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1

Partial pulpotomy for immature permanent teeth, its present and future.  

PubMed

Traumatic or carious exposure of a vital pulp in an immature permanent tooth presents a significant clinical challenge to maintain proper vitality. Currently available procedures include direct pulp capping, complete pulpotomy and partial pulpotomy. This paper reviews the application of partial pulpotomy in immature permanent teeth and provides prognostic and technique guidance. PMID:11874055

Fong, Cheng D; Davis, Martin J

2002-01-01

2

Prevalence of congenitally missing permanent teeth in Iran  

PubMed Central

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

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

2012-01-01

3

Enamel Demineralization in Primary and Permanent Teeth  

PubMed Central

Although enamel demineralization is important for our understanding of caries formation, no consensus has been reached regarding the possible differences in susceptibility of primary and permanent enamel. We used the constant composition (CC) technique to investigate the acid-induced demineralization of these tissues at a relative undersaturation with respect to hydroxyapatite (HAP) of 0.902, pH = 4.5, and ionic strength = 0.15 mol L?1. The demineralization rates showed significant differences, primary enamel having the greater susceptibility to dissolution during an initial linear stage: 1.5 ± 0.5 × 10?10 mol mm?2 min?1 compared with 2.6 ± 0.5 × 10?11 mol mm?2 min?1 for permanent enamel. During the reactions, we observed nanosized crystallites which attached to the enamel surfaces or escaped into the bulk solution. These nanosized crystallites were kinetically protected against further dissolution, even though the solutions remained undersaturated. It is hypothesized that they may contribute to the remarkable mechanical and dynamic characteristics of enamel. PMID:16567559

Wang, L.J.; Tang, R.; Bonstein, T.; Bush, P.; Nancollas, G.H.

2009-01-01

4

New Approaches in Vital Pulp Therapy in Permanent Teeth  

PubMed Central

Vitality of dental pulp is essential for long-term tooth survival. The aim of vital pulp therapy is to maintain healthy pulp tissue by eliminating bacteria from the dentin-pulp complex. There are several different treatment options for vital pulp therapy in extensively decayed or traumatized teeth. Pulp capping or pulpotomy procedures rely upon an accurate assessment of the pulp status, and careful management of the remaining pulp tissue. The purpose of this review is to provide an overview of new approaches in vital pulp therapy in permanent teeth. PMID:24396371

Ghoddusi, Jamileh; Forghani, Maryam; Parisay, Iman

2014-01-01

5

The endodontic management of traumatized permanent anterior teeth: a review.  

PubMed

Despite the many journal articles and reviews that have been published regarding the treatment of trauma to teeth, the endodontic management of these injuries is often still not fully understood. The purpose of this review is to establish clear and up-to-date guidelines for practitioners who are faced with treating dental injuries on a day-to-day basis, based on an assessment of current available scientific information relating to the endodontic management of these injuries. Treatment is discussed under the headings: infractions, uncomplicated crown fractures, complicated crown fractures, crown-root fractures, root fractures, luxation injuries, avulsion, root resorption, pulp canal obliteration and open-apex teeth. Emphasis is placed on the treatment of traumatized immature teeth where maintenance of pulp blood supply is important to encourage continued development of the root system. Only the treatment of traumatized permanent anterior teeth is reviewed. Information contained in this article is based on a review of the literature on dental trauma which involved a MEDLINE search using the key words "dental trauma" and the individual topics listed above. The guidelines produced by the International Association of Dental Traumatology, the American Academy of Pediatric Dentistry and the American Association of Endodontists were also reviewed and the recommendations contained in this paper are in concert with the major recommendations of these bodies. PMID:17546867

Moule, A J; Moule, C A

2007-03-01

6

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. PMID:24015025

Kalaskar, Ritesh R.; Kalaskar, Ashita R.

2013-01-01

7

Clinical complications in the revascularization of immature necrotic permanent teeth.  

PubMed

The purpose of this case series was to report on the use of a technique of revascularization for necrotic immature permanent teeth, several problems encountered, and solutions to those problems. Eighteen pulp revascularizations were performed in 2009 using the original protocol of revascularization (adapted from the AAE/AAPD joint meeting in 2007 in Chicago). The protocol consisted of opening the canal and disinfecting it with sodium hypochlorite, sealing in a triple antibiotic paste for 2-6 weeks, re-opening, re-irrigating, creating a blood clot in the canal, and sealing with an MTA barrier over the clot. Three problems were encountered during the treatment: (1) bluish discoloration of the crown; (2) failure to produce bleeding; and (3) collapse of the mineral trioxide aggregate (MTA) material into the canal. Modifications to solve these problems included: changing one of the antibiotics, using a local anesthesia without epinephrine, and adding collagen matrix to the blood clot. PMID:23211919

Dabbagh, Basma; Alvaro, Emanuel; Vu, Duy-Dat; Rizkallah, Jean; Schwartz, Stephane

2012-01-01

8

Boon of MTA Apexification in Young Permanent Posterior Teeth  

PubMed Central

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

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

2014-01-01

9

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

10

Revascularization of immature permanent teeth with apical periodontitis.  

PubMed

The aim of this minireview was to identify and review the scientific evidence regarding regenerative endodontic protocols claiming to revascularize permanent immature teeth with apical periodontitis. The literature was identified using the PubMed/MEDLINE, Scopus, Scirus, EMBASE and Cochrane databases up to February 2013. Studies were selected independently by two different researchers (kappa index: 0.88), based on established inclusion/exclusion criteria. The methodological quality of the reviewed papers was classified as high, medium or low (HQ, MQ, LQ). The search strategy identified 285 titles. Nine studies, both human and animal based, were selected after application of the criteria (LQ:5; MQ:4). In most of these studies (seven of nine), the revascularization protocol included a triple antibiotic combination as canal disinfectant for a period of 1-4 weeks after blood clot formation (LQ:5; MQ:4), although there is no clear consensus about the treatment protocol. Two studies reported tooth discoloration after the revascularization process (LQ:2), and only three (LQ:1; MQ:2) reported a success rate of 54.9% in dogs and 73.6% and 80% in humans, respectively. Revascularization of immature permanent teeth with apical periodontitis is possible and preferable to apexification. Nevertheless, there is a widespread lack of randomized clinical trials and blinded measures. In addition, the small sample sizes that are common in these studies as well as the generally low quality of the analysed publications require the results to be viewed with caution. There is a high risk of bias, with a low quality of available information, for developing clinical guidelines for regenerative endodontic protocols; rigorous randomized clinical trials are therefore needed. PMID:23889557

Moreno-Hidalgo, M C; Caleza-Jimenez, C; Mendoza-Mendoza, A; Iglesias-Linares, A

2014-04-01

11

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

2013-01-01

12

Mesiodistal root angulation of permanent teeth in children with mixed dentition and normal occlusion  

PubMed Central

Objective There is little information regarding the mesiodistal angulation of permanent teeth in mixed dentition. The aim of this study was to evaluate mesiodistal root angulation of permanent incisors, canines and first molars of 100 Brazilian children, using a new horizontal reference plane based on the midpoint of the intercuspation of primary canines and permanent first molars in panoramic radiographs during the mixed-dentition phase. Material and methods Children were equally divided between the genders with a mean age of 8.9 years (SD=0.76), normal occlusion and no eruptive disturbances. Results The angulation of the permanent maxillary first molars was close to the vertical, whereas the mandibular molars presented approximately 25 degrees of distal root angulation. The maxillary canines were the most distally angulated teeth, whereas the permanent mandibular canines were vertically positioned. The evaluation of the anterior maxillary area showed vertical position of permanent lateral, and central incisors with a slight distal angulation, whereas the permanent mandibular incisors tended to a mesial radicular convergence. Conclusions The proposed reference line could be useful in mixed dentition root angulation evaluation; there was a slight asymmetry in the mesiodistal angulation among homologous teeth, and also a small variation between the male and the female groups, but no difference between 8-and 10-year-old children. PMID:21308295

JESUINO, Flávia A. S.; COSTA, Luciane R.; VALLADARES-NETO, José

2010-01-01

13

The timing and sequence of emergence of permanent teeth in Malay schoolchildren in Kota Bharu, Malaysia  

Microsoft Academic Search

The purpose of this study was to determine the timing and sequence of emergence of the first 28 permanent teeth in a cross-section of Malay children in the district of Kota Bharu, in northeastern Peninsula Malaysia. The sample consists of 478 boys and 908 girls of Malay descent aged between 5-19 years. The criterion for tooth emergence was the appearance

Hussin AS; Mokhtar N; Mahmood Za

14

Distinctive Genetic Activity Pattern of the Human Dental Pulp between Deciduous and Permanent Teeth  

PubMed Central

Human deciduous and permanent teeth exhibit different developmental processes, morphologies, histological characteristics and life cycles. In addition, their pulp tissues react differently to external stimuli, such as the pulp sensitivity test, dental trauma and pulp therapy materials. These suggest differences in gene expression and regulation, and in this study we compared gene-expression profiles of the human dental pulp from deciduous and permanent teeth. Pulp tissues from permanent premolars and deciduous molars aged 11–14 years were extirpated and mRNA was isolated for cDNA microarray analysis, and quantitative real-time PCR (qPCR). Other teeth were used for immunohistochemical analysis (IHC). Microarray analysis identified 263 genes with a twofold or greater difference in expression level between the two types of pulp tissue, 43 and 220 of which were more abundant in deciduous and permanent pulp tissues, respectively. qPCR analysis was conducted for eight randomly selected genes, and the findings were consistent with the cDNA microarray results. IHC confirmed that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was broadly expressed in deciduous dental pulp tissue, but minimally expressed in permanent dental pulp tissue. Immunohistochemical analysis showed that calbindin 1 (CALB1), leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), and gamma-aminobutyric acid A receptor beta 1 (GABRB1) were abundantly expressed in permanent predentin/odontoblasts, but only minimally expressed in deciduous dental pulp tissue. These results show that deciduous and permanent pulp tissues have different characteristics and gene expression, suggesting that they may have different functions and responses to therapies focused on pulp or dentin regeneration. PMID:25047033

Kim, Ji-Hee; Jeon, Mijeong; Song, Je-Seon; Lee, Jae-Ho; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; DenBesten, Pamela K.; Kim, Seong-Oh

2014-01-01

15

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

PubMed Central

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

Asgary, Saeed; Ehsani, Sara

2013-01-01

16

Coronal microleakage of permanent lingual access restorations in endodontically treated anterior teeth.  

PubMed

Forty-six intact extracted human anterior teeth were treated endodontically with laterally condensed gutta-percha and sealer. The teeth were restored with a base of either zinc phosphate or temporary stopping and a permanent restoration of either acid etched composite resin with GLUMA as the dentin bonding agent or with Ketac-Fil glass ionomer. The teeth were thermocycled, coated with nail varnish (except for the access), immersed in silver nitrate, developed, and sectioned longitudinally. The linear dye penetration was measured. All restorations permitted leakage into the base. All groups had specimens which leaked into the gutta-percha. There was a tendency for the glass ionomer/zinc phosphate group to leak least, but there were no statistically significant differences among the groups. PMID:2561747

Wilcox, L R; Diaz-Arnold, A

1989-12-01

17

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

18

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

PubMed Central

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

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

2014-01-01

19

Age Estimation by Assessment of Dentin Translucency in Single Rooted Permanent Teeth  

PubMed Central

Background: To estimate the age by evaluating the area and length of dentin translucency in single-rooted ground sections of extracted teeth using digital Vernier caliper and stereomicroscope. Materials and Methods: Ground sections of single rooted permanent anterior teeth were made and stained with 1% methylene blue. The area and length of dentin translucency were measured using digital Vernier caliper and with the help of stereomicroscope. Results: Linear regressive analysis showed that estimation of age by assessing the area of dentin translucency with Vernier caliper was statistically significant and showed a high regression co-efficient (R = 0.7738) when compared to evaluation of age by assessment of length. Multilinear regressive analysis done to calculate age by both area and length also showed a high co-efficient of regression (R = 0.7797). Conclusion: The area of dentin translucency showed good correlation with age when compared to the length.

Kattappagari, Kiran Kumar; Kommalapati, Radhika Kalyani; Katuri, Deepthi; Murakonda, Raja Sekhar; Chitturi, Ravi Teja; Reddy, Baddam Venkat Ramana

2014-01-01

20

Osteoconduction capacity of human deciduous and permanent teeth ash in a rat calvarial bone defect model.  

PubMed

The aim of this study was to confirm the osteoconduction capacities and determine the potential of permanent teeth ash (PTA), and deciduous teeth ash (DTA) as bone substitutes. Rats (n = 71) were divided randomly into four groups: sham, micro macroporous biphasic calcium phosphate (MBCP), PTA, and DTA. A sample of the each group was transplanted into preformed 8-mm calvarial defects (one per rat). The density of new bone was calculated and the crystallinities of the PTA and DTA were analyzed by X-ray diffraction. The degree of new bone formation was high in the MBCP and DTA groups but low in the PTA groups. The DTA was highly crystalline, whereas the PTA was not. The percentages of ?-tricalcium phosphate in the DTA and PTA were 10.7 and 3.7 %, respectively. DTA has a high osteoconduction capacity, suggesting that it is a useful bone substitute. PMID:25407534

Min, Boram; Song, Je Seon; Kim, Seong-Oh; Kim, Kwang-Mahn; Park, Won Se; Lee, Jae-Ho

2014-11-19

21

Effect of needle insertion depth and apical diameter on irrigant extrusion in simulated immature permanent teeth.  

PubMed

The aim of this study was to compare the amount of irrigant extrusion in simulated immature permanent teeth when the apical diameter and needle insertion depth were varied. Thirty single-rooted maxillary incisors with straight root canals were selected. The root length was standardized to a length of 9 mm. The teeth were divided into two experimental groups according to the degree of apical enlargement (n = 15). The apices were enlarged to a diameter of 1.10 mm or 1.70 mm by using a #3 or #6 peeso reamer, respectively, to simulate immature teeth. The irrigation solution was applied 2 or 4 mm short of the working length (WL) in each experimental group. The glass vial model was used for the collection of extruded irrigant beyond the root apex. A two-way repeated measures analysis of variance test showed that there was no significant difference between different needle insertion depths (2 and 4 mm short of the WL) in the group with an apical diameter of 1.70 mm (p > 0.05). In the group with an apical diameter of 1.10 mm, a 32% increase in irrigant extrusion was observed when the needle was positioned at 2 mm (p < 0.05). Regarding the effect of apical diameter, the group with a diameter of 1.70 mm showed more apical extrusion of the irrigant (34% increase for the needle positioned at 2 mm and 68% increase for the needle positioned at 4 mm). It was observed that the needle insertion depth and apical diameter have a significant effect on irrigant extrusion in immature permanent teeth. PMID:25271966

Aksel, Hacer; Askerbeyli, Sevinc; Canbazoglu, Cigdem; Serper, Ahmet

2014-01-01

22

Timing of exchange of the maxillary deciduous and permanent teeth in boys with three types of orofacial clefts.  

PubMed

Timing of exchange of the deciduous and permanent maxillary teeth was investigated using dental plaster casts of 163 boys with total unilateral cleft (UCLP), 82 boys with bilateral cleft (BCLP), and 97 boys with isolated cleft palate (CP). All patients were treated at the Prague Plastic Surgery Clinic. The results were compared with a control group of 294 schoolboys. To evaluate the course of eruption, the proportion of each erupted teeth in each year of age was employed. In boys with UCLP, eruption of the permanent maxillary lateral incisors and the permanent maxillary second molar was retarded on the cleft side. On the non-affected side, no delay of eruption was observed, but earlier eruption was found in the permanent maxillary canine and in the permanent maxillary first and second premolars. In boys with BCLP, the highest retardation of eruption was found in the permanent maxillary lateral incisor and in the permanent maxillary first molar. The permanent maxillary canine and both permanent maxillary premolars erupted earlier than in the control group. In boys with CP, only the permanent maxillary central incisors erupted earlier. The maxillary deciduous canines and the second molars were both lost early. We conclude that the developmental disturbances of the maxillary jaw and teeth in patients with orofacial clefts are also associated with alteration of timing of dental exchange. PMID:8827389

Peterka, M; Peterková, R; Likovský, Z

1996-07-01

23

What can cause the pulps of immature, permanent teeth with open apices to become necrotic and what treatment options are available for these teeth.  

PubMed

Pulp necrosis of immature permanent teeth represents a significant challenge for clinical management as root development ceases and open apices remain. The aetiology of pulp necrosis in immature permanent teeth can include caries, trauma or the presence of the dental anomalies, dens invaginatus and dens evaginatus. Endodontic treatment is complicated by the resultant thin dentinal root walls and the lack of apical closure. The long-term prognosis is compromised by increased risk of cervical root fracture and reduced crown to root ratio. Currently there is a paradigm shift in the management of such cases from traditional apexification procedures towards regenerative endodontic procedures. Regenerative endodontics can promote continued root development and apical closure, which does not occur with calcium hydroxide or mineral trioxide aggregate apexification. As supporting evidence grows and clear treatment guidelines are developed for regenerative endodontics, it is likely to become the gold standard for management of such teeth. PMID:25470507

Flanagan, Thomas Andrew

2014-12-01

24

The combined effect of xylitol and fluoride in varnish on bovine teeth surface microhardness.  

PubMed

The aim of this study was to evaluate the combined effect of xylitol and fluoride in varnish on bovine tooth surface microhardness. Thirty caries-free bovine teeth were sectioned and embedded in self-cured acrylic resin and the buccal enamel surfaces were ground flat. Each tooth was then placed in demineralization solution for 40 hours. After demineralization, the teeth were randomly divided into 3 equal groups: group 1 was the control group (no treatment); group 2 was treated with fluoride varnish (Duraphat); group 3 was treated with a xylitol and fluoride varnish (Flor-Opal). All the specimens were then subjected to pH-cycling for 7 days, consisting of demineralization for 6 hours and remineralization for 18 hours repeated daily for five days followed by remineralization for 2 days. Surface microhardness was checked in each tooth at baseline, after demineralization and after pH-cycling. The results were recorded and the data were analyzed with the one-way ANOVA and Tukey tests. A p-value < 0.05 was considered significant. The mean surface microhardness values of the teeth treated with the fluoride varnish and the fluoride with xylitol varnish were not significantly different from each other and showed significantly better remineralization than control group. The fluoride and xylitol varnish combination was beneficial for preventing enamel demineralization but no better than in fluoride varnish alone in vitro. Adding xylitol to fluoride tooth varnish does not appear to give any significant benefit in vitro. PMID:24968693

Vongsavan, Kadkao; Surarit, Rudee; Rirattanapong, Praphasri

2014-03-01

25

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. PMID:23077415

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

2012-01-01

26

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. PMID:23229271

Robles, Maria J.; Bravo-Perez, Manuel; González, Encarnación; Peñalver, Maria A.

2013-01-01

27

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

28

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

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. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This scond part of the guidelines will focus on avulsion of permanent teeth. PMID:25252472

Diangelis, A J; Andreasen, J O; Ebeleseder, K A; Kenny, D J; Trope, M; Sigurdsson, A; Andersson, L; Bourguignon, C; Flores, M T; Hicks, M l; Lenzi, A R; Malmgren, B; Moule, A J; Pohl, Y; Tsukiboshi, M

2014-04-01

29

Mineral trioxide aggregate (MTA) apexification: a novel approach for traumatised young immature permanent teeth  

PubMed Central

Here, we report a case of 9-year-old boy who came with a chief complaint of pain and fractured upper front teeth. Significant history of trauma was revealed 6?months before reporting, during playing at his school time. Proper diagnosis was made with the help of radiological investigations. The available treatment options were discussed with the patient's parents and root canal therapy, using mineral trioxide aggregate, as an apical barrier was carried out in his upper right front teeth. However, later on, the boy was aesthetically rehabilitated in relation to his fractured upper front teeth with the help of post and core and acrylic crown. PMID:23314456

Vijayran, Manisha; Chaudhary, Seema; Manuja, Naveen; Kulkarni, Adwait Uday

2013-01-01

30

Circular Enamel Hypoplasia: A Rare Enamel Developmental Disturbance in Permanent Teeth  

PubMed Central

Circular enamel hypoplasia, a type of enamel hypoplasia is an extensive enamel disturbance that results in a demarcating line surrounding the crown of the injured teeth visible both clinically and radiographically that most frequently occurs as a result of trauma in children around the age of two years. Clinical features include poor aesthetics, dentin sensitivity, increased susceptibility to dental caries and malocclusion. Early radiographic diagnosis of such teeth is important for timely intervention and subsequent treatment. PMID:25302282

Gulia, Shweta; Nagpal, Mehak; Sachdev, Vinod

2014-01-01

31

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

PubMed

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

Namour, Mélanie; Theys, Stephanie

2014-01-01

32

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

PubMed Central

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

Namour, Mélanie

2014-01-01

33

International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth.  

PubMed

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and followup are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. 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 group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. PMID:22230724

Diangelis, Anthony J; Andreasen, Jens O; Ebeleseder, Kurt A; Kenny, David J; Trope, Martin; Sigurdsson, Asgeir; Andersson, Lars; Bourguignon, Cecilia; Flores, Marie Therese; Hicks, Morris Lamar; Lenzi, Antonio R; Malmgren, Barbro; Moule, Alex J; Pohl, Yango; Tsukiboshi, Mitsuhiro

2012-02-01

34

Dilaceration and Eruption Disturbances in Permanent Teeth: A Sequelae of Trauma to Their Predecessors-Diagnosis and Treatment Using Cone Beam CT  

PubMed Central

Alterations in the morphology of permanent teeth following trauma to their predecessors is a challenging task for diagnosis and it may require advanced imaging techniques. Newer imaging modalities have replaced the conventional radiological procedures, as they allow 3D reconstruction images and views which are free of superimposition. Cone Beam CT (CBCT) offers a three-dimensional view, which the conventional two-dimensional dental radiography fails to provide. The current article highlights the advantages of CBCT which are seen in evaluation of the morphological variations and eruptive disturbances in the permanent teeth, as sequelae to trauma in their predecessors. PMID:24995254

IG, Kanimozhi; M, Sivakumar

2014-01-01

35

Research about bovine teeth brightness with using dentifrice slurry including nano-hydroxyapatite  

Microsoft Academic Search

Hydroxyapatite has high affinity rate with organic substance in an oral cavity, therefore lately nano-sized hydroxyapatite is extensively researched to increase affinity to tooth and remineralization. The objective of this research is indirectly to investigate the effect of nano-hydroxyapatite on remineralization using valuation about brightness of the bovine tooth. We have designed in vitro test for this purpose. The bovine

Ji-Min Hwang; Jong-Oh Kang; Yong-duk Park; Young-suk Choi

2010-01-01

36

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

PubMed Central

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

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

2014-01-01

37

Strategies to manage permanent non-vital teeth with open apices: a clinical update.  

PubMed

If dental pulp injury occurs prior to complete root formation and apical closure, normal root development is halted. This condition produces several complications. Firstly, the apical diameter of the canal is often larger than the coronal diameter, so debridement is difficult. Secondly, the lack of an apical stop makes the obturation in all dimensions virtually impossible. And finally, the thin walls of the root canal are prone to fracture, so that surgical treatment is generally not a viable option. There are a number protocols to manage non-vital open-apex teeth such as apexification, apical barrier technique (one-visit apexification), orthograde root filling using MTA, triple antibiotic paste, and tissue engineering concept. The aim of this paper is to review these treatment protocols. PMID:21382030

Mohammadi, Zahed

2011-02-01

38

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. PMID:21998794

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

2010-01-01

39

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

2012-02-01

40

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

2012-03-01

41

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

PubMed Central

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

Heinrich-Weltzien, Roswitha; Monse, Bella

2013-01-01

42

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

PubMed Central

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

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

2014-01-01

43

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

PubMed Central

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

Xue, Dai Juan and Feng

2014-01-01

44

CBVT analysis of canal configuration of the mesio-buccal root of maxillary first permanent molar teeth: An in vitro study  

PubMed Central

Context: For successful endodontic treatment, it's imperative to locate and obturate all root canals. As concluded by Ingle, the major cause for failure of root canal therapy is in ability to recognize all theexisting canals and subsequent failure in their obturation. Aim: To analyze the canal configuration of the mesio-buccal root of maxillary first permanent molar teeth. Materials and Methods: A total of 30 recently extracted human permanent maxillary first molars were collected and stored in a container with 5% Sodium Chloride solution for four days. Teeth with open apices, external resorption, improperly formed roots and teeth with previous restorations were excluded. Using the dental modeling wax, teeth were arranged in a ‘U’ shaped arch with roots embedded inside the wax and occlusal surface remaining free. 10 teeth were arranged in each arch and three such sample plates were prepared. Flat surface of the base encasing enabled the plate to be mounted on flat plastic bite plate. With bite plate roughly centered in the focal trough area Axial, Coronal and Sagittal section Cone-Beam Computed Tomography (CBCT) images were taken with Kodak 9000 Extra-oral Imaging System. Images displayed on a monitor were inspected by two endodontists using Kodak Dental Imaging Software 3D Module V2.2. Statistical Analysis: When the data was observed, it was found that 24 teeth out of total 30 teeth examined showed some variation (i.e. possible additional canal) along the length of the mesio-buccal root canal. Out of these 24 teeth, 13 showed presence of additional canal at coronal third, 7 showed presence of additional canal at middle third and four showed presence of additional canal in apical third level. Percentage analysis was done as there was no group comparison to be done. Results: Cone-Beam Volumetric Tomography (CBVT) evaluation positively identified the variations in mesio-buccal canal in 80% of samples. Out of these, 54.16% were in coronal 3rd, 29.16% in middle 3rd and 16.66% were in apical 3rd. Conclusion: Within the limitations of this study, it can be concluded that- (1) more than half of maxillary first molars have four canals and (2) most of the additional canals were located in the MBR and CBVT is a good diagnostic tool to help diagnose these additional canals. Further investigations using larger sample sizes would be helpful. PMID:23293481

Shenoi, R. Pratima; Ghule, Hrishikesh M.

2012-01-01

45

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

46

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Hebrew edition].  

PubMed

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and follow up are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. 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 group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. The Hebrew Edition is part of the IADT global effort to provide accessibility to these guidelines worldwide. PMID:25252471

Diangelis, A J; Andreasen, J O; Ebeleseder, K A; Kenny, D J; Trope, M; Sigurdsson, A; Andersson, L; Bourguignon, C; Flores, M T; Hicks, M L; Lenzi, A R; Malmgren, B; Moule, A J; Pohl, Y; Tsukiboshi, M

2014-04-01

47

Influence of water-layer thickness on Er:YAG laser ablation of enamel of bovine anterior teeth.  

PubMed

Different ideas have been presented to describe the mechanism of augmented laser ablation of dental enamel with different shapes by adding water to the working environment. In this study, the influence of water-laser interaction on the surface of enamel during ablation was investigated at a wavelength of 2.94 microm with different distances between the laser tip and the enamel surface. A motion-control system was used to produce linear incisions uniformly on flat enamel surfaces of bovine anterior teeth, with free-running Er:YAG laser very short pulses (pulse length = 90-120 micros, repetition rate = 10 pulses per second). Four different output energies (100, 200, 300 and 400 mJ) were radiated on samples under distilled water from different distances (0.5, 0.75, 1, 1.25, 1.75 and 2.00 mm). The tooth slices were prepared with a cutting machine, and the surfaces of the ablated areas were measured with software under a light microscope. The average and standard deviation of all cut areas in different groups were reported. There was no significant difference when using a different pulse ablation speed (cm(3)/J) and a water-layer thickness between the tip and enamel surface of 0.5-1.25 mm with energy densities of 30-60 J/cm(2) (200-400 mJ). However, using an output energy of 15 J/cm(2) (100 mJ) and a thicker water layer than 1 mm, a linear ablation did not take place. This information led to a clearer view of the efficiency of Er:YAG laser in the conditions of this study. There are several hypotheses which describe a hydrokinetic effect of Er,Cr:YSGG. These basic studies could guide us to have a correct attitude regarding hydro-mechanical effects of water, although the wavelength of 2.78 microm has a better absorption in hydroxyl branch of water molecules. Therefore, our results do not directly interrupt with the series of investigations done with Er,Cr:YSGG. Water propagation and channel formation under water are investigated during the ablation of tooth enamel with the Er:YAG laser from different distances. Comparing the results of this study with the same research done with water/air spray concludes that the bubble formation and channel propagation in water with this wavelength leads to a more symmetric (linear) ablation process with cavity-preparation-recommended parameters. PMID:17952484

Mir, Maziar; Meister, Joerg; Franzen, Rene; Sabounchi, Shabnam S; Lampert, Friedrich; Gutknecht, Norbert

2008-10-01

48

Streptococcus uberis: A Permanent Barrier to the Control of Bovine Mastitis?  

Microsoft Academic Search

The prevalence of bovine mastitis has been reduced over the past 25 years due to the implementation of a five-point control plan aimed at reducing exposure, duration and transmission of intramammary infections by bacteria. This has markedly reduced the incidence of bovine mastitis caused by bacteria which show a contagious route of transmission, but has had little effect on the

J. A. LEIGH

1999-01-01

49

Determination of Frequency of the Second Mesiobuccal Canal in the Permanent Maxillary First Molar Teeth with Magnification Loupes (× 3.5)  

PubMed Central

INTRODUCTION: The mesiobuccal root of the maxillary first molar has generated more research and clinical investigation than any root. An inability to detect and treat a second mesiobuccal (MB2) canal is a reason for endodontic failure in maxillary first molars. Modifications in the endodontic access and detection techniques, along with advancements in illumination and magnification technology, have aided in the location and treatment with the second mesiobuccal canal of maxillary first molars. OBJECTIVE: To determine the frequency of the second mesiobuccal canal in the permanent maxillary first molars with magnification loupes (× 3.5). MATERIALS AND METHODS: A total of 53 teeth were assessed using a moderate magnification for second mesiobuccal canal in mesiobuccal root of first permanent maxillary molars in vivo. Detection of this canal in maxillary first molars was done through a clinical access cavity preparation under magnification loupes (× 3.5). Data was analyzed using SPSS 15.0. Frequency distribution of variables was determined and the level of significance was kept at 0.05. RESULTS: We were able to detect second mesiobuccal canal in 27 out of 53 (50.9%) of the permanent maxillary first molars that were studied. It was found that the males tend to have a higher proportion of second mesiobuccal canals (up to 31%) as compared to the females in whom the second mesiobuccal canals could be identified only 19% of the time. Whilst, there was no association found between age, gender and chamber obliteration with the presence of second mesiobuccal canal. CONCLUSIONS: In conclusion, within its limitations, this study suggested that the use of magnification loupes enhanced both the detection (50.9%) and negotiation (86.8%) of the second mesiobuccal canals in the permanent maxillary first molars beyond what could be achieved with naked eye. PMID:25324702

Hasan, Muhammad; Raza Khan, Farhan

2014-01-01

50

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

PubMed Central

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

Narang, Isha; Mittal, Neelam; Mishra, Navin

2015-01-01

51

A two-year clinical evaluation of TPH for restoration of Class II carious lesions in permanent teeth.  

PubMed

To evaluate the clinical suitability of a barium silicate-filled composite (TPH) for restoration of posterior teeth, 50 Class II restorations were restored in 36 patients. Restorations included 22 molars and 32 premolars. Cavity preparations were protected with calcium hydroxide or a resin-modified glass ionomer cement, or both. Enamel was etched for 30 seconds with 37 percent H3PO4. All dentin surfaces were treated with a dentin bonding system that was placed, cured, and restored in 2 microns increments. The restorations were finished using diamond burs, polishing points, and paste. Evaluation periods were at zero (50 restorations), 6 months (35 restorations), 1 year (31 restorations), and 2 years (29 restorations), using the USPHS System and M-L indirect scale. At zero time, 50 restorations were scored "a" in all categories by using two independent evaluators. After 6 months, 35 restorations were graded with one "a" in postoperative sensitivity. After 1 year, 31 restorations were evaluated with one additional "b" for marginal integrity. After 2 years, 2 additional "b" for marginal integrity and 1 "b" for surface staining were noted. No "c" was observed in any categories throughout this study. Wear analysis revealed, on average, 2 microns of wear after 6 months, 7.8 microns of wear after one year, and 10.3 microns of wear after 2 years. PMID:9515440

Perry, R D; Kugel, G; Habib, C M; McGarry, P; Settembrini, L

1997-01-01

52

Teething Tots  

MedlinePLUS

... the first molars (the back teeth used for grinding food), then finally the eyeteeth (the pointy teeth ... ON THIS TOPIC Mouth and Teeth Bruxism (Teeth Grinding or Clenching) Fluoride and Water How Do I ...

53

Specialized stem cell niche enables repetitive renewal of alligator teeth  

E-print Network

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

Chuong, Cheng-Ming

54

Management of multiple impacted teeth.  

PubMed

An impacted or missing permanent tooth can add significant complications to an otherwise straightforward case. When multiple impacted teeth are present, the case complexity increases further. Developing a treatment sequence, determining appropriate anchorage, and planning and executing sound biomechanics can be a challenge. The following case report illustrates a patient with three retained primary teeth and three impacted permanent canines. After careful treatment planning and extraction of multiple primary teeth;, followed by attempted guided eruption of impacted teeth, the patient finished with a significantly improved functional and aesthetic result. PMID:22557915

Bansal, Nidhi; Valiathan, Ashima; Bansal, Kshitij; Parkar, Farhan

2012-01-01

55

[The significance of the size and type of surface of prepared teeth for retention of permanent dentures fixed with zinc-phosphate cement].  

PubMed

The purpose of this paper was to establish, in vitro, the impact of different sizes and prepared teeth roughness on the adhesion strength with cast crowns. Twenty human intact premolars were used in the experiment. They were prepared and divided into two groups depending on the fineness of diamond prepared instrumentation. Sizes of prepared teeth were calculated mathematically, while the dentine roughness was measured by a profile meter. The cast crowns were made by a standard method for each group. The crowns were then cemented with a zinc phosphate cement. After seven days, testing of prepared teeth and cast crowns bonding strength was carried out mechanically in an electronic dynamometer. On the basis of the obtained results the relationship between the size and the accomplished roughness with the obtained values of the retention forces is observed. At the constant convergence angle of the stamp the retention is proportional to the stamp size and the roughness profile. PMID:14671594

Kruni?, N

2003-01-01

56

Sensitive Teeth  

MedlinePLUS

... tooth). When the dentin is exposed, cold or hot temperature or pressure can affect these nerve branches. This ... symptom. Less often, the teeth are sensitive to hot temperatures. If a single tooth becomes sensitive to heat, ...

57

Atomic force microscopic comparison of remineralization with casein-phosphopeptide amorphous calcium phosphate paste, acidulated phosphate fluoride gel and iron supplement in primary and permanent teeth: An in-vitro study  

PubMed Central

Context: Demineralization of tooth by erosion is caused by frequent contact between the tooth surface and acids present in soft drinks. Aim: The present study objective was to evaluate the remineralization potential of casein-phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste, 1.23% acidulated phosphate fluoride (APF) gel and iron supplement on dental erosion by soft drinks in human primary and permanent enamel using atomic force microscopy (AFM). Materials and Methods: Specimens were made from extracted 15 primary and 15 permanent teeth which were randomly divided into three treatment groups: CPP-ACP paste, APF gel and iron supplement. AFM was used for baseline readings followed by demineralization and remineralization cycle. Results and Statistics: Almost all group of samples showed remineralization that is a reduction in surface roughness which was higher with CPP-ACP paste. Statistical analysis was performed using by one-way ANOVA and Mann-Whitney U-test with P < 0.05. Conclusions: It can be concluded that the application of CPP-ACP paste is effective on preventing dental erosion from soft drinks. PMID:24808700

Agrawal, Nikita; Shashikiran, N. D.; Singla, Shilpy; Ravi, K. S.; Kulkarni, Vinaya Kumar

2014-01-01

58

Brutus' Teeth  

USGS Multimedia Gallery

Scientists examine the teeth of Brutus, a wolf being studied by USGS scientists, for patterns of wear that indicate age. The front incisors are worn without their lateral cusps present. The canines show some wear and are becoming rounded and stained but still maintain most of their length. One canin...

2009-10-19

59

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

PubMed Central

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

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

2014-01-01

60

Minor traumatic injuries to the permanent dentition.  

PubMed

Treatment of traumatized teeth generally occurs in two phases: short-term emergency treatment and stabilization followed by endodontic management and review. These authors recently reviewed the endodontic considerations in the treatment of traumatized permanent anterior teeth, and in this article review the early management of traumatized permanent teeth. Preoperative assessment and emergency management are emphasized, as is the treatment of immature teeth for which continued development of the root system must be encouraged. Factors influencing long-term prognosis are discussed and the influence of various management strategies evaluated. PMID:19958903

Moule, Alex J; Moule, Christopher A

2009-10-01

61

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

MedlinePLUS

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

62

Late Developing Supernumeraries in a Case of Nonsyndromic Multiple Supernumerary Teeth  

PubMed Central

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

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

2015-01-01

63

Supernumerary teeth: Report of four unusual cases  

PubMed Central

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

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

2012-01-01

64

Bilateral Supernumerary Teeth in Deciduous Dentition-A Rarity  

PubMed Central

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

Ghosh, Chiranjit; Mondal, Pradeep Kumar

2014-01-01

65

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. PMID:21494392

Yildirim, Gozde; Bayrak, Sule

2011-01-01

66

Tiger shark teeth  

NSDL National Science Digital Library

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

Stefan Kühn (None; )

2004-09-06

67

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.

68

Bone loss and teeth  

Microsoft Academic Search

Loss of teeth results in irreversible alveolar bone resorption, and untreated dental disease causes alveolar bone lysis that ultimately leads to loss of teeth. In addition to anchoring the teeth in the alveolar ridge, the maxillary and mandibular bone allows dental restoration procedures, such as construction of root-supported implants, fixed dentures, or removable dentures. However, the functional and cosmetic results

François Bodic; Luc Hamel; Emmanuelle Lerouxel; Michel Félix Baslé; Daniel Chappard

2005-01-01

69

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

70

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

PubMed

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

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

2012-09-01

71

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 ...

72

A Novel Technique in Restoring Fractured Anterior Teeth  

PubMed Central

Trauma to the anterior teeth is a common phenomenon in young children and in adolescents. Uncomplicated crown fracture to the permanent teeth has an intense effect not only on the patient’s appearance, but also on function and speech. This case report describes a novel technique in restoring an uncomplicated fractured maxillary anterior tooth in a young patient with direct composite, which is economical and requires less chair side time. PMID:24701546

K, Rajavardhan; Sankar, A.J. Sai; Shaik, Tanveer Ahmed; V, Naveen Kumar; K, Raj Kumar

2014-01-01

73

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

PubMed Central

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

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

2013-01-01

74

Impacted wisdom teeth  

PubMed Central

Introduction The incidence of impacted wisdom teeth is high, with some 72% of Swedish people aged 20 to 30 years having at least one impacted third molar. Impacted wisdom teeth occur because of a lack of space, obstruction, or abnormal position, and can cause inflammatory dental disease manifested by pain and swelling of infected teeth and may destroy adjacent teeth and bone. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: Should asymptomatic and disease-free impacted wisdom teeth be removed prophylactically? What are the effects of different surgical methods of removing impacted wisdom teeth? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We performed a GRADE evaluation of the quality of evidence for interventions. Results We found 25 systematic reviews, RCTs, or observational studies that met our inclusion criteria. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: prophylactic extraction, active surveillance, and different surgical methods of removing impacted wisdom teeth. PMID:21729337

2010-01-01

75

Malocclusion (Misaligned Teeth)  

MedlinePLUS

... and Teeth Lip and Tongue Disorders Tooth Disorders Periodontal Diseases Temporomandibular Disorders Urgent Dental Problems Topics in ... causing misalignment unless a dentist places a bridge, implant, or partial denture in the gap. Normally, lost ...

76

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

77

Types of Teeth  

MedlinePLUS

... also have a broader surface for chewing and grinding. On the upper jaw, the first premolars (directly ... large teeth with broad surfaces designed for crushing, grinding and chewing food. On the upper jaw, the ...

78

Permanent cosmetics.  

PubMed

Plastic surgery practices have become more accepting of the implantation of permanent cosmetics over the last few years. Many plastic surgery practices have added the implantation of permanent cosmetics into their offered services. Many clients who would not have considered having permanent cosmetics implanted because of having to go to a tattoo parlor are now having the procedures performed. The most popular procedures being performed are the implantation of permanent eyeliner followed by eyebrows and lip liner. Other implantations of permanent cosmetics are the full-lip applications, eye shadow application, cheek blush, and a beauty mark implantation. Micro pigmentation can be used for nipple coloration following reconstruction or camouflaging skin pigmentation problems due to trauma, birthmarks, cancer, etc. This article focuses on the use of micro pigmentation for the use of permanent cosmetics (WebMD, 2009). PMID:22929199

Wetzel, Christine L

2012-01-01

79

Eddy-current loss in the rotor magnets of permanent-magnet brushless machines having a fractional number of slots per pole  

Microsoft Academic Search

We develop an analytical model for predicting the eddy-current loss in the rotor magnets of permanent-magnet brushless machines that have a fractional number of slots per pole, when either all the teeth or only alternate teeth are wound, and in which the unwound teeth may be narrower than the wound teeth. The model enables the magnetic field distribution in the

Dahaman Ishak; Z. Q. Zhu; David Howe

2005-01-01

80

Prevalence of impacted and supernumerary teeth in the North Indian population  

PubMed Central

Objectives: Dental impaction is a very frequent problem. Supernumerary teeth, or hyperdontia, are the presence of additional teeth to the normal series in the either of the dentition. The presence of impacted and/or supernumerary teeth can cause various complications. The objective of the present study was to determine the prevalence of impacted and supernumerary teeth in the North Indian population. Study Design: The panoramic radiographic records of 4750 patients attending the Department of Oral Medicine and Radiology, Jodhpur Dental College General Hospital between September 2008 to December 2012 were examined for this retrospective study. The ages of the patients ranged from 8 to 72 years, with a mean of 34.6 years. Results: A total of 798 (16.8%) patients presented with 1126 impacted teeth. Impacted canines were the most prevalent (9.7%), followed by impacted premolars (4.3%). Supernumerary teeth (1.6%) and impacted molars (1.2%) were less prevalent. Among the 842 impacted teeth, the most frequently affected teeth were the canines (56.7%), followed by premolars (27.8%), and supernumerary teeth (9.3%), while the prevalence of impacted molars was quite lower (6.2%). Conclusion: The most frequently impacted teeth were maxillary canines and the mesiodens were the most common supernumerary tooth. The early diagnosis of supernumerary and impacted teeth is essential to prevent malocclusion and malalignment of permanent teeth demonstrating the importance of panoramic radiographs in their detection. Key words:Impacted, supernumerary, prevalence, canines, mesiodens. PMID:24790709

Maheshwari, Sneha

2014-01-01

81

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 ...

82

Taking Care of Your Teeth  

MedlinePLUS

... deposits. The particles are then rinsed off with water. After cleaning, the dental hygienist will polish your teeth. The process cleans and smoothes the surfaces of the teeth, removing stains and making it ...

83

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. PMID:22919229

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

2012-01-01

84

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

85

Immunohistochemical localization of amelogenins in enameloid of lower vertebrate teeth.  

PubMed

The indirect method of immunofluorescence was used to demonstrate the presence of amelogenins in the enameloid of teeth and dermal denticles of Chondrichthyes; in the enameloid of Teleostei and Amphibia; and in the enamel of Reptilia. Nonmammalian amelogenins are formed in the ectodermal cells of tooth organs and chemically are so similar to mammalian amelogenins that they interact with antiserum prepared from bovine enamel matrix. PMID:6986656

Herold, R C; Graver, H T; Christner, P

1980-03-21

86

Fluoride-induced early teeth wearing in Argentinian cattle.  

PubMed

The relationship between observed early teeth wearing in cattle and the existence of large areas where excess fluoride in underground water prevails in Argentina, but has never been studied. Average values of bone fluoride exceeding 5000 ppm and well water containing up to 10.5 ppm of this element were found in a farm (ETWF) where early teeth wearing is observed, while in a control farm (NETWF), those values were 1480 ppm and 3.0 ppm respectively. Urine samples from animals from the ETWF contained almost 4 times more fluoride than those from the latter. Forage in both farms contained about the same levels of fluoride (15 to 25 ppm). None of the farms was exposed to industrial, volcanic, or geothermal activity. Lactating and adult animals were transferred from one farm to the other. After 30 months, adult animals from the NETWF showed no damage in teeth, while adults from the ETWF continued a rapid teeth wearing. Young animals from the NETWF developed severely damaged permanent teeth, while young animals from the ETWF developed normal teeth. We concluded that the problem exists in the ETWF and being a standard farm, the condition could be extrapolated to other areas. PMID:7848549

Lopez, T A; Busetti, M R; Fort, M C; Bedotti, D O

1994-09-01

87

Mechanical properties of artificial teeth.  

PubMed

In selecting the teeth for fabrication of complete or partial dentures, each patient's anatomic and physiologic requirements and the properties of the artificial teeth themselves should be taken into consideration. The purpose of this study was to evaluate the mechanical properties of the artificial teeth by the static compression test and the impact test. Specimens were the lower first molar porcelain and resin teeth (Livdent FB-20 teeth by G. C. Co., Tokyo, Japan). All were of the same shape. In the static compression test, the fracture load and deformation of the artificial teeth were measured with an Instron-type universal testing machine at a cross-head speed of 1.0 mm/min. Elastic modulus, ultimate strength and absorbed energy were calculated. In the impact test, the acceleration of a falling impactor was measured with a drop impact apparatus. The load applied to the specimen was equivalent to 300N. Absorbed energy and deformation were calculated. The resin teeth showed a lower elastic modulus, higher fracture toughness and shock-absorbing ability than the porcelain teeth. Resin teeth should be selected when the first requisite is high shock-absorbing ability, and porcelain teeth should be selected when the first requisite is high masticating efficiency. PMID:8462117

Shimoyama, K; Uchida, T; Nagao, M; Odagiri, K; Shirasaki, Y; Tateishi, T

1993-03-01

88

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

89

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

PubMed Central

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

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

2015-01-01

90

Isolation and in vitro characterisation of dental pulp stem cells from natal teeth  

Microsoft Academic Search

Dental pulp stem cells were primarily derived from the pulp tissues of exfoliated deciduous teeth, primary incisors and permanent\\u000a third molar teeth. The aim of this study was to isolate and extensively characterise SCs derived from human natal dental pulp\\u000a (hNDP). For characterisation, proliferation capacity, phenotypic properties, ultrastructural and differentiation characteristics\\u000a and gene expression profiles were utilised. A comparison was

Erdal Karaöz; Burcu Nur Do?an; Ayça Aksoy; Gülçin Gacar; Serap Akyüz; Selda Ayhan; Zehra Seda Genç; Sinan Yürüker; Gökhan Duruksu; P?nar Çetinalp Demircan; Ayla Eker Sar?boyac?

2010-01-01

91

Bacteriological analysis of necrotic pulp and fistulae in primary teeth  

PubMed Central

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

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

2014-01-01

92

[Molecular biological studies on teeth inquests].  

PubMed

This paper deals with the following three areas: 1. Age estimation of tooth based on the racemization of component amino acids On the age estimation of a subject's tooth, the whole dentin prepared from the central vertical section showed a correlation coefficient of more than 0.99. The soluble peptide extracted from the dentin provided the highest correlation compared with the total content of amino acids or insoluble collagens, suggesting its usefulness as a component for estimating the age. The racemization rate was the highest for Asp, followed by Glu and Ala in order. As to the site from which a test dentin is sampled, the ratio of Asp from the lingual section was higher than its counterpart from the labial section. It is also noteworthy that the dentin from deciduous teeth was as useful as the permanent teeth for estimating the age of juvenile. 2. DNA typing analysis using tooth as specimen The pulp in a dried tooth is removed, from which DNA in extracted for DNA fingerprinting with the Y-specific probe. The sex determination was possible using a tooth that had been extracted up to 21 months before. Furthermore, a 30-cycle repetition of PCR enabled to accurately determine the sex from the DNA specimen that was considerably degraded as well as from freshly sampled DNA. 3. Inspection by dentists The dental and roentgenographic records provided by the families allowed rapid personal identification in major disasters, traffic accidents, fires etc.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1303428

Yamamoto, K

1992-12-01

93

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

94

Supernumerary Teeth in Nepalese Children  

PubMed Central

Objective. The objectives of the present study were to investigate the prevalence and characteristics of supernumerary teeth in a patient sample of Nepalese children. Study Design. A survey was performed on 2684 patients (1829 females and 1035 males) ranging in age from 6 to 14 for the presence of supernumerary teeth. For each patient with supernumerary teeth the demographic variables (age and sex), number, location, eruption status, and morphology were recorded. Descriptive statistics were performed. Results. Supernumerary teeth were detected in 46 subjects (1.6%), of which 26 were males and 20 were females with a male?:?female ratio of 1.3?:?1. The most commonly found supernumerary tooth was mesiodens followed by maxillary premolars, maxillary lateral incisor, and mandibular lateral incisor. Of the 55 supernumerary teeth examined, 58.18% (n = 32) had conical morphology, followed by tuberculate (30.90%, n = 17) and supplemental (10.90%, n = 6) forms. The majority of the supernumerary teeth were erupted (56.36%, n = 31). Conclusion. The prevalence of supernumerary teeth in Nepalese children was found to be 1.6%, the most frequent type being mesiodens. Conical morphology was found to be the most common form of supernumerary tooth. PMID:25506609

Singh, Varun Pratap

2014-01-01

95

Mouth and Teeth (For Parents)  

MedlinePLUS

... important role in our daily lives. Continue Basic Anatomy of the Mouth and Teeth The entrance to ... to have evolved thousands of years ago when human diets consisted of mostly raw foods that required ...

96

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

97

In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth  

PubMed Central

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

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

2014-01-01

98

Bilateral agenesis of maxillary permanent canines: Review of the literature  

PubMed Central

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

Borzabadi-Farahani, Ali

2015-01-01

99

An improved iron loss estimation for permanent magnet brushless machines  

Microsoft Academic Search

This paper presents an improved approach for predicting iron losses in permanent magnet brushless machines. The new approach is based on the fundamental concept that eddy current losses are proportional to the square of the time rate of change of flux density. Expressions are derived for predicting hysteresis and eddy current losses in the stator teeth and yoke. The so-called

Fang Deng

1999-01-01

100

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

PubMed

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

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

2013-08-01

101

A clinical and microbiological comparative study of deep carious lesion treatment in deciduous and young permanent molars  

Microsoft Academic Search

The aim of this study was to compare one-visit indirect pulp treatment (IPT), two-visit IPT, and direct complete excavation\\u000a (DCE) of deciduous and young permanent molars with deep carious lesions from clinical and microbiological points of view.\\u000a One hundred thirty-five teeth (83 deciduous molars and 52 young permanent molars) were included in the study. The teeth were\\u000a randomly selected and

Ayse I. Orhan; Firdevs T. Oz; Berrin Ozcelik; Kaan Orhan

2008-01-01

102

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

103

Cracked Teeth: A Review of the Literature  

PubMed Central

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

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

2013-01-01

104

Metal-ceramic dowel crown restorations for severely damaged teeth: a clinical report.  

PubMed

This clinical report describes an alternative prosthodontic treatment of a patient who had severely damaged endodontically-treated first molar teeth in all quadrants of her mouth. The young patient's severely damaged permanent molar teeth were treated with a restoration combining the advantage of the esthetics of dental porcelain, reinforced with the underlying cast gold dowel crown. Using this technique, the remaining sound tooth structure was preserved with function and esthetics accomplished. The described metal-ceramic one piece dowel crown restoration seemed to perform without any problems for the 12 month evaluation time. PMID:19336871

Yuzugullu, Bulem; Canay, Senay

2009-01-01

105

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. PMID:21887010

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

2009-01-01

106

Comparative Evaluation of Impact Strength of Fragment Bonded Teeth and Intact Teeth: An In Vitro Study  

PubMed Central

Background: To test and compare the impact strength of fragment bonded teeth with that of intact teeth by using impact testing machine (pendulum type) as a mode of load. Materials and Methods: Forty extracted, maxillary, central incisors selected for this study (20 control group and 20 experimental group). In experimental group, teeth crowns were fractured with a microtome at 2.5 mm from mesioincisal angle cervically, fractured portion is attached to original crown portion with 3 M single bond dentin bonding agent and 3 M Z ‘100’, composite resin. Impact strength of fragment bonded teeth and intact teeth tested with impact testing machine and compared. Results: Mean impact strength of fragment bonded teeth (30.76 KJ/M2 ) is not statistically significant deferent from mean impact strength of intact teeth (31.11 KJ/M2 ). Conclusion: Mean impact strength of fragment bonded teeth is not statistically different with that of intact teeth. Hence, after fracture of teeth if it is restored with fragment reattachment by using 3 M single bond dentin bonding agent and 3 M Z ‘100’ composite resin is having impact strength like that of intact teeth. How to cite the article: Venugopal L, Lakshmi MN, Babu DA, Kiran VR. Comparative evaluation of impact strength of fragment bonded teeth and intact teeth: An in vitro study. J Int Oral Health 2014;6(3):73-6. PMID:25083037

Venugopal, L; Lakshmi, M Narasimha; Babu, Devatha Ashok; Kiran, V Ravi

2014-01-01

107

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. PMID:22474647

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

2012-01-01

108

Dovetail spoke internal permanent magnet machine  

DOEpatents

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

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

2011-08-23

109

Method and apparatus for assembling permanent magnet rotors  

DOEpatents

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

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

1999-06-22

110

Method and apparatus for assembling permanent magnet rotors  

DOEpatents

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

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

1999-01-01

111

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

Microsoft Academic Search

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

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

1995-01-01

112

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

NASA Astrophysics Data System (ADS)

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

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

113

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

114

Transplantation of Cryopreserved Teeth: A Systematic Review  

PubMed Central

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

Osathanon, Thanaphum

2010-01-01

115

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. PMID:23857803

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

2013-10-01

116

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

2013-01-01

117

The Replacement of Missing Teeth  

PubMed Central

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

Zarb, George A.

1988-01-01

118

Oscillating Permanent Magnets.  

ERIC Educational Resources Information Center

Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

Michaelis, M. M.; Haines, C. M.

1989-01-01

119

Fracture resistance of posterior teeth restored with modern restorative materials  

PubMed Central

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

Hamouda, Ibrahim M.; Shehata, Salah H.

2011-01-01

120

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

121

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

122

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 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...

2012-04-01

123

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

124

21 CFR 872.6475 - Heat source for bleaching teeth.  

...2014-04-01 2014-04-01 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...

2014-04-01

125

Rugometric and microtopographic inspection of teeth enamel  

NASA Astrophysics Data System (ADS)

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

Costa, Manuel F.; Pereira, Pedro B.

2013-06-01

126

Talon cusp affecting permanent maxillary lateral incisors in 2 family members  

Microsoft Academic Search

The term talon cusp refers to a relatively rare dental anomaly in which an accessory cusplike structure projects from the cingulum area or cement-enamel junction. The condition can occur in either maxillary or mandibular anterior teeth in both the primary and permanent dentitions. This article reports 2 cases of talon cusp affecting consanguineous first cousins: a case of bilateral talon

Juan J. Segura; Alicia Jiménez-Rubio

1999-01-01

127

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

PubMed Central

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

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

2014-01-01

128

Management of complications after traumatic injuries to immature permanent maxillary incisors: a five years follow up case report.  

PubMed

The management of traumatic injuries to the teeth and soft tissues represent a challenge for the dental practitioner requiring knowledge and expertise necessary for adequate diagnosis and treatment. The purpose of this case report is to illustrate the emergency, short and long-term management of young permanent teeth involved with complex luxation injuries. Emergency management, orthodontic forced eruption and pulp therapy approaches used are described in details. The case was followed-up clinically and radiographically for 5 years. PMID:24984660

Halima, Abukabbos; Faisal, Alsineedi; Marcio, Guelmann

2014-06-01

129

Cleaning Your Child's Mouth and Teeth  

MedlinePLUS

... and Flossing Who Does the Brushing? Brushing Flossing Toothpaste From Mouth Wipes to Brushing and Flossing As ... sized toothbrush. Use a very small smear of toothpaste. Your child's teeth don't touch each other ...

130

Toothbrush Can Chip Teeth and Cause Choking  

MedlinePLUS

... has happened to some users of the battery-powered Arm & Hammer Spinbrush—or the Crest Spinbrush, as ... an injury.” Injuries reported from using the Spinbrush powered toothbrush include chipped or broken teeth cuts to ...

131

Taking Care of Your Teeth and Mouth  

MedlinePLUS

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

132

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.

133

Photomechanical investigations on post endodontically rehabilitated teeth.  

PubMed

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 restoration resulted in regions of high tensile stress and of stress concentrations in the remaining dentin structure. It was observed from mechanical testing that the fracture resistance in post-core restored teeth is significantly lower (p<0.0001) than that in intact tooth. There was a significant correspondence between the plane of stress concentrations identified in the photoelastic models and in those of the plane of fracture exhibited by the rehabilitated tooth specimens. While the fracture of post-core rehabilitated teeth was consistent, that of control teeth was not as distinct. The SEM highlighted varying dentin response to fracture propagation at the inner core and the outer regions. The fractographs showed brittle and ductile response to fracture propagation in the outer and inner core dentin, respectively. These photomechanical studies highlighted that the stress concentrations, high tensile stress and loss of inner ductile dentin associated with post endodontic rehabilitation diminished their resistance to fracture. PMID:11966313

Kishen, A; Asundi, A

2002-04-01

134

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. PMID:23960408

Raj, Makesh; Boaz, Karen; Srikant, N

2013-01-01

135

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

PubMed

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

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

2012-04-01

136

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

PubMed Central

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 maxilla and mandible, which are not present in the adult face. The effects of mechanical stress propagating through these very stiff structures have yet to be examined. Based on a heuristic model, we predicted that the enamel of the embedded developing teeth would act to reduce stresses in the surrounding bony elements of the juvenile face. We tested this hypothesis by simulating occlusal loading in a finite element (FE) model of a child's cranium with a complete set of deciduous teeth and the first permanent molars embedded in the bony crypt in the maxilla. We modeled bone and enamel with appropriate material properties and assessed the effect of embedding high-stiffness enamel structures on stress distribution in the juvenile face. Against expectation, the presence of unerupted enamel caps does not affect the magnitude or location of stresses in the juvenile face. Our results do not support the hypothesis that the unerupted secondary teeth act to moderate stresses in the juvenile face. PMID:22195003

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

2011-01-01

137

Unlocking the bovine genome  

Technology Transfer Automated Retrieval System (TEKTRAN)

The draft genome sequence of cattle (Bos taurus) has now been analyzed by the Bovine Genome Sequencing and Analysis Consortium and the Bovine HapMap Consortium, which together represent an extensive collaboration involving more than 300 scientists from 25 different countries. ...

138

IDENTIFICATION OF BOVINE MICRORNAS  

Technology Transfer Automated Retrieval System (TEKTRAN)

MicroRNAs are small ~22 nucleotides-long non-coding RNAs capable of controlling gene expression by inhibiting translation or targeting messenger RNA for degradation. Bovine genome sequence is not yet annotated for the microRNAs and there are currently no bovine miRNAs reported in the miRBase. Alignm...

139

P olya's Permanent Problem  

Microsoft Academic Search

A square real matrix is sign-nonsingular if it is forced to be nonsingular by its pattern of zero, negative, and positive entries. We give structural characterizations of sign-nonsingular matrices, digraphs with no even length dicycles, and square non- negative real matrices whose permanent and determinant are equal. The structural characterizations, which are topological in nature, imply polynomial algorithms.

William McCuaig

140

Treatment of Ectopic Mandibular Second Permanent Molar with Elastic Separators  

PubMed Central

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

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

2014-01-01

141

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

PubMed

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

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

1996-10-01

142

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

PubMed Central

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

2014-01-01

143

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

144

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

145

FEATURE ARTICLE Biomineralization of sea urchin teeth  

E-print Network

FEATURE ARTICLE Biomineralization of sea urchin teeth Yurong MA () and Limin QI Beijing National Species, College of Chemistry, Peking University, Beijing 100871, China The sea urchin tooth, which process, the crystal composition and orientation, and the mechanical properties of sea urchin tooth

Qi, Limin

146

Elephant teeth from the atlantic continental shelf  

USGS Publications Warehouse

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

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

1967-01-01

147

Congenital absence of multiple primary teeth.  

PubMed

Idiopathic agenesis of primary dentition is very rare. This is a case report of a 2-year and 6-month-old girl child who presented with 14 missing primary teeth. A review of the previous case reports is done and the management of these cases is discussed. PMID:21273725

Mohapatra, A; Reddy, C P; Sivakumar, N

2010-01-01

148

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

149

Form factors for generated unequal addendum and dedendum gear teeth  

E-print Network

PORN FACTORS FOR GEHERLTED DREQUkL LDDERDDH /AID DEDEHDDH GEAR TEETH GEORGE FREDERICK SHEETS, JH. approved as to style and oontent by: z Head of Departnent Hayi 1952 FORM FACTORS FOR GEEERATED UEEQUAL ADDEEDUM AED DEDEEDUM GEAR TEETH...

Sheets, George Frederick

2012-06-07

150

Ammonium hexafluorosilicate increased acid resistance of bovine enamel and dentine.  

PubMed

Although diamine silver fluoride (AgF: (NH3)2AgF) stains teeth black, it is known as a very effective agent to prevent the dental caries progress. In order to find another fluoride that has a similar anticariogenic effect without changing tooth color, we prepared ammonium hexafluorosilicate (SiF: (NH4)2SiF6), in which the silver of AgF is replaced with silicon. In this study, the anticariogenic effect of SiF was evaluated using bovine teeth. Fluoride solutions, SiF, AgF, acidulated phosphate fluoride (APF), and sodium fluoride (NaF), were applied to bovine enamel and dentine blocks, and the depth of demineralization was measured after exposure to a demineralizing solution for 24 h. Also, fluoride was applied to a simulated dentine caries specimen to evaluate the caries progress-preventing ability. For the dentine specimens, mineral loss (Delta Z) was also measured with microradiography. We found that SiF treated enamel showed better acid resistance than specimens treated with NaF or APF. AgF treated enamel also showed similar acid resistance, but was stained black. SiF and AgF treated caries-affected dentine showed reduced demineralization when exposed to a demineralization solution for 24 h. Mineral loss (Delta Z) was reduced to 85% and 75%, respectively. Although the acid resistance of the SiF treated teeth was inferior to that of the AgF treated teeth, we consider that SiF has good potential as anticariogenic agent, since it increased acid resistance without changing tooth color. PMID:15875257

Kawasaki, A; Suge, T; Ishikawa, K; Ozaki, K; Matsuo, T; Ebisu, S

2005-05-01

151

TeethClick: Input with Teeth Clacks Tamer Mohamed Lin Zhong  

E-print Network

-resilient, and user-friendly solution that incurs very little computation load. Our user studies indicate the cheek. It uses very effi- cient spectrum analysis to distinguish teeth clacks from other vocal

Zhong, Lin

152

Emerging therapies for the management of traumatized immature permanent incisors.  

PubMed

Early loss of immature permanent teeth due to pulpal necrosis secondary to trauma can have dire consequences for a child's growth and development. The treatment alternatives include surgical endodontics, traditional calcium hydroxide apexification, and mineral trioxide aggregate (MTA) apexification. These options pose potential complications, including: arrest of root development; weakened dentinal walls; and increased potential for fracture. Revascularization of the dentin-pulp complex is a new approach that involves disinfecting the root canal system followed by tissue repair and regeneration while allowing for continued root development and thickening of the lateral dentinal walls through deposition of new hard tissue. The purpose of this report was to present the revascularization of an immature permanent maxillary central incisor that had evidence of external root resorption. Six months later, internal bleaching was performed to remove cervical discoloration from the triple antibiotic paste. At 18 months, the tooth remained vital and had evidence of continued root development. PMID:22353461

Miller, Elizabeth K; Lee, Jessica Y; Tawil, Peter Z; Teixeira, Fabricio B; Vann, William F

2012-01-01

153

Late Cretaceous Plesiosaur Teeth from Axel Heiberg Island, Nunavut, Canada  

Microsoft Academic Search

We report the discovery of Late Cretaceous plesiosaur teeth from non-marine strata on Axel Heiberg Island in the Canadian High Arctic. In comparison to other plesiosaur teeth, these specimens are most similar to the teeth of elasmosaurs: they have a smooth outer surface and crenulated inner surface, with crenulations that extend nearly to the tip of the tooth. Comparisons with

DEBORAH VANDERMARK; JOHN A. TARDUNO; DONALD B. BRINKMAN

2006-01-01

154

Clinical effectiveness of flash teeth whitening, a novel method for teeth bleaching.  

PubMed

Flash teeth whitening is a two-step, once-daily method for whitening teeth that combines the use of a fine aerosol mist of a stabilized, concentrated hydrogen-peroxide solution and a saliva-activated, effervescent oral powder that is poured directly onto the tongue. An in-vivo study was conducted to evaluate the efficacy and safety of the flash teeth whitening method at three timed intervals in a 3-week period. Objective and subjective tooth-shade rating methods were used at baseline, after initial treatment, and after 1 and 3 weeks of once-daily use. A significant whitening effect was observed. Data also indicated a progressively improved whitening effect, suggesting that sequential use may optimize the whitening results, with maximum whitening occurring between 1 and 3 weeks of once-daily use. The study demonstrated that flash teeth whitening effectively whitens teeth. This novel method is suitable for safe use as an out-of-office treatment as a primary whitener, or as a maintenance method for keeping whitened teeth white, offering dentists a potential alternative tooth whitening recommendation that is easy to use, safe, and effective and improves the condition of soft tissue when used as directed. PMID:25508144

Arndt, Amanda; McLaren, Edward A; Ulman, Gwen

2014-06-01

155

Clinical effectiveness of flash teeth whitening, a novel method for teeth bleaching.  

PubMed

Flash teeth whitening is a two-step, once-daily method for whitening teeth that combines the use of a fine aerosol mist of a stabilized, concentrated hydrogen-peroxide solution and a saliva-activated, effervescent oral powder that is poured directly onto the tongue. An in-vivo study was conducted to evaluate the efficacy and safety of the flash teeth whitening method at three timed intervals in a 3-week period. Objective and subjective tooth-shade rating methods were used at baseline, after initial treatment, and after 1 and 3 weeks of once-daily use. A significant whitening effect was observed. Data also indicated a progressively improved whitening effect, suggesting that sequential use may optimize the whitening results, with maximum whitening occurring between 1 and 3 weeks of once-daily use. The study demonstrated that flash teeth whitening effectively whitens teeth. This novel method is suitable for safe use as an out-of-office treatment as a primary whitener, or as a maintenance method for keeping whitened teeth white, offering dentists a potential alternative tooth whitening recommendation that is easy to use, safe, and effective and improves the condition of soft tissue when used as directed. PMID:25469409

Arndt, Amanda; McLaren, Edward A; Ulman, Gwen

2014-06-01

156

Permanent magnet design methodology  

NASA Technical Reports Server (NTRS)

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

Leupold, Herbert A.

1991-01-01

157

Infectious Bovine Rhinotracheitis  

E-print Network

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

Sprott, L. R.

1998-11-30

158

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

159

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. PMID:24010086

Forghani, Maryam; Maghsoudlou, Amir

2013-01-01

160

Evaluation of the accuracy of different molar teeth measurements in assessing sex.  

PubMed

Teeth are considered to be a very useful tissue for sex determination and molars are among the most dimorphic teeth. Even though mesiodistal (MD) and buccolingual (BL) crown diameters are usually employed for sex assessment, alternative measurements like MD and BL cervical diameters as well as crown and cervical diagonal diameters have been developed. This study explores the utility of crown and cervical MD, BL and diagonal measurements of molars in sex assessment when used separately. A total of 254 permanent molars (excluded third molars) from 101 individuals (51 males, 50 females) from the Athens Collection were examined. Stepwise discriminant analysis was used to evaluate the accuracy of each diameter group in assessing sex. It was found that the accuracy ranges from 65.5 to 88.4 %. Cervical diagonal diameters are the most accurate followed by crown diagonal diameters, and crown and cervical MD and BL diameters. Therefore the high classification accuracy of diagonal diameters show that these measurements are more reliable for sex determination than the traditional MD and BL and can be considered a promising method for sex assessment from human teeth. PMID:22926774

Zorba, Eleni; Spiliopoulou, Chara; Moraitis, Konstantinos

2013-03-01

161

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

PubMed Central

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

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

2014-01-01

162

Optimized nanoscale composite behaviour in limpet teeth  

PubMed Central

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

Lu, Dun; Barber, Asa H.

2012-01-01

163

Natal and Neonatal Teeth: An Overview of the Literature  

PubMed Central

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

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

2013-01-01

164

Management of Multiple Impacted Teeth: A Case Report and Review  

PubMed Central

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

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

2014-01-01

165

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

PubMed

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

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

2014-06-01

166

Magnetite in the radular teeth of chitons  

Microsoft Academic Search

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

Manabu Mizota; Yutaka Maeda

1986-01-01

167

Permanent Turbidity-Standards  

PubMed Central

Permanent turbidity reference standards suitable for measurement of microbial suspensions were prepared by suspending finely divided titanium dioxide in aryl sulfonamide-formaldehyde or methylstyrene resins. Turbidities of these standards, adjusted to a useful range for microbiological and immunological studies, were compared with other reference standards in use today. Tube holders for a Coleman Photonephelometer and a Nepho-Colorimeter were modified to eliminate the water well and to allow use of optically standardized 10-, 16-, or 18-mm test tubes. The standards and the tube holders have been used satisfactorily for more than 12 years. Images Fig. 5 Fig. 6 PMID:6077410

Roessler, William G.; Brewer, Carl R.

1967-01-01

168

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

PubMed Central

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

Kianimanesh, Nasrin; Shayeghi, Bahareh

2014-01-01

169

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. PMID:24171027

Haghgoo, Roza; Arfa, Sara; Asgary, Saeed

2013-01-01

170

Achieving permanency for LGBTQ youth.  

PubMed

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

Jacobs, Jill; Freundlich, Madelyn

2006-01-01

171

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

PubMed Central

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

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

2013-01-01

172

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

173

Comparative outcome of revascularization in bilateral, non-vital, immature maxillary anterior teeth supplemented with or without platelet rich plasma: A case series  

PubMed Central

Loss of pulp vitality in an immature permanent tooth arrests root development. This leads to tooth with open apex and weak lateral dentinal walls. Management of such necrotic teeth with immature roots poses several treatment challenges. The documented study was performed to evaluate and compare apexogenesis induced by revascularization, with and without platelet rich plasma (PRP) in non-vital, immature anterior teeth. Three patients having bilateral, non-vital, immature maxillary central incisors with apical periodontitis were recruited after institutional ethical clearance. Subsequent to chemo-mechanical preparation, revascularization with and without PRP was randomly induced in either of the tooth. The cases were followed-up clinically and radiographically at 6 and 12 months. There was a marked difference in periapical healing, apical closure and dentinal wall thickening of teeth treated by revascularization with PRP. PMID:24347896

Jadhav, Ganesh Ranganath; Shah, Naseem; Logani, Ajay

2013-01-01

174

Eruption anomalies of the maxillary permanent cuspids in children with cleft lip and/or palate.  

PubMed

Eruption anomalies of the maxillary permanent cuspid on the cleft side was analyzed in a sample of 77 children with mono- and bi-lateral cleft lip/palate. The main findings were: 1) The permanent cuspid showed an initial mesial position in relation to the root of its primary predecessor in a relatively high number of cases. Nearly all those cuspids that showed an anomalous position (mesial or distal) in relation to the corresponding primary teeth at the time of the first observation erupted in malposition (palatally in the cleft area, mesially or distally to the primary cuspids). 2) In most cases presenting a mesially positioned permanent cuspid at the time of first observation, the permanent later incisor was congenitally missing, microdontic or in a mesial position in relation to the cleft. 3) Distally positioned permanent cuspids were always associated with a supernumerary lateral incisor. 4) A congenitally missing lateral incisor could represent a predisposing factor to a mesial position of the permanent cuspid. An early radiographic evaluation of the position of the permanent cuspid was suggested especially in those children presenting a congenitally missing lateral incisor. PMID:8619976

Vichi, M; Franchi, L

1996-01-01

175

[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 describing…

Bradley, Ben S.

1996-01-01

176

Permanent-Magnet Meissner Bearing  

NASA Technical Reports Server (NTRS)

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

Robertson, Glen A.

1994-01-01

177

Genotyping bovine coronaviruses.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bovine coronaviruses (BoCV) are enveloped, single-stranded, positive-sense RNA viruses of the Coronaviridae family. Infection is associated with enteritis and pneumonia in calves and Winter Dysentery in adult cattle. Strains, isolated more than 50 years ago, are used in vaccines and as laboratory ...

178

Protein Crystal Bovine Insulin  

NASA Technical Reports Server (NTRS)

The comparison of protein crystal, Bovine Insulin space-grown (left) and earth-grown (right). Facilitates the incorporation of glucose into cells. In diabetics, there is either a decrease in or complete lack of insulin, thereby leading to several harmful complications. Principal Investigator is Larry DeLucas.

1991-01-01

179

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 ...

180

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...

181

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

PubMed Central

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

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

2014-01-01

182

Facial lesions in piglets with intact or grinded teeth  

PubMed Central

Background Piglets are born with eight sharp teeth that during nursing can cause facial lesions on littermates and teat lesions on the sow. Teeth grinding in piglets is therefore often practiced to reduce these lesions. The aim of this study was to assess the consequences of grinding piglet teeth in regard to the occurrence of lesions. In this study the piglets' teeth were grinded in 28 litters, and in 36 litters the piglets' teeth were kept intact. Twice, one time during the first week and one time during the second week after birth facial lesions of the piglets were scored and the teats of the sows were examined for lesions. The facial lesion score accounted for the amount and severity of lesions. The individual observations on piglets in the litter were synthesized in a litter facial lesion score. Findings 69.8% and 43.5% of the piglets had facial lesions in week 1 and week 2 respectively. The effect of treatment was not significant on litter facial lesion score. The litter facial lesion score was higher in week 1 than in week 2 (p < 0.001) and higher in large litters (p = 0.003) than in small litters. Mortality between week 1 and week 2 was higher in litters with intact teeth (p = 0.02). Sow teat lesions only occurred if litters had intact teeth. Conclusions According to our results teeth grinding is only justifiable in large litters. PMID:22480262

2012-01-01

183

Complications after apicoectomy in maxillary premolar and molar teeth  

Microsoft Academic Search

This study was designed to enumerate the number of perforations to the maxillary sinus while performing apicoectomy on maxillary premolar and molar teeth and to evaluate possible complications as a result of these perforations. A total of 472 apicoectomies were performed in 440 patients; perforations occurred in 10.4% of teeth, 23% in molars, 13% in second premolars and 2% in

Alan Freedman; Isack Horowitz

1999-01-01

184

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

185

Impact strength of teeth restored by fragment-bonding.  

PubMed

The objective of this in vitro study was to investigate the impact strength of anterior teeth that have been fractured and restored by bonding with a dentin-bonding agent and a composite resin. Twenty sheep central incisors were divided into two groups, 10 in each. One group (intact teeth) served as the control and the teeth in the other group were fractured and then bonded with a bonding agent and a low-viscous composite resin. The specimens were tested in a modified impact-testing machine (pendulum type). The mean impact strength of the intact teeth was 30.6 +/- 2.16 KJ/m2 and of the bonded teeth was 30.2 +/- 1.86 KJ/m2. Statistics revealed that the two means were not significantly different. The results related well with the fracture strength obtained by loading intact and bonded teeth at constant but low speed until fracture. It was concluded that bonding fragments to the remaining tooth structure may restore the tooth to its original strength, measured at modest velocities of the applied force. In other words, reattaching the original coronal fragment of traumatised fractured anterior teeth restored with One-Step dentin bonding system and AEliteflo composite resin would withstand a second trauma to the same extent as intact teeth. PMID:11202874

Farik, B; Munksgaard, E C; Andreasen, J O

2000-08-01

186

Modified Anchor Shaped Post Core Design for Primary Anterior Teeth  

PubMed Central

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

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

2014-01-01

187

Clinical Decision-Making for Caries Management in Primary Teeth  

Microsoft Academic Search

The aim of this review of clinical decision-making for caries management in primary teeth is to integrate current knowledge in the field of cariology into clinically usable concepts and procedures to aid in the diagnosis and therapy of dental caries in primary teeth. The evidence for this paper is derived from other manuscripts of this conference; computer and hand searches

Joanna M. Douglass

2001-01-01

188

Measuring the density of dingo teeth with machine vision  

Microsoft Academic Search

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

John Billingsley; Kerry Withers

2004-01-01

189

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 ...

190

Non-syndromic multiple supernumerary teeth: a rare entity  

PubMed Central

Hyperdontia or supernumerary teeth without associated syndromes is a rare phenomenon, as supernumerary teeth are usually associated with cleft lip and palate or other syndromes such as Gardeners syndrome, cleidocranial dysplasia, trichorhinophalangic syndrome, etc. A 15-year-old girl reported for orthodontic treatment with a chief complaint of irregular teeth and unaesthetic smile. On examination class I malocclusion with severe crowding of upper anteriors, anterior open bite of 5?mm, cross bite with upper right posteriors, upper midline shift to right by 5?mm and two supernumerary teeth placed buccally in between 16 & 17 and 26 & 27, respectively, were found. On routine radiographical examination, two additional impacted supernumerary teeth were noticed distal to 18 and in mandibular arch in between roots of 35 and 36. A general physician was consulted who confirmed that there was no associated syndrome. Family history did not reveal any positive findings. PMID:23314450

Agrawal, Jiwanasha Manish; Agrawal, Manish Suresh; Nanjannawar, Lalita Girish; Adaki, Raghavendra Vithalappa

2013-01-01

191

Three-dimensional analysis of tubular permanent magnet machines  

NASA Astrophysics Data System (ADS)

This paper presents results from a three-dimensional finite element analysis of a tubular permanent magnet machine, and quantifies the influence of the laminated modules from which the stator core is assembled on the flux linkage and thrust force capability as well as on the self- and mutual inductances. The three-dimensional finite element (FE) model accounts for the nonlinear, anisotropic magnetization characteristic of the laminated stator structure, and for the voids which exist between the laminated modules. Predicted results are compared with those deduced from an axisymmetric FE model. It is shown that the emf and thrust force deduced from the three-dimensional model are significantly lower than those which are predicted from an axisymmetric field analysis, primarily as a consequence of the teeth and yoke being more highly saturated due to the presence of the voids in the laminated stator core.

Chai, J.; Wang, J.; Howe, D.

2006-04-01

192

Permanent Magnet Machines: Asychronous Operation  

Microsoft Academic Search

The permanent magnet motor operating at subsynchronous speeds, as during run-up, is treated with particular emphasis placed on the role that magnet excitation plays. The torque, during run-up, is separated into components called the \\

V. B. Honsinger

1980-01-01

193

Various reasons for permanent tooth extractions in a Caribbean population--Antigua.  

PubMed

A study was undertaken in September 1990 to investigate the reasons for permanent tooth extractions in Antigua. Eight out of 10 dentists on the island were requested to record permanent tooth extractions, including tooth type and reasons for extraction, during a 6 week study period. All 8 dentists provided data which indicated that 471 teeth were Extractions for orthodontic and impaction reasons comprised 4.3 per cent of tooth extrac-irregularly attending dental services. The principle reason for extractions was caries (61.6 per cent). Periodontitis (29.9 per cent) was the next most frequent reason for extractions and it became the predominant indication for tooth loss after 40 years of age. Extractions for orthodontic and impaction reasons comprised 4.3 per cent of tooth extraction, but these causes disappeared after 30 years of age. Restorable teeth were not commonly removed. The tooth types most frequently extracted due to caries were lower first molars and upper molars. Most commonly extracted, periodontally involved teeth were lower central incisors and upper third molars. PMID:8406950

Vignarajah, S

1993-06-01

194

Permanent deformation of asphalt mixes  

Microsoft Academic Search

This dissertation describes the results of a research that was conducted on the permanent deformation of asphalt mixtures. Central to this research was the separate characterization of the contribution of the aggregate skeleton and the bituminous mortar towards resistance to permanent deformation. The mixtures considered in this research included porous asphalt, stone mastic asphalt and dense asphalt concrete.\\u000a\\u000aThe test

P. M. Muraya

2007-01-01

195

Treatment options of untreatable traumatized anterior maxillary teeth for future use of dental implantation.  

PubMed

The anterior maxilla is the most traumatized region during childhood. Posttraumatic complications occasionally lead to tooth loss as well as the need for future implants. Unfortunately, it is contraindicated to place dental implants during childhood. A waiting period of approximately 8 to 10 years before completion of growth is required. For this patient to become a candidate for future dental implants, it is necessary to ensure the continuous growth and to preserve the dimensions of the alveolar process until growth has ceased from time of injury until joint maturation. To achieve these goals, it is essential to coordinate the treatment sequence at the time of trauma. After loss of a traumatized anterior permanent maxillary incisor in young adults, treatment options are limited: orthodontic closure of the gap and reshaping the adjacent teeth, or tooth extraction and maintaining the gap with a temporary restoration. Orthodontic space closure has limited indications and requires prosthetic restoration of at least 2 teeth. Extraction and temporary restoration will usually lead to bone augmentation before implantation. Other possible treatment options include orthodontic extrusion of the root remnant (in cases of untreatable root fracture or complicated crown-root fracture) and a temporary crown to serve the patient until the completion of growth and development, autogenous tooth transplantation, intentional extraction and immediate tooth replantation, distraction osteogenesis, and decoronation. Because general rules do not apply, individual treatment plans are necessary. PMID:15017299

Schwartz-Arad, Devorah; Levin, Liran; Ashkenazi, Malka

2004-03-01

196

Treatment options of untreatable traumatized anterior maxillary teeth for future use of dental implantation.  

PubMed

The anterior maxilla is the most traumatized region during childhood. Posttraumatic complications occasionally lead to tooth loss as well as the need for future implants. Unfortunately, it is contraindicated to place dental implants during childhood. A waiting period of approximately 8 to 10 years before completion of growth is required. For this patient to become a candidate for future dental implants, it is necessary to ensure the continuous growth and to preserve the dimensions of the alveolar process until growth has ceased from time of injury until joint maturation. To achieve these goals, it is essential to coordinate the treatment sequence at the time of trauma. After loss of a traumatized anterior permanent maxillary incisor in young adults, treatment options are limited: orthodontic closure of the gap and reshaping the adjacent teeth, or tooth extraction and maintaining the gap with a temporary restoration. Orthdontic space closure has limited indications and requires prosthetic restoration of at least 2 teeth. Extraction and temporary restoration will usually lead to bone augmentation before implantation. Other possible treatment options include orthodontic extrusion of the root remnant (in cases of untreatable root fracture or complicated crown-root fracture) and a temporary crown to serve the patient until the completion of growth and development, autogenous tooth transplantation, intentional extraction and immediate tooth replantation, distraction osteogenesis, and decoronation. Because general rules do not apply, individual treatment plans are necessary. PMID:15179087

Schwartz-Arad, Devorah; Levin, Liran; Ashkenazi, Malka

2004-06-01

197

The ins and outs of the evolutionary origin of teeth.  

PubMed

The role of teeth and jaws, as innovations that underpinned the evolutionary success of living jawed vertebrates, is well understood, but their evolutionary origins are less clear. The origin of teeth, in particular, is mired in controversy with competing hypotheses advocating their origin in external dermal denticles ("outside-in") versus a de novo independent origin ("inside-out"). No evidence has ever been presented demonstrating materially the traditional "outside-in" theory of teeth evolving from dermal denticles, besides circumstantial evidence of a commonality of structure and organogenesis, and phylogenetic evidence that dermal denticles appear earlier in vertebrate phylogeny that do teeth. Meanwhile, evidence has mounted in support of "inside-out" theory, through developmental studies that have indicated that endoderm is required for tooth development, and fossil studies that have shown that tooth-like structures evolved before dermal denticles (conodont dental elements), that tooth replacement evolving before teeth (thelodont pharyngeal denticles), and that teeth evolved many times independently through co-option of such structures. However, the foundations of "inside-out" theory have been undermined fatally by critical reanalysis of the evidence on which it was based. Specifically, it has been shown that teeth develop from dermal, endodermal or mixed epithelia and, therefore, developmental distinctions between teeth and dermal denticles are diminished. Furthermore the odontode-like structure of conodont elements has been shown to have evolved independently of dermal and internal odontodes. The tooth-like replacement encountered in thelodont pharyngeal odontodes has been shown to have evolved independently of teeth and tooth replacement and teeth have been shown to have evolved late within the gnathostome stem lineage indicating that it is probable, if not definitive, that teeth evolved just once in gnathostome evolution. Thus, the "inside-out" hypothesis must be rejected. The phylogenetic distribution of teeth and dermal denticles shows that these odontodes were expressed first in the dermal skeleton, but their topological distribution extended internally in association with oral, nasal and pharyngeal orifices, in a number of distinct evolutionary lineages. This suggests that teeth and oral and pharyngeal denticles emerged phylogenetically through extension of odontogenic competence from the external dermis to internal epithelia. Ultimately, internal and external odontodes appear to be distinct developmental modules in living jawed vertebrates, however, the evidence suggests that this distinction was not established until the evolution of jawed vertebrates, not merely gnathostomes. PMID:25219878

Donoghue, Philip C J; Rücklin, Martin

2014-09-15

198

A multidisciplinary approach to the treatment of an intruded maxillary permanent incisor complicated by the presence of two mesiodentes.  

PubMed

Treatment of a traumatically intruded maxillary incisor with an immature apex remains controversial. Treatment options include observation, surgical repositioning, or orthodontic forced eruption. Likewise, the ideal timing of surgical removal of a mesiodens is highly controversial: immediate versus delayed intervention. The complications associated with untreated supernumerary teeth include: overretention of primary teeth, delayed eruption of permanent incisors, rotations, impaction, diastema, pulp necrosis and root resorption. Less common sequelae include enlarged follicular sacs, cystic degeneration and nasal eruption. This paper describes another risk factor associated with delayed removal of a mesiodens previously not mentioned in the dental literature, namely potential complications arising from a traumatic injury, in particular intrusion, of the maxillary permanent incisors. PMID:11132511

Kupietzky, A; Rotstein, I; Kischinovsky, D

2000-01-01

199

Estimation of age from development and eruption of teeth  

PubMed Central

The developing dentition is used to assess maturity and estimate the age in many disciplines including anthropology, archeology, forensic science, pediatric dentistry and orthodontics. There is evidence that dental development is less effected than skeletal development by malnutrition and hormonal disorders. There are two methods of dental age assessment, radiographically and by clinically visualization of eruption of teeth. The clinical method to assess dental age is based on the emergence of teeth in the mouth. This method is more suitable since it does not require any special equipment, expertise and is more economical. Tooth formation is the best choice for estimating the age as variations are less as compared to other development factors. Eruption of teeth is one of the changes observed easily among the various dynamic changes that occur from the formation of teeth to the final shedding of teeth. The times of eruption of teeth are fairly constant and this can be made use of in ascertaining the average age of eruption of the tooth. Assessment of age of an individual by examination of teeth is one of the accepted methods of age determination. PMID:25125911

Manjunatha, B. S.; Soni, Nishit K.

2014-01-01

200

A Curriculum Vitae of Teeth: Evolution, Generation, Regeneration  

PubMed Central

The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body surface 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 dentition generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within the mouth cavity through mutual, delicate interactions between dental epithelium and oral ectomesenchyme. These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors. Congenital disturbances in tooth formation, acquired dental diseases and odontogenic tumors affect millions of people and rank human oral pathology as the second most frequent clinical problem. On the basis of substantial experimental evidence and advances in bioengineering, many scientists strongly believe that a deep knowledge of the evolutionary relationships and the cellular and molecular mechanisms regulating the morphogenesis of a given tooth in its natural position, in vivo, will be useful in the near future to prevent and treat teeth pathologies and malformations and for in vitro and in vivo teeth tissue regeneration. PMID:19266065

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

2009-01-01

201

Stator and Rotor Pole Combinations for Multi-Tooth Flux-Switching Permanent-Magnet Brushless AC Machines  

Microsoft Academic Search

A simple analytical method is developed for determining the optimal combination of stator pole and rotor pole numbers for a multi-tooth flux-switching permanent magnet (FSPM) machine, and the optimal design of the stator teeth for maximum torque. In addition, the rotor pole width and the split ratio are optimized by finite element analysis. The optimized multi-tooth FSPM machine exhibits a

J. T. Chen; Z. Q. Zhu; D. Howe

2008-01-01

202

Management of the pulp in primary teeth--an update.  

PubMed

Management of the pulpal tissue in primary teeth is a clinical challenge facing dental practitioners on a regular basis. This article reviews the most common treatments used at the present time in the management of the pulp in deciduous teeth. It gives an overview of treatment options and the indications and contra-indications for the different treatment modalities. The evidence behind the medicaments used, their actions and success rates are discussed. Practical guidelines for choosing to retain or extract deciduous teeth and management of the primary tooth pulp with different clinical presentations are discussed. Areas of future research are highlighted. PMID:25597190

Brosnan, M G; Natarajan, A K; Campbell, J M; Drummond, B K

2014-12-01

203

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

PubMed Central

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

Zilberman, Uri; Lasilla, Lippo

2014-01-01

204

Oral Biofilm Architecture on Natural Teeth  

PubMed Central

Periodontitis and caries are infectious diseases of the oral cavity in which oral biofilms play a causative role. Moreover, oral biofilms are widely studied as model systems for bacterial adhesion, biofilm development, and biofilm resistance to antibiotics, due to their widespread presence and accessibility. Despite descriptions of initial plaque formation on the tooth surface, studies on mature plaque and plaque structure below the gum are limited to landmark studies from the 1970s, without appreciating the breadth of microbial diversity in the plaque. We used fluorescent in situ hybridization to localize in vivo the most abundant species from different phyla and species associated with periodontitis on seven embedded teeth obtained from four different subjects. The data showed convincingly the dominance of Actinomyces sp., Tannerella forsythia, Fusobacterium nucleatum, Spirochaetes, and Synergistetes in subgingival plaque. The latter proved to be new with a possibly important role in host-pathogen interaction due to its localization in close proximity to immune cells. The present study identified for the first time in vivo that Lactobacillus sp. are the central cells of bacterial aggregates in subgingival plaque, and that Streptococcus sp. and the yeast Candida albicans form corncob structures in supragingival plaque. Finally, periodontal pathogens colonize already formed biofilms and form microcolonies therein. These in vivo observations on oral biofilms provide a clear vision on biofilm architecture and the spatial distribution of predominant species. PMID:20195365

Zijnge, Vincent; van Leeuwen, M. Barbara M.; Degener, John E.; Abbas, Frank; Thurnheer, Thomas; Gmür, Rudolf; M. Harmsen, Hermie J.

2010-01-01

205

The wear and tear of teeth.  

PubMed

A review is presented of the mechanical damage suffered by tooth crowns. This has been the subject of much recent research, resulting in a need to revise some of the thinking about the mechanisms involved. Damage is classified here by scale into macro-, meso- and microfracture. The focus is on the outer enamel coat because this is the contact tissue and where most fractures start. Enamel properties appear to be tailored to maximize hardness, but also to prevent fracture. The latter is achieved by the deployment of developmental flaws called enamel tufts. Macrofractures usually appear to initiate as extensions of tufts on the undersurface of the enamel adjacent to the enamel-dentine junction and extend from there into the enamel. Cracks that pass from the tooth surface tend to be deflected by an enamel region of high toughness; if they find the surface again, a chip (mesofracture) is produced. The real protection of the enamel-dentine junction here is the layer of decussating inner enamel. Finally, a novel analysis of mechanical wear (microfracture) suggests that the local toughness of the enamel is very important to its ability to resist tissue loss. Enamel and dentine have contrasting behaviours. Seen on a large scale, dentine is isotropic (behaving similarly in all directions) while enamel is anisotropic, but vice versa on a very small scale. These patterns have implications for anyone studying the fracture behaviour of teeth. © 2014 S. Karger AG, Basel. PMID:25427777

Lucas, Peter W; van Casteren, Adam

2015-01-01

206

Macroscopic and microscopic aspects of incinerated teeth.  

PubMed

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

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

1998-06-01

207

The determination of lead in human teeth  

NASA Astrophysics Data System (ADS)

The effects of lead poisoning may be much more extensive than had been realised until recently. Industrial workers and the inhabitants of big cities are continuously absorbing small quantities and it is important to be able to detect excessive amounts over long periods. This can be done by examining teeth which have been extracted for other reasons. Tooth sections have been bombarded with 3He ions from the Birmingham 152 cm cyclotron. Several alpha-emitting isotopes of polonium are produced from any lead present. After bombardment the sections are held against an alpha-sensitive plastic track detector for a few days. Examination of the plastic then shows a distribution of tracks proportional to the distribution of lead in the tooth. Standards irradiated at the same time enable us to determine the absolute concentration. It is found that the concentration in the absorbed enamel records the lead absorbed during the time of the formation of the tooth while that in pulpal dentine shows the integrated take-up during the life of the tooth.

Fremlin, J. H.; Edmonds, M. I.

1980-06-01

208

Current aspects of restoring traumatically fractured teeth.  

PubMed

Endodontic and restorative considerations are of primary significance in the treatment of tooth fractures. Since exposed dentinal tubules permit invasion of bacteria into the endodontic system, a protective dressing must be applied as part of the emergency treatment. Provided the dentin wound has been sealed, restorative treatment can also be carried out at a later stage. The fractured tooth fragment can be reattached using adhesive protocols in order to restore function and esthetic appearance. If reattachment is difficult or impossible, eg, in cases of multiple or missing fragments, current composite materials enable excellent esthetic results. Minimally-invasive direct composite restorations are preferred over the more invasive indirect restorations, at least in immature teeth with an extensive coronal pulp dimension. Restorative treatment of crown-root fractures is frequently demanding due to inaccessible subgingival fracture margins. Extrusion of the remaining root is an alternative method to surgical crown lengthening for re-establishing the biological width. This can be carried out either orthodontically (forced eruption), or surgically (intra-alveolar transplantation). Although the treatment of crown-root fractures is one of the most technically sensitive procedures in dental traumatology and is frequently considered as a long-term temporary restoration, tooth conservation up to the age at which implants can be placed may be regarded as a success. PMID:21734963

Krastl, Gabriel; Filippi, Andreas; Zitzmann, Nicola U; Walter, Clemens; Weiger, Roland

2011-01-01

209

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

PubMed Central

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

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

2014-01-01

210

Lodestone: Nature's own permanent magnet  

NASA Technical Reports Server (NTRS)

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

Wasilewski, P.

1976-01-01

211

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. PMID:24009032

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

2013-01-01

212

Chew on This: Healthy Teeth for Baby and Beyond  

MedlinePLUS

... teeth afterward. Also ask your child’s dentist about sealants—a simple, pain-free way to prevent tooth ... a small cavity is accidentally covered by a sealant, the decay won’t spread because germs trapped ...

213

A Review on Vital Pulp Therapy in Primary Teeth  

PubMed Central

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

Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

2015-01-01

214

Baby teething in early modern England: theory and therapeutic practice.  

PubMed

Oral and dental healthcare was a major medical concern in 16th- and 17th-century England. The analysis of a representative corpus from Early English Books Online (EEBO) reveals that the general principles and therapeutic management of baby teething were found most often in pediatric and midwifery treatises. The chapters devoted to this babyhood process usually gave information on factors determining teething onset, eruption schedule, order of appearance, associated disorders and short-term prognosis. Among the remedies available to alleviate children's pain, the authors mention anti-inflammatory herbal ointments, soothing fomentations, periodic mouthwashes, and minor surgery. Although the selected chapters on baby teething do not include detailed accounts of teething-related symptoms, one can find consistent data in the different descriptions and recipes provided. This scholarly agreement indicates systematic medical and midwifery practices to deal with a predictable, but frequently troublesome, stage of children's development. PMID:22372184

Dominguez-Rodriguez, Maria Victoria

2011-01-01

215

Orthodontics Align Crooked Teeth and Boost Self-Esteem  

MedlinePLUS

... news feeds delivered directly to your desktop! more... Orthodontics Align Crooked Teeth and Boost Self- esteem Article ... for the patient Reviewed: January 2012 Related Articles: Orthodontics Can Adults Wear Braces? There's More to Dentistry ...

216

Multiple teeth fractures in dentinogenesis imperfecta: a case report.  

PubMed

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

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

2014-01-01

217

Artificial teeth : dental biofilm analysis on a chip  

E-print Network

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

Lam, Raymond Hiu-wai

2010-01-01

218

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. PMID:23936247

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

2013-01-01

219

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

220

The prevention of contamination of teeth stored for transplantation.  

PubMed

Tissue culture media and their application to the storage of teeth are described. The problems of contamination in culture and a method of achieving a sterility level of 73 percent are discussed. Contamination was reduced at each stage, using unerupted teeth, chlorhexidine disinfection, saline irrigation, ultrasonics, a laminar-flow cabinet, and four antibiotics in culture. A method of microbiologic screening is outlined. PMID:6928300

Comfort, M B

1980-03-01

221

Laser light passage through restored and carious posterior teeth.  

PubMed

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

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

2014-08-01

222

Further observations on tertiary dentin in human deciduous teeth.  

PubMed

The structure of reparative tertiary dentin in human deciduous teeth has been studied. Reparative dentin is secreted by a new generation of odontoblast-like cells which have been subject to strong stimuli, e.g., trauma or deep active caries lesions with associated pulp inflammation. Ground sections of 25 teeth were prepared, and contact microradiographs were produced. Another 30 teeth were demineralized, embedded in paraffin, sectioned, and stained with hematoxylin and eosin. Some demineralized sections from each tooth were also studied in the scanning electron microscope. Most of the teeth showed some type of tertiary dentin formation. Mineralized tissue with a varied morphology was observed. In teeth which had been subject to trauma, the entire pulp chamber was sometimes obliterated. Mineralization seemed to start in the incisal region, and the central part of the pulp was the last part to be obliterated. Radiolucent voids and canals were seen. The organic matrix was dense and fibrous. In the pulp chamber and especially in the root canals, resorption had often occurred, indicating that signals giving rise to odontoclasts were also present. Resorption was often followed by deposition of various amounts of cementum-like repair tissue. The cells responsible for the formation of reparative dentin are believed to be subodontoblasts or undifferentiated ectomesenchymal cells. The varied morphology of the reparative dentin, observed in the pulp of the teeth examined, indicates that different stimuli lead to induction of hard-tissue-forming cells which produce different types of hard tissue. PMID:12640746

Klinge, R F

2001-08-01

223

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

PubMed Central

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

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

2014-01-01

224

Permanent GPS Network Project In Latvia  

NASA Astrophysics Data System (ADS)

The basic needs for permanent GPS stations in Latvia is scientific research and practical use for graphics designing. Permanent GPS also will be used in precise public or civil transports following, medicine or police or first aid coordination, air and sea navigation. Land surveying is the main user of permanent GPS. Permanent network planning in basic consists of many different parts. Planning GPS permanent stations network there are some facts, which must be taken in to consideration. · What is the basic users of permanent GPS stations, · Geographical constellation of antenna, · Security, · Power, communication source, · Data format requirement e. c. Permanent GPS network project in Latvia consist with about 30 stations. The main task of permanent GPS stations is to ensure interested institutions and civilians with online and postprocessed GPS data, corrections. In Latvia already have two permanent GPS stations for scientific use. These stations are taken as a primer for other stations.

Vallis, A.; Zvirgzds, J.; Kaminskis, J.

225

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

226

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

227

PERMANENT RESIDENCE PACKET PERMANENT LABOR CERTIFICATION (REGISTERED NURSE OR PHYSICAL THERAPIST)  

E-print Network

PERMANENT RESIDENCE PACKET PERMANENT LABOR CERTIFICATION (REGISTERED NURSE OR PHYSICAL THERAPIST (travel document) #12;2 VU DEPARTMENT REQUEST FOR PERMANENT RESIDENCE PETITION DOL has determined Nursing* positions. In addition, DOL has established that the employment of foreign nationals

Bordenstein, Seth

228

The retrieval of unerupted teeth in pedodontics: two case reports  

PubMed Central

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

2014-01-01

229

Cartilage (Bovine and Shark) (PDQ®)  

Cancer.gov

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

230

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. PMID:24155609

Al-Kahtani, Ahmed

2013-01-01

231

An unusual association of extraoral sinus tract with unerupted permanent tooth.  

PubMed

Cases have been reported in the literature in which extraoral sinus tracts of dental origin have been diagnosed and successfully treated. Similarly, the presence of an intracoronal radiolucency in unerupted permanent teeth has been found in the dental literature. The association of one with the other, however, is a rare occurrence. The purpose of this case report was to describe the treatment of a 7-year-old child who presented with an extraoral draining sinus originating from a carious, developing tooth bud of the unerupted permanent mandibular left second molar. After a thorough clinical and radiographic examination, a conclusive diagnosis was determined and surgical treatment was performed. The patient responded well, and the cutaneous lesion healed uneventfully. PMID:23756317

Kakade, Adesh; Juneja, Akanksha

2013-01-01

232

Failure after closed traction of an unerupted maxillary permanent canine: Diagnosis and treatment planning.  

PubMed

This report describes the treatment of a 13-year-old girl with unerupted maxillary permanent canines. It illustrates how recognizing an unexpected problem influenced the decision-making process. Despite 6 months of closed-eruption traction, the left canine had not erupted. However, the neighboring teeth were intruded, suggesting a diagnosis of canine ankylosis. When the site was surgically reopened, the wire chain used for the orthodontic traction appeared to be osseointegrated. It was renewed, and traction was applied for another 16 months, and the tooth was successfully brought into the arch. Bone tissue passing through the chain might have prevented forced eruption. In young patients with unerupted maxillary permanent canines, failure of closed traction can be attributed to ankylosis, and this accounts for tooth extraction as the treatment of choice. However, this clinical report suggests that additional measures might be warranted before the definitive diagnosis of ankylosis can be made and the tooth extracted. PMID:21724096

Alessandri Bonetti, Giulio; Incerti Parenti, Serena; Daprile, Giuseppe; Montevecchi, Marco

2011-07-01

233

Root Canal Morphology of Mandibular First Permanent Molars in an Indian Population  

PubMed Central

An in vitro study was performed to determine the number of roots, root canals per tooth, root canal configurations, and frequency of isthmi and apical deltas in mandibular first permanent molars in an Indian population. Hundred and fifty mandibular first permanent molars were collected and subjected to clearing technique. The cleared teeth were examined in a stereomicroscope under 7.5x magnifications. The canal configurations were categorized using Vertucci's classification. Overall 94.6% of the mandibular first molars had two roots, and 5.3% had extradistal roots (distolingual root). In addition, 64% of the specimens had three root canals, and 36% had four root canals. The most common canal configurations of mesial and distal roots were Vertucci type IV (54%) and type I (65.3%), respectively. Clinician should be aware of the complex root canal morphology of mandibular first molars among the Indian population before and during the root canal treatment. PMID:22287965

Chourasia, Hemant Ramesh; Meshram, Ganesh K.; Warhadpande, Manjusha; Dakshindas, Darshan

2012-01-01

234

From molecules to mastication: the development and evolution of teeth  

PubMed Central

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 small organs essential 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. Brief discussions of microRNAs and human disease as they apply to teeth are also included. PMID:24009032

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

2012-01-01

235

The development and replacement of teeth in viviparous caecilians.  

PubMed

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

Wake, M H

1976-01-01

236

Near-IR imaging of cracks in teeth  

PubMed Central

Dental enamel is highly transparent at near-IR wavelengths and several studies have shown that these wavelengths are well suited for optical transillumination for the detection and imaging of tooth decay. We hypothesize that these wavelengths are also well suited for imaging cracks in teeth. Extracted teeth with suspected cracks were imaged at several wavelengths in the near-IR from 1300-1700-nm. Extracted teeth were also examined with optical coherence tomography to confirm the existence of suspected cracks. Several teeth of volunteers were also imaged in vivo at 1300-nm to demonstrate clinical potential. In addition we induced cracks in teeth using a carbon dioxide laser and imaged crack formation and propagation in real time using near-IR transillumination. Cracks were clearly visible using near-IR imaging at 1300-nm in both in vitro and in vivo images. Cracks and fractures also interfered with light propagation in the tooth aiding in crack identification and assessment of depth and severity. PMID:24817806

Fried, William A.; Simon, Jacob C.; Lucas, Seth; Chan, Kenneth H.; Darling, Cynthia L.; Staninec, Michal; Fried, Daniel

2014-01-01

237

Permanently calibrated interpolating time counter  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

238

Large needle suction aspiration of permanent fillers.  

PubMed

Temporary injectable fillers have become so widely accepted within the cosmetic medical industry that permanent fillers with longer lasting effects are fast gaining popularity. Both patients and physicians alike have eagerly sought a product to minimize the inconvenience and cost of repeated injections. However, the fear is that the use of permanent fillers may lead to permanent problems. We describe here an in-office technique to remove permanent injectable fillers that achieves consistent, natural results with minimal risk of scarring. PMID:21898418

Wilson, Yushan L; Ellis, David A F

2011-10-01

239

Teaching Object Permanence: An Action Research Study  

ERIC Educational Resources Information Center

"Object permanence," also known as "object concept" in the field of visual impairment, is one of the most important early developmental milestones. The achievement of object permanence is associated with the onset of representational thought and language. Object permanence is important to orientation, including the recognition of landmarks.…

Bruce, Susan M.; Vargas, Claudia

2013-01-01

240

Isolation and in vitro characterisation of dental pulp stem cells from natal teeth.  

PubMed

Dental pulp stem cells were primarily derived from the pulp tissues of exfoliated deciduous teeth, primary incisors and permanent third molar teeth. The aim of this study was to isolate and extensively characterise SCs derived from human natal dental pulp (hNDP). For characterisation, proliferation capacity, phenotypic properties, ultrastructural and differentiation characteristics and gene expression profiles were utilised. A comparison was done between the properties of NDP-SCs and the properties of mesenchymal stem cells (MSCs) from bone marrow (BM) of the human. Stem cells isolated from hNDP and hBM were analysed by flow cytometry, reverse transcriptase-PCR, Real Time-PCR, and immunocytochemistry. Both cell lines were directionally differentiated towards adipogenic, osteogenic chondrogenic, myogenic and neurogenic lineages. hNDP-SCs and hBM-MSCs expressed CD13, CD44, CD90, CD146 and CD166, but not CD3, CD8, CD11b, CD14, CD15, CD19, CD33, CD34, CD45, CD117, and HLA-DR. Ultrastructural characteristics of hNDP-SCs showed more developed and metabolically active cells. hNDP-SCs and hBM-MSCs expressed some adipogenic (leptin, adipophilin and PPARgamma), myogenic (desmin, myogenin, myosinIIa, and alpha-SMA), neurogenic (gamma-enolase, MAP2a,b, c-fos, nestin, NF-H, NF-L, GFAP and betaIII tubulin), osteogenic (osteonectin, osteocalcin, osteopontin, Runx-2, and type I collagen) and chondrogenic (type II collagen, SOX9) markers without any stimulation towards differentiation under basal conditions. Embryonic stem cell markers Oct4, Rex-1, FoxD-3, Sox2, and Nanog were also identified. The differentiation potential of hNDP-SCs and hBM-MSCs to adipogenic, osteogenic, chondrogenic, myogenic and neurogenic was shown. This report described the first successful isolation and characterisation of hNDP-SCs. PMID:19816704

Karaöz, Erdal; Do?an, Burcu Nur; Aksoy, Ayça; Gacar, Gülçin; Akyüz, Serap; Ayhan, Selda; Genç, Zehra Seda; Yürüker, Sinan; Duruksu, Gökhan; Demircan, Pinar Cetinalp; Sariboyaci, Ayla Eker

2010-01-01

241

Blocking VEGF signaling delays development of replacement teeth in zebrafish.  

PubMed

The dentition in zebrafish is extremely and richly vascularized, but the function of the vasculature, in view of the continuous replacement of the teeth, remains elusive. Through application of SU5416, a vascular endothelial growth factor receptor inhibitor, we studied the role of the blood vessels in the dentition of the zebrafish. We were unable to show an effect on the development of first-generation teeth as well as first tooth replacement. However, in juvenile fish, a delay was observed in the developmental state of the replacement tooth compared with what was expected based on the maturation state of the functional tooth. Furthermore, we observed a difference between treated and nontreated fish in the distance between blood vessels and developing replacement teeth. In conclusion, our results provide support for a nutritive, rather than an inductive, function of the vasculature in the process of tooth development and replacement. PMID:25391620

Crucke, J; Huysseune, A

2015-01-01

242

Middle Pleistocene Hominin Teeth from Longtan Cave, Hexian, China  

PubMed Central

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

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

2014-01-01

243

Middle pleistocene hominin teeth from longtan cave, hexian, china.  

PubMed

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

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

2014-01-01

244

Automatic detection and classification of teeth in CT data.  

PubMed

We propose a fully automatic method for tooth detection and classification in CT or cone-beam CT image data. First we compute an accurate segmentation of the maxilla bone. Based on this segmentation, our method computes a complete and optimal separation of the row of teeth into 16 subregions and classifies the resulting regions as existing or missing teeth. This serves as a prerequisite for further individual tooth segmentation. We show the robustness of our approach by providing extensive validation on 43 clinical head CT scans. PMID:23285602

Duy, Nguyen The; Lamecker, Hans; Kainmueller, Dagmar; Zachow, Stefan

2012-01-01

245

Tetracycline-Induced Discoloration of Deciduous Teeth: Case Series  

PubMed Central

Tetracycline was the choice of antibiotic in some of the life-threatening bacterial infections. Due to its adverse effects and ability to cross-placental barrier, its use is contraindicated in pregnancy and in children. This is a case series of four patients with tetracycline-induced discoloration in primary teeth. How to cite the article: Vennila V, Madhu V, Rajesh R, Ealla KKR, Velidandla SR, Santoshi S. Tetracycline induced discoloration of deciduous teeth: Case series. J Int Oral Health 2014;6(3):115-9. PMID:25083046

Vennila, Vijayasree; Madhu, Vasapalli; Rajesh, R; Ealla, Kranti Kiran Reddy; Velidandla, Surekha Reddy; Santoshi, S

2014-01-01

246

Permanent-File-Validation Utility Computer Program  

NASA Technical Reports Server (NTRS)

Errors in files detected and corrected during operation. Permanent File Validation (PFVAL) utility computer program provides CDC CYBER NOS sites with mechanism to verify integrity of permanent file base. Locates and identifies permanent file errors in Mass Storage Table (MST) and Track Reservation Table (TRT), in permanent file catalog entries (PFC's) in permit sectors, and in disk sector linkage. All detected errors written to listing file and system and job day files. Program operates by reading system tables , catalog track, permit sectors, and disk linkage bytes to vaidate expected and actual file linkages. Used extensively to identify and locate errors in permanent files and enable online correction, reducing computer-system downtime.

Derry, Stephen D.

1988-01-01

247

Vaccination against bovine babesiosis.  

PubMed

Bovine babesiosis is an important disease caused by Babesia bovis, B. bigemina, and B. divergens. Solid immunity develops after infection and this feature has been exploited with the use of live attenuated organisms as immunogens. Attributes of live vaccines include a durable immunity to heterologous challenge after one vaccination. To overcome disadvantages relating to poor quality control (risk of contamination and adverse reactions), production procedures have been modified to meet the requirements of codes of good manufacturing practice. This includes development of methods to allow production of cryopreserved vaccine and limit antigenic drift. Killed vaccines have also been used on a limited basis and consist of antigens extracted from cultured material or blood of infected calves, and given with adjuvant. The degree and duration of immunity against heterologous challenge is not well documented. Attempts are being made to develop subunit vaccines but the progress has been slow. A better understanding of the mechanisms involved in the expression of protective immunity against Babesia spp will aid in the identification of protective antigens. PMID:11193669

De Vos, A J; Bock, R E

2000-01-01

248

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

E-print Network

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

Paris-Sud XI, Université de

249

Dental caries in primary and permanent molars in 7-8-year-old schoolchildren evaluated with Caries Assessment Spectrum and Treatment (CAST) index  

PubMed Central

Background No reports on a caries pattern covering the full spectrum of the disease could be found in the literature. The aim of this study was to evaluate caries in primary and first permanent molars of 7-8-year-old Polish children by the Caries Assessment Spectrum and Treatment (CAST) index and to find whether there was any correlation between the caries stages in such teeth. Methods The study covered 284 7-8-year-old children from randomly selected schools in the Bialystok District, Poland. The prevalence of CAST categories was evaluated with regard to the first and second primary, and first permanent, molars. The Spearman’s rank correlation coefficient was used to explore the correlation of the distribution of CAST codes among the evaluated teeth. The level of statistical significance was established at p?permanent molars, caries was observed in 14.8% to 17.3% of the molar and most lesions were scored at the non-cavitation level. Caries in primary molars was most often recorded at the stage of cavitated dentine lesion. Teeth with pulpal involvement, sepsis and extracted due to caries were found to be more prevalent in first, and then in second primary molars. A strong correlation was found between the status of teeth from the right and left sides of the oral cavity. The correlation of the status of first and second primary teeth was stronger for the left than for the right side of the mouth, r was 0.627 and 0.472 in maxilla and 0.513 and 0.483 in mandible (p?permanent molars the correlation was assessed to be weak. With regard to the teeth situated in opposite jaws the study revealed that the correlations were moderate - r between 0.33 and 0.49. The intra-examiner reliability was established at 0.96 for the primary dentition and at 0.878 for permanent molars. Conclusion The strongest correlation found in the evaluated population concerned the distribution of caries in primary molars on the left side of the mouth. The study proved the usefulness of the CAST index in epidemiological surveys. PMID:24952612

2014-01-01

250

Accuracy of developing tooth length as an estimate of age in human skeletal remains: the permanent dentition.  

PubMed

In this study, the accuracy of regression equations of developing permanent tooth length for age estimation (Liversidge and Molleson. J Forensic Sci. 1999;44:917) is tested on a sample of 88 Portuguese juvenile skeletons of known age at death. Results reveal an overall high accuracy for the method, showing an average difference between estimated and chronological age between 0.56 and 0.05 years, when using single teeth and 0.16 years, when using all available teeth. Accuracy tests indicate that age estimates can be obtained within +/-0.17 years with a 95% confidence interval when several teeth are used. Overall between-tooth agreement in age estimates decreases with increasing age but there is less variability of estimates with more teeth contributing to overall mean age. However, there is a tendency for overestimation of age of younger individuals (<6 years) and of age obtained from half of the dentition. Although the advantages of this technique probably make it the preferred method of age estimation of human immature skeletal remains, when microstructural methods are not an option, a possible positive secular trend effect and differences in socioeconomic conditions detected between populations may warrant caution in its applicability to modern forensic cases. PMID:19465800

Cardoso, Hugo F V

2009-06-01

251

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

PubMed Central

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

Komabayashi, Takashi; Zhu, Qiang

2010-01-01

252

Relapse in Angle Class II Division 1 malocclusion treated by tandem mechanics without extraction of permanent teeth: A retrospective analysis  

Microsoft Academic Search

Ideal orthodontic treatment should achieve long-term stability of the occlusion. The mandibular incisor segment has been described as the segment that is most likely to exhibit relapse after treatment and retention. Therefore, relapse of this is a challenge that clinicians need to address. The purpose of this study is to evaluate the amount of relapse that may occur in Angle

Javid Yavari; Michael K. Shrout; Carl M. Russell; Andrew J. Haas; Edward H. Hamilton

2000-01-01

253

Teeth of Embryos in Lamniform Sharks (Chondrichthyes: Elasmobranchii)  

Microsoft Academic Search

The dentitions of lamniform sharks possess a unique heterodonty, the lamnoid tooth pattern. However, in embryos, there are 'embryonic' and 'adult' dentitions. The teeth in the embryonic dentition are peg-like and appear to be attached to the jaw in an acrodont fashion. The adult dentition is characterized by the presence of replacement tooth series with the lamnoid tooth pattern. The

Kenshu Shimada

2002-01-01

254

Influence of apicoectomy on the pulps of replanted monkey teeth  

Microsoft Academic Search

A new modified apicoectomy technique developed to improve the revascularization and survival potential of replanted mature teeth was evaluated in this in vivo study comparing the pulpal responses of monkey incisors replanted following the modified apicoectomy with those of monkey incisors rep!anted without an apicoectomy or following a \\

David P. Durr; Odd B. Sveen

1986-01-01

255

An Interactive Geometric Technique for Upper and Lower Teeth Segmentation  

E-print Network

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

Azevedo, Ricardo

256

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

257

Tricho-Rhino-Phalangeal Syndrome with Supernumerary Teeth  

Microsoft Academic Search

Tricho-rhino-phalangeal syndromes (TRPS) are caused by mutation or deletion of TRPS1, a gene encoding a GATA transcription factor. These disorders are characterized by abnormalities of the hair, face, and selected bones. Rare cases of individuals with TRPS displaying supernumerary teeth have been reported, but none of these has been examined molecularly. We used two different approaches to investigate a possible

P. Kantaputra; I. Miletich; H.-J. Lüdecke; E. Y. Suzuki; V. Praphanphoj; R. Shivdasani; M. Wuelling; A. Vortkamp; D. Napierala; P. T. Sharpe

2008-01-01

258

Orthodontic management of non-syndromic multiple supernumerary teeth  

PubMed Central

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

Singhvi, Vijay; Nambiar, Supriya; Shetty, Siddarth

2013-01-01

259

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. PMID:22536243

Sharma, Amita; Singh, Varun Pratap

2012-01-01

260

Teeth Shape Modeling Pipeline for Oral Healthcare Appliances Development  

E-print Network

Teeth Shape Modeling Pipeline for Oral Healthcare Appliances Development (Invited Paper) Jacek to development of novel consumer oral healthcare devices. The pipeline is implemented in a processing framework changes. I. INTRODUCTION Oral healthcare consumer devices have come a long way from the classic, flat

Telea, Alexandru C.

261

BARIUM IN TEETH AS INDICATOR OF BODY BURDEN  

EPA Science Inventory

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

262

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

263

Analysis of abutment teeth in partially edentulous patients.  

PubMed

The aim of the study was to examine changes in the position of the abutment teeth (AT), size of undercuts for a denture clasp, as well as an existence of an adequate preparation of abutment teeth. A total of 156 casts of partially edentulous jaws, with 460 AT, were analyzed. The size of undercuts, a degree of abutment rotation, inclination and migration were measured using a dental parallelometer. The abutment teeth position was related to the level of occlusal plane in a dental articulator. Furthermore, the existence of an adequate preparation of abutment teeth, as well as a type of a denture and a type of a denture retention element were also considered. Analysis were carried out twice on casts made from a hard stone, the first time before the denture treatment had begun and the second time on the new casts obtained after new dentures had been delivered. The first analysis (prior dental treatment) revealed that a total of 33.9% of the analyzed AT were rotated, 31.3% were inclined, 12.1% had migrated, and 57.3% were elongated above the occlusal plane. On the casts obtained after the new dentures had been made, it was observed that none of the AT had an adequate preparation. Only 37.6% of all retention elements were located in adequate undercut positions on the AT. Upon the results of the present study a conclusion can be established that many abutment teeth are rotated, elongated, inclined, and migrated, which point to a requirement for AT preparation prior the manufacture of new denture; however none of the AT was adequately prepared considering insertion plane and many denture elements were located in an inadequate undercut size. PMID:25145006

Stanci?, Ivica; Popovac, Aleksandra; Rodi?, Teodora; Stipeti?, Jasmina; Strajni?, Ljiljana; Persi?, Sanja

2014-06-01

264

Design and analysis of new fault-tolerant permanent magnet motors for four-wheel-driving electric vehicles  

NASA Astrophysics Data System (ADS)

In this paper, a novel in-wheel permanent-magnet (PM) motor for four-wheel-driving electrical vehicles is proposed. It adopts an outer-rotor topology, which can help generate a large drive torque, in order to achieve prominent dynamic performance of the vehicle. Moreover, by adopting single-layer concentrated-windings, fault-tolerant teeth, and the optimal combination of slot and pole numbers, the proposed motor inherently offers negligible electromagnetic coupling between different phase windings, hence, it possesses a fault-tolerant characteristic. Meanwhile, the phase back electromotive force waveforms can be designed to be sinusoidal by employing PMs with a trapezoidal shape, eccentric armature teeth, and unequal tooth widths. The electromagnetic performance is comprehensively investigated and the optimal design is conducted by using the finite-element method.

Liu, Guohai; Gong, Wensheng; Chen, Qian; Jian, Linni; Shen, Yue; Zhao, Wenxiang

2012-04-01

265

Did the lateral enamel of Neandertal anterior teeth grow differently from that of modern humans?  

Microsoft Academic Search

The formation of lateral enamel in Neandertal anterior teeth has been the subject of recent studies. When compared to the anterior teeth of modern humans from diverse regions (Point Hope, Alaska; Newcastle upon Tyne, England; southern Africa), Neandertal anterior teeth appear to fall within the modern human range of variation for lateral enamel formation time. However, the lateral enamel growth

Debbie Guatelli-Steinberg; Donald J. Reid; Thomas A. Bishop

2007-01-01

266

Theoretical investigations of nonlinear loads on gear teeth in single gear transmission  

Microsoft Academic Search

In the paper the discrete-continuous model of a single gear transmission with nonlinear forces occurring between gear teeth is investigated. It is assumed that gear teeth have nonlinear stiffness having softening characteristics. Three nonlinear functions are proposed for the description of loads occurring on the gear teeth. In the discussion the wave approach is applied, as for the linear case

W?adys?aw Nadolski; Amalia Pielorz

2001-01-01

267

Surface ultrastructure of prestomal teeth of some flies in the families Calliphoridae, Muscidae and Sarcophagidae  

Microsoft Academic Search

Prestomal teeth of flies in the families Calliphoridae (Chrysomya pinguis, Chrysomya villeneuvi, and Chrysomya chani), Muscidae (Hydrotaea (= Ophyra) chalcogaster) and Sarcophagidae (Boettcherisca peregrina) were presented using scanning electron microscopy. The slight to deep bifurcation of the tips of their teeth were similarly observed in all species examined. The anatomical feature of prestomal teeth of the flies examined may contribute

Kabkaew L. Sukontason; Rungkanta Methanitikorn; Hiromu Kurahashi; Somsak Piangjai; Kom Sukontason

2005-01-01

268

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

PubMed Central

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

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

2014-01-01

269

Is CO2 ice permanent?  

NASA Technical Reports Server (NTRS)

Carbon dioxide ice has been inferred to exist at the south pole in summertime, but Earth based measurements in 1969 of water vapor in the Martian atmosphere suggest that all CO2 ice sublined from the southern polar cap and exposed underlying water ice. This implies that the observed summertime CO2 ice is of recent origin. It appears possible to construct an energy balance model that maintains seasonal CO2 ice at the south pole year round and still reasonably simulates the polar cap regression and atmospheric pressure data. This implies that the CO2 ice observed in the summertime south polar cap could be seasonal in origin, and that minor changes in climate could cause CO2 ice to completely vanish, as would appear to have happened in 1969. However, further research remains before it is certain whether the CO2 ice observed in the summertime south polar cap is seasonal or is part of a permanent reservoir.

Lindner, Bernhard Lee

1992-01-01

270

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

271

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

PubMed

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

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

2014-12-12

272

A partially mummified corpse with pink teeth and pink nails.  

PubMed

A female corpse in a state of advanced decomposition and putrefaction with pink teeth and an equivalent discolouration of several fingernails was found by a group of hunters in a forest. A combination of trimipramin intoxication, hypothermia and pneumonia could be established as the cause of death. Autolysis or blood congestion can only favour the occurrence of a pink discoloration. Pink phenomena depend on special anatomical features such as the existence of porus structures protected by a dense material, which explains the occurrence of a pink discoloration in teeth and fingernails. The non-specificity of congestion, its genesis and reinforcement by exogeneous factors does not allow pink phenomena to be used as specific forensic evidence. PMID:9457537

Ortmann, C; DuChesne, A

1998-01-01

273

Calcite orientations and composition ranges within teeth across Echinoidea.  

PubMed

Sea urchin's teeth from four families of order Echinoida and from orders Temnopleuroida, Arbacioida and Cidaroida were studied with synchrotron X-ray diffraction. The high and very high Mg calcite phases of the teeth, i.e. the first and second stage mineral constituents, respectively, have the same crystallographic orientations. The co-orientation of first and second stage mineral, which the authors attribute to epitaxy, extends across the phylogenic width of the extant regular sea urchins and demonstrates that this is a primitive character of this group. The range of compositions ?x for the two phases of Ca1-xMgxCO3 is about 0.20 or greater and is consistent with a common biomineralization process. PMID:25158180

Stock, Stuart R; Ignatiev, Konstantin; Lee, Peter L; Almer, Jonathan D

2014-08-01

274

Calcium hydroxide pulpotomy for primary teeth: a clinical study.  

PubMed

Calcium hydroxide pulpotomies were performed in 17 carious primary mandibular molars. Variables in the pulpotomy procedure were recognized and controlled in an attempt to obtain a more favorable result or end product. The effects of two methods of hemorrhage control were also evaluated. The duration of treatment for the study ranged from three to nine months. Treatment was clinically successful for all 17 teeth. The radiographic evaluations were more favorable for the experimental group than for the control group. Treatment was radiographically successful for 15 teeth, questionable for one tooth, and unsuccessful for one other tooth. The results of this study suggest that the aluminum chloride-calcium hydroxide pulpotomy may be a viable alternative to formocresol pulpotomies in the primary dentition. Although these findings encourage continued research, including a long-term follow-up, a histologic study is indicated. PMID:6588119

Heilig, J; Yates, J; Siskin, M; McKnight, J; Turner, J

1984-05-01

275

Comparison of periodontitis and root replacement in cat teeth with resorptive lesions.  

PubMed

Cat teeth with resorptive lesions and periodontitis may have a distinctly different clinical and radiographic appearance compared with teeth that have focal, lesion-associated gingivitis. A retrospective, case-controlled study was performed to determine the occurrence of root replacement in cats with resorptive lesions and associated periodontitis. Of 543 teeth evaluated with resorptive lesions, radiographic and/or clinical signs of periodontitis were identified in 236 (43.5%) teeth. Periodontitis was present in 43 of 275 (15.6%) teeth with root replacement and 193 of 268 (72.0%) teeth that had normal radiodensity and maintenance of the periodontal ligament. There was a significantly lower occurrence of root replacement in cat teeth with resorptive lesions and periodontitis. PMID:12108131

DuPont, Gregg A; DeBowes, Linda J

2002-06-01

276

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.

277

Apatite Mineralization in Teeth of the Chiton Acanthopleura echinata  

Microsoft Academic Search

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

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

2000-01-01

278

Stem-cell-based Tissue Engineering of Murine Teeth  

Microsoft Academic Search

Teeth develop from reciprocal interactions between mesenchyme cells and epithelium, where the epithelium provides the instructive information for initiation. Based on these initial tissue interactions, we have replaced the mesenchyme cells with mesenchyme created by aggregation of cultured non-dental stem cells in mice. Recombinations between non-dental cell-derived mesenchyme and embryonic oral epithelium stimulate an odontogenic response in the stem cells.

A. Ohazama; S. A. C. Modino; I. Miletich; P. T. Sharpe

2004-01-01

279

What is the Best Root Surface Treatment for Avulsed Teeth?  

PubMed Central

Dental avulsion is the most severe type of traumatic tooth injuries since it causes damage to several structures and results in avulsion of the tooth from its socket. Management protocols for avulsed teeth should include management of the pulp and periodontal ligament (PDL) cells in order to improve the long-term prognosis and survival of these teeth. The prognosis of the treatment as well as the survival of an avulsed tooth depends on intrinsic and extrinsic factors, such as the duration of the tooth’s extra-alveolar period, replantation time, the type of storage medium, PDL status and duration of splinting. Recent research has led to the development of storage media. However, there is not yet a single solution that fulfills all requirements to be considered as the ideal medium for temporary storage of avulsed teeth, and research on this field should carry on. On the other hand in case of delayed replantation, due to the great risk of tooth loss after avulsion, different root surface treatments have been proposed to prevent and delay root resorption before replantation. For this purpose, researchers have applied some different root surface treatment modalities in delayed replantation of avulsed teeth. Several protocols have been used to maintain PDL viability; some involve fluorides, steroids, sodium alendronate, enamel matrix derivatives (EMD) and basic fibroblast growth factor (bFGF, FGF-2). Among these applications, bFGF shows promising results in the regeneration of natural tooth structures and tissues. Better understanding of mechanism of bFGF may help to improve new technologies of regeneration of tooth structures. PMID:25317212

Tuna, Elif B; Yaman, Duygu; Yamamato, Seiko

2014-01-01

280

Forced eruption of maxillary incisor teeth from the lingual side.  

PubMed

A major disadvantage in using the forced eruption technique is the necessity for the placement of an unesthetic orthodontic appliance, especially when the tooth involved is a maxillary incisor. The aim of this article is to present two alternative simple, specific task-oriented devices that may be placed on the lingual side of the teeth and may be used in the anterior of the mouth without compromising appearance. PMID:15202587

Chaushu, Stella; Zahavi, Thomas; Becker, Adrian

2004-06-01

281

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

282

Cylindrical Hall thrusters with permanent magnets  

Microsoft Academic Search

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

Yevgeny Raitses; Enrique Merino; Nathaniel J. Fisch

2010-01-01

283

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

284

Quantitative evaluation of axial wall taper in prepared artificial teeth.  

PubMed

The purpose of this study was to quantitatively evaluate the axial wall taper of prepared artificial teeth using a non-contact three-dimensional shape measuring system. A total of 54 artificial teeth prepared by pre-clinical dental students for complete cast restorations were evaluated. For quantitative analysis, five cross sections were computer-graphically placed perpendicularly to the z-axis. The surface coordinate values (x, y, z) of each cross section were converted into polar coordinate values (r, theta), which were then graphically rendered to a two-dimensional plane. At four points, each 90 degrees from the distal center point of the cross section, the axial wall taper was quantitatively calculated using a formula based on the differences in radius between the highest and lowest positions of the cross sections of the prepared tooth. The average calculated taper was 5.8 degrees in the distal region, 21.7 degrees in the buccal region, 14.9 degrees in the mesial region and 12.5 degrees in the lingual region. These results suggest that the axial wall taper of prepared teeth can be quantitatively evaluated using this measuring system. PMID:16313090

Okuyama, Yayoi; Kasahara, Shin; Kimura, Kohei

2005-09-01

285

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

286

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

287

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

PubMed Central

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

Paulsamy, Sivachandran

2014-01-01

288

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

PubMed

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

Fukase, Hitoshi; Kondo, Osamu; Ishida, Hajime

2014-11-11

289

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

E-print Network

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

Paris-Sud XI, Université de

290

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

PubMed Central

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

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

2013-01-01

291

Talon cusps occurring concurrently with dens invaginatus on a permanent maxillary lateral incisor: a case report and literature review.  

PubMed

A talon cusp is a prominent accessory horn-like structure that projects from the cingulum or cementoenamel junction of the maxillary or mandibular teeth. It can occur in primary and permanent dentition and can lead to occlusal interference, irritation of the tongue, pulpal necrosis, caries, and periodontal problems. Talon cusp has been reported to affect both sexes, and may be unilateral or bilateral. Talon cusps occur most often on the palatal surface of permanent maxillary incisors. A comprehensive literature review revealed only 6 reported cases of facial talon cusps. A talon cusp occurring simultaneously with dens invaginatus in a tooth is extremely rare; to date, only 9 case reports have been published. This article presents a unique case of concurrent dens invaginatus and palatal and facial talon cusps in the right maxillary central incisor of a 12-year-old girl. PMID:24784523

Colak, Hakan; Yilmaz, Cicek; Keklik, Hakan; Colak, Tugba

2014-01-01

292

Malate dehydrogenase in bovine spermatozoa  

E-print Network

in the staining solution for 20 hours 49 51 17 Temperature effects of MDH activity of bovine sperm cells 52 r. INTRODUCTION I Malate dehydrogenase, widely distributed in mammalian , tissues, is an enzyme associated with the tricarboxylic ' acid cycle... acceptor which is reduced to an insoluble formazan iat the site of the enzyme-substrate reaction. Cytochemical demonstration of succinic dehydrogenase in intact rabbit spermatozoa had been studied by Edwards and Valentine (1962). They reported...

Lin, Hozong Robert

1973-01-01

293

Permanent Magnetic Bearing for Spacecraft Applications  

NASA Technical Reports Server (NTRS)

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

Morales, Winfredo; Fusaro, Robert; Kascak, Albert

2008-01-01

294

10 CFR 60.51 - License amendment for permanent closure.  

Code of Federal Regulations, 2012 CFR

... false License amendment for permanent closure. 60.51 Section 60.51 Energy...GEOLOGIC REPOSITORIES Licenses Permanent Closure § 60.51 License amendment for permanent closure. (a) DOE shall submit an...

2012-01-01

295

10 CFR 60.51 - License amendment for permanent closure.  

... false License amendment for permanent closure. 60.51 Section 60.51 Energy...GEOLOGIC REPOSITORIES Licenses Permanent Closure § 60.51 License amendment for permanent closure. (a) DOE shall submit an...

2014-01-01

296

10 CFR 60.51 - License amendment for permanent closure.  

Code of Federal Regulations, 2013 CFR

... false License amendment for permanent closure. 60.51 Section 60.51 Energy...GEOLOGIC REPOSITORIES Licenses Permanent Closure § 60.51 License amendment for permanent closure. (a) DOE shall submit an...

2013-01-01

297

29 CFR 2582.8478-3 - Permanent bonding requirements.  

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

2014-07-01

298

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

299

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

300

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

301

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

302

77 FR 55895 - Permanent Closure of Cincinnati Blue Ash Airport  

Federal Register 2010, 2011, 2012, 2013

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

2012-09-11

303

Replacement of maxillary permanent central incisors lost due to trauma in the mixed-dentition.  

PubMed

Traumatic injuries to anterior teeth in children range from minor chipping to total tooth loss and occur more often in boys than in girls. The treatment of permanent tooth loss in younger patients is complicated by the difficulty of doing restorative procedures which may be influenced by pulpal size, clinical crown height, and a dental profile which is constantly changing. This case report presented a situation involving a 9-year-old boy who had experienced traumatic loss of the maxillary central incisors. Innovative materials coupled with sound principles of removable partial denture design were utilized to fabricate a cast metal removable denture prosthesis to satisfy the esthetic, functional and psychological dental needs of the patient and his parents. PMID:25265859

Rubel, Barry; Hill, Edward E

2014-08-01

304

Replacement of Missing Anterior Teeth in a Patient with Temporomandibular Disorder  

PubMed Central

The loss of anterior teeth leads to extreme psychological trauma, along with functional and esthetic debilitations. Healthy anterior teeth play an important role of protecting the posterior teeth during excursive mandibular movement. Loss of anterior teeth induces posterior interference with extended disocclusion time. Posterior disocclusion is critical to remove the harmful force on the teeth temporomandibular joint and eliminate muscle hypertonicity. Occlusal interference is considered as contributing factor to temporomandibular disorder (TMD) symptoms. Prosthesis design should eliminate deleterious tooth contacts. Establishing optimum anterior guidance is a key to establishing harmonious functional occlusion in addition to the correction of the esthetic and phonetic disabilities. This case report explains the steps involved in the rehabilitation of the TMD patient with loss of maxillary anterior teeth. PMID:24715993

Haralur, Satheesh B.; Saeed Al-Shahrani, Omar

2014-01-01

305

Tailored order: the mesocrystalline nature of sea urchin teeth.  

PubMed

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

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

2014-09-01

306

Bonding auto-polymerising acrylic resin to acrylic denture teeth.  

PubMed

This study investigated the effect of surface treatments on the shear bond strength of an auto-polymerising acrylic resin cured to acrylic denture teeth. The surface treatments included a combination of grit-blasting and/or wetting the surface with monomer. Samples were prepared and then stored in water prior to shear testing. The results indicated that the application of monomer to the surface prior to bonding did not influence the bond strength. Grit blasting was found to significantly increase the bond strength. PMID:19839190

Nagle, Susan; Ray, Noel J; Burke, Francis M; Gorman, Catherine M

2009-09-01

307

Teeth and numerology from zodiac signs. A correlative study.  

PubMed

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

Kudva, S; Bhat, A P

2000-01-01

308

Multidisciplinary approach to traumatized teeth: a case report.  

PubMed

Treatment of crown fractures often requires a multidisciplinary approach. In the anterior teeth, reestablishment of proper esthetics and function is quite important for the patient. However, crown-root fractures with fracture line below the gingival attachment or alveolar bone crest presents restorative difficulties. This case report presents a cervical tooth fracture that had been treated with minimal invasive approach with different disciplines. The tooth had endodontic treatment and a glass-fiber post, and a composite core was accomplished. Then, the tooth was extruded to the desired level with orthodontic forced eruption before definitive restoration. PMID:18557751

Yüzügüllü, Bulem; Polat, Omür; Ungör, Mete

2008-10-01

309

Considerations for ceramic inlays in posterior teeth: a review  

PubMed Central

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

Hopp, Christa D; Land, Martin F

2013-01-01

310

Modeling and optimization of permanent magnetic motors  

E-print Network

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

Pinkham, Andrew P

2008-01-01

311

Nonuniform radiation damage in permanent magnet quadrupoles.  

PubMed

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

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

2014-08-01

312

Nonuniform radiation damage in permanent magnet quadrupoles  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

313

Manufacture of large castings in permanent molds  

SciTech Connect

A new technological process has been introduced for manufacturing large cast-iron pulley blanks in permanent molds. The pulley casting weighs 137 kg and has a rim diameter of 650 mm. The permanent mold is split horizontally. Before pouring metal the mold is heated with a gas torch to a temperature of 200-250/sup 0/C and coated with a layer of thermal insulation material. The molten metal is poured at a temperature of 1280-1300/sup 0/C within a period of 40-50 seconds. The casting is held in the mold for 4-5 minutes. A simple pneumatic machine has been designed for ejecting the castings. The permanent mold, being made of cast iron, can be used for more than 500 castings. Introduction of the new technological process for casting pulleys in permanent molds has reduced the labor requirement by four times, eliminated rejections caused by using sand molds, and improved the working conditions.

Panin, V.I.; Baryshnikov, V.G.; Papandopoulo, A.N.

1983-01-01

314

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

SciTech Connect

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

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

1983-04-01

315

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

Microsoft Academic Search

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

Göran Sundqvist; David Figdor; Sten Persson; Ulf Sjögren

1998-01-01

316

Reduction of gear fillet stresses by using one-sided involute asymmetric teeth  

Microsoft Academic Search

For increasing the load carrying capacity of geared power transmissions several tooth designs alternative to the standard involute have been proposed. The use of non-involute teeth has a number of disadvantages and for this reason asymmetric involute-type teeth have been studied as a promising alternative. In this paper the idea of one-sided involute asymmetric spur gear teeth is introduced to

Th. Costopoulos; V. Spitas

2009-01-01

317

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

PubMed Central

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

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

2015-01-01

318

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

319

Sporadic hemiplegic migraine with permanent neurological deficits.  

PubMed

By definition, the neurologic impairments of hemiplegic migraine are reversible. However, a few cases of permanent neurologic deficits associated with hemiplegic migraine have been reported. Herein, we present the case of a patient with permanent impairments because of hemiplegic migraine despite normalization of associated brain magnetic resonance imaging abnormalities. Cases like these suggest the need to consider aggressive prophylactic therapy for patients with recurrent hemiplegic migraine attacks. PMID:24117121

Schwedt, Todd J; Zhou, Jiying; Dodick, David W

2014-01-01

320

Permanent magnet edge-field quadrupole  

DOEpatents

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

Tatchyn, Roman O. (Mountain View, CA)

1997-01-01

321

Permanent education in health: a review  

PubMed Central

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

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

2014-01-01

322

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

NASA Astrophysics Data System (ADS)

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

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

2011-03-01

323

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

PubMed Central

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

Pol, Chetan A; Gosavi, Suchitra R

2014-01-01

324

Original article Bovine respiratory syncytial virus  

E-print Network

Original article Bovine respiratory syncytial virus: first serological evidence in Uruguay Mauro; accepted 18 November 1999) Abstract ­ Bovine respiratory syncytial virus (BRSV) is a major cause of respiratory disease in calves resulting in a substantial economic loss for the cattle industry worldwide

Boyer, Edmond

325

Bovine Respiratory Disease Max Irsik DVM, MAB  

E-print Network

Bovine Respiratory Disease Max Irsik DVM, MAB Beef Cattle Extension Veterinarian University of Florida College of Veterinary Medicine Disease of the respiratory tract is a major problem for cattle that continues to cause serious economic losses for producers. Bovine respiratory disease (BRD) causes increased

Watson, Craig A.

326

Communication The monitoring of bovine pregnancies derived  

E-print Network

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

Paris-Sud XI, Université de

327

Bovine Cytomegaloviruses: Identification and Differential Properties  

Microsoft Academic Search

SUMMARY Biological properties and restriction enzyme patterns of the slowly replicating herpesviruses isolated from cattle affected with different diseases in North America and Europe were analysed. These virus isolates induced identical plaques that developed within 7 to 9 days in bovine foetal spleen cells and within 5 days in actively growing Georgia bovine kidney cells. These virus isolates were found

J. Storz; B. Ehlers; W. J. Todd; H. Ludwig

1984-01-01

328

Disinfection of immature teeth with a triple antibiotic paste.  

PubMed

This study assessed the efficacy of a triple antibiotic paste in the disinfection of immature dog teeth with apical periodontitis. The canals were sampled before (S1) and after (S2) irrigation with 1.25% NaOCL and after dressing with a triple antibiotic paste (S3), consisting of metronidazole, ciprofloxacin, and minocycline. At S1, 100% of the samples cultured positive for bacteria with a mean CFU count of 1.7 x 10. At S2, 10% of the samples cultured bacteria-free with a mean CFU count of 1.4 x 10. At S3, 70% of the samples cultured bacteria-free with a mean CFU count of only 26. Reductions in mean CFU counts between S1 and S2 (p < 0.0001) as well as between S2 and S3 (p < 0.0001) were statistically significant. These results indicate the effectiveness of a triple antibiotic paste in the disinfection of immature teeth with apical periodontitis. PMID:15917683

Windley, William; Teixeira, Fabricio; Levin, Linda; Sigurdsson, Asgeir; Trope, Martin

2005-06-01

329

Neanderthal teeth from Moula-Guercy, Ardèche, France.  

PubMed

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

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

2013-07-01

330

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

331

Socket preservation using bovine bone mineral and collagen membrane: a randomized controlled clinical trial with histologic analysis.  

PubMed

After tooth extraction, varying amounts of bone resorption occur because of qualitative and quantitative changes at the edentulous site of the alveolar process. The aims of this randomized controlled clinical trial were (1) to compare the postextraction changes in residual ridge dimensions during spontaneous healing with those during socket preservation, (2) to analyze the histologic and histomorphometric aspects of the grafted sockets, and (3) to compare probing procket depth (PPD) and clinical attachment level (CAL) changes at teeth adjacent to extraction sites. Forty-eight teeth were extracted from 41 patients referred for extraction of 1 or more maxillary or mandibular premolars or molars. The edentulous sites were randomly assigned to the control (EXT, extraction alone) or experimental groups (SP, extraction and socket preservation). In the SP group, the sockets were filled with bovine bone mineral and covered with porcine collagen membrane. At baseline and after 4 months, PPD, gingival recession (REC), and CAL were measured at teeth adjacent to the edentulous sites. The changes in ridge dimensions from baseline to 4 months were assessed on dental casts. At 4 months, bone was harvested from the grafted areas in the SP group and the edentulous areas in the EXT group. PPD, REC, and CAL were comparable between groups. However, from baseline to 4 months, the SP group showed significantly less reduction in ridge width (1.04 ± 1.08 mm vs 4.48 ± 0.65 mm, P < .001) and height (0.46 ± 0.46 mm vs 1.54 ± 0.33 mm, P < .001). Histologically, the grafted sockets exhibited various stages of bone maturation and formation without inflammatory responses. No significant difference in the mineralized and nonmineralized fractions was noted between the groups. Socket preservation using bovine bone mineral and porcine collagen membrane considerably limits the amount of horizontal and vertical bone resorption when compared with extraction alone. PMID:22577648

Cardaropoli, Daniele; Tamagnone, Lorenzo; Roffredo, Alessandro; Gaveglio, Lorena; Cardaropoli, Giuseppe

2012-08-01

332

Did the lateral enamel of Neandertal anterior teeth grow differently from that of modern humans?  

PubMed

The formation of lateral enamel in Neandertal anterior teeth has been the subject of recent studies. When compared to the anterior teeth of modern humans from diverse regions (Point Hope, Alaska; Newcastle upon Tyne, England; southern Africa), Neandertal anterior teeth appear to fall within the modern human range of variation for lateral enamel formation time. However, the lateral enamel growth curves of Neandertals are more linear than those of these modern human samples. Other researchers have found that the lateral enamel growth curves of Neandertals are more linear than those of Upper Paleolithic and Mesolithic modern humans as well. The statistical significance of this apparent difference between Neandertal and modern human lateral enamel growth curves is analyzed here. The more linear Neandertal enamel growth curves result from the smaller percentage of total perikymata located in the cervical halves of their teeth. The percentage of total perikymata in the cervical halves of teeth is therefore compared between the Neandertal sample (n=56 teeth) and each modern human population sample: Inuit (n=65 teeth), southern African (n=114 teeth), and northern European (n=115 teeth). There are 18 such comparisons (6 tooth types, Neandertals vs. each of the three modern human populations). Eighteen additional comparisons are made among the modern human population samples. Statistically significant differences are found for 16 of the 18 Neandertal vs. modern human comparisons but for only two of the 18 modern human comparisons. Statistical analyses repeated for subsamples of less worn teeth show a similar pattern. Because surface curvature is thought to affect perikymata spacing, we also conducted measurements to assess surface curvature in thirty teeth. Our analysis shows that surface curvature is not a factor in this lateral enamel growth difference between Neandertals and modern humans. PMID:16965802

Guatelli-Steinberg, Debbie; Reid, Donald J; Bishop, Thomas A

2007-01-01

333

Adipogenesis of bovine perimuscular preadipocytes  

SciTech Connect

In this study, non-transformed progeny adipofibroblasts, derived from mature adipocyte dedifferentiation, was used as a novel in vitro model to study adipogenic gene expression in cattle. Adipofibroblasts from dedifferentiated mature perimuscular fat (PMF) tissue were cultured with differentiation stimulants until the cells exhibited morphological differentiation. Treated cells were harvested from day 2 to 16 for RNA extraction, whereas control cells were cultured without addition of stimulants. Results from time course gene expression assays by quantitative real-time PCR revealed that peroxisome proliferator-activated receptor gamma (PPAR-{gamma}), sterol regulatory element binding protein 1 (SREBP-1) and their six down-stream genes were co-expressed at day 2 post-differentiation induction. When compared to other adipogenesis culture systems, the adipogenic gene expression of bovine PMF adipofibroblasts culture was different, especially to the rodent model. Collectively, these results demonstrated PPAR-{gamma} and SREBP-1 cooperatively play a key role to regulate the re-differentiation of bovine adipofibroblasts, during early conversion stages in vitro.

Taniguchi, Masaaki; Le Luo Guan; Zhang Bing [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada); Dodson, Michael V. [Department of Animal Sciences, Washington State University, P.O. Box 646310, Pullman, WA 99164 (United States); Okine, Erasmus [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada); Moore, Stephen S. [Department of Agricultural, Food and Nutritional Science, University of Alberta, 410 Ag-For Centre, Edmonton, Alta., T6G 2P5 (Canada)], E-mail: Stephen.moore@ualberta.ca

2008-02-01

334

Live vaccines against bovine babesiosis.  

PubMed

Bovine babesiosis is an important tick-borne disease caused by Babesia bovis, B. bigemina and B. divergens. The first steps taken in the development of an effective vaccination strategy against bovine babesiosis followed the observations that animals, recovered from natural infection with Babesia were strongly protected against subsequent challenge. Further investigation indicated that the use of donor blood from recovered animals to infect recipient animals did not produce the severe form of the disease. The past century has seen a refinement of this original carrier-donor system to one using attenuated less virulent strains with standardized doses of known parasite concentration to ensure reliability. With the implementation of good manufacturing practices further changes were necessary in the production of these vaccines, such as freezing for long-term storage to allow sufficient time for pre-release safety and effectivity testing. Regardless of these improvements the vaccines are not without problems and breakdowns and breakthroughs occur from time to time. Despite considerable research efforts into the development of alternative more consumer friendly vaccines, none is immediately forthcoming and the live attenuated babesiosis vaccines are still used in many countries. PMID:16504404

de Waal, D T; Combrink, M P

2006-05-31

335

A Conservative Bioadhesive Approach to the Reattachment of Complicated Crown Fractures in Permanent First Molars: A Case Report with a 2-Year Followup  

PubMed Central

This paper presents a clinical report demonstrating combined restorative bioadhesive treatment and prosthetic rehabilitation of uncommon type of dental injury in an eighteen-year-old female involving crown fracture of all the permanent first molars and left upper premolars due to a bicycle riding accident. To restore the coronal fracture with invasion of biologic width, flap surgery with osteotomy and osteoplasty localized on the fractured teeth was performed, and the tooth remnant was reattached to the crown with a self-etch adhesive system. Frank pulp exposure was treated by self-etch dentin adhesive after surface disinfection prior to sealing of the wound site. At 2-year recall, the teeth continue to be aesthetically and functionally stable with a favourable pulpal and periapical environment. PMID:22431928

Mirikar, Pragati

2012-01-01

336

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

337

Erosion by Soft Drinks of Rat Molar Teeth Assessed by Digital Image Analysis  

Microsoft Academic Search

A digital imaging analysis (DIA) procedure for recording and assessing erosive changes on teeth was developed and evaluated against an older subjective method. Results after exposure of rats’ teeth to various soft drinks showed that the DIA system was superior to the conventional method, with improved precision. The system provided a direct and highly sensitive means of quantifying the erosion

M. Mistry; T. H. Grenby

1993-01-01

338

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

Microsoft Academic Search

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

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

2009-01-01

339

Quaternary International 164165 (2007) 139150 Stable isotope compositions of mammoth teeth from Niederweningen,  

E-print Network

, evolving over several stages from Mammuthus meridionalis, Mammuthus trogontherii to the woolly mammothQuaternary International 164­165 (2007) 139­150 Stable isotope compositions of mammoth teeth from Oxygen and carbon isotope compositions of well-preserved mammoth teeth from the Middle Wu¨ rmian (40

Schöne, Bernd R.

340

IMPACT DYNAMIC BEHAVIOUR OF MESHING LOADED TEETH IN TRANSMISSION DRIVE RATTLE  

Microsoft Academic Search

The paper describes a model of impact dynamics of meshing gear teeth-pairs under medium to heavy loads and in presence of backlash. The model incorporates classical Hertzian impact, governed by instantaneous geometry of the contact and the prevailing kinematics of contiguous surfaces for pairs of helical teeth. It also includes the effect of flank friction, contributed by a combination of

H. Rahnejat; S. Theodossiades; P. Kelly

341

Comparative study of experimentally induced and post-mortem pink teeth.  

PubMed

Forty-eight pink teeth from eight male cadavers, all dying from unnatural causes were studied for the pink tooth phenomenon. Perfusion with whole and lysed blood, at different temperatures was carried out, followed by longitudinal sectioning for histological observation. Another 30 unblemished human teeth were used to reproduce the phenomenon in vitro to help clarify its pathogenesis. PMID:9227078

de Almeida, C A; Daruge, E; Daruge, E; el-Guindy, M

1996-12-01

342

The effect of retention grooves in acrylic resin teeth on tooth denture-base bond.  

PubMed

A progressive shear compressive load was applied at an angle to the lingual surface of acrylic resin teeth bonded to denture base acrylic resin. No statistically significant advantage was derived by preparing retention grooves of different shapes in the ridge lap surface of the denture teeth. PMID:3514898

Cardash, H S; Liberman, R; Helft, M

1986-04-01

343

Characteristic Examination of New Synchronous Motor that Composes Craw Teeth of Soft Magnetic Composite  

Microsoft Academic Search

We examined the claw type teeth motor as one application of the soft magnetic composite to a motor core. In order to understand quantitatively the characteristics of the claw type teeth motor, we used the 3-dimensional electromagnetic field analysis to predict its characteristics in advance and manufactured a trial motor to estimate it. And we examined the advantages of the

Yuji Enomoto; Motoya Ito; Ryozo Masaki; Kazuo Asaka

2006-01-01

344

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

PubMed

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

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

2005-08-01

345

Influence of calcium hydroxide intracanal dressings on the prognosis of teeth with endodontically induced periapical lesions  

Microsoft Academic Search

Weiger R, Rosendahl R, Los t C. Influence of calcium hydroxide intracanal dressings on the prognosis of teeth with endodontically induced periapical lesions. International Endodontic Journal, 33, 219-226, 2000. Aim This prospective clinical study explored the influence of calcium hydroxide as an interappointment dressing on the healing of periapical lesions associated with pulpless teeth that had not been endodontically treated

R. Weiger; R. Rosendahl; C. Lost

2000-01-01

346

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

Microsoft Academic Search

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

Naoko Kubo; Kazuhiro Jo; Ken Matsunaga

2001-01-01

347

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

PubMed

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

Venkataraghavan, Karthik; Chan, John; Karthik, Sandhya

2014-01-01

348

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

PubMed

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

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

2012-09-01

349

Finding an alternative to formalin for sterilization of extracted teeth for teaching purposes.  

PubMed

Formalin is a known carcinogen, so there is a need to establish whether a safer alternative is available for the sterilization of human teeth destined for use in clinical training. Any disinfectant that is not capable of sterilizing 100 percent of the samples tested should be considered a failure. In this study, biofilms of oral bacteria were grown on previously autoclaved extracted human teeth. These biofilm-laden teeth were then screened against a range of disinfectants for an exposure time of seven days in a laboratory refrigerator. Culture methods were employed to validate the sterility of the tooth samples. Five percent Virkon and Gigasept PA proved effective against the laboratory model of disinfection and were carried forward to challenge freshly extracted human teeth. Gigasept PA was the only disinfectant that sterilized 100 percent of the tooth samples. Gigasept PA should be considered a safer and effective alternative to formalin for the sterilization of extracted teeth destined for teaching purposes. PMID:23314468

Hope, Christopher K; Griffiths, David A; Prior, Daniel M

2013-01-01

350

High-resolution ZTE imaging of human teeth.  

PubMed

MRI with zero echo time (ZTE) is achieved by 3D radial centre-out encoding and hard-pulse RF excitation while the projection gradient is already on. Targeting short-T(2) samples, the efficient, robust and silent ZTE approach was implemented for high-bandwidth high-resolution imaging requiring particularly rapid transmit-receive switching and algebraic image reconstruction. The ZTE technique was applied to image extracted human teeth at 11.7T field strength, yielding detailed depictions with very good delineation of the mineralised dentine and enamel layers. ZTE results are compared with UTE (ultra-short echo time) MRI and micro-computed tomography (?CT), revealing significant differences in SNR and CNR yields. Compared to ?CT, ZTE MRI appears to be less susceptible to artefacts caused by dental fillings and to offer superior sensitivity for the detection of early demineralisation and caries lesions. PMID:22290744

Weiger, Markus; Pruessmann, Klaas P; Bracher, Anna-Katinka; Köhler, Sascha; Lehmann, Volker; Wolfram, Uwe; Hennel, Franciszek; Rasche, Volker

2012-10-01

351

Apatite mineralization in teeth of the chiton Acanthopleura echinata.  

PubMed

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

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

2000-11-01

352

Endodontic treatment of fused teeth with talon cusp.  

PubMed

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

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

2014-01-01

353

Contact stresses in gear teeth: A new method of analysis  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

354

A new procedure for calculating contact stresses in gear teeth  

NASA Technical Reports Server (NTRS)

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

Somprakit, Paisan; Huston, Ronald L.

1991-01-01

355

Esthetic Rehabilitation of Anterior Teeth with Laminates Composite Veneers  

PubMed Central

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

Riva, Giancarlo

2014-01-01

356

Endodontic Treatment of Fused Teeth with Talon Cusp  

PubMed Central

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

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

2014-01-01

357

Newly recognized Pleistocene human teeth from Tabun Cave, Israel.  

PubMed

Seven human teeth from Tabun Cave, Israel, curated at the Natural History Museum London since 1955, are of uncertain provenance and identity. They are all from the upper dentition, without duplications, and are characterized by a similar preservation. The Catalogue of Fossil Hominids (1975) suggested that they might have derived from Tabun Layer A (Bronze Age to Recent). However, one of us (AC) noted some distinctive features of these teeth that warranted further study. They are here assigned to a single individual, Tabun BC7. Their morphology and metrics were then compared with the frequency of Late Pleistocene and Early Holocene groups from Europe, North Africa and Middle East. A fragment of the right M3 crown of Tabun BC7 was removed for ESR and U-analysis, and it was determined that only samples from Layer B have similar dose values. Using the sediment dose values of layer B, preliminary age estimates of 82 +/- 14 ka (early U-uptake) and 92+/-18 ka (linear uptake) were obtained. U-series disequilibrium determined from other samples attributed to Layer B resulted in a U-uptake history close to linear uptake, giving a very comparable age estimate of 90(+30)(-16) ka. The dose value previously obtained on an enamel fragment from the Tabun C1 dentition is nearly double the value measured for BC7, and tentative age estimates for C1 were in the range of 143+/-37 ka. However, due to uncertainties in the exact provenance of the human fossils, we cannot confirm that C1 is older than the new tooth sampled here, and both C1 and BC7 can be attributed to Layer B on chronological grounds. On the basis of chronology, dental morphology and metrics, the specimen named Tabun BC7 was identified as a probable Neanderthal. PMID:15964608

Coppa, Alfredo; Grün, Rainer; Stringer, Chris; Eggins, Stephen; Vargiu, Rita

2005-09-01

358

X-linked hypophosphatemia: the mutant gene is expressed in teeth as well as in kidney.  

PubMed Central

Mutation at a locus (HPDR) on the X chromosome (McKusick 30780 [HPDR1]; 30781 [HPDR2]) causes impaired renal phosphate transport, hypophosphatemia, and an associated impairment in the process of mineralization in bone and teeth (X-linked hypophosphatemia [XLH]). We measured the dental pulp profile area (PRATIO [= pulp area/tooth area]) and serum phosphorus (Pi) values in uniformly treated XLH patients (six males, 81 teeth, 1,457 Pi values; 11 females, 129 teeth, 1,439 Pi values). Serum Pi values, reflecting the metabolic environment of tooth development, were obtained by repeated measurement between 1 mo and 26 years of age during treatment. PRATIO values calculated from standardized Rinn radiographs were used as outcome measurements of tooth development in XLH patients and in age-matched controls (12 males, 100 teeth; 27 females, 275 teeth). Age-dependent serum Pi values were not different in the treated XLH males and females. In teeth forming primary dentin there was no gene dosage effect on PRATIO values apparent in subjects below 15 years of age. However, in teeth forming secondary dentin a gene dosage was found in the subjects aged 15 to 25 years: XLH male teeth (n = 65) mean +/- SD = 0.163 +/- 0.046; XLH female teeth (n = 75) mean +/- SD = 0.137 +/- 0.039; control teeth (n = 209) mean +/- SD = 0.116 +/- 0.023; (higher PRATIO values mean less development or mineralization of secondary dentin); differences in these PRATIO values (males vs. female and XLH vs. control) were significant by mixed-model analysis of variance.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2155529

Shields, E D; Scriver, C R; Reade, T; Fujiwara, T M; Morgan, K; Ciampi, A; Schwartz, S

1990-01-01

359

Bovine calves as ideal bio-indicators for fluoridated drinking water and endemic osteo-dental fluorosis.  

PubMed

Relative susceptibility to fluoride (F) toxicosis in the form of osteo-dental fluorosis was observed in an observational survey of 2,747 mature and 887 immature domestic animals of diverse species living in areas with naturally fluoridated (>1.5 ppm F) drinking water. These animals included buffaloes (Bubalus bubalis), cattle (Bos taurus), camels (Camelus dromedarius), donkeys (Equus asinus), horses (Equus caballus), goats (Capra hircus), and sheep (Ovis aries). Of these mature and immature animals, 899 (32.7 %) and 322 (36.3 %) showed evidence of dental fluorosis with varying grades, respectively. Their incisor teeth were stained with light to deep brownish color. On clinical examination, 31.2 % mature and 10.7 % immature animals revealed periosteal exostoses, intermittent lameness, and stiffness of tendons in the legs as signs of skeletal fluorosis. The maximum susceptibility to fluoride toxicosis was found in bovines (buffaloes and cattle) followed by equines (donkeys and horses), flocks (goats and sheep), and camelids (camels). The bovine calves were found to be more sensitive and highly susceptible to F toxicosis and revealed the maximum prevalence (92.2 %) of dental fluorosis. This indicates that bovine calves are less tolerant and give early sign of F poisoning (dental fluorosis) and therefore, they can be considered as bio-indicators for fluoridated water as well as for endemicity of osteo-dental fluorosis. Causes for variation in susceptibility to F toxicosis (fluorosis) in various species of domestic animal are also discussed. PMID:24671615

Choubisa, S L

2014-07-01

360

Bovine Mastitis: Frontiers in Immunogenetics  

PubMed Central

Mastitis is one of the most prevalent and costly diseases in the dairy industry with losses attributable to reduced milk production, discarded milk, early culling, veterinary services, and labor costs. Typically, mastitis is an inflammation of the mammary gland most often, but not limited to, bacterial infection, and is characterized by the movement of leukocytes and serum proteins from the blood to the site of infection. It contributes to compromised milk quality and the potential spread of antimicrobial resistance if antibiotic treatment is not astutely applied. Despite the implementation of management practises and genetic selection approaches, bovine mastitis control continues to be inadequate. However, some novel genetic strategies have recently been demonstrated to reduce mastitis incidence by taking advantage of a cow’s natural ability to make appropriate immune responses against invading pathogens. Specifically, dairy cattle with enhanced and balanced immune responses have a lower occurrence of disease, including mastitis, and they can be identified and selected for using the high immune response (HIR) technology. Enhanced immune responsiveness is also associated with improved response to vaccination, increased milk, and colostrum quality. Since immunity is an important fitness trait, beneficial associations with longevity and reproduction are also often noted. This review highlights the genetic regulation of the bovine immune system and its vital contributions to disease resistance. Genetic selection approaches currently used in the dairy industry to reduce the incidence of disease are reviewed, including the HIR technology, genomics to improve disease resistance or immune response, as well as the Immunity+™ sire line. Improving the overall immune responsiveness of cattle is expected to provide superior disease resistance, increasing animal welfare and food quality while maintaining favorable production levels to feed a growing population. PMID:25339959

Thompson-Crispi, Kathleen; Atalla, Heba; Miglior, Filippo; Mallard, Bonnie A.

2014-01-01

361

Bovine mastitis: frontiers in immunogenetics.  

PubMed

Mastitis is one of the most prevalent and costly diseases in the dairy industry with losses attributable to reduced milk production, discarded milk, early culling, veterinary services, and labor costs. Typically, mastitis is an inflammation of the mammary gland most often, but not limited to, bacterial infection, and is characterized by the movement of leukocytes and serum proteins from the blood to the site of infection. It contributes to compromised milk quality and the potential spread of antimicrobial resistance if antibiotic treatment is not astutely applied. Despite the implementation of management practises and genetic selection approaches, bovine mastitis control continues to be inadequate. However, some novel genetic strategies have recently been demonstrated to reduce mastitis incidence by taking advantage of a cow's natural ability to make appropriate immune responses against invading pathogens. Specifically, dairy cattle with enhanced and balanced immune responses have a lower occurrence of disease, including mastitis, and they can be identified and selected for using the high immune response (HIR) technology. Enhanced immune responsiveness is also associated with improved response to vaccination, increased milk, and colostrum quality. Since immunity is an important fitness trait, beneficial associations with longevity and reproduction are also often noted. This review highlights the genetic regulation of the bovine immune system and its vital contributions to disease resistance. Genetic selection approaches currently used in the dairy industry to reduce the incidence of disease are reviewed, including the HIR technology, genomics to improve disease resistance or immune response, as well as the Immunity(+)™ sire line. Improving the overall immune responsiveness of cattle is expected to provide superior disease resistance, increasing animal welfare and food quality while maintaining favorable production levels to feed a growing population. PMID:25339959

Thompson-Crispi, Kathleen; Atalla, Heba; Miglior, Filippo; Mallard, Bonnie A

2014-01-01

362

The epidemiology of bovine dermatophilosis in Zambia  

Microsoft Academic Search

Bovine dermatophilosis (Senkobo disease) has been reported annually in Zambia for many years. However, its epidemiology under Zambian conditions had never been adequately studied. Officially the disease has never been recognized as being of any economic consequence.

K. L. Samui; M. E. Hugh-Jones

1990-01-01

363

Processed bovine dentine as a bone substitute  

Microsoft Academic Search

ObjectivesDifferent forms of allogenic dentine have been studied for their potential use as bone substitutes. We report a new method for processing bovine dentine that results in a sterile bioactive material for repair and regeneration of bone.

Keyvan Moharamzadeh; Christine Freeman; Keith Blackwood

2008-01-01

364

Spectroscopic study of gamma irradiated bovine hemoglobin  

NASA Astrophysics Data System (ADS)

In the present study, the effects of ionizing radiation of Cs-137 and Co-60 from 4.95 to 743.14 Gy and from 40 Gy to 300 kGy, respectively, on some bovine hemoglobin characteristics were studied. Such an effect was evaluated using electron paramagnetic resonance (EPR) spectroscopy, and infra-red (IR) spectroscopy. Bovine hemoglobin EPR spectra were recorded and analyzed before and after irradiation and changes were explained in detail. IR spectra of unirradiated and irradiated Bovine hemoglobin were recorded and analyzed also. It was found that ionizing radiation may lead to the increase of free radicals production, the decrease in ?-helices contents, which reflects the degradation of hemoglobin molecular structure, or at least its incomplete performance. Results also show that the combined application of EPR and FTIR spectroscopy is a powerful tool for determining structural modification of bovine hemoglobin samples exposed to gamma irradiation.

Maghraby, Ahmed Mohamed; Ali, Maha Anwar

2007-10-01

365

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

E-print Network

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

Paris-Sud XI, Université de

366

A Correlation of Permanent Anterior Tooth Fracture with Type of Occlusion and Craniofacial Morphology  

PubMed Central

ABSTRACT Aims: To assess the relationship of anterior tooth fractures with type of occlusion and craniofacial morphology. Materials and methods: The study was conducted on 76 subjects of age group 9 to 13 years with at least one fractured permanent anterior teeth. Lateral cephalograms were taken and study models were prepared for each subject with prior consent of their parents. Then cephalometric tracings were done and overjet was recorded through study models. Statistical analysis used: Standard error of mean (SEM) and unpaired t-test has been applied to test the significant difference between the seven parameters under consideration. Karl Pearson correlation test has also been used to correlate all the parameters used in this study with each other. All the tests were performed at 5 and 1% levels of significance. Results: Frequency of tooth fracture increases with increasing overjet. At 5% level of significance, significant difference were observed between the standard values and observed values for overjet measurement, SNA angle, SNB angle, ANB angle, upper incisor to NA (angle), upper incisor to NA (linear) and interincisal angle for overall data and also for both male and female data separately. Conclusion: Probability of permanent anterior tooth fracture increases with increasing overjet. A significant difference was observed between the standard value and the observed values of all parameters under consideration. How to cite this article: Chaturvedi R, Kumar A, Rana V, Aggarwal A, Chandra L. A Correlation of Permanent Anterior Tooth Fracture with Type of Occlusion and Craniofacial Morphology. Int J Clin Pediatr Dent 2013;6(2):80-84. PMID:25206197

Kumar, Ashish; Rana, Vivek; Aggarwal, Abhai; Chandra, Lokesh

2013-01-01

367

PROCEDURE FOR ESTIMATING PERMANENT TOTAL ENCLOSURE COSTS  

EPA Science Inventory

The paper discusses a procedure for estimating permanent total enclosure (PTE) costs. (NOTE: Industries that use add-on control devices must adequately capture emissions before delivering them to the control device. One way to capture emissions is to use PTEs, enclosures that mee...

368

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

369

A Permanent Agenda for Science Teachers  

NSDL National Science Digital Library

It may seem a singular act of arrogance for us to suggest that a permanent agenda for science teaching exists. Trends come and go, and veteran professionals have seen the recurrence of familiar ideas. But the persistence of learning as a motivating force

Lynn W. Glass

2000-01-01

370

Permanent embryo arrest: molecular and cellular concepts  

PubMed Central

Developmental arrest is one of the mechanisms responsible for the elevated levels of embryo demise during the first week of in vitro development. Approximately 10–15% of IVF embryos permanently arrest in mitosis at the 2- to 4-cell cleavage stage showing no indication of apoptosis. Reactive oxygen species (ROS) are implicated in this process and must be controlled in order to optimize embryo production. A stress sensor that can provide a key understanding of permanent cell cycle arrest and link ROS with cellular signaling pathway(s) is p66Shc, an adaptor protein for apoptotic-response to oxidative stress. Deletion of the p66Shc gene in mice results in extended lifespan, which is linked to their enhanced resistance to oxidative stress and reduced levels of apoptosis. p66Shc has been shown to generate mitochondrial H2O2 to trigger apoptosis, but may also serve as an integration point for many signaling pathways that affect mitochondrial function. We have detected elevated levels of p66Shc and ROS within arrested embryos and believe that p66Shc plays a central role in regulating permanent embryo arrest. In this paper, we review the cellular and molecular aspects of permanent embryo arrest and speculate on the mechanism(s) and etiology of this method of embryo demise. PMID:18511487

Betts, D.H.; Madan, P.

2008-01-01

371

22 CFR 401.3 - Permanent offices.  

Code of Federal Regulations, 2010 CFR

...The permanent offices of the Commission shall be at Washington, in the District of Columbia, and at Ottawa, in the Province of Ontario, and, subject to the directions of the respective chairmen acting for their respective sections, the secretaries of the...

2010-04-01

372

22 CFR 401.3 - Permanent offices.  

Code of Federal Regulations, 2013 CFR

...The permanent offices of the Commission shall be at Washington, in the District of Columbia, and at Ottawa, in the Province of Ontario, and, subject to the directions of the respective chairmen acting for their respective sections, the secretaries of the...

2013-04-01

373

22 CFR 401.3 - Permanent offices.  

Code of Federal Regulations, 2012 CFR

...The permanent offices of the Commission shall be at Washington, in the District of Columbia, and at Ottawa, in the Province of Ontario, and, subject to the directions of the respective chairmen acting for their respective sections, the secretaries of the...

2012-04-01

374

22 CFR 401.3 - Permanent offices.  

Code of Federal Regulations, 2011 CFR

...The permanent offices of the Commission shall be at Washington, in the District of Columbia, and at Ottawa, in the Province of Ontario, and, subject to the directions of the respective chairmen acting for their respective sections, the secretaries of the...

2011-04-01

375

22 CFR 401.3 - Permanent offices.  

...The permanent offices of the Commission shall be at Washington, in the District of Columbia, and at Ottawa, in the Province of Ontario, and, subject to the directions of the respective chairmen acting for their respective sections, the secretaries of the...

2014-04-01

376

Performance improvement of permanent magnet ac motors  

E-print Network

) (Member) Reza Langari Chanan Singh (Member) (Head of Department) May 2005 Major Subject: Electrical Engineering iii ABSTRACT Performance Improvement of Permanent Magnet AC... and willingness to spend his precious time with me are beyond my appreciation. I express my sincere gratitude to the members of my graduate study committee: Prof. Shankar Bhattacharyya, Prof. Mehrdad Ehsani, and Prof. Reza Langari for taking the time...

Parsa, Leila

2005-08-29

377

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

378

Permanent magnet motor magnetizing and calibrating  

Microsoft Academic Search

The types of magnetizing equipment that are available include capacitive discharge, half-cycle and electromagnet units. The applications for, and limitations of, each type of unit are briefly reviewed. The range of permanent magnet materials commercially available. In designing an effective magnetizing and calibrating system, consideration must be given not only to the magnetizer to be used, but also to the

J. W. Aydelotte

1993-01-01

379

Multiscale Orientation and Recognition for Permanent Scatterers  

Microsoft Academic Search

How to effectively detect and identify permanent scatterers (PS) from SAR images is one of the crucial procedures in PS interferometric system. In this paper, a new method of PS detection is presented by using the wavelet multi-scale product and wavelet modulus maxima according to the PS targets' features and the characteristics of speckle noise in SAR image. This paper

Guan Zequn; Bai Junwu

2009-01-01

380

ENUMERATING CONTINGENCY TABLES VIA RANDOM PERMANENTS  

E-print Network

ENUMERATING CONTINGENCY TABLES VIA RANDOM PERMANENTS Alexander Barvinok March 2006 Abstract. Given sums r1, . . . , rm and the column sums c1, . . . , cn is called a contingency table with the margins R = (r1, . . . , rm) and C = (c1, . . . , cn). The problem of efficient enumeration of contingency tables

Barvinok, Alexander

381

Removal of a Permanent IVC Filter  

SciTech Connect

Inferior vena cava (IVC) filters are increasingly used for prevention of life-threatening pulmonary emboli in patients who have contraindications to anticoagulation therapy. We report a case of the removal of a permanent IVC filter, which was inadvertently inserted due to an incorrect ultrasound report.

Kumar, Bangalore C. Anil [Queen's Medical Centre, Department of Radiology (United Kingdom)], E-mail: anil.kumar@doctors.org.uk; Chakraverty, Sam; Zealley, Ian [Ninewells Hospital, Department of Radiology (United Kingdom)

2006-02-15

382

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

383

Permanent isolation surface barrier development plan  

SciTech Connect

The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no {open_quotes}proven{close_quotes} long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems.

Wing, N.R.

1994-01-01

384

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

PubMed Central

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

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

2012-01-01

385

Diagnostic tools used to predict the prevalence of supernumerary teeth: a meta-analysis  

PubMed Central

Objectives This study sought to (i) determine the variations in prevalence figures based on the diagnostic tools employed, and (ii) provide an insight into the prevalence of supernumerary teeth. Methods A comprehensive literature search of the prevalence reports on supernumerary teeth was conducted using two databases. Two independent observers rated these articles according to exclusion and inclusion criteria. 28 papers were included in the analysis to determine the variations in the prevalence figures in relation to the method of diagnosis, and 14 studies were included to estimate the prevalence figures for supernumerary teeth. Statistical analysis was computed using analysis of variance (ANOVA), Student Neumann–Keuls (SNK) test and multiple regression analysis. Results Statistically significant differences were evident in the prevalence figures based only on a clinical examination compared with groups that also employed radiographs (p < 0.05, ANOVA, SNK). The prevalence figures for supernumerary teeth ranged from 0% to 3%. The mean prevalence value for the European white population [1.6% (±0.6)] was lower than that of the southern Chinese population [2.7% (±0.14)]. The overall prevalence of supernumerary teeth for males was significantly higher than for females [relative risk = 1.37 (1.13–1.50)]. Conclusions Clinical examination plus some types of radiograph(s) are essential for determining the prevalence of supernumerary teeth; nevertheless, it is still underestimated. Several disparities in the prevalence reports make the available data on supernumerary teeth questionable. PMID:22752325

Anthonappa, RP; King, NM; Rabie, ABM

2012-01-01

386

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

PubMed Central

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

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

2013-01-01

387

Vinegar as a disinfectant of extracted human teeth for dental educational use  

PubMed Central

Context: Extracted human teeth are routinely used in dentistry to learn technical and preclinical skills. Centers for Disease Control and Prevention (CDC) has adopted guidelines for infection control of extracted teeth used for research and teaching, requiring that teeth be sterilized before use. Many of the proposed disinfection methods starting from use of formalin, sodium hypochlorite and to autoclaving have their own drawbacks and may not be practical. Aim: To assess the effectiveness of vinegar for disinfection/sterilization of extracted human teeth. Materials and Methods: A total of 80 extracted non-carious human teeth were kept in seven disinfectant media—10% formalin, 3% hydrogen peroxide, 5.25% sodium hypochlorite, 70% alcohol, vinegar, neem extract and normal saline. Ten samples were placed in each disinfectant individually for a period of 7 days, at room temperature. In all, 10 teeth were treated with microwave irradiation at 650 W for 3 min. Later, teeth from each group were placed individually in separate test tubes containing 10 ml of tryptic soy broth at 37°C for 48 h to observe the evidence of growth of microorganisms. Semiquantitative analysis of all the samples was done in Clade agar at 37°C for 48 h. Statistical Analysis Used: The number of teeth disinfected in each group was compared using Chi square test. Results: 10% formalin, 3% hydrogen peroxide and vinegar were totally effective. The result was statistically significant with a Chi square value of 61.414 and P < 0.001. Conclusions: Vinegar can be used as an effective disinfectant medium for extracted human teeth. PMID:24959031

Tijare, Manisha; Smitha, D; Kasetty, Sowmya; Kallianpur, Shreenivas; Gupta, Sandeep; Amith, HV

2014-01-01

388

Environmental influences on the trace element content of teeth--implications for disease and nutritional status.  

PubMed

The aim of this study was to compare the trace element content of children's primary teeth from Uganda and the UK. The Ugandan teeth were from children living in an area where endomyocardial fibrosis (EMF), a cardiac disease, is prevalent. The latter has been putatively linked to insufficient magnesium intake and excess cerium exposure. Primary teeth were collected from 21 Ugandan and 27 UK children. The crowns and roots of the teeth were separated and the former digested and analysed for several major and trace elements by inductively coupled plasma mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). In addition, the enamel and dentine of eight UK and seven Ugandan primary teeth were isolated via density separation and analysed as above. The data were assessed using non-parametric statistical tests. The Ugandan teeth contained significantly (P < 0.05) greater concentrations of strontium, barium, cerium, lanthanum, praseodymium and significantly less zinc than the UK teeth. No significant difference in the concentrations of aluminium, calcium, copper, magnesium, lead and uranium were found. Analysis of enamel and dentine demonstrated that the former was enriched with several elements including cerium. It is concluded, that the environment, influences the trace element content of primary teeth and this may be useful for monitoring nutritional status. With respect to a geochemical cause for EMF, there is no positive evidence that EMF in Uganda is associated with reduced magnesium and increased cerium uptake in primary teeth. This does not, however, exclude cerium from playing a role in the aetiology of EMF. PMID:15275858

Brown, Catriona J; Chenery, Simon R N; Smith, Barry; Mason, Carol; Tomkins, Andrew; Roberts, Graham J; Sserunjogi, Louise; Tiberindwa, John V

2004-09-01

389

Detection of bovine milk proteins in soymilk by Western blotting.  

PubMed

A Western blotting method for the detection of whey milk proteins in commercial soymilks was applied to assess the food safety. Soy proteins and milk proteins were separated by SDS-PAGE in PhastSystem equipment. After the electrophoretic separation, immunodetection with anti-bovine alpha-lactalbumin and anti-bovine beta-lactoglobulin antisera was performed. Adulteration with bovine protein in percentages of 0.1% in soy protein can be detected. Western blotting of bovine alpha-lactalbumin and bovine beta-lactoglobulin was applied to detect adulteration by bovine milk proteins in different soymilks: powdered soymilk and soy infant formulas. PMID:9874352

Molina, E; Amigo, L; Ramos, M

1998-12-01

390

Biologic Restoration: A Treatment Option for Reconstruction of Anterior Teeth  

PubMed Central

Several procedures are advised to manage fractured anterior tooth structure using acrylic resin, composite restoration, ceramic or metal crown with ceramic facing. Biologic restoration is a procedure to restore fractured tooth structure with natural tooth material. In this in vitro case we have made an attempt for aesthetic rehabilitation of maxillary central incisor with similar biologic crown taken form extracted maxillary central incisor. It was observed that biologic restoration is an aesthetic, economical, fast and functional procedure which can be used as an alternative method to restore fractured primary or permanent anteriors. PMID:25584332

Khanna, Priyanka; S, Shankar; Chaurasia, Vishwajit Rampratap; Masamatti, Vinaykumar S

2014-01-01

391

Don Quixote's countenance before and after losing his teeth.  

PubMed

The authors of this paper wish to draw attention to certain not-so-well-known aspects concerning the epithet "Knight of the Woeful Countenance", by which Cervantes' character Don Quixote is universally known. Cervantes used it to highlight the loss of his hero's molars and incisors; thus, the reduced vertical dimension of his face, along with his sagging cheeks and deepened facial furrows, was the reason for his permanently sorrowful countenance. Luis Martínez, a professional illustrator following instructions from the authors of this paper, has recreated the face of Don Quixote as Miguel de Cervantes may well have imagined it for his celebrated character. PMID:19278979

del Valle, A; Romero, M

2009-02-01

392

Contact stresses in meshing spur gear teeth: Use of an incremental finite element procedure  

NASA Technical Reports Server (NTRS)

Contact stresses in meshing spur gear teeth are examined. The analysis is based upon an incremental finite element procedure that simultaneously determines the stresses in the contact region between the meshing teeth. The teeth themselves are modeled by two dimensional plain strain elements. Friction effects are included, with the friction forces assumed to obey Coulomb's law. The analysis assumes that the displacements are small and that the tooth materials are linearly elastic. The analysis procedure is validated by comparing its results with those for the classical two contacting semicylinders obtained from the Hertz method. Agreement is excellent.

Hsieh, Chih-Ming; Huston, Ronald L.; Oswald, Fred B.

1992-01-01

393

Replantation of immature avulsed teeth with prolonged extraoral dry storage: a case report.  

PubMed

This case report presents delayed replantation of avulsed teeth after extended extraoral period and nonphysiological storage. Yet, long-term prognosis is not good, it presents alternate treatment modality to immediately restore esthetic and function as well as to promote the growth of alveolar crest for proper eruption of adjacent unaffected teeth until a definite prosthetic treatment seems appropriate. How to cite this article: Jain S, Agarwal V, Gupta AK, Prabhakar P. Replantation of Immature Avulsed Teeth with Prolonged Extraoral Dry Storage: A Case Report. Int J Clin Pediatr Dent 2012;5(1):68-71. PMID:25206138

Jain, Shweta; Agarwal, Vijay; Gupta, Arun Kumar; Prabhakar, Pramod

2012-01-01

394

Are full cast crowns mandatory after endodontic treatment in posterior teeth?  

PubMed Central

The success of endodontic treatment is not only measured by the alleviation of pain and formation of healthy bone, replacing the diseased periapical tissue. Concepts for restoring pulpless teeth have been formed more from clinical observation than valid scientific investigation. Endodontically treated posterior teeth present numerous problems because of coronal destruction from dental caries, fractures, and previous restorations or endodontic techniques. The result is loss of tooth structure and a reduction in the capacity of the tooth to resist a myriad of intraoral forces. A summary of this review article suggests that coronal coverage significantly improves the clinical success rate of endodontically treated posterior teeth. PMID:21217953

Tikku, Aseem Prakash; Chandra, Anil; Bharti, Ramesh

2010-01-01

395

Dentigerous cysts associated with impacted supernumerary teeth in the anterior maxilla  

PubMed Central

Dentigerous cysts are thought to be caused by a developmental abnormality derived from the reduced enamel epithelium of the tooth forming organ. Most typical dentigerous cysts are those associated with the third molar teeth of the mandible, but rarely involve impacted supernumerary teeth in the anterior maxilla. Swelling and/or pain may be the major complaints of the patients. Herein, we review the literature spanning the past 22 years concerning dentigerous cysts associated with supernumerary teeth in the anterior maxilla, and present four additional cases with emphasis given to the clinicopathological characteristics of this type of dentigerous cyst. PMID:22977579

JIANG, QIAN; XU, GUANG-ZHOU; YANG, CHI; YU, CHUANG-QI; HE, DONG-MEI; ZHANG, ZHI-YUAN

2011-01-01

396

Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.  

PubMed

One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The application of unfilled resin to the anatomical crown prevented infection. PMID:9206377

Love, R M

1996-12-01

397

Orthodontic-periodontic intervention of pathological migration of maxillary anterior teeth in advanced periodontal disease  

PubMed Central

This case report presents a female patient whose chief complaint was of mobile and palatally drifted upper left central incisor which led to malalignment of upper anterior teeth. Orthodontic treatment of upper left central incisor was done with the help of ‘Z’ spring for the alignment of the upper anterior teeth. It was followed by splinting of upper anterior teeth to improve the stability and masticatory comfort. Regenerative periodontal surgery with Decalcified freeze dried bone allograft was done in relation to upper left central incisor. PMID:24049341

Panchal, Anita H.; Patel, Vasumati G.; Bhavsar, Neeta V.; Mehta, Hardik V.

2013-01-01

398

Genetic diversity of bovine viral diarrhea viruses in commercial bovine serum batches of Chinese origin.  

PubMed

Bovine viral diarrhea virus (BVDV) is often detected in commercial bovine serum. BVDV genetic diversity was investigated in commercial bovine serum of Chinese origin. Twenty-two batches of bovine serum were obtained from 10 suppliers with different geographic origins in China, and 20 batches of bovine serum were positive by reverse-transcription polymerase chain reaction (RT-PCR) and sequencing. Phylogenetic reconstructions of partial 5'UTR sequences indicated that the samples examined in this work clustered within the BVDV type 1 and BVDV type 2 genotypes. Interestingly, 3 sample sequences clustered into CSFV. These results suggest a high genetic diversity in Chinese BVDV field isolates. This study will benefit epidemiological surveys of BVDV detected in China. PMID:25102030

Zhang, Shu-Qin; Tan, Bin; Guo, Li; Wang, Feng-Xue; Zhu, Hong-Wei; Wen, Yong-Jun; Cheng, Shipeng

2014-10-01

399

Inferring biological evolution from fracture patterns in teeth.  

PubMed

It is hypothesised that specific tooth forms are adapted to resist fracture, in order to accommodate the high bite forces needed to secure, break down and consume food. Three distinct modes of tooth fracture are identified: longitudinal fracture, where cracks run vertically between the occlusal contact and the crown margin (or vice versa) within the enamel side wall; chipping fracture, where cracks run from near the edge of the occlusal surface to form a spall in the enamel at the side wall; and transverse fracture, where a crack runs horizontally through the entire section of the tooth to break off a fragment and expose the inner pulp. Explicit equations are presented expressing critical bite force for each fracture mode in terms of characteristic tooth dimensions. Distinctive transitions between modes occur depending on tooth form and size, and loading location and direction. Attention is focussed on the relatively flat, low-crowned molars of omnivorous mammals, including humans and other hominins and the elongate canines of living carnivores. At the same time, allusion to other tooth forms - the canines of the extinct sabre-tooth (Smilodon fatalis), the conical dentition of reptiles, and the columnar teeth of herbivores - is made to highlight the generality of the methodology. How these considerations impact on dietary behaviour in fossil and living taxa is discussed. PMID:24012462

Lawn, Brian R; Bush, Mark B; Barani, Amir; Constantino, Paul J; Wroe, Stephen

2013-12-01

400

Immune Therapeutic Potential of Stem Cells from Human Supernumerary Teeth  

PubMed Central

Discoveries of immunomodulatory functions in mesenchymal stem cells (MSCs) have suggested that they might have therapeutic utility in treating immune diseases. Recently, a novel MSC population was identified from dental pulp of human supernumerary teeth, and its multipotency characterized. Herein, we first examined the in vitro and in vivo immunomodulatory functions of human supernumerary tooth-derived stem cells (SNTSCs). SNTSCs suppressed not only the viability of T-cells, but also the differentiation of interleukin 17 (IL-17)-secreting helper T (Th17) -cells in in vitro co-culture experiments. In addition, systemic SNTSC transplantation ameliorated the shortened lifespan and elevated serum autoantibodies and nephritis-like renal dysfunction in systemic lupus erythematosus (SLE) model MRL/lpr mice. SNTSC transplantation also suppressed in vivo increased levels of peripheral Th17 cells and IL-17, as well as ex vivo differentiation of Th17 cells in MRL/lpr mice. Adoptive transfer experiments demonstrated that SNTSC-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice showed a longer lifespan in comparison with non-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice, indicating that SNTSC transplantation suppresses the hyper-immune condition of MRL/lpr mice through suppressing T-cells. Analysis of these data suggests that SNTSCs are a promising MSC source for cell-based therapy for immune diseases such as SLE. PMID:23697344

Makino, Y.; Yamaza, H.; Akiyama, K.; Ma, L.; Hoshino, Y.; Nonaka, K.; Terada, Y.; Kukita, T.; Shi, S.; Yamaza, T.

2013-01-01

401

Indications and Case Series of Intentional Replantation of Teeth  

PubMed Central

This case series aims to comprehensively introduce intentional replantation with a focus on its indications and case selection in endodontics. In all represented cases, calcium enriched mixture (CEM) cement is used for root-end filling. This case series demonstrates twenty cases of IR and extraoral root-end resection and filling with CEM cement. All the selected teeth had a failed endodontic treatment and required surgical/nonsurgical endodontic (re)treatment or extraction. Subsequent to gentle tooth extraction, an appropriate root-end cavity was prepared and filled with CEM cement. Then the tooth was replanted; maximun procedure time was 15 min. A total of 18 cases (90%) were successful over a mean follow-up period of 15.5 months. It can be concluded that intentional replantation with careful case selection can have a high success rate over 2 years. Intentional replantation may be a suitable treatment option for both trained general practitioners and specialists provided that the extraction is simple and straightforward. PMID:24396380

Asgary, Saeed; Alim Marvasti, Laleh; Kolahdouzan, Alireza

2014-01-01

402

12 CFR 615.5205 - Minimum permanent capital standards.  

Code of Federal Regulations, 2010 CFR

...false Minimum permanent capital standards. 615.5205...and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ...AND FUNDING OPERATIONS Capital Adequacy § 615.5205 Minimum permanent capital standards. Each...

2010-01-01

403

ARE SALAMANDERS USEFUL INDICATORS OF HYDROLOGIC PERMANENCE IN HEADWATER STREAMS?  

EPA Science Inventory

Regulatory agencies need appropriate indicators of stream permanence to aid in jurisdictional determinations for headwater streams. We evaluated salamanders as permanence indicators because they are often abundant in fishless headwaters. Salamander and habitat data were collect...

404

The effect of wear on the cheek teeth and associated dental tissues of the lizard Uromastix aegyptius (Agamidae).  

PubMed

Serial coronal sections of the teeth and their surrounding tissues in the agamid lizard, Uromastix aegyptius, were examined with the light microscope in order to determine how these structures change as the teeth wear. Because new teeth are added only at the posterior end of the tooth row and older teeth are not replaced, the series of sections included the youngest as well as the oldest teeth. Two types of changes occur as the teeth become older: bone under the teeth changes from cancellous to compact, and the pulp chamber of the tooth is obliterated. Although the labial surface of the dentary lacks a periosteal covering and some of the bone lacks any covering at all, it remains functional throughout the life of the animal. PMID:458861

Throckmorton, G S

1979-05-01

405

Emerging permanent filler technologies: focus on Aquamid  

PubMed Central

A plethora of soft tissue fillers have been developed within the past decade to correct the cutaneous changes that occur with photoaging. Such fillers, whether nonpermanent, semipermanent, or permanent, are widely used to fill undesired facial rhytides. In addition, fillers are employed to correct atrophy of the face as well as other parts of the body such as the dorsum of the hands through volumization and contouring. The extensive long-term safety outcomes reported with fillers and the ease with which they are administered make them an ideal choice to correct rhytides and to contour the face. However, as with any cosmetic procedure, in order to ensure high patient satisfaction and a safe outcome, proper training in injection techniques, the choice of the proper candidate, and awareness of potential adverse events are essential. This review article focuses on the permanent filler, Aquamid, which is composed of polyacrylamide hydrogel. PMID:25336982

Yamauchi, Paul S

2014-01-01

406

Counterrotating brushless DC permanent magnet motor  

NASA Astrophysics Data System (ADS)

A brushless DC permanent magnet motor is provided for driving an autonomous underwater vehicle. In one embodiment, the motor comprises four substantially flat stators disposed in stacked relationship, with pairs of the stators being axially spaced and each of the stators comprising a tape-wound stator coil; first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of embedded permanent magnets. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and the drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs, and rotors mounted on opposite sides of the stators and driven by counterrotating shafts.

Hawsey, R. A.; Bailey, J. M.

1990-07-01

407

Steroidogenesis in fetal bovine gonads.  

PubMed Central

Gonadal steroidogenesis in bovine fetuses of 40 to 125 days gestation was examined using histochemical procedures and radioimmunoassay on gonadal cultures to determine the physiological correlates of gonadal morphogenesis in cattle. Gonadal morphology and the in vitro secretion patterns were distinct between the sexes by 45 days when testes secreted significantly higher levels of testosterone and androstenedione and lower levels of estrone and 17 beta-estradiol that the ovaries (p less than 0.0001). It would appear that the main steroid route in the ovaries of 45 to 70 day old fetuses is the androstenedione to estrone to 17 beta-estradiol pathway. The high estrone secretion and the decreasing levels of 17 beta-estradiol and testosterone in the ovaries of 70 to 125 day fetuses suggest an inhibition of 17 beta-hydroxysteroid dehydrogenase activity. It is postulated that this shift in steroid biosynthetic pathways may be related to the change in cellular events from mitosis to meiosis in fetal ovaries. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 7. PMID:3196968

Dominguez, M M; Liptrap, R M; Basrur, P K

1988-01-01

408

Impacted permanent incisors associated with compound odontoma.  

PubMed

Odontomas are the most common odontogenic tumours of the maxillary bones, characterised by a slow growth and benign behaviour. They are usually small, asymptomatic and diagnosed after routine radiographic examination. The aim of this study was to report a case of a compound odontoma in the anterior maxilla of a 7-year-old girl, which was causing the impaction of the maxillary right central and lateral incisors, as well as the prolonged retention of the corresponding primary teeth. We also aimed to review the literature about these tumours, since they are not part of the dentist's day-to-day clinical practice. The clinical and radiographic features, the diagnosis and treatment of the case were discussed in this work. PMID:25583937

Machado, Cintia de Vasconcellos; Knop, Luégya Amorin Henriques; Siquara da Rocha, Maria Celina Barreiros; Telles, Paloma Dias da Silva

2015-01-01

409

Sonnenlichtgetriggerte granulomatöse Reaktion auf Permanent Lip-Liner  

Microsoft Academic Search

Zusammenfassung Die Nachfrage nach Permanent Make-up und insbesondere Permanent Lip-Liner stieg in den letzten Jahren in Deutschland. Medizinische Komplikationen sind bisher kaum bekannt und in der Fachliteratur nicht dokumentiert, weil die Applikation von Permanent Make-up ein Gewerbe ist und daher keine Dokumentationspflicht wie in der Medizin besteht. Bei einer Patientin traten, nachdem 1 Jahr lang ein Permanent Lip-Liner komplikationslos vertragen wurde,

C. Jäger; W. Hartschuh; U. Jappe

2005-01-01

410

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 the Energy Information Administration'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.

2011-01-01

411

Freeze-branding to permanently mark bats  

Microsoft Academic Search

We tested the effectiveness of freeze-branding as a permanent marking technique on 4 species of bats: Brazilian free-tailed bat (Tadarida brasiliensis), Townsend's big-eared bat (Corynorhinus townsendil), big brown bat (Eptesicus fuscus), and western small-footed myotis (Myotis ciliolabrum). Small copper branding irons (9.3 g and 15.6 g) were cooled in a mixture of dry ice and ethyl alcohol and applied to

Richard E. Sherwin; Shauna Haymond; Rebeccah Olsen

412

"Permanence" - An Adaptationist Solution to Fermi's Paradox?  

NASA Astrophysics Data System (ADS)

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 emotional reactions often accompanying adaptationist explanations.

Cirkovic, Milan M.

413

Novel permanent magnet machines using Halbach cylinders  

Microsoft Academic Search

This paper describes various permanent magnet machines using Halbach cylinders (arrays), from using pre-magnetised anisotropic magnet segments having varying magnetisation orientations, to those moulded as bonded isotropic or anisotropic NdFeB ring magnets, which are subsequently impulse magnetised using a magnetisation fixture which produces a sinusoidal MMF distribution. Three possible magnetisation fixture designs are described. Various Halbach cylinder machine topologies are

Z. Q. Zhu; Z. P. Xia; K. Atallah; G. W. Jewell; D. Howe

2000-01-01

414

Quadrupole Magnetic Lens Using Permanent Ceramic Magnets  

Microsoft Academic Search

A quadrupole lens pair is described utilizing permanent ceramic magnets. The field gradient is 470 Oe?cm, across a 7.94-cm aperture. Variation in lens strength is achieved by driving the lenses over a mild steel magnetic shunt welded to the inside of the beam tube. The lenses are of relatively low cost, light weight, and simple construction. Of the two units

J. W. Jagger; P. J. Riley

1967-01-01

415

Full Mouth Rehabilitation of Severe Fluorozed Teeth with an Interdisciplinary Approach (6 Handed Dentistry)  

PubMed Central

Whenever the treatment revolves around structural balance and aesthetic harmony, the crux remains to be the periodontal health of the existing dentition. In such scenarios where restorations and aesthetics are of concern, biologic width (BW) is the initial and final frontier. Considering attrition of teeth, the resistance which is offered by them is definitely at a lower level as compared to teeth with adequate height. Clinical crowns of worn out teeth are seriously handicapped when it comes to bearing the occlusal loads, which can be brought back to normalcy by crown lengthening . Crown lengthening includes the surgical removal of soft and hard periodontal architecture to gain (vertical dimension) a supracrestal tooth length, thus allowing a longer clinical crown reestablishment of BW. This paper has described the full mouth rehabilitation of severe fluorozed and attrited teeth in a 35–year male with the use of an interdisciplinary approach (6 Handed Dentistry). PMID:24298538

Pradeep, Koppolu; Patil, Nagesh; Sood, Tanusree; Akula, Uttam; Gedela, Rajani

2013-01-01

416

On the management of root canals in teeth that exhibit a draining "fistulous" tract.  

PubMed

The clinical management of teeth with necrotic pulps, with and without draining fistulous tracts, has been the subject of a wide range of personal opinions and techniques for well over a century. Fortunately, prior to the advent of the focal infection theory in the early 1900s, dental clinicians made every attempt to treat and maintain these teeth as opposed to wholesale extraction. While the treatment approaches by some may have been questionable, others claimed great success. The success claimed was empirically-based, but those that achieved this goal used methods and techniques not dissimilar to present-day practices. However, the proponents of the focal infection theory failed to consider these achievements prior to their advocacy of extracting all teeth with necrotic pulps or those that demonstrated an active infection. This paper highlights some of the prevailing concepts from opposing treatment regimens in the late 1800s in which extensive efforts were made to retain teeth. PMID:25549400

Gutmann, James L

2014-01-01

417

Here Comes the Bride... and Her Teeth Are Nice and Bright  

MedlinePLUS

... JADA, Vol. 135, May 2004679 OTHER COSMETIC OPTIONS Bonding. If your teeth are chipped, broken, cracked or ... or have slight gaps, ask your dentist about bonding. Bonding is a cosmetic procedure that uses tooth- ...

418

Cutaneous Sinus Tract in Association with Traumatic Injury to the Teeth  

PubMed Central

ABSTRACT The present case report is of trauma episode of the lower anterior teeth, causing pulpal necrosis with periradicular periodontitis, resulting in the occurrence of cutaneous sinus tracts (fistula). Previous misdiagnosis and inappropriate medical treatment were ineffective. Only when properly referred to dentists, the differential diagnosis was made. The guideline to diagnose cutaneous sinus tracts (fistula) is based mainly on accurate pulp sensitivity tests of the involved traumatized teeth. Intraoral and dental examinations are critical in making the diagnosis. The case presented here shows that cutaneous odontogenic sinus tracts associated in traumatized teeth, even in absence of caries or tooth fracture. How to cite this article: Mishra R, Khan TS. Cutaneous Sinus Tract in Association with Traumatic Injury to the Teeth . Int J Clin Pediatr Dent 2013;6(3):205-207. PMID:25206224

Mishra, Rahul; Khan, Tayyeb Sultan

2013-01-01

419

Lamniform Shark Teeth from the Late Cretaceous of Southernmost South America (Santa Cruz Province, Argentina)  

PubMed Central

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. PMID:25141301

Schroeter, Elena R.; Egerton, Victoria M.; Ibiricu, Lucio M.; Lacovara, Kenneth J.

2014-01-01

420

Lamniform shark teeth from the late cretaceous of southernmost South America (Santa Cruz province, Argentina).  

PubMed

Here we report multiple lamniform shark teeth recovered from fluvial sediments in the (Campanian-Maastrichtian) Cerro Fortaleza Formation, Santa Cruz Province, Argentina. This small tooth assemblage is compared to various lamniform sharks possessing similar dental morphologies, including Archaeolamna, Cretalamna, Dwardius, Dallasiella, and Cretodus. Although the teeth share numerous morphological features with the genus Archaeolamna, including a developed neck that maintains a relatively consistent width along the base of the crown, the small sample size and incomplete nature of these specimens precludes definitive taxonomic assignment. Regardless, the discovery of selachian teeth unique from those previously described for the region broadens the known diversity of Late Cretaceous South American sharks. Additionally, the discovery of the teeth in fluvial sandstone may indicate a euryhaline paleobiology in the lamniform taxon or taxa represented by this tooth assemblage. PMID:25141301

Schroeter, Elena R; Egerton, Victoria M; Ibiricu, Lucio M; Lacovara, Kenneth J

2014-01-01

421

Restoration of anterior teeth using an indirect composite technique. Case report  

PubMed Central

SUMMARY Objective. This article presents a case report of restoration of anterior teeth using an indirect technique with composite veneers in order to restore the dental anatomy and to provide aesthetic and function of anterior teeth. Materials and methods. A treatment of upper anterior teeth with indirect micro-hybrid composite restoration was proposed to a 40-year-old woman with old discolored and fractured ceramic veneers. Upper six anterior teeth were prepared and, after impressions with VPS of maxillary arche, the composite veneers were placed. Discussion and results. There are several advantages offered by indirect techniques compared to direct techniques. The increased practice of veneering technique with indirect composites is due to improvement in the properties of composite materials in the last years. The results are very favourable and the patient is satisfied. Conclusions. The restorations with composite veneers have proved durable and aesthetic, protect tooth structure and aesthetic and function is predictably re-established. PMID:24971164

GARGARI, M.; CERUSO, F.M.; PUJIA, A.; PRETE, V.

2013-01-01

422

Modeling Of Permanent Magnet Motor Drives  

NASA Astrophysics Data System (ADS)

Recent 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 rectangular stator currents to produce constant torque. The PMSM is very similar to the wound rotor synchronous machine except that the PMSM that is used for servo applications tend not to have any damper windings and excitation is provided by a permanent magnet instead of a field winding. Hence the d,q model of the PMSM can be derived from the well known model of the synchronous machine with the equations of the damper windings and field current dynamics removed. Because of the nonsinusoidal variation of the mutual inductances between the stator and rotor in the BDCM, it is also shown in this paper that no particular advantage exists in transforming the abc equations of the BCDM to the d,q frame. Hence the solution of the original abc equations is proposed for the BDCM.

Pillay, P.; Krishnan, R.

1987-10-01

423

9 CFR 113.311 - Bovine Virus Diarrhea Vaccine.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Bovine Virus Diarrhea Vaccine. 113.311 Section...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Live Virus Vaccines § 113.311 Bovine...

2011-01-01

424

9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2011 CFR

...Bovine Rhinotracheitis Vaccine, Killed Virus. 113.216 Section 113.216 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine...

2011-01-01

425

Permanent-Magnet Length Effects in AC Machines  

Microsoft Academic Search

Permanent-magnet synchronous machines (PMSMs) are gaining popularity in the industry and, especially, in distributed generation, for instance in windmill applications. Some of the traditional analytical design principles seem not to be valid for permanent magnets in machine excitation. We report on the effects of the permanent-magnet length in machine design.

Juha Pyrhonen; Vesa Ruuskanen; Janne Nerg; Jussi Puranen; Hanne Jussila

2010-01-01

426

Permanent magnet design for high-speed superconducting bearings  

DOEpatents

A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

Hull, John R. (5519 S. Bruner, Hinsdale, IL 60521); Uherka, Kenneth L. (830 Ironwood, Frankfort, IL 60423); Abdoud, Robert G. (13 Country Oaks La., Barrington Hills, IL 60010)

1996-01-01

427

Teeth with periodontal bone loss, cigarette smoking and plasma cotinine levels.  

PubMed

The aim of the present study is to assess teeth with periodontal bone loss, cigarette smoking and plasma cotinine levels. We enrolled 120 untreated periodontal patients with chronic periodontitis into the study. The group comprised 48 men and 72 women, ranging in age from 21 to 75 years (mean age, 42.4 years). We divided the patients into five groups based on self-reported smoking status: (1) heavy smokers (n=35); (2) light smokers (n = 17); (3) recent former smokers (n = 8); (4) long-term former smokers (n = 17); (5) non-smokers (n = 43). We calculated packyear: (number of cigarette/day/20 x years) for all smokers. Smoking status was confirmed by measurement of plasma cotinine levels in 116 subjects. Periodontal disease was assessed on a full set of periapical radiographs. The number of teeth with bone loss was scored in four categories (no bone loss, light bone loss, moderate bone loss or serious bone loss) in all patients. The results demonstrated that plasma cotinine levels correlated significantly with the number of cigarettes smoked per day. Moreover, heavy smokers had fewer teeth with no bone loss (P < 0.001) and more teeth with moderate bone loss (P < 0.001) than non-smokers. In addition, we found a negative correlation between packyears and the number of teeth with no bone loss (P < 0.04) and a positive correlation between packyears and the number of teeth with light bone loss (P < 0.005). However, we found no correlation between plasma cotinine levels and the number of teeth with bone loss. These clinical findings suggest that cigarette smoking affects the number of teeth with or without periodontal bone loss, and this effect is related to the degree of smoking exposure. PMID:12685806

Xu, Li; Loos, B G; Craandijk, J; Ritsema, E; Huffels, R A M; van der Velden, U

2002-04-01

428

Fracture Resistance of Teeth Restored with Direct and Indirect Composite Restorations  

PubMed Central

Objective: Tooth fracture is a common dental problem. By extension of cavity dimensions, the remaining tooth structure weakens and occlusal forces may cause tooth fracture. The aim of this study was to evaluate and compare the fracture resistance of teeth restored with direct and indirect composite restorations. Materials and Methods: Sixty-five sound maxillary premolar teeth were chosen and randomly divided into five groups each comprising thirteen. Fifty-two teeth received mesio-occluso-distal (MOD) cavities with 4.5mm bucco-lingual width, 4mm pulpal depth and 3mm gingival depth and were divided into the following four groups. G-1: restored with direct composite (Z-250, 3M/ESPE) with cusp coverage, G-2: restored with direct composite (Z-250) without cusp coverage, G-3: restored with direct composite (Gradia, GC-international) with cusp coverage, G-4: restored with indirect composite (Gradia, GC-International) with cusp coverage. Intact teeth were used in G-5 as control. The teeth were subjected to a compressive axial loading using a 4 mm diameter rod in a universal testing machine with 1 mm/min speed. Data were analyzed using one-way ANOVA and Tukey tests. Results: The mean fracture strength recorded was: G-1: 1148.46N±262, G-2: 791.54N±235, G-3: 880.00N±123, G-4: 800.00N±187, G-5: 1051.54N±345. ANOVA revealed significant differences between groups (p<0.05). Tukey test showed significant difference between group 1 and the other groups. There was no significant difference among other groups. Conclusion: Direct composite (Z-250) with cusp coverage is a desirable treatment for weakened teeth. Treatment with Z-250 without cusp coverage, direct and indirect Gradia with cusp coverage restored the strength of the teeth to the level of intact teeth. PMID:24910649

Torabzadeh, Hassan; Ghasemi, Amir; Dabestani, Atoosa; Razmavar, Sara

2013-01-01

429

Bond Strength and Interfacial Morphology of Different Dentin Adhesives in Primary Teeth  

PubMed Central

Objective: To evaluate the interfacial morphology and the bond strength produced by the three-step, two-step and single-step bonding systems in primary teeth. Materials and Methods: Occlusal surfaces of 72 extracted human deciduous teeth were ground to expose the dentin. The teeth were divided into four groups: (a) Scotchbond Multipurpose (3M, ESPE), (b) Adh Se (Vivadent), (d) OptiBond All-in-One (Kerr) and (e)Futurabond NR (VOCO, Cuxhaven, Germany). The adhesives were applied to each group following the manufacturer’s instructions. Then, teeth from each group were divided into two groups: (A) For viewing interfacial morphology (32 teeth), with 8 teeth in each group, and (B) For measurement of bond strength (40 teeth), with 10 teeth in each group. All the samples were prepared for viewing under SEM. The statistical analysis was done using SPSS version 15.0 software. Results: Observational measurement of tag length in different adhesives revealed that Scotchbond had the most widely spread values with a range from 12.20 to 89.10?m while OptiBond AIO had the narrowest range (0 to 22.50). The bond strength of Scotchbond Multipurpose was significantly higher (7.4744±1.88763) (p<0.001) as compared to Futurabond NR (3.8070±1.61345), Adhe SE (4.4478 ± 1.3820) and OptiBond-all-in-one (4.4856±1.07925). Conclusion: The three-step bonding system showed better results as compared to simplified studied bonding systems PMID:24910694

Vashisth, Pallavi; Mittal, Mudit; Goswami, Mousumi; Chaudhary, Seema; Dwivedi, Swati

2014-01-01

430

In situ Raman spectroscopic studies of the teeth of the chiton Acanthopleura hirtosa  

Microsoft Academic Search

In situ Raman spectroscopy, in combination with energy dispersive spectroscopy, has been used for the first time to determine\\u000a the identities and locations, at the micron level, of mineral phases present in single chiton teeth that have been extensively\\u000a mineralized. At the later stages of development the major lateral teeth of the chiton Acanthopleura hirtosa show characteristic spectroscopic evidence for

Alasdair P. Lee; John Webb; D. J. Macey; Wilhelm van Bronswijk; Angela R. Savarese; G. Charmaine de Witt

1998-01-01

431

Pink teeth in a series of bodies recovered from a single shipwreck.  

PubMed

Pink teeth have most often been observed in victims of drowning but have also been reported in subjects who died suddenly and unnaturally. There is general agreement that there is no obvious connection between the occurrence of pink teeth and the cause of death, but the condition of the surroundings (especially humidity) must certainly play an important role in the development of the pink-tooth phenomenon. The frequency and distribution of postmortem pink coloration of the teeth have been studied among a representative sample of 52 cadavers. All the bodies were victims of a single shipwreck that occurred on March 13, 1997, in the middle of the Otranto Canal (Mediterranean Sea). The bodies were recovered from the seawater after approximately 7 months. A distinct pink coloration of the teeth was found in only 18 cadavers (13 females and 5 males) of ages ranging between 13 and 60 years. The phenomenon was more pronounced in younger individuals due to age-related changes of the root canal, less penetrable by the pigment responsible for the postmortem pink staining. By histochemical methods and autofluorescence, hemoglobin and its derivatives have been identified as the most likely pigments responsible for this postmortem process that can be considered analogous to postmortem lividity. These data are consistent with previous reports on pink teeth, indicating that the diffusion of the blood in the pulp into the dentinal tubules causes the red discoloration of the teeth. Based on the results, the pigmentation is more prominent on the teeth with single roots rather than in the posterior teeth with multiple roots. PMID:17133027

Campobasso, Carlo P; Di Vella, Giancarlo; De Donno, Antonio; Santoro, Valeria; Favia, Gianfranco; Introna, Francesco

2006-12-01

432

Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time  

PubMed Central

Isolated small theropod teeth are abundant in vertebrate microfossil assemblages, and are frequently used in studies of species diversity in ancient ecosystems. However, determining the taxonomic affinities of these teeth is problematic due to an absence of associated diagnostic skeletal material. Species such as Dromaeosaurus albertensis, Richardoestesia gilmorei, and Saurornitholestes langstoni are known from skeletal remains that have been recovered exclusively from the Dinosaur Park Formation (Campanian). It is therefore likely that teeth from different formations widely disparate in age or geographic position are not referable to these species. Tooth taxa without any associated skeletal material, such as Paronychodon lacustris and Richardoestesia isosceles, have also been identified from multiple localities of disparate ages throughout the Late Cretaceous. To address this problem, a dataset of measurements of 1183 small theropod teeth (the most specimen-rich theropod tooth dataset ever constructed) from North America ranging in age from Santonian through Maastrichtian were analyzed using multivariate statistical methods: canonical variate analysis, pairwise discriminant function analysis, and multivariate analysis of variance. The results indicate that teeth referred to the same taxon from different formations are often quantitatively distinct. In contrast, isolated teeth found in time equivalent formations are not quantitatively distinguishable from each other. These results support the hypothesis that small theropod taxa, like other dinosaurs in the Late Cretaceous, tend to be exclusive to discrete host formations. The methods outlined have great potential for future studies of isolated teeth worldwide, and may be the most useful non-destructive technique known of extracting the most data possible from isolated and fragmentary specimens. The ability to accurately assess species diversity and turnover through time based on isolated teeth will help illuminate patterns of evolution and extinction in these groups and potentially others in greater detail than has previously been thought possible without more complete skeletal material. PMID:23372708

Larson, Derek W.; Currie, Philip J.

2013-01-01

433

An In Vitro Analysis of Wear Resistance of Commercially Available Acrylic Denture Teeth  

Microsoft Academic Search

Posterior denture teeth wear faster than the anterior teeth, causing occlusal prematurities and loss of vertical dimension\\u000a of occlusion. The loss of vertical dimension of occlusion lays more stress on the anterior alveolar ridge, which in turn increases\\u000a the rate of residual ridge resorption and causes loss of alveolar ridge height in the anterior segment and compromises esthetics.\\u000a Hence it

Mallika S. Shetty; K. Kamalakanth Shenoy

2010-01-01

434

Study of meshing of beveled gears with normally decreasing arc teeth  

NASA Technical Reports Server (NTRS)

The meshing of beveled gears was studied by the direct and inverse approaches. Gear wheels with teeth of equal height are studied, and wheels with normally-decreasing arc teeth. Different coordinate systems are utilized to plot the determination of the rotation of the originating gear wheel and the meshing line of the gear wheel which is cut. Matrices are used to determine the equations of the originating surfaces and the unit vectors of the normals to these originating surfaces.

Litvin, F. L.; Kay, G.

1985-01-01

435

Current opinions concerning the restoration of endodontically treated teeth: basic principles  

PubMed Central

The goal of this general article is to present a survey of the current knowledge about the clinical approach of restoring endodontically treated teeth. The best way to restore teeth after root canal treatment has long been and still is a controversial subject of debate to this day. The clinical approach of restoring endodontically treated teeth needs taking into consideration several issues: aims of coronal restoration, criteria for establishing the various modalities of coronal restoration, clinical solutions of restoring teeth after endodontic treatment, guidelines regarding restorative materials and techniques, possibilities and limits of restoration using direct adhesive materials and techniques. The aims of coronal restoration of endodontically treated teeth are generally considered to be the following ones: to prevent recontamination of the root canal system and / or periapical space, to replace missing hard dental tissues and to restore coronal morphology and functions, to provide the necessary strength for the restoration/tooth complex in order to withstand functional stress and prevent crown and/or root fracture. The criteria for establishing the modalities of coronal restoration for endodontically treated teeth are: amount and quality of remaining hard dental tissues, topography and coronal morphology of the tooth, functional occlusal forces that the restoration/tooth complex has to withstand, restoring requirements in order to include the treated tooth in a comprehensive oral rehabilitation treatment plan, esthetic requirements. PMID:20108535

V?rlan, C; V?rlan, V; Bodnar, D; Suciu, I

2009-01-01

436

Tensile bond strength of four denture resins to porcelain teeth with different surface treatment  

PubMed Central

PURPOSE This study evaluated the bond strength between porcelain denture teeth (Bioblend 43D) and four different polymerized denture resins (Lucitone 199, Palapress, Acron MC, Triad) with and without a bonding agent and after four different types of surface treatment (polished, HF etched, sandblasted, air-abraded). MATERIALS AND METHODS Central incisor porcelain denture teeth were divided into 32 groups of 5 each. Tensile bond strength (MPa) was determined using a testing machine at crosshead speed of 0.5 mm/min. Mean and standard deviation are listed. Data were analyzed by two-way ANOVA. Means were compared by Tukey-Kramer intervals at 0.05 significance level. RESULTS All surface treatment increased bond strength compared to polished surface and the highest bond strength was found with Palapress resin with etched porcelain surface (8.1 MPa). Bonding agent improved the bond strength of all denture resins to porcelain teeth. Superior bonding was found with Palapress and air-abraded porcelain (39 MPa). CONCLUSION Resins with different curing methods affect the bond strength of porcelain teeth to denture bases. Superior bonding was found with auto-polymerized resin (Palapress). Application of ceramic primer and bonding agent to porcelain teeth with and without surface treatment will improve the bond strength of all denture resins to porcelain teeth. PMID:24353880

Powers, John

2013-01-01

437

Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population  

PubMed Central

Objective: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. Materials and Methods: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Armed Forces of Greece during the period 1997-2011 were initially analyzed for lateral incisor agenesis by two observers. After exclusion of the known orthodontic cases, a subgroup of 1636 examinees (mean age: 18.6 ± 0.44 years) was evaluated for canine impaction and supernumerary teeth. Results: Twenty-eight missing lateral incisors were observed in 22 military students, indicating an incidence of 1.3% in the investigated population. No lateral incisor agenesis was detected in the mandibular arch. A prevalence rate of 0.8% was determined for canine impaction in the sample of young adults. The majority of impacted teeth (86.7%) were diagnosed in the maxillary arch. Thirty-five supernumerary teeth were observed in 24 examinees (prevalence rate: 1.5%). The ratio of supernumerary teeth located in the maxilla versus the mandible was 2.2:1. The most common type of supernumerary tooth was the upper distomolar. Conclusion: The prevalence of lateral incisor agenesis, canine impaction, and supernumerary teeth ranged from 0.8 to 1.5% in the sample of male Greek military students. PMID:24926206

Delli, Konstantina; Livas, Christos; Bornstein, Michael M.

2013-01-01

438

Problems associated with reworked teeth in electron spin resonance (ESR) dating  

NASA Astrophysics Data System (ADS)

A single radiation-sensitive ESR signal at g = 2.0018 occurs in well crystallized fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (A ? needed to produce the observed ESR signal is the integral, with respect to time, of the natural, environmental dose rate experienced by the tooth after its deposition. Regardless of the uranium (U) uptake history assumed, a reliable age estimate requires a good estimate for the external dose rate during the tooth's history. If teeth in a stratigraphic unit have been reworked from older units or are post-depositional intrusions, external dose rates measured in situ do not accurately reflect those experienced by the tooth. For teeth from a single unit, significant variations in the calculated ages, A ?s, enamel or dentine U concentrations all indicate mixed sample collections. Where enough subsamples can be collected from single teeth, isochron analyses negate the need for a separate external dose measurement, while calculating the sample age and the external dose rate experienced by the tooth. Failing that, modelling the sedimentary dose rates using time-averaged total external dose calculations becomes necessary. These principles are illustrated using teeth from the australopithecine sites Sterkfontein and Swartkrans, South Africa.

Blackwell, Bonnie A.

439

Assessment of structural changes of human teeth by low-field nuclear magnetic resonance (NMR)  

NASA Astrophysics Data System (ADS)

A technique of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation is described for assessment of age-related structural changes (dentin and pulp) of human teeth in vitro. The technique involves spin-spin relaxation measurement and inversion spin-spin spectral analysis methods. The spin-spin relaxation decay curve is converted into a T2 distribution spectrum by a sum of single exponential decays. The NMR spectra from the extracted dentin-portion-only and dental pulp-cells-only were compared with the whole extracted teeth spectra, for the dentin and pulp peak assignments. While dentin and pulp are highly significant parameters in determining tooth quality, variations in these parameters with age can be used as an effective tool for estimating tooth quality. Here we propose an NMR calibration method—the ratio of the amount of dentin to the amount of pulp obtained from NMR T2 distribution spectra can be used for measuring the age-related structural changes in teeth while eliminating any variations in size of teeth. Eight teeth (third molars) extracted from humans, aged among 17-67 years old, were tested in this study. It is found that the intensity ratio of dentin to pulp sensitively changes from 0.48 to 3.2 approaching a linear growth with age. This indicates that age-related structural changes in human teeth can be detected using the low-field NMR technique.

Ni, Qingwen; Chen, Shuo

2010-01-01

440

Distribution of permanent canine agenesis in Down syndrome: 15 cases from a Centre for Special Care Dentistry.  

PubMed

The purpose of this study was to investigate the distribution of permanent canine agenesis in subjects with Down syndrome (DS). Subjects with canine agenesis were determined by means of panoramic radiographs from 150 DS subjects attending a center for special care dentistry. Our results confirm the high prevalence of agenetic canines in DS (21 canines, 14%). We found specific effects on the distribution both of phenotype and of location (jaw). In subjects with a mild expression of hypodontia (phenotype nonoligodontia) agenetic canines primarily occurred in the mandibula, whereas in subjects with severe hypodontia (phenotype oligodontia) agenetic canines virtually only occurred in the maxilla. In both phenotypes cooccurrence of an agenetic lateral incisor with an agenetic canine was observed in the maxilla. It was striking that canine agenesis in the mandibula did not cooccur with agenesis of other teeth. These results can be important for treatment planning. PMID:25081021

Reuland-Bosma, Wimke; Reuland, Merijn C; Bronkhorst, Ewald

2014-07-31

441

Review article Classification of worldwide bovine tuberculosis risk factors  

E-print Network

Review article Classification of worldwide bovine tuberculosis risk factors in cattle: a stratified Tilman, Belgium 2 National and OIE/FAO Bovine Tuberculosis Reference Laboratories, Bacterial Zoonoses ­ The worldwide status of bovine tuberculosis (bTB) as a zoonosis remains of great concern. This article reviews

Paris-Sud XI, Université de

442

Courte note MISE EN VIDENCE DU VIRUS BVD (BOVINE VIRAL  

E-print Network

Kidney) : 10 origines différentes dont 4 commerciales. GBK (Georgia Bovine Kidney! originaires de 3 labora- toires différents. AUBEK (Auburn University Bovine Embryo Kidney) : 2 lignées. BTC (Bovine) CRFK (rein de chat) VERO (rein de singe) RK13 (rein de lapin) HRT18 (human rectal tumor de Laporte) SK6

Paris-Sud XI, Université de

443

Mesiodistal crown diameters and tooth size discrepancy of permanent dentition in thalassemic patients  

PubMed Central

Objectives: To provide a description of mesiodistal crown diameters (MD) and tooth-size discrepancy (TSD) of the permanent dentition in patients with thalassemia major (TM) and to compare the results with those of unaffected control group. Study design: The sample consisted of 46 thalassemic patients, 25 males and 21 females aged 7.3 to 23.7 years (mean ± SD = 11.2 ± 3.9 years) and control group matched by age and sex. Dental casts of the participants were measured for MD, using a digital sliding caliper. Descriptive statistics were computed for each individual tooth. Student t-test was used for comparison of mean values between males and females as well as between thalassemic and control groups. The differences between sets of data were evaluated by analysis of variance (ANOVA). Results: All means for MD of thalassemic males and females were smaller than their controls, with 20 of the 24 comparisons being statistically significant (ranged from P<0.05 to P<0.001). In both thalassemic and control groups, males exhibited significantly larger MD than females in most instances. Canines displayed the most sexual dimorphic teeth in the dentition. Lateral incisors showed the greatest variability indicated by the coefficient of variation, while the first molars were the least variable teeth (7.6% vs. 5.3%). There were no statistically significant differences in the anterior and overall tooth-size discrepancy ratios between sexes or between thalassemic and control groups. The mean anterior ratio (79.5%) and overall ratio (92.4%) of the control group were significantly larger than of Bolton ratios; P< 0.001 and P<0.05, respectively. Conclusions: The present study demonstrated that thalassemic males and females exhibited significantly smaller MD than the control group. The TSD ratios in both thalassemic and control groups were significantly larger than those of Bolton sample. These findings should be taken into account when planning orthodontic treatment for thalassemic patients. Key words:Permanent dentition, tooth size, thalassemia major. PMID:24455089

2013-01-01

444

Structural behaviour of endodontically treated teeth under thermomechanical loading.  

PubMed

Choosing the optimal combination of post construction and restorative materials to minimize thermomechanical stresses in endodontically post-restored teeth is a very challenging task. In fact, while thermal properties of metallic alloys used for endodontic posts are rather similar to those of natural dental tissues, composite restorative materials used for constructing post and postcore usually possess better mechanical properties than metallic alloys. This may make it very difficult to evaluate directly thermomechanical stresses in the restored tooth. Therefore, this paper presents a detailed analysis of the structural behaviour of several post-endodontic restorations submitted to different combinations of thermomechanical load. The aim of the study is to compare the relative merits of different restoration concepts. Three-dimensional finite element method (FE) analysis is carried out for an upper incisor restored with composite as well as metallic post systems. Furthermore, customized and standard post constructions are compared. Two loading cases are considered: (a) exposure to cold irritants in absence of mastication; (b) mastication of cold or hot foods. Effects of thermal field inhomogeneity and occlusal force magnitude are also included in the analysis. Because of the transient nature of thermal loads, relative performance of different restorations is investigated as the thermal perturbation spreads through the restored tooth. Results indicate that composite post systems are globally more efficient than restorations including a metallic alloy post when thermal cycles and mastication act together. However, relative performance of different restoration concepts in the absence of mastication may depend strongly on the time of exposure to thermal irritants. PMID:17236524

Genovese, K; Lamberti, L; Pappalettere, C

2006-11-01

445

[Radiographic manifestations in teeth and jaws in chronic kidney insufficiency].  

PubMed

Forty-five patients affected with chronic renal failure (29 men and 16 women; mean age: 47.8 years), treated with hemodialysis for 4 to 245 months (mean: 66.9 months) were examined with panoramic and skeletal radiographs-the latter of the skull, hands, shoulders and clavicles, pelvis and spine. The control group (45 subjects with no renal diseases) was examined only with panoramic radiography. Dental and skeletal radio-graphs were given an 0-6 score and then compared to assess a possible relationship between skeletal and dental changes at radiography. Twenty-six dialysis patients (57.7%) had radiographic abnormalities in the maxillary bones-i.e., osteoporosis (100% of patients), focal osteosclerosis adjacent to the roots (11.5%), lamina dura reduction or loss (26.9%), calcifications of soft tissues or salivary glands (15.3%) and brown tumors (7.6%). In the teeth of dialysis patients, the dental pulp chamber was narrowed in 11.1% and hypercementosis of the roots was observed in 4.5%. Radiographic abnormalities in the hand, shoulder and pelvis were depicted in 51.1% of dialysis patients-in 86.9% of them with maxillary lesions. In the control group, 15.5% had mandibular bone lesions-i.e., osteopenia, cortex reduction at the mandibular angles and cyst-like lesions -but the evidence of caries and periodontal disease did not differ from that in the dialysis group. The diagnosis and follow-up of dialysis patients are currently made with serum biochemistry, radiography and histology. The purpose of skeletal radiology is to monitor the progression or regression of musculoskeletal abnormalities. Panoramic radiography might be useful in monitoring renal osteodystrophy, especially to assess the response to therapy-i.e., parathyroidectomy, calcium or vitamin-D therapy and renal transplant. PMID:9045243

Scutellari, P N; Orzincolo, C; Bedani, P L; Romano, C

1996-10-01

446

Bovine Eimeria species in Austria.  

PubMed

Bovine eimeriosis is considered to be of considerable importance for the productivity and health of cattle worldwide. Despite the importance of cattle farming in Austria, little is known in this country about the abundance and distribution of bovine Eimeria spp. The objective of this study was to obtain detailed information about the occurrence of different Eimeria spp. on Austrian dairy farms. Fecal samples from individual calves (n = 868) from 296 farms all over Austria (82 districts) were collected. Additionally, each farmer was questioned about the occurrence of calf diarrhea, and about the knowledge on coccidiosis and possible control measures. On 97.97% of the investigated farms, calves excreted Eimeria oocysts, and 83.67% of the individual samples were positive. After sporulation of positive samples pooled from each farm, 11 Eimeria species were found, with E. bovis (in 65.54% of the samples and 27.74% of the farms), E.zuernii (63.85%/13.86%), E. auburnensis (56.76%/13.41%) and E. ellipsoidalis (54.05%/14.38%) being the most prevalent, followed by E. alabamensis (45.61%/11.56%), E. subspherica (35.14%/5.5.05%), E. cylindrica (33.11%/7.00%), and E. canadensis (31.08%/7.74%). E. wyomingensis, E. pellita and E. bukidnonensis were only found sporadically (3.04-4.73% of the samples and 0.16-0.59% of the farms). Mixed infections were present on all farms (2-9 Eimeria species/farm). Prevalences by state provinces were high throughout with 77.1-87.9% of the samples and 93.8-100% of the farms. Lower Austria had the highest percentage of positive farms, and Vorarlberg the lowest. Individual OPG (oocysts per gram of feces) values were generally low; 75% of the samples had an OPG of 1,000 or less. The highest detected OPG was 72,400. The mean OPG was 2,525 with above average numbers in Tirol, Carinthia, and Lower Austria. The mean OPG values were significantly positively correlated with the cattle density in the different districts. The majority of the samples were from female Simmenthal calves. Clinical coccidiosis (diarrhea) was observed in 74 cases, and (semi-)liquid diarrhea (56 animals) was significantly correlated with OPG (p < 0.05). Linear regression on the OPG data showed that OPG values significantly decreased with increasing age of the calves, while the percentage of positive samples increased with age (p < 0.05 for both). The term "coccidia" was familiar to 45% of the farmers, and anticoccidial treatment was performed by 13.51% of them, most commonly with toltrazuril. Considering the ubiquitous occurrence and the possible clinical and economic relevance of calf eimeriosis, infections should receive increased attention by both farmers and veterinarians. PMID:22167365

Koutny, H; Joachim, A; Tichy, A; Baumgartner, W

2012-05-01

447

Comparison of human and bovine protoporphyria.  

PubMed Central

Protoporphyria (PP) is an inherited disorder of porphyrin metabolism in man in which there is excessive accumulation and excretion of protoporphyrin. Recently, a similar disorder has been described in cattle. In this report, the clinical, biochemical, and genetic features of bovine and human PP are compared. Human and bovine PP are characterized by photosensitivity and elevation of erythrocyte and fecal protoporphyrin levels. In both disorders, a deficiency of heme synthase activity is present in all tissues which have been examined. The diseases differ clinically in that hepatobiliary disease has been found thus far only in human PP. They also have different inheritance patterns. Human PP is an autosomal dominant disease, while initial studies strongly suggest that there is an autosomal recessive pattern of inheritance in bovine PP. PMID:392959

Brenner, D. A.; Bloomer, J. R.

1979-01-01

448

Arachidonate metabolism in bovine gallbladder muscle  

SciTech Connect

Incubation of (1-/sup 14/C)arachidonic acid (AA) with homogenates of bovine gallbladder muscle generated a large amount of radioactive material having the chromatographic mobility of 6-keto-PGF1 alpha (stable product of PGI2) and smaller amounts of products that comigrated with PGF2 alpha PGE2. Formation of these products was inhibited by the cyclooxygenase inhibitor indomethacin. The major radioactive product identified by thin-layer chromatographic mobility and by gas chromatography - mass spectrometric analysis was found to be 6-keto-PGF1 alpha. The quantitative metabolic pattern of (1-/sup 14/C)PGH2 was virtually identical to that of (1-/sup 14/C)AA. Incubation of arachidonic acid with slices of bovine gallbladder muscle released labile anti-aggregatory material in the medium, which was inhibited by aspirin or 15-hydroperoxy-AA. These results indicate that bovine gallbladder muscle has a considerable enzymatic capacity to produce PGI2 from arachidonic acid.

Nakano, M.; Hidaka, T.; Ueta, T.; Ogura, R.

1983-04-01

449

Genotypic effects on bovine fetal ontogeny  

E-print Network

GENOTYPIC EFFECTS ON BOVINE FETAL ONTOGENY A Thesis by ERIC HADLEY MCPHAIL Submitted to the Office of Graduate Studies of Texas A&M University in paruai l'ulfillmcnt of the requirements for thc degree of MASTER OF SCIENCE May 2tXX) Maior... Subject: Nuirition GENOTYPIC EFFECTS ON BOVINE FETAL ONTOGENY A Thesis by ERIC HADLEY MCPHAIL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE...

McPhail, Eric Hadley

2012-06-07

450

Effect of Side Permanent Magnets for Reluctance Interior Permanent Magnet Reluctance Machines  

SciTech Connect

A traditional electric machine uses two dimensional magnetic flux paths in its rotor. This paper presents the development work on the utilization of the third dimension of a rotor. As an example, the air gap flux of a radial gap interior permanent magnet motor can be significantly enhanced by additional permanent magnets (PM) mounted at the sides of the rotor. A prototype motor built with this concept provided higher efficiency and required a shorter stator core length for the same power output as the Toyota/Prius traction drive motor.

Hsu, John S [ORNL; Lee, Seong T [ORNL; Wiles, Randy H [ORNL; Coomer, Chester [ORNL; Lowe, Kirk T [ORNL

2007-01-01

451

Effectiveness of Ozone with or without the Additional Use of Remineralizing Solution on Non-Cavitated Fissure Carious Lesions in Permanent Molars  

PubMed Central

Objectives: The aim of this study was to evaluate the efficiency of ozone alone and with a re-mineralizing solution following application on initial pit and fissure caries lesions in permanent molars. Methods: Forty children (9–12 years) having non-cavitated fissure caries lesions on bilateral 40 first permanent mandibular molar teeth were participated in the study. Patients were randomly allocated to 2 experimental groups consisting of 20 subjects. In the first group, ozone was applied once for 40 seconds to the assigned test teeth of each pair. In the second group, ozone was applied once for 40 seconds to the assigned test teeth of each pair with the use of re-mineralizing solution. Progression or improvement of the caries was assessed at baseline, immediately after treatment and at 1-,2-,3-, and 6 month follow-up by comparing the DIAGNOdent values, Clinical Severity Indexes, Oral Hygiene Scores. The results were analyzed statistically by using the Wilcoxon-Test for dependent samples in each group. When comparing different test groups (control and experimental groups) the Friedman S test followed by the Mann-Whitney U test was used. Results: A statistically significant difference was found between all of the control and experimental test lesions in each group (P<.001). However, there was no statistically significant difference between the ozone treated groups and those using the additional re-mineralizing solution (P>.001). Conclusions: Ozone treatment either alone or combined with a re-mineralizing solution was found to be effective for remineralization of initial fissure caries lesions. PMID:22654551

Atabek, Didem; Oztas, Nurhan

2011-01-01

452

Strong permanent magnet-assisted electromagnetic undulator  

DOEpatents

This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

Halbach, Klaus (Berkeley, CA)

1988-01-01

453

Guided wave permanently installed pipeline monitoring system  

NASA Astrophysics Data System (ADS)

Permanently installed guided wave sensors are an attractive option for pipeline inspection as they offer significant inspection cost reductions and enhanced damage monitoring capabilities. This paper discusses the advantages of baseline subtraction in the pipeline inspection context as well as methods to address the unique challenges when compensating for signal changes due to environmental effects other than the growth of damage. It is shown that through the use of baseline subtraction and compensation for environmental effects it is possible to achieve significant damage sensitivity improvements over conventional ultrasonic guided wave inspection.

Galvagni, A.; Cawley, P.

2012-05-01

454

Permanent Service for Mean Sea Level  

NSDL National Science Digital Library

The Permanent Service for Mean Sea Level (PSMSL), hosted by the Proudman Oceanographic Laboratory (POL), is the global data bank for long term sea level change information from tide gauges. The PSMSL data set is the main source of information on long term changes in global sea level during the last two centuries. This site contains data sets, and information on other services such as vertical land movements and air pressure. There are answers to frequently asked questions about sea level changes, packets on data use available, annual reports, and other contacts for more information.

455

Batch fabrication of precision miniature permanent magnets  

DOEpatents

A new class of processes for fabrication of precision miniature rare earth permanent magnets is disclosed. Such magnets typically have sizes in the range 0.1 to 10 millimeters, and dimensional tolerances as small as one micron. Very large magnetic fields can be produced by such magnets, lending to their potential application in MEMS and related electromechanical applications, and in miniature millimeter-wave vacuum tubes. This abstract contains simplifications, and is supplied only for purposes of searching, not to limit or alter the scope or meaning of any claims herein.

Christenson, Todd R. (Albuquerque, NM); Garino, Terry J. (Albuquerque, NM); Venturini, Eugene L. (Albuquerque, NM)

2002-01-01

456

Permanent-magnet-less synchronous reluctance system  

SciTech Connect

A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

Hsu, John S

2012-09-11

457

Cutaneous complications related to permanent decorative tattooing.  

PubMed

Decorative tattooing involves the introduction of exogenous pigments and/or dyes into the dermis to produce a permanent design. Practiced for thousands of years, it has gained tremendous popularity during the past 20 years, especially among the young. Tattoo-associated cutaneous complications have only been reported since the end of the 19th Century. With the increased prevalence of tattooed individuals, dermatologists have witnessed increasing numbers of patients presenting with complaints about their tattoos. Complications primarily include infections, hypersensitivity reaction to tattoo pigments, benign and sometimes malignant tumors arising on tattoos, and the localization of various dermatoses to tattoos. PMID:20441423

Kluger, Nicolas

2010-05-01

458

An Epidemiological Study on Supernumerary Teeth: A Survey on 5,000 People  

PubMed Central

Background: The formation of dental tissues is a highly delicate and complex phenomenon. Any alteration in this process leads to various dental anomalies which affect the tooth number, size, shape and structure. Supernumerary teeth are one such anomaly which affects the tooth number. Supernumerary teeth can give rise to various complications and pathologies or they may have a familial / syndromic association. They may occur along with other dental anomalies. Thus, such teeth have a definite clinical significance. Aims and Objectives: The aim of the following study was to know the prevalence of the supernumerary teeth and the distribution of the cases according to the age, sex, jaw, region, eruption status, and the position. Materials and Methods: A total of 5000 patients were examined for a period of 1 year’s duration and they were divided into different groups. Group I consisted of individuals who were aged between 5-20 years, Group II consisted of individuals who were aged between 21-40 years, and Group III consisted of individuals who were aged 41 years and above. The dental examination was conducted by using a mouth mirror and a probe, to determine the presence of supernumerary teeth. All the cases with supernumerary teeth were further observed and the details were recorded in a prepared porforma. These cases were also subjected to general physical examinations (to rule out any syndromes) and radiographic examinations. Photographs were also made. Conclusion: Although supernumerary teeth is an unusual anomaly, it is not as rare as was previously reported. The identification of this anomaly could provide a hint towards the possibility of complications, pathologies, other dental anomalies, syndromes and a familial association. PMID:23998107

Kumar, Dara Kalyan; Gopal, K Saraswathy

2013-01-01

459

Loss of teeth and enamel in tetrapods: fossil record, genetic data and morphological adaptations.  

PubMed

Since their recruitment in the oral cavity, approximately 450 million years ago, teeth have been subjected to strong selective constraints due to the crucial role that they play in species survival. It is therefore quite surprising that the ability to develop functional teeth has subsequently been lost several times, independently, in various lineages. In this review, we concentrate our attention on tetrapods, the only vertebrate lineage in which several clades lack functional teeth from birth to adulthood. Indeed, in other lineages, teeth can be absent in adults but be functionally present in larvae and juveniles, can be absent in the oral cavity but exist in the pharyngeal region, or can develop on the upper jaw but be absent on the lower jaw. Here, we analyse the current data on toothless (edentate) tetrapod taxa, including information available on enamel-less species. Firstly, we provide an analysis of the dispersed and fragmentary morphological data published on the various living taxa concerned (and their extinct relatives) with the aim of tracing the origin of tooth or enamel loss, i.e. toads in Lissamphibia, turtles and birds in Sauropsida, and baleen whales, pangolins, anteaters, sloths, armadillos and aardvark in Mammalia. Secondly, we present current hypotheses on the genetic basis of tooth loss in the chicken and thirdly, we try to answer the question of how these taxa have survived tooth loss given the crucial importance of this tool. The loss of teeth (or only enamel) in all of these taxa was not lethal because it was always preceded in evolution by the pre-adaptation of a secondary tool (beak, baleens, elongated adhesive tongues or hypselodonty) useful for improving efficiency in food uptake. The positive selection of such secondary tools would have led to relaxed functional constraints on teeth and would have later compensated for the loss of teeth. These hypotheses raise numerous questions that will hopefully be answered in the near future. PMID:19422426

Davit-Béal, Tiphaine; Tucker, Abigail S; Sire, Jean-Yves

2009-04-01

460

Biology meets engineering: the structural mechanics of fossil and extant shark teeth.  

PubMed

The majority of studies on the evolution and function of feeding in sharks have focused primarily on the movement of cranial components and muscle function, with little integration of tooth properties or function. As teeth are subjected to sometimes extreme loads during feeding, they undergo stress, strain, and potential failure. As attributes related to structural strength such as material properties and overall shape may be subjected to natural selection, both prey processing ability and structural parameters must be considered to understand the evolution of shark teeth. In this study, finite element analysis was used to visualize stress distributions of fossil and extant shark teeth during puncture, unidirectional draw (cutting), and holding. Under the loading and boundary conditions here, which are consistent with bite forces of large sharks, shark teeth are structurally strong. Teeth loaded in puncture have localized stress concentrations at the cusp apex that diminish rapidly away from the apex. When loaded in draw and holding, the majority of the teeth show stress concentrations consistent with well designed cantilever beams. Notches result in stress concentration during draw and may serve as a weak point; however they are functionally important for cutting prey during lateral head shaking behavior. As shark teeth are replaced regularly, it is proposed that the frequency of tooth replacement in sharks is driven by tooth wear, not tooth failure. As the tooth tip and cutting edges are worn, the surface areas of these features increase, decreasing the amount of stress produced by the tooth. While this wear will not affect the general structural strength of the tooth, tooth replacement may also serve to keep ahead of damage caused by fatigue that may lead to eventual tooth failure. PMID:21210488

Whitenack, Lisa B; Simkins, Daniel C; Motta, Philip J

2011-02-01

461

Effects of applying antioxidants on bond strength of bleached bovine dentin  

PubMed Central

Objectives Some antioxidants are believed to restore dentin bond strength after dental bleaching. This study was done to evaluate the influence of antioxidants on the bond strength of bleached bovine dentin. Materials and Methods Thirty incisors were randomly assigned to 10 groups (two unbleached control and eight bleached groups: immediate bonding IB, 4 wk delayed bonding DB, 10% sodium ascorbate treated SA, 10% ?-tocopherol treated TP groups). Teeth in half of groups were subjected to thermal stress, whereas the remaining groups were not. Resin-dentin rods with a cross-sectional area of 2.25 mm2 were obtained and microtensile bond strength was determined at a crosshead speed of 1 mm/min. Fifteen specimens were prepared for SEM to compare the surface characteristics of each group. The change in dentin bond strength from thermal stress and antioxidant treatment was evaluated using two-way analysis of variance (ANOVA) and Sheffe's post hoc test at a significance level of 95%. Results The control group exhibited the highest bond strength values, whereas IB group showed the lowest value before and after thermocycling. The DB group recovered its bond strength similar to that of the control group. The SA and TP groups exhibited similar bond strength values with those of the control and DB groups before thermocycling. However, The TP group did not maintain bond strength with thermal stress, whereas the SA group did. Conclusions Applying a 10% sodium ascorbate solution rather than 10% ?-tocopherol solution for 60 sec is recommended to maintain dentin bond strength when restoring non-vitally bleached teeth. PMID:25671211

Whang, Hyo-Jin

2015-01-01

462

Detection and Identification of the Atypical Bovine Pestiviruses in Commercial Foetal Bovine Serum Batches  

PubMed Central

The recently emerging atypical bovine pestiviruses have been detected in commercial foetal bovine serum (FBS) of mainly South American origin so far. It is unclear how widely the viruses are presented in commercial FBS of different geographic origins. To further investigate the possible pestivirus contamination of commercially available FBS batches, 33 batches of FBS were obtained from ten suppliers and analysed in this study for the presence of both the recognised and the atypical bovine pestiviruses. All 33 batches of FBS were positive by real-time RT-PCR assays for at least one species of bovine pestiviruses. According to the certificate of analysis that the suppliers claimed for each batch of FBS, BVDV-1 was detected in all 11 countries and BVDV-2 was detected exclusively in the America Continent. The atypical pestiviruses were detected in 13 batches claimed to originate from five countries. Analysis of partial 5?UTR sequences showed a high similarity among these atypical bovine pestiviruses. This study has demonstrated, for the first time that commercial FBS batches of different geographic origins are contaminated not only with the recognised species BVDV-1 and BVDV-2, but also with the emerging atypical bovine pestiviruses. PMID:22174836

Xia, Hongyan; Vijayaraghavan, Balaje; Belák, Sándor; Liu, Lihong

2011-01-01

463

Risk factors for bovine viral diarrhea infection  

Microsoft Academic Search

Bovine viral diarrhea virus (BLVD.) causes a wide range of clinical signs in both dairy and beef cattle including: infertility, abortions, decreased production and increased incidence of respiratory infections. Due to the economical losses caused by BVDV in many countries, several countries of the European Union have established successful control and eradication programs and recently BVDV was included on the

Maria E Negron

2009-01-01

464

Toxicity of DMSO to Bovine Corneal Endothelium  

Microsoft Academic Search

The toxicity of DMSO to bovine corneal endothelial cells is evaluated by the staining of nuclei in damaged cells by Trypane blue. The number of cells damaged by DMSO in a purely synthetic medium increase with the concentration of DMSO and time. No correlation is found between DMSO toxicity and temperature. The effect of mechanical strain and exposure to DMSO

Steffen Sperling

1976-01-01