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1

Dental fluorosis in bovine temporary teeth  

SciTech Connect

Deciduous incisors from calves born to dams fed an average of 40 mg of fluoride/kg of forage ration (40 ppm) were compared with incisors from calves born to dams fed a normal dairy ration. Skeletal fluoride concentration in the calves born to fluoride-fed dams was increased 5 to 8 fold, but enamel mottling and hypoplasia, typical of permanent bovine incisor dental fluorosis were not seen by gross, histologic, or radiologic examination. Decreases in the amount of enamel on the tooth or hardness of the enamel were not observed. These data do not support recent reports of widespread dental fluorosis of deciduous bovine teeth as a clinical sign of fluoride toxicity.

Suttie, J.W.; Clay, A.B.; Shearer, T.R.

1985-02-01

2

Traumatic intrusion of permanent teeth. Part 1. An epidemiological study of 216 intruded permanent teeth.  

PubMed

An epidemiological study of traumatic intrusion of permanent teeth was performed on 216 teeth in 151 patients treated over a 50-year period at a major trauma center in Denmark (Copenhagen). This analysis showed that intrusion of permanent teeth was of rare injury only affecting 1.9% of traumatic injuries involving permanent teeth. The main etiologic factor appeared to be falling which resulted in axial impacts on maxillary or mandibular teeth. The most common injury patterns were intrusion without additional injuries (33.5%) and intrusion with crown fractures (60.5%). A few cases were combinations of intrusion and either crown/root-fractures or root fractures (6%). Most often one tooth was intruded (46.3%), followed by two teeth (32.4% ) and three or more teeth (21.3%). The majority of intruded teeth were displaced 2-8 mm. The age group of 6-12 years of age was most frequently involved and boys appeared to experience intrusion injuries more frequently than girls, and at an earlier age. Maxillary central and lateral incisors are the primary victims of intrusions and this seems to be identical to other trauma types and is possibly related to the known exposure to impacts of maxillary incisors. The reliability of clinical findings, such as lack of mobility (81.8%), metallic percussion tone (72.5%), and no pain to percussion (66%) was reasonably high, whereas a radiographic feature such as the obliteration of the periodontal ligament space appeared to be only a partly reliable diagnostic tool (52%). PMID:16499631

Andreasen, Jens Ove; Bakland, Leif K; Matras, Rannva C; Andreasen, Francis Meriam

2006-04-01

3

Dental fluorosis in bovine temporary teeth  

Microsoft Academic Search

Deciduous incisors from calves born to dams fed an average of 40 mg of fluoride\\/kg of forage ration (40 ppm) were compared with incisors from calves born to dams fed a normal dairy ration. Skeletal fluoride concentration in the calves born to fluoride-fed dams was increased 5 to 8 fold, but enamel mottling and hypoplasia, typical of permanent bovine incisor

J. W. Suttie; A. B. Clay; T. R. Shearer

1985-01-01

4

Supernumerary occlusal cusps on permanent human teeth  

Microsoft Academic Search

Supernumerary (central) cusps that appear on the occlusal surface of the teeth have already been grouped by many authors. The most comprehensive grouping of central cusps on the premolars is that by Schulze (1987). However, different central cusp forms may occur on the molar teeth, and cusp-like protrusions may also develop on the incisors and the canines. In the present

Gábor S Kocsis; Antónia Marcsik; Erzsébet L Kókai; Katalin S Kocsis

5

Interim storage of avulsed permanent teeth.  

PubMed

This literature review examines the effects of extra-alveolar duration and storage conditions on the healing of the periodontal ligament (PL) of avulsed teeth following replantation. A critical assessment of the so-called "reconstitution theory" for PL cells is also presented. The ideal treatment for an avulsed tooth is immediate replantation (i.e. less than five minutes). Unfortunately, immediate replantation is not the norm, and most avulsed teeth experience delayed replantation. The greatest risk to the vitality of the PL cells attached to the root of an avulsed tooth is desiccation. Not surprisingly, storage media affect PL healing. Storing avulsed teeth in an isotonic liquid is superior to dry storage. Numerous studies support the use of Modified Eagle's Medium, Hank's Balanced Salt Solution (HBSS), ViaSpan, saline, milk, and saliva as storage media. A recent study has suggested that chicken egg white may also prove to be a suitable storage medium for avulsed teeth. Of these media, only saliva is always present at the scene of an accident, however. Milk can usually be obtained on short notice, but even 10 minutes of desiccation can affect the outcome of replantation. From a practical standpoint, milk packed in ice seems to be the best alternative for the temporary storage of avulsed teeth, due to its wide availability and the minimal detrimental effects it has on PL cells. There is no evidence to support the suggestion that HBSS or any other media will "reconstitute" the PL cells when the extra-alveolar duration of avulsed teeth is greater than 30 minutes. PMID:9648418

Layug, M L; Barrett, E J; Kenny, D J

1998-05-01

6

[Injuries to the permanent teeth. Periodontal lesions].  

PubMed

Tooth luxations are relatively common. In case of concussion or subluxation the tooth is not displaced. The treatment will consist of relief of the tooth. Most frequent complications are pulp necrosis and obliteration of pulpal tissues. In case of extrusive luxation pulpal tissues and the periodontal ligament are injured. When tooth mobility is increased flexible splinting should be considered. Endodontic treatment is necessary after extrusive luxation of a tooth with completed root formation. Teeth with open apex often show pulpal obliteration after extensive luxation. Lateral luxation is more complex than extrusive luxation since the alveolar bone is also damaged. Repositioning and splinting of the tooth are necessary. When the apical foramen in closed, endodontic treatment will be necessary. Teeth with incomplete root formation will develop pulp obliteration. Following lateral luxation, external root resorption and loss of marginal bone are not infrequent. Intrusive luxation is the type of trauma with most unfavorable prognosis. All intruded teeth will become necrotic and external root resorption and marginal bone loss are frequent. There is no consensus regarding the therapeutic approach. Orthodontic extrusion or surgical mobilisation are possible options. In case of avulsion, both the pulpal tissues and the periodontal ligament are disrupted. Preservation of the vitality of the periodontal ligament covering the root will determine the prognosis of the reimplanted tooth. Therefore the tooth will be repositioned as soon as possible. When this is not possible, milk or a specific solution are most appropriate for tooth conservation. When the reimplanted tooth has complete root formation, devitalization will be performed one week after after repositioning. In case of a tooth with open apex revascularisation can be awaited. Healing of the periodontal ligament will determine prognosis. When a normal ligament is obtained during healing or when surface resorption is obtained, the tooth can be preserved for a long period. When progressive replacement resorption (ankylosis) develops, most teeth can remain in position for about 10 years. When inflammatory resorption develops, the tooth will be lost within a short time. PMID:9951347

Vinckier, F; Declerck, D; Verhaeghe, V; Vanassche, K

1998-01-01

7

Maturation of primary and permanent teeth in preterm infants  

PubMed Central

AIMS—To elucidate the development of primary and permanent teeth and to interpret the effect of different calcium, phosphorus, and vitamin D supplementation in the neonatal period on dental maturation in preterm children.?METHODS—Preterm infants were randomised to four groups to receive a vitamin D dose of 500 or 1000 IU/day and calcium and phosphorus supplemented or unsupplemented breast milk. The maturity of the primary and permanent teeth was recorded in 30 preterm children. Sixty children aged 2 years and 60 children aged 9-11 years served as controls. Bone mineral content/density was assessed in the preterm infants.?RESULTS—The median (range) corrected teething age was 7 (2-16) months in preterm infants and 6 (2-12) months in controls (p = 0.43). The median (range) number of erupted teeth at 2 years of age was 16 (11-19) in preterm infants and 16 (12-20) in controls (p = 0.16). Maturation of the permanent teeth in the preterm infants was not delayed compared with the controls (mean Demirjian SDS 0.16 v 0.49, p = 0.14). Early dietary intake of either mineral or vitamin D did not affect maturation of the primary dentition in preterm children. Children receiving the higher vitamin D dose in the neonatal period had more mature permanent dentition than those receiving the lower dose, but mineral intake did not affect maturation of the permanent teeth. Dental maturation did not correlate with bone mineral status.?CONCLUSIONS—This is the first longitudinal study to follow primary and permanent tooth maturation in the same preterm children. Premature birth has no appreciable late sequelae in tooth maturation.??

Backstrom, M; Aine, L; Maki, R; Kuusela, A; Sievanen, H; Koivisto, A; Ikonen, R; Maki, M

2000-01-01

8

Comparative analysis of human and bovine teeth: radiographic density.  

PubMed

Since bovine teeth have been used as substitutes for human teeth in in vitro dental studies, the aim of this study was to compare the radiographic density of bovine teeth with that of human teeth to evaluate their usability for radiographic studies. Thirty bovine and twenty human teeth were cut transversally in 1 millimeter-thick slices. The slices were X-rayed using a digital radiographic system and an intraoral X-ray machine at 65 kVp and 7 mA. The exposure time (0.08 s) and the target-sensor distance (40 cm) were standardized for all the radiographs. The radiographic densities of the enamel, coronal dentin and radicular dentin of each slice were obtained separately using the 'histogram' tool of Adobe Photoshop 7.0 software. The mean radiographic densities of the enamel, coronal dentin and radicular dentin were calculated by the arithmetic mean of the slices of each tooth. One-way ANOVA demonstrated statistically significant differences for the densities of bovine and human enamel (p < 0.05) and for bovine and human coronal dentin (p < 0.05). No statistically significant differences were found for the bovine and human radicular dentin (p > 0.05). Based on the results, the authors concluded that: a) the radiographic density of bovine enamel is significantly higher than that of human enamel; b) the radiodensity of bovine coronal dentin is statistically lower than the radiodensity of human coronal dentin; bovine radicular dentin is also less radiodense than human radicular dentin, although this difference was not statistically significant; c) bovine teeth should be used with care in radiographic in vitro studies. PMID:19148391

Tanaka, Jefferson Luis Oshiro; Medici Filho, Edmundo; Salgado, José Antônio Pereira; Salgado, Miguel Angel Castillo; Moraes, Luiz Cesar de; Moraes, Mari Eli Leonelli de; Castilho, Julio Cezar de Melo

9

Eruption Time of Permanent Teeth in Pakistani Children  

PubMed Central

Background: To determine the mean eruption time of permanent teeth of Pakistani children and to evaluate the effects of gender, type of schools, height, weight and body mass index on it. Methods: This cross sectional study was conducted from September 2007 to April 2008. 4370 children of ‘just erupted’ teeth were obtained from 102 randomly selected schools from 18 towns of Karachi, using systematic random sampling procedure. The dental examination was carried out for the selected child. Height, weight and date of birth were also obtained. Two sample‘t’ test and paired ‘t’ test were employed to compare the mean time of eruption between gender and type of schools (private/ public), and upper and lower jaws. Pearson and partial correlations were used to determine the significant relationship between eruption time with height, weight and BMI. Results: The right first molars of upper and lower jaws showed the minimum eruption time. Second molars were the last tooth to emerge. Only 3 teeth showed significant difference of eruption time between the genders. None of contralateral teeth showed any statistical significant difference. All the mandible teeth, except the premolars, erupted earlier than maxillary teeth. Private schools children showed early eruption than the public schools children. The Pearson and partial correlation were significant positively correlated with height. Eruption time of all the teeth, except one, showed positive correlation with weight. Conclusion: The eruption time of Pakistani children are different in many aspects with to other nationalities.

Khan, N

2011-01-01

10

[Age and content of certain mineral components in permanent teeth].  

PubMed

The chemical composition of the teeth is determined during its development, however, in the postdevelopmental period changes of inorganic components are possible, which have an important effect on the morphology, structure and chemical composition of teeth. Using the method of X-ray fluorescence the levels of Ca, P, Cl, S, K and Zn were determined in hard tissues of 218 permanent non-carietic teeth from all dental groups. The correlation between these various elements in the teeth and the age of the subjects, whose teeth were taken for the investigations, was expressed with the correlation coefficient r of Pearson. The significance of the correlation was analysed using Students t test. In case of significant correlation equations of regression were determined for predicting the expected value of the level of a given element in teeth for a given age. No significant differences were noted in the levels of Ca and P in relation to age. The levels of S, K and Zn rose with age, while the chloride content was decreasing. PMID:2640644

Struzak-Wysoki?ska, M; Kot, I

1989-02-01

11

Influence of Water Fluoridation on the Eruption of Permanent Teeth  

Microsoft Academic Search

The mean eruption times of permanent teeth before and after fluoridation of drinking water over a period of 12 years have been studied in a population of approximately 57,000 children (aged 4.04–15.09 years) living in the cities of Karl-Marx-Stadt (1.0 ppm of fluoride) and Plauen (0.2 ppm of fluoride). A direct effect of ingested fluoride on eruption has been excluded

W. Künzel

1976-01-01

12

Maturogenesis of non-vital immature permanent teeth  

PubMed Central

Pulpal necrosis in young permanent teeth often results in teeth with open apex, thin root walls and poor crown root ratio. Out of the available treatment options maturogenesis has been the most conservative option that exploits full potential of pulp for dentin deposition. Maturogenesis involves disinfecting the root canal system followed by stimulation of blood clot from the periapical tissue, which provides a matrix into which the cell could grow and sealing the coronal excess. In the present case report, tri antibacterial paste (3 Mix) was used as an intracanal medicament that proved successful in stimulating vital pulp cells of the periapical region for maturogenesis. Five months radiograph follow-up showed thickening of lateral dentinal walls, which progress until 15 months resulting in apical closure, thickening of lateral dentinal walls and increase root length.

Kalaskar, Ritesh R.; Kalaskar, Ashita R.

2013-01-01

13

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

14

Survey of anomalies in primary teeth and their correlation with the permanent dentition.  

PubMed

The purpose of the study was to investigate primary and permanent tooth anomalies of 5-year-old children in Taranaki; 1,680 children were examined by school dental therapists, and the presence of hypodontia, hyperdontia, and double teeth recorded. Panoramic radiographs were taken of those children with anomalies of the primary teeth. Anomalies of the primary teeth were detected in 23 children (1.4 percent). Six children (3 boys and 3 girls) had hypodontia, 3 children (2 boys and 1 girl) had a supernumerary tooth, and 14 children (9 boys and 5 girls) had double teeth. Six of the affected teeth (in 4 boys and 2 girls) were diagnosed as fusion, and 8 (5 boys and 3 girls) as gemination. The panoramic radiographs of the 23 children with anomalies of the primary teeth revealed that 14 (60.9 percent) also had anomalies of the succedaneous permanent teeth. Children with hypodontia in the primary dentition all had corresponding permanent teeth missing. In all but three children, only one tooth was involved. Nineteen of the 30 primary teeth (63 percent) and 12 of the 15 permanent teeth (80 percent) affected by hypodontia, gemination, or fusion were lateral incisors. For each type of anomaly, boys were affected more often than girls. The results of the study confirm that, when there is hypodontia, hyperdontia, gemination, or fusion of teeth in the primary dentition, there is an increased likelihood of anomalies of the succedaneous permanent teeth. Because of this close relationship between the dentitions, early identification of anomalies of the primary teeth can allow the dentist to investigate further and plan for treatment at the appropriate time. PMID:8649664

Whittington, B R; Durward, C S

1996-03-01

15

[Splinting technique for traumatic luxation of anterior permanent teeth].  

PubMed

Extrusive luxations of both, upper and lower incisors, represent a frequent event in dental traumatology. The Authors present some cases in which elastic splints have been used. In fact recent researches show that, even soon after a traumatic event, is not indicated to immobilize teeth with rigid fixed splints because they don't allow any dental function. It is therefore preferable the use of elastic splints for 2-4 weeks, instead of rigid splints for long periods. The Authors then describe the techniques, the methods and the radiographic controls and pulp tests used in this kind of traumatic pathology, showing the positive long term results obtained by using elastic splints instead of rigid splints which often present as result root resorptions or pulp necrosis. In fact with elastic splints is possible to replace and maintain luxated teeth, allowing at the same time a certain function of teeth and their support tissues. PMID:2076432

Caprioglio, D; Ronchin, M; Zappa, G

16

Dental agenesis patterns of permanent teeth in Apert syndrome.  

PubMed

Dental agenesis may either occur as an isolated trait (non-syndromic) or as a component in a congenital syndrome. The aim of the present study was to identify the prevalence of dental agenesis for each type of tooth and to look for dental agenesis patterns in persons with Apert syndrome. Serial panoramic radiographs of 23 individuals (five male patients and 18 female patients) were examined. Third molars were excluded. The prevalence of agenesis for at least one tooth was 34.8%. Up to two missing teeth were found for individuals with Apert syndrome. Maxillary lateral incisors and mandibular second premolars were the most frequently missing teeth. Four different dental agenesis patterns of the entire dentition were identified by using the tooth agenesis code (TAC). Two patterns occurred more frequently, both of which were symmetrical. One involved the simultaneous absence of teeth 12 and 22, and the other showed agenesis of teeth 35 and 45. In conclusion, patients with Apert syndrome were found to exhibit a high prevalence of dental agenesis. All dental agenesis patterns in which more than one tooth was missing were symmetrical. PMID:21564313

Stavropoulos, Dimitrios; Bartzela, Theodosia; Bronkhorst, Ewald; Mohlin, Bengt; Hagberg, Catharina

2011-04-26

17

Periapical and endodontic status of permanent teeth in patients with hypophosphatemic rickets.  

PubMed

Hypophosphatemic rickets (HR) is a rare hereditary disease in which dental problems in terms of spontaneous periapical infections are frequently reported. Most previous reports have been based on a small number of HR patients and have been published before the disease could be confirmed genetically. The aim of the present study was to describe the periapical and endodontic status of permanent teeth in patients with genetically and/or biochemically confirmed HR. The patients were recruited from a medical study on HR patients. The patients underwent a dental examination including a digital panoramic radiograph, which was scored for endodontically affected teeth (i.e. teeth with periapical radiolucencies and/or endodontically treated teeth). A total of 52 patients (age range: 5·7-74·5?years; 17 males and 35 females) were included. HR patients were characterised by a high number of endodontically affected teeth (mean: 4·2; s.d.: 5·0). The number of affected teeth rose significantly with age (P?teeth in the three tooth groups (incisors and canines, premolars, and molars) varied according to age. In the youngest age group, only incisors and canines were affected, while the relative proportion of affected premolars and molars increased with age. Endodontically affected teeth are common in HR patients, and the number of affected teeth increased significantly with age. Hence, the need for endodontic treatment among HR patients is comprehensive. PMID:21902707

Andersen, M G; Beck-Nielsen, S S; Haubek, D; Hintze, H; Gjørup, H; Poulsen, S

2011-09-08

18

Surgical management of multiple supernumerary teeth and an impacted maxillary permanent central incisor.  

PubMed

Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. It is a developmental anomaly and has been argued to arise from multiple aetiologies. The most common site is the maxillary incisor region; but the prevalence of more than three teeth supernumerary tooth is less than 1%. A case of 13 year male patient is reported with a multiple impacted supernumerary tooth in maxillary anterior region hindering the eruption of right permanent central incisor. The supernumerary tooth was treated via surgical approach followed by an interim prosthesis for permanent central incisor which later on erupted in due course of time. Background Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. The presence of supernumerary teeth in the premaxillary region often poses unique diagnostic and managerial concerns for the practitioner. Rarely is the surplus number compensated by an absence or deficiency of other teeth. Therefore, the dysfunctional nature of supernumerary teeth and their ability to create a variety of pathological disturbances in the normal eruption and position of adjacent teeth warrants their early detection and prudent management. Approximately 76-86% of cases represent single-tooth hyperdontia, with two supernumerary teeth noted in 12-23% and three or more extra teeth noted in less than 1% of cases. Multiple supernumerary teeth are also associated with many syndromes like cleidocranial dysplasia and Gardner’s syndrome etc. However, it is rare to find multiple supernumeraries in individuals with no other associated disease or syndrome. In such cases, the maxillary anterior region is the common site of occurrence. The exact aetiology is not clearly understood. The supernumerary teeth result from any disturbance in the initiation and proliferation stages of odontogenesis. There are several theories regarding the development of a supernumerary tooth-phylogenetic reversion (atavism) theory, dichotomy of tooth germ theory and hyperactivity of the dental lamina. The latter being the most accepted theory, states that the remnants of dental lamina or palatal offshoots of active dental lamina are induced to develop into an extra tooth bud, which results in the formation of a supernumerary tooth. Genetics is also considered to contribute to the development of supernumerary teeth, as these have been diagnosed in twins, siblings and sequential generations of a family. Classification of supernumerary teeth may be on the basis of position or form. Positional variations include mesiodens, paramolars, distomolars and parapremolars. Variations in form consist of conical types, tuberculate types, supplemental teeth and odontomes. Supernumerary teeth may, therefore, vary from a simple odontome, through a conical or tuberculate tooth to a supplemental tooth which closely resembles a normal tooth. Also, the site and number of supernumeraries can vary greatly. This report presents a case of a non-syndromic male patient with multiple supernumerary teeth and a permanent impacted tooth in the maxillary anterior region. PMID:23704467

Rallan, Mandeep; Rallan, Neelakshi Singh; Goswami, Mousumi; Rawat, Kamini

2013-05-22

19

Root lengths in the permanent teeth of Klinefelter (47,XXY) men  

Microsoft Academic Search

Earlier studies on human teeth have provided proof of an expression of the X and Y chromosome genes in tooth crown growth. The Y chromosome promotes the growth of permanent tooth crown enamel and dentin, whereas the effect of the X chromosome seems to be restricted mainly on enamel formation. Also, there are evidences that both of the sex chromosomes

Raija Lähdesmäki; Lassi Alvesalo

2007-01-01

20

Penetration of 38% Hydrogen Peroxide into the Pulp Chamber in Bovine and Human Teeth Submitted to Office Bleach Technique  

Microsoft Academic Search

This study evaluated the pulp chamber penetration of peroxide bleaching agent in human and bovine teeth after office bleach technique. All the teeth were sectioned 3 mm apical of the cement-enamel junction and were divided into 2 groups, A (70 third human molars) and B (70 bovine lateral incisors), that were subdivided into A1 and B1 restored by using composite

Samira Esteves Afonso Camargo; Marcia Carneiro Valera; Carlos Henrique Ribeiro Camargo; Maria Nadir Gasparoto Mancini; Marcia Maciel Menezes

2007-01-01

21

Histological study of therapy for infected nonvital permanent teeth with incompletely formed apices.  

PubMed

The histological response of periapical tissues to root canal fillings with calcium hydroxide (Ca(OH)2)-iodoform paste, Vitapex (Neo Dental Chemical Products Co., Ltd., Tokyo, Japan), and Ca(OH)2-camphorated paramonochlorophenol (CMCP) paste in nonvital permanent teeth with incompletely formed apices was investigated in 160 root canals from 90 dog premolar and incisor teeth. Periapical inflammatory lesions were initially induced in the experimental teeth. After debridement and cleaning, root canals were filled with one of the two materials. The animals were sacrificed after 30, 60, 120, or 180 days, and histological sections of each specimen were prepared with hematoxylin and eosin staining. Histological findings showed periapical repair and apical closure in both experimental groups. However, the differences in the level of inflammation, apical closure, and reparative process among the two groups were significant (p less than 0.05). It was concluded that the Ca(OH)2-iodoform paste, Vitapex, produced better results than Ca(OH)2-CMCP paste in treatment of infected nonvital permanent teeth with incompletely formed apices. PMID:1819442

Fujii, H; Machida, Y

1991-02-01

22

Regional odontodysplasia of the deciduous and permanent teeth associated with eruption disorders: A case report.  

PubMed

Regional odontodysplasia (RO) is an unusual, non-hereditary anomaly of the dental hard tissues with characteristic clinical, radiographic and histological findings. Clinically, RO affects the primary and permanent dentition in the maxilla and mandible or both jaws. Radiographically, there is a lack of contrast between the enamel dentin, both of which are less radiopaque than unaffected counterparts. Additionally, enamel and dentin layers are thin, giving the teeth a "ghost-like" appearance. Histologically, areas of hypocalcified enamel are visible and enamel prisms appear irregular in direction. Coronal dentin is fibrous, consisting of clefts and a reduced number of dentinal tubules; radicular dentin is generally more normal in structure and calcification. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. The treatment of RO has given rise to controversy. These cases require a continuous and multidisciplinary approach. Most clinicians advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement. Other clinicians prefer restorative procedures, if possible, to protect the affected erupted teeth. A case of RO in an 8 year-old male whose chief complaint was the absence of eruption of permanent teeth is presented. Clinical, radiographic and histological findings are described. PMID:18758400

Gündüz, Kaan; Zengin, Zeynep; Celenk, Peruze; Ozden, Bora; Kurt, Murat; Gunhan, Omer

2008-09-01

23

The role of endodontics in the treatment of luxated permanent teeth.  

PubMed

Pulp necrosis is a common complication following traumatic dental injuries and is related to the type and severity of the injury, as well as to the stage of development of the injured tooth. Endodontic intervention is required when there are clinical and radiographic signs of pulpal infection and its sequelae. Arrested tooth development with periradicular pathosis, external inflammatory root resorption, sinus tract formation and pain on percussion are indicative of root-canal infection in the post-traumatized teeth, and require immediate endodontic treatment. The use of calcium hydroxide in the treatment of teeth with post-traumatic pulp necrosis and its sequelae has been shown to be extremely beneficial for the long-term retention of the injured teeth. Calcium hydroxide has been shown to arrest and repair external inflammatory root resorptive defects, eliminate the endodontopathic microorganisms from the root canal system and induce hard-tissue barrier formation at the apex of non-vital immature teeth. This paper reviews the endodontic treatment required by post-traumatic non-vital permanent teeth. PMID:12184211

Barnett, Frederic

2002-04-01

24

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

25

A possible association between early apical resorption of primary teeth and ectodermal characteristics of the permanent dentition.  

PubMed

The hypothesis of this study is that children with unexpected early apical resorption of the primary teeth are also predisposed to resorption in the permanent dentition. Accordingly, the aim was to perform a longitudinal study focussing on the permanent teeth in children with unexpected early apical resorption in the primary dentition. Panoramic radiographs of 12 children (7 boys and 5 girls) aged 6 years 4 months to 8 years 9 months with unexpected early apical resorption of primary teeth were identified from a dental archive of 588 patients. After written request, follow-up radiographs were obtained (2-15 year interval between early and follow-up radiographs). The radiographs were examined in order to verify the abnormal resorption pattern of the primary teeth and dental deviations in the permanent teeth, known to predispose for root resorption (i.e. invaginations, narrow crowns, abrupt root deflections, slender roots, short roots, taurodontia, agenesis, deviant pattern of eruption). Primary dentition: Two phenotypically different resorption groups were identified: group I, eight patients (resorption of the roots only), and group II, four patients (resorption of root and crown). Permanent dentition: In all 12 children, dental deviations in the permanent dentition were observed. Additionally, idiopathic external apical resorption of the permanent teeth was seen in three children, two of whom had received orthodontic treatment. PMID:18678755

Bille, M L B; Kvetny, M J; Kjaer, I

2008-08-01

26

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.

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.; S?rensen, Thorkild I. A.; Melbye, Mads

2011-01-01

27

Radiographic and histologic evaluation of the effect of two concentrations of formocresol on pulpotomized primary and young permanent teeth in monkeys  

Microsoft Academic Search

The behavior of pulp tissue under two concentrations of formocresol was evaluated radiographically and histologically in pu\\/potomized primary and young permanent monkey teeth. A faster resorption rate of the roots of the treated primary teeth was observed with both concentrations. Evidence of vital tissue as expressed by continued root development was observed in the permanent teeth of both treated groups,

Anna B. Fuks

1983-01-01

28

Parental knowledge and attitudes regarding the emergency treatment of avulsed permanent teeth  

PubMed Central

Objective: The aim of this study was to examine parental knowledge and attitudes about avulsed permanent teeth and their emergency treatment in children. Methods: A total of 289 parents of children aged 6–12 years receiving care at the Ondokuz Mayis University Pediatric Dentistry Clinic were included in the study. Questionnaires were used to collect data on parents’ demographic characteristics, previous training in traumatic dental injury and treatment and knowledge of avulsed permanent teeth and their emergency management. Chi-square tests were used to identify differences in responses for different variables. Results: More than half of the participating parents were female (69.6%) and between the age of 30–39 years (64.4%). Most (90.7%) reported that they would not replant the avulsed tooth in its socket, and most (68.2%) gave correct answers regarding the optimum time for which an avulsed tooth should be left out of the mouth prior to replantation. However, most parents were not sufficiently informed about the appropriate method for cleaning a dirty avulsed tooth or transporting it to a dentist or doctor. None of the demographic characteristics or training status was found to have a statistically significant effect on the number of correct responses regarding appropriate management of avulsion injuries (P>.05) Conclusion: This study revealed that the parental level of knowledge about the emergency treatment of avulsion in children is inadequate and that educational campaigns are necessary to improve proper emergency management of dental avulsion.

Ozer, Sezin; Yilmaz, Elif Ipek; Bayrak, Sule; Tunc, Emine Sen

2012-01-01

29

Prevalence of enamel defects in primary and permanent teeth in a group of schoolchildren from Granada (Spain)  

PubMed Central

Objective: The purpose of this study was to determine and compare the prevalence and presentations of developmental defects of the enamel (DDE) in the primary and permanent dentitions of a group of healthy schoolchildren residing in Granada (Spain). Study Design: A total of 1,414 healthy schoolchildren were examined using modified DDE criteria for recording enamel defects. Results: The prevalence of DDE of any type was 40.2% in primary dentition and 52% in permanent dentition (p<0.033). Of the 31,820 primary and permanent teeth examined in the study, 699 (4.1%) primary and 1,232 (8.3%) permanent teeth had some form of DDE. Diffuse opacity was the most common type of DDE observed in primary teeth, and demarcated opacity in the permanent teeth. Enamel hypoplasia was the least prevalent defect in both dentition types. Conclusions: The study population showed a high prevalence of DDE in primary as well as in permanent dentition, reflecting the current increasing trend of this condition, which should be considered as a significant public health problem. Key words:Developmental enamel defects, enamel hypoplasia, demarcated opacity, diffuse opacity.

Robles, Maria J.; Bravo-Perez, Manuel; Gonzalez, Encarnacion; Penalver, Maria A.

2013-01-01

30

Assessment of some elements in human permanent healthy teeth, their dependence on number of metallic amalgam fillings, and interelements relationships.  

PubMed

In this study, 60 human permanent healthy teeth (without filling) were collected postmortem and analyzed using flame atomic absorption spectrometry (FAAS), cold vapor atomic absorption spectrometry (CVAAS), hydride generation atomic absorption spectrometry (HGAAS), and electrothermal atomic absorption spectrometry (ETAAS) for the determination of Ca, Hg, Se, Cu, and Ag. The concentration of these elements was assessed in carious and noncarious teeth, different tooth groups, with age and with number of amalgam fillings. A negative correlation was found between Ca and the number of amalgam fillings, and significant negative correlations were found between Ca and three other metals (Hg, Ag, and Cu) that indicate the possibility of substitutions of Ca by three other metals. Significant positive correlations were found among the number of amalgam fillings and Hg, Ag, Cu and Se showed metal concentration in permanent healthy teeth were affected by the presence of the number of amalgam filling. In addition, significant positive correlations between Hg and Ag, Hg and Cu, and Ag and Cu proved the suspicion that the Hg content in permanent healthy teeth was mainly found because of the influence of amalgam filling, not from other sources. Moreover, the significant positive correlation between Hg-Se and Ag-Se showed the formation of mercuric selenide and silver selenide complexes as part of a natural mechanism of detoxification. Consequently, the permanent healthy teeth would be considered as a bioindicator for the accumulation of long-term exposure of Hg and Ag. PMID:17646685

Saber-Tehrani, Mohammad; Givianrad, Mohammad H; Kahkashan, Parvin

2007-05-01

31

No evidence for effectiveness of interventions used to treat displaced permanent anterior teeth.  

PubMed

Data sourcesThe Cochrane Oral Health Group Trials register, Cochrane Central Register of Controlled trials (CENTRAL), Medline, Embase, LILACS and Dissertation, Theses and Abstracts databases.Study selectionRandomised controlled trials or quasi-randomised controlled trials that included a minimum follow-up period of 12 months.Data extraction and synthesisTwo review authors independently and in duplicate assessed the eligibility of all reports identified in the searches. Authors were contacted for additional information where required.ResultsNo randomised or quasi-randomised controlled trials were found.ConclusionsWe found no randomised or quasi-randomised trials of interventions to treat displaced luxated permanent front teeth. Current clinical guidelines are based on available information from case series studies and expert opinions. Randomised controlled trials in this area of dental trauma are required to robustly identify the benefits of different treatment strategies. PMID:24071677

Elkhadem, Ahmed; Nagi, Passant

2013-09-01

32

Effect of acidulated phosphate fluoride gel application time on enamel demineralization of deciduous and permanent teeth.  

PubMed

Although the effect of acidulated phosphate fluoride gel (APF gel) on caries reduction in permanent teeth is based on evidence, the relevance of the clinical application time is still under debate. Also, the effect of 4- versus 1-min application has not been evaluated in deciduous enamel. In a blind, crossover, in situ study of 14 days, 16 adult volunteers wore palatal appliances containing slabs of human permanent and deciduous enamel. At the beginning of each phase, the slabs were submitted to one of the following treatments: no APF application (negative control); APF gel (1.23% F) application for 1 or 4 min. Biofilm accumulation on the slab surface was allowed and the slabs were subjected eight times a day to 20% sucrose, simulating a high cariogenic challenge condition. On the 15th day of each phase, fluoride retained as CaF(2) and fluorapatite (FAp) was determined on the enamel of the slabs and demineralization was assessed by cross-sectional microhardness. Fluoride as CaF(2) and FAp, formed by APF gel application on the enamel slabs not subjected to the cariogenic challenge, was also determined. APF gel reduced demineralization in both enamel types (p < 0.05), but the difference between 1 and 4 min was not statistically significant (p > 0.05). CaF(2) and FAp formed and retained on deciduous and permanent enamel was significantly higher in APF gel groups (p < 0.05), but no significant difference was found between 1 and 4 min (p > 0.05). The findings suggest that 1 min of APF gel application provides a similar effect on inhibition of demineralization as 4 min, for both permanent and deciduous enamel. PMID:22237162

Calvo, A F B; Tabchoury, C P M; Del Bel Cury, A A; Tenuta, L M A; da Silva, W J; Cury, J A

2012-01-12

33

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

2012-01-18

34

Traumatic intrusion of permanent teeth: 10 years follow-up of 2 cases.  

PubMed

Intrusive luxation is a kind of traumatic injury characterized by an axial displacement of the tooth toward the alveolar bone. Its main causes are bicycle accidents, sports/recreational activities, and falls or collisions. Treatment strategies include waiting for the tooth to return to its position, immediate surgical repositioning, and repositioning through dental traction by orthodontic devices. In order to decide which treatment to follow, the degree of root formation, the patient's age, and intrusion severity should be taken into consideration. This study aimed to report a 10-year follow-up of two patients that suffered permanent incisor (PI) traumatic injury who had a similar root development (incomplete rooting) but different results. In the first case, the treatment of choice was follow-up. The patient showed gingival alteration and root resorption of tooth 21. Calcium hydroxide therapy and root canal filling were performed twice because of not attending callback. After finishing the endodontic treatment, follow-up visits showed no abnormalities. In the second case, the treatment of choice was watch and wait to the teeth 11 and 21. After 7 months spontaneous eruption of both teeth was detected. Radiographic examination showed atypical root formation and almost completely pulp canal obliteration, 8 years later. In the follow-up, visit after 10 years was observed complete crow and pulp canal obliteration. It was concluded that PI intrusion treatments are good intervention alternatives, as they proved to be successful after a 10-year follow-up period. PMID:22251243

Gomes, Genara Brum; da Costa, Catiara Terra; Bonow, Maria Laura Menezes

2012-01-18

35

Pulpal blood flow in vital and nonvital young permanent teeth measured by transmitted-light photoplethysmography: a pilot study  

Microsoft Academic Search

Purpose: The purpose of this study was to record transmitted-light photoplethys- mography (TLP) from young permanent teeth and examine its applicability to pulp vitality assessment. Methods: Twenty-six healthy and 7 nonvital upper maxillary incisors in 17 children (ages 7 years, 3 months to 14 years, 8 months) were examined. Recordings of TLP were made with and without opaque black rubber

Zenzo Miwa; Motohide Ikaw; Hideyo Iijima; Makoto Saito; Yuzo Takagi

2002-01-01

36

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

37

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…

Lind, Patricia; Germano, Catherine

38

[Determining the overall density of permanent human teeth and its relation to the carrier's age (author's transl)].  

PubMed

(1) The pyknometer method was used to determine the specific gravity of the roots, central portions (necks), and crowns of 130 human teeth (incisors, canines, premolars, molars) obtained during autopsies. The overall density or specific gravity was calculated as the mean of the values obtained for these portions of permanent teeth. To test the relation between the total specific gravity and the carrier's individual age, a simple linear regression was calculated. It was not possible for a definite relation to be found between the specific gravities of teeth and the age of their carriers. (2) Limits to determining the individual age from the specific gravity of teeth are set especially by the factors discussed in this paper, by pathological influences, and by variations of specific gravity within isolated hard dental tissue. In human teeth, age-dependent physiosclerosis of bradytrophic tissue obviously is in the form of re- or transmineralization without major changes in the degree of mineralization and is usually overlapped by other phenomena. In addition, preparative and technical faults may result in false specific gravities being obtained. (3) Specific gravities of portions of teeth and total specific gravities determined therefrom cannot be used to find the carrier's age and, therefore, should be dismissed as means of identifying age by methods of forensic stomatology. PMID:160159

Heuschkel, H J; Koch, R; Süssmann, H

1979-01-01

39

Update on Nonsurgical, Ultraconservative Approaches to Treat Effectively Non-Cavitated Caries Lesions in Permanent Teeth  

PubMed Central

Dental caries on tooth surfaces is still a problem in many industrialized countries. For many years, dentistry was influenced by a mechanical approach characterized by the use of high-speed rotary cutting instruments, and dentists predominantly used surgical methods to address caries. This included radical removal of diseased portions of the tooth, along with material-driven geometric extensions to areas that were assumed to be caries-resistant. This concept of extension for prevention was introduced by G. V. Black and influenced dentists for more than 120 years. Recently, a new paradigm of operative conservatism, sometimes referred to as “minimally invasive dentistry,” has gained popularity. This paradigm is designed to promote maximum preservation of healthy dental structures over a lifetime. The aim of this review is to discuss the efficacy of current nonsurgical treatments for non-cavitated caries lesions in permanent teeth. Based on results obtained from clinical trials, this review evaluates treatments such as consumption of CPP-ACP added gums, resin infiltration and fissure sealing. Although in a few cases an invasive approach is needed to arrest caries progression, the non-surgical approach generally provides potential benefits that include conserving structure by delaying intervention or minimizing the operative procedure. All current non-invasive methods are effective in treating non-cavitated caries lesions. The adoption of non-invasive approaches in the management of these lesions can preserve dental tissues, thus increasing tooth longevity.

Borges, Boniek Castillo Dutra; de Souza Borges, Juliane; de Araujo, Larissa Sgarbosa Napoleao; Machado, Claudia Tavares; dos Santos, Alex Jose Souza; de Assuncao Pinheiro, Isauremi Vieira

2011-01-01

40

Update on nonsurgical, ultraconservative approaches to treat effectively non-cavitated caries lesions in permanent teeth.  

PubMed

Dental caries on tooth surfaces is still a problem in many industrialized countries. For many years, dentistry was influenced by a mechanical approach characterized by the use of high-speed rotary cutting instruments, and dentists predominantly used surgical methods to address caries. This included radical removal of diseased portions of the tooth, along with material-driven geometric extensions to areas that were assumed to be caries-resistant. This concept of extension for prevention was introduced by G. V. Black and influenced dentists for more than 120 years. Recently, a new paradigm of operative conservatism, sometimes referred to as "minimally invasive dentistry," has gained popularity. This paradigm is designed to promote maximum preservation of healthy dental structures over a lifetime. The aim of this review is to discuss the efficacy of current nonsurgical treatments for non-cavitated caries lesions in permanent teeth. Based on results obtained from clinical trials, this review evaluates treatments such as consumption of CPP-ACP added gums, resin infiltration and fissure sealing. Although in a few cases an invasive approach is needed to arrest caries progression, the non-surgical approach generally provides potential benefits that include conserving structure by delaying intervention or minimizing the operative procedure. All current non-invasive methods are effective in treating non-cavitated caries lesions. The adoption of non-invasive approaches in the management of these lesions can preserve dental tissues, thus increasing tooth longevity. PMID:21494394

Borges, Boniek Castillo Dutra; de Souza Borges, Juliane; de Araujo, Larissa Sgarbosa Napoleao; Machado, Claudia Tavares; Dos Santos, Alex Jose Souza; de Assunçao Pinheiro, Isauremi Vieira

2011-04-01

41

Prevalence of talon cusps in Jordanian permanent teeth: a radiographic study  

PubMed Central

Background The aim of the study is to investigate the prevalence of talon cusps in a sample of Jordanians dental patients and their distribution among different types of teeth. Methods The data were collected from radiographic examination of 3,024 periapical films showing 9,377 teeth from a random sample of 1,660 patients. A tooth was considered having talon cusp if there was a V-shape radiopaque structure superimposed the tooth structure. Results Talon cusps were detected in 52 teeth (tooth prevalence = 0.55%). Maxillary canines were the most commonly affected teeth (46% of cases), followed by maxillary lateral incisor teeth (39% of cases) and maxillary central incisors teeth (15% of cases). Teeth with talon cusps were found in 40 subjects (person prevalence = 2.4%). Bilateral talon cusps were seen in 12 patients. Conclusions Attention should be paid to the presence of talon cusp and the treatment problems associated with it.

2010-01-01

42

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth.  

PubMed

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth. PMID:22409417

Andersson, Lars; Andreasen, Jens O; Day, Peter; Heithersay, Geoffrey; Trope, Martin; Diangelis, Anthony J; Kenny, David J; Sigurdsson, Asgeir; Bourguignon, Cecilia; Flores, Marie Therese; Hicks, Morris Lamar; Lenzi, Antonio R; Malmgren, Barbro; Moule, Alex J; Tsukiboshi, Mitsuhiro

2012-04-01

43

Teeth number anomalies in permanent dentition among non-syndromic dental patients.  

PubMed

The aim of this study was to establish teeth number anomalies in relation to gender, tooth type, location, distribution pattern and the association between frequently missing teeth among a group of dental patients in Turkey. A total of 378 non-syndromic patients (240 females and 138 males) with an age range of 7-45 (x +/- SD = 22.07 +/- 3.6) having evidence of absent or excess teeth were evaluated in the study. Pearson Chi-square, Fisher's exact, McNemar and Kappa coefficients were used for statistical analysis. 237 patients had a total of 546 congenitally missing teeth and 141 had 185 excess teeth. Congenitally missing teeth were more commonly seen rather than the presence of supernumerary teeth. Difference was determined in the frequent locations of congenital missing and supernumerary teeth. The most frequent missing tooth type was found to be the mandibular second premolar (26.6%), while the majority of supernumerary teeth were located in the anterior region of the maxillary arch (37.9%). Both teeth number anomalies were more commonly seen among females. In hypodontia cases the occurrence of symmetrical agenesis of laterals and second premolars in maxilla; centrals and second premolars in mandible was notable. Agenesis of mandibular centrals was found to be associated with maxillary lateral agenesis in males. Also higher prevalence of molar teeth agenesis was determined in the occurrence of at least 4 teeth agenesis. These findings will serve as information about the contemporary demographic pattern of teeth number anomalies among non-syndromic Turkish dental patients and can provide evidence that agenesis of some teeth symmetrically or together are the products of the same genetic mechanisms. PMID:23697259

Aslan, Belma I?ik; Akarslan, Zühre Zafersoy

2013-03-01

44

Concentration of selected elements in the roots and crowns of both primary and permanent teeth with caries disease  

Microsoft Academic Search

We examined the differences between the concentrations of chemical elements in caries-changed primary teeth and permanent\\u000a ones with a division into the root and the crown. The study comprised 27 children aged from 4 to 11 yr and 36 adults aged\\u000a from 36 to 71 yr. We examined the elements with the total reflection X-ray fluorescence method. The lowest concentrations

Barbara Gierat-Kucharzewska; Janusz Braziewicz; Urszula Majewska; Stanis?aw Gó?dz; Antoni Karasi?ski

2003-01-01

45

Penetration of 38% hydrogen peroxide into the pulp chamber in bovine and human teeth submitted to office bleach technique.  

PubMed

This study evaluated the pulp chamber penetration of peroxide bleaching agent in human and bovine teeth after office bleach technique. All the teeth were sectioned 3 mm apical of the cement-enamel junction and were divided into 2 groups, A (70 third human molars) and B (70 bovine lateral incisors), that were subdivided into A1 and B1 restored by using composite resin, A2 and B2 by using glass ionomer cement, and A3 and B3 by using resin-modified glass ionomer cement; A4, A5, B4, and B5 were not restored. Acetate buffer was placed in the pulp chamber, and the bleaching agent was applied for 40 minutes as follows: A1-A4 and B1-B4, 38% hydrogen peroxide exposure and A5 and B5, immersion into distilled water. The buffer solution was transferred to a glass tube in which leuco crystal violet and horseradish peroxidase were added, producing a blue solution. The optical density of the blue solution was determined by spectrophotometer and converted into microgram equivalents of hydrogen peroxide. Data were submitted to analysis of variance and Dunnett, Kruskal-Wallis, and Tukey tests (5%). A higher level of hydrogen peroxide penetrated into the pulp chamber in resin-modified glass ionomer cements in bovine (0.79 +/- 0.61 microg) and human (2.27 +/- 0.41 microg) groups. The bleaching agent penetration into the pulp chamber was higher in human teeth for any experimental situation. The penetration of the hydrogen peroxide depends on restorative materials, and under the conditions of this study human teeth are more susceptible to penetration of bleaching agent into the pulp chamber than bovine teeth. PMID:17931936

Camargo, Samira Esteves Afonso; Valera, Marcia Carneiro; Camargo, Carlos Henrique Ribeiro; Gasparoto Mancini, Maria Nadir; Menezes, Marcia Maciel

2007-05-23

46

Determinants of Loss of Permanent Teeth. Final Report for Phase 2.  

National Technical Information Service (NTIS)

Tooth loss remains an important problem. Caries and periodontal diseases are acknowledged to be the predominant pathological conditions associated with tooth loss. Previous studies indicate that a significant percentage of extracted teeth are restorable (...

T. Beazoglou J. Bader J. Crall D. Heffley D. Shugars

1996-01-01

47

Determinants of Loss of Permanent Teeth. Final Report for Phase 1.  

National Technical Information Service (NTIS)

Tooth loss remains an important problem. Caries and periodontal diseases are acknowledged to be the predominant pathological conditions associated with tooth loss. Previous studies indicate that a significant percentage of extracted teeth are restorable (...

T. Beazoglou J. Bader J. Crall D. Heffley D. Shugars

1994-01-01

48

Comparison of lead levels in human permanent teeth from Strasbourg, Mexico City, and rural zones of Alsace  

SciTech Connect

A comparative study of the mean lead concentrations in enamel and dentin of human premolars and permanent molars was conducted by means of a systematic sampling procedure with energy-dispersive x-ray fluorescence analysis. In a first series of analyses, no significant statistical differences in mean lead concentrations at various levels of enamel and dentin were noted between young patients of Strasbourg and those of small villages of Alsace, nor between elderly patients living in these two locations, despite the fact that motor traffic was significantly lower in the rural zones. However, in both locations, a significantly higher concentration of lead was observed in enamel and dentin in relation to age. In a second series of analyses, the mean lead concentrations of both dental hard tissues of premolars and permanent molars of young individuals from Strasbourg, rural Alsace, and Mexico City were compared. Significantly higher mean lead concentrations were found in enamel and dentin samples from Mexico City. This was most evident for inner coronal dentin (5.7 and 6.1 times greater than in teeth of Strasbourg and rural zones of Alsace, respectively) and for pulpal root dentin (6.9 and 8.9 times greater than in teeth of Strasbourg and rural zones of Alsace). It is proposed that the higher lead concentrations are related to the higher lead content of motor gasoline and to more intense traffic conditions. The dental hard tissues appear to be of value for the study of environmental lead pollution.

Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J. (Univ. Louis Pasteur, Strasbourg (France))

1990-01-01

49

Evaluation of experimental permanent-magnet brushless motor utilizing new magnetic material for stator core teeth  

Microsoft Academic Search

We prepared motors with experimental cores using a soft magnetic composite and an amorphous metal and evaluated their performance. We measured the magnetic and motor characteristics, such as iron loss, when the new materials were used in the stator core teeth. The amorphous metal was found to have very high permeability and low iron loss, whereas the soft magnetic composite

Y. Enomoto; M. Ito; H. Koharagi; R. Masaki; S. Ohiwa; C. Ishihara; M. Mita

2005-01-01

50

Results after replantation of avulsed permanent teeth. II. Periodontal healing and the role of physiologic storage and antiresorptive-regenerative therapy.  

PubMed

The status of the periodontal ligament (PDL) and of the pulp are decisive for the healing of avulsed and replanted teeth. A tooth rescue box was developed and distributed to offer optimal storage conditions for avulsed teeth. The therapy comprised extraoral endodontic treatment and applications of medicaments to enhance periodontal healing. In this long-term clinical study the healing results following avulsion and replantation were investigated. Twenty-eight permanent teeth in 24 patients were evaluated. The extraoral storage media and periods varied considerably. Soon after avulsion six teeth were stored in a cell culture medium (tooth rescue box Dentosafe) for 1-53 h; the PDL was defined as not compromised. Sixteen teeth were stored in a non-physiologic situation temporarily, the PDL was considered as compromised. Six teeth were stored in non-physiologic conditions for longer periods; the condition of the PDL was defined as hopeless. On 14 teeth antiresorptive-regenerative therapy (ART) with the local application of glucocorticoids and enamel matrix derivative and the systemic administration of doxycyclin was used. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. The mean observation period was 31.2 months (+/-24.1; 5.1-100.2; median: 23.8). All six teeth rescued physiologically healed with a functional PDL (functional healing, FH) irrespective of the storage period. Of eight teeth with a compromised PDL on which ART was used, three teeth healed with a functional PDL. All other teeth showed replacement resorption, in three teeth additionally infection-related resorption was recorded. The predominant influence on the healing results was the immediate physiologic rescue of avulsed teeth (chi-square, P = 0.0001). The use of ART seemed to support FH (chi-square, P = 0.0547) in teeth with a compromised PDL. No other factors (maturity of roots, crown fractures, gender, age, antibiotics) were related to healing. In a linear regression analysis physiologic storage (P = 0.0013) and ART (P = 0.0421) were related to FH. For a good prognosis avulsed teeth should be stored immediately in a cell-compatible medium. Therefore the tooth rescue box should be distributed at places with higher risks of accidents, in families with children and in emergency facilities. The use of ART might have potential for enhancing the prognosis of teeth with a PDL that is compromised but not in a hopeless condition. Extraoral endodontic treatment reduces infection-related complications; this item was discussed in the first part of the publication. PMID:15773888

Pohl, Yango; Filippi, Andreas; Kirschner, Horst

2005-04-01

51

Unerupted Primary Molar Teeth Positioned Inferior to the Permanent Premolar: A Case Report  

PubMed Central

Primary tooth impaction is a rare finding during the development of primary dentition. Several factors contribute to the impaction of a deciduous tooth. This report describes the diagnosis and treatment of a 10-year-old boy who presented an impacted second primary mandibular molar. This tooth, located inferior to the second premolar together with an odontoma, was positioned superior to the premolar teeth. Treatment consisted of surgical removal of the impacted deciduous tooth and odontoma and placement of a passive lower lingual holding arch. Periodic examination was indicated for follow-up. Early intervention was recommended to manage orofacial disfigurement and to avoid consequent problems.

Memarpour, M.; Rahimi, M.; Bagheri, A.; Mina, K.

2012-01-01

52

Direct pulp capping with a dentin adhesive resin system in children's permanent teeth after traumatic injuries: case reports.  

PubMed

Traumatic injuries in the permanent teeth of children and adolescents are one of the most frequent causes of dental treatment. The article presents the use of an enamel and dentin adhesive resin system, Syntac, and resin composite materials, Tetric and Variolink, as materials of choice for direct pulp capping after traumatic pulpal exposure (Ellis Class III). Exposed pulp in 10 patients was covered with Syntac and then Tetric and Variolink after etching of dental tissues with phosphoric acid. The follow-up period was from 12 to 48 months. In 1 patient, the treatment was a failure. In the remaining 9 patients, no signs or symptoms of pulpal inflammation or necrosis were observed during the clinical examination. PMID:11203931

Górecka, V; Suliborski, S; Biskupski, T

2000-04-01

53

Bond strengths of nine current dentine adhesive systems to primary and permanent teeth.  

PubMed

The aim of this study was to compare the shear bond strength (SBS) of nine dentine bonding systems (DBS) of different classes to human primary and permanent dentine. Flat dentine occlusal surfaces were produced on human molars (100 primary, 100 permanent) by wet grinding on a 800-grit SiC paper. Nine DBS were applied following the manufacturers' instructions: One total etch multi-step system: Scotchbond Multipurpose Plus (3M/ESPE); Four total etch one-bottle system: Prime &Bond 2.1 (Dentsply), One Step (Bisco), Scotchbond 1 (3M/ESPE), and OptibondSolo Plus (Kerr); Three two-step self-etching primer systems: Clearfil Liner Bond 2 (Kuraray), Clearfil SE Bond (Kuraray), and Prime &Bond NT with NRC (Dentsply); An 'all-in-one' self-etching system: Prompt L-Pop (3M/ESPE). Composite (Z100; 3M/ESPE) cylinders (2 mm diameter, 3 mm high) were polymerized on the treated dentine surfaces and the specimens were stored at 37 degrees C for 24 h prior to testing. Twenty experimental groups were produced and tested. Statistical analysis revealed both a substrate and a bonding system effect. Two adhesive systems (One Step, Prime &Bond NT) had significantly higher bond strengths on permanent than on primary dentine. There was an effect of dentine bonding system on the mode of fracture. Although eight of the 10 DBS tested exhibited higher median SBS values on permanent dentine than on primary dentine, the dependent pairwise comparison identified a significant difference only for two groups. The use of simplified bonding systems does not necessarily result in improved bond strength to primary or to permanent dentine. PMID:15790385

Courson, F; Bouter, D; Ruse, N D; Degrange, M

2005-04-01

54

In vitro Growth and Characterization of Stem Cells from Human Dental Pulp of Deciduous Versus Permanent Teeth  

PubMed Central

Objective: By date investigations have indicated the presence of stem cells within the pulp tissue of both temporary and permanent human teeth. In the present study, these stem cells were compared in terms of their growth kinetics and culture requirements. Materials and Methods: Stem cells within the pulp of the human third molar (permanent tooth) and the deciduous incisor (temporary tooth) were isolated, culture-expanded and characterized. Then the proliferation potential of the cells was compared using multiple cell growth indices as PDT (Population doubling time), colonogenic activity and growth curve. Furthermore, the cultures of both cells were optimized for maximal proliferation. Results: Stem cells of either pulp tissue appeared as fibroblastic cells capable of differentiating into osteoblastic, odontoblastic, adipocytic and chondrocytic cell lineages. In contrast to molar stem cells, those from the incisor tooth expressed neurogenic markers of ßIII Tubulin and Tau. Based on in vitro growth data, the cells from third molar tended to have a lower PDT value (20.79, SD=2.8 versus 25.55, SD=2.9 hours), higher colonogenic activity and better growth curve than those from the deciduous incisor (P<0.05). Both cells exhibited high expansion rate when being plated in a medium with 20% phosphate buffer solution at a density of 100 cells/cm2. Conclusion: Given the high proliferation capacity, the stem cells from the human third molar would be an appropriate candidate for use in experimental, preclinical and even clinical setups.

Eslaminejad, MR. Baghaban; Vahabi, S.; Shariati, M.; Nazarian, H.

2010-01-01

55

In vitro antimicrobial activity of sodium hypochlorite, chlorhexidine gluconate and octenidine dihydrochloride in elimination of microorganisms within dentinal tubules of primary and permanent teeth.  

PubMed

The aim of this study was to evaluate the effectiveness of different irrigation solutions at different time intervals for the elimination of E. faecalis and C. albicans penetrated into the dentine tubules of primary and permanent teeth in vitro. The 4 mm primary and permanent teeth sections were sterilized and contaminated with a mixture of E. faecalis and C. albicans strains. After the application of different irrigation solutions (Sodium hypochlorite, Chlorhexidine gluconate, Octenidine Dihydrochloride, saline) to the contaminated tooth sections according to study groups, neutralizers were applied for inactivation of the solutions after 30 sec, 1 min and 5 min. Dentine shavings were placed into TSB and 10 µL from each tube was inoculated on agar plates, followed by an incubation period of 24 h at 37°C. The colonies were counted macroscopically. The results were compared by using Kruskal-Wallis and Mann Whitney U tests, with a significance level at p<0.05. Among the irrigation solutions that were tested against E. faecalis on primary and permanent teeth, the most effective one was found as 5-minute application of 0.1% Octenidine Dihydrochloride. The antibacterial effects of the tested solutions on the same time periods against C. albicans revealed no significant difference. There were no statistically significant differences between primary and permanent teeth with respect to the antimicrobial activity of the tested solutions. Moreover, Octenidine Dihydrochloride may be used as an alternative endodontic irrigant. PMID:22143724

Tirali, Resmiye-Ebru; Bodur, Haluk; Ece, Gülden

2012-05-01

56

Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth.  

PubMed

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (± SD, in megapascals) were: 18.51 ± 5.68 in group 1, 8.06 ± 2.69 in group 2, and 17.33 ± 5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application. PMID:21336680

Shahabi, Sima; Bagheri, Hossein G; Ramazani, Kosar

2011-02-19

57

Chlorhexidine does not increase immediate bond strength of etch-and-rinse adhesive to caries-affected dentin of primary and permanent teeth.  

PubMed

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on immediate bond strength of etch-and-rinse adhesive to sound (SD) and caries-affected (CAD) primary dentin compared with permanent dentin. Flat dentin surfaces from 20 primary molars (Pri) and 20 permanent molars (Perm) were assigned to 8 experimental groups (n=5) according to tooth type (Pri or Perm), dentin condition (SD or CAD - pH-cycling for 14 days) and treatment (control - C or 60 s application of 2% CHX solution after acid etching - CHX). The bonding system (Adper Single Bond 2) was applied according to manufacturer's instructions followed by resin composite application (Filtek Z250). After 24 h water storage, specimens with cross-section area of 0.8 mm² were prepared for being tested under microtensile test (1 mm/min). Data were submitted to ANOVA and Tukey's post hoc test (?=0.05). Failure mode was evaluated using a stereomicroscope at ×400. Treatment with CHX did not result in higher bond strength values than no pre-treatment (C groups), independently of tooth type. Primary teeth and caries-affected dentin showed significantly lower (p<0.05) bond strength means compared with permanent teeth and sound dentin, respectively. Predominance of adhesive/mixed failure was observed for all groups. CHX did not influence the immediate bond strength to sound or caries-affected dentin of primary and permanent teeth. PMID:23207863

Lenzi, Tathiane Larissa; Tedesco, Tamara Kerber; Soares, Fabio Zovico Maxnuck; Loguercio, Alessandro Dourado; Rocha, Rachel de Oliveira

2012-01-01

58

Radiopacity of different resin-based and conventional luting cements compared to human and bovine teeth.  

PubMed

This study evaluated the radiopacity of different resin-based luting materials and compared the results to human and bovine dental hard tissues. Disc specimens (N=130, n=10 per group) (diameter: 6 mm, thickness: 1 mm) were prepared from 10 resin-based and 3 conventional luting cements. Human canine dentin (n=10), bovine enamel (n=10), bovine dentin (n=10) and Aluminium (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted and equivalent Al thickness values were determined for radiopacity measurements of each material. The radiopacity values of conventional cements and two resin luting materials (Rely X Unicem and Variolink II), were significantly higher than that of bovine enamel that could be preferred for restorations cemented on enamel. Since all examined resin-based luting materials showed radiopacity values equivalent to or greater than that of human and bovine dentin, they could be considered suitable for the restorations cemented on dentin. PMID:22277608

Pekkan, Gürel; Ozcan, Mutlu

2012-01-21

59

In vitro antimicrobial activity of Sodium hypochlorite, Chlorhexidine gluconate and Octenidine Dihydrochloride in elimination of microor- ganisms within dentinal tubules of primary and permanent teeth  

PubMed Central

The aim of this study was to evaluate the effectiveness of different irrigation solutions at different time intervals for the elimination of E.faecalis and C.albicans penetrated into the dentine tubules of primary and permanent teeth in vitro. The 4 mm primary and permanent teeth sections were sterilized and contaminated with a mixture of E.faecalis and C.albicans strains. After the application of different irrigation solutions (Sodium hypochlorite, Chlorhexidine gluconate, Octenidine Dihydrochloride, saline) to the contaminated tooth sections according to study groups, neutralizers were applied for inactivation of the solutions after 30 sec, 1 min and 5 min. Dentine shavings were placed into TSB and 10µL from each tube was inoculated on agar plates, followed by an incubation period of 24h at 37°C. The colonies were counted macroscopically. The results were compared by using Kruskal-Wallis and Mann Whitney U tests, with a significance level at p<0.05. Among the irrigation solutions that were tested against E.faecalis on primary and permanent teeth, the most effective one was found as 5-minute application of 0.1% Octenidine Dihydrochloride. The antibacterial effects of the tested solutions on the same time periods against C.albicans revealed no significant difference. There were no statistically significant differences between primary and permanent teeth with respect to the antimicrobial activity of the tested solutions. Moreover, Octenidine Dihydrochloride may be used as an alternative endodontic irrigant. Key words:Chlorhexidine gluconate, dentine tubules, irrigation solutions, Octenidine Dihydrochloride, Sodium hypochlorite.

Bodur, Haluk; Ece, Gulden

2012-01-01

60

Radiopacity of different shades of resin-based restorative materials compared to human and bovine teeth.  

PubMed

This study evaluated the radiopacity of different shades of resin-based restorative materials and compared the results to human and bovine dental hard tissues. Disk specimens 6 mm in diameter and 1 mm thick (N = 220, n = 10) were prepared from the following restorative materials: · eight shades of nanofilled composite (Aelite Aesthetic Enamel), · seven shades of nanohybrid composite (Grandio Universal), · six shades of photopolymerized polyacid modified compomer (Glasiosite), and · one shade of hybrid composite (X-tra fil U). Human canine dentin (n = 10), bovine enamel (n = 10), and an aluminum (Al) step wedge were used as references. The optical density values of each material were measured from radiographic images using a transmission densitometer. Al step wedge thickness and optical density values were plotted, and equivalent Al thickness (eq Al) values were determined for radiopacity measurements of each material. The data were analyzed using a non-parametric one-way ANOVA (Kruskal-Wallis), and multiple comparisons were made with a Student-Newman-Keuls post hoc test (a = 0.05). Different shades of resin-based restorative materials tested did not reveal statistically significant differences within each material group (p > 0.05). Radiopacity values of the resin-based restorative materials investigated varied depending on their types; however, within different shades of one material type, radiopacity values were comparable. Every shade of nanocomposite material other than Aelite Aesthetic Enamel Incisal LT Gray showed comparable radiopacity to human dentin. Other materials tested demonstrated higher radiopacity compared to human dentin and bovine enamel. PMID:22782058

Pekkan, Gurel; Ozcan, Mutlu

61

Anomalous findings of number, morphology and size of permanent teeth in 7-10 years children living in the Czech Republic.  

PubMed

6,043 children, who were ordinary patients and children of Caucasian population, were examined clinically and radiographically. 430 children were aged 7-10 years. Dental anomalies were diagnosed in 14.1% (61 children) of those observed between 7-10 years. We aimed at numerical anomalies (78.6% of children with anomalies), morphological anomalies (19.6% of children with anomalies), size anomalies (3.2% of children with anomalies) and combinations of diagnoses (1.4% reflects the combinations of teeth 2 times calculated in combinations of diagnoses). Congenital numerical variations, i.e. hypodontia and hyperodontia, are among the most common deviations of the permanent dentition. Both conditions can occur as isolated traits or in association with other syndromes. Many studies indicate that hereditary factors are involved in the aetiology of anomalies. Gen MSX1 involves a primary position in mediating interactions between epithelium and mesenchyme in the development of teeth. Occurrence of dental anomalies is not very frequent; problems can arise with diagnosis of those affected teeth. It can be done using Orthopantomogram or Computed Tomography and 3D reconstruction. Some of the children with anomalies may have difficulties in treatment of affected teeth but in most cases the prognosis is good. PMID:23777802

Ginzelová, K; Kripnerová, T; Dostálová, T

2013-01-01

62

Delayed endodontic and orthodontic treatment of cross-bite occurring after luxation injury in permanent incisor teeth.  

PubMed

A case is presented in which combined endodontic and orthodontic therapy was performed in traumatically injured teeth 12 months after an accident. Calcium hydroxide treatment was used to halt any possible resorption during orthodontic treatment. The teeth were repositioned in a desirable manner without any complication by orthodontic treatment. Root canal obturation was accomplished after the completion of active orthodontic treatment. Recall examination 12 months after completion of root canal treatment showed clinical and radiographic evidence of healing. PMID:9558513

Cali?kan, M K; Cinsar, A; Türkün, M; Akkemik, O

1997-12-01

63

Penetration of 35% hydrogen peroxide into the pulp chamber in bovine teeth after LED or Nd:YAG laser activation.  

PubMed

This aim of the present study was to evaluate the pulp chamber penetration of 35% hydrogen peroxide activated by LED (light-emitting diode) or Nd:YAG laser in bovine teeth, after an in-office bleaching technique. Forty-eight bovine lateral incisors were divided into four groups, acetate buffer was placed into the pulp chamber and bleaching agent was applied as follows: for group A (n = 12), activation was performed by LED; for group B (n = 12), activation was performed by Nd:YAG laser (60 mJ, 20 Hz); group C (n = 12) received no light or laser activation; and the control group (n = 12) received no bleaching gel application or light or laser activation. The acetate buffer solution was transferred to a glass tube and Leuco Crystal Violet and horseradish peroxidase were added, producing a blue solution. The optical density of this solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. The results were analysed using ANOVA and Tukey's test (5%). It was verified that the effect of activation was significant, as groups activated by LED or laser presented greater hydrogen peroxide penetration into the pulp chamber (0.499 +/- 0.622 microg) compared with groups that were not (0.198 +/- 0.218 microg). There was no statistically significant difference in the penetration of hydrogen peroxide into the pulp chamber between the two types of activation (LED or laser). The results suggest that activation by laser or LED caused an increase in hydrogen peroxide penetration into the pulp chamber. PMID:19655647

Camargo, Samira Esteves Afonso; Cardoso, Paula Elaine; Valera, Marcia Carneiro; de Araújo, Maria Amélia Máximo; Kojima, Alberto Noriyuki

2009-01-01

64

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

PubMed

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

2013-07-01

65

Socio-Demographic Features and Fluoride Technologies Contributing to Higher Fluorosis Scores in Permanent Teeth of Canadian Children  

Microsoft Academic Search

Objective: To examine levels of fluorosis among children in two Canadian communities exposed to flouride. Background: One community had discontinued flouride, the other had maintained it. Water supplies, however, were fluoridated for all the children when their esthetically important teeth were mineralized. Methods: We examined 8,277 children to assess Thystrup-Fejerskov Index (TFI) scores. Multivariate Poisson regression models were used to

G. Maupomé; J. D. Shulman; D. C. Clark; S. M. Levy

2003-01-01

66

Remineralization Effect of Topical NovaMin Versus Sodium Fluoride (1.1%) on Caries-Like Lesions in Permanent Teeth  

PubMed Central

Objective: NovaMin, a synthetic mineral composed of calcium, sodium, phosphorous and silica releases deposits of crystalline hydroxyl-carbonate apatite (HCA) structurally similar to tooth mineral composition. The aim of this investigation was to compare the potential remineralization effect of topical NovaMin and Sodium Fluoride gel on caries like lesions in permanent teeth. Materials and Methods: A total of 60 sound human freshly extracted teeth were subjected to a pH-cycling protocol. Specimens were randomly assigned to one of the two treatment groups with NovaMin contained dentifrice applied to group 1, while group 2 received a dentifrice containing 1.1% neutral Sodium Fluoride. Pastes were applied five times after the samples received a demineralization from an earlier cariogenic challenge. Specimens were then evaluated by a Surface Micro Hardness test (SMH, 25G, 5s). Post-treatment SMH measurements were conducted and Mann Whitney test was employed for statistical analysis. Results: Mean post lesion SMH values were 221.99±26.27 and 224.50±28.64 for the first and second groups, respectively. Post treatment SMH values were 232.52±24.34 for NovaMin and 232.03 ±24.46 for the fluoride group. Two way ANOVA test showed a highly significant difference between the two different treatment protocols (p<0.001). Conclusion: NovaMin dentifrice appears to have a greater effect on remineralization of carious-like lesions when compared to that of fluoride containing dentifrice in permanent teeth.

Vahid Golpayegani, M.; Sohrabi, A.; Biria, M.; Ansari, G.

2012-01-01

67

Evaluation of shear bond strength and interfacial micromorphology of direct restorations in primary and permanent teeth--an in vitro study.  

PubMed

This in vitro study sought to evaluate the bond strength and interfacial morphology of composite restorations in primary and permanent teeth that utilized different adhesive systems. In this study, 180 samples (n = 15 per subgroup) were submitted to shear bond strength tests while 72 samples were analyzed with scanning electron microscopy (n = 6 per subgroup). Fifty-four blocks of permanent enamel, 54 blocks of permanent dentin, 54 blocks of primary enamel, and 54 blocks of primary dentin were randomly assigned to three groups for bonding. All of the blocks received a resin composite restoration made with a matrix after the application of the dental bonding systems, according to the manufacturer's instructions. The shear bond strength test found no statistical differences among the tissues or the adhesive systems used. However, a difference in quality of the interfacial seal was observed when Single Bond restorations were compared to restorations bonded with AdheSE and Prompt-L-Pop. The Single Bond system formed an authentic hybrid layer that can ensure adequate adhesion. The other adhesive systems showed an interface with inadequate sealing and even with no sealing. The self-etching systems must be used with caution in composite restorations because the quality of the hybrid layer formed is as important as the bond strength when determining the efficacy of the adhesive. PMID:18254567

da Costa, Carolina Covolo; Oshima, Hugo Mitsuo Silva; Costa Filho, Luiz Cesar

68

Isolation, characterization and comparative differentiation of human dental pulp stem cells derived from permanent teeth by using two different methods.  

PubMed

Developing wisdom teeth are easy-accessible source of stem cells during the adulthood which could be obtained by routine orthodontic treatments. Human pulp-derived stem cells (hDPSCs) possess high proliferation potential with multi-lineage differentiation capacity compare to the ordinary source of adult stem cells(1-8); therefore, hDPSCs could be the good candidates for autologous transplantation in tissue engineering and regenerative medicine. Along with these benefits, possessing the mesenchymal stem cells (MSC) features, such as immunolodulatory effect, make hDPSCs more valuable, even in the case of allograft transplantation(6,9,10). Therefore, the primary step for using this source of stem cells is to select the best protocol for isolating hDPSCs from pulp tissue. In order to achieve this goal, it is crucial to investigate the effect of various isolation conditions on different cellular behaviors, such as their common surface markers & also their differentiation capacity. Thus, here we separate human pulp tissue from impacted third molar teeth, and then used both existing protocols based on literature, for isolating hDPSCs,(11-13) i.e. enzymatic dissociation of pulp tissue (DPSC-ED) or outgrowth from tissue explants (DPSC-OG). In this regards, we tried to facilitate the isolation methods by using dental diamond disk. Then, these cells characterized in terms of stromal-associated Markers (CD73, CD90, CD105 & CD44), hematopoietic/endothelial Markers (CD34, CD45 & CD11b), perivascular marker, like CD146 and also STRO-1. Afterwards, these two protocols were compared based on the differentiation potency into odontoblasts by both quantitative polymerase chain reaction (QPCR) & Alizarin Red Staining. QPCR were used for the assessment of the expression of the mineralization-related genes (alkaline phosphatase; ALP, matrix extracellular phosphoglycoprotein; MEPE & dentin sialophosphoprotein; DSPP).(14). PMID:23208006

Karamzadeh, Razieh; Eslaminejad, Mohamadreza Baghaban; Aflatoonian, Reza

2012-11-24

69

[Comparing of the results obtained from distalization of the upper molar teeth by applying extraoral forces to permanent and removable appliances].  

PubMed

The purpose of the present study is to compare the experimental and clinical results of permanent and removable appliances on headgears. 3 dimensional photoelastic models were used in the experimental work. On these models, forces applied to face bows which were attached to permanent and removable ancher units. After the experiment sagittal sections prepared and analyzed under polaroscope. The results of the 8 case with removable ancher units and 7 case with permanent ancher units were compared by cephalometric processes. As a result, there was no significant difference between permanent and removable headgears. PMID:2489129

Tezcan, S; Yi?it, M D; Enacar, A

1989-04-01

70

[Dependence of caries protective effect of fluoride varnishes applications on first permanent molars in schoolchildren on the intensity of caries of temporary teeth].  

PubMed

There are four-year clinical research results of the efficacy of the varnishes with different fluoride compounds on first permanent molars in young schoolchildren depending on the lesion of caries of temporary molars. It was determined that for children, whose molars were healthy during the basic examination, the highest caries protective effect was achieved with the help of varnish, containing CaF(2) (the reduction of increase of the intensity of caries of permanent molars formed 59.7%), and for children with initial high lesion of caries of permanent molars the best caries preventive effect was achieved with the varnish "Bifluorid 12®" (the reduction of increase of the intensity of caries of permanent molars formed 52.5%). PMID:22433648

Terekhova, T N; Borutta, A; Shakovets, N V; Klenovskaia, M I; Minchenia, O V

2011-01-01

71

Regional odontodysplasia (Ghost teeth). A case report.  

PubMed

Regional odontodysplasia is a rare development anomaly affecting the teeth with an unknown etiology. This dental abnormality involves the hard tissues of the teeth that are derived from both epithelial (enamel) and mesenchymal (dentine & cementum) components of the tooth forming apparatus. Teeth in a region or quadrant of maxilla or mandible are affected to the extent that they exhibit short roots, wide open apical foramen and large pulp chamber, the thinness and poor mineralisation qualities of th enamel and dentine layers have given rise to a faint radiolucent image, hence the term "Ghost teeth". Both the permanent teeth and the deciduous teeth are affected. Females are more commonly affected than males. There is a maxillary predominance (2.5:1) with a predilection for the anterior teeth. Eruption of the affected teeth is delayed or does not occur. Because of the poor quality of the affected teeth, they cannot be rehabilitated for functional use therefore the treatment of choice is extraction with prosthetic replacement. However, necrosis and facial cellulitis appear to be a complication if these teeth are retained. A unique case of regional odontodysplasia affecting the entire right quadrant of mandible is reported here. PMID:11987665

Kannan, S K; Saraswathi, K

72

Scanning Electron Microscopy of Teeth in Autosomal Dominant Osteogenesis Imperfecta: Support for Genetic Heterogeneity.  

National Technical Information Service (NTIS)

SEM studies were performed on 25 deciduous and permanent teeth from members of seven kindreds with autosomal dominant osteogenesis imperfecta (O.I.). Two families had normal teeth on clinical and radiological examination; five families had blue or brown o...

J. M. Brady L. S. Levin M. Melnick

1979-01-01

73

[Supernumerary teeth in the deciduous dentition].  

PubMed

The Authors presented sovrannumeraries (S) teeth in primary dentition, and the pedodontic, surgical and orthodontic problems. Semeiotics signs, and X Ray suggested, are described. All the types of S. teeth are showed: supplementaries, conoides, tuberculates and infundibuliformes. For every type characteristics, problems and surgical timing are described. Tuberculates and infundibuliformes teeth are the most dangerous for the permanent teeth interrupted: eruption delay, dilacerations, impactions, fusion, follicles, diseases, are reported. The direction of the growth of S. teeth must be analyzed. If the direction is external the timing of surgery is very important. Finally the Authors emphasized the role of cooperation of pedodontist, with oral surgeon and orthodontist for to obtain good results. PMID:2288972

Caprioglio, D; Resta, G; Brusotti, C; Caprioglio, A

74

A 25-year-old man with 50 teeth: Astonishing but true!!  

PubMed Central

Retained primary teeth is a well-known process but multiple retained primary, permanent, and supernumerary teeth that too in an asymptomatic, non-syndromic patient is a rare possibility that has rarely been reported in literature. This case report discusses the clinical and radiographic details along with treatment options in a 21-year-old patient having a total number of 50 teeth, i.e., 16 retained primary teeth, 32 permanent teeth, and 2 supernumerary teeth without being associated with any known syndrome complex or metabolic disorder.

Bhatia, Vishwas; Jain, Nitul; Bhatia, Garima; Garg, Rakesh

2013-01-01

75

An unusual distribution of supplemental teeth in the primary dentition.  

PubMed

Supernumerary teeth are more common in the permanent than the primary dentition. In the latter, the majority occur in the maxillary lateral incisor region or as a mesiodens. Indeed, in one study conducted in the USA, all 26 cases of primary supernumerary teeth examined were found to be lateral incisors. This report describes a case presenting with three erupted supernumerary (supplemental) teeth in the primary dentition, including, somewhat unusually, bilateral duplication of maxillary canines. PMID:16238658

Roberts, A; Barlow, S T; Collard, M M; Hunter, M L

2005-11-01

76

Supernumerary teeth: Report of four unusual cases.  

PubMed

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

2012-04-01

77

Early Diagnosis of Bilateral Supplemental Primary and Permanent Maxillary Lateral Incisors: A Case Report  

PubMed Central

Supernumerary teeth occur frequently in permanent dentition, but they are rarely found in primary dentition. Supernumerary teeth of orthodox shape and size that resemble normal dentition are called ‘supplemental teeth’. Supplemental teeth are less common than supernumerary teeth and are often overlooked because of their normal shape and size. Supplemental teeth may cause esthetic problems, delayed eruption and crowding, and they require early diagnosis and treatment to prevent complications. The case reported here is one of bilateral supplemental teeth impeding the eruption of permanent maxillary lateral incisors, and it emphasizes the importance of early diagnosis and treatment during early mixed dentition.

Yildirim, Gozde; Bayrak, Sule

2011-01-01

78

Supernumerary teeth in primary dentition and early intervention: a series of case reports.  

PubMed

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

2012-07-22

79

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.

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

2012-01-01

80

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.

81

Strontium in 19th century Australian children's teeth  

NASA Astrophysics Data System (ADS)

The enamel of teeth from 57 children, who died in the mid to late 1800s, were analysed to investigate strontium (Sr) concentrations in historic teeth. Teeth were analysed using proton induced X-ray emission at the Australian Nuclear Science and Technology Organisation (ANSTO). Where available, multiple teeth were analysed for each individual including permanent (molars and premolars) and deciduous teeth (molars). Preliminary results show that Sr does not appear to be affected by the postmortem environment. Sr levels in permanent molars strongly correlate with levels in the premolars but not with the deciduous molars. Concerns are raised over the large variation seen in Sr levels and the effect it would have on the interpretation of Sr levels in studies with small sample sizes.

Williams, A.-M. M.; Donlon, D. A.; Bennett, C. M.; Siegele, R.

2002-05-01

82

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.

Crosslin, Rick; Fortney, Mary; Indianapolis, The C.

2004-01-01

83

Natal teeth: a review.  

PubMed Central

The incidence of natal teeth is approximately 1:2,000 to 1:3,000 live births. The most commonly affected teeth are the lower primary central incisors. Natal teeth usually occur in pairs. The eruption of more than two natal teeth is rare. The majority of natal teeth represent the early eruption of normal primary deciduous dentition. Less than 10% of natal teeth are supernumerary. Natal teeth might resemble normal primary dentition in size and shape; however, the teeth are often smaller, conical and yellowish, and have hypoplastic enamel and dentin with poor or absent root formation. Complications include discomfort during suckling, sublingual ulceration, laceration of the mother's breasts and aspiration of the teeth. A dental roentgenogram is indicated to differentiate the premature eruption of a primary tooth from a supernumerary tooth. Tooth extraction is indicated if the tooth is supernumerary or excessively mobile. If the tooth does not interfere with breastfeeding and is otherwise asymptomatic, no treatment is necessary. Images Figure 1

Leung, Alexander K. C.; Robson, William Lane M.

2006-01-01

84

Armor for Your Teeth  

MedlinePLUS

Armor for Your Teeth What are sealants? Knights wear armor to protect them in battle. Sealants are like armor for your teeth. They seal the parts of ... bright, blue light makes the sealants hard like armor. Some sealants harden without the light. Last updated ...

85

Supernumerary teeth in the primary dentition: a report of two cases.  

PubMed

Supernumerary teeth occur frequently in the permanent dentition, but they are rare in the primary dentition. Mesiodens is a supernumerary tooth with a cone shaped crown and a short root. The supernumerary tooth which bears resemblance to the tooth with which it is associated is called a supplemental tooth. The etiology of supernumerary teeth is still unknown and not well understood. Radiographic examination of pre-school children is essential for their diagnosis. Early removal of these teeth is required so that complications such as delay in eruption of permanent teeth, crowding, diastema, rotations and certain pathologic conditions can be averted. PMID:12435029

Lehi, G; Kaur, A

2002-03-01

86

Treatment of avulsed teeth with Emdogain--a case report.  

PubMed

The present case report describes the reimplantation of avulsed teeth with the treatment of Emdogain. Case was avulsed right maxillary permanent central and lateral incisor in a 9-year-old girl suffering from a traumatic injury. After pretreatment of avulsed teeth, Emdogain was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. Evaluation parameters included horizontal and vertical percussion sound and periapical radiographs. At 1-2-6-12-month follow-up period, the clinical and radiographic appearance of the teeth showed resolution of mobility and no signs of replacement resorbption. PMID:15660758

Caglar, Esber; Tanboga, Ilknur; Süsal, Seckin

2005-02-01

87

Multiple teeth in a single dentigerous cyst follicle: A perplexity  

PubMed Central

Dentigerous cysts are always associated with an embedded or unerupted tooth; involvement of more than one permanent tooth in a single cyst follicle is exceedingly rare and only a few such cases can be found in the literature. The cysts reported in the literature involving multiple teeth typically consist of mesiodens or odontomas. Here we report a rare case of dentigerous cyst associated with two permanent teeth causing displacement of maxillary canine into the osteo meatal complex and maxillary premolar to lateral nasal wall. The possible etiopathogenesis of such cases is also discussed here.

Agrawal, Mamta; Raghavendra, Pramod D. S.; Singh, Bhawana; Agrawal, Neha

2011-01-01

88

Multiple teeth in a single dentigerous cyst follicle: A perplexity.  

PubMed

Dentigerous cysts are always associated with an embedded or unerupted tooth; involvement of more than one permanent tooth in a single cyst follicle is exceedingly rare and only a few such cases can be found in the literature. The cysts reported in the literature involving multiple teeth typically consist of mesiodens or odontomas. Here we report a rare case of dentigerous cyst associated with two permanent teeth causing displacement of maxillary canine into the osteo meatal complex and maxillary premolar to lateral nasal wall. The possible etiopathogenesis of such cases is also discussed here. PMID:23483109

Agrawal, Mamta; Raghavendra, Pramod D S; Singh, Bhawana; Agrawal, Neha

2011-07-01

89

Management of supernumerary teeth  

PubMed Central

Supernumerary paramolars are the rare anomalies of the maxillofacial complex. These are more common in the maxilla than in the mandible. This article reviews the etiology, frequency, classification, complications, diagnosis and management of supernumerary teeth (bilateral maxillary paramolars)

Parolia, Abhishek; Kundabala, M; Dahal, Marisha; Mohan, Mandakini; Thomas, Manuel S

2011-01-01

90

Types of Teeth  

MedlinePLUS

... the second molars, also called 12-year molars. Molars are large teeth with broad surfaces designed for crushing, grinding and chewing food. On the upper jaw, the molars have three well-separated roots. On the lower ...

91

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.

HÃ¥kan Svensson (None;)

2005-12-23

92

Clinical and radiographical evaluation of non-syndromic hypodontia and hyperdontia in permanent dentition  

Microsoft Academic Search

Objectives: The purpose of this study was to evaluate the clinical and radiographical characteristics of non-syn- dromic hypodontia and hyperdontia in the permanent dentition. Study design: This study included 139 patients. Clinical and radiographical examinations were carried out by two examiners. Number and localization of missing or supernumerary teeth, and pathologies associated with the teeth, were recorded. Other teeth in

Ilkay Peker; Elif Kaya; Sis Darendeliler-Yaman

93

Teeth and Other Tales  

Microsoft Academic Search

TEETH AND OTHER TALES is a novella and a collection of short stories that explore the blurry lines between illusion and reality.\\u000aTeeth, the novella, is narrated backward in time, chronicling the life of Lucy from the age of sixty-five back to seventeen. After years of surviving an oppressive marriage, Lucy escapes her husband, but in doing so abandons her

Alexandra M Handwerger

2012-01-01

94

Ultrasonic method for cleaning teeth  

US Patent & Trademark Office Database

An improved method for cleaning teeth is disclosed. The method for cleaning teeth includes: applying ultrasonic waves of a first frequency through a liquid media to the teeth for a first period of time; and applying ultrasonic waves of a second frequency through a liquid media to the teeth for a second period of time.

2005-04-19

95

A descriptive study of 113 unerupted supernumerary teeth in 79 pediatric patients in Barcelona  

Microsoft Academic Search

Unerupted supernumerary teeth, depending on the morphology, number and distribution can give rise to various alterations in the eruption and development of those permanent teeth to which they are related. Objectives: We aimed to make an epidemiological and descriptive study of the clinical characteristics of patients in Barcelona, their surgical treatment and how said treatment was hindered. Materials and methods:

Eduard Ferrés-Padró; Jordi Prats-Armengol; Elvira Ferrés-Amat

96

Enriched collagen solution as a pulp dressing in pulpotomized teeth in monkeys  

Microsoft Academic Search

The purpose of this study was to assess the pulp healing process in baboon teeth after pulpotomy using an enriched collagen solution (ECS) as a pulp dressing. Twenty-five noncarious permanent teeth of two young baboon monkeys were pulpotomized under a rubber dam. After coronal pulp resection and hemostasis, ECS was applied on the pulp stumps and covered with sterile dental

Anna B. Fuks; S. Shoshan; Y. Michaeli

1984-01-01

97

Taking Care of Your Teeth  

MedlinePLUS

... re choosing a toothpaste, make sure it contains fluoride . Fluoride makes your teeth strong and protects them from ... Dentist Bad Breath What's a Cavity? How Does Fluoride Work? Your Teeth Taking the Bite Out of ...

98

Multiple supernumerary teeth associated with an impacted maxillary central incisor: Surgical and orthodontic management  

PubMed Central

Various anomalies in the size, shape, number, structure and eruption of the teeth are often observed clinical conditions. Supernumerary teeth can be found in almost any region of the dental arch, and most of the times they are asymptomatic, and are routinely found during radiographic evaluation. The most common cause of impacted maxillary incisors is the presence of the supernumerary teeth. This paper describes a case of multiple supernumerary teeth associated with an impacted permanent maxillary central incisor in an 11-year old child along with its surgical and orthodontic management.

Yeluri, Ramakrishna; Hegde, Manjunath; Baliga, Sudhindra; Munshi, Autar Krishen

2012-01-01

99

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

100

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

Bradlaw, Robert

1936-01-01

101

Prevalence and morphology of supernumerary teeth in the population of a Swiss community. Short communication.  

PubMed

The objective of the study was to determine the current prevalence of supernumerary teeth (PST) in the population of a Swiss community. 3,004 orthopantomograms (OPTs) routinely produced during the annual school dental examinations in the Winterthur municipality from 1990 to 2005 served as the study basis (average age 9.45 years, 1391 girls, 1613 boys, age range 6-15 years). The study found 44 supernumerary teeth, which yields a prevalence of 1.5%. The prevalence among boys was higher than among girls, with 1.1% and 0.4%, respectively. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (38 of 44 teeth, 86%). Based on their position, 33 of these were classified as mesiodens. Five supernumerary teeth had the same shape as a maxillary lateral incisor. In the mandibular anterior region, five supernumerary teeth were shaped the same as the permanent mandibular incisors. 70% of the supernumerary teeth were conical. The prevalence of supernumerary teeth is low (1.5%) and comparable to similar studies in the literature. The majority (86%) of supernumerary teeth are located in the maxillary anterior region. Thus, in the case of retention or delayed eruption, dentists should bear in mind that supernumerary teeth may be the cause. PMID:21243544

Schmuckli, Regula; Lipowsky, Claudia; Peltomäki, Timo

2010-01-01

102

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.

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

2013-01-01

103

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

104

IMRA: Immediate maxillary replacement appliance for anterior teeth.  

PubMed

When faced with the need for emergency replacement of anterior teeth, the problem for dentists and their patients is how can lost teeth be replaced quickly? Laboratory-fabricated replacement appliances require significant time and expense, not to mention an extended period, during which the patient remains edentulous. This report describes a procedure to construct an immediate, low-cost replacement for one or more missing anterior teeth-one that requires no laboratory time. The resulting appliance is meant only as a stop gap and does not support chewing; but it does offer an esthetically pleasing, removable prosthesis that provides phonetic and lip support during the short time necessary to fabricate and place a permanent prosthesis. PMID:21894829

Silver, Joel; Apltauer, James; Blye, Jeffrey; Friedman, Lawrence J

105

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.

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

2013-01-01

106

The effects of periradicular inflamation and infection on a primary tooth and permanent successor.  

PubMed

Primary teeth and the permanent successors must be understood as interdependent units, where each one of them interacts with and depends on each other. Pulpal inflammation/infection of a primary tooth and the spread of this condition over the periradicular tissues can lead to alterations in the dental germ of the permanent successor and to the surrounding structures if no therapy is done, i.e. endodontics or extraction. This work will present cases of permanent teeth that showed alteration in eruption and / or in development, as a consequence of inflammation / infection of the preceding primary teeth, such as: hypoplasia, morphological alteration on the dental crown or total arrest of. radicular formation. The teeth analysed in this study belong to patients who attended the Universidade Federal de Santa Catarina Children's Dentistry Clinic. The earlier these lesions are diagnosed, the less were the destructive effects and the consequences on the primary tooth/permanent germ unit. PMID:15926433

Cordeiro, Mabel Mariela Rodriguez; Rocha, Maria Jose de Carvalho

2005-01-01

107

Accuracy of age estimation of radiographic methods using developing teeth.  

PubMed

Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895] (boys -0.05+/-0.81, girls -0.20+/-0.89, both -0.12 y+/-0.85), Demirjian [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994] overestimated age (boys 0.25+/-0.84, girls 0.23+/-0.84, both 0.24 y+/-0.86), while Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko's [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study, Proc. Finn. Dent. Soc. 66 (1970) 103-170] methods under-estimated age (boys -0.87+/-0.87, girls -1.18+/-0.96, both -1.02 y+/-0.93; boys -0.56+/-0.91, girls -0.79+/-1.11, both -0.67 y+/-1.01, respectively). For individual teeth using Haavikko's method, first premolar and second molar were most accurate; and more accurate than the mean value of all developing teeth. The 95% confidence interval of the mean was least for mean of all developing teeth using Haavikko (age 3-13.99 years), followed by identical values for Demirjian and Willems (sexes combined). PMID:16533584

Maber, M; Liversidge, H M; Hector, M P

2006-03-14

108

[Pulpotomy of deciduous teeth].  

PubMed

Rather easy to perform, pulpotomy of the deciduous teeth is the most frequent endodontic treatment performed on children, but also the most controversial. Based on the amputation of the pulp chamber and the conservation of the inflammation-free root canals, the clinical results can be good, depending on the materials used. In this, calcium hydroxide (Ca(OH)2) as well as zinc-oxide-eugenol (ZOE) have been proven very inflammatory whereas Formocresol (FC) remains the reference even if its clinical toxicity is still reported in literature on a very controversial way. Nevertheless, this was sufficient to trigger and stimulate a search for alternatives, and led to the proposition to use ferric sulfate and even more recently MTA as new bases for the treatment of the pulp stumps after pulp chamber amputation. PMID:15526642

Pilipili, Charles M; Vanden Abbeele, Astrid; van den Abbeele, Karyn

2004-01-01

109

Sterilization of Extracted Human Teeth.  

ERIC Educational Resources Information Center

|At present, there is no specific recommendation for sterilization of extracted human teeth used in dental technique courses. The purpose of this study was to determine whether autoclaving would be effective in the sterilization of extracted teeth without compromising the characteristics that make their use in clinical simulations desirable. (MLW)|

Pantera, Eugene A., Jr.; Schuster, George S.

1990-01-01

110

Sterilization of Extracted Human Teeth.  

ERIC Educational Resources Information Center

At present, there is no specific recommendation for sterilization of extracted human teeth used in dental technique courses. The purpose of this study was to determine whether autoclaving would be effective in the sterilization of extracted teeth without compromising the characteristics that make their use in clinical simulations desirable. (MLW)

Pantera, Eugene A., Jr.; Schuster, George S.

1990-01-01

111

Dental anomalies in the primary dentition and their repetition in the permanent dentition: a diagnostic performance study.  

PubMed

This study investigated the recurrence in the permanent dentition of dental anomalies of the primary dentition. A sample of 189 subjects (100 males, 89 females, mean age of 5 years and 7 months) with anomalies of primary teeth (tooth hypodontia, supernumerary teeth, geminated teeth, and fused teeth) was selected and re-analyzed at a mean age of 11 years and 2 months for the recurrence of the dental anomalies in the permanent dentition. As a control group, 271 subjects (123 males, 148 females) without dental anomalies in the primary dentition were selected. The recurrence in the permanent dentition of the dental anomalies in the primary dentition was evaluated by measures of diagnostic performance. The results showed high values for the repetition of hypodontia (positive likelihood ratio = 102.0); low score for the repetition of hyperdontia (positive likelihood ratio = 6.5); low positive likelihood ratio (9.1) for gemination of primary teeth resulting in supernumerary permanent teeth; high positive likelihood ratio (47.0) for fusion of primary teeth followed by missing permanent teeth. Dental anomalies in the primary dentition are associated with an increased likelihood of anomalies of the succedaneous permanent. PMID:21553067

Marinelli, Andrea; Giuntini, Veronica; Franchi, Lorenzo; Tollaro, Isabella; Baccetti, Tiziano; Defraia, Efisio

2011-05-07

112

The Effect of Unerupted Permanent Tooth Crowns on the Distribution of Masticatory Stress in Children  

Microsoft Academic Search

Human mothers wean their children from breast milk at an earlier developmental stage than do ape mothers, resulting in human children chewing solid and semi-solid foods using the deciduous dentition. Mechanical forces generated by chewing solid foods during the post-weaning period travel through not only the deciduous teeth, but also the enamel caps of the developing permanent teeth within the

Ashley S. Hammond; Elizabeth R. Dumont; Robert C. McCarthy

2011-01-01

113

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

114

Study of the frequency and the features of supranumerary teeth found in one Portuguese population.  

PubMed

The present study was performed on a population of subjects assisted at the dental clinic of Instituto Superior de Ciências da Saúde-Norte. The aims of the study were: (1) to analyse the prevalence of supernumerary teeth, (2) to characterise its gender distribution, and (3) to investigate the repercussions of supernumerary teeth over neighbouring teeth and tissues. From the records of all the patients received from 1993 to 2000, 16771 clinical files contained panoramic X-ray plates (8712 females and 8059 males) and were selected. A total of 151 supernumerary teeth were found in 127 patients (72 males and 55 females, aged from 5 to 63 years), corresponding to a prevalence of 0.76%. Other designed important issues were one supernumerary teeth for individual; the mesiodens type (followed by the 4th molar); conical morphology; the maxilla (namely on the maxillary medial line): location as predominant findings. Evolutionary state, 47 (31.1%) were erupted and 104 (68.9%) unerupted. In most cases 108 (71.5%), the radiological images didn't suggest alterations on adjacent teeth and/or tissues. The repercussions found, potentially associated to supernumerary teeth were: 12 (7.9%) displacement of adjacent teeth, nine (6%) delayed eruption of permanent teeth, and eight cases (5.3%) diastema formation. PMID:16335622

Costa Pinho, Teresa Maria; Figueiredo Pollmann, Maria Cristina

115

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.

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

2012-01-01

116

Do Fluoride Ions Protect Teeth?  

ERIC Educational Resources Information Center

|Begins with the procedure and results from an investigation on the effect of fluoride on the reaction between eggshell (substitute teeth) and dilute ethanoic acid. Describes an elegantly modified and improvised apparatus. (DDR)|

Parkin, Christopher

1998-01-01

117

The Site-specificity of Supragingival Calculus Deposition on the Lingual Surfaces of the Six Permanent Lower Anterior Teeth in Humans and the Effects of Age, Sex, Gum-chewing Habits, and the Time Since the Last Prophylaxis on Calculus Scores  

Microsoft Academic Search

The hypotheses to be tested were: (i) that chewing sugar-free gum frequently and for long periods would be associated with higher amounts of supragingival calculus, and (ii) that there would be no site-specificity of calculus deposition on the lingual surfaces of the 6 lower anterior teeth. Subjects, 436 in Glasgow and 191 in Winnipeg, were scored for calculus at mesial,

L. M. D. Macpherson; D. C. Girardin; N. J. Hughes; K. W. Stephen; C. Dawes

1995-01-01

118

Crown components of mandibular molar teeth in 45,X females (Turner syndrome)  

Microsoft Academic Search

This study was designed to determine the possible effect of one X-chromosome constitution on components of the human permanent and primary molar teeth. Enamel, dentine, pulp and crown dimensions were measured on radiographs of first and second permanent and second primary mandibular molars of 49 Finnish 45,X females (Turner syndrome), their 46 first-degree male and female relatives and 50 non-related

U. Zilberman; P. Smith; L. Alvesalo

2000-01-01

119

Approximating the ?-permanent  

Microsoft Academic Search

The standard matrix permanent is the solution to a number of combinatorial and graph-theoretic problems, and the ?-weighted permanent is the density function for a class of Cox processes called boson processes. The exact computation of the ordinary permanent is known to be #P-complete, and the same appears to be the case for the ?-permanent for most values of ?.

S. C. Kou; P. McCullagh

2009-01-01

120

Effects of toothless stator design on dynamic model parameters of permanent magnet generators  

Microsoft Academic Search

The effects of toothless stator design on the dynamic model parameters of permanent magnet (PM) generators are presented. These parameters, which include inductances and induced back EMFs, are determined for a 75 kVA, 208 V, 400 Hz, two-pole, permanent magnet generator. Two particular stator designs, a toothless stator, and a conventional type stator (with iron teeth), are considered. The method

A. A. Arkadan; R. Vyas

1993-01-01

121

Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst  

PubMed Central

Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens) is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning.

Kalaskar, Ritesh R.; Kalaskar, Ashita R.

2011-01-01

122

Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst.  

PubMed

Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens) is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning. PMID:22114457

Kalaskar, Ritesh R; Kalaskar, Ashita R

2011-01-01

123

Application to Forensic Odontology of Aspartic Acid Racemization in Unerupted and Supernumerary Teeth  

Microsoft Academic Search

Racemization of aspartic acid in dentin protein during the human lifetime progresses with age. The extent of racemization of aspartic acid in coronal dentin of normal permanent teeth can be used in forensic odontology to estimate the age of an individual at the time of death (Ogino et al., 1985). A series of experiments was conducted with dentin separated from

T. Ogino; H. Ogino

1988-01-01

124

Low speed high torque PMSM design based on unequal teeth structure  

Microsoft Academic Search

To satisfy the requirement of the low speed high torque permanent magnet synchronous motor (PMSM) used in the precise numerical control (NC) rotary table, the multipolar PMSM with similar pole number and slot number and unequal teeth structure is designed in this paper. This kind of motors can operate with lower speed, and the structure of similar pole number and

Jiakuan Xia; Ting Dong; Chengyuan Wang; Jianyu Zhao

2008-01-01

125

Nanocomposite Permanent Magnets.  

National Technical Information Service (NTIS)

A nanocomposite, rare earth permanent magnet comprising at least two rare earth- or yttrium-transition metal compounds. The nanocomposite, rare earth permanent magnet can be used at operating temperatures of about 130 to about 300 degrees C. and exhibits ...

D. Lee S. Liu

2004-01-01

126

Dental fluorosis prevalence and severity using Dean’s index based on six teeth and on 28 teeth  

Microsoft Academic Search

To contrast the sensitivity, specificity, and positive–negative predictive values between dental fluorosis prevalence scored\\u000a on 28 (DF28) and on six permanent teeth (DF6), we undertook a cross-sectional study on 1,538 adolescents (12 and 15 years\\u000a old) residing in Hidalgo State, Mexico, a naturally fluoridated (>0.7 ppm) area at an elevated altitude (>2,500 m above sea\\u000a level). Dental fluorosis was scored using Deans modified

Carlo Eduardo Medina-Solis; América Patricia Pontigo-Loyola; Gerardo Maupome; Hector Lamadrid-Figueroa; Juan Pablo Loyola-Rodríguez; Jesús Hernández-Romano; Juan José Villalobos-Rodelo; Ma. de Lourdes Marquez-Corona

2008-01-01

127

Cleaning Your Child's Mouth and Teeth  

MedlinePLUS

... to switch to a soft-bristled, infant-sized toothbrush. Use a very small smear of toothpaste. Your ... flossing your child's teeth. Flossing is essential because toothbrush bristles cannot reach between the baby teeth. This ...

128

Dovetail spoke internal permanent magnet machine  

SciTech Connect

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

129

Reconstructing Teeth with Bite Information  

Microsoft Academic Search

We propose a method for restoring the surface of a tooth crown so that the pose and anatomical features of the tooth will\\u000a work well for chewing. The system of teeth has been modeled with a 3D statistical multi-object shape model build from 3D scans\\u000a of dental cast models. The restoration is carried out using the shape model statistics in

Katrine Hommelhoff Jensen; Jon Sporring

2007-01-01

130

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.

Bayar, Gurkan Rasit; Ortakoglu, Kerim; Sencimen, Metin

2008-01-01

131

Cogging torque reduction in Dual-Rotor Permanent Magnet Generator for Direct Coupled Stand-Alone Wind Energy Systems  

Microsoft Academic Search

In a permanent magnet machine cogging torque is produced due to the interaction between the rotor magnets and the slots and teeth of the stator. This paper is a result of an ongoing research work that deals with reduction of cogging torque in dual-rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand-alone wind energy systems. The DRFPMG is

P. Sivachandran; P. Venkatesh; N. Kamaraj

2008-01-01

132

Bilateral fusion of permanent mandibular incisors with Talon's cusp: A rare case report  

PubMed Central

Whenever nature diverts from the “normal or usual” it gives rise to something called “abnormal or unusual,” which we call “a Disorder”. Fusion of two teeth is a common developmental disorder that is seen by a clinician. However, bilateral fusion along with Talon's cusp is very rarely seen and reported in literature. This article describes a rare case of the bilateral fusion of permanent mandibular central and lateral incisors, along with presence of Talon's cusp on the left fused teeth.

Prabhakar, Attiguppe Ramasetty; Kaur, Taranjot; Nadig, Basappa

2009-01-01

133

Rare earth permanent magnets  

Microsoft Academic Search

Permanent magnets were discovered centuries ago from what was known as {open_quotes}lodestone{close_quotes}, a rock containing large quantities of the iron-bearing mineral magnetite (FeâOâ). The compass was the first technological use for permanent magnetic materials; it was used extensively for navigational purposes by the fifteenth century. During the twentieth century, as new applications for permanent magnets were developed, interest and research

Major-Sosias

1993-01-01

134

Rare earth permanent magnets  

Microsoft Academic Search

A survey is given of the state of the art in rare earth permanent magnet research of materials based on Nd2Fe14B. The magnetic properties of various types of interstitially modified Fe-rich rare earth intermetallics are discussed, including the possibility to apply these materials in permanent magnets.

K. H. J. Buschow; F. H. Feijen; Kees de Kort

1995-01-01

135

Supernumerary teeth "mesiodens". Case report.  

PubMed

The supernumerary tooth is an anomaly of dental eruption that is not rare to find in the clinical practice. Among the supernumerary teeth the "mesiodens" is most frequent. The mesiodens is found in the region of the superior central incisors and it can be the cause of many complications. The aim of this work is the description of a rare symptomatic case of mesiodens and the diagnostic and therapeutic strategies to adopt when this dental anomaly occurs. In particular the authors suggest making radiographic examinations only in the family of patients with dental anomalies of number, thinking that the incidence of such anomalies is too low to justify mass radiographic examinations. PMID:14608252

Itro, A; Difalco, P

2003-09-01

136

Supernumerary teeth in non-syndromic patients  

PubMed Central

Hyperdontia or supernumerary teeth without associated syndrome is a rare phenomenon, as supernumerary teeth are usually associated with cleft lip and palate or other syndromes such as Gardner's syndrome, cleidocranial dysplasia, and so on. Five patients with supernumerary teeth visited our department. They had no familial history or other pathology, certain treatment protocols was modified due to the presence of supernumerary teeth. Non-syndromic supernumerary teeth, if asymptomatic, need to have periodical radiographic observation. If they showed no variation as they impacted in the jaw, careful examination is necessary because they may develop into pathological status such as dentigerous cysts. The importance of a precise clinical history and radiographic examination for patients with multiple supernumerary teeth should be emphasized.

Karjodkar, Freny Rashmiraj; Sontakke, Subodh; Sansare, Kaustubh

2012-01-01

137

[Regional odontodysplasia ("ghost teeth"). A case report].  

PubMed

The authors present a rare case of developmental anomaly called regional odontodysplasia. It is also called odontogenic dysplasia, ghost teeth. It is a disorder that affects both the ectodermal and mesodermal dental components. The teeth usually fail to erupt and they have wide pulp chambers. Any teeth may be affected, but the disease is usually restricted to single quadrants. The cause is unknown. PMID:2158617

Piatelli, A; Sesenna, E; Giannoni, R

1990-01-01

138

Mineral trioxide aggregate as a pulpotomy agent in immature teeth: Long-term case report  

PubMed Central

This case report aimed to present the long-term clinical performance of mineral trioxide aggregate (MTA) pulpotomies in immature permanent teeth. Four patients with complicated crown fractures of five maxillary immature central incisor teeth were treated with pulpotomy using gray MTA. An immature mandibular first molar showing signs of reversible pulpitis that was exposed mechanically during cavity preparation was also treated with MTA pulpotomy. Four of the 6 immature teeth were diagnosed vitally with complete root maturation and with the presence of dentin bridges after 55 months (mean time of follow-ups). MTA pulpotomy was assessed unsuccessfully in two fractured central incisors. Severe discoloration in the crowns was present in all 6 cases. MTA may induce pulp healing with dentin bridge formation and prevent necrosis at long-term periods in most of the pulpotomy cases. However, discoloration following MTA pulpotomy is a significant clinical complication.

Subay, Rustem Kemal; Ilhan, Banu; Ulukapi, Hasmet

2013-01-01

139

The relation between long-period incremental markings in dentine and daily cross-striations in enamel in human teeth  

Microsoft Academic Search

Ground sections of human permanent teeth were chosen where fluorescent labels in the dentine, resulting from repeated doses of tetracycline antibiotic, were unambiguously associated with accentuated markings in the enamel developing at the same time. Counts of daily cross-striations in enamel were continued from one tooth to another in a developmental sequence over a period of some 1200 days such

M. C. Dean; A. E. Scandrett

1996-01-01

140

Characterization of the calcium biomineral in the radular teeth of Chiton pelliserpentis.  

PubMed

The radula in a group of molluscan invertebrates, the chitons (Polyplacophora), is a ribbon-like apparatus used for feeding and which bears a series of distinctive mineralized teeth called the major lateral teeth. While some chiton species deposit only iron biominerals in these teeth, many others deposit both iron and calcium. In this study, the calcium biomineral in the teeth of one of the latter types of species, the Australian east-coast chiton, Chiton pelliserpentis, has been isolated and examined for the first time. Spectroscopic and crystallographic techniques have identified the biomineral as a carbonate-substituted apatite with significant fluoride substitution also likely. Fourier-transform infrared and laser Raman spectroscopy indicated that the carbonate content was less than that of either bovine tibia cortical bone or human tooth enamel. X-ray diffraction analysis showed the biomineral to be poorly crystalline due to small crystal size and appreciable anionic substitution. The lattice parameters were calculated to be a = 9.382 A and c = 6.883 A, which are suggestive of a fluorapatite material. It is postulated that structural and biochemical differences in the tooth organic matrix of different chiton species will ultimately determine if the teeth become partly calcified or iron mineralized only. PMID:10499087

Evans, L A; Alvarez, R

1999-04-01

141

Regenerative endodontic treatment of an immature permanent canine following infant oral mutilation.  

PubMed

Extracting primary canine tooth buds is a ritual ceremony that prevails in some African countries. This procedure is considered infant oral mutilation (IOM) and may damage the permanent successor and adjacent primary and permanent teeth, resulting in dysplastic or deformed teeth. The purpose of this report was to describe regenerative endodontic treatment of a permanent mandibular canine with extensive coronal hypoplasia, immature root, and a periapical radiolucency following damage to the permanent canine that was probably a result of infant oral mutilation. Regenerative endodontic treatment was initiated by irrigating the root canal, followed by applying triple antibiotic paste dressing over three weeks and creating a blood clot scaffold covered with mineral trioxide aggregate. A 4-year clinical and radiographic follow-up demonstrated healing of the periapical radiolucency. This treatment may serve as a substitute for traditional apexification with calcium hydroxide or creation of an artificial apical barrier with mineral trioxide aggregate. PMID:23930636

Noy, Avia Fux; Nuni, Eyal; Moskovitz, Moti

142

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.

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

2011-01-01

143

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

144

Replantation of 400 avulsed permanent incisors. 1. Diagnosis of healing complications.  

PubMed

A material of 322 patients with 400 avulsed and replanted permanent teeth were followed prospectively in the period from 1965 to 1988 (mean observation period = 5.1 yrs). The age of the patients at the time of replantation ranged from 5 to 52 yrs (mean = 13.7 yrs and median = 11.0 yrs). Standardized patient records were used through the entire period in order to obtain valid data concerning the extent of injury and treatment provided. At the follow-up period, pulpal and periodontal healing were monitored by clinical examination, mobility testing and standardized radiographic controls. Thirty-two of the replanted teeth (8%) showed pulpal healing. When related to teeth with incomplete root formation, where pulpal revascularization was anticipated (n = 94) the frequency of pulpal healing was 34%. Periodontal ligament healing (i.e. with no evidence of external root resorption) was found in 96 teeth (24%). Gingival healing was found in 371 teeth (93%). During the observation period, 119 teeth (30%) were extracted. Tooth loss was slightly more frequent in teeth with incomplete root formation at the time of replantation than in teeth with completed root formation. PMID:7641619

Andreasen, J O; Borum, M K; Jacobsen, H L; Andreasen, F M

1995-04-01

145

Relative nonlinearity and permanence  

Microsoft Academic Search

We modify the commonly used invasibility concept for coexistence of species to the stronger concept of uniform invasibility. For two-species discrete-time competition and predator–prey models, we use this concept to find broad easily checked sufficient conditions for the rigorous concept of permanent coexistence. With these results, permanent coexistence becomes a tractable concept for many discrete-time population models. To understand how

Yun Kang; Peter Chesson

2010-01-01

146

Retrospective study of 145 supernumerary teeth  

Microsoft Academic Search

Objective: The goal of the present retrospective study is to describe the distribution of the supernumerary teeth in a population of patients that have been attended at the Public Clinic of the Department of Oral Surgery. Background: Supernumerary teeth and multiple hyperdontia are usually associated with different syndromes, such as Gardner syndrome, or with facial fissures; however, they can appear

Paula Fernández Montenegro; Eduard Valmaseda Castellón; Leonardo Berini Aytés; Cosme Gay Escoda

147

Nasal Teeth: Report of Three Cases  

Microsoft Academic Search

Summary: The ectopic eruption of the teeth into the nasal cavity is a rare phenomenon. We report cases: two involving the nasal cavity and one involving the hard palate and complicated by Aspergillus rhinitis. We describe the clinical and radiologic presentation of these cases and discuss their etiology, complications, diagnosis, and treatment. Nasal teeth are a rare form of supernumerary

Albert Chen; Jon-Kway Huang; Sho-Jen Cheng; Chin-Yin Sheu

148

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

149

Teething myths among community health officers.  

PubMed

Many symptoms are attributed to teething in infants as a result of myths and opinions of people in the community. These myths have given false security with the belief that these symptoms are part of the teething process. The purpose of the study was to investigate the beliefs and practices of Community health Officers about teething. 60% of the respondents whose responses were analyzed believed that children have systemic problems during teething periods. Fever and diarrhea were the most frequent symptoms associated with teething. As health care providers at the community level, there is a need for this cadre of health care providers to separate cultural beliefs from scientific and proven medical practices. This can be achieved by their attendance at regular refresher courses organized for them after their graduation. PMID:16032942

Denloye, O; Bankole, O O; Aderinokun, G A

2005-03-01

150

Concrescent triplets involving primary anterior teeth  

PubMed Central

Odontogenesis is a complex process wherein more than 200 genes are known to play a significant role in tooth development. An imbalance can lead to an abnormality in the number, size, shape or structure of the developing tooth/teeth. The presence of an extra dental lamina forms a supernumerary tooth. The supernumerary teeth are of two types: A rudimentary tooth where the supernumerary tooth does not resemble any tooth in the normal series or a supplemental tooth in which this anomalous tooth resembles one in the normal series. It is also very rare to encounter triple teeth in primary dentition. The union of these teeth may be through fusion, gemination, concrescence or a combination of fusion and gemination. Presented is a rare case of concrescence involving maxillary deciduous incisors and a supplemental tooth in a 7-year-old boy. The differential diagnosis, etiology, and complications of primary anterior triple teeth are discussed.

Sharma, Urvashi; Gulati, Anubha; Gill, Namrata C.

2013-01-01

151

Are teeth evidence in acid environment  

PubMed Central

Aim: Teeth are the most durable structures that resist destruction more than skeletal tissue Commercially available acids can be used to destroy the body or a part, to mask human identification. The present study examines the effect of caustic acids on human dentition. Materials and Methods: Ten upper anterior teeth each were immersed in 37% hydrochloric acid (conc. HCl), 65% nitric acid (conc. HNO3) and 96% sulfuric acid (conc. H2SO4). Teeth were retrieved, washed in distilled water, dried, photographed and radiographed at intervals of 15 min, 30 min, 1 hr, 3 hr, 5 hr and 8 hr. Results: Teeth placed in conc. HCl and conc. HNO3 dissolved completely after 8 hours, while that placed in conc. H2SO4 retained its morphology and radiographic dimension even after 8 hours. Conclusion: Hence teeth can serve as a tool in identification (age estimation and sex determination) of the victim when in contact with conc. H2SO4.

Raj, Makesh; Boaz, Karen; Srikant, N

2013-01-01

152

Unerupted teeth associated with dentigerous cysts and treated with coronectomy: mini case series.  

PubMed

There is a resurgence of interest in coronectomy, but its appropriate application in the management of third molar teeth has yet to be defined. Dentigerous cysts associated with unerupted teeth are most commonly associated with mandibular third molars. In this case series we evaluate outcome after coronectomy of teeth with associated dentigerous cysts in cases where the inferior dental nerve was thought to be at risk, or there was an increased risk of mandibular fracture. We retrospectively studied 21 consecutive patients treated by coronectomy for dentigerous cysts at the Oral Surgery Department at Guy's Hospital. The most commonly affected teeth were mandibular third molars (20/21). One patient had permanent injury to the inferior dental nerve, but no mandibular fracture or recurrence of cyst was reported. One patient required secondary retrieval of the retained root because of eruption. Coronectomy of unerupted teeth associated with dentigerous cysts is an effective treatment when there is high risk of injury to the inferior dental nerve injury or potential for mandibular fracture. Further work with larger numbers and longer follow-up is required to discover the long-term outcome of the electively retained root. PMID:23522661

Patel, Vinod; Sproat, Chris; Samani, Meera; Kwok, Jerry; McGurk, Mark

2013-03-19

153

Dens invaginatus in ancient chinese teeth of 2,000 years ago.  

PubMed

Dens invaginatus (DI) is a developmental anomaly of teeth. Here we observed the characteristics of DI in 517 permanent teeth from 67 ancient Chinese people using micro-computed tomography (micro-CT) scanning techniques. The individuals were excavated from Shaanxi province of China and identified to be about 2,000 years old. Four DI categories are proposed to distinguish the different types of DI. The invaginated lingual fossa is classified into three classes. The overall prevalence of DI in 67 individuals was 31.34% (21 of 67). DI was found in 25 of 517 teeth (4.83%). All affected teeth were maxillary lateral incisors. The invaginated lingual fossa (Type I DI) occurred most frequently (84%), followed by radicular grooves (Type II; 16%), while Type III and Type IV were not found in the present study. Some of fossae correspond with radicular grooves (8 of 21; 3 located at mesial, 5 were distal). The bilateral incidence of DI was 19.05%. Comparing our results to those of a retrospective survey of DI from 1873 to present, we found a higher rate of DI in the excavated teeth of Chinese individuals 2,000 years ago. The use of the micro-CT technique and ethnic origin might have contributed to the higher incidence of DI. Anat Rec, 296:1628-1633, 2013. © 2013 Wiley Periodicals, Inc. PMID:23857803

Shi, Sasa; Duan, Xiaohong; Shao, Jinling; Duan, Qingbo; Peng, Shaobin

2013-07-16

154

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 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...

2013-04-01

155

Infrared Spectroscopic Identification of Chosen Dental Materials and Natural Teeth  

NASA Astrophysics Data System (ADS)

Studies using solid phase infrared spectroscopy in the range of 400 to 4000 wave numbers were conducted in order to quickly identify solid tooth fragments and differentiate them from dental materials used in the dental practice. The frequently employed dental materials were evaluated. Natural chemical structure of permanent teeth obtained from donors of various ages provided the reference material. The infrared vibrations detected in infrared transmission spectra depended on the chemical structure of examined compound. Comparable distinctive peaks in infrared spectra of natural teeth and inorganic dental materials (porcelain) were exhibited. Analogous infrared spectra of dental materials consisting of organic matrix with inorganic fillers were found. In the case of acrylic materials specific organic groups were enhanced. The prepared database of infrared transmission spectra included 23 dental materials, facilitating their appropriate identification. Application of infrared spectroscopy allowed for a quick differential identification of typical dental materials produced from organic compounds for inorganic restorations (porcelain) and of tooth structure-resembling hydroxyapatite and its contaminate forms with fluoride and carbonate ions.

H?dzelek, W.; Marcinkowska, A.; Domka, L.; Wachowiak, R.

2008-08-01

156

Analytical prediction of the cogging torque in radial-field permanent magnet brushless motors  

Microsoft Academic Search

A method for predicting the cogging torque in radial-field permanent magnet brushless motors, based on the analytical calculation of the airgap field distribution and the net lateral force acting on the stator teeth, is developed and validated. The technique is applicable to both internal and external rotor motor topologies, modeled in a cylindrical coordinate system. It can also be applied

Z. Q. Zhu; D. Howe

1992-01-01

157

Influence of design parameters on cogging torque in permanent magnet machines  

Microsoft Academic Search

The influence of various design parameters on the cogging torque developed by permanent magnet machines is investigated. It is shown that the slot and pole number combination has a significant effect on the cogging torque, and influences the optimal value of both skew angle and magnet arc, as well as determining the optimal number of auxiliary teeth\\/slots. A simple factor,

Z. Q. Zhu; David Howe

2000-01-01

158

Influence of design parameters on cogging torque in permanent magnet machines  

Microsoft Academic Search

The influence of various design parameters on the cogging torque developed by permanent magnet machines is investigated. It is shown that the slot and pole number combination has a significant effect on the cogging torque, and influences the optimal value of both the skew angle and the magnet arc, as well as determining the optimal number of auxiliary teeth and

Z. Q. Zhu; D. Howe

1997-01-01

159

Automatic teeth axes calculation for well-aligned teeth using cost profile analysis along teeth center arch.  

PubMed

In dental implantology and virtual dental surgery planning using computed tomography (CT) images, the examination of the axes of neighboring and/or biting teeth is important to improve the performance of the masticatory system as well as the aesthetic beauty. However, due to its high connectivity to neighboring teeth and jawbones, a tooth and/or its axis is very elusive to automatically identify in dental CT images. This paper presents a novel method of automatically calculating individual teeth axes. The planes separating the individual teeth are automatically calculated using cost profile analysis along the teeth center arch. In this calculation, a novel plane cost function, which considers the intensity and the gradient, is proposed to favor the teeth separation planes crossing the teeth interstice and suppress the possible inappropriately detected separation planes crossing the soft pulp. The soft pulp and dentine of each individually separated tooth are then segmented by a fast marching method with two newly proposed speed functions considering their own specific anatomical characteristics. The axis of each tooth is finally calculated using principal component analysis on the segmented soft pulp and dentine. In experimental results using 20 clinical datasets, the average angle and minimum distance differences between the teeth axes manually specified by two dentists and automatically calculated by the proposed method were 1.94° ± 0.61° and 1.13 ± 0.56 mm, respectively. The proposed method identified the individual teeth axes accurately, demonstrating that it can give dentists substantial assistance during dental surgery such as dental implant placement and orthognathic surgery. PMID:22287231

Kim, Gyehyun; Lee, Jeongjin; Seo, Jinwook; Lee, Wooshik; Shin, Yeong-Gil; Kim, Bohyoung

2012-01-24

160

Flouride. Ten-year prospective study of deciduous and permanent dentition.  

PubMed

A ten-year longitudinal prospective study compared the effect of fluoride on dentition of 1,500 children from infancy through age 10 years. In Kalamazoo, Mich, and Oneida, NY, parallel groups were given a fluoride-vitamin supplement from infancy and from age 4 and compared with fluoridated water and control groups. Incidence of new caries activity in both deciduous and permanent teeth was measured by mean number of new decayed and filled teeth, as well as percentage of children with no caries throughout the periods studied. Prevalence of caries was also studied in six-year molars. The results indicate a consistent (and, for selected groups, a statistically significant) diminution in caries activity for both deciduous and permanent teeth for groups ranked from greatest retardation of caries to least: infant fluoride group, water fluoride group, age 4 fluoride group, and controls. PMID:1096595

Margolis, F J; Reames, H R; Freshman, E; MaCauley, C D; Mehaffey, H

1975-07-01

161

Multiple Pulp Stones in Primary and Developing Permanent Dentition: A Report of 4 Cases  

PubMed Central

Pulp stones are foci of calcification or discrete calcifications in the dental pulp. They are frequently found on bitewing and periapical radiographs, but their occurrence in entire dentition is unusual. We are reporting four cases in which the occurrence of pulp stones ranged from their presence in just primary teeth (Cases 1 and 2) to involvement of young permanent teeth also (Case 3) and even unerupted permanent teeth (Case 4). In all the cases, dental, medical, and family histories as well as the findings from the clinical examination of the patient were not contributory. Histopathological report revealed true denticle. Metabolic evaluation of patients through liver function test, kidney function test, and blood investigation did not show any metabolic disorders. Patients were also evaluated for any systemic, syndromic, or genetic involvement, but this was also noncontributing. Therefore, it is suggested that these unusual cases may be of idiopathic origin.

Marwaha, Mohita; Chopra, Radhika; Chaudhuri, Payal; Gupta, Atul; Sachdev, Jayna

2012-01-01

162

Dual epithelial origin of vertebrate oral teeth.  

PubMed

The oral cavity of vertebrates is generally thought to arise as an ectodermal invagination. Consistent with this, oral teeth are proposed to arise exclusively from ectoderm, contributing to tooth enamel epithelium, and from neural crest derived mesenchyme, contributing to dentin and pulp. Yet in many vertebrate groups, teeth are not restricted only to the oral cavity, but extend posteriorly as pharyngeal teeth that could be derived either directly from the endodermal epithelium, or from the ectodermal epithelium that reached this location through the mouth or through the pharyngeal slits. However, when the oropharyngeal membrane, which forms a sharp ecto/endodermal border, is broken, the fate of these cells is poorly known. Here, using transgenic axolotls with a combination of fate-mapping approaches, we present reliable evidence of oral teeth derived from both the ectoderm and endoderm and, moreover, demonstrate teeth with a mixed ecto/endodermal origin. Despite the enamel epithelia having a different embryonic source, oral teeth in the axolotl display striking developmental uniformities and are otherwise identical. This suggests a dominant role for the neural crest mesenchyme over epithelia in tooth initiation and, from an evolutionary point of view, that an essential factor in teeth evolution was the odontogenic capacity of neural crest cells, regardless of possible 'outside-in' or 'inside-out' influx of the epithelium. PMID:18794902

Soukup, Vladimír; Epperlein, Hans-Henning; Horácek, Ivan; Cerny, Robert

2008-09-14

163

Intermetallics for permanent magnets  

SciTech Connect

Going back as far as 1931, it is shown by the examples MnAl, Fe-Nd, Fe-Nd-B, Fe(-Ti)-Sm how the history of permanent magnet materials might have evolved differently if hints had been heeded that were discernible long before a particular magnet development actually began. This account relates the lessons learned, discusses the directions being taken in the exploration of multicomponent alloy systems, and suggests ways to search for intermetallics that are potential permanent magnet materials.

Stadelmaier, H.H. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering)

1993-11-01

164

Operative Dentistry on Human and Swine Teeth.  

National Technical Information Service (NTIS)

The specific objective was to determine feasibility of using swine as test vehicle, other than human, to evaluate effects of new dental materials and operative methods. Procedures employed were the cutting of cavity preparations in teeth of swine and huma...

G. D. Stibbs J. T. Hodson W. J. Clarke

1970-01-01

165

21 CFR 872.5550 - Teething ring.  

Code of Federal Regulations, 2013 CFR

...5550 Section 872.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Therapeutic Devices § 872.5550 Teething ring. (a)...

2013-04-01

166

The Moon's Permanent Shadows  

NASA Video Gallery

Deep in the craters of the moon's south pole lurk permanently shadowed regions: areas that have not seen sunlight in more than two billion years. Now, NASA's Lunar Reconnaissance Orbiter is shedding a new light on some of our satellite's darkest mysteries. Credit: NASA's Goddard Space Flight Center › Download video in HD formats

gsfcvideo

2013-03-05

167

Permanent magnet alloy  

SciTech Connect

This patent describes a permanent magnet alloy consisting essentially of, in atomic percent, neodymium 8 to 15, thorium 6 to 10 with the total neodymium and thorium being within the range of 14 to 20, boron 4 to 14 and balance iron.

Narasimhan, K.S.V.L.; Ma, B.M.

1988-12-06

168

Alkaline "Permanent" Paper.  

ERIC Educational Resources Information Center

Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability is…

Pacey, Antony

1991-01-01

169

Alkaline "Permanent" Paper.  

ERIC Educational Resources Information Center

|Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability…

Pacey, Antony

1991-01-01

170

Permanents of Circulants.  

National Technical Information Service (NTIS)

A recurrence formula is obtained for permanents of circulants of the form alpha(I sub n) + beta P + gamma(P sup 2) and explicit formulas are deduced from it. It is shown that for doubly stochastic circulants alpha(I sub n) + beta P + gamma(P sup 2) the mi...

H. Minc

1971-01-01

171

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.

172

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

173

Permanent molar pulpotomy with a new endodontic cement: A case series  

PubMed Central

The aim of this case series was to determine the clinical and radiographic success rate of pulpotomy, with new endodontic cement (NEC), in human mature permanent molar teeth. Twelve molars with established irreversible pulpitis were selected from patients 14 – 62 years old. The selection criteria included carious pulp exposure with a positive history of lingering pain. After isolation, caries removal, and pulp exposure, pulpotomy with NEC was performed and a permanent restoration was immediately placed. At the first recall (+1 day) no patients reported postoperative pain. One wisdom tooth had been extracted after two months because of failure in coronal restoration. Eleven patients were available for the second recall, with a mean time of 15.8 months. Clinical and radiographic examination revealed that all teeth were functional and free of signs and symptoms. Histological examination of the extracted teeth revealed complete dentin bridge formation and a normal pulp. Although the results favored the use of NEC, more studies with larger samples and a longer recall period were suggested, to justify the use of this novel material for treatment of irreversible pulpitis in human permanent molar teeth.

Asgary, Saeed; Ehsani, Sara

2009-01-01

174

Permanent Magnet Generator Designing Guidelines  

Microsoft Academic Search

This paper discusses the requirements set to permanent magnet generators directly connected to electrical network especially when used in hydro electric plants. The influences of the requirements on the permanent magnet generator design parameters are discussed.

Tuomo Lindh; Pia Salminen; Juha Pyrhonen; Markku Niemela; Janne Kinnunen; Jorma Haataja

2007-01-01

175

Permanent magnet propulsion system  

US Patent & Trademark Office Database

A permanent magnet propulsion system wherein a steel ball is propelled up an inclined plane between two rows of permanent bar magnets, said magnets being in spaced relationship with all north seeking poles of one of the said rows facing in substantially the same direction and with all south seeking poles in the other row facing in substantially the same but opposite direction to the first of said rows. The magnetic axes of each of the magnets of the first said row are in staggered relationship to the axes of opposing magnets of the second said row. The magnetic field acting on the ball is configured whereby the ball after reaching the top of the inclined plane is able to drop from the said plane out of the field. A pair of parallel tracks positioned between the spaced rows of magnets guide the ball and a clamping means orient and retain the magnets.

1980-07-29

176

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

177

Permanent-Magnet Generators  

Microsoft Academic Search

Based on the theory of permanent-magnet generators piresented in Part I,1 design equations are derived for the short-circuit stabilized generator, and it is shown that the design may be optimized to yield the smallest machine for given specifications. A relationship between short-circuit current and inherent voltage regulation is given. The influence of some design parameters is discussed and recommendations are

D. J. Hanrahan; D. S. Toffolo

1963-01-01

178

Nerve growth factor receptor-like immunoreactivity in primary and permanent canine tooth pulps of the cat  

Microsoft Academic Search

The distribution of nerve growth factor receptor (NGF receptor)-like immunoreactivity in pulps of developing primary and mature permanent cat canine teeth was examined, by use of a monoclonal antibody against NGF receptor detected by fluorescence immunohistochemistry and pre-embedding immunocytochemical light- and electron microscopy. Both primary and permanent pulps contained a vast number of NGF receptor-like immunoreactive nerves. Immunolabelling appeared to

K. Fried; M. Risling

1991-01-01

179

Effect of toothless stator design and core and stator conductors eddy current losses in permanent magnet generators  

Microsoft Academic Search

Some advantages of toothless stator design in high-speed permanent magnet generators are presented. A computer-aided method was implemented to study the effect of stator teeth on the eddy current loss in the stator conductors as well as the core loss in the laminations of high-speed permanent magnet generators. The computer-aided method was applied to a 75 kVA, 208 V, 400

A. A. Arkadan; R. Vyas; J. G. Vaidya; M. J. Shah

1992-01-01

180

Differences in the D\\/L aspartic acid ratios in dentin among different types of teeth from the same individual and estimated age  

Microsoft Academic Search

We have studied the correlation between the level of D-aspartic acid in dentin and the period of dentin formation in different types of teeth from the same individual. Except for the third molar, it is generally agreed that the formation of permanent dentin follows the pattern of growth, occurring earliest in the first molar and last in the second molar.

S. Ohtani; R. Ito; T. Yamamoto

2003-01-01

181

Lead exchange in teeth and bone--a pilot study using stable lead isotopes.  

PubMed Central

Stable lead isotopes and lead concentrations were measured in the enamel and dentine of permanent (n = 37) and deciduous teeth (n = 14) from 47 European immigrants to Australia to determine whether lead exchange occurs in teeth and how it relates to lead exchange in bone. Enamel exhibits no exchange of its European-origin lead with lead from the Australian environment. In contrast, dentine lead exchanges with Australian lead to the extent of approximately 1% per year. In one subject, trabecular bone from the tooth socket exchanged almost all its European lead with Australian lead over a a 15-year period (turnover of approximately 6% per year), similar to the approximately 8% per year proposed for lead turnover in trabecular bone. The repository characteristics of intact circumpulpal dentine were investigated by analyses of four sets of contiguous slices from six teeth: 1) a set consisting of slices with intact circumpulpal dentine and cementum; 2) a set in which these areas were removed; 3) another set consisting of slices with intact circumpulpal dentine and cementum; and 4) a set without cementum. These analyses show relatively small differences in isotopic composition between contiguous slices except that circumpulpal dentine appears to be the dominant control on lead concentration. There is a significant correlation (R2 = 0.19, p = 0.01, n = 34) of dentine lead concentration and rate of exchange with residence time from the country of origin and Australian lead, but there is no such correlation with enamel lead concentration. Analyses of permanent and deciduous teeth of subjects from other countries who have resided in Australia for varying lengths of time should resolve some of the questions arising from this pilot study. Images Figure 1.

Gulson, B L; Gillings, B R

1997-01-01

182

[Rare earth magnets in conjunction with fixed orthodontics. An "attractive" solution for the positioning of impacted teeth].  

PubMed

Two rare earth permanent magnets are used to align impacted teeth: one is bonded on the crown of the ectopic tooth, the other, intraoral, guides the impacted tooth to the desired place by its attractive power. The intraoral magnet is fixed to an edgewise arch. The adjustments allowed by fixed appliance create better final tooth position than with removable appliance. Our experience depicts an improvement of stability in results and a diminution of periodontal breakdown. PMID:11862903

Dereudre, B

2001-11-01

183

ESR dating of teeth from Brazilian megafauna  

NASA Astrophysics Data System (ADS)

The study of radiation defects created in biomaterials, such as bone and teeth, can be used in dating with importance to palaeontology and archaeology. Two Stegomastodon teeth (AL1 and AL2) from north-eastern Brazilian megafauna were studied by electron spin resonance (ESR) spectroscopy. The samples were collected in Fazenda Ovo da Ema, (913349 / 3714965) UTM, Alagoas state, Brazil. The dating of these samples can contribute to the better knowledge of megafauna presence in this region as well as to the events associated to the extinction of these species.

Oliveira, L. C.; Kinoshita, A.; Barreto, A. M. F.; Figueiredo, A. M.; Silva, J. L. L.; Baffa, O.

2010-11-01

184

Evaluation of experimental permanent magnet brushless motor utilizing new magnetic material for stator teeth core  

Microsoft Academic Search

A magnetic characteristic measurement, a motor characteristic prediction, and an experimental evaluation of motors using various magnetic materials were performed to identify features of various magnetic materials, which are used in a motor core as a magnetic material. The results are as follows: (1) Motor with amorphous metal sheet showed very high motor efficiency, with its high permeability and extremely

Y. Enomoto; M. Ito; H. Koharagi; R. Masaki; S. Ohiwa; C. Ishihara; M. Mita

2005-01-01

185

Fatigue resistance of teeth restored with fiber posts and different post cementation strengths.  

PubMed

This study sought to evaluate how different post cementation strategies affected the fatigue resistance of bovine teeth restored with glass fiber posts. The canals of 63 single-rooted bovine teeth (each 16 mm in length) were prepared to 9 mm using a preparation drill from a double-tapered fiber post system. Each specimen was embedded in a PVC cylinder using acrylic resin up to 3 mm of the most coronal portion of the specimen and was allocated into one of seven groups (n = 9) based on the strategies for cementation. After cementation, a standard core build-up was made with composite resin. The specimens were stored for seven days and submitted to mechanical cycling (50 N, 8 Hz, 37 degrees C). After fatigue testing, a score was given to each specimen, based on the number of fatigue cycles required to fracture the specimens; the scores were submitted to statistic analysis (Kruskal-Wallis, alpha = 0.05). The strategy for post cementation did not affect the resistance to fatigue (P = 0.8669). Based on the results, the resistance to fatigue does not appear to depend on the post cementation strategy. PMID:19819817

Valandro, Luiz Felipe; Zardin, Lucas Wadas; de Villa, Marco Antonio; Amaral, Marina; Galhano, Graziela; Baldissara, Paolo; Bottino, Marco Antonio

186

Cryogenic Permanent Magnet Undulators  

SciTech Connect

For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

Chavanne, J.; Lebec, G.; Penel, C.; Revol, F. [European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble Cedex 9 (France); Kitegi, C. [Synchrotron SOLEIL-L'Orme des Merisiers Saint-Aubin-BP 48 91192 GIF-sur-YVETTE (France)

2010-06-23

187

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 Nd2Fe14B. 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 14.4T 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

188

Elephant teeth from the atlantic continental shelf.  

PubMed

Teeth of mastodons and mammoths 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, anz 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. PMID:17741070

Whitmore, F C; Emery, K O; Cooke, H B; Swift, D J

1967-06-16

189

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

190

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

191

Aesthetic Parameters of Lower Anterior Teeth.  

National Technical Information Service (NTIS)

The training in aesthetic parameters has been, for the most part, confined to the upper arch, yet there are studies which show that as age increases, more is seen of the lower anterior teeth. To design a lower anterior fixed prosthesis for good aesthetics...

L. Lorton P. Whitbeck

1979-01-01

192

Elephant Teeth from the Atlantic Continental Shelf  

Microsoft Academic Search

Teeth of mastodons and mammoths 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.

Frank C. Whitmore Jr.; K. O. Emery; H. B. S. Cooke; Donald J. P. Swift

1967-01-01

193

Expression of phosphoproteins and amelotin in teeth.  

PubMed

The organic material of our teeth consists of collagens and a number of calcium-binding phosphoproteins. Six of these phosphoproteins have recently been grouped in the family of the SIBLINGs (small integrin-binding ligand, N-linked glycoproteins), namely osteopontin, bone sialoprotein, dentin matrix protein (DMP1), dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE) and enamelin. We prepared a cDNA library from rat incisors in order to identify the genes involved in tooth formation. The library was screened by subtractive hybridization with two probes; one specific for teeth, the other for bone. We found that the vast majority of the clones from our library were expressed at similar levels in bone and teeth, demonstrating the close relationship of the two tissues. Only 7% of all the clones were expressed in a tooth-specific fashion. These included clones for the enamel proteins; amelotin, amelogenin, ameloblastin and enamelin; for the dentin proteins DSPP and DMP1; and for the intermediate filament protein cytokeratin 13. Several typical bone proteins, including collagen I, osteocalcin, alkaline phosphatase and FATSO, were also expressed at significantly higher levels in teeth than in bone, probably due to the extreme growth rate of rat incisors. The amino acid sequence of rat amelotin showed 62% identity with the sequence from humans. It was expressed considerably later than the other enamel proteins, suggesting that amelotin may serve a function different from those of amelogenin, ameloblastin and enamelin. PMID:17143547

Trueb, Beat; Taeschler, Sara; Schild, Christof; Lang, Niklaus P

2007-01-01

194

Other Ways to Clean between the Teeth  

MedlinePLUS

... to the tooth. But they are great for flushing out food and debris in pockets between teeth, or in braces. They also are used to deliver medicine to hard-to-reach areas. For example, prescription rinses can be sprayed into gum pockets with ...

195

Generalized familial crown resorptions in unerupted teeth.  

PubMed

This paper reports the case of 2 sisters with generalized familial crown resorptions, including co-occurrence of familial dental abnormalities of severe crown resorption, failure of eruption, and congenitally missing teeth, which have not been described earlier in the literature. PMID:21494390

Miloglu, Ozkan; Goregen, Mustafa; Akgul, Hayati Murat; Harorli, Abubekir

2011-04-01

196

Cartilage (Bovine and Shark) (PDQ)  

MedlinePLUS

... Research & Funding News About NCI Cartilage (Bovine and Shark) (PDQ®) Patient Version Health Professional Version Last Modified: 02/19/2013 Cartilage (Bovine and Shark) (PDQ®) Overview Questions and Answers About Cartilage (Bovine ...

197

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.

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

2012-01-01

198

Apexogenesis and revascularization treatment procedures for two traumatized immature permanent maxillary incisors: a case report  

PubMed Central

Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Endodontic treatment is often complicated in premature tooth with an uncertain prognosis. This article describes successful treatment of two traumatized maxillary central incisors with complicated crown fracture three months after trauma. The radiographic examination showed immature roots in maxillary central incisors of a 9-year-old boy with a radiolucent lesion adjacent to the right central incisor. Apexogenesis was performed for the left central incisor and revascularization treatment was considered for the right one. In 18-month clinical and radiographic follow-up both teeth were asymptomatic, roots continued to develop, and periapical radiolucency of the right central incisor healed. Considering the root development of these contralateral teeth it can be concluded that revascularization is an appropriate treatment method in immature necrotic teeth.

Forghani, Maryam; Maghsoudlou, Amir

2013-01-01

199

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

200

Natal teeth: Case report and review of literature  

PubMed Central

The presence of teeth at birth or within a month post-delivery is a rare condition. A newborn, a 2 days old female, with two mandibular incisor natal teeth was examined. The teeth were mobile and were extracted because of the fear of aspiration and refusal to feed. The purpose of this report is to review the literature related to natal teeth epidemiology and discuss their possible etiology and treatment.

Rao, Roopa S; Mathad, Sudha V

2009-01-01

201

Prevalence and pattern of hypodontia in the permanent dentition of 3374 Iranian orthodontic patients  

PubMed Central

Background: Hypodontia is the most common dental anomaly and might cause clinical complications. The aim of this study was to assess the prevalence and pattern of congenital missing in the permanent dentition dentition (excluding third molars), among Iranian orthodontic patients. Materials and Methods: In this descriptive cross-sectional study, all approved panoramic radiographs of 3374 orthodontic patients (aged 10 to 20 years old), who had visited the Orthodontic Departments of all Tehran Dentistry Universities and 10 private clinics during the years 1999 to 2009 were investigated, to establish the prevalence of hypodontia in the permanent dentition (excluding third molars). The data were analyzed using a chi-square test (? = 0.01). Results: Included were 2012 female and 1362 male patients. The prevalence of hypodontia was 5.21% (5.86% in females, 4.25% in males). The difference between the genders in terms of missing teeth was not significant (P = 0.202). A total of 298 teeth were missing (166 in females, 132 in males). The average of missing per individual was found to be 1.69 (1.40 missing for each girl, 2.32 for each boy). There was no significant difference between the number of missing teeth in males and females (P = 0.160). The most common missing teeth were maxillary lateral incisors (37.2%), mandibular second premolars (22.1%), and mandibular central incisors (10.7%). In both unilateral and bilateral hypodontia cases, the maxillary lateral had the highest prevalence of missing, followed by the mandibular second premolar. Missing was significantly more frequent (P = 0.001) in the maxilla (5.3%) compared to the mandible (3.5%). Conclusion Out of every 20 Iranian orthodontic patients, one might have some missing permanent teeth, needing early attention. Hypodontia was more prevalent in females (though not significantly) and in the maxilla. Although more females were affected, the number of missing per individual was greater in males.

Amini, Fariborz; Rakhshan, Vahid; Babaei, Pardis

2012-01-01

202

An endo-aesthetic management of crown dilaceration in a permanent mandibular central incisor.  

PubMed

Traumatic injuries to primary dentition may result in a wide range of developmental disturbances to succedaneous permanent teeth. The prevalence of morphological disturbances, secondary to dental injuries in the primary dentition, ranges from 12% to 69%. One of the morphological disturbances are crown dilacerations which are defined as the displacement of a portion of the developing crown at an angle to the longitudinal axis of the tooth. The prevalence of crown dilaceration constitutes 3% of the total injuries in developing teeth and is usually because of intrusion or avulsion of their primary predecessors. The present article narrates a case of crown dilaceration of a permanent mandibular right central incisor with open apex and large periradicular pathosis and its endo-aesthetic management with 2 years of follow-up. PMID:23417377

Wankhade, Abhijit D; Pandey, Ramesh Kumar; Singh, Rajeev Kumar; Naphade, Milind V

2013-02-14

203

Transplantation of premolars as an approach for replacing avulsed teeth.  

PubMed

Autotransplantation of premolars to the anterior region subsequent to tooth loss represent a unique treatment method that has a number of advantages in comparison with other tooth substitution methods. A tooth transplant has a bone inducing capacity implying that lost labial bone is regenerated. Secondly the tooth precipitates growth of the alveolar procces and allows treatment to be performed at an early age (10-12 years) where the trauma incidence is at its maximum. Finally transplanted teeth can be moved orthodontically. These characteristics make implant solutions appealing in a number of situations. The procedure consist in selecting a premolar in a optimal root development stage which is approximately three fourths root formation where optimal pulp and periodontal ligament healing can be achieved in more than 90 percent of the cases. The tooth is later after slight crown remodeling restored with composite or a porcelain laminate. Four recent long-term studies have shown survival rates between 90-98 percent and a single long term study (33 years) showed a survival rate of 90 percent, a survival rate not surpassed by any other type of tooth replacement (fixed or removable prostetics, implants). In conclusion premolar transplantation should be considered in cases of early loss of a permanent tooth. PMID:19455931

Andreasen, Jens Ove; Schwartz, Ole; Kofoed, Thomas; Daugaard-Jensen, Jette

204

Natural Teeth Replacing Artificial Teeth in a Partial Denture: A Case Report  

PubMed Central

The aesthetic replacement of anterior teeth in cases of immediate partial denture is always a challenging work for prosthodontists. There is always problem of matching size, colour, shade and shape of the replaced tooth with those of the natural teeth. It was most difficult to satisfy the patients who have high aesthetic demands. Here is a report of a case where patient’s own natural tooth was used for replacement in an immediate partial denture. An immediate denture is defined as “any removable dental prosthesis which is fabricated for placement immediately, following the removal of a natural tooth/teeth” . Patients with missing anterior teeth lack an impressive appearance aesthetically and as well as psychologically. Tooth loss leads to a certain degree of loss of function. This loss of function might lead to an impairment of oral health which is related to quality of life. An immediate denture can replace 1-16 teeth in either the maxillary or the mandibular arch, or in both arches. The need for the immediate replacement of a missing tooth is more in case of an anterior tooth, where aesthetics is of prime concern. The replacement of an anterior tooth is most technique sensitive, as it includes the patient’s expectations, which include, matching with proper shade, shape and size as those of his/her natural teeth. So, here is a case presentation where modern day patient expectations were taken into consideration.

Satapathy, Sukanta Kumar; Pillai, Ajay; Jyothi, Ramya; Annapurna, P. Durga

2013-01-01

205

Teeth and tongue discoloration after linezolid treatment in children.  

PubMed

We describe 3 children who developed teeth and tongue discoloration while receiving intravenous linezolid for 2 to 3 weeks. Linezolid was coadministered with piperacillin-tazobactam or meropenem. Teeth and tongue discoloration was reversible with dental cleaning after discontinuation of linezolid. We review the published pediatric and adult cases regarding teeth and tongue discoloration after linezolid administration. PMID:23934205

Petropoulou, Theoni; Lagona, Evagelia; Syriopoulou, Vassiliki; Michos, Athanasios

2013-11-01

206

Apexification of wide-open apices in nonvital, immature permanent incisors: a case report.  

PubMed

Apexification is the accepted procedure to form an apical stop in nonvital teeth with incomplete root formation. A case is presented in which apexification with calcium hydroxide was performed on two permanent central incisors with immature roots and wide-open apices; treatment concluded with gutta-percha root canal restoration. Spontaneous apical seal had probably been initiated before the calcium hydroxide was inserted, but it was weak and nonhomogenous. PMID:20830893

Peretz, B

1993-11-01

207

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...

208

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. Am J Phys Anthropol 152:163-164, 2013. © 2013 Wiley Periodicals, Inc. PMID:23907722

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

2013-07-30

209

Recovering the function and esthetics of fractured teeth using several restorative cosmetic approaches. Three clinical cases.  

PubMed

The teeth most commonly affected by trauma are the maxillary central incisors. The most frequent types of traumatic dental injuries to permanent teeth are enamel fractures, enamel and dentine fractures, and enamel and dentine fractures with pulp involvement. This article describes three clinical cases with different levels of traumatized maxillary incisors and several cosmetic approaches for recovery of the esthetics and the masticatory function, as well as the social/psychological aspects of treatment. All cases involved young adult men. The three clinical cases involve dentin and enamel fractures, dentin and enamel fractures with pulp exposure, and dentin and enamel fractures with pulp exposure associated with root fracture. The cosmetic treatments used to resolve fractures were direct composite resin by layering technique, indirect all-ceramic restorations (laminate veneer and ceramic crowns over the teeth), and immediate implant after extraction followed by immediate loading (ceramic abutments with ceramic crown over implant). In all three cases, excellent functional and esthetic results were achieved by use of these treatment modalities. The patients were very satisfied with the results. PMID:21854545

Anchieta, Rodolfo B; Rocha, Eduardo P; Watanabe, Maurício U; de Almeida, Erika O; Freitas-Junior, Amilcar C; Martini, Ana P; Barioni, Sônia R P

2011-08-19

210

Permanent Magnets in Power Tools  

Microsoft Academic Search

\\u000a The use of permanent magnets in the power tool industry is explored. The paper describes the benefits and issues of migrating\\u000a from ferrite to bonded Neodymium magnets. The power tool industry requests new materials from the permanent magnet industry.

Richard Walter; Brandon Verbrugge

211

Transient and permanent neonatal diabetes  

Microsoft Academic Search

Neonatal diabetes, which may be transient or permanent, is rare. Most patients are full-term but small- for-date infants. Typical symptoms of diabetes mellitus occur within the first 4 weeks of life, requiring insulin therapy and very strict blood glucose monitoring. Subsequent growth and psychomotor development are usually normal. In about 33% of these patients the diabetes remains permanent; the transient

Stephan Fösel

1995-01-01

212

Achieving Permanency for LGBTQ Youth  

Microsoft Academic Search

The Adoption and Safe Families Act (ASFA) of 1997 requires states to assure the permanency, safety and well being for all children and youth in the foster care system. Although there has been considerable progress in achieving permanency for many children and youth, some youth in foster care - particularly lesbian, gay, bisexual, transgender, and questioning (LGBTQ) youth - have

Madelyn Freundlich

213

Super strong permanent dipole magnet  

Microsoft Academic Search

The authors have been developing very strong permanent magnets. In the past, our magnets could generate greater than 5 Tesla dipole fields. We are now in a process of reaching much higher fields. The present paper is devoted to describing magnetic design developments in order to obtain super strong magnetic fields (of order of several Tesla magnitudes) with permanent magnets

Masayuki Kumada; Evgeny I. Antokhin; Yoshihisa Iwashita; Masaaki Aoki; Eiji Sugiyama

2004-01-01

214

[The Object Permanence Fallacy.] Commentary.  

ERIC Educational Resources Information Center

|Suggests that Greenberg's challenge to the centrality of object permanence in developmental thinking reveals that developmentalists' theories about childhood speak about their own self-images. Notes that developmentalists have been guilty of not only the object permanence fallacy but also the genetic fallacy, or the mistaken belief that…

Bradley, Ben S.

1996-01-01

215

Permanents in linear optical networks  

Microsoft Academic Search

We develop an abstract look at linear optical networks from the viewpoint of combinatorics and permanents. In particular we show that calculation of matrix elements of unitarily transformed photonic multi-mode states is intimately linked to the computation of permanents. An implication of this remarkable fact is that all calculations that are based on evaluating matrix elements are generically computationally hard.

Stefan Scheel

2004-01-01

216

Achieving Permanency for LGBTQ Youth  

ERIC Educational Resources Information Center

|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…

Jacobs, Jill; Freundlich, Madelyn

2006-01-01

217

Morphometric study of teeth in age calculation.  

PubMed

The diagnostic usefulness of some morphometric parameters of teeth in age determination were studied. In the first series 173 central incisors from 13-83 year-old individuals were examined and in the second series 72 teeth from 30 individuals (aged 39 to 80 years). Root transparency and dentinal tubule diameter were the most reliable parameters on the basis of image analysis (IBAS system) of scanning electron microscopic images. These variables were used in multiple linear regression analyses which led to the exclusion of secondary dentine as it did not improve the fit and therefore did not help to explain the dependent variable. The precise measurement of the morphometric variables we used facilitates age determination, reducing the mean error reported by other authors who used subjective estimates. Our results document the limited effectiveness of these parameters in age estimation due to individual variations caused by genetic factors and chewing habits. PMID:9227058

Lopez Nicolas, M; Morales, A; Luna, A

1993-06-01

218

Stimulus-evoked pain in teeth.  

PubMed

When pain occurs in teeth as a result of external stimulation it is more likely to be due to physical factors affecting the enamel and dentine than to pulp disease. The mechanisms are described, clinical conditions are mentioned and a speculative attempt is made to correlate them by introducing the idea of streaming potentials in the dentine and pulp. The pain perception threshold is considered in relation to different teeth, age, sex, lateral dominance, personality, and the area of electrode contact. The latter has proved interesting, for manipulation of it has led to possibly important findings on the nature of convergence in the trigeminal system, two-point discrimination, referred pain and somatopic representation of dental pulps in the medulla oblongata. PMID:1067220

Mumford, J M

1976-01-01

219

Teaching parents to look after children's teeth.  

PubMed

Children's toothpastes with fluoride help to prevent decay, but parents should ask their dentist before giving fluoride supplements to children. Overdosage is harmful. Sugars eaten as part of a meal do less harm to teeth than those eaten frequently as snacks. Sugar-free infant drinks and children's confectionery are now on the market and are more "tooth friendly". Look out for the "happy tooth" symbol. Babies can be registered with NHS dentists as soon as the first teeth start to come through, and should be taken regularly to the dentist throughout childhood. Under the NHS scheme, dentists are paid a capitation fee to provide continuing preventive care and treatment for children free of charge. PMID:8680157

Lloyd, S

1994-03-01

220

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

221

Dissolution of human teeth-derived hydroxyapatite.  

PubMed

We have been interested in human teeth which consist of hydroxyapatite (HA), but do not degrade for a long time. In order to overcome dissolution and mechanical degradation of man-made HA, biologically derived hydroxyapatite (BHA) ceramics were prepared from human teeth and their dissolving behavior was investigated in distilled water for 3-14 days and compared with an artificial HA made of synthetic HA powder. BHA ceramics were prepared by calcining freshly extracted human teeth at 900 degrees C and followed by sintering at 1200 degrees C for 2 h. All detectable peaks in the artificial HA are identical to HA lattice planes, whereas BHA consisted of a mixture of HA and beta-tricalcium phosphate (TCP). Although the artificial HA was expected to be stable in water, the surface dissolution initiated at grain boundaries followed by generated many separated grains and their associated pores. On the other hand, BHA showed that definite grains considered as beta-TCP were predominantly dissolved and the grains were separated from the matrix leaving pores. In the mean time, the rest region, mainly consisting of HA, did not show any evidence of dissolution. It indicates that BHA showed rather stable grain boundaries and lack of excessive dissolution in liquid environment. PMID:17943445

Seo, Dong Seok; Lee, Jong Kook

2007-10-18

222

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.

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

2013-01-01

223

Replacements of restorations in the primary and young permanent dentition.  

PubMed

The present study focused on the type of restorative material used and the reasons for replacements of restorations in the primary and the young permanent dentition. All patients with restorations and who were 8 and 19 years of age in 1995 and were regularly treated at 11 Public Dental Health clinics in Jönköping County, Sweden, participated in the study. Data were extracted from the records for all types of restorations in canines and molars for the preceeding of 5 years for the 8-year-olds (i.e. from 3 to 8 years of age; n = 546) and for approximal restorations in premolars and molars for the preceeding 13 years for the 19-year-olds (i.e. from 6 to 19 years of age; n = 606). In all, 6012 restorations were evaluated. The two most common restorative materials used in the primary dentition were compomer and glass ionomer cement and in the young permanent dentition composite and amalgam. In the primary dentition, 29% of the restorations had been replaced and 4% of the teeth with restorations had been extracted. Thus, 33% of the restorations in the primary dentition failed. The corresponding figure for the young permanent dentition was 13%. The most common reason for replacements in the permanent dentition was secondary caries. That restorations often fail because of caries and that the development of secondary caries is not prevented by replacement of an old restoration indicate that more attention should be paid to preventive dental care for patients with restorations in the primary as well as in the young permanent dentition. PMID:9850557

Wendt, L K; Koch, G; Birkhed, D

1998-01-01

224

Genes and their effects on dental caries may differ between primary and permanent dentitions.  

PubMed

The importance of genetic factors in the genesis of dental caries of both primary and permanent dentitions is well established; however, the degree to which genes contribute to the development of dental caries, and whether these genes differ between primary and permanent dentitions, is largely unknown. Using family-based likelihood methods, we assessed the heritability of caries-related phenotypes for both children and adults in 2,600 participants from 740 families. We found that caries phenotypes in the primary dentition were highly heritable, with genes accounting for 54-70% of variation in caries scores. The heritability of caries scores in the permanent dentition was also substantial (35-55%, all p < 0.01), although this was lower than analogous phenotypes in the primary dentition. Assessment of the genetic correlation between primary and permanent caries scores indicated that 18% of the covariation in these traits was due to common genetic factors (p < 0.01). Therefore, dental caries in primary and permanent teeth may be partly attributable to different suites of genes or genes with differential effects. Sex and age explained much of the phenotypic variation in permanent, but not primary, dentition. Further, including pre-cavitated white-spot lesions in the phenotype definition substantially increased the heritability estimates for dental caries. In conclusion, our results show that dental caries are heritable, and suggest that genes affecting susceptibility to caries in the primary dentition may differ from those in permanent teeth. Moreover, metrics for quantifying caries that incorporate white-spot lesions may serve as better phenotypes in genetic studies of the causes of tooth decay. PMID:20516689

Wang, X; Shaffer, J R; Weyant, R J; Cuenco, K T; DeSensi, R S; Crout, R; McNeil, D W; Marazita, M L

2010-05-27

225

School teachers' knowledge of tooth avulsion and dental first aid before and after receiving information about avulsed teeth and replantation.  

PubMed

School teachers can play an important role in improving the prognosis of avulsed permanent teeth of school children after they are informed about the immediate and proper dental first aid steps to be taken at the time of an accident. The aims of this study were: (i) to assess the knowledge level of emergency measures for tooth avulsion in Kuwaiti intermediate school teachers and (ii) to determine if a short lecture about tooth avulsion and replantation could improve teachers' knowledge on this topic. Eighty-five teachers at two intermediate schools (children 10-14 years old) in Kuwait were interviewed using a questionnaire about their first-aid knowledge with particular focus on the following five categories: General knowledge of teeth and avulsion, replantation of primary and permanent teeth, how to clean an avulsed tooth before replantation, extra-oral time and storage methods and media for an avulsed tooth. For each category, a score ranging from 0-3 was possible. An informative 30-min lecture about tooth avulsion and replantation was presented to a group of 43 teachers. After the lecture, the knowledge level of the teachers was re-tested using the same method. Descriptive statistics was used to describe and analyze the data. Improvement in teacher knowledge to an adequate (score of 2) or complete (score of 3) level was observed after the lecture in all five categories. The general knowledge of tooth avulsion and replantation improved from 39% to 97% and knowledge of avulsed permanent and primary teeth from 8% to 71%. Knowledge of how to clean an avulsed tooth improved from 5% to 93%. The knowledge level on the importance of extra-alveolar time before replantation increased from 1% to 74% and knowledge of a suitable storage medium for the avulsed tooth improved from 4% to 86%. Many avulsed permanent teeth in school children can be saved by replantation if school teachers learn what to do when a tooth is avulsed. A lecture followed by discussion proved to be an effective and efficient method of intervention to enhance the knowledge level of teachers so that proper dental first-aid procedures can be achieved. PMID:18173664

Al-Asfour, Adel; Andersson, Lars; Al-Jame, Quomasha

2008-02-01

226

The FiCTION dental trial protocol - filling children's teeth: indicated or not?  

PubMed Central

Background There is a lack of evidence for effective management of dental caries (decay) in children’s primary (baby) teeth and an apparent failure of conventional dental restorations (fillings) to prevent dental pain and infection for UK children in Primary Care. UK dental schools’ teaching has been based on British Society of Paediatric Dentistry guidance which recommends that caries in primary teeth should be removed and a restoration placed. However, the evidence base for this is limited in volume and quality, and comes from studies conducted in either secondary care or specialist practices. Restorations provided in specialist environments can be effective but the generalisability of this evidence to Primary Care has been questioned. The FiCTION trial addresses the Health Technology Assessment (HTA) Programme’s commissioning brief and research question “What is the clinical and cost effectiveness of restoration caries in primary teeth, compared to no treatment?” It compares conventional restorations with an intermediate treatment strategy based on the biological (sealing-in) management of caries and with no restorations. Methods/Design This is a Primary Care-based multi-centre, three-arm, parallel group, patient-randomised controlled trial. Practitioners are recruiting 1461 children, (3–7 years) with at least one primary molar tooth where caries extends into dentine. Children are randomized and treated according to one of three treatment approaches; conventional caries management with best practice prevention, biological management of caries with best practice prevention or best practice prevention alone. Baseline measures and outcome data (at review/treatment during three year follow-up) are assessed through direct reporting, clinical examination including blinded radiograph assessment, and child/parent questionnaires. The primary outcome measure is the incidence of either pain or infection related to dental caries. Secondary outcomes are; incidence of caries in primary and permanent teeth, patient quality of life, cost-effectiveness, acceptability of treatment strategies to patients and parents and their experiences, and dentists’ preferences. Discussion FiCTION will provide evidence for the most clinically-effective and cost-effective approach to managing caries in children’s primary teeth in Primary Care. This will support general dental practitioners in treatment decision making for child patients to minimize pain and infection in primary teeth. The trial is currently recruiting patients. Trial registration Protocol ID: NCTU: ISRCTN77044005

2013-01-01

227

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 ...

228

Teeth erupted from the buccal mucosa: simple odontogenic choristoma or accessory teeth?  

PubMed

The eruption of developed teeth from the buccal mucosa is a rare phenomenon in the head and neck region. Such phenomena are possibly choristomas, tumorlike masses of histologically normal tissue occurring in an abnormal position. However, the accurate classification of this abnormality remains debatable. This report describes a case of a congenital, maldevelopmental, and noncystic lesion in a 4-year-old girl without other anomalies. To the authors' knowledge, this is the first case of multiple supernumerary teeth forming in the buccal and zygomatic regions. PMID:23992778

Liu, Yanbin; Huang, Yi; Yu, Tao; Li, Longjiang

2013-08-29

229

Influence of fatigue testing and cementation mode on the load-bearing capability of bovine incisors restored with crowns and zirconium dioxide posts  

Microsoft Academic Search

The aim of the study was to evaluate the influence of fatigue and cementation mode on the fracture behavior of endodontically\\u000a treated bovine incisors restored with zirconium dioxide posts and crowns. Forty-eight endodontically treated bovine primary\\u000a incisors were restored with zirconium dioxide posts (Cerapost, Brasseler), composite build-ups, and crowns cast from a chromium\\u000a cobalt alloy. In 16 teeth, each of

F. P. Nothdurft; T. Schmitt; P. J. Motter; P. R. Pospiech

2008-01-01

230

Microleakage of CEM Cement and ProRoot MTA as Furcal Perforation Repair Materials in Primary Teeth  

PubMed Central

Introduction: Iatrogenic furcal perforation is a procedural accident in endodontic treatments of primary/permanent teeth; prognosis may be favorable if a complete seal with biomaterial is immediately established. The purpose of this in vitro study was to evaluate microleakage of calcium enriched mixture (CEM) cement and ProRoot mineral trioxide aggregate (MTA) for sealing primary molar furcal perforations. Materials and Methods This study was conducted on 38 extracted human primary molars. Furcation perforations were created in the pulp chamber floor. The teeth were divided randomly in two experimental groups (n=17) and two positive and negative controls (n=2). Perforations were then repaired with biomaterials. After 72 h, the teeth were submerged in 2% fuchsin dye solution for 24h. The samples were sectioned longitudinally and evaluated for dye leakage. Data analyzed statistically using ANOVA test. Results: The negative and positive controls behaved as expected. Dye microleakage was observed in all experimental samples; however, there was no statistically significant difference between the microleakage of MTA (4.411±2.042 mm) and CEM (3.647±1.040 mm) groups (P>0.05). Conclusion: Based on the findings of this in vitro study, CEM and tooth-colored ProRoot MTA have similar sealing ability for furcal perforation repair of primary molar teeth.

Haghgoo, Roza; Arfa, Sara; Asgary, Saeed

2013-01-01

231

Diffusion of metals from crown into teeth  

NASA Astrophysics Data System (ADS)

In an attempt to explore the diffusion of metals from crown to tooth interior, measurements have been made of distribution profiles for metal constituents of crowns on human teeth using PIXE spectroscopy. A beam of 3-MeV protons was collimated to provide spatial resolution of 300 ?m in order to measure element distribution across a section of tooth. Samples had different types of alloy used in building each crown and the crowns had existed for different time durations prior to study. Results are presented and discussed.

Tadi?, T.; Jakši?, M.; Babi?-Živko, J.; ?i?ek, J.; Fazini?, S.; Valkovi?, V.

1990-04-01

232

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.

2012-02-01

233

Coronal reconstruction following anterior teeth traumatism: multidisciplinary treatment.  

PubMed

This study describes how periodontology, endodontology, and dentistry were integrated for the coronal reconstruction of anterior teeth extensively destroyed by dental trauma. A 15-year-old girl suffered a bicycle accident that resulted in the fracture of teeth No. 8 and 9. Clinical and radiographic examinations confirmed coronal fracture in both teeth, in addition to compromised pulp vitality, invasion of the biologic periodontal space, and loss of coronal space due to mesialization of the neighboring teeth. The protocol consisted of endodontic treatment for the fractured teeth, periodontal surgery to augment the clinical crown and gingival recontouring, intracanal cementation of esthetic glass fiber posts, and coronal reconstruction with resin composite. At a longitudinal follow-up visit 1 year later, clinical and radiographic examinations revealed successful rehabilitation of the fractured teeth. PMID:23928439

Cohen-Carneiro, Flavio; Sponchiado, Emilio Carlos; Garcia, Lucas do Fonseca Roberti; Yurtsever, Fikriye Viga; Pontes, Danielson Guedes; Sena, Amilen

2013-08-01

234

Shape optimization of closed slot type permanent magnet motors for cogging torque reduction using evolution strategy  

SciTech Connect

Permanent magnet motors have been used in a wide variety of industrial applications. For the improvement of servo performances in the permanent magnet motors, a closed slot is adopted in the stator and a rare-earth magnet is used in the rotor. Here, the analysis of a permanent magnet type AC servo motor with both a closed slot and a ring shape magnet is performed by using the finite element method (FEM). The saturation of the bridge part connecting two slot teeth is considered for a nonlinear analysis. The optimal design of the stator is presented for minimizing cogging torque. The torques, i.e., cogging and rated torques are expressed in terms of vector potential computed by directly applying the Maxwell Stress Tensor formula. The minimization of cogging torque of sample model is achieved by using the (1+1) Evolution Strategy (ES) and the rated torque must be more than the specific value.

Chun, J.S.; Jung, H.K. [Seoul National Univ. (Korea, Republic of). School of Electrical Engineering; Yoon, J.S. [LG Industrial Systems Co., Ltd., Anyang, Kyongki (Korea, Republic of)

1997-03-01

235

Personal ViewIt's only teething... A report of the myths and modern approaches to teething  

Microsoft Academic Search

Paediatric dentistry is not my usual field of work. I am now based almost entirely in restorative dentistry and it is five years since I worked in the dental department of a children's hospital. An essay on teething would appear to be an unusual choice of topic. With the current professional climate of 'general professional education' and 'lifelong learning' I

M P Ashley

2001-01-01

236

Application of dimorphism in teeth to age calculation.  

PubMed

The objective of this study was to determine which teeth provide the most reliable data for use in age estimation. We studied 170 teeth from the anterior region (central and lateral incisors, and canines) and used an image analysis technique to analyse a number of morphometric features in thin sections of tooth. Our results showed root translucency to be the variable most clearly related to the subject's age, and the canine teeth to provide the most reliable information on this variable. PMID:9227075

López-Nicolás, M; Morales, A; Luna, A

1996-06-01

237

Fragment bonding of fractured anterior teeth: case report.  

PubMed

The unharmonious esthetic appearance of anterior teeth can be caused by changes in tooth color, shape, and size or by traumatic dental injury. Because the fragment bonding technique can restore functionality, morphology, and especially esthetics, it should be one of the choices in the restoration of fractured anterior teeth if the fragment is available. This article describes a clinical case of bonding of fractured anterior teeth and demonstrates how an esthetic appearance can be satisfactorily restored without wear to sound structure. PMID:20490387

Kina, Mônica; Ribeiro, Luciana Gazaniga Maia; Monteiro, Sylvio; de Andrada, Mauro Amaral Caldeira

2010-06-01

238

Cleidocranial dysplasia presenting with retained deciduous teeth in a 15-year-old girl: a case report  

PubMed Central

Introduction Cleidocranial dysplasia is a rare congenital defect of autosomal dominant inheritance caused by mutations in the Cbfa1 gene, also called Runx2, located on the short arm of chromosome 6. It primarily affects bones which undergo intramembranous ossification. This condition is of clinical significance to dentistry due to the involvement of the facial bones, altered eruption patterns and multiple supernumerary teeth. Case presentation Our patient, a 15-year-old Indian girl, presented with the typical features of prolonged retention of deciduous dentition and delayed eruption of permanent teeth, that is, mandibular prognathism along with other skeletal abnormalities like shrugged shoulder and the absence of clavicles. A multidisciplinary approach was followed, comprising orthodontic, surgical and pedodontic teams for management. Conclusion Successful treatment of such a case lies in a holistic approach that takes care of all aspects, including the primary pathology, the deformity itself and even the psychological angle.

2012-01-01

239

"C"-shaped canal configuration of mandibular second permanent molar.  

PubMed

Roots of the second mandibular molar often fuse so the purpose of this investigation was to examine the appearance of "C"-shaped root canals and to classify different root canal types. A hundred and twelve randomly chosen second lower permanent molars-after extraction due to periodontal disease-were prepared and then analysed. Contrast liquid (methylene blue) was injected into prepared teeth. Each tooth was cut into slices to view the root canal morphology. Results of the analysis revealed fusion, either total or partial in 14 cases (12.5%). As a conclusion various appearances were classified into 5 types according to the fused canal shapes and the frequency of different types varied from 0.89%-6.25%. PMID:10097434

Sutalo, J; Simeon, P; Tarle, Z; Prskalo, K; Pevalek, J; Stanici?, T; Udovici?, M

1998-06-01

240

Missing posterior teeth and risk of temporomandibular disorders.  

PubMed

There is disagreement about the association between missing posterior teeth and the presence of temporomandibular disorders (TMD). Here, the purpose was to investigate whether the number of missing posterior teeth, their distribution, age, and gender are associated with TMD. Seven hundred and forty-one individuals, aged 21-60 years, with missing posterior teeth, 386 with and 355 without TMD, were included. Four variables-gender, age, the number of missing posterior teeth, and the number of dental quadrants with missing posterior teeth-were analyzed with a logistic regression model. All four variables-gender (OR = 1.59, men = 1, women = 2), age (OR = 0.98), the number of missing posterior teeth (OR = 0.51), and the number of dental quadrants with missing posterior teeth (OR = 7.71)-were entered into the logistic model (P < 0.01). The results indicate that individuals who lose posterior teeth, with fewer missing posterior teeth but in more quadrants, have a higher prevalence of TMD, especially young women. PMID:19783804

Wang, M Q; Xue, F; He, J J; Chen, J H; Chen, C S; Raustia, A

2009-10-01

241

Sterilization of teeth by gamma radiation.  

PubMed

Clinical simulations and restorative materials research and development conducted in vitro require the use of large numbers of extracted teeth. The simultaneous need for infection control procedures and minimal alterations of structure and properties of the tissue prompted this study of gamma irradiation as a method to eliminate microbes associated with extracted teeth and their storage solutions. Evaluations of potential change in structure of dentin were conducted in terms of permeability, Fourier transform infrared spectroscopy (FTIR), and optical properties. The dose required for sterilization by gamma irradiation was established by means of a tooth model inoculated with Bacillus subtilis (10(8) organisms/mL). Sterilization occurred at a dose above 173 krad with use of a Cesium (Cs137) radiation source. Gamma irradiation did not affect permeability of crown segments of dentin. A comparative evaluation of the effects of four sterilization methods on dentin disks was based on FTIR and ultraviolet-visible-near infrared (UV/VIS/NIR) spectra before and after sterilization by (1) gamma irradiation; (2) ethylene oxide; (3) dry heat; and (4) autoclaving. No detectable changes were found with gamma irradiation, but all other methods introduced some detectable change in the spectra. This suggests that common methods of sterilization alter the structure of the dentin, but gamma irradiation shows promise as a method which both is effective and introduces no detectable changes as measured by FTIR, UV/VIS/NIR, or permeability. PMID:7929992

White, J M; Goodis, H E; Marshall, S J; Marshall, G W

1994-09-01

242

A permanent formula for the Jones polynomial  

Microsoft Academic Search

The permanent of a square matrix is defined in a way similar to the determinant, but without using signs. The exact computation of the permanent is hard, but there are Monte Carlo algorithms that can estimate general permanents. Given a planar diagram of a link L with n crossings, we define a 7n×7n matrix whose permanent equals the Jones polynomial

Martin Loebl; Iain Moffatt

2011-01-01

243

A permanent formula for the Jones polynomial  

Microsoft Academic Search

The permanent of a square matrix is defined in a way similar to the determinant, but without using signs. The exact computation of the permanent is hard, but there are Monte-Carlo algorithms that can estimate general permanents. Given a planar diagram of a link L with $n$ crossings, we define a 7n by 7n matrix whose permanent equals to the

Martin Loebl; Iain Moffatt

2007-01-01

244

Teething myths among nursing mothers in a Nigerian community  

PubMed Central

Background: Many symptoms had been associated with teething in children with the possibility of overlooking potentially fatal condition. Symptoms that had been associated with teething include diarrhoea, fever, vomiting and cough. The possibility that any of these symptoms could have been due to other causes call for thorough investigation of the child before concluding that it is only “teething”. Objectives: The study was carried out to assess the beliefs of nursing mothers concerning symptoms that are associated with teething among children and to identify those that would seek medical treatments in case of their children having such symptoms during teething. Materials and Methods: Two hundred and ninety nursing mothers whose children had erupted at least a tooth were interviewed in the immunisation clinics of the University College Hospital and Adeoyo Maternity Teaching Hospital, both in Ibadan, Nigeria, on their beliefs and practice concerning teething in children. Results: One hundred and eighty-eight (64.8%) of the mothers associated symptoms such as fever, cough, catarrh and diarrhoea with eruption of teeth in their children. Over half of the women agreed that a child having either fever (51.0%), ear infection (57.6%) or cough (50.3%) should be promptly taken for medical consultation and not be tagged “teething”, while for other symptoms such as gum pain (74.5%), sleepless night (56.6%), vomiting (51.4%) and diarrhoea (51.7%), over half of the mothers believed that the symptoms will resolve following the eruption of the teeth. Conclusion: The study demonstrated that mothers in the study attributes several symptoms to teething, which could be detrimental to the survival of their children as the symptom could have been due to other causes. There is, therefore, need for public enlightenment to create awareness on the possible effect of presumptuous belief that childhood diseases are due to teething process.

Ige, Opeodu Olanrewaju; Olubukola, Popoola Bamidele

2013-01-01

245

Infrared Absorption Bands of Enamel and Dentin Tissues from Human and Bovine Teeth  

Microsoft Academic Search

The chemical components present in the hard tissue such as water, phosphate, carbonate and organic material strongly absorb infrared radiation. The research in dentistry area has a fundamental interest in identifying the chemical origin of all the bands present in the infrared region to study the chemical and thermal action on the hard dental tissues. To improve this technique it

Luciano Bachmann; Rolf Diebolder; Raimund Hibst; Denise Maria Zezell

2003-01-01

246

How Permanent Is Permanent Placement for Substance-Exposed Infants?  

ERIC Educational Resources Information Center

|The authors describe a study of families in the Family Drug Treatment Court (FTDC), an effort to promote permanent placement for substance-exposed infants within time requirements mandated by the 1997 Adoption and Safe Families Act (ASFA). The purpose of the study was to evaluate parent functioning after FTDC involvement, infant developmental…

Twomey, Jean E.; Lester, Barry M.

2007-01-01

247

Comparative analysis of the effect of autoclaving and 10% formalin storage on extracted teeth: A microleakage evaluation  

PubMed Central

Aim: This study compares the effect of formalin and autoclaving the tooth samples by evaluating microleakage in-vitro. Materials and Methods: Forty-five extracted human permanent incisor teeth were taken and randomly divided into three groups (with different methods of storage and disinfection) with 15 teeth each: Group 1: Control-extracted teeth in this group were stored in normal saline, Group 2: the extracted teeth in this group were stored in 10 % formalin for two weeks and Group 3: the extracted teeth were Autoclaved at 121°C, at 15 psi pressure for 40 minutes. In all the groups after the specified storage period, class V cavities were prepared on the labial surface and restoration was performed with Z100 restorative. Finished and polished samples were subjected to 500 cycles of thermocycling. All specimens were immersed in methylene blue for 24 hours. After sectioning, the margins of restoration were evaluated for dye leakage at 10 X magnification, using an optical microscope. Data were subjected to nonparametric Kruskal Wallis one way analysis of variance. Inter-group comparisons were performed using the Mann Whitney test (P < 0.05). Results: The authors found that the microleakage in the formalin group was considerably lower than that in the control group. The autoclave group showed slightly higher mean microleakage, but the difference was not statistically significant. Conclusion: Both autoclaving and formalin storage affect, to a varying degree, the microleakage values in vitro. The results in the autoclaving group matched those of the control group more closely, with only a slight difference.

Attam, Kanika; Talwar, Sangeeta; Yadav, Seema; Miglani, Sanjay

2009-01-01

248

Teeth mobility measurement by laser Doppler vibrometer  

NASA Astrophysics Data System (ADS)

In this work a new procedure for the assessment of teeth mobility, based on a noncontact sensor (laser Doppler vibrometer), is presented. The procedure is based on the manual application of impulses applied with an instrumented hammer on the tooth crown. The ratio of the maximum displacement of the tooth to the peak of the input force has been considered as the mobility degree index. A basic mechanical model of the hammer-tooth impact based on the data extracted from literature has been realized. Results produced with the model mentioned above have been compared with those measured with in vitro and in vivo tests using the proposed procedure. Good agreement between data from the mechanical model and in vitro conditions has been found. Tests carried out in in vitro and in vivo conditions have demonstrated the validity of the procedure proposed. Measurement results compared to those found in the relevant literature show the validity of the procedure proposed.

Castellini, P.; Scalise, L.

1999-06-01

249

Bilateral dens evaginatus (talon cusp) in permanent maxillary lateral incisors: a rare developmental dental anomaly with great clinical significance.  

PubMed

Talon cusp is an accessory cusp-like structure which projects from the cingulum area or cementoenamel junction. It is important for dentists to be aware of the potential complications that may occur with talon cusp. Early diagnosis and treatment is important, especially to prevent pulpal complications in permanent teeth which may be in developing stage in paediatric patients. The purpose of this paper is to report a case of bilateral talon cusp in permanent maxillary lateral incisors. Associated dental anomalies and clinical problems are discussed along with successful management of the case with conservative therapy. PMID:23813995

Manuja, Naveen; Chaudhary, Seema; Nagpal, Rajni; Rallan, Mandeep

2013-06-24

250

Pulp Revascularization of Immature Dog Teeth With Apical Periodontitis  

Microsoft Academic Search

This study examined the ability of a collagen solution to aid revascularization of necrotic-infected root canals in immature dog teeth. Sixty immature teeth from 6 dogs were infected, disinfected, and randomized into experimental groups: 1: no further treatment; 2: blood in canal; 3: collagen solution in canal, 4: collagen solution + blood, and 5: negative controls (left for natural development).

Blayne Thibodeau; Fabricio Teixeira; Mitsuo Yamauchi; Daniel J. Caplan; Martin Trope

2007-01-01

251

Multiple congenitally missing primary teeth: report of a case.  

PubMed

The prevalence, possible etiological factors and management of multiple missing primary teeth was briefly reviewed. Oligodontia of the primary dentition is a rare finding. This paper reports a rare case of multiple missing (n=9) primary teeth in a 3-year-old male of Asian origin. PMID:11991318

Shashikiran, N D; Karthik, V; Subbareddy, V V

252

Bonding of acrylic denture teeth to resin denture bases.  

PubMed

Anterior teeth debonding from dentures is a common problem. This study tested the bond strength of denture teeth to two types of denture resin, with and without grooving the ridge-lap surface. Bond strength and fracture type of three different groups were compared: 1. Teeth bonded to heat-cured polymethyl methacrylate (PMMA); 2. Teeth bonded to pour-type PMMA; 3. Grooved teeth bonded to pour-type PMMA. Specimens were manufactured following ISO standard 22112. Force values at failure were analysed using one-way analysis of variance, using the mixed procedure with confidence interval of 95%. Types of failure were identified as adhesive, cohesive or combination. In descending order, mean failure forces were 418.55N (Group One), 367.55N (Group Two) and 290.05N (Group Three). There was no significant difference between the means of groups 1 and 2 (p = 0.0627). Group Three differed from both other groups (p < 0.001). Groups One and Two showed predominantly cohesive fractures wthin denture teeth (83% and 72% respectively); group Three showed predominantly cohesive fractures within the denture PMMA (75%). Without ridge-lap modification, the bond strengths of denture teeth to pour-type and heat-cured denture resin were similar. Failures were predominantly of cohesive nature within the teeth themselves. Grooving the ridge-lap reduced fracture resistance and led to breakages predominantly in denture PMMA. PMID:23185939

Geerts, G A V M; Stuhlinger, M E

2012-07-01

253

Photomechanical investigations on post-endodontically rehabilitated teeth  

Microsoft Academic Search

An investigation of the stress distribution patterns in post- core restored teeth and the behavior of dentin material to fracture propagation was conducted using experimental techniques such as digital photoelasticity (on photoelastic models), mechanical testing and scanning electron microscopy (SEM) (on extracted teeth). Digital photoelastic experiments showed that endodontic post-core restora- tion resulted in regions of high tensile stress and

Anil Kishen; Anand K. Asundi

2002-01-01

254

VITAL PULPOTOMY IN PRIMARY TEETH WITH MINERAL TRIOXIDE AGGREGATE (MTA)  

Microsoft Academic Search

SUMMARY Mortal pulpotomy is the most commonly used technique in Bulgaria for treatment of pulp chronic infections in primary teeth. Data from the special literature reveal another method for pulp treatment in primary teeth - vital pulpotomy associated with good adaptive healing response. During the past several years, special attention has been paid to Mineral Trioxide Aggregate -MTA as probable

N. Gateva

2009-01-01

255

Sterilization ofTeeth byGammaRadiation  

Microsoft Academic Search

Clinical simulations andrestorative materials research anddevelopment conducted invitro require the useoflarge numbers ofextracted teeth. Thesimultaneous needforinfection control procedures andminimal alterations ofstructure andproperties ofthetissue prompted this study ofgammairradiation asamethod to eliminate microbes associated withextracted teeth and their storage solutions. Evaluations ofpotential change in structure ofdentin wereconducted intermsof permeability, Fourier transform infrared spectroscopy (FTIR), andoptical properties. Thedoserequired for sterilization bygammairradiation wasestablished by

J. M. Whitel; H. E. Goodis; G. WMarshall

256

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

...Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth...AC-powered device that consists of a light or an electric heater intended to apply heat to a tooth after it is...

2009-04-01

257

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

...Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth...AC-powered device that consists of a light or an electric heater intended to apply heat to a tooth after it is...

2010-04-01

258

Esthetic rehabilitation of discolored anterior teeth with porcelain veneers.  

PubMed

The common man is bombarded by the media extolling the virtues of "the perfect smile." In the 21(st) century of esthetic dentistry, fractured, malformed, malposed, and discolored teeth can be changed and restored to highly desirable form due to introduction of wide range of esthetic materials and techniques. Porcelain veneers is a conservative method of restoring the appearance of discolored, pitted teeth, and teeth with diastemas that provide extremely good esthetic results. A 21-year-old female patient with staining in anterior teeth had reported to the Department of Prosthodontics for esthetic rehabilitation. The patient was treated with porcelain veneers on maxillary anterior teeth. The patient was satisfied with the enhanced esthetic appearance. PMID:23853471

Kamble, Vaibhav D; Parkhedkar, Rambhau D

2013-01-01

259

Improvement in properties of plastic teeth by electron beam irradiation  

NASA Astrophysics Data System (ADS)

Improvement of the comfort and esthetics of artificial plastic teeth is desirable for the recently increasing numbers of elderly in society. Plastic teeth made of polycarbonate (PC) were modified by electron beam (EB) irradiation under specific conditions, and the change in the chemical properties of the PC was investigated. The water absorption, glucose attachment, level of bis-phenol-A (BPA) extraction, maltose adhesion, and mucin adhesion on the PC teeth were measured before and after EB irradiation. EB irradiation to a dose of 3.5 kGy at 150 °C in a nitrogen gas atmosphere reduced the water absorption by 20%, glucose absorption by 40%, maltose adhesion by 20%, and the amount of various amino acids, formed as the hydrolysis products of mucin, adhering on the PC teeth were reduced by 60-99%. The BPA content was lower than the detection limit for analysis of both the original and the EB irradiated PC teeth.

Sano, Yuko; Ishikawa, Shun-Ichi; Seguchi, Tadao

2011-11-01

260

Performance Comparison and Winding Fault Detection of Duplex 2Phase and 3Phase Fault-Tolerant Permanent Magnet Brushless Machines  

Microsoft Academic Search

This paper analyses feasible slot and pole number combinations for multiplex 2-phase and 3-phase fault-tolerant permanent-magnet machines and evaluates their relative merits via a design case study. An effective winding short-circuit detection technique based on search coils wound around the stator teeth is also presented, and its performance is assessed. It is shown that the proposed detection technique can reliably

Jie Chai; Jiabin Wang; Kais Atallah; David Howe

2007-01-01

261

Making Space for Permanent Molars in Growing Baboon (Papio anubis) and Great Ape (Pan paniscus and P. troglodytes) Mandibles: Possible Ontogenetic Strategies and Solutions  

PubMed Central

While mandible proportions do not appear to constrain permanent molar initiation times, how adequate space is created in the corpus for these teeth in a timely way is not well understood. This question is important for explaining how primate tooth and jaw development and evolution are coordinated. Landmark and linear measurement data were used to characterize mandible shape, growth trajectory, and growth rate between two genera, Papio and Pan, with contrasting permanent molar initiation schedules and mandible proportions. 3D geometric morphometric and 2D bivariate analyses showed genus-level differences in mandible morphology from birth that were amplified by different postnatal growth trajectories. Different corpus proportions and regional variation in corpus growth rates helped create space in a timely way for the molars. Regional corpus growth rates may evolve alongside permanent molar morphology and developmental timing to modify space available in the corpus for these teeth.

Boughner, Julia C.

2011-01-01

262

Permanent scatterers in SAR interferometry  

Microsoft Academic Search

Temporal and geometrical decorrelation often prevents SAR interferometry from being an operational tool for surface deformation monitoring and topographic profile reconstruction. Moreover, atmospheric disturbances can strongly compromise the accuracy of the results. The authors present a complete procedure for the identification and exploitation of stable natural reflectors or permanent scatterers (PSs) starting from long temporal series of interferometric SAR images.

Alessandro Ferretti; Claudio Prati; Fabio Rocca

2001-01-01

263

ERS-ENVISAT Permanent Scatterers  

Microsoft Academic Search

The phase time series of a perfect point-wise Permanent Scatterer (PS) would show a phase jump passing from ERS to ENVISAT SAR images. A PS analysis has been carried out on a dataset including both ERS and ENVISAT images. For each PS, elevation, LOS velocity and phase jump have been jointly estimated and removed, allowing the identification of the atmospheric

Daniele Perissin; Claudio Prati; Fabio Rocca; Alessandro Ferretti

2004-01-01

264

Inequalities for Determinants and Permanents.  

National Technical Information Service (NTIS)

The authors give an upper bound for the determinant of a matrix with positive dominant diagonal and nonpositive off-diagonal elements. A lower bound is derived for the permanent of a nonnegative matrix with dominant diagonal. Conditions for equality are i...

G. M. Engel H. Schneider

1973-01-01

265

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

266

Planar High Energy Permanent Magnets.  

National Technical Information Service (NTIS)

The purpose of the program is to demonstrate the feasibility of fabricating cobalt-rare earth permanent magnets by the arc plasma spraying process. Property goals for spray-fabricated magnets consisted of a coercive force of 6000 oersteds and an energy pr...

M. C. Willson R. J. Janowiecki

1974-01-01

267

Planar High Energy Permanent Magnets.  

National Technical Information Service (NTIS)

The purpose of this program is to demonstrate the feasibility of fabricating cobalt-rare earth permanent magnets by the arc plasma spraying process. Property goals for spray-fabricated magnets consist of a coercive force of 6000 oersteds and a maximum ene...

M. C. Willson R. J. Janowiecki

1973-01-01

268

Effect of fluoride pretreatment on primary and permanent tooth surfaces by acid-etching.  

PubMed

This study observed the effect of fluoride application on a 37% phosphoric acid etching for 20 s of the enamel surfaces of primary and permanent teeth based on a clinical protocol employed in dental hospitals, through atomic force microscopy and scanning electron microscopy. Enamel samples were prepared from 84 exfoliated and noncarious teeth. Primary (groups 1-4) and permanent (groups 5-8) tooth samples were assigned randomly to one of eight groups based on the timing of acid-etching with 37% phosphoric acid after an acidulated phosphate fluoride (APF) treatment. Groups 1 and 5 received no fluoride application. Groups 2-4 and 6-8 were pretreated with fluoride and received acid-etching 2 weeks later (groups 2 and 6), 1 week later (groups 3 and 7), and immediately (groups 4 and 8). The acid-etching process led to a significant increase in roughness (p<0.0001), and the APF treatment led to a decrease in primary and permanent tooth surface roughness (p<0.005). An acid-etching procedure 2 weeks after performing an APF pretreatment might be recommended to obtain the maximum enamel adhesion of a resin composite. PMID:21254111

Choi, Samjin; Cheong, Youjin; Lee, Gi-Ja; Park, Hun-Kuk

2010-12-06

269

Morphology of apical foramen in permanent molars and premolars in a Turkish population.  

PubMed

Abstract Objective: To determine the number, shape and diameter of minor apical foramina, the distance between apical foramina and anatomical apex and the frequency of accessory foramina in a Turkish population. Materials and methods: Eight hundred permanent maxillary and mandibular teeth were collected. The roots were stained with methylene blue and the apices were examined with a stereomicroscope (×40) and transferred to a computer to perform the measurements using Adobe Photoshop software. Results: The incidence of one apical foramen was highest in distobuccal roots of the maxillary first molars and was lowest in the maxillary first premolars with single roots. The distance of deviation in all the teeth was between 0.271-0.519 mm. The frequency of accessory foramina was between 30-70% for the various tooth types. Conclusions: The results of this in vitro study indicate that the morphology of apical foramina in this Turkish population may present highly complex anatomical variations. PMID:23270574

Ayranci, L Benan; Yeter, Kübra Y; Arslan, Hakan; Kseo?lu, Mustafa

2012-12-28

270

Bovine Spongiform Encephalopathy  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bovine spongiform encephalopathy (BSE) is caused by a novel contagion, known to as a prion. Prions are proteins capable of converting a normal cellular protein into a prion, thereby propagating an infection. BSE is the first known prion zoonotic. As such it has attracted broad scientific and, to a r...

271

Heritable bovine fetal abnormalities  

Microsoft Academic Search

The etiologies for congenital bovine fetal anomalies can be divided into heritable, toxic, nutritional, and infectious categories. Although uncommon in most herds, inherited congenital anomalies are probably present in all breeds of cattle and propagated as a result of specific trait selection that inadvertently results in propagation of the defect. In some herds, the occurrence of inherited anomalies has become

Brian K. Whitlock; Lana Kaiser; Herris S. Maxwell

2008-01-01

272

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 ...

273

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....

274

Pathogenesis of bovine brucellosis  

Microsoft Academic Search

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

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

2010-01-01

275

Ultrasonic Wave Properties in Bone Axis Direction of Bovine Cortical Bone  

NASA Astrophysics Data System (ADS)

Quantitative ultrasonography (QUS) is a good method for measuring elastic properties of bone in vivo. Bovine cortical bone has two typical microstructures, plexiform and Haversian. In this study, the relationship between the speed of sound (SOS) and the hydroxyapatite (HAp) crystallite orientation in the axial direction was investigated in two different aged bovine cortical bones. The dependence of attenuation on anatomical position was also investigated. Two ring-permanent hyphen shaped cortical bone samples were obtained from 36- and 24-month-old bovine femurs. SOS was measured with a conventional ultrasonic pulse system. The integrated intensity of the (0002) peak obtained by X-ray diffraction was determine to evaluate the amount of preferred orientation. Regardless of the age of the bovine femurs, a significant correlation between SOS and the preferred orientation of HAp crystallites was observed in parts of the plexiform structure, and the gradient of the relationship showed a similar tendency. Attenuation seemed to depend on bone microstructure.

Yamamoto, Kazufumi; Yaoi, Yuichiro; Yamato, Yu; Yanagitan, Takahiko; Matsukawa, Mami; Yamazaki, Kaoru

2008-05-01

276

Natal and neonatal teeth among cleft lip and palate infants  

PubMed Central

Objective: Natal/neonatal teeth are reported to be more common among clefts and congenital anomalies. Data exclusively among clefts is sparse. The aim was to evaluate prevalence of natal teeth among cleft lip and palate neonates and review the causes, presentation, associated anomalies, complications and management. Materials and Methods: Out of 641operated patients, records of 151 infants with cleft lip and palate with less than three months of age presented to the department of plastic and reconstructive surgery from 2005 to 2011 were reviewed. Out of which 107 were unilateral complete lip and palate (ULCP), 15 bilateral cleft lip and isolated cleft palate constituted 29. Results: Three patients among the studied records showed neonatal teeth. Two had paired central mandibular incisor teeth along with associated other anomalies and one had a single maxillary neonatal tooth. All were present in unilateral cleft lip and none of the bilateral or isolated cleft palate infants showed neonatal teeth. The overall incidence of neonatal teeth was 1.98% and 2.8% in unilateral Cleft lip. Conclusion: Our study supports the incidence of 2% natal teeth among UCLP. Involvement of mandibular central incisors in contrast to the notion that maxillary alveolus is more commonly affected suggest that it is not only the anatomical disturbance but also all those possible common multifactorial etiological factors contributing to the congenital anomalies as such. Natal/neonatal teeth are rather under-diagnosed and reported than a rare phenomenon and the prevalence is higher in certain population. Riga-Fede disease unlikely to be seen in clefts with neonatal teeth due to anatomical factors. The extraction of non mobile tooth if necessary can be done during the primary surgery for the cleft lip.

Kadam, Manjushree; Kadam, Dinesh; Bhandary, Sanath; Hukkeri, Rajesh Y.

2013-01-01

277

Size and morphology of the permanent dentition in prehistoric Ohio Valley Amerindians.  

PubMed

Metric and morphological characterizations of the permanent teeth from a total of 155 prehistoric Amerindians are presented. The individuals represent samples from three Ohio Valley burial complexes (considered together as the Late Diffuse group): Glacial Kame, Adena and Ohio Hopewell. Metric data include common measures of central tendency and dispersion. From these measures estimates and analyses of the magnitude of sexual dimorphism and relative variability are presented as well as analyses of the patterns of these estimates. Forty morphological characters are also tabulated. The results indicate a number of provisional hypotheses: the generally larger tooth size of the Late Archaic Indian Knoll when compared to the Late Diffuse groups is consistent with the hypothesis of mitigated selective pressures in more technologically advanced groups; although tooth size is smaller in the Late Diffuse groups, dental morphology is as complex, or more so when compared to the Indian Knoll group. Since morphology and size do not covary exactly the biocultural forces resulting in smaller tooth size do not seem to act as strongly on dental morphology; odontological differences within the Late Diffuse arise primarily between the Glacial Kame-Adena and the Ohio Hopewell. These differences correspond to major biocultural changes in this area; although provisional hypotheses concerning odontological variability are erected, hypotheses concerning evolutionary trends must await the discovery of evolving lineages within these groups; similarities are noted among all compared groups including the pattern and magnitude of sexual dimorphism and relative variability. These parameters may be similar for all eastern Amerindians during this period; finally, the morphology of the deciduous dentition, which generally predicts that of the permanent teeth, is found to be less complex than the permanent teeth. This may be the result of a selective disadvantage for the individuals in the deciduous dentition sample which is reflected in the dentition. PMID:380360

Sciulli, P W

1979-05-01

278

Radiation Effects on Rare Earth Permanent Magnets.  

National Technical Information Service (NTIS)

With continuing improvements in rare earth permanent magnet (REPM) technology, applications for their use are being discovered that were previously not possible. Two such applications for permanent magnets are in focusing elements for linear accelerators ...

H. B. Luna

1988-01-01

279

Frequency of supernumerary teeth in Mexican population.  

PubMed

Supernumerary teeth (ST) are a not uncommon developmental anomaly which appears in 0.3 to 3.8 percent of the population. We studied the corresponding radiographs from 2241 patients, both sexes who seeked dental attention at the Outpatient Clinic of the División de Estudios de Posgrado e Investigación, Facultad de Odontología, UNAM in Mexico City. Of them, we found 72 patients (3.2%) with 102 ST. Of the 72 patients, 39 were males (54.2%) and 33 females (45.8%). Mesiodens was the most common ST (48.6%), followed by supernumerary premolars (26.4%), supernumerary laterals (11.1%) and fourth molars (9.7%). This series includes cases with one, two and three ST and one case comprising 10 ST. Our results suggest that frequency of ST in the population studied differs in some aspects with previously reported series and that frequency of ST shows different rates depending the population studied. As our results demonstrate, it is encouraged the need to have panoramic radiographs of all patients attended in dental offices, clinics and schools of Dentistry in order to detect and diagnose undiscovered pathologies. PMID:15580117

Salcido-García, Juan Francisco; Ledesma-Montes, Constantino; Hernández-Flores, Florentino; Pérez, Diego; Garcés-Ortíz, Maricela

280

Wide aperture permanent magnet solenoid  

NASA Astrophysics Data System (ADS)

Various configurations of rare earth permanent magnet solenoids with a large bore were simulated using finite element computer modeling. The configuration effect on the axial field, Bz, and its uniformity, ?Bz, was analyzed. The magnetic orientation of individual segments and the aspect-ratio of the solenoid have a significant effect on Bz and ?Bz. Two-layered configurations assembled with trapezoidal or arc segments result in a more uniform Bz compared to configurations assembled with five-faced polyhedrons. The two-layered configuration also has the advantage of easier fabrication. A permanent magnet solenoid prototype, based on the two-layered arc segment configuration and built using Nd-Fe-B magnets, was experimentally tested. The solenoid was designed to have a length to inner diameter ratio of approximately 5:3 and a peak axial field magnitude of 1.8 kGauss. Experimental measurements agree with simulation predictions to within < 5%.

Hoff, B. W.; Chen, C. H.; Horwath, J. C.; Haworth, M. D.; Mardahl, P. J.; Heidger, S. L.

2012-04-01

281

Rectangular Scott-type Permanents  

Microsoft Academic Search

Let $x_1,x_2,...,x_n$ be the zeroes of a polynomial P(x) of degree n and $y_1,y_2,...,y_m$ be the zeroes of another polynomial Q(y) of degree m. Our object of study is the permanent $\\\\per(1\\/(x_i-y_j))_{1\\\\le i\\\\le n, 1\\\\le j\\\\le m}$, here named \\

Guo-Niu Han; Christian Krattenthaler

2000-01-01

282

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

283

Permanent Income, Current Income, and Consumption  

Microsoft Academic Search

This article reexamines the consistency of the permanent-income hypothesis with aggregate postwar U.S. data. The permanent-income hypothesis is nested within a more general model in which a fraction of income accrues to individuals who consume their current income rather than their permanent income. This fraction is estimated to be about 50%, indicating a substantial departure from the permanent-income hypothesis. Our

John Y. Campbell; N. Gregory Mankiw

1990-01-01

284

Predicting Permanency Intentions Among Kinship Caregivers  

Microsoft Academic Search

This study examines kinship caregivers’ (n = 830) experiences and their perceptions of the children (n = 1,339) in their care in order to predict permanency intent. Permanency intent is a caregiver’s expressed intent to adopt\\u000a the child in his or her care or to provide permanent, legal guardianship. The results of this study reveal that most caregivers’\\u000a permanency choice is guardianship and not

Ramona W. Denby

2011-01-01

285

Permanency Options and Goals: Considering Multifaceted Definitions  

Microsoft Academic Search

This qualitative study examined permanency goal-setting and permanency outcomes for children in the New York City foster care system. Interviews were conducted with young adults formerly in foster care, birth parents of children formerly and currently in foster care, adoptive parents, and child welfare professionals. Findings indicated the need to individualize permanency goals, emphasize the emotional and relational aspects of

Madelyn Freundlich; Rosemary J. Avery; Sarah Gerstenzang; Sara Munson

2006-01-01

286

First Fossil Evidence for the Advance of Replacement Teeth Coupled with Life History Evolution along an Anagenetic Mammalian Lineage  

PubMed Central

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.

Jordana, Xavier; Marin-Moratalla, Nekane; Moncunill-Sole, Blanca; Bover, Pere; Alcover, Josep Antoni; Kohler, Meike

2013-01-01

287

Supernumerary Teeth in Indian Children: A Survey of 300 Cases  

PubMed Central

The aim of this investigation was to study children with supernumerary teeth who visited the Department of Pedodontics and Preventive Dentistry, Government Dental College and Hospital, Rohtak, Haryana, India. Only children with supernumerary teeth were included in the study while patients having supernumerary teeth with associated syndromes were excluded. Supernumeraries were detected by clinical and radiographic examination. The results indicated that males were affected more than females with a sex ratio of 2.9?:?1. Single supernumerary tooth was seen in 79% of the patients, 20% had double, and 1% had three or more supernumeraries. Premaxillary supernumeraries accounted for 93.8% of the cases. Conical shaped supernumerary teeth were the most common type (59.7%). Majority of supernumeraries remained unerupted (65%). Fusion of supernumerary tooth with a regular tooth was observed in 4% of the patients. Talon cusp, an associated dental anomaly, was seen in 5% of the cases. Simultaneous hypodontia occurred in 2.3% of patients with supernumeraries.

Sharma, Amita; Singh, Varun Pratap

2012-01-01

288

Detail from roadbed showing sprocket teeth in rolling segment and ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail from roadbed showing sprocket teeth in rolling segment and typical lateral bracing. View south - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

289

[Atypical surgical approach to the extraction of retained teeth].  

PubMed

Indication to extract deep impacted teeth as well as the surgical approaches is controversally discussed in the litterature. Based on a clinical case report we describe two atypical approaches, one is extraoral the other lingual for removing tow deeply impacted teeth. The revue of the litterature shows that atypical surgical approaches are only indicated in particular clinical situations. The indication to remove the teeth and the approach depends on the patient's compliance as well as the experience of the operator. In the reported case the extraoral approach is justified by the chronical dentogene infection with fistulisation and cutaneus changes in the submandibular region. Based on the much easier access to the tooth and the only minimal cutaneus modifications in this case, we recommand the extraoral approach for extraction of deep impacted teeth in some special cases like the one we present. PMID:15587600

Verdeja, Raúl; Franze, Thilo; Grätz, Klaus-Wilhelm

2004-01-01

290

Antimicrobial Efficacy of Reduced Concentrations of Parachlorophenol in Extracted Teeth.  

National Technical Information Service (NTIS)

The antimicrobial efficacy of subclinical amounts of aqueous parachlorophenol (PCP) on Streptococcus mitis, Sr faecalis, and Staphylococcus epidermidis was investigated in pulpal chambers of endodontically prepared, extracted human teeth. A 35% concentrat...

C. M. Kawahara P. F. Regan J. I. Tenca G. B. Pelleu

1975-01-01

291

Teeth grinding: Is Emotional Stability related to bruxism?  

Microsoft Academic Search

This study examines the association between personality traits and bruxism, the repetitive grinding or clenching of teeth. Community-dwelling participants (N=470) had a comprehensive oral examination by a dentist and completed a dental history and personality questionnaires. Consistent with the literature on state anxiety and depression as antecedents of bruxism, Neuroticism-related traits were associated with self-reported teeth grinding. These traits were

Angelina R. Sutin; Antonio Terracciano; Luigi Ferrucci; Paul T. Costa Jr.

2010-01-01

292

Microstructure and chemical composition of fossil mammalian teeth  

Microsoft Academic Search

Summary  Sectioned Cretaceous mammalian teeth were studied by light microscopy and SEM equipment with an electron microprobe. Structures\\u000a resembling odontoblast processes were found. Their S\\/Fe ratio was similar to that of rat odontoblast processes, but the amounts\\u000a of these elements were far higher than in processes of recent teeth. It was concluded that they consisted of pyrite, but their\\u000a reaction with

G. Fosse; N.-P. B. Justesen; G. B. R. Wesenberg

1981-01-01

293

Color distribution of three regions of extracted human teeth  

Microsoft Academic Search

Objectives.Knowledge of human tooth color and its distribution are critical to the understanding of shade matching in esthetic dentistry. The color of human teeth shows a gradation from the gingival to the incisal region. There have been many reports in the literature on the distribution of color in teeth, but not in the CIE 1976 L*a*b* system. This study was

William J. O'Brien; Henry Hemmendinger; Kenneth M. Boenke; Jackson B. Linger; Carole L. Groh

1997-01-01

294

Harmonic Fluxes and Electromagnetic Forces of Concentric Winding Brushless Permanent Magnet Motor  

NASA Astrophysics Data System (ADS)

Brushless permanent magnet motors have been widely used in home applications and industrial fields. These days, high efficiency and low noise motors are demanded from the view point of environment. Electromagnetic noise and iron loss of the motor are produced by the harmonic fluxes and electromagnetic forces. However, order and space pattern of these have not been discussed in detail. In this paper, fluxes, electromagnetic forces and magneto-motive forces of brushless permanent magnet motors with concentric winding were analyzed analytically, experimentally and numerically. Time harmonic fluxes and time electromagnetic forces in the air gap were measured by search coils on the inner surface of the stator teeth and analyzed by FEM. Space pattern of time harmonic fluxes and time electromagnetic forces were worked out with experiments and FEM. Magneto motive forces due to concentric winding were analyzed with equations and checked by FEM.

Ishibashi, Fuminori; Takemasa, Ryo; Matsushita, Makoto; Nishizawa, Takashi; Noda, Shinichi

295

Conservative management of an intruded immature maxillary permanent central incisor with healing complication of pulp bone.  

PubMed

Traumatic intrusion injury of permanent teeth is serious with multiple complications possible associated with the pulp, periodontal ligament, alveolar bone and Hertwig's epithelial root sheath. The optimal treatment for the management of an intrusion injury has not yet been determined. A case is presented involving the conservative management of an immature maxillary permanent central incisor intrusively luxated by allowing for re-eruption and orthodontic extrusion two weeks later. After a follow-up period of ten months, the intruded tooth continued to show a mobility of grade one, without metallic percussion tone or infra-occlusion, which confirmed periodontal ligament healing. Although the intruded tooth failed to respond to dry ice testing, no other signs of pulp necrosis were evident and the colour of the intruded tooth was within normal limits throughout the follow-up period. However, complications of healing of Hertwig's epithelial root sheath occurred, causing in-growth of bone and periodontal ligament into the root canal. PMID:11481877

Roberts, J; Olsen, C; Messer, H

2001-04-01

296

Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report  

PubMed Central

The endodontic management of immature permanent incisors in young children can be challenging. This case reported an avulsed immature maxillary central incisors that underwent complete endodontic obturation using mineral trioxide aggregate. A 10-year-old male who suffered a fall injury avulsed both his central incisors. The revascularization process was not possible due to patient compliance and geographic reasons. Mineral trioxide aggregate was utilized as a novel endodontic treatment. After one year post-injury, the teeth remained symptom-free, the clinical and radiographic follow-up showed evidence of healthy periodontium. How to cite this article: Al-Kahtani A. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report. J Int Oral Health 2013; 5(3):88-96.

Al-Kahtani, Ahmed

2013-01-01

297

BONES, TEETH AND GENES: A Genomic Homage to Harry Sicher's "Axial Movement of Teeth"  

PubMed Central

Aims We have used the model of the un-opposed rodent molar to study morphologic and genetic mechanisms of tooth eruption. Methods Left maxillary molar teeth of 12-day old Swiss-Webster mice were extracted under anesthesia and mandibular molars were allowed to super-erupt. To trace areas of tissue remodeling and to determine areas of new tissue formation, mice were injected with fluorescent dyes, tetracycline, alizarin red, and calcein blue. Subsequent to sacrifice, mandible tissue blocks were prepared for ultrathin ground sections, fluorescent microscopy, and von Kossa’s mineral detection procedure. A second set of specimen was prepared for RNA extraction and microarray analysis. Results Our data established significant eruption of first and second mandibular mouse molars following complete extraction of antagonists by 0.13 mm after 12 days. Labeled tissue sections revealed significant amounts of new bone and cementum apposition on the un-opposed side compared to the control side as revealed by fluorescent markers and ultrathin ground sections. Microarray transcript level comparisons between the experimental and the control group demonstrated significant (more than 2-fold) increase in gene expression of elastin and tenascin C extracellular matrix proteins; brevican, lumican, and biglycan proteoglycans; as well as fibroblast growth factor 9. Conclusion In this study we have established the un-opposed mouse molar as a model to study tissue dynamics during the axial movement of teeth. Our data indicated significant new formation of bone and cementum in tandem with increased expression of extracellular matrix-related genes.

Holliday, Sean; Schneider, Bernard; Galang, Maria Therese S.; Fukui, Tadayoshi; Yamane, Akira; Luan, Xianghong; Diekwisch, Thomas G.H.

2009-01-01

298

Characteristics of 351 supernumerary molar teeth In Turkish population  

PubMed Central

Objective: The aim of the present study was to evaluate the demographic profile of supernumerary molar (SM) teeth in people in various regions of Turkey. Study Design: A retrospective analysis was carried out on an initial sample of 104,902 subjects drawn from the ortopantographics files from 10 clinics in 7 Turkish cities with documentation of demographic data, the presence of SM teeth, their location, eruption, morphology, and position within the arch. In one region associated patho­logies and treatments were also evaluated. Results: Three hundred fifty-one SMs were detected in 288 patients, constituting 0.33% of the study subjects, with a greater frequency in females (56.4%). SMs were found more frequently in the maxilla (87.7%) than in the mandible, and distomolars (62.9%) were more common than paramolars. The SMs encountered were mostly of conical shape (45.7%), impacted (81.1%), and in a vertical position (52.1). The 33% of SM teeth were related to impacted molar teeth. Conclusion: The most common complication involving these teeth was soft tissue irritation. Demographic data from such specific extensive studies are crucial for improved diagnosis of SM teeth. Early detection allows for measures against complications and more successful therapy. Key words:Supernumerary molars, distomolar, paramolar, prevalence.

Kara, Muhammed I.; Ay, Sinan; Bereket, Cihan; Sener, Ismail; Bulbul, Mehmet; Ezirganl?, Seref; Polat, Hidayet B.

2012-01-01

299

Splinting of traumatized teeth with focus on adhesive techniques.  

PubMed

Splinting of traumatized teeth is an important step in the treatment of periodontally injured teeth and a precondition of healing of the periodontal tissues. Although it has been shown in animal experiments that replanted teeth without splinting showed analogous healing outcomes compared to splinted teeth, the placement of a splint in dental trauma situations is warranted for medico-legal reasons, for the comfort of the patient, and for the avoidance of additional trauma during periodontal healing. Ideally, the splinting of traumatized teeth should be an easy and fast procedure for the dentist. Trauma splints should be comfortable and easy to keep clean for the patient. The splint should allow some physiologic mobility to promote healing of the periodontal tissues. The widely used and recommended wire-composite splint, with material variations, meets the ideal requirements of current splinting concepts in dental traumatology. Times of using destructive tissue-coverage splints are definitely gone. They are too rigid, compromise periodontal and gingival healing, and are uncomfortable to the patient. The objective of this article is to present the current concepts in splinting of traumatized teeth. The given recommendations about splinting techniques and splinting periods are based on experimental and clinical studies. PMID:16033040

von Arx, Thomas

2005-05-01

300

Bovine surgery of the skin.  

PubMed

Occasionally, the bovine practitioner is presented situations requiring application of techniques regarding wound repair and healing. Less commonly encountered in bovine practice than equine practice for example, principles and management of traumatic wound healing should be regarded as similar. Frequently, bovine practitioners need to apply knowledge of healing principles when wounds are surgically induced during horn and mass removal. Consideration of surgical approach, tension-relieving techniques, and dermal transposition flaps (see the ocular surgery article by Schulz in this issue) can be applied effectively in bovine practice. PMID:18929958

Miesner, Matt D

2008-11-01

301

Permanent dentition caries through the first half of life.  

PubMed

Aim To describe the occurrence of dental caries at the person, tooth and tooth surface level from childhood to early mid-life.Background No studies have reported on age and caries experience in a population-based sample through the first half of life.Methods Prospective cohort study of a complete birth cohort (n = 1,037) born in 1972/73 in Dunedin, New Zealand. Dental examinations were conducted at ages 5, 9, 15, 18, 26, 32 and 38, and participation rates remained high. Surface-level caries data were collected at each age (WHO basic methods). Statistical analyses and graphing of data were undertaken using Intercooled Stata Version 10.Results Data are presented on dental caries experience in the permanent dentition at ages 9, 15, 18, 26, 32 and 38. Percentile curves are charted and reported for person-level caries experience. Data are also presented on the number of decayed teeth and tooth surfaces, (including root surfaces at age 38), as a function of the number of teeth and surfaces present, respectively. Across the cohort, the number of tooth surfaces affected by dental caries increased by approximately 0.8 surfaces per year (on average), while the percentage of at-risk tooth surfaces affected by caries increased by approximately 0.5% per year, with negligible variation in that rate throughout the observation period.Conclusion These unique data show clearly that dental caries continues as a disease of adulthood, remaining important beyond childhood and adolescence and that rates of dental caries over time remain relatively constant. PMID:24113990

Broadbent, J M; Page, L A Foster; Thomson, W M; Poulton, R

2013-10-11

302

High-performance permanent magnets.  

PubMed

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. PMID:11129942

Goll, D; Kronmüller, H

2000-10-01

303

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.

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

2013-01-01

304

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

SciTech Connect

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

305

Interfacial and surface characterization of two self-etching adhesive systems and a total-etch adhesive after bonding to ground and unground bovine enamel—a qualitative study  

Microsoft Academic Search

The purpose of the study was to evaluate the enamel surface and interface morphology of two self-etching adhesive systems (SAS) vs a total-etch control, after bonding to ground and unground enamel using field emission scanning electron microscopy (FESEM). Thirty bovine incisors were used in this study. The buccal enamel surface of 15 teeth was ground flat to resemble freshly cut

Gabriela Ibarra; Marcos A. Vargas; Werner Geurtsen

2006-01-01

306

Dexamethasone bovine pharmacokinetics  

Microsoft Academic Search

Summary  Dexamethasone phosphate (DXM-PHO) is an ester which is quickly hydrolysed by the bovine and the dexamethasone (DXM) plasma\\u000a half-life was 5.16 h. It has been demonstrated that 54h after DXM-PHO injection, DXM concentrations were lower than 0.1 mg\\/ml.\\u000a \\u000a \\u000a Tritiated dexamethasone was also administered twice to an another young bull for metabolite investigation. The elapsed time\\u000a required to recover, in plasma,

Ph. Gaignage; G. Lognay; D. Bosson; D. Vertongen; Ph. Dreze; M. Marlier; M. Severin

1991-01-01

307

Ankylosis of traumatized permanent incisors: pathogenesis and current approaches to diagnosis and management.  

PubMed

Ankylosis is a known complication of replanted or severely intruded permanent incisors and can be diagnosed by the characteristic sound emitted when the tooth is tapped. The ankylosed incisor demonstrates a lack of physiologic mobility and, later, radiographic evidence of replacement resorption. If the patient is pre-adolescent or adolescent at the time of trauma, infraocclusion relative to adjacent teeth will become apparent during jaw growth. Despite considerable knowledge about the pathogenesis of ankylosis garnered from animal studies and observation of human replanted teeth, there is no known treatment to arrest this condition. Management techniques and rehabilitation options for addressing ankylosis and its consequences are supported by little evidence, do not appear to be widely adopted and do not offer any proven long-term benefit. Avulsion and severe intrusion of permanent incisors are rare injuries. Should the decision be made to intervene by replantation or reduction of the intrusion, the clinician must be prepared to diagnose ankylosis, identify its negative consequences and develop treatment plans accordingly. PMID:16324230

Campbell, Karen M; Casas, Michael J; Kenny, David J

2005-11-01

308

Development of deciduous and permanent dentitions in the upper jaw of the house shrew (Suncus murinus).  

PubMed

The diphyodont tooth replacement in mammals is characterized by a single replacement of a deciduous dentition by a permanent dentition. Despite its significance in mammalian biology and paleontology, little is known about the developmental mechanisms regulating the diphyodont replacement. Because the mouse never replaces its teeth, this study used the house shrew, Suncus murinus, as a model to investigate the control of the diphyodont replacement of a deciduous dentition by successions and additions of permanent teeth. Using morphological and gene expression analyses of serial sections, we have demonstrated the development of the upper dentition of the house shrew. In this species, the deciduous tooth germs are formed but soon become vestigial, whereas the successional and accessional (molar) germs are subsequently formed and developed. There are distinct Shh expression domains in the deciduous, successional, and accessional tooth germs, and those of the latter two germs are identified from the appearance of their primary enamel knots. The developmental sequence of tooth germs in the house shrew indicates that two adjacent primary enamel knots of the successional and accessional germs do not develop simultaneously, but with a constant time lag. We suggest that this mode of tooth succession and accession can be explained by a sequential inhibitory cascade model in which the timing of initiation and the spacing of tooth development are determined by the inhibition from the primary enamel knots of developmentally preceding adjacent tooth germs. PMID:20303065

Yamanaka, Atsushi; Yasui, Kinya; Sonomura, Takahiro; Iwai, Haruki; Uemura, Masanori

2010-03-19

309

Proteomic analysis of bovine nucleolus.  

PubMed

Nucleolus is the most prominent subnuclear structure, which performs a wide variety of functions in the eukaryotic cellular processes. In order to understand the structural and functional role of the nucleoli in bovine cells, we analyzed the proteomic composition of the bovine nucleoli. The nucleoli were isolated from Madin Darby bovine kidney cells and subjected to proteomic analysis by LC-MS/MS after fractionation by SDS-PAGE and strong cation exchange chromatography. Analysis of the data using the Mascot database search and the GPM database search identified 311 proteins in the bovine nucleoli, which contained 22 proteins previously not identified in the proteomic analysis of human nucleoli. Analysis of the identified proteins using the GoMiner software suggested that the bovine nucleoli contained proteins involved in ribosomal biogenesis, cell cycle control, transcriptional, translational and post-translational regulation, transport, and structural organization. PMID:20970743

Patel, Amrutlal K; Olson, Doug; Tikoo, Suresh K

2010-09-01

310

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.

Gunes, Betul; Aydinbelge, Hale Ari

2012-01-01

311

Torque Performance and Permanent Magnet Arrangement for Interior Permanent Magnet Synchronous Motor  

NASA Astrophysics Data System (ADS)

The use of the interior permanent magnet synchronous motor (IPMSM) has increased in the industrial field because of its excellent characteristics, such as high efficiency, wide range of speed operation and flexibility of the rotor structure. Therefore, the IPMSM, especially one using the rare earth permanent magnet, is being actively studied. In the IPMSM using the rare earth permanent magnet, typically the permanent magnet is deeply embedded in the rotor. However, torque performances are significantly influenced by the rotor structures. This paper describes the torque performances for a single-layer IPMSM using the rare earth permanent magnet when the permanent magnet arrangements are changed.

Matsumoto, Naohisa; Sanada, Masayuki; Morimoto, Shigeo; Takeda, Yoji

312

Changes of concentrations of elements in deciduous teeth with age.  

PubMed

The aim of this study was to describe the issue of changes in the concentration of some elements (Mn, Fe, Mg, Cu, K, Cr, Pb, Cd, and Ca) in the mineral composition of deciduous teeth and to answer the question whether there was a tendency to change the metal concentration, depending on children's age. Physiological replacement of deciduous teeth is preceded with the remodeling process occurring in the mineral structure. The elemental composition of deciduous teeth tissue during their natural loss is the result of these transformations. The subject of the study was deciduous teeth taken from the children (n?=?45, aged 5-14 years), residing in southern Poland, obtained as a result of noninvasive physiological replacement. The concentration of metals in samples was determined over the atomic absorption spectroscopy method. The results of the research showed a statistically significant decrease in the concentration of the analyzed elements in deciduous teeth of older children compared to younger children. The total concentration of all metals studied against the Ca content, expressed as the value of the constant cationic equilibrium, did not change in a statistically significant manner, depending on the age of the children (p?>?0.05). PMID:23836368

Fischer, Agnieszka; Wiechu?a, Danuta; Przyby?a-Misztela, Celina

2013-07-09

313

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.

Komabayashi, Takashi; Zhu, Qiang

2010-01-01

314

Gating of Permanent Molds for ALuminum Casting  

Microsoft Academic Search

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

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

2004-01-01

315

Organic Matrix-related mineralization of sea urchin spicules, spines, test and teeth  

PubMed Central

The camarodont echinoderms have five distinct mineralized skeletal elements: the embryonic spicules and mature test; spines, lantern stereom and teeth. The embryonic spicules are transient structural elements of the larval skeleton whereas the spines and test plates are permanent structural elements. The teeth are continuously growing structures, matching wear at the incisal adoral end to the rate of new production at the aboral plumula. The mineral in all cases is a high magnesium calcite, but the magnesium content, crystal shape and growth pattern is different in each type of skeletal element. The crystal shape and organization into macro structures depends on the presence of an organic matrix which creates the spaces and controls the environments for crystal initiation and growth. The detailed mechanisms of crystal regulation are not known, but much work has been done on defining the proteins which appear to be involved. Phosphorylated matrix proteins may be of special importance. Biochemical isolation of proteins, construction and analysis of cDNA libraries, and most recently high-throughput proteomic analysis in conjunction with the sequencing of the complete genome have yielded a detailed list of protein components likely to be involved in the mineralization processes. However, the proteome-genome analyses have not yet provided insight into the mechanisms of crystallization, calcite composition, and orientation applicable to all skeletal elements. Although the embryonic pluteus and their spicules are the best studied system, it appears that spicule is not representative of the mature skeletal elements. Now armed with the compositions of most of the proteins involved, the next phase of research will have to focus on the specific localization of the proteins and individual biochemistries of each system with regard to mineral content and placement.

Veis, Arthur

2012-01-01

316

[Measurement of thermal expansion coefficient of human teeth].  

PubMed

The coefficient of thermal expansion of specimens from 60 freshly extracted sound human teeth was measured by a dilatometer over the range 10-80 degrees C. The coefficient increased rapidly above 50 degrees C, but there was no significant variation with the tooth age between 10 and 70 years. At 10-50 degrees C, the coefficient of thermal expansion was almost constant. The human teeth are usually at this temperature range in oral cavity. The authors suggest that the average values obtained can be used as quotable values. PMID:2128231

Xu, H C

1990-07-01

317

Carbon dioxide laser oral safety parameters for teeth  

SciTech Connect

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 CO{sub 2} laser is damage to the enamel surface, which could be inflicted with as little as 5 W for 0.2 second and a 1 mm beam. Care should be exercised to prevent inadvertent damage to the surface enamel of teeth even at very low energy levels.

Powell, G.L.; Whisenant, B.K.; Morton, T.H. (Univ. of Utah, Salt Lake City (USA))

1990-01-01

318

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.

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

2013-01-01

319

Demagnetization Analysis of Permanent Magnets According to Rotor Types of Interior Permanent Magnet Synchronous Motor  

Microsoft Academic Search

This paper shows a study on the demagnetization performance analysis of permanent magnet according to three kinds of rotor types of an interior permanent magnet synchronous motor (IPMSM). It is very important to consider demagnetization performance as well as motor performance such as rated torque, output current, and efficiency when designing IPMSM. Three kinds of rotor types according to permanent

Ki-Chan Kim; Kwangsoo Kim; Hee Jun Kim; Ju Lee

2009-01-01

320

Detection of bovine herpesvirus 4 in aborted bovine placentas  

Microsoft Academic Search

Diagnostic studies on aborted placentas of cattle usually do not determine any reason for abortions. In this paper, five bovine herpesviruses (BoHVs) and some bacteriological agents were investigated by several methods in 33 aborted bovine placentas. Inclusion bodies, PCR and in situ DNA hybridization proved the presence of BoHV-4 DNA in six (18.18%) tested placentas. Positive DNA hybridization signal localized

Zoltán Deim; Levente Szeredi; Veronika Tompó; László Egyed

2006-01-01

321

Object permanence: results from developmental robotics  

Microsoft Academic Search

Object permanence is an important theoretical construct that has been researched with infants. For the last twenty years, a debate as whether object permanence is an innate conceptual knowledge or a gradually constructed perceptual capability has been raised. However, the lack of autonomous computational models leaves this issue still widely open. A neurologically inspired computational model based on priming is

Yi Chen; Juyang Weng; Xiao Huang

2004-01-01

322

Radiation effects on rare earth permanent magnets  

Microsoft Academic Search

With continuing improvements in rare earth permanent magnet (REPM) technology, applications for their use are being discovered that were previously not possible. Two such applications for permanent magnets are in focusing elements for linear accelerators and ion sources, and in insertion devices (wigglers and undulators) used to produce synchrotron radiation. However, these magnetic transport elements are subjected to high radiation

Henry B. Luna

1988-01-01

323

Modeling of permanent magnet motor drives  

Microsoft Academic Search

Research has indicated that the permanent magnet motor drives, which include the permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) could become serious competitors to the induction motor for servo applications. The PMSM has a sinusoidal back EMF and requires sinusoidal stator currents to produce constant torque while the BDCM has a trapezoidal back EMF and requires

PRAGASAN PILLAY; R. Krishnan

1988-01-01

324

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

325

Permanent Magnet Machine Design Practice and Optimization  

Microsoft Academic Search

The complexity of the permanent magnet (PM) machine structure makes the optimal design of the PM machine always a difficult task. The multiple objectives of an optimal design make most classic optimization algorithms inapplicable, due to the nonlinearity and some discontinous variables. In this paper, two interior permanent magnet (IPM) machine design practices with modular stator structure and conventional stator

Wen Ouyang; Damir Zarko; T.A. Lipo

2006-01-01

326

Standards on the permanence of recording materials  

Microsoft Academic Search

The permanence of recording materials is dependent upon many factors, and these differ for photographic materials, magnetic tape and optical disks. Photographic permanence is affected by the (1) stability of the material, (2) the photographic processing, and (3) the storage conditions. American National Standards on the material and the processing have been published for different types of film and standard

Peter Z. Adelstein

1996-01-01

327

Procollagenase from bovine gingiva.  

PubMed

1. Collagenase (EC 3.4.24.3) is released from bovine gingival explants in vitro as a zymogen. The zymogen does not hydrolyze collagen and does not form a complex with alpha2-macroglobulin (alpha2-M). It elutes in gel filtration with an apparent molecular weight of approx. 80 000. 2. Incubation of the zymogen with trypsin results in a 15 000-20 000 dalton decrease in molecular weight and imparts to the enzyme the ability to hydrolyze collagen and to form a complex with alppha2-M. 3. The zymogen can be completely separated from the active enzyme to alpha2-M. Likewise, the zymogen can be harvested from cultures supplemented with serum. PMID:177066

Birkedal-Hansen, H; Cobb, C M; Taylor, R E; Fullmer, H M

1976-03-11

328

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

2009-09-03

329

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

330

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

331

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

332

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.; da Silva, Luciana X.

1997-05-01

333

Erosive effects of common beverages on extracted premolar teeth  

Microsoft Academic Search

Background: Dental erosion is highly prevalent today, and acidic drinks are thought to be an important cause. The aim of the present investigation was to determine the erosive potential of a range of common beverages on extracted human teeth. Methods: The beverages were tested for their individual pHs using a pH meter. The clinical effects of the most erosive beverages

WK Seow; KM Thong

2005-01-01

334

From molecules to mastication: the development and evolution of teeth.  

PubMed

Teeth are unique to vertebrates and have played a central role in their evolution. The molecular pathways and morphogenetic processes involved in tooth development have been the focus of intense investigation over the past few decades, and the tooth is an important model system for many areas of research. Developmental biologists have exploited the clear distinction between the epithelium and the underlying mesenchyme during tooth development to elucidate reciprocal epithelial/mesenchymal interactions during organogenesis. The preservation of teeth in the fossil record makes these organs invaluable for the work of paleontologists, anthropologists, and evolutionary biologists. In addition, with the recent identification and characterization of dental stem cells, teeth have become of interest to the field of regenerative medicine. Here, we review the major research areas and studies in the development and evolution of teeth, including morphogenesis, genetics and signaling, evolution of tooth development, and dental stem cells. WIREs Dev Biol 2013, 2:165-182. doi: 10.1002/wdev.63 For further resources related to this article, please visit the WIREs website. PMID:24009032

Jheon, Andrew H; Seidel, Kerstin; Biehs, Brian; Klein, Ophir D

2012-05-03

335

Barium in Teeth as Indicator of Body Burden.  

National Technical Information Service (NTIS)

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....

R. G. Miller J. D. B. Featherstone M. E. J. Curzon T. S. Mills C. P. Shields

1985-01-01

336

Green teeth in a premature infant following hemolytic jaundice.  

PubMed

Green staining of the dentition is a phenomenon associated with the deposition of bilirubin in the matrix of hard tissue during formation. This article presents a case of green teeth in a patient born 28 weeks premature with a medical history of hemolytic jaundice and grade IV intraventricular hemorrhage at birth. PMID:23823340

Rammal, M; Meador, M; Rodriguez, M; Lish, B

2013-07-01

337

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

338

Knowledge of first-aid measures of avulsion and replantation of teeth: an interview of 221 Kuwaiti schoolchildren.  

PubMed

The prognosis of replantation of an avulsed tooth is determined by which first-aid measures are taken during the first 15 min after avulsion. Knowledge of the correct first-aid measures is therefore crucial to successful replantation. The aims of this study were (i) to assess the present knowledge level of emergency measures for tooth avulsion in Kuwaiti schoolchildren, and (ii) to design and test an interview form with structured standardized questions. A total of 221 Kuwaiti schoolchildren (aged 7-15 years old) were interviewed by professionals using a standardized method to score several areas of knowledge about tooth avulsion and replantation. Earlier experience of first-aid information and subjection to dental trauma was registered. The following fields of knowledge were assessed: general body injury treatment principles, tooth avulsion and replantation principles, avulsed permanent/primary teeth, cleaning of avulsed tooth before replantation, extra alveolar time and storage media. The form for interviewing children proved to be sufficiently structured in performing the interviews and data management. The results of the interviews showed that 30.3% of the children had been exposed to dental trauma in the past. Among children 7-9 years of age, 25% had received information on general first aid as compared with 75% in children 10 years and older. Children 10 years and older, in general, had a high knowledge level of general principles of how to manage injuries to the body. Regardless of age group, there were generally a low knowledge level regarding tooth avulsion, replantation, extra-alveolar time and storage media. We conclude that first-aid knowledge in Kuwaiti schoolchildren is low on avulsion and replantation of teeth despite a high knowledge level of body injuries. The knowledge level of first-aid measures on avulsion and replantation of teeth could be increased through intervention programs. PMID:16499627

Andersson, Lars; Al-Asfour, Adel; Al-Jame, Qumasha

2006-04-01

339

Uptake of fluoride into developing sheep teeth, following the 1995 volcanic eruption of Mt Ruapehu, New Zealand  

NASA Astrophysics Data System (ADS)

In the southern Spring of 1995 (mid-October) the active volcano Mt Ruapehu in the central North Island of New Zealand erupted explosively, spreading up to 40 million m3 of rhyolite tephra over thousands of km2 of farmland during the lambing season. This ash contained a high concentration of soluble fluoride, and more than 2000 lactating ewes died of acute fluoride poisoning. To investigate the effects of this brief but acute dose on the teeth of grazing animals we examined the distributions of fluorine and calcium in the permanent incisor teeth of sheep which were one year old at the time. Where part of an incisor had been in the first (secretory) stage of calcification the erupted tooth disclosed surface pitting, a thin layer of enriched mineral across the enamel with as much as 1000 ppm F w/w, and a separate layer with ~4000 ppm down the dentine. The part of an incisor which had attained the later (maturation) stage showed enriched layers only in the outer enamel and in the dentine. This study has demonstrated some important features of the calcification process, and the risk of fluoride toxicity to grazing animals.

Coote, G. E.; Cutress, T. W.; Suckling, G. W.

1997-07-01

340

Teeth of the red fox Vulpes vulpes (L., 1758) as a bioindicator in studies on fluoride pollution.  

PubMed

An examination was made of fluoride content in the mandibular first molars of the permanent teeth of the red fox Vulpes vulpes living in north-west (NW) Poland. The teeth were first dried to a constant weight at 105°C and then ashed. Fluorides were determined potentiometrically, and their concentrations were expressed in dry weight (DW) and ash. The results were used to perform an indirect estimation of fluoride pollution in the examined region of Poland. The collected specimens (n?=?35) were classified into one of the three age categories: immature (im, 6-12 months), subadult (subad, from 12 to 20 months) and adult (ad, >20 months). The mean concentrations (geometric mean) of fluoride were similar in the im and subad groups (230 and 296 mg/kg DW and 297 and 385 mg/kg ash, respectively), and significantly smaller than in the ad group (504 and 654 mg/kg, respectively, in DW and ash). Basing on other reports that the ?400 mg/kg DW concentration of fluoride in bones in the long-lived wild mammals generally reflects the geochemical background, it was found that 57% of the foxes in NW Poland exceeded this value by 9% to 170%. This indirectly reflects a moderate fluoride contamination in the tested region. PMID:21957316

Kalisi?ska, El?bieta; Palczewska-Komsa, Mirona

2011-04-21

341

Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient.  

PubMed

Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth), conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome. PMID:17687179

Srivatsan, Pavithra; Aravindha Babu, N

342

9 CFR 113.311 - Bovine Virus Diarrhea Vaccine.  

Code of Federal Regulations, 2010 CFR

...Bovine Virus Diarrhea Vaccine. Bovine Virus Diarrhea Vaccine...follows: (1) Twenty-five bovine virus diarrhea susceptible...vaccinates and five controls). Blood samples shall be drawn from...be considered susceptible to bovine virus diarrhea virus...

2010-01-01

343

9 CFR 113.311 - Bovine Virus Diarrhea Vaccine.  

Code of Federal Regulations, 2010 CFR

...Bovine Virus Diarrhea Vaccine. Bovine Virus Diarrhea Vaccine...follows: (1) Twenty-five bovine virus diarrhea susceptible...vaccinates and five controls). Blood samples shall be drawn from...be considered susceptible to bovine virus diarrhea virus...

2009-01-01

344

Re-establishing esthetics of fluorosis-stained teeth using enamel microabrasion and dental bleaching techniques.  

PubMed

Dental fluorosis manifests itself as white stains on the enamel of teeth exposed to excessive doses of fluoride during their formation. Fluorosis usually occurs as a result of the ingestion of dentifrices, gels and fluoridated solutions. It may be diagnosed as mild, moderate or severe, and in some cases, it may cause the loss of the surface structure of dental enamel. The aim of this study was to report the clinical case of a female patient of 18 years with moderate fluorosis, whose smile was reestablished by the use of an enamel microabrasion technique, followed by in-office bleaching. A microabrasion technique with 6% hydrochloric acid associated with silica carbide showed to be a safe and efficient method for removing white fluorosis stains, while dental bleaching was useful for obtaining a uniform tooth shade. The association of these techniques presented excellent results and the patient was satisfied. Both techniques are painless, fast and easy to perform, in addition to preserving the dental structure. Treatment showed immediate and permanent results; this technique must be divulged among professionals and their patients. PMID:22645728

Pontes, Danielson Guedes; Correa, Ketlen Michele; Cohen-Carneiro, Flávia

2012-01-01

345

MTA apical plugs in the treatment of traumatized immature teeth with large periapical lesions.  

PubMed

This case report describes the management of a late-referral case of periapically involved, traumatized immature permanent incisors by endodontic treatment and the use of mineral trioxide aggregate (MTA) apical plugs. A 10-year-old boy was referred to the clinic with a chief complaint of pain in his maxillary central incisors, which had experienced subluxation trauma 2 years earlier. Periapical radiograph of the teeth showed incomplete root development with wide-open apices and large periradicular lesions. The canals were gently debrided using K-files in conjunction with 2.5% NaOCl irrigation and 2% chlorhexidine for final flush. The root canals became asymptomatic after employing the same endodontic regimen for three visits. MTA plugs were placed in the apical area of the root canals, and the rest of the canal space was obturated by warm compaction of gutta-percha and AH Plus sealer. Resolution of the large periapical lesions was observed 2 months after treatment. At 18 months, the periapical areas revealed radiographic evidence of bone healing. Following successful removal of the toxic content of the root canal, placement of MTA plugs resulted in both healing of the periradicular radiolucency and regeneration of the periapical tissue. PMID:21129158

Cehreli, Zafer C; Sara, Sezgi; Uysal, Serdar; Turgut, Melek D

2010-12-05

346

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

347

Study of the Chronologic Development and Eruption of Teeth in Elasmobranchs  

Microsoft Academic Search

By the use of intravital labeling with tetracycline antibiotics, it has been possible to determine calcification patterns and the rate of exfoliation of elasmobranch teeth. The results indicate that young lemon sharks lose the most peripheral row of teeth in 14-day sequences, with a continuous replacement mechanism restoring the lost teeth from the deeper dental lamina. The technic used is

Philip J. Boyne

1970-01-01

348

Static and fatigue fracture resistances of pulpless teeth restored with post–cores  

Microsoft Academic Search

ObjectivesSuperior restorative methods for effectively strengthening pulpless teeth need to be identified, since vertical root fractures of pulpless teeth are still a major problem in everyday clinical practice. The present study tested the null hypothesis that there were no differences in static and fatigue fracture resistances of pulpless teeth restored with different types of post–core systems.

Mikako Hayashi; Atsushi Sugeta; Yutaka Takahashi; Satoshi Imazato; Shigeyuki Ebisu

2008-01-01

349

Minerals in human teeth: differences between preindustrial and contemporary Hopi Indians.  

PubMed

Mineral elements in dentin from 17th century Hopis were compared with samples from contemporary Hopis living in the same geographic area. Less lead, zinc, and copper, and more strontium were found in the preindustrial teeth. Trace element levels in the contemporary Hopi teeth were similar to those in suburban Californian teeth. PMID:326020

Kuhnlein, H V; Calloway, D H

1977-06-01

350

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

351

Bovine coronavirus structural proteins.  

PubMed Central

The tissue culture-adapted strain (Mebus) of bovine coronavirus was grown in the presence of isotopically labeled amino acids, glucosamine, or orthophosphate for the purpose of analyzing the virion structural proteins. Five species of polypeptides were identified when purified virions were solubilized in urea and sodium dodecyl sulfate and resolved by polyacrylamide gel electrophoresis. Four species were glycosylated and had apparent molecular weights of 140,000, 120,000, 100,000, and 26,000. The glycoproteins were susceptible to proteolytic cleavage and enzymatic iodination when intact virions were studied and are thus at least partially external to the virion envelope. The 140,000-molecular-weight glycoprotein is apparently a dimer of 65,000-molecular-weight glycopolypeptides held together by disulfide linkages. Species 5 was phosphorylated and had an apparent molecular weight of 52,000. In the intact virion, it was unaffected by protease and was not enzymatically iodinated. It is therefore apparently an internal protein. Images

King, B; Brian, D A

1982-01-01

352

STUDIES IN BOVINE MASTITIS  

PubMed Central

It seems clearly established that non-hemolytic streptococci are responsible for a considerable number of cases of bovine mastitis. Of the 81 animals examined, 31 were suffering from infections of this type. The lesions produced in invaded quarters varied from an involvement of only the lining epithelium of the large milk ducts to severe degeneration and necrosis of the secreting epithelium. In one instance a considerable portion of the glandular elements had been replaced with connective tissue. The streptococci fall into two groups when their action on the various carbohydrates is considered. Thirty-four strains fermented dextrose, lactose, saccharose, maltose, and salicin; five others attacked the first four sugars but failed to produce acid in salicin. All mastitis streptococci failed to act upon raffinose, inulin, or mannite. One species isolated from a mammary abscess produced acid in all the carbohydrates. All the strains were agglutinated with an antiserum prepared from one typical strain. The agglutination titer varied over wide limits, although all the streptococci were agglutinated at a dilution of 1:500. None of the strains inoculated proved pathogenic for rabbits. A pig fed on the milk from two typical cases of mastitis remained well.

Jones, F. S.

1918-01-01

353

Permanent disability social insurance programs in Japan.  

PubMed

This article examines Japan's permanent disability social insurance programs. Because there is limited information available about these programs in the literature outside Japan, this analysis helps to further international disability research. Primary public pension systems and their corresponding programs for permanently disabled workers and their families are described, including trends in the number of beneficiaries and benefit expenditures. Importantly, the article analyzes the determination and appeals processes in Japan for claiming permanent social insurance disability pensions. The study also references the Social Security Disability Insurance program operating in the United States and offers comparisons with the system in Japan, which provides insights about operational procedures to researchers and policymakers in both countries. Permanent disability programs in Japan and the United States share similar characteristics, including aspects of their benefit determination and appeals procedures. However, these country program experiences diverge markedly in several areas, making the comparison worthwhile from a policy perspective. PMID:20337138

Rajnes, David

2010-01-01

354

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. 10 figs.

Tatchyn, R.O.

1997-01-21

355

Object permanence in cats and dogs  

Microsoft Academic Search

Object permanence was assessed for cats and dogs, using tasks analogous to those typically employed for human infants. Neither\\u000a species solved all of the problems correctly when rewarded only by the discovery of a hidden toy. However, both species showed\\u000a that they had fully developed concepts of object permanence when the problems were changed so that the animals had to

Estrella Triana; Robert Pasnak

1981-01-01

356

Permanent magnet excited brushed DC motors  

Microsoft Academic Search

Brushed DC motors excited with permanent magnet material can be found in a wide range of applications. The largest market segment for this type of motor and their predominant use is found in the low-power range. New developments in the area of high-energy permanent magnet material offer the opportunity of miniaturization and promise a cost-effective design. Starting with a brief

Kay Hameyer; Ronnie J. M. Belmans

1996-01-01

357

Design Calculations for Permanent-Magnet Generators  

Microsoft Academic Search

This paper describes a simplified method for calculating the performance of permanent-magnet generators using equations, concepts, and units familiar to the designer of conventional a-c generators. The equations and curves permit the calculation of open-circuit voltage, transient performance, short-circuit current, synchronous impedance, and voltage regulation for various power factors. Leakage equations are presented for the most common type of permanent-magnet

David Ginsberg; Leo J. Misenheimer

1953-01-01

358

Ultraminiaturized Milliwatt-Scale Permanent Magnet Generators  

Microsoft Academic Search

This paper reports the design, fabrication and experimental characterization of ultraminiaturized, axial-flux, permanent-magnet (PM) generators intended for milliwatt range systems. The miniaturization of PM machines is attractive because scaling laws are favorable, but integration of ultra-small permanent magnets is challenging. The generators are 2-pole, multi-turn, 2-mm diameter machines. A single-phase, open-circuit voltage of 51 mVrms has been measured at 392

F. Herrault; C.-H. Ji; R. H. Shafer; S.-H. Kim; M. G. Allen

2007-01-01

359

Permanent magnet planar micro-generators  

Microsoft Academic Search

Different types of axial-flux permanent magnet electromagnetic ?-generators have been developed in LEG in collaboration with Laboratoire d’Electronique de Technologie de l’Information (LETI), CEA Grenoble. A Ø8mm planar generator consists of a permanent magnet disc rotor cut out of bulk SmCo5 or NdFeB, and a silicon stator with electroplated three-phase planar coils. High speed electrical tests exhibit an output power

Hynek Raisigel; Orphée Cugat; Jérôme Delamare

2006-01-01

360

NATIVE AND REGENERATED BOVINE ALBUMIN  

PubMed Central

1. Whole bovine albumin, homogeneous in diffusion and sedimentation, and essentially homogeneous in electrophoresis, has been prepared by a method involving ammonium sulfate precipitation of the globulins in the cold and of the albumin at room temperature, isoelectric precipitation of the euglobulins, and reprecipitation of the albumin. 2. The product has been characterized by chemical analysis and by viscosity, diffusion, sedimentation, and electrophoresis measurements. The carbohydrate content is 0.38 per cent, the nitrogen content, 15.2 per cent. The molecular shape approximates that of a prolate ellipsoid with an axial ratio of 3.1, assuming 33 per cent hydration; the average molecular weight is 65,000. 3. Bovine albumin is readily denatured by concentrated solutions of urea or guanidine hydrochloride, gross changes in molecular shape resulting. 4. Regeneration of bovine albumin denatured in solutions of 8 M urea or guanidine hydrochloride yields a material closely resembling the native in carbohydrate content, in molecular size and shape, and in electrophoretic properties. However, the regenerated protein differs from the native in susceptibility to tryptic digestion, and, in this respect, appears to be in a denatured state. 5. In 8 M solutions of guanidine hydrochloride a limiting yield of regenerated albumin equivalent to 95 per cent of the original protein is approached. 6. Bovine crystalbumin, a crystalline carbohydrate-free fraction of the whole albumin, appears to be more susceptible to denaturation than whole bovine albumin.

Putnam, Frank W.; Erickson, John O.; Volkin, Elliot; Neurath, Hans

1943-01-01

361

[Adaptation of permanent bovine kidney cells to serum free hormone supplemented cell culture media].  

PubMed

The examinations show, that it is possible to adapt MDBK-cells (ATCC CCL 22) to serum-poor (0.1% fetal calf serum) and to serum-free, adequate supplemented media. Morphology of the cells remained unchanged. The components of the serum-free medium are a 50:50 mixture of Dulbecco's modified Eagle's medium and HAM's F12 medium, supplemented with insulin (5 micrograms ml-1), transferrin (10 micrograms ml-1), thyroglobulin (10 micrograms ml-1), prostaglandin E1 (50-100 ng ml-1). Seeding cells at a density of 26.10(3) cm-2 at day 0 resulted in better multiplication than a higher seeding density. PMID:2267892

Binder, S; Beutel, M; Lindl, T

1990-11-01

362

An example of the application of Markov models in dentistry--a prediction of the fate of molar teeth in 12-year-old Scottish children.  

PubMed

Markov analysis is a mathematical modelling technique which is particularly useful for predicting prognoses and probabilities of chronic diseases within populations. This paper applies Markov analysis to data concerning the condition of upper left permanent first molars in a group of individuals who were surveyed at age 12 and 15 years in Scotland by the Office of Population Censuses and Surveys. The Markov analysis predicted that in 1998, when the group of individuals would be 27 years old, 3.6 per cent of upper left first permanent molar teeth would be sound, 2.6 per cent would be decayed, 58.4 per cent would be filled and 35.4 per cent would be missing. A comparison of the Markov prediction for 18 year-olds in Scotland in 1989 with United Kingdom data for 16-24 year-olds published in 1988 indicated that the observed health status of the teeth was considerably better than that predicted by the Markov technique. The applicability of the Markov method to tooth status may therefore lie less in its ability to predict events as in being able to provide 'baselines' for future dental states in particular groups. Such an application of the Markov method could be used to determine whether dental deterioration among a group is occurring at a faster or slower rate than in the past. PMID:8269336

Kay, E J; Nuttall, N M

1993-09-01

363

Histopathology of the teeth in segmental odontomaxillary dysplasia: new findings.  

PubMed

Histological examination of the deciduous teeth in two cases of segmental odontomaxillary dysplasia (SOMD) showed fibrous enlargement of the pulps, an irregular pulp/dentine interface displaying many pseudoinclusions and pulp stones. There were tubular defects in the coronal dentine from pulp horn to cusp tip, an irregular tubular structure to the circumpulpal dentine of the apical half, a focally deficient odontoblast layer and widespread external resorption. Together with the clinical features of unilateral maxillary enlargement, upper alveolar expansion in the distal segment, increased spacing and delayed eruption of the deciduous molars and absence of premolar teeth, these histological appearances allow distinction of this condition from fibrous dysplasia (FD), segmental hemifacial hypertrophy (SHH) and regional odontodysplasia (ROD). PMID:15061714

Armstrong, Conor; Napier, Séamus S; Boyd, Robert C; Gregg, Terry A

2004-04-01

364

[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

365

[Usefulness of radiological examinations in the diagnosis of supernumerary teeth].  

PubMed

Existence of the supernumerary teeth has been found in 39 persons at the age of 8 to 69. There were 61.6% of the cases at the age when dentition exchange takes place and 38.4% of the cases during maturity. Clinical and radiological examinations have been carried out in these patients. The radiograms obtained have been found useful in detection, description and treatment of this dental anomaly. PMID:2640637

Struzak-Wysoki?ska, M; Wysoki?ska-Miszczuk, J; Kami?ska, K

1989-01-01

366

Composite lingual buttons for correction of rotated premolar teeth.  

PubMed

Composite lingual buttons can be an invaluable alternative for bondable stainless steel lingual buttons on the lingual surfaces of rotated premolars as these surfaces are more vulnerable for bond failures due to their varied morphology, inadequate bonding surfaces, aprismatic enamel, salivary contamination and inferior etch pattern. Their use can also be extended to the molars and other teeth as they can be used as attachments for correction of cross-bites. PMID:23941025

Yezdani, A Arif

2013-01-01

367

Technique for repair of multiple abutment teeth under preexisting crowns.  

PubMed

This technique describes a simple procedure for repairing multiple fractured or broken-down abutment teeth under existing crowns. The technique uses a Teflon tape polytetrafluoroethylene (PTFE) as a matrix and separating medium for fabrication of an autopolymerizing composite core material with digital pressure. This technique enables the dentist to solve an emergency clinical situation in a relatively short amount of time, pending further restoration with endodontic treatment and a cast post and core procedure. PMID:12589296

Chan, Daniel C N

2003-01-01

368

Multiple Unerupted Teeth with Amelogenesis Imperfecta in Siblings  

PubMed Central

Amelogenesis imperfecta encompasses a group of inherited abnormalities that are generally considered to primarily affect the formation and/or calcification of enamel. This case report describes the unusual presentation of amelogenesis imperfecta in siblings as multiple unerupted teeth, multiple pulpal calcifications, and multiple dilacerations of roots along with the defect in the enamel. The intent of our report is to highlight a rare co-occurrence of amelogenesis imperfecta with multiple morphologic alterations in siblings.

Hegde, Shruthi

2012-01-01

369

Stable isotope ratios in hair and teeth reflect biologic rhythms.  

PubMed

Biologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient's heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals. PMID:17653263

Appenzeller, Otto; Qualls, Clifford; Barbic, Franca; Furlan, Raffaello; Porta, Alberto

2007-07-25

370

Stable Isotope Ratios in Hair and Teeth Reflect Biologic Rhythms  

PubMed Central

Biologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient's heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals.

Appenzeller, Otto; Qualls, Clifford; Barbic, Franca; Furlan, Raffaello; Porta, Alberto

2007-01-01

371

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

372

Taxonomic attribution of the La Grive hominoid teeth.  

PubMed

The two hominoid teeth--a central upper incisor (NMB G.a.9.) and an upper molar (FSL 213981)--from the Middle Miocene site of La Grive-Saint-Alban (France) have been traditionally attributed to Dryopithecus fontani (Hominidae: Dryopithecinae). However, during the last decade discoveries in the Vallès-Penedès Basin (Spain) have shown that several hominoid genera were present in Western Europe during the late Middle Miocene. As a result, the attribution of the dryopithecine teeth from La Grive is not as straightforward as previously thought. In fact, similarities with the upper incisor of Pierolapithecus have led to suggestions that either the latter taxon is present at La Grive, or that it is a junior synonym of Dryopithecus. Here, we re-describe the La Grive teeth and critically revise their taxonomic assignment based on metrical and morphological comparisons with other Middle to Late Miocene hominoids from Europe and Turkey, with particular emphasis on those from the Vallès-Penedès Basin. Our results suggest that the I(1) differs in several respects from those of Pierolapithecus and Hispanopithecus, so that an attribution to either Dryopithecus or Anoiapithecus (for which this tooth is unknown) seems more likely. The molar, in turn, most likely corresponds to the M(1) of a female individual. Compared to other Middle Miocene taxa, its occlusal morphology enables its distinction from Pierolapithecus, whereas relative crown height agrees well with Dryopithecus. Therefore, based on available evidence, we support the traditional attribution of the La Grive hominoid to D. fontani. PMID:23754569

Pérez de los Ríos, Miriam; Alba, David M; Moyà-Solà, Salvador

2013-06-11

373

Esthetic direct restorations in endodontically treated anterior teeth.  

PubMed

Composite resins are the most commonly used materials in restorative dentistry. When first introduced in dental practice, they began to change the esthetic approach to anterior teeth treatments. At first they simply represented a 'white' alternative to unesthetic materials. Today, the clinician can select different materials depending on the characteristics required, such as opalescence, fluorescence, translucency, transparency, viscosity, elasticity, and, obviously, shade. It is no longer a mere matter of selecting the right single syringe. The thicknesses of one or several materials may drastically change the final outcome. A three-dimensional way of planning restorations has overcome the old monochromatic bi-dimensional one. Sound tooth preservation, affordable treatments, and reparability are only a few of the advantages of using composite resins. Clinicians generally consider non-vital anterior teeth a big challenge from an esthetic point of view and they very often prefer to treat them with full or partial indirect ceramic restorations. In the present article, through the analysis of several step-by-step clinical cases, the authors point out that direct restorations could lead to successful esthetic outcomes if correct techniques are applied in order to make up for the differences between vital and non-vital teeth. PMID:23390620

Paolone, Gaetano; Saracinelli, Monaldo; Devoto, Walter; Putignano, Angelo

2013-01-01

374

A microbiological profile of symptomatic teeth with primary endodontic infections.  

PubMed

The aim of this study was to evaluate the composition of the microbiota of primary endodontic infections associated with symptomatic teeth. Samples were collected by means of a #15 H-type file and 2 sterile paper points from 60 symptomatic (n = 30) or asymptomatic (n = 30) single-rooted teeth with necrotic pulp. The presence of 40 bacterial species was determined by the checkerboard DNA-DNA hybridization method. The species found in higher counts (x10(5)) in symptomatic cases were Fusobacterium nucleatum ssp. vincentii, Veillonella parvula, Treponema socranskii, Enterococcus faecalis, and Campylobacter gracilis and in asymptomatic cases were F. nucleatum ssp. vincentii, Fusobacterium nucleatum ssp. nucleatum, E. faecalis, Eubacterium saburreum, and Neisseria mucosa. Total bacterial counts and counts of Tannerella forsythia were significant higher in symptomatic cases (p < 0.05), whereas levels of Propionibacterium acnes were reduced in this group of teeth. The data of the present investigation suggested an association between higher total bacterial counts and levels of T. forsythia and the presence of pain. PMID:18436031

Sassone, Luciana M; Fidel, Rivail A; Faveri, Marcelo; Guerra, Rafael; Figueiredo, Luciene; Fidel, Sandra R; Feres, Magda

2008-03-07

375

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

376

Are referred inaccessible human primary molar teeth really inaccessible?  

PubMed

Despite a body of compelling evidence pertaining to the root canal accessibility of primary teeth, the number of referrals for inaccessibility of primary molars is considerable. The aim of the present study was to evaluate the prevalence of true and false primary molar inaccessibility among subjects who had been referred by general and pediatric dentists. We examined 199 primary molars in 156 patients (87 males, 69 females) aged 3-7 years who were referred by 215 general and 35 pediatric dentists. Problems related to inaccessibility were recorded for each tooth and any individual canal. One hundred seventy-five inaccessible teeth (87.9%) were successfully rehabilitated to accessible status (P < 0.001). The most frequent cause of inaccessibility was an inappropriate access cavity (42.3%), followed by difficult canals (32.6%) and orifice calcification (25.2%). The tooth most frequently reported as inaccessible was the maxillary first molar (40.2%), and that least frequently reported was the mandibular second molar (11.6%). The distobuccal canal of the maxillary first molar and the mesiolingual canal of the mandibular first molar were the most commonly inaccessible canals (P < 0.001). Only 1 out of 8 teeth referred as inaccessible was truly inaccessible. It seems that root canal inaccessibility is mostly attributable to lack of expertise among individual practitioners. PMID:23748457

Asl Aminabadi, Naser; Sighari Deljavan, Alireza; Samiei, Mohammad; Jamali, Zahra

2013-01-01

377

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

378

Quantitative analysis of trace metal accumulation in teeth using laser-induced breakdown spectroscopy  

NASA Astrophysics Data System (ADS)

The technique of laser ablation is receiving increasing attention for applications in dentistry, specifically for the treatment of teeth (e.g. drilling of micro-holes and plaque removal). In the process of ablation a luminous micro-plasma is normally generated which may be exploited for elemental analysis. Here we report on quantitative Laser-Induced Breakdown Spectroscopy (LIBS) analysis to study the presence of trace minerals in teeth. A selection of teeth of different age groups has been investigated, ranging from the first teeth of infants, through the second teeth of children, to adults to trace the influence of environmental factors on the accumulation of a number of elements in teeth. We found a close link between elements detected in tooth fillings and toothpastes with those present in teeth.

Samek, O.; Beddows, D. C. S.; Telle, H. H.; Morris, G. W.; Liska, M.; Kaiser, J.

379

Multispecialty team management of a case with impacted maxillary permanent canines.  

PubMed

A fifteen-year-old Chinese girl presented with unerupted maxillary permanent canines impacted against the roots of the central incisors, causing malalignment of the maxillary incisors. The canines were fully formed and their apices closed. The potential path of eruption of the canines contraindicated surgical exposure, followed by orthodontic traction. It was decided to transplant the impacted canines to their normal positions, and then align the maxillary anterior teeth, using a fixed orthodontic appliance. The transplantations and the orthodontic treatment were successful, and neither transplant showed signs of root resorption, periodontal pockets, mobility, or pain, three years after surgery. Root canal therapy was performed on the canines after transplantation, because their apices were closed. They were stained by the amalgam in the access cavities, but both responded well to nonvital bleaching using 30 percent H2O2. PMID:1629441

Tang, E L

380

Effects of threaded post placement on strain and stress distribution of endodontically treated teeth.  

PubMed

The aim of this study was to evaluate the effect of parallel and tapered threaded post placement on the strain and stress distribution of endodontically treated teeth. Fifteen bovine incisors were sectioned 15 mm from their apices, endodontically treated, and divided into three groups (n=5) according to three different threaded posts: parallel threaded post (Radix-Anker, RA); tapered threaded post (Euro-Post, EP) and tapered threaded post (Reforpost II, RII). A strain-gauge was fixed on the proximal surface perpendicular to the long root axis, 2 mm from the cervical limit. Strain generated during post placement was recorded and compared using one-way ANOVA and Tukey's test (?=.05). A scanning electron microscope was used to examine the longitudinal root sections. Stress was evaluated for each group in a two-dimensional finite element analysis. The models were meshed with tetrahedron elements and loaded with 2 N at an angle of 135° to the lingual face. The equivalent Von Mises stress was calculated. The one-way ANOVA showed significant difference among the groups. The RA group (150.0±12.2 A) produced higher external strain than the RII (80.0±12.2 B) and the EP (70.0±6.1 B) groups. The inner strain was approximately five times greater than the external dentin strain. High stress concentrations in each thread of the posts were observed. Scanning electron micrographs showed cracks that started in the threads of the posts. The threaded post placement induced root strain mainly on the parallel side post. Root strain and stress concentration on the post threads tended to create cracks in the inner root canal dentin. PMID:23903859

Santos Filho, Paulo César Freitas; Soares, Paulo Vinícius; Reis, Bruno Rodrigues; Veríssimo, Crisnicaw; Soares, Carlos José

381

Theropod teeth from the Prince Creek Formation (Cretaceous) of northern Alaska, with speculations on Arctic Dinosaur paleoecology  

Microsoft Academic Search

Theropod teeth are taxonomically diagnostic components of dinosaur assemblages. Seventy teeth have been recovered from six different localities in the Kogosukruk Tongue of the Prince Creek Formation (Upper Cretaceous) of the North Slope of Alaska. This assemblage of teeth shows slightly less diversity compared to well documented assemblages of teeth from the slightly older Judith River Formation of south-central Montana,

Anthony R. Fiorillo; Roland A. Gangloff

2001-01-01

382

The structure of bovine periodontal ligament with special reference to the epithelial cell rests.  

PubMed

The aim of this study was to determine the structure of the bovine periodontal ligament, with special reference to epithelial cell rests (ECR) and their cytokeratin content. Periodontal ligament was obtained from bovine molar teeth and studied at both the light microscopic and electron microscopic levels. Cytokeratin content was determined using immunohistochemistry against a number of cytokeratin antibodies and specificity tested against bovine and human oral mucosa. Collagen fibril diameters and the area of a fiber bundle occupied by collagen were determined using a digital planimeter with a digitizing tablet. The majority of periodontal fibroblasts possessed considerable quantities of roughened endoplasmic reticulum, indicating rapid synthesis and secretion of collagen, but no intracellular collagen profiles were present. Endothelial cells showed Weibel-Palade bodies. Collagen fibril diameters showed a unimodal distribution with a mean collagen fibril diameter of 55.3 nm. The mean percentage area of the extracellular matrix occupied by collagen was 42%. Structurally, ECR were unusual in exhibiting large numbers of microvilli and conspicuous amounts of cytokeratin filaments. Bovine ECR showed a positive reaction to the pancytokeratin MNF116 (which reacts with the cytokeratins 5, 6, 8, 17, and probably 19), to PCK-26 (which reacts with the type II cytokeratins 1, 5, 6, and 8) and to cytokeratin 13. There was no reaction for cytokeratins 1, 4, 10, 11 and 18. Structurally, bovine periodontal ligament showed features common to other species. However, ECR in terms of both structure and cytokeratin content showed features indicative of important species differences which may have relevance when considering the etiology of radicular cysts. PMID:9379337

Berkovitz, B K; Whatling, R; Barrett, A W; Omar, S S

1997-09-01

383

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

384

Permanent magnet materials and their application  

SciTech Connect

Permanent magnets are of great industrial importance in industrial drives, consumer products, computers, and automobiles. Since 1970, new classes of magnet materials have been developed. This book reviews the older and newer materials and is presented as a comprehensive design text for permanent magnets and their applications. After an initial chapter on the fundamentals of magnetism, the author discusses magnetic physics considerations specific to permanent magnets and describes the fabrications and characteristics of commercial materials: alnico, samarium-cobalt, ferrite, and neodymium-iron-boron. Thermal stability, magnet design procedures, magnetic field analysis methods, and measurement methods are discussed in subsequent chapters, followed by a concluding chapter reviewing commercial and industrial products that use permanent magnets. The chapter on thermal properties of magnet materials is of particular interest, bringing together information not readily found elsewhere. The review of applications is also deserving of attention, specifically the sections on motors and actuators. Although particle accelerator applications are discussed, the use of permanent magnet sextuples in modern ECR ion sources is not mentioned.

Campbell, P.

1994-12-31

385

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

386

Factors Controlling Hydrologic Permanence of Headwater Streams  

NASA Astrophysics Data System (ADS)

Headwater streams compose the majority of stream miles within most drainages. Interest in monitoring headwater streams is increasing because these streams are vital linkages between upland land use and downstream water bodies. However, traditional stream assessment tools are often unsuitable because many headwater streams are prone to natural drying. Our objective was to identify physical characteristics of headwater reaches that are indicative of hydrologic permanence, a critical first step in applying a stream assessment. We surveyed 61 reaches along 17 headwater streams (< 2.6 km2) across 4 forests in Indiana, Kentucky and Ohio. Reaches varied in hydrologic permanence over the 2-year study. Exploratory data analysis (CART and discriminant analysis) was used to identify physical parameters for classifying reaches by hydrologic permanence. Drainage area was a consistent parameter discriminating permanence categories and consistently separated ephemeral from perennial and intermittent reaches. Secondary parameters that distinguished intermittent from ephemeral and perennial reaches included bankfull width, maximum pool depth, and channel entrenchment. These factors represent basin and reach scales, suggesting that hydrologic permanence in stream networks should be investigated in a hierarchical context. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

Fritz, K. M.; Johnson, B. R.; Walters, D. M.

2005-05-01

387

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

388

OPTIMIZING BOVINE SNP DISCOVERY EFFORTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cow genome sequencing is underway at Baylor College of Medicine (BCM) sequencing center and will be completed in the next few months. The bovine genome sequencing white paper indicated a goal to identify 100,000 SNP for use in identification and mapping of quantitative trait loci (QTL) regions. The ...

389

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

390

GENOME OF BOVINE HERPESVIRUS 5  

Technology Transfer Automated Retrieval System (TEKTRAN)

Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138,390-bp genome encodes 70 putative proteins and resembles the a2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 ...

391

Microtensile bond strength of resin composite to dentin treated with Er:YAG laser of bleached teeth.  

PubMed

The objective of this study was to evaluate the influence of Er:YAG laser (? = 2.94 ?m) on microtensile bond strength (?TBS) and superficial morphology of bovine dentin bleached with 16% carbamide peroxide. Forty bovine teeth blocks (7 × 3 × 3 mm(3)) were randomly assigned to four groups: G1- bleaching and Er:YAG irradiation with energy density of 25.56 J/cm(2) (focused mode); G2 - bleaching; G3 - no-bleaching and Er:YAG irradiation (25.56 J/cm(2)); G4 - control, non-treated. G1 and G2 were bleached with 16% carbamide peroxide for 6 h during 21 days. Afterwards, all blocks were abraded with 320 to 600-grit abrasive papers to obtain flat standardized dentin surfaces. G1 and G3 were Er:YAG irradiated. Blocks were immediately restored with 4-mm-high composite resin (Adper Single Bond 2, Z-250-3 M/ESPE). After 24 h, the restored blocks (n = 9) were serially sectioned and trimmed to an hour-glass shape of approximately 1 mm(2) at the bonded interface area, and tested in tension in a universal testing machine (1 mm/ min). Failure mode was determined at a magnification of 100× using a stereomicroscope. One block of each group was selected for scanning electron microscope (SEM) analysis. ?TBS data was analyzed by two-way ANOVA and Tukey test (? = 0.05). Mean bond strengths (SD) in MPa were: G1- 32.7 (5.9)(A); G2- 31.1 (6.3)(A); G3- 25.2 (8.3)(B); G4- 36.7 (9.9).(A) Groups with different uppercase letters were significantly different from each other (p < .05). Enamel bleaching procedure did not affect ?TBS values for dentin adhesion. Er:YAG laser irradiation with 25.56 J/cm(2) prior to adhesive procedure of bleached teeth did not affect ?TBS at dentin and promoted a dentin surface with no smear layer and opened dentin tubules observed under SEM. On the other hand, Er:YAG laser irradiation prior to adhesive procedure of non-bleached surface impaired ?TBS compared to the control group. PMID:20859649

Leonetti, Eduardo dos Santos; Rodrigues, José Augusto; Reis, André Figueiredo; Navarro, Ricardo Scarparo; Aranha, Ana Cecília Correa; Cassoni, Alessandra

2010-09-22

392

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

393

Analysis of a spherical permanent magnet actuator  

SciTech Connect

This paper describes a new form of actuator with a spherical permanent magnet rotor and a simple winding arrangement, which is capable of a high specific torque by utilizing a rare-earth permanent magnet. The magnetic-field distribution is established using an analytical technique formulated in spherical coordinates, and the results are validated by finite element analysis. The analytical field solution allows the prediction of the actuator torque and back emf in closed forms. In turn, these facilitate the characterization of the actuator and provide a firm basis for design optimization, system dynamic modeling, and closed-loop control law development. {copyright} {ital 1997 American Institute of Physics.}

Wang, J.; Jewell, G.W.; Howe, D. [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

1997-04-01

394

Magnetic guns with cylindrical permanent magnets  

NASA Astrophysics Data System (ADS)

The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative of the magnetostatic interaction energy. For comparison, the forces involved are also calculated numerically using finite elements methods. Based on the conservation of the magnetostatic and kinetic energies, the exit and asymptotic velocities are determined. The derived formulas can be used to optimize the generated forces and motion of the inner cylindrical magnet.

Vokoun, David; Beleggia, Marco; Heller, Lud?k

2012-05-01

395

Migration of mercury from dental amalgam through human teeth.  

PubMed

Exposure to mercury from dental amalgams, with possible negative health effects, has generally been considered to occur via either erosion or evaporation directly from the surface of fillings, followed by ingestion. The aim of this study was to determine the relative importance of the direct migration of mercury through the tooth as an alternative exposure pathway. X-ray fluorescence imaging has been used to determine quantitatively the spatial distribution of Hg, Ca, Zn and Cu in sections of human teeth that had been filled with amalgam for more than 20 years. X-ray absorption near-edge spectroscopy (XANES) was also employed to gain chemical information on the mercury present in the teeth. Hg (up to approximately 10 mg g(-1)) and Zn (>100 mg g(-1)) were detected in the teeth several millimetres from the location of the amalgams. At high resolution, Hg showed higher concentrations in dentinal tubules while Zn was generally evenly distributed. XANES showed that the chemical form of Hg that had migrated into the tooth had been altered from that present in the amalgam. The differing spatial distributions of Hg and Zn suggest distinct transport mechanisms for the two metals, presumably chemical for Zn and initially physical for Hg. Subsequent oxidation of Hg may lead to a loss of mobility or the development of a secondary transport mechanism. Most importantly the detection of Hg in areas of the tooth that once contained an active bloodstream and in calculus indicates that both exposure pathways should be considered as significant. PMID:18296776

Harris, Hugh H; Vogt, Stefan; Eastgate, Harold; Legnini, Daniel G; Hornberger, Benjamin; Cai, Zhonghou; Lai, Barry; Lay, Peter A

2008-02-19

396

Age estimation by IBAS image analysis of teeth.  

PubMed

The study of teeth to estimate age in a cadaver or in remains has become widely accepted in legal medicine, especially since the appearance of Gustafson's work in 1950. However, many studies published since that time have questioned the accuracy of these determinations. Computerized image analysis (IBAS) provides much more precise measurements of the parameters involved in these studies. An IBAS I (Kontron) image analysis system was used to study 19 different morphological parameters in midsagittal sections of a total of 173 upper and lower central incisors from as many live subjects. The data thus obtained provide useful information for determining the subject's age. PMID:2335328

López-Nicolás, M; Canteras, M; Luna, A

1990-03-01

397

Propose of Speech Recognition using Acceleration Sensor Attached to Teeth  

NASA Astrophysics Data System (ADS)

In our development of a new monitoring system for human utterance, we investigated temporal variation when a participant verbalized five Japanese vowels by using an acceleration sensor attached to the lower teeth. We then analyzed the variation by wavelet transform and obtained the temporal spectral density. We were able to observe the frequencies corresponding to voice sound and the lower jaw movements. The results indicated that the possibility of speech recognition with not only voice sounds but also lower jaw movements by our system.

Takizawa, Yukako; Higuchi, Kohei; Maenaka, Kazusuke; Saiki, Tsunemasa

398

Bilateral geminated teeth with talon cusps: A case report  

PubMed Central

Talon cusps and gemination are rare dental anomalies that can cause significant aesthetic and clinical problems. Bilateral talon cusps on geminated teeth have not been reported so far. The case of gemination with talon cusps on both maxillary central incisors was presented in this report. The main complaints of the patient were tongue irritation and aesthetic problems. The talon cusps were gradually reduced at 2 consecutive sittings and the exposed surface was treated with a fluoride gel. The aesthetical appearance was improved using a composite resin. Fixed orthodontic treatment was initiated for repositioning the left maxillary lateral incisor. A long term, multidisciplinary approach is necessary for the treatment of gemination with talon cusps.

Sener, Sevgi; Unlu, Nimet; Basciftci, Faruk Ayhan; Bozdag, Guldane

2012-01-01

399

Osteoid osteoma associated with the teeth: unusual presentation.  

PubMed

Osteoid osteoma is a rare benign osseous neoplasm which rarely affects the jaws. It is more common in long bones which can lead to postural scoliosis. The clinical characteristic feature of this tumour is the unexplained pain that is relieved by the intake of analgesics. Histologically it is characterized by the formation of central nidus with surrounding sclerotic bone. The diagnostic dilemma in this case report is aggravated by its unusual association with the teeth. The use of CT scanning is advised to distinguish from other odontogenic tumours. Treatment for this tumour is surgical removal or excisional biopsy to avoid recurrence and progression to malignant changes. PMID:22658497

Mohammed, I; Jannan, N A; Elrmali, A

2012-06-02

400

Anesthetic efficacy of infiltrations in mandibular anterior teeth.  

PubMed Central

The purpose of this prospective, randomized, double-blind study was to measure the degree of anesthesia obtained with a labial infiltration of either 2% lidocaine with 1:50,000 or 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Another objective was to measure the degree of anesthesia obtained with a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Through use of a repeated-measures design, 40 subjects randomly received a labial infiltration at the lateral incisor apex of either 1.8 mL of 2% lidocaine with 1:100,000 epinephrine or 1.8 mL of 2% lidocaine with 1:50,000 epinephrine at 2 separate appointments. An additional 40 subjects received a lingual infiltration at the lateral incisor apex of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. The mandibular anterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. For the 3 infiltrations, success rates for the lateral incisor ranged from 43 to 50%. Adjacent teeth had success rates of 27 to 63%. There was no significant difference (P > 0.05) in success between the labial infiltration of 2% lidocaine with 1:100,000 epinephrine and 2% lidocaine with 1:50,000 epinephrine or the lingual infiltration of 2% lidocaine with 1:100,000 epinephrine when compared with the labial infiltration of 2% lidocaine with 1:100,000 epinephrine. Duration of pulpal anesthesia declined steadily for all solutions over the 60 minutes. In conclusion, the success rate of 43-50% and declining duration of pulpal anesthesia over an hour indicates that a labial infiltration of 1.8 mL of either 2% lidocaine with 1:100,000 epinephrine or 1: 50,000 epinephrine or a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine over the lateral incisor apex cannot be recommended clinically to provide profound pulpal anesthesia.

Yonchak, T.; Reader, A.; Beck, M.; Clark, K.; Meyers, W. J.

2001-01-01

401

Root canal obturation of primary teeth: disposable injection technique.  

PubMed

The aim of the study was to outline a simple, cost-effective technique for obturation of primary tooth root canals. A total of 75 primary teeth were treated in 52 subjects by the technique discussed, i.e. injecting plastic flowable material into the root canals after desired preparation, using disposable needle and syringe. All the patients were followed up for 3 years and 6 months, with no clinical or radiologic evidence of pathology or need for untimely extraction. In conclusion, the technique described is simple, economical, can be used with almost all filling materials used for the purpose, and is easy to master with minimal chances of failure. PMID:22565512

Bhandari, S K; Prajapati, U

402

Restoration of badly broken, endodontically treated posterior teeth  

PubMed Central

It is generally agreed that the successful treatment of a badly broken tooth with pulpal disease depends not only on good endodontic therapy, but also on good prosthetic reconstruction of the tooth after the endodontic therapy is complete. Often, we come across an endodontically treated tooth with little or no clinical crown in routine clinical cases. In such cases, additional retention and support of the restoration are difficult to achieve. Two case reports are discussed here where structurally compromised, endodontically treated, posterior teeth were restored using the Richmond crown in the first case, and by the use of two nonparallel cast posts in the second case.

Gogna, Rupika; Jagadish, S; Shashikala, K; Keshava Prasad, BS

2009-01-01

403

The function of teeth chattering in male Barbary macaques (Macaca sylvanus).  

PubMed

Teeth chattering is seen in many primate species and has been proposed to have a range of social functions. This observational study tested specific hypotheses relating to the function of teeth chattering in a semi-free-ranging group of Barbary macaques, Macaca sylvanus. During focal watches of males, the outcome of male-male dyadic social interactions in which teeth chattering was present or absent was compared. Using these data, we tested the predictions of four hypotheses: teeth chattering functions as a signal of submission, appeasement, affiliation or reassurance. Support was found for all four hypotheses. In addition, in some contexts, an exchange of teeth chattering appeared to have a greater impact on the outcome of interactions than one male alone giving this signal. These findings suggest that teeth chattering serves an important role in coordinating the social interactions of male Barbary macaques. PMID:17358007

Wiper, Susan M; Semple, Stuart

2007-10-01

404

Impacted maxillary anterior supernumerary teeth: a survey of forty-two cases.  

PubMed

The purpose of this retrospective study was to examine the location of impacted maxillary anterior supernumerary teeth that subsequently were removed from pediatric patients at Children's Hospital of New York-Presbyterian. The study population consisted of 42 children diagnosed with impacted maxillary anterior supernumerary teeth. The impacted maxillary anterior supernumerary teeth were surgically removed by one faculty member in the hospital operating room with the aid of general anesthesia between 1994 and 2000. The total number of impacted maxillary anterior supernumerary teeth was 51. All were located palatally on either side of the midline and were surgically removed from a palatal access. In the absence of clear imaging evidence to the contrary, it is recommended that the preferred surgical approach for the removal of impacted maxillary anterior supernumerary teeth should be the palatal approach. Relatedly, the term mesiodens is misleading and is generally inaccurate for describing impacted maxillary anterior supernumerary teeth. Palatodens would be a more appropriate descriptive term. PMID:19195233

Yoon, Richard K; Chussid, Steven; Davis, Martin J

2008-11-01

405

An unusual presentation of generalized aggressive periodontitis with multiple impacted supernumerary teeth  

PubMed Central

Aggressive periodontitis is a rare condition that progresses rapidly but affects only a small percentage of population. Most of the cases are familial. The presence of supernumerary teeth is also rather rare and often familial. Therefore, a concomitant presentation of aggressive periodontitis and supernumerary teeth in an individual has generated a great interest among clinicians. Here, we report a rare nonsyndromic case of generalized aggressive periodontitis with multiple impacted supernumerary teeth.

Salman, Arif; Meethil, Archana

2012-01-01

406

Rat wct mutation induces a hypomineralization form of amelogenesis imperfecta and cyst formation in molar teeth  

Microsoft Academic Search

Our previous findings have demonstrated that the rat autosomal-recessive mutation, whitish chalk-like teeth (wct), induces enamel defects resembling those of human amelogenesis imperfecta (AI) in continuously growing incisor teeth. The\\u000a present study clarifies the effect of the wct mutation on the morphogenesis and calcification of rat molar teeth. Formalin-fixed maxillae obtained from animals aged 4-30 days\\u000a were examined by electron probe

Masaru Osawa; Shin-ichi Kenmotsu; Taku Masuyama; Kazuyuki Taniguchi; Takashi Uchida; Chikara Saito; Hayato Ohshima

2007-01-01

407

[Effect of selective polishing of teeth on local circulation in prosthetic treatment by implantation].  

PubMed

An effect of occlusion disorders on a regional circulation was studied in periodontal tissues of abutment teeth, antagonist teeth, periimplant zone at different stages of preparation for a prosthesis by normalization of occlusion ratios by means of selective polishing of teeth. The terms and the periodicity of selective polishing promoting redistribution of the masticating pressure were determined. The connection of these factors was examined with periodontal vessel tonicity and periimplant zone on the basis of the rheoparodontographic findings. PMID:12532892

Zolotareva, Iu B; Guseva, I E; Diudin, A N

2002-01-01

408

Bovine herpesvirus meningoencephalitis association with infectious bovine rhinotracheitis (IBR) vaccine  

Microsoft Academic Search

During 1992, on a farm in the Tokachi district of Hokkaido, Japan, approximately 20 Holstein-Friesian calves showed neuroparalysis and died within 7–10 days after routine vaccination. Six male calves, aged about 1.5 months, were submitted to our laboratory for pathological examination and diagnosed as acute or subacute necrotizing meningoencephalitis due to bovine herpes virus (BHV) infection. The main necropsy findings

H. Furuoka; N. Izumida; M. Horiuchi; S. Osame; T. Matsui

1995-01-01

409

PERMANENCE - AN ADAPTATIONIST SOLUTION TO FERMI'S PARADOX?  

Microsoft Academic Search

A new solution of Fermi's paradox sketched by SF writer Karl Schroeder in his 2002. novel Permanence is investigated. It is argued that this solution is tightly connected with adaptationism - a widely discussed working hypothesis in evolutionary biology. Schroeder's hypothesis has important ramifications for astrobiology, SETI projects, and future studies. Its weaknesses should be explored without succumbing to the

Milan M. ?irkovi?

410

A Life Span Approach to Object Permanence  

Microsoft Academic Search

The development of the concept of object permanence is traced in infants, children, and adults. In infancy, this development takes the form of a gradual change in understanding of objects’ identity parameters – the cues that, if altered, lead to a sense that the object’s identity has changed. Studies are reviewed which suggest that by 2 years of age, children

E. V. Subbotskii

1991-01-01

411

Complications infectieuses cutanées associées au tatouage permanent  

Microsoft Academic Search

Decorative tattooing is made by introducing exogenous pigments and\\/or dyes into the dermis to permanently mark the body for decorative or other reasons. Unfortunately, this procedure is not harmless and various complications may occur including the potential inoculation of virulent microorganisms in the dermis. Cutaneous infections usually develop within days to weeks after the procedure and may include: pyogenic infections

N. Kluger

2011-01-01

412

Applications of rare earth permanent magnets  

Microsoft Academic Search

Trends in the main application area of rare earth permanent magnets, data storage, are presented with the focus on miniaturization. Three examples of magnet applications, a CD-lens actuator, two spindle motors and the voice coil motor of hard disk drives, are discussed in detail and a brief sketch of other application areas is given. With respect to material properties we

Rob H. J. Fastenau; Evert J. van Loenen

1996-01-01

413

Trends in rare earth permanent magnets  

Microsoft Academic Search

A brief description is given of trends in research and development of permanent magnet materials, these trends being dictated on the one hand by industrial needs, on the other hand by limitations of the physical and crystal chemical properties of the intermetallic phases concerned. Recent results of materials based on Nd2Fe4B, solid solutions of interstitial N and C atoms in

K. H. J. Buschow

1994-01-01

414

Trends in rare earth permanent magnets  

Microsoft Academic Search

A brief description is given of trends in research and development of permanent magnet materials, these trends being dictated on the one hand by industrial needs, on the other hand by limitations of the physical and crystal chemical properties of the intermetallic phases concerned. Recent results are discussed of materials based on Nd2 Fe14B, solid solutions of interstitial N and

K. H. J. Buschow; K. H. J

1994-01-01

415

Improving permanent pasture's growth: An organic approach  

Microsoft Academic Search

SUMMARY - Organic agriculture claims to provide a sustainable way to produce enough quality food for today's needs. Within the framework of organic agriculture exists the biodynamic school of agriculture. The effect of the application of biodynamic preparations on permanent pastures along the altitudinal gradient in the NW of Madrid is presented here. During a period of three and a

R. Colmenares; J. M. De Miguel

416

Modified asphalt mixtures resistance to permanent deformations  

Microsoft Academic Search

Permanent deformations, primarily in the form of ruts, are one of the basic asphalt pavement damages impairing its service properties. Application of appropriate asphalt mixtures and binder modification are effective methods for improving asphalt courses resistance. While being manufactured, stored, fitted into a road pavement and during long term service, bitumen binders and asphalt mixtures are subject to continuous unfavourable

Piotr Radziszewski

2007-01-01

417

Permanent Switchboard Monitoring using Embedded Web Server  

Microsoft Academic Search

The proposed paper discusses the realization of a system prototype able to perform a permanent monitoring of a switchboard in order to allow the manufacturer the complete management of all the measurable quantities in the switchboard, specially the sensed voltage for each line. The main purpose is to prevent any fault that can affect the switchboard and provide an instant

F. Fioretti; S. Pasqualini; A. Andreoli; P. Pierleoni

418

[Pets as permanent excretors of zoonoses pathogens].  

PubMed

When scrutinizing zoonoses with regard to risks for human beings, the spectrum of pathogens with dogs, cats and birds leading to persistent infections and consequently to the fact that the animals become carriers and permanent excretors is relatively small. Most of the zoonoses cause clinical symptoms and will be taken care of correspondingly. With regard to dogs there is a multitude of persistent infections that are transferred from the pet to the human being and vice versa. In reality, however, the importance of the dog as permanent excretor of zoonosis pathogens endangering human health is minimal, except for some parasitoses. As far as cats are concerned, the situation is totally different. Cats are carriers and permanent excretors of pasteurella, the pathogens of the so-called cat-scratch disease, trichophyton and microsporum species, toxoplasmosis and orthopox viruses. The new zoonosis feline pox serves as an example of the necessity of a permanent observation of persistently infected pets. Healthy, but persistently infected birds form a source of infection not to be underestimated. Through the beat of their wings they constantly stir up dried infectious excrements and dust and thus favour the airborn infection of human beings. Chlamydia psittaci, the Newcastle disease virus and Mycobacterium avium are of major importance in this context. The risk of transferring zoonosis pathogens from persistently infected pets to human beings can be minimized through prophylactic diagnosis, strict measures of hygiene, observation of the schedule of vaccinations for the respective species and regular use of anthelmintica. PMID:8333899

Mayr, B

1993-02-01

419

Sexism and Permanent Exclusion from School  

ERIC Educational Resources Information Center

|Focussing on narratives collected during a two year participant observation research project in the children's services department of an urban local authority, this article addresses the intersection between incidents of permanent exclusion from school and assumptions made on the basis of a young person's gender. The article considers gendered…

Carlile, Anna

2009-01-01

420

Kinship care: Issues in permanency planning  

Microsoft Academic Search

Kinship care represents one of the newest paradigms in program options in public child welfare services and is one of the fastest growing segments in the child welfare system. This paper assesses the implementation of the goal of permanency planning articulated in the 1997 Adoption and Safe Families Act (ASFA), with a group of children placed with relatives by the

Carrie Jefferson Smith; Claire Rudolph; Peter Swords

2002-01-01

421

Modular permanent magnet brushless servo motors  

NASA Astrophysics Data System (ADS)

This article discusses the suitability of modular permanent magnet brushless machines for applications where servo characteristics are key performance requirements. It is shown that among the large number of feasible combinations of slot number and pole number, optimum combinations exist, which exhibit good servo characteristics.

Ede, J. D.; Atallah, K.; Howe, D.

2003-05-01

422

Stability of the Permanent Magnet Parameters.  

National Technical Information Service (NTIS)

The data on time, temperature and radiation stability of parameters of permanent magnets based on the barium ferrite, alnico alloys and SmCo sub 5 have been presented. The magnet parameters have been constant during 10 exp 4 -10 exp 5 h. The results on th...

V. I. Ilyushchenko

1978-01-01

423

Object Permanence Tests on Gibbons (Hylobatidae)  

Microsoft Academic Search

Ten gibbons of various species (Symphalangus syndactylus, Hylobates lar, Nomascus gabriellae, and Nomascus leucogenys) were tested on object permanence tasks. Three identical wooden boxes, presented in a linear line, were used to hide pieces of food. The authors conducted single visible, single invisible, double invisible, and control displacements, in both random and nonrandom order. During invisible displacements, the experimenter hid

Anna Fedor; Gabriella Skollár; Nóra Szerencsy; Mária Ujhelyi

2008-01-01

424

Torque analysis of permanent magnet synchronous motors  

Microsoft Academic Search

The torque capability of permanent magnet synchronous motor (PMSM) drives above rated speed is analyzed based on a proposed representation of the vector diagram. Mathematical equations and methods for graphical presentation of the torque capability are shown and applied to select motor parameters in a traction application. A commercially available salient pole PMSM is analyzed

A. K. Adnanes

1991-01-01

425

Permanent Base Groups in Broadcast Journalism Instruction.  

ERIC Educational Resources Information Center

|An instructor increases student performance, participation, and motivation in broadcast journalism and other media courses through the base group cooperative learning model. Base groups are a specific form of cooperative learning which enables students to become actively involved in small-group discussions and learning with a permanent group of…

Boldoc, William J.

426

Core losses in permanent magnet motors  

Microsoft Academic Search

It is pointed out that the conventional approach to core loss prediction using the Fourier series of the space wave of air gap flux density is not applicable to surface mounted permanent magnet (PM) motors. An alternative approach based on the concept that eddy current losses are proportional to the square of the time rate of change of the flux

G. R. Slemon; X. Liu

1990-01-01

427

War Crimes Tribunals: A Permanent Criminal Court?  

ERIC Educational Resources Information Center

Reports on the establishment and jurisdiction of war crimes tribunals in recent years. The tribunals, established and supported by the United Nations, investigate atrocities and other crimes committed during wartime. Discusses the tribunals in Rwanda and Yugoslavia, and the political opposition to the establishment of a permanent court. (MJP)

Dorsey, James E.; Rudelius-Palmer, Kristi

1997-01-01

428

Direct torque control of permanent magnet drives  

Microsoft Academic Search

Many permanent magnet motor drives use an open loop form of torque control, based on the assumption that output torque is proportional to applied current. In a practical motor this assumption may not always be correct, due to suboptimal alignment of magnets, nonuniformity of magnetic material, current sensor nonlinearities, and current controller limitations. These factors, together with nonoptimized current references,

Chris French; Paul Acarnley

1996-01-01

429

Permanent junctional reciprocating tachycardia misdiagnosed as 'cardiomyopathy'.  

PubMed

In a nine-year-old female, cardiac failure was erroneously attributed to idiopathic cardiomyopathy and cardiac transplantation was planned. The actual cause of cardiac failure was permanent junctional reciprocating tachycardia (PJRT), a rare form of supraventricular tachycardia. The diagnostic error was discovered before transplantation was performed and the arrhythmia was treated surgically. This resulted in return of near normal cardiac function. PMID:1872752

McGuire, M A; Lau, K C; Davis, L M; Knight, P; Uther, J B; Ross, D L

1991-04-01

430

When Do Commercial Reactors Permanently Shut Down?  

EIA Publications

For those wishing to obtain current data, the following resources are available: U.S. reactors, go to EIA's nuclear reactor shutdown list. (Note: As of April 30, 2010, the last U.S. reactor to permanently shut down was Big Rock Point in 1997.) Foreign Reactors, go to the Power Reactor Information System (PRIS) on the International Atomic Energy Agency's website.

Information Center

2011-05-10

431

Sexism and Permanent Exclusion from School  

ERIC Educational Resources Information Center

Focussing on narratives collected during a two year participant observation research project in the children's services department of an urban local authority, this article addresses the intersection between incidents of permanent exclusion from school and assumptions made on the basis of a young person's gender. The article considers gendered…

Carlile, Anna

2009-01-01

432

Permanent Magnet Generator Rotor Containment Study.  

National Technical Information Service (NTIS)

The design, development and testing of an advanced containment structure for high speed permanent magnet machines is presented. The primary intent of the program was to achieve a reduction in system weight, volume and cost through the use of an improved c...

E. U. A. Siddiqui

1983-01-01

433

Permanent Magnet Generators for Portable Military Power.  

National Technical Information Service (NTIS)

The United States Army MERDC has a continuing program to develop and update a family of portable and/or mobile power generation sets for use by the United States military services. In the past decade, a number of new permanent magnet materials have been d...

E. F. Hammond A. E. King A. L. Jokl

1971-01-01

434

Common indications of permanent pacemaker insertion.  

PubMed

Approximately one million people in the US have permanent pacemakers. These patients are usually seen in general practice and referred to a cardiologist. Therefore, it is important for the internists and hospitalists to be aware of the indications and complications of cardiac pacing. PMID:18681108

Ahmed, Syed Mashood; Ansari, Muhammad Jaffer

2008-01-01

435

Permanent Digital Function Storage using Neon Tubes  

Microsoft Academic Search

For some purposes, such as storage of tables needed in computations, an electronic memory unit which does not have the capability of changing its contents may be used. The required information may therefore be permanently wired in at the time of construction or be changed only by manual operations. A memory of this type utilizing the presence or absence of

Martin S. Raphael; Arthur S. Robinson

1956-01-01

436

Nonorthogonally magnetised permanent-magnet Faraday isolators  

SciTech Connect

This paper describes a novel configuration of permanent-magnet magnetic systems for high-power Faraday isolators that are used in high-power lasers. An increase in magnetic field is ensured by magnets with a magnetisation vector inclined to the isolator axis. Numerical simulation results agree well with experimentally determined magnetic field distributions. (quantum electronic devices)

Mironov, E A; Voitovich, A V; Palashov, O V [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2011-01-31

437

Modular permanent magnet brushless servo motors  

Microsoft Academic Search

This article discusses the suitability of modular permanent magnet brushless machines for applications where servo characteristics are key performance requirements. It is shown that among the large number of feasible combinations of slot number and pole number, optimum combinations exist, which exhibit good servo characteristics.

J. D. Ede; K. Atallah; D. Howe

2003-01-01

438

Laced permanent magnet quadrupole drift tube magnets  

SciTech Connect

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 an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.

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

1988-10-01

439

Burke's palimpsest: Rereading permanence and change  

Microsoft Academic Search

This essay develops the argument that the two different versions of Permanence and Change, read against the shifting context of American literary radicalism from the thirties to the present, offer us three different Burkes—the pragmatic Marxist, the neoconservative critic of Marxism, and finally the unrepentant left liberal. Each Burke represents as coherent an ideological position as any, although it may

James Arnt Aune

1991-01-01

440

Pupil Dilation and Object Permanence in Infants  

ERIC Educational Resources Information Center

|This paper examines the relative merits of looking time and pupil diameter measures in the study of early cognitive abilities of infants. Ten-month-old infants took part in a modified version of the classic drawbridge experiment used to study object permanence (Baillargeon, Spelke, & Wasserman, 1985). The study involved a factorial design where…

Sirois, Sylvain; Jackson, Iain R.

2012-01-01

441

Dentigerous cyst in a child associated with multiple inverted supernumerary teeth: a rare occurrence  

PubMed Central

Background: Dentigerous cysts associated with supernumerary teeth are rare with most of them developing around a mesiodens in the anterior maxilla. Dentigerous cysts from multiple supernumerary teeth, especially with inverted tooth, are rare in other regions of the maxilla. Case report: We report a unique case of a dentigerous cyst in a child associated with multiple inverted supernumerary teeth and relevant review of literarature. Conclusion: Dentigerous cyst arising from multiple supernumerary teeth and not anterior maxillary mesiodens is quite uncommon. In a child, such findings associated with inverted tooth are still rare. Such cysts should be managed by excision as soon as possible.

Agrawal, Neeraj K

2012-01-01

442

[Biomechanical basis splinting of loose teeth while preserving their mobility at physiological].  

PubMed

The aim of this study was biomechanical rationale for splinting mobile teeth with periodontitis according to the height and slope of teeth crowns, their degree of mobility, and type of occlusion. The research studied the effect of axial vertical and horizontal loads on the functioning of the proposed method of splinting. Set clear indications and contraindications for the use of the method of splinting. Biomechanically proven unreasonableness includes teeth with III degree of mobility in the splinted construction. Clinical variant of splinting is only possible at the height of the anatomical crowns of the teeth of at least 7 mm, otherwise the preferred laboratory methods for the manufacture of tires. PMID:24099811

Belikova, N; Petrushanko, T

2013-09-01

443

Endodontic therapy on the mandibular second molar: easiest to treat of the difficult, molar teeth.  

PubMed

Molar teeth present more problems during endodontic therapy than do bicuspid or anterior teeth. The major reasons for this are that molars can have complicated canal systems with unexpectedly large numbers of teeth with four canals, and they often have quite curved canals, which are more difficult to prepare and fill. The mandibular second molar generally is the easiest of these difficult teeth to treat, but they do have some areas of complication, too. The mesial root almost always has two--not one--canals and a rarely described condition, the C-shaped canal system, may be present. PMID:7987904

Weine, F S

1994-09-01

444

Cone beam computed tomography for diagnosis and treatment planning of supernumerary teeth.  

PubMed

Conventional radiographic images are frequently used to detect supernumerary teeth. However, recent developments in 3D imaging systems have enabled dentists to better visualize supernumerary teeth, with better contrast and more details. Cone beam computed tomography (CBCT) has improved diagnosis and treatment planning of patients with supernumerary teeth. The decision to use CBCT should be based on the diagnostic information required. This article presents three case reports of patients with supernumerary teeth to demonstrate the need for accurate diagnosis and treatment planning based on a comprehensive evaluation using CBCT. PMID:22623467

Gurgel, Carla Vecchione; Costa, Ana Lidia Soares; Kobayashi, Tatiana Yurico; Rios, Daniela; Silva, Salete Moura Bonifacio; Machado, Maria Aperecida de Andrade Moreira; Oliveira, Thais Marchini

445

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

446

Cultural alteration of human teeth in the Mariana Islands.  

PubMed

Evidence of cultural dental modification in a precontact (pre-1521) skeletal sample from the Academy of Our Lady of Guam gymnasium site in Agana, Guam, is documented. Two of the four individuals recovered at the Academy Gym site exhibit modification of the maxillary teeth. One individual displays vertical incising of a single tooth, and the other exhibits horizontal abrading of the anterior teeth which may be a purposeful or an incidental alteration. Although deliberate alteration of the dentition, including tooth extraction, notching, filing, and drilling, has been documented in human groups worldwide, little has been written about these cultural practices in the Mariana Islands. Examination of the available literature on precontact human remains from the region reveals at least three patterns of dental incising and similar cases of dental abrasion. While the origins of these practices are not known, the presence and style of these cultural alterations may be sex-specific, cosmetic in nature, or an indication of status in a ranked society. Alternatively, they may signify membership in a particular group or lineage, or mark a rite of passage. Because the comparative samples are limited in number and small, and the provenience of many of the skeletons is obscure, temporal variation cannot be ruled out. PMID:9408542

Ikehara-Quebral, R; Douglas, M T

1997-11-01

447

Effect of Tongue Thrust Swallowing on Position of Anterior Teeth  

PubMed Central

Background and aims There is no consensus about the effect of tongue thrusting on incisor position. The purpose of this study was to evaluate the position of anterior teeth in growing children with tongue thrust swallowing. Materials and methods In the present study 193 subjects with an age range of 9 to 13 years participated. All the patients were examined by a trained investigator and those having tongue thrust swallowing were selected and the position of their anterior teeth was compared with a control group consisting of 36 subjects with normal occlusion. Data was analyzed by independent sample t-test. Results Among the 193 students who were examined in this study, 10 cases (5%) were diagnosed to be tongue thrusters. Overjet was significantly increased in tongue thrust individuals (P < 0.05), while the other variables were not statistically different from the controls (P > 0.05). Conclusion The results indicated that tongue thrust may have an environmental effect on dentofacial structures. Considering the high incidence of tongue thrust in orthodontic patients, it is suggested that dental practitioners observe patients of all ages and those in all stages of orthodontic treatment for evidence of tongue thrust swallowing.

Jalaly, Tahereh; Ahrari, Farzaneh; Amini, Foroozandeh

2009-01-01

448

Discoloration of teeth from tetracyclines--even today?  

PubMed

The aim of this study was to examine whether brownish crown and root discoloration of wisdom teeth was related to treatment of acne with tetracyclines. For this purpose, 17 discolored third molars from nine patients were embedded without being decalcified, ground along the tooth axis, and examined using fluorescence microscopy. A thorough medical history served to determine the start and duration of any administration of tetracyclines. This confirmed the use of drugs against acne containing minocycline in all cases except one. The microscopic analyses of all teeth revealed intensely fluorescent bands in the dentin, which corresponded to the mineralization front at the time of tetracycline intake. More or less uniform discoloration of the entire crown was seen in association with treatment against acne prior to the completion of crown formation at the age of about 15 years. This uniform staining can be attributed to incorporation of minerals during ongoing maturation of the occlusal enamel, which is concomitant with the formation of the cervical crown regions. When acne was treated between 15 and 22 years of age, only the roots of the third molars displayed annular discolorations, which seemed to result from the incorporation of tetracyclines into dentin, while fine fluorescent incremental lines in root cementum were too thin to be apparent clinically. Three accidentally removed interradicular bony septa revealed that tetracyclines incorporated into alveolar bone remained there for about 2 years, but thereafter disappeared as a result of physiological remodelling. PMID:21656385

Antonini, Linda G; Luder, Hans Ulrich

2011-01-01

449

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.

Al-Fouzan, Khalid S.

2010-01-01

450

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

PubMed

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

2010-04-14

451

Infectious bovine rhinotracheitis virus: Experimental attempts at inducing bovine abortion with a New Zealand isolate  

Microsoft Academic Search

ExtractThere are numerous reports of infectious bovine rhinotracheitis (IBR) virus being incriminated as a cause of bovine abortion usually in the U.S.A. The relevent literature has been reviewed by Durham (1974).

P. J. K. Durham; Judith C. Forbes-Faulkner; W. S. H. Poole

1975-01-01

452

Human Antibodies to Bovine ?-Globulin  

Microsoft Academic Search

Antibodies to bovine ?-globulin (anti-BGG antibodies) were detectable by a radio-immunoassay in 70% of healthy blood donors but, generally, the titres were low. Significantly increased concentrations of anti-BGG antibodies were found in patients lacking IgA but not in patients with allergic disorders. The anti-BGG antibodies were shown to give rise to falsely high IgE values in the radio-immunosorbent test for

T. Foucard; H. Bennich; S. G. O. Johansson; U. Lundkvist

1975-01-01

453

Biochemical Approach to Bovine Leukemia  

Microsoft Academic Search

Many bovine leukemic lymphocytes produce virus particles when kept in survival cultures in Eagle’s Minimum Essential Medium supplemented with 20% of inactivated fetal calf serum. Virus particles equilibrate at a density of 1.16 g\\/ml in sucrose gradients and at a density of 1.12 g\\/ml in metrizamide gradients. Simultaneous detection tests show that a high molecular weight RNA-reverse transcriptase complex exists

R. Kettmann; M. Mammerickx; D. Dekegel; J. Ghysdael; D. Portetelle; A. Burny

1975-01-01

454

Failure to detect antibody to bovine respiratory syncytial virus in bovine fetal serum.  

PubMed Central

Sera obtained from 147 bovine fetuses estimated to be between 120 and 270 days of gestation at an abattoir were tested for antibody to bovine respiratory syncytial virus. Antibody to bovine respiratory syncytial virus was not detected in any of the sera examined. Based on the results of this study and a review of the literature, it appears that transplacental infection by bovine respiratory syncytial virus does not occur, or is uncommon.

Baker, J C; Ciszewski, D K; Kirk, J H

1989-01-01

455

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  

Microsoft Academic Search

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

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

2007-01-01

456

Sequence homology between bovine and human adenoviruses.  

PubMed Central

Cross-hybridization has been detected between corresponding regions of the genomes of bovine adenovirus type 3 and human adenovirus type 2. The most conserved region on the viral genomes encodes the hexon polypeptide. The nucleotide sequence of this region in bovine adenovirus type 3 has been determined. Comparison of the predicted amino acid sequences of the bovine adenovirus type 3 and human adenovirus type 2 hexon polypeptides reveals three regions of nonhomology. Images

Hu, S L; Hays, W W; Potts, D E

1984-01-01

457

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...Killed Virus. Infectious Bovine Rhinotracheitis Vaccine...paragraph. (i) Eight infectious bovine rhinotracheitis susceptible...after the last vaccination, blood samples shall be drawn and the...inactivated and tested for infectious bovine rhinotracheitis virus...

2010-01-01

458

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...Killed Virus. Infectious Bovine Rhinotracheitis Vaccine...paragraph. (i) Eight infectious bovine rhinotracheitis susceptible...after the last vaccination, blood samples shall be drawn and the...inactivated and tested for infectious bovine rhinotracheitis virus...

2009-01-01

459

9 CFR 113.310 - Bovine Rhinotracheitis Vaccine.  

Code of Federal Regulations, 2010 CFR

...Virus Vaccines § 113.310 Bovine Rhinotracheitis Vaccine. Bovine Rhinotracheitis Vaccine...1) Twenty-five infectious bovine rhinotracheitis susceptible...vaccinates and five controls). Blood samples shall be drawn...

2010-01-01

460

9 CFR 113.310 - Bovine Rhinotracheitis Vaccine.  

Code of Federal Regulations, 2010 CFR

...Virus Vaccines § 113.310 Bovine Rhinotracheitis Vaccine. Bovine Rhinotracheitis Vaccine...1) Twenty-five infectious bovine rhinotracheitis susceptible...vaccinates and five controls). Blood samples shall be drawn...

2009-01-01

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