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1

Prevalence of congenitally missing permanent teeth in Iran  

PubMed Central

Background: Hypodontia or congenitally missing teeth is among dental anomalies with different prevalence in each region. The aim of this study was to evaluate the prevalence of congenitally missing permanent teeth in Iranian population. Materials and Methods: A descriptive, retrospective and cross-sectional study was done. Panoramic radiographs of 2422 Iranian patients (1539 girls and 883 boys), 7-25 years old, were collected. The radiographs were studied for evidence of congenitally missing teeth. Data were analyzed using Paired t-test, Mann-Whitney test, Fisher exact test and Chi-square test (? = 0.05). Results: Prevalence of congenitally missing teeth was totally 45.7% and 34.8% for third molars. The most frequent congenitally missing teeth was mandibular second premolars (23.34%) followed by maxillary second premolars (22.02%). Upper jaw showed significantly higher number of congenitally missing teeth (P value < 0.001). According to Chi-square test, congenital missing teeth was found approximately 10.9% in both females and males and there were no statistically significant difference between sexes (P = 0.19). Conclusion: The prevalence of congenitally missing teeth (CMT) in Iranian permanent dentition was 10.9%. The most common congenitally missing teeth were mandibular second premolar fallowed by maxillary second premolars. PMID:23814548

Sheikhi, Mahnaz; Sadeghi, Mohammad Ali; Ghorbanizadeh, Sajad

2012-01-01

2

Boon of MTA Apexification in Young Permanent Posterior Teeth  

PubMed Central

Single visit apexification using mineral trioxide aggregate (MTA) is a new boon in effective management of nonvital tooth with an open apex which has steadily gained popularity with clinicians; also it shortens the treatment period and improves patient compliance. Importance of this approach lies in expedient cleaning and shaping of the root canal system, followed by its apical seal with MTA. There are several case reports available describing the use of MTA as an apexification agent in incisors and premolar, but presented cases are the unique case reports demonstrating successful apexification procedure using MTA in young permanent mandibular molars. After eight-month follow-up, teeth were without any abnormal clinical symptoms; rather there were radiographic resolution of the periapical lesion and induction of root end closure with new hard tissue formation over MTA. PMID:25431690

Kumar, Vinod; Prasad, Vijaya; Mahantesh, T.

2014-01-01

3

Bond strength with various etching times on young permanent teeth  

SciTech Connect

Tensile bond strengths of an orthodontic resin cement were compared for 15-, 30-, 60-, 90-, or 120-second etching times, with a 37% phosphoric acid solution on the enamel surfaces of young permanent teeth. Fifty extracted premolars from 9- to 16-year-old children were used for testing. An orthodontic composite resin was used to bond the bracket directly onto the buccal surface of the enamel. The tensile bond strengths were tested with an Instron machine. Bond failure interfaces between bracket bases and teeth surfaces were examined with a scanning electron microscope and calculated with mapping of energy-dispersive x-ray spectrometry. The results of tensile bond strength for 15-, 30-, 60-, or 90-second etching times were not statistically different. For the 120-second etching time, the decrease was significant. Of the bond failures, 43%-49% occurred between bracket and resin interface, 12% to 24% within the resin itself, 32%-40% between resin and tooth interface, and 0% to 4% contained enamel fragments. There was no statistical difference in percentage of bond failure interface distribution between bracket base and resin, resin and enamel, or the enamel detachment. Cohesive failure within the resin itself at the 120-second etching time was less than at other etching times, with a statistical significance. To achieve good retention, to decrease enamel loss, and to reduce moisture contamination in the clinic, as well as to save chairside time, a 15-second etching time is suggested for teenage orthodontic patients.

Wang, W.N.; Lu, T.C. (School of Dentistry, National Defense Medical Center, Taipei, Taiwan (China))

1991-07-01

4

The Incidence of Staining of Permanent Teeth by the Tetracyclines  

PubMed Central

In this investigation an attempt has been made to determine the relationship between the staining of permanent teeth by tetracycline administered during the period of tooth formation with the dosage of the drug and the duration of therapy. Of 238 subjects whose hospital records indicated ingestion of stated doses of tetracycline, some 49 were seen to have staining which was confirmed by fluorescence, and a further six had staining which did not fluoresce and hence could not be confirmed. A definite relationship between total dosage and staining and duration of administration and staining was established; the condition occurred with greater frequency (in more than one-third of the children) when the total dosage exceeded 3 g. or the duration of treatment was longer than 10 days. However, as staining was seen at all dosage levels, whatever the duration, physicians should continue to follow previous advice and prescribe other antibiotics where possible for children under 8 years of age or for women in the last trimester of pregnancy. PMID:5447715

Conchie, J. M.; Munroe, J. D.; Anderson, D. O.

1970-01-01

5

Appearance of the first cemental annulation of permanent incisor teeth of the domestic cat (Felis catus)  

E-print Network

studied histologically to analyze the early growth pattern of dental cementum of permanent teeth. Thin sections (H-E stained) of incisor teeth were prepared and examined microscopically. The observations of individual teeth were recorded.... The references herein are consistent with the style and format of Laboratory Animal Science. REVIEW OF LITERATURE Annulation counts in dental cementum have been used to determine age in mammals. The formation of dentinal and cemental layers have been shown...

Choi, In-Back

1983-01-01

6

Age estimation by Chinese permanent teeth with image analysis.  

PubMed

A total of 567 human teeth except third molars were studied to estimate age, using a combined method of multiple regression analysis of data from a scoring system, direct measurements with image analyser, and logarithmic transformation. As a result, the standard errors of estimate were 4.8-5.4 years in the working sample, and 2.9-5.4 years in the control sample respectively, by using a single tooth. By testing the formulae on forensic autopsy cases in Guang Dong and Guang Xi, (People's Republic of China), it is demonstrated that the standard error of estimate is 3.7 and 2.6 years respectively for any single tooth (incisor, canine, premolar or molar) except the third molar. Age determination from multiple teeth of the same individual has also been studied. As a result, according to the different age grouping, the standard errors of estimate ranged from 0.8 to 2.6 years (2 teeth from the same individual) and 0.6 to 2.3 years (3 teeth from the same individual). It is concluded that the method presented here is helpful in improving the accuracy of age determination from teeth. PMID:7830510

Xu, X; Zhu, J; Philipsen, H P; Pang, K M

1994-10-01

7

Recent trends in the management of dentoalveolar traumatic injuries to primary and young permanent teeth.  

PubMed

One of the commonly encountered dental emergencies is dentoalveolar traumatic injuries (DTIs). Unfortunately, DTIs result in fractured, displaced, or lost anterior teeth and this could have significant negative functional, esthetic, speech, and psychological effects on children thus affecting their quality of life. Although it is impossible to guarantee permanent retention of a traumatized tooth, patient age, severity of injury, and timely treatment and follow up of the tooth using recommended procedures can maximize the chances for success. This review examines the recent trends in the management of DTI to primary and young permanent teeth. Electronic search of scientific papers written in English from 1990s to 2009 was accomplished using Pub Med search engine. Dental practitioners should follow current literature and consider carefully evidenced-based recommendations that may enhance periodontal healing and revascularization of avulsed permanent teeth. PMID:21244628

Turkistani, Jihan; Hanno, Azzah

2011-02-01

8

Teething  

MedlinePLUS

... because this can lead to infection. Avoid teething powders. NEVER give your child aspirin or place it against the gums or teeth. DO NOT rub alcohol on your baby's gums. Avoid teething products such ...

9

Prospective Study of the Association between Fluoride Intake and Dental Fluorosis in Permanent Teeth  

Microsoft Academic Search

Objective: To evaluate the relationship between fluoride intake and dental fluorosis in permanent central incisors and first molars. Methods: Fluoride intake (mg F\\/kg body weight\\/day) from diet, dentifrice and both combined was determined on a single occasion in 1998 among children aged 19–39 months living in two fluoridated Brazilian communities (0.6–0.8 ppm F). Six years later, when the permanent teeth

C. C. Martins; S. M. Paiva; Y. B. Lima-Arsati; M. L. Ramos-Jorge; J. A. Cury

2008-01-01

10

A prospective clinical study of mineral trioxide aggregate for partial pulpotomy in cariously exposed permanent teeth.  

PubMed

The aim of this study was to evaluate the success of using gray mineral trioxide aggregate (MTA) for partial pulpotomy in cariously exposed young permanent first molars. Thirty-one first permanent molars of 23 patients with a carious exposure were treated using a partial pulpotomy technique. The age of the patients ranged from 7.2 to 13.1 yr with an average of 10 yr. Clinical and radiographic examination revealed a pulpal response within normal limits and normal appearance of the periradicular area respectively. A diagnosis of reversible pulpitis and normal periapex was established. After isolation, caries removal and carious exposure, the exposed pulp tissue was removed with a diamond bur to a depth of 2 to 4 mm. After hemostasis, 2 to 4 mm of gray MTA paste was placed against the fresh wound. The floor of the cavity was covered with a base of glass ionomer. The teeth were restored with amalgam or stainless steel crowns. Teeth were reviewed radiographically and clinically at 3, 6, 12, and 24 month intervals. Twenty-two of the treated teeth did not show any clinical or radiographic signs of failure during the follow-up evaluation period. Six teeth did not respond to vitality testing at the final follow-up period; however, no radiographic signs of failure or clinical symptoms were detected. Gray MTA was a suitable dressing agent for parital pulpotomy in cariously exposed young permanent first molars. PMID:16861071

Barrieshi-Nusair, Kefah Mahmood; Qudeimat, Muawia Abdulla

2006-08-01

11

Can Accidental Local Application of A Drug Cause Discolouration of Permanent Teeth?  

PubMed Central

Thorough knowledge on the aetiology of tooth staining is of importance to dental surgeons, in order to enable a correct diagnosis to be made when examining a discoloured dentition and it allows the dental practitioner to explain to the patient the exact nature of the condition. Tetracyclines are a group of drugs which can discolour teeth permanently. One such case of discolouration of adult teeth caused by administration of tetracycline(oxytetracycline) has been reported here and it has been discussed in detail. PMID:24551734

Hans, Manoj Kumar; Nagpal, Ajay; Shetty, Shashit; Hans, Rinki

2013-01-01

12

Teeth  

NSDL National Science Digital Library

This video segment from IdahoPTV's D4K takes you to the dentist where you discover the different types of teeth animals have, how many teeth and the kinds humans have, the parts of a tooth and how to keep your teeth healthy.

Idaho PTV

2011-10-05

13

Periradicular Surgery of Human Permanent Teeth with Calcium-Enriched Mixture Cement  

PubMed Central

Introduction Root-end preparation and restoration with an endodontic material are required when nonsurgical endodontic retreatment has failed or is impossible. The present clinical study reports the treatment outcomes of periradicular surgery using calcium-enriched mixture (CEM) cement. Materials and Methods A prospective outcome study of periradicular surgery using CEM was conducted on 14 permanent teeth with persistent apical periodontitis. Using a standardized surgical protocol, 2-3 mm of the root apex was resected; approximately 3 mm deep root-end cavities were ultrasonically prepared and filled with CEM cement. All patients were available for recall. Results Clinical and radiographic examination revealed complete healing of periradicular lesions, i.e. regeneration of periodontal ligament and lamina dura in 13 teeth (93% success) during a mean time of 18 months; moreover, the teeth were functional and asymptomatic. Conclusion Favorable treatment outcomes in this prospective clinical study suggested that CEM cement may be a suitable root-end filling biomaterial. PMID:23922577

Asgary, Saeed; Ehsani, Sara

2013-01-01

14

Growth and development of permanent teeth germ of transplacental Yu-Cheng babies in Taiwan  

SciTech Connect

This paper is intended to present a study of transplacental Yu-Cheng babies in Taiwan. The focus of the study is to demonstrate how a contaminated food source can affect the growth and development of permanent teeth germ in children. A sporadic outbreak of a peculiar skin disease was reported in Japan in October of 1968. An epidemiological study revealed the outbreak of this disease was caused by contaminated Kanemi rice oil. This episode of rice oil poisoned with polychlorinated biphenyls (PCB) was the first reported outbreak of PCB poisoning in the world. A second episode occurred in central Taiwan eleven years after the Japanese episode. Registered data from the Taiwan Provincial Government Health Department reported 1,843 cases in 1980. Of this group, more than 800 women were child-bearing age and most of these women would or soon would be married and pregnant. The offsprings of these women were in danger, because it has been proven that PCB intoxication could affect the fetus. These babies, only contaminated through the placenta, are called PCB transplacental Yusho babies in Japan and PCB transplacental Yu-Cheng babies in Taiwan. Babies with PCB poisoning could have Fetal PCB syndrome (FPS) and may have retarded eruption of permanent teeth and other anomalies such as reduced numbers of teeth and abnormal shaped roots. The study of transplacental Yu-Cheng babies is an important public health issue for Taiwan. Although there may be other issues, this study focuses only on the growth and development of permanent teeth of those babies affected by PCB transplacental contamination.

Lan, Shoujen; Yen, Yeayin; Ko, Yingchin; Chen, Engrin (School of Public Health of Kaohsiung Medical College, Kaohsiung City (Taiwan))

1989-06-01

15

Idiopathic failure of eruption of multiple permanent teeth: report of 2 adults with a highlight on molecular biology.  

PubMed

Multiple unerupted teeth with no obvious etiology is a rare dental anomaly. Various local and systemic factors have been implicated in the failure of eruption of multiple permanent teeth. But the localization of the genetic defect in the phenotype of failure of eruption is largely unknown at present. Our aims in this article were to consolidate and organize the available information regarding the molecular biology of tooth eruption and to corroborate the current evidence with the report of 2 adult cases of failure of eruption of multiple permanent teeth without a known cause. PMID:18005845

Sivakumar, Arunachalam; Valiathan, Ashima; Gandhi, Sumit; Mohandas, Ashil A

2007-11-01

16

Outcomes of Different Vital Pulp Therapy Techniques on Symptomatic Permanent Teeth: A Case Series  

PubMed Central

In modern endodontics, vital pulp therapy (VPT) has been considered an ultra-conservative treatment modality. Based on the level of pulp preservation, VPT includes stepwise excavation, indirect pulp capping (IDPC), direct pulp capping (DPC), miniature pulpotomy (MP), partial/Cvek pulpotomy and coronal/complete pulpotomy (CP). The present article reviews the treatment outcomes of 94 permanent teeth with irreversible pulpitis treated with either IDPC (n=28), DPC (n=28), MP (n=29) or CP (n=9) using calcium-enriched mixture (CEM) cement. After a mean follow-up time of 12.3 months, 93 treated teeth were radiographic/clinically successful; only one radiographic failure was observed in the DPC group. PMID:25386213

Asgary, Saeed; Fazlyab, Mahta; Sabbagh, Sedigheh; Eghbal, Mohammad Jafar

2014-01-01

17

Genome-Wide Association Study Identifies Four Loci Associated with Eruption of Permanent Teeth  

PubMed Central

The sequence and timing of permanent tooth eruption is thought to be highly heritable and can have important implications for the risk of malocclusion, crowding, and periodontal disease. We conducted a genome-wide association study of number of permanent teeth erupted between age 6 and 14 years, analyzed as age-adjusted standard deviation score averaged over multiple time points, based on childhood records for 5,104 women from the Danish National Birth Cohort. Four loci showed association at P<5×10?8 and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10?11. Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9–4.1) fewer permanent teeth than children with 0 or 1 of these alleles. PMID:21931568

Zhang, Hao; Shaffer, John R.; Hansen, Thomas; Esserlind, Ann-Louise; Boyd, Heather A.; Nohr, Ellen A.; Timpson, Nicholas J.; Fatemifar, Ghazaleh; Paternoster, Lavinia; Evans, David M.; Weyant, Robert J.; Levy, Steven M.; Lathrop, Mark; Smith, George Davey; Murray, Jeffrey C.; Olesen, Jes; Werge, Thomas; Marazita, Mary L.; Sørensen, Thorkild I. A.; Melbye, Mads

2011-01-01

18

Genome-wide association study identifies four loci associated with eruption of permanent teeth.  

PubMed

The sequence and timing of permanent tooth eruption is thought to be highly heritable and can have important implications for the risk of malocclusion, crowding, and periodontal disease. We conducted a genome-wide association study of number of permanent teeth erupted between age 6 and 14 years, analyzed as age-adjusted standard deviation score averaged over multiple time points, based on childhood records for 5,104 women from the Danish National Birth Cohort. Four loci showed association at P<5×10(-8) and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10(-11). Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9-4.1) fewer permanent teeth than children with 0 or 1 of these alleles. PMID:21931568

Geller, Frank; Feenstra, Bjarke; Zhang, Hao; Shaffer, John R; Hansen, Thomas; Esserlind, Ann-Louise; Boyd, Heather A; Nohr, Ellen A; Timpson, Nicholas J; Fatemifar, Ghazaleh; Paternoster, Lavinia; Evans, David M; Weyant, Robert J; Levy, Steven M; Lathrop, Mark; Smith, George Davey; Murray, Jeffrey C; Olesen, Jes; Werge, Thomas; Marazita, Mary L; Sørensen, Thorkild I A; Melbye, Mads

2011-09-01

19

Comparative Gene Expression Analysis of the Human Periodontal Ligament in Deciduous and Permanent Teeth  

PubMed Central

There are histological and functional differences between human deciduous and permanent periodontal ligament (PDL) tissues. The aim of this study was to determine the differences between these two types of tissue at the molecular level by comparing their gene expression patterns. PDL samples were obtained from permanent premolars (n?=?38) and anterior deciduous teeth (n?=?31) extracted from 40 healthy persons. Comparative cDNA microarray analysis revealed several differences in gene expression between the deciduous and permanent PDL tissues. These findings were verified by qRT-PCR (quantitative reverse-transcription–polymerase chain reaction) analysis, and the areas where genes are expressed were revealed by immunohistochemical staining. The expressions of 21 genes were up-regulated in deciduous relative to PDL tissues, and those of 30 genes were up-regulated in permanent relative to deciduous PDL tissues. The genes that were up-regulated in deciduous PDL tissues were those involved in the formation of the extracellular matrix (LAMC2, LAMB3, and COMP), tissue development (IGF2BP, MAB21L2, and PAX3), and inflammatory or immune reactions leading to tissue degradation (IL1A, CCL21, and CCL18). The up-regulated genes in permanent PDL tissues were related to tissue degradation (IL6 and ADAMTS18), myocontraction (PDE3B, CASQ2, and MYH10), and neurological responses (FOS, NCAM2, SYT1, SLC22A3, DOCK3, LRRTM1, LRRTM3, PRSS12, and ARPP21). The analysis of differential gene expressions between deciduous and permanent PDL tissues aids our understanding of histological and functional differences between them at the molecular level. PMID:23593441

Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; Park, Wonse; Choi, Hyung-Jun

2013-01-01

20

Tooth mobility changes subsequent to root fractures: a longitudinal clinical study of 44 permanent teeth.  

PubMed

The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured with a Mühlemanns periodontometer and noninjured incisors served as controls. The mobility values represented the labial-lingual excursion of the root measured in ?m when the tooth received a frontal and a palatal impact of 100 g force. In 18 cases of hard tissue healing (HT), a slightly increased mobility was seen after 3 months and 1 year, and a normalization of mobility value was usually found after 5 and 10 years. In 17 cases of PDL healing, generally a higher mobility was found in comparison with root fractures healing with hard tissue, and a consistent decrease in mobility value was found in the course of the 10 year observation period. A tendency for reduced mobility over time was found, a relation that could possibly be explained by the known general decrease in tooth mobility with increasing age. Finally, nine cases of nonhealing with initial interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment resulted in increasing mobility values possibly related to a lateral breakdown of the PDL in relation to the fracture line. In control teeth, a lowering of mobility was found over the course of a 10-year observation period. In conclusion, mobility changes appeared to reflect the radiographic healing stages and known age effects upon tooth mobility. PMID:22251277

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

2012-10-01

21

Health Instruction Packages: Permanent Teeth, Dental Deposits, and Dental Instruments. Dientes Permanentes, Depositos Dentales y Instrumentos Dentales.  

ERIC Educational Resources Information Center

These five learning modules use text interspersed with illustrations and reinforcement exercises to instruct dental aide and dental hygiene students about jaw bones and gums, dental deposits, and dental instruments. The first four modules were prepared by Patricia Lind in both Spanish and English. "The Gum and Bone of Permanent Teeth" ("La Encia y…

Lind, Patricia; Germano, Catherine

22

The effect of low-level laser therapy (810 nm) on root development of immature permanent teeth in dogs.  

PubMed

Traumatic injuries and dental caries can be a big challenge to immature teeth. In these cases, the main purpose of treatment is to maintain the pulp vitality. The purpose of this study was to investigate the effect of low-level laser therapy on accelerating the rate of dentinogenesis in pulpotomy of immature permanent teeth (apexogenesis). Three dogs, 4-6 months old, were used in this study. One jaw in each dog was randomly assigned to laser irradiation group. All selected teeth were pulpotomized with mineral trioxide aggregate (MTA) and restored with amalgam. In the laser group, the Ga-Al-As laser (810 nm, 0.3 W, 4 J/cm(2), 9 s) was used on buccal and lingual gingiva of each tooth in 48 h intervals for 2 weeks. In order to observe the newly formed dentine, tetracycline was injected on the 1st, 3rd, 7th, and 14th day after the operation. Then, ground sections of teeth were observed under a fluorescence microscope. The data was analyzed with Generalized Estimating Equations (GEE) test. The mean distance between the lines of tetracycline formed on the 1st and 14th day was significantly higher in the laser group (P?=?0.005). Within the limitation of this study, irradiation of Ga-Al-As laser (810 nm) can accelerate the rate of dentinogenesis in apexogenesis of immature permanent teeth with MTA in dogs. PMID:24858234

Fekrazad, Reza; Seraj, Bahman; Ghadimi, Sara; Tamiz, Parvin; Mottahary, Pouriya; Dehghan, Mohammad-Mehdi

2015-05-01

23

Reasons for and patterns relating to the extraction of permanent teeth in a subset of the Saudi population  

PubMed Central

Background The purpose of this study was to investigate the reasons for and patterns of extraction of permanent teeth in a subset of the Saudi population. Methods During a 3-month period, dentists were asked to record, using a specially designed survey form, the reasons for every extraction of a permanent tooth. The reasons for tooth extraction were assigned to different causes, ie, dental caries, periodontal disease, eruption problems, trauma, orthodontics, failed root canal treatment, and others. The data requested for each extraction were: patient age, gender, nationality, and type of tooth removed and the reason for its extraction. Results The highest percentage of extractions was observed in young females aged 10–30 years. Presence of caries was observed to be the main reason for extraction (50.2%) followed by orthodontic problems (18.2%), eruption problems (17.5%), and periodontal problems (8.2%). The most frequently extracted posterior teeth were the third mandibular molar (19.4%), the third maxillary molar (16.4%), the first maxillary premolar (13.2%), and the first mandibular molar (10.9%). Conclusion Dental caries was found to be the most common reason for extraction of teeth. Molar teeth were found to be the most frequently extracted, with an increased number of extracted first premolars as a result of orthodontic treatment. The highest percentage of extractions was observed in young females aged 10–30 years. PMID:23986651

Alesia, Khalil; Khalil, Hesham S

2013-01-01

24

Posttraumatic Displacement Management: Lateral Luxation and Alveolar Bone Fracture in Young Permanent Teeth with 5 Years of Follow-Up  

PubMed Central

Dental trauma is an important public health problem due to high prevalence and associated limitations. The external impact accounting for trauma may result in different injury types to teeth and supporting structures. This paper describes a clinical case of tooth trauma in an 8-year-old patient exhibiting the displacement of three permanent teeth with open root apexes. Although the traumatic impact resulted in two injury types to teeth and supporting tissues (lateral luxation and alveolar bone fracture), the therapeutic approach was the same in both situations. The bone and teeth were repositioned by digital pressure, stabilized by semirigid splint, and followed up at every week. After six weeks, the splint was removed. At that moment, the clinical and radiographic findings indicated normal soft/hard tissues and absence of pulp/periodontal pathologies. At the fifth year of follow-up, the treatment success of the case was confirmed, although it has been observed that all lower incisors exhibited pulp obliteration as a consequence of the dental trauma.

Honório, Heitor Marques; de Alencar, Catarina Ribeiro Barros; Pereira Júnior, Edmer Silvestre; de Oliveira, Daniela Silva Barroso; de Oliveira, Gabriela Cristina; Rios, Daniela

2015-01-01

25

Pulp Revascularization of Immature Permanent Teeth: A Review of the Literature and a Proposal of a New Clinical Protocol  

PubMed Central

Tissue engineering is a growing field. In the near future, it will probably be possible to generate a complete vital tooth from a single stem cell. Pulp revascularization is dependent on the ability of residual pulp and apical and periodontal stem cells to differentiate. These cells have the ability to generate a highly vascularized and a conjunctive rich living tissue. This one is able to colonize the available pulp space. Revascularization is a new treatment method for immature necrotic permanent teeth. Up to now, apexification procedures were applied for these teeth, using calcium dihydroxide or MTA to produce an artificial apical barrier. However, the pulp revascularization allows the stimulation of the apical development and the root maturation of immature teeth. Two pulp revascularization techniques are used in the literature, one using calcium dihydroxide and the second using a triple antibiotic paste. Based on these two different pulp revascularization protocols, which obtain the desired therapeutic success, the literature will be reviewed and analyzed according to the relevance of their choice of materials. Based on the literature, we propose a new relevant protocol and a new mixture of antibiotics. PMID:25383384

Namour, Mélanie

2014-01-01

26

Eruption of teeth in the nose following trauma to the primary and permanent dentitions  

Microsoft Academic Search

Oro-facial trauma is common and forms a large component of any maxillofacial service workload. Even minor trauma can result in significant oro-facial and dental injury. This report reinforces the importance of a careful dental history and thorough examination, particularly when teeth remain missing after initial inspection. Other anatomical sites should be considered to ensure they do not contain traumatically displaced

W P Smith; M J Gilbride

2005-01-01

27

Radiographic assessment of clinical root-crown ratios of permanent teeth in a healthy Korean population  

PubMed Central

PURPOSE The aim of this study was to determine the absolute value of the root/crown ratio (R/C ratio) using panoramic radiographs (PRGs) in a healthy Korean population. MATERIALS AND METHODS In total, 99 patient radiographs (of 50 males and 49 females subjects; aged 16 to 24 years old) were examined, and 2,770 teeth were analyzed. Crown lengths and root lengths were measured with modified Lind's measurements using PACS tools by two examiners in two separate sessions two months apart. All data were analyzed using SPSS. The independent t-test was used to assess for gender differences, and the paired t-test was used to compare both arches with a significance level of P<.05. RESULTS The mean R/C ratios varied from 1.29 to 1.89 (male: 1.28-1.84; females: 1.31-1.94). The highest R/C ratios were recorded for the mandibular canines (1.89), followed by the maxillary canines (1.79). The lowest R/C ratios were recorded for the maxillary second molars (1.31). In comparison with the maxillary teeth (1.29-1.78), the mandibular teeth yielded the higher R/C ratio (1.47-1.89), and this difference was significant in the females (P<.05). The difference between the genders was not statistically significant, except for the maxillary central incisors, mandibular canines and mandibular first premolars. CONCLUSION These data may enhance the understanding of the clinical R/C ratio as a useful guideline for determining the status of teeth and the ethnic difference. PMID:25006380

Yun, Hee-Jung; Jeong, Jin-Sun; Pang, Nan-Sim; Kwon, Il-Keun

2014-01-01

28

Fatigue resistance of bovine teeth restored with resin-bonded fiber posts: effect of post surface conditioning.  

PubMed

This study evaluated the effect of post surface conditioning on the fatigue resistance of bovine teeth restored with resin-bonded fiber-reinforced composite (FRC). Root canals of 20 single-rooted bovine teeth (16 mm long) were prepared to 12 mm using a preparation drill of a double-tapered fiber post system. Using acrylic resin, each specimen was embedded (up to 3.0 mm from the cervical part of the specimen) in a PVC cylinder and allocated into one of two groups (n = 10) based on the post surface conditioning method: acid etching plus silanization or tribochemical silica coating (30 pm SiO(x) + silanization). The root canal dentin was etched (H2PO3 for 30 seconds), rinsed, and dried. A multi-step adhesive system was applied to the root dentin and the fiber posts were cemented with resin cement. The specimens were submitted to one million fatigue cycles. After fatigue testing, a score was given based on the number of fatigue cycles until fracture. All of the specimens were resistant to fatigue. No fracture of the root or the post and no loss of retention of the post were observed. The methodology and the results of this study indicate that tribochemical silica coating and acid etching performed equally well when dynamic mechanical loading was used. PMID:18254561

Zamboni, Sandra C; Baldissara, Paolo; Pelogia, Fernanda; Bottino, Marco Antonio; Scotti, Roberto; Valandro, Luiz Felipe

2008-01-01

29

Gastroesophageal reflux in children with cerebral palsy and its relationship to erosion of primary and permanent teeth.  

PubMed

Patients with cerebral palsy are known to have a high incidence of feeding difficulties, including problems with swallowing, vomiting, recurrent chest infections, and irritability. Gastroesophageal reflux (GER) is an involuntary passage of the gastric contents into the esophagus. It has been found in a higher prevalence (up to 75 percent) in cerebral palsy patients. Long-term gastric acid attacks teeth and can cause dental erosion. Bargen and Austin first discovered the relationship between GER and dental erosion in 1937 when they concluded that the loss of dental hard tissue could be an indicator and the predominant oral manifestation of GER. The purpose of this study is to investigate the correlation between GER and dental erosion in primary and permanent teeth in cerebral palsy patients. Twenty-one patients participated in this study. Results showed that out of the 21 patients, 15 had erosion and 11 of them had GER history. The chi-square analysis with the p value of less than or equal to 0.025 showed the distribution to be significant. The severity of the erosion was correlated to the duration of the disease, frequency of vomiting, pH of the acid, type of acid, and quantity and quality of saliva. The study revealed that children with cerebral palsy have an increased prevalence of tooth erosion, which may be attributed to the existing gastroesophageal reflux. PMID:12886578

Su, Jo-Mei; Tsamtsouris, Anthi; Laskou, Meletia

2003-01-01

30

Qualitative Histological Evaluation of Hard and Soft Tissue Components of Human Permanent Teeth Using Various Decalcifying Agents - A Comparative Study  

PubMed Central

Introduction: Decalcification is the commonly employed technique in histopathology laboratories as a part of calcified tissue preparation for the microscopic examination. Chemical agents are most commonly used for routine decalcification procedures, though some agents adversely affect the tissue integrity and staining properties. Aim: To compare the efficacy of various decalcifying agents by histological evaluation of hard and soft tissue components of teeth. Materials and Methods: The five decalcifying agents namely 10% Nitric acid (HNO3), 10% Formal nitric acid (FNA), 10 % Formic acid (FA), 8% Potassium formate (KF) + 8% Formic acid (FA) and Neutral Ethylenediamenetetracetic acid (EDTA) were used to decalcify 60 human permanent teeth. The specimens were subjected to routine processing, sectioning and staining with hematoxylin and eosin. The stained sections were observed under light microscope by three independent observers and grading was done. Statistical Analysis: Paired sample t-test was done for inter-observer variation. One-way-ANOVA and Post-hoc test was applied to compare the effects of different decalcifying agents. Results: Considering preservation and staining characteristics of both hard and soft tissues, superior results were obtained with 10% HNO3 followed by 10% FNA and EDTA which was according to the respective mean values obtained. But statistically significant difference was shown only with 10% FA & 8% KF + 8% FA. Conclusion: HNO3 was showing the most efficient result as it balances both tissue integrity and time factor suggesting that it can be used as a stable decalcifying agent for routine histopathological diagnosis. PMID:25386527

Jawanda, Manveen Kaur; SM, Manjunath; Bharti, Achla

2014-01-01

31

Teeth Injuries (For Parents)  

MedlinePLUS

... if a permanent tooth is dislodged, it's a dental emergency. Permanent teeth have the best chance of survival if replaced ... steps: Find the tooth. Call a dentist or emergency room right away if you aren't sure if it's a permanent tooth (baby teeth have smooth edges). Hold the tooth by the ...

32

Influence of effective number of pulses on the morphological structure of teeth and bovine femur after femtosecond laser ablation  

NASA Astrophysics Data System (ADS)

Femtosecond lasers have been widely used in laser surgery as an instrument for contact-free tissue removal of hard dental, restorative materials, and osseous tissues, complementing conventional drilling or cutting tools. In order to obtain a laser system that provides an ablation efficiency comparable to mechanical instruments, the laser pulse rate must be maximal without causing thermal damage. The aim of this study was to compare the different morphological characteristics of the hard tissue after exposure to lasers operating in the femtosecond pulse regime. Two different kinds of samples were irradiated: dentin from human extracted teeth and bovine femur samples. Different procedures were applied, while paying special care to preserving the structures. The incubation factor S was calculated to be 0.788+/-0.004 for the bovine femur bone. These results indicate that the incubation effect is still substantial during the femtosecond laser ablation of hard tissues. The plasma-induced ablation has reduced side effects, i.e., we observe less thermal and mechanical damage when using a superficial femtosecond laser irradiation close to the threshold conditions. In the femtosecond regime, the morphology characteristics of the cavity were strongly influenced by the change of the effective number of pulses.

Nicolodelli, Gustavo; de Fátima Zanirato Lizarelli, Rosane; Salvador Bagnato, Vanderlei

2012-04-01

33

Relationship between Malnutrition and the Number of Permanent Teeth in Filipino 10- to 13-Year-Olds  

PubMed Central

In the present study, we determined whether there is a delay in the eruption of permanent teeth (PT) among Filipino adolescents with stunting or thinness. Height, weight, and number of PT were recorded in 1554 Filipino 10- to 13-year-olds (711 boys; 843 girls). z-scores for height (HAZ) and body mass index (BMI) were calculated according to the WHO growth reference, and their correlations to the number of PT were assessed. 54.9% of the children have at least one form of malnutrition. Significantly, more boys (22.9%) than girls (16.5%) were thin, while no sex difference in stunting was noted (boys 48.5%; girls 44.0%). The number of PT was significantly correlated to HAZ and BMI-z-score. Stunted and thin students had significantly fewer PT than their nonaffected peers. These differences tended to be the result of delay in tooth eruption in thin and stunted adolescents. In 13-year-old girls, all PT were erupted regardless of their nutritional status indicating a catch-up. Thin and stunted boys had one tooth less than normal boys at this age. Impaired physical growth and dental development seem to have common risk factors. Therefore, regular monitoring of growth and dental development might be helpful for targeting support programmes in developing countries. PMID:24069590

Heinrich-Weltzien, Roswitha; Monse, Bella

2013-01-01

34

Bacterial 16S Sequence Analysis of Severe Caries in Young Permanent Teeth ?  

PubMed Central

Previous studies have confirmed the association of the acid producers Streptococcus mutans and Lactobacillus spp. with childhood caries, but they also suggested these microorganisms are not sufficient to explain all cases of caries. In addition, health-associated bacterial community profiles are not well understood, including the importance of base production and acid catabolism in pH homeostasis. The bacterial community composition in health and in severe caries of the young permanent dentition was compared using Sanger sequencing of the ribosomal 16S rRNA genes. Lactobacillus species were dominant in severe caries, and levels rose significantly as caries progressed from initial to deep lesions. S. mutans was often observed at high levels in the early stages of caries but also in some healthy subjects and was not statistically significantly associated with caries progression in the overall model. Lactobacillus or S. mutans was found either at low levels or not present in several samples. Other potential acid producers observed at high levels in these subjects included strains of Selenomonas, Neisseria, and Streptococcus mitis. Propionibacterium FMA5 was significantly associated with caries progression but was not found at high levels. An overall loss of community diversity occurred as caries progressed, and species that significantly decreased included the Streptococcus mitis-S. pneumoniae-S. infantis group, Corynebacterium matruchotii, Streptococcus gordonii, Streptococcus cristatus, Capnocytophaga gingivalis, Eubacterium IR009, Campylobacter rectus, and Lachnospiraceae sp. C1. The relationship of acid-base metabolism to 16S rRNA gene-based species assignments appears to be complex, and metagenomic approaches that would allow functional profiling of entire genomes will be helpful in elucidating the microbial pathogenesis of caries. PMID:20826648

Gross, Erin L.; Leys, Eugene J.; Gasparovich, Stephen R.; Firestone, Noah D.; Schwartzbaum, Judith A.; Janies, Daniel A.; Asnani, Kashmira; Griffen, Ann L.

2010-01-01

35

Comparative evaluation of Shear bond strength of different Pit and fissure Sealants in Primary and Permanent teeth - An In-Vitro Study  

PubMed Central

Background: Dental caries among children is one of the greatest challenges faced by dentists globally; especially that of susceptible surfaces like the Pit and fissures. Dental sealants have proved to be an effective way to prevent caries development. The Clinical success of any material depends upon its adhesion to tooth structure, resistance to wear and ability to withstand the masticatory or occlusal forces. Hence it is important to evaluate the shear bond strength (SBS). The Present study’s aim was to evaluate and compare the shear bond strength of different pit and fissure sealants placed on Primary molars and Permanent Premolars. Materials & Methods: Sixty noncarious extracted teeth comprising of thirty Primary molars and thirty Permanent Premolars were divided into four groups of 15 each. The buccal surfaces of all teeth were dried, etched and the etched surfaces of Primary molars (Group I) and Permanent Premolars (Group III) were placed with Helioseal-F while Groups II and IV, that included Primary molars and Permanent Premolars received Clinpro. Shear bond strength was evaluated and the mean was obtained for all the groups. The results were analyzed using twoway analysis of variance followed by Tukeys post hoc procedure to check for significant differences. Results: The specimens of unfilled sealant Clinpro (Groups II & IV) showed higher Shear bond strength when compared to the specimens of filled sealant Helioseal-F (Groups I & III). Conclusion: The unfilled sealant showed a better Shear bond strength compared to the filled sealant. The bond strength in Primary molars was slightly higher compared to Permanent Premolars. How to cite the article: Pushpalatha HM, Ravichandra KS, Srikanth K, Divya G, Done V, Krishna KB, Patil V. Comparative evaluation of Shear bond strength of different Pit and fissure Sealants in Primary and Permanent teeth - An In-Vitro Study. J Int Oral Health 2014;6(2):84-9. PMID:24876707

Pushpalatha, H M; Ravichandra, K S; Srikanth, Koya; Divya, G; Done, Vasanthi; Krishna, K Bala; Patil, Vishwanath

2014-01-01

36

Combined Orthodontic-surgical Treatment for Skeletal Class III Malocclusion with Multiple Impacted Permanent and Supernumerary Teeth: Case Report  

PubMed Central

In this report we describe a combined orthodontic and surgical treatment for a 14-year-old boy with severe skeletal class III deformity and dental problem. His upper posterior primary teeth in the left side were over-retained and 6 maxillary teeth (bilateral central incisors and canines, left first and second premolars) were impacted, together with 5 supernumerary teeth in both arches. The treatment protocol involved extraction of all the supernumerary and deciduous teeth, surgical exposure and orthodontic traction of the impacted teeth, a bimaxillary orthognathic approach including Lefort I osteotomy. Bilateral sagittal split ramus osteotomy (BSSRO) and genioplasty was performed to correct skeletal problem. After treatment, all of the impacted teeth were brought to proper alignment in the maxillary arch. A satisfied profile and good posterior occlusion was achieved. Treatment mechanics and consideration during different stages are discussed. PMID:24893948

Xue, Dai Juan and Feng

2014-01-01

37

Diastema (Gap between Teeth)  

MedlinePLUS

... big for the jaw, teeth will be crowded. Spaces develop for a few other reasons as well. Sometimes some teeth are missing ... the permanent teeth and the jaw size, the spaces can be expected to remain throughout life. Gaps caused by a tongue thrust habit or ...

38

Diffusion analysis of one photosensitizer in bovine teeth using fluorescence optical imaging  

NASA Astrophysics Data System (ADS)

Some photosensitizers (PSs) used for PACT (Antimicrobial Photodynamic Therapy) show an affinity for bacterial walls and can be photo-activated to cause the desired damage. However, on dentine bacterias may be less susceptible to PACT as a result of limited penetration of the PS. The aim of this study was to evaluate the diffusion of one PS based on hematoporphyrin on dentine structures. Twelve bovine incisors were used. Class III cavities (3 x 3 x 1mm) were prepared on the mesial or distal surfaces using a diamond bur. Photogem® solution at 1 mg/mL (10 uL for each cavity) was used. The experimental Groups were divided according to thickness of dentine remaining and etched or no-etched before the PS application. The fluorescence excitation source was a VelScope® system. For image capture a scientific CCD color camera PixelFly® was coupled to VelScope. For image acquisition and processing, a computational routine was developed at Matlab®. Fick's Law was used to obtain the average diffusion coefficient of PS. Differences were found between all Groups. The longitudinal temporal diffusion was influenced by the different times, thickness and acid etching.

Montanha, S.; Pratavieira, S.; Jacomassi, D. P.; Rastelli, A. N. S.; Bagnato, V. S.

2012-01-01

39

Morphogenesis and age-related structure of permanent canine teeth in the brown bear, Ursus arctos L., in Arctic Alaska  

Microsoft Academic Search

Morphogenesis of the canine teeth of the brown bear, Ursus arctos L., is described, based upon 101 skulls from the central Brooks Range, in arctic Alaska. The formation of annual layers in the calcified tissues (dentin and cementum) is attributed to interruption of growth and odontogenesis during the annual period of denning.

Robert L. Rausch

1969-01-01

40

An infected dentigerous cyst associated with an impacted permanent maxillary canine, inverted mesiodens and impacted supernumerary teeth  

PubMed Central

A dentigerous cyst is an odontogenic cyst associated with the crown of the impacted or unerupted teeth. Such cyst remain initially completely asymptomatic unless when infected and can be discovered only on routine radiographic examination. Here, such a case of dentigerous cyst, which was discovered on routine radiographic examination, is discussed here. PMID:23956591

Mohan, Karthik Rajaram; Natarajan, Balan; Mani, Sudhaamani; Sahuthullah, Yasmeen ahmed; Kannan, Arivukkadal Vijaya; Doraiswamy, Haritha

2013-01-01

41

A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study  

PubMed Central

Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF), platelet-rich plasma (PRP), and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher's exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2) which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot. PMID:25684914

Narang, Isha; Mittal, Neelam; Mishra, Navin

2015-01-01

42

Apical Extrusion of Irrigants in Immature Permanent Teeth by Using EndoVac and Needle Irrigation: An In Vitro Study  

PubMed Central

Objective: Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation. Materials and Methods: Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20): EndoVac Microcannula (group I), EndoVac Macrocannula (group II), NaviTip irrigation needle (group III) and Max-i-Probe Irrigating needle (group IV); 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically. Results: Group I, group III and group IV showed 100% extrusion (20/20) but group II showed only 40% extrusion (8/20). The difference in this respect between group II and other groups was statistically significant (P<0.001). With regards to the volume of extrusion, group II had only 0.23 ml of extruded irrigant. Group I extruded 7.53ml of the irrigant. Group III and group IV extruded the entire volume of irrigant delivered. Conclusion: EndoVac Macrocannula resulted in the least extrusion of irrigant in immature teeth when compared to EndoVac Microcannula and conventional needle irrigation. PMID:25584055

Velmurugan, N; Sooriaprakas, C; Jain, Preetham

2014-01-01

43

Specialized stem cell niche enables repetitive renewal of alligator teeth  

E-print Network

for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose

Chuong, Cheng-Ming

44

Teething Tots  

MedlinePLUS

... appear. Next to break through are the first molars (the back teeth used for grinding food), then finally the eyeteeth (the pointy teeth in the upper jaw). Most kids have all 20 of their primary teeth by their third birthday. (If your child's teeth come in much ...

45

Dinosaur Teeth  

NSDL National Science Digital Library

In this classroom activity, middle school students learn what kinds of information can be gained by studying teeth. The activity opens with background information for teachers about dinosaur teeth. Working in small groups, students examine their own teeth; hypothesize about how incisors, canine teeth, and molars are used; and test their hypotheses with carrots. The activity concludes with a student worksheet that challenges them to identify the uses of different dinosaur teeth.

46

Comparative study of CO2 and Nd:YAG laser on dentin layer of human root canals of permanent teeth utilizing scanning electron microscopy  

Microsoft Academic Search

The present paper investigated the effects of two different laser beams on dentin and root canal walls. Five human intact teeth (incisors and canines), with endodontic treatment accomplished by Paiva and Antoniazzi technique, had their crowns separated from the roots using a diamond teeth. After polishing the dentin surfaces, they were irradiated with CO2 and NdYag laser and analyzed using

Aldo Brugnera; Marcia C. Lopes; Koukichi Matsumoto; S. Watanabe II

1998-01-01

47

Sensitive Teeth  

MedlinePLUS

... down, rather than side to side Using a fluoride toothpaste and mouth rinse Using a toothpaste that ... After a cleaning, your dentist may apply a fluoride varnish to protect your teeth. This temporarily reduces ...

48

Variations in the vestibular cortical bone of permanent canine teeth in orthodontic patients. a comparative study: linear tomography vs. cbct (3d accuitomo).  

PubMed

The aim of this study was to compare the results of measuring the height of the vestibular cortical bone of canine teeth by linear tomography (LT) and 3-D Accuitomo cone beam computed tomography (CBCT) before and after aligning dental arches by orthodontic treatment. LT and CBCT were performed before and after orthodontic alignment on 12 canines in three patients undergoing orthodontic treatment, and the height of the canine vestibular cortical bones measured in mm. Measurements were taken by double-blinded operators. The mean variation in height of the vestibular cortical bone with orthodontic treatment was - 0,33 mm} 0.233 standard error using CBCT and -0,08mm } 0.55 standard error using LT. Analysis of variance (ANOVA) was performed to compare the techniques, the patients and upper and lower canines. No significant difference was found for any of the cases. Using LT to evaluate vestibular crest cortical bone in canines is comparable in efficiency to using CBCT. Height in millimeters is less in LT because image resolution is lower and when it is very thin it is not appreciable by this method. PMID:25523955

Mateu, María E; Martínez, M E; Dagum, H; Benítez Rogé, Sandra C; Bruno, Gabriela I; Hecht, Pedro; Folco, Alejandra A

2014-01-01

49

The study of barium concentration in deciduous teeth, impacted teeth, and facial bones of Polish residents.  

PubMed

The study determines the concentration of Ba in mineralized tissues of deciduous teeth, permanent impacted teeth, and facial bones. The study covers the population of children and adults (aged 6-78) living in an industrial area of Poland. Teeth were analyzed in whole, with no division into dentine and enamel. Facial bones and teeth were subjected to the following preparation: washing, drying, grinding in a porcelain mortar, sample weighing (about 0.2 g), and microwave mineralization with spectrally pure nitric acid. The aim of the study was to determinate the concentration of Ba in deciduous teeth, impacted permanent teeth, and facial bones. The concentration of barium in samples was determined over the ICP OES method. The Ba concentration in the tested bone tissues amounted to 2.2-15.5 ?g/g (6.6 ?g/g ± 3.9). The highest concentration of Ba was present in deciduous teeth (10.5 ?g/g), followed by facial bones (5.2 ?g/g), and impacted teeth (4.3 ?g/g) (ANOVA Kruskal-Wallis rank test, p = 0.0002). In bone tissue and impacted teeth, Ba concentration increased with age. In deciduous teeth, the level of Ba decreased with children's age. PMID:25077468

Fischer, Agnieszka; Malara, Piotr; Wiechu?a, Danuta

2014-10-01

50

Armor for Your Teeth  

MedlinePLUS

... on your back teeth. These teeth are called molars. The tops of these teeth have little grooves. ... hygienist will put sealants on when your adult molars come in. Your first adult molars come in ...

51

Prevalence, etiology, diagnosis, treatment and complications of supernumerary teeth  

PubMed Central

The aim of this article was to review the literature on supernumerary teeth, analyzing their prevalence, etiology, diagnosis, treatment and possible complications. An electronic search was made in the Pubmed-Medline database up to January 2014 using the key search terms “multiple supernumerary teeth” (n=279), “prevalence supernumerary teeth” (n=361), and “supernumerary teeth” (n=2412). In addition to the articles initially identified, others were included in the review proceeding from a manual search and from any references considered of relevance. Supernumerary teeth are those that exceed the normal dental formula. They are more common in men, more common in the upper maxilla, and more prevalent in permanent dentition. Complications associated with supernumerary teeth include dental impaction, delayed eruption, ectopic eruption, overcrowding, spacing anomalies and the formation of follicular cysts. The treatment of supernumerary teeth depends on their type, position, and possible complications, detected clinically and radiographically. No clear consensus exists as to the best time to extract unerupted supernumerary teeth. Key words:Hyperdoncia, supernumerary teeth, impacted teeth, treatment, permanent teeth, deciduous teeth. PMID:25593666

Ata-Ali, Fadi; Peñarrocha-Oltra, David; Peñarrocha-Diago, Miguel

2014-01-01

52

Dental Hygiene: How to Care for Your Child's Teeth  

MedlinePLUS

... Once your child is preschool-age, start using fluoride toothpaste. Don't cover the brush with toothpaste; ... most of the toothpaste, and swallowing too much fluoride toothpaste can cause permanent stains on their teeth. ...

53

Late Developing Supernumeraries in a Case of Nonsyndromic Multiple Supernumerary Teeth  

PubMed Central

Objective. This case report presents 3-year follow-up of a case of nonsyndromic multiple supernumerary teeth (NSMST) with 11 supernumerary teeth, 2 of which showed subsequent formation. Case Report. A 10-year-old girl was referred to the dental clinic with the chief complaint of delayed eruption. Radiographic examination showed 9 retained supernumerary teeth. The treatment plan consisted of extraction of the supernumerary teeth and associated primary teeth in order to allow the permanent teeth to erupt. After 2 years of follow-up, 2 additional supernumerary teeth were observed. Conclusion. Regular follow-up for late forming supernumeraries is crucial for NSMST cases. PMID:25649422

Bozkurt, Mine; Tüzüner Öncül, Ay?egül; Göçer, Rukiye; Sar?, ?aziye

2015-01-01

54

Supernumerary teeth: Report of four unusual cases  

PubMed Central

Supernumerary tooth denotes duplication of tooth in the normal series. It is a developmental anomaly and has been argued to arise from multiple etiologies. These teeth may remain embedded in the alveolar bone or can erupt into the oral cavity. The supernumerary tooth might cause esthetic and/or functional problems, especially if it is situated in the maxillary anterior region. Complications reported were delayed or prevented eruption of succedaneous teeth, displacement or rotation, crowding of the affected region, abnormal diastema, dilacerations, cystic formation, and sometime eruption into the nasal cavity. In this case report, four unusual cases of supernumerary teeth that resulted in varying degrees of disturbances in permanent dentition are presented. Conservative surgical intervention and light orthodontic forces were used to bring the teeth into normal position with minimal disturbance to the surrounding oral structures. PMID:22629072

Kumar, Arun; Namdev, Ritu; Bakshi, Lokesh; Dutta, Samir

2012-01-01

55

Wisdom Teeth Management  

MedlinePLUS

... c) may arise from impacted teeth. Wisdom Teeth Management Research has shown that once periodontal disease is ... of third molars, disease status, and to suggest management options ranging from removal to a monitored retention ...

56

Tiger shark teeth  

NSDL National Science Digital Library

Carnivores eat meat. Their teeth are designed to slice through the meat they catch. Their teeth are pointed and often have serrations, or cuts, made into the actual tooth so that it is jagged like a knife blade.

Stefan Kühn (None; )

2004-09-06

57

What Teeth Tell Us  

NSDL National Science Digital Library

In this classroom activity, young students investigate what paleontologists can tell from a dinosaur's teeth. The activity opens with background information for teachers about dinosaur teeth. Students begin by looking at animal photos and describing each creature's teeth. They then conduct an experiment that helps them differentiate between the teeth of meat-eaters and plant-eaters .The activity concludes with a student worksheet that challenges them to identify meat-eating and plant-eating dinosaurs.

58

Bilateral Supernumerary Teeth in Deciduous Dentition-A Rarity  

PubMed Central

Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition and more often seen in males. A supernumerary tooth in the primary dentition can cause ectopic or delayed eruption of permanent central incisors which will further alter occlusion and may compromise esthetics and formation of dentigerous cysts. Here we discuss a case of bilateral supernumerary teeth in deciduous dentition in a female child. PMID:24995257

Ghosh, Chiranjit; Mondal, Pradeep Kumar

2014-01-01

59

Supernumerary Teeth in Primary Dentition and Early Intervention: A Series of Case Reports  

PubMed Central

Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stages. They are of great concern to the dentists and parents because of the eruption, occlusal, and esthetic problems they can cause. Supernumerary teeth occur more frequently in the permanent dentition but rarely in primary dentition. Mesiodens is the most common type of supernumerary teeth but rarely seen in lower arch. Early recognition and diagnosis of supernumerary teeth is important to prevent further complications in permanent dentition. Four cases of supernumerary teeth with mesiodens in upper and lower arch in primary dentition and their management have been discussed. PMID:22888456

Bahadure, Rakesh N.; Thosar, Nilima; Jain, Eesha S.; Kharabe, Vidhi; Gaikwad, Rahul

2012-01-01

60

Fossilized Dinosaur Teeth Adaptations  

NSDL National Science Digital Library

In this activity, learners use models of fossilized dinosaur teeth to understand how dinosaur teeth were used. Learners specifically research Tyrannosaurus rex and Triceratops horridus dinosaurs and determine that Triceratops teeth work the way pliers and scissors operate, and T. rex teeth are like sharp knives. Learners match and sort dinosaurs by the type and use of their teeth. This activity is featured on pp.14-18 (part of a lesson that begins on p.7) of the "Dinosphere" unit of study for grades 3-5.

Rick Crosslin

2004-01-01

61

Natal and neonatal teeth.  

PubMed

Natal teeth (teeth present at birth) and neonatal teeth (teeth observed in the first 30 days of life) are uncommon. They may cause feeding problems and ulcerations on the ventral surface of the tongue. They can also be alarming to parents and cause discomfort with breastfeeding. A review of literature was conducted to review their etiology, significance, and clinical features with special emphasis on the complications and management. The opportunity of establishing a dental home through the early dental visits was highlighted. Furthermore, this case report details the examination and management of a 24-hour old neonate with 2 neonatal teeth. Natal teeth, although uncommon, are best referred to pediatric dentists for investigation and management. PMID:24825813

Farsi, Deema J; Ahmed, Muhammad M

2014-05-01

62

Taking Care of Your Teeth  

MedlinePLUS

... a toothache, they had their teeth pulled out. Finally, people learned that cleaning their teeth was important, ... was only about 100 years ago that someone finally created a minty cream to clean teeth. Not ...

63

Mouth and Teeth (For Parents)  

MedlinePLUS

... system , but it does much more than get digestion started. The mouth — especially the teeth, lips, and ... Mouth and Teeth Do The first step of digestion involves the mouth and teeth. Food enters the ...

64

Shark Teeth Classification  

NSDL National Science Digital Library

On a recent autumn afternoon at Harmony Leland Elementary in Mableton, Georgia, students in a fifth-grade science class investigated the essential process of classification--the act of putting things into groups according to some common characteristics or attributes. While they may have honed these skills earlier in the week by grouping their own shoes or school supplies, this class provided the unique opportunity to classify objects that are inherently fascinating to students--shark teeth fossils! This article describes how by using the teeth to estimate the length of ancient sharks, students got a classification activity they could really sink their teeth into.

Sally Creel

2009-03-01

65

Sequential Supernumerary Teeth Development in a Non-Syndromic Patient; Report of a Rare Case  

PubMed Central

Isolated impacted supernumerary teeth are quite rare, but they can be seen associated with several syndromes such as cleidocranial dysostosis or Gardner’s syndrome. This article aims to discuss a case of sequential formation of supernumerary teeth with no other associated disease or syndrome. A 17-year-old Iranian male with 8 impacted supernumerary teeth was referred to the department of pediatric dental clinic at Shahid Beheshti Medical University in Tehran with a history of several impacted unerupted teeth. Repeated and periodical clinical and radiographic examinations revealed newly formed teeth buds in unusual dental ages. All extra teeth were associated with generalized enamel hypoplasia to some degree on their relative permanent adjacent teeth. The patient did not have any record of a systemic disease or any syndromic condition to relate his dental problem to. This rare condition involved repeated and continued formation of extra teeth out of the normal numbers and dental age evident in serial radiographs. PMID:24910667

Jafarian, Mohammad; Nazemi, Bahareh; Bargrizan, Majid; Ramezani, Jamileh; Ansari, Ghassem

2013-01-01

66

Determination of fracture toughness of human permanent and primary enamel using an indentation microfracture method.  

PubMed

The purpose of the present study was to examine the fracture toughness and Vickers microhardness number of permanent and primary human enamel using the indentation microfracture method. Crack resistance and a parameter indirectly related to fracture toughness were measured in 48 enamel specimens from 16 permanent teeth and 12 enamel specimens obtained from six primary teeth. The Vickers microhardness number of the middle portion was greater than the upper portion in primary enamel. The fracture toughness was highest in the middle portion of permanent enamel, because fracture toughness greatly depends upon microstructure. These findings suggest that primary teeth are not miniature permanent teeth but have specific and characteristic mechanical properties. PMID:22639149

Hayashi-Sakai, Sachiko; Sakai, Jun; Sakamoto, Makoto; Endo, Hideaki

2012-09-01

67

Types of Teeth  

MedlinePLUS

... of 12). They are numbered first, second or third molars depending on their location. The first molars, also ... mouth, directly next to the second premolars. The third molars are also called the wisdom teeth. They are ...

68

Human teeth model  

NSDL National Science Digital Library

Humans are omnivores, meaning they eat both meat and plants. Omnivores generally have a mix of canines to shred meat and flat teeth to grind vegetation. The canines are less sharp than those seen in strict meat-eaters.

Håkan Svensson (None; )

2005-12-23

69

Initiation of teeth from the dental lamina in the ferret.  

PubMed

Mammalian tooth development is characterized by formation of primary teeth that belong to different tooth classes and are later replaced by a single set of permanent teeth. The first primary teeth are initiated from the primary dental lamina, and the replacement teeth from the successional dental lamina at the lingual side of the primary teeth. An interdental lamina connects the primary tooth germs together. Most mammalian tooth development research is done on mouse, which does not have teeth in all tooth classes, does not replace its teeth, and does not develop an interdental lamina. We have used the ferret (Mustela putorius furo) as a model animal to elucidate the morphological changes and gene expression during the development of the interdental lamina and the initiation of primary teeth. In addition we have analyzed cell-cell signaling taking place in the interdental lamina as well as in the successional lamina during tooth replacement. By 3D reconstructions of serial histological sections we observed that the morphogenesis of the interdental lamina and the primary teeth are intimately linked. Expression of Pitx2 and Foxi3 in the interdental lamina indicates that it has odontogenic identity, and there is active signaling taking place in the interdental lamina. Bmp4 is coexpressed with the stem cell factor Sox2 at its lingual aspect suggesting that the interdental lamina may retain competence for tooth initiation. We show that when tooth replacement is initiated there is Wnt pathway activity in the budding successional lamina and adjacent mesenchyme but no active Fgf or Eda signaling. Genes associated with human tooth replacement phenotypes, including Runx2 and Il11r?, are mostly expressed in the mesenchyme around the successional lamina in the ferret. Our results highlight the importance of the dental lamina in the mammalian tooth development during the initiation of both primary and replacement teeth. PMID:24393477

Jussila, Maria; Crespo Yanez, Xenia; Thesleff, Irma

2014-01-01

70

Delayed Replantation of Avulsed Teeth: Two Case Reports  

PubMed Central

This case report presents two cases of delayed replantation of avulsed maxillary central incisors after an extended dry extra-alveolar period. Eight-year-old boy and 10-year-old boy presented with avulsed maxillary central incisors due to trauma occurring 27 and 7 hours earlier, respectively. Treatment guidelines for avulsed mature/immature permanent teeth with prolonged extra-oral time were carried out for the teeth and the extra-oral endodontic treatment was completed. After having been repositioned, the teeth were stabilized for 4 weeks and prophylactic antibiotic was prescribed. Clinical and radiographic controls were done after 18 months for Case I and 12 months for Case II. During the follow-up periods the teeth reported in these cases have remained in a stable, functional position but revealed clinical initial replacement resorption and ankylosis.

Savas, Selcuk; Kucukyilmaz, Ebru; Akcay, Merve; Koseoglu, Serhat

2015-01-01

71

Scanning microscopy of platypus teeth  

Microsoft Academic Search

Anorganic unerupted developing teeth and airdired erupted teeth of the platypus (Ornithorhynchus anatinus) were examined in a scanning electron microscope and in a tandem scanning reflected light microscope. Typically mammalian developing fronts of enamel and dentine were identified in the anorganic unerupted specimens. The developing teeth were particularly small and fragile and the enamel elusive and difficult to examine in

Keith S. Lester; Alan Boyde

1986-01-01

72

Remarkable resilience of teeth  

PubMed Central

Tooth enamel is inherently weak, with fracture toughness comparable with glass, yet it is remarkably resilient, surviving millions of functional contacts over a lifetime. We propose a microstructural mechanism of damage resistance, based on observations from ex situ loading of human and sea otter molars (teeth with strikingly similar structural features). Section views of the enamel implicate tufts, hypomineralized crack-like defects at the enamel–dentin junction, as primary fracture sources. We report a stabilization in the evolution of these defects, by “stress shielding” from neighbors, by inhibition of ensuing crack extension from prism interweaving (decussation), and by self-healing. These factors, coupled with the capacity of the tooth configuration to limit the generation of tensile stresses in largely compressive biting, explain how teeth may absorb considerable damage over time without catastrophic failure, an outcome with strong implications concerning the adaptation of animal species to diet. PMID:19365079

Chai, Herzl; Lee, James J.-W.; Constantino, Paul J.; Lucas, Peter W.; Lawn, Brian R.

2009-01-01

73

The Innervation of Teeth  

PubMed Central

The author, using the staining methods of Bielschowski, Gross, Beckwith, Weigert-Pal and Cajal in frozen and serial paraffin and celloidin sections, has investigated the dental innervations of man, monkey, dog, cat, and guinea-pig in health and disease. He discusses the anatomy and physiology of the dental innervation and the effect of section of the inferior dental nerve on the trophic, vasomotor, protective, and sensory functions, with special reference to the relation between dental disease and neuropathies. He describes the innervation of the tooth germ and the nature of the growing fibrils seen before calcification in the dentinal papilla and draws attention to the innervation of the periodontal membrane. He has found that these nerves anastomose across the crest of the interdental septa with their fellows and demonstrates coiled sub-cemental nerve-endings. He has been unable to find any difference in the eruption and casting of teeth after section of the inferior dental nerve, and does not find degeneration of the nerves of deciduous teeth prior to casting to be inevitable. He discusses the effect of local anæsthesia on the dental pulp, some of the causes of odontalgia and neuralgia and the effect of old age and general disease on the dental innervation. He has failed with lethal or continued sublethal doses of ethyl and methyl alcohol, lead or tetanus and diphtheria toxins, using the oral, gastric, subcutaneous and intravenous route, to produce dental neuronic change. The effects of fracture of teeth and jaws, the introduction of arsenic into the pulp chamber and amputation and extirpation of the pulp are examined. The vital resistance of the pulp and the significance of granulomata as a protective mechanism are discussed. The author has found that after extraction although there is at first degeneration of the nerve-fibres concerned, there may subsequently be regeneration, sometimes in the form of plexiform neuroma. He has produced degenerative changes in both the nerves and the Gasserian ganglia on both the operated and unoperated sides by the introduction of tetanus and diphtheria toxins into extraction sockets, where the neuronic involvement is proportionate to the degree of trauma with which the extraction is effected. The rôle of innervation in tooth movement during eruption and orthodontic correction, and after the extraction of anterior teeth, has been investigated, the latter by roentgencinematography. ImagesFig. 3Fig. 4Fig. 1Fig. 2Fig. 5Fig. 6 PMID:19990651

Bradlaw, Robert

1936-01-01

74

Classical music and the teeth.  

PubMed

Teeth and their pathologies are frequent themes in classical music. The teeth have inspired popular songwriters such as Thomas Crecquillon, Carl Loewe, Amilcare Ponchielli & Christian Sinding; as well as composers whose works are still played all over the world, such as Robert Schumann and Jacques Offenbach. This paper examines several selections in which the inspiring theme is the teeth and the pain they can cause, from the suffering of toothache, to the happier occasion of a baby's first tooth. PMID:23691776

Eramo, Stefano; Di Biase, Mary Jo; De Carolis, Carlo

2013-01-01

75

Anomalies in primary dentition: Their distribution and correlation with permanent dentition  

PubMed Central

Background: Anomalies in primary dentition are often found to be associated with anomalies in permanent dentition. Aims: This study was performed to evaluate the prevalence of supernumerary teeth, hypodontia, double teeth, and talon cusp in the primary dentition, and their effect on succedaneous permanent teeth. Materials and Methods: In this prospective cross-sectional study, we clinically investigated 2757 Bengali speaking nursery children (1474 girls and 1283 boys), of age four to six years, at their respective schools, and the presence of supernumerary teeth, hypodontia, double teeth, and talon cusp in the primary dentition were recorded. Children with anomalous primary teeth were further subjected to periapical and panoramic radiographic examination, to determine the status of the underlying permanent teeth. Results: The total prevalence of all anomalies in this study was 1.8%. A total of 38 children (21 girls and 17 boys) had anomalies. The prevalence of anomalies was as follows: Supernumerary teeth (0.4%), hypodontia (0.5%), double teeth (0.4%), and talon cusp (0.07%), in both sexes combined. Radiographic examination showed 50% of the patients (19 children) had anomalies in the permanent dentition. Conclusions: Anomalies in primary dentition exhibited a correlation with anomalies in permanent dentition. PMID:24678213

Mukhopadhyay, Santanu; Mitra, Sanjib

2014-01-01

76

How to Care for Your Baby's Teeth  

MedlinePLUS

... doctor before using teething gels. What about breastfeeding, bottles and sippy cups? Teething does not have to ... starts teething. If you give your baby a bottle, always hold the baby when you feed him ...

77

Brief communication: The distribution of perikymata on Qafzeh anterior teeth.  

PubMed

Recent studies have suggested that Neandertals and modern humans differ in the distribution of perikymata (enamel growth increments) over their permanent anterior tooth crowns. In modern humans, perikymata become increasingly more compact toward the cervix than they do in Neandertals. Previous studies have suggested that a more homogeneous distribution of perikymata, like that of Neandertals, characterizes the anterior teeth of Homo heidelbergensis and Homo erectus as well. Here, we investigated whether Qafzeh anterior teeth (N = 14) differ from those of modern southern Africans, northern Europeans, and Alaskans (N = 47-74 depending on tooth type) in the percentage of perikymata present in their cervical halves. Using the normally distributed modern human values for each tooth type, we calculated Z-scores for the 14 Qafzeh teeth. All but two of the 14 Qafzeh teeth had negative Z-scores, meaning that values equal to these would be found in the bottom 50% of the modern human samples. Seven of the 14 would be found in the lowest 5% of the modern human distribution. Qafzeh teeth therefore appear to differ from those of modern humans in the same direction that Neandertals do: with generally lower percentages of perikymata in their cervical regions. The similarity between them appears to represent the retention of a perikymata distribution pattern present in earlier members of the genus Homo, but not generally characteristic of modern humans from diverse regions of the world. PMID:19902531

Guatelli-Steinberg, Debbie; Reid, Donald J

2010-01-01

78

Bacteriological analysis of necrotic pulp and fistulae in primary teeth  

PubMed Central

Objectives Primary teeth work as guides for the eruption of permanent dentition, contribute for the development of the jaws, chewing process, preparing food for digestion, and nutrient assimilation. Treatment of pulp necrosis in primary teeth is complex due to anatomical and physiological characteristics and high number of bacterial species present in endodontic infections. The bacterial presence alone or in association in necrotic pulp and fistula samples from primary teeth of boys and girls was evaluated. Material and Methods Necrotic pulp (103) and fistula (7) samples from deciduous teeth with deep caries of 110 children were evaluated. Bacterial morphotypes and species from all clinical samples were determined. Results A predominance of gram-positive cocci (81.8%) and gram-negative coccobacilli (49.1%) was observed. In 88 out of 103 pulp samples, a high prevalence of Enterococcus spp. (50%), Porphyromonas gingivalis (49%), Fusobacterium nucleatum (25%) and Prevotella nigrescens (11.4%) was observed. Porphyromonas gingivalis was detected in three out of seven fistula samples, Enterococcus spp. in two out of seven samples, and F. nucleatum, P. nigrescens and D. pneumosintes in one out of seven samples. Conclusions Our results show that Enterococcus spp. and P. gingivalis were prevalent in necrotic pulp from deciduous teeth in boys from 2 to 5 years old, and that care of the oral cavity of children up to five years of age is important. PMID:24676582

FABRIS, Antônio Scalco; NAKANO, Viviane; AVILA-CAMPOS, Mario Júlio

2014-01-01

79

Scorching effects of heat on extracted teeth - A forensic view  

PubMed Central

Context: Fire investigation is the multidisciplinary basis of the exploration, which involves investigations concerning the origin of fire, its cause as well as the identification of victims. At times, victim identification in fire disasters becomes nearly impossible owing to complete destruction of soft tissues. In such circumstances, teeth may prove to be of value since they are extremely hard. A precise understanding of physical and histological changes in teeth subjected to high temperature can provide valuable clues in fire and crime investigations, when dental evidence remains. Aim: The main aim and objective of the study was to investigate structural damage in freshly extracted teeth to heating, at different temperatures for a certain length of time in the laboratory. Settings and Design: Fifty-four freshly extracted teeth of different age groups had been subjected to different temperatures for a period of 15 minutes in the laboratory furnace. Physical and microscopic findings were correlated to the temperature. Materials and Methods: Freshly extracted 54 permanent teeth of different age groups were collected and were subjected to temperatures of 100°C, 300°C, and 600°C. Teeth were then examined for any physical changes such as change in color, texture, or morphology that occurred. Then the teeth were subjected for decalcification following which the tissues were kept for routine processing and were embedded in paraffin wax. Sections of 4 ?m thickness were made and stained in hematoxylin and eosin (H and E) to correlate the microscopic findings to the temperature. Statistical Analysis: Physical and microscopic findings were correlated to the temperature. Results: Microscopic examination revealed definite histological patterns, which were explicitly seen at a particular temperature. The samples showed cracks and charring of the tooth structure with microscopic findings such as widening of dentinal tubules and altered histological staining. Conclusion: Evaluation of incinerated dental remains may provide additional forensic investigative avenues in victim identification because of the consistency of morphological changes, the histological patterns at temperatures that are commonly encountered in common domestic fires. PMID:25177142

Prakash, Ajay P.; Reddy, Shyam D. P.; Rao, Madhusudan T.; Ramanand, O. V.

2014-01-01

80

Cogging Force Minimization in a Permanent Magnet Linear Generator for Sea Wave Energy Extraction Applications  

Microsoft Academic Search

This paper analyses the stator teeth geometry effects on cogging force of permanent magnet linear generators. The method making translator adjacent sides' permanent magnet allotropic is proposed to minimize the cogging force of four sided permanent magnet linear generators. The dynamic modeling of the generator's performance is based on finite element method. The generator is coupled to a particular mechanical

Dan Li; Baodong Bai; Qing Yu; Dezhi Chen

2009-01-01

81

Triple Teeth: Report of an Unusual Case  

PubMed Central

Fusion or synodontia is a union of two or more than two developing teeth. Commonly fusion occurs between teeth of the same dentition, mixed dentition, or between normal and supernumerary teeth. Fused primary teeth present with several clinical problems like caries, periodontal problem, arch asymmetry, delayed eruption, ectopic eruption of succedaneous teeth, aesthetic, and other complications. This paper presents a rare and unusual case of triple teeth in mandibular primary dentition. PMID:23346424

Babaji, Prashant; Prasanth, M. A.; Gowda, Ajith R.; Ajith, Soumya; D'Souza, Henston; Ashok, K. P.

2012-01-01

82

Apexification in Non-Vital Teeth with Immature Roots: Report of Two Cases  

PubMed Central

Apexification is a method of inducing apical closure for non-vital immature permanent teeth. During this treatment a mineralized barrier is induced [with long term calcium hydroxide (CH) treatment]; or artificially created [with mineral trioxide aggregate (MTA) plug]. This article describes two cases of apexification in immature necrotic teeth treated with these two different techniques. After 6 years of follow-up, clinical and radiographic control showed that both treatments were successful. PMID:25598816

Silva, Rogério Vieira; Silveira, Frank Ferreira; Nunes, Eduardo

2015-01-01

83

[Teeth arrangement of anterior artificial teeth. 1. Age and teeth exposure].  

PubMed

In selecting and arranging anterior artificial teeth for edentulous patients, it is necessary to consider their sex, personality, age and other factors. The relation of upper and lower lip lines to incisal edge has been one of the standards for the selection and the arrangement of anterior artificial teeth. The purpose of this report was to establish and to evaluate decision bases for the selection and arrangement. We recorded and measured the exposure rate of anterior natural teeth (48 men, 46 women) during function, such as smile, pronunciation, by means of the image analysis. Following results were obtained. 1. As the age of patients increased, upper anterior teeth appeared less than lower's. 2. Differences in exposure ratio between upper and lower teeth were found more remarkable in smiling rather than in pronunciation. PMID:2134794

Ishii, K; Maeda, Y; Idoji, S; Sogo, M; Mori, T; Okada, M; Nokubi, T; Okuno, Y; Tsutsumi, S

1990-04-01

84

Non-Syndromic Oligodontia of Primary and Permanent Dentition: 5 Year Follow Up- A Rare Case Report  

PubMed Central

Oligodontia designates the congenital absence of six or more permanent teeth, excluding the third molars. Oligodontia of primary and permanent dentition is a rare observance. This case report describes the missing teeth in primary and permanent dentition of an 8 year old boy. Early diagnosis, and comprehensive treatment planning with good coordination and timing of the individual treatment phases are decisive for a successful treatment outcome. PMID:23730675

Moses, Joyson; Gurunathan, Deepa; Rangeeth, B.N.; Kannan, K.S

2013-01-01

85

In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth  

PubMed Central

Background and aims. Heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). Geometrical characteristics of immature teeth are different from those of mature teeth. The purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the use of LED light-curing units (LCU). Materials and methods. This study was performed on the second mandibular premolars. This experimental investiga-tion was carried out for recording temperature variations of different sites of tooth and two dimensional finite element models were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the model validation phase. Results. Overall, thermal stimulation for 30 seconds with a low-intensity LED LCU increased the temperature from 28°C to 38°C in IIT (intact immature tooth) and PIT (cavity-prepared immature tooth). When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are required to determine thermal conductivity of immature teeth. PMID:25587383

Talebi, Maryam; Moghimi, Sahar; Shafagh, Mina; Kalani, Hadi; Mazhari, Fatemeh

2014-01-01

86

Delayed replantation of rat teeth after use of reconstituted powdered milk as a storage medium.  

PubMed

Minimal extraoral dry storage period and moist storage for the avulsed tooth are identified as key steps for the treatment protocol of tooth replantation. Among the possible moist storage media, bovine milk has stood out because of its capacity of preserving the integrity of the periodontal ligament (PDL) fibers. This condition has attracted the attention to investigate the use of powdered milk, which is one of the presentation forms of bovine milk, as a feasible storage medium in cases of delayed tooth replantation. The aim of this study was to evaluate the healing process after delayed replantation of rat teeth stored in reconstituted powdered milk and long shelf-life (ultra high temperature) whole milk. Forty maxillary right rat incisors were assigned to four groups (n = 10): group I--the teeth were extracted and immediately replanted into theirs sockets; group II--the teeth were stored for 60 min in 200 ml of freshly reconstituted powdered milk; group III--the teeth were stored for 60 min in 200 ml of long shelf-life whole milk; group IV--the teeth were kept dry for the same time. All procedures were performed at room temperature. Next, the root canals of teeth in groups II, III, and IV were instrumented, filled with a calcium hydroxide-based paste, and replanted into their sockets. All animals received systemic antibiotic therapy and were killed by anesthetic overdose 60 days after replantation. The pieces containing the replanted teeth were removed, fixed, decalcified, and paraffin-embedded. Semi-serial 6-microm-thick sections were obtained and stained with hematoxylin and eosin for histomorphological analysis. There was statistically significant difference (P < 0.05) between groups I and IV regarding the presence of replacement resorption and PDL remnants on root surface. The powdered milk and long shelf-life whole milk presented similar results to each other and may be indicated as storage media for avulsed teeth. PMID:19208010

dos Santos, Cláudia Letícia Vendrame; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Sundefeld, Maria Lúcia Marçal Mazza; Negri, Márcia Regina

2009-02-01

87

Compromised first permanent molars: an orthodontic perspective.  

PubMed

The first permanent molar (FPM) is commonly subject to significant compromise which may arise due to caries or endodontic complication, or from developmental anomalies such as hypoplasia. Compromised teeth with questionable prognosis may result in short and long-term clinical dilemmas. This review article highlights the factors that require careful consideration when a compromised FPM is detected and the importance of timely FPM extraction. Several clinical cases are described in detail to discuss possible treatment options from the orthodontic perspective. PMID:20415906

Ong, D C-V; Bleakley, J E

2010-03-01

88

Disinclusion of unerupted teeth by mean of self-ligating brackets: Effect of blood contamination on shear bond strength  

PubMed Central

Objectives: The aim of this study was to assess the effect of blood contamination on the shear bond strength and failure site of three different orthodontic self-ligating brackets. Study Design: 240 bovine permanent mandibular incisors were randomly divided into 12 groups of 20 specimens each. Orthodontic self-ligating brackets were tested under four different enamel surface conditions: a) dry, b) blood contamination before priming, c) blood contamination after priming, d) blood contamination before and after priming. Brackets were bonded to the teeth and subsequently tested using a Instron universal testing machine. Shear bond strength values and adhesive failure rate were recorded. Statistical analysis was performed using ANOVA and Tukey tests (strength values), and Chi squared test (ARI Scores). Results: Non-contaminated enamel surfaces showed highest bond strengths for all self ligating brackets. Under blood-contamination shear bond strengths lowered for all brackets tested. Groups contaminated before and after primer application showed the lowest shear bond strength. Significant differences in debond locations were found among the groups under the various enamel surface conditions. Conclusions: Blood contamination of enamel during the bonding procedure lowers bond strength values of self ligating brackets, expecially when contamination occur in different times of the bonding procedure. Key words:Disinclusion, self ligating brackets, blood, contamination, enamel, orthodontics, oral surgery. PMID:23229253

Sfondrini, Maria F.; Gatti, Sara; Gandini, Paola

2013-01-01

89

Nanoindentation and storage of teeth.  

PubMed

This study determined changes in nanomechanical properties of dentin and enamel during storage in deionized water, calcium chloride buffered saline solution and Hank's balanced salts solution (HBSS). Atomic force microscopy based nanoindentation showed that storing teeth in deionized water or CaCl(2)-solution resulted in a large decrease in elastic modulus and hardness. At 1 day a decrease in the mechanical properties values of up to 20% and 30% was observed for enamel and dentin, respectively. After 1 week, mechanical properties dropped below 50% of their starting values, which is attributed to a demineralization process during storage. In contrast, storing teeth in HBSS did not significantly alter the mechanical properties for a time interval of 2 weeks. The use of HBSS for storage of samples from teeth is recommended. PMID:12052404

Habelitz, Stefan; Marshall, Grayson W; Balooch, Mehdi; Marshall, Sally J

2002-07-01

90

Multiple dens invaginatus, mulberry molar and conical teeth. Case report and genetic considerations  

Microsoft Academic Search

Dens in dente, also known as dens invaginatus and dilated compound odontoma, is a malformation that can occur on primary, permanent, or supernumerary teeth that is characterized by a deep invagination of the surface of a crown or root covered with enamel. This abnormality in tooth morphology generally affect the maxillary lateral incisors but several cases of multiple dens invaginatus

Heddie O. Sedano; Fabian Ocampo-Acosta; Rosa I. Naranjo-Corona; Maria E. Torres-Arellano

91

3 Dimensional Diagnosis Unravelling Prognosis of Multiple Impacted Teeth – A Case Report  

PubMed Central

Impaction of teeth results from the interplay between nature and nurture. Radiographs play an important role in assessment of both the location and the typing of impacted teeth. In general, periapical, occlusal, and/or panoramic radiographs are sufficient for providing the information required by the clinician. Recent advances in diagnostic imaging enables to visualize , diagnose and prognose the treatment outcome of the impacted teeth. This case report discusses the value of cone beam computerized tomography (CBCT) for evaluation of the critical parameters like bone thickness , tooth position and tooth morphology of multiple impacted teeth by 3 dimensional radiography – CBCT. In this report, we present a case of 27-year-old male patient with multiple missing teeth. Radiographs revealed multiple impacted permanent teeth, though medical and family history along with physical examination was not suggestive of any syndromes. Intraoral periapical radiograph, Orthopantomograph, Occlusal radiograph, Cone beam computed tomography were taken for the same patient to determine the exact position of multiple impacted teeth and prognose the treatment plan with the associated factors to impacted teeth. Cone beam computed tomography is an accurate modality to localize and determine the prognosing factors associated with multiple impacted teeth. Three-dimensional volumetric imaging might provide information for improved diagnosis and treatment plans, and ultimately result in more successful treatment outcomes and better care for patients. How to cite this article: Gopinath A, Reddy NA, Rohra MG. 3 Dimensional Diagnosis Unravelling Prognosis of Multiple Impacted Teeth – A Case Report. J Int Oral Health 2013; 5(4):78-83. PMID:24155625

Gopinath, Adusumilli; Reddy, Naveen Admala; Rohra, Mayur G

2013-01-01

92

3 dimensional diagnosis unravelling prognosis of multiple impacted teeth - a case report.  

PubMed

Impaction of teeth results from the interplay between nature and nurture. Radiographs play an important role in assessment of both the location and the typing of impacted teeth. In general, periapical, occlusal, and/or panoramic radiographs are sufficient for providing the information required by the clinician. Recent advances in diagnostic imaging enables to visualize , diagnose and prognose the treatment outcome of the impacted teeth. This case report discusses the value of cone beam computerized tomography (CBCT) for evaluation of the critical parameters like bone thickness , tooth position and tooth morphology of multiple impacted teeth by 3 dimensional radiography - CBCT. In this report, we present a case of 27-year-old male patient with multiple missing teeth. Radiographs revealed multiple impacted permanent teeth, though medical and family history along with physical examination was not suggestive of any syndromes. Intraoral periapical radiograph, Orthopantomograph, Occlusal radiograph, Cone beam computed tomography were taken for the same patient to determine the exact position of multiple impacted teeth and prognose the treatment plan with the associated factors to impacted teeth. Cone beam computed tomography is an accurate modality to localize and determine the prognosing factors associated with multiple impacted teeth. Three-dimensional volumetric imaging might provide information for improved diagnosis and treatment plans, and ultimately result in more successful treatment outcomes and better care for patients. How to cite this article: Gopinath A, Reddy NA, Rohra MG. 3 Dimensional Diagnosis Unravelling Prognosis of Multiple Impacted Teeth - A Case Report. J Int Oral Health 2013; 5(4):78-83. PMID:24155625

Gopinath, Adusumilli; Reddy, Naveen Admala; Rohra, Mayur G

2013-08-01

93

Clinical and radiological evaluation of inverse impaction of supernumerary teeth  

PubMed Central

Objective: To describe the clinical and radiological features of children with inverted supernumerary teeth. Study Design: Thirty eight patients with inverted supernumerary teeth (ST) were enrolled in this descriptive and restrospective study. Data from patient records including age, gender, status of dentition, number of ST, number of ST in inverted position, coexistence of ST in inverted and normal direction of eruption, location, orientation, morphology, clinical complications, management and radiography were assessed during 3-years period. Results: Thirty eight patients with a mean age of 9.10±1.97 years (range:6-13) and a strong male preponderance of 3.7:1 (male:30, female:8) had a total of 69 ST, of which 41 were in inverted position. Thirty five patients had one (92.1%) inverted tooth, whereas 3 patients had two inverted teeth per case (7.9%). All cases were located in the maxilla. Midline was the most frequent site for the single inverted supernumerary tooth in 18 (47.4%) patients, followed equally by the right and left premaxillary region in 10 patients each (26.3%). Regarding morphology, 30 patients had conical (78.9%) and 8 (21.1%) had incisiform ST. No tuberculate shaped ST was detected. There was no statistically significant difference between number of inverted teeth and delayed tooth eruption, diastema, local malocclusion, palatinal swelling (p>0.05). There was no statistically significant difference between complications and age (p>0.05). Surgical removal at the time of diagnosis with subsequent follow-up during completion of permanent dentition was the treatment approach in all cases. Conclusions: Thorough clinical examination followed by a comprehensive radiographic screening is the crucial determinant of an accurate diagnosis of an impacted ST. Early diagnosis and timely management are key factors to prevent or minimize the complications, which may influence function and esthetics of the teeth and even psychological condition of the growing child. Key words:Supernumerary tooth, impaction, inverted. PMID:23722132

Kurklu, Esma; Gencay, Koray; Ak, Gulsum

2013-01-01

94

Parts of Your Teeth and Gums  

MedlinePLUS

... planes of bone. Within the bone are small craters that mark where the teeth had been. These craters are the alveolar sockets. The walls of the craters are called the alveolar processes. As teeth erupt ...

95

“Early baby teeth”: Folklore and facts  

PubMed Central

Variations in the newborns’ oral cavity have been an enduring interest to the pediatric dentist. The occurrence of natal and neonatal teeth is a rare anomaly, which for centuries has been associated with diverse superstitions among many different ethnic groups. Natal teeth are more frequent than neonatal teeth, the ratio being approximately 3:1. The purpose of this case report is to review the literature related to the natal teeth folklore and misconceptions and discuss their possible etiology and treatment. PMID:23066283

Maheswari, N. Uma; Kumar, B. P.; Karunakaran; Kumaran, S. Thanga

2012-01-01

96

Bilateral agenesis of maxillary permanent canines: Review of the literature  

PubMed Central

Oligodontia, or agenesis of six or more teeth, excluding third molars, which involves canine agenesis is rare, and restorative management can be challenging. Bilateral agenesis of a permanent canine in the general population often indicates a several missing adult teeth. The most common sign of it is the primary canine retention beyond its exfoliation age. The multistage restorative management includes the early diagnosis, excluding associated medical problems as well as assessment of patient's malocclusion and facial skeletal pattern, life span of deciduous teeth, possibility of premolar substitution, minimum required number of prosthetic units, patient's preferences, and the cost of treatment. A 10-year-old boy with bilateral agenesis of maxillary permanent canines is described. Some thoughts on the multidisciplinary restorative management of this case are discussed. PMID:25657989

Borzabadi-Farahani, Ali

2015-01-01

97

Whitening non vital teeth – a case report  

PubMed Central

Commonly used in cosmetic dentistry teeth whitening can be used combined with other restorative techniques during dental treatment. Non-vital teeth whitening is necessary whenever we need an improvement of their aspect, as it’s a known fact that these teeth can have a grey or pink-grey coloration when they are not correctly endodontical treated. PMID:24778849

Moraru, Iren; ?uculin?, Mihaela; B?t?iosu, Marilena; Gheorghi??, Lelia; Diaconu, Oana

2012-01-01

98

Cracked Teeth: A Review of the Literature  

PubMed Central

Although cracked teeth are a common problem for patients and dentists, there is a dearth of evidence-based guidelines on how to prevent, diagnose, and treat cracks in teeth. The purpose of this article is to review the literature to establish what evidence exists regarding the risk factors for cracked teeth and their prevention, diagnosis, and treatment. PMID:20590967

Lubisich, Erinne B.; Hilton, Thomas J.; FERRACANE, JACK

2013-01-01

99

Natal Teeth: A Case Report and Reappraisal  

PubMed Central

The presence of teeth at birth (natal teeth) or within a month after delivery (neonatal teeth) is a rare condition. Natal and neonatal teeth are conditions of significant importance to pediatric dentists and pediatricians. This report discusses a case in which a five-day-old infant required extraction of a mobile mandibular natal tooth to avoid the risk of aspiration and interference with feeding. Also, a review of the literature was conducted to discuss the etiology, clinical features, complications, and management of natal and neonatal teeth. PMID:25722895

Malki, Ghadah A.; Al-Badawi, Emad A.; Dahlan, Mohammad A.

2015-01-01

100

Genetic background of supernumerary teeth  

PubMed Central

Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed. PMID:25713500

Subasioglu, Asli; Savas, Selcuk; Kucukyilmaz, Ebru; Kesim, Servet; Yagci, Ahmet; Dundar, Munis

2015-01-01

101

Multiple Impacted Teeth: Report of 3 Cases  

PubMed Central

While impaction of tooth is widespread, multiple impacted teeth by itself is a rare condition and often found in association with syndromes such as cleidocranial dysplasia or Gardner’s syndrome. A light of radiographic examination, we describe three Turkish young males with multiple impacted teeth who didn’t possess any systemic conditions or syndromes involving both jaws. The first patient, a 21-year-old young male, had 16 unerupted teeth and 5 unerupted supernumerary teeth. The second patient with totally edentulous mandible, a 20-year-old young male, had 31 unerupted teeth. The third patient, a 21-year-old young male, had 22 unerupted teeth and 4 unerupted supernumerary teeth. Based on the clinical presentation, radiographic examination and histopathological studies, this paper discusses the differential diagnosis and management of such cases. PMID:19212513

Bayar, Gürkan Ra?it; Ortako?lu, Kerim; Sencimen, Metin

2008-01-01

102

Iron deposition in modern and archaeological teeth  

NASA Astrophysics Data System (ADS)

Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment.

Williams, A.-M. M.; Siegele, R.

2014-09-01

103

Can we move traumatized teeth?  

PubMed

Dental traumas affect primarily the upper central incisors. The risk is particularly high in cases with protrusive maxillary teeth. Often the trauma will happen in a young patient when the root is not completely formed. With all the complications that can occur on a short-term and also on a long-term, it is legitimate to ask the question of feasibility of orthodontic treatment following a dental trauma. In this article, presenting a clinical case, we will demonstrate that not only is it possible but also that there is a need for orthodontics to minimize the risk of another dental trauma at a later time. PMID:25745717

Costi, Arnaud

2014-01-01

104

Tooth Sensitivity in Fluorotic Teeth  

PubMed Central

Objectives: The aim of this study was to compare the demographic and clinical features of tooth sensitivity (TS) in subjects with and without fluorosis. Methods: A total of 2249 subjects (378 subjects with fluorosis and 1871 subjects without fluorosis) were examined for TS during a study period of one year and TS was determined in 122 subjects. The level of TS was evaluated on a visual analogue scale (VAS). The sensitivity evaluation was made by applying tactile and cold air stimuli. In teeth sensitive to any stimuli, the plaque index (PI), gingival index (GI), gingival recession (GR) and periodontal pocket depth (PPD) were recorded. Fluorosis was assessed using the Dean Index. Results: One hundred and twenty-two participants were found to have TS (5.42%). The frequency of TS in subjects with fluorosis was 9.26%, while the frequency of TS in subjects without fluorosis was 4.65%. There was a statistically significant difference between the groups in terms of TS frequency (P=0.0003). In contrast, there were no significant differences between the groups for periodontal parameters except PI. Conclusions: The results of the study showed that the subjects with fluorosis may have been suffering from TS more than the subjects with normal dentition. Further studies are necessary to determine the factors that contribute to sensitivity of teeth with fluorosis. PMID:21769268

Tonguc, Mine Ozturk; Ozat, Yener; Sert, Tugba; Sonmez, Yonca; Kirzioglu, F. Yesim

2011-01-01

105

Dielectrophoresis: a model to transport drugs directly into teeth.  

PubMed

The article describes an innovative delivery system based on the principles of dielectrophoresis to transport drugs directly into site-specific intraoral targets. The hypothesis that a drug can be driven into tooth enamel during the application of an applied electrical potential difference was tested by the authors in in vitro studies comparing dielectrophoresis to diffusion to transport carbamide peroxide and fluoride. The studies showed that these agents can be transported directly into teeth using an alternating current (AC) electric field more effectively than diffusion. It was found that a 20-min bleaching treatment on human teeth with dielectrophoresis increased carbamide peroxide absorption by 104% and, on average, improved the change in shade guide unit 14 times from 0.6 SGU to 9 SGU. After applying a 1.23% acidulated phosphate fluoride gel to bovine incisors for 20 min by dielectrophoresis or diffusion, analysis with wavelength dispersive spectrometry determined that dielectrophoresis doubled fluoride uptake in the superficial layers compared to diffusion, and drove the fluoride significantly deeper into enamel with an uptake 600% higher than diffusion at 50 ?m depth. Finally, dielectrophoresis promises to be a viable model that can potentially be used clinically to deliver other targeted drugs of variable molecular weight and structure. PMID:22589112

Ivanoff, Chris S; Hottel, Timothy L; Garcia-Godoy, Franklin

2012-04-01

106

Evaluation of Mineral Trioxide Aggregate and Calcium Hydroxide Cement as Pulp-capping Agents in Human Teeth  

Microsoft Academic Search

This study evaluated the histomorphologic response of human dental pulps capped with mineral trioxide aggregate (MTA) and Ca(OH)2 cement (CH). Pulp exposures were performed on the occlusal floor of 40 human permanent premolars. After that, the pulp was capped either with CH or MTA and restored with composite resin. After 30 and 60 days, teeth were extracted and processed for

Maria de Lourdes R. Accorinte; Roberto Holland; Alessandra Reis; Marcelo C. Bortoluzzi; Sueli S. Murata; Eloy Dezan; Valdir Souza; Loguercio Dourado Alessandro

2008-01-01

107

Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report  

PubMed Central

Background: Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the clinical examination by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. Results: This is the first reported case of mesiodens mirror images in dizygotic twins. The de-scribed mesiodens caused the eruption failure of maxillary permanent incisors. The super-numerary teeth were removed to facilitate the spontaneous eruption of the impacted perma-nent maxillary incisors. Clinical Implications: Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach. Key words:Supernumerary teeth, twins, dental development.

Altieri, Federica; Giordano, Alessandra

2015-01-01

108

Disinfection of Human Teeth for Educational Purposes.  

ERIC Educational Resources Information Center

A study investigated the efficacy of glutaraldehyde and several other disinfectants for disinfecting teeth to be used for teaching and research, as an alternative to autoclaving for teeth with amalgam restorations. Results indicate that formalin was the only disinfectant that penetrated tooth pulp chambers in effective antimicrobial…

Tate, William H.; White, Robert S.

1991-01-01

109

NATURAL VARIATION IN SPOTTING, HYOID TEETH COUNTS,  

E-print Network

^i^^- fV/ NATURAL VARIATION IN SPOTTING, HYOID TEETH COUNTS, AND COLORATION OF YELLOWSTONE grazing and forestry programs on federally owned range and commercial forest lands; protects fish and Wildlife, Daniel H. Janzen, Director NATURAL VARIATION IN SPOTTING, HYOID TEETH COUNTS, AND COLORATION

110

Drug-induced Disorders of Teeth  

Microsoft Academic Search

It is essential that every health care professional who is involved with the prescription or recommendation of drugs be fully aware of any resultant disorders that may arise as a side-effect. A range of drugs can affect the teeth. In this review article, drugs that have the potential to induce changes in teeth have been classified as those leading to

C. J. Tredwin; C. Scully; J.-V. Bagan-Sebastian

2005-01-01

111

Transplantation of Cryopreserved Teeth: A Systematic Review  

PubMed Central

The aim of this article was to examine the research articles regarding biological and mechanical properties of cryopreserved teeth for potential use in tooth transplantation. A systematic review of literatures was performed by Pubmed searching with assigned key words from January 1, 1990 to June 8, 2009. All articles were examined for inclusion criteria. Secondary search was conducted by hand-search through references of included articles from primary search. A total of 24 articles were obtained from both primary and secondary search and used as fundamental articles in this review. Periodontal ligament tissues of cryopreserved teeth were able to maintain their biological properties resulted in a satisfactory healing of periodontium. Dental pulp tissues, however, may be compromised by limitation of permeability of cryopreservative agent into pulp cavity. Therefore, an endodontic treatment of transplanted cryopreserved teeth was recommended. Cryopreserved teeth had comparable mechanical properties to those of normal teeth. Importantly, the success of cryopreserved tooth transplantation treatment in orthodontic patients was reported. The cryopreserved teeth for tooth banking have a potential clinical application for treatment of missing teeth. Case selection, however, is critical for treatment success. More studies and data regarding masticatory function and periodontal healing of transplanted cryopreserved teeth are needed. PMID:20737931

Osathanon, Thanaphum

2010-01-01

112

Electrical Conductance of Fissure Enamel in Recently Erupted Molar Teeth as Related to Caries Status  

Microsoft Academic Search

Pit-and-fissure caries lesions contribute greatly to the caries incidence in permanent molar teeth in children. To date, the diagnosis of occlusal caries is still performed mainly by visual inspection, periodically aided by bite-wing radiography. However, in detecting small occlusal carious lesions, these methods perform inadequately, especially in low caries prevalence populations or individuals. The use of electrical conductance measurements (ECMs)

Y. L. Ie; E. H. A. M. Verdonschot; M. J. M. Schaeken; M. A. van’t Hof

1995-01-01

113

Glycosaminoglycans of the odontoblast-predentine layer in dentinogenically active porcine teeth  

Microsoft Academic Search

The glycosaminoglycans (GAGs) in the odontoblast-predentine layer, dissected out from dentinogenically active permanent porcine teeth, have been isolated and analyzed with the following results. 1. Light and electron microscopy indicated that odontoblasts and predentine were present in roughly equal amounts. 2. The total hexosamines accounted for 0.84 ?g\\/mg tissue wet weight (2.9 ?g\\/mg dry weight). 3. Cellulose acetate membrane electrophoresis

Anders Linde

1973-01-01

114

The Replacement of Missing Teeth  

PubMed Central

Dentists have used a great deal of ingenuity in replacing lost teeth. Until recently, however, it was not possible to duplicate the natural situation and attach tooth-root analogues to the host bone. Osseointegration allows such an attachment, in which threaded unalloyed titanium implants are placed in the bone by means of a meticulous surgical procedure. The documented successful use of this process has already altered profoundly the predicament of the edentulous patient. The application of osseointegration as a treatment modality for partial edentulism offers exciting challenges for the dentist. This article reviews preliminary experiences in this area from the University of Toronto's Clinical Osseointegration Unit. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6aFigure 6bFigure 6c PMID:21253206

Zarb, George A.

1988-01-01

115

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Heat source for bleaching teeth. 872.6475... Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an...

2010-04-01

116

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Heat source for bleaching teeth. 872.6475... Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an...

2011-04-01

117

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Heat source for bleaching teeth. 872.6475 Section 872...Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device...

2014-04-01

118

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Heat source for bleaching teeth. 872.6475 Section 872...Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device...

2013-04-01

119

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Heat source for bleaching teeth. 872.6475 Section 872...Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device...

2012-04-01

120

Fracture resistance of posterior teeth restored with modern restorative materials  

PubMed Central

We studied the fracture resistance of maxillary premolars restored with recent restorative materials. Fifty maxillary premolars were divided into five groups: Group 1 were unprepared teeth; Group 2 were teeth prepared without restoration; Group 3 were teeth restored with tetric ceram HB; Group 4 were teeth restored with InTen S; and Group 5 were teeth restored with Admira. The samples were tested using a universal testing machine. Peak loads at fracture were recorded. The teeth restored with Admira had the highest fracture resistance followed by those restored with InTen-S and tetric ceram HB. Prepared, unrestored teeth were the weakest group. There was a significant difference between the fracture resistance of intact teeth and the prepared, unrestored teeth. There was also a significant difference among the tested restorative materials. Teeth restored with Admira showed no significant difference when compared with the unprepared teeth. It was concluded that the teeth restored with Admira exhibited the highest fracture resistance. PMID:23554719

Hamouda, Ibrahim M.; Shehata, Salah H.

2011-01-01

121

Can Milk Teeth be Impacted? Why Not: A Case of Six Impacted Primary Teeth  

PubMed Central

ABSTRACT% The prevalence rate of impacted primary teeth is rare, still we can see impacted teeth in ectodermal dysplasia anhydrotic (EDA), endocrine deficiencies, metabolic disorders and local factors like cysts, tumors, trauma and thickened overlying bone or soft tissue. In cases of EDA, delayed tooth eruption is one of the characteristic finding. Present case report related to a rare case of primary teeth impaction of a 3 years old male child along with EDA. Intraoral examination and radiographs confirmed impacted primary maxillary and mandibular centrals and mandibular lateral incisors. Treatment carried out was surgical exposure of impacted primary teeth, then after patient was followed up for regular visits to check eruption status of the teeth. How to cite this article: Yadiki JV, Kategari YB, Chada P, Vallakatla V. Can Milk Teeth be Impacted? Why Not: A Case of Six Impacted Primary Teeth. Int J Clin Pediatr Dent 2014; 7(3):220-222. PMID:25709307

Kategari, Yellamma Bai; Chada, Pujita; Vallakatla, Venu

2014-01-01

122

Essure Permanent Birth Control  

MedlinePLUS

... Medical Devices Products and Medical Procedures Implants and Prosthetics Essure Permanent Birth Control Benefits of Essure FDA’s ... More in Products and Medical Procedures Implants and Prosthetics Essure Permanent Birth Control Phakic Intraocular Lenses Breast ...

123

Spatial and Functional Modeling of Carnivore and Insectivore Molariform Teeth  

E-print Network

Spatial and Functional Modeling of Carnivore and Insectivore Molariform Teeth Alistair R. Evans (Greaves, 1972; Fortelius, 1985), and carnivore molariform teeth (Mellett, 1981, 1985; Bryant and Russell

Evans, Alistair

124

Dovetail spoke internal permanent magnet machine  

DOEpatents

An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple pair of permanent magnets for generating a magnetic field, which magnetic field interacts with the stator magnetic field to produce a torque. The multiple pair of permanent magnets are disposed between the stacks. The rotor assembly also includes multiple middle wedges mounted between each pair of the multiple permanent magnets.

Alexander, James Pellegrino (Ballston Lake, NY); EL-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Shah, Manoj Ramprasad (Latham, NY); VanDam, Jeremy Daniel (West Coxsackie, NY)

2011-08-23

125

Method and apparatus for assembling permanent magnet rotors  

DOEpatents

A permanent magnet assembly for assembly in large permanent magnet motors and generators includes a two-piece carrier that can be slid into a slot in the rotor and then secured in place using a set screw. The invention also provides an auxiliary carrier device with guide rails that line up with the teeth of the rotor, so that a permanent magnet assembly can be pushed first into a slot, and then down the slot to its proper location. An auxiliary tool is provided to move the permanent magnet assembly into position in the slot before it is secured in place. Methods of assembling and disassembling the magnet assemblies in the rotor are also disclosed. 2 figs.

Hsu, J.S.; Adams, D.J.

1999-06-22

126

Method and apparatus for assembling permanent magnet rotors  

DOEpatents

A permanent magnet assembly (22) for assembly in large permanent magnet (PM) motors and generators includes a two-piece carrier (23, 24) that can be slid into a slot (13) in the rotor (10) and then secured in place using a set screw (37). The invention also provides an auxiliary carrier device (50) with guide rails (51) that line up with the teeth (12) of the rotor, so that a permanent magnet assembly (22) can be pushed first into a slot (13), and then down the slot (13) to its proper location. An auxiliary tool (50) is provided to move the permanent magnet assembly (22) into position in the slot (13) before it is secured in place. Methods of assembling and disassembling the magnet assemblies (22) in the rotor (10) are also disclosed.

Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN)

1999-01-01

127

Effective of diode laser on teeth enamel in the teeth whitening treatment  

NASA Astrophysics Data System (ADS)

This research purpose is to investigate the changing of teeth color and to study the surface of teeth after treatment by laser diode at different power densities for tooth whitening treatment. In the experiment, human-extracted teeth samples were divided into 7 groups of 6 teeth each. After that laser diode was irradiated to teeth, which were coated by 38% concentration of hydrogen peroxide, during for 20, 30 and 60 seconds at power densities of 10.9 and 52.1 W/cm2. The results of teeth color change were described by the CIEL*a*b* systems and the damage of teeth surface were investigated by scanning electron microscopy (SEM). The results showed that the power density of the laser diode could affect the whiteness of teeth. The high power density caused more luminous teeth than the low power density did, but on the other hand the high power density also caused damage to the teeth surface. Therefore, the laser diode at the low power densities has high efficiency for tooth whitening treatment and it has a potential for other clinical applications.

Klunboot, U.; Arayathanitkul, K.; Chitaree, R.; Emarat, N.

2011-12-01

128

A case report of green pigmentation in the permanent dentition.  

PubMed

Intrinsic green discoloration of teeth is an uncommon condition which mainly affects the primary dentition. Children can be teased about this, resulting in a loss of self-esteem and problems with social integration. The purpose of this paper was to present a case of green pigmentation in the permanent dentition caused by hyperbilirubinemia during infancy and an intermediate restorative approach to mask the esthetic deficiency arising from this. PMID:23433625

Chambers, Colin P; O'Morain, Donnchadh; Keightley, Alexander; Welbury, Richard R

2012-01-01

129

Rugometric and microtopographic inspection of teeth enamel  

NASA Astrophysics Data System (ADS)

The roughness of teeth' enamel is an important parameter in orthodontics. One example is the application in the process of decreasing tooth-size by reducing the interproximal enamel surfaces (stripping) of teeth. In order to achieve smooth surfaces clinicians have been testing various methods and progressively improved this therapeutic technique. The evaluation the surface roughness following teeth interproximal reduction is fundamental in the process. In general tooth' surface is not flat presenting a variety of complex geometries. In this communication we will report on the metrological procedure employed on the rugometric and microtopographic inspection by optical active triangulation of raw and processed (interproximal stripping) tooth surfaces.

Costa, Manuel F.; Pereira, Pedro B.

2013-06-01

130

Morphology and microanalysis of teeth in scleroderma.  

PubMed

The studies were carried out on teeth extracted for stomatological reasons in the persons with generalized scleroderma. The studies included: morphologic examination of the longitudinal and cross-ground sections in the light and scanning microscope, and microanalytic examination of the longitudinal halves of the teeth in the X-ray microprobe. In the course of scleroderma morphological changes of the mesenchymal origin occurred in the teeth hard tissues. The deviation in the calcium and phosphorus contents was relatively significant and an absence of magnesium in the dentine and distinct de?rease in the calcium-phosphorus ratio were observed. PMID:3556669

Knychalska-Karwan, Z; Pawlicki, R; Karwan, T

1986-01-01

131

Agenesis of Multiple Primary Teeth and  

PubMed Central

ABSTRACT Agenesis of multiple primary teeth is rare. A 6-year-old girl visited our department, in the absence of any other systemic abnormalities, on clinical and radiographic evaluation, it was revealed that she had only 6 primary teeth in her mouth. Maxillary and mandibular removable partial dentures were fabricated for prosthodontic rehabilitation. At the 6 months follow-up nutrition of the patient as well as self-confident appearance was improved. How to cite this article: Nirmala SVSG, Gokhale N, Sivakumar N, Quadar MA. Agenesis of Multiple Primary Teeth and Its Rehabilitation: A Case Report. Int J Clin Pediatr Dent 2013; 6(1):55-57. PMID:25206190

Gokhale, Niraj; Sivakumar, N; Quadar, Md Akhil

2013-01-01

132

Performance comparison of three-phase flux reversal permanent magnet motors in BLDC and BLAC operation mode  

NASA Astrophysics Data System (ADS)

The paper presents a comparison of torque capability and flux-weakening performance of three-phase flux reversal permanent magnet motors with surface and inset permanent magnets. Finite element analysis is employed to determine the performance of each motor in BLDC and BLAC operation mode. It is shown that the torque capability and flux-weakening performance of surface or inset permanent magnet configuration is strongly dependent on the stator teeth number/rotor pole number combination.

Štumberger, B.; Štumberger, G.; Hadžiselimovi?, M.; Hamler, A.; Gori?an, V.; Jesenik, M.; Trlep, M.

133

Laser and LED external teeth-bleaching  

NASA Astrophysics Data System (ADS)

Teeth-bleaching is an initial phase in the reproduction of an aesthetic smile; thus, it is very important that the dentist knows how to diagnose the causes of color changes and indicate whitening before proposing dental treatment. Technological advances in teeth-whitening lead to the development of new techniques, improving comfort, security and decreasing time of execution: argon laser, diode Laser, LED whitening, xenon light whitening. The clearing agent used in all techniques, including home whitening, is hydrogen peroxide (H2O2) in different concentrations. In this study, the authors describe mechanisms of gel activation, the use of Laser and LED"s for teeth-bleaching, the importance of diagnosis and the comfort of the patient in in-office teeth-bleaching techniques.

Zanin, Fatima A.; Brugnera, Aldo, Jr.; Marchesan, Melissa A.; Pecora, Jesus D.

2004-09-01

134

Laser and LED external teeth-bleaching  

NASA Astrophysics Data System (ADS)

Teeth-bleaching is an initial phase in the reproduction of an aesthetic smile; thus, it is very important that the dentist knows how to diagnose the causes of color changes and indicate whitening before proposing dental treatment. Technological advances in teeth-whitening lead to the development of new techniques, improving comfort, security and decreasing time of execution: argon laser, diode laser, LED whitening, xenon light whitening. The clearing agent used in all techniques, including home whitening, is hydrogen peroxide (H2O2) in different concentrations. In this study, the authors describe mechanisms of gel activation, the use of Laser and LED's for teeth-bleaching, the importance of diagnosis and the comfort of the patient in in-office teeth-bleaching techniques.

Zanin, Fatima; Brugnera, Aldo, Jr.; Marchesan, Melissa A.; Pecora, Jesus D.

2004-05-01

135

Cleaning Your Child's Mouth and Teeth  

MedlinePLUS

... routine. Floss is available in many different sizes, coatings, flavors and forms. If you have trouble using ... teeth. Slide it up and down against that tooth. Next, wrap the floss against the other tooth ...

136

Taking Care of Your Teeth and Mouth  

MedlinePLUS

... can protect your teeth from decay by using fluoride toothpaste. If you are at a higher risk ... of medicines you take), you might need more fluoride. Your dentist or dental hygienist may give you ...

137

Severe Impaction of the Primary Mandibular Second Molar Accompanied by Displacement of the Permanent Second Premolar  

PubMed Central

Tooth impaction is defined as any tooth that fails to erupt into a normal functional position and remains unerupted beyond the time at which it should normally erupt. Reports of impaction and eruption failure in primary teeth are relatively rare compared to permanent teeth. We report 2 rare cases where the second premolar was located on the occlusal side of the impacted mandibular second primary molar. In the first case, the succedaneous permanent tooth erupted after extraction of the primary tooth, fenestration, and traction. In the second case, the succedaneous permanent tooth erupted without fenestration or traction. Although the etiology of the tooth displacement was unknown in both cases, inhibition of the eruptive movement of the primary molar may have been associated with displacement of the succedaneous permanent premolar.

Matsuyama, Junko; Kinoshita-Kawano, Shoko; Hayashi-Sakai, Sachiko; Mitomi, Tomoe; Sano-Asahito, Tomiko

2015-01-01

138

Drug-induced disorders of teeth.  

PubMed

It is essential that every health care professional who is involved with the prescription or recommendation of drugs be fully aware of any resultant disorders that may arise as a side-effect. A range of drugs can affect the teeth. In this review article, drugs that have the potential to induce changes in teeth have been classified as those leading to tooth discoloration (intrinsic and extrinsic), physical damage to tooth structure (enamel, dentin, and cementum), and alteration in tooth sensitivity. PMID:15972585

Tredwin, C J; Scully, C; Bagan-Sebastian, J-V

2005-07-01

139

Nova Scotia Dental Association: Healthy Teeth  

NSDL National Science Digital Library

What exact role does sugar play in the formation of cavities? Find the answer to this question and many more at Healthy Teeth, a comprehensive and lively oral health education website for 3rd-6th graders and created by the Nova Scotia Dental Association. The site contains sections on Cavities, Teeth and Gums, Prevention, and more. The sections are student-friendly with straightforward text and fun animated images. Additionally, the site offers hands-on classroom activities and experiments.

140

Can Pacifiers and Baby Bottles Ruin My Baby's Teeth?  

MedlinePLUS

... If baby teeth are removed or lost early, other teeth can move into the space that's left. This can cause the adult teeth to come in crowded or crooked. As with adult teeth, dental infections can become life-threatening if left untreated. Preventing Decay Decay can ...

141

Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study  

PubMed Central

ABSTRACT Objectives: The study is to evaluate changes in microhardness of enamel after exposure to acidic center filled chewing gum on primary and permanent teeth. Methods: Thirty primary and 30 permanent molar extracted teeth were painted with acid resistant varnish except a small window over buccal surface. Teeth were divided into four groups according to type of teeth and type of chewing gum (Center fresh and Bubbaloo) (D1, P1, D2 and P2); each tooth was exposed to whole chewing gum mashed with 5 ml of artificial saliva for five minutes at room temperature twice a day for 5 days. After the exposure, teeth were stored in deionized water and submitted for microhardness tests. Results: Paired t-test and independent sample t-test were used for statistical analysis. A significant reduction in microhardness was found between exposed and unexposed areas in all groups. There was no statistically significant difference in reduction of microhardness to chewing gums, and between primary and permanent enamel. Conclusion: There is a definite reduction in microhardness in all groups exposed to chewing gums. Both the chewing gums are equally erosive; both permanent and primary teeth were affected. How to cite this article: Mudumba VL, Muppa R, Srinivas NCH, Kumar DM. Evaluation and Comparison of Changes in Microhardness of Primary and Permanent Enamel on Exposure to Acidic Center-filled Chewing Gum: An in vitro Study. Int J Clin Pediatr Dent 2014;7(1):24-29. PMID:25206233

Muppa, Radhika; Srinivas, NCH; Kumar, Duddu Mahesh

2014-01-01

142

Permanent magnet assembly  

DOEpatents

A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

Chell, Jeremy; Zimm, Carl B.

2006-12-12

143

Associations between dental treatment in the primary and permanent dentitions using insurance claims data  

Microsoft Academic Search

Purpose: The purpose of this study was to assess the associations between dental treatment in the early primary dentition and later treatment in the primary and permanent teeth. Methods: Delta Dental Plan of Michigan insurance claims data on 9,886 children who were born in 1990 and were covered by dental insurance from 1990-1998 were used. Risk ratios (RR), screening test

Keith E. Heller; Stephen A. Eklund; James Pittman; Amid A. Ismail

144

Solid modeling of fossil small mammal teeth  

NASA Astrophysics Data System (ADS)

This paper presents an approach to create solid models of fossil small mammal teeth using a combination of microcomputed tomography, object based image analysis and voxel modeling. Small mammal teeth, because of their durability, are widely found in Cenozioc sediments the world over and play a key role in stratigraphy as well as in researching the rapid evolution and the paleogeographic spreading of small mammals. Recent advances in microcomputed tomography make this non-destructive analysis method an ideal data source for high-resolution 3D models of fossil small animal teeth. To derive internally consistent solid models of such fossils from micro-CT imagery, we propose a combination of 3D object based image analysis and solid modeling. Incorporating paleontological expert knowledge in the image processing cycle, object based image analysis yields topologically consistent image stacks classified by the main tooth components—enamel, dentine and pulp. Forwarding these data to a voxel modeling system, they can be quantitatively analyzed in an unprecedented manner: going beyond the possibilities of the state-of-art surface models, solid models are capable of unambiguously portraying the entire object volume—teeth can be peeled by material properties, subvolumes can be extracted and automatically analyzed by Boolean operations. The proposed method, which can be flexibly extended to handle a range of paleontological and geological micro-objects, is demonstrated with two typical fossil small mammal teeth.

Marschallinger, Robert; Hofmann, Peter; Daxner-Höck, Gudrun; Ketcham, Richard A.

2011-09-01

145

Management of a Nonvital Young Permanent Tooth by Pulp Revascularization  

PubMed Central

ABSTRACT% This report presents the case of a 10-year-old patient with a nonvital young permanent tooth which was managed by pulp revascularization. Following disinfection of the canal by irrigation with NaOCl and use of a triantibiotic paste, a scaffold was created by inducing the formation of a blood clot within the canal. At the subsequent follow-up visits, the patient was asymptomatic, with normal response to percussion, normal periodontal probing depths, and no abnormal mobility. The radiographs showed evidence of continued apical root development with increase in root length, signs of apical closure and increase in thickness of dentinal walls. Thus, this case adds to the growing evidence supporting the revascularization approach as an option for management of nonvital young permanent teeth. How to cite this article: Chandran V, Chacko V, Sivadas G. Management of a Nonvital Young Permanent Tooth by Pulp Revascularization. Int J Clin Pediatr Dent 2014;7(3):213-216. PMID:25709305

Chandran, Vidya; Sivadas, G

2014-01-01

146

Immunohistochemical and Western blot analyses of collar enamel in the jaw teeth of gars, Lepisosteus oculatus, an actinopterygian fish.  

PubMed

Although most fish have no enamel layer in their teeth, those belonging to Lepisosteus (gars), an extant actinopterygian fish genus, do and so can be used to study amelogenesis. In order to examine the collar enamel matrix in gar teeth, we subjected gar teeth to light and electron microscopic immunohistochemical examinations using an antibody against bovine amelogenin (27 kDa) and antiserum against porcine amelogenin (25 kDa), as well as region-specific antibodies and antiserum against the C-terminus and middle region, and N-terminus of porcine amelogenin, respectively. The enamel matrix exhibited intense immunoreactivity to the anti-bovine amelogenin antibody and the anti-porcine amelogenin antiserum in addition to the C-terminal and middle region-specific antibodies, but not to the N-terminal-specific antiserum. These results suggest that the collar enamel matrix of gar teeth contains amelogenin-like proteins and that these proteins possess domains that closely resemble the C-terminal and middle regions of porcine amelogenin. Western blot analyses of the tooth germs of Lepisosteus were also performed. As a result, protein bands with molecular weights of 78 kDa and 65 kDa were clearly stained by the anti-bovine amelogenin antibody as well as the antiserum against porcine amelogenin and the middle-region-specific antibody. It is likely that the amelogenin-like proteins present in Lepisosteus do not correspond to the amelogenins found in mammals, although they do possess domains that are shared with mammalian amelogenins. PMID:24611716

Sasagawa, Ichiro; Ishiyama, Mikio; Yokosuka, Hiroyuki; Mikami, Masato; Shimokawa, Hitoyata; Uchida, Takashi

2014-06-01

147

Congenitally missing teeth (hypodontia): A review of the literature concerning the etiology, prevalence, risk factors, patterns and treatment  

PubMed Central

Congenitally missing teeth (CMT), or as usually called hypodontia, is a highly prevalent and costly dental anomaly. Besides an unfavorable appearance, patients with missing teeth may suffer from malocclusion, periodontal damage, insufficient alveolar bone growth, reduced chewing ability, inarticulate pronunciation and other problems. Treatment might be usually expensive and multidisciplinary. This highly frequent and yet expensive anomaly is of interest to numerous clinical, basic science and public health fields such as orthodontics, pediatric dentistry, prosthodontics, periodontics, maxillofacial surgery, anatomy, anthropology and even the insurance industry. This essay reviews the findings on the etiology, prevalence, risk factors, occurrence patterns, skeletal changes and treatments of congenitally missing teeth. It seems that CMT usually appears in females and in the permanent dentition. It is not conclusive whether it tends to occur more in the maxilla or mandible and also in the anterior versus posterior segments. It can accompany various complications and should be attended by expert teams as soon as possible. PMID:25709668

Rakhshan, Vahid

2015-01-01

148

Congenitally missing teeth (hypodontia): A review of the literature concerning the etiology, prevalence, risk factors, patterns and treatment.  

PubMed

Congenitally missing teeth (CMT), or as usually called hypodontia, is a highly prevalent and costly dental anomaly. Besides an unfavorable appearance, patients with missing teeth may suffer from malocclusion, periodontal damage, insufficient alveolar bone growth, reduced chewing ability, inarticulate pronunciation and other problems. Treatment might be usually expensive and multidisciplinary. This highly frequent and yet expensive anomaly is of interest to numerous clinical, basic science and public health fields such as orthodontics, pediatric dentistry, prosthodontics, periodontics, maxillofacial surgery, anatomy, anthropology and even the insurance industry. This essay reviews the findings on the etiology, prevalence, risk factors, occurrence patterns, skeletal changes and treatments of congenitally missing teeth. It seems that CMT usually appears in females and in the permanent dentition. It is not conclusive whether it tends to occur more in the maxilla or mandible and also in the anterior versus posterior segments. It can accompany various complications and should be attended by expert teams as soon as possible. PMID:25709668

Rakhshan, Vahid

2015-01-01

149

Extreme strength observed in limpet teeth  

PubMed Central

The teeth of limpets exploit distinctive composite nanostructures consisting of high volume fractions of reinforcing goethite nanofibres within a softer protein phase to provide mechanical integrity when rasping over rock surfaces during feeding. The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material, outperforming the high strength of spider silk currently considered to be the strongest natural material, and approaching values comparable to those of the strongest man-made fibres. This considerable tensile strength of limpet teeth is attributed to a high mineral volume fraction of reinforcing goethite nanofibres with diameters below a defect-controlled critical size, suggesting that natural design in limpet teeth is optimized towards theoretical strength limits. PMID:25694539

Barber, Asa H.; Lu, Dun; Pugno, Nicola M.

2015-01-01

150

Extreme strength observed in limpet teeth.  

PubMed

The teeth of limpets exploit distinctive composite nanostructures consisting of high volume fractions of reinforcing goethite nanofibres within a softer protein phase to provide mechanical integrity when rasping over rock surfaces during feeding. The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material, outperforming the high strength of spider silk currently considered to be the strongest natural material, and approaching values comparable to those of the strongest man-made fibres. This considerable tensile strength of limpet teeth is attributed to a high mineral volume fraction of reinforcing goethite nanofibres with diameters below a defect-controlled critical size, suggesting that natural design in limpet teeth is optimized towards theoretical strength limits. PMID:25694539

Barber, Asa H; Lu, Dun; Pugno, Nicola M

2015-04-01

151

Brittle teeth with brittle bone in a family for four generations: Case report and literature review  

PubMed Central

Dentinogenesis imperfect (DI) is a hereditary dentine disorder affecting both deciduous and permanent teeth. DI is caused by mutations in genes encoding for type I collagen leading to discoloration of teeth. Shield around 30 years ago classified DI into 3 types (type I, II, and III). DI type I is associated with osteogenesis imperfect (OI), which is an inheritable disorder of connective tissue. Bone fragility and fracture of bone with minor trauma are hallmarks of this disorder. The objective of this article is to report and review a rare case of DI with OI affecting 4 generations of the family. Through this article, we intend to highlight genetic influence that affected a family for many generations, discuss the oral manifestations that can lead to the diagnosis of OI, and the importance of early diagnosis of OI. PMID:22919223

Shilpa, P. S.; David, Chaya M.; Kaul, Rachna; Sanjay, C. J.; Narayan, B. K. Ram

2012-01-01

152

[Sex identification from DNA in old teeth].  

PubMed

The sex determination was carried out on 80 fresh and 15 old teeth by amplifying sex chromosome specific sequences with the polymerase chain reaction. The DNA content in the tooth significantly decreases with aging. There was no correlation between days after evulsion and the amounts of DNA extracted from fresh teeth that had been preserved less than 186 days. The sex determination based on fresh teeth was successful using multi locus markers, DYZ-1 and DYZ-3 in combination with DXZ-1. However, amelogenin and pseudoautosomal boundary, both that are single locus markers and specific for both sex chromosomes with different lengths, could not be detected in three samples, of which DNA contents were extremely low. However, the sex determination by amelogenin amplified with fluorescent probes was possible in these three samples. We also determined sexes of 30 old specimens (15 teeth and 15 bones) from 15 human skulls using sex chromosomes locus markers. Prior to molecular sex determination, two forensic specialists determined the sex of the skull morphologically. From the 15 skulls, sex identification using multi locus marker (DYZ-1 or DYZ-3) was possible for 12 of 15 teeth and 7 of 15 bones. The sex was successfully determined from 11 teeth and 9 bones by amplification of the amelogenin locus. However, the coincidence rate of the molecular test with morphological examination was < 20%. In conclusion, sex determination on the fresh tooth would be successful using any sex chromosome marker. However, in cases on samples that have spent considerable years in the ground, pollution and putrefaction, especially, by humicolous, must be considered. Thus, sex determination by DNA testing should be regarded as accurate, when the results from two or more molecular markers are coincident. Hokkaido J Med Sci 80(2), 191-199, 2005 PMID:15835301

Yoshida, Masatugu; Suno, Manabu; Asari, Masaru; Ogawa, Kento; Awaya, Toshio; Shimizu, Keiko; Matsubara, Kazuo; Kita, Shinnichi; Shiono, Hiroshi

2005-03-01

153

A case report of a rare finding of supernumerary primary and permanent canines  

PubMed Central

A supernumerary tooth is a tooth that is additional to the normal series of teeth. These can occur anywhere in the primary or permanent dentition and are most commonly found in the anterior maxilla. Supernumerary canines are rare with little available literature and case reports in this area. This case presents a patient with a unilateral maxillary supernumerary deciduous and permanent canine associated with an unusual cleft of the alveolus. How to cite the article: Parker K, Hay N. A case report of a rare finding of supernumerary primary and permanent canines. J Int Oral Health 2014;6(2):129-131. PMID:24876714

Parker, Kate; Hay, Norman

2014-01-01

154

Study on high-strength plastic teeth. Tooth discoloration.  

PubMed

Conventional plastic teeth (CV teeth) are inferior to porcelain teeth in maintaining an adequate esthetic appearance with wear and discoloration, and thus have a shorter period of durability. Recently, high-strength plastic teeth (HS teeth) have been developed and applied to overcome the wear problems of CV teeth. Since HS teeth made of hard resin are still susceptible to staining with pigments, it has been observed that the esthetics of removable partial dentures made from such plastic teeth are gradually impaired in many patients. To investigate the susceptibility of HS teeth to pigments, we conducted an in vitro study by immersing three types of artificial teeth in three coloring liquids. It was found that the HS teeth tended to be less susceptible to the test pigments than the CV teeth to various degrees. In contrast, they showed markedly stronger susceptibility to the pigments than porcelain teeth. For all three artificial tooth types, daily tooth cleaning with an ultrasonic vibrator had a tendency to reduce the coloration in comparison with their counterparts without ultrasonic cleaning. PMID:8246042

Satoh, Y; Nagai, E; Azaki, M; Morikawa, M; Ohyama, T; Toyoma, H; Itoh, S; Sakurai, H; Iwasawa, A; Ohwa, M

1993-09-01

155

Mineral minimization in nature's alternative teeth  

E-print Network

REVIEW Mineral minimization in nature's alternative teeth Christopher C. Broomell1, , Rashda K, University of California, Santa Barbara, CA 93106, USA Contrary to conventional wisdom, mineralization, with little to no help from mineralization. Based on biochemical analyses, three of these mouthparts, the jaws

Zok, Frank

156

Teething & Dental Hygiene for Young Children  

MedlinePLUS

... learn to rinse and spit. Swallowing too much fluoride toothpaste can make white or brown spots on your child's adult teeth. You'll hear all kinds of advice on whether the best brushing motion is up and down, back and forth, or ...

157

Teeth: Among Nature's Most Durable Biocomposites  

NASA Astrophysics Data System (ADS)

This paper addresses the durability of natural teeth from a materials perspective. Teeth are depicted as smart biocomposites, highly resistant to cumulative deformation and fracture. Favorable morphological features of teeth at both macroscopic and microscopic levels contribute to an innate damage tolerance. Damage modes are activated readily within the brittle enamel coat but are contained from spreading catastrophically into the vulnerable tooth interior in sustained occlusal loading. Although tooth enamel contains a multitude of microstructural defects that can act as sources of fracture, substantial overloads are required to drive any developing cracks to ultimate failure—nature's strategy is to contain damage rather than avoid it. Tests on model glass-shell systems simulating the basic elements of the tooth enamel/dentin layer structure help to identify important damage modes. Fracture and deformation mechanics provide a basis for analyzing critical conditions for each mode, in terms of characteristic tooth dimensions and materials properties. Comparative tests on extracted human and animal teeth confirm the validity of the model test approach and point to new research directions. Implications in biomechanics, especially as they relate to dentistry and anthropology, are outlined.

Lawn, Brian R.; Lee, James J.-W.; Chai, Herzl

2010-08-01

158

Simulating Clinical Carious Lesions in Composition Teeth.  

ERIC Educational Resources Information Center

A step-by-step technique to alter stock composition teeth and create simulated carious conditions that are ideal or otherwise is presented. The procedures provide the student with life-like lesions, suitable in texture and location and similar to conditions found in the oral cavity. (MLW)

Ambrose, E. R.; And Others

1981-01-01

159

Riga-Fede disease and neonatal teeth  

PubMed Central

SUMMARY Aim The aim of this study is to present a case of Riga-Fede disease (RFD). RFD is a benign and uncommon mucosal disorder, characterized by an ulceration of the tongue, often caused by repetitive traumatic injuries due to backward and forward movements of the tongue over the mandibular anterior incisors. RFD is most commonly associated with the eruption of primary lower incisor in older infants or natal-neonatal teeth in newborns. Methods A 2-month-old female infant was referred to our Paediatric Dentistry Unit for ulceration (13 mm diameter) on the ventral surface of the tongue and neonatal teeth. The extraction of neonatal teeth was selected as treatment of choice, over more conservative treatments, for the rapid resolution of the lesion and for the limited risk of inadequate nutrients intake. The extracted teeth underwent a macroscopic/microscopic examination. The complete healing of the lesion took 4 weeks; subsequently, the infant, revised at the 1-year follow-up visit. Conclusion Early detection of RFD is recommended because such lesions properly may induce deformity or mutilation of tongue, dehydration, inadequate nutrients intake by the infant and growth retardation. PMID:23285403

COSTACURTA, M.; MATURO, P.; DOCIMO, R.

2012-01-01

160

Elephant teeth from the atlantic continental shelf  

USGS Publications Warehouse

Teeth of mastodons and mastodons have been recovered by fishermen from at least 40 sites on the continental shelf as deep as 120 meters. Also present are submerged shorelines, peat deposits, lagoonal shells, and relict sands. Evidently elephants and other large mammals ranged this region during the glacial stage of low sea level of the last 25.000 years.

Whitmore, F.C., Jr.; Emery, K.O.; Cooke, H.B.S.; Swift, D.J.P.

1967-01-01

161

Hierarchical structure and biomineralization in cricket teeth  

NASA Astrophysics Data System (ADS)

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

Xing, Xue-Qing; Gong, Yu; Cai, Quan; Mo, Guang; Du, Rong; Chen, Zhong-Jun; Wu, Zhong-Hua

2013-02-01

162

Comparison of fracture resistance of endodontically treated teeth using different coronal restorative materials: An in vitro study  

PubMed Central

Aim/Objective: To evaluate the in vitro effect of bonded restorations on the fracture resistance of root canal-treated teeth. Materials and Methods: One hundred twenty extracted, maxillary, permanent premolars were collected. After preparing the access cavity, the teeth were biomechanically prepared and obturated. Samples were divided into six groups based on the type of restorative material used to restore them. Teeth were embedded in acrylic resin and their fracture strength was measured using a Universal Testing Machine. Data were evaluated statistically using one-way ANOVA-F and unpaired t-test. Results: Teeth restored with bonded amalgam and composite resin showed higher fracture resistance than those restored with conventional amalgam. Fracture strengths of bonded restorations and intact teeth were not statistically different. The results suggested that the group restored with conventional amalgam had the lowest fracture resistance. No statistically significant differences were found between the bonded amalgam and composite resin groups. Conclusion: Conventional amalgam core showed the least fracture resistance whereas; composite resin and bonded amalgam core showed fracture resistance was similar to that of natural tooth. PMID:20543925

Monga, Prashant; Sharma, Vivek; Kumar, Sukesh

2009-01-01

163

Microflora around teeth and dental implants  

PubMed Central

Background: When an implant is exposed to oral cavity, its surface gets colonized by micro-organisms. The aim of this study is to comparatively assess the microbiological parameters in sulci around the teeth and the crowns supported by dental implants. Materials and Methods: In this prospective, cross-sectional study, 34 partially edentulous patients aged between 40 and 50 years with total 50 anterior maxillary single implants with cemented crowns (depth of sulci <4 mm) and 34 similar teeth in the same jaw of the same patients were included. Excluded were the patients with compromised systemic and periodontal health and smoking habits. None of the patients had used any antimicrobial mouthwashes during at least two weeks before the study. All of the implants (ITI) were at least 6 months in place covered by definitive prostheses. Samples of gingival sulci were taken around teeth with paper cone and transported to Stuart transport medium. Samples were cultured and examined by a dark field microscope and eight laboratory tests were performed to determine the micro-organisms The data were evaluated statistically using Chi-square test (?=0.05). Results: Six anerobic bacteria found in teeth and implants sulci were Gram-positive cocci, Gram-negative cocci, Prevotella, Porphyromonas gingivalis, Bacteroid Fragilis and Fusobacterium. Gram-positive cocci and Gram-negative cocci had maximum and minimum percentage frequency in the two groups, respectively. There were no significant differences between the two groups (P value >0.05). Conclusion: The present study indicated that microflora in implant sulci is similar to the tooth sulci, when the depth of sulci is normal (<4 mm). As a result, implants’ susceptibility to inflammation is the same as teeth. PMID:22623941

Shahabouee, Mohammad; Rismanchian, Mansour; Yaghini, Jaber; Babashahi, Akram; Badrian, Hamid; Goroohi, Hossein

2012-01-01

164

Morphometric, densitometric and mechanical properties of mandibular deciduous teeth in 5-month-old Polish Merino sheep  

PubMed Central

Background Caries, enamel hypoplasia, molar incisor hipomineralization, amylogenesis imperfecta, dentine dysplasia, hypophosphatasia and other dental disorders lead to tooth mineralization disturbances and structural abnormalities, decreasing masticatory organ functions. Dental disorders in sheep can lead to premature slaughter before they have attained final stage of their reproductive life and induce economic loss due to high flock replacement costs. Growth rate, health status and meat quality of sheep depends on tooth properties and quality determining in large extent efficiency of the masticatory apparatus and initial food break up. Considering lack of basic anatomical and physiological data on teeth properties in sheep, the aim of the study was to evaluate morphometric, densitometric and mechanical traits of deciduous mandibular incisor, canine and the second premolar obtained at the slaughter age of 5 months of life. Results The obtained results have shown the highest values of weight, total tooth volume, enamel volume and dentine volume in second premolar. Morphometric and mechanical parameters of incisors reached the highest values in first incisor and decreased gradually in second and third incisor, and in canine. Densitometric measurements have not revealed significant differences of the volumetric tooth mineral density in hard dental tissues between the investigated teeth. Conclusions In conclusion, proposed methodological approach is noninvasive since the deciduous teeth undergo physiological replacement with permanent teeth. Deciduous teeth can be easy collected for analyses from large animal population and may reflect mineral status and metabolism resulting from postnatal growth and development of the whole flock. In individual cases, evaluation of properties of deciduous teeth may serve for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory system functions. PMID:24548814

2014-01-01

165

A Curriculum Vitae of Teeth: Evolution, Generation, Regeneration  

Microsoft Academic Search

The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body sur- face of jawless fishes. Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity. In addition, the total number of teeth per denti- tion generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within

Despina S. Koussoulakou; Lukas H. Margaritis; Stauros L. Koussoulakos

2009-01-01

166

Experimental rotordynamic coefficient results for teeth-on-rotor and teeth-on-stator labyrinth gas seals  

NASA Technical Reports Server (NTRS)

An experimental test facility is used to measure the rotordynamic coefficients of teeth-on-rotor and teeth-on-stator labyrinth gas seals. Direct damping coefficients are presented for these seals for the first time. The results are presented for the two seal configurations at identical operating conditions, and show that, in a rotordynamic sense, the teeth-on-stator seal is more stable than the teeth-on-rotor seal, for inlet tangential velocity in the direction of rotation.

Childs, D. W.; Scharrer, J. K.

1986-01-01

167

Experimental rotordynamic coefficient results for teeth-on-rotor and teeth-on-stator labyrinth gas seals  

NASA Technical Reports Server (NTRS)

An experimental test facility is used to measure the rotordynamic coefficients of teeth-on-rotor and teeth-on-stator labyrinth gas seals. Direct damping coefficients are presented for these seals for the first time. The results are presented for the two seal configurations at identical operating conditions, and show that, in a rotordynamic sense, the teeth-on-stator seal is more stable than the teeth-on-rotor seal, for inlet tangential velocity in the direction of rotation.

Childs, Dara W.; Scharrer, Joseph K.

1987-01-01

168

AFM characterization of bovine enamel and dentine after acid-etching.  

PubMed

Teeth are constituted mainly of hydroxyapatite molecules (Ca(10)(PO(4))(6)(OH)(2)), grouped in different microstructural arrangements, depending on the dental layer considered (enamel or dentine). In the present work, these dental microstructural arrangements were characterized by atomic force microscopy. Enamel and dentine samples were cut from freshly extracted bovine incisor teeth. After metallographic polishing, the dental surfaces were etched with lactic acid (113.8 mmol/L, pH 3.3). Three etching times were tested: 1, 3 and 5 min. Atomic force micrographs showed that 1 min of etching time was effective to remove the smear layer, polishing debris and scratches, and display the characteristics of interest for both enamel and dentine. Although the bovine dental enamel rod cross-section presented keyhole-like shape, its measured dimensions (8.8 microm of major axis and 3.7 microm of minor axis) exhibited an insignificant discrepancy from human prisms diameters. Bovine dentinal tubules displayed larger mean diameters (4.0 microm) and a lower density (approximately 17,100 tubules/mm(2)) than human dentine, suggesting that the use of bovine dentine as a substitute for human dentine in resin adhesion investigations should be reconsidered. Apatite nanoparticles presented a mean radius (22-23 nm) considerably smaller than that of human teeth. PMID:19138525

Sanches, Roberto Pizarro; Otani, Choyu; Damião, Alvaro José; Miyakawa, Walter

2009-06-01

169

Replantation after extended dry storage of avulsed permanent incisors: report of a case.  

PubMed

A 15-year-old boy lost his maxillary right and left central incisor teeth in a bicycle accident. He was referred to our clinic 1 week after the injury. The crown-root integrities of both the teeth were not damaged. Although the teeth were stored under dry conditions for 1 week, reimplantation of the teeth was planned to retain the teeth in the mouth for as long a period as possible because of the patient's age. Following the debridement and sterilization of root surfaces in 2.5% NaOCl, root canals were prepared and filled with calcium hydroxide. Then, about 2 mm of the apexes were resected to ensure that the roots easily seated in the alveolar socket and the prepared cavities in root ends were obturated with the amalgam. The teeth were placed into their respective sockets and splinted temporarily. The root canal therapy was completed 5 weeks later. Ankylosis was observed radiographically after 10 months. The patient is now 23 years old and he is still able to use both the central incisors functionally. However, there is a pink appearance on the cervical buccal surface of left central incisor because of progressive replacement resorption. In this case, the new treatment plan is to perform a permanent restoration with dental implants following the extraction of both teeth. Even though the long-term prognosis is uncertain, this treatment technique has provided an advantage for the patient in his adolescent period by maintaining the height of alveolar bone and making the provision of an aesthetically acceptable permanent restoration at a later age possible. PMID:17635361

Cobankara, Funda Kont; Ungor, Mete

2007-08-01

170

The evaluation of a novel method comparing quantitative light-induced fluorescence (QLF) with spectrophotometry to assess staining and bleaching of teeth  

Microsoft Academic Search

This study reports the development and evaluation of a novel method using quantitative light-induced fluorescence (QLF), which\\u000a enables its use for quantifying and assessing whole tooth surface staining and tooth whitening. The method was compared with\\u000a a spectrophotometer to assess reliability. Two experimental phases, intrinsic stain formation and tooth whitening, were conducted\\u000a in vitro on 16 extracted bovine teeth. Intrinsic

A. A. Adeyemi; F. D. Jarad; E. de Josselin de Jong; N. Pender; S. M. Higham

2010-01-01

171

Optimized nanoscale composite behaviour in limpet teeth  

PubMed Central

Limpet teeth are striking examples of a biological fibrous nanocomposite consisting of goethite mineral within a polymeric chitin matrix. The mechanical function of limpet teeth is critically dependent on the efficient composite behaviour of goethite, formed as distinct discontinuous nanofibres, reinforcing the matrix. The mechanical properties of discrete volumes from a limpet tooth measured using atomic force microscopy indicate how the tooth structure can be approximated as a short fibre-reinforced composite. Short fibre composite analysis reveals how the goethite nanofibres have a length optimized for the transfer of stress from the matrix to fibre and highlight how this limpet tooth structure is efficient in a mechanical load-bearing function. PMID:22158842

Lu, Dun; Barber, Asa H.

2012-01-01

172

Incidence of pulp necrosis subsequent to pulp canal obliteration from trauma of permanent incisors.  

PubMed

Little long-term data are available on the frequency by which pulp canal obliteration (PCO) subsequent to trauma leads to pulp necrosis (PN). In this study, 82 concussed, subluxated, extruded, laterally luxated, and intruded permanent incisors presenting with PCO were followed for a period of 7 to 22 yr (mean 16 yr). At final clinical examination, 51% of the observed teeth responded normally to electric pulp testing (EPT). An additional 40% of the teeth although not responding to EPT were clinically and radiographically within normal limits. Yellow discoloration was a frequent finding. During the observation period, periapical bone lesions suggesting PN developed in seven teeth (8.5%). Twenty-yr pulp survival rate was 84%, as determined from life-table calculations. There was no higher frequency of PN in obliterated teeth subjected to caries, new trauma, orthodontic treatment, or complete crown coverage than intact teeth. Although the incidence of PN in teeth displaying PCO seems to increase over the course of time, prophylactic endodontic intervention on a routine basis does not seem justified. PMID:9198446

Robertson, A; Andreasen, F M; Bergenholtz, G; Andreasen, J O; Norén, J G

1996-10-01

173

Treatment of Ectopic Mandibular Second Permanent Molar with Elastic Separators  

PubMed Central

Ectopic eruption is a developmental disturbance in which the tooth fails to follow its normal eruption pathway. Ectopic eruption of the second molar is relatively rare. This paper presents the case of thirteen-year-old male with an ectopic mandibular second permanent molar. The condition was corrected with surgical exposure and placement of elastic separators. This case report lays emphasis on the practice of basic methods to obtain acceptable results rather than extensive surgical or orthodontic corrections. It is advised that ectopic teeth should not be neglected especially when it concerns developing caries and malocclusion. PMID:25050182

Rajesh, R.; Naveen, V.; Amit, S.; Baroudi, Kusai; Sampath Reddy, C.; Namineni, Srinivas

2014-01-01

174

Natal and neonatal teeth: an overview of the literature.  

PubMed

The occurrence of natal and neonatal teeth is an uncommon anomaly, which for centuries has been associated with diverse superstitions among different ethnic groups. Natal teeth are more frequent than neonatal teeth, with the ratio being approximately 3?:?1. It must be considered that natal and neonatal teeth are conditions of fundamental importance not only for a dental surgeon but also for a paediatrician since their presence may lead to numerous complications. Early detection and treatment of these teeth are recommended because they may induce deformity or mutilation of tongue, dehydration, inadequate nutrients intake by the infant, and growth retardation, the pattern and time of eruption of teeth and its morphology. This paper presents a concise review of the literature about neonatal teeth. PMID:24024038

Mhaske, Shubhangi; Yuwanati, Monal B; Mhaske, Ashok; Ragavendra, Raju; Kamath, Kavitha; Saawarn, Swati

2013-01-01

175

Natal and Neonatal Teeth: An Overview of the Literature  

PubMed Central

The occurrence of natal and neonatal teeth is an uncommon anomaly, which for centuries has been associated with diverse superstitions among different ethnic groups. Natal teeth are more frequent than neonatal teeth, with the ratio being approximately 3?:?1. It must be considered that natal and neonatal teeth are conditions of fundamental importance not only for a dental surgeon but also for a paediatrician since their presence may lead to numerous complications. Early detection and treatment of these teeth are recommended because they may induce deformity or mutilation of tongue, dehydration, inadequate nutrients intake by the infant, and growth retardation, the pattern and time of eruption of teeth and its morphology. This paper presents a concise review of the literature about neonatal teeth. PMID:24024038

Mhaske, Shubhangi; Yuwanati, Monal B.; Mhaske, Ashok; Ragavendra, Raju; Kamath, Kavitha; Saawarn, Swati

2013-01-01

176

Management of multiple impacted teeth: a case report and review.  

PubMed

Interdisciplinary care for the management of impacted teeth provides a holistic method of treating patients. Careful planning is necessary to reach the desired treatment goals. This article attempts to highlight the importance of diagnosis and adequate treatment planning for successful eruption of impacted teeth. The concept of forced eruption to improve the bone morphology of the impacted teeth has been used to treat a case of multiple impacted teeth. This paper reviews the diagnosis and management of impacted teeth. A case report of multiple impacted maxillary anterior teeth of a 13-year-old female patient has been presented. How to cite the article: Ajith SD, Shetty S, Hussain H, Nagaraj T, Srinath M. Management of multiple impacted teeth: A case report and review. J Int Oral Health 2014;6(3):93-8. PMID:25083041

Ajith, Sreedevi D; Shetty, Smitha; Hussain, Huma; Nagaraj, Tejavathy; Srinath, M

2014-06-01

177

Decalcification of teeth in a microwave oven  

Microsoft Academic Search

Summary  The effects of microwave radiation in reducing decalcification time were evaluated by measuring rates of calcium removal from samples of rat and cat teeth in 0.1 mol l–1 EDTA. In some cases, 3% glutaraldehyde was added to the decalcifying solution. Test specimens were placed in a microwave oven at 39±2°C for repeated periods of 1–2h. Control specimens were placed in

N. Vongsavan; B. Matthews; G. K. Harrison

1990-01-01

178

Magnetite in the radular teeth of chitons  

Microsoft Academic Search

To understand the process by which living organisms synthesize magnetite, we measured the Mössbauer spectra on the teeth at\\u000a different maturation stages along the radula of chitons. Our results show that magnetite is progressively mineralized from\\u000a hydrous ferric oxide precursor in the early stage of maturation. As the denticles become fully mineralized, a part of magnetite\\u000a is oxidized to maghemite

Manabu Mizota; Yutaka Maeda

1986-01-01

179

Cleidocranial Dysplasia Case Report: Remodeling of Teeth as Aesthetic Restorative Treatment  

PubMed Central

Cleidocranial dysplasia (CCD), is an autosomal dominant disorder with a prevalence of 1 in 1,000,000 individuals. It is generally characterized by orofacial manifestations, including enamel hypoplasia, retained primary teeth, and impacted permanent and supernumerary teeth. The successful treatment involving a timing intervention (orthodontic-maxillofacial surgeons-restorative) is already described. However, the restorative treatment might improve the aesthetic final result in dentistry management for patients with cleidocranial dysplasia. Objective. Therefore, this clinical report presents a conservative restorative management (enamel microabrasion, dental bleaching, and direct composite resin) for aesthetic solution for a patient with CCD. Clinical Considerations. The cosmetic remodeling is a conservative, secure, and low cost therapy that can be associated with other procedures such as enamel microabrasion and dental bleaching to achieve optimal outcome. Additionally, the Golden Proportion can be used to guide dental remodeling to improve the harmony of the smile and the facial composition. Conclusions. Thus, dentists must know and be able to treat dental aesthetic problems in cleidocranial dysplasia patients. The intention of this paper is to describe a restorative approach with the cosmetic remodeling teeth (by grinding or addicting material) associated with enamel microabrasion and dental bleaching to reestablish the form, shape, and color of smile for patients with cleidocranial dysplasia. PMID:25045546

da Cunha, Leonardo Fernandes; Caetano, Isabela Maria; Dalitz, Fernando; Gonzaga, Carla Castiglia; Mondelli, José

2014-01-01

180

Palatal displacement of canine is genetic and related to congenital absence of teeth.  

PubMed

The palatally displaced canine is a harmful complication of dental development. It appears in 1 to 2% of the Western population. According to our clinical experience, this anomaly is seen in families in which missing and peg-shaped teeth are common. It could be caused by the same genetic component that causes incisor-premolar hypodontia. We examined 106 patients who had been operated on and treated orthodontically for palatally impacted canine(s). The patients and their family members were examined for dental anomalies. One hundred and ten first- and 93 second-degree relatives were clinically and radiologically examined, and 35 pedigrees were constructed. Thirty-six percent of the patients had congenitally missing permanent teeth (hypodontia), which is 4.5 times the population prevalence. Hypodontia was noted in 19 to 20% of both the first- and second-degree relatives. This is 2.5 times the population prevalence. Frequency of missing teeth, analyzed by tooth groups, was of the same order as that shown for incisor-premolar hypodontia in the Western population. In six of the 35 pedigrees, a palatally impacted canine was noted in several generations of the same family. Prevalence of this anomaly was 4.9% in the studied group, which is 2.5 times the population prevalence. From the findings, we conclude that the palatally displaced canine belongs to the spectrum of dental abnormalities related to hypodontia. PMID:8955668

Pirinen, S; Arte, S; Apajalahti, S

1996-10-01

181

Bovine viral diarrhea viruses  

Technology Transfer Automated Retrieval System (TEKTRAN)

Infections with bovine viral diarrhea viruses (BVDV) result in significant economic losses for beef and dairy producers worldwide. BVDV is actually an umbrella term for two species of viruses, BVDV1 and BVDV2, within the Pestivirus genus of the Flavivirus family. While denoted as a bovine pathogen...

182

Permanent magnet applications  

Microsoft Academic Search

Rare-earth permanent magnets are ideally suited to generate magnetic fields comparable to their spontaneous polarization JS. Near-square hysteresis loops and large values of the coercivity and anisotropy fields greatly simplify magnet design, as each magnet block is effectively transparent to the magnetic fields produced elsewhere in the magnet assembly. The fields generated by compact and efficient magnet structures requiring no

J. M. D. Coey

2002-01-01

183

Modified cuspal relationships of mandibular molar teeth in children with Down's syndrome  

PubMed Central

A total of 50 permanent mandibular 1st molars of 26 children with Down's syndrome (DS) were examined from dental casts and 59 permanent mandibular 1st molars of normal children were examined from 33 individuals. The following measurements were performed on both right and left molars (teeth 46 and 36 respectively): (a) the intercusp distances (mb-db, mb-d, mb-dl, db-ml, db-d, db-dl, db-ml, d-dl, d-ml, dl-ml); (b) the db-mb-ml, mb-db-ml, mb-ml-db, d-mb-dl, mb-d-dl, mb-dl-d angles; (c) the area of the pentagon formed by connecting the cusp tips. All intercusp distances were significantly smaller in the DS group. Stepwise logistic regression, applied to all the intercusp distances, was used to design a multivariate probability model for DS and normals. A model based on 2 distances only, mb-dl and mb-db, proved sufficient to discriminate between the teeth of DS and the normal population. The model for tooth 36 for example was as follows: formula here A similar model for tooth 46 was also created, as well as a model which incorporated both teeth. With respect to the angles, significant differences between DS and normals were found in 3 out of the 6 angles which were measured: the d-mb-dl angle was smaller than in normals, the mb-d-dl angle was higher, and the mb-dl-d angle was smaller. The dl cusp was located closer to the centre of the tooth. The change in size occurs at an early stage, while the change in shape occurs in a later stage of tooth formation in the DS population. PMID:10029186

PERETZ, BENJAMIN; SHAPIRA, JOSEPH; FARBSTEIN, HANNA; ARIELI, ELIAHU; SMITH, PATRICIA

1998-01-01

184

Variable Permanent Magnet Quadrupole  

SciTech Connect

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.

Mihara, T.; Iwashita, Y.; /Kyoto U.; Kumada, M.; /NIRS, Chiba; Spencer, C.M.; /SLAC

2007-05-23

185

Optical characterization of one dental composite resin using bovine enamel as reinforcing filler  

NASA Astrophysics Data System (ADS)

The use of composite resins for restorative procedure in anterior and posterior cavities is highly common in Dentistry due to its mechanical and aesthetic properties that are compatible with the remaining dental structure. Thus, the aim of this study was to evaluate the optical characterization of one dental composite resin using bovine enamel as reinforcing filler. The same organic matrix of the commercially available resins was used for this experimental resin. The reinforcing filler was obtained after the gridding of bovine enamel fragments and a superficial treatment was performed to allow the adhesion of the filler particles with the organic matrix. Different optical images as fluorescence and reflectance were performed to compare the experimental composite with the human teeth. The present experimental resin shows similar optical properties compared with human teeth.

Tribioli, J. T.; Jacomassi, D.; Rastelli, A. N. S.; Pratavieira, S.; Bagnato, V. S.; Kurachi, C.

2012-01-01

186

Permanent magnet design methodology  

NASA Technical Reports Server (NTRS)

Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.

Leupold, Herbert A.

1991-01-01

187

Permanent homelessness in America?  

Microsoft Academic Search

This paper seeks to determine the approximate number of homeless persons in the U.S., the rate of change in the number, and whether or not the problem is likely to be permanent or transitory. It makes particular use of a new 1985 survey of over 500 homeless people in New York City. It finds that:(1)the much-maligned 1984 study by the

Richard B. Freeman; Brian Hall

1987-01-01

188

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth  

PubMed Central

Objectives The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. Materials and Methods A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope. Results Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. Conclusions Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application. PMID:25110641

Kianimanesh, Nasrin; Shayeghi, Bahareh

2014-01-01

189

Superconducting permanent magnets  

SciTech Connect

The concept of superconducting permanent magnets with fields trapped in shells or cylinders of Type II superconductors is an old one. Unfortunately, the low values of 0.5 to 1T for the first flux jump field, which is independent of the actual current density, have frustrated its implementation with classical Type II superconductors. The fact that the flux jump fields for high temperature superconductors should be an order of magnitude larger at liquid nitrogen temperatures allows us to reconsider these options. Analysis of the hysteresis patterns, based on the critical state model, shows that, if the dimensions are chosen so that the sample is penetrated at a field B/sub p/, which is equal to or just less than the first flux jump field, B/sub fj/, a temporarily applied field of 2B/sub fj/ will trap 0.5 B/sub fj/. Thus for a 90 K superconductor with a B/sub fj/ of 6T, a permanent field of 3 T should be trapped, with an energy product of 1.8 MJ/m/sup 3/ (225 MG . Oe). This is five times as large as for the best permanent magnet materials. The authors discuss means to verify the analysis and the limitations imposed by the low critical current densities in presently available high temperature superconductors.

Wipf, S.L.; Laquer, H.L.

1989-03-01

190

Natal teeth: a sign of fortuity or grave misfortune.  

PubMed

Natal teeth are defined as those present in the mouth at birth. They are uncommon and most frequently occur in the anterior mandible as a pair of primary incisors. They are usually small and poorly developed with little or no root formation. Only 10% of these teeth are supernumerary. Problems arising are difficulty suckling, severe ulceration of the child's tongue or the mother's breast and the risk of aspiration. These situations would warrant extraction. If the natal teeth are firm and asymptomatic, conservative management is indicated. Negative cultural attitudes towards natal teeth demand good parental counselling and vigilant management in relation to child protection. PMID:21436818

Sothinathan, R; Shakib, K

2011-03-26

191

Enamel hypoplasia and essential staining of teeth from erythroblastosis fetalis.  

PubMed

The dental, clinical, radiological, pedigree and dermatoglyphic findings of a patient showing hypoplasia of enamel and intrinsic staining of the teeth from erythroblastosis fetalis are presented. PMID:9641102

Atasu, M; Genc, A; Ercalik, S

1998-01-01

192

Exodontics: extraction of teeth in the dog and cat.  

PubMed

Dental disease can have a profound effect on the comfort and well-being of pets. Oral disease can be difficult to detect. Patients often hide their discomfort. The identification and treatment or removal of diseased teeth are the responsibility of the veterinarian. When diseased teeth cannot be saved by specialized care, extraction of teeth is necessary. Proper extraction of teeth in dogs and cats can be challenging and frustrating, but with review of the oral anatomy, proper instrumentation, and gentle tissue-handling techniques, this can be a rewarding part of clinical practice. PMID:23643022

Gengler, Bill

2013-05-01

193

Infectious Bovine Rhinotracheitis  

E-print Network

Infectious bovine rhinotracheitis (IBR) is a complex of disease syndromes occuring throughout the United States and the other major cattle-producing areas of the world. It affects cattle and some wild ruminants. This publication describes...

Sprott, L. R.

1998-11-30

194

Diagnostic of human teeth using photoacoustic response  

NASA Astrophysics Data System (ADS)

Laser-induced photoacoustic spectroscopy (LIPS) can be used to measure trace-element concentration in materials, down to parts-per-million. In this paper we investigate the use of laser-induced photoacoustic response in carious teeth detection. First, we found the Q-switched Nd:YAG laser of a wavelength of 1064 nm to produce detectable response in teeth. Then, we implemented two detection techniques using a piezoelectric transducer and Michelson Interferometer. The accurately detected response of a tooth sample by the piezoelectric transducer was analyzed using spectral analysis. However, in dentistry we do not necessarily mead an exact quantitative measurement; thus we designed a more physically realizable system that measures the acoustically-induced surface displacement using Michelson Interferometer. Monitoring this surface displacement we were able to determine the physical and optical properties of the tooth sample which could be used as a basis in diagnostics. The responses obtained by both detectors were equally confined to the categorization of a carious tooth from a normal one.

El-Sharkawy, Yasser H.; Badr, Y.; Gadallah, M.; El-Sherif, Ashraf F.

2006-02-01

195

Bovine Mastitis and Biofilms  

Microsoft Academic Search

\\u000a Biofilm formation in bovine mastitis Staphylococcus aureus isolates was studied since the beginnings of biofilm research, even before the name “biofilm” was actually invented. Compared\\u000a to other major bovine mastitis pathogens, such as E. coli and Streptococcus uberis relatively much research information is available on S. aureus biofilm formation, biofilm antimicrobial susceptibility and the role of several biofilm related genes.

Marielle B. Melchior

196

Evaluation of the coefficient of thermal expansion of human and bovine dentin by thermomechanical analysis.  

PubMed

The mismatch of thermal expansion and contraction between restorative materials and tooth may cause stresses at their interface, which may lead to microleakage. The present work compared the coefficient of thermal expansion (CTE) with the thermomechanical behavior of human and bovine teeth and determined if the CTE is a suitable parameter to describe tooth behavior. Fifteen human third molar and 15 bovine incisor tooth slices (6×5×2 mm) were allocated to 3 groups according to the test environment: G1 - room condition, G2 - 100% humidity, G3 - desiccated and tested in dry condition. Each specimen was weighed, heated from 20 to 70ºC at 10ºC min-1 and reweighed. The CTE was measured between 20 and 50ºC. Fresh dentin (human -0.49% ± 0.27, bovine -0.22% ± 0.16) contracted on heating under dry condition. Under wet conditions, only human teeth (-0.05% ± 0.04) showed contraction (bovine 0.00% ± 0.03) accompanied by a significantly lower (p<0.05) weight loss than in dry specimens (human 0.35% ± 0.15, bovine 0.45% ± 0.20). The desiccated dentin expanded on heating without obvious weight changes (0.00% ± 0.00). The CTE found was, respectively, in dry, wet and dissected conditions in ºC(-1): human (-66.03×10(-6), -6.82×10(-6), 5.52×10(-6)) and bovine (-33.71×10(-6), 5.47×10(-6), 4.31×10(-6)). According to its wet condition, the dentin showed different CTEs. The thermal expansion behavior of human and bovine dentin was similar. A simple evaluation of the thermal expansion behavior of tooth structure by its CTE value may not be appropriate as a meaningful consideration of the effects on the tooth-material interface. PMID:22460307

Lopes, Murilo Baena; Yan, Zhuoqun; Consani, Simonides; Gonini Júnior, Alcides; Aleixo, Anderson; McCabe, John F

2012-01-01

197

Pharyngeal Teeth of the Freshwater Drum (Aplodinotus grunniens) a Predator of the Zebra Mussel (Dreissena polymorpha)  

Microsoft Academic Search

The morphology of pharyngeal teeth of freshwater drum (Aplodinotus grunniens) was studied to determine changes that occur during growth of drum that may relate to consumption of zebra mussel (Dreissena polymorpha) by larger fish. Pharyngeal teeth were of three types. Cardiform teeth were replaced by villiform teeth, which were replaced by molariform teeth as the size class of drum increased.

John R. P. French III

1997-01-01

198

The bleaching efficiency of KTP and diode 810 nm lasers on teeth stained with different substances: An in vitro study.  

PubMed Central

Background and aims: The purpose of this study was to evaluate the bleaching efficiency of two different lasers (KTP and diode 810 nm) on teeth, randomly divided by means an Excel function (Microsoft Excel 2010 “Fx causale”) and stored in physiological solution, that were previously stained with different substances commonly considered as a cause of tooth discoloration, such as coffee, tea and red fruits and to investigate the role of laser irradiation in an experimental model, during the dental bleaching process. Methods: Three groups of 45 bovine teeth were created and immersed for one week in a solution of tea, coffee or red fruits respectively. Each group was divided into three sub-groups of fifteen teeth. One was bleached with a 30% hydrogen peroxide gel for 30 min only as control, another 15 teeth group was bleached with the gel plus 810 nm diode laser irradiation and the last group was bleached with the gel plus KTP irradiation. The lasers were applied in three cycles of 30 sec each with a power of 1.5 W localized on a 10 mm spot on the teeth. The temperature of the gel was checked during the bleaching procedure using a thermometer and the colour of each tooth was measured by a spectrophotometer. Results: Statistical analysis of the collected data was performed using Graph Pad Prism, version 6.01 software, Kruskal-Wallis test and Dunn's multiple comparison test and Mann-Whitney test. P value <0.0001 was considered extremely significant (***), P value between 0.001 to 0.01 very significant (**), P value between 0.01 to 0.05 significant (*) and P value >0.05 not significant (ns). By these tests diode laser was effective only at bleaching teeth stained with coffee meanwhile the KTP laser was efficient at bleaching teeth with coffee, tea and red fruits stains. Conclusion: This study suggests that a relation between the laser wavelength and the type of staining on the dental enamel and the efficacy of the whitening treatment exists. PMID:24771968

Lagori, G; Vescovi, P; Merigo, E; Meleti, M.; Fornaini, C

2014-01-01

199

Sex estimation based on deciduous and permanent dentition in a contemporary Spanish population.  

PubMed

Sex estimation of skeletal remains with satisfactory allocation accuracy represents an essential step in reconstructing the biological profile of unknown individuals in archaeological research and forensic practice. Teeth are among the most frequently recovered physical elements of an individual that remain after death due to their hardness, durability, and resistance to postmortem insults. This study was based on the deciduous and permanent dentition of 269 individuals (150 males and 119 females) from the Granada osteological collection of identified infants, young children, and adults (Granada, Spain). Mesiodistal, buccolingual, and diagonal crown and cervical diameters of both dentitions were measured, and logistic regression analyses were performed to create equations for sex discrimination. The results show that the first and second deciduous molars and the permanent canines are the teeth with the greatest sexual dimorphism, providing percentages of correct assignment of sex between 78.1 and 93.1% in deciduous dentition and between 79.4 and 92.6% in permanent teeth, depending on the dimensions used. The results indicate that this method may be applicable as an adjunct with other accepted procedures for sex estimation when fragmentary skeletal remains are encountered in archaeological excavations and in forensic contexts. PMID:23907722

Viciano, Joan; López-Lázaro, Sandra; Alemán, Inmaculada

2013-09-01

200

Permanent pacemakers in pregnancy.  

PubMed

Advances in cardiology and cardiovascular surgery have increased the use of permanent pacemakers in young adults such that there are more women with pacemakers becoming pregnant. This case report describes the pregnancy and delivery of a young woman with a demand pacemaker and reviews the principles of management of cardiac pacemakers in pregnancy. As part of the multidisciplinary team including cardiology, anesthesia, nursing and caring for these patients, it is important that obstetricians be informed and follow the principles of management of cardiac pacemakers in pregnancy to continue to achieve successful pregnancy outcomes. PMID:21995172

Coolen, J; Turnelp, R; Vonder Muhll, I; Chandra, S

2011-01-01

201

New permanent magnets  

NASA Astrophysics Data System (ADS)

Permanent magnets play an important role and are widely spread in daily-life applications. Due to their very low costs, large availability of the row materials and their high chemical stability, hard ferrites are still dominant in the permanent magnet market although their relatively poor magnetic properties are a distinct disadvantage. Today's high-performance magnets are mostly made from Nd 2Fe 14B. The aim of research is to combine the large spontaneous magnetization of 3d metals with strong anisotropy fields known from rare-earth transition-metal compounds and, at the same time, to maintain a high value of the Curie temperature. However, the number of iron-rich rare-earth intermetallics is very limited and, consequently, not much success can be noted in this field for the last 10 years. One alternative concept is to use magnetic fields trapped in type II superconductors where much higher fields can be achieved compared to conventional rare-earth magnets. Very recently, we obtained a trapped field as high as 14.4 T in a melt-textured YBCO bulk sample of a few centimeters in diameter. This is the highest value ever achieved in a bulk superconductor. The trapped field of a superconductor is not governed by the Laplace equation and, therefore, levitation works without any additional (active) stabilization. The disadvantage of these magnets is their low working temperature (of liquid nitrogen and below).

Müller, K.-H.; Krabbes, G.; Fink, J.; Gruß, S.; Kirchner, A.; Fuchs, G.; Schultz, L.

2001-05-01

202

Modified Anchor Shaped Post Core Design for Primary Anterior Teeth  

PubMed Central

Restoring severely damaged primary anterior teeth is challenging to pedodontist. Many materials are tried as a post core but each one of them has its own drawbacks. This a case report describing a technique to restore severely damaged primary anterior teeth with a modified anchor shaped post. This technique is not only simple and inexpensive but also produces better retention. PMID:25379294

Rajesh, R.; Baroudi, Kusai; Reddy, K. Bala Kasi; Praveen, B. H.; Kumar, V. Sumanth; Amit, S.

2014-01-01

203

Measuring the density of dingo teeth with machine vision  

Microsoft Academic Search

Collaboration between a mechatronics engineer and a biologist resulted in an unlikely application of machine vision. To deduce the density of the porous teeth, the volume had to be found. An expedient method was constructed for scanning the teeth before they had to be returned to their source and a simple method was derived for deducing their volume.

John Billingsley; Kerry Withers

2004-01-01

204

Storage media for avulsed teeth: a literature review.  

PubMed

Dental avulsion is the most severe type of traumatic tooth injuries because it causes damage to several structures and results in the complete displacement of the tooth from its socket in the alveolar bone. The ideal situation is to replant an exarticulated tooth immediately after avulsion because the extraoral time is a determinant factor for treatment success and for a good prognosis. However, it is not always possible. The success of replantation depends on a number of factors that may contribute to accelerate or minimize the occurrence of root resorption or ankylosis, among which is the type and characteristics of the medium used for temporary storage during the time elapsed between avulsion and replantation. Maintaining the tooth in an adequate wet medium that can preserve, as longer as possible, the vitality of the periodontal ligament cells that remain on root surface is the key to success of replantation. Recent research has led to the development of storage media that produce conditions that closely resemble the original socket environment, with adequate osmolality (cell pressure), pH, nutritional metabolites and glucose, and thus create the best possible conditions for storage. Although these storage media can now be purchased in the form of retail products, the most common scenario is that such a product will not be readily available at the moment of the accident This paper reviews the literature on the different storage media that have been investigated for avulsed teeth based on full-length papers retrieved from PubMed/Medline, Lilacs, BBO and SciELO electronic databases using the key words 'storage medium', 'transportation medium', 'avulsion', 'tooth avulsion', 'replantation', 'tooth replantation', 'milk' and 'propolis'. After application of inclusion and exclusion criteria, 39 papers were selected and critically reviewed with respect to the characteristics, efficacy and ease of access of the storage medium. The review of the literature showed that a wide array of types of wet storage media have been evaluated in laboratory studies and clinical reports, including cell and tissue culture solutions like Hank's Balanced Salt Solution (HBSS); medical/hospital products developed specifically for organ storage purposes, such as Viaspan® and Euro-Collins®; culture media, like Minimum Essential Medium (MEM); saline; natural products like water, saliva, bovine milk and its variations, propolis, green tea, Morus rubra (red mulberry), egg white and coconut water; rehydrating solutions, like Gatorade® and Ricetral, and even contact lens solutions. Based on the literature, it could be stated that, so far, apart from Based on the literature, it could be stated that, so far, apart from solutions designed specifically for storage and culture purposes, regular pasteurized whole milk is the most frequently recommended and with the best prognosis among other solutions that are likely to be available at the scene of an accident, such as water, saline or saliva. Its advantages include its high availability, ready accessibility, physiologically compatible pH and osmolality (fluid pressure) with the root-surface adhered PDL cells, presence of nutrients and growth factors. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on. PMID:24474282

Poi, Wilson Roberto; Sonoda, Celso Koogi; Martins, Christine Men; Melo, Moriel Evangelista; Pellizzer, Eduardo Pizza; de Mendonça, Marcos Rogério; Panzarini, Sônia Regina

2013-01-01

205

Frequency and distribution of early tooth loss and endodontic treatment needs of permanent first molars in a Turkish pediatric population  

PubMed Central

Objectives: The objective of this study is to evaluate the frequency and distribution of early tooth loss and endodontic treatment needs of permanent first molars in a Turkish pediatric population. Materials and Methods: A total of 7,895 panoramic radiographs taken for routine dental examination at the Department of Oral Maxillofacial Radiology between 2008 and 2012 years were investigated. Two independent specialists evaluated early tooth loss and endodontic treatment needs of permanent first molars using panoramic radiography and patient anamnesis forms. The teeth were classified according to the following data: (a) Missing teeth, (b) teeth requiring extraction, (c) endodontically treated teeth (ETT), (d) teeth requiring endodontic therapy. The data also classified according to four factors: Age group (6-12 and 13-16), gender (boy and girl), jaw (mandible and maxilla) and side (right and left). A Chi-square test was used for statistical analyses. Results: A total of 19,488 and 12,092 teeth were evaluated in the child group and adolescent group respectively. All data were higher in adolescents than children (P < 0.001). For gender factor, only ETT was higher in girls than it was in boys (P < 0.001). For the jaw factor, all data were higher (P < 0.001) in mandible than in the maxilla. For the side factor, no statistical difference existed between right and left. Conclusions: Early tooth loss and endodontic treatment needs of permanent first molars showed variability according to age groups and jaws. When the results were compared according to the side and gender factors, no statistical difference was found (P > 0.05) except with the data of ETT in gender groups. PMID:24966738

Demirbuga, Sezer; Tuncay, Oznur; Cantekin, Kenan; Cayabatmaz, Muhammed; Dincer, Asiye Nur; Kilinc, Halil ?brahim; Sekerci, Ahmet Ercan

2013-01-01

206

Does incomplete caries removal reduce strength of restored teeth?  

PubMed

Little information is available about whether the presence of residual caries beneath an occlusal restoration affects fracture strength of the tooth. This in vitro study tested the hypothesis that restored teeth after incomplete excavation have lower fracture strengths than restored teeth after complete excavation. Fourteen pairs of molars were randomly assigned to an experimental (incomplete excavation) or to a control group (complete excavation) and loaded vertically (after cyclic loading). Failure load and fracture mode were recorded. Restored teeth in the incomplete excavation group resulted in reduced fracture strength (p < 0.001) of the tooth-restoration complex (1276 N ± 626 N) compared with the control group (2768 N ± 710 N). Teeth in the complete excavation group all fractured vertically, while in the experimental group, cracks in the restoration were observed, characterized as 'ice-cracks'. The fracture strength of teeth restored over incomplete caries excavation was significantly reduced, possibly resulting in long-term clinical failure. PMID:20858783

Hevinga, M A; Opdam, N J; Frencken, J E; Truin, G J; Huysmans, M C D N J M

2010-11-01

207

Pharyngeal teeth of the freshwater drum (Aplodinotus grunniens) a predator of the zebra mussel (Dreissena polymorpha)  

USGS Publications Warehouse

The morphology of pharyngeal teeth of freshwater drum (Aplodinotus grunniens) was studied to determine changes that occur during growth of drum that may relate to consumption of zebra mussel (Dreissena polymorpha) by larger fish. Pharyngeal teeth were of three types. Cardiform teeth were replaced by villiform teeth, which were replaced by molariform teeth as the size class of drum increased. Molariform teeth comprised over 85% of total surface area of dentition in fish 265 mm long.

French, John R. P., III

1997-01-01

208

Achieving permanency for LGBTQ youth.  

PubMed

This article brings together two significant efforts in the child welfare field: achieving permanence for youth in out-of-home care and meeting the needs of lesbian, gay, bisexual, transgender and questioning (LGBTQ) youth. During the past several years, a national movement has taken place to assure all children and youth have a permanent family connection before leaving the child welfare system; however, LGBTQ youth are not routinely included in the permanency discussions. At the same time, efforts in addressing the needs of LGBTQ youth have increased, but permanency is rarely mentioned as a need. This article offers models of permanence and practices to facilitate permanence with LGBTQ youth and their families. It also offers a youth-driven, individualized process, using youth development principles to achieve relational, physical, and legal permanence. Reunification efforts are discussed, including services, supports, and education required for youth to return to their family of origin. For those who cannot return home, other family resources are explored. The article also discusses cultural issues as they affect permanence for LGBTQ youth, and, finally, addresses the need for ongoing support services to sustain and support permanency. PMID:16846117

Jacobs, Jill; Freundlich, Madelyn

2006-01-01

209

Persistently infected cattle stabilise bovine viral diarrhea virus leading to herd specific strains  

Microsoft Academic Search

Animals persistently infected with BVDV are important in the epizootiology of the Bovine Viral Diarrhea (BVD) because they are a permanent source of contamination within a herd. These animals produce large quantities of virus and have, therefore, been proposed as responsible for generating antigenic variability. However, limited studies have failed to detect antigenic or genetic changes in viruses isolated at

C Hamers; C Lecomte; G Kulcsar; M Lambot; P.-P Pastoret

1998-01-01

210

Ameloblastic fibroma of the mandible associated with root resorption and unerupted teeth: a case report.  

PubMed

Ameloblastic fibroma (AF) is an uncommon benign odontogenic mixed tumor. A case of an AF associated with unerupted and missing teeth is presented. A 13-year-old girl was referred for evaluation of a painless swelling of her right mandible. The most remarkable finding was the resorption of the proximal root of the permanent first molar. The lesion was completely enucleated. Follow-up showed satisfactory bony healing, and the resorbed root was completely surrounded by a continuous layer of intact lamina dura. In most cases, the patient presents to the clinician complaining of an unerupted tooth at the posterior area of the mandible. The most remarkable finding in our case, however, was the coexisting root resorption. This finding could indicate a more aggressive form of AF. AF has a very good prognosis. Malignant transformation is extremely rare. PMID:19057751

Dimitrakopoulos, Ioannis; Psomaderis, Konstantinos; Zaramboukas, Thomas

2008-06-01

211

Association between third molar agenesis patterns and agenesis of other teeth in a Japanese orthodontic population.  

PubMed

The purpose of this study was to investigate the patterns of third molar agenesis and incidence of agenesis of other permanent teeth in a Japanese orthodontic patient group. A total of 417 Japanese subjects (134 males and 283 females) with agenesis of one or more third molars were divided into four groups according to the agenesis pattern, and 874 other Japanese subjects (302 males and 572 females) without third molar agenesis were assigned to a control group. Panoramic radiographs and medical and dental records were used to examine for tooth agenesis. The Chi-square test and odds ratio were used to make statistical comparisons. The prevalence of third molar agenesis worked out at 32.3% with no statistically significant gender difference. A high prevalence rate of agenesis of third molars, unilateral or bilateral, could be considered characteristic of the Japanese orthodontic population. Significant increases in occurrence of oligodontia, and unilateral or bilateral agenesis of other teeth, including maxillary lateral incisors and maxillary and mandibular second premolars, were observed in all or almost all of the third molar agenesis groups, compared with the controls. A significantly increased prevalence rate of mandibular lateral incisor agenesis was observed in almost all of the third molar agenesis groups. The Japanese patients with third molar agenesis had a significantly increased occurrence of oligodontia, and unilateral or bilateral agenesis of maxillary and mandibular lateral incisors and second premolars, except for bilateral agenesis of mandibular lateral incisors. PMID:23990107

Endo, Saori; Sanpei, Sugako; Ishida, Rieko; Sanpei, Shinya; Abe, Ryota; Endo, Toshiya

2015-01-01

212

[Ectopic teeth in the area of the paranasal sinuses].  

PubMed

In contrast to dentogenious affections of the sinus maxillaris ectopic or supernumerary teeth in the paranasal sinuses are seldom. Ectopic teeth located at the ostium of the sinus maxillaris are rare, intranasal teeth are very rare and ectopic/supernumerary teeth in the sinus etmoidalis are a curiosity. We report about two patients with such ectopic teeth. A 55 year old woman had a rootless tooth in her right sinus ethmoidalis which had caused a "pseudopolyposis" with consecutive nasal airway obstruction and severe headache. A 59 year old man had ectopic teeth in both sinus maxillaris which obstructed the left ostium, causing dumbness of the left cheek and severe headache. Both patients have been cured by operation. However the presented patients demonstrate that even elaborated radiological efforts could not prove diagnosis. The etiology, diagnostical steps and treatment of these teeth are discussed. The surrounding soft tissue should be examined histologically after resection of such a tooth to prevent the development of a residual cyst and to notice the extremely rare development of malignancies deriving from the highly potential tissue of the dental follicle. PMID:8365919

Weber, B P; Kempf, H G; Mayer, R; Braunschweig, R

1993-06-01

213

Permanent-Magnet Meissner Bearing  

NASA Technical Reports Server (NTRS)

Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

Robertson, Glen A.

1994-01-01

214

Intraocclusal distance between the anterior teeth in intercuspal position.  

PubMed

We recorded intercuspal occlusal contacts using silicone for 20 subjects with complete dentition maintaining their masseter muscle contraction levels at 10 and 30% of maximum EMG activity. A computer-aided video system was used to read the silicone image and translate the intensity of transmitted light to the thickness corresponding to the distance between opposing teeth. The intraocclusal distance was greater in the anterior than in the posterior teeth. The intraocclusal distance in the canines was intermediate between that in the incisors and posterior teeth. Although these tendencies were the same at the 10 and 30% EMG levels, an increase in the EMG level decreased all the distances. PMID:1819657

Tosa, J; Takada, H; Tanaka, M; Kawazoe, T

1991-10-01

215

Fluoride distribution in teeth using a silicate model.  

PubMed

The fluoride determinations were done on enamel biopsies taken before and after restoration of extracted teeth with silicate cement. Two sites, one near the restoration and one 3 mm or more away from the restoration, were assayed. No difference was noted in pre- and post-restoration biopsies when teeth were restored with a fluoride-free silicate. Post-restoration biopsies at sites near and away from the restoration were significantly higher in fluoride as compared to pre-restoration biopsies when the teeth were restored with a fluoride-containing silicate. PMID:6932416

Swartz, M L; Phillips, R W; Clark, H E; Norman, R D; Potter, R

1980-10-01

216

Macroscopic and microscopic aspects of incinerated teeth.  

PubMed

Fifty-eight premolars, extracted for orthodontic reasons, were incinerated for one hour in a furnace at temperatures varying from 150 degrees C to 1150 degrees C, increasing at 100 degrees C intervals. Between 150 degrees C and 700 degrees C the teeth changed from light yellow to bluish-white passing through brown. The scanning electron microscope showed that at 150 degrees C cracks appeared in the enamel, increasing in number as the temperature rose. At 450 degrees C the internal surface detached from the dentine and showed the same cracked surface as the exterior. Above 1100 degrees C the enamel fragments had a prismatic structure difficult to identify due to their melted structure. Dentine retained its tubular structure up to 1150 degrees C even when the tubules' diameter decreased at 700 degrees C. The cementum cracked as the temperature increased. Certain cracked areas actually detached at 600 degrees C giving a corroded aspect to the cementum and the residual zones became irregular when the temperature rose and eventually at 1150 degrees C the cementum was no longer identifiable. PMID:9922754

Muller, M; Berytrand, M F; Quatrehomme, G; Bolla, M; Rocca, J P

1998-06-01

217

[Bovine graft as arteriovenous fistula for hemodialysis].  

PubMed

We used the bovine carotid artery (BCA) as arteriovenous shunt for hemodialysis in 11 patients since December 1975. We discuss our results. For implantations we used two methods: straight and loop grafts. The BCA have many advantages as: good access for punction, anticoagulation not permanently necessary, volume of shunt more than 250 ml/min; the disadvantages are: increased tendence to infection and thrombosis. Thrombosis in BCA can be easier removed than in other grafts. Reduction of the complications incidence is possible with an accurate technique. We think that the BCA is very useful when Cimino-Brescia fistula has failed or is unavailable; we prefer BCA to a saphenous arteriovenous graft in these situations. PMID:624647

Zingher, E; Gianella, C; Colombi, A; Vogt, B

1978-01-01

218

DIAGNOSIS OF BOVINE NEOSPOROSIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The protozoan parasite Neospora caninum is a major cause of abortion in cattle. The diagnosis of neosporosis-associated mortality and abortion in cattle is difficult. In the present papers we review histologic, serologic, immunohistochemical, and molecular methods for dignosis of bovine neosporosis....

219

Bovine milk exosome proteome  

Technology Transfer Automated Retrieval System (TEKTRAN)

Exosomes are 40-100 nm membrane vesicles of endocytic origin and are found in blood, urine, amniotic fluid, bronchoalveolar lavage (BAL) fluid, as well as human and bovine milk. Exosomes are extracellular organelles important in intracellular communication/signaling, immune function, and biomarkers ...

220

Composite indicators of dental health: functioning teeth and the number of sound-equivalent teeth (T-Health).  

PubMed

This study investigated whether two new composite dental indicators--"the number of functioning teeth" and "the number of sound-equivalent teeth"--are more efficient than the conventional DMFT index in revealing the social and behavioural factors which are significantly related to oral health status. The arbitrary set of weights given to the T-Health indicator was also evaluated. The number of functioning teeth was defined as the aggregate of filled (otherwise sound) and sound teeth. The T-Health was defined as a weighted average of sound teeth, filled (otherwise sound) teeth and teeth with some decay, the weights intended in principle to represent the relative amounts of sound tissue in these three categories of teeth. An arbitrary set of weights was used: 4, 2, and 1 for sound, filled, and decayed teeth, respectively. 164 families (father, mother and at least one 13-yr-old child) from Belo Horizonte, Brazil, were randomly selected from 13-yr-old children from private and state schools. The parents' ages ranged from 35 to 44 yr. Socio-economic status, area of residence, level of education, family income, sugar consumption, toothbrushing frequency and type of dental attendance were the social and behavioural oral health risk-factors considered in this study. The results indicated that the two new dental indicators are more sensitive to the influence of social and behavioural factors, such as those investigated here, than is the traditional DMFT index. A different set of weights (4, 1, and 1 for sound, filled, and decayed) was suggested for the construction of the T-Health. PMID:8306616

Marcenes, W S; Sheiham, A

1993-12-01

221

The Use of Glass-fibers Ribbon and Composite for Prosthetic Restoration of Missing Primary Teeth-Laboratory and Clinical Research  

PubMed Central

Very few modalities can be used for restoring missing primary anterior teeth, although the impact of missing anterior teeth during early childhood can be harmful. In the permanent dentition the use of glass-fibers ribbon and composite materials are frequently used for restoring missing teeth with no or minimal preparation. The purpose of this study was to examine the possibility to use the glass-fibers ribbon (ever-Stick from GC Corporation, Japan) together with esthetic composite materials (G-aenial A1 from GC Corporation, Japan) for restoring anterior primary teeth and to determine the best methodology and bonding system to be used. The effect of etching time was analyzed using 20-80 sec on primary buccal enamel with SEM and the results showed that at least 60 second is necessary in order to remove the prismless layer and to affect the prismatic layer similar (as observed by SEM) to the 20 sec etching time on permanent enamel. Three bonding systems (SE Bond by Kurary, Japan, Scotchbond Universal by 3M/ESPE, Germany and G-aenial bond by GC Company, Japan) were compared for bonding the glass-fibers ribbon to the primary enamel and microtensile strength analyses were performed. Mean tensile strength ranged from 10.9 to 13 MPa with no statistically significant differences between all three systems. Based on the laboratory results it can be concluded that the glass-fibers ribbon together with the composite material can be used clinically to restore missing primary teeth for esthetic and functional reasons. Two clinical cases are presented that show favorable results. PMID:25553140

Zilberman, Uri; Lasilla, Lippo

2014-01-01

222

Anatomical, pathological and clinical study of donkey teeth   

E-print Network

Eighty normal cheek teeth and 26 normal incisors extracted from 14 donkeys (median age 19 years) at post mortem were anatomically examined including grossly and by computerised axial tomography (CAT) imaging. Decalcified ...

du Toit, Nicole

2009-01-01

223

Multiple teeth fractures in dentinogenesis imperfecta: a case report.  

PubMed

Dentinogenesis imperfecta (DGI) is a hereditary defect consisting of opalescent teeth composed of irregularly formed and hypomineralized dentin. This paper presents the multiple fractures of DGI-affected teeth and suggests the reason of low fracture resistance by observing the dentin microstructures directly using scanning electron microscope (SEM) and by measuring its surface hardness using the Vickers hardness test. SEM revealed that while the enamel microstructure was similar in the DGI-affected and normal teeth, the microstructure of the DGI-affected dentin was poorly woven and more loosely packed than that of the normal dentin. The Vickers hardness of the DGI-affected dentin was 4.89 times softer than the normal dentin. The low fracture resistance of DGI-affected teeth can be attributed to the poorly woven microstructure of their dentin, which leads to a reduction in hardness. PMID:25571690

Min, Boram; Song, Je Seon; Lee, Jae-Ho; Choi, Byung-Jai; Kim, Kwang-Mahn; Kim, Seong-Oh

2014-01-01

224

Evolutionary modification of development in mammalian teeth: Quantifying gene  

E-print Network

Evolutionary modification of development in mammalian teeth: Quantifying gene expression patterns Geographic Information Systems. We investi- gated how genetic markers for epithelial signaling centers known, usually involve little initial modification of morphology. One system that offers promise for linking

Jernvall, Jukka

225

Artificial teeth : dental biofilm analysis on a chip  

E-print Network

In this thesis, an "artificial teeth" microfluidic device is developed that provides unprecedented control over the conditions required to simulate the growth of complex dental biofilm. Dental plaque formation is not only ...

Lam, Raymond Hiu-wai

2010-01-01

226

A Review on Vital Pulp Therapy in Primary Teeth  

PubMed Central

Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed. PMID:25598803

Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

2015-01-01

227

Form factors for generated unequal addendum and dedendum gear teeth  

E-print Network

PORN FACTORS FOR GEHERLTED DREQUkL LDDERDDH /AID DEDEHDDH GEAR TEETH GEORGE FREDERICK SHEETS, JH. approved as to style and oontent by: z Head of Departnent Hayi 1952 FORM FACTORS FOR GEEERATED UEEQUAL ADDEEDUM AED DEDEEDUM GEAR TEETH.... . . . . . . 7 2. Stress distribution at root of tooth 3. Plastic template for generating tooth profile 4, . Developsmnt of gear tooth . 14 15 5. Ron-standard gear engaging basic rack . 6. Plastic template and gear blank . 17 7. Comparison of old and net...

Sheets, George Frederick

1952-01-01

228

A Double-Sided Linear Primary Permanent Magnet Vernier Machine  

PubMed Central

The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed.

2015-01-01

229

Laser light passage through restored and carious posterior teeth.  

PubMed

Laser Doppler flowmetry (LDF) has been used to investigate pulpal blood flow as a means of pulp vitality testing. Transmission of laser light from the tooth surface to the pulp space may be influenced by caries and restorations. One hundred and twenty-two first and second molars that had caries into dentine, restorations or significant loss of coronal tissue were sectioned in half axio-bucco-lingually. The two sections were illuminated with a laser from their buccal and lingual aspects 2 mm coronal to the amelocemental junction. Light reaching the pulp space was recorded. Buccal and lingual illumination sites were equally effective for 67 teeth (55%). Buccal sites alone were effective for 35 teeth (29%), despite over one-third of these surfaces being restored or featuring enamel or dentine caries. A lingual position alone was effective for 20 teeth (16%). Caries affected light transmission, but for over half the teeth, the pulp could be illuminated from all four probe positions. No effect was found when the influence of mesial and distal restorations on transmission into the corresponding tooth section was examined. The pulp spaces of most (84%) restored, and carious posterior teeth could be illuminated by laser light from their buccal aspect and these teeth could potentially be vitality tested using LDF. PMID:24750450

Chandler, N P; Pitt Ford, T R; Monteith, B D

2014-08-01

230

Genetics Home Reference: Permanent neonatal diabetes mellitus  

MedlinePLUS

... literature OMIM Genetic disorder catalog Conditions > Permanent neonatal diabetes mellitus On this page: Description Genetic changes Inheritance ... definitions Reviewed July 2011 What is permanent neonatal diabetes mellitus? Permanent neonatal diabetes mellitus is a type ...

231

A Key to the Common Genera of Neogene Shark Teeth Robert W. Purdy  

E-print Network

A Key to the Common Genera of Neogene Shark Teeth by Robert W. Purdy Revised March 2006 #12 Sexual Dimorphism in Teeth 11 Abnormal Teeth 11 Using Artificial Tooth Sets to Identify Fossil Shark Teeth 12 Hexanchiform Sharks 12 Squaliform Sharks 13 Lamniform Sharks 13 Carcharhiniform Sharks 14

Mathis, Wayne N.

232

Variation in composition and abundance of Miocene shark teeth from Calvert Cliffs, Maryland  

Microsoft Academic Search

Shark teeth are the most common vertebrate fossils found along the western shore of Chesapeake Bay at Calvert Cliffs in Maryland. The stratigraphic distribution of teeth within the cliffs has not yet been documented. We utilized museum collections of in situ teeth to access their distribution within stratigraphic beds and a large selection of float teeth retrieved from Calvert County

Christy C. Visaggi; Stephen J. Godfrey

2010-01-01

233

Bleaching effect of ozone on pigmented teeth  

PubMed Central

Background: There have been numerous researches on ozone application in dentistry; yet the data regarding its whitening effect is very limited. The present study compares the bleaching effect of ozone with office bleaching. Materials and Methods: In this experimental study, 15 maxillary premolar teeth were selected and sectioned mesio-distally and bucco-lingually. The sections were then placed in tea for 1 week according to the Sulieman method and were divided into three groups each comprised of 15 sections. The samples were bleached as followed; Group I: Bleached with 35% hydrogen peroxide in three intervals of 8 min each, Group II: Underwent ozone treatment using Ozotop unite for 4 min and Group III: Bleached with a combination of both methods. The color indices of the samples, i.e., (a) green-red pigment, (b) blue-yellow pigment, (L) brightness, (?E) overall color change, were evaluated pre- and post-bleaching utilizing a digital camera, Photoshop software and CIE lab index. The color changes of specimens then were calculated and analyzed through randomized analysis of variance and Tukey tests. P < 0.001 was considered to be significant. Results: The color change (?E) in Group II was significantly lower than those in the two other groups (P < 0.001). There was no significant difference between the color change of Groups I and III (P = 0.639). In addition, the results of L, a and b brought forth a similar pattern to the findings obtained from ?E. Conclusion: The hydrogen peroxide gel has a more powerful whitening effect than ozone; in addition, ozone has no synergistic effect when is used simultaneously with hydrogen peroxide. PMID:25709670

Zanjani, Vagharedin Akhavan; Ghasemi, Amir; Torabzadeh, Hassan; Jamali, Mahbobeh; Razmavar, Sara; Baghban, Alireza Akbarzadeh

2015-01-01

234

First fossil evidence for the advance of replacement teeth coupled with life history evolution along an anagenetic mammalian lineage.  

PubMed

In mammals that grow up more slowly and live longer, replacement teeth tend to appear earlier in sequence than in fast growing mammals. This trend, known as 'Schultz's Rule', is a useful tool for inferring life histories of fossil taxa. Deviations from this rule, however, suggest that in addition to the pace of life history, ecological factors may also drive dental ontogeny. Myotragus balearicus is an extinct insular caprine that has been proved to be an excellent test case to correlate morphological traits with life history. Here we show that Myotragus balearicus exhibits a slow signature of dental eruption sequence that is in agreement with the exceptionally slow life history of this species, thus conforming to 'Schultz's Rule'. However, our results also show an acceleration of the absolute pace of development of the permanent incisors in relation to that of the posterior teeth. The rodent-like incisors of Myotragus balearicus erupted early not only in relative but also in absolute terms (chronological age), suggesting that feeding characteristics also plays an important role in dental ontogeny. This is in agreement with ecological hypotheses based on primates. Our study documents a decoupling of the pace of development of teeth in mammals that is triggered by different selection pressures on dental ontogeny. Moreover, we show that Myotragus kopperi from the early Pleistocene (a direct ancestor of the late Pleistocene-Holocene M. balearicus) follows the pattern of first incisor replacement known in living bovids. Hence, the advance in the eruption sequence of the first incisors occurs along the Myotragus evolutionary lineage over a period of about 2.5 Myr. To our knowledge, this is the first fossil evidence of an advance of the emergence of the permanent first incisor along an anagenetic mammalian lineage. PMID:23936247

Jordana, Xavier; Marín-Moratalla, Nekane; Moncunill-Solé, Blanca; Bover, Pere; Alcover, Josep Antoni; Köhler, Meike

2013-01-01

235

The effects of racemization rate for age estimation of pink teeth.  

PubMed

Pink teeth is thought to result from the seepage of hemoglobin caused by dental pulp decomposition. We investigated whether racemization can be applied for age estimation in cases of pink teeth where the whole tooth is used. The pink teeth used were three cases and the normal teeth for control were five mandibular canines of known age. Age of the pink teeth was calculated on the basis of regression formula obtained from the five control teeth. Only a slight error was noted between the actual and estimated ages of the pink teeth (R(2)  = 0.980, r = 0.990): Cases 1-3 actually aged 23, 53, and 59 years were estimated to be 26, 52, and 60 years. Based on our results of testing pink teeth of known age, we suggest that racemization techniques allow for the age estimation of pink teeth using the same methods for normally colored teeth. PMID:25684096

Sakuma, Ayaka; Saitoh, Hisako; Ishii, Namiko; Iwase, Hirotaro

2015-03-01

236

Post-Obturation pain following one-visit and two-visit root canal treatment in necrotic anterior teeth  

PubMed Central

Background: To investigate and compare the post-obturation pain after one-visit and two-visit root canal treatment in non-vital anterior teeth. Materials & Methods: One hundred forty eight patients requiring root canal therapy on permanent anterior non-vital teeth with single root were included in this study. Patients were randomly assigned to either the one-appointment or the twoappointment group. The standardized protocol for all the teeth involved local anesthesia, isolation and access, engine-driven rotary nickel-titanium canal instrumentation with 2.5% NaOCl irrigation and obturation. Teeth in group 1 (n = 74) were obturated during the first appointment by using laterally condensed gutta-percha and resin sealer. Teeth in group 2 (n = 74) were given closed dressing and were obturated during the second appointment, 7 to 14 days later. A modified Visual Analogue Scale was used to measure pain after 6 hours, 24 hours, 48 hours and 7 days after the treatment. Statistical analysis was done to compare groups at each interval by using an independent-samples t test. Results: The incidence and intensity of post-obturation pain in both Group ‘A’ and Group ‘B’ gradually reduced over the study period. When the incidence of pain was compared in the single and two visit group, it was found that the single-visit group experienced slightly less pain than the two-visit group during all study intervals, but the difference found was not statistically significant. Conclusion: There was no difference in postoperative pain between patients treated in only one appointment and patients treated in two appointments. The majority of patients in both groups reported no pain or only minimal pain after 7 days of treatment. How to cite the article: Rao KN, Kandaswamy R, Umashetty G, Rathore VP, Hotkar C, Patil BS. Post-Obturation pain following one-visit and two-visit root canal treatment in necrotic anterior teeth. J Int Oral Health 2014;6(2):28-32. PMID:24876699

Rao, K Nandan; Kandaswamy, Raghavendra; Umashetty, Girish; Rathore, Vishnu Pratap Singh; Hotkar, Chetan; Patil, Basanagouda S

2014-01-01

237

The retrieval of unerupted teeth in pedodontics: two case reports  

PubMed Central

Introduction The retrieval of unerupted teeth in pedodontics is always significant to preserve the trophism of adjacent tissues, establish the correct space, provide adequate function and maintain good esthetics for the patient. The treatment plan is based on radiographic examinations and measurements, and on an accurate clinical evaluation; it aims to achieve the best treatment possible depending on the complexity of the specific case. In the most difficult clinical cases it is very important to have an early diagnosis, which is essential to plan the treatment and achieve success. In these cases, the pediatrician is in a strategic position to give an early diagnosis through a child’s medical history and by counting the child’s teeth. Case presentation This article presents two different difficult clinical cases of impacted teeth diagnosed during pediatric age, with a radiological analysis, and successfully treated with orthodontic devices designed for these specific cases. Clinical case 1 describes a 13-year-old Italian girl; clinical case 2 describes a 9-year-old Italian girl. The use of these devices achieved the desired treatment goals. The problems associated with impacted teeth and the biomechanical interventions used for these patients are discussed. Conclusions An early and careful diagnosis followed by an accurate treatment plan for the individual cases can lead to retrieval of the impacted teeth without affecting other anatomic structures and adjacent teeth. In these cases, the pediatrician is in a strategic position to give an early diagnosis through a child’s medical history and by counting the child’s teeth. PMID:25301242

2014-01-01

238

Effect of Cigarette Smoke on Acrylic Resin Teeth  

PubMed Central

Background: The discolouration of artificial teeth, which hampers aesthetics, is one of the negative effects of cigarette smoking. Therefore, the effect of cigarette smoke on the colour stability of commercially available acrylic resin teeth needs to be evaluated for clinical success and to ascertain as to which brand has superior properties. Material and Methods: Three commercially available acrylic teeth were evaluated, after division into Group A (Premadent), Group B (Astra), and Group C (Sanyo- Dent). Selected brands were subdivided as study group and control group. Each set of acrylic resin teeth were stored in artificial saliva at 37±1°C for 24 hours. After 24 hours of immersion, the colour measurement of each tooth (T0) was performed. Second colour measurements were done after 21 days (T21) of exposure to cigarette smoke for study group and after immersion in artificial saliva for control group. All data was statistically analyzed by using Repeated Measures ANOVA and Two-way ANOVA (p<0.05). Results: Group A showed least total colour change on exposure to cigarette smoke, followed by Group B and Group C had the highest total colour change. In control group, after immersion in artificial saliva, a slight increase in total colour change was observed for all groups, which was clinically acceptable. Conclusion: Group A (crosslinked acrylic resin teeth) was more colour stable and more resistant to the discolouration which was caused by cigarette smoke, followed by Group B (crosslinked acrylic resin teeth). Group C (Non-crosslinked acrylic resin teeth) was least colour stable and most susceptible to discolouration which was caused by cigarette smoke. PMID:24179942

Patil, Seema S.; M.R., Dhakshaini; Gujjari, Anil Kumar

2013-01-01

239

Root-Crown Ratio in Permanent Dentition Using Panoramic Radiography in a Selected Iranian Population  

PubMed Central

Statement of the Problem: Determining the crown-root ratio is crucial in many dental clinical decisions. There are no reliable data presented for Iranian population. Purpose: The aim of this study was to assess the root-crown ratio of permanent teeth with regards to the relationship of gender and jaw type using panoramic radiographs. The reliability of method was also assessed. Materials and Method: The crown and root lengths of teeth were measured by a digital caliper on panoramic radiographs of 185 individuals except for the third molars. A total of 1994 teeth was studied and 50.8% of the teeth belonged to males and 49.2% belonged to females. The modified Lind method was applied. Results: The highest mean root-crown ratios in both arches of both genders were obtained in the second premolars, followed by the first premolars and canines. In both genders, the lowest root-crown ratios were found in the maxillary central incisors. In male patients, the mean root-crown ratio was higher (p= 0.003) than that of females. Using Bland-Altman analysis, a non-significant difference of 0.006 (95% CI: -0.012-0.024) and 0.0002 (95% CI: -0.011-0.011) were found for intra-observer and inter-observer agreement, respectively. Conclusion: Assessment of the root-crown ratio in permanent dentition could be performed on panoramic radiographs with acceptable reproducibility in an Iranian Population. Considering observed differences, our findings suggest that for the accurate assessment, this ratio must be calculated for male and female patients and also for the upper and lower jaws, separately. PMID:25469356

Haghanifar, Sina; Moudi, Ehsan; Abbasi, Shirin; Bijani, Ali; Poorsattar Bejeh Mir, Arash; Ghasemi, Nafiseh

2014-01-01

240

Late Middle Pleistocene hominin teeth from Panxian Dadong, South China.  

PubMed

The hominin teeth and evidence of hominin activities recovered from 1991 to 2005 at the Panxian Dadong site in South China are dated to the late Middle Pleistocene (MIS 8-6 or ca. 130-300 ka), a period for which very little is known about the morphology of Asian populations. The present study provides the first detailed morphometric description and comparisons of four hominin teeth (I(1), C1, P(3) and P3) from this site. Our study shows that the Panxian Dadong teeth combine archaic and derived features that align them with Middle and Upper Pleistocene fossils from East and West Asia and Europe. These teeth do not display any typical Neanderthal features and they are generally more derived than other contemporaneous populations from Asia and Africa. However, the derived traits are not diagnostic enough to specifically link the Panxian Dadong teeth to Homo sapiens, a common problem when analyzing the Middle Pleistocene dental record from Africa and Asia. These findings are contextualized in the discussion of the evolutionary course of Asian Middle Pleistocene hominins, and they highlight the necessity of incorporating the Asian fossil record in the still open debate about the origin of H. sapiens. PMID:23465337

Liu, Wu; Schepartz, Lynne A; Xing, Song; Miller-Antonio, Sari; Wu, Xiujie; Trinkaus, Erik; Martinón-Torres, María

2013-05-01

241

The development and replacement of teeth in viviparous caecilians.  

PubMed

Tooth development and replacement in fetal and adult viviparous caecilians (Amphibia: Gymnophiona) are described and analyzed according to current theories of tooth succession. The fetal dentition differs from that of the adult in morphology, position, and function. Teeth are used by fetuses to scrape the oviducal epithelium, thus stimulating the secretion of a nutrient substance. Fetal dentitions vary in morphology and position in different species. The ontogeny of teeth of several species is described and the patterns of addition of loci and of replacement are analyzed. Loci are added both posteriorly along the jaw and between existing loci as the jaw grows prior to ossification; subsequently addition is restricted to the posterior part of the jaw. Tooth replacement is alternate. The several rows and patches of teeth are the result of retention of replacement series on the dentigerous elements. Tooth development and replacement in a series of juveniles and adults of different sizes in a single species are also considered. Post-fetal patterns of development and replacement are similar to those seen in larvae and adults of oviparous species. Variation in numbers of teeth and proportions of teeth at particular stages occurs ontogenetically and among individuals of the same size, though proportions occur in a similar pattern throughout the series. The general pattern of tooth replacement in fetuses and adults can be explained by either Edmund's Zahnreihen theory or by Osborn's Tooth Family theory, but replacement in fetal tooth patches and the fetal-adult dentitional transition are explained by neither. PMID:1246080

Wake, M H

1976-01-01

242

Correlation between three color coordinates of human teeth  

NASA Astrophysics Data System (ADS)

The objective was to determine whether there were significant correlations in the three color coordinates within each of two color coordinate systems, such as the Commission Internationale de l'Eclairage (CIE) L*a*b* system, and the lightness, chroma, and hue angle system, of human vital teeth. The color of six maxillary and six mandibular anterior teeth was measured by the Shade Vision System. Pearson correlations between each pair of the color coordinates were determined (?=0.01). The influence of two color coordinates on the other color coordinate was determined with a multiple regression analysis (?=0.01). Based on correlation analyses, all the color coordinate pairs showed significant correlations except for the chroma and hue angle pair. The CIE L* was negatively correlated with the CIE a*, b*, and chroma, but positively correlated with the hue angle. The CIE a* was positively correlated with the CIE b* and chroma. Tooth color coordinates were correlated each other. Lighter teeth were less chromatic both in the CIE a* and b* coordinates. Therefore, it was postulated that the three color coordinates of human teeth were harmonized within certain color attribute ranges, and a lack of correlations in these coordinates might indicate external/internal discolorations and/or anomalies of teeth.

Lee, Yong-Keun

2014-11-01

243

Masculinization of the eruption pattern of permanent mandibular canines in opposite sex twin girls.  

PubMed

The aim of this study is to explore the effect of prenatal androgenization on the clinical eruption of permanent teeth expressing dimorphism and bimaturism. The eruption curves of permanent teeth (except third molars), including those that make up the canine complex (permanent canines, lower first premolars), are compared among opposite sex twins (OS twins) relative to single-born boys and girls. The comparisons are made with regard to three phases of eruption (pierced mucosa, half- erupted, and completely erupted) from a cross-sectional sample of dental casts, using Kaplan-Meier survival and Cox regression analyzes. The casts were collected from 2159 school children from the US Collaborative Perinatal Project, including 39 pairs of OS-twins, of which 12 pairs (30.8%) were Euro-Americans and 27 pairs (69.2%) were of African-American ancestry. The eruption patterns of the incisors, upper first molars, and lower canines were found to be significantly masculinized (delayed) among OS twin girls. The differences in most other teeth were either not significant, or the number of observations of active eruption phases were too few, such as in the upper first molars and incisors, to yield strong evidence and meaningful results. The masculinization of the tooth eruption pattern in OS twin girls is intriguing because of the lower canine responses during puberty, as well as canine primordial formation during early fetal androgenization of their co-twin during the 8th to 14th gestational weeks. The present results offer a challenge for future research exploring tooth eruption mechanisms, and may also highlight some cases of delayed or ectopic canines, which are biased toward females. PMID:23754587

Heikkinen, Tuomo; Harila, Virpi; Tapanainen, Juha S; Alvesalo, Lassi

2013-08-01

244

Horizontal root fractures in posterior teeth: a case series.  

PubMed

This case series describes observations of 12 patients who developed horizontal root fractures in non-endodontically treated teeth. Using clinical and radiographic examination, horizontal fractures were observed in eight maxillary first molars, one maxillary second molar, one mandibular first premolar and four mandibular second premolars. A total of 12 teeth had clinically intact crowns and 2 had carious. Eight fractures of maxillary molars occurred in the palatal roots, while one fracture was observed in the distobuccal root. Eleven patients experienced pain from the affected teeth during mastication. Within the limits of this case series, it was concluded that these fractures were related to; root morphology, damaging masticatory habits and excessive occlusal forces. PMID:21281441

Wang, Ping; Lv, Haipeng; Sun, Hantang; Lin, Yuan; He, Wenxi

2011-04-01

245

Lodestone: Nature's own permanent magnet  

NASA Technical Reports Server (NTRS)

Magnetic hysteresis and microstructural details are presented which explain why the class of magnetic iron ores defined as proto-lodestones, can behave as permanent magnets, i.e. lodestones. Certain of these proto-lodestones which are not permanent magnets can be made into permanent magnets by charging in a field greater than 1000 oersted. This fact, other experimental observations, and field evidence from antiquity and the middle ages, which seems to indicate that lodestones are found as localized patches within massive ore bodies, suggests that lightning might be responsible for the charging of lodestones. The large remanent magnetization, high values of coercive force, and good time stability for the remanent magnetization are all characteristics of proto-lodestone iron ores which behave magnetically as fine scale ( 10 micrometer) intergrowths when subjected to magnetic hysteresis analysis. The magnetic results are easily understood by analysis of the complex proto lodestone microstructural patterns observable at the micrometer scale and less.

Wasilewski, P.

1976-01-01

246

Middle Pleistocene Hominin Teeth from Longtan Cave, Hexian, China  

PubMed Central

Excavations at the Longtan Cave, Hexian, Anhui Province of Eastern China, have yielded several hominin fossils including crania, mandibular fragments, and teeth currently dated to 412±25 ka. While previous studies have focused on the cranial remains, there are no detailed analyses of the dental evidence. In this study, we provide metric and morphological descriptions and comparisons of ten teeth recovered from Hexian, including microcomputed tomography analyses. Our results indicate that the Hexian teeth are metrically and morphologically primitive and overlap with H. ergaster and East Asian Early and mid-Middle Pleistocene hominins in their large dimensions and occlusal complexities. However, the Hexian teeth differ from H. ergaster in features such as conspicuous vertical grooves on the labial/buccal surfaces of the central incisor and the upper premolar, the crown outline shapes of upper and lower molars and the numbers, shapes, and divergences of the roots. Despite their close geological ages, the Hexian teeth are also more primitive than Zhoukoudian specimens, and resemble Sangiran Early Pleistocene teeth. In addition, no typical Neanderthal features have been identified in the Hexian sample. Our study highlights the metrical and morphological primitive status of the Hexian sample in comparison to contemporaneous or even earlier populations of Asia. Based on this finding, we suggest that the primitive-derived gradients of the Asian hominins cannot be satisfactorily fitted along a chronological sequence, suggesting complex evolutionary scenarios with the coexistence and/or survival of different lineages in Eurasia. Hexian could represent the persistence in time of a H. erectus group that would have retained primitive features that were lost in other Asian populations such as Zhoukoudian or Panxian Dadong. Our study expands the metrical and morphological variations known for the East Asian hominins before the mid-Middle Pleistocene and warns about the possibility that the Asian hominin variability may have been taxonomically oversimplified. PMID:25551383

Xing, Song; Martinón-Torres, María; Bermúdez de Castro, José María; Zhang, Yingqi; Fan, Xiaoxiao; Zheng, Longting; Huang, Wanbo; Liu, Wu

2014-01-01

247

Does trauma in the primary dentition cause sequelae in permanent successors? A systematic review.  

PubMed

This systematic review sought scientific evidence (in the literature) that trauma in the primary incisors cause sequelae in permanent successors. Also this work verified whether there was a relation between the presence and type of sequelae in permanent teeth with the child's age at the time of injury and type of trauma. Electronic databases, including the PubMed, Scopus, The Cochrane Library, LILACS, and Web of Science were used to search for original articles up to June 2013. Prospective and retrospective studies that assessed the association of trauma in deciduous incisors and developmental disturbances in permanent successors were selected. Two authors independently reviewed and extracted the data from the included studies. A methodological quality assessment evaluation of the selected studies was performed. The search retrieved 258 citations. Initially, 19 studies fulfilled the selection criteria; however, one (1) was excluded, leaving 18 for the final selection. Despite some limitations in the study designs were observed, especially the lack of a control group in most studies, the evidence found suggests that individuals with trauma in their primary incisors have more developmental disorders in the permanent successors than individuals without a previous trauma. Furthermore, the younger the child is at the time of injury, the more frequent and more severe are the sequelae to the permanent successor incisors. More severe traumas such as intrusion and avulsion are associated to more serious developmental disorders. These results should be analyzed carefully because very few studies evaluated had a control group. PMID:25382149

Lenzi, Michele Machado; Alexandria, Adílis Kalina; Ferreira, Daniele Masterson T P; Maia, Lucianne Cople

2015-04-01

248

Infectious bovine keratoconjunctivitis (pinkeye).  

PubMed

As is the case for controlling other infectious livestock diseases, the most successful efforts to control infectious bovine keratoconjunctivitis (IBK) will include consideration of the host, the environment, herd management, and ongoing surveillance even after the immediate crisis has passed. Research over many years has led to the discovery of a variety of antibiotic treatments and antibiotic regimens that can be effective against IBK. The discoveries of Mor bovoculi and reports of IBK associated with Mycoplasma spp without concurrent Mor bovis or Mor bovoculi have raised new questions into the roles that other organisms may play in IBK pathogenesis. PMID:25576389

Angelos, John A

2015-03-01

249

Odontomas and Supernumerary Teeth: Is There a Common Origin?  

PubMed Central

The aim of the present work is to analyze all scientific evidence to verify whether similarities supporting a unified explanation for odontomas and supernumerary teeth exist. A literature search was first conducted for epidemiologic studies indexed by PubMed, to verify their worldwide incidence. The analysis of the literature data shows some interesting similarities between odontomas and supernumerary teeth concerning their topographic distribution and pathologic manifestations. There is also some indication of common genetic and immuno-histochemical factors. Although from a nosological point of view, odontomas and supernumeraries are classified as distinct entities, they seem to be the expression of the same pathologic process, either malformative or hamartomatous. PMID:25419174

Pippi, Roberto

2014-01-01

250

Non-syndrome patient with bilateral supernumerary teeth: Case report and 9-year follow-up  

PubMed Central

The presence of supernumerary teeth, also known as hyperdontia, is the condition of having teeth in addition to the regular number of teeth. The occurrence of multiple supernumerary teeth is often found in association with syndromes such as Gardner syndrome, Anderson-Fabry disease, Ellis-van Creveld syndrome, Ehlers-Danlos syndrome, incontinentia pigmenti, and Tricho-rhino-phalangeal syndrome. Only a few examples of nonsyndromic multiple supernumerary teeth have been reported in literature. In this report, we present the unusual case and 9-year follow up of a non-syndrome female patient with bilateral supernumerary teeth that occurred with an interval of several years. PMID:23408107

Akgun, Ozlem Marti; Sabuncuoglu, Fidan; Altug, Ayberk; Altun, Ceyhan

2013-01-01

251

Root Canal Morphology of Permanent Maxillary and Mandibular Canines in Indian Population Using Cone Beam Computed Tomography  

PubMed Central

Aim. To investigate the root canal anatomy of single-rooted permanent maxillary and mandibular canines in an Indian population using cone beam computed tomography (CBCT). Methodology. A total of 250 permanent maxillary canines and 250 permanent mandibular canines were selected and scanned using CBCT. The root anatomy of each tooth was evaluated for the following parameters: the pattern of the root canals, anatomic length of the crown and the root, the presence of accessory canals, the shape of the access cavity, the position of the apical foramina, root diameter, and dentin thickness of the root. Results. Majority of the teeth had a Type I canal configuration in both maxillary canines (81.6%) and mandibular canines (79.6%). In maxillary canine the other canal patterns found were Type III (11.6%), Type II (2.8%), Type V (2%), Type XIX (1.2%), and Type IV (0.8%). In mandibular canines the various other canal patterns found were Type III (13.6%), Type II (3.2%), Type V (2%), and Type XIX (1.6%). Apical foramina were laterally positioned in the majority of the teeth, 70.4% and 65.6% in maxillary and mandibular canines, respectively. 12% of the maxillary canines and 12.8% of the mandibular canines had accessory canals. Conclusion. The root canal anatomy of permanent maxillary and mandibular canines varied widely in an Indian population. PMID:24895538

Somalinga Amardeep, Nikhita; Raghu, Sandhya; Natanasabapathy, Velmurugan

2014-01-01

252

EDITORIAL: Permanent revolution - or evolution?  

Microsoft Academic Search

Honorary Editor It was that temporary Bolshevik Leon Trotsky who developed the principle of `permanent revolution', a principle that perhaps characterizes the recent history of education in (south) Britain more than does, say, principles traditionally associated with the Conservative or Labour parties. As this editorial is being written, changes are being made to primary school education, and the long-awaited details

Ken Dobson

1998-01-01

253

Microfilm Permanence and Archival Quality  

ERIC Educational Resources Information Center

The facts about microfilm permanence and archival quality are presented in simple terms. The major factors, including the film base material, the film emulsion, processing, and storage conditions are reviewed. The designations on the edge of the film are explained and a list of refernces provided. (14 references) (Author)

Avedon, Don M.

1972-01-01

254

Magnetic Fields: Visible and Permanent.  

ERIC Educational Resources Information Center

Children will be able to see the concept of a magnetic field translated into a visible reality using the simple method outlined. Standard shelf paper, magnets, iron filings, and paint in a spray can are used to prepare a permanent and well-detailed picture of the magnetic field. (Author/JN)

Winkeljohn, Dorothy R.; Earl, Robert D.

1983-01-01

255

Frictionless Bearing Uses Permanent Magnets  

NASA Technical Reports Server (NTRS)

The purpose of this innovation was to develop a frictionless bearing for high speed, light load applications. The device involves the incorporation of permanent magnets in the bearing design. The repulsion of like magnetic poles provides concentric support of the inner member so that no metallic contact occurs between the bearing surfaces.

1965-01-01

256

An Interactive Geometric Technique for Upper and Lower Teeth Segmentation  

E-print Network

in cranio-maxillofacial (CMF) surgery, orthodontics and dentistry. It is especially true when cone-beam CT machines. One of the main interests in CMF surgery and orthodontics is the teeth. In order to quantify due to dental restoration and orthodontic braces. #12;to appear in the Proceedings of MICCAI 2009

Azevedo, Ricardo

257

Characterization of crocodile teeth: correlation of composition, microstructure, and hardness.  

PubMed

Structure and composition of teeth of the saltwater crocodile Crocodylus porosus were characterized by several high-resolution analytical techniques. X-ray diffraction in combination with elemental analysis and infrared spectroscopy showed that the mineral phase of the teeth is a carbonated calcium-deficient nanocrystalline hydroxyapatite in all three tooth-constituting tissues: Dentin, enamel, and cementum. The fluoride content in the three tissues is very low (<0.1 wt.%) and comparable to that in human teeth. The mineral content of dentin, enamel, and cementum as determined by thermogravimetry is 71.3, 80.5, and 66.8 wt.%, respectively. Synchrotron X-ray microtomography showed the internal structure and allowed to visualize the degree of mineralization in dentin, enamel, and cementum. Virtual sections through the tooth and scanning electron micrographs showed that the enamel layer is comparably thin (100-200 ?m). The crystallites in the enamel are oriented perpendicularly to the tooth surface. At the dentin-enamel-junction, the packing density of crystallites decreases, and the crystallites do not display an ordered structure as in the enamel. The microhardness was 0.60±0.05 GPa for dentin, 3.15±0.15 GPa for enamel, 0.26±0.08 GPa for cementum close to the crown, and 0.31±0.04 GPa for cementum close to the root margin. This can be explained with the different degree of mineralization of the different tissue types and is comparable with human teeth. PMID:24091039

Enax, Joachim; Fabritius, Helge-Otto; Rack, Alexander; Prymak, Oleg; Raabe, Dierk; Epple, Matthias

2013-11-01

258

CO2 laser on apical seal of retrofilled teeth  

NASA Astrophysics Data System (ADS)

The CO2 laser has been suggested for occlusion of dentinal tubuli and sterilization of the beveled root surfaces, avoiding degrees of irritants from the root canal system into periapical tissues. This study has evaluated marginal leakage in 40 human single rooted teeth divided into 4 groups of 8 teeth which received retrofillings, and 2 control groups of 4 teeth each. Group A: Super EBA; group B: Super EBA and CO2 laser irradiation; group C: Glass Ionomer Cement; group D: Glass ionomer Cement and laser; group E: positive control; group F: negative control. In groups B and D the power set was 2 watts, 20 msec, with a CT3105 ceramic point. Teeth were placed in 5 percent methylene blue dye for 24 hs and the dye penetration was lower in B. The higher penetration was seen in C. Analysis of variance found statistical difference between groups. In this study the laser irradiation was able to change the amount of dye penetration. It can be assumed that Super EBA and Glass Ionomer Cement have their sealing abilities improved by laser irradiation.

Aun, Carlos E.; Gavini, Giulio; Clasen, Naya F.; Silva Kfouri, Luciana

1997-05-01

259

BARIUM IN TEETH AS INDICATOR OF BODY BURDEN  

EPA Science Inventory

A study was conducted to determine the biological availability of naturally occurring barium in a municipal drinking water by the analysis of barium in deciduous teeth of children. The grade school children of two Illinois towns were chosen for the study. The towns were chosen ba...

260

A Fast Segmentation Method for STL Teeth Model  

Microsoft Academic Search

Based on fast marching watersheds and marker-controlled method, a teeth model segmentation algorithm for Virtual Orthodontics System is presented in this paper. Three critical techniques: interactive marker, threshold setting and stack operation theory, is used in the algorithm .To reduce stack operations, a combination technique of automatic threshold setting and manual threshold regulating is proposed, which obviously overcome the difficulty

Zhanli Li; Xiaojuan Ning; Zengbo Wang

2007-01-01

261

Orthodontic management of non-syndromic multiple supernumerary teeth  

PubMed Central

Hyperdontia amounts to an odontostomatologic anomaly wherein, there is an increase in tooth number irrespective of the location. This case report represents a form of hyperdontia characterized by bilateral multiple supernumerary teeth in both the jaws without any evident familial history. PMID:24403806

Singhvi, Vijay; Nambiar, Supriya; Shetty, Siddarth

2013-01-01

262

Nd:YAG laser pulpotomy of human primary teeth  

Microsoft Academic Search

Formocresol has been a popular pulpotomy medicament in the primary teeth for the past 60 years. However, its toxic effect has been of concern. Laser therapy is a non-pharmacologic hemostatic technique for pulpotomy procedure. But research on laser therapy for primary tooth pulpotomy is sparse. The purpose of this study was to evaluate the effects of Nd:YAG laser pulpotomy on

Jengfen Liu

2003-01-01

263

Carbon dioxide laser oral safety parameters for teeth  

Microsoft Academic Search

The carbon dioxide laser is used in the oral cavity for a variety of procedures. Although the procedures may not involve the teeth directly, precaution should be exercised to preserve their integrity. The results of this study indicate that the most limiting parameter for oral use of the COâ laser is damage to the enamel surface, which could be inflicted

G. Lynn Powell; Brian K. Whisenant; Thomas H. Morton

1990-01-01

264

Calcium hydroxide induced apical barrier in fractured nonvital immature permanent incisors.  

PubMed

Management of trauma to an immature permanent incisor is a challenge, especially when the pulp is necrotic. The aim of this study is to discuss the management of fractured maxillary right and left central incisors with immature root apex. Radiographic evaluation revealed that the tooth 11 had convergent apical walls, whereas tooth 21 had parallel apical walls; both the incisors were treated with pure calcium hydroxide paste to induce apical development. Follow-up clinical and radiographic examinations confirmed apical barrier at 3 months. Radiograph of tooth 11 with convergent roots showed continued apical development, whereas tooth 21 showed apical bridging, following which root canal was completed in both the teeth. Therefore, in view of the simplicity of this method, we believe that calcium hydroxide can be reemphasized as one of the treatment alternatives for fractured nonvital immature permanent incisors to induce apical barrier. PMID:20660978

Vellore, K G

2010-01-01

265

A KEY TO THE COMMON GENERA OF NEOGENE SHARK TEETH ROBERT W. PURDY  

E-print Network

A KEY TO THE COMMON GENERA OF NEOGENE SHARK TEETH BY ROBERT W. PURDY Revised April 2003 #12;2 Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Using Artificial Tooth Sets to Identify Fossil Shark Teeth . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Hexanchiform Sharks

Mathis, Wayne N.

266

Localized intrinsic staining of teeth due to pulpitis and pulp necrosis in dogs.  

PubMed

Dental charts and records of 71 dogs were received and 84 intact tooth crowns were noted to have been entirely discolored in shades of pink, purple, grey, or tan. Endodontic therapy was performed on 49 of these teeth allowing gross examination of the entire pulp. In exploratory pulpotomy was performed in 15 teeth prior to exodontic therapy in order to assess the integrity of the coronal pulp. Gross signs of partial or total pulp necrosis were present in 59 (92.2%) of these teeth. The pulp was not observed grossly in 20 teeth which received exodontic therapy. Overall, of the 84 teeth evaluated, 36 (42.9%) had no radiographic signs of endodontic disease. Gross or radiographic signs of endodontic disease were absent in only 2 (4.1%) discolored teeth receiving endodontic therapy. Based on the low incidence of vital, affected teeth in the dogs of this study, endodontic on exodontic therapy is recommended for discolored teeth. PMID:11968908

Hale, F A

2001-03-01

267

Fracture Resistance of Teeth Restored with Post-retained Restorations: An Overview  

Microsoft Academic Search

IntroductionPosts have been used efficiently to retain restorations for badly destructed teeth. This article critically analyzes the concerned topics related to the fracture resistance of teeth restored with dowel-retained restorations.

Mahmoud Khaled AL-Omiri; Ahmad Abdelaziz Mahmoud; Mohammad Ramadan Rayyan; Osama Abu-Hammad

2010-01-01

268

Genetics Home Reference: Short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething ...  

MedlinePLUS

... disorder catalog Conditions > Short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething delay (often shortened to ... is SHORT syndrome? Short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething delay, commonly known by ...

269

Preliminary surface analysis of etched, bleached, and normal bovine enamel  

SciTech Connect

X-ray photoelectron spectroscopic (XPS) and secondary ion-mass spectroscopic (SIMS) analyses were performed on unground un-pumiced, unground pumiced, and ground labial enamel surfaces of young bovine incisors exposed to four different treatments: (1) immersion in 35% H2O2 for 60 min; (2) immersion in 37% H3PO4 for 60 s; (3) immersion in 35% H2O2 for 60 min, in distilled water for two min, and in 37% H3PO4 for 60 s; (4) immersion in 37% H3PO4 for 60 s, in distilled water for two min, and in 35% H2O2 for 60 min. Untreated unground un-pumiced, unground pumiced, and ground enamel surfaces, as well as synthetic hydroxyapatite surfaces, served as controls for intra-tooth evaluations of the effects of different treatments. The analyses indicated that exposure to 35% H2O2 alone, besides increasing the nitrogen content, produced no other significant change in the elemental composition of any of the enamel surfaces investigated. Exposure to 37% H3PO4, however, produced a marked decrease in calcium (Ca) and phosphorus (P) concentrations and an increase in carbon (C) and nitrogen (N) concentrations in unground un-pumiced specimens only, and a decrease in C concentration in ground specimens. These results suggest that the reported decrease in the adhesive bond strength of resin to 35% H2O2-treated enamel is not caused by a change in the elemental composition of treated enamel surfaces. They also suggest that an organic-rich layer, unaffected by acid-etching, may be present on the unground un-pumiced surface of young bovine incisors. This layer can be removed by thorough pumicing or by grinding. An awareness of its presence is important when young bovine teeth are used in a model system for evaluation of resin adhesiveness.

Ruse, N.D.; Smith, D.C.; Torneck, C.D.; Titley, K.C. (Univ. of Toronto, Ontario (Canada))

1990-09-01

270

Pathogenesis of bovine brucellosis.  

PubMed

Bovine brucellosis is one of the most important zoonotic diseases worldwide, and is of particular significance in developing countries. The disease, which results in serious economic losses due to late term abortion, stillborn and weakly calves, is caused by Gram negative coccobacilli bacteria of the genus Brucella. Lesions consist of necrotic placentitis and interstitial mastitis in pregnant cows, and fibrinous pleuritis with interstitial pneumonia in aborted fetuses and newborn calves. This article considers the pathogenesis of Brucella abortus and reviews the ability of the pathogen to invade phagocytic and non-phagocytic host cells, resist the acidified intraphagosomal environment, and inhibit phagosome-lysosome fusion. Significant aspects of innate and adaptive immunity against brucellosis are also discussed. PMID:19733101

Carvalho Neta, Alcina V; Mol, Juliana P S; Xavier, Mariana N; Paixão, Tatiane A; Lage, Andrey P; Santos, Renato L

2010-05-01

271

Revisiting the supernumerary: the epidemiological and molecular basis of extra teeth  

Microsoft Academic Search

Supernumerary teeth are a common clinical and radiographic finding and may produce occlusal and dental problems. The aetiological basis of extra teeth is poorly understood in human populations; however, the mouse provides a useful model system to investigate the complex genetics of tooth development. This article describes recent advances in our understanding of the genetic basis of supernumerary teeth. We

P. S. Fleming; G. M. Xavier; A. T. DiBiase; M. T. Cobourne

2010-01-01

272

Apical barrier formation after incomplete orthograde MTA apical plug placement in teeth with open apex--report of two cases.  

PubMed

Two cases are reported in which incomplete placement of 4 mm mineral trioxide aggregate (MTA) plug was performed unintentionally at the apical third of permanent immature teeth with open apex and apical periodontitis. As confirmed radiographically, there were gaps between MTA and dentinal walls along the MTA-dentin interface. After setting of MTA was confirmed, endodontic treatment was completed and access was sealed with composite resin. At 6 to 16 months follow-up examinations, formation of dentin in contact with the MTA surface, as well as apical closure and periapical healing were ideied radiographically for both cases. The results of these cases showed that apical barrier formation and complete periapical healing is possible despite the incomplete apical placement of the MTA plug. This might be due to the biological properties of the MTA. Even so, an incomplete three-dimensional placement of the filling material is not advocated. PMID:23780353

Floratos, Spyros G; Tsatsoulis, Ioannis N; Kontakiotis, Evangelos G

2013-01-01

273

Cartilage (Bovine and Shark) (PDQ®)  

Cancer.gov

Expert-reviewed information summary about the use of bovine and shark cartilage as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

274

Bovine mycoplasmosis: silent and deadly.  

PubMed

The first international conference on bovine mycoplasmosis, held in Saskatoon, Canada, in 2009, marked an official recognition of the importance of mycoplasmas in bovine respiratory disease, mastitis, arthritis and other disorders. Furthermore, bovine mycoplasmosis has been identified as a major emerging infectious disease by the European Community 7th Framework Programme under the EMIDA ERA-NET, which is funding a three-year study into the development of improved diagnosis and control of bovine mycoplasmosis involving the UK, Germany, Italy and Israel. These developments coincide with the publication of the complete sequence of the Mycoplasma bovis genome, which offers fresh insight into the properties of this tiny wall-less bacterium. With this in mind, it is an appropriate time to review our knowledge of cattle diseases caused by mycoplasmas. PMID:21527487

Nicholas, R A J

2011-04-30

275

Innovative endodontic therapy for anti-inflammatory direct pulp capping of permanent teeth with a mature apex  

PubMed Central

Direct pulp capping is a treatment of an exposed vital pulp with a dental material to facilitate the formation of reparative dentin and maintenance of vital pulp. It has been studied as an alternate way to avoid vital pulp extirpation. However, the success rate of pulp capping is much lower than that of vital pulp extirpation. Therefore, direct pulp capping is currently considered controversial by many clinicians. To increase success rate, a critical need exists to develop new biologically-based therapeutics that reduce pulp inflammation, promote the continued formation of new dentin-pulp complex, and restore vitality by stimulating the regrowth of pulpal tissue. Bioengineered anti-inflammatory direct pulp capping materials, together with adhesive materials for leakage prevention, have great potential to improve the condition of the existing pulp from an inflamed to a non-inflamed status and lead to a high rate of long-term success. PMID:20416524

Komabayashi, Takashi; Zhu, Qiang

2010-01-01

276

Permanently calibrated interpolating time counter  

NASA Astrophysics Data System (ADS)

We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20?ps) despite significant changes in the ambient temperature (from ?10 to 60?°C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure.

Jachna, Z.; Szplet, R.; Kwiatkowski, P.; Ró?yc, K.

2015-01-01

277

Mineral trioxide aggregate apical plug method for the treatment of nonvital immature permanent maxillary incisors: Three case reports  

PubMed Central

Treatment of nonvital immature permanent teeth with calcium-hydroxide is associated with some difficulties such as weakened tooth fracture, root canal reinfection and long treatment time. Mineral trioxide aggregate (MTA) apical plug method is an alternative treatment option for open apices, and has gained popularity in the recent times. In this case report, we have attempted to present successful treatment of three maxillary incisors with open apices and periapical lesions with MTA. After preparing the access cavity, the working length was determined. The root canals were irrigated with 2.5% Sodium hypochlorite (NaOCl) and disinfected with calcium-hydroxide for two weeks. MTA was then placed in the apical 3 millimeters of the root canal. The remaining part of the root canal was filled with gutta-percha and the coronal restoration was finished with composite resin. After six months the radiographic examination showed a decrease of periapical lesions. At a 1-year and 18-months follow up, radiological and clinical successful healing of the incisor teeth was seen. MTA seems as an effective material for the apical plug method for the treatment of nonvital immature permanent teeth with open apices. PMID:22368340

Güne?, Betül; Aydinbelge, Hale Ari

2012-01-01

278

High-performance permanent magnets  

Microsoft Academic Search

High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as\\u000a on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE–TM intermetallic alloys\\u000a which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE=Nd, Pr, Sm) with\\u000a transition metals (TM=Fe, Co), in particular magnets based on

D. Goll; H. Kronmüller

2000-01-01

279

76 FR 26239 - Bovine Tuberculosis and Brucellosis; Public Meetings  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. APHIS-2011-0044] Bovine Tuberculosis and Brucellosis; Public Meetings AGENCY...framework being developed for the bovine tuberculosis and brucellosis programs in the United...revisions to its programs regarding bovine tuberculosis (TB) and bovine brucellosis in...

2011-05-06

280

76 FR 38602 - Bovine Tuberculosis and Brucellosis; Program Framework  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. APHIS-2011-0044] Bovine Tuberculosis and Brucellosis; Program Framework...framework being developed for the bovine tuberculosis and brucellosis programs in the United...revisions to its programs regarding bovine tuberculosis (TB) and bovine brucellosis in...

2011-07-01

281

Permanent magnet modelling for dynamic applications  

Microsoft Academic Search

Rare earth permanent magnets are very sensitive to temperature as an overheating can lead to a partial or a total demagnetization. It is then necessary to determine the losses in the permanent magnets to design with accuracy an electromagnetic system. In fact, if the permanent magnet experiences a high frequency magnetic field, significant losses appear. In the literature, these losses

A. Benabou; S. Georges; S. Clénet

2008-01-01

282

Permanent Magnet System for PET Cyclotron  

Microsoft Academic Search

The recent paper is devoted to design, manufacturing and testing the permanent magnet system to be used for Positron Emission Tomography (PET) cyclotron. The using permanent magnet material instead of copper coils allows essential electric power savings during PET cyclotron operation, though it comes to some increasing construction cost. The main problem why until now permanent magnets were not used

E. Antokhin; M. Kumada; Y. Iwashita; S. Wakasa; S. Matsumoto; T. Fujisawa; I. Bolhsakova; R. Holyaka; V. Erashok; E. Sugiyama; H. Shimizu

2008-01-01

283

Systematic assessment of color removal following vital bleaching of intrinsically stained teeth.  

PubMed

Various treatment variables associated with a standard bleaching technique were systematically recorded in 53 individuals exhibiting intrinsic discoloration of permanent teeth. These variables (predictors) included: (1) etiology (fluoride or tetracycline); (2) age of the patient; (3) the presented color of the stain; (4) the intensity of that color; (5) a long versus short bleaching time technique; and (6) the number of bleaching sessions. These were assessed as to their relationship with the results of treatment (dependent variable). The findings of a multiple regression analysis revealed that the contributions of the individual predictors were significantly different between those stains caused by tetracycline ingestion (N = 27) and those stains due to fluoride ingestion (N = 20). The analysis also revealed that those variables contributing to a significant proportion of the variance in results of treatment when tetracycline was the cause were: (1) the color of the stain and (2) the number of bleaching sessions. When fluoride was apparently the causal agent: (1) the bleaching time technique; (2) age of the patient; (3) color of the stain; and (4) the number of bleaching sessions contributed to a significant proportion of the variance in the results of treatment. PMID:3855898

Seale, N S; Thrash, W J

1985-03-01

284

Gender Determination Using Diagonal Measurements of Maxillary Molar and Canine Teeth in Davangere Population  

PubMed Central

Background: Mesiodistal and buccolingual measurements of the teeth have been the traditional means of determining gender which sometimes are difficult to measure. Aims and Objectives: To assess the degree of sexual dimorphism in upper permanent canines and first molars using diagonal diameters and to evaluate the applicability of diagonal measurements in sex determination. Materials and Methods: Mesiobuccal-distolingual (MBDL) and distobuccal-mesiolingual (DBML) measurements of the crown and cervix of maxillary canine and maxillary molar were taken using digital vernier callipers in 100 upper dental casts obtained from 50 males and 50 females of the age group of 17-25 y. Results: With step wise discriminant function analysis, results were statistically significant with males showing higher diagonal measurement values. The classification accuracy for males was 69% and in females was 73% with overall accuracy of 71%. Results showed that canines exhibited highest accuracy with cervical measurements being more dimorphic. MBDL measurements were found to be more reliable. Most dimorphicmeasurements included right molar cervical MBDL, left molar cervical MBDL followed by right and left molar crown MBDL. Conclusion: In cases of tooth rotations, crowding, certain fillings and attritions where traditional mesio-distal and bucco-lingual measurements are not applicable, diagonal measurements could be of help in predicting gender. PMID:25584308

Tarigoppula, Ratna Kumari V. N.; Kulkarni, Pavan G; BS, Anil

2014-01-01

285

Interim Restorative Approach for the Management of Congenitally Missing Permanent Mandibular Incisors: Presentation of Three Cases  

PubMed Central

Congenital missing of mandibular permanent incisors with retained primary incisors may jeopardize the esthetic appearance and psychological development of children, especially during the years of transition into adolescence. The retained primary teeth are necessary for the maintenance and normal development of alveolar bone, which in turn is essential for future definitive rehabilitation. In such situations, an interim restoration may be provided before any definitive treatment is given to comfort the young patient during this transition period. Interim restorations may include resin-modified additions to the existing teeth as well as more sophisticated restorations such as resin-retained bridge and removable partial dentures. However, this restoration differs for different clinical situations based on various factors such as age and patient compliance, and also consideration has to be given for the growth changes of the child. The aim of this present paper is to discuss the esthetic management of three cases with bilateral agenesis of permanent mandibular incisors and retained primary incisors with composite interim restoration. PMID:22567446

Prakash, Prashanth; Hallur, Jayadev M.; Gowda, Rachana Narse

2011-01-01

286

77 FR 15847 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products  

Federal Register 2010, 2011, 2012, 2013, 2014

...and Importation of Commodities,'' published in the Federal Register on January 4...and Products Derived from Bovines,'' published in the Federal Register on September...discussed in detail in a final rule APHIS published in the Federal Register on...

2012-03-16

287

National clinical guidelines for the extraction of first permanent molars in children.  

PubMed

This article summarises recently updated guidelines produced by the Clinical Governance Directorate of the British Orthodontic Society through the Clinical Standards Committee of the Faculty of Dental Surgery, Royal College of Surgeons of England (FDSRCS) on the extraction of first permanent molars in children. The first permanent molar is susceptible to chronological enamel defects, molar-incisor hypomineralisation and caries, which may necessitate enforced extraction in the developing dentition. In the right circumstances, the extraction of these teeth can be followed by successful eruption of the second permanent molar and ultimately, third molar eruption to complete the molar dentition. For this reason, elective extraction of first permanent molars with a questionable long-term prognosis should be considered when planning enforced extractions. However, a number of factors can influence the decision-making process, including the necessity for a general anaesthetic to allow extraction, potential cooperation with restorative or orthodontic treatment and likely future preventative practice within the family. Moreover, the presence of any underlying malocclusion also needs to be evaluated within the context of extraction planning. The current available evidence has been evaluated and awarded a grade based upon those recommended by the Scottish Intercollegiate Guidelines Network. PMID:25476643

Cobourne, M T; Williams, A; Harrison, M

2014-12-01

288

High speed internal permanent magnet machine and method of manufacturing the same  

DOEpatents

An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple permanent magnets for generating a magnetic field, which interacts with the stator magnetic field to produce torque. The permanent magnets are disposed between the stacks. The rotor assembly also includes multiple bottom wedges disposed on the bottom structures of the shaft and configured to hold the multiple stacks and the multiple permanent magnets.

Alexander, James Pellegrino (Ballston Lake, NY); EL-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Shah, Manoj Ramprasad (Latham, NY); VanDam, Jeremy Daniel (West Coxsackie, NY)

2011-09-13

289

Evidence for a single loss of mineralized teeth in the common avian ancestor.  

PubMed

Edentulism, the absence of teeth, has evolved convergently among vertebrates, including birds, turtles, and several lineages of mammals. Instead of teeth, modern birds (Neornithes) use a horny beak (rhamphotheca) and a muscular gizzard to acquire and process food. We performed comparative genomic analyses representing lineages of nearly all extant bird orders and recovered shared, inactivating mutations within genes expressed in both the enamel and dentin of teeth of other vertebrate species, indicating that the common ancestor of modern birds lacked mineralized teeth. We estimate that tooth loss, or at least the loss of enamel caps that provide the outer layer of mineralized teeth, occurred about 116 million years ago. PMID:25504730

Meredith, Robert W; Zhang, Guojie; Gilbert, M Thomas P; Jarvis, Erich D; Springer, Mark S

2014-12-12

290

Smokers have less dense bones and fewer teeth.  

PubMed

Women and men who smoke are more slender than their non-smoking counterparts and have a bone density appropriate to their degree of slenderness. As a result, they are more likely to sustain a fracture than their non-smoking counterparts. The lower bone density found in smokers may arise because of less stress and strain imposed on the skeleton by a slim physique. Smokers have poorer oral hygiene and less teeth than their non-smoking counterparts. The relationship between smoking and tooth pathology remains unclear: smoking may either act via a direct mechanism based on the toxicity of tobacco smoke or indirectly through body weight (ie the effect on teeth is part of a wider effect on bone structure). PMID:7844791

Johnston, J D

1994-10-01

291

[Phylogeny, form and function of canine teeth in the horse].  

PubMed

The canine teeth of the horse developed phylogenically from the simple, pointed, short-rooted tooth form of the leaf eating, in pairs living, Eocene horse Hyracotherium and served up to the Oligocene as a means of defense (self preservation). In the Miocene the living conditions of the Merychippus changed and they took to eating grass and adopted as a new behavior the life in a herd. The canine teeth possibly played an important role in fights for social ranking; they changed from a crown form to knife-like shape. In the Pliohippus the canine tooth usually remained in male horses and since the Pliocene, it contributed to the fights between stallions, to ensure that the offspring only came from the strongest animals (preservation of the species). Form and construction of the canine tooth are described and discussed in detail under the above mentioned phylogenic and ethologic aspects. PMID:12919071

Vollmerhaus, B; Roos, H; Gerhards, H; Knospe, C

2003-08-01

292

Teeth Segmentation and Feature Extraction for Odontological Biometrics  

Microsoft Academic Search

During the past few years, advancements in high end computers and sensor techniques made it possible to develop a real-time odontological biometric identification and verification system apart from the existing offline forensic odontological systems. However, this requires highly automated teeth image segmentation and feature extraction algorithms. In this paper, we propose a novel non-forensic biometric technique, employing 3D optical sensors

Danish Mairaj; Stephen D. Wolthusen; Christoph Busch

2010-01-01

293

Comparative clinical wettability of teeth and intraoral mucosa  

Microsoft Academic Search

The observed reduced adhesiveness of human intraoral mucosa, as compared with adjacent teeth, was determined for 14 healthy humans to correlate with differing measured intraoral contact angles for a variety of otherwise non-interacting test liquids on these two equally water-wettable surfaces under clinical conditions. Measurements were made on the front maxillary tooth surfaces and the-inner lower lip mucosal surfaces of

PER-OLOF J. Glantz; Robert E. Baier; Rolf Attstrom; Anne E. Meyer; Hermann Gucinski

1991-01-01

294

A functional explanation for denticulation in theropod dinosaur teeth.  

PubMed

The serrated, or denticulated, ziphodont teeth of theropod dinosaurs display variability in their extent of denticulation. The functional model proposed here tests the hypothesis that denticles will not exist in areas that do not frequently contact the substrate. This area, defined as the "dead-space," is determined by the direction the tooth moves through the fleshy substrate. The extent of denticulation, as well as the dead-space dimensions, is measured from photographs of 235 isolated and in situ theropod teeth, to determine a meaningful relationship between the two variables. Both Euclidean and geometric morphometric methods are employed, and the data are expressed in bivariate and ordination plots. The model predicts the direction of tooth movement through the curvature of the tip/apex. Tooth position and taxon are considered. The results show that the mesial margin is usually partially denticulated, while the distal margin is usually totally denticulated. Curved teeth have large dead-spaces, and tend to be less denticulated mesially. Straighter teeth are more extensively denticulated, to the point where they became symmetrical. The mesial denticulation is determined by the dead-space, and dictated by the substrate contact. The dead-space almost always predicted less extensive denticulation; a consequence of the model's limitations. Tooth curvature increases with a more distal position, due to rotation based on the proximity to the hinge. Denticulation indicates that theropods used a distally oriented puncture to modify the substrate, similar to modern analogues. Although there is little taxonomic variation, Troodontidae show unique and extreme degrees of mesial denticulation. PMID:19711461

D'Amore, Domenic C

2009-09-01

295

Electrical properties of teeth regarding the electric vitality testing  

Microsoft Academic Search

\\u000a In this paper we concentrate on electrical properties of tooth during electrical stimulation using various electrode- tooth\\u000a interfaces. Established resistances of teeth connections are compared for each type of electrode. Total impedance as well\\u000a as the voltage step response of tooth is recorded with different electrodes. The current stabilized pulp-tester is built and\\u000a used to measure the required parameters of

T. Marjanovi?; Z. Stare; M. Ranilovi?

296

Apatite Mineralization in Teeth of the Chiton Acanthopleura echinata  

Microsoft Academic Search

.   Raman spectroscopy has been used to demonstrate, for the first time, that calcium mineralization in the core of the major\\u000a lateral teeth of the chiton Acanthopleura echinata takes place as an ordered process, with crystalline carbonated apatite being the first mineral deposited. Deposition begins\\u000a at the top of the tooth core, under the so-called tab region, progresses down the

A. P. Lee; L. R. Brooker; D. J. Macey; W. van Bronswijk; J. Webb

2000-01-01

297

Development of a novel bone grafting material using autogenous teeth.  

PubMed

We developed a novel bone grafting material that incorporates autogenous teeth (AutoBT), and provided the basis for its clinical application. AutoBT contains organic and inorganic mineral components and is prepared from autogenous grafting material, thus eliminating the risk of an immune reaction that may lead to rejection. AutoBT was used at the time of implant placement, simultaneously with osteoinduction surgery, and excellent bony healing by osteoinduction and osteoconduction was confirmed. PMID:20060336

Kim, Young-Kyun; Kim, Su-Gwan; Byeon, Ju-Hee; Lee, Hyo-Jung; Um, In-Ung; Lim, Sung-Chul; Kim, Suk-Young

2010-04-01

298

Identification of bovine dendritic cell phenotype from bovine peripheral blood.  

PubMed

Dendritic cells (DCs) are professional antigen presenting cells, which initiate primary immune responses and also play an important role in the generation of peripheral tolerance. There is no reliable method established for the isolation of bovine peripheral blood DCs, and furthermore, the phenotypes and the functions of bovine DCs are still not fully clear. In the present study, we have attempted to identify bovine peripheral blood DCs by negative-selection. In bovine peripheral blood mononuclear cells (PBMC), we have newly characterized the phenotype of DCs, which is CD11c+/CD172a+. These cells display features of myeloid type DCs. In the thymic medulla, CD11c+/CD172a+ cells were also present and CD1+/CD172a+ cells were additionally detected as a population of DCs. The data suggest that one of the bovine DCs phenotypes from PBMC is derived from myeloid lineages lacking a CD1 molecule, which then drift to several tissues, and that they then may express a CD1 molecule upon their functional differentiation. PMID:16253299

Miyazawa, Kohtaro; Aso, Hisashi; Honda, Masashi; Kido, Taketomo; Minashima, Takeshi; Kanaya, Takashi; Watanabe, Kouichi; Ohwada, Shyuichi; Rose, Michael T; Yamaguchi, Takahiro

2006-08-01

299

Radiographic Assessment and Chair Time of Rotary Instruments in the Pulpectomy of Primary Second Molar Teeth: A Randomized Controlled Clinical Trial  

PubMed Central

Background and aims. The superiority of rotary systems has been reported in several clinical studies on permanent teeth. This study consisted of radiographic assessment and chair time of rotary instruments in the pulpectomy of primary second molar teeth. Materials and methods. In this randomized controlled clinical study, 46 children, 3-6 years of age, were selected. The patients were divided randomly into two groups. In the first group (group A) pulpectomy was carried out with hand instruments and in the second group (group B) the Rotary FlexMaster System was used. T-test and chi-squared test were used to analyze data. Results. The mean instrumentation time in group A was significantly more than that in group B (P<0.001). Also there was a significant difference between both groups in relation to the distance between the apex of mesial root (P<0.001) and distal root (P=0.007) and the canal filling level. Conclusion. Superior radiographic findings and less chair time of pulpectomy with rotary instruments in second primary molar teeth were achieved. PMID:25093051

Makarem, Abbas; Ravandeh, Navid; Ebrahimi, Masoumeh

2014-01-01

300

Color alteration in teeth subjected to different bleaching techniques  

NASA Astrophysics Data System (ADS)

This study evaluated the color alteration of teeth subjected to the action of different bleaching agents and the influence of light sources commonly used in association with these products, In GI, the specimens remained immersed in artificial saliva. The specimens in GII were bleached with a 10% carbamide peroxide gel 4 hours/day during 3 weeks; the teeth in the other three groups were subjected to three sessions of three 10-min applications of 35% hydrogen peroxide gel at 7-day intervals. In GIII, no light was used, while in GIV and GV the gel was associated with a quartz-tungsten-halogen light and a LED/laser source, respectively. The teeth color was evaluated before and 7 days after the bleaching sessions by reflectance spectrophotometry. Data were analyzed statistically by ANOVA and Fisher's test (? = 0.05), and showed that a significant color change was obtained in all treated groups. After the first week of treatment and at the end of it, the bleaching protocols showed similar results. The results of the present study indicate that association of a light source is not necessary to obtain the bleaching effect and that optimal bleaching can be achieved with all techniques tested.

Briso, A. L. F.; Fonseca, M. S. M.; de Almeida, L. C. A. G.; Mauro, S. J.; Dos Santos, P. H.

2010-12-01

301

Modular turbine airfoil and platform assembly with independent root teeth  

DOEpatents

A turbine airfoil (22E-H) extends from a shank (23E-H). A platform (30E-H) brackets or surrounds a first portion of the shank (23E-H). Opposed teeth (33, 35) extend laterally from the platform (30E-H) to engage respective slots (50) in a disk. Opposed teeth (25, 27) extend laterally from a second portion of the shank (29) that extends below the platform (30E-H) to engage other slots (52) in the disk. Thus the platform (30E-H) and the shank (23E-H) independently support their own centrifugal loads via their respective teeth. The platform may be formed in two portions (32E-H, 34E-H), that are bonded to each other at matching end-walls (37) and/or via pins (36G) passing through the shank (23E-H). Coolant channels (41, 43) may pass through the shank beside the pins (36G).

Campbell, Christian X; Davies, Daniel O; Eng, Darryl

2013-07-30

302

Bending strength model for internal spur gear teeth  

NASA Technical Reports Server (NTRS)

Internal spur gear teeth are normally stronger than pinion teeth of the same pitch and face width since external teeth are smaller at the base. However, ring gears which are narrower have an unequal addendum or are made of a material with a lower strength than that of the meshing pinion may be loaded more critically in bending. In this study, a model for the bending strength of an internal gear tooth as a function of the applied load pressure angle is presented which is based on the inscribed Lewis constant strength parabolic beam. The bending model includes a stress concentration factor and an axial compression term which are extensions of the model for an external gear tooth. The geometry of the Lewis factor determination is presented, the iteration to determine the factor is described, and the bending strength J factor is compared to that of an external gear tooth. This strength model will assist optimal design efforts for unequal addendum gears and gears of mixed materials.

Savage, Michael; Rubadeux, K. L.; Coe, H. H.

1995-01-01

303

Histologic Analysis of Fetal Bovine Derived Acellular Dermal Matrix in Tissue Expander Breast Reconstruction.  

PubMed

BACKGROUND: This study seeks to determine human host response to fetal bovine acellular dermal matrix (ADM) in staged implant-based breast reconstruction. METHODS: A prospective study was performed for patients undergoing immediate breast reconstruction with tissue expander placement and SurgiMend acellular fetal bovine dermis. At the time of exchange for permanent implant, we obtained tissue specimens of SurgiMend and native capsule. Histological and immunohistochemical assays were performed to characterize the extent of ADM incorporation/degradation, host cell infiltration, neovascularization, inflammation, and host replacement of acellular fetal bovine collagen. RESULTS: Seventeen capsules from 12 patients were included in our study. The average "implantation" time of SurgiMend was 7.8 months (range, 2-23 months). Histological analysis of the biopsy of tissue revealed rare infiltration of host inflammatory cells, even at 23 months. One patient had an infection requiring removal of the tissue expander at 2 months. Contracture, inflammatory changes, edema, and polymorphonuclear leukocyte infiltration were rare in the ADM. An acellular capsule was seen in many cases, at the interface of SurgiMend with the tissue expander. CONCLUSIONS: SurgiMend demonstrated a very infrequent inflammatory response. An antibody specific to bovine collagen allowed for direct identification of bovine collagen separate from human collagen. Cellular infiltration and neovascularization of SurgiMend correlated with the quality of the mastectomy skin flap rather than the duration of implantation. Future studies are needed to further characterize the molecular mechanisms underlying tissue incorporation of this product. PMID:23486129

Gaster, Richard S; Berger, Aaron J; Monica, Stefanie D; Sweeney, Robert T; Endress, Ryan; Lee, Gordon K

2013-03-11

304

DISTRIBUTION OF BOVINE LEUKEMIA VIRUS PROVIRAL SEQUENCES IN TISSUES OF BOVINE,  

E-print Network

DISTRIBUTION OF BOVINE LEUKEMIA VIRUS PROVIRAL SEQUENCES IN TISSUES OF BOVINE, OVINE AND HUMAN Leukemia Virus is implicated in the etiology of Enzootic Bovine Leukosis (EBL) (Burny et al., 1978 sequences. Abbreviations BLV Bovine leukemia virus cDNA DNA complementary-to a RNA tem- plate Cot Product

Paris-Sud XI, Université de

305

Method of making permanent magnets  

DOEpatents

A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.

McCallum, R. William (Ames, IA); Dennis, Kevin W. (Ames, IA); Lograsso, Barbara K. (Ames, IA); Anderson, Iver E. (Ames, IA)

1993-09-07

306

Method of making permanent magnets  

DOEpatents

A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.

McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

1993-09-07

307

Dentists Make Larger Holes in Teeth Than They Need to If the Teeth Present a Visual Illusion of Size  

PubMed Central

Background Health care depends, in part, on the ability of a practitioner to see signs of disease and to see how to treat it. Visual illusions, therefore, could affect health care. Yet there is very little prospective evidence that illusions can influence treatment. We sought such evidence. Methods and Results We simulated treatment using dentistry as a model system. We supplied eight, practicing, specialist dentists, endodontists, with at least 21 isolated teeth each, randomly sampled from a much larger sample of teeth they were likely to encounter. Teeth contained holes and we asked the endodontists to cut cavities in preparation for filling. Each tooth presented a more or less potent version of a visual illusion of size, the Delboeuf illusion, that made the holes appear smaller than they were. Endodontists and the persons measuring the cavities were blind to the parameters of the illusion. We found that the size of cavity endodontists made was linearly related to the potency of the Delboeuf illusion (p<.01) with an effect size (Cohen’s d) of 1.41. When the illusion made the holes appear smaller, the endodontists made cavities larger than needed. Conclusions The visual context in which treatment takes place can influence the treatment. Undesirable effects of visual illusions could be counteracted by a health practitioner’s being aware of them and by using measurement. PMID:24194880

O’Shea, Robert P.; Chandler, Nicholas P.; Roy, Rajneesh

2013-01-01

308

Size and placement of developing anterior teeth in immature Neanderthal mandibles from Dederiyeh Cave, Syria: Implications for emergence of the modern human chin.  

PubMed

Evolutionary and functional significance of the human chin has long been explored from various perspectives including masticatory biomechanics, speech, and anterior tooth size. Recent ontogenetic studies have indicated that the spatial position of internally forming anterior teeth partially constrains adult mandibular symphyseal morphology. The present study therefore preliminarily examined the size and placement of developing anterior teeth in immature Neanderthal mandibles of Dederiyeh 1 and 2, compared with similarly-aged modern humans (N = 16) and chimpanzees (N = 7) whose incisors are comparatively small and large among extant hominids, respectively. The Dederiyeh 1 mandible is described as slightly presenting a mental trigone and attendant mental fossa, whereas Dederiyeh 2 completely lacks such chin-associated configurations. Results showed that, despite symphyseal size being within the modern human range, both Dederiyeh mandibles accommodated overall larger anterior dentition and displayed a remarkably wide bicanine space compared to those of modern humans. Dederiyeh 2 had comparatively thicker deciduous incisor roots and more enlarged permanent incisor crypts than Dederiyeh 1, but both Dederiyeh individuals exhibited a total dental size mostly intermediate between modern humans and chimpanzees. These findings potentially imply that the large deciduous/permanent incisors collectively distended the labial alveolar bone, obscuring an incipient mental trigone. It is therefore hypothesized that the appearance of chin-associated features, particularly of the mental trigone and fossa, can be accounted for partly by developmental relationships between the sizes of the available mandibular space and anterior teeth. This hypothesis must be, however, further addressed with more referential samples in future studies. Am J Phys Anthropol 156:482-488, 2015. © 2014 Wiley Periodicals, Inc. PMID:25388672

Fukase, Hitoshi; Kondo, Osamu; Ishida, Hajime

2015-03-01

309

Original article Chromosome analysis of bovine  

E-print Network

development of reliable techniques for the in vitro maturation and fertilization of bovine oocytes (Leibfreid with in vitro fertilization and culture of bovine oocytes and served as control observations for the oocyteOriginal article Chromosome analysis of bovine oocytes cultured in vitro BR Yadav* WA King* KP Xu

Paris-Sud XI, Université de

310

Original article Hyperimmune bovine colostrum treatment  

E-print Network

Original article Hyperimmune bovine colostrum treatment of moribund Leopard geckos (Eublepharis on the protective passive immunity of hyperimmune bovine colostrum (HBC) was applied to 12 moribund Leopard geckos. / cryptosporidiosis / oocyst / hyperimmune bovine colostrum / gecko * Correspondence and reprints Tel.: ( 1 ) 410 614

Paris-Sud XI, Université de

311

High-performance permanent magnets  

NASA Astrophysics Data System (ADS)

High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE-TM intermetallic alloys which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE=Nd, Pr, Sm) with transition metals (TM=Fe, Co), in particular magnets based on (Nd,Pr)2Fe14B and Sm2(Co,Cu,Fe,Zr)17. Their development during the last 20 years has involved a dramatic improvement in their performance by a factor of >15 compared with conventional ferrite pms therefore contributing positively to the ever-increasing demand for pms in many (including new) application fields, to the extent that RE-TM pms now account for nearly half of the worldwide market. This review article first gives a brief introduction to the basics of ferromagnetism to confer an insight into the variety of (permanent) magnets, their manufacture and application fields. We then examine the rather complex relationship between the microstructure and the magnetic properties for the two highest-performance and most promising pm materials mentioned. By using numerical micromagnetic simulations on the basis of the Finite Element technique the correlation can be quantitatively predicted, thus providing a powerful tool for the further development of optimized high-performance pms.

Goll, D.; Kronmüller, H.

312

GWAS of Dental Caries Patterns in the Permanent Dentition  

PubMed Central

The importance of susceptibility genes in the risk for dental caries has been clearly established. While many candidate caries genes have been proposed, to date, few of them have been rigorously validated through observational and experimental studies. Moreover, most genetic epidemiological studies have analyzed global caries phenotypes that ignore the possibility that genes may exert differential effects across tooth surfaces of the dentition. Therefore, we performed genome-wide association studies (GWAS) of 5 novel dental caries phenotypes (developed by clustering the permanent dentition into categories of tooth surfaces based on co-occurrence of caries) to nominate new candidate caries genes. GWAS was performed in 920 self-reported white participants, aged 18 to 75 years, with genotype data on 518,997 genetic variants. We identified a significant genetic association between dental caries of the anterior mandibular teeth and LYZL2 (p value = 9e-9), which codes a bacteriolytic agent thought to be involved in host defense. We also identified a significant genetic association between caries of the mid- dentition tooth surfaces and AJAP1 (p value = 2e-8), a gene possibly involved in tooth development. Suggestive genetic associations were also observed for ABCG2, PKD2, the dentin/bone SCPP sub-family, EDNRA, TJFBR1, NKX2-3, IFT88, TWSG1, IL17D, and SMAD7 (p values < 7e-6). We nominate these novel genes for future study. PMID:23064961

Shaffer, J.R.; Feingold, E.; Wang, X.; Lee, M.; TCuenco, K.; Weeks, D.E.; Weyant, R.J.; Crout, R.; McNeil, D.W.; Marazita, M.L.

2013-01-01

313

A Comparative Evaluation of Efficacy of Different Obturation Techniques used in Root Canal Treatment of Anterior Teeth: An in vitro Study  

PubMed Central

ABSTRACT Aim: This study was undertaken to evaluate the percentage of gutta-percha-filled area (PGFA) using microscopic analysis of the cross-sections in the apical third of root canals when filled either with Thermafil technique, Warm Vertical Condensation technique and Cold Lateral Condensation technique without using sealers. Materials and methods: Sixty single rooted extracted per-manent teeth were collected. After crown amputation, the teeth were randomly divided into three experimental groups of 20 specimens each. Group I–Thermafil obturation technique, group II–warm vertical condensation obturation technique and group III–cold lateral condensation obturation technique. Obturation was performed by specific techniques without using sealers. After obturation, the teeth were cross-sectioned horizontally at 2 to 3 mm from apex with the help of double sided diamond disk. Sections were digitally photographed and measured under Stereomicroscope at magnification of 50×. Using a KS 100 imaging system the area of canals and the gutta-percha was recorded, also the percentage of gutta-percha filled area (PGFA) was calculated. The observations thus ob-tained were subjected to statistical analysis using ANOVA and student ‘t’ test. Results: Maximum group difference was observed between groups I and III (3.558 ± 0.138) while minimum difference was observed between groups I and II (1.223 ± 0.137). Thus, all the between group differences were statistically significant. Conclusion: This study supports the belief that the Thermafil Obturation technique produces significantly higher percentage of gutta-percha filled area (PGFA) than the warm vertical condensation technique or cold lateral condensation technique. How to cite this article: Samadi F, Jaiswal JN, Saha S, Garg N, Chowdhary S, Samadi F, Tripathi VP. A Comparative Evaluation of Efficacy of Different Obturation Techniques used in Root Canal Treatment of Anterior Teeth: An in vitro Study. Int J Clin Pediatr Dent 2014;7(1):1-5. PMID:25206229

Samadi, Firoza; Jaiswal, JN; Saha, Sonali; Garg, Nishita; Chowdhary, Swati; Samadi, Fahad

2014-01-01

314

Evaluation of Pain in Single and Multi Rooted Teeth Treated in Single Visit Endodontic Therapy  

PubMed Central

Background: The incidence of post-operative pain was compared following single-visit canal treatment in single- and multi-rooted teeth, with and without periapical radiolucency. The article also reviews the issues of postoperative pain and healing, following single-visit and multi-visit endodontic therapy. Single-visit endodontic therapy (SVE) was performed in 50 single-rooted teeth and 60 multiple-rooted teeth. Materials & Methods: Single-visit endodontic therapy (SVE) was performed in 50 single-rooted teeth and 60 multiple-rooted teeth. The subjects were divided as follows: Group I -Single-rooted teeth with periapical radiolucency (n=25); Group II–Single-rooted teeth without periapical radiolucency (n=25); Group III–Multiple-rooted teeth with periapical radiolucency (n=30); and Group IV-Multiple-rooted teeth without periapical radiolucency (n=30). Assessment of postoperative pain was done at 24hrs, 3 days and 1 week using a self report questionnaire. The data was analyzed using non-parametric Kruskal -Wallis test. Results: No statistically significant difference was observed in postoperative pain following SVE between the single-rooted and multiple-rooted teeth groups at 24hrs, 3 days and 1 week. The presence or absence of periapical radiolucency had no significant influence on the incidence of reported postoperative pain following SVE. Conclusion: There was no difference in incidence of pain in single rooted teeth and multi-rooted teeth with and without periapical radiolucencies following SVE. Thus, incidence of post-operative pain does not seem to be a valid comparison criterion between single- and multiple-visit endodontic therapies. Also, the literature suggests similar success rates with single-visit and multiple-visit root canal treatment. How to cite the article: Raju TB, Seshadri A, Vamsipavani B, Abhilash K, Subhash AV, Kumari KV. Evaluation of Pain in Single and Multi Rooted Teeth Treated in Single Visit Endodontic Therapy. J Int Oral Health 2014;6(1):27-32. PMID:24653599

Raju, T B V G; Seshadri, Abitha; Vamsipavani, B; Abhilash, K; Subhash, A V; Kumari, K V Halini

2014-01-01

315

Laced permanent magnet quadrupole drift tube magnets  

Microsoft Academic Search

A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in

B. Feinberg; G. U. Behrsing; K. Halbach; J. S. Marks; M. E. Morrison; D. H. Nelson

1988-01-01

316

Tailored order: the mesocrystalline nature of sea urchin teeth.  

PubMed

We investigated the pattern of crystal co-orientation at different length scales, together with variations in chemical composition and nanomechanical properties in the teeth of the modern sea urchin Paracentrotus lividus with electron backscatter diffraction (EBSD), electron probe microanalysis, energy-dispersive X-ray spectroscopy and nanoindentation testing. Modern sea urchin teeth are Mg-dominated calcite composite materials. They are distinctly harder than inorganically precipitated calcite. Some parts exceed even the hardness of dolomite. The teeth show a structuring of their mechanical properties that can be correlated to variations in major element chemical composition, such that their hardness is positively correlated to their magnesium contents. Mg/Ca ratio in Paracentrotus lividus varies between 10 and 26mol.%. Nanohardness of the tooth scatters between 3.5 and >8GPa compared to values of 3.0±0.2, 7.3±0.1 and 9.2±0.9GPa measured on the (104) planes of inorganic calcite, dolomite and magnesite, respectively. High-resolution EBSD shows that major structural units and subunits of the tooth of Paracentrotus lividus are tilted to each other by ?3-5° and 1-2°, respectively. This indicates that the tooth is not a single crystal. With EBSD we can show that the tooth of the sea urchin Paracentrotus lividus is a hierarchically assembled biological mesocrystal with a mosaic texture. In comparison to the misorientation spread of 0.5° of calcite grown from solution, misorientation in the tooth varies between 2° and 4°. Thus, the self-sharpening feature of the tooth is enabled by a close interplay of its highly evolved micro- to nanostructure, structural unit size variations with a varying degree of crystal orientation, chemical structuring of the mineral component and a gradation of incorporated organic polymers. PMID:24937138

Goetz, Andreas J; Griesshaber, E; Abel, R; Fehr, Th; Ruthensteiner, B; Schmahl, W W

2014-09-01

317

New permanent magnets; manganese compounds.  

PubMed

The exponential growth of maximum energy product that prevailed in the 20th century has stalled, leaving a market dominated by two permanent magnet materials, Nd2Fe14B and Ba(Sr)Fe12O19, for which the maximum theoretical energy products differ by an order of magnitude (515 kJ m(-3) and 45 kJ m(-3), respectively). Rather than seeking to improve on optimized Nd-Fe-B, it is suggested that some research efforts should be devoted to developing appropriately priced alternatives with energy products in the range 100-300 kJ m(-3). The prospects for Mn-based hard magnetic materials are discussed, based on known Mn-based compounds with the tetragonal L10 or D022 structure or the hexagonal B81 structure. PMID:24469291

Coey, J M D

2014-02-12

318

Rehabilitation of endodontically treated teeth using the radiopaque fiber post.  

PubMed

Metallic posts fall short of satisfying contemporary guidelines for ideal post/core rehabilitation. Along with technological improvements in adhesive resins, cements, and composite restoratives, the evolution of fiber-reinforced posts allows the rehabilitation of endodontically treated teeth with greater esthetics and virtually no predisposition to root fracture. At least one fiber post system now complies with all of the ideal post characteristics described in the endodontic text. This article describes the potential for displacement of metal posts by low-modulus fiber posts, the differences between them, and the development and placement of a radiopaque, translucent, double-tapered fiber post. PMID:12769029

Brown, Philip L; Hicks, Norman L

2003-04-01

319

Considerations for ceramic inlays in posterior teeth: a review  

PubMed Central

This review of ceramic inlays in posterior teeth includes a review of the history of ceramic restorations, followed by common indications and contraindications for their use. A discussion on the potential for tooth wear is followed by a review of recommended preparation design considerations, fabrication methods, and material choices. Despite the improved materials available for fabrication of porcelain inlays, fracture remains a primary mode of inlay failure. Therefore, a brief discussion on strengthening methods for ceramics is included. The review concludes with a section on luting considerations, and offers the clinician specific recommendations for luting procedures. In conclusion, inlay success rates and longevity, as reported in the literature, are summarized. PMID:23750101

Hopp, Christa D; Land, Martin F

2013-01-01

320

Teeth and numerology from zodiac signs. A correlative study.  

PubMed

Comparative anatomical descriptions have been time and again mentioned in the literature. Based on these aspects, an attempt is made to correlate the morphological features of the human teeth, the zodiac sun signs and numerology. This unique study (first ever of its kind) is also done with a purpose as to whether a particular 'Zodiac Sunsign' or numerology can predict about an individual dental health, the same way the future predictions are being made. It was quite interesting to note that there are few definite attributable dental morphological traits and health to the specific sun signs and numerology. PMID:11307432

Kudva, S; Bhat, A P

2000-01-01

321

Microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative re-treatment  

Microsoft Academic Search

Objective. The purposes of this study were to determine what microbial flora were present in teeth after failed root canal therapy and to establish the outcome of conservative re-treatment.Study design. Fifty-four root-filled teeth with persisting periapical lesions were selected for re-treatment. After removal of the root filling, canals were sampled by means of advanced microbiologic techniques. The teeth were then

Göran Sundqvist; David Figdor; Sten Persson; Ulf Sjögren

1998-01-01

322

Integrated liquid crystal optical switch based on double teeth-shaped structure at telecom wavelengths  

Microsoft Academic Search

The characteristics of a double teeth-shaped plasmonic optical switch are analyzed. Based on the metal–insulator–metal waveguide consisting of double rectangular teeth, a nanoscale liquid crystal optical switch is proposed and numerically simulated by using the finite difference time domain method with a perfectly matched layer absorbing boundary condition. It is found that the double teeth-shaped structure filled with liquid crystal

Jia Hu Zhu; Xu Guang Huang; Jin Tao; Xiao Ping Jin; Xian Mei; Yun Jin Zhu

2011-01-01

323

Fracture Resistance of Simulated Immature Teeth Filled with Resilon, Gutta-Percha, or Composite  

Microsoft Academic Search

The purpose of this study was to evaluate the fracture resistance gained by filling root canals of simulated immature teeth with either Resilon, gutta-percha, a self-curing flowable composite resin (BisFil 2B), or a self-curing hybrid composite resin (BisFil II). Seventy-two sheep incisors were divided into six groups of 12 teeth each. Negative controls received no treatment. Teeth in all other

Kim L. Wilkinson; Thomas J. Beeson; Timothy C. Kirkpatrick

2007-01-01

324

Bovine spongiform encephalopathy: epidemiological studies  

Microsoft Academic Search

This study, initiated in June 1987, describes the epidemiology of bovine spongiform encephalopathy (BSE), a recently described novel neurological disease of domestic cattle first identified in Great Britain in November 1986. Records suggested that the earliest suspected cases occurred in April 1985. There was variability in the presenting signs and the disease course, but the majority of cases developed behavioural

JW Wilesmith; GA Wells; MP Cranwell; JB Ryan

1988-01-01

325

L'encéphalopathie spongiforme bovine  

Microsoft Academic Search

The identification of variant Creutzfeldt-Jakob disease (vCJD) in human strongly reinforced the perception of risks associated with the infectious agent involved in Bovine Spongiform Encephalopathy (BSE). The development of rapid tests for the diagnosis of BSE by the detection of the abnormal prion protein allowed a huge increase in surveillance of the cattle disease. This first revealed a higher prevalence

T. Baron; D. Calavas

2005-01-01

326

Bovine Acidosis: Implications on Laminitis  

Microsoft Academic Search

Bovine lactic acidosis syndrome is associated with large increases of lactic acid in the rumen, which result from diets that are high in ruminally available carbohydrates, or forage that is low in effective fiber, or both. The syndrome involves two separate anatom- ical areas, the gastrointestinal tract and body fluids, and is related to the rate and extent of lactic

James E. Nocek

1997-01-01

327

APHIS Factsheet: Bovine Spongiform Encephalopathy  

NSDL National Science Digital Library

The resurgence of Bovine Spongiform Encephalopathy, or "mad cow disease," in the European Union raised eyebrows of economists and animal science professionals, alike. The US Department of Agriculture (USDA) has posted several online documents on BSE. This resource, also from USDA, is a FactSheet on BSE.

2002-01-01

328

Laser ultrasound characterization of normal and decayed teeth by measuring elastic properties of surface layers  

NASA Astrophysics Data System (ADS)

We firstly investigate the mechanic and acoustic properties of human teeth by using the laser generation of surface acoustic wave (SAW) technique. The materials investigated included normal and decayed teeth, which have the same grain size and different thickness, are used as the samples. The tissue responds to the laser-induced stress by thermoelastic expansion. We can obtain the shape of acoustic pulse and the phase velocity was determined for the teeth system and extract information on the teeth thickness, density, and transverse sound velocity that could be used as diagnostic parameters.

El-Sharkawy, Yasser H.; ElSherif, Ashraf F.

2011-03-01

329

Scanning electron microscopic analysis of incinerated teeth: An aid to forensic identification  

PubMed Central

Background: Forensic dental identification of victims involved in fire accidents is often a complex and challenging endeavor. Knowledge of the charred human dentition and residues of restorative material can help in the recognition of bodies burned beyond recognition. Aim: To observe the effects of predetermined temperatures on healthy unrestored teeth and different restorative materials in restored teeth, by scanning electron microscope, for the purpose of identification. Materials and Methods: The study was conducted on 135 extracted teeth, which were divided into four groups. Group 1-healthy unrestored teeth, group 2-teeth restored with all ceramic crowns, group 3-teeth restored with class I composite resin and group 4-teeth restored with class I glass ionomer cement (GIC). Results: The scanning electron microscope is useful in the analysis of burned teeth, as it gives fine structural details, requires only a small sample and does not destroy the already fragile specimen. Conclusion: Scanning electron microscope can be a useful tool for the characterization and study of severely burnt teeth for victim identification. PMID:24959034

Pol, Chetan A; Gosavi, Suchitra R

2014-01-01

330

Reduction of Cogging Torque in Dual Rotor Permanent Magnet Generator for Direct Coupled Wind Energy Systems  

PubMed Central

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1?kW, 120?rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions. PMID:25202746

Paulsamy, Sivachandran

2014-01-01

331

Reduction of cogging torque in dual rotor permanent magnet generator for direct coupled wind energy systems.  

PubMed

In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions. PMID:25202746

Paulsamy, Sivachandran

2014-01-01

332

Neanderthal teeth from Moula-Guercy, Ardèche, France.  

PubMed

Here we describe dental remains from a Neanderthal fossil assemblage from Moula-Guercy, France. Our report demonstrates that the Moula-Guercy hominid remains contribute important morphological, developmental, and behavioral data to understanding Neanderthal evolutionary history. We include gross comparative morphological descriptions and enamel surface microstructure and microwear data. These teeth reveal numerous characteristics that are diagnostic of Neanderthals and provide no evidence for the presence of any other hominid taxa. Enamel growth increment data from the Moula-Guercy specimens yield evidence of a Neanderthal pattern of development, although at the lower end of the range of variation. The presence of a significant number of linear enamel hypoplasias indicates that these individuals were stressed during childhood. Molar microwear data suggest that these Neanderthals did not differ significantly from modern humans in terms of the fracture properties of the food they were consuming. The incisor microwear and macro striations provide evidence that these individuals may have been using their anterior teeth as tools, similar to the practices of several modern human populations such as the Inuit, Ipiutak, and Australian Aboriginals, and reminiscent of evidence from other Neanderthals from Krapina, Croatia, as well as the 600,000 year old hominids from Sima de los Huesos, Spain. Am J Phys Anthropol 151:477-491, 2013.© 2013 Wiley Periodicals, Inc. PMID:23737145

Hlusko, Leslea J; Carlson, Joshua P; Guatelli-Steinberg, Debbie; Krueger, Kristin L; Mersey, Ben; Ungar, Peter S; Defleur, Alban

2013-07-01

333

Wear Resistance of Coating Films on Hob Teeth  

NASA Astrophysics Data System (ADS)

The wear resistance of coating films on hob teeth is investigated through the simulated hobbing tests with a flytool. The coating films on hob teeth are titanium family ceramics such as TiN, TiCN, TiSiN and TiAlN and aluminum chromium family ceramics such as AlCrN and AlCrSiN. The wear of coated tools is shown about film thickness, film materials, ingredient ratio in a film component and the oxidization of coating films. The oxidization is clarified from a result of the influence on the crater wear progress through wear cutting tests in atmosphere of nitrogen gas or oxygen gas. The oxidization of TiAlN coating films produces oxide products on the tool rake face, and this oxidation relates to the amount of crater wear. The increase of aluminum concentration in the TiAlN film improves the crater wear resistance in air atmosphere, while it has a reverse effect in nitrogen gases. The AlCrSiN film has effective wear resistance against the abrasive wear and/or oxidization wear. The oxidation film formed on the AlCrSiN film is very firm and this suppresses the oxidation wear on the rake face and works against the abrasive wear advantageously.

Umezaki, Yoji; Funaki, Yoshiyuki; Kurokawa, Syuhei; Ohnishi, Osamu; Doi, Toshiro

334

Histopathological evaluation of root canal filling materials for primary teeth.  

PubMed

This study aimed to assess the response of apical and periapical tissues of dogs' teeth after root canal filling with different materials. Forty roots from dogs' premolars were prepared biomechanically and assigned to 4 groups filled with: Group I: commercial calcium hydroxide and polyethylene glycol-based paste (Calen) thickened with zinc oxide; Group II: paste composed of iodoform, Rifocort and camphorated paramonochlorophenol; Group III: zinc oxide-eugenol cement; Group IV: sterile saline. After 30 days, the samples were subjected to histological processing. The histopathological findings revealed that in Groups I and IV the apical and periapical regions exhibited normal appearance, with large number of fibers and cells and no resorption of mineralized tissues. In Group II, mild inflammatory infiltrate and mild edema were observed, with discrete fibrogenesis and bone resorption. Group III showed altered periapical region and thickened periodontal ligament with presence of inflammatory cells and edema. It may be concluded that the Calen paste thickened with zinc oxide yielded the best tissue response, being the most indicated material for root canal filling of primary teeth with pulp vitality. PMID:20464319

Silva, Léa Assed Bezerra da; Leonardo, Mário Roberto; Oliveira, Daniela S B de; Silva, Raquel Assed Bezerra da; Queiroz, Alexandra Mussolino de; Hernández, Patrícia Gatón; Nelson-Filho, Paulo

2010-01-01

335

Cylindrical Hall thrusters with permanent magnets  

Microsoft Academic Search

The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction in both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50-300 W. The discharge and plasma plume measurements

Yevgeny Raitses; Enrique Merino; Nathaniel J. Fisch

2010-01-01

336

Augmented railgun using a permanent magnet  

Microsoft Academic Search

The use of a permanent magnet instead of an electromagnet has been proposed for the augmentation of the magnetic field of a railgun driven by a current of approximately 20 kA. A permanent magnet has the following advantages in comparison with conventional augmentations using additional turns: (1) simple configuration of the system, (2) temporally and spatially constant magnetic fields, and

S. Katsuki; H. Akiyama; N. Eguchi; T. Sueda; M. Soejima; S. Maeda; K. N. Sato

1995-01-01

337

Super Strong Permanent Magnet Quadrupole for  

Microsoft Academic Search

The field strength generated by permanent magnets has been further extended by introduction of saturated iron. A permanent magnet quadrupole (PMQ) lens with such saturated iron is one of the candidates for the final focus lens for an e+e- Linear Collider accelerator, because of its compactness and low power consumption. The first prototype of the PMQ has been fabricated and

Takanori Mihara; Yoshihisa Iwashita; Masayuki Kumada; Antokhin Evgeny; Cherrill M. Spencer

338

Analysis of brushless permanent magnet synchronous motors  

Microsoft Academic Search

A brief design review of permanent magnet synchronous motors has been presented. A procedure has been developed to predict the steady state and dynamic performances of a brushless permanent magnet synchronous motor. Finite element analysis has been combined with a lumped parameter circuit model in order to provide satisfactory engineering information. To this end, two coordinated steps are involved. One

M. Azizur Rahman; Ping Zhou

1996-01-01

339

Performance improvement of permanent magnet ac motors  

E-print Network

. Experiments have been conducted on a 5kW five-phase surface mount permanent magnet motor and a 3kW five-phase interior permanent magnet motor by using TMS320C32 DSP. The results obtained are consistent with theoretical studies and simulation analysis, which...

Parsa, Leila

2005-08-29

340

Permanent magnet torque\\/force transfer apparatus  

Microsoft Academic Search

There is presented a torque\\/force transfer apparatus including an annular ring having therein permanent first magnets side by side about the interior of the ring. The first magnets are arranged so as to alternate in polar orientation to present an inside circumference of alternating north and south magnetic poles. The apparatus further comprises a cylindrical central member having therein permanent

Chahee P. Cho; Ralph A. Bidingfield

1994-01-01

341

Gating of Permanent Molds for ALuminum Casting  

SciTech Connect

This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

David Schwam; John F. Wallace; Tom Engle; Qingming Chang

2004-03-30

342

Permanent magnet multipole with adjustable strength  

DOEpatents

Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

Halbach, Klaus (Berkeley, CA)

1985-01-01

343

Permanent-magnet multipole with adjustable strength  

DOEpatents

Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling there between. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

Halbach, K.

1982-09-20

344

Permanent magnet multipole with adjustable strength  

SciTech Connect

Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to eqch other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

Halbach, K.

1985-10-22

345

Nuclear reprogramming in embryos generated by the transfer of yak (Bos grunniens) nuclei into bovine oocytes and comparison with bovine-bovine SCNT and bovine IVF embryos.  

PubMed

Although inter-species SCNT may be useful for increasing and preserving populations of endangered species, there are many reports that inter-species nuclear transfer embryos only develop to the blastocyst stage. In this study, yak-bovine SCNT blastocysts were successfully implanted in the surrogate bovine uterus but failed to develop to term or aborted. To clarify the reasons, we examined yak-bovine SCNT blastocyst development, total cell number, inner cell mass (ICM) number, trophoblast (TE) cell number and relative gene expression in yak fibroblast cells and yak-bovine SCNT embryos at various stages. The potential for development of yak-bovine SCNT embryos to blastocysts was 30+/-5.7% (mean+/-S.E.M.); the total cell number was 85.3+/-16.3, fewer than in IVF bovine embryos (106.2+/-18.2) but within the reported range (60-300). The yak-bovine SCNT blastocysts had a lower ratio of TE cells to total cells (43.9+/-8.7%) than bovine IVF embryos (59.4+/-3.4%; P<0.05) or bovine-bovine SCNT (69.5+/-5.4%; P<0.05). Also, several yak-bovine SCNT embryos had abnormal initiation of expression of both Mash2 and IL6. However, expression of vimentin, collagen, Cx43 and PSMC3 were normal in yak fibroblast cells and yak-bovine SCNT embryos. In conclusion, we inferred that the normal allocation of ICM and TE cells in yak-bovine SCNT embryos and embryo-specific gene reprogramming may be important for successful inter-species animal cloning. PMID:17416410

Li, Y; Li, S; Dai, Y; Du, W; Zhao, C; Wang, L; Wang, H; Li, R; Liu, Y; Wan, R; Li, N

2007-05-01

346

A survey of root canal treatment of molar teeth by general dental practitioners in private practice in Saudi Arabia  

PubMed Central

The purpose of this study was to evaluate the practice and depth of knowledge of root canal treatment by general dental practitioners working in private dental centers in different cities within the Kingdom of Saudi Arabia. A questionnaire was distributed to 400 general dental practitioners. Completed questionnaires were analyzed in term of simple summary statistics. A total of 252 (63%) practitioners responded. The majority of the respondents were Syrians (59%) and Egyptians (32%). Ninety-one per cent of the respondents indicated that they performed root canal treatment. Amongst those who carried out root canal treatment, only seven practitioners (3%) used rubber dam for isolation. More than half of the respondents (55%) used saline to irrigate canals during treatment. Forty-six per cent of practitioners used formocresol as an inter appointment medicament. The standardized and step-back preparation techniques were the method of choice for the majority of the respondents (91%). Ninety-seven per cent of the practitioners used stainless steel hand instruments to prepare root canals and the majority (92%) used gutta-percha for obturation. Seventy-four per cent of the respondent used cold lateral condensation. The average number of radiographs routinely taken for root canal treatment was four. Ninety-three per cent indicated that they usually completed a root canal treatment of molar teeth in three or more visits. Eighty-eight per cent of the practitioners preferred waiting for 1 or 2 weeks to restore the teeth permanently. Results of this study confirm that many general dental practitioners are not following quality guidelines for endodontic treatment. PMID:23960485

Al-Fouzan, Khalid S.

2010-01-01

347

A COMPARISON OF THE BOVINE LEUKEMIA AND BOVINE SYNCYTIAL VIRUS STATUS IN UTERO-TUBAL CELLS RECOVERED FROM FLUIDS USED  

E-print Network

A COMPARISON OF THE BOVINE LEUKEMIA AND BOVINE SYNCYTIAL VIRUS STATUS IN UTERO-TUBAL CELLS) (Samagh et al 1977, Serological diagno- sis of bovine leukemia virus infection using dual (glycoprotein, Rotterdam, Aug 29ih-30th ; pp 69-77) that both bovine leukemia virus (BLV) and bovine syncytial virus (BSV

Paris-Sud XI, Université de

348

Leadership in a (permanent) crisis.  

PubMed

The current economic crisis is not just another rough spell. Today's mix of urgency, high stakes, and uncertainty will continue even after the recession ends. The immediate crisis--which we will get through with policy makers' expert technical adjustments--sets the stage for a sustained, or even permanent, crisis, a relentless series of challenges no one has encountered before. Instead of hunkering down and relying on their familiar expertise to deal with the sustained crisis, people in positions of authority--whether they are CEOs or managers heading up a company initiative--must practice what the authors call adaptive leadership. They must, of course, tackle the underlying causes of the crisis, but they must also simultaneously make the changes that will allow their organizations to thrive in turbulent environments. Adaptive leadership is an improvisational and experimental art, requiring some new practices. Like Julie Gilbert, who overcame internal resistance to reorient Best Buy toward female purchasers, adaptive leaders get things done to meet today's challenges and then modify those things to thrive in tomorrow's world. They also embrace disequilibrium, using turbulence as an opportunity to build crucial new capacities, as Paul Levy did to rescue Beth Israel Deaconess Medical Center from a profound financial crisis. Finally, adaptive leaders, such as Egon Zehnder, the founder of an executive search firm, draw out the leadership skills that reside deep in the organization, recognizing the interdependence of all employees and mobilizing everyone to generate solutions. PMID:19630256

Heifetz, Ronald; Grashow, Alexander; Linsky, Marty

2009-01-01

349

[Complications of permanent cardiac pacing].  

PubMed

The implantation of a pacemaker is an everyday medical procedure. New indications are under evaluation. However, it should be recalled that this is a surgical intervention with implantation of a prosthesis with possible complications. This should, therefore, be a considered decision. There are early complications which occur in the first 6 weeks after implantation. Their incidence is underestimated (up to 7%) as is their seriousness. There are late complications. Some are responsible for pacemaker dysfunction, the risk of which is proportional to the dependence of the patient on permanent cardiac pacing. The migration of a pacing catheter or the fracture of an Accufix catheter expose the patient to much greater risk. Venous complications are overlooked as they are usually asymptomatic. The superior vena cava syndrome is, however, a serious complication of cardiac pacing. Two recent studies (MOST and DAVID) underline the deleterious haemodynamic effects of unnecessary right ventricular pacing. This right ventricular pacing may have a pro-arrhythmic effect on the ventricles and be responsible for sudden death. It may also cause atrial arrhythmia even if atrio-ventricular synchronisation is preserved. Infectious complications are also under-reported, partially because of the difficulty of diagnosis. They may be life-threatening and require extraction of the implanted material. In conclusion, it is wrong to think that even if a patient does not benefit from his implanted device this cannot have deleterious consequences. Pacemakers should be adjusted especially to avoid inappropriate right ventricular stimulation. PMID:15272521

Klug, D; Marquié, C; Lacroix, D; Kacet, S

2003-12-01

350

Infectious bovine keratoconjunctivitis I. Experimental production.  

PubMed Central

One or both eyes of 20 calves were inoculated one or more time with variou(s combinations of microorganism (live oor killed Moraxella bovis, infectious bovine rhinotracheitis virus, bovine adenovirus, bovine parainfluenza-3 virus and Mycoplasma bovoculi) by conjunctival instillation or direct inoculation of the conjunctivea or cornea. The eyes of all the calves received natural or artificial ultraviolet irradiation. Neither the adenovirus nor parainfluenza-3 virus became established in the eye or produced keratoconjunctivitis. Both M. bovis and infectious bovine rhinotracheitis virus became established in the bovine eye and produced disease. Subconjunctival or intracorneal inoculation of M. bovis caused a severe disease, simulating natural infectious bovine keratoconjunctivitis. Only the intracorneal inoculation of mycoplasma produced severe keratoconjunctivits. Eyes that on initial exposure to M. bovis became severly inflamed were more resistant to a second or third exposure to M. bovis, presumably by enhanced local defence mechanisms. Images Fig. 1. Figs. 2 and 3. Fig. 4. Fig. 5. PMID:163126

Nayar, P S; Saunders, J R

1975-01-01

351

78 FR 1718 - Approved Tests for Bovine Tuberculosis in Cervids  

Federal Register 2010, 2011, 2012, 2013, 2014

...Approved Tests for Bovine Tuberculosis in Cervids AGENCY...antibodies to bovine tuberculosis in certain species...has waived its review under Executive...tests as official tuberculosis tests for captive...tuberculosis tests for bovine...

2013-01-09

352

Late Miocene Teeth from Middle Awash, Ethiopia, and Early Hominid Dental Evolution  

Microsoft Academic Search

Late Miocene fossil hominid teeth recovered from Ethiopia's Middle Awash are assigned to Ardipithecus kadabba. Their primitive morphology and wear pattern demonstrate that A. kadabba is distinct from Ardipithecus ramidus. These fossils suggest that the last common ancestor of apes and humans had a functionally honing canine-third premolar complex. Comparison with teeth of Sahelanthropus and Orrorin, the two other named

Yohannes Haile-Selassie; Gen Suwa; Tim D. White

2004-01-01

353

TSI (teething ring sound instrument): a design of the sound instrument for the baby  

Microsoft Academic Search

In this paper, we will describe the TSI (Teething ring Sound Instrument), a new sound instrument given to babies, which consists of a teething ring, a knob, an I-CubeX Digitizer [1] and a computer which processes MIDI messages. The TSI is designed to bring music experience to baby with the movement of the babies reflex sucking motion. We provided the

Naoko Kubo; Kazuhiro Jo; Ken Matsunaga

2001-01-01

354

Biology Meets Engineering: The Structural Mechanics of Fossil and Extant Shark Teeth  

E-print Network

Biology Meets Engineering: The Structural Mechanics of Fossil and Extant Shark Teeth Lisa B of feeding in sharks have focused primarily on the movement of cranial components and muscle func- tion processing ability and structural parameters must be considered to understand the evolu- tion of shark teeth

Motta, Philip J.

355

Unusual case of green pigmentation in human teeth resulting from neonatal hyperbilirubinemia.  

PubMed

Green pigmentation in teeth is an uncommon condition that is associated with bilirubin deposits in dental hard tissues. This article presents a case involving an 8-year-old girl with green teeth associated with intrinsic pigmentation by bilirubin. The reported case confirms the relevance of a medical history in establishing a diagnosis of green pigmentation. PMID:21444267

Sommer, Suzana; Kramer, Paulo Floriani; Magagnin, Karina; Tovo, Maximiano Ferreira

2008-01-01

356

Dental morphology and variation in theropod dinosaurs: implications for the taxonomic identification of isolated teeth.  

PubMed

Isolated theropod teeth are common Mesozoic fossils and would be an important data source for paleoecology biogeography if they could be reliably identified as having come from particular taxa. However, obtaining identifications is confounded by a paucity of easily identifiable characters. Here we discuss a quantitative methodology designed to provide defensible identifications of isolated teeth using Tyrannosaurus as a comparison taxon. We created a standard data set based as much as possible on teeth of known taxonomic affinity against which to compare isolated crowns. Tooth morphology was described using measured variables describing crown length, base length and width, and derived variables related to basal shape, squatness, mesial curve shape, apex location with respect to base, and denticle size. Crown curves were described by fitting the power function Y = a + bX(0.5) to coordinate data collected from lateral-view images of mesial curve profiles. The b value from these analyses provides a measure of curvature. Discriminant analyses compared isolated teeth of various taxonomic affinities against the standard. The analyses classified known Tyrannosaurus teeth with Tyrannosaurus and separated most teeth known not to be Tyrannosaurus from Tyrannosaurus. They had trouble correctly classifying teeth that were very similar to Tyrannosaurus and for which there were few data in the standard. However, the results indicate that expanding the standard should facilitate the identification of numerous types of isolated theropod teeth. PMID:15986487

Smith, Joshua B; Vann, David R; Dodson, Peter

2005-08-01

357

Clinical evaluation of the measuring accuracy of ROOT ZX in primary teeth  

Microsoft Academic Search

Objective. The aim of this study was to assess the accuracy of an electronic device (Root ZX; Morita, Tokyo, Japan) for measuring the root canal length in primary teeth. Study design. The pulp tissue was removed from 71 nonrestorable teeth scheduled to be extracted under general anesthesia, and the root canals (n = 105) were irrigated (H2O2, 3%; NaOCl, 1%).

Andrej M. Kielbassa; Ursula Muller; Inka Munz; Jürgen Schulte Monting

2003-01-01

358

Characterization of biominerals in the radula teeth of the chiton, Acanthopleura hirtosa  

Microsoft Academic Search

Understanding biomineralization processes provides a route to the formation of novel biomimetic materials with potential applications in fields from medicine to materials engineering. The teeth of chitons (marine molluscs) represent an excellent example of a composite biomineralized structure, comprising variable layers of iron oxide, iron oxyhydroxide and apatite. Previous studies of fully mineralized teeth using X-ray diffraction, Raman spectroscopy and

Martin Saunders; Charlie Kong; Jeremy A. Shaw; David J. Macey; Peta L. Clode

2009-01-01

359

Cuspal reinforcement in primary teeth: an in vitro comparison of three restorative materials  

Microsoft Academic Search

The purpose of this study was to evaluate cuspal flexure in posterior primary teeth following restoration with three dif- ferent materials. Twelve primary second molars were ob- tained. A precision strain gage was attached to the buccal surface of each tooth and balanced at zero. The teeth were mounted and then loaded with a 10 kg force; the strain appearing

Kevin James Donly; Mark E. Jensen

1988-01-01

360

Evolutionary trends of the histological pattern in the teeth of Edentata (Xenarthra).  

PubMed

In a comparative study of the dental structure of Edentata, the central tissue was identified as a modified orthodentine, except in the Glyptodontidae where an osteodentine was found. Some evolutionary trends of the tissues in these teeth may have been related with the extinction of ground sloths. Comparative studies of the tissues in mammalian teeth seem to be good tests for systematics. PMID:3857888

Ferigolo, J

1985-01-01

361

Comparison of the clinical abrasion resistance of six commercially available denture teeth  

Microsoft Academic Search

Purpose. Clinical abrasion of denture teeth has certain implications when dentures are worn in excess of the average useful lifetime. The purpose of this study was to evaluate clinical denture tooth wear over a period of 3 years.Material and Methods. The wear of six commercially available denture teeth (Premierdent, Acrotone, Vitapan, Rx1, Duravite, and Ivoclar Orthosit) and a seventh combination

Con Jooste; Greta Geerts; Laurie Adams

1997-01-01

362

Bovine Spongiform Encephalopathy A Review  

Microsoft Academic Search

Bovine spongiform encephalopathy (BSE) or ‘mad cow disease’ is a new disease with an elusive transmissible agent. However, a ‘Prion protein’ (PrP) of about 27K Dalton has been observed to play an essential role in the pathogenecity of BSE. Friesian cattle of 3–6 years of age have been found susceptible. Common symptoms include weight loss, unmanageable behaviour, traumatic damage due

Madhu Chansoriya; J. L. Vegad

1992-01-01

363

Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study  

PubMed Central

Purpose: The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. Materials and Methods: One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18–45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III). Results: MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I–III, respectively. Conclusion: This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals. PMID:25684916

Das, Suroopa; Warhadpande, Manjusha M.; Redij, Saurabh A.; Jibhkate, N. G.; Sabir, Husain

2015-01-01

364

Stress distribution in reduced periodontal supporting tissues surrounding splinted teeth.  

PubMed

The aim of this study was to analyze the distribution of occlusal stresses for splinted and nonsplinted mandibular anterior incisors and to compare different splinting materials. A mandibular model was generated from a patient's computed tomography scan using three-dimensional (3D) software. The mandibular model presented with four periodontally compromised incisors and two canines with optimal bone support (two-thirds crown-root ratio). Three different splint materials (composite resin, metal-reinforced, and fiber-reinforced) were selected. Vertical and transverse loads were applied, and stress levels around the periodontal structures and splint materials were analyzed with 3D finite element analysis. The results showed that when bone levels around teeth decreased, the stress on the canine increased. Tested splinting materials were successful in stress distribution, and metal was better than the other splinting materials at distributing the stresses. PMID:25171045

Kurgan, Sivge; Terzioglu, Hakan; Y?lmaz, Burak

2014-01-01

365

Esthetic rehabilitation of anterior teeth with laminates composite veneers.  

PubMed

No- or minimal-preparation veneers associated with enamel preservation offer predictable results in esthetic dentistry; indirect additive anterior composite restorations represent a quick, minimally invasive, inexpensive, and repairable option for a smile enhancement treatment plan. Current laboratory techniques associated with a strict clinical protocol satisfy patients' restorative and esthetic needs. The case report presented describes minimal invasive treatment of four upper incisors with laminate nanohybrid resin composite veneers. A step-by-step protocol is proposed for diagnostic evaluation, mock-up fabrication and trial, teeth preparation and impression, and adhesive cementation. The resolution of initial esthetic issues, patient satisfaction, and nice integration of indirect restorations confirmed the success of this anterior dentition rehabilitation. PMID:25013730

Re, Dino; Augusti, Gabriele; Amato, Massimo; Riva, Giancarlo; Augusti, Davide

2014-01-01

366

An Experimental Study of Fretting of Gear Teeth  

NASA Technical Reports Server (NTRS)

Experiments were conducted to study fretting of gears. The gears were made from case-carburized AISI 9310 alloy to match the material of a flight actuator gearbox of interest. The objective of the testing was to produce damage representative of that observed on flight hardware. The following correlations and observations were noted. The amplitude of dithering motion very strongly influenced the type and magnitude of damage. Sliding amounts on the order of 30% of the width of the line contact were judged to most readily produce fretting damage. There was observed an incubation period on the order of tens-of-thousands of cycles, and the incubation period was influenced by surface roughness, torque, and the motion extent. Fretting damage could be produced for any of the torques tested, and the severity of damage increased slightly with torque. Gear teeth having surface roughness of 0.7-0.8 micrometer were somewhat more resistant to fretting than were smoother surfaces.

Krantz, Timothy L.

2008-01-01

367

Endodontic Treatment of Fused Teeth with Talon Cusp  

PubMed Central

Tooth anomalies are rare phenomena that may be reported by patients as chief complaints or may be discovered by dentists in the oral examination. In a few cases, rare anomalies are found together in one mouth. Decision to treat such anomalies depends on whether or not they interfere with function and esthetics and also the patient's preference. In the present case, a 19-year-old male presented with two right maxillary fused central and lateral incisors and a geminated left maxillary central incisor. A talon-like projection was found at the junction site of the fused teeth. His chief complaint was sensitivity to cold at the site of the giant fused tooth. This report describes the process of diagnosis and treatment of the two anomalies according to patient preference and needs. PMID:24575307

Miri, Shima Sadat; Ghorbani, Hakimeh; Rashed Mohassel, Anousheh

2014-01-01

368

Esthetic Rehabilitation of Anterior Teeth with Laminates Composite Veneers  

PubMed Central

No- or minimal-preparation veneers associated with enamel preservation offer predictable results in esthetic dentistry; indirect additive anterior composite restorations represent a quick, minimally invasive, inexpensive, and repairable option for a smile enhancement treatment plan. Current laboratory techniques associated with a strict clinical protocol satisfy patients' restorative and esthetic needs. The case report presented describes minimal invasive treatment of four upper incisors with laminate nanohybrid resin composite veneers. A step-by-step protocol is proposed for diagnostic evaluation, mock-up fabrication and trial, teeth preparation and impression, and adhesive cementation. The resolution of initial esthetic issues, patient satisfaction, and nice integration of indirect restorations confirmed the success of this anterior dentition rehabilitation. PMID:25013730

Riva, Giancarlo

2014-01-01

369

Endodontic treatment of fused teeth with talon cusp.  

PubMed

Tooth anomalies are rare phenomena that may be reported by patients as chief complaints or may be discovered by dentists in the oral examination. In a few cases, rare anomalies are found together in one mouth. Decision to treat such anomalies depends on whether or not they interfere with function and esthetics and also the patient's preference. In the present case, a 19-year-old male presented with two right maxillary fused central and lateral incisors and a geminated left maxillary central incisor. A talon-like projection was found at the junction site of the fused teeth. His chief complaint was sensitivity to cold at the site of the giant fused tooth. This report describes the process of diagnosis and treatment of the two anomalies according to patient preference and needs. PMID:24575307

Miri, Shima Sadat; Ghorbani, Hakimeh; Rashed Mohassel, Anousheh

2014-01-01

370

A new procedure for calculating contact stresses in gear teeth  

NASA Technical Reports Server (NTRS)

A numerical procedure for evaluating and monitoring contact stresses in meshing gear teeth is discussed. The procedure is intended to extend the range of applicability and to improve the accuracy of gear contact stress analysis. The procedure is based upon fundamental solution from the theory of elasticity. It is an iterative numerical procedure. The method is believed to have distinct advantages over the classical Hertz method, the finite-element method, and over existing approaches with the boundary element method. Unlike many classical contact stress analyses, friction effects and sliding are included. Slipping and sticking in the contact region are studied. Several examples are discussed. The results are in agreement with classical results. Applications are presented for spur gears.

Somprakit, Paisan; Huston, Ronald L.

1991-01-01

371

Topical application of antibiotics in primary teeth: an overview.  

PubMed

Root canal infections are polymicrobial in nature, consisting of both aerobic and anaerobic species. The successful treatment of both primary and secondary endodontic infections involves effective eradication of the causative microorganisms during root canal treatment procedures. Reduction and elimination of microorganisms from the infected root canal provides optimal opportunity for treatment success. Local application of antibiotics has been considered an effective way to deliver antibiotics. A combination of antibiotic drugs have been tried under the concept of lesion sterilization and tissue repair therapy to eliminate the target bacteria, which are possible sources of endodontic lesions. The purpose of this article is to discuss the lesion sterilization and tissue repair therapy technique in primary teeth. PMID:24011295

Kayalvizhi, Gurusamy; Subramaniyan, Balaji; Suganya, Gurusamy

2013-01-01

372

Protocol for immediate implant replacement of infected teeth.  

PubMed

Extraction and immediate implant placement has become routine procedure due to reduced treatment time and the preservation of anatomical structures. However, in many cases, this technique involves teeth with different degrees of tissue compromise due to underlying infections. Until now, the degree of implant compromise has not been described, nor has a clinical management protocol been established for these cases. The aim of this article is to report the clinical results of a protocol used for immediate implant placement and provisionalization in infected extraction sockets. A classification of the implant surface compromise (in contact with previously infected tissue) is also described to facilitate the comparative analysis. It is possible to maintain the benefits of immediate implant placement and provisionalization in infected sites by applying a clinical protocol that considers antibiotic therapy, a thorough curettage of the infected tissue, antisepsis, and sufficient primary implant stability. PMID:22814552

Jofre, Jorge; Valenzuela, Daniela; Quintana, Paula; Asenjo-Lobos, Claudia

2012-08-01

373

Multiple Bilateral Taurodontic Teeth in Primary Dentition: A Case Report  

PubMed Central

ABSTRACT Taurodontism describes the tendency for the body of the tooth to enlarge at the expense of the roots. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. These anatomic variations may hinder location of canal orifices, complete removal of pulp, proper instrumentation and obturation. Importance of radiographic interpretation for the diagnosis of this alteration cannot be overlooked. This article describes a case of multiple bilateral taurodontism involving all the deciduous molars in a 3½ year old female. The child reported with a chief complaint of multiple carious lesions. How to cite this article: Vashisth P, Dwivedi S, Arora S, Mayall S. Multiple Bilateral Taurodontic Teeth in Primary Dentition: A Case Report. Int J Clin Pediatr Dent 2013;6(2):132-133. PMID:25206208

Dwivedi, Swati; Arora, Satyaki; Mayall, Sandeep

2013-01-01

374

Contact stresses in gear teeth - A new method of analysis  

NASA Technical Reports Server (NTRS)

A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth is presented. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.

Somprakit, Paisan; Huston, Ronald L.; Oswald, Fred B.

1991-01-01

375

Contact stresses in gear teeth: A new method of analysis  

NASA Technical Reports Server (NTRS)

A new, innovative procedure called point load superposition for determining the contact stresses in mating gear teeth. It is believed that this procedure will greatly extend both the range of applicability and the accuracy of gear contact stress analysis. Point load superposition is based upon fundamental solutions from the theory of elasticity. It is an iterative numerical procedure which has distinct advantages over the classical Hertz method, the finite element method, and over existing applications with the boundary element method. Specifically, friction and sliding effects, which are either excluded from or difficult to study with the classical methods, are routinely handled with the new procedure. Presented here are the basic theory and the algorithms. Several examples are given. Results are consistent with those of the classical theories. Applications to spur gears are discussed.

Somprakit, Paisan; Huston, Ronald L.; Oswald, Fred B.

1991-01-01

376

Apatite mineralization in teeth of the chiton Acanthopleura echinata.  

PubMed

Raman spectroscopy has been used to demonstrate, for the first time, that calcium mineralization in the core of the major lateral teeth of the chiton Acanthopleura echinata takes place as an ordered process, with crystalline carbonated apatite being the first mineral deposited. Deposition begins at the top of the tooth core, under the so-called tab region, progresses down the interior surface of the tab and lepidocrocite layer, and then extends outwards to the anterior surface. Mineralization is not initiated until the lepidocrocite layer has isolated the core of the tooth from the magnetite cap. The last region to be infiltrated is the anterior basal region of the tooth cusp, immediately above the junction zone. The junction zone is also a region of high ion density, as determined by energy dispersive spectroscopy (EDS) analysis, but we show here for the first time that it is free of mineral deposits, acting instead as a transfer and storage region. PMID:11136540

Lee, A P; Brooker, L R; Macey, D J; van Bronswijk, W; Webb, J

2000-11-01

377

Eruption of permanent dentition in rhesus monkeys exposed to ELF (extremely low frequency) fields. Interim report  

SciTech Connect

In a study initiated to determine the biological effects of ELF electric and magnetic fields associated with a submarine communications system ELF-exposed male rhesus monkeys gained weight at a slightly faster rate than control males. In order to obtain sufficient data on the physiological effects of electromagnetic fields, a second ELF study was initiated. Whereas the first study was initiated with wild-caught young adult animals, the second study utilized colony-bred animals beginning at 30 days of age. The emphasis of the second study was to substantiate previous findings and determine the underlying mechanisms involved. As in the first study, 30 primates (male and female) were exposed to the ELF electric and magnetic fields, and 30 control animals received the same care and treatment, but were not exposed. This report deals with the development of the permanent teeth relative to ELF exposure and sex. A consistent trend noted was that the teeth of female animals erupted at a slightly earlier age than males. However, no significant differences due to ELF exposure or sex were detected.

David, T.D.; Harris, G.A.; Bley, J.A. Jr

1983-04-01

378

Permanent multipole magnets with adjustable strength  

SciTech Connect

Preceded by a short discussion of the motives for using permanent magnets in accelerators, a new type of permanent magnet for use in accelerators is presented. The basic design and most important properties of a quadrupole will be described that uses both steel and permanent magnet material. The field gradient produced by this magnet can be adjusted without changing any other aspect of the field produced by this quadrupole. The generalization of this concept to produce other multipole fields, or combination of multipole fields, will also be presented.

Halbach, K.

1983-03-01

379

Permanent Magnetic Bearing for Spacecraft Applications  

NASA Technical Reports Server (NTRS)

A permanent, totally passive magnetic bearing rig was designed, constructed, and tested. The suspension of the rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm using an air impeller. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

Morales, Winfredo; Fusaro, Robert; Kascak, Albert

2008-01-01

380

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2010-07-01

381

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2012-07-01

382

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2014-07-01

383

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2013-07-01

384

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2011-07-01

385

77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration Permanent Closure of Cincinnati Blue Ash Airport AGENCY: Federal Aviation Administration...Notice of permanent closure of Cincinnati Blue Ash Airport (ISZ...it was permanently closing Cincinnati Blue Ash Airport (ISZ), Cincinnati,...

2012-09-11

386

Survival of abutment teeth used for telescopic abutment retainers in removable partial dentures.  

PubMed

This retrospective clinical study investigated the survival of 385 abutment teeth retaining 117 removable partial dentures with 3 types of telescopic abutment retainers. Within a mean service time of 6.26 years, 8.8% of 385 abutment teeth were extracted. Cox regression analysis revealed a significantly higher risk of tooth loss for posterior teeth (odds ratio: 2.985) and for teeth with root canal treatment (odds ratio: 3.298), whereas age, sex, and number and type of telescopic retainer had no influence on survival. Root canal-treated teeth did not show a higher fracture rate, excluding this as an explanation for an increased risk of tooth loss. PMID:18717090

Dittmann, Britta; Rammelsberg, Peter

2008-01-01

387

Polycarbonate crowns for primary teeth revisited: restorative options, technique and case reports.  

PubMed

Esthetics by definition is the science of beauty - that particular detail of an animate or inanimate object that makes it appealing to the eye. In the modern, civilized, and cosmetically conscious world, well-contoured and well-aligned white teeth set the standard for beauty. Such teeth are not only considered attractive but are also indicative of nutritional health, self esteem, hygienic pride, and economic status. Numerous treatment approaches have been proposed to address the esthetics and retention of restorations in primary teeth. Even though researchers have claimed that certain restorations are better than the others, particularly owing to the issues mentioned above, the search for the ideal esthetic restoration for the primary teeth continues. This paper revisits and attempts to reintroduce the full coverage restoration, namely, polycarbonate crown, for use in primary anterior teeth. PMID:24739917

Venkataraghavan, Karthik; Chan, John; Karthik, Sandhya

2014-01-01

388

[Strategies for posterior teeth reconstruction after endodontic treatment: a case report].  

PubMed

Reconstruction of hard dental tissue after endodontic treatment is a difficult and important duty of the dentist. According to the general opinion, endodontically treated teeth are inferior in quality, more brittle, predisposed to fractures and cracking. Logically, such teeth require reconstruction to prevent fractures, cracks, and bacterial microleakage leading to reinfection. The procedure of choice in the nineties of the 20th century was restoration with a metal post and prosthetic crown. Advances in materials resulting in improved adhesion to hard dental tissue have prompted a change in the reconstruction strategy for posterior teeth after endodontic treatment. In the case of molars, the crown can be restored with composite materials thanks to additional retention offered by the chamber of these teeth. The recommendation for premolars is to reinforce them with a glass fiber post. We now present a case which illustrates the actual trends in reconstruction of posterior teeth after endodontic treatment. PMID:20349613

Zarow, Maciej; Steinder, Joanna

2009-01-01

389

Custom Metal Occlusal Surface for Acrylic Resin Denture Teeth to Enhance Wear Resistance: A Case Report  

PubMed Central

Wear of the occlusal surface of the denture is a known fact which leads to subsequent changes in jaw relation, vertical dimension, loss of aesthetics, aged looks, and decrease in masticatory efficiency. Treatment modalities includes, change of denture set after a regular interval of 4-5 years, use of wear resistant denture teeth that includes wear resistant resin or porcelain teeth, teeth with cast metal occlusal surface, and altering occlusal contact areas of denture teeth by use of silver amalgam fillings. A case report of a patient who had increased tendency of occlusal wear was treated with custom made metal occlusal surface of denture teeth to enhance wear resistance and to improve the masticatory efficiency. PMID:22997592

Shivji, Rizwan Ali; Kamble, Vaibhav D.; Khan, Mohd. Atif

2012-01-01

390

Proteomic analysis from the mineralized radular teeth of the giant Pacific chiton, Cryptochiton stelleri (Mollusca).  

PubMed

The biomineralized radular teeth of chitons are known to consist of iron-based magnetic crystals, associated with the maximum hardness and stiffness of any biomineral. Based on our transmission electron microscopy analysis of partially mineralized teeth, we suggest that the organic matrix within the teeth controls the iron oxide nucleation. Thus, we used Nano-LC-MS to perform a proteomic analysis of the organic matrix in radular teeth of the chiton Cryptochiton stelleri in order to identify the proteins involved in the biomineralization process. Since the genome sequence of C. stelleri is not available, cross-species similarity searching and de novo peptide sequencing were used to screen the proteins. Our results indicate that several proteins were dominant in the mineralized part of the radular teeth, amongst which, myoglobin and a highly acidic peptide were identified as possibly involved in the biomineralization process. PMID:22833255

Nemoto, Michiko; Wang, Qianqian; Li, Dongsheng; Pan, Songqin; Matsunaga, Tadashi; Kisailus, David

2012-09-01

391

Determination of drugs of abuse in bovine dentin using liquid chromatography-electrospray ionization tandem mass spectrometry.  

PubMed

Drugs deposited in human teeth are well preserved; the spectrum of toxicological investigations may therefore be supplemented by an analysis method for drugs in teeth. A liquid chromatography-electrospray ionization tandem mass spectrometry assay for the detection and quantification of basic drugs of abuse in bovine dentin samples was developed and validated. The drugs and metabolites amphetamine, methamphetamine, methylenedioxymethylamphetamine, methylenedioxyethylamphetamine, codeine, morphine, cocaine and benzoylecgonine were extracted from 50 mg ground dentin powder by ultrasonication for 60 min in methanol 3 times. The extracts were analyzed on a triple-quadrupole mass-spectrometer in multiple reaction monitoring mode. The method was validated and proved to be accurate, precise, selective, specific and stable with good linearity within the calibration range and a lower limit of quantification of 10 to 20?pg/mg. To artificially load bovine dentin samples with drugs, the natural process of de- and remineralization in the oral cavity was mimicked by a pH-cycling experiment. The artificially drug-loaded dentin samples showed drug concentrations of 20 to 80?pg/mg. The method can be applied in further in vitro experiments as well as in post-mortem cases, especially where limited sample tissue is available. PMID:25476949

Spinner, J; Klima, M; Kempf, J; Huppertz, L M; Auwärter, V; Altenburger, M J; Neukamm, M A

2014-12-01

392

27 CFR 18.38 - Permanent discontinuance.  

Code of Federal Regulations, 2011 CFR

...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes After Original Establishment § 18.38 Permanent discontinuance. A...

2011-04-01

393

27 CFR 18.38 - Permanent discontinuance.  

Code of Federal Regulations, 2010 CFR

...Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS PRODUCTION OF VOLATILE FRUIT-FLAVOR CONCENTRATE Qualification Changes After Original Establishment § 18.38 Permanent discontinuance. A...

2010-04-01

394

Nonuniform radiation damage in permanent magnet quadrupoles  

SciTech Connect

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

2014-08-15

395

Nonuniform radiation damage in permanent magnet quadrupoles.  

PubMed

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components. PMID:25173260

Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

2014-08-01

396

Modeling and optimization of permanent magnetic motors  

E-print Network

This thesis develops analytic models for the prediction and optimization of radial-flux permanent magnet motor torque and efficiency. It also facilitates the design optimization of electromagnetically-powered rotorcraft ...

Pinkham, Andrew P

2008-01-01

397

Nonuniform radiation damage in permanent magnet quadrupoles  

NASA Astrophysics Data System (ADS)

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G.

2014-08-01

398

Micromachined permanent magnets and their MEMS applications  

NASA Astrophysics Data System (ADS)

In this research, new micromachined permanent magnets have been proposed, developed and characterized for MEMS applications. In realizing micromachined permanent magnets, a new electroplating technique using external magnetic field and a bumper filling technique using a photolithographically defined mold with resin bonded magnetic particles have been developed. The newly developed micromachining techniques allow thick film-type permanent magnet components to be integrated to magnetic MEMS devices with dimensional control and alignment. Permanent magnet arrays with the dimensions ranging from 30 mum to 200 mum have been developed with an energy density up to 2.7 kJ/m3 in precisely defined forms in the micro scale. For the applications of the permanent magnets developed in this work, three novel magnetic MEMS devices such as a bi-directional magnetic actuator, a magnetically driven optical scanner, and a magnetic cell separator have been successfully realized. After design and modeling, each device has been fabricated and fully characterized. The bi-directional actuator with the electroplated permanent magnet array has achieved bi-directional motion clearly and shown good agreement with the analytical and simulated models. The optical scanner has shown linear bi-directional response under static actuation and stable bi-directional scanning performance under dynamic actuation. As a potential BioMEMS application of the developed permanent magnet, the prototype magnetic cell separator using the electroplated permanent magnet strip array has been proposed and demonstrated for magnetic bead patterning. In conclusion, new thick film-type, electroplated CoNiMnP and epoxy resin bonded Sr-ferrite permanent magnets have been developed and characterized, and then, three new magnetic MEMS devices using the permanent magnets such as a bi-directional magnetic actuator, an optical scanner and a magnetic cell separator have been realized in this research. The new micromachined permanent magnets, fabrication techniques and the new devices in this work can be applied to many MEMS devices that demand a constant magnetic field source and large bi-directional actuation, in the areas of light beam, flow and biological cell handling.

Cho, Hyoung Jin

2002-01-01

399

Permanent education in health: a review  

PubMed Central

OBJECTIVE To undertake a meta-synthesis of the literature on the main concepts and practices related to permanent education in health. METHODS A bibliographical search was conducted for original articles in the PubMed, Web of Science, LILACS, IBECS and SciELO databases, using the following search terms: “public health professional education”, “permanent education”, “continuing education”, “permanent education health”. Of the 590 articles identified, after applying inclusion and exclusion criteria, 48 were selected for further analysis, grouped according to the criteria of key elements, and then underwent meta-synthesis. RESULTS The 48 original publications were classified according to four thematic units of key elements: 1) concepts, 2) strategies and difficulties, 3) public policies and 4) educational institutions. Three main conceptions of permanent education in health were found: problem-focused and team work, directly related to continuing education and education that takes place throughout life. The main strategies for executing permanent education in health are discussion, maintaining an open space for permanent education, and permanent education clusters. The most limiting factor is mainly related to directly or indirect management. Another highlight is the requirement for implementation and maintenance of public policies, and the availability of financial and human resources. The educational institutions need to combine education and service aiming to form critical-reflexive graduates. CONCLUSIONS The coordination between health and education is based as much on the actions of health services as on management and educational institutions. Thus, it becomes a challenge to implement the teaching-learning processes that are supported by critical-reflexive actions. It is necessary to carry out proposals for permanent education in health involving the participation of health professionals, teachers and educational institutions. PMID:24789649

Miccas, Fernanda Luppino; Batista, Sylvia Helena Souza da Silva

2014-01-01

400

Permanent magnet edge-field quadrupole  

DOEpatents

Planar permanent magnet edge-field quadrupoles for use in particle accelerating machines and in insertion devices designed to generate spontaneous or coherent radiation from moving charged particles are disclosed. The invention comprises four magnetized rectangular pieces of permanent magnet material with substantially similar dimensions arranged into two planar arrays situated to generate a field with a substantially dominant quadrupole component in regions close to the device axis.

Tatchyn, Roman O. (Mountain View, CA)

1997-01-01

401

Laced permanent magnet quadrupole drift tube magnets  

Microsoft Academic Search

Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL (Lawrence Berkeley Laboratory), marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce

B. Feinberg; G. U. Behrsing; K. Halbach; J. S. Marks; M. E. Morrison; D. H. Nelson

1989-01-01

402

Permanent magnet system of alpha magnetic spectrometer  

Microsoft Academic Search

Alpha magnetic spectrometer (AMS) is the first large magndtic spectrometer in space. Its precursor flioht was completed successfully\\u000a in June 1998. The key part of AMS is the permanent magnet system, which was built by the lnstitute of Electric Engineering,\\u000a the institute of High Energy Physics and the Chinese Academy of Launch Vehicle Technology. This system includes a permanent\\u000a magnet

Hesheng Chen

2000-01-01

403

Permanent Magnets Design and Magnetic Field Analysis of Multi-disc Coreless Permanent Magnet Synchronous Motor  

Microsoft Academic Search

This paper presents a new multi-disc coreless permanent magnet synchronous motor whose permanent magnets are arranged in the “Halbach array”. Unit motor combined structure is adopted to simplify processing technology of the motor. Airgap magnetic flux density is increased taking advantage of high remanence and coercive force of NdFeB permanent magnet material and high gathering magnetism function of Halbach array.

Xiao-yuan WANG; Fang ZHAO; Jing-juan DU; Li-xiao QI; Ren-yuan TANG

2006-01-01

404

Temporal trend of mercury in polar bears (Ursus maritimus) from4 Svalbard using teeth as a biomonitoring tissue5  

E-print Network

1 1 2 3 Temporal trend of mercury in polar bears (Ursus maritimus) from4 Svalbard using teeth and carbon stable isotopes in teeth of polar bear29 (Ursus maritimus) from Svalbard as biotracers of temporal exposure, and in total 8731 teeth of polar bears were analysed. Dental Hg levels ranged from 0.6 to 72.3 ng

Paris-Sud XI, Université de

405

Characterization of the bovine major histocompatibility complex  

E-print Network

and found in a small, continuous region of about 300Mb of DNA. However, genes of the bovine MHC are found in two clusters on chromosome 23 separated by approximately 20Mb of DNA. The disruption of the organization of the bovine MHC was caused by a large...

McArthur, Monica

2013-02-22

406

Soluble antigen of bovine viral diarrhea virus  

Microsoft Academic Search

Summary Complement-fixing (CF) soluble antigen (SA) was detectable intra-cellularly prior to the appearance of infectious NADL-MD bovine viral diarrhea (BVD) virus during synthesis in roller flask cultures of bovine embryonic kidney cells. The release of infective virus into the extracellular fluid was concomitant with the release of SA.

Donald E. Gutekunst; Winston A. Malmquist

1965-01-01

407

Review article Pathobiology of bovine leukemia virus  

E-print Network

Review article Pathobiology of bovine leukemia virus I Schwartz D Lévy URA-INRA d-Alfort cedex, France (Received 16 March 1994; accepted 25 July 1994) Summary ― Bovine leukemia virus (BLV) is a retrovirus similar to the human T-cell leukemia virus (HTLV). Most BLV infected animals (70

Boyer, Edmond

408

Original article Bovine respiratory syncytial virus  

E-print Network

Original article Bovine respiratory syncytial virus: first serological evidence in Uruguay Mauro; accepted 18 November 1999) Abstract ­ Bovine respiratory syncytial virus (BRSV) is a major cause virus / recombinant N protein / epidemiology / baculovirus / Uruguay Résumé ­ Première mise en évidence

Boyer, Edmond

409

QUANTITATIVE TRAIT LOCI FOR INFECTIOUS BOVINE KERATOCONJUNCTIVITIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Infectious bovine keratoconjunctivitis, also known as pinkeye, is an economically important disease in cattle. The objective of this study was to detect quantitative trait loci associated with infectious bovine keratoconjunctivitis in offspring from a Brahman x Hereford sire. The sire was mated to H...

410

Phytate inhibits bovine pericardium calcification in vitro  

Microsoft Academic Search

Objective: The present study examined the inhibitory effects of pyrophosphate, etidronate, and phytate on bovine pericardium calcification in vitro. Methods: Bovine pericardium was glutaraldehyde fixed and then placed in a flow chamber in the presence of a synthetic physiological fluid alone (control) or the fluid plus various concentrations of pyrophosphate, etidronate, or phytate. Following a 96-h incubation, fragments were removed

Félix Grases; Pilar Sanchis; Antonia Costa-Bauzá; Oriol Bonnin; Bernat Iserna; Joan Perelló; Rafael M. Prieto

411

Bovine Growth Hormone: Human Food Safety Evaluation  

Microsoft Academic Search

Scientists in the Food and Drug Administration (FDA), after reviewing the scientific literature and evaluating studies conducted by pharmaceutical companies, have concluded that the use of recombinant bovine growth hormone (rbGH) in dairy cattle presents no increased health risk to consumers. Bovine GH is not biologically active in humans, and oral toxicity studies have demonstrated that rbGH is not orally

Judith C. Juskevich; C. Greg Guyer

1990-01-01

412

AFFINITY ENRICHMENT OF BOVINE LACTOFERRIN IN WHEY  

Microsoft Academic Search

Bovine lactoferrin was enriched in various whey samples by affinity chromatography using immobilized gangliosides. Bovine gangliosides were isolated from fresh buttermilk using a combination of ultrafiltration and organic extraction. Isolated gangliosides were covalently immobilized onto controlled-pore glass beads. The immobilized matrix contained 66 micrograms of gangliosides per gram of beads. After loading the matrix with reconstituted whey protein isolate (WPI)

M. K. Walsh; S. H. Nam

2001-01-01

413

Communication The monitoring of bovine pregnancies derived  

E-print Network

/ embryo transfer / in vitro fertilization / nuclear transfer Reprod. Nutr. Dev. 42 (2002) 613­624 613Communication The monitoring of bovine pregnancies derived from transfer of in vitro produced are associated with bovine pregnancies obtained from in vitro produced embryos. This thus requires for a more

Paris-Sud XI, Université de

414

Tooth development in a model reptile: functional and null generation teeth in the gecko Paroedura picta  

PubMed Central

This paper describes tooth development in a basal squamate, Paroedura picta. Due to its reproductive strategy, mode of development and position within the reptiles, this gecko represents an excellent model organism for the study of reptile development. Here we document the dental pattern and development of non-functional (null generation) and functional generations of teeth during embryonic development. Tooth development is followed from initiation to cytodifferentiation and ankylosis, as the tooth germs develop from bud, through cap to bell stages. The fate of the single generation of non-functional (null generation) teeth is shown to be variable, with some teeth being expelled from the oral cavity, while others are incorporated into the functional bone and teeth, or are absorbed. Fate appears to depend on the initiation site within the oral cavity, with the first null generation teeth forming before formation of the dental lamina. We show evidence for a stratum intermedium layer in the enamel epithelium of functional teeth and show that the bicuspid shape of the teeth is created by asymmetrical deposition of enamel, and not by folding of the inner dental epithelium as observed in mammals. PMID:22780101

Zahradnicek, Oldrich; Horacek, Ivan; Tucker, Abigail S

2012-01-01

415

ABO blood grouping from hard and soft tissues of teeth by modified absorption-elution technique  

PubMed Central

Background: Teeth have always been known as stable tissue that can be preserved both physically and chemically for long periods of time. Blood group substances have been known to be present in both the hard and soft tissues of the teeth. Objectives: This study aimed at detection of ABO blood group substances from soft and hard tissues of teeth and also to evaluate the reliability of teeth stored for a relatively long period as a source of blood group substances by absorption–elution technique with some modifications. Results: Blood group obtained from the teeth was compared with those obtained from the blood sample. Pulp showed a very large correlation in both fresh and long-standing teeth though it decreased slightly in the latter. Hard tissue showed a large correlation in both the groups indicating that hard tissue is quite reliable to detect blood group and that there is no much difference in the reliability in both the groups. However, combining pulp and hard tissue, correlation is moderate. Correlation of blood grouping with the age, sex, and jaw distribution was carried out. Conclusion: Blood group identification from hard and soft tissues of teeth aids in the identification of an individual. PMID:23960412

Ramnarayan, BK; Manjunath, M; Joshi, Anagha Ananth

2013-01-01

416

EFFECTIVENESS OF CARBAMIDE PEROXIDE AND SODIUM PERBORATE IN NON-VITAL DISCOLORED TEETH  

PubMed Central

Objective: To evaluate the efficacy of 16% carbamide peroxide gel (CP16%), tetrahydrate sodium perborate (SP) and mixture (CP16% + SP), in walking bleaching of non-vital discolored teeth. Materials and methods: Sixty single-rooted human premolars with intact crowns were used and initial color was assessed using Vita shade guide and standardized photos. The teeth were stained using rabbit fresh blood for 18 days and photos of discolored teeth and color evaluation were performed. The teeth were divided into 4 groups (n = 15), according to bleaching agent used: G1) CP16% gel; G2) CP16% gel + SP; G3) SP + distilled water; G4: control. The bleaching agents were replaced twice at 7-day intervals for 21 days. All teeth were evaluated by two endodontists at days 0, 7, 14 and 21 and the color changes were assessed using Vita shade guide and standardized photos. The results were analyzed by Kruskal-Wallis and Dunn's tests (p=0.05). Results: The experimental groups presented statistically similar bleaching results (p>0.05) at the end of 7, 14 and 21 days. These groups presented significantly higher bleaching efficacy than control group (G4) (p<0.05). The mixture CP16% + SP promoted return of original color in 100% of teeth at the end of 21 days. Conclusion: It was concluded that three bleaching agents were effective in bleaching of stained teeth with blood products, especially at the end of 21 days. PMID:19466262

Valera, Marcia Carneiro; Camargo, Carlos Henrique Ribeiro; Carvalho, Cláudio Antonio Talge; de Oliveira, Luciane Dias; Camargo, Samira Esteves Afonso; Rodrigues, Cristiana Martins

2009-01-01

417

Influence of the remaining coronal structure on the resistance of teeth with intraradicular retainer.  

PubMed

The aim of this study was to compare the resistance of endodontically treated teeth with intraradicular retainer different amounts of remaining coronal structure. Fifty freshly extracted maxillary canines were endodontically treated and randomly assigned to five groups (n=10), as follows: group 1 (control) = teeth with custom cast post and core; group 2 = teeth without remaining coronal structure; group 3, 4 and 5 = teeth with 1 mm, 2 mm and 3 mm of remaining coronal structure, respectively. All specimens in groups 2 to 5 were restored with prefabricated post and resin core. The teeth were embedded in acrylic resin and the fracture strength was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed statistically by one-way analysis of variance and Tukey's test. There was no significant differences (p>0.05) between the control group and group 2, and between groups 3, 4 and 5 (p>0.05). Control group and group 2 had significantly higher resistance strength than groups 3, 4 and 5 (p<0.00001). The findings of this study showed that teeth without remaining coronal structure had significantly higher fracture strength than those with remaining coronal structure (1 mm, 2 mm and 3 mm). When the dental crown was not completely removed, the amount of remaining coronal dentin did not significantly affect the fracture strength of endodontically treated teeth with intraradicular retainer. PMID:16429184

Pereira, Jefferson Ricardo; Neto, Tatiany de Mendonça; Porto, Vinícius de Carvalho; Pegoraro, Luiz Fernando; do Valle, Accácio Lins

2005-01-01

418

Characterization of transparent dentin in attrited teeth using optical coherence tomography.  

PubMed

Attrition and wear of tooth surface occur with aging and result in loss of enamel, with exposure and histological changes in dentin. Dealing with attrited teeth and restoration of the lost tissue are clinically challenging. The main objective of this study is to characterize the exposed transparent dentin in the occlusal surface of attrited teeth by optical coherence tomography (OCT). Naturally attrited, extracted human teeth with occlusal-transparent dentin were investigated in comparison to sound and carious teeth. The teeth were subjected to OCT imaging and then cross-sectioned and polished. OCT B-scans were compared to light microscopy images of the same cross section. In OCT images, some changes were evident at the transparent dentin in attrited teeth. An OCT attenuation coefficient parameter (? t) was derived based on the Beer-Lambert law as a function of backscatter signal slope. The mean values of ? t were 1.05?±?0.3, 2.23?±?0.4, and 0.61?±?0.27 mm(-1) for sound, carious, and transparent dentins, respectively. One-way ANOVA with Tukey's post-hoc showed a significant difference between groups (p?teeth and can be used in the future as a clinical adjunct tool. PMID:24532117

Mandurah, Mona M; Sadr, Alireza; Bakhsh, Turki A; Shimada, Yasushi; Sumi, Yasunori; Tagami, Junji

2015-05-01

419

EDITORIAL: Permanent revolution - or evolution?  

NASA Astrophysics Data System (ADS)

Honorary Editor It was that temporary Bolshevik Leon Trotsky who developed the principle of `permanent revolution', a principle that perhaps characterizes the recent history of education in (south) Britain more than does, say, principles traditionally associated with the Conservative or Labour parties. As this editorial is being written, changes are being made to primary school education, and the long-awaited details of the post-Dearing reorganizing of post-16 education are yet to hit the overful bookshelves and filing cabinets of school heads and examination board officials. But something unique has happened recently which might have surprised even Trotsky. The Secretary of State for Education has set up targets for primary school pupils' attainment and threatened (or promised) to resign if they are not met within the lifetime of our newly elected parliament. Of course, if Mr Blunkett is still in a position to resign at that stage he will have been the longest serving Secretary of State since time immemorial. But we should not carp: this is truly a revolutionary idea. Not the promise to resign - although this idea is not so fashionable now as it once was. The revolutionary idea is that a major change to an educational process is actually being made that carries with it a predicted and testable outcome. By contrast, when school physics was refreshed a generation ago by the introduction of Nuffield courses at both pre- and post-16 stages, no `targets' were set. I and many other physics teachers certainly preferred teaching these to teaching their predecessor syllabuses, and might even dare to assert that the pupils liked them too. But we still don't really know whether or not they learned more - or even better - physics. Very little happened as far as the outside world was concerned: the usual fraction of students gave up physics at the usual ages, and those who were examined didn't really get a better reward for their more up-to-date and more enjoyably learned physics. The same fraction of candidates passed at O- and A-level, with much the same distribution of grades. But then at least, amongst other things, we may claim to have produced happier and more knowledgeable failures. Mr Blunkett's revolutionary idea should be extended so that any major educational change must be capable of evaluation. The customers/victims should actually be shown to have benefited - more of them should do better! It is a regrettable fact of history that most revolutions have resulted in tears before bedtime, however bright the following dawn. One problem with revolutions, as Maxim Gorky often pointed out, is that `inside every revolutionary there is a gendarme'. It is one thing to specify a target, another to direct in detail how every child and teacher in the land should achieve it. The latter is very difficult to manage, and when patience inevitably runs out there is likely to be a tendency towards gendarmerie. The control structure begins to dominate the educational one, and the means of control become more important than the ends. Rigidity replaces creativity, fossilization replaces evolution, and the energies and skills of practitioners may be devoted more to conforming passively with or ingeniously evading the constraints of a rule-bound system. There were signs that this effect exists and has been growing, but happily these signs have been detected by the `gendarmerie' and recognized as being deleterious. Government agencies are now consulting, seriously, with practitioners and such organizations as the IoP. It may well be that when the magic number 2000 arrives there will be a well-designed, self-organizing and self-monitoring National Curriculum that will engage the hearts as well as develop the minds of the young.

Dobson, Ken

1998-03-01

420

Models of bovine babesiosis including juvenile cattle.  

PubMed

Bovine Babesiosis in cattle is caused by the transmission of protozoa of Babesia spp. by ticks as vectors. Juvenile cattle ([Formula: see text]9 months of age) have resistance to Bovine Babesiosis, rarely show symptoms, and acquire immunity upon recovery. Susceptibility to the disease varies between breeds of cattle. Models of the dynamics of Bovine Babesiosis transmitted by the cattle tick that include these factors are formulated as systems of ordinary differential equations. Basic reproduction numbers are calculated, and it is proved that if these numbers are below the threshold value of one, then Bovine Babesiosis dies out. However, above the threshold number of one, the disease may approach an endemic state. In this case, control measures are suggested by determining target reproduction numbers. The percentage of a particular population (for example, the adult bovine population) needed to be controlled to eradicate the disease is evaluated numerically using Columbia data from the literature. PMID:25715822

Saad-Roy, C M; Shuai, Zhisheng; van den Driessche, P

2015-03-01

421

Identification of bovine CD14.  

PubMed

Six monoclonal antibodies (mAbs) that clustered together in a statistical analysis of data submitted to the Third Workshop on Ruminant Leucocyte Antigens and mAb CC-G33 were tested for ability to stain COS-7 cells transfected with cDNA encoding human CD14. Only mAb CC-G33 recognised the human molecule. The six mAbs were compared with mAb CC-G33 by flow cytometry and three were shown to be directed against bovine CD14. PMID:8896221

Sopp, P; Kwong, L S; Howard, C J

1996-08-01

422

Biologic Restoration: A Treatment Option for Reconstruction of Anterior Teeth  

PubMed Central

Several procedures are advised to manage fractured anterior tooth structure using acrylic resin, composite restoration, ceramic or metal crown with ceramic facing. Biologic restoration is a procedure to restore fractured tooth structure with natural tooth material. In this in vitro case we have made an attempt for aesthetic rehabilitation of maxillary central incisor with similar biologic crown taken form extracted maxillary central incisor. It was observed that biologic restoration is an aesthetic, economical, fast and functional procedure which can be used as an alternative method to restore fractured primary or permanent anteriors. PMID:25584332

Khanna, Priyanka; S, Shankar; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S

2014-01-01

423

Biologic restoration: a treatment option for reconstruction of anterior teeth.  

PubMed

Several procedures are advised to manage fractured anterior tooth structure using acrylic resin, composite restoration, ceramic or metal crown with ceramic facing. Biologic restoration is a procedure to restore fractured tooth structure with natural tooth material. In this in vitro case we have made an attempt for aesthetic rehabilitation of maxillary central incisor with similar biologic crown taken form extracted maxillary central incisor. It was observed that biologic restoration is an aesthetic, economical, fast and functional procedure which can be used as an alternative method to restore fractured primary or permanent anteriors. PMID:25584332

Babaji, Prashant; Khanna, Priyanka; S, Shankar; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S

2014-11-01

424

Contact stresses in meshing spur gear teeth: Use of an incremental finite element procedure  

NASA Technical Reports Server (NTRS)

Contact stresses in meshing spur gear teeth are examined. The analysis is based upon an incremental finite element procedure that simultaneously determines the stresses in the contact region between the meshing teeth. The teeth themselves are modeled by two dimensional plain strain elements. Friction effects are included, with the friction forces assumed to obey Coulomb's law. The analysis assumes that the displacements are small and that the tooth materials are linearly elastic. The analysis procedure is validated by comparing its results with those for the classical two contacting semicylinders obtained from the Hertz method. Agreement is excellent.

Hsieh, Chih-Ming; Huston, Ronald L.; Oswald, Fred B.

1992-01-01

425

Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.  

PubMed

One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The application of unfilled resin to the anatomical crown prevented infection. PMID:9206377

Love, R M

1996-12-01

426

Advances in the treatment of diseased equine incisor and canine teeth.  

PubMed

Dental therapies for equid incisor and canine teeth have modernized significantly over the last 2 decades. Basic principles in incisor reduction have become more conservative, and extraction procedures more exacting. Periodontal and endodontic treatments are described to save teeth that would have succumbed to extraction in the past. Pathologic impacts on treatment decisions for equine odontoclastic tooth resorption and hypercementosis are significant, and veterinarians and owners need to be aware of treatment options and outcomes. Easy access to equid incisor and canine teeth offers a variety of therapeutic options, and this article reviews some of the practical procedures available. PMID:23915667

Rawlinson, Jennifer T; Earley, Edward

2013-08-01

427

Opal phytoliths found on the teeth of the extinct ape Gigantopithecus blacki: implications for paleodietary studies.  

PubMed Central

Identification of opal phytoliths bonded to the enamel surface of the teeth of Gigantopithecus blacki indicates that this extinct ape had a varied diet of grasses and fruits. By using the scanning electron microscope at magnifications of 2000-6000x specific opal phytoliths were observed and photographed on the fossilized teeth of an extinct species. Since opal phytoliths represent the inorganic remains of once-living plant cells, their documentation on the teeth of Gigantopithecus introduces a promising technique for the determination of diet in extinct mammalian species which should find numerous applications in the field of paleoanthropology as well as vertebrate paleontology. Images PMID:2236026

Ciochon, R L; Piperno, D R; Thompson, R G

1990-01-01

428

Permanent magnetic system design for the wall-climbing robot  

Microsoft Academic Search

This paper presents the design of the permanent magnetic system for the wall climbing robot with permanent magnetic tracks. A proposed wall climbing robot with permanent magnetic adhesion mechanism for inspecting the oil tanks is briefly put forward, including the mechanical system architecture. The permanent magnetic adhesion mechanism and the tracked locomotion mechanism are employed in the robot system. By

Weimin Shen; Jason Gu; Yanjun Shen

2005-01-01

429

BOVINE TUMOR NECROSIS FACTOR RECEPTOR-1 AND METHODS OF USE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The invention relates to nucleic acid sequences encoding a bovine tumor necrosis factor receptor-1 (TNF-R1). Also within the invention is a soluble bovine TNF-R1, which is a potent inhibitor of bovine tumor necrosis factor-alpha (TNF-alpha). The invention demonstrates that soluble bovine TNF-R1 has ...

430

Original article Effects of bovine colostrum acid protein on bone  

E-print Network

Original article Effects of bovine colostrum acid protein on bone loss and hemobiochemistry indexes that bovine milk and its basic proteins, and bovine colostrums (BC) and their extracts have positive effects hazard on blood lipids of rats under present experimental condition. bovine colostrum / acid protein

Boyer, Edmond

431

Root canal morphology of South Asian Indian maxillary molar teeth  

PubMed Central

Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars. PMID:25713497

Singh, Shishir; Pawar, Mansing

2015-01-01

432

Odontology or philologic: medical disputation about the teeth.  

PubMed

The dissertation, here rendered, was published at the gymnasium of Hof in 1669. It is remarkable that the respondent, who was probably also its author, declared in the title page that he intends to do his task "following the custom of the blessed Hebrews and any other conventions of true Israelites" and cites in the following text repeated proverbs of Rabbis. Therefore, we suppose him to have been a Jew converted to the Christian faith. His Odontology is a large collection of knowledge about the teeth, the etymology of this term, the question of them belonging to the bones, their anatomy and fixation in the jaws, and their tasks in the crushing of foods and helping in pronunciation, and in animals for self-protection. With respect to their removal, he emphasizes that one read Sennert's Institutiones Medicae. The points of view discussed by the author depended more heavily on philological than on medical authors. Nevertheless, there are mentioned also "paramedical" opinions of the general population. The monograph seems to us important for the history of dentistry. PMID:17848044

Lorber, Curt Gerhard; Lorber, Wilma Dorotheé

2007-01-01

433

Radix mesiolingualis and radix distolingualis in a collection of permanent maxillary molars.  

PubMed

Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis (RML)) or distolingually (radix distolingualis (RDL)). The available literature refers only to the existence and location of RML and RDL Very small materials have, quite simply, hitherto precluded a more detailed description of these roots. The large collection of extracted teeth at the School of Dentistry in Copenhagen now includes a non-random subcollection of 145 permanent maxillary molars, the root complex of which contains 2 lingual root structures. Based on this material it was possible to undertake a modern, systematic analysis of the macromorphological variation of RMLs and RDLs. In this study, which was mainly non-metric, criteria for the identification of RML and RDL were established. The analysis also showed that the lingual supernumerary roots were only rarely found on the first molar, but with increasing frequency on the second and third molars. Both separate and non-separate RML and RDL were observed. In the material, degrees of separation greater than 0.9 were registered, degrees of divergence up to approximately 45 degrees, an apical bend of approximately 90 degrees, and extreme apical slenderness. Even though the supernumerary roots described here do not occur very often, knowing about them is nevertheless clinically relevant in for example endodontic and surgical contexts. PMID:11144874

Carlsen, O; Alexandersen, V

2000-10-01

434

Cylindrical Hall Thrusters with Permanent Magnets  

SciTech Connect

The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT. __________________________________________________

Yevgeny Raitses, Enrique Merino and Nathaniel J. Fisch

2010-10-18

435

Effect of Side Permanent Magnets for Reluctance Interior Permanent Magnet Reluctance Machines  

Microsoft Academic Search

A traditional electric machine uses two dimensional magnetic flux paths in its rotor. This paper presents the development work on the utilization of the third dimension of a rotor. As an example, the air gap flux of a radial gap interior permanent magnet motor can be significantly enhanced by additional permanent magnets (PM) mounted at the sides of the rotor.

John S Hsu; Seong T Lee; Randy H Wiles; Chester Coomer; Kirk T Lowe

2007-01-01

436

Effect of Side Permanent Magnets for Reluctance Interior Permanent Magnet Machines  

Microsoft Academic Search

A traditional electric machine uses two dimensional magnetic flux paths in its rotor. This paper presents the development work on the utilization of the third dimension of a rotor. As an example, the air gap flux of a radial gap interior permanent magnet motor can be significantly enhanced by additional permanent magnets (PM) mounted at the sides of the rotor.

J. S. Hsu; S. T. Lee; R. H. Wiles; C. L. Coomer; K. T. Lowe; T. A. Burress

2007-01-01

437

Study on the Permanent Magnet Demagnetization Fault in Permanent Magnet Synchronous Machines  

Microsoft Academic Search

This article studies the permanent magnet demagnetization fault in permanent magnet synchronous machines (PMSM). The study is carried out by analyzing the harmonics obtained using the fast Fourier transform (FFT) of stator and zero sequence currents at nominal torque for the whole range of machine operation speeds. The appropriate combination of analyses on the different currents makes it possible to

J. A. Rosero; J. Cusido; A. Garcia; J. A. Ortega; L. Romeral

2006-01-01

438

Thermal analysis of a large permanent magnet synchronous motor for different permanent magnet rotor configurations  

Microsoft Academic Search

The aim of this paper is to study the temperature distribution effect on the permanent magnets for a chosen cooling system when designing a permanent magnet synchronous motor (PMSM) with radial flux distribution for ship propulsion drives. The electromechanical characteristics of the motor are computed using a two-dimensional finite element analysis (FEA), while the thermal analysis is achieved using a

M. Negrea; M. Rosu

2001-01-01

439

Adipogenesis of bovine perimuscular preadipocytes  

SciTech Connect

In this study, non-transformed progeny adipofibroblasts, derived from mature adipocyte dedifferentiation, was used as a novel in vitro model to study adipogenic gene expression in cattle. Adipofibroblasts from dedifferentiated mature perimuscular fat (PMF) tissue were cultured with differentiation stimulants until the cells exhibited morphological differentiation. Treated cells were harvested from day 2 to 16 for RNA extraction, whereas control cells were cultured without addition of stimulants. Results from time course gene expression assays by quantitative real-time PCR revealed that peroxisome proliferator-activated receptor gamma (PPAR-{gamma}), sterol regulatory element binding protein 1 (SREBP-1) and their six down-stream genes were co-expressed at day 2 post-differentiation induction. When compared to other adipogenesis culture systems, the adipogenic gene expression of bovine PMF adipofibroblasts culture was different, especially to the rodent model. Collectively, these results demonstrated PPAR-{gamma} and SREBP-1 cooperatively play a key role to regulate the re-differentiation of bovine adipofibroblasts, during early conversion stages in vitro.

Taniguchi, Masaaki; Le Luo Guan; Zhang Bing [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada); Dodson, Michael V. [Department of Animal Sciences, Washington State University, P.O. Box 646310, Pullman, WA 99164 (United States); Okine, Erasmus [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada); Moore, Stephen S. [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada)], E-mail: Stephen.moore@ualberta.ca

2008-02-01

440

A study on the permanent magnet overhang effect in permanent magnetic actuator using 3-dimension equivalent magnetic circuit network method  

Microsoft Academic Search

This paper presents the analysis of the permanent magnet overhang effect for permanent magnetic actuator. Generally, The overhang is often used to increase the force density in permanent magnet machineries. The overhang is especially profitable to reduce the volume after increasing the force density per volume when using the overhang effect of the permanent magnet. Therefore, 3D equivalent magnetic circuit

Ho Kwon; S.-Y. Kwon; Ju Lee; Seung-kil Choi; Soo-Hyun Baek

2003-01-01

441

Lamniform shark teeth from the late cretaceous of southernmost South America (Santa Cruz province, Argentina).  

PubMed

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. PMID:25141301

Schroeter, Elena R; Egerton, Victoria M; Ibiricu, Lucio M; Lacovara, Kenneth J

2014-01-01

442

Teeth segmentation of dental periapical radiographs based on local singularity analysis.  

PubMed

Teeth segmentation for periapical raidographs is one of the most critical tasks for effective periapical lesion or periodontitis detection, as both types of anomalies usually occur around tooth boundaries and dental radiographs are often subject to noise, low contrast, and uneven illumination. In this paper, we propose an effective scheme to segment each tooth in periapical radiographs. The method consists of four stages: image enhancement using adaptive power law transformation, local singularity analysis using Hölder exponent, tooth recognition using Otsu's thresholding and connected component analysis, and tooth delineation using snake boundary tracking and morphological operations. Experimental results of 28 periapical radiographs containing 106 teeth in total and 75 useful for dental examination demonstrate that 105 teeth are successfully isolated and segmented, and the overall mean segmentation accuracy of all 75 useful teeth in terms of (TP, FP) is (0.8959, 0.0093) with standard deviation (0.0737, 0.0096), respectively. PMID:24252317

Lin, P L; Huang, P Y; Huang, P W; Hsu, H C; Chen, C C

2014-02-01

443

Full Mouth Rehabilitation of Severe Fluorozed Teeth with an Interdisciplinary Approach (6 Handed Dentistry)  

PubMed Central

Whenever the treatment revolves around structural balance and aesthetic harmony, the crux remains to be the periodontal health of the existing dentition. In such scenarios where restorations and aesthetics are of concern, biologic width (BW) is the initial and final frontier. Considering attrition of teeth, the resistance which is offered by them is definitely at a lower level as compared to teeth with adequate height. Clinical crowns of worn out teeth are seriously handicapped when it comes to bearing the occlusal loads, which can be brought back to normalcy by crown lengthening . Crown lengthening includes the surgical removal of soft and hard periodontal architecture to gain (vertical dimension) a supracrestal tooth length, thus allowing a longer clinical crown reestablishment of BW. This paper has described the full mouth rehabilitation of severe fluorozed and attrited teeth in a 35–year male with the use of an interdisciplinary approach (6 Handed Dentistry). PMID:24298538

Pradeep, Koppolu; Patil, Nagesh; Sood, Tanusree; Akula, Uttam; Gedela, Rajani

2013-01-01

444

Restoration of anterior teeth using an indirect composite technique. Case report  

PubMed Central

SUMMARY Objective. This article presents a case report of restoration of anterior teeth using an indirect technique with composite veneers in order to restore the dental anatomy and to provide aesthetic and function of anterior teeth. Materials and methods. A treatment of upper anterior teeth with indirect micro-hybrid composite restoration was proposed to a 40-year-old woman with old discolored and fractured ceramic veneers. Upper six anterior teeth were prepared and, after impressions with VPS of maxillary arche, the composite veneers were placed. Discussion and results. There are several advantages offered by indirect techniques compared to direct techniques. The increased practice of veneering technique with indirect composites is due to improvement in the properties of composite materials in the last years. The results are very favourable and the patient is satisfied. Conclusions. The restorations with composite veneers have proved durable and aesthetic, protect tooth structure and aesthetic and function is predictably re-established. PMID:24971164

GARGARI, M.; CERUSO, F.M.; PUJIA, A.; PRETE, V.

2013-01-01

445

Here Comes the Bride... and Her Teeth Are Nice and Bright  

MedlinePLUS

... JADA, Vol. 135, May 2004679 OTHER COSMETIC OPTIONS Bonding. If your teeth are chipped, broken, cracked or ... or have slight gaps, ask your dentist about bonding. Bonding is a cosmetic procedure that uses tooth- ...

446

Extrinsic Iron Staining in Infant Teeth from Iron-Fortified Formula and Rice Cereal  

PubMed Central

Extrinsic staining of teeth due to excessive iron intake has been reported previously in the literature. We describe a 7-month-old infant who presented with extrinsic teeth staining due to inadvertent over consumption of dietary iron. The infant was fed iron-fortified formula and rice cereal. Rice cereal, fortified with iron, was being used as part of a normal infant diet and as a thickening agent when added to the formula for treatment of gastroesophageal reflux. After several months of administration, “blackening” of the infant's teeth was noted by the mother. The stain was removed by the pediatric dentist who simply scraped the affected teeth. No further staining occurred after the amount of dietary iron was reduced. PMID:23055877

Adcock, Kim G.; Hogan, Shirley M.

2008-01-01

447

Lamniform Shark Teeth from the Late Cretaceous of Southernmost South America (Santa Cruz Province, Argentina)  

PubMed Central

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. PMID:25141301

Schroeter, Elena R.; Egerton, Victoria M.; Ibiricu, Lucio M.; Lacovara, Kenneth J.

2014-01-01

448

Lateral condensation in treatment of pulpitis and pulp gangrene: studies on dog canine teeth.  

PubMed

The clinical investigation, carried out in dogs, comprises selected cases of chronic pulpitis and pulpal gangrene of canine teeth resulting from injuries. A group of 20 teeth (group 1) underwent extirpation of pulp, as well as elaboration of a root canal and its filling with Endomethasone paste, under general anaesthesia during a one-stage procedure. The second group of 20 teeth differed from the first in an additional concentration of the paste, due to an introduction of gutta-percha points (lateral condensation). This sealing modification proved to diminish the risk of leaving empty spaces after pulp removal in the pulpitis state. However, in teeth where gangrenous pulp extirpation was performed, lateral condensation was endangered by pushing the paste through beyond the apex. Both anomalies were likely to predispose to the development of apical periodontitis. PMID:9673569

Ratajczak, K; Gawor, J

1998-04-01

449

Survival time of endodontically treated teeth: a 7-year retrospective clinical study  

NASA Astrophysics Data System (ADS)

The aim of this retrospective clinical study was to examine the survival time of endodontically treated teeth (ETT) and the factors that may influence the failure risk, over a period of up to 7 years. The files of 67 patients that received metal free post and core restorations using a standardized technique were analyzed. The survival probability was assessed using Kaplan-Meyer analysis and Log Rank (Matel-Cox). Cox regression was used to assess the risk of failure and to identify possible covariates. The average survival time of the ETT was 6.6 Years. The cumulative failure rate was 5.82% for all type of the restored endodontically treated teeth. The main failure type was encountered in the cervical area of the teeth, and due to the extensive hard tissue loss, the teeth were extracted.

Baldea, Bogdan; Canjau, Silvana; Popescu, Dragos; Tudor, Anca; Todea, Carmen

2014-01-01

450

A kind of potential permanent magnet film  

NASA Astrophysics Data System (ADS)

Fe48Co52 nanowire arrays with various diameters and interpore distances were fabricated by electrochemical deposition. The dependences of the permanent magnetic properties on the diameter and interpore distance of the nanowire were investigated. The magnetic dipolar interaction among nanowires was employed to explain the experimental results. After annealing at 550°C, the excellent permanent magnetic properties were obtained. The coercivity Hc is 3.99kOe, the squareness Mr/Ms is 0.96, and the maximum energy product of the whole composite film (BH)mf is estimated to be 7.1MGOe, which avails Fe-Co nanowire arrays prospective as a kind of potential permanent magnet film.

Su, H. L.; Ji, G. B.; Tang, S. L.; Chen, W.; Li, Z.; Gu, B. X.; Du, Y. W.

2005-06-01

451

Permanent magnet array for the magnetic refrigerator  

NASA Astrophysics Data System (ADS)

Recent research into the development of magnetic refrigeration (MR) operating at room temperature has shown that it can provide a reliable, energy-efficient cooling system. To enhance the cooling power of the magnetic refrigerator, it is required to use a magnetic refrigerant material with large magnetocaloric effect (MCE) at the appropriate temperature. Most advanced magnetic refrigerant materials show largest MCE at high applied magnetic fields generated by a superconducting magnet. For application of MCE to air conditioners or household refrigerators, it is essential to develop a permanent magnet array to form a compact, strong, and energy-efficient magnetic field generator. Generating a magnetic field well above the remanence of a permanent magnet material is hard to achieve through conventional designs. A permanent magnet array based on a hollow cylindrical flux source is found to provide an appropriate geometry and magnetic field strength for MR applications.

Lee, S. J.; Kenkel, J. M.; Pecharsky, V. K.; Jiles, D. C.

2002-05-01

452

Laced permanent magnet quadrupole drift tube magnets  

SciTech Connect

Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.

Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.

1989-03-01

453

IN VITRO WEAR RESISTANCE OF THREE TYPES OF POLYMETHYL METHACRYLATE DENTURE TEETH  

PubMed Central

The wear resistance of denture teeth is important to the longevity of removable prostheses of edentulous patients. The ability of denture teeth to maintain a stable occlusal relationship over time may be influenced by this property. The purpose of this in vitro study was to evaluate the wear resistance of polymethyl methacrylate (PMMA) denture teeth based on their chemical composition when opposed by a ceramic antagonist. The maxillary canines (n=10) of 3 PMMA denture teeth (Trubyte Biotone, cross-linked PMMA; Trilux, highly cross-linked IPN (interpenetrating polymer network)-PMMA; and Vivodent, highly cross-linked PMMA) were secured in an in vitro 2-body wear-testing apparatus that produced sliding contact of the specimens (4.5 cycles/s, sliding distance of 20 mm, under 37°C running water) against glazed or airborne particle abraded ceramic. Wear resistance was measured as height loss (mm) under 300 g (sliding force) after 100,000 cycles, using a digital measuring microscope. Mean values were analyzed by 2-way ANOVA and Tukey's test (?=0.05). The wear of Trubyte Biotone (0.93 ± 0.14 mm) was significantly higher than that of both other types of teeth tested against abraded ceramic (p<0.05). The Vivodent tooth (0.64 ± 0.17 mm) exhibited the best wear resistance among the denture teeth tested against airborne particle abraded ceramic. There were no statistically significant differences (p>0.05) in wear among the 3 denture teeth evaluated against glazed ceramic. Trilux and Vivodent teeth tested against either glazed or airborne particle abraded ceramic did not differ significantly from each other (p<0.05). All teeth showed significantly more wear against airborne particle abraded ceramic than against glazed ceramic (p<0.05). In conclusion, the three types of PMMA denture teeth presented significantly different wear resistance against the abraded ceramic. The high-strength PMMA denture teeth were more wear-resistant than the conventional PMMA denture tooth. PMID:19089214

Reis, Katia Rodrigues; Bonfante, Gerson; Pegoraro, Luiz Fernando; Conti, Paulo Cesar Rodrigues; de Oliveira, Pedro Cesar Garcia; Kaizer, Osvaldo Bazzan

2008-01-01

454

Bond Strength and Interfacial Morphology of Different Dentin Adhesives in Primary Teeth  

PubMed Central

Objective: To evaluate the interfacial morphology and the bond strength produced by the three-step, two-step and single-step bonding systems in primary teeth. Materials and Methods: Occlusal surfaces of 72 extracted human deciduous teeth were ground to expose the dentin. The teeth were divided into four groups: (a) Scotchbond Multipurpose (3M, ESPE), (b) Adh Se (Vivadent), (d) OptiBond All-in-One (Kerr) and (e)Futurabond NR (VOCO, Cuxhaven, Germany). The adhesives were applied to each group following the manufacturer’s instructions. Then, teeth from each group were divided into two groups: (A) For viewing interfacial morphology (32 teeth), with 8 teeth in each group, and (B) For measurement of bond strength (40 teeth), with 10 teeth in each group. All the samples were prepared for viewing under SEM. The statistical analysis was done using SPSS version 15.0 software. Results: Observational measurement of tag length in different adhesives revealed that Scotchbond had the most widely spread values with a range from 12.20 to 89.10?m while OptiBond AIO had the narrowest range (0 to 22.50). The bond strength of Scotchbond Multipurpose was significantly higher (7.4744±1.88763) (p<0.001) as compared to Futurabond NR (3.8070±1.61345), Adhe SE (4.4478 ± 1.3820) and OptiBond-all-in-one (4.4856±1.07925). Conclusion: The three-step bonding system showed better results as compared to simplified studied bonding systems PMID:24910694

Vashisth, Pallavi; Mittal, Mudit; Goswami, Mousumi; Chaudhary, Seema; Dwivedi, Swati

2014-01-01

455

All-optical broadband variable optical attenuators and switches in plasmonic teeth waveguides  

Microsoft Academic Search

All-optical broadband variable optical attenuators (VOAs) and switches based on plasmonic teeth shaped waveguides have been proposed and numerically investigated. The Finite Difference Time Domain (FDTD) simulation results reveal that VOAs based on three teeth structure filled with CdSe-doped PMMA can continuously attenuate the power of a light beam from 3.7dB to 39dB within a broad forbidden band by an

Jin Tao; Xu Guang Huang; Ji Huan Chen; Jia Hu Zhu

2010-01-01

456

All-optical broadband variable optical attenuators and switches in plasmonic teeth waveguides  

Microsoft Academic Search

All-optical broadband variable optical attenuators (VOAs) and switches based on plasmonic teeth shaped waveguides have been proposed and numerically investigated. The Finite Difference Time Domain (FDTD) simulation results reveal that VOAs based on three teeth structure filled with CdSe-doped PMMA can continuously attenuate the power of a light beam from 3.7 dB to 39 dB within a broad forbidden band

Jin Tao; Xu Guang Huang; Ji Huan Chen; Jia Hu Zhu

2010-01-01

457

Effects of orthodontic load on the periodontium of autogenously transplanted teeth in beagle dogs*  

PubMed Central

Objective: To observe the periodontal healing of autogenously transplanted teeth loaded orthodontically after autotransplantation in Beagle dogs. Methods: Forty-eight teeth were autogenously transplanted, 24 of which were loaded postoperatively with orthodontic force at different time points and for different durations. Periodontal healing was evaluated by probing pocket depth (PPD), the expression of relevant proteins, and histomorphometric analyses. Results: The dental pockets of loaded and non-loaded teeth were both much deeper after the first postoperative week than before transplantation (P<0.05). Later, the PPD, which was measured after postoperative weeks 1, 3, 5, 9 and 13, gradually became shallow. The expressions of alkaline phosphatase (ALP) and basic fibroblast growth factor (bFGF) were higher in loaded teeth than in non-loaded teeth (P<0.05), and in groups subjected to two weeks duration of loading than in other groups at the same load time point (P<0.05). For the same load duration, the expressions of ALP and bFGF in teeth loaded after postoperative week 4 were higher than those of other treatments (P<0.05). According to histomorphometric analyses, an orthodontic force on transplanted teeth applied after postoperative weeks 4 or 8 for two weeks duration should be favorable for periodontal healing. Conclusions: It is advisable to apply an appropriate magnitude of force on autotransplanted teeth, such as orthodontic force, at appropriate time points and for a suitable duration, to achieve the optimal clinical prognosis following autogenous tooth transplantation. These results may serve as a basis for subsequent studies in humans so as to make clinical improvements. PMID:24190448

Lu, Lu; Sun, Hui-fang; Xue, Han; Guo, Jing; Chen, Yang-xi

2013-01-01

458

Socio-demographic inequalities and teeth extraction in the last 12 months in Italy  

PubMed Central

Summary Aims Teeth loss represents a major concern for the global oral health status of a population. The aim of this study was to describe the prevalence of teeth extraction among the Italian adult population, analyzing the association between teeth extraction in the last 12 months and socio-demographic characteristics. Methods This cross-sectional study is based on the national survey ‘Health Conditions and Healthcare Services Use’, carried out by the Italian National Centre of Statistics (ISTAT) in 2005. A univariate analysis was performed to investigate the association between the dependent and the independent variables (teeth extraction Vs socio-demographic characteristics). Multiple logistic regression analysis was conducted to assess the influence on the outcome (teeth extraction Yes/No). Results The present study highlights the relationship between teeth extraction and socio-demographic factors. Out of 128,040 individuals, the sampled population consisted of 124,677 subjects, representing 56,400,323 individuals in the Italian population. The prevalence of teeth extraction in the last 12 months was 8.2%. Subjects who underwent teeth extraction in the last 12 months were prevalent female (8.6%), smokers (10.4%), with a primary education (9.2%), married (9.2%), in poor health conditions (9.3%), age category of 55–64 years (11.1%), from Northeast of Italy (8.5%), with scarce household income (8.4%). The multivariate analysis confirmed most of the results of the univariate analysis. Conclusions Inequalities in health among groups of various socioeconomic status constitute one of the main challenges for public health; these inequalities might be reduced by improving educational opportunities, income distribution, health-related behaviour, or accessibility to health care. PMID:25774248

La Torre, Giuseppe; Romeo, Umberto; Iarocci, Gianluca; Brugnoletti, Orlando; Semyonov, Leda; Galanakis, Alexandros; Barbato, Ersilia

2014-01-01

459

Modern restorative management of patients with congenitally missing teeth: 3. Conventional restorative options and considerations.  

PubMed

Restoration of spaces in hypodontia patients needs to take into account many factors including, the number of missing teeth, the distribution of space, the size of the teeth, and the age of the patient. This paper considers adhesive and conventional bridgework, as well as removal alternatives for the restoration of spaces. The various merits of each are discussed, together with treatment planning considerations for such cases. PMID:17348556

Bishop, Karl; Addy, Liam; Knox, Jeremy

2007-01-01

460

Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time  

PubMed Central

Isolated small theropod teeth are abundant in vertebrate microfossil assemblages, and are frequently used in studies of species diversity in ancient ecosystems. However, determining the taxonomic affinities of these teeth is problematic due to an absence of associated diagnostic skeletal material. Species such as Dromaeosaurus albertensis, Richardoestesia gilmorei, and Saurornitholestes langstoni are known from skeletal remains that have been recovered exclusively from the Dinosaur Park Formation (Campanian). It is therefore likely that teeth from different formations widely disparate in age or geographic position are not referable to these species. Tooth taxa without any associated skeletal material, such as Paronychodon lacustris and Richardoestesia isosceles, have also been identified from multiple localities of disparate ages throughout the Late Cretaceous. To address this problem, a dataset of measurements of 1183 small theropod teeth (the most specimen-rich theropod tooth dataset ever constructed) from North America ranging in age from Santonian through Maastrichtian were analyzed using multivariate statistical methods: canonical variate analysis, pairwise discriminant function analysis, and multivariate analysis of variance. The results indicate that teeth referred to the same taxon from different formations are often quantitatively distinct. In contrast, isolated teeth found in time equivalent formations are not quantitatively distinguishable from each other. These results support the hypothesis that small theropod taxa, like other dinosaurs in the Late Cretaceous, tend to be exclusive to discrete host formations. The methods outlined have great potential for future studies of isolated teeth worldwide, and may be the most useful non-destructive technique known of extracting the most data possible from isolated and fragmentary specimens. The ability to accurately assess species diversity and turnover through time based on isolated teeth will help illuminate patterns of evolution and extinction in these groups and potentially others in greater detail than has previously been thought possible without more complete skeletal material. PMID:23372708

Larson, Derek W.; Currie, Philip J.

2013-01-01

461

Dental age estimation through volume matching of teeth imaged by cone-beam CT  

Microsoft Academic Search

A custom-made voxel counting software for calculating the ratio between pulp canal versus tooth volume based on cone-beam CT tooth images was developed and evaluated. The aim of this study was to attempt establishing a correlation between the chronological age of a certain individual and the pulp\\/tooth volume ratio of one of the teeth. Twenty-eight single rooted teeth of 19

Fan Yang; Reinhilde Jacobs; Guy Willems

2006-01-01

462

Dental age estimation through volume matching of teeth imaged by cone-beam CT  

Microsoft Academic Search

A custom-madevoxel counting software for calculating the ratio between pulp canal versus tooth volume based on cone-beam CT tooth images was developed and evaluated. The aim of this study was to attempt establishing a correlation between the chronological age of a certain individual and the pulp\\/tooth volume ratio of one of the teeth. Twenty-eight single rooted teeth of 19 individuals

Fan Yang; Reinhilde Jacobs; Guy Willems

2006-01-01

463

[Biologico-periodontal considerations in restoration of teeth partially destroyed by caries or traumatism].  

PubMed

Since a great number of teeth could be rehabilitated and not extracted, in this paper we analyze the relation Perio-protesis by the point of the biology of marginal periodontal ligament, and the different options to establish this relations when are lost by decay or traumatism. We discuss the contraindications to avoid greater problems than benefits when intend to rehabilitate lost teeth. PMID:1975497

Carrillo Martínez, J J; Zermeño Ibarra, J A; Mercado Martínez, E G; Villanueva Neuman, Y; Castellanos Olmedo, R

1990-01-01

464

Pink teeth in a series of bodies recovered from a single shipwreck.  

PubMed

Pink teeth have most often been observed in victims of drowning but have also been reported in subjects who died suddenly and unnaturally. There is general agreement that there is no obvious connection between the occurrence of pink teeth and the cause of death, but the condition of the surroundings (especially humidity) must certainly play an important role in the development of the pink-tooth phenomenon. The frequency and distribution of postmortem pink coloration of the teeth have been studied among a representative sample of 52 cadavers. All the bodies were victims of a single shipwreck that occurred on March 13, 1997, in the middle of the Otranto Canal (Mediterranean Sea). The bodies were recovered from the seawater after approximately 7 months. A distinct pink coloration of the teeth was found in only 18 cadavers (13 females and 5 males) of ages ranging between 13 and 60 years. The phenomenon was more pronounced in younger individuals due to age-related changes of the root canal, less penetrable by the pigment responsible for the postmortem pink staining. By histochemical methods and autofluorescence, hemoglobin and its derivatives have been identified as the most likely pigments responsible for this postmortem process that can be considered analogous to postmortem lividity. These data are consistent with previous reports on pink teeth, indicating that the diffusion of the blood in the pulp into the dentinal tubules causes the red discoloration of the teeth. Based on the results, the pigmentation is more prominent on the teeth with single roots rather than in the posterior teeth with multiple roots. PMID:17133027

Campobasso, Carlo P; Di Vella, Giancarlo; De Donno, Antonio; Santoro, Valeria; Favia, Gianfranco; Introna, Francesco

2006-12-01

465

In situ Raman spectroscopic studies of the teeth of the chiton Acanthopleura hirtosa  

Microsoft Academic Search

In situ Raman spectroscopy, in combination with energy dispersive spectroscopy, has been used for the first time to determine\\u000a the identities and locations, at the micron level, of mineral phases present in single chiton teeth that have been extensively\\u000a mineralized. At the later stages of development the major lateral teeth of the chiton Acanthopleura hirtosa show characteristic spectroscopic evidence for

Alasdair P. Lee; John Webb; D. J. Macey; Wilhelm van Bronswijk; Angela R. Savarese; G. Charmaine de Witt

1998-01-01

466

Magnetic and Structural Properties of Magnetite in Radular Teeth of Chiton Acanthochiton Rubrolinestus  

Microsoft Academic Search

The major radular lateral teeth of Polyplacophora Chiton comprise a magnetite biomineral cap.We have investigated the structure and magnetic properties of the biomineralized magnetite crystallites in mature teeth of Chiton Acanthochiton Rubrolinestus. From the measurement of magnetic properties of tooth particles using SQUID magnetometry we find that the saturation magnetization and the Verwey transition temperature (Tv) are 78.4 emu\\/g and

Y. N. Han; C. L. Liu; L. D. Yao; Y. Wang; X. F. Han

2008-01-01

467

The phylogeny of permanent prostate brachytherapy  

PubMed Central

Permanent prostate brachytherapy has been practiced for more than a century. This review examines the influence of earlier procedures on the modern transperineal ultrasound-directed technique. A literature review was conducted to examine the origin of current clinical practice. The dimensions of the modern brachytherapy seed, the prescription dose, and implant/teletherapy sequencing are vestigial features, which may be suboptimal in the current era of low-energy photon-emitting radionuclides and computerized dose calculations. Although the modern transperineal permanent prostate implant procedure has proven to be safe and effective, it should undergo continuous re-evaluation and evolution to ensure that its potential is maximized. PMID:23878553

Aronowitz, Jesse N.

2013-01-01

468

Vertical bone growth following autotransplantation of the developing maxillary third molar to replace a retained mandibular permanent molar: a case report.  

PubMed

A retained permanent mandibular first molar caused arrested development and a defect of the alveolar bone in a 16-year-old girl. Extraction of the ankylosed tooth was immediately followed by autotransplantation of the developing maxillary third molar. At the 3-year follow-up examination the interproximal bone level at the autotransplanted molar was equal to that of the neighboring teeth. Cone beam computed tomography showed bone at the labial aspect of the transplant. The eruption of the autotransplanted tooth stimulated vertical alveolar bone development and repaired the bone defect. Additionally, there was closure of the posterior open bite that was initially present at the ankylosed molar site. PMID:25171037

Plakwicz, Pawe?; Czochrowska, Ewa Monika; Milczarek, Anna; Zadurska, Malgorzata

2014-01-01

469

Invasion of Ureaplasma diversum in bovine spermatozoids  

PubMed Central

Background Ureaplasma diversum has been associated with infertility in cows. In bulls, this mollicute colonizes the prepuce and distal portion of the urethra and may infect sperm cells. The aim of this study is to analyze in vitro interaction of U. diversum isolates and ATCC strains with bovine spermatozoids. The interactions were observed by confocal microscopy and the gentamycin internalization assay. Findings U. diversum were able to adhere to and invade spermatozoids after 30 min of infection. The gentamicin resistance assay confirmed the intracellularity and survival of U. diversum in bovine spermatozoids. Conclusions The intracellular nature of bovine ureaplasma identifies a new difficulty to control the reproductive of these animals. PMID:22032232

2011-01-01