Plata - CONICET Local Comittee Dr Gustavo Abraham Universidad Nacional de Mar del Plata - CONICET Dra Josefina Ballarre Universidad Nacional de Mar del Plata - CONICET Dr Eduardo Blotta Universidad Nacional de Mar del Plata Dra Agustina Bouchet Universidad Nacional de Mar del Plata Dr Marcel Brun Universidad Nacional de Mar del Plata Dra Silvia Ceré Universidad Nacional de Mar del Plata - CONICET Dra Mariela Azul Gonzalez Universidad Nacional de Mar del Plata - CONICET Dra Lucia Isabel Passoni Universidad Nacional de Mar del Plata Dr Juan Ignacio Pastore Universidad Nacional de Mar del Plata - CONICET Dra Adriana Scandurra Universidad Nacional de Mar del Plata SCIENTIFIC ADVISORY COMMITTEE

  3. Corticotomy-/osteotomy-assisted tooth movement microCTs differ.

    Science.gov (United States)

    Lee, W; Karapetyan, G; Moats, R; Yamashita, D-D; Moon, H-B; Ferguson, D J; Yen, S

    2008-09-01

    Corticotomy-assisted and osteotomy-assisted tooth movement involves surgical incisions through the alveolar bone. To ascertain whether teeth move by distraction osteogenesis or by regional accelerated phenomenon (RAP), we randomly assigned 30 Sprague-Dawley rats to one of 5 experimental groups: corticotomy alone, corticotomy-assisted tooth movement, osteotomy alone, osteotomy-assisted tooth movement, or tooth movement alone. Each animal was imaged by microtomography immediately after surgery, after 21 days, and after 2 months. After 21 days, regional accelerated phenomenon was observed in the alveolar bone of the corticotomy-treated animals and distraction osteogenesis in the osteotomy-assisted tooth movement animals. Pixel count data were analyzed by nested ANOVA for 5 experimental groups, split-mouth controls, 3 levels along the root, and 5 sites per level. The most demineralized sites after 21 days differed for each of the experimental groups. Our study indicates that osteotomies and corticotomies induce different alveolar bone reactions, which can be exploited for tooth movement. PMID:18719214

  4. An automatic tooth preparation technique: A preliminary study.

    Science.gov (United States)

    Yuan, Fusong; Wang, Yong; Zhang, Yaopeng; Sun, Yuchun; Wang, Dangxiao; Lyu, Peijun

    2016-01-01

    The aim of this study is to validate the feasibility and accuracy of a new automatic tooth preparation technique in dental healthcare. An automatic tooth preparation robotic device with three-dimensional motion planning software was developed, which controlled an ultra-short pulse laser (USPL) beam (wavelength 1,064 nm, pulse width 15 ps, output power 30 W, and repeat frequency rate 100 kHz) to complete the tooth preparation process. A total of 15 freshly extracted human intact first molars were collected and fixed into a phantom head, and the target preparation shapes of these molars were designed using customised computer-aided design (CAD) software. The accuracy of tooth preparation was evaluated using the Geomagic Studio and Imageware software, and the preparing time of each tooth was recorded. Compared with the target preparation shape, the average shape error of the 15 prepared molars was 0.05-0.17 mm, the preparation depth error of the occlusal surface was approximately 0.097 mm, and the error of the convergence angle was approximately 1.0°. The average preparation time was 17 minutes. These results validated the accuracy and feasibility of the automatic tooth preparation technique. PMID:27125874

  5. An automatic tooth preparation technique: A preliminary study

    Science.gov (United States)

    Yuan, Fusong; Wang, Yong; Zhang, Yaopeng; Sun, Yuchun; Wang, Dangxiao; Lyu, Peijun

    2016-04-01

    The aim of this study is to validate the feasibility and accuracy of a new automatic tooth preparation technique in dental healthcare. An automatic tooth preparation robotic device with three-dimensional motion planning software was developed, which controlled an ultra-short pulse laser (USPL) beam (wavelength 1,064 nm, pulse width 15 ps, output power 30 W, and repeat frequency rate 100 kHz) to complete the tooth preparation process. A total of 15 freshly extracted human intact first molars were collected and fixed into a phantom head, and the target preparation shapes of these molars were designed using customised computer-aided design (CAD) software. The accuracy of tooth preparation was evaluated using the Geomagic Studio and Imageware software, and the preparing time of each tooth was recorded. Compared with the target preparation shape, the average shape error of the 15 prepared molars was 0.05–0.17 mm, the preparation depth error of the occlusal surface was approximately 0.097 mm, and the error of the convergence angle was approximately 1.0°. The average preparation time was 17 minutes. These results validated the accuracy and feasibility of the automatic tooth preparation technique.

  6. Permanent tooth calcification in chimpanzees (Pan troglodytes): patterns and polymorphisms.

    Science.gov (United States)

    Kuykendall, K L; Conroy, G C

    1996-01-01

    Tooth calcification is an important developmental marker for use in constructing models for early hominid life history, particularly for its application to the fossil record. As chimpanzees are commonly utilized in interspecific comparisons in such research, this study aims to improve available baseline data for tooth calcification patterns in chimpanzees (Pan troglodytes), and to quantify basic patterns and polymorphisms. We present an analysis of developmental patterns for the left mandibular dentition (I1-M3) based on intraoral radiographs obtained from a cross-sectional sample of chimpanzees (58 males, 60 females) housed at LEMSIP (NYU Medical Center) and Yerkes (Emory University). No significant differences with previous descriptions of the basic sequences of tooth calcification in chimpanzees were found, but variation in such patterns was documented for the first time. In the overall sequence, polymorphisms between the canine and the group (M2 P4 P3) reached significant levels. This is due to the relative delay in canine crown formation compared to other teeth. Differences in the basic sequence between males and females were recorded, but are due to minor shifts in the percentages of occurrence for polymorphic sequences which are common to both genders. Perhaps our most important findings are that a) different polymorphic sequences occur in tooth calcification and tooth emergence in chimpanzees, and b) developmental relationships among teeth fluctuate throughout tooth calcification. Thus, characterizations of dental developmental patterns based on particular stages of development cannot necessarily be extrapolated to other stages without supporting data. PMID:8928717

  7. Corticision: A Flapless Procedure to Accelerate Tooth Movement.

    Science.gov (United States)

    Park, Young Guk

    2016-01-01

    Orthodontic tooth movement results from applied forces to the teeth evoking cellular responses in the teeth and their surrounding tissues, including the periodontal ligament, alveolar bone and gingiva. It is advantageous for the orthodontist to be well informed of the detailed process of the biological events that unfold during tooth movement, since some of these details may differ from one person to another due to biological differences such as periodontal metabolism or alveolar bone density. This led us to emphasize that orthodontics is a field of endeavor where the integration of mechanics and biology is materialized, and to affirm the fact that tooth movement is conducted in individual human beings, each composed of a unique and intricate physiological system. Biological variations may be the foundation of the differences that are frequently observed in the outcomes of orthodontic treatment in particular with reference to treatment duration between patients with similar malocclusions and who were treated identically. A wide diversity of clinical trials has been carried out to control the tissue resistance to facilitate orthodontic tooth movement, which involves biomechanical, pharmaceutical, surgical, electrical regimens or tissue engineering technology. The term 'Corticision' is a neologism which indicates 'cortical bone incision'. It is a minimally invasive periodontal procedure without flap elevation, thus accelerating tooth movement with an enhanced turnover rate of the surrounding structures. This chapter introduces the technical procedure, and the biological background of how such a minor surgical procedure can receive the accelerated tooth movement with impunity and thereby shorten the duration of treatment. PMID:26599124

  8. [Rehabilitation of Charcot-Marie-Tooth Disease].

    Science.gov (United States)

    Tajima, Fumihiro; Nakamura, Takeshi; Nishimura, Yukihide; Arakawa, Hideki; Kawasaki, Takashi; Ogawa, Takahiro; Nishiyama, Kazunari

    2016-01-01

    Charcot-Marie-Tooth disease (CMT) is one of the most commonly inherited neuromuscular diseases causing progressive muscle weakness; contracture; deformity in the feet, legs, and hands; and impairments of ambulation and handgrip. Reduced physical ability can be attributed not only to the disease but also to physical deconditioning. Previously, most physicians in the field of rehabilitation were anxious about the hypothesis of overwork weakness in CMT, and did not conduct intensive exercise programs for patients with CMT. However, recent studies have reported that progressive resistance strengthening programs for lower extremities are feasible, safe, beneficial, and improve exercise intolerance and undue fatigue in patients with CMT. Although the improvement in exercise tolerance may be partly due to the reversal of deconditioning effect of related sedentary lifestyle, progressive resistance training and physical fitness can improve walking function, activities of daily living, and subjective perception of pain and fatigue in patients with CMT. To increase the daily physical function, some studies described the potential benefits of ankle-foot orthoses (AFOs); however, no control study supported it. So far, the training programs on CMT have been dependent on the exercise programs for able-bodied individuals. To increase the effects of rehabilitation, optimal programs that combine the training protocol and AFO strategies will have to be designed for patients with CMT. PMID:26764300

  9. Tooth-surface-specific Effects of Xylitol

    Science.gov (United States)

    Ritter, A.V.; Bader, J.D.; Leo, M.C.; Preisser, J.S.; Shugars, D.A.; Vollmer, W.M.; Amaechi, B.T.; Holland, J.C.

    2013-01-01

    The Xylitol for Adult Caries Trial was a three-year, double-blind, multi-center, randomized clinical trial that evaluated the effectiveness of xylitol vs. placebo lozenges in the prevention of dental caries in caries-active adults. The purpose of this secondary analysis was to investigate whether xylitol lozenges had a differential effect on cumulative caries increments on different tooth surfaces. Participants (ages 21-80 yrs) with at least one follow-up visit (n = 620) were examined at baseline, 12, 24, and 33 months. Negative binomial and zero-inflated negative binomial regression models were used to estimate incidence rate ratios (IRR) for xylitol’s differential effect on cumulative caries increments on root and coronal surfaces and, among coronal surfaces, on smooth (buccal and lingual), occlusal, and proximal surfaces. Participants in the xylitol arm developed 40% fewer root caries lesions (0.23 D2FS/year) than those in the placebo arm (0.38 D2FS/year; IRR = 0.60; 95% CI [0.44, 0.81]; p < .001). There was no statistically significant difference between xylitol and control participants in the incidence of smooth-surface caries (p = .100), occlusal-surface caries (p = .408), or proximal-surface caries (p = .159). Among these caries-active adults, xylitol appears to have a caries-preventive effect on root surfaces (ClinicalTrials.gov NCT00393055). PMID:23589387

  10. Relationship between tooth dimensions and malocclusion

    International Nuclear Information System (INIS)

    Objective: To observe the difference in dimension of teeth among adult females with and without malocclusion. Methods: The cross-sectional study was conducted at Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, from April 2011 to April 2013, and used non-probability consecutive sampling. Mesiodistal and buccolingual crown dimensions were measured on study casts by using digital sliding caliper in 2 groups of females. Group1 had 150 subjects with normal occlusion, while Group 2 had 234 with malocclusion. Independent t test was conducted to evaluate the difference between the dimensions of teeth of the two groups. Statistical analysis was done on SPSS version 16, and p value was considered significant at 0.05. Results: Overall, the difference between the groups showed a greater tooth dimension in the malocclusion group of population compared to the normal group, and the most significant difference was observed in the mesiodistal dimension of maxillary 2nd premolar, which was 0.9+-0.6801mm greater in dimension in the malocclusion group compared to the normal group. The least difference was observed in the buccolingual dimension of the mandibular central incisor where the malocclusion group had only 0.08+-0.5247mm larger mandibular central incisors in the buccolingual dimension compared to the normal group. Conclusion: Mesiodistal and buccolingual crown dimensions were characteristically larger in the malocclusion group. (author)

  11. Trace Elements in Human Tooth Enamel

    International Nuclear Information System (INIS)

    The trace elements are considered to play a role in the resistance of teeth to dental caries. The exact mechanism by which they act has not yet been fully established. Estimations of trace elements have been undertaken in sound human teeth. By means of activation analysis it has been possible to determine trace element concentrations in different layers of enamel in the same tooth. The concentrations of the following elements have been determined: arsenic, antimony, copper, zinc, manganese, mercury, molybdenum and vanadium. The distribution of trace elements in enamel varies from those with a narrow range, such as manganese, to those with a broad range, such as antimony. The elements present in the broad range are considered to be non-essential and their presence is thought to result from a chance incorporation into the enamel. Those in the narrow range appear to be essential trace elements and are present in amounts which do not vary unduly from other body tissues. Only manganese and zinc were found in higher concentrations in the surface layer of enamel compared with the inner layers. The importance of the concentration of trace elements on this surface layer of enamel is emphasized as this layer is the site of the first attack by the carious process. (author)

  12. [A new method for combined auto-alloplastic tooth reimplantation with a parallel A1203-ceramic root].

    Science.gov (United States)

    Kirschner, H; Bolz, U; Enomoto, S; Hüttemann, R W; Meinel, W; Sturm, J

    1978-09-01

    The operative procedure for partially replacing the root with A12O3 ceramic represents a good possibility for preserving teeth in which the pulpa is devitalized. The method used in connection with the well known autoplastic reimplantation not only presents an alternative to the traditional apicoectomy but also provides additional stabilization of the tooth by lengthing the root with cocotostabile and biocompatible A1203 ceramic. The method was tested in humans and monkeys. Argumentation was based on histological examination via light microscopy. PMID:100304

  13. Comparison of the effect of thermal stresses on tooth-colored posts, cores and tooth structures by finite element analysis

    OpenAIRE

    Levent Nalbant; Ferhan Egilmez

    2012-01-01

    Objectives: The aims of this study were to analyze the influence of cold heat flow in all ceramic crown material, composite core, zirconium and glass fiber reinforced composite post materials, resin based luting cement and root dentin; and to compare these two tooth-colored post systems about their temperature and thermal stress distributions.
    Materials and Methods: A 3-dimesional finite element model of maxillary left canine tooth was constructed. All ceramic crown, composite cor...

  14. In Vitro Spectrophotometry of Tooth Discoloration Induced by Tooth-Colored Mineral Trioxide Aggregate and Calcium-Enriched Mixture Cement

    OpenAIRE

    Arman, Marjan; Khalilak, Zohreh; Rajabi, Moones; Esnaashari, Ehsan; Saati, Keyvan

    2015-01-01

    Introduction: There are numerous factors that can lead to tooth discoloration after endodontic treatment, such as penetration of endodontic materials into the dentinal tubules during root canal treatment. The aim of this in vitro study was to compare discoloration induced by tooth colored mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement in extracted human teeth. Methods and Materials: Thirty two dentin-enamel cuboid blocks (7×7×2 mm) were prepared from extracted maxi...

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

    OpenAIRE

    Cho, Yong-Wook; Park, Sung-Ho

    2014-01-01

    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...

  16. Management of External Invasive Cervical Resorption Tooth with Mineral Trioxide Aggregate: A Case Report

    Directory of Open Access Journals (Sweden)

    Anuja Ikhar

    2013-01-01

    Full Text Available Invasive cervical resorption is entirely uncommon entities and the etiology is poorly understood. A 19 year old patient presented with fractured upper left central incisor and sinus tract opening on the distobuccal aspect in cervical region. Radiographic examination shows irregular radiolucency over the coronal one-third and it extended externally towards the external invasive resorption. After sectional obturation, the defect was accessed surgically. The resorption area was chemomechanically debrided using irrigant solution. Fibre post placement using flowable composite resin and Mineral Trioxide Aggregate (MTA was used to fill the resorptive defect, and the coronal access was temporarily sealed. Composite restoration was subsequently replaced with ceramic crown after 4 years. Radiographs at 1 and 4 years showed adequate repair of the resorption and endodontic success. Clinically and radiographically the tooth was asymptomatic, and no periodontal pocket was found after a 4-year followup.

  17. Indirect pulp capping and primary teeth: is the primary tooth pulpotomy out of date?

    Science.gov (United States)

    Coll, James A

    2008-07-01

    Formocresol pulpotomy (FP) in the United States is most frequently used to treat asymptomatic caries near the pulp in primary teeth. Indirect pulp therapy (IPT) is also indicated and has a significantly higher long-term success. Pulpotomy is thought to be indicated for primary teeth with carious pulp exposures, but research shows the majority of such teeth are nonvital or questionable for treatment with vital pulp therapy. IPT has a significantly higher success in treating all primary first molars, but especially those with reversible pulpitis compared with FP. The purpose of this article was to review the dental literature and new research in vital pulp therapy to determine the following: (1) Is a pulpotomy indicated for a true carious pulp exposure? (2) Is there a diagnostic method to reliably identify teeth that are candidates for vital pulp therapy? (3) Is primary tooth pulpotomy out of date, and should indirect pulp therapy replace pulpotomy? PMID:18565370

  18. Does Timing of Eruption in First Primary Tooth Correlate with that of First Permanent Tooth? A 9-years Cohort Study

    Science.gov (United States)

    Poureslami, Hamidreza; Asl Aminabadi, Naser; Sighari Deljavan, Alireza; Erfanparast, Leila; Sohrabi, Azin; Jamali, Zahra; Ghertasi Oskouei, Sina; Hazem, Kameliya; Shirazi, Sajjad

    2015-01-01

    Background and aims. Predicting the teeth eruption time is a valuable tool in pediatric dentistry since it can affects scheduling dental and orthodontic treatments. This study investigated the relationship between the eruption time of first primary and permanent teeth and the variation in the eruption time considering socioeconomic status (SES) in a 9-year population- based cohort study. Materials and methods. 307 subjects were examined at bimonthly intervals during the first and second years of life and then at six-month intervals until the eruption of first permanent tooth. Eruption times of primary and permanent tooth were recorded for each child. A modified form of Kuppuswamy’s scale was used to assess the SES. Results. Among 267 subjects completed all follow-ups, the eruption time for first primary and permanent teeth indicated a direct strong correlation; in that one month delayed or early eruption of firstprimary tooth resulted in 4.21 months delayed or early eruption of first appearing permanent tooth (r = 0.91, n = 267, P <0.001). No significant correlation was observed between the eruption time of first primary and first permanent teeth and SES (P = 0.67, P = 0.75, respectively). Conclusion. The eruption timing for the first primary tooth had a correlation with the first permanent tooth eruption tim-ing, while SES did not have any influence on eruption times. PMID:26236432

  19. Experimental replacement of pig trachea with novel bioprosthesis from harp seal.

    Science.gov (United States)

    Agathos, E Andreas; Tomos, Periklis; Lachanas, Elias; Gakiopoulou, Harikleia; Pantopoulou, Alkystis; Perrea, Despina

    2010-12-01

    Tracheal replacement has been a challenging problem for thoracic surgeons for over half of a century. We evaluated the in-vivo performance of a new tracheal bioprosthesis derived from Harp seal (Phoca groelandica) trachea that was fixed and preserved in 0.625% buffered glutaraldehyde solution for 3 months. Ten young male pigs weighing 27-32 kg (mean, 28.7 kg) underwent replacement of a tracheal segment with this new bioprosthesis. The length of replaced trachea was 1.8-2.4 cm (mean, 2.17 cm), representing 2-3 cartilage rings. All pigs survived the operation uneventfully. No immunosuppression drugs were used. The pigs eventually developed dyspnea and were euthanized on postoperative day 17-39 (mean, 30.8 days). Macroscopic and histological analysis showed an intact bioprosthesis but near-total occlusion of the native trachea by a ring of inflammatory infiltration at the site of distal anastomosis. More experiments involving a different concentration of the preservation agent, different management, and perhaps the use of bioengineering techniques are needed to improve the performance of this novel bioprosthesis. PMID:21149405

  20. Using your shoulder after replacement surgery

    Science.gov (United States)

    Joint replacement surgery - using your shoulder; Shoulder replacement surgery - after ... You have had shoulder replacement surgery to replace the bones of your shoulder joint with artificial parts. The parts include a stem made ...

  1. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... and E-poly antioxidant-infused technology during a hip replacement through the anterior supine intramuscular approach. “OR- ... Dr. Keith Berend perform an anterior approach total hip replacement with the patient on a regular OR ...

  2. Comparative evaluation of stresses in tooth implant connected fixed partial denture by varying the implant design and position: A 3D finite element study

    Directory of Open Access Journals (Sweden)

    K V Pratheep

    2013-01-01

    Full Text Available Aim: This study aims at evaluating stresses generated in a fixed tooth to implant connected fixed partial denture (FPD by finite element method by varying implant design and position, in unilateral distal extension cases, i.e. for replacing mandibular 1 st and 2 nd molars. Materials and Methods: Four models were created, Model 1-A finite element model (FEA model of a crestal implant-tooth connected metal ceramic FPD with pontic in 36 region. The 35 region simulated the second premolar. Model 2-A FEA model of a basal implant-tooth connected metal ceramic FPD. Model 3-A FEA model of a crestal implant in 36 region connected to tooth 35 and cantilevered posteriorly with pontic in 37 region, made of metal ceramic. Model 4-A FEA model of a basal implant in 36 region connected to tooth 35 and cantilevered posteriorly with pontic in 37 region, made of metal ceramic. A vertical force of 100N directed evenly on the nodes on the occlusal surface of each of the three crowns. The models displayed stress both numerically and by color coding. Results: On comparing models 1 and 2, the model 1 showed comparatively more stresses in crestal bone area of the implant. On comparing models 3 and 4, model 3 showed lesser von misses stress values. Conclusion: In case of tooth implant connected FPDs without any cantilevers, basal implants show better stress distribution when compared to crestal implants. In case of cantilever designs, crestal implant design showed lower stress values, but the difference in stresses were less.

  3. Anterior tooth relations in Kenyan Africans.

    Science.gov (United States)

    Hassanali, J; Pokhariyal, G P

    1993-04-01

    Dental plaster casts of 235 Maasai, 116 Kikuyu and 61 Kalenjin children aged 3-16 yr were studied to determine the incidence and magnitude of diastemas, overbite, overjet and anterior open bite. The highest prevalence of diastema was amongst the Maasai (61.3%), of overbite (84%) and overjet (99%) amongst the Kikuyu, and of anterior open bite amongst Kalenjin (24%), with values greater than 0.4 mm up to 11.5 mm. Comparison of the mean values showed that diastema (1.77 mm) and overjet (4.4 mm) were greatest in Maasai, overbite (3.53 mm) in Kalenjin, and anterior open bite (3.50 mm) in Kikuyu. In the total sample, the prevalence and mean of diastema were 49%, 1.68 mm; of overbite 77.4%, 2.96 mm; of overjet 88.6%, 3.83 mm; and of anterior open bite 16.5%, 2.69 mm (with values between 0.4-11.5 mm), while 5.5% had an edge-to-edge bite (-0.5-0.5 mm). The prevalence of diastema decreased whilst its magnitude increased with age. The mean values of overbite and overjet increased, while those for anterior open bite decreased with age. The mean values of diastema, overbite and overjet were greater amongst the females, but the difference was significant only for overjet. The high prevalence and greater values of measurements of anterior tooth relations may be related to variable growth of the bimaxillary dentoalveolar complex and soft tissue influences. This may be important in orthodontic treatment planning, dental prostheses and other clinical dental treatments in Kenyan populations. PMID:8517805

  4. Living part on soil bioengineering structures in Appennino Tosco-emiliano

    Science.gov (United States)

    Guastini, Enrico; Preti, Federico; Dani, Andrea

    2014-05-01

    From analisys headed up in soil bioengineered areas in different parts of Tuscany, the suitest root systems in slope stabilization turn out to be those spreading from seed-born plants, while adventitious roots from cuttings are often absent in the part more distant from the neck, and in some cases are insufficient to grant life support just in case of minor stress conditions. Genus Alnus shows it's adaptation capability to restore initial restoration steps and to create renovation prerequisites for other species through ammending litter production and symbiosis for nitrogen fixation with Frankia genus bacteria; other similar symbiosis (with Rhizobium and fungi) are carried out by Robinia pseudacacia. Soil fecundity increase is confirmed by the following entrance of more demanding species, as Ostrya carpinifolia and Acer pseudoplatanus at the tree level, Urtica dioica and Rubus Ulmifolius (nitrophilouses) at grass level. In the project phase it ought to imagine a well-structured implant, including rooted plants, cuttings and posibly a seed mix of colonising species aiming to form a germplasm on the structure itself in order to sprout whenever the local conditions allow it. Verifying that many after developed species came from ornithocore dissemination (Ficus carica, Pinus spp., Rosa canina, Sambucus nigra), lead to toughts about bedding out bird-attracting species on structures in order to realise a faster (and maybe more complex) succession development. This higher velocity could grant in a shorter period the production of a root mass spread in a more disomogeneous and complex pattern than that deriving from cuttings disposed in the traditional way; such a variability could allow a better interaction with other biological factors in the soil (bacteria, fungi, nematodes, ...) that are important for the plant nutrient cicle (Ohsowski et al., 2012) and then the constituion of an articulate, long-term system.

  5. Molecular and bioengineering strategies to improve alginate and polydydroxyalkanoate production by Azotobacter vinelandii

    Directory of Open Access Journals (Sweden)

    Espín Guadalupe

    2007-02-01

    Full Text Available Abstract Several aspects of alginate and PHB synthesis in Azotobacter vinelandii at a molecular level have been elucidated in articles published during the last ten years. It is now clear that alginate and PHB synthesis are under a very complex genetic control. Genetic modification of A. vinelandii has produced a number of very interesting mutants which have particular traits for alginate production. One of these mutants has been shown to produce the alginate with the highest mean molecular mass so far reported. Recent work has also shed light on the factors determining molecular mass distribution; the most important of these being identified as; dissolved oxygen tension and specific growth rate. The use of specific mutants has been very useful for the correct analysis and interpretation of the factors affecting polymerization. Recent scale-up/down work on alginate production has shown that oxygen limitation is crucial for producing alginate of high molecular mass, a condition which is optimized in shake flasks and which can now be reproduced in stirred fermenters. It is clear that the phenotypes of mutants grown on plates are not necessarily reproducible when the strains are tested in lab or bench scale fermenters. In the case of PHB, A. vinelandii has shown itself able to produce relatively large amounts of this polymer of high molecular weight on cheap substrates, even allowing for simple extraction processes. The development of fermentation strategies has also shown promising results in terms of improving productivity. The understanding of the regulatory mechanisms involved in the control of PHB synthesis, and of its metabolic relationships, has increased considerably, making way for new potential strategies for the further improvement of PHB production. Overall, the use of a multidisciplinary approach, integrating molecular and bioengineering aspects is a necessity for optimizing alginate and PHB production in A. vinelandii.

  6. Bioengineered periosteal progenitor cell sheets to enhance tendon-bone healing in a bone tunnel

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    Chih-Hsiang Chang

    2012-12-01

    Full Text Available Background: Tendon-bone tunnel healing is crucial for long term success in anterior cruciate liga­ment (ACL reconstruction. The periosteum contains osteochondral progenitor cells that can differenti­ate into osteoblasts and chondroblasts during tendon-bone healing. We developed a scaf­fold-free method using polymerized fibrin-coated dishes to make functional periosteal progenitor cell (PPC sheets. Bioengineered PPC sheets for enhancing tendon-bone healing were evaluated in an extra-articular bone tunnel model in rabbit. Methods: PPC derived from rabbit tibia periosteum, cultivated on polymerized fi­brin-coated dishes and harvested as PPC sheet. A confocal microscopy assay was used to evaluate the morphology of PPC sheets. PPC sheets as a periosteum to wrap around hamstring tendon grafts were pulled into a 3-mm diameter bone tunnel of tibia, and compared with a tendon graft without PPC sheets treatment. Rabbits were sacrificed at 4 and 8 weeks postoperatively for biochemical as­say and histological assay to demonstrate the enhancement of PPC sheets in tendon-bone healing. Results: PPC spread deposit on fibrin on the dish surface with continuous monolayer PPC was ob­served. Histological staining revealed that PPC sheets enhance collagen and glycosaminoglycans deposi­tion with fibrocartilage formation in the tendon-bone junction at 4 weeks. Collagen fiber with fibrocartilage formation at tendon-bone junction was also found at 8 weeks. Matured fibrocartilage and dense collagen fiber were formed at the tendon-bone interface at 8 weeks by Masson trichrome and Safranin-O staining Conclusions: Periosteal progenitor cell monolayer maintains the differentiated capacity and osteochon­dral potential in order to promote fibrocartilage formation in tendon-bone junction. Bioengi­neered PPC sheets can offer a new feasible therapeutic strategy of a novel approach to en­hance tendon-bone junction healing.

  7. Transcriptomic analysis and 3D bioengineering of astrocytes indicate ROCK inhibition produces cytotrophic astrogliosis

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    Ross D O'Shea

    2015-02-01

    Full Text Available Astrocytes provide trophic, structural and metabolic support to neurons, and are considered genuine targets in regenerative neurobiology, as their phenotype arbitrates brain integrity during injury. Inhibitors of Rho kinase (ROCK cause stellation of cultured 2D astrocytes, increased L-glutamate transport, augmented G-actin, and elevated expression of BDNF and anti-oxidant genes. Here we further explored the signposts of a cytotrophic, healthy phenotype by data-mining of our astrocytic transcriptome in the presence of Fasudil. Gene expression profiles of motor and autophagic cellular cascades and inflammatory / angiogenic responses were all inhibited, favouring adoption of an anti-migratory phenotype. Like ROCK inhibition, tissue engineered bioscaffolds can influence the extracellular matrix. We built upon our evidence that astrocytes maintained on 3D poly-Ɛ-caprolactone (PCL electrospun scaffolds adopt a cytotrophic phenotype similar to that produced by Fasudil. Using these procedures, employing mature 3D cultured astrocytes, Fasudil (100 µM or Y27632 (30 µM added for the last 72 h of culture altered arborization, which featured numerous additional minor processes as shown by GFAP and AHNAK immunolabelling. Both ROCK inhibitors decreased F-actin, but increased G-actin labelling, indicative of disassembly of actin stress fibres. ROCK inhibitors provide additional beneficial effects for bioengineered 3D astrocytes, including enlargement of the overall arbour. Potentially, the combined strategy of bio-compatible scaffolds with ROCK inhibition offers unique advantages for the management of glial scarring. Overall these data emphasize that manipulation of the astrocyte phenotype to achieve a healthy biology offers new hope for the management of inflammation in neuropathologies.

  8. Extraction and characterization of highly purified collagen from bovine pericardium for potential bioengineering applications

    International Nuclear Information System (INIS)

    Bovine pericardium is widely used as a raw material in bioengineering as a source of collagen, a fundamental structural molecule. The physical, chemical, and biocompatibility characteristics of these natural fibers enable their broad use in several areas of the health sciences. For these applications, it is important to obtain collagen of the highest possible purity. The lack of a method to produce these pure biocompatible materials using simple and economically feasible techniques presents a major challenge to their production on an industrial scale. This study aimed to extract, purify, and characterize the type I collagen protein originating from bovine pericardium, considered to be an abundant tissue resource. The pericardium tissue was collected from male animals at slaughter age. Pieces of bovine pericardium were enzymatically digested, followed by a novel protocol developed for protein purification using ion-exchange chromatography. The material was extensively characterized by electrophoresis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and infrared spectroscopy. The results showed a purified material with morphological properties and chemical functionalities compatible with type I collagen and similar to a highly purified commercial collagen. Thus, an innovative and relatively simple processing method was developed to extract and purify type I collagen from bovine tissue with potential applications as a biomaterial for regenerative tissue engineering. - Highlights: ► Type I collagen was obtained from bovine pericardium, an abundant tissue resource. ► A simple and feasible processing technique was developed to purify bovine collagen. ► The appropriate process may be performed on industrial scale. ► The pure collagen presented appropriate morphological and molecular characteristics. ► The purify collagen has shown potential use as a biomaterial in tissue engineering.

  9. Monitoring and evaluation of soil bioengineering interventions for watershed management, disaster mitigation and environmental restoration in Latin America

    Science.gov (United States)

    Petrone, Alessandro; Preti, Federico

    2013-04-01

    In recent decades the institutions responsible for land management and civil protection have showed a great interest in relation to the use of more environmentally friendly techniques to mitigate the risk of landslides and floods. Soil bioengineering has responded to this need and several research groups are carrying out experimentations using the techniques of this discipline in the countries in the developing world. The Deistaf from University of Florence has concentrated its activities in this area over the past decade promoting the use of the techniques of Soil bioengineering in Latin America through the implementation of training and experimentation programmes. Numerous works have been completed both in riverbanks and on slopes in Nicaragua, Guatemala, Ecuador and Colombia. It was decided to make a census of interventions in Latin America from different institutions that may be related to Soil bioengineering in order to obtain an overview of the state of the art in the specific context taking into account also environmental and socio-economic issues. Taking advantage of its network of contacts, DEISTAF has collected dozens of sheets that describe interventions. These sheets describe, among other fields focused on the environment in which the work has been carried out, the materials and techniques used, and the impact of the intervention. In the sheets we present also the monitoring that has been realized for some of these works in the months of October and November 2012; we include the identification of the current condition and functionality of the intervention and, in the case of the presence of some damages, the formulation of instructions to fix them as well as the economic quantification of the repairs to be carried out.

  10. Bioengineer effects on understory species richness, diversity, and composition change along an environmental stress gradient: Experimental and mensurative evidence

    Science.gov (United States)

    Watt, Cortney A.; Scrosati, Ricardo A.

    2013-05-01

    Canopy-forming bioengineer species are commonly assumed to increase local species richness and diversity. We tested this notion by investigating the effects of fucoid seaweed canopies on understory communities along rocky intertidal elevation gradients in Atlantic Canada. Such gradients exhibit increasing thermal extremes and variation from low to high elevations, and are broadly used in stress gradient studies. A manipulative experiment created canopy and no-canopy treatments at the low, middle, and high intertidal zones, eliminating all species (except fucoid canopies) from replicate quadrats. After recolonization, overall richness and diversity (considering all primary producers and consumers) were higher under canopies than uncovered by canopies at the high and middle zones, but no effects occurred at the low zone. Similarly, species composition was affected by canopies at the high and middle zones, but not at the low zone. A mensurative study that surveyed the full range of canopy cover (0-100%) using nearly five times more quadrats from pristine areas yielded the same results: richness and diversity increased with canopy cover at the high and middle zones (approaching stabilization toward high cover values), but no effects occurred at the low zone. Lack of canopy effects at low elevations is related to mild habitat conditions, which canopies are unable to modify, while positive effects at higher elevations relate to the capacity of canopies to ameliorate harsh conditions. This is the first time that a combined experimental and mensurative approach shows that the same bioengineer species affect overall species richness, diversity, and composition differently along a stress gradient. Overall, protecting canopy-forming bioengineers to preserve local biodiversity should be most effective in stressful environments.

  11. Bioengineering of Tobacco Mosaic Virus to Create a Non-Infectious Positive Control for Ebola Diagnostic Assays

    Science.gov (United States)

    Lam, Patricia; Gulati, Neetu M.; Stewart, Phoebe L.; Keri, Ruth A.; Steinmetz, Nicole F.

    2016-03-01

    The 2014 Ebola epidemic is the largest to date. There is no cure or treatment for this deadly disease; therefore there is an urgent need to develop new diagnostics to accurately detect Ebola. Current RT-PCR assays lack sensitive and reliable positive controls. To address this critical need, we devised a bio-inspired positive control for use in RT-PCR diagnostics: we encapsulated scrambled Ebola RNA sequences inside of tobacco mosaic virus to create a biomimicry that is non-infectious, but stable, and could therefore serve as a positive control in Ebola diagnostic assays. Here, we report the bioengineering and validation of this probe.

  12. Soil bioengineering measures for disaster mitigation and environmental restoration in Central America: authochtonal cuttings suitability and economic efficiency

    Science.gov (United States)

    Petrone, A.; Preti, F.

    2009-04-01

    The use of Soil Bio-Engineering techniques in Developing countries is a relevant issue for Disaster mitigation, environmental restoration and poverty reduction. Research on authochtonal plants suitable for this kind of works and on economic efficiency is essential for the divulgation of this Discipline. The present paper is focused on this two issues related to the realization of various typologies of Soil Bio-engineering works in the Humid tropic of Nicaragua. In the area of Río Blanco, located in the Department of Matagalpa, Soil bio-engineering installations were built in several sites. The particular structures built were: drainages with live fascine mattress, a live palisade, a vegetated live crib wall for riverbank protection, a vegetative covering made of a metallic net and biotextile coupled with a live palisade made of bamboo. In order to evaluate the suitability of the various plants used in the works, monitorings were performed, one in the live palisade alongside an unpaved road and the other on the live crib wall along a riverbank, collecting survival rate and morphological parameters data. Concerning the economic efficiency we proceed to a financial analysis of the works and once the unit price was obtained, we converted the amount in EPP Dollars (Equal Purchasing Power) in order to compare the Nicaraguan context with the Italian one. Among the used species we found that Madero negro (Gliricidia sepium) and Roble macuelizo (Tabebuia rosea) are adequate for Soil-bioengineering measure on slopes while Helequeme (Erythrina fusca) reported a successful behaviour only in the crib wall for riverbank protection. In the comparison of the costs in Nicaragua and in Italy, the unit price reduction for the central American country ranges between 1.5 times (for the vegetative covering) and almost 4 times (for the fascine mattress) if it's used the EPP dollar exchange rate. Thus, a conclusion can be reached with regard to hydrological-risk mitigating actions

  13. Comparative clinical evaluation of two professional tooth-whitening products.

    Science.gov (United States)

    Kowitz, G M; Nathoo, S A; Wong, R

    1994-01-01

    A 2-week study was conducted to compare the tooth-whitening efficacy of two 10% carbamide peroxide products: Colgate Platinum Professional Toothwhitening System and Rembrandt Lighten Bleaching Gel. Fifty subjects were divided into two groups and assigned a product to use for 2 weeks. Change in tooth color was measured by reflectance spectroscopy at the initiation of study, at 1 week, and at 2 weeks into the study. Color change was calculated using the color-difference equation established by the Commission International de L'Eclairage. Results showed that Colgate Platinum was 62% more effective at tooth whitening after 1 week and 83% more effective after 2 weeks of treatment vs Rembrandt. At the termination of the study, the mean color difference (deltaE) for Colgate Platinum was 4.29 and 2.34 for Rembrandt. Statistical analysis demonstrated that the Colgate product is significantly superior at increasing tooth whiteness, increasing tooth lightness, reducing redness, and reducing yellowness. In this study, no adverse reactions were noted on clinical examination and none were reported by panelists with normal healthy dentition. PMID:8205580

  14. The effect of light-activation sources on tooth bleaching

    Directory of Open Access Journals (Sweden)

    Kusai Baroudi

    2014-01-01

    Full Text Available Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system. Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. Conclusions: The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching.

  15. 41Ca - a possible neutron specific biomarker in tooth enamel

    Science.gov (United States)

    Wallner, A.; Arazi, A.; Faestermann, T.; Knie, K.; Korschinek, G.; Maier, H. J.; Nakamura, N.; Rühm, W.; Rugel, G.

    2004-08-01

    The measurement of long-lived radionuclides, produced by neutrons originating from the atomic-bomb explosions, offers the possibility to reconstruct neutron fluences to which survivors in Hiroshima and Nagasaki were exposed. The long-lived radionuclide, 41Ca (T1/2=103 000 years), is suggested here as a means for a retrospective determination of thermal neutron fluences, directly within the human body of a survivor. As proper material tooth enamel is proposed. The 41Ca signal in tooth enamel may be correlated with the exposure to A-bomb induced thermal neutron fluences, provided the natural background level of 41Ca/Ca is significantly lower. Therefore, tooth samples of unexposed survivors of the A-bomb explosions have been examined by means of accelerator mass spectrometry, in order to quantify the natural background level of 41Ca/Ca. Measured 41Ca/Ca ratios were confirmed to be as low as about 2 × 10-15. Thus, the A-bomb induced additional signal should be detectable for survivors at epidemiological relevant distances. Since tooth enamel had already been used as a dosemeter for gamma radiation from the A-bomb explosion, the detection of 41Ca in tooth enamel would allow, for the first time, an assessment of both, γ-ray and neutron exposures in the same biological material.

  16. Implant-Root Proximity and Pulp Vitality of the Tooth

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    Tasharoie

    2015-12-01

    Full Text Available Background When dental implants are applied in partially edentulous patients, there is the risk of placing the implants in close proximity or in direct contact with the adjacent roots. In this situation assurance of pulp vitality of the adjacent tooth is neessary. Objectives The current study aimed to assess pulp response of the tooth after root proximity with dental implant. Patients and Methods After investigating 2800 records of patients, 31 implants in 29 patients were included in this study. A parallel peri-apical radiography was taken and pulp vitality tests (cold, heat and electrical pulp tests were conducted for each patient. Results Among the 31 assessed implants and the adjacent intact teeth, 13 implants had direct contact and 18 implants had proximity of less than 1 mm with the adjacent root. All of the teeth had positive (normal pulp response to all tests. The most prevalent areas for proximity of implant-tooth were upper first premolar implants and upper canine teeth. The most approximation area was apical third of root of the teeth. Conclusions Based on the clinical and radiographic examinations, implant-tooth approximation (less than 1 mm or direct contact is not related to pulp vitality of the tooth. Further studies with larger sample sizes are necessary to confirm the results of the study.

  17. The development of complex tooth shape in reptiles

    Directory of Open Access Journals (Sweden)

    Oldrich eZahradnicek

    2014-02-01

    Full Text Available Reptiles have a diverse array of tooth shapes, from simple unicuspid to complex multicuspid teeth, reflecting functional adaptation to a variety of diets and eating styles. In addition to cusps, often complex longitudinal labial and lingual enamel crests are widespread and contribute to the final shape of reptile teeth. The simplest shaped unicuspid teeth have been found in piscivorous or carnivorous ancestors of recent diapsid reptiles and they are also present in some extant carnivores such as crocodiles and snakes. However, the ancestral tooth shape for squamate reptiles is thought to be bicuspid, indicating an insectivorous diet. The development of bicuspid teeth in lizards has recently been published, indicating that the mechanisms used to create cusps and crests are very distinct from those that shape cusps in mammals. Here, we introduce the large variety of tooth shapes found in lizards and compare the morphology and development of bicuspid, tricuspid and pentacuspid teeth, with the aim of understanding how such tooth shapes are generated. Next, we discuss whether the processes used to form such morphologies are conserved between divergent lizards and whether the underlying mechanisms share similarities with those of mammals. In particular, we will focus on the complex teeth of the chameleon, gecko, varanus and anole lizards using SEM and histology to compare the tooth crown morphology and embryonic development.

  18. Twist1 Is Essential for Tooth Morphogenesis and Odontoblast Differentiation.

    Science.gov (United States)

    Meng, Tian; Huang, Yanyu; Wang, Suzhen; Zhang, Hua; Dechow, Paul C; Wang, Xiaofang; Qin, Chunlin; Shi, Bing; D'Souza, Rena N; Lu, Yongbo

    2015-12-01

    Twist1 is a basic helix-loop-helix-containing transcription factor that is expressed in the dental mesenchyme during the early stages of tooth development. To better delineate its roles in tooth development, we generated Twist1 conditional knockout embryos (Twist2(Cre) (/+);Twist1(fl/fl)) by breeding Twist1 floxed mice (Twist1(fl/fl)) with Twist2-Cre recombinase knockin mice (Twist2(Cre) (/+)). The Twist2(Cre) (/+);Twist1(fl/fl) embryos formed smaller tooth germs and abnormal cusps during early tooth morphogenesis. Molecular and histological analyses showed that the developing molars of the Twist2(Cre) (/+);Twist1(fl/fl) embryos had reduced cell proliferation and expression of fibroblast growth factors 3, 4, 9, and 10 and FGF receptors 1 and 2 in the dental epithelium and mesenchyme. In addition, 3-week-old renal capsular transplants of embryonic day 18.5 Twist2(Cre) (/+);Twist1(fl/fl) molars showed malformed crowns and cusps with defective crown dentin and enamel. Immunohistochemical analyses revealed that the implanted mutant molars had defects in odontoblast differentiation and delayed ameloblast differentiation. Furthermore, in vitro ChIP assays demonstrated that Twist1 was able to bind to a specific region of the Fgf10 promoter. In conclusion, our findings suggest that Twist1 plays crucial roles in regulating tooth development and that it may exert its functions through the FGF signaling pathway. PMID:26487719

  19. Effect of Orthodontic Tooth Movement on Salivary Aspartate Aminotransferase Activity

    Directory of Open Access Journals (Sweden)

    Steiven Adhitya

    2013-07-01

    Full Text Available 72 1024x768 Aspartate aminotransferase is one of biological indicator in gingival crevicular fluid (CGF. Force orthodontic application could increase activity of aspartate aminotransferase in CGF. However, the increase activity of aspartate aminotransferase in saliva due to orthodontic force and its correlation between aspartate aminotransferase activity and tooth movement remains unclear. Objectives: To evaluate application orthodontic force on the aspartate aminotransferase activity in saliva based on the duration of force and finding correlation between tooth movement and aspartate aminotransferase activity. Methods: Twenty saliva samples collected before extraction of first premolar, at the time of force application for canine retraction and after force application. The canines retraction used 100 grams of interrupted force (module chain for thirty days. The collection of saliva and the measurement of tooth movement were carried out 1 day, 7 days, 14 days, 21 days, and 28 days after force application. The measurement of aspartate aminotransferase activity in saliva was done using spectrophotometer. Results: Application of orthodontic force influences the salivary aspartate aminotransferase activity (F=25.290, p=0.000. Furthermore, tooth movement correlated with aspartate aminotransferase activity (F=0.429, p=0.000. Conclusion: Aspartate aminotransferase activity could be used as tooth movement indicator that related to the duration of force application.DOI : 10.14693/jdi.v20i1.128

  20. The development of complex tooth shape in reptiles.

    Science.gov (United States)

    Zahradnicek, Oldrich; Buchtova, Marcela; Dosedelova, Hana; Tucker, Abigail S

    2014-01-01

    Reptiles have a diverse array of tooth shapes, from simple unicuspid to complex multicuspid teeth, reflecting functional adaptation to a variety of diets and eating styles. In addition to cusps, often complex longitudinal labial and lingual enamel crests are widespread and contribute to the final shape of reptile teeth. The simplest shaped unicuspid teeth have been found in piscivorous or carnivorous ancestors of recent diapsid reptiles and they are also present in some extant carnivores such as crocodiles and snakes. However, the ancestral tooth shape for squamate reptiles is thought to be bicuspid, indicating an insectivorous diet. The development of bicuspid teeth in lizards has recently been published, indicating that the mechanisms used to create cusps and crests are very distinct from those that shape cusps in mammals. Here, we introduce the large variety of tooth shapes found in lizards and compare the morphology and development of bicuspid, tricuspid, and pentacuspid teeth, with the aim of understanding how such tooth shapes are generated. Next, we discuss whether the processes used to form such morphologies are conserved between divergent lizards and whether the underlying mechanisms share similarities with those of mammals. In particular, we will focus on the complex teeth of the chameleon, gecko, varanus, and anole lizards using SEM and histology to compare the tooth crown morphology and embryonic development. PMID:24611053

  1. Interactive Tooth Separation from Dental Model Using Segmentation Field.

    Science.gov (United States)

    Li, Zhongyi; Wang, Hao

    2016-01-01

    Tooth segmentation on dental model is an essential step of computer-aided-design systems for orthodontic virtual treatment planning. However, fast and accurate identifying cutting boundary to separate teeth from dental model still remains a challenge, due to various geometrical shapes of teeth, complex tooth arrangements, different dental model qualities, and varying degrees of crowding problems. Most segmentation approaches presented before are not able to achieve a balance between fine segmentation results and simple operating procedures with less time consumption. In this article, we present a novel, effective and efficient framework that achieves tooth segmentation based on a segmentation field, which is solved by a linear system defined by a discrete Laplace-Beltrami operator with Dirichlet boundary conditions. A set of contour lines are sampled from the smooth scalar field, and candidate cutting boundaries can be detected from concave regions with large variations of field data. The sensitivity to concave seams of the segmentation field facilitates effective tooth partition, as well as avoids obtaining appropriate curvature threshold value, which is unreliable in some case. Our tooth segmentation algorithm is robust to dental models with low quality, as well as is effective to dental models with different levels of crowding problems. The experiments, including segmentation tests of varying dental models with different complexity, experiments on dental meshes with different modeling resolutions and surface noises and comparison between our method and the morphologic skeleton segmentation method are conducted, thus demonstrating the effectiveness of our method. PMID:27532266

  2. From hopeless to good prognosis: journey of a failing tooth.

    Science.gov (United States)

    Gupta, Saurabh; Deshmukh, Jeevanand; Khatri, Richa; Kulkarni, Vinaya Kumar; Karthik, B

    2015-02-01

    Chronic periodontitis, along with associated clinical findings such as pathologic tooth migration, diastema, functional and aesthetic aberrations, poses an immense challenge to a dental professional. These findings convert clinical decision making into a daunting task and adversely affect the prognosis and the treatment plan for the presenting clinical problem. An interdisciplinary approach aimed at restoring functional and aesthetic needs of the affected individual within the limitations of such a compromised clinical scenario may be a viable alternative to any radical treatment causing loss of natural tooth structure such as extraction. This article reports the usefulness of the interdisciplinary route for managing an otherwise hopeless clinical situation of chronic periodontitis complicated with extreme mobility and pathologic tooth migration, which resulted in compromised function and aesthetics. PMID:25859109

  3. Computer-Assisted Technique for Surgical Tooth Extraction

    Directory of Open Access Journals (Sweden)

    Hosamuddin Hamza

    2016-01-01

    Full Text Available Introduction. Surgical tooth extraction is a common procedure in dentistry. However, numerous extraction cases show a high level of difficulty in practice. This difficulty is usually related to inadequate visualization, improper instrumentation, or other factors related to the targeted tooth (e.g., ankyloses or presence of bony undercut. Methods. In this work, the author presents a new technique for surgical tooth extraction based on 3D imaging, computer planning, and a new concept of computer-assisted manufacturing. Results. The outcome of this work is a surgical guide made by 3D printing of plastics and CNC of metals (hybrid outcome. In addition, the conventional surgical cutting tools (surgical burs are modified with a number of stoppers adjusted to avoid any excessive drilling that could harm bone or other vital structures. Conclusion. The present outcome could provide a minimally invasive technique to overcome the routine complications facing dental surgeons in surgical extraction procedures.

  4. Is a three-dimensional-printed tooth filling possible?

    Directory of Open Access Journals (Sweden)

    Muhammet Kerim Ayar

    2016-01-01

    Full Text Available Introduction: Three-dimensional (3-D printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce treatment costs and technique-sensitivity of the placement of restorative material. The Hypothesis: Here, the hypothesis that a 3-D-printed tooth filling approach could be an alternative to traditional approaches to treatment of decayed teeth is proposed. Evaluation of the Hypothesis: The actual implementation of the 3-D-printed tooth filling technique in the practice of restorative dentistry was discussed in this manuscript.

  5. Retrieval and reattachment of an elusive tooth fragment

    Directory of Open Access Journals (Sweden)

    Savita Sangwan

    2011-01-01

    Full Text Available Traumatic dental injuries of uncomplicated nature are a common finding and upper central incisors are the most commonly affected teeth. Sometimes, the fractured fragment or the tooth gets embedded in the surrounding soft tissues and is often missed. There are few case reports regarding the retrieval and reattachment of tooth fragment. This report presents the case of an 8-year-old girl who came with the chief complaint of pain, irritation, and tingling sensation in the lower lip since one year when her upper central incisors got fractured due to trauma along with lip laceration. A soft tissue radiograph of lower lip revealed the presence of fractured tooth fragment which was then surgically removed and reattached to one of the fractured incisors. The patient was found to be asymptomatic after the procedure. This report further highlights the importance of proper radiographic diagnosis along with clinical examination immediately after trauma in order to prevent any complications in future.

  6. Computer-Assisted Technique for Surgical Tooth Extraction

    Science.gov (United States)

    Hamza, Hosamuddin

    2016-01-01

    Introduction. Surgical tooth extraction is a common procedure in dentistry. However, numerous extraction cases show a high level of difficulty in practice. This difficulty is usually related to inadequate visualization, improper instrumentation, or other factors related to the targeted tooth (e.g., ankyloses or presence of bony undercut). Methods. In this work, the author presents a new technique for surgical tooth extraction based on 3D imaging, computer planning, and a new concept of computer-assisted manufacturing. Results. The outcome of this work is a surgical guide made by 3D printing of plastics and CNC of metals (hybrid outcome). In addition, the conventional surgical cutting tools (surgical burs) are modified with a number of stoppers adjusted to avoid any excessive drilling that could harm bone or other vital structures. Conclusion. The present outcome could provide a minimally invasive technique to overcome the routine complications facing dental surgeons in surgical extraction procedures.

  7. Precise modeling of arc tooth face-gear with transition curve

    Institute of Scientific and Technical Information of China (English)

    Cui Yanmei; Fang Zongde; Su Jinzhan; Feng Xianzhang; Peng Xianlong

    2013-01-01

    A fabrication method is adopted for which an imaginary gear simultaneously realizes conjugated meshing with an arc tooth cylindrical gear and an arc tooth face-gear. The cutter fillet and tooth crest edge form the tooth root fillet of the gear, and the linear tooth surface equation of the imaginary gear and the position vector of the curvature center of the cutter fillet are constructed with certain cutter inclination to deduce a working arc tooth surface equation. The tooth root fillet equation of the arc tooth face-gear is derived from the meshing geometry and kinematics. A numer-ically controlled machining model of the arc tooth face-gear is established through the transforma-tion of adjustment parameters from the cutter-tilt milling machine to a common multi-axis NC machine. Motion parameters of each movement axis of the NC machine are acquired. A processing example is presented to verify the precision of the fabrication method in processing the arc tooth face-gear. The method provides a theoretical and tentative basis for the analysis of tooth surface contact stress, tooth root bending stress and dynamics. A hobbing test is conducted to demonstrate the good meshing condition of the arc tooth face-gear pair.

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