WorldWideScience

Sample records for replacement tooth initiation

  1. Replacing a Missing Tooth

    Science.gov (United States)

    ... lateral incisor. This may be accomplished by adding plastic or porcelain filling material or a porcelain crown ... This type of bridge requires much less tooth reduction of adjacent teeth, and there is no danger ...

  2. Autogenous tooth transplantation for replacing a lost tooth: case reports

    Directory of Open Access Journals (Sweden)

    Ji-Youn Kang

    2013-02-01

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

  3. Autogenous tooth transplantation: an alternative to replace extracted tooth

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2015-09-01

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

  4. Autogenous Transplantation for Replacing a Hopeless Tooth.

    Science.gov (United States)

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

    2017-01-01

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

  5. Evolution of high tooth replacement rates in sauropod dinosaurs.

    Science.gov (United States)

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

    2013-01-01

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

  6. 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

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

    Directory of Open Access Journals (Sweden)

    Wahiduj Jaman

    2017-06-01

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

  8. 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.

  9. Economic evaluation of single-tooth replacement: dental implant versus fixed partial denture.

    Science.gov (United States)

    Kim, Younhee; Park, Joo-Yeon; Park, Sun-Young; Oh, Sung-Hee; Jung, YeaJi; Kim, Ji-Min; Yoo, Soo-Yeon; Kim, Seong-Kyun

    2014-01-01

    This study assessed the cost-effectiveness from a societal perspective of a dental implant compared with a three-unit tooth-supported fixed partial denture (FPD) for the replacement of a single tooth in 2010. A decision tree was developed to estimate cost-effectiveness over a 10-year period. The survival rates of single-tooth implants and FPDs were extracted from a meta-analysis of single-arm studies. Medical costs included initial treatment costs, maintenance costs, and costs to treat complications. Patient surveys were used to obtain the costs of the initial single-tooth implant or FPD. Maintenance costs and costs to treat complications were based on surveys of seven clinical experts at dental clinics or hospitals. Transportation costs were calculated based on the number of visits for implant or FPD treatment. Patient time costs were estimated using the number of visits and time required, hourly wage, and employment rate. Future costs were discounted by 5% to convert to present values. The results of a 10-year period model showed that a single dental implant cost US $261 (clinic) to $342 (hospital) more than an FPD and had an average survival rate that was 10.4% higher. The incremental cost-effectiveness ratio was $2,514 in a clinic and $3,290 in a hospital for a prosthesis in situ for 10 years. The sensitivity analysis showed that initial treatment costs and survival rate influenced the cost-effectiveness. If the cost of an implant were reduced to 80% of the current cost, the implant would become the dominant intervention. Although the level of evidence for effectiveness is low, and some aspects of single-tooth implants or FPDs, such as satisfaction, were not considered, this study will help patients requiring single-tooth replacement to choose the best treatment option.

  10. HST Replacement Battery Initial Performance

    Science.gov (United States)

    Krol, Stan; Waldo, Greg; Hollandsworth, Roger

    2009-01-01

    The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

  11. The Permian reptile Opisthodontosaurus carrolli: a model for acrodont tooth replacement and dental ontogeny.

    Science.gov (United States)

    Haridy, Yara; LeBlanc, Aaron R H; Reisz, Robert R

    2018-03-01

    Continuous tooth replacement is common for tetrapods, but some groups of acrodont lepidosaurs have lost the ability to replace their dentition (monophyodonty). Acrodonty, where the tooth attaches to the apex of the jawbone, is an unusual form of tooth attachment that has been associated with the highly autapomorphic condition of monophyodonty. Beyond Lepidosauria, very little is known about the relationship between acrodonty and monophyodonty in other amniotes. We test for this association with a detailed study of the dentition of Opisthodontosaurus, an unusual Early Permian captorhinid eureptile with acrodont dentition. We provide clear evidence, both histological and morphological, that there were regular tooth replacement events in the lower jaw of Opisthodontosaurus, similar to its captorhinid relatives. Thus, our study of the oldest known amniote with an acrodont dentition shows that acrodonty does not inhibit tooth replacement, and that many of the characteristics assigned to lepidosaurian acrodonty are actually highly derived features of lepidosaurs that have resulted secondarily from a lack of tooth replacement. In the context of reptilian dental evolution, we propose the retention of the simple definition of acrodonty, which only pertains to the relative position of the tooth at the apex of the jaw, where the jaw possesses equal lingual and labial walls. This definition of implantation therefore focuses solely on the spatial relationship between the tooth and the jawbone, and separates this relationship from tooth development and replacement. © 2017 Anatomical Society.

  12. Replacement of missing tooth in esthetic zone with implant-supported fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Sunil Kumar Mishra

    2017-01-01

    Full Text Available In the anterior region, the common reason for tooth loss is due to traumatic injury or congenital anomaly. Loss of a single tooth may cause functional and esthetic deficits to the patient. There are different treatment options available for replacing a missing incisor. Implant dentistry should be considered as first treatment alternative for replace a missing tooth. This case report presents the replacement of a missing maxillary left central incisor in a compromised site with dental implants along with bone graft followed by frenectomy to obtain a good clinical result and for better function and esthetics of the patient.

  13. Osteoblast and osteoclast behaviors in the turnover of attachment bones during medaka tooth replacement.

    Science.gov (United States)

    Mantoku, Akiko; Chatani, Masahiro; Aono, Kazushi; Inohaya, Keiji; Kudo, Akira

    2016-01-15

    Tooth replacement in polyphyodont is a well-organized system for maintenance of homeostasis of teeth, containing the dynamic structural change in skeletal tissues such as the attachment bone, which is the supporting element of teeth. Histological analyses have revealed the character of tooth replacement, however, the cellular mechanism of how skeletal tissues are modified during tooth replacement is largely unknown. Here, we showed the important role of osteoblasts for controlling osteoclasts to modify the attachment bone during tooth replacement in medaka pharyngeal teeth, coupled with an osterix-DsRed/TRAP-GFP transgenic line to visualize osteoblasts and osteoclasts. In the turnover of the row of attachment bones, these bones were resorbed at the posterior side where most developed functional teeth were located, and generated at the anterior side where teeth were newly erupted, which caused continuous tooth replacement. In the cellular analysis, osteoclasts and osteoblasts were located at attachment bones separately, since mature osteoclasts were localized at the resorbing side and osteoblasts gathered at the generating side. To demonstrate the role of osteoclasts in tooth replacement, we established medaka made deficient in c-fms-a by TALEN. c-fms-a deficient medaka showed hyperplasia of attachment bones along with reduced bone resorption accompanied by a low number of TRAP-positive osteoclasts, indicating an important role of osteoclasts in the turnover of attachment bones. Furthermore, nitroreductase-mediated osteoblast-specific ablation induced disappearance of osteoclasts, indicating that osteoblasts were essential for maintenance of osteoclasts for the proper turnover. Taken together, our results suggested that the medaka attachment bone provides the model to understand the cellular mechanism for tooth replacement, and that osteoblasts act in the coordination of bone morphology by supporting osteoclasts. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up

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    R. Ebru Tirali

    2013-01-01

    Full Text Available Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

  15. Unique method of tooth replacement in durophagous placodont marine reptiles, with new data on the dentition of Chinese taxa.

    Science.gov (United States)

    Neenan, James M; Li, Chun; Rieppel, Olivier; Bernardini, Federico; Tuniz, Claudio; Muscio, Giuseppe; Scheyer, Torsten M

    2014-05-01

    The placodonts of the Triassic period (~252-201 mya) represent one of the earliest and most extreme specialisations to a durophagous diet of any known reptile group. Exceptionally enlarged crushing tooth plates on the maxilla, dentary and palatine cooperated to form functional crushing areas in the buccal cavity. However, the extreme size of these teeth, combined with the unusual way they occluded, constrained how replacement occurred. Using an extensive micro-computed tomographic dataset of 11 specimens that span all geographic regions and placodont morphotypes, tooth replacement patterns were investigated. In addition, the previously undescribed dental morphologies and formulae of Chinese taxa are described for the first time and incorporated into the analysis. Placodonts have a unique tooth replacement pattern and results follow a phylogenetic trend. The plesiomorphic Placodus species show many replacement teeth at various stages of growth, with little or no discernible pattern. On the other hand, the more derived cyamodontoids tend to have fewer replacement teeth growing at any one time, replacing teeth unilaterally and/or in functional units, thus maintaining at least one functional crushing area at all times. The highly derived placochelyids have fewer teeth and, as a result, only have one or two replacement teeth in the upper jaw. This supports previous suggestions that these taxa had an alternative diet to other placodonts. Importantly, all specimens show at least one replacement tooth growing at the most posterior palatine tooth plates, indicating increased wear at this point and thus the most efficient functional crushing area. © 2014 Anatomical Society.

  16. Identification of putative dental epithelial stem cells in a lizard with life-long tooth replacement.

    Science.gov (United States)

    Handrigan, Gregory R; Leung, Kelvin J; Richman, Joy M

    2010-11-01

    Most dentate vertebrates, including humans, replace their teeth and yet the process is poorly understood. Here, we investigate whether dental epithelial stem cells exist in a polyphyodont species, the leopard gecko (Eublepharis macularius). Since the gecko dental epithelium lacks a histologically distinct site for stem cells analogous to the mammalian hair follicle bulge, we performed a pulse-chase experiment on juvenile geckos to identify label-retaining cells (LRCs). We detected LRCs exclusively on the lingual side of the dental lamina, which exhibits low proliferation rates and is not involved in tooth morphogenesis. Lingual LRCs were organized into pockets of high density close to the successional lamina. A subset of the LRCs expresses Lgr5 and other genes that are markers of adult stem cells in mammals. Also similar to mammalian stem cells, the LRCs appear to proliferate in response to gain of function of the canonical Wnt pathway. We suggest that the LRCs in the lingual dental lamina represent a population of stem cells, the immediate descendents of which form the successional lamina and, ultimately, the replacement teeth in the gecko. Furthermore, their location on the non-tooth-forming side of the dental lamina implies that dental stem cells are sequestered from signals that might otherwise induce them to differentiate.

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

    DEFF Research Database (Denmark)

    Gotfredsen, Klaus

    2004-01-01

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

  18. Tooth replacement related to number of natural teeth in a dentate adult population in Bulgaria: a cross-sectional study

    NARCIS (Netherlands)

    Damyanov, N.D.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2013-01-01

    PURPOSE: This study aimed to explore the relationships among tooth replacement, number of present natural teeth, and sociodemographic and behavioral factors in an adult population in Bulgaria. MATERIALS AND METHODS: Quota sampling was used to recruit 2,531 dentate subjects aged 20 years and over

  19. 'Your whole life is lived through your teeth': biographical disruption and experiences of tooth loss and replacement.

    Science.gov (United States)

    Rousseau, Nikki; Steele, Jimmy; May, Carl; Exley, Catherine

    2014-03-01

    The experience and meaning of tooth loss and replacement has varied historically and culturally but has received relatively little attention from social scientists. Our study set out to understand these experiences in the context of the arrival of newer, dental implant treatments. Semi-structured qualitative interviews were carried out with 39 men and women who had experienced tooth loss and replacement. A thematic analysis was sensitised by previous sociological work on chronic illness, particularly Bury's notion of biographical disruption. We found that while for some individuals the loss of a tooth was relatively insignificant, for others it was devastating and disruptive. In seeking to understand this difference, the concept of biographical disruption was a helpful analytical tool. Our analysis identified two forms of disruption. The first related to the meanings of tooth loss (the neglected mouth) and denture wearing (a marker of old age). The second, embodied, disruption concerned the relationship between the self and mouth in those wearing dentures (the invaded, unreliable mouth) and could occur even where tooth loss and denture wearing had been biographically anticipated. © 2013 The Authors. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd.

  20. 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...

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

    Directory of Open Access Journals (Sweden)

    Mladenović Dragan

    2013-01-01

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

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

    Science.gov (United States)

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

    2013-09-01

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

  3. 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

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

    International Nuclear Information System (INIS)

    Yang Xu; Liu Xue; Zhang Heng; Deng Yan; Guo Zhaozhong; Zhang Yufeng

    2011-01-01

    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)

  5. Differences of isolated dental stem cells dependent on donor age and consequences for autologous tooth replacement.

    Science.gov (United States)

    Kellner, Manuela; Steindorff, Marina M; Strempel, Jürgen F; Winkel, Andreas; Kühnel, Mark P; Stiesch, Meike

    2014-06-01

    Autologous therapy via stem cell-based tissue regeneration is an aim to rebuild natural teeth. One option is the use of adult stem cells from the dental pulp (DPSCs), which have been shown to differentiate into several types of tissue in vitro and in vivo, especially into tooth-like structures. DPSCs are mainly isolated from the dental pulp of third molars routinely extracted for orthodontic reasons. Due to the extraction of third molars at various phases of life, DPSCs are isolated at different developmental stages of the tooth. The present study addressed the question whether DPSCs from patients of different ages were similar in their growth characteristics with respect to the stage of tooth development. Therefore DPSCs from third molars of 12-30 year-old patients were extracted, and growth characteristics, e.g. doubling time and maximal cell division potential were analysed. In addition, pulp and hard dental material weight were recorded. Irrespective of the age of patients almost all isolated cells reached 40-60 generations with no correlation between maximal cell division potential and patient age. Cells from patients <22 years showed a significantly faster doubling time than the cells from patients ≥22 years. The age of patients at the time of stem cell isolation is not a crucial factor concerning maximal cell division potential, but does have an impact on the doubling time. However, differences in individuals regarding growth characteristics were more pronounced than age-dependent differences. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Tooth replacements in young adults with severe hypodontia: Orthodontic space closure, dental implants, and tooth-supported fixed dental prostheses. A follow-up study.

    Science.gov (United States)

    Hvaring, Christina L; Øgaard, Bjørn; Birkeland, Kari

    2016-10-01

    Children with severe hypodontia have a substantial impairment of their dental health starting early in life. The purpose of this study was to describe types and locations of substitutes for missing teeth in patients with severe hypodontia and to compare the crown and soft tissue morphologies of orthodontic space closure, dental implants, and tooth-supported fixed dental prostheses for replacing teeth in the anterior region. Fifty patients missing 6 or more teeth and aged 18 years or older (mean age, 25.6 years) took part in a follow-up study. The patients were examined clinically with panoramic radiographs and clinical photographs. Crown and soft tissue variables (mucosal discoloration, crown morphology, color, and papilla index) were compared for orthodontic space closure, dental implant fixtures, and fixed dental prostheses. Dental implants, orthodontic space closure, and retaining deciduous teeth were the most commonly prescribed treatments. Persisting deciduous teeth showed a good survival rate at the follow-up examination. Mucosal discoloration was seen only for implant fixtures and was evident for almost all fixtures in the anterior mandible and two thirds of those in the anterior maxilla. The papilla index scored poorer for both implant fixtures and fixed dental prostheses compared with orthodontic space closure. Dental implants in the anterior region proved to be an inadequate treatment modality in patients with severe hypodontia because of pronounced mucosal discoloration. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  7. [Application of single-retainer all-ceramic resin-bonded fixed partial denture in replacing single anterior tooth].

    Science.gov (United States)

    Lili, Yang; Debiao, Du; Ruoyu, Ning; Deying, Chen; Junling, Wu

    2017-08-01

    Objective In this study, we aimed to evaluate the clinical effect of single-retainer all-ceramic resin-bonded fixed partial denture (RBFPD) on the single anterior tooth loss patients. Methods A total of 20 single-retainer all-ceramic RBFPD
were fabricated and evaluated in a two-year follow-up observation. The restorations were examined on the basis of the American Public Health Association (APHA) criteria. Results A total of 20 single-retainer all-ceramic RBFPD achieved class A evaluation after a six-month follow-up observation. One single-retainer all-ceramic RBFPD was classified as class B for secondary caries after a one-year follow-up observation. After a two-year follow-up observation, one single-retainer all-ceramic RBFPD was classified as class B because of secondary caries, and one single-retainer all-ceramic RBFPD was classified as class B because of fracture. Conclusion Single-retainer all-ceramic RBFPD is a promising and optional method in replacing single anterior tooth.

  8. Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures : A prospective randomized clinical study

    NARCIS (Netherlands)

    Meijndert, Leo; Meijer, Henny J. A.; Stellingsma, Kees; Stegenga, Boudewijn; Raghoebar, Gerry M.

    2007-01-01

    Objectives: The aim of this study was to evaluate the aesthetics of implant-supported single-tooth replacements using different augmentation procedures in a prospective study with the use of an objective rating index and with a subjective patient questionnaire, and to compare the results with each

  9. Long-term neuroplasticity of the face primary motor cortex and adjacent somatosensory cortex induced by tooth loss can be reversed following dental implant replacement in rats.

    Science.gov (United States)

    Avivi-Arber, Limor; Lee, Jye-Chang; Sood, Mandeep; Lakschevitz, Flavia; Fung, Michelle; Barashi-Gozal, Maayan; Glogauer, Michael; Sessle, Barry J

    2015-11-01

    Tooth loss is common, and exploring the neuroplastic capacity of the face primary motor cortex (face-M1) and adjacent primary somatosensory cortex (face-S1) is crucial for understanding how subjects adapt to tooth loss and their prosthetic replacement. The aim was to test if functional reorganization of jaw and tongue motor representations in the rat face-M1 and face-S1 occurs following tooth extraction, and if subsequent dental implant placement can reverse this neuroplasticity. Rats (n = 22) had the right maxillary molar teeth extracted under local and general anesthesia. One month later, seven rats had dental implant placement into healed extraction sites. Naive rats (n = 8) received no surgical treatment. Intracortical microstimulation (ICMS) and recording of evoked jaw and tongue electromyographic responses were used to define jaw and tongue motor representations at 1 month (n = 8) or 2 months (n = 7) postextraction, 1 month postimplant placement, and at 1-2 months in naive rats. There were no significant differences across study groups in the onset latencies of the ICMS-evoked responses (P > 0.05), but in comparison with naive rats, tooth extraction caused a significant (P rats. These novel findings suggest that face-M1 and adjacent face-S1 may play a role in adaptive mechanisms related to tooth loss and their replacement with dental implants. © 2015 Wiley Periodicals, Inc.

  10. Initial arch wires for tooth alignment during orthodontic treatment with fixed appliances.

    Science.gov (United States)

    Jian, Fan; Lai, Wenli; Furness, Susan; McIntyre, Grant T; Millett, Declan T; Hickman, Joy; Wang, Yan

    2013-04-30

    Initial arch wires are the first arch wires to be inserted into the fixed appliance at the beginning of orthodontic treatment and are used mainly for the alignment of teeth by correcting crowding and rotations. With a number of different types of orthodontic arch wires available for initial tooth alignment, it is important to understand which wire is most efficient, as well as which wires cause the least amount of root resorption and pain during the initial aligning stage of treatment. This is an update of the review 'Initial arch wires for alignment of crooked teeth with fixed orthodontic braces' first published in the Cochrane Database of Systematic Reviews 2010, Issue 4. To assess the effects of initial arch wires for alignment of teeth with fixed orthodontic braces in relation to alignment speed, root resorption and pain intensity. We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 2 August 2012), CENTRAL (The Cochrane Library 2012, Issue 7), MEDLINE via OVID (1950 to 2 August 2012) and EMBASE via OVID (1980 to 2 August 2012). We also searched the reference lists of relevant articles. There was no restriction with regard to publication status or language of publication. We contacted all authors of included studies to identify additional studies. We included randomised controlled trials (RCTs) of initial arch wires to align teeth with fixed orthodontic braces. Only studies involving participants with upper and/or lower full arch fixed orthodontic appliances were included. Two review authors were responsible for study selection, validity assessment and data extraction. All disagreements were resolved by discussion amongst the review team. Corresponding authors of included studies were contacted to obtain missing information. Nine RCTs with 571 participants were included in this review. All trials were at high risk of bias and a number of methodological limitations were identified. All trials had at least one

  11. Levels of matrix metalloproteinase-7 and osteopontin in human gingival crevicular fluid during initial tooth movement

    Directory of Open Access Journals (Sweden)

    Dhaval Oswal

    2015-01-01

    Full Text Available Purpose: During orthodontic treatment, the early response of periodontal tissues to mechanical stress involves several metabolic changes that allow tooth movement. The purpose of this investigation was to evaluate osteopontin (OPN and matrix metalloproteinase (MMP-7 in the gingival crevicular fluid (GCF of human teeth exposed to orthodontic force. Materials and Methods: GCF samples were obtained from 15 healthy orthodontic patients (age, 12-22 years. In each patient, the left maxillary canine having the fixed orthodontic appliance was used as the test tooth, and its antagonist, with no appliance, was the control. Orthodontic force, 75 g was applied using a 16 × 22 beta titanium closing loop. The GCF sampling on the disto-buccal aspects of experimental and control tooth was performed at specific time interval with sterilized absorbent paper point. Processing was carried out with enzyme-linked immunosorbent assay to detect OPN and MMP-7 levels. Results: The peak level of OPN was seen after 1 h application of orthodontic force which was 1280.36 pg/ml ± 185.02. The peak level of MMP-7 was seen at 0 h which was 598.3 pg/ml ± 107.5. The levels of OPN after 1 h increased to 1280.36 pg/ml ± 185.02, and they decreased at 24 h to 1012.86 pg/ml ± 168.47 (P = 0.001. The levels of MMP-7 after 1 h decreased to 478 pg/ml ± 99.7 which increased at 24 h to 526.9 pg/ml ± 99.2. Conclusions: Orthodontic forces affect both OPN and MMP-7 protein levels on the compression side in a time-dependent fashion.

  12. An in vitro study to compare the accuracy of the master cast fabricated by four different transfer impression techniques for single-tooth implant replacement.

    Science.gov (United States)

    Lahori, Manesh; Nagrath, Rahul; Agrawal, Prateek

    2014-03-01

    Single tooth implant retained crowns have become a recognized technique for the replacement of the missing teeth. With the predictable integration of implants, the emphasis is shifted towards precise prosthesis. Minor movement of the impression coping retained inside the impression material can occur during all the procedures, leading to the three-dimensional spatial inaccuracies in the master casts. Therefore, the present study was undertaken with the purpose to evaluate the accuracy of single-tooth implant impression techniques using four different impression copings, so as to obtain a precise definitive cast for a single-unit implant restoration. A maxillary acrylic resin model with a standard single implant in the first molar region was used to simulate a clinical situation. A total of 60 impressions were made with polyvinylsiloxane impression material, which were divided into four groups of 15 impressions each. Group I used non-modified square impression coping, while in group II, III and IV square impression coping were modified differently. Master casts fabricated for all the groups were analyzed to detect rotational position change of the hexagon on the implant replicas in the master casts in reference to the resin model. The master casts obtained with the roughened and adhesive-coated impression copings showed a lower amount of rotational movement than the masters casts achieved with the non-modified impression copings. Hence, the clinician should use sandblasted and adhesive coated impression copings to achieve a more accurate and precise orientation of the implant replicas in the laboratory master casts in single-tooth implant restorations.

  13. Replacement

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2014-03-01

    Full Text Available The fishmeal replaced with Spirulina platensis, Chlorella vulgaris and Azolla pinnata and the formulated diet fed to Macrobrachium rosenbergii postlarvae to assess the enhancement ability of non-enzymatic antioxidants (vitamin C and E, enzymatic antioxidants (superoxide dismutase (SOD and catalase (CAT and lipid peroxidation (LPx were analysed. In the present study, the S. platensis, C. vulgaris and A. pinnata inclusion diet fed groups had significant (P < 0.05 improvement in the levels of vitamins C and E in the hepatopancreas and muscle tissue. Among all the diets, the replacement materials in 50% incorporated feed fed groups showed better performance when compared with the control group in non-enzymatic antioxidant activity. The 50% fishmeal replacement (best performance diet fed groups taken for enzymatic antioxidant study, in SOD, CAT and LPx showed no significant increases when compared with the control group. Hence, the present results revealed that the formulated feed enhanced the vitamins C and E, the result of decreased level of enzymatic antioxidants (SOD, CAT and LPx revealed that these feeds are non-toxic and do not produce any stress to postlarvae. These ingredients can be used as an alternative protein source for sustainable Macrobrachium culture.

  14. Use of nonsteroidal anti-inflammatory drugs prior to chronic renal replacement therapy initiation

    DEFF Research Database (Denmark)

    Kristensen, Søren Lund; Fosbøl, Emil L; Kamper, Anne-Lise

    2012-01-01

    PURPOSE: Nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with severe renal complications, including acute renal failure, reduced glomerular filtration rate and interstitial nephritis. Caution against NSAIDs is therefore recommended in advanced chronic kidney disease. In this study......, we examined NSAID use, aetiology and comorbidity among a national cohort of patients before the initiation of chronic renal replacement therapy (RRT). METHODS: Patients initiated on chronic RRT in the period 1997-2006 were identified in the Danish National Registry on Regular Dialysis...

  15. Phase transformations in a human tooth tissue at the initial stage of caries.

    Directory of Open Access Journals (Sweden)

    Pavel Seredin

    Full Text Available The aim of the paper is to study phase transformations in solid tissues of the human teeth during the development of fissure caries by Raman and fluorescence microspectroscopy. The study of the areas with fissure caries confirmed the assumption of the formation of a weak interaction between phosphate apatite enamel and organic acids (products of microorganisms. The experimental results obtained with by Raman microspectroscopy showed the formation of dicalcium phosphate dihydrate - CaHPO4-2H2O in the area of mural demineralization of carious fissure. A comparative analysis of structural and spectroscopic data for the intact and carious enamel shows that emergence of a more soluble phase - carbonate-substituted hydroxyapatite - is typical for the initial stage of caries. It is shown that microareas of dental hard tissues in the carious fissure due to an emerging misorientation of apatite crystals have a higher fluorescence yield than the area of the intact enamel. These areas can be easily detected even prior to a deep demineralization (white spot stage for the case of irreversibly changed organomineral complex and intensive removal of the mineral component.

  16. Phase Transformations in a Human Tooth Tissue at the Initial Stage of Caries

    Science.gov (United States)

    Prutskij, Tatiana; Ippolitov, Yury

    2015-01-01

    The aim of the paper is to study phase transformations in solid tissues of the human teeth during the development of fissure caries by Raman and fluorescence microspectroscopy. The study of the areas with fissure caries confirmed the assumption of the formation of a weak interaction between phosphate apatite enamel and organic acids (products of microorganisms). The experimental results obtained with by Raman microspectroscopy showed the formation of dicalcium phosphate dihydrate - CaHPO4-2H2O in the area of mural demineralization of carious fissure. A comparative analysis of structural and spectroscopic data for the intact and carious enamel shows that emergence of a more soluble phase - carbonate-substituted hydroxyapatite - is typical for the initial stage of caries. It is shown that microareas of dental hard tissues in the carious fissure due to an emerging misorientation of apatite crystals have a higher fluorescence yield than the area of the intact enamel. These areas can be easily detected even prior to a deep demineralization (white spot stage) for the case of irreversibly changed organomineral complex and intensive removal of the mineral component. PMID:25901743

  17. Tooth anatomy

    Science.gov (United States)

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

  18. Assessment of myeloperoxidase activity at different force levels in gingival crevicular fluid during initial phase of orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Honey Gurbaxani

    2017-01-01

    Full Text Available Background: Orthodontic movements promote remodeling of the alveolar bone, which is mediated by inflammatory reactions such as characterized by vascular changes and infiltration of leukocytes. Changes in the periodontium occur, depending on the magnitude, duration, and direction of applied force. These changes are often seen in the saliva and gingival fluids through the various substances secreted in them. Aim: The present study aimed to assess myeloperoxidase (MPO activity at different force levels in gingival crevicular fluid (GCF during the initial phase of orthodontic tooth movement by varying the effective force levels to 50, 75, 100, and 150 g. Materials and Methods: A total of thirty participants between the age groups of 18–25 years requiring upper first premolar extractions were included in the study. They were divided into three groups (I, II, and III of ten individuals each, again subdivided into two Subgroups A and B depending on the amount of force applied to the canine. Subgroup A of all the three groups used 150 g, whereas Subgroup B used 50, 75, and 100 g of force, respectively. GCF was collected at 2 h, 7 days, and 14 days of force application. Statistical Analysis: Paired t-test and ANOVA test were used to provide the descriptive statistics of mean optical density to detect the presence of MPO in GCF. Results and Conclusion: There was a highly significant increase in the MPO levels in the GCF at 14th day after force application which can be correlated to the onset of inflammatory reactions in the periodontium.

  19. Feasibility of Early-Initiated Progressive Resistance Training after Total Hip Replacement

    DEFF Research Database (Denmark)

    Mikkelsen, Lone Ramer; Mechlenburg, Inger; Petersen, Annemette Krintel

    during the exercises were measured at each training session. Isometric muscle strength was measured before and 4 weeks after the THR. Findings / Results: Pain during exercises and resting pain before and after each training session was unchanged or decreased during the 4 weeks of training. Averaged...... across exercises pain during training decreased from 3.6 (sd: 2.8) at the first session to 1.52 (sd: 1.8) VAS-mm at the last session, ptraining load increased progressively for all 4 exercises during the 4 weeks of training. For example: 2nd, 5th and 8th training session. Hip......Background: Muscle atrophy, reduced hip muscle strength and function are documented within the first weeks after Total Hip Replacement (THR). Purpose / Aim of Study: The purpose of this study was to evaluate the feasibility of early-initiated progressive resistance training (PRT) after THR...

  20. Advances in in vivo EPR Tooth Biodosimetry: Meeting the targets for initial triage following a large-scale radiation event

    International Nuclear Information System (INIS)

    Flood, Ann Barry; Schreiber, Wilson; Du, Gaixin; Wood, Victoria A.; Kmiec, Maciej M.; Petryakov, Sergey V.; Williams, Benjamin B.; Swartz, Harold M.; Demidenko, Eugene; Boyle, Holly K.; Dong, Ruhong; Geimer, Shireen; Jarvis, Lesley A.; Kobayashi, Kyo; Nicolalde; Roberto, J.; Crist, Jason; Gupta, Ankit; Raynolds, Timothy; Brugger, Spencer; Budzioh, Pawel; Carr, Brandon; Feldman, Matthew; Gimi, Barjor; Grinberg, Oleg; Krymov, Vladimir; Lesniewski, Piotr; Mariani, Michael; Meaney, Paul M.; Rychert, Kevin M.; Salikhov, Ildar; Tipikin, Dmitriy S.; Tseytlin, Mark; Edwards, Brian R.; Herring, Christopher D.; Lindsay, Catherine; Rosenbaum, Traci; Ali, Arif; Carlson, David; Froncisz, Wojciech; Hirata, Hiroshi; Sidabras, Jason; Swarts, Steven G.

    2016-01-01

    Several important recent advances in the development and evolution of in vivo Tooth Biodosimetry using Electron Paramagnetic Resonance (EPR) allow its performance to meet or exceed the U.S. targeted requirements for accuracy and ease of operation and throughput in a large-scale radiation event. Ergonomically based changes to the magnet, coupled with the development of rotation of the magnet and advanced software to automate collection of data, have made it easier and faster to make a measurement. From start to finish, measurements require a total elapsed time of 5 min, with data acquisition taking place in less than 3 min. At the same time, the accuracy of the data for triage of large populations has improved, as indicated using the metrics of sensitivity, specificity and area under the ROC curve. Applying these standards to the intended population, EPR in vivo Tooth Biodosimetry has approximately the same diagnostic accuracy as the purported 'gold standard' (dicentric chromosome assay). Other improvements include miniaturisation of the spectrometer, leading to the creation of a significantly lighter and more compact prototype that is suitable for transporting for Point of Care (POC) operation and that can be operated off a single standard power outlet. Additional advancements in the resonator, including use of a disposable sensing loop attached to the incisor tooth, have resulted in a biodosimetry method where measurements can be made quickly with a simple 5-step workflow and by people needing only a few minutes of training (which can be built into the instrument as a training video). In sum, recent advancements allow this prototype to meet or exceed the US Federal Government's recommended targets for POC biodosimetry in large-scale events. (authors)

  1. Extent of tooth decay in the mouth and increased need for replacement of dental restorations: the New England Children's Amalgam Trial.

    Science.gov (United States)

    Trachtenberg, Felicia; Maserejian, Nancy Nairi; Tavares, Mary; Soncini, Jennifer Ann; Hayes, Catherine

    2008-01-01

    The purpose of this study was to assess the relationship between baseline caries experience and the restoration replacement rate in children. The 5-year New England Children's Amalgam Trial recruited 534 6- to 10-year-old children with 2 or more carious posterior teeth. The association between decoy and longevity of restorations was assessed. Restorations with no follow-up (N = 391) were excluded from analysis. The average follow-up was 3.0 +/- 1.6 years in 489 children. Restorations with follow-up (N = 3,604) were placed in mouths with a median of 15 dfs/DFS and 8 dft/DFT. The need for replacement increased significantly (P or = 14 dfs/DFS needed replacement, compared to 9% for 2 to 5 dfs/DFS. Comparing dft/DFT after 5 years of follow-up, there was a 23% replacement rate for > or = 12 dft/DFT compared to 10% for 2 to 3 dft/DFT. Decoy in the mouth had a greater association with the need for replacement due to new caries compared to replacement due to recurrent caries. Children with more decoy at the time of restoration placement were at higher risk for replacement of restorations.

  2. Initiating Heavy-atom Based Phasing by Multi-Dimensional Molecular Replacement

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu

    2014-01-01

    -based approaches, which however may fail when only poorly diffracting derivative crystals are available, as often the case for e.g. membrane proteins. Here we present an approach for heavy atom site identification based on a Molecular Replacement Parameter Matrix (MRPM) search. It involves an n-dimensional search...... to test a wide spectrum of molecular replacement parameters, such as clusters of different conformations. The result is scored by the ability to identify heavy-atom positions, from anomalous difference Fourier maps, that allow meaningful phases to be determined. The strategy was successfully applied...... but correct molecular replacement solutions with maximum contrast to prime experimental phasing efforts....

  3. A comparison of early versus late initiation of renal replacement therapy in critically ill patients with acute kidney injury

    DEFF Research Database (Denmark)

    Karvellas, Constantine J; Farhat, Maha R; Sajjad, Imran

    2011-01-01

    Introduction: Our aim was to investigate the impact of early versus late initiation of renal replacement therapy (RRT) on clinical outcomes in critically ill patients with acute kidney injury (AKI). Methods: Systematic review and meta-analysis were used in this study. PUBMED, EMBASE, SCOPUS, Web ...

  4. Recommendations for initiation and cessation of enzyme replacement therapy in patients with Fabry disease

    DEFF Research Database (Denmark)

    Biegstraaten, Marieke; Arngrímsson, Reynir; Barbey, Frederic

    2015-01-01

    INTRODUCTION: Fabry disease (FD) is a lysosomal storage disorder resulting in progressive nervous system, kidney and heart disease. Enzyme replacement therapy (ERT) may halt or attenuate disease progression. Since administration is burdensome and expensive, appropriate use is mandatory. We aimed ...

  5. 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.

  6. Test Tube Tooth: The Next Big Thing.

    Science.gov (United States)

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

    2016-06-01

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

  7. Estimating ages of white-tailed deer: Age and sex patterns of error using tooth wear-and-replacement and consistency of cementum annuli

    Science.gov (United States)

    Samuel, Michael D.; Storm, Daniel J.; Rolley, Robert E.; Beissel, Thomas; Richards, Bryan J.; Van Deelen, Timothy R.

    2014-01-01

    The age structure of harvested animals provides the basis for many demographic analyses. Ages of harvested white-tailed deer (Odocoileus virginianus) and other ungulates often are estimated by evaluating replacement and wear patterns of teeth, which is subjective and error-prone. Few previous studies however, examined age- and sex-specific error rates. Counting cementum annuli of incisors is an alternative, more accurate method of estimating age, but factors that influence consistency of cementum annuli counts are poorly known. We estimated age of 1,261 adult (≥1.5 yr old) white-tailed deer harvested in Wisconsin and Illinois (USA; 2005–2008) using both wear-and-replacement and cementum annuli. We compared cementum annuli with wear-and-replacement estimates to assess misclassification rates by sex and age. Wear-and-replacement for estimating ages of white-tailed deer resulted in substantial misclassification compared with cementum annuli. Age classes of females were consistently underestimated, while those of males were underestimated for younger age classes but overestimated for older age classes. Misclassification resulted in an impression of a younger age-structure than actually was the case. Additionally, we obtained paired age-estimates from cementum annuli for 295 deer. Consistency of paired cementum annuli age-estimates decreased with age, was lower in females than males, and decreased as age estimates became less certain. Our results indicated that errors in the wear-and-replacement techniques are substantial and could impact demographic analyses that use age-structure information. 

  8. The initial bearing capacities of subchondral bone replacements considerably contributing to chondrogenesis

    Czech Academy of Sciences Publication Activity Database

    Petrtýl, M.; Danešová, J.; Lísal, J.; Šenolt, L.; Hulejová, H.; Polanská, M.; Bastl, Zdeněk; Kruliš, Zdeněk; Černý, P.

    2010-01-01

    Roč. 12, č. 3 (2010), s. 59-65 ISSN 1509-409X R&D Projects: GA ČR GA106/06/0761 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40500505 Keywords : biomechanics * osteochondral defects * polymer replacement Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.432, year: 2010

  9. Initiating heavy-atom-based phasing by multi-dimensional molecular replacement.

    Science.gov (United States)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu; Karlsen, Jesper Lykkegaard; Nissen, Poul

    2016-03-01

    To obtain an electron-density map from a macromolecular crystal the phase problem needs to be solved, which often involves the use of heavy-atom derivative crystals and concomitant heavy-atom substructure determination. This is typically performed by dual-space methods, direct methods or Patterson-based approaches, which however may fail when only poorly diffracting derivative crystals are available. This is often the case for, for example, membrane proteins. Here, an approach for heavy-atom site identification based on a molecular-replacement parameter matrix (MRPM) is presented. It involves an n-dimensional search to test a wide spectrum of molecular-replacement parameters, such as different data sets and search models with different conformations. Results are scored by the ability to identify heavy-atom positions from anomalous difference Fourier maps. The strategy was successfully applied in the determination of a membrane-protein structure, the copper-transporting P-type ATPase CopA, when other methods had failed to determine the heavy-atom substructure. MRPM is well suited to proteins undergoing large conformational changes where multiple search models should be considered, and it enables the identification of weak but correct molecular-replacement solutions with maximum contrast to prime experimental phasing efforts.

  10. Optimal timing of renal replacement therapy initiation in acute kidney injury: the elephant felt by the blindmen?

    Science.gov (United States)

    Shiao, Chih-Chung; Huang, Tao-Min; Spapen, Herbert D; Honore, Patrick M; Wu, Vin-Cent

    2017-06-20

    Renal replacement therapy (RRT) is a key component in the management of severe acute kidney injury (AKI) in critically ill patients. Many cohort studies, meta-analyses, and two recent large randomized prospective trials which evaluated the relationship between the timing of RRT initiation and patient outcome remain inconclusive due to substantial differences in study design, patient population, AKI definition, and RRT indication. A cause-specific diagnosis of AKI based on current staging criteria plus a sensitive biomarker (panel) that allows creating a homogeneous study population is definitely needed to assess the impact of early versus late initiation of RRT on patient outcome.

  11. Tooth wear

    Directory of Open Access Journals (Sweden)

    Tušek Ivan

    2014-01-01

    Full Text Available Tooth wear is the loss of dental hard tissue that was not caused by decay and represents a common clinical problem of modern man. In the etiology of dental hard tissue lesions there are three dominant mechanisms that may act synergistically or separately:friction (friction, which is caused by abrasion of exogenous, or attrition of endogenous origin, chemical dissolution of dental hard tissues caused by erosion, occlusal stress created by compression and flexion and tension that leads to tooth abfraction and microfracture. Wear of tooth surfaces due to the presence of microscopic imperfections of tooth surfaces is clinically manifested as sanding veneers. Tribology, as an interdisciplinary study of the mechanisms of friction, wear and lubrication at the ultrastructural level, has defined a universal model according to which the etiopathogenesis of tooth wear is caused by the following factors: health and diseases of the digestive tract, oral hygiene, eating habits, poor oral habits, bruxism, temporomandibular disorders and iatrogenic factors. Attrition and dental erosion are much more common in children with special needs (Down syndrome. Erosion of teeth usually results from diseases of the digestive tract that lead to gastroesophageal reflux (GER of gastric juice (HCl. There are two basic approaches to the assessment of the degree of wear and dental erosion. Depending on the type of wear (erosion, attrition, abfraction, the amount of calcium that was realised during the erosive attack could be determined qualitatively and quantitatively, or changes in optical properties and hardness of enamel could be recorded, too. Abrasion of teeth (abrasio dentium is the loss of dental hard tissue caused by friction between the teeth and exogenous foreign substance. It is most commonly provoked by prosthetic dentures and bad habits, while its effect depends on the size of abrasive particles and their amount, abrasive particle hardness and hardness of tooth

  12. Role of multiple cusps in tooth fracture.

    Science.gov (United States)

    Barani, Amir; Bush, Mark B; Lawn, Brian R

    2014-07-01

    The role of multiple cusps in the biomechanics of human molar tooth fracture is analysed. A model with four cusps at the bite surface replaces the single dome structure used in previous simulations. Extended finite element modelling, with provision to embed longitudinal cracks into the enamel walls, enables full analysis of crack propagation from initial extension to final failure. The cracks propagate longitudinally around the enamel side walls from starter cracks placed either at the top surface (radial cracks) or from the tooth base (margin cracks). A feature of the crack evolution is its stability, meaning that extension occurs steadily with increasing applied force. Predictions from the model are validated by comparison with experimental data from earlier publications, in which crack development was followed in situ during occlusal loading of extracted human molars. The results show substantial increase in critical forces to produce longitudinal fractures with number of cuspal contacts, indicating a capacity for an individual tooth to spread the load during mastication. It is argued that explicit critical force equations derived in previous studies remain valid, at the least as a means for comparing the capacity for teeth of different dimensions to sustain high bite forces. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Patterns of Ninety-Day Readmissions Following Total Joint Replacement in a Bundled Payment Initiative.

    Science.gov (United States)

    Behery, Omar A; Kester, Benjamin S; Williams, Jarrett; Bosco, Joseph A; Slover, James D; Iorio, Richard; Schwarzkopf, Ran

    2017-04-01

    Alternative payment models aim to improve quality and decrease costs associated with total joint replacement. Postoperative readmissions within 90 days are of interest to clinicians and administrators as there is no additional reimbursement beyond the episode bundled payment target price. The aim of this study is to improve the understanding of the patterns of readmission which would better guide perioperative patient management affecting readmissions. We hypothesize that readmissions have different timing, location, and patient health profile patterns based on whether the readmission is related to a medical or surgical diagnosis. A retrospective cohort of 80 readmissions out of 1412 total joint replacement patients reimbursed through a bundled payment plan was analyzed. Patients were grouped by readmission diagnosis (surgical or medical) and the main variables analyzed were time to readmission, location of readmission, and baseline Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores capturing pre-existing state of health. Nonparametric tests and multivariable regressions were used to test associations. Surgical readmissions occurred earlier than medical readmissions (mean 18 vs 33 days, P = .011), and were more likely to occur at the hospital where the surgery was performed (P = .035). Perioperative Orthopaedic Surgical Home and American Society of Anesthesiologists scores did not predict medical vs surgical readmissions (P = .466 and .879) after adjusting for confounding variables. Readmissions appear to follow different patterns depending on whether they are surgical or medical. Surgical readmissions occur earlier than medical readmissions, and more often at the hospital where the surgery was performed. The results of this study suggest that these 2 types of readmissions have different patterns with different implications toward perioperative care and follow-up after total joint replacement. Copyright © 2016 Elsevier Inc

  14. Tooth wear

    OpenAIRE

    Tušek Ivan; Tušek Jasmina

    2014-01-01

    Tooth wear is the loss of dental hard tissue that was not caused by decay and represents a common clinical problem of modern man. In the etiology of dental hard tissue lesions there are three dominant mechanisms that may act synergistically or separately:friction (friction), which is caused by abrasion of exogenous, or attrition of endogenous origin, chemical dissolution of dental hard tissues caused by erosion, occlusal stress created by compression and flexion and tension that leads to toot...

  15. Incidence and severity of gingival invaginations associated with early versus late initiation of orthodontic space closure after tooth extraction : A multicenter pilot and randomized controlled trial.

    Science.gov (United States)

    Reichert, Christoph; Kutschera, Eric; Plötz, Christina; Scharf, Sven; Gölz, Lina; Fimmers, Rolf; Fuhrmann, Christine; Wahl, Gerhard; Braumann, Bert; Jäger, Andreas

    2017-09-01

    Gingival invaginations are a common side effect of orthodontic extraction-space closure. The timing of initiating the closure of an extraction space varies greatly in clinical practice. In this multicenter pilot and randomized controlled trial, we prospectively investigated whether initiating space closure in the early stage of wound healing would benefit the incidence and severity of invaginations developing in the extraction sites. A total of 368 patients were screened for indications to extract at least one mandibular premolar. Those recruited were randomly assigned to one of two treatment arms: initiation of space closure either 2-4 weeks (arm A) or ≥12 weeks (arm B) after tooth extraction. Clinical data regarding treatment process and periodontal tissue response were recorded during and after space closure and analyzed by a specialized biometrics unit. The study was performed under continuous surveillance by an independent study control center. A total of 74 extraction sites were analyzed. Regarding the incidence of gingival invaginations, there were no significant intergroup differences [p = 0.13; group A comprising 37/44 (84.1%) and group B 29/30 (96.7%) invaginated sites]. The same was true based on either maxillary (p = 0.52) or mandibular (p = 0.21) sites only, and the severity of the invaginations did not differ between the treatment arms. As to the incidence and severity of gingival invaginations, we did not notice any statistically significant differences between the two timeframes. Our data do, however, provide a basis to identify additional confounders and to improve the accuracy of case-load estimations for future trials.

  16. Comparison of functionally orientated tooth replacement and removable partial dentures on the nutritional status of partially dentate older patients: a randomised controlled clinical trial.

    Science.gov (United States)

    McKenna, Gerald; Allen, P Finbarr; O'Mahony, Denis; Flynn, Albert; Cronin, Michael; DaMata, Cristiane; Woods, Noel

    2014-06-01

    The aims of this study were to conduct a randomised controlled clinical trial (RCT) of partially dentate older adults comparing functionally orientated treatment based on the SDA concept with conventional treatment using RPDs to replace missing natural teeth. The two treatment strategies were evaluated according to their impact on nutritional status measured using haematological biomarkers. A randomised controlled clinical trial (RCT) was conducted of partially dentate patients aged 65 years and older (Trial Registration no. ISRCTN26302774). Each patient provided haematological samples which were screened for biochemical markers of nutritional status. Each sample was tested in Cork University Hospital for serum Albumin, serum Cholesterol, Ferritin, Folate, Vitamin B12 and 25-hydroxycholecalciferol (Vitamin D). A mixed model analysis of covariance (ANCOVA) indicated that for Vitamin B12 (p=0.9392), serum Folate (p=0.5827), Ferritin (p=0.6964), Albumin (p=0.8179), Serum Total Cholesterol (p=0.3670) and Vitamin D (p=0.7666) there were no statistically significant differences recorded between the two treatment groups. According to the mixed model analysis of covariance (ANCOVA) for Vitamin D there was a significant difference between levels recorded at post-operative time points after treatment intervention (p=0.0470). There was an increase of 7% in 25-hydroxycholecalciferol levels recorded at 6 months compared to baseline (p=0.0172). There was no further change in recorded levels at 12 months (p=0.6482) and these increases were similar within the two treatment groups (p>0.05). The only measure which illustrated consistent significant improvements in nutritional status for either group were Vitamin D levels. However no significant difference was recorded between the two treatment groups. Functionally orientated prosthodontic rehabilitation for partially dentate older patients was no worse than conventional removable partial dentures in terms of impact on nutritional

  17. Timing of initiation of enzyme replacement therapy after diagnosis of type 1 Gaucher disease: effect on incidence of avascular necrosis

    Science.gov (United States)

    Mistry, Pramod K; Deegan, Patrick; Vellodi, Ashok; Cole, J Alexander; Yeh, Michael; Weinreb, Neal J

    2009-01-01

    Data from the International Collaborative Gaucher Group Gaucher Registry were analysed to assess the relationship between enzyme replacement therapy with imiglucerase (ERT) and incidence of avascular necrosis (AVN) in type 1 Gaucher disease (GD1), and to determine whether the time interval between diagnosis and initiation of ERT influences the incidence rate of AVN. All patients with GD1 enrolled in the Gaucher Registry who received ERT and did not report AVN prior to starting therapy (n = 2700) were included. The incidence rate of AVN following initiation of ERT was determined. An incidence rate of AVN of 13·8 per 1000 person-years was observed in patients receiving ERT. Patients who initiated ERT within 2 years of diagnosis had an incidence rate of 8·1 per 1000 person-years; patients who started ERT ≥2 years after diagnosis had an incidence rate of 16·6 per 1000 person-years. The adjusted incidence rate ratio was 0·59 [95% confidence interval (CI) 0·36–0·96, P = 0·0343]. Splenectomy was an independent risk factor for AVN (adjusted incidence rate ratio 2·23, 95% CI 1·61–3·08, P < 0·0001). In conclusion, the risk of AVN was reduced among patients who initiated ERT within 2 years of diagnosis, compared to initiating treatment ≥2 years after diagnosis. A higher risk of AVN was observed among patients who had previously undergone splenectomy. PMID:19732054

  18. Can ultrasound extended emergency (EFAST) replace the chest radiograph in the initial approach to trauma?

    International Nuclear Information System (INIS)

    Aguirre Jimenez, Marcela

    2010-01-01

    The sensitivity diagnosed between ultrasound Extended emergency (EFAST) and portable radiography was compared. Life-threatening pathologies are detected in the initial approach to trauma, through an analysis comparative between EFAST and portable chest radiography. So, the need or not both studies or if the use of EFAST as the only diagnostic method in primary evaluation of trauma can be limited. The study has concluded that the EFAST can be used as the only tool for polytrauma patients, although in this analysis the sample has been very small [es

  19. Cutting blade dentitions in squaliform sharks form by modification of inherited alternate tooth ordering patterns

    Science.gov (United States)

    Underwood, Charlie; Johanson, Zerina; Smith, Moya Meredith

    2016-11-01

    The squaliform sharks represent one of the most speciose shark clades. Many adult squaliforms have blade-like teeth, either on both jaws or restricted to the lower jaw, forming a continuous, serrated blade along the jaw margin. These teeth are replaced as a single unit and successor teeth lack the alternate arrangement present in other elasmobranchs. Micro-CT scans of embryos of squaliforms and a related outgroup (Pristiophoridae) revealed that the squaliform dentition pattern represents a highly modified version of tooth replacement seen in other clades. Teeth of Squalus embryos are arranged in an alternate pattern, with successive tooth rows containing additional teeth added proximally. Asynchronous timing of tooth production along the jaw and tooth loss prior to birth cause teeth to align in oblique sets containing teeth from subsequent rows; these become parallel to the jaw margin during ontogeny, so that adult Squalus has functional tooth rows comprising obliquely stacked teeth of consecutive developmental rows. In more strongly heterodont squaliforms, initial embryonic lower teeth develop into the oblique functional sets seen in adult Squalus, with no requirement to form, and subsequently lose, teeth arranged in an initial alternate pattern.

  20. Effects of cultivar and grazing initiation date on fall-grown oat for replacement dairy heifers.

    Science.gov (United States)

    Coblentz, W K; Brink, G E; Esser, N M; Cavadini, J S

    2015-09-01

    Fall-grown oat has shown promise for extending the grazing season in Wisconsin, but the optimum date for initiating grazing has not been evaluated. Our objectives for this project were (1) to assess the pasture productivity and nutritive value of 2 oat cultivars [Ogle and ForagePlus (OG and FP, respectively)] with late-September (EG) or mid-October (LG) grazing initiation dates; and (2) to evaluate growth performance by heifers grazing these oat forages compared with heifers reared in confinement (CON). A total of 160 gravid Holstein heifers (80 heifers/yr) were assigned to 10 research groups (8 heifers/group). Mean initial body weight was 509±40.5 kg in 2013 and 517±30.2 kg in 2014. Heifer groups were assigned to specific pastures arranged as a 2×2 factorial of oat cultivars and grazing initiation dates. Grazing heifer groups were allowed to strip-graze oat pastures for 6 h daily before returning to the barn, where they were offered a forage-based basal total mixed ration. Main effects of oat cultivar and sampling date interacted for forage characteristics in 2013, but not in 2014. During 2013, oat forage mass increased until early November before declining in response to freezing weather conditions, thereby exhibiting linear and quadratic effects of sampling date, regardless of oat cultivar. Similar trends over time were observed in 2014. For 2013, the maximum forage mass was 5,329 and 5,046 kg/ha for FP and OG, respectively, whereas the mean maximum forage mass for 2014 was 4,806 kg/ha. ForagePlus did not reach the boot stage of growth during either year of the trial; OG matured more rapidly, reaching the late-heading stage during 2013, but exhibited only minor maturity differences from FP in 2014. For 2013, average daily gain for CON did not differ from grazing heifer groups (overall mean=0.63 kg/d); however, average daily gain from FP was greater than OG (0.68 vs. 0.57 kg/d), and greater from EG compared with LG (0.82 vs. 0.43 kg/d). For 2013, advantages in

  1. Can an Arthroplasty Registry Help Decrease Transfusions in Primary Total Joint Replacement? A Quality Initiative.

    Science.gov (United States)

    Markel, David C; Allen, Mark W; Zappa, Nicole M

    2016-01-01

    Standardized care plans are effective at controlling cost and quality. Registries provide insights into quality and outcomes for use of implants, but most registries do not combine implant and care quality data. In 2012, several Michigan area hospitals and a major insurance provider formed a voluntary statewide total joint database/registry, the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI), to collect procedural, hospital, discharge, and readmission data. Noting substantial variation in transfusion practices after total joint arthroplasty (TJA) in our institutions, we used these prospectively collected data to examine whether awareness and education of the American Association of Blood Banks' (AABB) transfusion guidelines would result in decreased transfusions. (1) Can an established arthroplasty registry help implement a quality initiative (QI) designed to decrease the proportion of transfused postoperative patients undergoing TJA? (2) Do data-driven transfusion protocols decrease length of stay without increasing ischemic complications (myocardial infarctions and cerebrovascular accidents)? (3) Are decreased transfusion proportions associated with decreased readmissions, nonischemic morbidity (including deep vein thrombosis and deep prosthetic infection), and mortality in postoperative patients who had undergone TJA? After reviewing data from the recently established MARCQI registry, the orthopaedic department noticed many discrepancies and practice variances regarding blood transfusions among their providers. In October 2013, a QI was implemented to raise awareness of the discrepancies and education about the AABB guidelines was presented at the monthly orthopaedic service line meeting. A total of 1872 TJA cases were reviewed; 50 were excluded for incomplete data and two for intraoperative transfusions for the period before education (May 2012 to June 2013, n = 1240) and after education (November 2013 to April 2014, n = 580). Data

  2. Neurodevelopmental and body composition outcomes in children with congenital hypothyroidism treated with high-dose initial replacement and close monitoring.

    Science.gov (United States)

    Albert, Benjamin B; Heather, Natasha; Derraik, José G B; Cutfield, Wayne S; Wouldes, Trecia; Tregurtha, Sheryl; Mathai, Sarah; Webster, Dianne; Jefferies, Craig; Gunn, Alistair J; Hofman, Paul L

    2013-09-01

    Despite newborn screening and early levothyroxine replacement, there are continued reports of mild neurocognitive impairment in children with congenital hypothyroidism (CHT). In Auckland, New Zealand, cases are identified by a neonatal screening program with rapid institution of high-dose levothyroxine replacement (10-15 μg/kg·d), producing prompt normalization of thyroid function. Subsequently, frequent monitoring and dose alterations are performed for 2 years. We aimed to assess whether the Auckland treatment strategy prevents impairment of intellectual and motor development. This study encompassed all children with CHT born in 1993-2006 in Auckland and their siblings. Neurocognitive assessments included the following: 1) intelligence quotient via Weschler Preschool and Primary Scale of Intelligence III or Weschler Intelligence Scale for Children IV; 2) Movement Assessment Battery for Children; and 3) Beery Developmental Test of Visual-Motor Integration. Body composition was assessed by dual-energy x-ray absorptiometry. Forty-four CHT cases and 53 sibling controls aged 9.6 ± 3.9 years were studied. Overall intelligence quotient was similar among CHT cases and controls (95.2 vs 98.6; P = .20), and there were also no differences in motor function. Severity of CHT did not influence outcome, but greater time to normalize free T4 was associated with worse motor balance. There were no differences in anthropometry or body composition between groups. These findings suggest that a strategy of rapidly identifying and treating infants with CHT using high-dose levothyroxine replacement is associated with normal intellectual and motor development. The subtle negative impact on motor function associated with time to normalize free T4 levels is consistent with benefit from rapid initial correction.

  3. University students and faculty have positive perceptions of open/alternative resources and their utilization in a textbook replacement initiative

    Directory of Open Access Journals (Sweden)

    Nicole Delimont

    2016-06-01

    Full Text Available This is contribution no. 16-114-J from the Kansas Agricultural Experiment Station.The Kansas State University Open/Alternative Textbook Initiative provides grants to faculty members to replace textbooks with open/alternative educational resources (OAERs that are available at no cost to students. Open educational resources are available for anyone to access, while alternative educational resources are not open. The objective of this study was to determine the perceptions towards OAERs and the initiative, of students enrolled in, and faculty members teaching, courses using OAERs. A survey was sent out to 2,074 students in 13 courses using the OAERs. A total of 524 (25.3% students completed the survey and a faculty member from each of the 13 courses using OAERs was interviewed. Students rated the OAERs as good quality, preferred using them instead of buying textbooks for their courses, and agreed that they would like OAERs used in other courses. Faculty felt that student learning was somewhat better and it was somewhat easier to teach using OAERs than when they used the traditional textbooks. Nearly all faculty members preferred teaching with OAERs and planned to continue to do so after the funding period. These results, combined with the tremendous savings to students, support the continued funding of the initiative and similar approaches at other institutions.

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

    Directory of Open Access Journals (Sweden)

    Masaki J. Honda

    2010-02-01

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

  5. Tooth breakage in patients injected with 224Ra

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  6. Hip Replacement Surgery

    Science.gov (United States)

    ... Outreach Initiative Breadcrumb Home Health Topics English Español Hip Replacement Surgery Basics In-Depth Download Download EPUB ... PDF What is it? Points To Remember About Hip Replacement Surgery Hip replacement surgery removes damaged or ...

  7. The optimal time of initiation of renal replacement therapy in acute kidney injury: A meta-analysis.

    Science.gov (United States)

    Luo, Kaiping; Fu, Shufang; Fang, Weidong; Xu, Gaosi

    2017-09-15

    The impact on the timing of renal replacement therapy (RRT) initiation on clinical outcomes for patients with acute kidney injury (AKI) remains controversial. We searched the Cochrane Library, EMBASE, Global Health, MEDLINE, PubMed, the International Clinical Trials Registry Platform, and Web of Science. We included 49 studies involving 9698 patients. Pooled analysis of 5408 critically ill patients with AKI showed that early RRT was significantly associated with reduced mortality compared to late RRT [odds ratio (OR), 0.40; 95% confidential intervals (CI), 0.32 - 0.48; I 2 , 50.2%]. For 4290 non-critically ill patients with AKI, there was no statistically significant difference in the risk of mortality between early and late RRT (OR, 1.07; 95% CI, 0.79 - 1.45; I 2 , 73.0%). Early RRT was markedly associated with shortened intensive care units (ICU) length of stay (LOS) and hospital LOS compared to late RRT in both critically ill and non-critically ill patients with AKI. Early RRT probably reduce the mortality, ICU and hospital LOS in critically ill patients with AKI. Inversely, early RRT in non-critically ill patients with AKI did not decrease the mortality, but shortened the ICU and hospital LOS.

  8. Tooth engineering: searching for dental mesenchymal cells sources.

    Directory of Open Access Journals (Sweden)

    Laetitia eKeller

    2011-03-01

    Full Text Available The implantation of cultured re-associations between embryonic dental mesenchymal cells and epithelial cells from mouse molars at ED14 allowed making full teeth with crown, root, periodontal ligament fibers and bone. Although representing valuable tools to set up methodologies embryonic cells are not easily available. This work thus aimed to replace the embryonic cells by dental mesenchymal cell lines or cultured expanded embryonic cells, and to test their ability to mediate tooth development in vitro when re-associated with a competent dental epithelium. Histology, immunostaining and RT-PCR allowed getting complementary sets of results. Two different immortalized cell lines from ED18 dental mesenchyme failed in mediating tooth formation. The potentialities of embryonic dental mesenchymal cells decreased from ED14 to ED16 and were lost at ED18. This is likely related to a change in the mesenchymal cell phenotype and/or populations during development. Attempts to cultivate ED14 or ED16 embryonic dental mesenchymal cells prior to re-association led to the loss of their ability to support tooth development. This was accompanied by a down-regulation of Fgf3 transcription. Supplementation of the culture medium with FGF2 allowed restoring Fgf3 expression, but not the ability of mesenchymal cells to engage in tooth formation. Altogether, these observations suggest that a competent cell population exists in the dental mesenchyme at ED14, progressively decreases during development, and cannot as such be maintained in vitro. This study evidenced the need for specific conditions to maintain the ability of dental mesenchymal cells to initiate whole tooth formation, when re-associated with an odontogenic epithelium. Efforts to improve the culture conditions will have to be combined with attempts to characterize the competent cells within the dental mesenchyme.

  9. Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.

    Directory of Open Access Journals (Sweden)

    M Aleksander Wysocki

    Full Text Available Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month. Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo. Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.

  10. Using a Novel Absolute Ontogenetic Age Determination Technique to Calculate the Timing of Tooth Eruption in the Saber-Toothed Cat, Smilodon fatalis.

    Science.gov (United States)

    Wysocki, M Aleksander; Feranec, Robert S; Tseng, Zhijie Jack; Bjornsson, Christopher S

    2015-01-01

    Despite the superb fossil record of the saber-toothed cat, Smilodon fatalis, ontogenetic age determination for this and other ancient species remains a challenge. The present study utilizes a new technique, a combination of data from stable oxygen isotope analyses and micro-computed tomography, to establish the eruption rate for the permanent upper canines in Smilodon fatalis. The results imply an eruption rate of 6.0 millimeters per month, which is similar to a previously published average enamel growth rate of the S. fatalis upper canines (5.8 millimeters per month). Utilizing the upper canine growth rate, the upper canine eruption rate, and a previously published tooth replacement sequence, this study calculates absolute ontogenetic age ranges of tooth development and eruption in S. fatalis. The timing of tooth eruption is compared between S. fatalis and several extant conical-toothed felids, such as the African lion (Panthera leo). Results suggest that the permanent dentition of S. fatalis, except for the upper canines, was fully erupted by 14 to 22 months, and that the upper canines finished erupting at about 34 to 41 months. Based on these developmental age calculations, S. fatalis individuals less than 4 to 7 months of age were not typically preserved at Rancho La Brea. On the whole, S. fatalis appears to have had delayed dental development compared to dental development in similar-sized extant felids. This technique for absolute ontogenetic age determination can be replicated in other ancient species, including non-saber-toothed taxa, as long as the timing of growth initiation and growth rate can be determined for a specific feature, such as a tooth, and that growth period overlaps with the development of the other features under investigation.

  11. Tooth - abnormal colors

    Science.gov (United States)

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

  12. Dental Caries (Tooth Decay)

    Science.gov (United States)

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

  13. Overview of Tooth Disorders

    Science.gov (United States)

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

  14. Dental Caries (Tooth Decay)

    Science.gov (United States)

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

  15. Patient-related predictors of implant failure after primary total hip replacement in the initial, short- and long-terms

    DEFF Research Database (Denmark)

    Johnsen, S.P.; Sørensen, H.T.; Lucht, Ulf

    2006-01-01

    replacement, an age of 80 years or more and hip replacement undertaken as a sequela of trauma, for avascular necrosis or paediatric conditions, were associated with an increased risk of failure. However, during six months to 8.6 years after surgery, being less than 60 years old was associated...

  16. Use of hormone replacement therapy in the Hong Kong public health sector after the Women's Health Initiative trial.

    Science.gov (United States)

    Leung, K Y; Ling, Matina; Tang, G W K

    2005-01-01

    To determine the impact of Women Health Initiative (WHI) trial on the use of hormone replacement therapy (HRT) in the Hong Kong public health sector. The central prescription database of the Hospital Authority was used to describe the half-yearly trend in the use of HRT between July 2000 and December 2003. The data of hysterectomy was retrieved from another clinical database. Before the publication of the WHI trial in July 2002, conjugated equine estrogens (CEE) and its related products dominated HRT prescribing. Relative to the first half of 2002, there was an immediate and substantial decline by 43.5% in the prescriptions of combined CEE/progestogen products and a modest decline by 22.4% in the prescriptions of CEE-alone therapy in the second half of 2002. In the first half of 2003, a decline in the prescriptions of all HRT preparations except raloxifene was observed. However, in the second half of 2003, there were no more declines in overall HRT users. Relative to the first half of 2002, the decline in the overall HRT users in the first half of 2003 was more than 46% in women aged 50-69. The decline was greater in women with a history of hysterectomy (60.3%) than women without (38.6%), but was similar between gynaecology specialty (41.7%) and non-gynaecology specialty (43.9%). Similar to the U.S., an immediate and substantial decline in the use of CEE and its related products was observed in Hong Kong after the publication of the WHI trial.

  17. Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative

    International Nuclear Information System (INIS)

    Eckstein, Felix; Wirth, Wolfgang; Cotofana, Sebastian; Boudreau, Robert; Wang, Zhijie; Hannon, Michael J.; Duryea, Jeff; Guermazi, Ali; Roemer, Frank; Nevitt, Michael; John, Markus R.; Ladel, Christoph; Sharma, Leena; Hunter, David J.; Kwoh, C.K.

    2016-01-01

    To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement. Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI. Changes between the annual visit before replacement (T 0 ) and 2 years before T 0 (T -2 ) were compared using conditional logistic regression. One hundred and nineteen knees from 102 participants (55.5 % women; age 64.2 ± 8.7 [mean ± SD] years) were studied. Fixed-location JSW change at 22.5 % from medial to lateral differed more between replaced and control knees (case-control [cc] OR = 1.57; 95 % CI: 1.23-2.01) than minimum medial JSW change (ccOR = 1.38; 95 % CI: 1.11-1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed-location JSW. Location-independent thinning and thickening scores were elevated prior to knee replacement. Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. (orig.)

  18. Comparison of radiographic joint space width and magnetic resonance imaging for prediction of knee replacement: A longitudinal case-control study from the Osteoarthritis Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Eckstein, Felix; Wirth, Wolfgang; Cotofana, Sebastian [Paracelsus Medical University Salzburg and Nuremberg Austria and Chondrometrics GmbH, Institute of Anatomy, Ainring (Germany); Boudreau, Robert [University of Pittsburgh, Department of Epidemiology, Graduate School of Public Health, Pittsburgh, PA (United States); Wang, Zhijie; Hannon, Michael J. [University of Pittsburgh and Pittsburgh VAHS, Division of Rheumatology and Clinical Immunology, Pittsburgh, PA (United States); Duryea, Jeff [Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Guermazi, Ali [Boston University School of Medicine and Boston Imaging Core Lab (BICL), LLC, Boston, MA (United States); Roemer, Frank [Boston University School of Medicine and Boston Imaging Core Lab (BICL), LLC, Boston, MA (United States); University of Erlangen-Nuremberg, Department of Radiology, Erlangen (Germany); Nevitt, Michael [OAI Coordinating Ctr., UCSF, San Francisco, CA (United States); John, Markus R. [Novartis Pharma AG, Basel (Switzerland); Ladel, Christoph [Merck KGaA, Darmstadt (Germany); Sharma, Leena [Northwestern University, Department of Medicine, Feinberg School of Medicine, Chicago, IL (United States); Hunter, David J. [University Sydney, Royal North Shore Hospital and Institute of Bone and Joint Research, Kolling Institute, Sydney, NSW (Australia); Kwoh, C.K. [University of Arizona, Division of Rheumatology and the University of Arizona Arthritis Center, Tucson, AZ (United States); Collaboration: OAI Investigators

    2016-06-15

    To evaluate whether change in fixed-location measures of radiographic joint space width (JSW) and cartilage thickness by MRI predict knee replacement. Knees replaced between 36 and 60 months' follow-up in the Osteoarthritis Initiative were each matched with one control by age, sex and radiographic status. Radiographic JSW was determined from fixed flexion radiographs and subregional femorotibial cartilage thickness from 3 T MRI. Changes between the annual visit before replacement (T{sub 0}) and 2 years before T{sub 0} (T{sub -2}) were compared using conditional logistic regression. One hundred and nineteen knees from 102 participants (55.5 % women; age 64.2 ± 8.7 [mean ± SD] years) were studied. Fixed-location JSW change at 22.5 % from medial to lateral differed more between replaced and control knees (case-control [cc] OR = 1.57; 95 % CI: 1.23-2.01) than minimum medial JSW change (ccOR = 1.38; 95 % CI: 1.11-1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed-location JSW. Location-independent thinning and thickening scores were elevated prior to knee replacement. Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. (orig.)

  19. Comparison of Radiographic Joint Space Width and Magnetic-Resonance-Imaging for Prediction of Knee Replacement – A Longitudinal Case-Control Study from the Osteoarthritis Initiative

    Science.gov (United States)

    Eckstein, Felix; Boudreau, Robert; Wang, Zhijie; Hannon, Michael J.; Duryea, Jeff; Wirth, Wolfgang; Cotofana, Sebastian; Guermazi, Ali; Roemer, Frank; Nevitt, Michael; John, Markus R.; Ladel, Christoph; Sharma, Leena; Hunter, David J.; Kwoh, C. Kent

    2015-01-01

    Objective To evaluate whether change in fixed location measures of radiographic joint space width (JSW) and in cartilage thickness by MRI predict knee replacement. Methods Knees replaced between 36-60 months follow-up (M) in the Osteoarthritis Initiative were each matched with one control by age, sex, and radiographic status. Radiographic JSW was determined from fixed flexion radiographs, and subregional femorotibial cartilage thickness from 3 Tesla MRI. Changes between the annual visit before replacement (T0) and 2 years before T0 (T-2) were compared using conditional logistic regression. Results One hundred and nineteen knees from 102 participants (55.5% women; age 64.2±8.7 [mean±SD]) were studied. Fixed location JSW change at 22.5% from medial to lateral differed more between replaced and control knees (case-control [cc] OR=1.57; 95%CI: 1.23,2.01) than minimum medial JSW change (ccOR=1.38; 95%CI: 1.11,1.71). Medial femorotibial cartilage loss displayed discrimination similar to minimum JSW, and central tibial cartilage loss similar to fixed location JSW. Location-independent thinning and thickening scores were both elevated prior to knee replacement. Conclusions Discrimination of structural progression between knee pre-placement cases versus controls was stronger for fixed-location than for minimum radiographic JSW. MRI displayed similar discrimination to radiography and suggested greater simultaneous cartilage thickening and loss prior to knee replacement. PMID:26376884

  20. Predictive value of semi-quantitative MRI-based scoring systems for future knee replacement: data from the osteoarthritis initiative

    International Nuclear Information System (INIS)

    Hafezi-Nejad, Nima; Eng, John; Demehri, Shadpour; Zikria, Bashir; Carrino, John A.

    2015-01-01

    To evaluate, in a confirmatory fashion, whether baseline and change from baseline to 24-month follow-up in cartilage damage, bone marrow lesions and meniscal damage are predictors of knee replacement (KR) in subjects with a high risk of osteoarthritis (OA), independent of the level of physical activity, symptom severity and radiographic abnormalities. Data from the Osteoarthritis Initiative's (OAI) baseline and 24-month follow-up knee MRIs of 115 patients (age range: 45-78 years; 48 % female; BMI: 20.9-48.7) were analyzed. Cartilage, bone marrow and menisci were semi-quantitatively scored according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and Boston-Leeds Osteoarthritis Knee Score (BLOKS) systems in all compartments. Baseline and 24-month interval changes in structural tissue damage assessed by BLOKS and WORMS were used as predictors of KR independent of clinical and radiographic parameters using Cox hazard analysis. Adjustments were performed for age, gender, BMI and physical activity (Physical Activity Scale for the Elderly: PASE), Western Ontario and McMaster Questionnaire (WOMAC) total score and radiographic Kellgren-Lawrence (KL) score. BLOKS and WORMS baseline cartilage scores were predictors of KR independent of the PASE, WOMAC and KL score. One score increase in the average baseline BLOKS full-thickness cartilage defect score was associated with a [hazard ratio (95 % CI)] 13.55 (3.61-50.89) times greater risk of KR independent of the PASE, WOMAC and KL score. Net reclassification improvements (NRIs) of the additional evaluation of 24-month follow-up MRI scores and assessment of changes were not significant for prediction of KR (NRI range: - 7.23 - 24.8 %). The BLOKS cartilage score for full-thickness cartilage defects had the highest hazard for KR. Follow-up MRI changes in structural tissue damage, detected by BLOKS and WORMS cartilage, bone marrow or meniscus scores (up to 24 months) had no significant predictive value in addition

  1. Predictive value of semi-quantitative MRI-based scoring systems for future knee replacement: data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hafezi-Nejad, Nima; Eng, John; Demehri, Shadpour [Johns Hopkins University School of Medicine, Musculoskeletal Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Zikria, Bashir [Johns Hopkins University, Department of Orthopedic Surgery, Baltimore, MD (United States); Carrino, John A. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States)

    2015-11-15

    To evaluate, in a confirmatory fashion, whether baseline and change from baseline to 24-month follow-up in cartilage damage, bone marrow lesions and meniscal damage are predictors of knee replacement (KR) in subjects with a high risk of osteoarthritis (OA), independent of the level of physical activity, symptom severity and radiographic abnormalities. Data from the Osteoarthritis Initiative's (OAI) baseline and 24-month follow-up knee MRIs of 115 patients (age range: 45-78 years; 48 % female; BMI: 20.9-48.7) were analyzed. Cartilage, bone marrow and menisci were semi-quantitatively scored according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and Boston-Leeds Osteoarthritis Knee Score (BLOKS) systems in all compartments. Baseline and 24-month interval changes in structural tissue damage assessed by BLOKS and WORMS were used as predictors of KR independent of clinical and radiographic parameters using Cox hazard analysis. Adjustments were performed for age, gender, BMI and physical activity (Physical Activity Scale for the Elderly: PASE), Western Ontario and McMaster Questionnaire (WOMAC) total score and radiographic Kellgren-Lawrence (KL) score. BLOKS and WORMS baseline cartilage scores were predictors of KR independent of the PASE, WOMAC and KL score. One score increase in the average baseline BLOKS full-thickness cartilage defect score was associated with a [hazard ratio (95 % CI)] 13.55 (3.61-50.89) times greater risk of KR independent of the PASE, WOMAC and KL score. Net reclassification improvements (NRIs) of the additional evaluation of 24-month follow-up MRI scores and assessment of changes were not significant for prediction of KR (NRI range: - 7.23 - 24.8 %). The BLOKS cartilage score for full-thickness cartilage defects had the highest hazard for KR. Follow-up MRI changes in structural tissue damage, detected by BLOKS and WORMS cartilage, bone marrow or meniscus scores (up to 24 months) had no significant predictive value in addition

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

    Science.gov (United States)

    Tsami, Alexandra; Pepelassi, Eudoxie; Kodovazenitis, George; Komboli, Mado

    2009-09-01

    Investigators have evaluated predictive parameters of tooth loss during the maintenance phase (MP). The authors conducted a retrospective study to evaluate the rate of tooth loss and to explore the parameters that affect tooth loss during MP in a Greek population. A periodontist administered periodontal treatment and maintenance care to 280 participants with severe periodontitis for a mean period +/- standard deviation of 10.84 +/- 2.13 years. The periodontist recorded the following parameters for each participant: oral hygiene index level, simplified gingival index level, clinical attachment level, probing depth measurements, initial tooth prognosis, smoking status, tooth loss during active periodontal treatment and MP, and compliance with suggested maintenance visits. The authors found that total tooth loss during active treatment (n = 1,427) was greater than during MP (n = 918) and was associated with the initial tooth prognosis, tooth type group, participants' compliance with suggested maintenance visits, smoking status and acceptability of the quality of tooth restorations. Most of the teeth extracted during maintenance had an initial guarded prognosis (n = 612). Participants whose compliance was erratic had a greater risk of undergoing tooth extraction than did participants whose compliance was complete. Participants' initial tooth prognosis, tooth type, compliance with suggested maintenance visits and smoking status affected tooth loss during MP. Initial guarded prognosis and erratic compliance increased the risk of undergoing tooth extraction during maintenance. Determining predictive parameters for disease progression and tooth loss provides critical information to clinicians so that they can develop and implement rational treatment planning.

  3. Stem cells for tooth engineering

    Directory of Open Access Journals (Sweden)

    G Bluteau

    2008-07-01

    Full Text Available Tooth development results from sequential and reciprocal interactions between the oral epithelium and the underlying neural crest-derived mesenchyme. The generation of dental structures and/or entire teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin and enamel. Although mesenchymal stem cells from different origins have been extensively studied in their capacity to form dentin in vitro, information is not yet available concerning the use of epithelial stem cells. The odontogenic potential resides in the oral epithelium and thus epithelial stem cells are necessary for both the initiation of tooth formation and enamel matrix production. This review focuses on the different sources of stem cells that have been used for making teeth in vitro and their relative efficiency. Embryonic, post-natal or even adult stem cells were assessed and proved to possess an enormous regenerative potential, but their application in dental practice is still problematic and limited due to various parameters that are not yet under control such as the high risk of rejection, cell behaviour, long tooth eruption period, appropriate crown morphology and suitable colour. Nevertheless, the development of biological approaches for dental reconstruction using stem cells is promising and remains one of the greatest challenges in the dental field for the years to come.

  4. OMERACT/OARSI initiative to define states of severity and indication for joint replacement in hip and knee osteoarthritis

    DEFF Research Database (Denmark)

    Gossec, Laure; Hawker, Gillian; Davis, Aileen M

    2007-01-01

    OBJECTIVE: Time to theoretical indication of joint replacement surgery has been proposed as a primary outcome for potential structure-modifying interventions for osteoarthritis (OA). The objectives of this OMERACT/OARSI Working Group were to identify pain, physical function, and structure states ...

  5. Initial non-opioid based anesthesia in a parturient having severe aortic stenosis undergoing cesarean section with aortic valve replacement

    Directory of Open Access Journals (Sweden)

    Subrata Podder

    2015-01-01

    Full Text Available Pregnancy in presence of severe aortic stenosis (AS causes worsening of symptoms needing further intervention. In the advanced stages of pregnancy, some patients may even require aortic valve replacement (AVR and cesarean delivery in the same sitting. Opioid based general anesthesia for combined lower segment cesarean section (LSCS with AVR has been described. However, the use of opioid may lead to fetal morbidity and need of respiratory support for the baby. We describe successful anesthetic management for LSCS with AVR in a >33 week gravida with severe AS and congestive heart failure. We avoided opioids till delivery of the baby AVR; the delivered neonate showed a normal APGAR score.

  6. Advances and perspectives in tooth tissue engineering.

    Science.gov (United States)

    Monteiro, Nelson; Yelick, Pamela C

    2017-09-01

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

  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 teeth was associated with age, gender, and socioeconomic status; tooth loss due to caries was associated with age, tribe, frequency of tooth-brushing, and a low 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.

  8. Application of model of incremental haemodialysis, based on residual renal function, at the initiation of renal replacement therapy

    Directory of Open Access Journals (Sweden)

    José L. Merino

    2017-01-01

    Conclusions: Incremental HD treatment, with twice-weekly HD, may be an alternative in selected patients. This approach can largely preserve residual renal function at least for the first year. Although this pattern probably is not applicable to all patients starting RRT, it can and should be an initial alternative to consider.

  9. To Tell the Tooth

    Science.gov (United States)

    ... Activity Sheets 2018 Brushing Calendar Sports Safety National Nutrition Month Choose Water for a Sparkling Smile Holiday Workshop Thanksgiving Back to School Fourth of July Fun Tooth Fairy Sugar Wars Valentine's Day Halloween Defeat Monster Mouth! Color and ...

  10. Improvement in Total Joint Replacement Quality Metrics: Year One Versus Year Three of the Bundled Payments for Care Improvement Initiative.

    Science.gov (United States)

    Dundon, John M; Bosco, Joseph; Slover, James; Yu, Stephen; Sayeed, Yousuf; Iorio, Richard

    2016-12-07

    In January 2013, a large, tertiary, urban academic medical center began participation in the Bundled Payments for Care Improvement (BPCI) initiative for total joint arthroplasty, a program implemented by the Centers for Medicare & Medicaid Services (CMS) in 2011. Medicare Severity-Diagnosis Related Groups (MS-DRGs) 469 and 470 were included. We participated in BPCI Model 2, by which an episode of care includes the inpatient and all post-acute care costs through 90 days following discharge. The goal for this initiative is to improve patient care and quality through a patient-centered approach with increased care coordination supported through payment innovation. Length of stay (LOS), readmissions, discharge disposition, and cost per episode of care were analyzed for year 3 compared with year 1 of the initiative. Multiple programs were implemented after the first year to improve performance metrics: a surgeon-directed preoperative risk-factor optimization program, enhanced care coordination and home services, a change in venous thromboembolic disease (VTED) prophylaxis to a risk-stratified protocol, infection-prevention measures, a continued emphasis on discharge to home rather than to an inpatient facility, and a quality-dependent gain-sharing program among surgeons. There were 721 Medicare primary total joint arthroplasty patients in year 1 and 785 in year 3; their data were compared. The average hospital LOS decreased from 3.58 to 2.96 days. The rate of discharge to an inpatient facility decreased from 44% to 28%. The 30-day all-cause readmission rate decreased from 7% to 5%; the 60-day all-cause readmission rate decreased from 11% to 6%; and the 90-day all-cause readmission rate decreased from 13% to 8%. The average 90-day cost per episode decreased by 20%. Mid-term results from the implementation of Medicare BPCI Model 2 for primary total joint arthroplasty demonstrated decreased LOS, decreased discharges to inpatient facilities, decreased readmissions, and

  11. Tooth positioners and their effects on treatment outcome.

    Science.gov (United States)

    Pravindevaprasad, A; Therese, Beena Agnes

    2013-07-01

    Malocclusion can also be corrected by means of clear removable appliances called as "tooth positioners" or "aligners". A tooth positioner is used to control settling and to minimize or eliminate relapse of the teeth after an orthodontic treatment. In this article, a complete review of the objectives, course of treatment, fabrication, and the materials used for fabrication of tooth positioners along with their importance and disadvantages were discussed. Tooth positioners did improve the overall orthodontic treatment outcome as quantified by the ABO (American Board of orthodontics) objective scoring method. But once the initial occlusal contact was achieved, the vertical movement of teeth was found to be inhibited.

  12. Using multidetector-row CT in neonates with complex congenital heart disease to replace diagnostic cardiac catheterization for anatomical investigation: initial experiences in technical and clinical feasibility

    International Nuclear Information System (INIS)

    Lee, Tain; Tsai, I.C.; Chen, Min-Chi; Fu, Yun-Ching; Jan, Sheng-Lin; Wang, Chung-Chi; Chang, Yen

    2006-01-01

    Echocardiography is the first-line modality for the investigation of neonatal congenital heart disease. Diagnostic cardiac catheterization, which has a small but recognized risk, is usually performed if echocardiography fails to provide a confident evaluation of the lesions. To verify the technical and clinical feasibilities of replacing diagnostic cardiac catheterization with multidetector-row CT (MDCT) in neonatal complex congenital heart disease. Over a 1-year period we prospectively enrolled all neonates with complex congenital heart disease referred for diagnostic cardiac catheterization after initial assessment by echocardiography. MDCT was performed using a 40-detector-row CT scanner with dual syringe injection. A multidisciplinary congenital heart disease team evaluated the MDCT images and decided if further diagnostic cardiac catheterization was necessary. The accuracy of MDCT in detecting separate cardiovascular anomalies and bolus geometry of contrast enhancement were calculated. A total of 14 neonates were included in the study. No further diagnostic cardiac catheterization was needed in any neonate. The accuracy of MDCT in diagnosing separate cardiovascular anomalies was 98% (53/54) with only one atrial septal defect missed in a patient with coarctation syndrome. The average cardiovascular enhancement in evaluated chambers was 471 HU. No obvious beam-hardening artefact was observed. The technical and clinical feasibility of MDCT in complex congenital heart disease in neonates is confirmed. After initial assessment with echocardiography, MDCT could probably replace diagnostic cardiac catheterization for further anatomical clarification in neonates. (orig.)

  13. Developments on ASME Code Cases to Risk-Informed Repair/Replacement Activities in Support of Risk-Informed Regulation Initiatives

    International Nuclear Information System (INIS)

    Balkey, Kenneth R.; Holston, William C.

    2002-01-01

    ASME Code Case N-658, 'Risk-Informed Safety Classification for Use in Risk-Informed Repair/Replacement Activities' and Code Case N-660, 'Alternative Repair/Replacement Requirements For Items Classified In Accordance With Risk-Informed Processes' are being completed to expand the breadth of risk-informed requirements for pressure-retaining items. This initiative, which is built from prior ASME Section XI risk-informed inservice inspection developments over the past decade, has been undertaken in conjunction with U.S. risk-informed regulation efforts. The U.S. Nuclear Regulatory Commission (NRC) is working with the industry on risk informing Title 10 Code of Federal Regulations Part 50 (10CFR50). The Nuclear Regulatory Commission's basic proposal is to allow modification of some of the special treatment requirements of 10CFR50. Their effort is proceeding via an Advanced Notice of Public Rulemaking, March 3, 2000, and an announcement of Availability of Draft Rule Wording, November 29, 2001, to add 10 CFR 50.69, 'Risk-Informed Treatment of Structures, Systems and Components'. A parallel task by the Nuclear Energy Institute (NEI) to develop a guideline on how to implement the results of the rulemaking is also well underway via NEI 00-04 (Draft Revision B), 'Option 2 Implementation Guideline', May 2001. This paper summarizes the content and status of approval of the proposed ASME Code Cases, including how they relate to the above NRC and NEI efforts. Some initial results from trial application of the Code Cases will also be cited. (authors)

  14. Ankle replacement

    Science.gov (United States)

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... Ankle replacement surgery is most often done while you are under general anesthesia. This means you will ...

  15. Atypical Odontalgia (Phantom Tooth Pain)

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2016-01-01

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

  17. 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

  18. Tooth development in Ambystoma mexicanum: phosphatase activities, calcium accumulation and cell proliferation in the tooth-forming tissues.

    Science.gov (United States)

    Wistuba, Joachim; Ehmcke, Jens; Clemen, Günter

    2003-06-01

    Prerequisites of tooth formation, cell proliferation in the tooth-forming tissues, calcium accumulation and the enzymatic activities of alkaline (ALP) and acid phosphatases (ACP) were investigated by immunohistochemical and histochemical methods in various developmental stages of the Mexican Axolotl, Ambystoma mexicanum. During the growth of replacement teeth, the tooth-forming tissues continually recruit cells from the surrounding regions. The basal layer of the oral epithelium, the dental lamina and sometimes even the outer enamel epithelium provide cells for the differentiated inner enamel epithelium, in which the active ameloblasts are localized. The differentiating odontoblasts are derived from proliferating cells situated basally to the replacement teeth in the mesenchymal tissue. When differentiation has started and the cells have become functional, proliferative activity can no longer be observed. Calcium is accumulated close to the site of mineralization in the inner enamel epithelium and in the odontoblasts as it is in mammals, elasmobranchii and teleostei. The activities of ACP and ALP related to the mineralization of the replacement teeth are separated spatially and not sequentially as they are in mammals. However, the results indicate a similar function of these enzymatic components in relation to tooth formation and maturation of mineral deposition. Most of the substantial processes related to tooth formation reported from other vertebrates occur in a manner similar to that in Ambystoma mexicanum, but there also seem to be basic mechanisms present that are realised in a unique way in this urodele.

  19. U-curve association between timing of renal replacement therapy initiation and in-hospital mortality in postoperative acute kidney injury.

    Directory of Open Access Journals (Sweden)

    Chih-Chung Shiao

    Full Text Available BACKGROUND: Postoperative acute kidney injury (AKI is associated with poor outcomes in surgical patients. This study aims to evaluate whether the timing of renal replacement therapy (RRT initiation affects the in-hospital mortality of patients with postoperative AKI. METHODOLOGY: This multicenter retrospective observational study, which was conducted in the intensive care units (ICUs in a tertiary hospital (National Taiwan University Hospital and its branch hospitals in Taiwan between January, 2002, and April, 2009, included adult patients with postoperative AKI who underwent RRT for predefined indications. The demographic data, comorbid diseases, types of surgery and RRT, and the indications for RRT were documented. Patients were categorized according to the period of time between the ICU admission and RRT initiation as the early (EG, ≦1 day, intermediate (IG, 2-3 days, and late (LG, ≧4 days groups. The in-hospital mortality rate censored at 180 day was defined as the endpoint. RESULTS: Six hundred forty-eight patients (418 men, mean age 63.0±15.9 years were enrolled, and 379 patients (58.5% died during the hospitalization. Both the estimated probability of death and the in-hospital mortality rates of the three groups represented U-curves. According to the Cox proportional hazard method, LG (hazard ratio, 1.527; 95% confidence interval, 1.152-2.024; P = 0.003, compared with IG group, age (1.014; 1.006-1.021, diabetes (1.279; 1.022-1.601; P = 0.031, cirrhosis (2.147; 1.421-3.242, extracorporeal membrane oxygenation support (1.811; 1.391-2.359, initial neurological dysfunction (1.448; 1.107-1.894; P = 0.007, pre-RRT mean arterial pressure (0.988; 0.981-0.995, inotropic equivalent (1.006; 1.001-1.012; P = 0.013, APACHE II scores (1.055; 1.037-1.073, and sepsis (1.939; 1.536-2.449 were independent predictors of the in-hospital mortality (All P<0.001 except otherwise stated. CONCLUSIONS: The current study found a U

  20. 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.

  1. Knee Replacement

    Science.gov (United States)

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  2. Utilization of Teeth Replacement Service Among the Elderly ...

    African Journals Online (AJOL)

    . However, its utilization by the elderly has not been extensively studied. Aim: To determine the utilization of tooth replacement services among the elderly. Materials and Methods: This was a retrospective study of 440 patients aged 60 years ...

  3. Primary culprit for tooth loss!!

    OpenAIRE

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

    2016-01-01

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

  4. CT should replace three-view radiographs as the initial screening test in patients at high, moderate, and low risk for blunt cervical spine injury: a prospective comparison.

    Science.gov (United States)

    Bailitz, John; Starr, Frederic; Beecroft, Matthew; Bankoff, Jon; Roberts, Roxanne; Bokhari, Faran; Joseph, Kimberly; Wiley, Dorian; Dennis, Andrew; Gilkey, Susan; Erickson, Paul; Raksin, Patricia; Nagy, Kimberly

    2009-06-01

    injury in 7 high risk (46% sensitive), 7 moderate risk (37% sensitive), and 4 low risk patients (25% sensitive). Our results demonstrate the superiority of CCT compared with CSR for the detection of clinically significant cervical spine injury. The improved ability to exclude injury rapidly provides further evidence that CCT should replace CSR for the initial evaluation of blunt cervical spine injury in patients at any risk for injury.

  5. OARSI/OMERACT initiative to define states of severity and indication for joint replacement in hip and knee osteoarthritis. An OMERACT 10 Special Interest Group

    DEFF Research Database (Denmark)

    Gossec, Laure; Paternotte, Simon; Bingham, Clifton O

    2011-01-01

    To define pain and physical function cutpoints that would, coupled with structural severity, define a surrogate measure of "need for joint replacement surgery," for use as an outcome measure for potential structure-modifying interventions for osteoarthritis (OA)....

  6. 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.

  7. Replacing penalties

    Directory of Open Access Journals (Sweden)

    Vitaly Stepashin

    2017-01-01

    Full Text Available УДК 343.24The subject. The article deals with the problem of the use of "substitute" penalties.The purpose of the article is to identify criminal and legal criteria for: selecting the replacement punishment; proportionality replacement leave punishment to others (the formalization of replacement; actually increasing the punishment (worsening of legal situation of the convicted.Methodology.The author uses the method of analysis and synthesis, formal legal method.Results. Replacing the punishment more severe as a result of malicious evasion from serving accused designated penalty requires the optimization of the following areas: 1 the selection of a substitute punishment; 2 replacement of proportionality is serving a sentence other (formalization of replacement; 3 ensuring the actual toughening penalties (deterioration of the legal status of the convict. It is important that the first two requirements pro-vide savings of repression in the implementation of the replacement of one form of punishment to others.Replacement of punishment on their own do not have any specifics. However, it is necessary to compare them with the contents of the punishment, which the convict from serving maliciously evaded. First, substitute the punishment should assume a more significant range of restrictions and deprivation of certain rights of the convict. Second, the perfor-mance characteristics of order substitute the punishment should assume guarantee imple-mentation of the new measures.With regard to replacing all forms of punishment are set significant limitations in the application that, in some cases, eliminates the possibility of replacement of the sentence, from serving where there has been willful evasion, a stricter measure of state coercion. It is important in the context of the topic and the possibility of a sentence of imprisonment as a substitute punishment in cases where the original purpose of the strict measures excluded. It is noteworthy that the

  8. Orthodontic tooth movement with clear aligners.

    Science.gov (United States)

    Drake, Carl T; McGorray, Susan P; Dolce, Calogero; Nair, Madhu; Wheeler, Timothy T

    2012-01-01

    Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5 mm. every two weeks using clear aligners. A duplicate aligner was provided for the second week of each cycle. Weekly polyvinyl siloxane (PVS) impressions were taken, and digital models were fabricated to measure OTM. Initial and final cone beam computed tomography (CBCT) images were obtained to characterize OTM. Results were compared to data from a similar protocol, where subjects received a new aligner biweekly. No significant difference was found in the amount of OTM between the two groups, with mean total OTM of 1.11 mm. (standard deviation (SD) 0.30) and 1.07 mm. (SD 0.33) for the weekly aligner and biweekly control groups, respectively (P = 0.72). Over eight weeks, in two-week intervals, material fatigue does not play a significant role in the rate or amount of tooth movement.

  9. The junctional epithelium originates from the odontogenic epithelium of an erupted tooth.

    Science.gov (United States)

    Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

    2014-05-02

    The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period.

  10. Tooth loss caused by displaced elastic during simple preprosthetic orthodontic treatment

    Science.gov (United States)

    Dianiskova, Simona; Calzolari, Chiara; Migliorati, Marco; Silvestrini-Biavati, Armando; Isola, Gaetano; Savoldi, Fabio; Dalessandri, Domenico; Paganelli, Corrado

    2016-01-01

    The use of elastics to close a diastema or correct tooth malpositions can create unintended consequences if not properly controlled. The American Association of Orthodontists recently issued a consumer alert, warning of “a substantial risk for irreparable damage” from a new trend called “do-it-yourself” orthodontics, consisting of patients autonomously using elastics to correct tooth position. The elastics can work their way below the gums and around the roots of the teeth, causing damage to the periodontium and even resulting in tooth loss. The cost of implants to replace these teeth would well exceed the cost of proper orthodontic care. This damage could also occur in a dental office, when a general dentist tries to perform a simplified orthodontic correction of a minor tooth malposition. The present case report describes a case of tooth loss caused by a displaced intraoral elastic, which occurred during a simple preprosthetic orthodontic treatment. PMID:27672645

  11. Erosive tooth wear in children

    NARCIS (Netherlands)

    Carvalho, T.S.; Lussi, A.; Jaeggi, T.; Gambon, D.L.; Lussi, A.; Ganss, C.

    2014-01-01

    Erosive tooth wear in children is a common condition. Besides the anatomical differences between deciduous and permanent teeth, additional histological differences may influence their susceptibility to dissolution. Considering laboratory studies alone, it is not clear whether deciduous teeth are

  12. 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...

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

    Directory of Open Access Journals (Sweden)

    Rishi Raj

    2016-01-01

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

  14. The single-tooth implant treatment of congenitally missing maxillary lateral incisors using angled abutments: A clinical report

    Directory of Open Access Journals (Sweden)

    Suleyman Hakan Tuna

    2009-01-01

    Full Text Available The maxillary lateral incisor is the second most common congenitally absent tooth. There are several treatment options for replacing the missing maxillary lateral incisor, including canine substitution, tooth-supported restoration, or single-tooth implant. Dental implants are an appropriate treatment option for replacing missing maxillary lateral incisor teeth in adolescents when their dental and skeletal development is complete. This case report presents the treatment of a patient with congenitally missing maxillary lateral incisors using dental implants with angled abutments.

  15. Knee Replacement

    Science.gov (United States)

    ... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

  16. 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.

  17. Natural tooth pontic with splinting of periodontally weakened teeth using fiber-reinforced composite resin

    Directory of Open Access Journals (Sweden)

    Gauri Srinidhi

    2014-01-01

    Full Text Available Replacement of missing anterior teeth due to periodontal reasons is challenging due to the poor support of abutment teeth. This prevents the use of fixed partial dentures (FPDs. Fiber-reinforced splinting provides a viable alternative to the dentist while choosing a treatment plan in replacing missing anterior teeth in periodontally compromised patients as opposed to conventional modalities like FPDs or removable partial dentures. Replacing missing teeth using either patient′s own tooth or a denture tooth as pontic can be done by splinting adjacent teeth with fiber reinforced composite. The splinting has an additional advantage of stabilizing adjacent mobile teeth. This case report details the case selection, procedure with follow-up of a case where the natural extracted tooth of the patient was used as pontic to replace a missing anterior tooth. The splinting was done with fiber reinforced composite resin. Fiber-reinforced composite resin splinting of patient′s extracted natural tooth is economical, fast, and easy to use chairside technique with the added benefit of periodontal stabilization.

  18. 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.

  19. Primary culprit for tooth loss!!

    Directory of Open Access Journals (Sweden)

    Sailavanya Nuvvula

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-12-01

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

  1. Energy harvesting from mastication forces via a smart tooth

    Science.gov (United States)

    Bani-Hani, Muath; Karami, M. Amin

    2016-04-01

    The batteries of the current pacing devices are relatively large and occupy over 60 percent of the size of pulse generators. Therefore, they cannot be placed in the subtle areas of human body. In this paper, the mastication force and the resulting tooth pressure are converted to electricity. The pressure energy can be converted to electricity by using the piezoelectric effect. The tooth crown is used as a power autonomous pulse generator. We refer to this envisioned pulse generator as the smart tooth. The smart tooth is in the form of a dental implant. A piezoelectric vibration energy harvester is designed and modeled for this purpose. The Piezoelectric based energy harvesters investigated and analyzed in this paper initially includes a single degree of freedom piezoelectric based stack energy harvester which utilizes a harvesting circuit employing the case of a purely resistive circuit. The next step is utilizing and investigating a bimorph piezoelectric beam which is integrated/embedded in the smart tooth implant. Mastication process causes the bimorph beam to buckle or return to unbuckled condition. The transitions results in vibration of the piezoelectric beam and thus generate energy. The power estimated by the two mechanisms is in the order of hundreds of microwatts. Both scenarios of the energy harvesters are analytically modeled. The exact analytical solution of the piezoelectric beam energy harvester with Euler-Bernoulli beam assumptions is presented. The electro-mechanical coupling and the geometric nonlinearities have been included in the model for the piezoelectric beam.

  2. The effect of light-activation sources on tooth bleaching

    Science.gov (United States)

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-01-01

    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. PMID:25298598

  3. 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.

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Child First See a Dentist? The History of Dental Advances Why is Oral Health Important for Men? What is Baby Bottle Tooth Decay? Learn what those dental words mean. The Life of a Tooth Home | ...

  5. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Dentist Your Family's Oral Health About the AGD Dental care and oral health information you need from ... Menstrual Calendar for Tooth Extraction Learn what those dental words mean. The Life of a Tooth Home | ...

  6. Replacement rod

    International Nuclear Information System (INIS)

    Hatfield, S.C.

    1989-01-01

    This patent describes in an elongated replacement rod for use with fuel assemblies of the type having two end fittings connected by guide tubes with a plurality of rod and guide tube cell defining spacer grids containing rod support features and mixing vanes. The grids secured to the guide tubes in register between the end fittings at spaced intervals. The fuel rod comprising: an asymmetrically beveled tip; a shank portion having a straight centerline; and a permanently diverging portion between the tip and the shank portion

  7. Autotransplantation donor tooth site harvesting using piezosurgery

    OpenAIRE

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

    2016-01-01

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

  8. AUTOGENOUS TOOTH TRANSPLANTATION IN ADULT ...

    African Journals Online (AJOL)

    drclement

    ABSTRACT. A case of autotransplantation of a tooth in a 26 year old female African cleft palate patient is reported. This case report emphasizes the possibility and success of autotransplantation in our centre, it also emphasizes that transplantation is only technique sensitive but less equipment sensitive. It further stresses.

  9. High- Versus Low-Gradient Severe Aortic Stenosis: Demographics, Clinical Outcomes, and Effects of the Initial Aortic Valve Replacement Strategy on Long-Term Prognosis.

    Science.gov (United States)

    Taniguchi, Tomohiko; Morimoto, Takeshi; Shiomi, Hiroki; Ando, Kenji; Kanamori, Norio; Murata, Koichiro; Kitai, Takeshi; Kawase, Yuichi; Izumi, Chisato; Miyake, Makoto; Mitsuoka, Hirokazu; Kato, Masashi; Hirano, Yutaka; Matsuda, Shintaro; Inada, Tsukasa; Nagao, Kazuya; Murakami, Tomoyuki; Takeuchi, Yasuyo; Yamane, Keiichiro; Toyofuku, Mamoru; Ishii, Mitsuru; Minamino-Muta, Eri; Kato, Takao; Inoko, Moriaki; Ikeda, Tomoyuki; Komasa, Akihiro; Ishii, Katsuhisa; Hotta, Kozo; Higashitani, Nobuya; Kato, Yoshihiro; Inuzuka, Yasutaka; Maeda, Chiyo; Jinnai, Toshikazu; Morikami, Yuko; Saito, Naritatsu; Minatoya, Kenji; Kimura, Takeshi

    2017-05-01

    There is considerable debate on the management of patients with low-gradient severe aortic stenosis (LG-AS), defined as aortic valve area strategy: n=977, and conservative strategy: n=1120) with high-gradient severe aortic stenosis (HG-AS) and 1712 patients (initial AVR strategy: n=219, and conservative strategy: n=1493) with LG-AS. AVR was more frequently performed in HG-AS patients than in LG-AS patients (60% versus 28%) during the entire follow-up. In the comparison between the initial AVR and conservative groups, the propensity score-matched cohorts were developed in both HG-AS (n=887 for each group) and LG-AS (n=218 for each group) strata. The initial AVR strategy when compared with the conservative strategy was associated with markedly lower risk for a composite of aortic valve-related death or heart failure hospitalization in both HG-AS and LG-AS strata (hazard ratio, 0.30; 95% confidence interval, 0.25-0.37; P strategy was associated with a better outcome than the conservative strategy (adjusted hazard ratio, 0.37; 95% confidence interval, 0.23-0.59; P strategy was associated with better outcomes than the conservative strategy in both HG-AS and LG-AS patients, although AVR was less frequently performed in LG-AS patients than in HG-AS patients. The favorable effect of initial AVR strategy was also seen in patients with LG-AS with preserved left ventricular ejection fraction. URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: UMIN000012140. © 2017 American Heart Association, Inc.

  10. Multiphoton microscopy imaging of developing tooth germs

    Directory of Open Access Journals (Sweden)

    Pei-Yu Pan

    2014-01-01

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

  11. Long-life slab replacement concrete.

    Science.gov (United States)

    2015-03-01

    This research was initiated following reports of high incidence of cracking on FDOT concrete pavement replacement : slab projects. Field slabs were instrumented for data acquisition from high-early-strength concrete pavement : replacement slabs place...

  12. Effect of a vegetable-oil emulsion on body composition; a 12-week study in overweight women on a meal replacement therapy after an initial weight loss: a randomized controlled trial.

    Science.gov (United States)

    Olsson, Johan; Sundberg, Birgitta; Viberg, Annika; Haenni, Arvo

    2011-06-01

    The maintenance of an obtained lower weight level is often found to be difficult. The aim of this study was to determine weight maintenance after an initial weight loss by consumption of a meal replacement with a vegetable-oil emulsion associated with prolonged satiety. After a 6-week weight loss period with very low calorie diet (VLCD), subjects with >5% body weight (BW) loss were randomized to a 12-week weight maintenance follow-up period, comparing a partial meal replacement diet containing a vegetable-oil emulsion (test) or dairy fat (control). Anthropometric data and safety variables were collected at baseline and after 4, 8 and 12 weeks. A significant weight loss was observed during the 12-week weight maintenance diet in the test and control group, respectively; 1.0 ± 2.1 kg (p Body fat mass (BFM) decreased significantly (p initial weight loss using VLCD was associated with decreased BFM by 0.9% without any change in BW between the two groups.

  13. Uneven distribution of enamel in the tooth crown of a Plains Zebra (Equus quagga

    Directory of Open Access Journals (Sweden)

    Daniela E. Winkler

    2015-06-01

    Full Text Available Unworn teeth of herbivorous mammals are not immediately functional. They have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. We use the Plains Zebra (Equus quagga as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. We find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lower enamel content here could promote early wear. Besides this uneven enamel distribution, we note that the third molar has a higher overall enamel content than any other tooth position. The M3 is thus likely to have a slightly different functional trait in mastication, resisting highest bite forces along the tooth row and maintaining functionality when anterior teeth are already worn down.

  14. Uneven distribution of enamel in the tooth crown of a Plains Zebra (Equus quagga).

    Science.gov (United States)

    Winkler, Daniela E; Kaiser, Thomas M

    2015-01-01

    Unworn teeth of herbivorous mammals are not immediately functional. They have to be partially worn to expose enamel ridges which can then act as shear-cutting blades to break the food down. We use the Plains Zebra (Equus quagga) as a hypsodont, herbivorous model organism to investigate how initial wear of the tooth crown is controlled by underlying structures. We find that the enamel proportion is smaller at the apical half of the tooth crown in all upper tooth positions and suggest that lower enamel content here could promote early wear. Besides this uneven enamel distribution, we note that the third molar has a higher overall enamel content than any other tooth position. The M3 is thus likely to have a slightly different functional trait in mastication, resisting highest bite forces along the tooth row and maintaining functionality when anterior teeth are already worn down.

  15. 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

  16. 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.

  17. 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; Arthroplasty - shoulder - discharge

  18. 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.

  19. Tooth eruption and browridge formation.

    Science.gov (United States)

    Russell, M D

    1982-05-01

    One of the most reasonable hypotheses regarding the functional significance of the browridge is that the supraorbital torus forms in response to masticatory stress during development. Oyen, Walker, and Rice (1979) have recently proposed a model that tests this hypothesis: if browridges are functionally related to masticatory stresses on the cranial vault, then changes in the biomechanics of the masticatory system ought to be reflected by changes in the browridge. To test their model they attempted to relate biomechanical discontinuities resulting from tooth eruption to episodes of bone deposition on the supraorbital tori of a developmental series of dry Papio crania. This paper reports on a parallel test of the model on a cross-sectional sample of Australian Aboriginal juvenile crania. This sample showed no relation between tooth eruption and the supraorbital surface morphology thought to be indicative of active bone deposition. It is also demonstrated that no significant relationship between tooth eruption and episodes of bone deposition is shown by the Papio sample. It is concluded that the use of small cross-sectional samples of dry crania does not provide a valid test of the model.

  20. [Assessment of tooth bleaching efficacy with spectrophotometer].

    Science.gov (United States)

    Zhu, Wenhao; Liu, Chang; Pan, Jie

    2014-06-01

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

  1. Hip joint replacement

    Science.gov (United States)

    Hip arthroplasty; Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... Your hip joint is made up of 2 major parts. One or both parts may be replaced during surgery: ...

  2. Mesenchymal Wnt/β-catenin signaling limits tooth number.

    Science.gov (United States)

    Järvinen, Elina; Shimomura-Kuroki, Junko; Balic, Anamaria; Jussila, Maria; Thesleff, Irma

    2018-02-21

    Tooth agenesis is one of the predominant developmental anomalies in humans, usually affecting the permanent dentition generated by sequential tooth formation and, in most cases, caused by mutations perturbing epithelial Wnt/β-catenin signaling. In addition, loss-of-function mutations in the Wnt feedback inhibitor AXIN2 lead to human tooth agenesis. We have investigated the functions of Wnt/β-catenin signaling during sequential formation of molar teeth using mouse models. Continuous initiation of new teeth, which is observed after genetic activation of Wnt/β-catenin signaling in the oral epithelium, was accompanied by enhanced expression of Wnt antagonists and a downregulation of Wnt/β-catenin signaling in the dental mesenchyme. Genetic and pharmacological activation of mesenchymal Wnt/β-catenin signaling negatively regulated sequential tooth formation, an effect partly mediated by Bmp4. Runx2 , a gene whose loss-of-function mutations result in sequential formation of supernumerary teeth in the human cleidocranial dysplasia syndrome, suppressed the expression of Wnt inhibitors Axin2 and Drapc1 in dental mesenchyme. Our data indicate that increased mesenchymal Wnt signaling inhibits the sequential formation of teeth, and suggest that Axin2 / Runx2 antagonistic interactions modulate the level of mesenchymal Wnt/β-catenin signaling, underlying the contrasting dental phenotypes caused by human AXIN2 and RUNX2 mutations. © 2018. Published by The Company of Biologists Ltd.

  3. Anterior maxillary distraction using a tooth-borne device for hypoplastic cleft maxillas-a pilot study.

    Science.gov (United States)

    Richardson, Sunil; Agni, Nisheet A; Selvaraj, Dhivakar

    2011-12-01

    The management of maxillary retrusion in a patient with cleft lip and palate is performed using Le Fort I advancement or distraction osteogenesis using an external or an internal device. Distraction mostly involves movement of the entire maxilla at the Le Fort I level and is characterized by a higher relapse rate and a hampering of speech. Hence, distraction of the anterior maxilla was performed using a tooth-borne palatal distractor similar to the one proposed by Gunaseelan et al (J Oral Maxillofac Surg 65:1044, 2007). However, the technique was modified by placing the distractor preoperatively before performing the osteotomy cut. The main advantage of this modification is that more control over the vector can be achieved and chances of cement failure caused by contamination and an inability to achieve isolation is drastically decreased. This study investigated the efficacy and stability of anterior maxillary distraction in the management of cleft maxillary retrognathia and any resulting complications. Fourteen patients older than 12 years with cleft maxillary retrognathia were included in the study irrespective of gender, type of cleft lip and palate, and the amount of advancement needed. The patients were evaluated using Orthopantomogram and lateral cephalograms preoperatively and at 3 months postoperatively (ie, before appliance removal) and at 6 months postoperatively. The distractor was fabricated extraorally on a cast and cemented into the patient's mouth the day before surgery. The initial deficiency, amount of advancement achieved, and relapses at 6 months, if any, were studied. The data were tabulated and analyzed. Only 1 of the 14 patients showed a relapse, of 2 mm, because this patient was lost to follow-up and thus delayed tooth replacement. Anterior maxillary distraction with a tooth-borne device is a feasible modality for the management of cleft maxillary retrognathia, with stable results. Copyright © 2011 American Association of Oral and

  4. Tooth supported overdenture: A concept overshadowed but not yet forgotten!

    OpenAIRE

    Rupandeep Kaur Samra; Shreenivas Vasant Bhide; Chhavi Goyal; Taranjit Kaur

    2015-01-01

    The concept of conventional tooth-retained overdentures is a simple and cost effective treatment than the implant overdentures. When few firm teeth are present in an otherwise compromised dentition, they can be retained and used as abutments for overdenture fabrication. This helps improve the retention and stability of the final prosthesis significantly. Bone is a dynamic tissue. The extraction of teeth results in the initiation of the bone resorption pattern. However, when tensile stress is ...

  5. Initiation and patterning of the snake dentition are dependent on Sonic hedgehog signaling.

    Science.gov (United States)

    Buchtová, Marcela; Handrigan, Gregory R; Tucker, Abigail S; Lozanoff, Scott; Town, Liam; Fu, Katherine; Diewert, Virginia M; Wicking, Carol; Richman, Joy M

    2008-07-01

    Here we take the first look at cellular dynamics and molecular signaling in the developing snake dentition. We found that tooth formation differs from rodents in several respects. The majority of snake teeth bud off of a deep, ribbon-like dental lamina rather than as separate tooth germs. Prior to and after dental lamina ingrowth, we observe asymmetries in cell proliferation and extracellular matrix distribution suggesting that localized signaling by a secreted protein is involved. We cloned Sonic hedgehog from the African rock python Python sebae and traced its expression in the species as well as in two other snakes, the closely-related Python regius and the more derived corn snake Elaphe guttata (Colubridae). We found that expression of Shh is first confined to the odontogenic band and defines the position of the future dental lamina. Shh transcripts in pythons are progressively restricted to the oral epithelium on one side of the dental lamina and remain in this position throughout the prehatching period. Shh is expressed in the inner enamel epithelium and the stellate reticulum of the tooth anlagen, but is absent from the outer enamel epithelium and its derivative, the successional lamina. This suggests that signals other than Shh are responsible for replacement tooth formation. Functional studies using cyclopamine to block Hh signaling during odontogenesis prevented initiation and extension of the dental lamina into the mesenchyme, and also affected the directionality of this process. Further, blocking Hh signaling led to disruptions of the inner enamel epithelium. To explore the role of Shh in lamina extension, we looked at its expression in the premaxillary teeth, which form closer to the oral surface than elsewhere in the mouth. Oral ectodermal Shh expression in premaxillary teeth is lost soon after the teeth form reinforcing the idea that Shh is controlling the depth of the dental lamina. In summary, we have found diverse roles for Shh in patterning the

  6. Analysis of tooth tissues using Raman spectroscopy

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  7. Contemporary permanent tooth dimensions, with comparisons to G.V. Black's data.

    Science.gov (United States)

    Harris, Edward F; Burris, Benjamin G

    2003-01-01

    The tooth dimensions most commonly cited in the dental literature are those published by the famous restorative dentist G. V. Black late in the 19th century. We report here on the crown dimensions of a large series of contemporary North American Whites and show that Black's values differ significantly from modern values, but not in any consistent or predictable fashion. Black supplied no information about the nature of his sample. We suggest that it may be time to replace Black's data with modern tooth size standards.

  8. 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…

  9. Investigation of EPR signals on tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-12-15

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

  10. Orthodontic Tooth Movement: A Historic Prospective.

    Science.gov (United States)

    Will, Leslie A

    2016-01-01

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

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

    Science.gov (United States)

    Połowniak, Piotr; Sobolak, Mariusz

    2017-12-01

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

  12. Biologically Based Restorative Management of Tooth Wear

    Directory of Open Access Journals (Sweden)

    Martin G. D. Kelleher

    2012-01-01

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

  13. Autotransplantation of Mandibular Third Molar with Buccal Cortical Plate to Replace Vertically Fractured Mandibular Second Molar: A Novel Technique.

    Science.gov (United States)

    Zufía, Juan; Abella, Francesc; Trebol, Ivan; Gómez-Meda, Ramón

    2017-09-01

    Tooth replacement often leads to inadequate vertical volume in the recipient site bone when a tooth has been extracted because of a vertical root fracture (VRF). This case report presents the autotransplantation of a mandibular third molar (tooth #32) with the attached buccal cortical plate to replace a mandibular second molar (tooth #31) diagnosed with a VRF. After extraction of tooth #31, the recipient socket was prepared based on the size measured in advance with cone-beam computed tomographic imaging. The precise and calculated osteotomy of the cortical bone of tooth #32 allowed for the exact placement of the donor tooth in the position of tooth #31. The total extraoral time was only 25 minutes. The block was fixed to the recipient socket with an osteosynthesis screw and splinted with a double resin wire for 8 weeks. At the 6-month follow-up, the screw was removed, and the stability of the tooth and the regeneration obtained throughout the vestibular area were confirmed. At the 2-year follow-up, the transplanted tooth was asymptomatic and maintained a normal bone level. Advantages of autotransplantation over dental implants include maintenance of proprioception, possible orthodontic movements, and a relatively low cost. This case report demonstrates that an autotransplantation of a third molar attached to its buccal cortical plate is a viable option to replace teeth with a VRF. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Tooth whitening: what we now know.

    Science.gov (United States)

    Carey, Clifton M

    2014-06-01

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

  15. Transcatheter aortic valve replacement

    Science.gov (United States)

    ... gov/ency/article/007684.htm Transcatheter aortic valve replacement To use the sharing features on this page, please enable JavaScript. Transcatheter aortic valve replacement (TAVR) is surgery to replace the aortic valve. ...

  16. Nicotine replacement therapy

    Science.gov (United States)

    Smoking cessation - nicotine replacement; Tobacco - nicotine replacement therapy ... Before you start using a nicotine replacement product, here are some things to know: The more cigarettes you smoke, the higher the dose you may need to ...

  17. Nuclear reactor fuel replacement system

    International Nuclear Information System (INIS)

    Kayano, Hiroyuki; Joge, Toshio.

    1976-01-01

    Object: To permit the direction in which a fuel replacement unit is moving to be monitored by the operator. Structure: When a fuel replacement unit approaches an intermediate goal position preset in the path of movement, renewal of data display on a goal position indicator is made every time the goal position is changed. With this renewal, the prevailing direction of movement of the fuel replacement unit can be monitored by the operator. When the control of movement is initiated, the co-ordinates of the intermediate goal point A are displayed on a goal position indicator. When the replacement unit reaches point A, the co-ordinates of the next intermediate point B are displayed, and upon reaching point B the co-ordinates of the (last) goal point C are displayed. (Nakamura, S.)

  18. The Impact of Regression to the Mean on Economic Evaluation in Quasi-Experimental Pre-Post Studies: The Example of Total Knee Replacement Using Data from the Osteoarthritis Initiative.

    Science.gov (United States)

    Schilling, Chris; Petrie, Dennis; Dowsey, Michelle M; Choong, Peter F; Clarke, Philip

    2017-12-01

    Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression to the mean (RTM). Ignoring RTM could bias the economic evaluation. We investigated this issue using the contemporary example of total knee replacement (TKR), a common treatment for end-stage osteoarthritis of the knee. Data (n = 4796) were obtained from the Osteoarthritis Initiative database, a longitudinal observational study of osteoarthritis. TKR patients (n = 184) were matched to non-TKR patients, using propensity score matching on the predicted hazard of TKR and exact matching on osteoarthritis severity and health-related quality of life (HrQoL). The economic evaluation using the matched control group was compared to the standard method of using the pre-surgery score as the control. Matched controls were identified for 56% of the primary TKRs. The matched control HrQoL trajectory showed evidence of RTM accounting for a third of the estimated QALY gains from surgery using the pre-surgery HrQoL as the control. Incorporating RTM into the economic evaluation significantly reduced the estimated cost effectiveness of TKR and increased the uncertainty. A generalized ICER bias correction factor was derived to account for RTM in cost-effectiveness analysis. RTM should be considered in economic evaluations based on quasi-experimental pre-post studies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Tooth Retained Implant: No More an Oxymoron

    Directory of Open Access Journals (Sweden)

    Divya Bhat

    2011-03-01

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

  20. Structure, attachment, replacement and growth of teeth in bluefish, Pomatomus saltatrix (Linnaeus, 1776), a teleost with deeply socketed teeth.

    Science.gov (United States)

    Bemis, William E; Giuliano, Anne; McGuire, Betty

    2005-01-01

    Tooth replacement poses many questions about development, pattern formation, tooth attachment mechanisms, functional morphology and the evolution of vertebrate dentitions. Although most vertebrate species have polyphyodont dentitions, detailed knowledge of tooth structure and replacement is poor for most groups, particularly actinopterygians. We examined the oral dentition of the bluefish, Pomatomus saltatrix, a pelagic and coastal marine predator, using a sample of 50 individuals. The oral teeth are located on the dentary and premaxillary bones, and we scored each tooth locus in the dentary and premaxillary bones using a four-part functional classification: absent (A), incoming (I), functional (F=fully ankylosed) or eroding (E). The homodont oral teeth of Pomatomus are sharp, deeply socketed and firmly ankylosed to the bone of attachment. Replacement is intraosseus and occurs in alternate tooth loci with long waves of replacement passing from rear to front. The much higher percentage of functional as opposed to eroding teeth suggests that replacement rates are low but that individual teeth are quickly lost once erosion begins. Tooth number increases ontogenetically, ranging from 15-31 dentary teeth and 15-39 premaxillary teeth in the sample studied. Teeth increase in size with every replacement cycle. Remodeling of the attachment bone occurs continuously to accommodate growth. New tooth germs originate from a discontinuous dental lamina and migrate from the lingual (dentary) or labial (premaxillary) epithelium through pores in the bone of attachment into the resorption spaces beneath the existing teeth. Pomatomus shares unique aspects of tooth replacement with barracudas and other scombroids and this supports the interpretation that Pomatomus is more closely related to scombroids than to carangoids.

  1. 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.

  2. Power Consumption Optimization in Tooth Gears Processing

    Science.gov (United States)

    Kanatnikov, N.; Harlamov, G.; Kanatnikova, P.; Pashmentova, A.

    2018-01-01

    The paper reviews the issue of optimization of technological process of tooth gears production of the power consumption criteria. The authors dwell on the indices used for cutting process estimation by the consumed energy criteria and their applicability in the analysis of the toothed wheel production process. The inventors proposed a method for optimization of power consumptions based on the spatial modeling of cutting pattern. The article is aimed at solving the problem of effective source management in order to achieve economical and ecological effect during the mechanical processing of toothed gears. The research was supported by Russian Science Foundation (project No. 17-79-10316).

  3. Tooth fractures in canine clinical practice

    International Nuclear Information System (INIS)

    Capik, I.; Ledecky, V.; Sevcik, A.

    2001-01-01

    Tooth fractures constitute a considerable fraction of all tooth diseases. Out of the 5,370 dogs treated during four years, 492 were presented with dental problems and 28.3 % of the latter were treated for tooth fractures. Canines were the most frequently affected teeth (38.8 %), followed by premolars (33.1 %), incisors (25.9 %), and molars (2.2 %), 55.4 % of the patients with canine and incisor fractures being large breed dogs. Fractures of premolars (mostly of 108, 208) were divided evenly irrespective of breed or body size. Nonsurgical endodontic treatment yielded good therapeutic results in most cases, but repeated treatment was necessary in some patients

  4. Defining line replaceable units

    NARCIS (Netherlands)

    Parada Puig, J. E.; Basten, R. J I

    2015-01-01

    Defective capital assets may be quickly restored to their operational condition by replacing the item that has failed. The item that is replaced is called the Line Replaceable Unit (LRU), and the so-called LRU definition problem is the problem of deciding on which item to replace upon each type of

  5. Tooth resorption in cats: contribution of vitamin D and inflammation

    NARCIS (Netherlands)

    Vrieling, H.E.

    2010-01-01

    Tooth resorption in cats Tooth resorption affecting several teeth is a painful disease with a prevalence of up to 75% in household cats and is often accompanied by periodontitis. Tooth resorption is caused by an increased number and activity of tooth-resorbing odontoclasts, cells that share

  6. Autotransplantation donor tooth site harvesting using piezosurgery.

    Science.gov (United States)

    Ylikontiola, Leena P; Sándor, George K

    2016-01-01

    The harvesting of a tooth as a candidate for tooth autotransplantation requires that the delicate dental tissues around the tooth be minimally traumatized. This is especially so for the periradicular tissues of the tooth root and the follicular tissues surrounding the crown. The aim of this report is to describe the use of piezosurgery as an attempt at morbidity reduction in the harvesting of teeth for autotransplantation. A piezosurgical handpiece and its selection of tips were easily adapted to allow the harvesting and delivery of teeth for autotransplantation purposes. Twenty premolar teeth were harvested using a piezosurgical device. The harvested teeth were subsequently successfully autotransplanted. All twenty teeth healed in a satisfactory manner without excessive mobility or ankyloses. Piezosurgery avoids some of the traumatic aspects of harvesting teeth and removing bone which are associated with thermal damage from the use of conventional rotary instruments or saws. Piezosurgery can be adapted to facilitate the predictable harvesting of teeth for autotransplantation purposes.

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Is My Child at Risk for Early Childhood Tooth Decay? What is a Composite Resin (White Filling)? How Do I Care for My Child's Baby Teeth? Learn what those dental words mean. The Life ...

  8. Gear Tooth Wear Detection Algorithm

    Science.gov (United States)

    Delgado, Irebert R.

    2015-01-01

    Vibration-based condition indicators continue to be developed for Health Usage Monitoring of rotorcraft gearboxes. Testing performed at NASA Glenn Research Center have shown correlations between specific condition indicators and specific types of gear wear. To speed up the detection and analysis of gear teeth, an image detection program based on the Viola-Jones algorithm was trained to automatically detect spiral bevel gear wear pitting. The detector was tested using a training set of gear wear pictures and a blind set of gear wear pictures. The detector accuracy for the training set was 75 percent while the accuracy for the blind set was 15 percent. Further improvements on the accuracy of the detector are required but preliminary results have shown its ability to automatically detect gear tooth wear. The trained detector would be used to quickly evaluate a set of gear or pinion pictures for pits, spalls, or abrasive wear. The results could then be used to correlate with vibration or oil debris data. In general, the program could be retrained to detect features of interest from pictures of a component taken over a period of time.

  9. Ultrasonographic Detection of Tooth Flaws

    Science.gov (United States)

    Bertoncini, C. A.; Hinders, M. K.; Ghorayeb, S. R.

    2010-02-01

    The goal of our work is to adapt pulse-echo ultrasound into a high resolution imaging modality for early detection of oral diseases and for monitoring treatment outcome. In this talk we discuss our preliminary results in the detection of: demineralization of the enamel and dentin, demineralization or caries under and around existing restorations, caries on occlusal and interproximal surfaces, cracks of enamel and dentin, calculus, and periapical lesions. In vitro immersion tank experiments are compared to results from a handpiece which uses a compliant delay line to couple the ultrasound to the tooth surface. Because the waveform echoes are complex, and in order to make clinical interpretation of ultrasonic waveform data in real time, it is necessary to automatically interpret the signals. We apply the dynamic wavelet fingerprint algorithms to identify and delineate echographic features that correspond to the flaws of interest in teeth. The resulting features show a clear distinction between flawed and unflawed waveforms collected with an ultrasonic handpiece on both phantom and human cadaver teeth.

  10. 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.

  11. Orthodontic Tooth Movement with Clear Aligners

    OpenAIRE

    Drake, Carl T.; McGorray, Susan P.; Dolce, Calogero; Nair, Madhu; Wheeler, Timothy T.

    2012-01-01

    Clear aligners provide a convenient model to measure orthodontic tooth movement (OTM). We examined the role of in vivo aligner material fatigue and subject-specific factors in tooth movement. Fifteen subjects seeking orthodontic treatment at the University of Florida were enrolled. Results were compared with data previously collected from 37 subjects enrolled in a similar protocol. Subjects were followed prospectively for eight weeks. An upper central incisor was programmed to move 0.5 mm. ev...

  12. Tooth wear and wear investigations in dentistry.

    Science.gov (United States)

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

    2012-03-01

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

  13. Numeric simulation model for long-term orthodontic tooth movement with contact boundary conditions using the finite element method.

    Science.gov (United States)

    Hamanaka, Ryo; Yamaoka, Satoshi; Anh, Tuan Nguyen; Tominaga, Jun-Ya; Koga, Yoshiyuki; Yoshida, Noriaki

    2017-11-01

    Although many attempts have been made to simulate orthodontic tooth movement using the finite element method, most were limited to analyses of the initial displacement in the periodontal ligament and were insufficient to evaluate the effect of orthodontic appliances on long-term tooth movement. Numeric simulation of long-term tooth movement was performed in some studies; however, neither the play between the brackets and archwire nor the interproximal contact forces were considered. The objectives of this study were to simulate long-term orthodontic tooth movement with the edgewise appliance by incorporating those contact conditions into the finite element model and to determine the force system when the space is closed with sliding mechanics. We constructed a 3-dimensional model of maxillary dentition with 0.022-in brackets and 0.019 × 0.025-in archwire. Forces of 100 cN simulating sliding mechanics were applied. The simulation was accomplished on the assumption that bone remodeling correlates with the initial tooth displacement. This method could successfully represent the changes in the moment-to-force ratio: the tooth movement pattern during space closure. We developed a novel method that could simulate the long-term orthodontic tooth movement and accurately determine the force system in the course of time by incorporating contact boundary conditions into finite element analysis. It was also suggested that friction is progressively increased during space closure in sliding mechanics. Copyright © 2017. Published by Elsevier Inc.

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

    Science.gov (United States)

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

    2017-01-01

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

  15. Conservative treatment of an ankylosed tooth after delayed replantation: a case report.

    Science.gov (United States)

    Díaz, Jaime Andrés; Sandoval, Hector Paulo; Pineda, Patricia Irene; Junod, Pablo Antonio

    2007-10-01

    An 8-year-old boy sustained avulsion of his upper right maxillary central incisor and lateral luxation of his upper left maxillary incisors. Subsequently, the upper right maxillary central incisor developed replacement resorption, and both upper left maxillary incisors developed pulpal canal obliteration. In the ankylosed tooth, decoronation procedure was performed, and in the 44-month follow-up period the involved alveolar site showed vertical apposition of bone and continuing replacement resorption. Decoronation is a surgical procedure that allows preservation of the bone volume for the future, avoiding aesthetic disturbances and more aggressive treatments in cases where other therapeutic alternatives are not feasible.

  16. CHARCOT-MARIE-TOOTH DISEASE

    Directory of Open Access Journals (Sweden)

    Lea Leonardis

    2003-09-01

    Full Text Available Background. Charcot-Marie-Tooth (CMT disease is a common inherited disorder of the peripheral nervous system. In our paper, different types of CMT are described with their typical clinical pictures, electrophysiological signs and molecular genetic studies. CMT is classified as demyelinative and axonal type and distal motor neuronopathy.Conclusions. CMT can be of autosomal dominant, recessive and X-linked inheritance. The most frequent form of CMT is the result of the dominantly inherited duplication of chromosome 17p11.2 and is marked as CMT1A. The same group involves also rare patients with point mutation in the peripheral myelin protein-22 gene. CMT1B is associated with point mutations in protein zero gene. CMT1C is linked to chromosome 16p13.1–12.3. Patients with point mutations in early growth response 2 gene (EGR2 are included in group CMT1D. The disease can be also inhereted X-linked (CMTX with the mutations in connexin-32 gene. In autosomal recessive inherited demyelinating polyneuropathies (CMT4, mutations are found in the myotubularin-related protein-2 (CMT4B, N-myc downstream-regulated gene 1 (CMT4D, EGR2 (CMT4E, and in the periaksin (CMT4F genes. In axonal inherited neuropathy, mutations are found in KIF1beta (CMT2A and in light neurofilament (CMT2E genes, other forms map to different chromosomal loci (CMT2B, CMT2D, CMT2F. Some suggestions for the diagnostic procedures of patients with CMT are given.

  17. Relative tooth size at birth in primates: Life history correlates.

    Science.gov (United States)

    Smith, Timothy D; Muchlinski, Magdalena N; Bucher, Wade R; Vinyard, Christopher J; Bonar, Christopher J; Evans, Sian; Williams, Lawrence E; DeLeon, Valerie B

    2017-11-01

    Dental eruption schedules have been closely linked to life history variables. Here we examine a sample of 50 perinatal primates (28 species) to determine whether life history traits correlate with relative tooth size at birth. Newborn primates were studied using serial histological sectioning. Volumes of deciduous premolars (dp 2 -dp 4 ), replacement teeth (if any), and permanent molars (M 1-2/3 ) of the upper jaw were measured and residuals from cranial length were calculated with least squares regressions to obtain relative dental volumes (RDVs). Relative dental volumes of deciduous or permanent teeth have an unclear relationship with relative neonatal mass in all primates. Relative palatal length (RPL), used as a proxy for midfacial size, is significantly, positively correlated with larger deciduous and permanent postcanine teeth. However, when strepsirrhines alone are examined, larger RPL is correlated with smaller RDV of permanent teeth. In the full sample, RDVs of deciduous premolars are significantly negatively correlated with relative gestation length (RGL), but have no clear relationship with relative weaning age. RDVs of molars lack a clear relationship with RGL; later weaning is associated with larger molar RDV, although correlations are not significant. When strepsirrhines alone are analyzed, clearer trends are present: longer gestations or later weaning are associated with smaller deciduous and larger permanent postcanine teeth (only gestational length correlations are significant). Our results indicate a broad trend that primates with the shortest RGLs precociously develop deciduous teeth; in strepsirrhines, the opposite trend is seen for permanent molars. Anthropoids delay growth of permanent teeth, while strepsirrhines with short RGLs are growing replacement teeth concurrently. A comparison of neonatal volumes with existing information on extent of cusp mineralization indicates that growth of tooth germs and cusp mineralization may be selected for

  18. Ankle replacement - discharge

    Science.gov (United States)

    ... total - discharge; Total ankle arthroplasty - discharge; Endoprosthetic ankle replacement - discharge; Osteoarthritis - ankle ... You had an ankle replacement. Your surgeon removed and reshaped ... an artificial ankle joint. You received pain medicine and were ...

  19. Artificial Disc Replacement

    Science.gov (United States)

    ... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

  20. Partial knee replacement - slideshow

    Science.gov (United States)

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

  1. Flued head replacement alternatives

    International Nuclear Information System (INIS)

    Smetters, J.L.

    1987-01-01

    This paper discusses flued head replacement options. Section 2 discusses complete flued head replacement with a design that eliminates the inaccessible welds. Section 3 discusses alternate flued head support designs that can drastically reduce flued head installation costs. Section 4 describes partial flued head replacement designs. Finally, Section 5 discusses flued head analysis methods. (orig./GL)

  2. Capital Equipment Replacement Decisions

    OpenAIRE

    Batterham, Robert L.; Fraser, K.I.

    1995-01-01

    This paper reviews the literature on the optimal replacement of capital equipment, especially farm machinery. It also considers the influence of taxation and capital rationing on replacement decisions. It concludes that special taxation provisions such as accelerated depreciation and investment allowances are unlikely to greatly influence farmers' capital equipment replacement decisions in Australia.

  3. Implementing Replacement Cost Accounting

    Science.gov (United States)

    1976-12-01

    cost accounting Clickener, John Ross Monterey, California. Naval Postgraduate School http://hdl.handle.net/10945/17810 Downloaded from NPS Archive...Calhoun IMPLEMENTING REPLACEMENT COST ACCOUNTING John Ross CHckener NAVAL POSTGRADUATE SCHOOL Monterey, California THESIS IMPLEMENTING REPLACEMENT COST ...Implementing Replacement Cost Accounting 7. AUTHORS John Ross Clickener READ INSTRUCTIONS BEFORE COMPLETING FORM 3. RECIPIENT’S CATALOG NUMBER 9. TYRE OF

  4. Tooth loss due to periodontal abscess: a retrospective study.

    Science.gov (United States)

    McLeod, D E; Lainson, P A; Spivey, J D

    1997-10-01

    This retrospective study focused on the frequency of tooth loss due to periodontal abscess among 42 patients who were treated by a single clinician over a 5- to 29-year period. A total of 114 patients were selected from the active periodontal recall schedule of a single periodontist at The University of Iowa College of Dentistry. The criteria for inclusion in the study included having a history of moderate to advanced periodontitis, being on 3 to 6 month recall periodontal maintenance care, and completion of active periodontal therapy prior to October 1987. Other parameters evaluated were age; gender; number of teeth present and missing at the initial, reevaluation, and last periodontal recall visit; initial periodontal prognosis; furcation involvement; non-surgical and surgical periodontal therapy; and reasons for tooth loss. Patients were grouped according to the number of teeth lost following active periodontal treatment into well-maintained (0 to 3), downhill (4 to 9), and extreme downhill (10 to 23) groups. Forty-two of the 114 patients were identified as having one or more periodontal abscesses. A total of 109 teeth were affected by periodontal abscess of which 49 (45%) teeth were lost and 60 (55%) were successfully maintained over an average of 12.5 years (5 to 29 years). More furcated teeth were lost than nonfurcated teeth and teeth given a hopeless prognosis were lost more consistently than those given a questionable prognosis in all groups. The frequency of periodontal abscess and tooth loss per patient was greater in the downhill and extreme downhill response groups than the well-maintained group. This suggests that teeth with a history of periodontal abscess can be treated and maintained for several years.

  5. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the substantiation of a health claim related to “non - fermentable ” carbohydrates and maintenance of tooth mineralisation by decreasing tooth demineralisation pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    on the scientific substantiation of a health claim related to Nutriose® which should replace “fermentable carbohydrates” in foods or beverages in order to obtain the claimed effect, i.e. maintenance of tooth mineralisation by reducing tooth demineralisation. From the information provided, the Panel noted......” carbohydrates in foods or beverages in order to obtain the claimed effect. The Panel considers that maintaining tooth mineralisation by reducing tooth demineralisation resulting from acid production in plaque caused by the fermentation of carbohydrates is a beneficial physiological effect. The Panel concludes...... that a cause and effect relationship has been established between the consumption of foods/beverages containing “fermentable” carbohydrates at an exposure frequency of four or more times daily and an increased tooth demineralisation, and that the consumption of foods/beverages containing “non...

  6. Preventing Tooth Decay: A Guide for Implementing Self-Applied Fluoride in Schools.

    Science.gov (United States)

    National Inst. of Dental Research (NIH), Bethesda, MD.

    This guidebook was developed to assist citizens in initiating programs to prevent tooth decay in young children through the use of fluoridation. It contains outlines for determining the needs of the school and community for fluoride in drinking water, and presents the various steps and activities that are necessary for developing and implementing…

  7. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events

    OpenAIRE

    Feller, Liviu; Khammissa, Razia A. G.; Thomadakis, George; Fourie, Jeanine; Lemmer, Johan

    2016-01-01

    Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resor...

  8. Histochemical demonstration of activity of acid phosphatase and beta-glucuronidase in bovine incisor tooth germs

    DEFF Research Database (Denmark)

    Kirkeby, S; Salling, E; Moe, D

    1983-01-01

    . After initiation of enamel formation, a change in localization and intensity of the colored reaction product was observed in the ameloblasts. The activity appeared stronger and was restricted to a narrow zone just apical to the nucleus. It is proposed that the acid hydrolases in the tooth forming cells...

  9. Roentgenologic investigations for the anterior tooth length

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Pyo; Ahn, Hyung Kyu [College of Dentistry, Seoul National University , Seoul (Korea, Republic of)

    1972-11-15

    The author measured the length of crown, root and tooth on the films which was taken by intraoral bisecting technic with mesh plate on the films. The films were taken from the dry skulls, dentiform, same patients who had to be removed their upper incisors, and the other patients who admitted for dental care. From this serial experiment the results were made as follows: 1. By using the film and mesh plate in the oral cavity, the real tooth length can be measured easily on the film surfaces. 2. The film distortion in the oral cavity can be avoided when taking the film using the mesh plate and film together. 3. When measuring the film, length of crown was elongated and length of root was shortened. 4. When using the well-trained bisecting technic, the real tooth length can be measured directly on the intraoral film.

  10. Effect of drugs on orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Siti Sarah Aulia Amrullah

    2016-06-01

    Full Text Available Orthodontic tooth movement is basically a biological response to mechanical forces given to the teeth in orthodontic treatment, which involving the periodontal tissue and alveolar bone, resulting in the release of numerous substances from the dental tissues and surrounding structure. Remodeling changes in periodontal tissues are considered to be essential in effecting orthodontic tooth movement which is the base of orthodontic correction. Molecules produced in various diseased tissues or drugs and nutrients consumed regularly by patients, can influence mechanically stressed periodontal tissue through the circulation and interact with target cell combination of which may be inhibitory, additive or synergize. Medications might have an important influence on the rate of tooth movement, and information on their consumption is essential to adequately discuss treatment planning with patients. Therefore it is imperative to the practitioners being in medical profession, must pay close attention to the drug consumption history of every patient before and during the course of treatment.

  11. Side effects of external tooth bleaching

    DEFF Research Database (Denmark)

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

    2013-01-01

    Objective The study was performed to assess the risk of at-home and in-office bleaching procedures, and to recognise potential predictors for side effects. Design Multi-centre, questionnaire-based prospective study with follow-ups at around 14 days and around one year post-treatment. Setting...... General practices and university clinics during the years 2007‑2009 in Scandinavia. Subjects Patients with tooth bleaching as part of the treatment plan. Results The prevalence of experienced tooth sensitivity at first follow-up was independent of bleaching procedure (at-home = 50.3% [n = 143]; in...... 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...

  12. Prioritization methodology for chemical replacement

    Science.gov (United States)

    Cruit, Wendy; Goldberg, Ben; Schutzenhofer, Scott

    1995-01-01

    Since United States of America federal legislation has required ozone depleting chemicals (class 1 & 2) to be banned from production, The National Aeronautics and Space Administration (NASA) and industry have been required to find other chemicals and methods to replace these target chemicals. This project was initiated as a development of a prioritization methodology suitable for assessing and ranking existing processes for replacement 'urgency.' The methodology was produced in the form of a workbook (NASA Technical Paper 3421). The final workbook contains two tools, one for evaluation and one for prioritization. The two tools are interconnected in that they were developed from one central theme - chemical replacement due to imposed laws and regulations. This workbook provides matrices, detailed explanations of how to use them, and a detailed methodology for prioritization of replacement technology. The main objective is to provide a GUIDELINE to help direct the research for replacement technology. The approach for prioritization called for a system which would result in a numerical rating for the chemicals and processes being assessed. A Quality Function Deployment (QFD) technique was used in order to determine numerical values which would correspond to the concerns raised and their respective importance to the process. This workbook defines the approach and the application of the QFD matrix. This technique: (1) provides a standard database for technology that can be easily reviewed, and (2) provides a standard format for information when requesting resources for further research for chemical replacement technology. Originally, this workbook was to be used for Class 1 and Class 2 chemicals, but it was specifically designed to be flexible enough to be used for any chemical used in a process (if the chemical and/or process needs to be replaced). The methodology consists of comparison matrices (and the smaller comparison components) which allow replacement technology

  13. Mathematical models for the synthesis and optimization of spiral bevel gear tooth surfaces. [for helicopter transmissions

    Science.gov (United States)

    Litvin, F. L.; Rahman, P.; Goldrich, R. N.

    1982-01-01

    The geometry of spiral bevel gears and to their rational design are studied. The nonconjugate tooth surfaces of spiral bevel gears are, in theory, replaced (or approximated) by conjugated tooth surfaces. These surfaces can be generated by two conical surfaces, and by a conical surface and a revolution. Although these conjugated tooth surfaces are simpler than the actual ones, the determination of their principal curvatures and directions is still a complicated problem. Therefore, a new approach, to the solution of these is proposed. Direct relationships between the principal curvatures and directions of the tool surface and those of the generated gear surface are obtained. With the aid of these analytical tools, the Hertzian contact problem for conjugate tooth surfaces can be solved. These results are useful in determining compressive load capacity and surface fatigue life of spiral bevel gears. A general theory of kinematical errors exerted by manufacturing and assembly errors is developed. This theory is used to determine the analytical relationship between gear misalignments and kinematical errors. This is important to the study of noise and vibration in geared systems.

  14. Tooth-germ damage by ionizing radiation

    International Nuclear Information System (INIS)

    Sobkowiak, E.M.; Beetke, E.; Bienengraeber, V.; Held, M.; Kittner, K.H.

    1977-01-01

    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. Tooth microwear formation rate in Gasterosteus aculeatus.

    Science.gov (United States)

    Baines, D C; Purnell, M A; Hart, P J B

    2014-05-01

    Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. © 2014 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  16. Herbal extracts and symbiotic mixture replacing antibiotics in piglets at the initial phase Extratos herbais e mistura simbiótica em substituição aos antibióticos para suínos na fase inicial

    Directory of Open Access Journals (Sweden)

    Márcio Gilberto Zangeronimo

    2011-05-01

    Full Text Available The objective of this work was to evaluate the use of vegetable extract based addictives associated or not to symbiotics as an alternative for antibiotic as growth promoters for piglets at initial phase. It was used 125 pigs of commercial genetic line with initial weight of 7.4 ± 1.1 kg, weaned at 20 days of age, during 50 days. The experimental design used was randomized blocks (initial weight, with five treatments and five replicates with five animals per experimental unit. The experimental diets were a basal diet, without additive, and other four diets, one diet containing antibiotic (colistin + zinc oxide; diet with 0.3% of a symbiotic mixture; diet with 0.3% of a symbiotic mixture plus 0.05% of herbal mix (plant extracts and microencapsulated essential oils; and another diet with 0.3% of symbiotic mixture plus 0.1% of herbal mixture. It was observed that the use of the symbiotic mixture associated to 0.05% of herbal mixture showed positive results, similar to the ones obtained with diets containing antibiotics for the final weight, average weight gain, average daily feed intake and pH of stomach and diarrhea incidence. The use of symbiotics promoted smaller vilous:depth crypt ratio, except when associated to 0.1% of herbal mixture, which was similar to the diet without addictives. There was no differences in the feed conversion, coliform and lactobacillus count in the jejune and in the cecum and in the pH of cecum. The use of herbal mixture associated to symbiotic is a viable alternative for replacing the use of antibiotics as growth promoters for piglets in the initial phase. However, the concentration of the herbal mixture is an important factor to be considered.O objetivo neste trabalho foi avaliar o uso de aditivos à base de extratos vegetais associados ou não ao uso de simbióticos como alternativa aos antibióticos como promotores de crescimento para suínos na fase inicial. Foram utilizados 125 leitões de genética comercial, com

  17. Assessment of reliability of CAD-CAM tooth-colored implant custom abutments.

    Science.gov (United States)

    Guilherme, Nuno Marques; Chung, Kwok-Hung; Flinn, Brian D; Zheng, Cheng; Raigrodski, Ariel J

    2016-08-01

    Information is lacking about the fatigue resistance of computer-aided design and computer-aided manufacturing (CAD-CAM) tooth-colored implant custom abutment materials. The purpose of this in vitro study was to investigate the reliability of different types of CAD-CAM tooth-colored implant custom abutments. Zirconia (Lava Plus), lithium disilicate (IPS e.max CAD), and resin-based composite (Lava Ultimate) abutments were fabricated using CAD-CAM technology and bonded to machined titanium-6 aluminum-4 vanadium (Ti-6Al-4V) alloy inserts for conical connection implants (NobelReplace Conical Connection RP 4.3×10 mm; Nobel Biocare). Three groups (n=19) were assessed: group ZR, CAD-CAM zirconia/Ti-6Al-4V bonded abutments; group RC, CAD-CAM resin-based composite/Ti-6Al-4V bonded abutments; and group LD, CAD-CAM lithium disilicate/Ti-6Al-4V bonded abutments. Fifty-seven implant abutments were secured to implants and embedded in autopolymerizing acrylic resin according to ISO standard 14801. Static failure load (n=5) and fatigue failure load (n=14) were tested. Weibull cumulative damage analysis was used to calculate step-stress reliability at 150-N and 200-N loads with 2-sided 90% confidence limits. Representative fractured specimens were examined using stereomicroscopy and scanning electron microscopy to observe fracture patterns. Weibull plots revealed β values of 2.59 for group ZR, 0.30 for group RC, and 0.58 for group LD, indicating a wear-out or cumulative fatigue pattern for group ZR and load as the failure accelerating factor for groups RC and LD. Fractographic observation disclosed that failures initiated in the interproximal area where the lingual tensile stresses meet the compressive facial stresses for the early failure specimens. Plastic deformation of titanium inserts with fracture was observed for zirconia abutments in fatigue resistance testing. Significantly higher reliability was found in group ZR, and no significant differences in reliability were

  18. Tooth for a tooth: Tissue engineering made easy at dental chairside

    Directory of Open Access Journals (Sweden)

    Vandana Kharidhi Laxman

    2017-01-01

    Full Text Available Background: Stem cells are unspecialized, multipotent cells which can differentiate into different cell types. The human periodontal ligament encloses subpopulation of Periodontal Ligament Stem Cells (PDLSCs which are able to regenerate the periodontium by differentiating into various cells of PDL. Literature have shown the promising results of periodontal regeneration by exvivo cultured transplantation of PDLSCs into the osseous defects. Methods: Based on current literature on use of ex vivo culture and associated problems, a novel technique is being presented , Stem cell application in periodontal regeneration (SAI-PRT which uses autologous PDLSCs along with its niche adhering to extracted tooth root for direct application using gelatin sponge as scaffold in regeneration of intrabony periodontal defect bypassing ex-vivo culture. Results: The cases initiated under SAI-PRT protocol, and have shown excellent clinical and radiographic improvement in intrabony defect using direct transplant of autologous PDLSCs . Conclusions: SAI-PRT can be used for the treatment of periodontal osseous defects at chair side.

  19. Clinical tooth preparations and associated measuring methods: a systematic review.

    Science.gov (United States)

    Tiu, Janine; Al-Amleh, Basil; Waddell, J Neil; Duncan, Warwick J

    2015-03-01

    The geometries of tooth preparations are important features that aid in the retention and resistance of cemented complete crowns. The clinically relevant values and the methods used to measure these are not clear. The purpose of this systematic review was to retrieve, organize, and critically appraise studies measuring clinical tooth preparation parameters, specifically the methodology used to measure the preparation geometry. A database search was performed in Scopus, PubMed, and ScienceDirect with an additional hand search on December 5, 2013. The articles were screened for inclusion and exclusion criteria and information regarding the total occlusal convergence (TOC) angle, margin design, and associated measuring methods were extracted. The values and associated measuring methods were tabulated. A total of 1006 publications were initially retrieved. After removing duplicates and filtering by using exclusion and inclusion criteria, 983 articles were excluded. Twenty-three articles reported clinical tooth preparation values. Twenty articles reported the TOC, 4 articles reported margin designs, 4 articles reported margin angles, and 3 articles reported the abutment height of preparations. A variety of methods were used to measure these parameters. TOC values seem to be the most important preparation parameter. Recommended TOC values have increased over the past 4 decades from an unachievable 2- to 5-degree taper to a more realistic 10 to 22 degrees. Recommended values are more likely to be achieved under experimental conditions if crown preparations are performed outside of the mouth. We recommend that a standardized measurement method based on the cross sections of crown preparations and standardized reporting be developed for future studies analyzing preparation geometry. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  20. Accuracy in tooth positioning with a fully customized lingual orthodontic appliance.

    Science.gov (United States)

    Grauer, Dan; Proffit, William R

    2011-09-01

    To understand orthodontic tooth movement, a method of quantification of tooth position discrepancies in 3 dimensions is needed. Brackets and wires now can be fabricated by CAD/CAM technology on a setup made at the beginning of treatment, so that treatment should produce a reasonably precise duplicate of the setup. The extent of discrepancies between the planned and actual tooth movements can be quantified by registration of the setup and final models. The goal of this study was to evaluate the accuracy of a CAD/CAM lingual orthodontic technique. Dental casts of 94 consecutive patients from 1 practice, representing a broad range of orthodontic problems, were scanned to create digital models, and then the setup and final models for each patient were registered individually for the maxillary and mandibular dental arches. Individual tooth discrepancies between the setup and actual outcome were computed and expressed in terms of a six-degrees-of-freedom rectangular coordinate system. Discrepancies in position and rotation between the setup and outcome were small for all teeth (generally less than 1 mm and 4°) except for the second molars, where some larger discrepancies were observed. Faciolingual expansion in the posterior teeth was greater in the setup than in the final models, especially at the second molars. Linear mixed models showed that age, type of tooth, jaw, initial crowding, time in slot-filling wire, use of elastics, days in treatment, interproximal reduction, and rebonding, were all influences on the final differences, but, for most of these factors, the influence was small, explaining only a small amount of the discrepancy between the planned and the actual outcomes. These fully customized lingual orthodontic appliances were accurate in achieving the goals planned at the initial setup, except for the full amount of planned expansion and the inclination at the second molars. This methodology is the first step toward understanding and measuring tooth

  1. 21 CFR 872.5525 - Preformed tooth positioner.

    Science.gov (United States)

    2010-04-01

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

  2. Aeronautical Information System Replacement -

    Data.gov (United States)

    Department of Transportation — Aeronautical Information System Replacement is a web-enabled, automation means for the collection and distribution of Service B messages, weather information, flight...

  3. Tooth wear and erosion: methodological issues in epidemiological and public health research and the future research agenda.

    Science.gov (United States)

    Ganss, C; Young, A; Lussi, A

    2011-09-01

    This paper addresses methodological issues in the field of tooth wear and erosion research including the epidemiological indices, and identifies future work that is needed to improve knowledge about tooth wear and erosion. The paper is result of the work done at the meetings of the Special Interest Group "Tooth Surface Loss and Erosion" at the 2008, 2009 and 2010 conferences of the European Association for Dental Public Health, and the Workshop "Current Erosion indices- flawed or valid" which took place in Basel in 2007. Although there is consensus about the definition and the diagnostic criteria of various forms of tooth wear, gaps in research strategies have been identified. A basic problem is that fundamental concepts of wear and erosion as an oral health problem, have not yet been sufficiently defined. To a certain extent, tooth wear is a physiological condition, and there is no consensus as to whether it can be regarded as a disease. Furthermore, the multitude of indices and flaws in existing indices, make published data difficult to interpret. Topics for the research agenda are: the initiation of a consensus process towards an internationally accepted index, and the initiation of data collection on the prevalence of various forms of wear on a population-based level. There should be an emphasis on promoting communication between basic and clinical sciences, and the area of Public Health Dentistry. Furthermore, the question of whether tooth wear is a public health problem remains open for debate.

  4. Tooth Decay Process: How to Reverse It and Avoid a Cavity

    Science.gov (United States)

    ... Health Info Health Topics Tooth Decay Tooth decay (dental caries) is damage to a tooth that can happen ... Clinical Trials Show All Clinical Trials Data & Statistics Dental caries (tooth decay) remains the most prevalent chronic disease ...

  5. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Dentist Your Family's Oral Health About the AGD Dental care and oral health information you need from the Academy of General Dentistry Friday, May 11, 2018 About | Contact InfoBites Quick Reference ... Resin (White Filling)? Check Menstrual Calendar for Tooth Extraction What is Dental Amalgam (Silver Filling)? Learn what those dental words ...

  6. 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...

  7. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... 2018 About | Contact InfoBites Quick Reference Learn more Oral Health and Overal Health Headaches and Jaw Pain? Check ... Tooth Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site Map | Reprints ...

  8. Bleaching of the discolored traumatized tooth

    DEFF Research Database (Denmark)

    Dahl, Jon E.; Kopperud, Siemen E.; Pallesen, Ulla

    2018-01-01

    This chapter focuses on the treatment of discolored traumatized teeth, most of them being non-vital and subsequently, endodontically treated. Tooth bleaching based upon hydrogen peroxide as the active agent, applied directly or produced in a chemical reaction from sodium perborate or carbamide pe...

  9. 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

  10. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Dental Advances Learn what those dental words mean. The Life of a Tooth Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site Map | Reprints and Permissions | Privacy Statement | Terms and Conditions © 1996-2018 Academy of General Dentistry. All Rights Reserved.

  11. Age effect on orthodontic tooth movement

    NARCIS (Netherlands)

    Ren, Yijin

    2003-01-01

    This study was performed to investigate the effect of age on the efficiency of orthodontic tooth movement based on critical literature reviews, studies on a standardized orthodontic animal model and a non-invasive clinical investigation. A systematic review was performed on the optimum force for

  12. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... friv Home InfoBites Find an AGD Dentist Your Family's Oral Health About the AGD Dental care and ... a Tooth Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site ...

  13. Cigarette smoking, tooth brushing characteristics, and perceived ...

    African Journals Online (AJOL)

    This study was conducted among four hundred non-dental undergraduates of University of Benin, Benin City, Nigeria to assess the prevalence of cigarette smoking, tooth brushing characteristics, perceived efficacy in oral self-care and preventing gingivodental diseases among them. The result showed that the perceived ...

  14. Storing tooth segments for optimal esthetics

    NARCIS (Netherlands)

    Tuzuner, T.; Turgut, S.; Özen, B.; Kılınç, H.; Bagis, B.

    2016-01-01

    Objective: A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Study design: Sixty

  15. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... June 1, 2018 About | Contact InfoBites Quick Reference Learn more Nutrition - Adults When Should My Child First See a Dentist? Check Menstrual Calendar for Tooth Extraction Temporomandibular Joint Disorder Men: Looking for a Better Job? Start by Visiting the Dentist Are You ...

  16. 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.

  17. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... oyunlarý bakugan oyunlarý geta poker friv Home InfoBites Find an AGD Dentist Your Family's Oral Health About ... mean. The Life of a Tooth Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About ...

  18. Life of a Tooth: A Visual Timeline

    Medline Plus

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

  19. 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

  20. Bevarage consumption during television viewing and tooth ...

    African Journals Online (AJOL)

    Aim: The study assessed the television (TV) viewing habits, preferred energy and acidic drinks consumed when watching television and the history of tooth sensitivity among adolescents who watched television >2 hours daily (HTV) and <2 hour daily. (LTV). Subjects and Methods: This is a descriptive study conducted in Ife ...

  1. EPR dosimetry with tooth enamel: A review

    International Nuclear Information System (INIS)

    Fattibene, Paola; Callens, Freddy

    2010-01-01

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

  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. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Contact InfoBites Quick Reference Learn more Children's Oral Health Check Menstrual Calendar for Tooth Extraction The History ... Home | InfoBites | Find a Dentist | Your Family's Oral Health | RSS About AGD | Contact AGD | Site Map | Reprints ...

  4. Life of a Tooth: A Visual Timeline

    Medline Plus

    Full Text Available ... Bomberman atari oyunlarý bakugan oyunlarý geta poker friv Home InfoBites Find an AGD Dentist Your Family's Oral ... dental words mean. The Life of a Tooth Home | InfoBites | Find a Dentist | Your Family's Oral Health | ...

  5. Gastroesophageal Reflux Disease and Tooth Erosion

    Directory of Open Access Journals (Sweden)

    Sarbin Ranjitkar

    2012-01-01

    Full Text Available The increasing prevalence of gastroesophageal reflux disease (GERD in children and adults, and of “silent refluxers” in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

  6. Joint Replacement Surgery: Health Information Basics for You and Your Family

    Science.gov (United States)

    ... Initiative Breadcrumb Home Health Topics English Español Joint Replacement Surgery Basics In-Depth Download Download EPUB Download ... What is it? Points To Remember About Joint Replacement Surgery Joint replacement surgery removes damaged or diseased ...

  7. Effect of the vitality of the overdenture abutment tooth on stability of the tooth

    Directory of Open Access Journals (Sweden)

    Khalid Ahmad Omar Arafa

    2016-01-01

    Conclusion: It was concluded that the overdenture over vital abutment teeth was more stable, with a lower incidence of tooth mobility and less attachment loss than overdentures placed on nonvital teeth.

  8. 21 CFR 872.3580 - Preformed gold denture tooth.

    Science.gov (United States)

    2010-04-01

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

  9. 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…

  10. 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...

  11. 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.

  12. Nasomaxillary hypoplasia with a congenitally missing tooth treated with LeFort II osteotomy, autotransplantation, and nickel-titanium alloy wire.

    Science.gov (United States)

    Ishida, Takayoshi; Ikemoto, Shigehiro; Ono, Takashi

    2015-09-01

    In some skeletal Class III adult patients with nasomaxillary hypoplasia, the LeFort I osteotomy provides insufficient correction. This case report describes a 20-year-old woman with a combination of nasomaxillary hypoplasia and a protrusive mandible with a congenitally missing mandibular second premolar. We performed a LeFort II osteotomy for maxillary advancement. Autotransplantation of a tooth was also performed; the donor tooth was used to replace the missing permanent tooth. To increase the chance of success, we applied light continuous force with an improved superelastic nickel-titanium alloy wire technique before extraction and after transplantation. The patient's profile and malocclusion were corrected, and the autotransplanted tooth functioned well. The postero-occlusal relationships were improved, and ideal overbite and overjet relationships were achieved. The methods used in this case represent a remarkable treatment. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  13. Dental histology of Coelophysis bauri and the evolution of tooth attachment tissues in early dinosaurs.

    Science.gov (United States)

    Fong, Raymond K M; LeBlanc, Aaron R H; Berman, David S; Reisz, Robert R

    2016-07-01

    Studies of dinosaur teeth have focused primarily on external crown morphology and thus, use shed or in situ tooth crowns, and are limited to the enamel and dentine dental tissues. As a result, the full suites of periodontal tissues that attach teeth to the jaws remain poorly documented, particularly in early dinosaurs. These tissues are an integral part of the tooth and thus essential to a more complete understanding of dental anatomy, development, and evolution in dinosaurs. To identify the tooth attachment tissues in early dinosaurs, histological thin sections were prepared from the maxilla and dentary of a partial skull of the early theropod Coelophysis bauri from the Upper Triassic (Rhaetian- 209-201 Ma) Whitaker Quarry, New Mexico, USA. As one of the phylogenetically and geologically oldest dinosaurs, it is an ideal candidate for examining dental tissues near the base of the dinosaurian clade. The teeth of C. bauri exhibited a fibrous tooth attachment in which the teeth possessed five tissues: enamel, dentine, cementum, periodontal ligament (PDL), and alveolar bone. Our findings, coupled with those of more recent studies of ornithischian teeth, indicate that a tripartite periodontium, similar to that of crocodilians and mammals, is the plesiomorphic condition for dinosaurs. The occurrence of a tripartite periodontium in dinosaurs adds to the growing consensus that the presence of these tissues is the plesiomorphic condition for the major amniote clades. Furthermore, this study establishes the relative timing of tissue development and growth directions of periodontal tissues and provides the first comparative framework for future studies of dinosaur periodontal development, tooth replacement, and histology. J. Morphol. 277:916-924, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. 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.

  15. Spectrophotometric assessment of tooth bleaching under orthodontic braquets bonded with different materials

    Directory of Open Access Journals (Sweden)

    Camila Maria Lima de CASTRO

    2017-10-01

    Full Text Available Abstract Introduction patients have been submitted to tooth bleaching during orthodontic treatment for aesthetic purposes or to anticipate the replacement of restorations after completion of the treatment. Objective to evaluate the effectiveness of tooth bleaching under orthodontic brackets bonded with different materials. Material and method a hundred bovine enamel blocks were divided into two groups, at-home and in-office tooth bleaching. In-office bleaching was subdivided into five groups (n = 10: HP (control - without brackets; SA(t - brackets bonded with Transbond XT, without bleaching; SA(fm - brackets bonded with Orthodontic Fill Magic, without bleaching; HP(t - brackets bonded with Transbond XT subjected to bleaching; and HP(fm - brackets bonded with Orthodontic Fill Magic subjected to bleaching. At-home bleaching followed the same treatments, only replacing the bleaching agent. Spectrophotometric assessment was used for tooth color determination at three moments: 1 before staining (baseline; 2 after staining; 3 after bonding the brackets and bleaching procedures. Data were submitted to ANOVA and analyzed by Tukey's test (p < 0.05. Result For both types of bleaching, the control group had an effective bleaching action. Groups using Transbond XT presented greater bleaching potential among the groups with orthodontic accessory, but the bleaching action differed from the positive control. Groups using Orthodontic Fill Magic presented no bleaching action, resembling the negative control groups (artificial saliva. Conclusion the orthodontic bracket impaired the effectiveness of the at-home and in-office bleaching treatment, regardless of the resin used for bonding.

  16. Antenna Controller Replacement Software

    Science.gov (United States)

    Chao, Roger Y.; Morgan, Scott C.; Strain, Martha M.; Rockwell, Stephen T.; Shimizu, Kenneth J.; Tehrani, Barzia J.; Kwok, Jaclyn H.; Tuazon-Wong, Michelle; Valtier, Henry; Nalbandi, Reza; hide

    2010-01-01

    The Antenna Controller Replacement (ACR) software accurately points and monitors the Deep Space Network (DSN) 70-m and 34-m high-efficiency (HEF) ground-based antennas that are used to track primarily spacecraft and, periodically, celestial targets. To track a spacecraft, or other targets, the antenna must be accurately pointed at the spacecraft, which can be very far away with very weak signals. ACR s conical scanning capability collects the signal in a circular pattern around the target, calculates the location of the strongest signal, and adjusts the antenna pointing to point directly at the spacecraft. A real-time, closed-loop servo control algorithm performed every 0.02 second allows accurate positioning of the antenna in order to track these distant spacecraft. Additionally, this advanced servo control algorithm provides better antenna pointing performance in windy conditions. The ACR software provides high-level commands that provide a very easy user interface for the DSN operator. The operator only needs to enter two commands to start the antenna and subreflector, and Master Equatorial tracking. The most accurate antenna pointing is accomplished by aligning the antenna to the Master Equatorial, which because of its small size and sheltered location, has the most stable pointing. The antenna has hundreds of digital and analog monitor points. The ACR software provides compact displays to summarize the status of the antenna, subreflector, and the Master Equatorial. The ACR software has two major functions. First, it performs all of the steps required to accurately point the antenna (and subreflector and Master Equatorial) at the spacecraft (or celestial target). This involves controlling the antenna/ subreflector/Master-Equatorial hardware, initiating and monitoring the correct sequence of operations, calculating the position of the spacecraft relative to the antenna, executing the real-time servo control algorithm to maintain the correct position, and

  17. Could wind replace nuclear?

    International Nuclear Information System (INIS)

    2017-01-01

    This article aims at assessing the situation produced by a total replacement of nuclear energy by wind energy, while facing consumption demand at any moment, notably in December. The authors indicate the evolution of the French energy mix during December 2016, and the evolution of the rate between wind energy production and the sum of nuclear and wind energy production during the same month, and then give briefly some elements regarding necessary investments in wind energy to wholly replace nuclear energy. According to them, such a replacement would be ruinous

  18. Expression of Sox genes in tooth development.

    Science.gov (United States)

    Kawasaki, Katsushige; Kawasaki, Maiko; Watanabe, Momoko; Idrus, Erik; Nagai, Takahiro; Oommen, Shelly; Maeda, Takeyasu; Hagiwara, Nobuko; Que, Jianwen; Sharpe, Paul T; Ohazama, Atsushi

    2015-01-01

    Members of the Sox gene family play roles in many biological processes including organogenesis. We carried out comparative in situ hybridization analysis of seventeen sox genes (Sox1-14, 17, 18, 21) during murine odontogenesis from the epithelial thickening to the cytodifferentiation stages. Localized expression of five Sox genes (Sox6, 9, 13, 14 and 21) was observed in tooth bud epithelium. Sox13 showed restricted expression in the primary enamel knots. At the early bell stage, three Sox genes (Sox8, 11, 17 and 21) were expressed in pre-ameloblasts, whereas two others (Sox5 and 18) showed expression in odontoblasts. Sox genes thus showed a dynamic spatio-temporal expression during tooth development.

  19. New method of control of tooth whitening

    Science.gov (United States)

    Angelov, I.; Mantareva, V.; Gisbrecht, A.; Valkanov, S.; Uzunov, Tz.

    2010-10-01

    New methods of control of tooth bleaching stages through simultaneous measurements of a reflected light and a fluorescence signal are proposed. It is shown that the bleaching process leads to significant changes in the intensity of a scattered signal and also in the shape and intensity of the fluorescence spectra. Experimental data illustrate that the bleaching process causes essential changes in the teeth discoloration in short time as 8-10 min from the beginning of the application procedure. The continuation of the treatment is not necessary moreover the probability of the enamel destroy increases considerably. The proposed optical back control of tooth surface is a base for development of a practical set up to control the duration of the bleaching procedure.

  20. Tooth structure and fracture strength of cavities

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  1. Large scale study of tooth enamel

    International Nuclear Information System (INIS)

    Bodart, F.; Deconninck, G.; Martin, M.T.

    Human tooth enamel contains traces of foreign elements. The presence of these elements is related to the history and the environment of the human body and can be considered as the signature of perturbations which occur during the growth of a tooth. A map of the distribution of these traces on a large scale sample of the population will constitute a reference for further investigations of environmental effects. On hundred eighty samples of teeth were first analyzed using PIXE, backscattering and nuclear reaction techniques. The results were analyzed using statistical methods. Correlations between O, F, Na, P, Ca, Mn, Fe, Cu, Zn, Pb and Sr were observed and cluster analysis was in progress. The techniques described in the present work have been developed in order to establish a method for the exploration of very large samples of the Belgian population. (author)

  2. Slab replacement maturity guidelines.

    Science.gov (United States)

    2014-04-01

    This study investigated the use of maturity method to determine early age strength of concrete in slab : replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive : maturity-strength relationship ...

  3. Partial knee replacement

    Science.gov (United States)

    ... good range of motion in your knee. The ligaments in your knee are stable. However, most people with knee arthritis have a surgery called a total knee arthroplasty (TKA). Knee replacement is most often done in people age 60 ...

  4. Carbohydrates as Fat Replacers.

    Science.gov (United States)

    Peng, Xingyun; Yao, Yuan

    2017-02-28

    The overconsumption of dietary fat contributes to various chronic diseases, which encourages attempts to develop and consume low-fat foods. Simple fat reduction causes quality losses that impede the acceptance of foods. Fat replacers are utilized to minimize the quality deterioration after fat reduction or removal to achieve low-calorie, low-fat claims. In this review, the forms of fats and their functions in contributing to food textural and sensory qualities are discussed in various food systems. The connections between fat reduction and quality loss are described in order to clarify the rationales of fat replacement. Carbohydrate fat replacers usually have low calorie density and provide gelling, thickening, stabilizing, and other texture-modifying properties. In this review, carbohydrates, including starches, maltodextrins, polydextrose, gums, and fibers, are discussed with regard to their interactions with other components in foods as well as their performances as fat replacers in various systems.

  5. Hip joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the ... to slide 5 out of 5 Overview The hip joint is made up of two major parts: ...

  6. Tool Inventory and Replacement

    Science.gov (United States)

    Bear, W. Forrest

    1976-01-01

    Vocational agriculture teachers are encouraged to evaluate curriculum offerings, the new trends in business and industry, and develop a master tool purchase and replacement plan over a 3- to 5-year period. (HD)

  7. Knee joint replacement

    Science.gov (United States)

    ... to make everyday tasks easier. Practice using a cane, walker , crutches , or a wheelchair correctly. On the ... ask your doctor Knee joint replacement - discharge Preventing falls Preventing falls - what to ask your doctor Surgical ...

  8. Product Platform Replacements

    DEFF Research Database (Denmark)

    Sköld, Martin; Karlsson, Christer

    2012-01-01

    . To 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...... replacement was chosen in each company. Findings – The study shows that platform replacements primarily challenge managers' existing knowledge about platform architectures. A distinction can be made between “width” and “height” in platform replacements, and it is crucial that managers observe this in order...... to challenge their existing knowledge about platform architectures. Issues on technologies, architectures, components and processes as well as on segments, applications and functions are identified. Practical implications – Practical implications are summarized and discussed in relation to a framework...

  9. The challenges of treating a fused tooth

    OpenAIRE

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

    2012-01-01

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

  10. Orthodontic-Surgical Alternatives for Tooth Ankylosis

    OpenAIRE

    Giraldo-Mira, Juan Felipe; Velásquez Velásquez, Mariluz

    2014-01-01

    Treatment for tooth ankylosis poses a big challenge in dentistry. Orthosurgical techniques must be included to obtain a satisfactory esthetic and functional result. The treatment options are surgical removal, segmentary osteotomy with immediate repo- sition and segmentary osteotomy with distraction osteogenesis, which can be done using distractors or orthodontics, thus achieving acceptable long-term outcomes. El tratamiento de dientes anquilosados presenta un gran desafio en odontologia. E...

  11. 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. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  12. Enamel alteration following tooth bleaching and remineralization

    OpenAIRE

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

    2015-01-01

    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.\\ud \\ud 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 ...

  13. Abutment tooth loss in patients with overdentures.

    Science.gov (United States)

    Ettinger, Ronald L; Qian, Fang

    2004-06-01

    Since the 1960s, the use of natural teeth as overdenture abutments has become part of accepted clinical practice. Several longitudinal studies have been conducted, but tooth loss has not been reported to be a significant problem. The aim of this study was to identify the incidence and causes of tooth loss in a prospective cohort study of subjects wearing overdentures. The study, conducted between 1973 and 1994, evaluated 273 subjects (62.3 percent male) with a mean age of 59.6 years. Of the 273 subjects with 666 abutments, 74 lost 133 abutments. The most common cause of tooth loss was periodontal disease (29.3 percent) followed by periapical lesions (18.8 percent) and caries (16.5 percent). Through logistic regression, the authors found that subjects who lost teeth were more likely to have medical problems that could cause soft-tissue lesions of the oral mucosa, were less likely to use fluoride daily and were less likely to return for yearly recall visits. The authors found 22 vertical fractures in 17 subjects. Chi2 analysis revealed that overdenture teeth in the maxillary arch that were opposed by natural teeth were more likely to experience vertical fractures. In a study that followed up some patients for as long as 22 years, the rate of tooth loss was 20.0 percent. Many of these failures could have been prevented if patients had practiced better oral hygiene. The findings suggest that if a dentist recommends overdenture therapy, the patient needs to be examined regularly to reduce the risk of experiencing caries and periodontal disease. Also, if the abutments are in the maxilla and are opposed by natural teeth, the dentist should consider using thimble crowns to reduce the risk of vertical fractures.

  14. 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 - others:GA ČR(CZ) GAP502/12/1285 Program:GA Institutional research plan: CEZ:AV0Z50450515 Keywords : tooth * apoptosis * mineralisation Subject RIV: FF - HEENT, Dentistry Impact factor: 1.549, year: 2012

  15. Clear aligners generations and orthodontic tooth movement.

    Science.gov (United States)

    Hennessy, Joe; Al-Awadhi, Ebrahim A

    2016-03-01

    Clear aligner technology has evolved over the last 15 years, with these appliances continually being modified to increase the range of tooth movements that they can achieve. However, there is very little clinical research available to show how these appliances achieve their results. This article describes the different generations of clear aligners that are available and highlights their use. However, until more clinical research becomes available, aligners cannot be routinely prescribed as an effective alternative to fixed labial appliances.

  16. Tooth damage in captive orcas (Orcinus orca).

    Science.gov (United States)

    Jett, John; Visser, Ingrid N; Ventre, Jeffrey; Waltz, Jordan; Loch, Carolina

    2017-12-01

    Tooth damage as a result of oral stereotypies is evident in captive orca, yet little research on the topic exists. This study examines the associations between dental pathology, sex, facility, duration of captivity and other factors in captive orca. We evaluated mandibular and maxillary teeth from dental images of 29 captive orca owned by a US-based theme park. Each tooth was scored for coronal wear, wear at or below gum line and bore holes. Fractured and missing teeth were also noted. Summary statistics described the distribution and severity of pathologies; inferential statistics examined how pathologies differed between sexes, between wild-captured and captive-born orcas and between captive orca at four facilities. We also evaluated how dental pathology and duration of captivity were related. Approximately 24% of whales exhibited "major" to "extreme" mandibular coronal tooth wear, with coronal wear and wear at or below gum line highly correlated. More than 60% of mandibular teeth 2 and 3 exhibited fractures. Bore holes were observed primarily among anterior mandibular teeth, with more than 61% of teeth 2 and 3 bearing evidence of having been drilled. Four of five orca with the highest age-adjusted tooth pathology indices were captive-born. Various dental pathologies were observed across all whales, with pathologies beginning at a young age. Oral stereotypies exhibited by captive orca contributed to the observed dental damage. By making dental and health records of captive whales publicly available, the theme park industry is uniquely positioned to provide further insight into dental pathology and resultant health consequences in captive orca. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The replacement research reactor

    International Nuclear Information System (INIS)

    Cameron, R.

    1999-01-01

    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

  18. ISS protocol for EPR tooth dosimetry

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  19. 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.

  20. Tooth Wear Inclination in Great Ape Molars.

    Science.gov (United States)

    Knight-Sadler, Jordan; Fiorenza, Luca

    2017-01-01

    Primate dietary diversity is reflected in their dental morphology, with differences in size and shape of teeth. In particular, the tooth wear angle can provide insight into a species' ability to break down certain foods. To examine dietary and masticatory information, digitized polygon models of dental casts provide a basis for quantitative analysis of wear associated with tooth attrition. In this study, we analyze and compare the wear patterns of Pongo pygmaeus, Gorilla gorillagorilla and Pan troglodytes schweinfurthii lower molars, focusing on the degree of inclination of specific wear facets. The variation in wear angles appears to be indicative of jaw movements and the specific stresses imposed on food during mastication, reflecting thus the ecology of these species. Orangutans exhibit flatter wear angles, more typical of a diet consisting of hard and brittle foods, while gorillas show a wear pattern with a high degree of inclination, reflecting thus their more leafy diet. Chimpanzees, on the other hand, show intermediate inclinations, a pattern that could be related to their highly variable diet. This method is demonstrated to be a powerful tool for better understanding the relationship between food, mastication and tooth wear processes in living primates, and can be potentially used to reconstruct the diet of fossil species. © 2017 S. Karger AG, Basel.

  1. 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

  2. A Comparison of Equivalent Doses of Lidocaine and Articaine in Maxillary Posterior Tooth Extractions: Case Series

    Directory of Open Access Journals (Sweden)

    Christopher C. Friedl

    2012-06-01

    Full Text Available Objectives: Local anaesthesia is the standard of care during dental extractions. With the advent of newer local anesthetic agents, it is often difficult for the clinician to decide which agent would be most efficacious in a given clinical scenario. This study assessed the efficacy of equal-milligram doses of lidocaine and articaine in achieving surgical anaesthesia of maxillary posterior teeth diagnosed with irreversible pulpitis. Material and Methods: This case-series evaluated a total of 41 patients diagnosed with irreversible pulpitis in a maxillary posterior tooth. Patients randomly received an infiltration of either 3.6 mL (72 mg 2% lidocaine with 1:100,000 epinephrine or 1.8 mL (72 mg 4% articaine with 1:100,000 epinephrine in the buccal fold and palatal soft tissue adjacent to the tooth. After 10 minutes, initial anaesthesia of the tooth was assessed by introducing a sterile 27-gauge needle into the gingival tissue adjacent to the tooth, followed by relief of the gingival cuff. Successful treatment was considered to have occurred when the tooth was extracted with no reported pain. Data was analyzed with the Fisher’s exact test, unpaired t-test and normality test. Results: Twenty-one patients received lidocaine and 20 received articaine. Forty of the 41 patients achieved initial anaesthesia 10 minutes after injection: 21 after lidocaine and 19 after articaine (P = 0.488. Pain-free extraction was accomplished in 33 patients: 19 after lidocaine and 14 after articaine buccal and palatal infiltrations (P = 0.226. Conclusions: There was no significant difference in efficacy between equivalent doses of lidocaine and articaine in the anaesthesia of maxillary posterior teeth with irreversible pulpitis.

  3. A Radiographic Study of Fused and Geminated Tooth

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-02-15

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

  4. A Radiographic Study of Fused and Geminated Tooth

    International Nuclear Information System (INIS)

    Park, Chul Jae; Lee, Sang Rae

    1990-01-01

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

  5. Educating My Replacement

    Science.gov (United States)

    Tarter, Jill

    , in partnership with the dedicated teachers out there, I think I can help promote the critical thinking skills and scientific literacy of the next generation of voters. Hopefully, I can also help train my replacement to be a better scientist, capable of seizing all the opportunities generated by advances in technology and our improved understanding of the universe to craft search strategies with greater probability of success than those I have initiated.

  6. Risk factors for developing tooth sensitivity and gingival irritation associated with nightguard vital bleaching.

    Science.gov (United States)

    Leonard, R H; Haywood, V B; Phillips, C

    1997-08-01

    The purpose of this study was to determine risk factors in the development of tooth sensitivity and gingival irritation associated with the nightguard vital bleaching technique. The potential risk factors evaluated (sex, age, reported allergy, whitening solution, number of times the solution was changed daily [its usage pattern], and dental arch) were collected from the daily log form turned in by each of the 64 participants after completion of the 6-week lightening process. Also evaluated for each participant, from color slides, were tooth characteristics such as gingival recession, defective restorations, abfraction lesions, enamel-cementum abrasion, etc, and reported side effects. The generalized Mantel-Haenszel statistic was used to assess the association between the potential risk factors and the development of tooth sensitivity and/or gingival irritation. No statistical relationship existed between age, sex, allergy, tooth characteristics, or the dental arch lightened and the development of side effects. Initially, a statistically significant association existed between side effects and the whitening solution used. However, when the analysis was controlled for usage pattern, this relationship disappeared. Patients who changed the whitening solution more than once a day reported statistically significantly more side effects than did those who did not change the whitening solution during their usage time.

  7. Effect of Atorvastatin on Orthodontic Tooth Movement in Male Wistar Rats

    Science.gov (United States)

    MirHashemi, Amir Hossein; Afshari, Maryam; Alaeddini, Mojgan; Etemad-Moghadam, Shahroo; Dehpour, Ahmadreza; Sheikhzade, Sedigheh; Akhoundi, Mohammad Sadegh Ahmad

    2013-01-01

    Objectives: Statins are used as cholesterol-lowering drugs by many patients and have been recently shown to affect bone metabolism. The aim of this study was to determine the effect of atorvastatinon on orthodontic tooth movement (OTM) in rats. Materials and Methods: Thirty-six adult male Sprague-Dawley rats were randomly divided into three groups of 12 samples each. Group A, served as control with no medication while groups B and C received a daily gavage of carboxymethyl cellulose (CMC) as vehicle and atorvastatin (5 mg/kg) as test substance, respectively. In all three groups, 6mm nickel-titanium closed-coil springs were ligated between the maxillary incisors and first left molars to deliver an initial force of 60g. Tooth movement was measured following sacrifice, 21 days after appliance insertion. Root resorption, PDL width and osteoclast number were histologically evaluated and compared between the groups. Results: The mean amount of tooth movement was 0.62 mm in group A, 0.59 mm in group B and 0.38 mm in group C. OTM reduction following administration of atorvastatin was statistically significant (p0.05). Conclusion: According to the results obtained in the current study, atorvastatin appears to reduce tooth movement in rats; however its effect on osteoclasts, especially osteoclastic function, requires further investigation. PMID:24910664

  8. Improving patient safety through a clinical audit spiral: prevention of wrong tooth extraction in orthodontics.

    Science.gov (United States)

    Anwar, H; Waring, D

    2017-07-07

    Introduction With an increasing demand to improve patient safety within the NHS, it is important to ensure that measures are undertaken to continually improve patient care. Wrong site surgery has been defined as a 'never event'. This article highlights the importance of preventing wrong tooth extraction within orthodontics through an audit spiral over five years investigating the accuracy and clarity of orthodontic extraction letters at the University Dental Hospital of Manchester.Aims To examine compliance with the standards for accuracy and clarity of extraction letters and the incidence of wrong tooth extractions, and to increase awareness of the errors that can occur with extraction letters and of the current guidelines.Method A retrospective audit was conducted examining extraction letters sent to clinicians outside the department.Results It can be seen there has been no occurrence of a wrong site tooth extraction. The initial audit highlighted issues in conformity, with it falling below expected standards. Cycle two generally demonstrated a further reduction in compliance. Cycle three appeared to result in an increase in levels of compliance. Cycles 4 and 5 have demonstrated gradual improvements. However, it is noteworthy that in all cycles the audit standards were still not achieved, with the exception of no incidences of the incorrect tooth being extracted.Conclusion This audit spiral demonstrates the importance of long term re-audit to aim to achieve excellence in clinical care. There has been a gradual increase in standards through each audit.

  9. Regenerative treatment of an immature, traumatized tooth with apical periodontitis: report of a case.

    Science.gov (United States)

    Cotti, Elisabetta; Mereu, Manuela; Lusso, Daniela

    2008-05-01

    This case report describes the treatment of a necrotic immature permanent central incisor with complete crown fracture, suspected root fracture, and sinus tract, which was not treated with conventional apexification techniques. Instead, a regenerative approach based on the trauma literature's methods for revascularization was provided. The root canal was gently debrided of necrotic tissue with a sharp spoon excavator and irrigated for only one third of its length with NaOCl and then medicated with calcium hydroxide. After 15 days the sinus tract had healed, and the tooth was asymptomatic. The tooth was accessed, calcium hydroxide was removed, bleeding was stimulated to form an intracanal blood clot, and mineral trioxide aggregate was placed coronally to the blood clot. After 8 months, a coronal calcified barrier was radiographically evident and accompanied with progressive thickening of the root wall and apical closure. Two and a half years after treatment was initiated, the tooth remained asymptomatic, and the sinus tract had not reappeared. The progressive increase in the thickness of the dentinal walls and subsequent apical development suggest that appropriate biologic responses can occur with this type of treatment of the necrotic immature permanent tooth with sinus tract.

  10. "Drink beer regularly - it's good for you (and us)": selling Tooth's Beer in a depressed market.

    Science.gov (United States)

    Crawford, Robert

    2007-01-01

    This study examines the unique publicity activities devised by the Tooth's brewery in Sydney during the Great Depression and the 1930s. Unlike many advertisers, the brewery did not turn its back on advertising or marketing. Recognising the importance of publicity, the brewery developed innovative advertising and marketing initiatives in an attempt to arrest its declining sales. Such strategies included the development of co-operative advertising campaigns, the creation of advertisements directly targeting female consumers, and the renovation of pubs owned by the brewery. However, the significance of these initiatives extends beyond the immediate economic concerns. They were also celebration of modernity. By locating Tooth's advertising, marketing, and public relations activities within the broader social, cultural, and political context, this study provides a revealing insight into the way in which such campaigns simultaneously informed and reflected the Australian experience of modernity during the 1930s.

  11. [Orthodontic Management of the Impacted Mandibular Second Molar Tooth].

    Science.gov (United States)

    Mah, Michael; Takada, Kenji

    2016-09-01

    When the mandibular permanent second molar becomes impacted, it is identified as a malocclusion that needs treatment as it often leads to unwanted complications such as caries and periodontitis of the adjacent permanent first molar. Other less common complications include root resorption of the adjacent first molar root or continued root development to be in close proximity to the inferior dental alveolar nerve. This paper seeks to differentiate various levels of severity of impaction and review treatment options that are considered clinically available for the proper management of the impacted mandibular permanent second molar. Treatment options that will be discussed in this article include timing of second molar removal for replacement by the third molar, relief of impaction via second premolar removal, surgical repositioning and the combination of third molar removal, surgical exposure and orthodontic uprighting of the impacted tooth. Depending on the severity of the impaction, most impactions can be easily and predictably corrected with nickel titanium archwires or auxillary open coil springs or uprighting springs. Uncommonly, the mandibular permanent second molar can become severely impacted and in close proximity to the inferior dentoalveolar nerve. In these instances, the use of temporary anchorage devices such as microimplants has shown to be successful in uprighting the severely impacted mandibular permanent second molars. © EDP Sciences, SFODF, 2016.

  12. A Proposed Methodology to Assess the Accuracy of 3D Scanners and Casts and Monitor Tooth Wear Progression in Patients.

    Science.gov (United States)

    Ahmed, Khaled E; Whitters, John; Ju, Xiangyang; Pierce, S Gareth; MacLeod, Charles N; Murray, Colin A

    2016-01-01

    The aim of this study was to detail and assess the capability of a novel methodology to 3D-quantify tooth wear progression in a patient over a period of 12 months. A calibrated stainless steel model was used to identify the accuracy of the scanning system by assessing the accuracy and precision of the contact scanner and the dimensional accuracy and stability of casts fabricated from three different types of impression materials. Thereafter, the overall accuracy of the 3D scanning system (scanner and casts) was ascertained. Clinically, polyether impressions were made of the patient's dentition at the initial examination and at the 12-month review, then poured in type IV dental stone to assess the tooth wear. The anterior teeth on the resultant casts were scanned, and images were analyzed using 3D matching software to detect dimensional variations between the patient's impressions. The accuracy of the 3D scanning system was established to be 33 μm. 3D clinical analysis demonstrated localized wear on the incisal and palatal surfaces of the patient's maxillary central incisors. The identified wear extended to a depth of 500 μm with a distribution of 4% to 7% of affected tooth surfaces. The newly developed 3D scanning methodology was found to be capable of assessing and accounting for the various factors affecting tooth wear scanning. Initial clinical evaluation of the methodology demonstrates successful monitoring of tooth wear progression. However, further clinical assessment is needed.

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

    Science.gov (United States)

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

    2015-04-01

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

  14. Direct Resin Composite Restoration of Maxillary Central Incisors with Fractured Tooth Fragment Reattachment: Case Report.

    Science.gov (United States)

    Szmidt, Monika; Górski, Maciej; Barczak, Katarzyna; Buczkowska-Radlińska, Jadwiga

    This article presents a clinical protocol to reconstruct two accidentally damaged maxillary central incisors using composite resin material and a fractured tooth component. A patient was referred to the clinic with fracture of the two maxillary central incisors. Clinical examination revealed that both teeth were fractured in the middle third of the crown and that the fractures involved enamel and dentin with no pulp exposure. The patient had also suffered a lower lip laceration. When the lip was evaluated, a fractured fragment of the maxillary right central incisor was found inside the wound. The missing part of the tooth was replaced via adhesive attachment. Due to the damage of the fractured part of the maxillary left central incisor, direct composite restoration of this tooth was performed. With the advent of adhesive dentistry, the process of fragment reattachment has become simplified and more reliable. This procedure provides improved function, is faster to perform, and provides long-lasting effects, indicating that reattachment of a coronal fragment is a realistic alternative to placement of conventional resin composite restorations.

  15. Some economic aspects of steam generator replacements in nuclear power plants

    International Nuclear Information System (INIS)

    Lebegner, J.

    1995-01-01

    The steam generator replacements performed over last decade (about 25 replacements until now), indicate trends towards improved techniques, shorter schedules and reduced total exposure and total costs. The goal of this paper is to give a worldwide review of SG replacement experience with accent on the economic aspect of the SG replacement. The main information about carried out replacements will be presented: cost, schedules, exposures, SG supplier and type, date of replacement, etc. Furthermore, the paper will contain the list of planned steam generator replacements in Europe, Japan and US future replacement plans. Finally, some of NPPs will be described whose initial nominal power has been increased along with SG replacement. (author)

  16. Infrared light sensor applied to early detection of tooth decay

    Science.gov (United States)

    Benjumea, Eberto; Espitia, José; Díaz, Leonardo; Torres, Cesar

    2017-08-01

    The approach dentistry to dental care is gradually shifting to a model focused on early detection and oral-disease prevention; one of the most important methods of prevention of tooth decay is opportune diagnosis of decay and reconstruction. The present study aimed to introduce a procedure for early diagnosis of tooth decay and to compare result of experiment of this method with other common treatments. In this setup, a laser emitting infrared light is injected in core of one bifurcated fiber-optic and conduced to tooth surface and with the same bifurcated fiber the radiation reflected for the same tooth is collected and them conduced to surface of sensor that measures thermal and light frequencies to detect early signs of decay below a tooth surface, where demineralization is difficult to spot with x-ray technology. This device will can be used to diagnose tooth decay without any chemicals and rays such as high power lasers or X-rays.

  17. 2H Stable Isotope Analysis of Tooth Enamel: A Pilot Study

    Science.gov (United States)

    Holobinko, Anastasia; Kemp, Helen; Meier-Augenstein, Wolfram; Prowse, Tracy; Ford, Susan

    2010-05-01

    Stable isotope analysis of biogenic tissues such as tooth enamel and bone mineral has become a well recognized and increasingly important method for determining provenance of human remains, and has been used successfully in bioarchaeological studies as well as forensic investigations (Lee-Thorp, 2008; Meier-Augenstein and Fraser, 2008). Particularly, 18O and 2H stable isotopes are well established proxies as environmental indicators of climate (temperature) and source water and are therefore considered as indicators of geographic life trajectories of animals and humans (Hobson et al., 2004; Schwarcz and Walker, 2006). While methodology for 2H analysis of human hair, fingernails, and bone collagen is currently used to determine geographic origin and identify possible migration patterns, studies involving the analysis of 2H in tooth enamel appear to be nonexistent in the scientific literature. The apparent lack of research in this area is believed to have two main reasons. (1) Compared to the mineral calcium hydroxylapatite Ca10(PO4)6(OH)2, in tooth enamel forming bio-apatite carbonate ions replace some of the hydroxyl ions at a rate of one CO32 replacing two OH, yet published figures for the degree of substitution vary (Wopenka and Pasteris, 2005). (2) Most probably due to the aforementioned no published protocols exist for sample preparation and analytical method to obtain δ2H-values from the hydroxyl fraction of tooth enamel. This dilemma has been addressed through a pilot study to establish feasibility of 2H stable isotope analysis of ground tooth enamel by continuous-flow isotope ratio mass spectrometry (IRMS) coupled on-line to a high-temperature conversion elemental analyzer (TC/EA). An array of archaeological and modern teeth has been analyzed under different experimental conditions, and results from this pilot study are being presented. References: Lee-Thorp, J.A. (2008) Archaeometry, 50, 925-950 Meier-Augenstein, W. and Fraser, I. (2008) Science & Justice

  18. Temperament and perception of tooth bleaching results

    Directory of Open Access Journals (Sweden)

    Katarzyna Mehr

    2016-09-01

    Full Text Available Background . The neurophysiological process of perceiving the results of tooth bleaching requires the correct interaction between the central nervous system and the organs of sight. Exaggerated beliefs concerning defective facial features may enhance inner attitudes about one’s own color of dentition, as well as a feeling of dissatisfaction with the degree of leaching. Objectives. The study aimed to assess the degree of the patient satisfaction with the results of tooth bleaching in relation to their temperament. Material and methods. There were 68 generally healthy volunteers, aged 28–38 years, with external discolorations of the teeth. They had never undergone dental bleaching and their frontal teeth did not have any fillings. After clinical evaluation and the completion of formalities, the patients were asked to fill in Strelau’s temperament questionnaire. Questionnaires and visual status were assessed three times by three doctors: before bleaching, and then 24 hours and two weeks after the home-bleaching operation, which was done with the use of Opalescence (Ultradent in uniform sequence. Results . There were practically no adverse side results, except a periodic dentin hypersensitivity that occurred periodically in 44 patients. The results of the visual assessment performed by the physicians did not differ. The questionnaire data showed that women were more critical of the results in relation to the expectations. Among elancholics, full satisfaction was declared by 41%, whereas among sanguine people, full satisfaction was obtained by 85%. Satisfaction with the aesthetic results was associated with bleaching by at least 4 degrees. Conclusions . Patients’ temperament affects their subjective evaluation of the effectiveness of tooth bleaching, which should be taken into consideration in the patient’s individual dental treatment plan.

  19. Tooth color: effects on judgments of attractiveness and age.

    Science.gov (United States)

    Grosofsky, Alexis; Adkins, Sarah; Bastholm, Robert; Meyer, Leif; Krueger, Lisa; Meyer, Joshua; Torma, Peter

    2003-02-01

    Tooth whitening has become a very popular procedure. Advertisements for whitening products imply that whiter teeth are more attractive than yellower teeth. We tested this idea empirically by manipulating the tooth color of pictures of male and female targets. Participants' ratings of attractiveness were not influenced by tooth color. Exp. 2 yielded a negative correlation between attractiveness and age ratings: targets judged to be older were rated as less attractive. Unless whiter teeth help in some other way, e.g., improved self-esteem or confidence, it seems that tooth whitening procedures or products are not associated with increased attractiveness to others.

  20. Autosomal recessive Charcot-Marie-Tooth neuropathy.

    Science.gov (United States)

    Espinós, Carmen; Calpena, Eduardo; Martínez-Rubio, Dolores; Lupo, Vincenzo

    2012-01-01

    Charcot-Marie-Tooth (CMT) disease, a hereditary motor and sensory neuropathy that comprises a complex group of more than 50 diseases, is the most common inherited neuropathy. CMT is generally divided into demyelinating forms, axonal forms and intermediate forms. CMT is also characterized by a wide genetic heterogeneity with 29 genes and more than 30 loci involved. The most common pattern of inheritance is autosomal dominant (AD), although autosomal recessive (AR) forms are more frequent in Mediterranean countries. In this chapter we give an overview of the associated genes, mechanisms and epidemiology of AR-CMT forms and their associated phenotypes.

  1. Thermal induced EPR signals in tooth enamel

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  2. ESR dating of tooth enamel samples

    International Nuclear Information System (INIS)

    Chen Tiemei; Yang quan; Wu En

    1993-01-01

    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

  3. Clinical evaluation of a newly designed orthodontic tooth brush - A clinical study

    Directory of Open Access Journals (Sweden)

    C S Saimbi

    2009-01-01

    In this study, the newly designed orthodontic tooth brush is compared with an ordinary tooth brush. Results of this study show that the newly designed orthodontic tooth brush is superior in its cleaning efficiency as compared to the ordinary tooth brush. The results show that plaque removing capacity of orthodontic tooth brush is nearly 95-99%.

  4. Motion planning and synchronized control of the dental arch generator of the tooth-arrangement robot.

    Science.gov (United States)

    Jiang, Jin-Gang; Zhang, Yong-De

    2013-03-01

    The traditional, manual method of reproducing the dental arch form is prone to numerous random errors caused by human factors. The purpose of this study was to investigate the automatic acquisition of the dental arch and implement the motion planning and synchronized control of the dental arch generator of the multi-manipulator tooth-arrangement robot for use in full denture manufacture. First, the mathematical model of the dental arch generator was derived. Then the kinematics and control point position of the dental arch generator of the tooth arrangement robot were calculated and motion planning of each control point was analysed. A hardware control scheme is presented, based on the industrial personal computer and control card PC6401. In order to gain single-axis, precise control of the dental arch generator, we studied the control pulse realization of high-resolution timing. Real-time, closed-loop, synchronous control was applied to the dental arch generator. Experimental control of the dental arch generator and preliminary tooth arrangement were gained by using the multi-manipulator tooth-arrangement robotic system. The dental arch generator can automatically generate a dental arch to fit a patient according to the patient's arch parameters. Repeated positioning accuracy is 0.12 mm for the slipways that drive the dental arch generator. The maximum value of single-point error is 1.83 mm, while the arc-width direction (x axis) is -33.29 mm. A novel system that generates the dental arch has been developed. The traditional method of manually determining the dental arch may soon be replaced by a robot to assist in generating a more individual dental arch. The system can be used to fabricate full dentures and bend orthodontic wires. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Correlation of natural tooth colour with aging in the Spanish population.

    Science.gov (United States)

    Gómez Polo, Cristina; Gómez Polo, Miguel; Montero, Javier; Martínez Vazquez De Parga, Juan Antonio; Celemin Viñuela, Alicia

    2015-10-01

    To analyse natural tooth colour in the Spanish population according to the colour coordinates lightness (L*), chroma (C*), hue (h*), red-green axis (a*) and yellow-blue axis (b*) in order to quantify the correlation and changes of tooth colour with age and sex. Natural tooth colour was measured in a sample of 1,361 Spanish participants of both sexes distributed within an age range of 16 to 89 years. The Easyshade Compact spectrophotometer was used and the CIELAB and CIELCh systems were followed. Pearson's bivariate correlations between age and colour coordinates were highly significant for L* (r=-0.674, P≤0.001), h* (r=-0.468, P≤0.001) and C* (r=0.417, P≤0.001). The correlation between age and colour coordinates was stronger for men than for women, for all colour coordinates. The results showed that C*, b* and a* increased by 0.60, 0.56 and 0.26 units/year on average, respectively, whereas L* and h* decreased progressively with age (by 0.60 units/year, on average), and colour differences increased in a systematic way as the gap between the ages being compared grew wider. The strongest correlation was found between age and L*, then between age and h* (both inverse relationships) and then between age and a*, C* and b* (direct relationships). In addition, a similar degree of change in the colour coordinates L*, C* and h* (of 0.60 units/year on average) was observed for natural tooth colour. Knowledge of the chromatic range of natural teeth may help to choose colour for the replacement of missing elements. © 2015 FDI World Dental Federation.

  6. Prioritizing equipment for replacement.

    Science.gov (United States)

    Capuano, Mike

    2010-01-01

    It is suggested that clinical engineers take the lead in formulating evaluation processes to recommend equipment replacement. Their skill, knowledge, and experience, combined with access to equipment databases, make them a logical choice. Based on ideas from Fennigkoh's scheme, elements such as age, vendor support, accumulated maintenance cost, and function/risk were used.6 Other more subjective criteria such as cost benefits and efficacy of newer technology were not used. The element of downtime was also omitted due to the data element not being available. The resulting Periop Master Equipment List and its rationale was presented to the Perioperative Services Program Council. They deemed the criteria to be robust and provided overwhelming acceptance of the list. It was quickly put to use to estimate required capital funding, justify items already thought to need replacement, and identify high-priority ranked items for replacement. Incorporating prioritization criteria into an existing equipment database would be ideal. Some commercially available systems do have the basic elements of this. Maintaining replacement data can be labor-intensive regardless of the method used. There is usually little time to perform the tasks necessary for prioritizing equipment. However, where appropriate, a clinical engineering department might be able to conduct such an exercise as shown in the following case study.

  7. Thyroid hormone replacement therapy

    NARCIS (Netherlands)

    Wiersinga, W. M.

    2001-01-01

    Thyroid hormone replacement has been used for more than 100 years in the treatment of hypothyroidism, and there is no doubt about its overall efficacy. Desiccated thyroid contains both thyroxine (T(4)) and triiodothyronine (T(3)); serum T(3) frequently rises to supranormal values in the absorption

  8. Can photovoltaic replace nuclear?

    International Nuclear Information System (INIS)

    2017-01-01

    As the French law on energy transition for a green growth predicts that one third of nuclear energy production is to be replaced by renewable energies (wind and solar) by 2025, and while the ADEME proposes a 100 per cent renewable scenario for 2050, this paper proposes a brief analysis of the replacement of nuclear energy by solar photovoltaic energy. It presents and discusses some characteristics of photovoltaic production: production level during a typical day for each month (a noticeable lower production in December), evolution of monthly production during a year, evolution of the rate between nuclear and photovoltaic production. A cost assessment is then proposed for energy storage and for energy production, and a minimum cost of replacement of nuclear by photovoltaic is assessed. The seasonal effect is outlined, as well as the latitude effect. Finally, the authors outline the huge cost of such a replacement, and consider that public support to new photovoltaic installations without an at least daily storage mean should be cancelled

  9. Fluorescent Lamp Replacement Study

    Science.gov (United States)

    2017-07-01

    not be cited for purposes of advertisement. DISPOSITION INSTRUCTIONS: Destroy this document when no longer needed. Do not return to the... recycling , and can be disposed safely in a landfill. (2) LEDs offer reduced maintenance costs and fewer bulb replacements, significantly reducing... recycling . Several fixtures, ballasts and energy efficient fluorescent bulbs that were determined to be in pristine condition were returned to ATC

  10. Replacing Recipe Realism

    OpenAIRE

    Saatsi, J

    2017-01-01

    Many realist writings exemplify the spirit of ‘recipe realism’. Here I characterise recipe realism, challenge it, and propose replacing it with ‘exemplar realism’. This alternative understanding of realism is more piecemeal, robust, and better in tune with scientists’ own attitude towards their best theories, and thus to be preferred.

  11. 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.

  12. Labiogingival groove: A rare developmental tooth anomaly

    Directory of Open Access Journals (Sweden)

    Shiva Chauhan

    2017-01-01

    Full Text Available Labiogingival groove is a congenital morphologic dental anomaly, in which an infolding of the inner enamel epithelium and Hertwig's epithelial root sheath create a groove extending varying depth into root. Epithelial attachment can be breached by gingival irritation secondary to plaque accumulation creating a periodontal defect that spreads to the pulp causing primary periodontal/secondary endodontic. A 12-year-old boy reported with the complaint of painful tooth with pus discharge from labial gingival surface in the maxillary right lateral incisor for 4 months. Intraoral examination revealed bluish red gingiva with loss of contour in relation to maxillary right lateral incisor and purulent discharge in relation to it. A provisional diagnosis of localized gingival abscess in relation to maxillary right incisor (primary periodontic and secondary endodontic involvement was given, and required treatment was carried out. On exposure of the involved tooth, a labiogingival groove was noticed which could have been a contributing factor for the progression of the condition.

  13. Massive clot formation after tooth extraction

    Directory of Open Access Journals (Sweden)

    Santosh Hunasgi

    2015-01-01

    Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.

  14. Measurement of opalescence of tooth enamel.

    Science.gov (United States)

    Lee, Yong-Keun; Yu, Bin

    2007-08-01

    Opalescent dental esthetic restoratives look natural and esthetic in any light, react to light in the same manner as the natural tooth and show improved masking effect. The objective of this study was to determine the opalescence of tooth enamel with reflection spectrophotometers. Color of intact bovine and human enamel was measured in the reflectance and transmittance modes. Two kinds of spectrophotometers were used for bovine and one kind was used for human enamel. The opalescence parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Deltab(*)) and red-green color coordinate (CIE Deltaa(*)) between the reflected and transmitted colors. Mean OP value of bovine enamel was 10.6 (+/-1.4) to 19.0 (+/-2.1), and varied by the configuration of spectrophotometers. Mean OP value of human enamel was 22.9 (+/-1.9). Opalescence varied by the configuration of measuring spectrophotometer and the species of enamel. These values could be used in the development of esthetic restorative materials.

  15. Tooth cusp sharpness as a dietary correlate in great apes.

    Science.gov (United States)

    Berthaume, Michael A

    2014-02-01

    Mammalian molars have undergone heavy scrutiny to determine correlates between morphology and diet. Here, the relationship between one aspect of occlusal morphology, tooth cusp radius of curvature (RoC), and two broad dietary categories, folivory and frugivory, is analyzed in apes. The author hypothesizes that there is a relationship between tooth cusp RoC and diet, and that folivores have sharper teeth than frugivores, and further test the correlation between tooth cusp RoC and tooth cusp size. Eight measures of tooth cusp RoC (two RoCs per cusp) were taken from 53 M(2) s from four species and subspecies of frugivorous apes (Pongo pygmaeus, Pan troglodytes troglodytes, Pan troglodytes schweinfurthii, and Gorilla gorilla gorilla) and two subspecies of folivorous apes (Gorilla beringei beringei, and Gorilla beringei graueri). Phylogenetically corrected ANOVAs were run on the full dataset and several subsets of the full dataset, revealing that, when buccolingual RoCs are taken into account, tooth cusp RoCs can successfully differentiate folivores and frugivores. PCAs revealed that folivores consistently had duller teeth than frugivores. In addition, a weak, statistically significant positive correlation exists between tooth cusp size and tooth cusp RoC. The author hypothesizes differences in tooth cusp RoC are correlated with wear rates, where, per vertical unit of wear, duller cusps will have a longer length of exposed enamel ridge than sharper cusps. More data need to be gathered to determine if the correlation between tooth cusp RoC and tooth cusp size holds true when small primates are considered. Copyright © 2013 Wiley Periodicals, Inc.

  16. Esthetic Reconstruction of Diastema with Adhesive Tooth-Colored Restorations and Hyaluronic Acid Fillers

    Directory of Open Access Journals (Sweden)

    Supawadee Naorungroj

    2017-01-01

    Full Text Available Objective. This report presents a comprehensive esthetic treatment with adhesive tooth-colored restorations in a combination with hyaluronic acid (HA fillers of diastema in an orthodontic patient with relapse. Case Report. A 36-year-old female patient consulted about 1.5–2 mm midline diastema after an orthodontic relapse of replacing missing central incisors with lateral incisors and dark-colored gingival tissue as a result of a metal post and core with porcelain fused to a metal (PFM crown at the left lateral incisor. Restorative treatments included replacing the PFM with all-ceramic material and placing a ceramic veneer on the right lateral incisor. To close the space, crown forms of both lateral incisors were altered. A direct resin composite was then used to reform right and left canines to a more ideal lateral incisor shape. An HA fillers injection was used to fill the remaining open gingival embrasure. Eighteen months after treatment, the interdental papilla remained stable and the patient was satisfied with the result. Conclusion. Esthetic reconstruction of diastema and open gingival embrasure in this case can be accomplished without orthodontic retreatment. Tooth-colored restorations and HA filler injection appear as a promising modality to address this patient’s esthetic concern.

  17. 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.

  18. Effects of local and whole body irradiation on appearance of osteoclasts during wound healing of tooth extraction sockets in rats

    International Nuclear Information System (INIS)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Tanaka, Likinobu; Okumura, Kazuhiko; Yajima, Toshihiko; Kaneko, Masayuki

    2007-01-01

    We examined effects of local and whole body irradiation before tooth extraction on appearance and differentiation of osteoclasts in the alveolar bone of rat maxillary first molars. Wistar rats weighting 100 g were divided into three groups: non-irradiation group, local irradiation group, and whole body irradiation group. In the local irradiation group, a field made with lead blocks was placed over the maxillary left first molar tooth. In the whole body irradiation group, the animals were irradiated in cages. Both groups were irradiated at 8 Gy. The number of osteoclasts around the interradicular alveolar bone showed chronological changes common to non-irradiated and irradiated animals. Several osteoclasts appeared one day after tooth extraction, and the maximal peak was observed 3 days after extraction. Local irradiation had no difference from non-irradiated controls. In animals receiving whole body irradiation, tooth extraction one day after irradiation caused smaller number of osteoclasts than that 7 day after irradiation during the experimental period. Whole body-irradiated rats had small osteoclasts with only a few nuclei and narrow resorption lacunae, indicating deficiency of radioresistant osteoclast precursor cells. Injection of intact bone marrow cells to whole body-irradiated animals immediately after tooth extraction recovered to some content the number of osteoclasts. These findings suggest that bone resorption in the wound healing of alveolar socket requires radioresistant, postmitotic osteoclast precursor cells from hematopoietic organs, but not from local sources around the alveolar socket, at the initial phase of wound healing. (author)

  19. Effects of local and whole body irradiation on appearance of osteoclasts during wound healing of tooth extraction sockets in rats.

    Science.gov (United States)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Tanaka, Likinobu; Okumura, Kazuhiko; Yajima, Toshihiko; Kaneko, Masayuki

    2007-07-01

    We examined effects of local and whole body irradiation before tooth extraction on appearance and differentiation of osteoclasts in the alveolar bone of rat maxillary first molars. Wistar rats weighting 100 g were divided into three groups: non-irradiation group, local irradiation group, and whole body irradiation group. In the local irradiation group, a field made with lead blocks was placed over the maxillary left first molar tooth. In the whole body irradiation group, the animals were irradiated in cages. Both groups were irradiated at 8 Gy. The number of osteoclasts around the interradicular alveolar bone showed chronological changes common to non-irradiated and irradiated animals. Several osteoclasts appeared one day after tooth extraction, and the maximal peak was observed 3 days after extraction. Local irradiation had no difference from non-irradiated controls. In animals receiving whole body irradiation, tooth extraction one day after irradiation caused smaller number of osteoclasts than that 7 day after irradiation during the experimental period. Whole body-irradiated rats had small osteoclasts with only a few nuclei and narrow resorption lacunae, indicating deficiency of radioresistant osteoclast precursor cells. Injection of intact bone marrow cells to whole body-irradiated animals immediately after tooth extraction recovered to some content the number of osteoclasts. These findings suggest that bone resorption in the wound healing of alveolar socket requires radioresistant, postmitotic osteoclast precursor cells from hematopoietic organs, but not from local sources around the alveolar socket, at the initial phase of wound healing.

  20. SIGNS Molar tooth sign − looking beyond the obvious

    African Journals Online (AJOL)

    tooth are represented by thick, perpendicular, non-decussated superior cerebellar peduncles, while the 'body' of the molar tooth is formed by the cerebral peduncles of the brainstem with a deep interpeduncular fossa (Fig. 1a).[3]. Diffusion tensor tractography confirms the failure of superior cerebellar peduncle decussation.

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

    Indian Academy of Sciences (India)

    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 ...

  2. Assessment of the progression of tooth wear on dental casts

    NARCIS (Netherlands)

    Vervoorn-Vis, G.M.G.J.; Wetselaar, P.; Koutris, M.; Visscher, C.M.; Evälahti, M.; Ahlberg, J.; Lobbezoo, F.

    2015-01-01

    Many methods are available for the grading of tooth wear, but their ability to assess the progression of wear over time has not been studied frequently. The aim was to assess whether the occlusal/incisal grading scale of the Tooth Wear Evaluation System (TWES) was sensitive enough for the detection

  3. Reasons for tooth mortality as perceived by dental professionals in ...

    African Journals Online (AJOL)

    Conclusion: The results of the present study suggest that among the patients attending dental clinics and hospitals in Udaipur city, dental caries and periodontal disease was found to be the two major causes of tooth mortality. This is probably the first study to report on the trends in tooth loss in general practice in Udaipur ...

  4. Association between Severity of Tooth Wear and Dentinal Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Ashok Ayer

    2016-11-01

    Full Text Available Background & Objectives: Tooth wear (attrition, abrasion, erosion, and abfraction is perceived globally as ever increasing problem. Several outcome of the tooth wear are hypersensitivity, esthetic problems, functional impairment, annoyance to the patient, and fracture of the tooth. Among these, the measurable and more commonly reported outcome is hypersensitivity to stimuli. Although dentin hypersensitivity is a common clinical condition and is generally reported by the patient after experiencing a sharp, short pain caused by one of the several different external stimuli, it is often inadequately understood. None of the scientific literature available till date attempted to establish the relationship between tooth wear and dentin hypersensitivity which could be a key factor in monitoring those patients.  The aim of the study was to estimate the association between severity of teeth wear and sensitivity in the patients with reported dentinal hypersensitivity.Materials & Methods: Fifty patients with dentin hypersensitivity were investigated for tooth wear. Tooth wear measured using exact tooth wear index and level of sensitivity to stimuli was recorded using a numerical rating scale. Results: Enamel wear at cervical region of teeth showed a positive correlation (p=.010, similarly, dentin wear at cervical region of teeth showed positive correlation and significant association (p<.001 with dentinal hypersensitivity.Conclusion: The observation supports a significant association between severities of tooth surface wear and dentinal hypersensitivity.

  5. Accelerated tooth eruption in children with diabetes mellitus.

    Science.gov (United States)

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

    2008-05-01

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

  6. Outcome of Endodontically Treated Teeth Diagnosed With Cracked Tooth

    Science.gov (United States)

    2015-06-01

    However, variable symptoms complicate the diagnosis (9). In a study of 32 patients presenting with diffuse longstanding orofacial pain eventually...883-92. 22)Byrnjulsen A, Fristad I, Grevstad T, Hals-Kvinnsland I. Incompletely fractured teeth associated with diffuse longstanding orofacial pain ...cracked tooth is highly associated with discomfort. Patients often describe a momentary, sudden, sharp, lancinating pain that results in continuous tooth

  7. Innovative Design and Performance Evaluation of Bionic Imprinting Toothed Wheel.

    Science.gov (United States)

    Zhang, Zhihong; Wang, Xiaoyang; Tong, Jin; Stephen, Carr

    2018-01-01

    A highly efficient soil-burrowing dung beetle possesses an intricate outer contour curve on its foreleg end-tooth. This study was carried out based on evidence that this special outer contour curve has the potential of reducing soil penetration resistance and could enhance soil-burrowing efficiency. A toothed wheel is a typical agricultural implement for soil imprinting, to increase its working efficiency; the approach of the bionic geometrical structure was utilized to optimize the innovative shape of imprinting toothed wheel. Characteristics in the dung beetle's foreleg end-tooth were extracted and studied by the edge detection technique. Then, this special outer contour curve was modeled by a nine-order polynomial function and used for the innovative design of imprinting the tooth's cutting edge. Both the conventional and bionic teeth were manufactured, and traction tests in a soil bin were conducted. Taking required draft force and volume of imprinted microbasin as the evaluating indexes, operating efficiency and quality of different toothed wheels were compared and investigated. Results indicate that compared with the conventional toothed wheel, a bionic toothed wheel possesses a better forward resistance reduction property against soil and, meanwhile, can enhance the quality of soil imprinting by increasing the volume of the created micro-basin.

  8. Orientation and deformation of mineral crystals in tooth surfaces.

    Science.gov (United States)

    Fujisaki, Kazuhiro; Todoh, Masahiro; Niida, Atsushi; Shibuya, Ryota; Kitami, Shunsuke; Tadano, Shigeru

    2012-06-01

    Tooth enamel is the hardest material in the human body, and it is mainly composed of hydroxyapatite (HAp)-like mineral particles. As HAp has a hexagonal crystal structure, X-ray diffraction methods can be used to analyze the crystal structure of HAp in teeth. Here, the X-ray diffraction method was applied to the surface of tooth enamel to measure the orientation and strain of the HAp crystals. The c-axis of the hexagonal crystal structure of HAp was oriented to the surface perpendicular to the tooth enamel covering the tooth surface. Thus, the strain of HAp at the surface of teeth was measured by X-ray diffraction from the (004) lattice planes aligned along the c-axis. The X-ray strain measurements were conducted on tooth specimens with intact surfaces under loading. Highly accurate strain measurements of the surface of tooth specimens were performed by precise positioning of the X-ray irradiation area during loading. The strains of the (004) lattice plane were measured at several positions on the surface of the specimens under compression along the tooth axis. The strains were obtained as tensile strains at the labial side of incisor tooth specimens. In posterior teeth, the strains were different at different measurement positions, varying from tensile to compressive types. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Glaucoma after corneal replacement.

    Science.gov (United States)

    Baltaziak, Monika; Chew, Hall F; Podbielski, Dominik W; Ahmed, Iqbal Ike K

    Glaucoma is a well-known complication after corneal transplantation surgery. Traditional corneal transplantation surgery, specifically penetrating keratoplasty, has been slowly replaced by the advent of new corneal transplantation procedures: primarily lamellar keratoplasties. There has also been an emergence of keratoprosthesis implants for eyes that are high risk of failure with penetrating keratoplasty. Consequently, there are different rates of glaucoma, pathogenesis, and potential treatment in the form of medical, laser, or surgical therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. The replacement research reactor

    International Nuclear Information System (INIS)

    Cameron, R.; Horlock, K.

    2001-01-01

    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

  11. Clinical Evaluation of Periodontal Tissue Status in Prosthodontic Treatment of Patients with Partial Tooth Loss and Generalized Periodontitis

    Directory of Open Access Journals (Sweden)

    A. Kushlyk

    2018-01-01

    . Results and discussion. The application of direct dental prosthetic rehabilitation method after mobile tooth removal in combination treatment of generalized periodontitis allows stabilizing degenerative and inflammatory processes in the periodontium in the initial stages, as well as increasing the resistance of the capillaries and bone mineral density of the interdental septa. The obtained data indicated that the application of the proposed direct fixed sectional dental bridge was more effective as compared to conventional prosthetics methods. Conclusions. 1. Direct fixed prosthodontics using direct fixed sectional dental bridge is essential in combination treatment of generalized periodontitis, especially if mobile tooth extraction is needed. It allows increasing the effectiveness of treatment in comparison with direct removable prosthodontics using direct plastic laminar immediate prosthesis (Group I and traditional treatment methods (Group II. 2. We have proved the advantages of direct fixed prosthodontics in treatment of patients with generalized periodontitis, II-III degree based on the improvement of oral hygiene indices, the gingival bleeding index, the papillary-marginal-alveolar index, the periodontal index and the depth of periodontal pockets 6-12 months after treatment.

  12. Apparatus for fuel replacement

    International Nuclear Information System (INIS)

    Imada, Takahiko.

    1974-01-01

    Object: To support a telescope mast such that no deforming load is applied to it even during massive vibration, it is held fixed at the time of fuel replacement to permit satisfactory remote control operation by automatic operation. Structure: The body of the fuel replacement apparatus is provided with telescope mast fixing means comprising a slide base supported for reciprocal movement with respect to a telescope mast, an operating arm pivoted at the slide base, a wrist member mounted on the free end of the operating arm and an engagement member for restricting the slide base and operating arm at the time of loading and unloading the fuel. When loading and unloading the fuel, the slide base and operating arm are restrained by the engagement member to reliably restrict the vibration of the telescope mast. When the fuel replacement apparatus is moved, the means provided on the operating arm is smoothly displaced to follow the swing (vibration) of the telescope mast to prevent the deforming load from being applied to the support portion or other areas. The wrist member supports the telescope mast such that it can be rotated while restraining movement in the axial direction, and it is provided with revolution drive means for rotating the telescope mast under remote control. (Kamimura, M.)

  13. Power loss analysis in altered tooth-sum spur gearing

    Directory of Open Access Journals (Sweden)

    Sachidananda H. K.

    2018-01-01

    Full Text Available The main cause of power loss or dissipation of heat in case of meshed gears is due to friction existing between gear tooth mesh and is a major concern in low rotational speed gears, whereas in case of high operating speed the power loss taking place due to compression of air-lubricant mixture (churning losses and windage losses due to aerodynamic trial of air lubricant mixture which controls the total efficiency needs to be considered. Therefore, in order to improve mechanical efficiency it is necessary for gear designer during gear tooth optimization to consider these energy losses. In this research paper the power loss analysis for a tooth-sum of 100 altered by ±4% operating between a specified center distance is considered. The results show that negative altered tooth-sum gearing performs better as compared to standard and positive altered tooth-sum gearing.

  14. Cracked tooth syndrome: A report of three cases.

    Science.gov (United States)

    Sadasiva, Kadandale; Ramalingam, Sathishmuthukumar; Rajaram, Krishnaraj; Meiyappan, Alagappan

    2015-08-01

    Cracked tooth syndrome (CTS), the term was coined by Cameron in 1964, which refers to an incomplete fracture of a vital posterior tooth extending to the dentin and occasionally into the pulp. CTS has always been a nightmare to the patient because of its unpredictable symptoms and a diagnostic dilemma for the dental practitioner due to its variable, bizarre clinical presentation. The treatment planning and management of CTS has also given problems and challenges the dentist as there is no specific treatment option. The management of CTS varies from one case to another or from one tooth to another in the same individual based on the severity of the symptoms and depth of tooth structure involved. After all, the prognosis of such tooth is still questionable and requires continuous evaluation. This article aims at presenting a series three cases of CTS with an overview on the clinical presentation, diagnosis and the different treatment options that varies from one case to another.

  15. An Analysis of the Symptomatic Domains Most Relevant to Charcot Marie Tooth Neuropathy (CMT) Patients

    Science.gov (United States)

    2017-06-09

    Charcot Marie Tooth Disease (CMT); Hereditary Sensory and Motor Neuropathy; Nerve Compression Syndromes; Tooth Diseases; Congenital Abnormalities; Genetic Diseases, Inborn; Heredodegenerative Disorders, Nervous System

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  17. Diagnosis of Charcot-Marie-Tooth Disease

    Directory of Open Access Journals (Sweden)

    Isabel Banchs

    2009-01-01

    Full Text Available Charcot-Marie-Tooth (CMT disease or hereditary motor and sensory neuropathy (HMSN is a genetically heterogeneous group of conditions that affect the peripheral nervous system. The disease is characterized by degeneration or abnormal development of peripheral nerves and exhibits a range of patterns of genetic transmission. In the majority of cases, CMT first appears in infancy, and its manifestations include clumsiness of gait, predominantly distal muscular atrophy of the limbs, and deformity of the feet in the form of foot drop. It can be classified according to the pattern of transmission (autosomal dominant, autosomal recessive, or X linked, according to electrophysiological findings (demyelinating or axonal, or according to the causative mutant gene. The classification of CMT is complex and undergoes constant revision as new genes and mutations are discovered. In this paper, we review the most efficient diagnostic algorithms for the molecular diagnosis of CMT, which are based on clinical and electrophysiological data.

  18. EPR TOOTH DOSIMETRY OF SNTS AREA INHABITANTS.

    Science.gov (United States)

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

    2007-07-01

    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", were found to lie in the range from zero to approximately 2 Gy, with one exception, a dose for one person from Semipalatinsk city was approximately 9 Gy. The variability of reconstructed doses within each of the settlements demonstrated heterogeneity of the deposited fallout as well as variations in lifestyle. The village mean external gamma doses for residents of nine[ settlements were in the range from a few tens of mGy to approximately 100 mGy.

  19. EPR tooth dosimetry of SNTS area inhabitants

    Energy Technology Data Exchange (ETDEWEB)

    Sholom, Sergey [Scientific Center for Radiation Medicine, Melnikova str., 53, Kiev (Ukraine); Desrosiers, Marc [Ionizing Radiation Division, National Institute of Standards and Technology, Gaithersburg, MD (United States); Bouville, Andre; Luckyanov, Nicholas [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Boulevard, Bethesda, MD (United States); Chumak, Vadim [Scientific Center for Radiation Medicine, Melnikova str., 53, Kiev (Ukraine); Simon, Steven L. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Boulevard, Bethesda, MD (United States)], E-mail: ssimon@mail.nih.gov

    2007-07-15

    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', were found to lie in the range from zero to approximately 2 Gy, with one exception, a dose for one person from Semipalatinsk city was approximately 9 Gy. The variability of reconstructed doses within each of the settlements demonstrated heterogeneity of the deposited fallout as well as variations in lifestyle. The village mean external gamma doses for residents of nine settlements were in the range from a few tens of mGy to approximately 100 mGy.

  20. Charcot-Marie-Tooth disease in Denmark

    DEFF Research Database (Denmark)

    Vaeth, Signe; Vaeth, Michael; Andersen, Henning

    2017-01-01

    OBJECTIVES: Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system, yet no studies have compared the mortality in patients with CMT with that of the general population, and prevalence estimates vary considerably. We performed a nationwide register....... The prevalence was estimated by 31 December 2012, and the incidence rate was calculated based on data from 1988 to 2012. We calculated a standardised mortality ratio (SMR) and an absolute excess mortality rate (AER) stratified according to age categories and disease duration. RESULTS: A total of 1534 patients...... a significantly higher SMR in cases below 50 years of age, and in cases with disease duration of more than 10 years. CONCLUSIONS: We found a reduced life expectancy among patients diagnosed with CMT. To our knowledge, this is the first study of CMT to use nationwide register-based data, and the first to report...

  1. Unusual intraosseous transmigration of impacted tooth

    International Nuclear Information System (INIS)

    Kumar, Santosh; Urala, Arun Srinivas; Kamath, Abhay Taranath; Jayaswal, Priyanka; Valiathan, Ashima

    2012-01-01

    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.

  2. Canadian Eskimo permanent tooth emergence timing.

    Science.gov (United States)

    Mayhall, J T; Belier, P L; Mayhall, M F

    1978-08-01

    To identify the times of emergence of the permanent teeth of Canadian Eskimos (Inuit), 368 children and adolescents were examined. The presence or absence of all permanent teeth except the third molars was recorded and these data subjected to probit analysis. Female emergence times were advanced over males. Generally, the Inuit of both sexes showed statistically significant earlier emergence times than Montreal children, except for the incisors. The present results do not support hypotheses indicating that premature extraction of the deciduous teeth advances the emergence of their succedaneous counterparts. There is some indication the controls of deciduous tooth emergence continue to play some part in emergence of the permanent dentition, especially the first permanent teeth that emerge.

  3. 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.

  4. Biogeneric tooth: a new mathematical representation for tooth morphology in lower first molars.

    Science.gov (United States)

    Mehl, Albert; Blanz, Volker; Hickel, Reinhard

    2005-08-01

    A mathematical representation of tooth morphology may help to improve and automate restorative computer-aided design processes, virtual dental education, and parametric morphology. However, to date, no quantitative formulation has been identified for the description of dental features. The aim of this study was to establish and to validate a mathematical process for describing the morphology of first lower molars. Stone replicas of 170 caries-free first lower molars from young patients were measured three-dimensionally with a resolution of about 100,000 points. First, the average tooth was computed, which captures the common features of the molar's surface quantitatively. For this, the crucial step was to establish a dense point-to-point correspondence between all teeth. The algorithm did not involve any prior knowledge about teeth. In a second step, principal component analysis was carried out. Repeated for 3 different reference teeth, the procedure yielded average teeth that were nearly independent of the reference (less than +/- 40 microm). Additionally, the results indicate that only a few principal components determine a high percentage of the three-dimensional shape variability of first lower molars (e.g. the first five principal components describe 52% of the total variance, the first 10 principal components 72% and the first 20 principal components 83%). With the novel approach presented in this paper, surfaces of teeth can be described efficiently in terms of only a few parameters. This mathematical representation is called the 'biogeneric tooth'.

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

    Science.gov (United States)

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

    2015-06-01

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

  6. Toleration, Synthesis or Replacement?

    DEFF Research Database (Denmark)

    Holtermann, Jakob v. H.; Madsen, Mikael Rask

    2016-01-01

    , in order to answer is not yet another partisan suggestion, but rather an attempt at making intelligible both the oppositions and the possibilities of synthesis between normative and empirical approaches to law. Based on our assessment and rational reconstruction of current arguments and positions, we...... therefore outline a taxonomy consisting of the following three basic, ideal-types in terms of the epistemological understanding of the interface of law and empirical studies: toleration, synthesis and replacement. This tripartite model proves useful with a view to teasing out and better articulating...

  7. Upgrade, rebuild or replace?

    International Nuclear Information System (INIS)

    Forbes, C.A.

    1990-01-01

    Ageing reactor simulators present some tough decisions for utility managers. Although most utilities have chosen the cheaper, upgrading solution as the best compromise between costs and outage length, some US utilities have found that for them, replacement represents the best option. Simulators may be less than ten years old, but they have limited instructor systems, older low fidelity models that cannot reproduce important training scenarios, and out of date, difficult to maintain computers that do not permit much expansion of the models anyway. Perhaps worse than this is the possibility that the simulator may no longer be a faithful reproduction of the referenced plant, or have poor (or non-existent) documentation. (author)

  8. Functional aspects of treatment with implant-supported single crowns: a quality control study in subjects with tooth agenesis

    DEFF Research Database (Denmark)

    Goshima, Kenichi; Lexner, Michala O; Thomsen, Carsten Eckhart

    2010-01-01

    -Related Quality of Life (OHRQoL) in subjects with tooth agenesis. MATERIAL AND METHODS: In nine females and nine males (32 + or - 10 years) with agenesis treated with one to four ISSC (68% in the premolar region), the treatment effect and masticatory function were assessed. The evaluation was performed first...... after implant placement shortly before crown cementation, and again 1 month after cementation. It consisted of questionnaires [including Oral Health Impact Profile (OHIP-49)] and functional examination with plastic strips, the Dental Prescale Film and the Occluzer system, Xylitol color-changeable gum...... with ISSCs in subjects with tooth agenesis significantly increased masticatory function subjectively and clinically as well as OHRQoL. However, as the functional parameters before replacement of the teeth corresponded to values in subjects with complete dentitions, the functional importance of the increase...

  9. Severe Heterotopic Ossification following Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Alexander L. Dodds

    2014-01-01

    Full Text Available Although the incidence of minor heterotopic ossification is probably higher than what is usually expected, severe heterotopic ossification (HO is an extremely rare event following total knee replacement surgery. We present the case of a 66-year-old woman who initially had achieved an excellent range of motion following bilateral uncemented rotating platform total knee replacement, before presenting with pain and loss of range of motion at 2 months after surgery. Severe HO was diagnosed on X-rays. Treatment consisted of nonoperative measures only, including physiotherapy with hydrotherapy and anti-inflammatories. She eventually regained her range of motion when seen at 8 months after operation. This case illustrates that nonoperative treatment without the use of radiotherapy or surgery can be used to safely resolve stiffness caused by HO after total knee replacement.

  10. Prosthetic replacement vs space closure for maxillary lateral incisor agenesis: A systematic review.

    Science.gov (United States)

    Silveira, Giordani Santos; de Almeida, Natália Valli; Pereira, Daniele Masterson Tavares; Mattos, Cláudia Trindade; Mucha, José Nelson

    2016-08-01

    Defining the best treatment for maxillary lateral incisor agenesis is a challenge. Our aim in this study was to determine, with the evidence available in the literature, the best treatment for maxillary lateral incisor agenesis in the permanent dentition, evaluating the esthetic, occlusal (functional), and periodontal results between prosthetic replacement and orthodontic space closure. Electronic databases (CENTRAL, PubMed, Web of Science, Scopus, and LILACS) were searched in September 2014 and updated in January 2015, with no restriction on language or initial date. A manual search of the reference lists of the potential studies was performed. Risk of bias was assessed by the Newcastle Ottawa Scale. The search identified 2174 articles, of which 1196 were excluded because they were duplicates. Titles and abstracts of 978 articles were accessed, and 957 were excluded. In total, 21 articles were read in full, and 9 case-control studies were included after applying the inclusion and exclusion criteria. Data were extracted from the articles selected, and a table was compiled for comparison and analysis of the results. There were no randomization and blinding, and the risk of bias evaluation found gaps in compatibility and outcome domains in almost all selected studies. Tooth-supported dental prostheses of maxillary lateral incisor agenesis had worse scores in the periodontal indexes than did orthodontic space closure. Space closure is evaluated better esthetically than prosthetic replacements, and the presence or absence of a Class I relationship of the canines showed no relationship with occlusal function or with signs and symptoms of temporomandibular disorders. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  11. Safety issues of tooth whitening using peroxide-based materials.

    Science.gov (United States)

    Li, Y; Greenwall, L

    2013-07-01

    In-office tooth whitening using hydrogen peroxide (H₂O₂) has been practised in dentistry without significant safety concerns for more than a century. While few disputes exist regarding the efficacy of peroxide-based at-home whitening since its first introduction in 1989, its safety has been the cause of controversy and concern. This article reviews and discusses safety issues of tooth whitening using peroxide-based materials, including biological properties and toxicology of H₂O₂, use of chlorine dioxide, safety studies on tooth whitening, and clinical considerations of its use. Data accumulated during the last two decades demonstrate that, when used properly, peroxide-based tooth whitening is safe and effective. The most commonly seen side effects are tooth sensitivity and gingival irritation, which are usually mild to moderate and transient. So far there is no evidence of significant health risks associated with tooth whitening; however, potential adverse effects can occur with inappropriate application, abuse, or the use of inappropriate whitening products. With the knowledge on peroxide-based whitening materials and the recognition of potential adverse effects associated with the procedure, dental professionals are able to formulate an effective and safe tooth whitening regimen for individual patients to achieve maximal benefits while minimising potential risks.

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

    International Nuclear Information System (INIS)

    Kim, Jae Duk; Kim, Jin Soo; You, Choong Hyun

    2005-01-01

    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.

  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. 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.

  15. Cadmium plating replacements

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  16. 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...

  17. 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.

  18. Angulation change of the third molar tooth in orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Ardiansyah S. Pawinru

    2017-04-01

    Full Text Available Objective : Impaction of the third molar tooth mandibular is often found in patients with orthodontic treatment. In orthodontic treatment, extraction cases of impaction of the third molar tooth are usually performed, but the patients often refuse this extraction. Extraction of premolar has a good effect on the third molar mandibular angulation during treatment. Material and Methods : This study is a retrospective clinical study with descriptive analytic to find out the effect of the first mandibular premolar tooth extraction to angulation change of the third molar mandibular in orthodontic treatment with a standard edgewise method. Angulation change was performed by comparing the third molar mandibular angulation before and after orthodontic treatment with panoramic radiographs. Angulation of the third molar tooth mandibular was calculated from the angle formed between the long axis of the tooth with the reference line infraorbita. Results : The sample comprised 60 of impacted mandibular third molar region of the left and right regions of 30 patients who had been treated declared cured in clinic of orthodontic specialist of Dentistry Faculty Padjadjaran University. The sample was divided into three (3 groups of patients before treatment angulation of the third molar tooth mandibular under 300, 300 to 600 and above 60o, then measured change of angulation and observed whether it increased, fixed or decreased. Results were analyzed by T- test and Wilcoxon test showed that there was a significant change in angulation of the third molar mandibular in orthodontic treatment with the first premolar tooth mandibular extraction. Conclusion : This study is that the first premolar tooth mandibular extraction affects the angulation of the third molar tooth mandibular after orthodontic treatment.

  19. 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.

  20. Tooth loss prevalence among cardiac males and females

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  1. Tooth supported overdenture: A concept overshadowed but not yet forgotten!

    Directory of Open Access Journals (Sweden)

    Rupandeep Kaur Samra

    2015-01-01

    Full Text Available The concept of conventional tooth-retained overdentures is a simple and cost effective treatment than the implant overdentures. When few firm teeth are present in an otherwise compromised dentition, they can be retained and used as abutments for overdenture fabrication. This helps improve the retention and stability of the final prosthesis significantly. Bone is a dynamic tissue. The extraction of teeth results in the initiation of the bone resorption pattern. However, when tensile stress is received by bone, additional bone formation takes place. Such stresses occur when occlusal forces are transmitted to the alveolar bone by the periodontal ligament. This principle helps preserve bone. The concept of overdentures may not be the elixir, but it is a positive means for delaying the process of complete endentulism and helps in the preservation of bone. To top it all, it gives the patient the satisfaction of having prosthesis with his natural teeth still present. In this article, case reports with three different types of Overdentures are discussed: Overdenture with cast copings with short dowels, O-ring attachments, and a customized bar supported overdenture with copings.

  2. DENTAL SPLINTS: TYPES AND TIME OF IMMOBILIZATION POST TOOTH AVULSION

    Directory of Open Access Journals (Sweden)

    Samuel Rodrigo de Andrade VERAS

    2017-12-01

    Full Text Available Avulsion is defined as the complete displacement of the tooth out of its socket with disruption of the fibers of periodontal ligament, remaining some of them adhered to the cementum and the rest to the alveolar bone. This condition is more frequent in young permanent teeth, because the root development is still incomplete. Splints are used to immobilize traumatized teeth that suffered damage in their structures of support, preventing their constant movement. The literature has shown that after replantation, it is necessary to use splints in order to immobilize the teeth during the initial period, which is essential for the repair of periodontal ligament; the use of semi-rigid splint is more indicated than the rigid one, and long periods of splinting showed that substitutive resorption or ankylosis is an expected complication. Thus, the aim of this review is to describe the different types of splints; their time of permanency, and its influence on the process of healing and reparation on the occurrence of substitutive resorption or ankylosis. It is very important to keep gathering knowledge about this content, since it has been proved that the approaches and the protocols keep changing over time.

  3. 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. © 2015 Wiley Periodicals, Inc.

  4. 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.

  5. Periodontal profile classes predict periodontal disease progression and tooth loss.

    Science.gov (United States)

    Morelli, Thiago; Moss, Kevin L; Preisser, John S; Beck, James D; Divaris, Kimon; Wu, Di; Offenbacher, Steven

    2018-02-01

    Current periodontal disease taxonomies have limited utility for predicting disease progression and tooth loss; in fact, tooth loss itself can undermine precise person-level periodontal disease classifications. To overcome this limitation, the current group recently introduced a novel patient stratification system using latent class analyses of clinical parameters, including patterns of missing teeth. This investigation sought to determine the clinical utility of the Periodontal Profile Classes and Tooth Profile Classes (PPC/TPC) taxonomy for risk assessment, specifically for predicting periodontal disease progression and incident tooth loss. The analytic sample comprised 4,682 adult participants of two prospective cohort studies (Dental Atherosclerosis Risk in Communities Study and Piedmont Dental Study) with information on periodontal disease progression and incident tooth loss. The PPC/TPC taxonomy includes seven distinct PPCs (person-level disease pattern and severity) and seven TPCs (tooth-level disease). Logistic regression modeling was used to estimate relative risks (RR) and 95% confidence intervals (CI) for the association of these latent classes with disease progression and incident tooth loss, adjusting for examination center, race, sex, age, diabetes, and smoking. To obtain personalized outcome propensities, risk estimates associated with each participant's PPC and TPC were combined into person-level composite risk scores (Index of Periodontal Risk [IPR]). Individuals in two PPCs (PPC-G: Severe Disease and PPC-D: Tooth Loss) had the highest tooth loss risk (RR = 3.6; 95% CI = 2.6 to 5.0 and RR = 3.8; 95% CI = 2.9 to 5.1, respectively). PPC-G also had the highest risk for periodontitis progression (RR = 5.7; 95% CI = 2.2 to 14.7). Personalized IPR scores were positively associated with both periodontitis progression and tooth loss. These findings, upon additional validation, suggest that the periodontal/tooth profile classes and the derived

  6. Unique case of a geminated supernumerary tooth with trifid crown

    International Nuclear Information System (INIS)

    Ather, Amber; Ather, Hunaiza; Sheth, Sanket Milan; Muliya, Vidya Saraswathi

    2012-01-01

    Gemination, a relatively uncommon dental anomaly, is characterized by its peculiar representation as a tooth with a bifid crown and a common root and root canal. It usually occurs in primary dentition. To come across gemination in a supernumerary tooth is a rare phenomenon. The purpose of this paper is to present a unique case of hyperdontia wherein gemination in an impacted supernumerary tooth resulted in a trifid crown unlike the usual bifid crown. The role of conventional radiographs as well as computed tomography, to accurately determine the morphology and spatial location, and to arrive at a diagnosis, is also emphasized in this paper.

  7. Bmp 2 and bmp 7 induce odonto- and osteogenesis of human tooth germ stem cells.

    Science.gov (United States)

    Taşlı, P Neslihan; Aydın, Safa; Yalvaç, Mehmet Emir; Sahin, Fikrettin

    2014-03-01

    Bone morphogenetic proteins (BMPs) initiate, promote, and maintain odontogenesis and osteogenesis. In this study, we studied the effect of bone morphogenic protein 2 (BMP 2) and bone morphogenic protein 7 (BMP 7) as differentiation inducers in tooth and bone regeneration. We compared the effect of BMP 2 and BMP 7 on odontogenic and osteogenic differentiation of human tooth germ stem cells (hTGSCs). Third molar-derived hTGSCs were characterized with mesenchymal stem cell surface markers by flow cytometry. BMP 2 and BMP 7 were transfected into hTGSCs and the cells were seeded onto six-well plates. One day after the transfection, hTGSCs were treated with odontogenic and osteogenic mediums for 14 days. For confirmation of odontogenic and osteogenic differentiation, mRNA levels of BMP2, BMP 7, collagen type 1 (COL1A), osteocalsin (OCN), and dentin sialophosphoprotein (DSPP) genes were measured by quantitative real-time PCR. In addition to this, immunocytochemistry was performed by odontogenic and osteogenic antibodies and mineralization obtained by von Kossa staining. Our results showed that the BMP 2 and BMP 7 both promoted odontogenic and osteogenic differentiation of hTGSCs. Data indicated that BMP 2 treatment and BMP 7 treatment induce odontogenic differentiation without affecting each other, whereas they induce osteogenic differentiation by triggering expression of each other. These findings provide a feasible tool for tooth and bone tissue engineering.

  8. Spatiotemporal expression of caveolin-1 and EMMPRIN during mouse tooth development.

    Science.gov (United States)

    Shi, Lu; Li, Lingyun; Wang, Ding; Li, Shu; Chen, Zhi; An, Zhengwen

    2016-06-01

    Caveolin-1 is a scaffolding protein involved in the formation of cholesterol-rich caveolae lipid rafts within the plasma membrane and is capable of collecting signaling molecules into the caveolae and regulating their activity, including extracellular matrix metalloproteinase inducer (EMMPRIN). However, detailed expression patterns of caveolin-1 and EMMPRIN in the developing dental germ are largely unknown. The present study investigated the expression patterns of caveolin-1 and EMMPRIN in the developing mouse tooth germ by immunohistochemistry and real-time polymerase chain reaction. At the bud stage, caveolin-1 expression was initiated in the epithelium bud and mesenchymal cells, while EMMPRIN was weakly expressed at this stage. At the cap stage, caveolin-1 protein was located in the lingual part of the tooth germ; however, EMMPRIN protein was located in the labial part. From the bell stage to 2 days postnatal, caveolin-1 expression was detected in the ameloblasts and cervical loop area; with EMMPRIN expression in the ameloblasts and odontoblasts. Real-time polymerase chain reaction results showed that both caveolin-1 and EMMPRIN mRNA levels increased gradually with progression of developmental stages, and peaked at day two postnatal. The current finding suggests that both caveolin-1 and EMMPRIN take part in mouse tooth development, especially in the differentiation and organization of odontogenic tissues.

  9. Effects of calcitonin on orthodontic tooth movement and associated root resorption in rats.

    Science.gov (United States)

    Guan, Ling; Lin, Suai; Yan, Weijun; Chen, Lei; Wang, Xiaofeng

    2017-11-01

    Our main aim was to evaluate the effects of calcitonin (CT) on orthodontic tooth movement (OTM) and orthodontic root resorption in a rat model. Eighty male Wistar rats were randomly divided into five groups. Rats in the negative control group were not given any appliances or injections. All the remaining rats were used to establish a model of OTM. The positive control group were then injected with normal saline, while rats in the three experimental groups were injected with 0.2 IU, 1 IU or 5 IU/kg/day CT. Nickel-titanium closed-coil springs were used to deliver an initial 50 g mesial force to the left maxillary first molar for 14 days in rats in the positive control group and the experimental groups. Each group was randomly subdivided into two groups, one for analysis of tooth movement, tissue changes and tartrate-resistant acid phosphatase (TRAP)-positive cells in alveolar bone, the other to examine root resorption by scanning electron microscopy. The OTM distance, the number of force-induced osteoclasts and root resorption areas were significantly decreased in CT-injected rats in a dose-dependent manner. Administration of CT reduces the root resorption area and may therefore be effective as a novel adjunctive orthodontic approach to diminish undesired tooth movement via enhancing anchorage or preventing relapse after OTM.

  10. Coupling image processing and stress analysis for damage identification in a human premolar tooth.

    Science.gov (United States)

    Andreaus, U; Colloca, M; Iacoviello, D

    2011-08-01

    Non-carious cervical lesions are characterized by the loss of dental hard tissue at the cement-enamel junction (CEJ). Exceeding stresses are therefore generated in the cervical region of the tooth that cause disruption of the bonds between the hydroxyapatite crystals, leading to crack formation and eventual loss of enamel and the underlying dentine. Damage identification was performed by image analysis techniques and allowed to quantitatively assess changes in teeth. A computerized two-step procedure was generated and applied to the first left maxillary human premolar. In the first step, dental images were digitally processed by a segmentation method in order to identify the damage. The considered morphological properties were the enamel thickness and total area, the number of fragments in which the enamel is chipped. The information retrieved by the data processing of the section images allowed to orient the stress investigation toward selected portions of the tooth. In the second step, a three-dimensional finite element model based on CT images of both the tooth and the periodontal ligament was employed to compare the changes occurring in the stress distributions in normal occlusion and malocclusion. The stress states were analyzed exclusively in the critical zones designated in the first step. The risk of failure at the CEJ and of crack initiation at the dentin-enamel junction through the quantification of first and third principal stresses, von Mises stress, and normal and tangential stresses, were also estimated. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Replace with abstract title

    Science.gov (United States)

    Coho, Aleksander; Kioussis, Nicholas

    2003-03-01

    We use the semidiscrete variational generelized Peierls-Nabarro model to study the effect of Cu alloying on the dislocation properties of Al. First-principles density functional theory (DFT) is used to calculate the generalized-stacking-fault (GSF) energy surface when a plane, on which one in four Al atoms has been replaced with a Cu atom, slips over a pure Al plane. Various dislocation core properties (core width, energy, Peierls stress, dissociation tendency) are investigated and compared with the pure Al case. Cu alloying lowers the intrinsic stacking fault (ISF) energy, which makes dislocations more likely to dissociate into partials. We also try to understand the lowering of ISF energy in terms of Al-Cu and Al-Al bond formation and braking during shearing along the direction. From the above we draw conclusions about the effects of Cu alloying on the mechanical properties of Al.

  12. 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...

  13. 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. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Relationship between natural tooth shade and skin colour.

    Science.gov (United States)

    Nourbakhsh, M; Mousavinejad, N; Adli, A R; Harati, M

    2013-06-01

    The purpose of this study was to assess the correlation of skin colour and tooth shade. One hundred and twenty six individuals aging between 18 to 25 years participated in this study. Colour of the maxillary central incisors was examined by VITA easy shade. Tooth shades were assigned to four ordinal values. Nivea Beauty Protect Foundation shade sample was used as a guide to assess facial skin colour Shin colours were also assigned to four ordinal values. Spearman test revealed that there was a significant relationship between tooth shade and skin colour Total co-relation factor was 51.6% (p men (p <0 .01). The highest tooth shade prevalence belonged to the second group and the highest skin colour prevalence was also in the second skin colour group.

  15. Retrospective individual dosimetry using EPR of tooth enamel

    International Nuclear Information System (INIS)

    Skvortzo, V.; Ivannikov, A.; Stepanenko, V.; Wieser, A.; Bougai, A.; Brick, A.; Chumak, V.; Radchuk, V.; Repin, V.; Kirilov, V.

    1996-01-01

    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

  16. Drugs influencing orthodontic tooth movement: An overall review

    Directory of Open Access Journals (Sweden)

    Kamatchi Diravidamani

    2012-01-01

    Full Text Available Orthodontic treatment is based on the premise that when force is delivered to a tooth and thereby transmitted to the adjacent investing tissues, certain mechanical, chemical, and cellular events take place within these tissues, which allow for structural alterations and contribute to the movement of that tooth. Molecules present in drugs and nutrients consumed regularly by patients can reach the mechanically stressed paradental tissues through the circulation and interact with local target cells. The combined effect of mechanical forces and one or more of these agents may be inhibitory, additive, or synergistic. Current orthodontic research aims to develop methods of increasing the tissue concentration of molecules promoting tooth movement, while simultaneously decreasing the concentration of unwanted elements which can produce harmful side effects. This article discusses in detail the various possible drugs that can bring about alterations in the desired orthodontic tooth movement.

  17. Causes of Charcot-Marie-Tooth Disease (CMT)

    Science.gov (United States)

    ... Marie-Tooth Disease (CMT) Congenital Muscular Dystrophy (CMD) Duchenne Muscular Dystrophy (DMD) Emery-Dreifuss Muscular Dystrophy Endocrine Myopathies Metabolic Diseases of Muscle Mitochondrial Myopathies (MM) Myotonic Dystrophy (DM) Spinal-Bulbar ...

  18. Geographic Variations in the EPR Spectrum of Tooth Enamel

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  19. Circumscribed Lipoatrophy of the Chin after Tooth Extraction

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2017-07-01

    Full Text Available We describe the rare occurrence of circumscribed facial lipoatrophy after tooth extraction. Correction by minimal invasive esthetic techniques such as soft tissue fillers or autologous fat transfer is possible but was not warranted.

  20. Basic School Teachers' Knowledge and Attitude about Tooth Decay ...

    African Journals Online (AJOL)

    Basic School Teachers' Knowledge and Attitude about Tooth Decay and Practice ... Background: The important role of teachers in oral health education cannot be ... 60.3% of the teachers claimed spending time promoting for oral health.

  1. Tooth brushing, tongue cleaning and snacking behaviour of dental ...

    African Journals Online (AJOL)

    2010-08-12

    Aug 12, 2010 ... frequency, duration and technique of tooth brushing and tongue cleaning as well as information on ... All the students in Year 1Б4 were included in the study. .... agents which are beneficial for prevention and treatment.

  2. Tooth extraction education at dental schools across Europe

    NARCIS (Netherlands)

    Brand, H.S.; van der Cammen, C.C.J.; Roorda, S.M.E.; Baart, J.A.

    2015-01-01

    Objectives/Aims: To explore students’ opinion about theoretical and clinical training in tooth extraction at different European dental schools. Materials and Methods: An online questionnaire, containing 36 dichotomous, multiple choice and Likert scale rating questions, was distributed among students

  3. Claustral single cell reactions to tooth pulp stimulation in cats.

    Science.gov (United States)

    Jastreboff, P; Sikora, M; Frydrychowski, A; Słoniewski, P

    1983-01-01

    Single unit activity in the central region of the claustrum, evoked by electrical stimulation of tooth pulp or paws was studied on cats under chloralose anesthesia. The majority of cells responded in similar manner to stimulation of tooth pulp or paws, but there were cells with clear preference to a given type of stimulation. Latencies of reactions evoked by tooth pulp stimulation were significantly shorter than those for limb stimulation. In the former case latencies as short as 8 rns were observed. It is postulated that the central region of the claustrum receives a projection from the tooth pulp, and that in those cases with very short latency the projection is direct and does not involve the cerebral cortex.

  4. Replacement of the Advanced Test Reactor control room

    International Nuclear Information System (INIS)

    Durney, J.L.; Klingler, W.B.

    1989-01-01

    The control room for the Advanced Test Reactor has been replaced to provide modern equipment utilizing current standards and meeting the current human factors requirements. The control room was designed in the early 1960 era and had not been significantly upgraded since the initial installation. The replacement did not change any of the safety circuits or equipment but did result in replacement of some of the recorders that display information from the safety systems. The replacement was completed in concert with the replacement of the control room simulator which provided important feedback on the design. The design successfully incorporates computer-based systems into the display of the plant variables. This improved design provides the operator with more information in a more usable form than was provided by the original design. The replacement was successfully completed within the scheduled time thereby minimizing the down time for the reactor. 1 fig., 1 tab

  5. Replacement of the Advanced Test Reactor control room

    International Nuclear Information System (INIS)

    Durney, J.L.; Klingler, W.B.

    1990-01-01

    The control room for the Advanced Test Reactor has been replaced to provide modern equipment utilizing current standards and meeting the current human factors requirements. The control room was designed in the early 1960 era and had not been significantly upgraded since the initial installation. The replacement did not change any of the safety circuits or equipment but did result in replacement of some of the recorders that display information from the safety systems. The replacement was completed in concert with the replacement of the control room simulator which provided important feedback on the design. The design successfully incorporates computer-based systems into the display of the plant variables. This improved design provides the operator with more information in a more usable form than was provided by the original design. The replacement was successfully completed within the scheduled time thereby minimizing the down time for the reactor

  6. Relationship between tooth dimensions and malocclusion

    International Nuclear Information System (INIS)

    Farooq, J.; Ahmed, I.; Erum, G.

    2014-01-01

    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)

  7. Antibiotics to prevent complications following tooth extractions.

    Science.gov (United States)

    Lodi, Giovanni; Figini, Lara; Sardella, Andrea; Carrassi, Antonio; Del Fabbro, Massimo; Furness, Susan

    2012-11-14

    The most frequent indications for tooth extractions are dental caries and periodontal infections, and these extractions are generally done by general dental practitioners. Antibiotics may be prescribed to patients undergoing extractions to prevent complications due to infection. To determine the effect of antibiotic prophylaxis on the development of infectious complications following tooth extractions. The following electronic databases were searched: the Cochrane Oral Health Group's Trials Register (to 25 January 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1948 to 25 January 2012), EMBASE via OVID (1980 to 25 January 2012) and LILACS via BIREME (1982 to 25 January 2012). There were no restrictions regarding language or date of publication. We included randomised double-blind placebo-controlled trials of antibiotic prophylaxis in patients undergoing tooth extraction(s) for any indication. Two review authors independently assessed risk of bias for the included studies and extracted data. We contacted trial authors for further details where these were unclear. For dichotomous outcomes we calculated risk ratios (RR) and 95% confidence intervals (CI) using random-effects models. For continuous outcomes we used mean differences (MD) with 95% CI using random-effects models. We examined potential sources of heterogeneity. The quality of the body of evidence has been assessed using the GRADE tool. This review included 18 double-blind placebo-controlled trials with a total of 2456 participants. Five trials were assessed at unclear risk of bias, thirteen at high risk, and none at low risk of bias. Compared to placebo, antibiotics probably reduce the risk of infection in patients undergoing third molar extraction(s) by approximately 70% (RR 0.29 (95% CI 0.16 to 0.50) P antibiotics to prevent one infection following extraction of impacted wisdom teeth. There is evidence that antibiotics may reduce

  8. Trace Elements in Human Tooth Enamel

    Energy Technology Data Exchange (ETDEWEB)

    Nixon, G. S. [Turner Dental School, University Of Manchester, Manchester (United Kingdom); Smith, H.; Livingston, H. D. [Department of Forensic Medicine, University Of Glasgow, Glasgow (United Kingdom)

    1967-10-15

    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)

  9. Effect of Cervical Lessions on the Tooth FEM Study

    OpenAIRE

    Gabriela Bereşescu; Ligia Brezeanu; Claudia Şoaita

    2010-01-01

    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 a...

  10. Estimation of Tooth Size Discrepancies among Different Malocclusion Groups

    OpenAIRE

    Hasija, Narender; Bala, Madhu; Goyal, Virender

    2014-01-01

    ABSTRACT Regards and Tribute: Late Dr Narender Hasija was a mentor and visionary in the light of knowledge and experience. We pay our regards with deepest gratitude to the departed soul to rest in peace. Bolton’s ratios help in estimating overbite, overjet relationships, the effects of contemplated extractions on posterior occlusion, incisor relationships and identification of occlusal misfit produced by tooth size discrepancies. Aim: To determine any difference in tooth size discrepancy in a...

  11. Electron paramagnetic resonance biophysical radiation dosimetry with tooth enamel

    International Nuclear Information System (INIS)

    Khan, Rao F.H.

    2003-01-01

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

  12. Variables affecting orthodontic tooth movement with clear aligners.

    Science.gov (United States)

    Chisari, Justin R; McGorray, Susan P; Nair, Madhu; Wheeler, Timothy T

    2014-04-01

    In this study, we examined the impacts of age, sex, root length, bone levels, and bone quality on orthodontic tooth movement. Clear aligners were programmed to move 1 central incisor 1 mm over the course of 8 weeks. Thirty subjects, ages 19 to 64, were enrolled, and measurements were made on digital models (percentage of tooth movement goal achieved). Morphometric features and bone quality were assessed with cone-beam computed tomography. Data from this study were combined with data from 2 similar studies to increase the power for some analyses. The mean percentage of tooth movement goal achieved was 57% overall. Linear regression modeling indicated a cubic relationship between age and tooth movement, with a decreasing rate of movement from ages 18 to 35 years, a slightly increasing rate from ages 35 to 50, and a decreasing rate from ages 50 to 70. The final decreasing trend was not apparent for women. As would be expected, the correlation was significant between the percentage of the goal achieved and the cone-beam computed tomography superimposed linear measures of tooth movement. A significant negative correlation was found between tooth movement and the measurement apex to the center of rotation, but bone quality, as measured by fractal dimension, was not correlated with movement. The relationship between age and tooth movement is complex and might differ for male and female patients. Limited correlations with cone-beam computed tomography morphology and rate of tooth movement were detected. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  13. Replacing Heavily Damaged Teeth by Third Molar Autotransplantation With the Use of Cone-Beam Computed Tomography and Rapid Prototyping.

    Science.gov (United States)

    Verweij, Jop P; Anssari Moin, David; Wismeijer, Daniel; van Merkesteyn, J P Richard

    2017-09-01

    This article describes the autotransplantation of third molars to replace heavily damaged premolars and molars. Specifically, this article reports on the use of preoperative cone-beam computed tomographic planning and 3-dimensional (3D) printed replicas of donor teeth to prepare artificial tooth sockets. In the present case, an 18-year-old patient underwent autotransplantation of 3 third molars to replace 1 premolar and 2 molars that were heavily damaged after trauma. Approximately 1 year after the traumatic incident, autotransplantation with the help of 3D planning and rapid prototyping was performed. The right maxillary third molar replaced the right maxillary first premolar. The 2 mandibular wisdom teeth replaced the left mandibular first and second molars. During the surgical procedure, artificial tooth sockets were prepared with the help of 3D printed donor tooth copies to prevent iatrogenic damage to the actual donor teeth. These replicas of the donor teeth were designed based on the preoperative cone-beam computed tomogram and manufactured with the help of 3D printing techniques. The use of a replica of the donor tooth resulted in a predictable and straightforward procedure, with extra-alveolar times shorter than 2 minutes for all transplantations. The transplanted teeth were placed in infraocclusion and fixed with a suture splint. Postoperative follow-up showed physiologic integration of the transplanted teeth and a successful outcome for all transplants. In conclusion, this technique facilitates a straightforward and predictable procedure for autotransplantation of third molars. The use of printed analogues of the donor teeth decreases the risk of iatrogenic damage and the extra-alveolar time of the transplanted tooth is minimized. This facilitates a successful outcome. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    Energy Technology Data Exchange (ETDEWEB)

    Gan, Yangzhou; Zhao, Qunfei [Department of Automation, Shanghai Jiao Tong University, and Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai 200240 (China); Xia, Zeyang, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn; Hu, Ying [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, and The Chinese University of Hong Kong, Shenzhen 518055 (China); Xiong, Jing, E-mail: zy.xia@siat.ac.cn, E-mail: jing.xiong@siat.ac.cn [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 510855 (China); Zhang, Jianwei [TAMS, Department of Informatics, University of Hamburg, Hamburg 22527 (Germany)

    2015-01-15

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm{sup 3}) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm{sup 3}, 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm{sup 3}, 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0

  15. Toward accurate tooth segmentation from computed tomography images using a hybrid level set model

    International Nuclear Information System (INIS)

    Gan, Yangzhou; Zhao, Qunfei; Xia, Zeyang; Hu, Ying; Xiong, Jing; Zhang, Jianwei

    2015-01-01

    Purpose: A three-dimensional (3D) model of the teeth provides important information for orthodontic diagnosis and treatment planning. Tooth segmentation is an essential step in generating the 3D digital model from computed tomography (CT) images. The aim of this study is to develop an accurate and efficient tooth segmentation method from CT images. Methods: The 3D dental CT volumetric images are segmented slice by slice in a two-dimensional (2D) transverse plane. The 2D segmentation is composed of a manual initialization step and an automatic slice by slice segmentation step. In the manual initialization step, the user manually picks a starting slice and selects a seed point for each tooth in this slice. In the automatic slice segmentation step, a developed hybrid level set model is applied to segment tooth contours from each slice. Tooth contour propagation strategy is employed to initialize the level set function automatically. Cone beam CT (CBCT) images of two subjects were used to tune the parameters. Images of 16 additional subjects were used to validate the performance of the method. Volume overlap metrics and surface distance metrics were adopted to assess the segmentation accuracy quantitatively. The volume overlap metrics were volume difference (VD, mm 3 ) and Dice similarity coefficient (DSC, %). The surface distance metrics were average symmetric surface distance (ASSD, mm), RMS (root mean square) symmetric surface distance (RMSSSD, mm), and maximum symmetric surface distance (MSSD, mm). Computation time was recorded to assess the efficiency. The performance of the proposed method has been compared with two state-of-the-art methods. Results: For the tested CBCT images, the VD, DSC, ASSD, RMSSSD, and MSSD for the incisor were 38.16 ± 12.94 mm 3 , 88.82 ± 2.14%, 0.29 ± 0.03 mm, 0.32 ± 0.08 mm, and 1.25 ± 0.58 mm, respectively; the VD, DSC, ASSD, RMSSSD, and MSSD for the canine were 49.12 ± 9.33 mm 3 , 91.57 ± 0.82%, 0.27 ± 0.02 mm, 0.28 ± 0.03 mm

  16. Halocarbons as Halon Replacements. Volume 1. Technology Review and Initiation

    Science.gov (United States)

    1991-03-01

    Gas Phase Reaction Rate Theory, Ronald Press, New York, p. 339, 1966. 73. Gaffney , J. S., and Levine, S. Z., "Predicting Gas Phase Organic Molecule...Technologies for the Control of Hazardous Wastes, Noyes Data Corporation, Park Ridge , New Jersey, 1983. 107. Bonner, T., Desai, B., Fullenkamp, J...Hughes, T., Kennedy, E., McCormick, R., Peters, J., and Zanders, D., Hazardous Waste Incineration EngineerinS, Noyes Data Corporation, Park Ridge , New

  17. Effect of Melamine Sponge on Tooth Stain Removal.

    Science.gov (United States)

    Otsuka, Takero; Kawata, Toshitsugu

    2015-01-01

    To investigate the stain removal ability of melamine sponge before aesthetic tooth whitening in extracted teeth. Melamine sponge of thickness 40 mm was compressed and the destruction of the partition wall structure during the compression process was examined under a stereoscopic microscope. An extracted human tooth was cleaned by normal polishing or with melamine sponge for 90 s. To evaluate the stain level, the tooth surfaces were photographed under a stereoscopic microscope at 0, 30, 60 and 90 s. The residual stained region was traced in a high-magnification photograph, and the stain intensity was presented as a change, relative to the intensity before the experiment (0 s). Mechanical cleaning by toothbrushing produced polishing scratches on the tooth surface, whereas use of the melamine sponge resulted in only minimal scratches. As the compression level increased, the stain-removing effect tended to become stronger. Melamine sponge can remove stains from the tooth surface more effectively and less invasively compared to a conventional toothbrush. As no new scratches are made on the tooth surface when using a melamine sponge brush, the risk of re-staining is reduced. Cleaning using a melamine sponge brush can be easily and effectively performed at home and in a dental office.

  18. 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.

  19. Behavioral changes during dental appointments in children having tooth extractions

    Directory of Open Access Journals (Sweden)

    Mariana Gonzalez Cademartori

    2017-01-01

    Full Text Available Background: Tooth extractions are associated with anxiety-related situations that can cause behavioral problems in pediatric dental clinics. Aim: We aimed to describe the behavior of children during tooth extraction appointments, compare it to their behavior in preceding and subsequent dental appointments, and assess the behavioral differences according to gender, age, type of dentition, and reason for extraction. Settings and Design: This was a retrospective study based on information obtained from records of children between 6 and 13 years of age who were cared for at the Dentistry School in Pelotas, Brazil. Materials and Methods: Child behavior was assessed during the dental appointment that preceded the tooth extraction, during the tooth extraction appointment, and in the subsequent dental appointment using the Venham Behavior Rating Scale. Statistical Analysis: Results were analyzed using the Pearson Chi-square and McNemar tests. Results: Eighty-nine children were included. Cooperative behavior prevailed in all the dental appointments. The prevalence of “mild/intense protest” was higher in the tooth extraction appointments than in the previous or subsequent dental appointments (P < 0.001. No significant differences in behavior were detected between the type of dentition (primary or permanent teeth, reason for extraction or gender. Conclusion: In this sample of children treated at a dental school, the occurrence of uncooperative behavior was higher during the tooth extraction appointments than in the preceding and subsequent dental appointments.

  20. Steam generator replacement from ALARA aspects

    International Nuclear Information System (INIS)

    Terry, I.; Breznik, B.

    2003-01-01

    This paper is going to consider radiological related parameters important for steam generator replacement (SGR) implementation. These parameters are identified as ALARA related parameters, owner-contractor relationship, planning, health physics with logistic services, and time required for the replacement. ALARA related parameters such as source or initial dose rate and plant system configuration define the initial conditions for the planning. There is room to optimise work planning. managerial procedures and also the staff during the implementation phase. The overview of these general considerations is based on the following background: using internationally available data and the experience of one of the vendors, i.e. Siemens-Framatome, and management experience of SG replacement which took place at Krsko NPP in the spring of 2000. Generally plant decisions on maintenance or repair procedures under radiation conditions take into account ALARA considerations. But in the main it is difficult to adjudge the results of an ALARA study, usually in the form of a collective dose estimate, because a comparison standard is missing. That is, very often the planned work is of a one-off nature so comparisons are not possible or the scopes are not the same. In such a case the collective doses for other types of work are looked at and a qualitative evaluation is made. In the case of steam generator replacement this is not the case. Over years of steam generator replacements world-wide a standard has been developed gradually. The first part of the following displays an overview of SGR and sets the Krsko SGR in perspective by applying dose analysis. The second part concentrates on the Krsko SGR itself and its ALARA aspects. (authors)

  1. Invisalign® treatment in the anterior region: were the predicted tooth movements achieved?

    Science.gov (United States)

    Krieger, Elena; Seiferth, Jörg; Marinello, Ivana; Jung, Britta A; Wriedt, Susanne; Jacobs, Collin; Wehrbein, Heinrich

    2012-09-01

    Based on our previous pilot study, the objective of this extended study was to compare (a) casts to their corresponding digital ClinCheck® models at baseline and (b) the tooth movement achieved at the end of aligner therapy (Invisalign®) to the predicted movement in the anterior region. Pre- and post-treatment casts as well as initial and final ClinChecks® models of 50 patients (15-63 years of age) were analyzed. All patients were treated with Invisalign® (Align Technology, Santa Clara, CA, USA). Evaluated parameters were: upper/lower anterior arch length and intercanine distance, overjet, overbite, dental midline shift, and the irregularity index according to Little. The comparison achieved/predicted tooth movement was tested for equivalence [adjusted 98.57% confidence interval (- 1.00; + 1.00)]. Before treatment the anterior crowding, according to Little, was on average 5.39 mm (minimum 1.50 mm, maximum 14.50 mm) in the upper dentition and 5.96 mm (minimum 2.00 mm, maximum 11.50 mm) in the lower dentition. After treatment the values were reduced to 1.57 mm (minimum 0 mm, maximum 4.5 mm) in the maxilla and 0.82 mm (minimum 0 mm, maximum 2.50 mm) in the mandible. We found slight deviations between pretreatment casts and initialClinCheck® ranging on average from -0.08 mm (SD ± 0.29) for the overjet and up to -0.28 mm (SD ± 0.46) for the upper anterior arch length. The difference between achieved/predicted tooth movements ranged on average from 0.01 mm (SD ± 0.48) for the lower anterior arch length, up to 0.7 mm (SD ± 0.87) for the overbite. All parameters were significantly equivalent except for the overbite (-1.02; -0.39). Performed with aligners (Invisalign®), the resolvement of the partly severe anterior crowding was successfully accomplished. Resolving lower anterior crowding by protrusion of the anterior teeth (i.e., enlargement of the anterior arch length) seems well predictable. The initial ClinCheck® models provided high accuracy compared to the

  2. Tooth contact analysis of spur gears. Part 1-SAM analysis of standard gears

    Directory of Open Access Journals (Sweden)

    Creţu Spiridon

    2017-01-01

    Full Text Available The involute gears are sensitive to the misalignment of their axes which determines transmission errors and perturbations of pressures distributions along the tooth flank. The concentrated contacts in gears are no longer as Hertz type. A semi-analytical method was developed to find the contact area, pressures distribution and depth stresses state. The matrix of initial separations is found analytically for standard and non-standard spur gears. The presence of misalignment as well as the flank crowning and flank end relief are included in the numerical analysis process.

  3. Tooth contact analysis of spur gears. Part 2-Analysis of modified gears

    Directory of Open Access Journals (Sweden)

    Pop Nicolae

    2017-01-01

    Full Text Available The misalignment between gears axes or direction deviations of teeth leads accentuate the edge effect, Modified spur gears which localize the initial bearing contact by proper modifications of the lead profile are used to avoid the development of the edge effect. A semi-analytical method was involved to find the contact area, pressures distribution and depth stresses states for the standard gears and gears with modified lead profile. The lead modifications concerned the crowning of the flank surface and the end relieving of the tooth flanks, both being applied to the pinion teeth only.

  4. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events.

    Science.gov (United States)

    Feller, Liviu; Khammissa, Razia A G; Thomadakis, George; Fourie, Jeanine; Lemmer, Johan

    2016-01-01

    Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption.

  5. Apical External Root Resorption and Repair in Orthodontic Tooth Movement: Biological Events

    Directory of Open Access Journals (Sweden)

    Liviu Feller

    2016-01-01

    Full Text Available Some degree of external root resorption is a frequent, unpredictable, and unavoidable consequence of orthodontic tooth movement mediated by odontoclasts/cementoclasts originating from circulating precursor cells in the periodontal ligament. Its pathogenesis involves mechanical forces initiating complex interactions between signalling pathways activated by various biological agents. Resorption of cementum is regulated by mechanisms similar to those controlling osteoclastogenesis and bone resorption. Following root resorption there is repair by cellular cementum, but factors mediating the transition from resorption to repair are not clear. In this paper we review some of the biological events associated with orthodontically induced external root resorption.

  6. A fixed partial appliance approach towards treatment of anterior single tooth crossbite: Report of two cases

    Directory of Open Access Journals (Sweden)

    M Gawthaman

    2017-01-01

    Full Text Available Crossbite can be treated using both removable and fixed appliances. This paper describes the report of two cases by a method of treating anterior single tooth in crossbite which is locked out of arch form with a simple fixed partial appliance. Orthodontic treatment was initiated by creating space for the locked out incisor using open coil spring and further corrected using MBT brackets and nitinol archwire for alignment. Treatment goals were achieved, and esthetics and occlusion were maintained postoperatively. Treatment objectives were obtained within a short duration using this technique, and there was an improvement in patients' smile.

  7. Development of Plastic Gear for Power Transmission : Abnormal Wear on the Tooth Root and Tooth Fracture near Pitch Point

    OpenAIRE

    Terashima, Kenichi; Tsukamoto, Naohisa; Nishida, Noriteru; Shi, Jiasun

    1986-01-01

    Plastic gears have many excellent characteristics which are locking in metallic gears, such as corrosion resistance, self-lubrication, quiet running, and so forth. The meshing behavior of plastic gears is very different from that of metallic gears. Therefore, the life estimation is very difficult for plastic gears. In this paper, generating and growing mechanisms of abnormal wear which appears fatally near the root of plastic tooth are analyzed, and then it is clarified that tooth fractures w...

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Yong-Wook Cho

    2014-02-01

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

  10. Cellular and molecular basis of tooth eruption

    Science.gov (United States)

    Wise, GE

    2009-01-01

    Objectives Tooth eruption requires the presence of a dental follicle (DF), alveolar bone resorption for an eruption pathway, and alveolar bone formation at the base of the bony crypt. The objectives of our investigations have been to determine how the DF regulates both the osteoclastogenesis and osteogenesis needed for eruption. Material & Methods Multiple experimental methods have been employed. Results The DF regulates osteoclastogenesis and osteogenesis by regulating the expression of critical genes in both a chronological and spatial fashion. In the rat 1st mandibular molar there is a major burst of osteoclastogenesis at day 3 postnatally and a minor burst at day 10. At day 3, the DF maximally expresses colony-stimulating factor-1 (CSF-1) to down-regulate the expression of osteoprotegerin such that osteoclastogenesis can occur. At day 10, the minor burst of osteoclastogenesis is promoted by upregulation of VEGF and RANKL in the DF. Spatially, the bone resorption is in the coronal portion of the bony crypt and genes such as RANKL are expressed more in the coronal region of the DF than in its basal one-half. For osteogenesis, bone formation begins at day 3 at the base of the bony crypt and maximal growth is at days 9–14. Osteo-inductive genes such as BMP-2 appear to promote this and are expressed more in the basal half of the DF than in the coronal. Conclusion The osteoclastogenesis and osteogenesis needed for eruption are regulated by differential gene expression in the DF both chronologically and spatially. PMID:19419449

  11. Periodontal Disease, Tooth Loss, and Cancer Risk.

    Science.gov (United States)

    Michaud, Dominique S; Fu, Zhuxuan; Shi, Jian; Chung, Mei

    2017-01-01

    Periodontal disease, which includes gingivitis and periodontitis, is highly prevalent in adults and disease severity increases with age. The relationship between periodontal disease and oral cancer has been examined for several decades, but there is increasing interest in the link between periodontal disease and overall cancer risk, with systemic inflammation serving as the main focus for biological plausibility. Numerous case-control studies have addressed the role of oral health in head and neck cancer, and several cohort studies have examined associations with other types of cancers over the past decade. For this review, we included studies that were identified from either 11 published reviews on this topic or an updated literature search on PubMed (between 2011 and July 2016). A total of 50 studies from 46 publications were included in this review. Meta-analyses were conducted on cohort and case-control studies separately when at least 4 studies could be included to determine summary estimates of the risk of cancer in relation to 1) periodontal disease or 2) tooth number (a surrogate marker of periodontal disease) with adjustment for smoking. Existing data provide support for a positive association between periodontal disease and risk of oral, lung, and pancreatic cancers; however, additional prospective studies are needed to better inform on the strength of these associations and to determine whether other cancers are associated with periodontal disease. Future studies should include sufficiently large sample sizes, improved measurements for periodontal disease, and thorough adjustment for smoking and other risk factors. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. The prevalence of deciduous tooth wear in six-year-old children and its relationship with potential explanatory factors.

    Science.gov (United States)

    Rios, Daniela; Magalhães, Ana Carolina; Honório, Heitor Marques; Buzalaf, Marília Afonso Rabelo; Lauris, José Roberto Pereira; Machado, Maria Aparecida Andrade Moreira

    2007-01-01

    To evaluate the prevalence and aetiological factors involved with wear of deciduous teeth. A convenience sample of 356 children (aged 6 years old) was selected at Bauru, SP (Brazil). Clinical examinations were carried out by 1 examiner (Kappa = 0.87), using the Tooth Wear Index (G0-G4). A questionnaire addressing the aetiological factors of tooth wear was applied to parents. Wear on the incisors was diagnosed in 34.8% of children (91.1% G1 and 6.4% G2); 78.1% presented wear in canines (64.7% G1 and 33.1% G2); and 40.7% in molars (89.6% G1 and 9.0% G2). No significant correlation was observed between gastro-oesophageal reflux, toothbrushing habits, or consumption of citrus fruits/soft drinks and the presence of tooth wear for all groups of teeth. The wear showed correlation with the presence of bruxism for canines and with the habit of holding drinks in the mouth before swallowing for incisors (Chi-square test, p < 0.05). The findings indicate that the wear of incisors could be considered physiological for this age. Further longitudinal studies should be conducted in order to measure the wear in canines and molars in the period close to their replacement by permanent teeth.

  13. Australia's replacement research reactor project

    International Nuclear Information System (INIS)

    Harris, K.J.

    1999-01-01

    HIFAR, a 10 MW tank type DIDO Class reactor has operated at the Lucas Heights Science and Technology Centre for 43 years. HIFAR and the 10 kW Argonaut reactor 'Moata' which is in the Care and Maintenance phase of decommissioning are Australia's only nuclear reactors. The initial purpose for HIFAR was for materials testing to support a nuclear power program. Changing community attitude through the 1970's and a Government decision not to proceed with a planned nuclear power reactor resulted in a reduction of materials testing activities and a greater emphasis being placed on neutron beam research and the production of radioisotopes, particularly for medical purposes. HIFAR is not fully capable of satisfying the expected increase in demand for medical radiopharmaceuticals beyond the next 5 years and the radial configuration of the beam tubes severely restricts the scope and efficiency of neutron beam research. In 1997 the Australian Government decided that a replacement research reactor should be built by the Australian Nuclear Science and Technology Organisation at Lucas Heights subject to favourable results of an Environmental Impact Study. The Ei identified no reasons on the grounds of safety, health, hazard or risk to prevent construction on the preferred site and it was decided in May 1999 that there were no environmental reasons why construction of the facility should not proceed. In recent years ANSTO has been reviewing the operation of HIFAR and observing international developments in reactor technology. Limitations in the flexibility and efficiency achievable in operation of a tank type reactor and the higher intrinsic safety sought in fundamental design resulted in an early decision that the replacement reactor must be a pool type having cleaner and higher intensity tangential neutron beams of wider energy range than those available from HIFAR. ANSTO has chosen to use it's own resources supported by specialised external knowledge and experience to identify

  14. Effect of light energy on peroxide tooth bleaching.

    Science.gov (United States)

    Luk, Karen; Tam, Laura; Hubert, Manfred

    2004-02-01

    Light-activated bleaching is a method of tooth whitening. The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources. The authors randomly assigned 250 extracted human teeth halves into experimental groups (n = 10). A placebo gel (control), a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light (control); a halogen curing light; an infrared, or IR, light; an argon laser; or a carbon dioxide, or CO2, laser. Color changes were evaluated immediately, one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer. The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer. Color and temperature changes were significantly affected by an interaction of the bleach and light variables. The application of lights significantly improved the whitening efficacy of some bleach materials, but it caused significant temperature increases in the outer and inner tooth surfaces. The IR and CO2 laser lights caused the highest tooth temperature increases. Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used, as well as the potential risks of heating teeth. A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching.

  15. Hip Replacement: MedlinePlus Health Topic

    Science.gov (United States)

    ... invasive hip replacement (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Hip Replacement updates ... replacement - precautions Minimally invasive hip replacement Related Health Topics Hip Injuries and Disorders National Institutes of Health ...

  16. Technique: imaging earliest tooth development in 3D using a silver-based tissue contrast agent.

    Science.gov (United States)

    Raj, Muhammad T; Prusinkiewicz, Martin; Cooper, David M L; George, Belev; Webb, M Adam; Boughner, Julia C

    2014-02-01

    Looking in microscopic detail at the 3D organization of initiating teeth within the embryonic jaw has long-proved technologically challenging because of the radio-translucency of these tiny un-mineralized oral tissues. Yet 3D image data showing changes in the physical relationships among developing tooth and jaw tissues are vital to understand the coordinated morphogenesis of vertebrate teeth and jaws as an animal grows and as species evolve. Here, we present a new synchrotron-based scanning solution to image odontogenesis in 3D and in histological detail using a silver-based contrast agent. We stained fixed, intact wild-type mice aged embryonic (E) day 10 to birth with 1% Protargol-S at 37°C for 12-32 hr. Specimens were scanned at 4-10 µm pixel size at 28 keV, just above the silver K-edge, using micro-computed tomography (µCT) at the Canadian Light Source synchrotron. Synchrotron µCT scans of silver-stained embryos showed even the earliest visible stages of tooth initiation, as well as many other tissue types and structures, in histological detail. Silver stain penetration was optimal for imaging structures in intact embryos E15 and younger. This silver stain method offers a powerful yet straightforward approach to visualize at high-resolution and in 3D the earliest stages of odontogenesis in situ, and demonstrates the important of studying the tooth organ in all three planes of view. Copyright © 2013 Wiley Periodicals, Inc.

  17. Rapid and selective removal of composite from tooth surfaces with a 9.3 µm CO2 laser using spectral feedback.

    Science.gov (United States)

    Chan, Kenneth H; Hirasuna, Krista; Fried, Daniel

    2011-09-01

    Dental composite restorative materials are color matched to the tooth and are difficult to remove by mechanical means without excessive removal or damage to peripheral enamel and dentin. Lasers are ideally suited for selective ablation to minimize healthy tissue loss when replacing existing restorations, sealants, or removing composite adhesives such as residual composite left after debonding orthodontic brackets. In this study, a carbon dioxide laser operating at 9.3-µm with a pulse duration of 10-20-microsecond and a pulse repetition rate of ∼200 Hz was integrated with a galvanometer based scanner and used to selectively remove composite from tooth surfaces. Spectra of the plume emission were acquired after each laser pulse and used to differentiate between the ablation of dental enamel or composite. Microthermocouples were used to monitor the temperature rise in the pulp chamber during composite removal. The composite was placed on tooth buccal and occlusal surfaces and the carbon dioxide laser beam was scanned across the surface to selectively remove the composite without excessive damage to the underlying sound enamel. The residual composite and the damage to the underlying enamel was evaluated using optical microscopy. The laser was able to rapidly remove composite from tooth buccal and occlusal surfaces with minimal damage to the underlying sound enamel and without excessive heat accumulation in the tooth. This study demonstrated that composite can be selectively removed from tooth surfaces at clinically relevant rates using a CO(2) laser operating at 9.3-µm with high pulse repetition rates with minimal heat deposition and damage to the underlying enamel. Copyright © 2011 Wiley-Liss, Inc.

  18. Transforming Normal Programs by Replacement

    NARCIS (Netherlands)

    Bossi, Annalisa; Pettorossi, A.; Cocco, Nicoletta; Etalle, Sandro

    1992-01-01

    The replacement transformation operation, already defined in [28], is studied wrt normal programs. We give applicability conditions able to ensure the correctness of the operation wrt Fitting's and Kunen's semantics. We show how replacement can mimic other transformation operations such as thinning,

  19. Minimally invasive aortic valve replacement

    DEFF Research Database (Denmark)

    Foghsgaard, Signe; Schmidt, Thomas Andersen; Kjaergard, Henrik K

    2009-01-01

    In this descriptive prospective study, we evaluate the outcomes of surgery in 98 patients who were scheduled to undergo minimally invasive aortic valve replacement. These patients were compared with a group of 50 patients who underwent scheduled aortic valve replacement through a full sternotomy...... operations were completed as mini-sternotomies, 4 died later of noncardiac causes. The aortic cross-clamp and perfusion times were significantly different across all groups (P replacement...... is an excellent operation in selected patients, but its true advantages over conventional aortic valve replacement (other than a smaller scar) await evaluation by means of randomized clinical trial. The "extended mini-aortic valve replacement" operation, on the other hand, is a risky procedure that should...

  20. Erosive and Mechanical Tooth Wear in Viking Age Icelanders.

    Science.gov (United States)

    Richter, Svend; Eliasson, Sigfus Thor

    2017-08-29

    (1) Background: The importance of the Icelandic Sagas as a source of information about diet habits in medieval Iceland, and possibly other Nordic countries, is obvious. Extensive tooth wear in archaeological material worldwide has revealed that the main cause of this wear is believed to have been a coarse diet. Near the volcano Hekla, 66 skeletons dated from before 1104 were excavated, and 49 skulls could be evaluated for tooth wear. The purpose of this study was to determine the main causes of tooth wear in light of diet and beverage consumption described in the Sagas; (2) Materials and methods: Two methods were used to evaluate tooth wear and seven for age estimation; (3) Results: Extensive tooth wear was seen in all of the groups, increasing with age. The first molars had the highest score, with no difference between sexes. These had all the similarities seen in wear from a coarse diet, but also presented with characteristics that are seen in erosion in modern Icelanders, through consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and was used for the preservation of food in Iceland, until fairly recently; (4) Conclusions: It is postulated that the consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear seen in ancient Icelanders.

  1. 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

  2. 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

  3. Canine tooth size and fitness in male mandrills (Mandrillus sphinx).

    Science.gov (United States)

    Leigh, Steven R; Setchell, Joanna M; Charpentier, Marie; Knapp, Leslie A; Wickings, E Jean

    2008-07-01

    Sexual selection theory explains the evolution of exaggerated male morphologies and weaponry, but the fitness consequences of developmental and age-related changes in these features remain poorly understood. This long-term study of mandrill monkeys (Mandrillus sphinx) demonstrates how age-related changes in canine tooth weaponry and adult canine size correlate closely with male lifetime reproductive success. Combining long-term demographic and morphometric data reveals that male fitness covaries simply and directly with canine ontogeny, adult maximum size, and wear. However, fitness is largely independent of other somatometrics. Male mandrills sire offspring almost exclusively when their canines exceed approximately 30 mm, or two-thirds of average adult value (45 mm). Moreover, sires have larger canines than nonsires. The tooth diminishes through wear as animals age, corresponding with, and perhaps influencing, reproductive senescence. These factors combine to constrain male reproductive opportunities to a brief timespan, defined by the period of maximum canine length. Sexually-selected weaponry, especially when it is nonrenewable like the primate canine tooth, is intimately tied to the male life course. Our analyses of this extremely dimorphic species indicate that sexual selection is closely intertwined with growth, development, and aging, pointing to new directions for sexual selection theory. Moreover, the primate canine tooth has potential as a simple mammalian system for testing genetically-based models of aging. Finally, the tooth may record details of life histories in fossil primates, especially when sexual selection has played a role in the evolution of dimorphism.

  4. 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.

  5. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

    International Nuclear Information System (INIS)

    Motazavi, Hamed; Bharvand, Maryam

    2016-01-01

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as 'jaw lesion', 'jaw disease', 'impacted tooth', and 'unerupted tooth'. More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs

  6. Australian aboriginal tooth succession, interproximal attrition, and Begg's theory.

    Science.gov (United States)

    Corruccini, R S

    1990-04-01

    In 1954, P.R. Begg analyzed interproximal attrition as a prehistorically universal mechanism to reduce tooth size. With modern processed diets and the virtual disappearance of constant interproximal attrition, Begg asserted, teeth remain too large for the arches and become crowded. Later investigators have questioned Begg's estimate of attritional tooth-size reduction, as well as aspects of his theory relating the succession sequence of permanent teeth to different malocclusions. The present paper examines the theory using longitudinal casts and records of modern Australian aborigines who are among the first generation lacking notable interproximal attrition thanks to a "modernized" diet. Deciduous and permanent tooth size, arch size, and occlusal relational variables were analyzed with respect to the expected occlusal outcomes in the absence of attritional tooth reduction. Permanent incisor overjet correlated with crowding status, as predicted by Begg. On the other hand, longer teeth did not relate to crowding in general nor to crowding in relevant local areas or during developmental stages. Unfavorable leeway space did not relate clearly to crowding or other malocclusions. Lowered correlations among structures and narrowness of the maxilla related more significantly to malocclusion. These results are in keeping with recent thinking that small jaws rather than large teeth underlie tooth/arch discrepancy.

  7. Monte Carlo modeling of human tooth optical coherence tomography imaging

    International Nuclear Information System (INIS)

    Shi, Boya; Meng, Zhuo; Wang, Longzhi; Liu, Tiegen

    2013-01-01

    We present a Monte Carlo model for optical coherence tomography (OCT) imaging of human tooth. The model is implemented by combining the simulation of a Gaussian beam with simulation for photon propagation in a two-layer human tooth model with non-parallel surfaces through a Monte Carlo method. The geometry and the optical parameters of the human tooth model are chosen on the basis of the experimental OCT images. The results show that the simulated OCT images are qualitatively consistent with the experimental ones. Using the model, we demonstrate the following: firstly, two types of photons contribute to the information of morphological features and noise in the OCT image of a human tooth, respectively. Secondly, the critical imaging depth of the tooth model is obtained, and it is found to decrease significantly with increasing mineral loss, simulated as different enamel scattering coefficients. Finally, the best focus position is located below and close to the dental surface by analysis of the effect of focus positions on the OCT signal and critical imaging depth. We anticipate that this modeling will become a powerful and accurate tool for a preliminary numerical study of the OCT technique on diseases of dental hard tissue in human teeth. (paper)

  8. Jaw lesions associated with impacted tooth: A radiographic diagnostic guide

    Energy Technology Data Exchange (ETDEWEB)

    Motazavi, Hamed; Bharvand, Maryam [Dept. of Oral Medicine, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-09-15

    This review article aimed to introduce a category of jaw lesions associated with impacted tooth. General search engines and specialized databases such as Google Scholar, PubMed, PubMed Central, MedLine Plus, Science Direct, Scopus, and well-recognized textbooks were used to find relevant studies using keywords such as 'jaw lesion', 'jaw disease', 'impacted tooth', and 'unerupted tooth'. More than 250 articles were found, of which approximately 80 were broadly relevant to the topic. We ultimately included 47 articles that were closely related to the topic of interest. When the relevant data were compiled, the following 10 lesions were identified as having a relationship with impacted tooth: dentigerous cysts, calcifying odontogenic cysts, unicystic (mural) ameloblastomas, ameloblastomas, ameloblastic fibromas, adenomatoid odontogenic tumors, keratocystic odontogenic tumors, calcifying epithelial odontogenic tumors, ameloblastic fibro-odontomas, and odontomas. When clinicians encounter a lesion associated with an impacted tooth, they should first consider these entities in the differential diagnosis. This will help dental practitioners make more accurate diagnoses and develop better treatment plans based on patients' radiographs.

  9. Elderly complete denture wearers: a social approach to tooth loss.

    Science.gov (United States)

    Papadaki, Eftychia; Anastassiadou, Vassiliki

    2012-06-01

    To correlate emotional reactions to tooth loss with denture satisfaction attributes in elderly complete denture wearers. Total tooth loss is a serious life event, and poor oral health has an impact on daily life. Edentulism treated by rehabilitation with dentures can have a positive effect on patients' self-image and social behaviour. A group of 80 edentulous subjects undergoing routine prosthetic care in a Greek Department of Prosthetic Dentistry were interviewed using two structured questionnaires. The first questionnaire explored reactions to tooth loss, whereas the second measured their subjective experience of complete dentures. The responses to both questionnaires were compared using the statistical package SPSS v.17. The results showed significant correlation between aspects of tooth loss experience and complete denture satisfaction. Despite the fact that a substantial proportion of patients were satisfied with their complete dentures, some patients experienced increased social and psychological problems related to their edentulousness and the wearing of complete dentures. The aesthetic and functional aspects of complete dentures affected both patients' social behaviour and self-confidence. Total tooth loss was not only reflected in patient's social behaviour and self-image, but it had a complex and multifaceted impact on satisfaction from complete dentures. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  10. Replaceable LMFBR core components

    International Nuclear Information System (INIS)

    Evans, E.A.; Cunningham, G.W.

    1976-01-01

    Much progress has been made in understanding material and component performance in the high temperature, fast neutron environment of the LMFBR. Current data have provided strong assurance that the initial core component lifetime objectives of FFTF and CRBR can be met. At the same time, this knowledge translates directly into the need for improved core designs that utilize improved materials and advanced fuels required to meet objectives of low doubling times and extended core component lifetimes. An industrial base for the manufacture of quality core components has been developed in the US, and all procurements for the first two core equivalents for FFTF will be completed this year. However, the problem of fabricating recycled plutonium while dramatically reducing fabrication costs, minimizing personnel exposure, and protecting public health and safety must be addressed

  11. Orthodontic buccal tooth movement by nickel-free titanium-based shape memory and superelastic alloy wire.

    Science.gov (United States)

    Suzuki, Akihiro; Kanetaka, Hiroyasu; Shimizu, Yoshinaka; Tomizuka, Ryo; Hosoda, Hideki; Miyazaki, Shuichi; Okuno, Osamu; Igarashi, Kaoru; Mitani, Hideo

    2006-11-01

    To examine the mechanical properties and the usefulness of titanium-niobium-aluminum (Ti-Nb-Al) wire in orthodontic tooth movement as compared with nickel-titanium (Ni-Ti) wire. The load deflection of expansion springs was gauged with an original jig. The gradient of the superelastic region was measured during the unloading process. Expansion springs comprising the two types of alloy wires were applied to upper first molars of rats. The distance between the first molars was measured with micrometer calipers. The force magnitude of the Ti-Nb-Al expansion spring was lower than that of the Ni-Ti expansion spring over the entire deflection range. The initial force magnitude and the gradient in the superelastic region of the Ti-Nb-Al expansion springs were half those of the Ni-Ti expansion springs. Thus, Ti-Nb-Al expansion springs generated lighter and more continuous force. Tooth movement in the Ni-Ti group proceeded in a stepwise fashion. On the other hand, tooth movement in the Ti-Nb-Al group showed relatively smooth and continuous progression. At 17 days after insertion of expansion springs, there were no significant differences between the Ti-Nb-Al and Ni-Ti groups in the amount of tooth movement. These results indicate that Ti-Nb-Al wire has excellent mechanical properties for smooth, continuous tooth movement and suggest that Ti-Nb-Al wire may be used as a practical nickel-free shape memory and superelastic alloy wire for orthodontic treatment as a substitute for Ni-Ti wire.

  12. Metabolism in tooth enamel and reliability of retrospective EPR dosimetry connected with Chernobyl accident

    International Nuclear Information System (INIS)

    Brik, A.; Radchuk, V.; Scherbina, O.; Matyash, M.; Gaver, O.

    1996-01-01

    It is shown that the results of retrospective EPR dosimetry by tooth enamel are essentially determined by the fact that tooth enamel is the mineral of biological origin. The structure of tooth enamel, properties of radiation defects and the role of metabolism in tooth enamel are discussed. It is shown that at deep metamorphic modifications tooth enamel don't save information about its radiation history. The reliability and accuracy of retrospective EPR dosimetry are discussed. Because after Chernobyl accident have passed 10 years the application of tooth enamel for reconstruction of doses which are connected with Chernobyl accident need care and additional investigations

  13. Anomalies of tooth formation in hypohidrotic ectodermal dysplasia

    DEFF Research Database (Denmark)

    Lexner, Michala O; Bardow, Allan; Hertz, Jens Michael

    2007-01-01

    OBJECTIVE: The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study is the fi......OBJECTIVE: The X-linked hypohidrotic ectodermal dysplasia (HED) is the most common type of ectodermal dysplasia. The clinical identification of possible heterozygous females can be difficult because of the varying degrees of clinical signs caused by X-chromosome inactivation. This study...... affected males had multiple missing permanent teeth and tooth malformations. The heterozygous females had a significantly higher frequency of agenesis of permanent teeth compared to normative data. The heterozygous females had an increased prevalence of tooth malformations and reduced tooth size...

  14. Functional fixation of autotransplanted tooth germs by using bioresorbable membranes.

    Science.gov (United States)

    Gérard, Eric; Membre, Hervé; Gaudy, Jean-François; Mahler, Patrick; Bravetti, Pierre

    2002-12-01

    The purpose of this study was to evaluate the contribution of a bioresorbable membrane placement to the healing of immature teeth after autotransplantation of tooth buds. Six cases were selected: 2 transplantations of wisdom teeth, 2 for premolar agenesis, 1 for ectopia, and 1 premolar in an incisor position. The crown of each tooth germ and the marginal alveolar bone were covered with a resorbable membrane. The radicular edification was nearly complete, neither ankylosis nor inflammatory resorption was observable, the pulp vitality was preserved, and the periodontal integration was identical to that of other teeth. The membrane ensured contention and stabilization of the transplant, allowed functional stimulation, permitted protection of the coagulum and periodontal cells, and kept the epithelium at a distance. The transplantations of immature teeth were improved by the use of a resorbable membrane, which caused an optimal functional fixation of the transplanted tooth.

  15. Computerized Analysis of Digital Photographs for Evaluation of Tooth Movement.

    Science.gov (United States)

    Toodehzaeim, Mohammad Hossein; Karandish, Maryam; Karandish, Mohammad Nabi

    2015-03-01

    Various methods have been introduced for evaluation of tooth movement in orthodontics. The challenge is to adopt the most accurate and most beneficial method for patients. This study was designed to introduce analysis of digital photographs with AutoCAD software as a method to evaluate tooth movement and assess the reliability of this method. Eighteen patients were evaluated in this study. Three intraoral digital images from the buccal view were captured from each patient in half an hour interval. All the photos were sent to AutoCAD software 2011, calibrated and the distance between canine and molar hooks were measured. The data was analyzed using intraclass correlation coefficient. Photographs were found to have high reliability coefficient (P > 0.05). The introduced method is an accurate, efficient and reliable method for evaluation of tooth movement.

  16. 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.

  17. In phantom dosimetric response of tooth enamel to neutrons

    International Nuclear Information System (INIS)

    Fattibene, P.; Angelone, M.; Pillon, M.; De Coste, V.

    2004-01-01

    Electron Paramagnetic Resonance dosimetry based on tooth enamel has one important application in dose reconstruction of nuclear plant workers, where the contribution of neutrons to individual dose is often important. Evaluation of tooth enamel response to neutrons is thus an important goal. A few experimental data at thermal and fast neutron energies are available. A first evaluation of the tooth enamel relative response to 60 Co in monoenergetic neutron flux of 2.8 and of 14 MeV, published elsewhere, has provided results apparently non-consistent with the results obtained at lower and higher energies. A comparison of those results in the 2.8 and 14 MeV beams with those available in the literature for other beams is reported and possible reasons for incongruities are discussed. Dose conversion factors of enamel to the water and air are also calculated and reported. (authors)

  18. Stability of interceptive/corrective orthodontic treatment for tooth ankylosis and Class II mandibular deficiency: A case report with 10 years follow-up

    OpenAIRE

    Carlos Henrique Guimarães; José Fernando Castanha Henriques; Guilherme Janson; Wilana S Moura

    2015-01-01

    The purpose of this article is to present the treatment of a 8-year-old boy with tooth ankylosis in teeth 85 and Class II division 1 malocclusion and to report a 10-year follow-up result. The patient was initially treated with a sagittal removable appliance, followed by an eruption guidance appliance and braces. The interceptive orthodontic treatment performed to recover the space lost by ankylosis of a deciduous tooth allowed a spontaneous eruption and prevented progression of the problem. T...

  19. Patients Unicondylar Knee Replacement vs. Total Knee Replacement

    OpenAIRE

    Hedra Eskander

    2017-01-01

    The aim of this review article is to analyse the clinical effectiveness of total knee replacement (TKR) compared to unicondylar knee replacement (UKR) on patients. In terms of survival rates, revision rates and postoperative complications. The keywords used were: knee arthroplasty. Nearly three thousand articles were found on 25 August 2016. Of those, only twenty-five were selected and reviewed because they were strictly focused on the topic of this article. Compared with those who have TKR, ...

  20. Generation of gear tooth surfaces by application of CNC machines

    Science.gov (United States)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  1. Three dimensional mathematical model of tooth for finite element analysis

    Directory of Open Access Journals (Sweden)

    Puškar Tatjana

    2010-01-01

    Full Text Available Introduction. The mathematical model of the abutment tooth is the starting point of the finite element analysis of stress and deformation of dental structures. The simplest and easiest way is to form a model according to the literature data of dimensions and morphological characteristics of teeth. Our method is based on forming 3D models using standard geometrical forms (objects in programmes for solid modeling. Objective. Forming the mathematical model of abutment of the second upper premolar for finite element analysis of stress and deformation of dental structures. Methods. The abutment tooth has a form of a complex geometric object. It is suitable for modeling in programs for solid modeling SolidWorks. After analyzing the literature data about the morphological characteristics of teeth, we started the modeling dividing the tooth (complex geometric body into simple geometric bodies (cylinder, cone, pyramid,.... Connecting simple geometric bodies together or substricting bodies from the basic body, we formed complex geometric body, tooth. The model is then transferred into Abaqus, a computational programme for finite element analysis. Transferring the data was done by standard file format for transferring 3D models ACIS SAT. Results. Using the programme for solid modeling SolidWorks, we developed three models of abutment of the second maxillary premolar: the model of the intact abutment, the model of the endodontically treated tooth with two remaining cavity walls and the model of the endodontically treated tooth with two remaining walls and inserted post. Conclusion Mathematical models of the abutment made according to the literature data are very similar with the real abutment and the simplifications are minimal. These models enable calculations of stress and deformation of the dental structures. The finite element analysis provides useful information in understanding biomechanical problems and gives guidance for clinical research.

  2. Root canal treatment of mandibular second premolar tooth with taurodontism

    Directory of Open Access Journals (Sweden)

    Vujašković Mirjana

    2008-01-01

    Full Text Available INTRODUCTION Taurodontism is a morphoanatomical change in the shape of a tooth. An enlarged body of a tooth with smaller than usual roots is a characteristic feature. Internal tooth anatomy correlates with this appearance, which means that a taurodontal tooth has a large pulp chamber and apically positioned furcations. This dental anomaly may be associated with different syndromes and congenital discoders. CASE OUTLINE The case report presents the patient of a rare case of taurodontism in the mandibular second premolar with chronic periodontitis. Endodontic treatment was performed after dental history and clinical examination. Special care is required in all segments of endodontic treatment of a taurodontal tooth from the identification orifice, canal exploration, determining working length, cleaning and shaping and obturation of the root canal. Precurved K-file was used for canal exploration and location of the furcation. One mesial and one distal canal with the buccal position were identified in the apical third of the root canal. The working lengths of two canals were determined by radiographic interpretation with two K-files in each canal and verified with the apex locator. During canal instrumentation, the third canal was located in the disto-lingual position. The working length of the third canal was established using the apex locator. CONCLUSION Thorough knowledge of tooth anatomy and its variations can lead to lower percentage of endodontic failure. Each clinical case involving these teeth should be investigated carefully, clinically and radiographically to detect additional root canals. High quality radiographs from different angles and proper instrumentarium improve the quality of endodontic procedure.

  3. Mesenchymal stem cell-mediated functional tooth regeneration in swine.

    Directory of Open Access Journals (Sweden)

    Wataru Sonoyama

    2006-12-01

    Full Text Available Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla. Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance.

  4. Resection of the Tooth Apex with Diode Laser

    Directory of Open Access Journals (Sweden)

    Uzunov Tz.

    2014-06-01

    Full Text Available An “in vitro” experimental study has been carried out on 70 extracted teeth. A laser resection of the root apex has been carried out with diode laser beam with a wavelength of - 810 ± 10 nm. Sequentially a radiation with increasing power has been applied, as follows: 1,3 W, 2W, 3W, 4W, 5W, 6W, 7W, in electro surgery mode. Successful resection of the tooth apex has been performed at: 3W; 4W; 5W; 6W and 7W power. It was established that when laser resected the tooth apex carbonizes.

  5. Tooth enamel sample preparation using alkaline treatment in ESR dosimetry

    International Nuclear Information System (INIS)

    Yongzeng, Zhou; Jiadong, Wang; Xiaomei, Jia; Ke, Wu; Jianbo, Cong

    2002-01-01

    Tooth enamel sample preparation using alkaline treatment was studied and compared with traditional mechanical method in this paper. 20 adult teeth were used. Samples were placed into NaOH solution. This method requires 4-5 weeks and the enamel was separated from dentin. Experimental results show that 8M NaOH was appropriate for separating enamel from dentin and that there is no difference in background signal relative intensity between samples prepared by mechanical and by chemical methods. There is also no difference in radiosensitivity between samples prepared by two methods mentioned above. Dose response curve for tooth enamel samples isolated by 8M NaOH solution was obtained

  6. 3D exemplar-based random walks for tooth segmentation from cone-beam computed tomography images

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Yuru, E-mail: peiyuru@cis.pku.edu.cn; Ai, Xingsheng; Zha, Hongbin [Department of Machine Intelligence, School of EECS, Peking University, Beijing 100871 (China); Xu, Tianmin [School of Stomatology, Stomatology Hospital, Peking University, Beijing 100081 (China); Ma, Gengyu [uSens, Inc., San Jose, California 95110 (United States)

    2016-09-15

    Purpose: Tooth segmentation is an essential step in acquiring patient-specific dental geometries from cone-beam computed tomography (CBCT) images. Tooth segmentation from CBCT images is still a challenging task considering the comparatively low image quality caused by the limited radiation dose, as well as structural ambiguities from intercuspation and nearby alveolar bones. The goal of this paper is to present and discuss the latest accomplishments in semisupervised tooth segmentation with adaptive 3D shape constraints. Methods: The authors propose a 3D exemplar-based random walk method of tooth segmentation from CBCT images. The proposed method integrates semisupervised label propagation and regularization by 3D exemplar registration. To begin with, the pure random walk method is to get an initial segmentation of the teeth, which tends to be erroneous because of the structural ambiguity of CBCT images. And then, as an iterative refinement, the authors conduct a regularization by using 3D exemplar registration, as well as label propagation by random walks with soft constraints, to improve the tooth segmentation. In the first stage of the iteration, 3D exemplars with well-defined topologies are adapted to fit the tooth contours, which are obtained from the random walks based segmentation. The soft constraints on voxel labeling are defined by shape-based foreground dentine probability acquired by the exemplar registration, as well as the appearance-based probability from a support vector machine (SVM) classifier. In the second stage, the labels of the volume-of-interest (VOI) are updated by the random walks with soft constraints. The two stages are optimized iteratively. Instead of the one-shot label propagation in the VOI, an iterative refinement process can achieve a reliable tooth segmentation by virtue of exemplar-based random walks with adaptive soft constraints. Results: The proposed method was applied for tooth segmentation of twenty clinically captured CBCT

  7. Esthetic enhancement of a traumatized anterior tooth with a combination of forced eruption and tooth alignment: a case report

    Science.gov (United States)

    Kang, So-Hee; Jin, Myoung-Uk; Kim, Sung-Kyo

    2016-01-01

    Exposing sound structure of a subgingivally fractured tooth using orthodontic extrusion is considered to be a conservative way to re-establish biologic width without sacrificing esthetics or jeopardizing periodontal support of neighboring teeth. When a misaligned tooth is traumatically involved, a more comprehensive approach combining tooth extrusion and re-alignment may be necessary for a successful restorative outcome. This case report describes a successful esthetic management of a patient with complicated crown-root fracture on the maxillary right central incisor and pre-existing malocclusion in the maxillary anterior region. Forced eruption along with re-alignment of teeth by orthodontic movement seems to allow re-positioning of the fracture line to a favorable position and correction of crowding, providing a better esthetic result. PMID:27508163

  8. Slab replacement maturity guidelines : [summary].

    Science.gov (United States)

    2014-04-01

    Concrete sets in hours at moderate temperatures, : but the bonds that make concrete strong continue : to mature over days to years. However, for : replacement concrete slabs on highways, it is : crucial that concrete develop enough strength : within ...

  9. Prolonged Intermittent Renal Replacement Therapy.

    Science.gov (United States)

    Edrees, Fahad; Li, Tingting; Vijayan, Anitha

    2016-05-01

    Prolonged intermittent renal replacement therapy (PIRRT) is becoming an increasingly popular alternative to continuous renal replacement therapy in critically ill patients with acute kidney injury. There are significant practice variations in the provision of PIRRT across institutions, with respect to prescription, technology, and delivery of therapy. Clinical trials have generally demonstrated that PIRRT is non-inferior to continuous renal replacement therapy regarding patient outcomes. PIRRT offers cost-effective renal replacement therapy along with other advantages such as early patient mobilization and decreased nursing time. However, due to lack of standardization of the procedure, PIRRT still poses significant challenges, especially pertaining to appropriate drug dosing. Future guidelines and clinical trials should work toward developing consensus definitions for PIRRT and ensure optimal delivery of therapy. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  10. Is gingival recession a consequence of an orthodontic tooth size and/or tooth position discrepancy? "A paradigm shift".

    Science.gov (United States)

    Richman, Colin

    2011-01-01

    Gingival recession (GR) is a commonly observed dental lesion. The underlying etiology has not been clearly identified, although several theories have been suggested. Tooth crowding or tooth malalignment is also frequently observed, with both conditions appearing to be more prevalent in developed countries with heterogeneous populations. A total of 25 consecutively treated patients representing 72 teeth and demonstrating facial clinical GR of > 3 mm were examined clinically, photographically, and with 3-dimensional radiology using conebeam computed tomography. All examined teeth presented with normal interproximal probing depths and attachment levels (teeth demonstrating > 3 mm of GR presented with significantly prominent facial tooth contours and associated alveolar bone dehiscences. Most involved teeth presented with their root structures extending beyond the facial alveolar bony housing (fenestrations). This represents a discrepancy between tooth size and alveolar bone dimensions in the buccolingual, axial, and sagittal orientation. Fewer involved teeth were malpositioned toward the buccal aspect. Both conditions were associated with facial alveolar bone dehiscences and associated GR. This study suggests tooth volume and/or tooth position within the alveolar bony housing strongly correlate with GR. All nonperiodontitis-involved teeth with GR were associated with either wider teeth or facially aligned teeth. However, it is emphasized that all facially aligned teeth, or "larger" teeth, do not necessarily present with GR. Based on these findings, the radiographic-supporting bone index is proposed. This index should facilitate appropriate evaluation of the alveolar bone supporting the mucogingival complex, both on the facial and lingual aspect of teeth. Further investigations are needed to support these preliminary data.

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

    Science.gov (United States)

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

    1998-03-01

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

  12. Hyperglycemia and xerostomia are key determinants of tooth decay in type 1 diabetic mice.

    Science.gov (United States)

    Yeh, Chih-Ko; Harris, Stephen E; Mohan, Sumathy; Horn, Diane; Fajardo, Roberto; Chun, Yong-Hee Patricia; Jorgensen, James; Macdougall, Mary; Abboud-Werner, Sherry

    2012-06-01

    Insulin-dependent type 1 diabetes mellitus (DM) and oral diseases are closely interrelated. Poor metabolic control in diabetics is associated with a high risk of gingivitis, periodontitis and tooth loss. Salivary flow declines in diabetics and patients suffer from xerostomia. Reduced saliva predisposes to enamel hypomineralization and caries formation; however, the mechanisms that initiate and lead to progression of tooth decay and periodontitis in type 1 DM have not been explored. To address this issue, we analyzed tooth morphology in Akita ⁻/⁻ mice that harbor a point mutation in the Ins2 insulin gene, which leads to progressive hyperglycemia. Mandibles from Akita ⁻/⁻ and wild-type littermates were analyzed by microCT, scanning EM and histology; teeth were examined for amelogenin (Amel) and ameloblastin (Ambn) expression. Mice were injected with pilocarpine to assess saliva production. As hyperglycemia may alter pulp repair, the effect of high glucose levels on the proliferation/differentiation of cultured MD10-F2 pulp cells was also analyzed. Results showed that Akita ⁻/⁻ mice at 6 weeks of age showed chalky white incisors that correlated with marked hyperglycemia and impaired saliva production. MicroCT of Akita ⁻/⁻ teeth revealed excessive enamel wearing and hypomineralization; immunostaining for Amel and Ambn was decreased. A striking feature was invasion of dentinal tubules with Streptococcus mitis and microabcesses that originated in the coronal pulp and progressed to pulp necrosis and periapical periodontitis. High levels of glucose also inhibited MD10-F2 cell proliferation and differentiation. Our findings provide the first evidence that hyperglycemia in combination with reduced saliva in a model of type1 DM leads to decreased enamel mineralization/matrix proteins and predisposes to excessive wearing and decay. Importantly, hyperglycemia adversely affects enamel matrix proteins and pulp repair. Early detection and treatment of hyperglycemia

  13. Effects of different preparation procedures during tooth whitening on enamel bonding.

    Science.gov (United States)

    Wilson, Dustin; Xu, Changqi; Hong, Liang; Wang, Yong

    2009-04-01

    The objective of this study was to assess effects of some clinically related preparation procedures during tooth whitening on enamel bonding properties. Sixty-two extracted human teeth were cleaned and divided into four groups. Forty-two of the teeth were left with their natural surface intact while 20 teeth were polished to form a flat surface. Half of the tooth served as the experimental side and received one of the two whitening products: Opalescence (10% carbamide peroxide) and Crest Whitestrips (6.5% hydrogen peroxide), for 2 weeks. Post-bleaching intervals included: 1 day, 1 week, and 2 weeks. On these days, tooth (10 mm x 1.5 mm x 1.5 mm) sections were evaluated using Raman spectroscopy, scanning electron microscopy and tensile bond strength tests. T-test, ANOVA test, and mixed model regression analysis were used to assess the differences. No significant difference existed between natural surface and polished surface teeth for all groups at both Day One and Week Two (P > 0.05). On Day One, both treated groups had significant lower bond strength than the control group (P = 0.002). After 2 weeks, no significant difference existed between any group (P = 0.381). SEM indicated that resin-enamel interfaces in bleached enamel exhibited more defects in granular formations when compared to the control. Raman results indicated a lower degree of polymerization (DP) of adhesive at the interface for treated teeth surfaces. In summary, pre-bleaching surface treatments such as polish or non-polish, had no effect on bond strength. Bleaching significantly decreased bond strength initially, but after 2 weeks, bleaching had no significant effect on bond strength. Storage time had significant effect on Opalescence treated enamel, but not on control and Whitestrip treated enamel. The decrease of bond strength may be related to interfacial defects and low DP due to oxygen release after bleaching.

  14. Replacement of sub-systems

    International Nuclear Information System (INIS)

    Rosen, S.E.

    1992-01-01

    This paper describes a number of quality aspects related to replacement of important systems or components in a nuclear power station. Reference is given to the steam generator replacement and power uprating performed at Ringhals 2 in Sweden in 1989. Since quality is a wide concept there has been put special emphasis in this paper to the important aspects that traditionally are not connected to quality. (author) 1 fig

  15. [Dynamics of tooth decay prevalence in children receiving long-term preventive program in school dental facilities].

    Science.gov (United States)

    Avraamova, O G; Kulazhenko, T V; Gabitova, K F

    2016-01-01

    The paper presents the assessment of tooth decay prevalence in clinically homogenous groups of children receiving long-term preventive program (PP) in school dental facilities. Five-years PP were introduced in clinical practice in 2 Moscow schools. Preventive treatment was performed by dental hygienist. The results show that systematic preventive treatment in school dental offices starting from elementary school allows reducing dental caries incidence 46-53% and stabilize the incidence of caries complications. It should be mentioned though that analysis of individualized outcomes proves heterogeneity of study results despite of equal conditions of PP. Potentially significant hence is early diagnostics and treatment of initial caries forms as demineralization foci, especially in children with intensive tooth decay. Optimization of pediatric dentist and dental hygienist activity in school dental facilities is the main factor of caries prevention efficiency.

  16. Feeder replacement tooling and processes

    International Nuclear Information System (INIS)

    Mallozzi, R.; Goslin, R.; Pink, D.; Askari, A.

    2008-01-01

    Primary heat transport system feeder integrity has become a concern at some CANDU nuclear plants as a result of thinning caused by flow accelerated corrosion (FAC). Feeder inspections are indicating that life-limiting wall thinning can occur in the region between the Grayloc hub weld and second elbow of some outlet feeders. In some cases it has become necessary to replace thinned sections of affected feeders to restore feeder integrity to planned end of life. Atomic Energy of Canada Limited (AECL) and Babcock and Wilcox Canada Ltd. (B and W) have developed a new capability for replacement of single feeders at any location on the reactor face without impacting or interrupting operation of neighbouring feeders. This new capability consists of deploying trained crews with specialized tools and procedures for feeder replacements during planned outages. As may be expected, performing single feeder replacement in the congested working environment of an operational CANDU reactor face involves overcoming many challenges with respect to access to feeders, available clearances for tooling, and tooling operation and performance. This paper describes some of the challenges encountered during single feeder replacements and actions being taken by AECL and B and W to promote continuous improvement of feeder replacement tooling and processes and ensure well-executed outages. (author)

  17. Associations between the number of natural teeth in postmenopausal women and hormone replacement therapy.

    Science.gov (United States)

    Han, Kyungdo; Ko, Youngkyung; Park, Yong-Gyu; Park, Jun-Beom

    2016-12-01

    Increasing research suggests that periodontal status is associated with hormone replacement therapy in postmenopausal women. This study was performed to assess the relationship between the number of natural teeth and ever use of hormone replacement therapy in postmenopausal women using nationally representative Korean data. Data from the Korea National Health and Nutrition Examination Survey between 2010 and 2012 were used, and the analysis in this study was confined to a total of 4869 respondents over 19 years old who had gone through menopause and who had no missing data for the reproductive factors and outcome variables in that study. The total number of natural teeth was then calculated after excluding third molars. The time of day when tooth brushing was done was recorded as representative oral health behavior. Multiple logistic regression analyses were used to assess association between the number of natural teeth and the use of hormone replacement therapy. Among participants who had ever used hormone replacement therapy, the proportions (percentage and standard error) with no teeth, 1-9 teeth, 10-19 teeth, 20-27 teeth, and 28 teeth were 5.0±2.4%, 6.7±1.4%, 12.5±1.7%, 18.9±1.0%, and 20.7±1.6%, respectively (Preplacement therapy, after adjustments. The analysis revealed that the use of hormone replacement therapy by postmenopausal women showed positive effects for retention of natural teeth. Lack of hormone replacement therapy may be considered to be an independent risk indicator for tooth loss in Korean postmenopausal women. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Restoration of noncarious tooth defects by dentists in The Dental Practice-Based Research Network

    DEFF Research Database (Denmark)

    Nascimento, Marcelle M; Gordan, Valeria V; Qvist, Vibeke

    2011-01-01

    The authors conducted a study to quantify the reasons for restoring noncarious tooth defects (NCTDs) by dentists in The Dental Practice-Based Research Network (DPBRN) and to assess the tooth, patient and dentist characteristics associated with those reasons....

  19. Accuracy of Invisalign® treatments in the anterior tooth region. First results.

    Science.gov (United States)

    Krieger, Elena; Seiferth, Jörg; Saric, Ivana; Jung, Britta A; Wehrbein, Heinrich

    2011-03-01

    To analyse (a) to what extent the pretreatment model at the beginning of the treatment corresponds to the initial position in the ClinCheck® and (b) to what extent the predicted treatment result corresponds to the actual result of the therapy at the end of the treatment. Pre- and posttreatment models as well as the initial and final position of the ClinCheck with a total of 35 patients aged between 15 and 59 were measured; all of whom were treated by using the Invisalign® technology (Invisalign®, Align Technology, S.C., Calif., USA). The measurement of the initial and final models was conducted by using an electronic digital calliper rule, i.e. that of ClinCheck® using the measurement tool ToothMeasure® of Invisalign® Software. The following parameters in the anterior region were measured: Overjet, Overbite, dental midline shift. Pretreament models and the initial ClinChecks® revealed slight deviations in the parameters overjet 0.08 mm (standard deviation (SD) 0.3), overbite 0.3 mm (SD 0.4) and dental midline deviation 0.1mm (SD 0.4). The final model and the final ClinCheck® revealed larger deviations: the differences for the Overjet were on average 0.4 mm (SD 0.7), Overbite 0.9 mm (SD 0.9) and dental midline shift 0.4 mm (SD 0.5). The IT-based transmission of mal-aligned teeth into the ClinCheck® presentation provides sufficiently good accuracy. Tooth corrections in the vertical plane were more difficult to realize. A vertical overcorrection in the final ClinCheck®, a case refinement at the end of the treatment or additional measures (e.g. horizontal beveled attachments or vertical elastics) seems useful to achieve the individually intended therapeutic goal.

  20. Technical Modifications of Tooth-borne Distraction Device for Anterior Maxillary Distraction in Cleft Patients

    Directory of Open Access Journals (Sweden)

    Dhivakar Selvaraj

    2014-01-01

    Full Text Available The tooth-borne distractor gained popularity for anterior maxillary distraction because of the effective treatment outcome, no need for external fixation, noninvasive, less chewing difficulty, social tolerance and economical. Tooth-borne distractor device needs modification in terms of maxillary deficiency, tooth position, retained deciduous tooth, and fistula. Hence, we recommend the following modifications in certain circumstances for the successful treatment outcome.

  1. The annual frequency of root fillings, tooth extractions and pulp-related procedures in Danish adults during 1977-2003

    DEFF Research Database (Denmark)

    Bjørndal, L.; Reit, C.

    2004-01-01

    endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions......endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions...

  2. The Impact of the Eda Pathway on Tooth Root Development.

    Czech Academy of Sciences Publication Activity Database

    Fons Romero, J.M.; Star, H.; Lav, R.; Watkins, S.; Harrison, M.; Hovořáková, Mária; Headon, D.; Tucker, Abigail

    2017-01-01

    Roč. 96, č. 11 (2017), s. 1290-1297 ISSN 0022-0345 R&D Projects: GA ČR(CZ) GB14-37368G Institutional support: RVO:68378041 Keywords : tooth * ectodermal dysplasia * epithelium Subject RIV: EA - Cell Biology OBOR OECD: Developmental biology Impact factor: 4.755, year: 2016

  3. Patient Discomfort Following Single-Tooth Implant Placement

    DEFF Research Database (Denmark)

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

    2014-01-01

    scores for pain and swelling decreased continuously over the time period in both groups. Conclusions: The longer treatment time in IR didn't increase patients' perception of pain, bleeding and swelling, compared to CR. The impact of immediate tooth restoration on patients' esthetic outcome should...

  4. Diagnostics of power transmissions system with tooth gear

    Directory of Open Access Journals (Sweden)

    Grzegorz WOJNAR

    2008-01-01

    Full Text Available This paper presents results of laboratory tests that were aimed at detecting early stages of various faults in toothed wheels by measurement and analysis of transverse vibration speed of the transmission gear shafts. In experimental investigation, cracking of the root tooth and chipping of the tooth were detected. The laser vibrometer Ometron VH300+ was used for non-contact measurement of shaft transversal vibration speed. Gear vibrations were recorded in selected points of gear housing and gear shafts at different speeds and gear loads. Results were analyzed and compared but in this paper is presented only selected examples. This paper shows that on the basis of the transverse vibration speed of transmission gear shafts, it is possible to detect defects at an earlier stage than on the basis of the housing vibration accelerations. In the case of measuring gear shaft vibration velocity, the way of the signal generated by the defect of a gear wheel (or bearing is shortened as well as the influence of composed transmittance of the bearing-gear housing system is eliminated. WV time-frequency analysis and complex continuous wavelet transformations were used for detection. The authors introduced a measure of local tooth damage, which was proportional to the size of damage. The results of research presented in this paperconfirmed that the defect's measure is very sensitive to the development of teeth faults.

  5. Smokeless tobacco use, tooth loss and oral health issues among ...

    African Journals Online (AJOL)

    Background: Tobacco use in smokeless and smoked forms is preventable cause of mortality and morbidity worldwide. Objective: To determine the prevalence of smokeless tobacco use and the association with tooth loss and oral health problems among adults in Cameroon. Methods: Adults dwelling in the Fokoue area of ...

  6. Treatment of Necrotic Calcified Tooth Using Intentional Replantation Procedure

    Directory of Open Access Journals (Sweden)

    Nima Moradi Majd

    2014-01-01

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

  7. Graphene-based Wireless Bacteria Detection on Tooth Enamel

    Science.gov (United States)

    2012-05-27

    to reproduce , publish, or otherwise use the work for Federal purposes, and to authroize others to do so (DODGARS §32.36). The views, opinions and...2004). 4. Neat, M. L., Peacock , R. & Brittain, R. T. Implantation of electrodes in the dentine of an upper canine tooth in the dog. Br. J. Pharmacol

  8. Apical Revascularization after Delayed Tooth Replantation: An Unusual Case

    Directory of Open Access Journals (Sweden)

    Marília Pacífico Lucisano

    2016-01-01

    Full Text Available The aim of this paper is to present the clinical and radiological outcome of the treatment involving a delayed tooth replantation after an avulsed immature permanent incisor, with a follow-up of 1 year and 6 months. An 8-year-old boy was referred after dental trauma that occurred on the previous day. The permanent maxillary right central incisor (tooth 11 had been avulsed. The tooth was hand-held during endodontic therapy and an intracanal medication application with calcium hydroxide-based paste was performed. An apical plug with mineral trioxide aggregate (MTA was introduced into the apical portion of the canal. When the avulsed tooth was replanted with digital pressure, a blood clot had formed within the socket, which moved the MTA apical plug about 2 mm inside of the root canal. These procedures developed apical revascularization, which promoted a successful endodontic outcome, evidenced by apical closure, slight increase in root length, and absence of signs of external root resorption, during a follow-up of 1 year and 6 months.

  9. An interdisciplinary approach to treat crown‑root‑fractured tooth ...

    African Journals Online (AJOL)

    Restoration of a crown‑root subgingival fractured tooth, especially at anterior aesthetic zones is still a great challenge for restorative dentists. Crown lengthening procedure alone has the disadvantage of high gingival curve of the final restoration, which was not discontinuous to adjacent teeth and thus compromise cosmetic ...

  10. Rare and Common Variants Conferring Risk of Tooth Agenesis

    DEFF Research Database (Denmark)

    Jonsson, L; Magnusson, T E; Thordarson, A

    2018-01-01

    We present association results from a large genome-wide association study of tooth agenesis (TA) as well as selective TA, including 1,944 subjects with congenitally missing teeth, excluding third molars, and 338,554 controls, all of European ancestry. We also tested the association of previously ...

  11. Seasonality, behaviour and philopatry of spotted ragged-tooth ...

    African Journals Online (AJOL)

    Spotted ragged-tooth sharks Carcharias taurus occur along the southern and eastern coasts of South Africa. We report on movements of juveniles and adults within a known nursery area on the Eastern Cape coast using acoustic telemetry. The focus area of the study was Algoa Bay, where six VEMCO VR2 ultrasonic ...

  12. Focal hyalinization during experimental tooth movement in beagle dogs.

    NARCIS (Netherlands)

    Böhl, Martina von; Maltha, J.C.; Hoff, J.W. Von den; Kuijpers-Jagtman, A.M.

    2004-01-01

    The aim was to study morphological differences between the periodontal structures of beagle dogs showing different rates of tooth movement under identical experimental conditions. An orthodontic appliance was placed on the mandibular second premolar and the first molar to exert a continuous and

  13. Functional convergence in bat and toothed whale biosonars

    DEFF Research Database (Denmark)

    Madsen, P T; Surlykke, A

    2013-01-01

    Echolocating bats and toothed whales hunt and navigate by emission of sound pulses and analysis of returning echoes to form a self-generated auditory scene. Here, we demonstrate a striking functional convergence in the way these two groups of mammals independently evolved the capability to sense ...

  14. Tooth Bleaching: Current Concepts of the Procedure in Cosmetic ...

    African Journals Online (AJOL)

    Less caustic agents more recently introduced, in the late 1900s, have revived the interest of the dental profession in the art of tooth bleaching. These agents are now being packaged as bleaching kits, which may be used for in-office bleaching by the dentist or used at home by the patient under the supervision of the dentist.

  15. Tetracycline tooth discolouration in Benin City | Sede | Journal of ...

    African Journals Online (AJOL)

    Journal of Medicine and Biomedical Research ... This retrospective study was conducted to examine the incidence and pattern of tetracycline-related tooth discolouration in patients seen at the restorative dental clinic of ... These patients accounted for 2.2% of the 3750 patients that were seen during the period under review.

  16. Tooth loss strongly associates with malnutrition in chronic kidney disease.

    Science.gov (United States)

    Ioannidou, E; Swede, H; Fares, G; Himmelfarb, J

    2014-07-01

    In chronic kidney disease (CKD), inadequate nutritional intake, inflammation, and increased oxidative stress have been the major contributing factors in malnutrition pathogenesis. However, there is still a paucity of evidence assessing the magnitude of the effect of tooth loss on malnutrition in CKD populations. The authors hypothesize that among patients with CKD, tooth loss may affect nutritional status, using the National Health and Nutrition Examination Survey 1988 to 1994 (NHANES III). Glomerular filtration rate (GFR) was estimated based on cystatin C levels using the relevant equation. Urinary albumin-to-creatinine ratio (albuminuria) was calculated in milligrams per gram with a cutoff point of 30 mg/g. CKD was defined based on estimated GFR protein and caloric intake (P = 0.02 and 0.01, respectively). Serum albumin reached a frequency peak in the fully edentulous group without dentures (group 4, 19.2%). In the same group, individuals had lower protein (30.1%) and caloric intake (30.2%) (P = 0.01 and 0.02, respectively). Furthermore, logistic regression analysis confirmed the significant role of tooth loss on serum albumin and protein and energy intake in this population even after adjusting for confounding variables. Tooth loss independently predicts low energy and protein intake, as well as serum albumin levels, biomarkers of malnutrition in CKD.

  17. Identification of a research protocol to study orthodontic tooth movement

    Directory of Open Access Journals (Sweden)

    Annalisa Dichicco

    2014-06-01

    Full Text Available Aim: The orthodontic movement is associated with a process of tissue remodeling together with the release of several chemical mediators in periodontal tissues. Each mediator is a potential marker of tooth movement and expresses biological processes as: tissue inflammation and bone remodeling. Different amounts of every mediator are present in several tissues and fluids of the oral cavity. Therefore, there are different methods that allow sampling with several degrees of invasiveness. Chemical mediators are also substances of different molecular nature, and multiple kind of analysis methods allow detection. The purpose of this study was to draft the best research protocol for an optimal study on orthodontic movement efficiency. Methods: An analysis of the international literature have been made, to identify the gold standard of each aspect of the protocol: type of mediator, source and method of sampling and analysis method. Results: From the analysis of the international literature was created an original research protocol for the study and the assessment of the orthodontic movement, by using the biomarkers of the tooth movement. Conclusions: The protocol created is based on the choice of the gold standard of every aspect already analyzed in the literature and in existing protocols for the monitoring of orthodontic tooth movement through the markers of tooth movement. Clinical trials re required for the evaluation and validation of the protocol created.

  18. Autogenous Tooth Transplantation In Adult Orofacial Cleft Deformity ...

    African Journals Online (AJOL)

    A case of autotransplantation of a tooth in a 26 year old female African cleft palate patient is reported. This case report emphasizes the possibility and success of autotransplantation in our centre, it also emphasizes that transplantation is only technique sensitive but less equipment sensitive. It further stresses that an ...

  19. Charcot-Marie-Tooth disease type 1A

    DEFF Research Database (Denmark)

    Hertz, Jens Michael; Børglum, A D; Brandt, C A

    1994-01-01

    Charcot-Marie-Tooth disease type 1A (CMT1A) is an autosomal dominant peripheral neuropathy associated with a DNA duplication on chromosome 17p11.2-p12 in the majority of cases. Most of the sporadic cases are due to a de novo duplication. We have screened for this duplication in 11 Danish patients...

  20. Chapter 3: Design of the Saber-Tooth Project.

    Science.gov (United States)

    Ward, Phillip

    1999-01-01

    Used data from interviews, surveys, and document analysis to describe the methods and reform processes of the Saber Tooth Project, examining selection of sites; demographics (school sites, teachers, data sources, and project assumptions); and project phases (development, planning, implementation, and support). The project's method of reform was…

  1. Chapter 1: An Introduction to the Saber-Tooth Project.

    Science.gov (United States)

    Ward, Phillip

    1999-01-01

    Introduces a theme issue on the Saber-Tooth Project, an ongoing reform effort involving a university and school district that collaborate to improve middle school physical education by improving teaching conditions and engaging teachers in professional development emphasizing curriculum improvement. The monograph explains the nature of…

  2. Tooth brushing, tongue cleaning and snacking behaviour of dental ...

    African Journals Online (AJOL)

    Objective: To determine the tooth brushing, tongue cleaning and snacking behaviour of dental technology and therapist students. Methods: A descriptive cross-sectional study of students of Federal School of Dental Therapy and Technology Enugu, Nigeria. Self-administered questionnaire was used to obtain information on ...

  3. The basic chemistry and photochemistry behind hydrogen peroxide tooth whitening

    NARCIS (Netherlands)

    Young, N.D.; Fairley, P.D.; Mohan, V.; Jumeaux, C.

    2013-01-01

    Tooth whitening using hydrogen peroxide gel formulation is a complexprocess which involves both chemistry and physics, and there is still some controversy about the efficiency of whitening processes, particularly with respect to the roles of temperature and irradiation with light. In this work we

  4. Surgical treatments of the impacted canine tooth in young dogs

    International Nuclear Information System (INIS)

    Amimoto, A.; Iwamoto, S.; Hachimura, H.; Sasaki, K.; Taura, Y.; Nakama, S.; Yamanouchi, T.

    1993-01-01

    Surgical treatments of the impacted canine tooth were carried out in 8 young dogs, and the results were successful in 12 out of 14 cases (85.7%). The treatments consisting of surgical correction by immediate tipping movement, fenestration of the gingiva, and removal of the impacted tooth, were applied to 14 cases radiographically showing the immature tooth root and no abnormalities in the tooth root or alveolar bone. Impacted teeth were seen in 8 regions of the maxilla and 6 regions of the mandible. Mesioversion was seen in almost all maxillary impacted teeth, while linguoversion or lingual mesioversion in all mandibular cases. Surgical correction was carried out by immediate tipping movement after removal of the retained deciduous canine with or without resection of the alveolar bone. Fixation of the moved teeth was done using a wedge made from the deciduous canine root, which was driven into the vacant alveolar cavity after moving. An additional fixation using a steel wire and/or self-curing resin was done, if necessary

  5. Radicular Cyst With Actinomycotic Infection in an Upper Anterior Tooth

    Directory of Open Access Journals (Sweden)

    Shuei-Kuen Tseng

    2009-10-01

    Full Text Available Actinomycosis is an infection caused by filamentous, branching, Gram-positive anaerobic bacteria. It rarely infects the jawbone. This case report describes a patient with a left maxillary central incisor with an apical lesion and actinomycotic infection. A 23-year-old male patient underwent conventional root canal treatment of tooth 21, in a local dental clinic for about 1 year. However, percussion pain and a sinus tract that originated from tooth 21 were still present after treatment. Nonsurgical root canal treatment of tooth 21 was performed again but failed to relieve the symptoms. Therefore, apicoectomy and retrograde filling of the apical root canal with mineral trioxide aggregate were carried out. Periradicular bony defect was grafted by biocompatible material, and postoperative antibiotics (250 mg amoxicillin were given three times daily for 5 days. Pathological examination of the removed periapical tissue showed a radicular cyst with actinomycosis. At the 9-month postoperative recall, the sinus tract had disappeared and radiographic examination showed healing of the apical lesion. Periradicular actinomycosis is one important reason for failure of nonsurgical endodontic treatment. Clinically, if the tooth shows a recurrent sinus tract and poor response to conventional root canal treatment combined with antibiotic control, apical actinomycotic infection should be highly suspected, and an alternative endodontic surgical approach is needed for successful treatment.

  6. Tooth wear : a systematic review of treatment options

    NARCIS (Netherlands)

    Muts, Erik-Jan; van Pelt, Hans; Edelhoff, Daniel; Krejci, Ivo; Cune, Marco

    2014-01-01

    STATEMENT OF PROBLEM: Treatment of tooth wear is increasing. Because no evidence-based guidelines are available, the clinician may have difficulties deciding which treatment option to choose to resolve complex situations. PURPOSE: The purpose of this systematic review was to identify similarities

  7. When is an implant ready for a tooth?

    Science.gov (United States)

    Tupac, Robert G

    2003-12-01

    The capability of placing an osseointegrated implant at the time of tooth extraction and immediately placing a restoration on the implant depends upon a number of factors. This paper describes the traditional Brånemark protocol, the evolution of single-stage surgery, the guidelines for immediate placement, the measurement of implant stability, and the considerations critical to immediately loading.

  8. A longitudinal study of tooth erosion in adolescents.

    NARCIS (Netherlands)

    El Aidi, H.; Bronkhorst, E.M.; Truin, G.J.

    2008-01-01

    Incidence studies on tooth erosion among adolescents are scarce. This longitudinal study aimed at estimating the prevalence, incidence, progression, and distribution of erosion in young adolescents over a 1.5-year period. Erosion at baseline was present in 32.2% of the 622 children (mean age, 11.9

  9. Three-dimensional analysis of mandibular growth and tooth eruption

    DEFF Research Database (Denmark)

    Krarup, S.; Darvann, Tron Andre; Larsen, Per

    2005-01-01

    Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth...

  10. Factors influencing patients' choice of treatment for a tooth with ...

    African Journals Online (AJOL)

    Dental caries is a post eruptive pathologic process of bacterial origin involving the dissolution of dental hard tissues with resultant cavity formation and it may progress to irreversible pulpitis and apical periodontitis. The options for managing involved teeth include pulp therapy and tooth extraction. Despite the high success ...

  11. Prosthetic clone and natural human tooth comparison by speckle interferometry

    Science.gov (United States)

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

    2010-09-01

    New trends in dental prosthodontic interventions tend to preserve the maximum of "body" structure. With the evolution of CAD-CAM techniques, it is now possible to measure "in mouth" the remaining dental tissues. The prosthetic crown is then designed using this shape on which it will be glued on, and also by taking into account the contact surface of the opposite jaw tooth. Several theories discuss on the glue thickness and formulation, but also on the way to evolve to a more biocompatible crown and also new biomechanical concepts. In order to validate these new concepts and materials, and to study the mechanical properties and mechanical integrity of the prosthesis, high resolution optical measurements of the deformations of the glue and the crown are needed. Samples are two intact premolars extracted for orthodontics reasons. The reference sample has no modifications on the tooth while the second sample tooth is shaped to receive a feldspathic ceramic monoblock crown which will be glued. This crown was manufactured with a chairside CAD-CAM system from an intra-oral optical print. The software allows to realize a nearly perfect clone of the reference sample. The necessary space for the glue is also entered with ideal values. This duplication process yields to obtain two samples with identical anatomy for further processing. The glue joint thickness can also be modified if required. The purpose is to compare the behaviour of a natural tooth and its prosthetic clone manufactured with "biomechanical" concepts. Vertical cut samples have been used to deal with planar object observation, and also to look "inside" the tooth. We have developed a complete apparatus enabling the study of the compressive mechanical behaviour of the concerned tooth by speckle interferometry. Because in plane displacements are of great interest for orthodontic measurements1, an optical fiber in-plane sensitive interferometer has been designed. The fibers are wrapped around piezoelectric

  12. Assessment of the amount of tooth wear on dental casts and intra-oral photographs

    NARCIS (Netherlands)

    Wetselaar, P.; Wetselaar-Glas, M.J.M.; Koutris, M.; Visscher, C.M.; Lobbezoo, F.

    2016-01-01

    Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues. Many grading scales are available to assess the amount of tooth wear, one of which is the tooth wear evaluation system (TWES). A grading scale can be used chairside, on casts and on photographs. The aim was to test

  13. A comparison of new and conventional methods for quantification of tooth color

    NARCIS (Netherlands)

    Burgt, van der T.P.; Bosch, ten J.J.; Borsboom, P.C.F.; Kortsmit, W.J.P.M.

    1990-01-01

    Tooth color is caused by volume reflection, that is, passage of incident light through the tooth followed by backward emergence. This passage is concurrent with sideward displacement of photons that, in effect, influences the result of usual instrumental methods of determining tooth color. This

  14. 21 CFR 872.3750 - Bracket adhesive resin and tooth conditioner.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bracket adhesive resin and tooth conditioner. 872... SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3750 Bracket adhesive resin and tooth conditioner. (a) Identification. A bracket adhesive resin and tooth conditioner is a device...

  15. Near-surface structural examination of human tooth enamel subject to in vitro demineralization and remineralization

    Science.gov (United States)

    Gaines, Carmen Veronica

    The early stages of chemical tooth decay are governed by dynamic processes of demineralization and remineralization of dental enamel that initiates along the surface of the tooth. Conventional diagnostic techniques lack the spatial resolution required to analyze near-surface structural changes in enamel at the submicron level. In this study, slabs of highly-polished, decay-free human enamel were subjected to 0.12M EDTA and buffered lactic acid demineralizing agents and MI Paste(TM) and calcifying (0.1 ppm F) remineralizing treatments in vitro. Grazing incidence x-ray diffraction (GIXD), a technique typically used for thin film analysis, provided depth profiles of crystallinity changes in surface enamel with a resolution better than 100 nm. In conjunction with nanoindentation, a technique gaining acceptance as a means of examining the mechanical properties of sound enamel, these results were corroborated with well-established microscopy and Raman techniques to assess the nanohardness, morphologies and chemical nature of treated enamel. Interestingly, the average crystallite size of surface enamel along its c-axis dimension increased by nearly 40% after a 60 min EDTA treatment as detected by GIXD. This result was in direct contrast to the obvious surface degradation observed by microscopic and confocal Raman imaging. A decrease in nanohardness from 4.86 +/- 0.44 GPa to 0.28 +/- 0.10 GPa was observed. Collective results suggest that mineral dissolution characteristics evident on the micron scale may not be fully translated to the nanoscale in assessing the integrity of chemically-modified tooth enamel. While an intuitive decrease in enamel crystallinity was observed with buffered lactic acid-treated samples, demineralization was too slow to adequately quantify the enamel property changes seen. MI Paste(TM) treatment of EDTA-demineralized enamel showed preferential growth along the a-axis direction. Calcifying solution treatments of both demineralized sample types

  16. Tooth fragment reattachment techniques-A systematic review.

    Science.gov (United States)

    Garcia, Fernanda Cristina P; Poubel, Déborah L N; Almeida, Júlio César F; Toledo, Isabela P; Poi, Wilson R; Guerra, Eliete N S; Rezende, Liliana V M L

    2018-03-07

    Several strategies have been developed for tooth fragment reattachment following fracture. Although many techniques have been reported, there is no consensus on which one has the best results in terms of the bond strength between the fragment and the dentin over time. The aim of this study was to assess the currently reported tooth fragment reattachment techniques for fractured crowns of anterior teeth. The PubMed, LILACS, Web of Science, Cochrane, and Scopus databases were searched in October 2016, and the search was updated in February 2017. A search of the gray literature was performed in Google Scholar and OpenGrey. Reference lists of eligible studies were cross-checked to identify additional studies; gray literature and ongoing trials were investigated. Two authors assessed studies to determine inclusion and undertook data extraction. Case reports/series of three or more cases, cross-sectional studies, cohort studies, and in vivo clinical trials in all languages were included. Five articles remained after screening. These studies predominantly reported on fragment reattachment with composite resin and resin cement. There was little consistency among the studies in regard to the technique used for tooth fragment reattachment and length of the follow-up period. According to the evidence found in the studies included in this review, simple tooth fragment reattachment was the preferred reattachment technique. An increase in the bond strength between tooth fragment and dentin was observed when an intermediate material was used. Further investigation is needed, using standard follow-up periods and larger samples. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Enamel subsurface damage due to tooth preparation with diamonds.

    Science.gov (United States)

    Xu, H H; Kelly, J R; Jahanmir, S; Thompson, V P; Rekow, E D

    1997-10-01

    In clinical tooth preparation with diamond burs, sharp diamond particles indent and scratch the enamel, causing material removal. Such operations may produce subsurface damage in enamel. However, little information is available on the mechanisms and the extent of subsurface damage in enamel produced during clinical tooth preparation. The aim of this study, therefore, was to investigate the mechanisms of subsurface damage produced in enamel during tooth preparation by means of diamond burs, and to examine the dependence of such damage on enamel rod orientation, diamond particle size, and removal rate. Subsurface damage was evaluated by a bonded-interface technique. Tooth preparation was carried out on two enamel rod orientations, with four clinical diamond burs (coarse, medium, fine, and superfine) used in a dental handpiece. The results of this study showed that subsurface damage in enamel took the form of median-type cracks and distributed microcracks, extending preferentially along the boundaries between the enamel rods. Microcracks within individual enamel rods were also observed. The median-type cracks were significantly longer in the direction parallel to the enamel rods than perpendicular to the rods. Preparation with the coarse diamond bur produced cracks as deep as 84 +/- 30 microns in enamel. Finishing with fine diamond burs was effective in crack removal. The crack lengths in enamel were not significantly different when the removal rate was varied. Based on these results, it is concluded that subsurface damage in enamel induced by tooth preparation takes the form of median-type cracks as well as inter- and intra-rod microcracks, and that the lengths of these cracks are sensitive to diamond particle size and enamel rod orientation, but insensitive to removal rate.

  18. Lip and tooth injuries at public swimming pools in Austria.

    Science.gov (United States)

    Lechner, Katharina; Connert, Thomas; Kühl, Sebastian; Filippi, Andreas

    2017-06-01

    There is an increased risk of orofacial injuries in swimming pool facilities. Nevertheless, only a few studies have addressed this issue. The aim of this study was to identify the frequency of lip and tooth injuries at public swimming pools in Austria. A further aim was to examine which gender and age groups were affected, where and why these injuries occurred, and whether pool attendants had sufficient knowledge of dental first-aid measures. A total of 764 pool attendants in Austria were contacted by telephone and 689 participated in the study (90.2%). The attendants were interviewed retrospectively about accident occurrences in 2014 by a standardized questionnaire. Responses to the provision of first aid and choice of storage medium for avulsed teeth were subsequently evaluated. The frequency of lip injuries was 19.0%, and tooth injuries were 11.3%. Male bathers (P < .05) and children under 12 years (P < .001) most frequently suffered injuries. The waterslide was the most common accident site. The most common cause of lip injuries was slipping on wet surfaces (39.0%), and for tooth injuries it was collisions with other persons or objects (each 28.1%). The pool attendants' responses were predominantly good or sufficient on first aid, with the exception of what storage medium to choose. Tooth rescue boxes were available in only 8.6% of all pool facilities. Orofacial injuries are a frequently occurring problem in swimming pool facilities. The pool attendants' knowledge on first-aid care of tooth injuries could still be improved. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Esthetic evaluation of single-tooth implants in the anterior mandible.

    Science.gov (United States)

    Hof, Markus; Tepper, Gabor; Koller, Barbara; Krainhöfner, Martin; Watzek, Georg; Pommer, Bernhard

    2014-09-01

    Single-tooth replacement of anterior mandibular teeth is frequently complicated by insufficient bucco-lingual bone width and limited mesio-distal space available for implant placement. The aim of the present study was to assess implant esthetics in the partially edentulous anterior mandible. Esthetic evaluation of 43 anterior mandibular single-tooth implants in 15 women and 28 men was performed using esthetic indices (PES = Pink Esthetic Score, PI = Papilla Index, SES = Subjective Esthetic Score) as well as subjective patients' Visual Analogue Scale (VAS) ratings. Clinical and radiological parameters (implant and crown dimensions, pocket depth, bleeding on probing, plaque, keratinized mucosa, marginal bone level, and distance to adjacent teeth) were tested for influence. Implant esthetics were judged satisfactory (PES ≤10) in 42% of implants compared with a patient satisfaction rate of 87%. Correlation between objective indices (PES/PI: rs  = 0.62, PES/SES: rs  = -0.73, PI/SES: rs  = -0.48) was highly significant (P ≤ 0.001); however, no association to subjective patients' ratings could be observed. Type of prosthetic restoration (single crown vs. tulip-shaped double crowns), mesio-distal crown width as well as anatomic crown length significantly affected esthetic scores. Patients' judgment, by contrast, could not be associated to any prognostic factor. Subjective patient satisfaction with implant esthetics in the partially edentulous anterior mandible is high, however, remains hard to predict or objectively quantify. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Agreement between the results of meta-analyses from case reports and from clinical studies regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I who initiated enzyme replacement therapy in adult age: An example of case reports meta-analyses as an useful tool for evidence-based medicine in rare diseases.

    Science.gov (United States)

    Sampayo-Cordero, Miguel; Miguel-Huguet, Bernat; Pardo-Mateos, Almudena; Moltó-Abad, Marc; Muñoz-Delgado, Cecilia; Pérez-López, Jordi

    2018-02-01

    Case reports might have a prominent role in the rare diseases field, due to the small number of patients affected by one such disease. A previous systematic review regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I (MPS-I) who initiated enzyme replacement therapy (ERT) in adult age has been published. The review included a meta-analysis of 19 clinical studies and the description of eleven case reports. It was of interest to perform a meta-analysis of those case reports to explore the role of such meta-analyses as a tool for evidence-based medicine in rare diseases. The study included all case reports with standard treatment regimen. Primary analysis was the percentage of case reports showing an improvement in a specific outcome. Only when that percentage was statistically higher than 5%, the improvement was confirmed as such. The outcomes that accomplished this criterion were ranked and compared to the GRADE criteria obtained by those same outcomes in the previous meta-analysis of clinical studies. There were three outcomes that had a significant improvement: Urine glycosaminoglycans, liver volume and 6-minute walking test. Positive and negative predictive values, sensitivity and specificity for the results of the meta-analysis of case reports as compared to that of clinical studies were 100%, 88.9%, 75% and 100%, respectively. Accordingly, absolute (Rho=0.82, 95%CI: 0.47 to 0.95) and relative agreement (Kappa=0.79, 95%CI: 0.593 to 0.99) between the number of case reports with improvement in a specific outcome and the GRADE evidence score for that outcome were good. Sensitivity analysis showed that agreement between the meta-analysis of case reports and that of the clinical studies were good only when using a strong confirmatory strategy for outcome improvement in case reports. We found an agreement between the results of meta-analyses from case reports and from clinical studies in the efficacy of laronidase therapy in

  1. Novel Method for Superposing 3D Digital Models for Monitoring Orthodontic Tooth Movement.

    Science.gov (United States)

    Schmidt, Falko; Kilic, Fatih; Piro, Neltje Emma; Geiger, Martin Eberhard; Lapatki, Bernd Georg

    2018-04-18

    Quantitative three-dimensional analysis of orthodontic tooth movement (OTM) is possible by superposition of digital jaw models made at different times during treatment. Conventional methods rely on surface alignment at palatal soft-tissue areas, which is applicable to the maxilla only. We introduce two novel numerical methods applicable to both maxilla and mandible. The OTM from the initial phase of multi-bracket appliance treatment of ten pairs of maxillary models were evaluated and compared with four conventional methods. The median range of deviation of OTM for three users was 13-72% smaller for the novel methods than for the conventional methods, indicating greater inter-observer agreement. Total tooth translation and rotation were significantly different (ANOVA, p < 0.01) for OTM determined by use of the two numerical and four conventional methods. Directional decomposition of OTM from the novel methods showed clinically acceptable agreement with reference results except for vertical translations (deviations of medians greater than 0.6 mm). The difference in vertical translational OTM can be explained by maxillary vertical growth during the observation period, which is additionally recorded by conventional methods. The novel approaches are, thus, particularly suitable for evaluation of pure treatment effects, because growth-related changes are ignored.

  2. Sea urchin tooth mineralization: Calcite present early in the aboral plumula

    Science.gov (United States)

    Stock, Stuart R.; Veis, Arthur; Xiao, Xianghui; Almer, Jonathan D.; Dorvee, Jason R.

    2012-01-01

    In both vertebrate bone, containing carbonated hydroxyapatite as the mineral phase, and in invertebrate hard tissue comprised of calcium carbonate, a popular view is that the mineral phase develops from a long-lived amorphous precursor which later transforms into crystal form. Important questions linked to this popular view are: When and where is the crystallized material formed, and is amorphous solid added subsequently to the crystalline substrate? Sea urchin teeth, in which the earliest mineral forms within isolated compartments, in a time and position dependent manner, allow direct investigation of the timing of crystallization of the calcite primary plates. Living teeth of the sea urchin Lytechinus variegatus, in their native coelomic fluid, were examined by high-energy synchrotron x-ray diffraction. The diffraction data show that calcite is present in the most aboral portions of the plumula, representing the very earliest stages of mineralization, and that this calcite has the same crystal orientation as in the more mature adoral portions of the same tooth. Raman spectroscopy of the aboral plumula confirms the initial primary plate mineral material is calcite and does not detect amorphous calcium carbonate; in the more mature adoral incisal flange, it does detect a broader calcite peak, consistent with two or more magnesium compositions. We hypothesize that some portion of each syncytial membrane in the plumula provides the information for nucleation of identically oriented calcite crystals that subsequently develop to form the complex geometry of the single crystal sea urchin tooth. PMID:22940703

  3. Effect of foods and drinks on primary tooth enamel after erosive challenge with hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Késsia Suênia Fidelis de MESQUITA-GUIMARÃES

    2015-01-01

    Full Text Available The aim of this study was to evaluate the effect of industrialised foods and drinks on primary tooth enamel previously eroded with hydrochloric acid (HCl. The crowns of one hundred two specimens were subjected to an erosive challenge with HCl and randomly divided into six groups (n = 17: Chocolate Milk (Toddynho® - Pepsico - negative control; Petit Suisse Yogurt (Danoninho® - Danone; Strawberry Yogurt (Vigor; Apple puree (Nestlé; Fermented Milk (Yakult® - Yakult; and Home Squeezed Style Orange Juice (del Valle - positive control. The 28-day immersion cycles for the test products were performed twice daily and were interspersed with exposure of the test substrate to artificial saliva. Measurements of enamel surface microhardness (SMH were performed initially, after immersion in HCl and at 7, 14, 21 and 28 days of experimentation. A two-way ANOVA, according to a split-plot design, followed by the sum of squares decomposition and Tukey’s test, revealed a significant effect for the interaction between Foods and Drinks and Length of Exposure (p < 0.00001. Orange juice resulted in greater mineral loss of enamel after 28 days. None of the test products was associated with recovery of tooth enamel microhardness.

  4. New developed cylindrical TM010 mode EPR cavity for X-band in vivo tooth dosimetry.

    Directory of Open Access Journals (Sweden)

    Guo Junwang

    Full Text Available EPR tooth in vivo dosimetry is an attractive approach for initial triage after unexpected nuclear events. An X-band cylindrical TM010 mode resonant cavity was developed for in vivo tooth dosimetry and used in EPR applications for the first time. The cavity had a trapezoidal measuring aperture at the exact position of the cavity's cylindrical wall where strong microwave magnetic field H1 concentrated and weak microwave electric field E1 distributed. Theoretical calculations and simulations were used to design and optimize the cavity parameters. The cavity features were evaluated by measuring DPPH sample, intact incisor samples embed in a gum model and the rhesus monkey teeth. The results showed that the cavity worked at designed frequency and had the ability to make EPR spectroscopy in relative high sensitivity. Sufficient modulation amplitude and microwave power could be applied into the aperture. Radiation induced EPR signal could be observed remarkably from 1 Gy irradiated intact incisor within only 30 seconds, which was among the best in scan time and detection limit. The in vivo spectroscopy was also realized by acquiring the radiation induced EPR signal from teeth of rhesus monkey whose teeth was irradiated by dose of 2 Gy. The results suggested that the cavity was sensitive to meet the demand to assess doses of significant level in short time. This cavity provided a very potential option for the development of X-band in vivo dosimetry.

  5. Sea urchin tooth mineralization: calcite present early in the aboral plumula.

    Science.gov (United States)

    Stock, Stuart R; Veis, Arthur; Xiao, Xianghui; Almer, Jonathan D; Dorvee, Jason R

    2012-11-01

    In both vertebrate bone, containing carbonated hydroxyapatite as the mineral phase, and in invertebrate hard tissue comprised of calcium carbonate, a popular view is that the mineral phase develops from a long-lived amorphous precursor which later transforms into crystal form. Important questions linked to this popular view are: when and where is the crystallized material formed, and is amorphous solid added subsequently to the crystalline substrate? Sea urchin teeth, in which the earliest mineral forms within isolated compartments, in a time and position dependent manner, allow direct investigation of the timing of crystallization of the calcite primary plates. Living teeth of the sea urchin Lytechinus variegatus, in their native coelomic fluid, were examined by high-energy synchrotron X-ray diffraction. The diffraction data show that calcite is present in the most aboral portions of the plumula, representing the very earliest stages of mineralization, and that this calcite has the same crystal orientation as in the more mature adoral portions of the same tooth. Raman spectroscopy of the aboral plumula confirms the initial primary plate mineral material is calcite and does not detect amorphous calcium carbonate; in the more mature adoral incisal flange, it does detect a broader calcite peak, consistent with two or more magnesium compositions. We hypothesize that some portion of each syncytial membrane in the plumula provides the information for nucleation of identically oriented calcite crystals that subsequently develop to form the complex geometry of the single crystal sea urchin tooth. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Intramembranous bone healing process subsequent to tooth extraction in mice: micro-computed tomography, histomorphometric and molecular characterization.

    Science.gov (United States)

    Vieira, Andreia Espindola; Repeke, Carlos Eduardo; Ferreira Junior, Samuel de Barros; Colavite, Priscila Maria; Biguetti, Claudia Cristina; Oliveira, Rodrigo Cardoso; Assis, Gerson Francisco; Taga, Rumio; Trombone, Ana Paula Favaro; Garlet, Gustavo Pompermaier

    2015-01-01

    Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray) characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0 h), the development of a provisional immature granulation tissue is evident (7 d), characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa), cytokines (TNFα, IL-10), chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4), matrix (Col1a1-2, ITGA4, VTN, MMP1a) and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146) markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14 d), characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9), bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST) markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2). No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21 d) when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the

  7. Intramembranous bone healing process subsequent to tooth extraction in mice: micro-computed tomography, histomorphometric and molecular characterization.

    Directory of Open Access Journals (Sweden)

    Andreia Espindola Vieira

    Full Text Available Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0 h, the development of a provisional immature granulation tissue is evident (7 d, characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa, cytokines (TNFα, IL-10, chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4, matrix (Col1a1-2, ITGA4, VTN, MMP1a and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146 markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14 d, characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9, bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2. No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21 d when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the

  8. Optimization of station battery replacement

    International Nuclear Information System (INIS)

    Jancauskas, J.R.; Shook, D.A.

    1994-01-01

    During a loss of ac power at a nuclear generating station (including diesel generators), batteries provide the source of power which is required to operate safety-related components. Because traditional lead-acid batteries have a qualified life of 20 years, the batteries must be replaced a minimum of once during a station's lifetime, twice if license extension is pursued, and more often depending on actual in-service dates and the results of surveillance tests. Replacement of batteries often occurs prior to 20 years as a result of systems changes caused by factors such as Station Blackout Regulations, control system upgrades, incremental load growth, and changes in the operating times of existing equipment. Many of these replacement decisions are based on the predictive capabilities of manual design basis calculations. The inherent conservatism of manual calculations may result in battery replacements occurring before actually required. Computerized analysis of batteries can aid in optimizing the timing of replacements as well as in interpreting service test data. Computerized analysis also provides large benefits in maintaining the as-configured load profile and corresponding design margins, while also providing the capability of quickly analyze proposed modifications and response to internal and external audits

  9. Replacement research reactor for Australia

    International Nuclear Information System (INIS)

    Miller, Ross

    1998-01-01

    In 1992, the Australian Government commissioned a review into the need for a replacement research reactor. That review concluded that in about years, if certain conditions were met, the Government could make a decision in favour of a replacement reactor. A major milestone was achieved when, on 3 September 1997, the Australian Government announced the construction of a replacement research reactor at the site of Australia's existing research reactor HIFAR, subject to the satisfactory outcome of an environmental assessment process. The reactor will be have the dual purpose of providing a first class facility for neutron beam research as well as providing irradiation facilities for both medical isotope production and commercial irradiations. The project is scheduled for completion before the end of 2005. (author)

  10. Report on the meeting for examining replacing core

    International Nuclear Information System (INIS)

    1977-01-01

    At the time of examining the application for approval of reactor installation, it must be confirmed that the safety of the concerned reactor is secured with not only the initially loaded core but also the replacing core. Besides, it must be confirmed again that the various criteria concerning the safety are satisfied after the start of operation, because a part of the parameters of the replacing core is dependent on the operational history. On the above described viewpoints, the main parameters affecting the safety and the nuclear and thermal limits of replacing core were reviewed. Moreover, the contents of description concerning replacing core in the application form were examined. As the general matters concerning the safety of replacing core, the scram reactivity curves for BWRs and PWRs, the method of description in the application form concerning the fuel containing gadolinia, and the use of burnable poison in replacing core were examined. The meeting for examining replacing core was organized on September 20, 1976, at the Committee for Examining Reactor Safety, and this report was compiled as the results of 10 meetings. (Kako, I.)

  11. Joint replacement in Zambia: A review of Hip & Knee Replacement ...

    African Journals Online (AJOL)

    Methods: Data captured by the different variables entered into the Joint Register covering the pre-op, intra-op and post-op period of all total hip and knee replacement surgery done at the ZIOH from 1998 to 2010 was entered into a spreadsheet after verification with individual patient medical records. This was then imported ...

  12. Replacement of the computerized control system at NPP under operation

    International Nuclear Information System (INIS)

    Ermolaev, A.D.; Rakitin, I.D.

    1985-01-01

    Reasons and preconditions for replacement of the computerized control systems (CCS) at NPP under operation are consi-- dered. Problems dealing with management of CCS replacement, maintenance of a new CCS as well as NPP personnel training for the new system maintenance are discussed. A necessity of NPP personnel participation in these works in order to adapt CCS to requirements of NPP operation personnel and to initiate the training process is underlined. Replacement of CCS at NPP under operation is associated, as a rule, with obsolescence of old systems not ensuring growing requirements to NPP workability and safety. Principles observed at CCS replacement are reduced, mainly, to the following; maximum utilizatian of existing equipment, metal strUctures, cables, instruments, power supplies, ventilation system minimum of construction works and new communications; the least change of acting panels and boxes; changes in control desks should be introduced on the basis of the analysis of operator actions '

  13. Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats

    International Nuclear Information System (INIS)

    Hosokawa, Yoichiro; Kudo, Kohsei; Kashiwakura, Ikuo; Sakakura, Yasunori; Irie, Kazuharu

    2010-01-01

    Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing. (author)

  14. Effects of local and whole body irradiation on the appearance of osteoblasts during wound healing in tooth extraction sockets in rats.

    Science.gov (United States)

    Hosokawa, Yoichiro; Sakakura, Yasunori; Irie, Kazuharu; Kudo, Kohsei; Kashiwakura, Ikuo

    2010-01-01

    Irradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing.

  15. Insurance for replacement power costs

    International Nuclear Information System (INIS)

    Cleaver, A.

    1980-01-01

    Although careful consideration is given to insurance against physical damage to plant and equipment, little thought is given to the costs that will be incurred in replacing the power that is lost while a relatively efficient system is out of action. The results of an investigation carried out for a generating authority with an installed capacity of about 3000 MW is given. Replacement power costs for different cases of severity of damage range from Pound1.17m per month for damage to central services taking out all four units. (author)

  16. Replacing fuel alignment in Germany

    International Nuclear Information System (INIS)

    Poetz, F.; Kalthoff, W.

    1991-01-01

    Up to the end of 1989 varying numbers of broken fuel alignment pins were detected in several German PWRs (80 broken pins in all). The distribution of these broken pins over the core cross-section was more or less random. The problem was due to the stress corrosion cracking of the pin material and was restricted to individual pins. It was concluded that all fuel alignment pins made of Inconel X-750 should be replaced. The development of a new pin, more resistant to intergranular stress corrosion, and the replacement technique are outlined. (author)

  17. A design of speed reducer with trapezoidal tooth profile for robot manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Won Ki; Oh, Se Hoon [Chung-Ang University, Seoul (Korea, Republic of)

    2011-01-15

    Robots are increasingly performing human work as manufacturing is automated. Accordingly, the use of precision speed reducers has become essential for achieving precise control of the robot arm position. Curved tooth profiles, such as cycloid or involute tooth profiles, are generally used in precision speed reducers. Speed reducers with cycloid tooth profiles, which enable high precision control, are widely used to manipulate robot systems. This study proposes a speed reducer that has a trapezoidal tooth profile with straight lines. In this work, we mechanically analyzed trapezoidal tooth profiles, and then measured performance was by various tests using a prototype manufactured specifically for this study.

  18. A design of speed reducer with trapezoidal tooth profile for robot manipulator

    International Nuclear Information System (INIS)

    Nam, Won Ki; Oh, Se Hoon

    2011-01-01

    Robots are increasingly performing human work as manufacturing is automated. Accordingly, the use of precision speed reducers has become essential for achieving precise control of the robot arm position. Curved tooth profiles, such as cycloid or involute tooth profiles, are generally used in precision speed reducers. Speed reducers with cycloid tooth profiles, which enable high precision control, are widely used to manipulate robot systems. This study proposes a speed reducer that has a trapezoidal tooth profile with straight lines. In this work, we mechanically analyzed trapezoidal tooth profiles, and then measured performance was by various tests using a prototype manufactured specifically for this study

  19. A Dental Hygienist's and Therapist's Guide to the Management of Tooth Erosion.

    Science.gov (United States)

    Ariyanayagam, Yana

    2016-08-01

    Dental care professionals can support patients to prevent and manage tooth erosion. The role of the dentist is to restore the structure and function of teeth damaged by acid erosion, while the role of the dental hygienist therapist is to work alongside the dentist to help manage and reduce the risk of tooth erosion. This article will highlight how the dental hygienist or therapist can identify tooth erosion. It will describe the features of tooth erosion and outline the causes. This article will discuss preventative care options for patients who are at risk of tooth erosion, including specific oral hygiene instructions, fluoride advice and use of other dental products.

  20. Immediate loading versus immediate provisionalization of maxillary single-tooth replacements: a prospective randomized study with BioComp implants

    NARCIS (Netherlands)

    Lindeboom, Jerome A.; Frenken, Joost W.; Dubois, Leander; Frank, Michael; Abbink, Ingmar; Kroon, Frans H.

    2006-01-01

    PURPOSE: The aim of this prospective randomized study was to evaluate the clinical outcome of immediately loaded solid plasma sprayed (TPS) BioComp (BioComp Industries BV, Vught, The Netherlands) implants versus immediate provisionalized but non-loaded BioComp implants in the anterior and premolar