Note: This page contains sample records for the topic bovine permanent teeth from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

[Congenital absence of permanent teeth].  

PubMed

In 76 patients treated at the Department of Conservative Stomatology, Institute of Stomatology, Medical Academy in Lublin congenital absence of anlages of permanent teeth was found. The patients were aged 8 to 18 years, including 49 girls and 27 boys. In the whole group absence of 214 teeth was noted, i.e. 136 in girls and 78 in boys. In the examinations it was observed that congenital absence of permanent teeth was more frequent in girls than in boys, 2) most frequently only one tooth was absent in a given patient, 3) upper teeth were lacking more frequently than lower teeth, and absence of right teeth was more frequent than left teeth, 4) the greatest group among absent teeth were upper lateral incisors, while second upper molars in the maxilla were least frequently absent. PMID:2104345

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

1990-04-01

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.

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

2012-01-01

3

Comparative analysis of human and bovine teeth: radiographic density.  

PubMed

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

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

2008-01-01

4

Mesiodistal crown diameters of permanent teeth in jordanians  

Microsoft Academic Search

Mesiodistal crown diameters were measured from dental casts of the permanent teeth of 198 Jordanians (86 males and 112 females), aged 13.4–19.1 years. The differences in the crown diameters between the right- and left-hand sides of the dental arch were not significant, suggesting that either right- or left-side measurements could be taken to represent the tooth size of the study

F. N. Hattab; S. Al-Khateeb; I. Sultan

1996-01-01

5

Traumatic injuries to permanent teeth in Turkish children, Ankara.  

PubMed

The aim of this study was to identify the types and etiologies of dento-alveolar injuries among patients who were treated for injuries to maxillary and/or mandibular permanent teeth at the Gulhane Medical Academy, Department of Pediatric Dentistry, Center of Dental Sciences in Ankara, Turkey to provide a basis for determining optimal treatment approaches and educational needs. From a total of 4956 children aged 6-12 years (mean age: 8.91 +/- 1.95) applying to the Center, 472 children (9.5%) were found to have suffered dental injuries during a period of 2 years. Injuries were classified according to drawings and texts based on the WHO classification system, as modified by Andreasen and Andreasen. Injury rates were highest among children age 6 and ages 8-10. The most frequently injured permanent teeth were the maxillary central incisors (88.2%), and the maxillary right central permanent incisor made up 47.2% of all injured teeth. The most common cause of dental trauma was falling while walking or running (40.3%). Most injuries involved a single tooth (64.8%). The most common type of injury was enamel fracture (44.6%). There was a significant difference in gender, where boys more often suffered from a dental hard tissue and pulp injury than girls (P = 0.019), whereas there was no difference in gender (P = 0.248) in the distribution of periodontal injuries. Injuries were found to occur more frequently during the summer (P < 0.001). Children with increased overjet were 2.19 times more likely to have dental injuries than other children. Considering that the incidence of traumatic dental injury is highest among children ages 6 and ages 8-10 as well as the fact that patients with increased overjet are more prone to dental trauma, preventive orthodontic treatment in early mixed dentition may play an important role in reducing traumatic dental injuries. PMID:19583580

Altun, Ceyhan; Ozen, Bu?ra; Esenlik, Elçin; Guven, Günseli; Gürbüz, Ta?kin; Acikel, Cengizhan; Basak, Feridun; Akbulut, Erman

2009-06-01

6

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

7

A longitudinal study of time trends in the eruption of permanent teeth in Danish children  

Microsoft Academic Search

The purpose was: (1) to estimate mean eruption times of permanent teeth in Danish schoolchildren for the birth cohorts from 1969 to 1982; and (2) to determine any time trends in eruption. For teeth with a low proportion of aplasia, the distribution of the eruption time was close to normal. For teeth with a higher proportion of aplasia there was

Erik T. Parner; Jens M. Heidmann; Michael Væth; Sven Poulsen

2001-01-01

8

Bacteria of Dental Caries in Primary and Permanent Teeth in Children and Young Adults  

Microsoft Academic Search

Although Streptococcus mutans has been implicated as a major etiological agent of dental caries, our cross-sectional preliminary study indicated that 10% of subjects with rampant caries in permanent teeth do not have detectable levels of S. mutans. Our aims were to use molecular methods to detect all bacterial species associated with caries in primary and permanent teeth and to determine

Jørn A. Aas; Ann L. Griffen; Sara R. Dardis; Alice M. Lee; Ingar Olsen; Floyd E. Dewhirst; Eugene J. Leys; Bruce J. Paster

2008-01-01

9

Enamel thickness in 47,XYY males' permanent teeth.  

PubMed

Enamel thickness of the maxillary permanent central incisors and canines in 14 47,XYY males, their male and female relatives and population-control males and females were determined from radiographs. The results indicated, although not fully unambiguously, that the thickness of enamel and that of 'dentin' (distance between mesial and distal dentino-enamel junctions) are increased in the teeth of 47,XYY males compared with normal controls. Earlier results have indicated a direct growth-promoting effect of the Y chromosome on tooth growth by influencing both enamel formation and, possibly through cell proliferations, growth of dentin. The present results can be considered additional evidence for the presence of the factors within the Y chromosome controlling different growth processes. Tooth size measurements in two males with deletions of the parts of the y chromosome suggested that there may be a specific growth-promoting gene(s) in the non-fluorescent part of the long arm. It is suggested that the way of influence of the Y chromosome on the amelogenesis is regulatory, and that the difference in tooth size between males and females is explained by a differential growth-promoting effect of the Y chromosome compared to the X chromosome. PMID:4062237

Alvesalo, L; Tammisalo, E; Hakola, P

1985-01-01

10

Pulpotomy of Symptomatic Permanent Teeth with Carious Exposure Using Mineral Trioxide Aggregate  

PubMed Central

Introduction To evaluate the clinical and radiographic outcomes of pulpotomy treatment with mineral trioxide aggregate (MTA) in symptomatic mature permanent teeth with carious exposure. Materials and Methods Ten patients aged 27-54 years presented with 11 symptomatic permanent teeth (n=11). Each offending carious tooth was clinically and radiographically determined. We removed caries as conservatively as possible; however pulp exposure was inevitable. ProRoot MTA pulpotomy was performed on these teeth. The patients were followed-up clinically and radiographically for 24-42 months. Results Immediate relief of patients` symptoms occurred. Moreover, teeth responses to the electric pulp tester were within normal range on follow-up appointment and the radiographs did not reveal any abnormality/lesion in the periapical areas. Conclusion Pulpotomy using MTA could be a good alternative for root canal therapy (RCT) for managing symptomatic mature permanent teeth with carious exposure, however further large-scale multicenter clinical trials are highly encouraged to confirm this hypothesis.

Barngkgei, Imad Hassan; Halboub, Esam Saleh; Alboni, Roula Safouh

2013-01-01

11

[Absence of permanent teeth buds in three generations of a family].  

PubMed

Hypodontia is described in three generations of a family. Absence of the buds of permanent teeth was noted in 6 out of 12 family members. These cases confirm the hereditary aetiology of this anomaly. PMID:2104354

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

1990-05-01

12

A review of pulp therapy for primary and immature permanent teeth.  

PubMed

The aim of pulp therapy in primary and young permanent teeth is to maintain a functional tooth so that arch integrity is preserved in a growing child. History, clinical evaluation and radiographic findings should be integrated to arrive at pulp diagnosis. Vital pulp therapy should be attempted whenever the pulp is diagnosed to be vital. Nonvital pulp therapy should be performed for strategically important primary teeth. Revascularization is an emerging technique for immature necrotic teeth. PMID:24073497

Ritwik, Priyanshi

2013-08-01

13

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

Microsoft Academic Search

The sequence and timing of permanent tooth eruption is thought to be highly heritable and can have important implications for the risk of malocclusion, crowding, and periodontal disease. We conducted a genome-wide association study of number of permanent teeth erupted between age 6 and 14 years, analyzed as age-adjusted standard deviation score averaged over multiple time points, based on childhood

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

2011-01-01

14

Sexual dimorphism in permanent teeth of modern Greeks  

Microsoft Academic Search

Sex determination is considered an important step in reconstructing the biological profile of unknown individuals from a forensic context. Forensic anthropologists have long used teeth as an additional tool for sex determination as they resist postmortem destruction. In this case the use of population-specific data is necessary since sexual dimorphism varies between different populations. Currently there are no odontometric standards

Eleni Zorba; Konstantinos Moraitis; Sotiris K. Manolis

2011-01-01

15

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

PubMed Central

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

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

2013-01-01

16

Influence of surgical repositioning of mature permanent dog teeth following experimental intrusion: a histologic assessment.  

PubMed

The aim of this study was to evaluate, through histologic examination, the effect of surgical repositioning of intruded dog teeth upon the pulpal and surrounding tissues. Thirty teeth in 10 adult dogs, aged 2-3 years, were used. Fifteen teeth were intruded, surgically repositioned and fixed using orthodontics wire, composite resin, and enamel acid conditioning. All these teeth served as the experimental group. The remaining intruded teeth were not treated (control group). The animals were sacrificed to allow observations at 7, 15, and 30 post-operative days. The maxillary and mandibular arches were removed and processed for histologic exam. Based on the methodology and observed results, we concluded that: pulpal necrosis, external root resorption and ankylosis were common sequelae to severe traumatic intrusion; a careful immediate surgical repositioning of severed intruded permanent tooth with complete root formation has many advantages with few disadvantages. PMID:12656863

Cunha, R F; Pavarini, A; Percinoto, C; Lima, J E O

2002-12-01

17

Frequently asked questions in direct pulp capping of permanent teeth.  

PubMed

Direct pulp capping is a proven method of preserving tooth vitality of a mature permanent tooth in cases of pulp exposures. The indications for this treatment, treatment modalities and materials are discussed in this paper. Clinical Relevance: This paper answers many of the frequently asked questions by general practitioners, dental students and specialists about direct pulp capping. PMID:24930251

Mouawad, Stéphanie; Artine, Simon; Hajjar, Pétra; McConnell, Robert; Fahd, Jean-Claude; Sabbagh, Joseph

2014-05-01

18

Unknown syndrome: peculiar face, severe hypodontia of permanent teeth, and precocious choroid calcifications.  

PubMed Central

We describe a mother and her twin daughters affected with severe hypodontia of the permanent teeth, precocious calcification of the choroid plexus, and minor digital anomalies. The presence of inner telecanthus, broad and flattened nasal bridge, mild ocular proptosis, small nose with anteverted nostrils, and slight microretrognathia gives them an unusual appearance. All three affected persons are of normal intelligence. Images

Pallotta, R; Fusilli, P

1998-01-01

19

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.

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

20

Microleakage of new dentin bonding systems using human and bovine teeth.  

PubMed

The objective of this study was twofold: to evaluate the microleakage behavior of three dentin bonding systems and to determine if bovine teeth are comparable substrates to human teeth when studying the microleakage of various materials. The materials evaluated were Scotchbond Multi-Purpose Adhesive, Prisma Universal Bond 3, and All-Bond 2. All three bonding systems were used in combination with Prisma APH hybrid composite for comparison of microleakage behavior. Sixty class 5 preparations were cut at the cementoenamel junction for groups containing 30 human and 30 bovine teeth. A 1 mm 45 degree bevel was placed at the enamel margin. Teeth were grouped according to the dentin bonding system used and then restored according to the manufacturer's directions. After restoration, the teeth from each group were stored in distilled water at 37 degrees C for 3 days. The teeth were then thermocycled between 4 degrees C and 58 degrees C for 100 cycles and returned to distilled water at 37 degrees C for an additional 4 days. The teeth were then sealed with nail polish up to 1 mm from the margins of the restoration and placed in 45Ca isotope for 2 hours. The teeth were then sectioned and placed on x-ray film to produce autoradiographs. Microleakage was evaluated for the enamel and dentin margins separately using the following scale: 0 = no leakage, 1 = penetration of isotope to less than 1/2 the distance to the axial wall, 2 = penetration of isotope greater than 1/2 of the distance to the axial wall but short of the axial wall, and 3 = penetration of isotope to the axial wall or beyond. The materials were compared to each other using the Mann-Whitney U and Kruskal-Wallis tests. The gingival margins were compared to the incisal margins for all materials. No statistically significant differences in microleakage were revealed between the incisal and gingival location for human substrates, but there was statistically significant greater gingival microleakage for bovine substrates. All-Bond 2 leaked significantly more than Scotchbond Multi-Purpose for human substrates at the incisal margin. All-Bond 2 had significantly more microleakage than Prisma Universal Bond 3 at both dentin and enamel margins for the bovine substrate. There were no statistically significant differences in microleakage among the bonding systems for the human substrate. No statistically significant differences between the microleakage behavior of human and bovine substrates were found. These results support the use of bovine teeth for in vitro microleakage studies. PMID:8710704

Reeves, G W; Fitchie, J G; Hembree, J H; Puckett, A D

1995-01-01

21

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.

Asgary, Saeed; Ehsani, Sara

2013-01-01

22

Case series: management of immature permanent teeth with pulpal necrosis: a case series.  

PubMed

The management of immature permanent teeth with necrotic pulps has changed in recent years from apexification techniques to regenerative endodontic procedures, which enable apexogenesis with physiologic maturation of the roots. This regenerative technique lies squarely in the endodontist's scope of practice, but children presenting with necrotic immature incisors may pose behavior management problems that endodontists are untrained and unwilling to handle. Treatment of these immature permanent teeth provides an excellent opportunity for collaboration and shared patient management between pediatric dentists and endodontists that can yield optimal clinical outcomes. The purpose of this paper was to report a series of 32 regenerative endodontic cases in 28 children treated at the Nationwide Children's Hospital, Columbus, Ohio. The report describes procedural and patient management issues and the need for a collaborative relationship between pediatric dentists and endodontists in tackling these challenging cases. PMID:23635900

McTigue, Dennis J; Subramanian, Kumar; Kumar, Ashok

2013-01-01

23

Biologically based treatment of immature permanent teeth with pulpal necrosis: a case series.  

PubMed

This case series reports the outcomes of 8 patients (ages 9-4 years) who presented with 9 immature permanent teeth with pulpal necrosis and apical periodontitis. During treatment, 5 of the teeth were found to have at least some residual vital tissue remaining in the root canal systems. After NaOCI irrigation and medication with ciprofloxacin, metronidazole, and minocycline, these teeth were sealed with mineral trioxide aggregate and restored. The other group of 4 teeth had no evidence of any residual vital pulp tissue. This second group of teeth was treated with NaOCl irrigation and medicated with ciprofloxacin, metronidazole, and minocycline followed by a revascularization procedure adopted from the trauma literature (bleeding evoked to form an intracanal blood clot). In both groups of patients, there was evidence of satisfactory postoperative clinical outcomes (1-5 years); the patients were asymptomatic, no sinus tracts were evident, apical periodontitis was resolved, and there was radiographic evidence of continuing thickness of dentinal walls, apical closure, or increased root length. PMID:22866415

Jung, Il-Young; Lee, Seung-Jong; Hargreaves, Kenneth M

2012-06-01

24

Comparative study to quantify demineralized enamel in deciduous and permanent teeth using laser- and light-induced fluorescence techniques.  

PubMed

Caries is a disease that affects both deciduous and permanent dentitions. Caries progresses more rapidly in deciduous enamel than in permanent enamel. Therefore, new caries diagnostic methods need to be tested on the deciduous teeth as well. Quantitative laser-induced fluorescence (QLF I) as well as the quantitative light-induced fluorescence (QLF II) seem promising for the quantification of mineral loss from dental caries but have only been tested on the permanent dentition. The objective of this study was to determine and compare the ability of QLF I and QLF II to quantify mineral loss from carious lesions in both deciduous and permanent teeth. Thirty sound deciduous and 30 sound permanent teeth were cleaned and divided into three groups each containing 10 deciduous and 10 permanent teeth. Windows on the buccal or labial enamel surfaces were demineralized for 48, 72, or 96 h. Images of demineralized enamel were captured using QLF I and QLF II. The images were analyzed to determine the mean change in fluorescence radiance (Delta F, %). The teeth were then sectioned for assessment of lesion depth (microm) and integrated mineral loss (IML, vol% x microm) using transverse microradiography (TMR), as the 'gold standard' for lesion analysis. The results indicated a good correlation for Delta F between QLF I and QLF II in both deciduous (r = 0.96) and permanent teeth (r = 0.98). There was a good correlation between Delta F and TMR (lesion depth and IML) in deciduous teeth (r = 0.76 and 0.84 with QLF I, r = 0.81 and 0.88 with QLF II). In permanent teeth, the correlation between Delta F and TMR (lesion depth and IML) was lower than in deciduous teeth (r = 0.07 and 0.53 with QLF I, r = 0.15 and 0.62 with QLF II). From these results it can be concluded that either QLF method is capable of quantifying mineral loss in early carious lesions in deciduous teeth. Moreover, under the conditions of this study, the use of either QLF method to quantify mineral loss in early carious lesions in deciduous teeth is slightly more accurate than in permanent teeth. PMID:11799288

Ando, M; van Der Veen, M H; Schemehorn, B R; Stookey, G K

2001-01-01

25

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

PubMed Central

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

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

2011-01-01

26

Comparative Study to Quantify Demineralized Enamel in Deciduous and Permanent Teeth Using Laser– and Light–Induced Fluorescence Techniques  

Microsoft Academic Search

Caries is a disease that affects both deciduous and permanent dentitions. Caries progresses more rapidly in deciduous enamel than in permanent enamel. Therefore, new caries diagnostic methods need to be tested on the deciduous teeth as well. Quantitative laser–induced fluorescence (QLF I) as well as the quantitative light–induced fluorescence (QLF II) seem promising for the quantification of mineral loss from

Masatoshi Ando; Monique H. van der Veen; Bruce R. Schemehorn; George K. Stookey

2001-01-01

27

Prevalence of hypodontia and developmental malformation of permanent teeth in Saudi Arabian schoolchildren.  

PubMed

This study was carried out to determine the prevalence of hypodontia and congenital malformation in permanent teeth of Saudi Arabian male children. Five-hundred schoolchildren were investigated, selected randomly from Riyadh city. The age group of the examined sample ranged from 13 years and 6 months to 14 years and 6 months. Clinical and radiographic examinations were performed. The findings indicated that hypodontia was present in about 4 per cent of the children; most frequently affected was the mandibular second premolars, maxillary laterals, and maxillary second premolars. Tooth malformations, mainly peg-shaped upper lateral incisors were also observed in about 4 per cent of the sample. PMID:2192761

al-Emran, S

1990-05-01

28

Age, period and cohort trends in caries of permanent teeth in four developed countries.  

PubMed

Objectives. We assessed the relative influences of age, period, and cohort effects on trends in caries experience of permanent teeth in 4 different populations. Methods. We used data from England and Wales, United States, Japan, and Sweden in which numerous cross-sectional, nationally representative surveys have been conducted periodically since the early 1960s. For each country, trends in caries experience (measured by DMFT index-the number of decayed, missing, and filled permanent teeth) were analyzed in an age, period, and cohort (APC) analysis using partial least square regression. Results. A strong effect of age manifested in caries experience, period and cohort effects aside. Caries levels increased through to adolescence; thereafter, there was a larger increase in DMFT in adulthood. Compared with the aging effect, period and cohort effects on caries experience were small. Population DMFT scores decreased over time in all countries except Japan. Cohort effects on caries experience displayed a nonlinear pattern in all 4 countries, with slightly lower caries levels among the oldest and most recent generations. Conclusions. Despite marked recent declines in caries among children, caries levels increase with age and remain problematic in adults. PMID:24832427

Bernabé, Eduardo; Sheiham, Aubrey

2014-07-01

29

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

PubMed Central

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

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

2013-01-01

30

Three-year evaluation of the ART approach in Class III and V restorations in permanent anterior teeth.  

PubMed

This study evaluated the survival of class III and V restorations using the atraumatic restorative treatment (ART) approach in permanent anterior teeth, after 3 years. A total of 151 restorations were performed in 60 patients. After 3 years, 107 restorations (47 patients) were evaluated. Data were analyzed using exact 95% confidence interval. A total of 97 restorations (91% with 95% CI = 83-99), 76 class III (92% with 95% CI = 82-100) and 21 class V (88% with 95% CI = 77-98) were classified as successful. The survival rate of the ART approach in class III and V restorations in permanent anterior teeth was considered high. PMID:16946606

Cefaly, D F G; Tapety, C M C; Mondelli, R F L; Lauris, J R P; Phantumvanit, P; Navarro, M F L

2006-01-01

31

[Anomalies in the number of permanent teeth in orthodontic patients in 2 localities in Croatia].  

PubMed

The authors investigated the frequency of anomalies among permanent teeth in two regions in Yugoslavia--Istria and Slavonia--in a group of 4449 orthodontic patients (1890 boys and 2559 girls, age 6-18 years; in Istria: 1060 boys and 1341 girls, in Slavonia: 830 boys and 1218 girls). The anomalies were diagnosed by clinical examination and by orthopantomogram analysis. The anomalies were significantly more frequent in children of Istria compared to the ones of Slavonia, i.e. hypodontia was found in 6.25% versus 2.34% and hyperdontia in 1.37% versus 0.63%. Hypodontia in the mandible prevailed among the children in Istria while that in the maxilla among the children in Slavonia. The differences in the sequence of the hypodontia frequency for each tooth in both sexes have been established separately for the two regions. PMID:2320986

Legovi?, M; Cerani?, I; Cehich, A

1990-01-01

32

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

PubMed

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

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

2012-01-01

33

Bacteria of Dental Caries in Primary and Permanent Teeth in Children and Young Adults?  

PubMed Central

Although Streptococcus mutans has been implicated as a major etiological agent of dental caries, our cross-sectional preliminary study indicated that 10% of subjects with rampant caries in permanent teeth do not have detectable levels of S. mutans. Our aims were to use molecular methods to detect all bacterial species associated with caries in primary and permanent teeth and to determine the bacterial profiles associated with different disease states. Plaque was collected from 39 healthy controls and from intact enamel and white-spot lesions, dentin lesions, and deep-dentin lesions in each of 51 subjects with severe caries. 16S rRNA genes were PCR amplified, cloned, and sequenced to determine species identities. In a reverse-capture checkerboard assay, 243 samples were analyzed for 110 prevalent bacterial species. A sequencing analysis of 1,285 16S rRNA clones detected 197 bacterial species/phylotypes, of which 50% were not cultivable. Twenty-two new phylotypes were identified. PROC MIXED tests revealed health- and disease-associated species. In subjects with S. mutans, additional species, e.g., species of the genera Atopobium, Propionibacterium, and Lactobacillus, were present at significantly higher levels than those of S. mutans. Lactobacillus spp., Bifidobacterium dentium, and low-pH non-S. mutans streptococci were predominant in subjects with no detectable S. mutans. Actinomyces spp. and non-S. mutans streptococci were predominant in white-spot lesions, while known acid producers were found at their highest levels later in disease. Bacterial profiles change with disease states and differ between primary and secondary dentitions. Bacterial species other than S. mutans, e.g., species of the genera Veillonella, Lactobacillus, Bifidobacterium, and Propionibacterium, low-pH non-S. mutans streptococci, Actinomyces spp., and Atopobium spp., likely play important roles in caries progression.

Aas, J?rn A.; Griffen, Ann L.; Dardis, Sara R.; Lee, Alice M.; Olsen, Ingar; Dewhirst, Floyd E.; Leys, Eugene J.; Paster, Bruce J.

2008-01-01

34

Multidisciplinary approach on rehabilitation of primary teeth traumatism repercussion on the permanent successor: 6-year follow-up case report.  

PubMed

Traumatic lesions in primary teeth are frequent in pediatric patients and can cause problems both to the deciduous tooth and permanent successor. The impact strength on deciduous tooth can reach the growing permanent tooth, affecting its morphology, structure and position, or even hampering its proper development. This report describes an aesthetic-functional rehabilitation process in an 8 year 10 month old boy during a multidisciplinary treatment held at the Clinical Center of Dental Trauma in Primary Teeth of the Pediatric Dentistry of Dental College of University of São Paulo, Brazil. The patient presented bilateral posterior cross bite and the permanent left upper central incisor with ectopic eruption and enamel hypoplasy, preceded by avulsion of element 61, occurred when the patient was 1.6 years old. After diagnosis and treatment planning, a quick expansion of jaws was recommended with Hass-type rapid expander and orthodontic leveling with fixed braces. Due to the ectopic eruption, the gingival contour had been altered and hypertrophia was found, compromising aesthetics and avoiding local hygienic procedures. Gingivoplasty was carried out with high-intensity Diode Laser, followed by aesthetic restoration with compound resin. It was concluded that after deciduous teeth traumatism it is important that the patient undergoes clinic and radiographic assistance until the permanent teeth erupt so that an adequate multidisciplinary treatment can be offered to the patient. PMID:19736508

Mello-Moura, A C V; Bonini, G A V C; Suga, S S; Navarro, R S; Wanderley, M T

2009-01-01

35

Three-Year Evaluation of the ART Approach in Class III and V Restorations in Permanent Anterior Teeth  

Microsoft Academic Search

This study evaluated the survival of class III and V restorations using the atraumatic restorative treatment (ART) approach in permanent anterior teeth, after 3 years. A total of 151 restorations were performed in 60 patients. After 3 years, 107 restorations (47 patients) were evaluated. Data were analyzed using exact 95% confidence interval. A total of 97 restorations (91% with 95%

D. F. G. Cefaly; C. M. C. Tapety; R. F. L. Mondelli; J. R. P. Lauris; P. Phantumvanit; M. F. L. Navarro

2006-01-01

36

[Changes in the properties of the enamel of the permanent teeth in children using fluoride-containing toothpastes].  

PubMed

Focal demineralization of the enamel of permanent teeth was studied in 104 schoolchildren aged 9 to 12 over the course of prophylaxis (cleaning the teeth with fluorine-containing toothpastes). The parameters checked up were the intensity of coloring, size and electric conductivity of the spots, and the rate of remineralization of the enamel of permanent teeth. For a year a strong correlation between the tested characteristics of the enamel and saliva was observed. Some age-specific characteristics of permanent teeth enamel were detected. Age group of 11 to 12 years should be distinguished in prophylactic and control groups, because it is at this age that all the tested properties of the enamel are the most liable to change: electric conductivity, permeability, and remineralization rate. This period seems to be characterized by a specific reaction of all systems and organs of the body to environmental exposures. Remineralizing prophylaxis was found to be the most effective at the age of 9 to 10 years. The findings permit us emphasize the contribution of fluorine contained in the Blendax fluorine-containing toothpaste used by the children to the major components of the pathologic process (white spots) and enamel remineralization at the stage of its maturation. PMID:7732536

Ashirov, K A

1994-01-01

37

An Evaluation of Various Permanent Restorative Materials' Effect on the Shade of Bleached Teeth.  

National Technical Information Service (NTIS)

Thirty-six teeth were stained, bleached and restored using four restorative techniques. The final tooth shade was determined subjectively by visual observance, and objectively by actual measurement of light transference. The teeth with silicate in the can...

W. F. Freccia D. D. Peters L. Lorton

1981-01-01

38

Degradation of resin-dentin bonds of etch-and-rinse adhesive system to primary and permanent teeth.  

PubMed

The aim of this in vitro study was to compare the degradation of resin-dentin bonds of an etch-and-rinse adhesive system to primary and permanent teeth. Flat superficial coronal dentin surfaces from 5 primary second molars and 5 permanent third molars were etched with phosphoric acid and bonded with an adhesive system (Adper Single Bond 2, 3M ESPE). Blocks of resin composite (Z250, 3M ESPE) were built up and the teeth sectioned to produce bonded sticks with a 0.8 mm² cross-sectional area. The sticks of each tooth were randomly divided and assigned to be subjected to microtensile testing immediately (24 h) or after aging by water storage (6 months). Data were analyzed by two-way repeated measures ANOVA and Tukey post hoc test (? = 0.05). Failure mode was evaluated using a stereomicroscope (400×). Microtensile values significantly decreased after the 6 months aging, independent of the dentin substrate. In 24 h, the values obtained to primary dentin were lower compared with permanent dentin. This difference was not maintained after aging. Adhesive/mixed failure was predominant in all experimental groups. In conclusion, degradation of resin-dentin bonds of the etch-and-rinse adhesive system occurred after 6 months of water storage; however, the reduction in bond strength values was higher for permanent teeth. PMID:23019083

Lenzi, Tathiane Larissa; Soares, Fabio Zovico Maxnuck; Rocha, Rachel de Oliveira

2012-01-01

39

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

PubMed Central

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

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

2011-01-01

40

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

PubMed Central

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

Alesia, Khalil; Khalil, Hesham S

2013-01-01

41

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

Microsoft Academic Search

In this study, 60 human permanent healthy teeth (without filling) were collected postmortem and analyzed using flame atomic\\u000a absorption spectrometry (FAAS), cold vapor atomic absorption spectrometry (CVAAS), hydride generation atomic absorption spectrometry\\u000a (HGAAS), and electrothermal atomic absorption spectrometry (ETAAS) for the determination of Ca, Hg, Se, Cu, and Ag. The concentration\\u000a of these elements was assessed in carious and noncarious

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

2007-01-01

42

Timing of mineralization of homologues permanent teeth--an evaluation of the dental maturation in panoramic radiographs.  

PubMed

Clinically the condition Molar Incisor Hypomineralization (MIH),varies considerably between individuals, where any number of molars, from one to all four permanent first molars, may be affected with different degrees of hypomineralized enamel within the same dentition. An explanation to these variations could be that the start of the enamel mineralization differs between homologues teeth. The aim of this study was to compare the dental development between homologues teeth in digital panoramic radiographs (PRs),from children aged 7 to 11 years, using the Gleiser & Hunt method on second and third molars and to calculate the crown/root ratio for the mandibular premolars.77 PRs, from individuals between 7.3 and 11.0 years of age, were studied. Differences in developmental stages between homologues teeth (second and third molars) were studied. In 72 of these PRs, the crown/root ratio of mandibular premolars was also compared. In 31 of the PRs, a difference in development was found between the right and left maxillary second molar. In 22 PRs, a difference in development between the right and left mandibular second molar was found. In 17 of the PRs, a difference in development was found between the right and left maxillary third molars. In 26 PRs,a difference in-between the right and left mandibular third molar was found. In 72 PRs, the crown/root ratio of mandibular premolars was measured and differences were found. All these differences were significant. A possible explanation to the variations in expressivity of MIH may be a result of differences in the start of mineralization between homologues teeth. Timing of mineralization of homologues permanent teeth--An evaluation of the dental maturation in panoramic radiographs. PMID:24341164

Sahlstrand, Pia; Lith, Agneta; Hakeberg, Magnus; Norén, Jörgen G

2013-01-01

43

In vitro and in vivo characteristics of stem cells derived from the periodontal ligament of human deciduous and permanent teeth.  

PubMed

In many studies, adult stem cells have been found in human periodontal ligament (PDL), but in most cases they were found in the permanent teeth. The aim of the present study was to characterize stem cells from the PDL of deciduous teeth (dPDLSCs) and compare them with those from the PDL of permanent teeth (pPDLSCs). Stem cell markers were examined by a flow cytometric analysis. The results of in vitro differentiation into adipogenic and osteogenic lineages were analyzed by histochemical staining and quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results of in vivo transplantation were analyzed by histological staining, immunohistochemical staining, and quantitative RT-PCR. There were no significant differences in the proliferation rate, cell cycle distribution, expressions of stem cell markers such as Stro-1 and CD146, or in vitro differentiation. The pPDLSC transplants made more typical cementum/PDL-like tissues and expressed more cementum/PDL-related genes (CP23 and collagen XII) than did the dPDLSC transplants. Together, these results suggest that pPDLSCs are better candidates for use in reconstructing periodontium. PMID:22571499

Song, Je Seon; Kim, Seong-Oh; Kim, Seung-Hye; Choi, Hyung-Jun; Son, Heung-Kyu; Jung, Han-Sung; Kim, Chang-Sung; Lee, Jae-Ho

2012-10-01

44

Pulpal and periodontal reactions of immature permanent teeth in the dog to intrusive trauma.  

PubMed

Pulpal and periodontal tissues of immature incisors of 10 dogs were radiographically and histopathologically evaluated immediately, 7, 15, 30 and 60 days after experimental intrusion induced by mechanical blows. Forty upper central and mesial lateral incisors showing incomplete root formation on radiographs were submitted to intrusive force. After the observation periods, the dogs were killed, two at a time. The hemi-maxilas were removed and processed for histopathologic examination. The traumatized teeth showed accelerated apical formation with reduced radicular length. Pulpal vitality was maintained and the subjacent tissues did not present irreversible changes. All traumatized teeth re-erupted spontaneously. PMID:7641617

Cunha, R F; Pavarini, A; Percinoto, C; Lima, J E

1995-04-01

45

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

PubMed Central

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

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

2014-01-01

46

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.

IG, Kanimozhi; M, Sivakumar

2014-01-01

47

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

PubMed

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

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

2012-05-01

48

Root growth in the permanent teeth of 45,X/46,XX females.  

PubMed

Studies on individuals with sex chromosome anomalies have provided proof of a direct differential promoting effect of the X and Y chromosome genes on tooth crown growth. 45,X/46,XX females are one subgroup of Turner patients who have both normal XX and one X sex chromosome cell lines. Their permanent tooth crown size is reduced, which is mainly due to thin enamel. 45,X females likewise show reduced crown size and enamel thickness, and their root size is reduced. By contrast, the lengths of the roots in 47,XYY males or males with an extra Y chromosome and 46,XY females or females with a male sex chromosome constitution are increased. The aim of the present study was to investigate permanent tooth root lengths in 45,X/46,XX females to obtain additional information on their dental growth. The study group consisted of 15 45,X/46,XX females, mean age 23.4 years; 10 female relatives, mean age 24.5 years; and 47 population control females, mean age 29.8 years, from the Kvantti research project. Root length measurements were made from panoramic radiographs on both sides of the jaw using a sliding digital calliper. The results showed that permanent tooth root lengths in 45,X/46,XX females were, in most cases, significantly shorter than those of the population controls or relatives. It is apparent that a reduced tooth crown size in 45,X/46,XX females is followed by reduced root growth. This begins 3 years after birth and continues to at least 14 years of age. It is suggested that the reduction in crown and root growth in 45,X/4,XX females is due to a deficiency in the amount of dental growth-promoting genes on the sex chromosomes. PMID:16679328

Lähdesmäki, Raija; Alvesalo, Lassi

2006-08-01

49

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

50

CCL3 and CXCL12 production in vitro by dental pulp fibroblasts from permanent and deciduous teeth stimulated by Porphyromonas gingivalis LPS  

PubMed Central

Objective: The aim of this study was to compare the production of the chemokines CCL3 and CXCL12 by cultured dental pulp fibroblasts from permanent (PDPF) and deciduous (DDPF) teeth under stimulation by Porphyromonas gingivalis LPS (PgLPS). Material and Methods: Primary culture of fibroblasts from permanent (n=3) and deciduous (n=2) teeth were established using an explant technique. After the fourth passage, fibroblasts were stimulated by increasing concentrations of PgLPS (0 - 10 µg/mL) at 1, 6 and 24 h. The cells were tested for viability through MTT assay, and production of the chemokines CCL3 and CXCL12 was determined through ELISA. Comparisons among samples were performed using One-way ANOVA for MTT assay and Two-way ANOVA for ELISA results. Results: Cell viability was not affected by the antigen after 24 h of stimulation. PgLPS induced the production of CCL3 by dental pulp fibroblasts at similar levels for both permanent and deciduous pulp fibroblasts. Production of CXCL12, however, was significantly higher for PDPF than DDPF at 1 and 6 h. PgLPS, in turn, downregulated the production of CXCL12 by PDPF but not by DDPF. Conclusion: These data suggest that dental pulp fibroblasts from permanent and deciduous teeth may present a differential behavior under PgLPS stimulation.

SIPERT, Carla Renata; MORANDINI, Ana Carolina de Faria; MODENA, Karin Cristina da Silva; DIONISIO, Thiago Jose; MACHADO, Maria Aparecida Andrade Moreira; de OLIVEIRA, Sandra Helena Penha; CAMPANELLI, Ana Paula; SANTOS, Carlos Ferreira

2013-01-01

51

Stem cells obtained from pulp of deciduous or permanent teeth and of dental germ, able to produce human bone tissue  

US Patent & Trademark Office Database

In this invention is described a method that foresees the isolation of a new subpopulation of stem cells derived form dental pulp, whose differentiation is osteoblasts lead to the subsequent production and employment of a bone tissue, called LAB (Living Autologous Bone). Specifically, the invention describes: 1) the isolation of stem cells from the pulp of deciduous and permanent teeth and of dental germs, obtained from human subjects; 2) the growth of these cells in vitro, under specific conditions that allow the isolation of a cellular sub-population, which, after differentiation in osteoblasts, is able to produce in vitro an extracellular matrix, identical to that detectable in bone tissue; 3) the use of this selected and differentiated cell population in order to produce autologous bone tissue in vitro, containing vital osteoblasts; 4) the preservation of the LAB under conditions which guarantee cellular vitality; 5) the use of the LAB in donor patients to reconstruct bone tissue, as required in the daily practice in dentistry, maxillo-facial surgery and orthopedics.

2011-06-07

52

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.

Heinrich-Weltzien, Roswitha; Monse, Bella

2013-01-01

53

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

54

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

PubMed

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

2014-04-01

55

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.

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

2014-01-01

56

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

57

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

PubMed

Femtosecond lasers have been widely used in laser surgery as an instrument for contact-free tissue removal of hard dental, restorative materials, and osseous tissues, complementing conventional drilling or cutting tools. In order to obtain a laser system that provides an ablation efficiency comparable to mechanical instruments, the laser pulse rate must be maximal without causing thermal damage. The aim of this study was to compare the different morphological characteristics of the hard tissue after exposure to lasers operating in the femtosecond pulse regime. Two different kinds of samples were irradiated: dentin from human extracted teeth and bovine femur samples. Different procedures were applied, while paying special care to preserving the structures. The incubation factor S was calculated to be 0.788±0.004 for the bovine femur bone. These results indicate that the incubation effect is still substantial during the femtosecond laser ablation of hard tissues. The plasma-induced ablation has reduced side effects, i.e., we observe less thermal and mechanical damage when using a superficial femtosecond laser irradiation close to the threshold conditions. In the femtosecond regime, the morphology characteristics of the cavity were strongly influenced by the change of the effective number of pulses. PMID:22559697

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

2012-04-01

58

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

PubMed Central

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

Bodur, Haluk; Ece, Gulden

2012-01-01

59

In vitro evaluation of the cariostatic action of esthetic restorative materials in bovine teeth under severe cariogenic challenge.  

PubMed

Considering that caries around restorations is a serious problem in dentistry, and some restorative materials with fluoride may be important in inhibiting these lesions, this research is aimed at performing an in vitro evaluation of the cariostatic action of some esthetic restorative materials. Standardized cavities were prepared in the center of either intact blocks of bovine enamel or with bovine teeth containing early artificial carious lesions. The specimens were restored with a high viscosity glass ionomer cement (Molar Ketac), a resin-modified glass ionomer cement (Vitremer), a polyacid-modified resin composite (Dyract AP) and a conventional resin composite (Z-250). In addition to the restored specimens, four corresponding control groups were evaluated. All groups, except for two control groups, were subjected to a demineralization/remineralization cycling model for 14 days, simulating a situation of severe cariogenic challenge. The blocks were then longitudinally sectioned through the restorations. Mineral loss was evaluated in these specimens using the Knoop microhardness profiles in longitudinal sections at three different distances of the cavities and at eight distinct depths in relation to the external enamel surface. Statistical analysis of the results showed significant differences (p < 0.05) among the groups, although none of the study materials completely inhibited creation of the lesions. Vitremer demonstrated the best cariostatic action in intact bovine enamel. Ketac Molar, in intact or demineralized enamel, and Vitremer, in demineralized enamel, presented intermediate cariostatic potential. Z-250 and Dyract AP did not demonstrate any cariostatic effect. The data suggests that glass ionomer cements demonstrated better cariostatic action compared to the other restorative materials. PMID:15986958

Pin, Maria Ligia Gerdullo; Abdo, Ruy Cesar Camargo; Machado, Maria Aparecida de Andrade Moreira; da Silva, Salete Moura Bonifácio; Pavarini, Aymar; Marta, Sara Nader

2005-01-01

60

Scanning electron microscopic preliminary study of the efficacy of SmearClear and EDTA for smear layer removal after root canal instrumentation in permanent teeth.  

PubMed

This study aimed to evaluate the efficacy of SmearClear (SybronEndo, Orange, CA) and EDTA for smear layer removal from root canals of permanent teeth after instrumentation. Thirty extracted human permanent teeth (n = 10) were randomly assigned to the following groups: group 1 = 14.3% EDTA, group 2 = SmearClear, and group 3 = no smear layer removal procedure was undertaken (control). The specimens were submitted to scanning electron microscopy analysis. Magnifications of 200x and 750x were used to evaluate cleaning at the apical, middle, and cervical thirds according to a three-point scoring system. Data were analyzed statistically by the Mann-Whitney U test (5% significance level). Groups 1 and 2 differed significantly from group 3 (p < 0.01). However, there was no statistically significant difference (p > 0.05) between groups 1 and 2. In conclusion, SmearClear was able to remove the smear layer from the root canals of permanent teeth similarly as 14.3% EDTA, suggesting that both solutions may be indicated for such purpose. PMID:19026891

da Silva, Lea Assed Bezerra; Sanguino, Ana Carolina Meng; Rocha, Cristiane Tomaz; Leonardo, Mario Roberto; Silva, Raquel Assed Bezerra

2008-12-01

61

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.

Xue, Dai Juan and Feng

2014-01-01

62

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

PubMed Central

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

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

2013-01-01

63

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

PubMed Central

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

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

2012-01-01

64

SEM study of a self-etching primer adhesive system used for dentin bonding in primary and permanent teeth  

Microsoft Academic Search

Purpose: The purpose of this study was to evaluate the interfa- cial micromorphology of direct esthetic restorations bonded to primary or permanent tooth dentin with a self-etching primer adhesive system. Methods: Superficial dentin at the occlusal surface of 15 pri- mary and 15 permanent molars was exposed with a carbide bur. Prompt-L-Pop was applied in one half of each surface.

Paloma Dias da Silva; Maria Aparecida; A. Moreira Machado; Jacques Eduardo; Nör DDS

65

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

66

Histological structures and acidic etching sensitivities of the enamels at the occlusal pit parts in the deciduous and permanent teeth  

Microsoft Academic Search

The purpose of this study is to compare the histological structures and acidic etching sensitivities of the enamels at the occlusal pit parts between the deciduous molars and permanent molars. They were observed by the polarizing and scanning electron microscopies. The enamel rods were less made slender by EDTA etching and the outlines of the apatite crystals, constituting the enamel

Masashi Takahashi; Jinhua Zheng; Kazuhisa Mori; Izumi Mataga; Kan Kobayashi

2006-01-01

67

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

PubMed

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

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

2012-01-01

68

Dinosaur Teeth  

NSDL National Science Digital Library

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

69

Anomalous morphologic formation of deciduous and permanent teeth in a 5-year-old 15th century child: a variant of the Ekman-Westborg-Julin syndrome.  

PubMed

A gross morphologic anomaly affecting both the primary and secondary teeth of unknown cause is presented. A 5-year-old American Indian child exhibited macrodontia, extreme shovel-shaping, agenesis, three-rooted deciduous molars, dens invaginatus, and other less striking dental features. This case represents the earliest example of a variant of the Ekman-Westborg-Julin syndrome reported in the New World. PMID:2196508

Mann, R W; Dahlberg, A A; Stewart, T D

1990-07-01

70

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

NASA Astrophysics Data System (ADS)

The present paper investigated the effects of two different laser beams on dentin and root canal walls. Five human intact teeth (incisors and canines), with endodontic treatment accomplished by Paiva and Antoniazzi technique, had their crowns separated from the roots using a diamond teeth. After polishing the dentin surfaces, they were irradiated with CO2 and NdYag laser and analyzed using SEM and light microscopy. The light microscopy revealed some cicunscribed carbonized areas with some cracks of varied depths in all samples but indicated that the CO2 laser, at power level of 5 watts, was more effective than NdYag laser at power level of 2 watts. The SEM showed formation of circular depressions with areas containing dentin fusion, melted dentin on small holes on the vitrified surfaces. From the data obtained, it was concluded that the methods analyzed are able to remove the remaining residues on the dentin layer and root canal walls. However, no complete fusion of the dentin layer occurred.

Brugnera, Aldo, Jr.; Lopes, Marcia C. S.; Matsumoto, Koukichi; Watanabe-Sei, Ii

1998-04-01

71

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.

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

2014-01-01

72

Dentist and practice characteristics associated with restorative treatment of enamel caries in permanent teeth: multiple-regression modeling of observational clinical data from The National Dental PBRN  

PubMed Central

Purpose Current evidence in dentistry recommends non-surgical treatment to manage enamel caries lesions. However, surveyed practitioners report they would restore enamel lesions that are confined to the enamel. We used actual clinical data to evaluate patient, dentist, and practice characteristics associated with restoration of enamel caries, while accounting for other factors. Methods We combined data from a National Dental Practice-Based Research Network observational study of consecutive restorations placed in previously unrestored permanent tooth surfaces and practice/demographic data from 229 participating network dentists. Analysis of variance and logistic regression, using generalized estimating equations (GEE) and variable selection within blocks, were used to test the hypothesis that patient, dentist, and practice characteristics were associated with variations in enamel restorations of occlusal and proximal caries compared to dentin lesions, accounting for dentist and patient clustering. Results Network dentists from 5 regions placed 6,891 restorations involving occlusal and/or proximal caries lesions. Enamel restorations accounted for 16% of enrolled occlusal caries lesions and 6% of enrolled proximal caries lesions. Enamel occlusal restorations varied significantly (p<0.05) by patient age and race/ethnicity, dentist use of caries risk assessment, network region, and practice type. Enamel proximal restorations varied significantly (p<0.05) by dentist race/ethnicity, network region, and practice type. CLINICAL SIGNIFICANCE Identifying patient, dentist, and practice characteristics associated with enamel caries restorations can guide strategies to improve provider adherence to evidence-based clinical recommendations.

Fellows, Jeffrey L; Gordan, Valeria V.; Gilbert, Gregg H.; Rindal, D. Brad; Qvist, Vibeke; Litaker, Mark S.; Benjamin, Paul; Flink, Hakan; Pihlstrom, Daniel J.; Johnson, Neil

2014-01-01

73

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

PubMed

Retained primary teeth is a well-known process but multiple retained primary, permanent, and supernumerary teeth that too in an asymptomatic, non-syndromic patient is a rare possibility that has rarely been reported in literature. This case report discusses the clinical and radiographic details along with treatment options in a 21-year-old patient having a total number of 50 teeth, i.e., 16 retained primary teeth, 32 permanent teeth, and 2 supernumerary teeth without being associated with any known syndrome complex or metabolic disorder. PMID:24082755

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

2013-07-01

74

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

PubMed Central

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

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

2013-01-01

75

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.

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

2012-01-01

76

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.

Ghosh, Chiranjit; Mondal, Pradeep Kumar

2014-01-01

77

Wisdom Teeth Management  

MedlinePLUS

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

78

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

79

Whiter Teeth: What Works?  

MedlinePLUS

... with perfect teeth to have a bright smile. Tooth whitening , or bleaching, can usually erase stains and discoloration ... products tend to cost less than having your teeth whitened by a dentist. However, they aren't ideal . ...

80

Teeth Injuries (For Parents)  

MedlinePLUS

... Breastfeeding FAQs Pregnant? Your Baby's Growth First Aid: Teeth Injuries KidsHealth > Parents > First Aid & Safety > Printable Safety ... or young child injures the gums or baby teeth: Apply pressure to the area (if it's bleeding) ...

81

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.

82

Bilateral radicular cysts of mandibular deciduous teeth: a case report.  

PubMed

While common in adult teeth, radicular cysts are uncommon in deciduous teeth. When they do occur, they are associated with non-vital teeth and typically present 6 months to 5 years after vitality is lost. They cause swelling, bone-loss and permanent tooth bud displacement. Often, they are incidental findings. A case involving radicular cysts on the left and right sides of the mandible is presented. If non-vital deciduous teeth receive pulp therapy, regular post- operative reviews are recommended. PMID:23019771

Gaynor, Wanda N

2012-09-01

83

Idiopathic multiple impacted unerupted teeth: Case report and discussion.  

PubMed

Multiple impacted permanent teeth are usually related to syndromes, metabolic and hormonal disorders. However, in some cases, impaction of multiple teeth is not associated with any syndrome. In this report, we present a case of 17-year-old male patient with missing teeth. Radiographs revealed multiple impacted permanent teeth, though medical and family history along with physical examination was not suggestive of any syndromes. If other investigations are negative, an idiopathic case of multiple impacted teeth is suggested to be the possible diagnosis. The objective of this report is to increase awareness of such cases especially in the absence of hereditary/genetic/metabolic factors usually inherent in such scenarios. The patient management in such cases needs to be planned specifically from a multidisciplinary standpoint. PMID:22438652

Sujatha, G; Sivapathasundharam, B; Sivakumar, G; Nalinkumar, S; Ramasamy, M; Prasad, T Srinivasa

2012-01-01

84

Brushless dc generator without permanent magnet  

Microsoft Academic Search

This paper presents characteristic analysis of a without permanent magnet Brushless dc (WPMBLDC) generator. Proposed configuration is a 9\\/6 BLDC generator in which permanent magnet is replaced with assisted field coil in the rotor. Due to dc current in the assistant field winding, the magnetic field flows axially through the rotor shaft and closes through the stator teeth and the

H. Moradi; M. Seyed Yazdi; E. Afjei

2010-01-01

85

Natal teeth: a review.  

PubMed Central

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

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

2006-01-01

86

Tuberculate and odontoma type supernumerary teeth.  

PubMed

An 8-and-a-half-year-old girl with supernumerary teeth of tuberculate and odontoma type is described. Treatment of the patient is carried out on conventional lines with a combination of surgical and orthodontic methods. The upper tuberculate type supernumerary teeth were extracted and, after surgical exposure, the upper permanent first incisors were aligned with removable appliances. After secondary dentition was completed, the lower odontoma type supernumerary tooth was removed surgically, and also the maxillary and mandibular first premolars were extracted because of severe crowding, and fixed orthodontic appliances were used to align the permanent dentition. Early diagnosis and treatment of this anomaly is necessary to avoid more serious consequences and to prevent severe orthodontic disturbances. PMID:16327561

Tarján, Ildikó; Gyulai, Szabolcs G; Soós, Attila; Rózsa, Noémi

2005-11-01

87

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.

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

2014-01-01

88

Shark Teeth Classification  

NSDL National Science Digital Library

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

Creel, Sally; Brown, Tom; Lee, Velda

2009-03-01

89

Management of supernumerary teeth  

PubMed Central

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

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

2011-01-01

90

Malocclusion (Misaligned Teeth)  

MedlinePLUS

... Resources for Help and Information The One-Page Merck Manual of Health Medical Terms Conversion Tables Manuals ... Inflammation Toothache Malocclusion Teeth Grinding Recurrent Aphthous Stomatitis Merck Manual > Patients & Caregivers > Mouth and Dental Disorders > Symptoms ...

91

Use of Cantilever Mechanics for Impacted Teeth: Case Series  

PubMed Central

This paper describes the orthodontic treatment, and the biomechanics of cantilevers for the impaction of permanent teeth in youngs, adolescents, and adults. In these case series, multibracket straightwire fixed appliances, together with cantilever mechanics, were used to treat the impaired occlusion.

Paduano, Sergio; Spagnuolo, Gianrico; Franzese, Gerardo; Pellegrino, Gioacchino; Valletta, Rosa; Cioffi, Iacopo

2013-01-01

92

Orthodontic movement in traumatically intruded teeth: a case report.  

PubMed

Intrusive luxation of permanent mature teeth is one of the most serious injuries to the periodontal ligament in dental traumatology. Various treatment approaches are currently practised. The treatment of choice for traumatically intruded teeth was to combine orthodontic repositioning and endodontic treatment. This case report describes the treatment of a 50-year-old male patient, with four completely intruded mature permanent maxillary incisors. Orthodontic extrusion was initiated 1 week after the trauma. After 10 days, the crowns of the teeth were exposed to start endodontic therapy. Nine weeks after the injury and 8 weeks after the beginning of orthodontic extrusion, the intruded incisors were back about to their original position before the displacement occurred. All treatment management as well as a follow-up 8 years after the trauma are described. PMID:14708656

Calasans-Maia, José de Albuquerque; Calasans-Maia, Mônica Diuana; da Matta, Edgard Norões Rodrigues; Ruellas, Antonio Carlos de Oliveira

2003-10-01

93

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.

Maheshwari, Sneha

2014-01-01

94

Initiation of teeth from the dental lamina in the ferret.  

PubMed

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

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

2014-01-01

95

Repairing Children's Teeth  

MedlinePLUS

... steel crown. Some dentists also are now using zirconia crowns (which are tooth colored). Either of these types of crowns can be placed in a single visit. Adult crowns usually require two visits. More about Repairing Children's Teeth Managing Anxiety in Children Types of Fillings Used ...

96

Mouth and Teeth (For Parents)  

MedlinePLUS

... is essential to maintaining healthy teeth and avoiding tooth decay and gum disease. Common mouth and dental diseases ... and causing tooth loss. Disorders of the Teeth Cavities and tooth decay. When bacteria and food particles ...

97

[Statistical studies on numerical anomalies of teeth in children using orthopantomograms--congenital hypodontia].  

PubMed

Statistical studies on numerical anomalies of teeth using orthopanthomograms had been attempted. In this paper, congenital hypodontia had been researched using 4009 orthopanthomograms of pedodontic patients. The tested were following; Male: Age 2-5 1036, 6-11 905, 12-22 Total 1963 Female: Age 2-5 1032, 6-11 985, 12-29 Total 2046 respectively. Many interesting results have been acquired, i.e. A. Congenital Hypodontia of Deciduous Teeth total 62 cases (78 teeth) 1 tooth defect--46 cases 2 teeth defect--16 cases B. Congenital Hypodontia of Permanent Teeth total 314 cases (566 teeth) 1 tooth defect--150 cases 2 teeth defect--115 cases 3 teeth defect--23 cases 4 teeth defect--18 cases 5 teeth defect--6 cases 6 teeth defect--0 case 7 teeth defect--1 case 8 teeth defect--1 case C. Defect Position deciduous teeth i2--83.3% permanent teeth P2--42.4% I2--36.4% D. Rare cases Symmetric defect (upper and lower): 2 cases, bisymmetric defect (right and left): 93 cases, symmetric and bisymmetric defect: 7 cases, defect of deciduous teeth and the succeeding permanent teeth: 37 cases, or in other expression, 2 B 1 case, 5/5 1 case, B 2 B B 1 case, 2 2 17 cases, 2 2 4 cases, 1 1 1 case, 3 3 1 case, 5 5 1 case, 3 2 2 3 1 case, 5 2 2 5 1 case, 5 4 4 5 1 case, 7 2 2 7 1 case, 7 3 3 7 1 case, 7 5 5 7 1 case, 7 5 2/2 2/2 5 7 1 case, 5/5 5/5 7 cases and 2B 2B 1 case, 3C 3C 1 case, B2 B2 8 cases, C3 C3 2 cases, 2B 5 cases, 2B 1 case, B2 10 cases, A1 1 case, A1 1 case, B2 6 cases' E5 1 case... In addition, the data have no significant difference in right and left, male and female. And for many reasons, we criticize the established theory (?) that congenital hypodontia is a systemic degeneration in human evolution. So we propose a following, simple and not incompatible concept--eventually congenital hypodontia except hereditary cases appear in many chances when development of dental germs (I2, P2, M3) is later than the surroundings and the space for it is remarkably deficient. PMID:2134882

Yanagida, I; Mori, S

1990-12-01

98

Remarkable resilience of teeth  

PubMed Central

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

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

2009-01-01

99

Remarkable resilience of teeth.  

PubMed

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

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

2009-05-01

100

Congenital absence of permanent teeth among Irish school-children.  

PubMed

The Orthodontic records of 3,056 patients attending a Regional Orthodontic Unit were examined, to assess the prevalence of hypodontia. Orthopantomogram radiographs were available for all patients. The congenital absence of third molars was not considered. The prevalence of hypodontia was 11.3% which was high in comparison with previous studies. However it was in keeping with more recent studies from the U.K. and Ireland. PMID:2098447

O'Dowling, I B; McNamara, T G

1990-01-01

101

Management of Internal Root Resorption on Permanent Teeth  

PubMed Central

Internal root resorption (IRR) is a particular category of pulp disease characterized by the loss of dentine as a result of the action of clastic cells stimulated by pulpal inflammation. This review article explains the etiology, the prevalence of IRR, and, in addition to the clinical data, the contribution of the three-dimensional imaging (CBCT) to the diagnosis, the clinical decision, and the therapeutic management of IRR. The authors discussed the various therapeutic options including the orthograde or retrograde fillings of the root canal resorption area. Root canal treatment remains the treatment of choice of internal root resorption as it removes the granulation tissue and blood supply of the clastic cells. The authors describe with different clinical cases the modern endodontic techniques including optical aids, ultrasonic improvement of chemical debridement, and the use of alternative materials such as calcium silicate combined with thermoplastic filling (warm gutta-percha). In these conditions, the prognosis of the conservative treatment of internal resorptions, even if root walls are perforated, is good.

Bonte, Eric; Bayet, Francois; Lasfargues, Jean-Jacques

2013-01-01

102

A Talon Cusp on Fused Teeth Associated with Hypodontia: Report of a Unique Case  

PubMed Central

Fusion and talon cusps are rare developmental dental anomalies affecting both primary and permanent dentitions. Talon cusps normally occur on the palatal surface of permanent maxillary incisors, while fused teeth are more common in the primary anterior dentition. An understanding of these dental anomalies and their associated problems are important to provide prophylactic measures, thereby preventing or minimizing possible complications. This paper presents a unique case of fused mandibular permanent incisors with a lingual talon cusp associated with hypodontia of an adjacent tooth.

Dinesh Rao, B; Hegde, Sapna

2010-01-01

103

The Innervation of Teeth  

PubMed Central

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

Bradlaw, Robert

1936-01-01

104

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

PubMed Central

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

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

2013-01-01

105

Complete anodontia of the permanent dentition: case report.  

PubMed

A disturbance during the embryology of tooth formation of the seven-year-old girl presented in this case resulted in her having the unusual combination of nearly a complete complement of primary teeth but anodontia of the permanent dentition. It could not be determined if this child had any of the many syndromes or conditions characterized by missing teeth. Clinical characteristics and management of this case are described. PMID:2133936

Schneider, P E

1990-01-01

106

Fracture Modes in Human Teeth  

Microsoft Academic Search

The structural integrity of teeth under stress is vital to functional longevity. We tested the hypothesis that this integrity is limited by fracture of the enamel. Experiments were conducted on molar teeth, with a metal rod loaded onto individual cusps. Fracture during testing was tracked with a video camera. Two longitudinal modes of cracking were observed: median cracking from the

J. J.-. W. Lee; J.-Y. Kwon; H. Chai; P. W. Lucas; V. P. Thompson; B. R. Lawn

2009-01-01

107

Taking Care of Your Teeth and Mouth  

MedlinePLUS

... care should keep your teeth and gums strong. Tooth Decay Teeth are covered in a hard, outer coating ... in the enamel. This hole is called a cavity. Brushing and flossing your teeth can protect you ...

108

Triple teeth: report of an unusual case.  

PubMed

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

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

2012-01-01

109

Nestin Expression in Embryonic and Adult Human Teeth under Normal and Pathological Conditions  

PubMed Central

Nestin is an intermediate filament most related to neurofilaments and expressed predominantly in the developing nervous system and muscles. In the present study we examined the in vivo distribution of nestin in human teeth during embryonic development and in permanent teeth under normal and pathological conditions. The results show that nestin is first expressed at the bell stage and that its distribution is restricted in pulpal cells located at the cusp area of the fetal teeth. In young permanent teeth, nestin is found only in functional odontoblasts, which produce the hard tissue matrix of dentin. Expression is progressively down-regulated and nestin is absent from older permanent teeth. In carious and injured teeth, nestin expression is up-regulated in a selective manner in odontoblasts surrounding the injury site, showing a link between tissue repair competence and nestin up-regulation under pathological conditions. In an in vitro assay system of human dental pulp explants, nestin is up-regulated after local application of bone morphogenic protein-4. A similar effect is seen in cultures of primary pulp cells during their differentiation into odontoblasts. Taken together, these results suggest that nestin plays a potential role in odontoblast differentiation during normal and pathological conditions and that bone morphogenic protein-4 is involved in nestin up-regulation.

About, Imad; Laurent-Maquin, Dominique; Lendahl, Urban; Mitsiadis, Thimios A.

2000-01-01

110

[Congenital absence and loss of teeth in an orthodontic patient group].  

PubMed

Panoramic radiographs of 1,160 orthodontic patients, 655 females and 505 males, 6-15 years of age were selected for study in congenital absence, loss of permanent teeth and premature loss of deciduous teeth. The result from this investigation showed congenital absence for 100 subjects (8.6%, not including third molars) and 185 subjects (16%, third molars included). The permanent upper lateral incisors are most frequently missing (22.4%, third molars excluded), followed by upper second premolar, 17.8%, lower second premolar, 15.1%, and then lower lateral incisor, 12.5%. The study also showed loss of permanent teeth of 105 subjects (9.1%). The lower first molars are most frequently lost (52.8%), followed by the upper first molar (18.2%). There is no statistical significance (alpha = 0.01) between females and males in both congenital absence and loss of permanent teeth. The premature loss of deciduous teeth was found in 467 subjects (40.3%). The most frequently loss happened to second deciduous molars, followed by first deciduous molars and then deciduous canines. There is more statistical significance (alpha = 0.01) in females than in males. PMID:2074329

Dechkunakorn, S; Chaiwat, J; Sawaengkit, P

1990-01-01

111

Jaws and Teeth of Mammals  

NSDL National Science Digital Library

This image from Biology by Kenneth R. Miller and Joseph Levine illustrates the relationship between structure and function by comparing the jaws and teeth of two animals with very different ways of life: the wolf and the horse.

2007-12-12

112

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

113

Keeping Your Child's Teeth Healthy  

MedlinePLUS

... to keep teeth and gums healthy). Continue Preventing Cavities The American Dental Association (ADA) recommends that a ... a child seems to be at risk for cavities or other problems, the dentist may start applying ...

114

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

Microsoft Academic Search

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

A. A. Arkadan; R. Vyas

1993-01-01

115

Determination of working length for teeth with wide or immature apices: a review.  

PubMed

Practitioners face several challenges during the root canal treatment of teeth with wide or immature apices, one of which is working length determination. There is relatively little data regarding the value of radiography and electronic apex locator (EAL) use when root formation is incomplete, and supplementary measurement techniques may be helpful. This review considers length determination for canals with wide or completely open apices in permanent and primary teeth. The Ovid Medline, Web of Science and Scopus databases were searched individually and in combinations to August 2012 using the subject headings 'working length determination' and 'open apex' and revealed only one article. Further headings, 'tooth apex', 'apical constriction', 'resorption', 'foramen size', 'mature root apex', 'immature root apex', 'working length determination', 'apexification', 'open apices', 'open apex', 'open apical foramina', 'canal length determination', 'immature teeth', 'apical diameters', 'electronic apex locators', 'primary teeth', 'treatment outcome' and 'clinical outcome' were entered. Potentially useful articles were chosen for a manual search of bibliography as well as a forward search of citations. Other investigations revealed case reports and some research related to open apices and laboratory studies evaluating EALs, radiography and tactile methods. Some involved permanent teeth of various apical diameters and primary teeth with and without resorption. There is a need to define the term 'open apex'. Clinicians should be aware of the benefits and limitations of all canal measuring techniques involved in managing this problem. PMID:23216284

Kim, Y J A; Chandler, N P

2013-06-01

116

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

PubMed Central

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

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

2013-01-01

117

Restoration of endodontically treated teeth.  

PubMed

The restoration of endodontically treated teeth has undergone significant changes in the last 20 years. Most of these changes are associated with the preservation of tooth structure, this has been achieved first of all with the increasing use of operative microscopes, nickel titanium instruments and more recently cone beam computed tomography; these instruments have allowed the clinicians to reduce significantly the amount of coronal and radicular hard tooth tissue removed in the process of cutting access cavities. The use of composites has also allowed the clinicians to restore with adhesive techniques teeth that would otherwise require extensive and destructive mechanical retentions. The use of partial crowns is becoming increasingly popular and this also helps prevent tooth structure loss. This article will focus on the choices available to restore both anterior and posterior teeth and will focus more on these contemporary adhesive techniques. PMID:24651340

Mannocci, F; Cowie, J

2014-03-01

118

Use of MTA for orthograde obturation of nonvital teeth with open apices: report of two cases.  

PubMed

The purpose of this report is to present the treatment of 2 immature necrotic permanent incisors with the use of apical plugs of mineral trioxide aggregate (MTA) for apexification. With this technique, MTA mixture is used to create an artificial stop against which to condense gutta-percha in pulpless teeth with open apices. The report of these cases confirms that MTA acts an apical barrier and can be considered as an effective material to support regeneration of apical tissue in immature necrotic teeth. The treated teeth were asymptomatic, and radiographic follow-ups showed healing of periradicular tissues and new hard tissue formation in the apical area of the affected teeth. PMID:17625928

D'Arcangelo, Camillo; D'Amario, Maurizio

2007-10-01

119

Parts of Your Teeth and Gums  

MedlinePLUS

... the antibiotic tetracycline while the teeth are developing. Teeth also can darken with age. This type of discoloration can often be improved with dental whitening. Pulp and pulp cavity — At the core of ...

120

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

121

Whitening non vital teeth - a case report  

PubMed Central

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

Moraru, Iren; Tuculina, Mihaela; Bataiosu, Marilena; Gheorghita, Lelia; Diaconu, Oana

2012-01-01

122

Fracture modes in human teeth.  

PubMed

The structural integrity of teeth under stress is vital to functional longevity. We tested the hypothesis that this integrity is limited by fracture of the enamel. Experiments were conducted on molar teeth, with a metal rod loaded onto individual cusps. Fracture during testing was tracked with a video camera. Two longitudinal modes of cracking were observed: median cracking from the contact zone, and margin cracking along side walls. Median cracks initiated from plastic damage at the contact site, at first growing slowly and then accelerating to the tooth margin. Margin cracks appeared to originate from the cemento-enamel junction, and traversed the tooth wall adjacent to the loaded cusp from the gingival to the occlusal surface. All cracks remained confined within the enamel shell up to about 550 N. At higher loads, additional crack modes--such as enamel chipping and delamination--began to manifest themselves, leading to more comprehensive failure of the tooth structure. PMID:19329454

Lee, J J-W; Kwon, J-Y; Chai, H; Lucas, P W; Thompson, V P; Lawn, B R

2009-03-01

123

[The effects of actovegin on cell proliferation of permanent lines].  

PubMed

The influence of Actovegin on proliferation activity and mitotic regimen of cells of permanent lines PK-15-IEKVM and BHK-21 clone 13/04 was investigated. Addition of Actovegin into growth media containing bovine serums of different components and concentrations stimulates cell proliferation. Conclusion has been made that Actovegin can be used in cell culture biotechnology. PMID:18411759

Gulevski?, A K; Trifonova, A V; Lavrik, A A

2008-01-01

124

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

125

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

126

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

Microsoft Academic Search

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

P. Sivachandran; P. Venkatesh; N. Kamaraj

2008-01-01

127

Occlusion between removable dentures and natural teeth.  

PubMed

Study casts on thirty-five partially edentulous patients were analysed at their arch level and at the interarch levels. At the arch level the crest of the residual ridge is located lingually to the position of the remaining teeth in the maxilla as well as in the mandible. The spatial interarch relationship between the residual edentulous ridge and the antagonist natural teeth in the buccolingual plane indicated that the crest of the residual ridge is lingual to the occlusal surfaces of the antagonist teeth. In the maxilla the positioning of the artificial teeth in the area previously occupied by the natural extracted teeth will place the denture teeth far buccal as well as away from the crest of the residual ridge. Other possibilities are to place the artificial teeth in a cross bite relation or to eliminate the buccal cusps of the replacement teeth. In the mandible the denture teeth can be placed at the position occupied formerly by the natural teeth. PMID:268416

Pietrokovski, J; Mejias, J E

1977-07-01

128

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

129

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) [Oak Ridge, TN; Adams, Donald J. (Knoxville, TN) [Knoxville, TN

1999-01-01

130

Bilateral Agenesis of Permanent Mandibular Central Incisors: Report of Two Cases  

PubMed Central

General dentists most commonly encounter one or more congenitally missing teeth on routine oral examination. Hypodontia and oligodontia are the two most commonly encountered genetic disorders. When one or less than six teeth are missing congenitally they are termed hypodontia. Environmental factors, radiation, trauma, infection, genetic mutations have all been considered as the probable cause for hypodontia. Well documentation of such condition becomes necessary to enrich the knowledge about congenitally missing teeth. How to cite the article: Satish BN, Kumar P, Furquan M, Hugar D, Saraswati FK. Bilateral agenesis of permanent mandibular central incisors: Report of two cases. J Int Oral Health 2014;6(3):103-5.

Satish, B N V S; Kumar, Prashant; Furquan, Mohammad; Hugar, Deepa; Saraswati, F K

2014-01-01

131

Rare earth permanent magnets  

Microsoft Academic Search

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

Major-Sosias

1993-01-01

132

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.

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

2014-01-01

133

Anodontia of the permanent dentition: fourteen years after initial diagnosis.  

PubMed

The congenital absence of teeth, total anodontia, may involve both the primary and permanent dentitions. This paper updates the dental history of a twenty-eight-year-old Greek-American woman first reported in 1977 by Herman and Moss, when she was fourteen. Five complete sets of dentures had been made for her in thirteen years. Treatment was more complex due to an underdeveloped maxilla and a prognathic mandible. PMID:2319058

Scherer, W; Cooper, H; Haray, R

1990-01-01

134

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.

135

Dielectrophoresis: a model to transport drugs directly into teeth.  

PubMed

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

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

2012-04-01

136

AFM characterization of bovine enamel and dentine after acid-etching  

Microsoft Academic Search

Teeth are constituted mainly of hydroxyapatite molecules (Ca10(PO4)6(OH)2), grouped in different microstructural arrangements, depending on the dental layer considered (enamel or dentine). In the present work, these dental microstructural arrangements were characterized by atomic force microscopy. Enamel and dentine samples were cut from freshly extracted bovine incisor teeth. After metallographic polishing, the dental surfaces were etched with lactic acid (113.8mmol\\/L,

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

2009-01-01

137

Management of immature teeth by dentin-pulp regeneration: a recent approach.  

PubMed

Treatment of the young permanent tooth with a necrotic root canal system and an incompletely developed root is very difficult and challenging. Few acceptable results have been achieved through apexification but use of long-term calcium hydroxide might alter the mechanical properties of dentin. Thus, one alternative approach is to develop and restore a functional pulp-dentin complex. Procedures attempting to preserve the potentially remaining dental pulp stem cells and mesenchymal stem cells of the apical papilla can result in canal revascularization and the completion of root maturation. There are several advantages of promoting apexogenesis in immature teeth with open apices. It encourages a longer and thicker root to develop thus decreasing the propensity of long term root fracture. So, the present article reviews the recent approach of regeneration of pulp-dentin complex in immature permanent teeth. PMID:21743418

Neha, Kansal; Kansal, Rajnish; Garg, Pratibha; Joshi, Rajesh; Garg, Deepika; Grover, Harpreet-Singh

2011-11-01

138

Intrusion and uprighting teeth for fixed prosthesis with temporary anchorage device.  

PubMed

The mandibular first permanent molar is usually first to erupt around the age of six. Therefore, if the oral hygiene is not impeccable, it is usually also the first permanent tooth decayed in a child's mouth. A plethora of circumstances may lead to pulpal involvement, periapical pathosis, and endodontic treatment and in unfortunate situations, removal of this tooth. If this tooth is not replaced, or the extraction space is not retained for a considerable amount of time, the posterior occlusion will collapse. The most common occurrence is tipping of teeth in juxtaposition to the extraction site and extrusion of at least one opposing tooth. This article will describe efficient uprighting and intrusion of offending teeth prior to placement of fixed prosthesis. The author will explain the procedure step by step, first on acrylic models and then on the actual patient. PMID:23094553

Palencar, Adrian J

2012-01-01

139

Rare earth permanent magnets  

Microsoft Academic Search

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

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

1995-01-01

140

An augmented reality based teeth shade matching system  

Microsoft Academic Search

In this paper, we present an augmented reality (AR) based teeth shade matching system for helping dentists verify the correctness of teeth shade matching and evaluate the acceptance of virtual teeth in cosmetic dentistry. The appearance of teeth is captured by a modified camera based on the measurements from cosmetic dentistry. After generating the shade matching map of teeth, we

Chen Qiao; Yongtian Wang; Dongdong Weng; Hongyu Qi

2011-01-01

141

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

142

The biomechanics and evolution of shark teeth  

Microsoft Academic Search

Measuring the effects of morphology on performance, and performance on fitness, is necessary to gain a full picture of selection, adaptation, ecology, and evolution. The performance of an organism's feeding apparatus, of which teeth are an integral part, has obvious implications for its fitness and survival. Extant shark teeth encompass a wide variety of shapes, and are often ascribed qualitative

Lisa Beth Whitenack

2008-01-01

143

Take Care of Your Child's Teeth  

MedlinePLUS

... your child’s teeth to protect your child from tooth decay (cavities). Tooth decay can: Cause your child pain Make it hard ... child’s adult teeth Take simple steps to prevent tooth decay. Most babies will get their first tooth between ...

144

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

Zarb, George A.

1988-01-01

145

Are teeth evidence in acid environment  

PubMed Central

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

Raj, Makesh; Boaz, Karen; Srikant, N

2013-01-01

146

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

PubMed

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

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

2013-10-01

147

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.

Hamouda, Ibrahim M.; Shehata, Salah H.

2011-01-01

148

Tattoos and Permanent Makeup  

MedlinePLUS

... Temporary Tattoos, Henna/Mehndi, and "Black Henna." Reporting Adverse Reactions FDA urges consumers and healthcare providers to report adverse reactions from tattoos, permanent makeup, and temporary tattoos, as ...

149

Microscopical aspects of root resorption of human deciduous teeth.  

PubMed

In order to obtain detailed information on the tissue changes which occur during physiological root resorption, 52 human deciduous teeth at various stages of resorption were studied under light microscopy. The early stage of root resorption was defined as resorption of not more than one third of the root length; the late stage was defined as resorption of more than one third. A close topographical interrelationship was found among che sites of pressure of the permanent tooth, the extent of root resorption and the types of tissue changes. Linear resorption (which reflects suspension or marked slowing down of resorption) and redeposition of hard tissue were more pronounced at the early stage of resorption, while lacunar resorption was more pronounced at the late stage. There were pronounced haemorrhagic and inflammatory infiltrates within the pulp at the late stage of resorption and the subodontoblastic cells disappeared as the infiltrates took over the tooth. False denticles were found frequently, especially at the early stage of resorption. Unexpectedly, acellular cementum was found to be deposited against secondary dentine at the cuspidal tip of the pulp chamber of seven teeth, independently of any sign of resorption nearby. These data indicate that: 1) the pressure exerted by a permanent tooth is the most important factor in the differentiation of odontoclasts. 2) the extent of lacunar (i.e., active) resorption correlates directly with the resorption rate, which is higher at the late stage of root resorption. 3) inflammation is a consequence, rather than a cause, of resorption; it may lead to the loss of subodontoblastic cells and a consequent decrease in the ability of the pulp cells to replace damaged odontoblasts. 4) the pulp of the deciduous tooth might be cementogenic in some way, given that about 13% of the samples were found to be so. PMID:1285684

Francini, E; Mancini, G; Vichi, M; Tollaro, I; Romagnoli, P

1992-01-01

150

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

151

Cogging torque reduction of flux-switching permanent magnet machines without skewing  

Microsoft Academic Search

The flux-switching permanent magnet (FSPM) machine exhibits competitive torque capability and power density due to the high flux density. As a penalty, the cogging torque is relative large, resulting in unfavorable torque pulsation. Due to the simple and robust rotor construction, additional dummy slots are adopted to reduce the cogging torque without skewing magnets or teeth. The optimal dimensions of

Wei Hua; Ming Cheng

2008-01-01

152

Eddy-Current Calculation of Solid Components in Fractional Slot Axial Flux Permanent Magnet Synchronous Machines  

Microsoft Academic Search

This paper investigates eddy-current in an axial flux permanent magnet (AFPM) machine, which consist of the segmented stator teeth and concentrated winding, with one inner rotor and double stators. Analytical methods was developed to calculate the eddy-current loss of PMs and other solid components, including effect of winding harmonics and permeance variation due to slot opening. Eddycurrent losses were analyzed

Jian Li; Da-Woon Choi; Chang-Hum Cho; Dae-Hyun Koo; Yun-Hyun Cho

2011-01-01

153

First Permanent Molar Restoration Differences between Those with or without Dental Sealants.  

ERIC Educational Resources Information Center

The study examined differences in the number of restorations in permanent, posterior teeth for those children receiving dental sealants with cost sharing when compared to children who do not receive sealants. Results indicated a 51 percent reduction in restoration rates for each quadrant sealed. Findings have implications for cost savings and…

Kuthy, Raymond A.; And Others

1990-01-01

154

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

PubMed

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

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

1975-07-01

155

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

PubMed Central

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

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

2012-01-01

156

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 ...

157

Laser and LED external teeth-bleaching  

NASA Astrophysics Data System (ADS)

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

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

2004-09-01

158

Laser and LED external teeth-bleaching  

NASA Astrophysics Data System (ADS)

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

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

2004-05-01

159

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

PubMed Central

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

Parker, Kate; Hay, Norman

2014-01-01

160

Multiple supernumerary teeth associated with bony malformations.  

PubMed

Full blown cases of cleidocranial dysplasia (CCD) have been reported earlier but a case with a rarity of 60 teeth associated with bony malformations, is seldom observed Because of the oral findings this condition has been diagnosed at an early age, thus helping to achieve a better oral harmony. This article reports an atypical case with 16 supernumerary teeth associated with bony malformations. PMID:22524086

Kamatham, R; Sharada, J; Mohapatra, A; Nuvvula, S

2011-01-01

161

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.

2007-03-19

162

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.

163

Experimental teeth clenching in man.  

PubMed

The thesis develops an electromyographic (EMG) method to quantify maximum voluntary teeth clenching (MVC), studies the onset and endurance of jaw muscle fatigue and pain from MVC, and explores the prevention of the discomforts through pharmacological and physical means. MVC, or maximum voluntary static work efforts by the elevator muscles of the mandible, was quantified by continuous (integral) functions of variations in both time and recruitment/rate coding of motor units in the masseter muscle. Fatigue was felt in the masseter muscle after about 30 seconds of MVC; differential calculus suggested that the appearance and disappearance of fatigue was associated with primarily recruitment and decruitment of masseteric motor units, respectively. About 60 seconds of MVC elicited a mild pain in the masseter and temporalis muscles; about 120 seconds of MVC induced a moderate pain and complete exhaustion of the isometrically contracting muscles. Although pain releasing maximum static work efforts are stable variables they cannot predict the pain magnitude of brief and prolonged MVC, probably because of modulations (recruitment/decruitment/rate coding) of masseteric motor units. It is suggested that the modulations begin with the onset of fatigue, are practically complete with the onset of pain, and are absent or negligible with an experience of exhaustion. A single oral dose of 1000 mg of ibuprofen did not affect the onset, endurance, and magnitude of pain from MVC. By contrast, 30 minutes of cooling (ice) of the masseter muscle effectively prevented the onset of pain; it also increased the masseteric EMG, credibly because of modulations of myoelectrical signals and, possibly, increased MVC efforts in the absence of pain. PMID:2652364

Christensen, L V

1989-01-01

164

Hypersensitive teeth. Part II: Treatment.  

PubMed

If the hydrodynamic theory for pain transmission were accepted, occlusion of the patent dentinal tubules would appear to be essential for treatment efficacy. There are many compounds with seemingly varied chemical forms that have been shown to be effective. Their exact mode of action however, is not clearly defined because well-designed, nonbiased, and controlled comparison studies between agents are lacking. The various toothpastes may have ingredients that actually occlude patent tubules or they may cause secondary desensitization by irrational or abrasive action. In any pain study, the nature of the placebo effect and other psychogenic factors play a significant role. Fluoride preparation with and without iontophoresis has been shown to alter tubule structure and form microprecipitates. The natural desensitization process, although slow, is nature's protection, allowing dentinal sclerosis of secondary dentin formation. Although the resin-adhesive systems, especially the new light-cured dentin bonding agents, appear immediately to be effective, the effect on the pulp remains unknown. Perhaps a combination of iontophoresis with sodium fluoride and light-cured dentin bonding material may yield protection and desensitization at a high level of predictability. With the population trends toward a more geriatric society, further research, knowledge, and understanding of dentinal hypersensitivity is of paramount importance. The expected increase in longevity of the dentition suggests that dentin exposure and sensitivity will increase as a clinical problem. There is a clear time-age relationship involved in gingival recession, erosion and attrition of the teeth, and the need for periodontal surgical therapy. For total comprehensive care, patient comfort is important and should be provided along with sound periodontal health and ideal restorative function. PMID:3528461

Krauser, J T

1986-09-01

165

Bovine colostrum immunoglobulin concentrate for cryptosporidiosis in AIDS  

Microsoft Academic Search

Lactobin-R is a commercial hyperimmune bovine colostrum with potent anticryptosporidial activity. It was administered to a 4 year old child with AIDS and severe diarrhoea associated with cryptosporidiosis. There was significant clinical improvement in the diarrhoea and permanent elimination of the parasite from the gut as assessed through serial jejunal biopsy and stool specimens.

J Shield; C Melville; V Novelli; G Anderson; I Scheimberg; D Gibb; P Milla

1993-01-01

166

Immediate esthetic treatment of an avulsed/replanted permanent incisor with extensive root resorption: a case report.  

PubMed

This article describes the treatment of a 10 year-old patient with complete root resorption of the maxillary permanent incisor following avulsion and replantation 4 years earlier. The remaining natural crown was used to immediately solve the esthetic problem created by its extraction. The crown was attached with an orthodontic wire and composite resin to adjacent teeth. This temporary treatment does not elicit any damage to adjacent teeth, and can be easily removed. Therefore, it does not affect any plans that might be considered in the future as the permanent treatment. PMID:8619974

Holan, G; Botzer, E

1996-01-01

167

Effect of teeth clenching on swallowing motor patterns in humans.  

PubMed

The purpose of this study was to investigate the effect of teeth clenching on swallowing motor patterns. Seven healthy humans participated in this study. Electromyograms (EMGs) were recorded from the right masseter muscle, the suprahyoid muscles, and the right infrahyoid muscles. Three motor tasks were performed while the EMGs were recorded: swallowing without teeth clenching, and two tasks of swallowing with teeth clenching, one with masseter EMG activity at 20% of maximum, and one with masseter EMG activity at 40% of maximum. The duration of suprahyoid EMG activity with teeth clenching was significantly longer than that without teeth clenching. The duration of infrahyoid EMG activity with teeth clenching was significantly shorter than that without teeth clenching. The whole duration of swallowing with teeth clenching was significantly shorter than that without teeth clenching. Teeth clenching changes the swallowing motor pattern, indicating that activity of the masticatory center affects activity of the swallowing center. PMID:16861164

Hiraoka, Koichi

2006-08-01

168

Alkaline "Permanent" Paper.  

ERIC Educational Resources Information Center

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

Pacey, Antony

1991-01-01

169

Permanents of Circulants.  

National Technical Information Service (NTIS)

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

H. Minc

1971-01-01

170

Teeth clenching reduces arm abduction force.  

PubMed

It has been reported that the 90° arm abduction force counteracting external adduction loads appeared to be smaller under teeth clenching condition than under non-clenching condition. To elucidate the physiological mechanism underlying the possible inhibitory effect of teeth clenching on the arm abduction, we have attempted to quantify the difference in the force induced against the fast and slow ramp load between the arm abductions under teeth non-clenching and clenching conditions. When the load of adduction moment was linearly increased, the abductor force increased to a maximal isometric contraction force (MICF) and further increased to a maximal eccentric contraction force (MECF) with forced adduction. The MICF measured under teeth clenching was significantly lower than that under non-clenching, despite no significant difference in the MECF between the two conditions. The reduction in MICF caused by teeth clenching was enhanced by increasing the velocity of the load. These results suggest that clenching inhibits abduction force only during isometric contraction phase. The invariability of MECF would indicate the lack of involvement of fatigue in such inhibitory effects of clenching. To discover the source of the inhibition, we have examined the effects of teeth clenching on the stretch reflex in the deltoid muscle. The stretch reflex of deltoid muscles was inhibited during clenching, contrary to what was expected from the Jendrassik maneuver. Taken together, our results suggest that the teeth clenching reduced the MICF by depressing the recruitment of deltoid motoneurones presumably via the presynaptic inhibition of spindle afferent inputs onto those motoneurones. PMID:24687460

Sato, Hajime; Kawano, Tsutomu; Saito, Mitsuru; Toyoda, Hiroki; Maeda, Yoshinobu; Türker, Kemal Sitki; Kang, Youngnam

2014-07-01

171

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

172

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

PubMed Central

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

Asgary, Saeed; Ehsani, Sara

2009-01-01

173

Conservation of root-fractured primary teeth--report of a case.  

PubMed

A 3.5-year-old girl presented to our clinic experiencing pain in her maxillary central incisors following traumatic injury during a fall. Radiographic examination revealed both primary maxillary central incisors with mid-root and apical third horizontal root fractures, respectively. Splinting with orthodontic brackets and stainless steel wire was performed. At 2 weeks, resorption of the apical fragments in both injured teeth was observed, and after 3 months, almost complete resorption was noted on radiographs. Tooth mobility at this point was back to physiologic levels and the splint was removed. After 2.5 years, the primary maxillary incisors were replaced by permanent incisors demonstrating normal tooth color, position, and root development. Although this case illustrated the favorable prognosis of two primary teeth with root fractures and severely mobile coronal fragments by a conservative approach, more scientific evidences are needed and frequent recalls are necessary when primary root fractures are attempted to be managed with splinting. PMID:23067514

Liu, Xin; Huang, Jing; Bai, Yudi; Wang, Xiaojing; Baker, Andrew; Chen, Faming; Wu, Li-an

2013-12-01

174

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.

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

2014-01-01

175

Variable Permanent Magnet Quadrupole  

SciTech Connect

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

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

2007-05-23

176

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

Microsoft Academic Search

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

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

1992-01-01

177

Permanent Magnet Generator Designing Guidelines  

Microsoft Academic Search

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

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

2007-01-01

178

Permanent-Magnet Generators  

Microsoft Academic Search

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

D. J. Hanrahan; D. S. Toffolo

1963-01-01

179

Permanent homelessness in America?  

Microsoft Academic Search

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

Richard B. Freeman; Brian Hall

1987-01-01

180

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

PubMed

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

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

2014-06-01

181

Permanent neonatal diabetes mellitus  

PubMed Central

Summary Background: Neonatal diabetes is a rare cause of hyperglycemia, affecting 1: 500,000 births, with persistent hyperglycemia occurring in the first months of life lasting more than 2 weeks and requiring insulin. This condition in infants less than 6 months of age is considered as permanent neonatal diabetes mellitus. Case Report: A rare case of permanent neonatal diabetes mellitus presented with intrauterine growth retardation (IUGR; birth weight: 1460 grams; female), hyperglycemia, glycosuria, and mild dehydration, a normal Apgar score of 8 and 9 at 1 and 5 minutes, respectively. The parents, of consanguineous union, had no prior history of diabetes mellitus. Of their 4 children, the first child had a diagnosis similar to the patient (their last child). The patient was initially started on continuous infusion of insulin, and then switched to regular insulin subcutaneously, but response was sub-optimal. She was started on neutral protamine Hagedorn, following which her condition improved. She was discharged on neutral protamine Hagedorn with regular follow-up. Conclusions: In view of widespread consanguinity in Saudi Arabia it appears prudent and pertinent to suspect permanent neonatal diabetes mellitus following diagnosis of hyperglycemia in small-for-age infants, especially those with positive family history of diabetes. Close blood glucose monitoring is essential as long as hyperglycemia persists. Prolong follow-up is imperative.

Al-Matary, Abdulrahman; Hussain, Mushtaq; Nahari, Ahmed; Ali, Jaffar

2012-01-01

182

ESR dating of teeth from Brazilian megafauna  

NASA Astrophysics Data System (ADS)

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

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

2010-11-01

183

Treatment selection for anterior endodontically involved teeth.  

PubMed

Innovations in material science and clinical techniques have expanded the number of treatment options available for nonvital anterior teeth. These options include the use of composite to fill the access opening with no additional treatment, crown placement, orthodontic extrusion, crown lengthening with or without orthodontic extrusion, dowel restorations with crown placement, and fixed bridge or implant therapy when extraction is necessary. Clinicians need to understand the benefits and limitations of each option in order to provide their patients with optimum function and aesthetics. Using case presentations, this article describes predictable approaches for the diagnosis, treatment planning, and restoration or replacement of endodontically treated teeth in the anterior region. PMID:15543690

Rifkin, Robert; McLaren, Ed

2004-09-01

184

Longitudinal study of accuracy of clinical examination for detection of permanent tooth aplasia.  

PubMed

It was the aim of the present investigation to evaluate the accuracy of clinical examination for the detection of permanent tooth aplasia in the 3rd/4th grade and again 1 yr later and to record the number of children initiating orthodontic treatment in the interval between the two examinations. The validating criterion for tooth aplasia was a panoramic radiograph taken in a routine procedure. 628 children participated in the study. The clinical examinations were performed without knowledge of the radiographic evidence. During the examination children exhibiting symptoms of permanent tooth aplasia were selected for radiography. At both occasions clinical examination was very sensitive for the detection of children with aplasia of permanent incisors (nosological sensitivity = 1.00). It was, however, less sensitive for the detection of children with premolar aplasia (nosological sensitivity = 0.22 at both examinations). The nosological specificity for identification of children without aplasia of incisors and premolars was more than 0.90 at both examinations. Twenty-two children had started orthodontic treatment in the timespan between the two clinical examinations, but only three on the basis of observations on their radiographs alone (aplasia of permanent teeth). The present clinical method would have selected two of these children, thus in only one child postponing panorama screening might have affected treatment prognosis. Between the two examinations all permanent teeth mesial to the permanent second molars had erupted in 181 children who might therefore totally avoid screening radiography. PMID:2249409

Hintze, H; Wenzel, A

1990-10-01

185

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

186

Cartilage (Bovine and Shark) (PDQ)  

MedlinePLUS

... Research & Funding News About NCI Cartilage (Bovine and Shark) (PDQ®) Patient Version Health Professional Version Last Modified: 06/05/2013 Cartilage (Bovine and Shark) (PDQ®) Overview Questions and Answers About Cartilage (Bovine ...

187

Fiber-reinforced composite bridge and splint. Replacing congenitally missing teeth.  

PubMed

The congenital absence of permanent teeth, also known as partial anodontia, is a relatively common problem. The patient missing one or both lateral incisors is a frequent occurrence. The treatment of missing laterals involves both functional and esthetic considerations. Options include: cuspid lateralization; implant placement; conventional three-unit bridge; Maryland bridge; and a fiber-reinforced composite bridge (direct or indirect). Direct fiber-reinforced composite bridges provide a minimally invasive restorative option that allows for future implant placement. Selection of appropriate fiber reinforcement and placement of the fibers allows long-term clinical success. Adherence to appropriate adhesive protocol is mandatory. PMID:15332565

Trushkowsky, Richard

2004-01-01

188

Biological Interpretation of the Correlation of Emergence Times of Permanent Teeth  

Microsoft Academic Search

The eruption mechanism is not fully understood. It is known that the dental follicle is essential and that experimentally provoked denervation influence the process of eruption. Accordingly, the purpose of this study was to elucidate the eruption pattern in a human population and relate this pattern to the pattern of jaw innervation. The eruption pattern was evaluated from the correlation

E. T. Parner; J. M. Heidmann; I. Kjaer; M. Vaeth; S. Poulsen

2002-01-01

189

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

190

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

1967-01-01

191

Do We Need National Standards with Teeth?  

ERIC Educational Resources Information Center

The author, director of the University of Chicago School Mathematics Project, tackles the following question: Should the United States have national standards with teeth, that is, a single set of standards tied to assessments and agreed to by the states? Proponents advance five main arguments for implementing such a standard. In his rebuttal, the…

Usiskin, Zalman

2007-01-01

192

Simulating Clinical Carious Lesions in Composition Teeth.  

ERIC Educational Resources Information Center

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

Ambrose, E. R.; And Others

1981-01-01

193

Modification Of Gear Teeth To Reduce Vibrations  

NASA Technical Reports Server (NTRS)

Computer simulations yield data useful in designing for low noise. Effects of modifications in shape of gear teeth upon static transmission error and dynamic loading of gears now analyzed systematically. Design curves generated by conducting numerical simulations of dynamic effects at successive incremental modifications of gear systems operated at various applied loads. Modifications that result in minimum dynamic effect determined from design curves.

Townsend, Dennis P.; Oswald, Fred B.; Lin, Hsiang Hsi

1990-01-01

194

Computing Contact Stresses In Gear Teeth  

NASA Technical Reports Server (NTRS)

Improved method of computing contact stresses in gear teeth accounts for complicating effects like those of static and sliding friction. Provides iterative procedure for determination of contact region and nodal contact forces along with contact stresses. Method based on equations and computational procedure incorporating these effects routinely.

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

1995-01-01

195

Thermosonic imaging of cracks: applications to teeth  

NASA Astrophysics Data System (ADS)

A novel nondestructive imaging technique, thermosonics, which combines ultrasonic/sonic excitation and advanced infrared imaging, will be described. In this paper, the authors will illuminate the physical principles underlining this technique, and demonstrate its applications to detection of cracks in teeth.

Han, Xiaoyan; Favro, Lawrence D.; Thomas, Robert L.

2001-10-01

196

Permanent refueling pool seal  

SciTech Connect

This patent describes a permanent pool seal and neutron shield for providing an effective water barrier over the annular space between a nuclear reactor vessel flange and a surrounding annular ledge. It comprises an annular space-spanning deck structure supported underneath by circumferentially spaced radially disposed ribs spanning the annular space with the inner ends of the ribs supported by the vessel flange and the outer ends of the ribs supported by the ledge; and flexible seals between the deck structure and the vessel flange and the deck structure and the ledge.

McDonald, M.S.; Siegel, E.A.; Roebelen, G.J.; Schukei, G.E.; Brookins, R.H.; Ayres, D.J.

1992-04-07

197

Permanent soft tissue fillers.  

PubMed

As our youth-oriented society ages, interest in nonsurgical aesthetic techniques has generated a dramatic rise in the use of filling agents for facial rejuvenation. Backed by multiple published studies documenting safety and efficacy, soft tissue fillers are often viewed as treatments with minimal recovery time and limited risk of complications when compared with traditional surgical interventions. This has led to a genuine demand for fillers with similar safety profiles but ever increasing longevity in their aesthetic corrections. This review addresses many of the permanent soft tissue fillers that are commercially available worldwide as well as important concerns regarding their complications. PMID:22205527

Wilson, YuShan L; Ellis, David A F

2011-12-01

198

Mouth and Teeth: How To Keep Them Healthy  

MedlinePLUS

... Healthy Taking good care of your mouth and teeth throughout your whole life can help prevent problems as you get older. Taking care of your teeth means brushing and flossing every day and seeing ...

199

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

MedlinePLUS

... cause stains on your child's teeth. What are cavities? Cavities are holes that are formed when bacteria (germs) ... acid. This acid eats away at the teeth. Cavities are common in children. Good tooth care can ...

200

Natal teeth: Case report and review of literature  

PubMed Central

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

Rao, Roopa S; Mathad, Sudha V

2009-01-01

201

Cryogenic Permanent Magnet Undulators  

NASA Astrophysics Data System (ADS)

For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm2Co17 or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

Chavanne, J.; Lebec, G.; Penel, C.; Revol, F.; Kitegi, C.

2010-06-01

202

Natural teeth replacing artificial teeth in a partial denture: a case report.  

PubMed

The aesthetic replacement of anterior teeth in cases of immediate partial denture is always a challenging work for prosthodontists. There is always problem of matching size, colour, shade and shape of the replaced tooth with those of the natural teeth. It was most difficult to satisfy the patients who have high aesthetic demands. Here is a report of a case where patient's own natural tooth was used for replacement in an immediate partial denture. An immediate denture is defined as "any removable dental prosthesis which is fabricated for placement immediately, following the removal of a natural tooth/teeth" . Patients with missing anterior teeth lack an impressive appearance aesthetically and as well as psychologically. Tooth loss leads to a certain degree of loss of function. This loss of function might lead to an impairment of oral health which is related to quality of life. An immediate denture can replace 1-16 teeth in either the maxillary or the mandibular arch, or in both arches. The need for the immediate replacement of a missing tooth is more in case of an anterior tooth, where aesthetics is of prime concern. The replacement of an anterior tooth is most technique sensitive, as it includes the patient's expectations, which include, matching with proper shade, shape and size as those of his/her natural teeth. So, here is a case presentation where modern day patient expectations were taken into consideration. PMID:24086926

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

2013-08-01

203

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

PubMed Central

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

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

2013-01-01

204

Unlocking the bovine genome  

PubMed Central

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.

Tellam, Ross L; Lemay, Danielle G; Van Tassell, Curtis P; Lewin, Harris A; Worley, Kim C; Elsik, Christine G

2009-01-01

205

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

PubMed

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

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

2009-06-01

206

Teeth and tongue discoloration after linezolid treatment in children.  

PubMed

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

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

2013-11-01

207

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

208

The transition from pulpitis to periapical periodontitis in dogs' teeth  

Microsoft Academic Search

The purpose of the study was to histologically analyse transition from pulpitis to periapical periodontitis on dog's teeth. Pulps of mandibular premolars (37 roots) were exposed using a low-speed handpiece. Teeth were left open to the oral environment for 20, 35, 50 and 65 days. After the experimental period animals were sacrificed. Undemineralised teeth with surrounding bone, embedded in methylmetacrylate,

Maja Kovacevic; Tomislav Tamarut; Nives Jonjic ´; Alen Braut; Miljenko Kovacevic ´

2008-01-01

209

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

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

2012-04-01

210

21 CFR 872.6475 - Heat source for bleaching teeth.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Heat source for bleaching teeth. 872.6475 Section 872.6475 Food...872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that...

2010-04-01

211

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

PubMed Central

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

Forghani, Maryam; Maghsoudlou, Amir

2013-01-01

212

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

PubMed Central

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

Amini, Fariborz; Rakhshan, Vahid; Babaei, Pardis

2012-01-01

213

The permanent catheter.  

PubMed

An elderly woman receiving hemodialysis via a right brachiocephalic arteriovenous fistula presented to the clinic for elective removal of a tunneled hemodialysis catheter inserted 5 years ago. The catheter had not been removed earlier at the patient's request. Removal was now unsuccessful in the clinic. Exploration in the operating room revealed the innominate vein had fibrosed around the length of the catheter. The procedure was abandoned, catheter cut short and the remnant left in situ. This case serves as a reminder to exercise caution if there is difficulty in removing the catheter even after the cuff is dissected free, and to remove them once a working fistula or graft is available. Failing which, the patient bears an unnecessary risk of line infection, or as in this case, the catheter may unintentionally end up what its common misnomer "perm-cath" alludes to--becoming truly "permanent." PMID:24164973

Tan, Ek Khoon; Tan, Seck Guan

2014-04-01

214

Permanent Parahisian Pacing  

PubMed Central

Right Ventricular Apical permanent pacing could have negative hemodynamic effects. A physiologic pacing modality should preserve a correct atrio-ventricular and interventricular synchronization. This can be obtained through biventricular pacing, left ventricular pacing, or from alternative right ventricular pacing sites. Direct His Bundle Pacing (DHBP) was documented as reliable and effective for preventing the desynchronization and negative effects of right ventricular apical pacing. It is, however, a complex method that requires longer average implant times, cannot be carried out on all patients and presents high pacing thresholds. On the contrary, the parahisian pacing, with simpler feasibility and reliability criteria, seems to guarantee an early invasion of the His-Purkinje conduction system, with a physiological ventricular activation, very similar to the one that can be obtained with direct His bundle pacing. We present our experience on 68 patients who underwent a permanent right ventricular pacing in hisian/parahisian region, for advanced AV block and narrow QRS. In the first 17 patients we performed a double-blind randomized controlled study, with two 6-months cross-over periods in parahisian and apical pacing, documenting a significant improvement of NYHA class, exercise tolerance, quality of life score, mitral and tricuspidal regurgitation degree, and interventricular mechanical delay. In the subsequent 51 patients, in a mean follow of 21 months/patient, the pacing threshold remained stable (0.7±0.5 V implant; 0.9±0.7 V follow-up; p=0.08). The ejection fraction maintained medium-long term stable values, confirming the fact that the parahisian pacing can prevent deterioration of the left ventricular function. Parahisian pacing, therefore, has proven to be a reliable method, easy to apply and effective in preventing the negative effects induced by non-physiological right ventricular apical pacing.

Occhetta, Eraldo; Bortnik, Miriam; Marino, Paolo

2007-01-01

215

Aesthetic treatment of discoloration of nonvital teeth.  

PubMed

Attempts to treat discoloration in nonvital teeth were first reported a century ago. This article discusses two potential causes of nonvital tooth discoloration-trauma and endodontic treatment-along with a step-by-step clinical procedure for treatment of the discoloration. In trauma, hemoglobin is released into the tissues; iron oxides, formed by oxygen and iron in hemoglobin, cause discoloration and swelling that infringes on pulp space, forcing the pulp to recede with a potential loss of tooth vitality. After endodontic treatment, either hemorrhaging, materials used, or incomplete removal and breakdown of necrotic tissue may cause staining. The learning objective of this article is to review the causes and the prevention/treatment of discoloration in nonvital teeth. PMID:9002908

Miara, P

1995-09-01

216

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.

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

2014-01-01

217

Investigation on the utility of permanent maxillary molar cusp areas for sex estimation  

Microsoft Academic Search

Digital photogrammetric methods were employed to assess the level of sexual dimorphism present in permanent maxillary molar\\u000a cusp areas of black South Africans (130 males, 105 females). Odontometric standards were then developed for diagnosing sex,\\u000a based on the cusp area data derived for these teeth. Results demonstrated that all cusp area measurements of both the first\\u000a and second maxillary molars

P. James Macaluso Jr

2011-01-01

218

Residual stresses in fillets of gear teeth  

Microsoft Academic Search

1.The method proposed makes it possible to determine the residual stresses to a great depth, from the thinnest surface layer down to the unhardened material.2.Induction hardening of gear teeth creates residual compressive stresses in the fillets; in the transition zone these become tensile stresses. Polishing usually creates residual tensile stresses in the hardened surface layer.3.Polishing with removal of 0.2–0.3 mm

P. A. Lankin; A. N. Ovseenko

1968-01-01

219

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.

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

2014-01-01

220

Natural teeth and cognitive function in humans.  

PubMed

A number of neurobiological, psychological and social factors may account for cognitive impairment. In animal studies a relation between dental status and cognitive performance has been found. It is unclear whether such a relation exists for humans. In a first step we compared the performance of 1,351 participants (53% women, 47% men; age M = 54.0) with natural teeth to 487 edentulous participants (59% women, 41% men; age M = 71.3) on 12 cognitive tests. The natural teeth group had a lower mean age, fewer women, more years of education, higher mini-mental state (MMSE), and performed significantly higher on several cognitive tests. In a subsequent analysis, the cognitive performance of a subset of the participants (50-85 years) was examined. In this analysis, 211 had natural dentition and 188 were edentulous. The groups were matched for gender, age, social variables, diseases, stress and MMSE. The cognitive disadvantage of the edentulous group was still apparent. The results suggest that functional natural teeth relate to relatively preserved cognitive functioning in older age. PMID:18028078

Bergdahl, Maud; Habib, Reza; Bergdahl, Jan; Nyberg, Lars; Nilsson, Lars-Göran

2007-12-01

221

Bovine coronavirus associated syndromes.  

PubMed

Bovine coronaviruses, like other animal coronaviruses, have a predilection for intestinal and respiratory tracts. The viruses responsible for enteric and respiratory symptoms are closely related antigenically and genetically. Only 4 bovine coronavirus isolates have been completely sequenced and thus, the information about the genetics of the virus is still limited. This article reviews the clinical syndromes associated with bovine coronavirus, including pneumonia in calves and adult cattle, calf diarrhea, and winter dysentery; diagnostic methods; prevention using vaccination; and treatment, with adjunctive immunotherapy. PMID:20117547

Boileau, Mélanie J; Kapil, Sanjay

2010-03-01

222

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

PubMed

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

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

2013-09-01

223

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

PubMed Central

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

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

1998-01-01

224

Permanently Linked, Rigid, Magnetic Chains.  

National Technical Information Service (NTIS)

One aspect of the present invention relates to a permanently linked, rigid, magnetic chain of particles prepared by sol-gel methods. A second aspect of the present invention relates to a method of preparing a permanently linked, rigid, magnetic chain of p...

H. Singh T. A. Hatton

2004-01-01

225

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

226

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

Microsoft Academic Search

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

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

2008-01-01

227

Bovine Mastitis and Biofilms  

Microsoft Academic Search

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

Marielle B. Melchior

228

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

229

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.

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

2013-01-01

230

Regional structural characteristics of bovine periodontal ligament samples and their suitability for biomechanical tests  

PubMed Central

Mechanical testing of the periodontal ligament requires a practical experimental model. Bovine teeth are advantageous in terms of size and availability, but information is lacking as to the anatomy and histology of their periodontium. The aim of this study, therefore, was to characterize the anatomy and histology of the attachment apparatus in fully erupted bovine mandibular first molars. A total of 13 teeth were processed for the production of undecalcified ground sections and decalcified semi-thin sections, for NaOH maceration, and for polarized light microscopy. Histomorphometric measurements relevant to the mechanical behavior of the periodontal ligament included width, number, size and area fraction of blood vessels and fractal analysis of the two hard–soft tissue interfaces. The histological and histomorphometric analyses were performed at four different root depths and at six circumferential locations around the distal and mesial roots. The variety of techniques applied provided a comprehensive view of the tissue architecture of the bovine periodontal ligament. Marked regional variations were observed in width, surface geometry of the two bordering hard tissues (cementum and alveolar bone), structural organization of the principal periodontal ligament connective tissue fibers, size, number and numerical density of blood vessels in the periodontal ligament. No predictable pattern was observed, except for a statistically significant increase in the area fraction of blood vessels from apical to coronal. The periodontal ligament width was up to three times wider in bovine teeth than in human teeth. The fractal analyses were in agreement with the histological observations showing frequent signs of remodeling activity in the alveolar bone – a finding which may be related to the magnitude and direction of occlusal forces in ruminants. Although samples from the apical root portion are not suitable for biomechanical testing, all other levels in the buccal and lingual aspects of the mesial and distal roots may be considered. The bucco-mesial aspect of the distal root appears to be the most suitable location.

Bosshardt, Dieter D; Bergomi, Marzio; Vaglio, Giovanna; Wiskott, Anselm

2008-01-01

231

Numerical Simulation Of Cutting Of Gear Teeth  

NASA Technical Reports Server (NTRS)

Shapes of gear teeth produced by gear cutters of specified shape simulated computationally, according to approach based on principles of differential geometry. Results of computer simulation displayed as computer graphics and/or used in analyses of design, manufacturing, and performance of gears. Applicable to both standard and non-standard gear-tooth forms. Accelerates and facilitates analysis of alternative designs of gears and cutters. Simulation extended to study generation of surfaces other than gears. Applied to cams, bearings, and surfaces of arbitrary rolling elements as well as to gears. Possible to develop analogous procedures for simulating manufacture of skin surfaces like automobile fenders, airfoils, and ship hulls.

Oswald, Fred B.; Huston, Ronald L.; Mavriplis, Dimitrios

1994-01-01

232

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

Microsoft Academic Search

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

M P Ashley

2001-01-01

233

U.S. Legal Permanent Residents: 2011.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or green card recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, LP...

J. Yankay R. Monger

2012-01-01

234

22 CFR 401.3 - Permanent offices.  

Code of Federal Regulations, 2013 CFR

...true Permanent offices. 401.3 Section 401.3 Foreign Relations INTERNATIONAL JOINT COMMISSION, UNITED STATES AND CANADA RULES OF PROCEDURE General § 401.3 Permanent offices. The permanent offices of the Commission shall be at...

2013-04-01

235

The importance and representation of teeth in archaeozoological material.  

PubMed

Archaeologists, in most cases, neglect animal bones and teeth, which present common material on archaeological sites. Analysis of archaeozoological material from Vucedol (Baden culture) and prehistoric cave site Vela spila on Korcula, has been applied to stress the importance of that material (especially single animal teeth) in archaeozoological samples. It is obvious that a higher percentage of single teeth influence the number of identified animal species on particular sites. One species were identified only by teeth. For the reconstruction of the environment and behavior of ancient peoples, every evidence obtained from sites is important, and because of that sieving must be part of every excavation. PMID:12971169

Kuzir, Snjezana; Trbojevi? Vukicevi?, Tajana; Babi?, Kresimir; Miheli?, Damir; Radionov, Dubravka

2003-01-01

236

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.

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

2013-01-01

237

Permanent Magnet Circuit Design Primer.  

National Technical Information Service (NTIS)

The advent of rare-earth permanent magnets (REPM) has brought the realization of novel magnetic structures that are not practicable otherwise. So different are these remarkable materials from the earlier magnets that conventional design wisdom is inadequa...

H. A. Leupold E. Potenziani

1996-01-01

238

Microbial Contamination of Bovine Serum.  

National Technical Information Service (NTIS)

Development and application of viral screening methods to detect endogenous bovine virus contaminants in bovine sera used as a medium supplement in live virus vaccine production. Methods included: (1) an ultra-centrifugation concentration technique with p...

A. Kniaziff

1976-01-01

239

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

SciTech Connect

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

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

1997-03-01

240

Bovine factor XIIa inhibitor.  

PubMed

Bovine factor XIIa inhibitor was purified by an improved method employing affinity for heparin. N-terminal amino acid sequencing revealed a unique sequence without homology to any other known protein sequences. Peptide sequencing, however, showed that a part of the bovine factor XIIa inhibitor was homologous to human C1-inhibitor with a fraction of identical amino acid residues around 70%. Deglycosylation studies and carbohydrate analysis showed the presence of N- and O-linked carbohydrate. Bovine factor XIIa inhibitor did not inhibit plasma kallikrein and trypsin. The reactive site comprised an Arg-Asn bond, and represents the first example of asparagine as a P1' residue in Serpins with well documented inhibitory activity. PMID:8457651

Muldbjerg, M; Markussen, S; Magnusson, S; Halkier, T

1993-02-01

241

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

PubMed

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

2014-03-27

242

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

Microsoft Academic Search

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

N. Gateva

2009-01-01

243

Composite occlusal surfaces for acrylic resin denture teeth  

Microsoft Academic Search

Acrylic resin denture teeth often exhibit rapid occlusal wear, which may lead to a loss of chewing efficiency and a loss of vertical dimension of occlusion. The use of metal occlusal surfaces on the acrylic resin denture teeth will minimize occlusal wear. Several articles have described methods to construct metal occlusal surfaces; however, these methods are time-consuming, costly, and sometimes

Carlos Eduardo Vergani; Eunice Teresinha Giampaolo; Ana Lucia Machado Cucci

1997-01-01

244

The Vikings bare their filed teeth.  

PubMed

Finds of deliberate dental modification have for the first time been found in archaeological human skeletal material from Europe. The type of modification is a horizontally filed furrow on the frontal upper part of the tooth crown. The furrows are single or, more usually, multiple, and are found on the front teeth in the maxilla. The affected individuals are 24 men from the Viking Age (ca. 800-1050 AD), found in present day Sweden and Denmark. The marks are so well-made that it is most likely they were filed by a person of great skill. The reason for, and importance of, the furrows are obscure. The affected individuals may have belonged to a certain occupational group (such as tradesmen), or the furrows could have been pure decoration. PMID:16134162

Arcini, Caroline

2005-12-01

245

Elemental mapping of teeth using ?SRXRF  

NASA Astrophysics Data System (ADS)

Human teeth were analysed by X-ray microfluorescence analysis using synchrotron radiation (?SRXRF). The aim of this work was to study the elemental distribution for Ca, Zn and Sr along the dental regions, enamel, dentine and pulp from patterns of relative fluorescence intensities. The measurements were performed in standard geometry of 45° incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that Ca distribution is quite constant and it is independent of the tooth type and individuals characteristics. An increase of the Zn concentration was found for the pulp region and for untreated carious areas. Ca and Sr distributions show a similar behavior.

Anjos, M. J.; Barroso, R. C.; Pérez, C. A.; Braz, D.; Moreira, S.; Dias, K. R. H. C.; Lopes, R. T.

2004-01-01

246

Teeth mobility measurement by laser Doppler vibrometer  

NASA Astrophysics Data System (ADS)

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

Castellini, P.; Scalise, L.

1999-06-01

247

Improvement in properties of plastic teeth by electron beam irradiation  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

248

Esthetic rehabilitation of discolored anterior teeth with porcelain veneers  

PubMed Central

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

Kamble, Vaibhav D.; Parkhedkar, Rambhau D.

2013-01-01

249

Limited evidence for main reason for failure of partially excavated and restored teeth.  

PubMed

Data sourcesMedline, PubMed, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched between Jan 1967 and Dec 2012. No grey literature searches were carried out.Study selectionRandomised and non-randomised, controlled and uncontrolled, pro- and retrospective clinical studies (in English or German) that investigated one- or two-step incomplete dentinal caries removal (where caries was >1/2 dentine thickness) were eligible. Studies had to have teeth that were clinically and/or radiologically vital, primary or permanent teeth requiring a restoration but with no pulp exposure.The main outcomes were; clinical or radiological failure based on reported re-treatment. Failures were classified where possible into pulpal (pain, clinical or radiographic signs of pathology) and non-pulpal (tooth or restoration fracture, restoration loss or breach in integrity, secondary or progressing residual caries or non-pulpal failures).Data extraction and synthesisTwo authors independently reviewed the title and abstract of the articles (without blinding to authors or journals) and both extracted data, with discrepancies resolved through discussion or consultation with a third reviewer. Risk of bias was carried out using Cochrane collaboration guidelines and studies were assessed using GRADE criteria.Failure was calculated per year and annual failure rates weighted according to the number of teeth. Weighted annual failure rates were then used as the effect estimate for frequency and type of failure. Subgroup analyses were carried out, for factors influencing failure, in studies that compared teeth within one or more of the following groups: primary or permanent teeth; pulpal symptoms prior to treatment; single or multi-surface cavities; one- or two-step incomplete excavation; lining material; and restorative material.ResultsTwenty-nine articles reporting 19 trials (12 randomised controlled trials, two controlled trials, five case series & retrospective studies), with a median follow up of 24 months (IQR; 12 to 48), were included. In 11 studies pulpal complications were the main reason for failure and only two studies found more non-pulpal than pulpal failures. Median annual failure rate was 3.8 (IQR; 1.4 to 4.4)From the sub-group analyses, there was significantly lower risk of failure for teeth with one- compared to those with two-step excavation (OR=0.21, 95%CI [0.08 to 0.55]) and for those with single compared with multi-surface lesions (OR=0.33, 95%CI [0.16 to 0.67]. Risk of bias scores varied widely and the quality of the studies was very low.ConclusionsFollowing incomplete removal of deep caries, pulpal failure (pain, clinical or radiographic signs of pathology) was the most common failure type. One-step incomplete excavation for deep caries lesions reduced the risk of failure compared to two-step removal and multi-surface lesions had a higher risk of failure than single surface lesions. PMID:24763170

Fontana, Margherita

2014-03-01

250

Bovine besnoitiosis in Germany.  

PubMed

This paper reports a case of natural occurring bovine besnoitiosis in Germany. The skin lesions consisted of multifocal hypotrichosis and alopecia, lichenification, erythema and seborrhoea. Histopathologic findings revealed characteristic cysts of Besnoitia spp. The diagnosis was confirmed by serology and the species Besnoitia besnoiti was identified by polymerase chain reaction (PCR). PMID:20230585

Rostaher, Ana; Mueller, Ralf S; Majzoub, Monir; Schares, Gereon; Gollnick, Nicole S

2010-08-01

251

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

252

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

253

Management of immature teeth with apical infections using mineral trioxide aggregate.  

PubMed

Traumatic injuries to the young permanent teeth lead to devitalization of the pulp with concomitant arrest in further development of the immature root of the involved tooth. Hermetic seal of the root canal system during obturation is not possible in such cases, due to the lack of an apical constriction. The traditional management technique in such cases has been apexification involving induction of a calcific barrier at the apex using calcium hydroxide, which in turn facilitates obturation of the root canal. However this becomes complicated when there is persistent infection leading to periapical changes. This case report describes the use of mineral trioxide aggregate (MTA) for management of a periapically compromised immature tooth. PMID:22114380

Nuvvula, Sivakumar; Melkote, Tejas H; Mohapatra, Abinash; Nirmala, Svsg

2010-01-01

254

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

255

Optimized Design Considering the Mass Influence of an Axial Flux Permanent-Magnet Synchronous Generator With Concentrated Pole Windings  

Microsoft Academic Search

In this paper, the efficiency optimization of an axial flux permanent-magnet synchronous generator with concentrated pole windings is examined for a 3.6 kW\\/2000 rpm combined heat and power application. Because the efficiency of the machine is important, specific measures are taken in order to reduce losses in the machine: thin laminated grain oriented material in the teeth, concentrated pole windings,

Hendrik Vansompel; Peter Sergeant; Luc Dupre

2010-01-01

256

Ultrasonic Wave Properties in Bone Axis Direction of Bovine Cortical Bone  

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

257

Structure, composition, and mechanical properties of shark teeth.  

PubMed

The teeth of two different shark species (Isurus oxyrinchus and Galeocerdo cuvier) and a geological fluoroapatite single crystal were structurally and chemically characterized. In contrast to dentin, enameloid showed sharp diffraction peaks which indicated a high crystallinity of the enameloid. The lattice parameters of enameloid were close to those of the geological fluoroapatite single crystal. The inorganic part of shark teeth consisted of fluoroapatite with a fluoride content in the enameloid of 3.1 wt.%, i.e., close to the fluoride content of the geological fluoroapatite single crystal (3.64 wt.%). Scanning electron micrographs showed that the crystals in enameloid were highly ordered with a special topological orientation (perpendicular towards the outside surface and parallel towards the center). By thermogravimetry, water, organic matrix, and biomineral in dentin and enameloid of both shark species were determined. Dentin had a higher content of water, organic matrix, and carbonate than enameloid but contained less fluoride. Nanoindentation and Vicker's microhardness tests showed that the enameloid of the shark teeth was approximately six times harder than the dentin. The hardness of shark teeth and human teeth was comparable, both for dentin and enamel/enameloid. In contrast, the geological fluoroapatite single crystal was much harder than both kinds of teeth due to the absence of an organic matrix. In summary, the different biological functions of the shark teeth ("tearing" for Isurus and "cutting" for Galeocerdo) are controlled by the different geometry and not by the chemical or crystallographic composition. PMID:22503701

Enax, Joachim; Prymak, Oleg; Raabe, Dierk; Epple, Matthias

2012-06-01

258

Application of biomimetic mineralization: a prophylactic therapy for cracked teeth?  

PubMed

Cracked teeth are usually found and easily ignored in clinic. If not found in time, they can lead to pulpitis and teeth fractures, which even can make the cracked teeth pulled out. The current treatments for cracked teeth include occlusal adjustments or preventive fillings, and the root canal therapy or complete crown restoration, which is decided according to the depth of cracks. However, the successful rate of preserving cracked teeth is less than 50% through occlusal adjustments and preventive fillings. Although the successful rate can reach 80% through the root canal therapy and complete crowns, the pulp and normal tooth can not be reserved. So the harms are very serious that prevention of its further development is extremely important. Nanobacteria have a very unique role in biological mineralization, which can produce crystalline apatites in the conditions of physiological calcium and phosphorus concentrations. Therefore, a hypothesis is put forward that application of nanobacteria may mineralize the cracks of teeth. Then the development of cracked teeth would be completely stopped. PMID:19596523

Lin, Yixin; Zheng, Ren; He, Hao; Du, Huali; Lin, Yinghe

2009-10-01

259

Study of Thrust Ripple Suppression Using Interpoles of Intermittent Stator Permanent Magnet Linear Synchronous Motor  

NASA Astrophysics Data System (ADS)

For short and intermediate distance conveyance using intermittent stator permanent magnet linear synchronous motor (ISPM-LSM), a linear synchronous motor with a short stator (armature) is desirable for increasing the stroke length. A PM-LSM with four poles and three teeth has previously been proposed. However, in the case of few teeth, the generated thrust at the outlet edge decreases and a ripple is produced for the generated thrust. In addition, the generated thrust is affected by the cogging force. This paper discusses the use of an interpole at the stator outlet edge and a method to decrease the thrust ripple. Moreover, a method to decrease the cogging force is also presented.

Suzuki, Kenji; Ishikawa, Atsushi; Dohmeki, Hideo

260

Root Canal Morphology of Human Mandibular First Permanent Molars in an Iranian Population  

PubMed Central

Background and aims The knowledge of variations in root canal morphology is critical for a successful endodontic treatment. The purpose of this study was to investigate variations in the root canal system of human mandibular first permanent molars in an Iranian population. Materials and methods In this study, 209 mandibular first molar teeth were decalcified, dye-injected, and cleared in order to determine the number and configuration of the root canals. Results The results demonstrated that 65.56% of the mandibular first molars under study had three, 31.57% had four and 2.87% had two canals. Conclusion According to the results of this study and considering variations in the root canal systems of the mandibular first molars, it seems that great care should be taken in the root canal treatment of these teeth.

Shahi, Shahriar; Yavari, Hamid Reza; Rahimi, Saeed; Torkamani, Reza

2008-01-01

261

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

PubMed

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

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

2010-01-01

262

Natal and neonatal teeth among cleft lip and palate infants  

PubMed Central

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

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

2013-01-01

263

Elimination of permanent injuries to the inferior alveolar nerve following surgical intervention of the "high risk" third molar.  

PubMed

We aimed to find out whether improved preoperative assessment and surgical planning with cone beam computed tomography (CT) could reduce damage to the inferior alveolar nerve when high risk impacted mandibular third molars are extracted. We recorded the presence or absence of postoperative neuropathy after extraction of 200 lower third molars in 185 patients (where cone beam CT had shown contact between the nerve and root) after treatment in the oral surgery department of King's College Hospital. All patients had had cone beam CT of the teeth after panoramic radiography had indicated increased risk of injury to the nerve during extraction. Experienced oral surgeons did all the operations and postoperative reviews. Patients reported temporary alteration of sensation after operation in 12% of teeth but it resolved in all cases and no patient reported permanent loss of sensation. Permanent sensory disturbance in the distribution of the inferior alveolar nerve after third molars have been removed can be eliminated in high risk cases if operations are planned carefully (including cone beam CT), and the procedure is done by a skilled surgeon who has an appreciation of the anatomy of the nerve and roots, and an insight into the mechanical effect of their surgical manipulation. The incidence of permanent neurosensory dysfunction in this study was zero even though all teeth were intimately related to the inferior alveolar canal. PMID:23010201

Umar, G; Obisesan, O; Bryant, C; Rood, J P

2013-06-01

264

Permanence of High School Learning  

Microsoft Academic Search

What is the permanence of learning in those studies carried in high school, but not pursued in college? A group of seniors, 16 men and 18 women, were used as subjects for this investigation. To get at this there was first obtained a rough estimate of the students' ability from their final semester grades in each subject while in high

D. H. Eickenberry

1923-01-01

265

Microfilm Permanence and Archival Quality  

ERIC Educational Resources Information Center

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

Avedon, Don M.

1972-01-01

266

Magnetic Fields: Visible and Permanent.  

ERIC Educational Resources Information Center

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

Winkeljohn, Dorothy R.; Earl, Robert D.

1983-01-01

267

[Choice of size of anterior teeth in black African patients].  

PubMed

The choice of the size of artificial teeth takes an important place in the treatment of edentulism with removable prosthesis. However, the standards or proportions commonly used as guide have been developed mainly on Caucasian populations. This study have been undertaken to determine some proportions between anterior upper teeth and some maxillo-facial structures in black African subjects. The results suggest that the proportions generally used to choice the anterior upper artificial teeth in Caucasian subjects can not been applied in melanoderme African patients. PMID:12680129

N'Dindin, A C; N'Guessan, K S; Assi, K D; Bitty, M J; Ohomon, O R

2002-12-01

268

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.

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

2010-01-01

269

Mycotic bovine nasal granuloma.  

PubMed

A case of mycotic bovine nasal granuloma in a 10 year-old Jersey cow, produced by Drechslera halodes is presented. Histopathological sections showed abundant hyaline and pigmented extra and intracellular fungal structures together with a polymorphic cellular granuloma formed by neutrophils, lymphocytes, plasmocytes, histiocytes and giant cells of the Langhans type. It is the first case of mycotic bovine nasal granuloma recognized in Uruguay although this disease seems to be frequent according to the opinion of veterinarian specialists. Another similar clinical case also in a Jersey cow from the same dairy house with an intense cellular infiltrate rich in eosinophils without granulomatous image, together with extracellular hyaline and fuliginous fungal forms, is also referred for comparative purposes. Geotrichum sp. was isolated. The need of an early diagnosis and treatment of the disease is stressed. PMID:12870067

Conti Díaz, Ismael Alejandro; Vargas, Roberto; Apolo, Ada; Moraña, José Antonio; Pedrana, Graciela; Cardozo, Elena; Almeida, Edgardo

2003-01-01

270

A minimally invasive technique for the management of severely fluorosed teeth: A two-year follow-up  

PubMed Central

Objective: Severely fluorosed and heavily discolored teeth that have large enamel defects give rise to esthetic concerns and require permanent treatment. In such cases, restorative techniques such as porcelain or composite laminate veneers or crowns are generally preferred, in which tooth preparation is inevitably required. Materials and Methods: This clinical report describes a patient with severely fluorosed teeth who was successfully treated with a minimally invasive technique including enamel microabrasion (6.6% hydrochloric acid slurry with silicon carbide micro-particles, Opalustre, Ultradent Products, Inc., South Jordan, UT, USA) followed by in-office bleaching (38% hydrogen peroxide, Opalescence Boost, Ultradent). Enamel microabrasion was conducted in two visits while three visits were required for in-office bleaching. Patient was followed-up after 2 years. Result: A slight staining had occurred during this period, but it was acceptable for patient. No adverse effects were observed. Conclusions: The minimally invasive technique including enamel microabrasion and in-office bleaching was efficient and may represent a good alternative to traditional restorative techniques for the management of severely fluorosed teeth.

Yildiz, Gul; Celik, Esra Uzer

2013-01-01

271

Bovine leukocyte adhesion deficiency in Holstein cattle.  

PubMed Central

Two Holstein heifers with persistent and recurrent infections including ulcerative gingivitis, periodontitis, pneumonia, loss of teeth and stunted growth associated with marked neutrophilia were evaluated clinically and for neutrophil function, CD18 expression on neutrophils and CD18 genotype analysis by DNA-polymerase chain reaction (PCR) test. Adherence to nylon fibers and phagocytic activity of neutrophils from affected animals were significantly (p < 0.05) impaired as compared with those of controls. Neutrophils from affected heifers had decreased chemiluminescent (CL) responses when stimulated with opsonized zymosan, compared with those of controls. In contrast, neutrophils from affected heifers produced increased CL responses when stimulated with latex beads and phorbol myristate acetate compared with those of controls. The clinical findings, functional leukocyte abnormalities, deficiency in expression of CD18 on neutrophils, and the D128G mutation detected by DNA-PCR testing of affected heifers demonstrated that these heifers have bovine leukocyte adhesion deficiency (BLAD). Although both animals were confirmed to be homozygotes for BLAD by DNA-PCR test, they had differences in clinical, hematological and neutrophil functional characteristics. Images Fig. 2.

Nagahata, H; Nochi, H; Tamoto, K; Taniyama, H; Noda, H; Morita, M; Kanamaki, M; Kociba, G J

1993-01-01

272

Longitudinal clinical and radiographic evaluation of severely intruded permanent incisors in a pediatric population.  

PubMed

Intrusion is defined as the axial dislodgment of the tooth into its socket and is considered one of the most severe types of dental trauma. This longitudinal outcome study was undertaken to evaluate clinically and radiographically severely intruded permanent incisors in a population of children and adolescents. All cases were treated between September 2003 and February 2008 in a dental trauma service. Clinical and radiographic data were collected from 12 patients (eight males and four females) that represented 15 permanent maxillary incisors. Mean age at the time of injury was 8 years and 9 months (range 7-14 years and 8 months). Mean time elapsed to follow-up was 26.6 months (range 10-51 months). The analysis of data showed that tooth intrusion was twice as frequent in males. The maxillary central incisors were the most commonly intruded teeth (93.3%), and falling at home was the main etiologic factor (60%). More than half of the cases (53.3%) were multiple intrusions, 73.3% of the intruded teeth had incomplete root formation and 66.6% of the teeth suffered other injuries concomitant to intrusion. Immediate surgical repositioning was the treatment of choice in 66.7% of the cases, while watchful waiting for the tooth to return to its pre-injury position was adopted in 33.3% of the cases. The teeth that suffered additional injuries to the intrusive luxation presented a fivefold increased relative risk of developing pulp necrosis. The immature teeth had six times more chances of presenting pulp canal obliteration that the mature teeth and a lower risk of developing root resorption. The most frequent post-injury complications were pulp necrosis (73.3%), marginal bone loss (60%), inflammatory root resorption (40%), pulp canal obliteration (26.7%) and replacement root resorption (20%). From the results of this study, it was not possible to determine whether the type immediate treatment had any influence on the appearance of sequelae like pulp necrosis and root resorption after intrusive luxation, but the existence of additional injuries and the stage of root development influenced the clinical case outcome in a negative and positive manner, respectively. PMID:19614934

Neto, José Jeová Siebra Moreira; Gondim, Juliana Oliveira; de Carvalho, Fernanda Matias; Giro, Elisa Maria Aparecida

2009-10-01

273

Antimicrobial Efficacy of Reduced Concentrations of Parachlorophenol in Extracted Teeth.  

National Technical Information Service (NTIS)

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

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

1975-01-01

274

Lead concentrations in white-tailed deer mandibles and teeth  

SciTech Connect

Mandibles and teeth of 48 white-tailed deer from 6 counties in Pennsylvania were analyzed for lead by flame atomic absorption spectrophotometry. Results indicate little influence of age, sex, and county on lead levels. (JMT)

Witkowski, S.A.; Ault, S.R.; Field, R.W.

1982-05-01

275

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

MedlinePLUS

... Baby's Teeth? Are Pacifiers a Problem? Early Childhood Tooth Decay: The Roles of the Bottle and Breastfeeding Long- ... water. This will increase your child's risk of tooth decay. Use positive reinforcement to encourage older children to ...

276

About Kids' Teeth: Baby Tooth Decay is Real  

MedlinePLUS

... Tooth Decay Thumb sucking Prevent Decay Nutrition Baby Tooth Decay Is Real As soon as teeth appear in ... news – decay is mostly preventable . What Are Cavities? Causes of Decay Tooth decay begins when cavity- ...

277

Astronauts Culbertson and Bursch brush their teeth on Discovery's middeck  

NASA Technical Reports Server (NTRS)

Astronauts Frank L. Culbertson (right), mission commander, and Daniel W. Bursch, mission specialist, brush their teeth on Discovery's middeck. Two sleep restraints form part of the backdrop for the photograph.

1993-01-01

278

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

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

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

279

[Optimal reconstruction of destructed teeth by pin constructions].  

PubMed

327 patients with dentures supported by 318 pulpless teeth reinforced by pin constructions were under observation. Main types of complications after pin use were identified. By math simulation the system "covering construction-artificial stump-root pin-root of the tooth" was studied for teeth 11, 13, 15, 16, 41, 43, 45, 46 in two projections--vestibulo-oral and mesio-distal. Margins of strength properties of teeth armed by special pin constructions (made as individual casting) and artificial stump with standard pins made of different materials were determined. Optimal parameters of height and width of off-root part and intra-root pin sizes in different teeth groups in conformity with their individual anatomic peculiarities were established. PMID:16353035

Arutiunov, A S; Lebedenko, I Iu; Arutiunov, S D; Zubov, V S; Chumachenko, E N

2005-01-01

280

Removable partial denture on osseointegrated implants and natural teeth.  

PubMed

Implants have been designed to provide edentulous patients with fixed prostheses or overdentures. Recently, implant-supported fixed partial prostheses and single crowns have become successful treatment alternatives to removable and fixed partial dentures. However, few researchers have examined "removable partial dentures on implants and natural teeth". In this article, we report two patients fitted with "removable partial dentures on implants and natural teeth". The patients were satisfied with their dentures in terms of function and aesthetics. Regular follow-up visits revealed that the periodontal and peri-implant conditions were stable. There was no evidence of excessive intrusion or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. Since the average duration of observation was about 38 months, further follow-up examinations are necessary to determine whether these dentures remain stable long-term. PMID:17760280

Chang, Li-Ching; Wang, Jen-Chyan; Tasi, Chi-Cheng

2007-01-01

281

A computer aided design procedure for generating gear teeth  

NASA Technical Reports Server (NTRS)

A procedure for computer aided design (CAD) of gear teeth is presented. It is developed for generated teeth fabricated by a hob cutter or a shaper. It provides a means for analytically and numerically determining the tooth profile, given the cutter profile. An illustrative example with involute tooth profiles is given. Application with non-standard profiles and with bevel, spiral bevel, and hypoid gears is discussed.

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

1984-01-01

282

Bone density changes around teeth during orthodontic treatment  

Microsoft Academic Search

The objective of this study was to evaluate bone density changes around the teeth during orthodontic treatment by using cone\\u000a beam computed tomography (CBCT). CBCT was used to measure the bone densities around six teeth (both maxilla central incisors,\\u000a lateral incisors, and canines) before and after 7 months of orthodontic treatment in eight patients. In addition, each root\\u000a was divided into

Jui-Ting Hsu; Hsin-Wen Chang; Heng-Li Huang; Jian-Hong Yu; Yu-Fen Li; Ming-Gene Tu

2011-01-01

283

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

PubMed Central

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

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

2013-01-01

284

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

285

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

Microsoft Academic Search

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

Christy C. Visaggi; Stephen J. Godfrey

2010-01-01

286

Muscles Advance the Teeth in Sand Dollars and Other Sea Urchins  

Microsoft Academic Search

We demonstrate the action of the dental promoter muscles in advancing the continuously growing teeth of sand dollars and sea urchins. Teeth wear at the occlusal end, while new calcite is added to the opposite end. Dental ligaments rigidly hold teeth during chewing, but soften and reform during advancement. The source of forces that advance the teeth was unknown until

Olaf Ellers; Malcolm Telford

1997-01-01

287

Optimizing and restructuring the cleaning teeth motion flow in the stomatology hospital  

Microsoft Academic Search

The paper analyzes the cleaning teeth motion flow of dentist by observing the process of cleaning teeth for the patient in the stomatology hospital with the basic industrial engineering theory and method. It studies also dentist and nurse's collaborating operation of cleaning teeth. It establishes a new cleaning teeth motion flow by optimizing and restructuring. The research indicates that comparing

Wei Guo; Fan-sen Kong; Qiu Jiang

2011-01-01

288

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

289

Permanent Income, Current Income, and Consumption  

Microsoft Academic Search

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

John Y. Campbell; N. Gregory Mankiw

1990-01-01

290

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.

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

2014-01-01

291

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

292

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

PubMed Central

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

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

2014-01-01

293

Root canal morphology of permanent maxillary and mandibular canines in Indian population using cone beam computed tomography.  

PubMed

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

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

2014-01-01

294

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.

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

2012-01-01

295

Serotypes of bovine astrovirus.  

PubMed Central

Three isolates of bovine astrovirus, one from the United Kingdom and two from the United States, possessed common antigens by immunofluorescence and strain-specific antigens by neutralization and were designated as two, and probably three, distinct serotypes. The isolate US2, despite being a different serotype, possessed the same restrictive cell tropism and cytopathology as previously reported for isolate US1, of the M cells of the dome epithelium of the Peyer's patches. Serotyping of 16 field isolates indicated the presence of more undefined serotypes.

Woode, G N; Gourley, N E; Pohlenz, J F; Liebler, E M; Mathews, S L; Hutchinson, M P

1985-01-01

296

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

Microsoft Academic Search

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

Gabriela Ibarra; Marcos A. Vargas; Werner Geurtsen

2006-01-01

297

Mineral trioxide aggregate in endodontic treatment for immature teeth.  

PubMed

The aim of the present study was to test the hypothesis that the fracture strength of calcium hydroxide and mineral trioxide aggregate (MTA) filled immature teeth decrease over time. Immature mandibular incisors from sheep were extracted and the pulps were extirpated using an apical approach with a barbed broach, and the teeth were divided into three experimental groups. Group 1: Untreated teeth. Group 2: The root canal was filled with calcium hydroxide paste (Ultradent-UltraCal XS). Group 3: The root canal was filled with ProRoot MTA system (Dentsply, USA). All specimens were kept in saline with 1% antibiotics at 4 degres C for certain periods of time: two weeks, two months and one year. All teeth were tested for fracture strength in an Instron testing machine at the indicated observation periods. The results were subjected to statistical analysis by a one-way analysis of variance and with the t-test at a 5% level of significance. One tooth from each group was selected randomly for the histological study. The mean fracture strengths decreased over time for all the three groups. The fracture strengths were not found significantly different from the untreated, calcium hydroxide-treated or MTA-treated teeth at two-week or two-month (p>0.05). However, the results for MTA-treated teeth were significantly higher than the other two groups at one year (p=0.0137). The teeth with root treatment with MTA showed the highest fracture resistance at one year (p<0.05), since only MTA induced the expression of TIMP-2 in the dentin matrix and possibly prevents rapid destruction of collagen. PMID:17946495

Hatibovic-Kofman, Sahza; Raimundo, Lin; Chong, Lawrence; Moreno, Jorge; Zheng, Lei

2006-01-01

298

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

299

Bovine respiratory coronavirus.  

PubMed

Bovine coronaviruses (BCoVs) cause respiratory and enteric infections in cattle and wild ruminants. BCoV is a pneumoenteric virus that infects the upper and lower respiratory tract and intestine. It is shed in feces and nasal secretions and also infects the lung. BCoV is the cause of 3 distinct clinical syndromes in cattle: (1) calf diarrhea, (2) winter dysentery with hemorrhagic diarrhea in adults, and (3) respiratory infections in cattle of various ages including the bovine respiratory disease complex or shipping fever of feedlot cattle. No consistent antigenic or genetic markers have been identified to discriminate BCoVs from the different clinical syndromes. At present, there are no BCoV vaccines to prevent respiratory BCoV infections in cattle, and the correlates of immunity to respiratory BCoV infections are unknown. This article focuses on respiratory BCoV infections including viral characteristics; epidemiology and interspecies transmission; diagnosis, pathogenesis, and clinical signs; and immunity and vaccines. PMID:20619189

Saif, Linda J

2010-07-01

300

Near-IR imaging of cracks in teeth  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

301

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.

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

2012-01-01

302

Viability of pulp stromal cells in cryopreserved deciduous teeth.  

PubMed

The cryopreservation of exfoliated deciduous teeth and harvesting of stem cells from them as required would reduce the costs and efforts associated with banking stem cells from primary teeth. The aim of this study was determine whether the viability of pulp stromal cells from deciduous teeth was influenced by the cryopreservation process itself or the period of cryopreservation. In total, 126 deciduous teeth were divided into three groups: (1) fresh, (2) cryopreserved for <3 months (cryo<3), and (3) cryopreserved for 3-9 months (cryo3-9). The viability of the pulp tissues was compared among the three groups by evaluating the outgrowth from pulp tissues and cell activity within those pulp tissues. In addition, the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay was performed to compare cell apoptosis within fresh pulp tissue and pulp tissue that had been cryopreserved for 4 months. The outgrowth from and cell activity within the pulp tissues did not differ significantly between the fresh and cryo<3 pulp tissues. However, these parameters were significantly reduced in the cryo3-9 pulp tissue. In TUNEL assay, 4-month cryopreserved pulp tissues has more apoptotic cells than fresh group. In conclusion, it is possible to acquire pulp stromal cells from cryopreserved deciduous teeth. However, as the period of cryopreservation becomes longer, it is difficult to get pulp cells due to reduced cell viability. PMID:23670172

Ji, Eun Hye; Song, Je Seon; Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Lee, Jae Ho

2014-03-01

303

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.

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

2014-01-01

304

High-performance permanent magnets  

NASA Astrophysics Data System (ADS)

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

Goll, D.; Kronmüller, H.

305

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

DOEpatents

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

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

2011-09-13

306

CBCT evaluation of multiple idiopathic internal resorptions in permanent molars: case report  

PubMed Central

Background Internal inflammatory root resorption is a rare condition in permanent teeth, which requires the presence of necrotic and infected pulp tissue within the coronal portion of the root canal system as well as inflamed pulp tissue apical to the resorptive defect. The aetiology of internal root resorption is not completely understandable, trauma and chronic pulpitis are considered the main risk factors. Case presentation We report a rare case of the multiple idiopathic resorption in the permanent maxillary and mandibular molars in a healthy 33-year-old female patient. In addition to clinical examination the patient was imaged using conventional radiography techniques and cone beam computed tomography (CBCT).The patient had recurrent throbbing pain in her # 46. The radiographic examination including “panoramic radiography and CBCT” revealed that radiographic evidence of internal resorption in #37 #36 #35 #34 #33 #47 #46 #45 #44 #43 #16 #15 #14 #13 and also including in unerupted #17, #26, #27, #28 teeth. The definitive diagnosis was made with the histopathological examination of the extracted tooth. Conclusions Internal root resorption is a rare clinical process that should be examined using different radiographic modalities. CBCT seems to be useful in evaluation of the lesions with superior diagnostic performance.

2014-01-01

307

The optimal design of involute gear teeth with unequal addenda  

NASA Technical Reports Server (NTRS)

The design of a gear mesh is treated with the objective of minimizing the gear size for a given gear ratio, pinion torque, pressure angle, and allowable tooth lengths. Tooth strengths considered include scoring, pitting fatigue, and bending fatigue. Kinematic involute interference is avoided. The design variation on standard spur gear teeth called the long and short addendum system, is considered. In this system the mesh center distance and pressure angle are maintained as is the ability to manufacture the teeth with standard tooling. However, the pinion and gear tooth proportions are altered in order to obtain fewer teeth numbers for the same ratio as standard gears without kinematic involute interference. The effect of this nonstandard gearing geometry with on tooth strengths and gear mesh size are studied. For a 2:1 gearing ratio, the optimal nonstandard gear design is compared with the optimal standard gear design.

Savage, M.; Coy, J. J.; Townsend, D. P.

1982-01-01

308

Flap Hitching Technique to the Teeth after Oral Cancer Resection  

PubMed Central

Objectives: After resection of the tumors of oral cavity adjacent to the mandible, it is a common situation that the whole of one side of the gingival mucosal segment has to be stripped off the mandible to get an adequate margin. When a cutaneous flap is used for reconstruction, it has to be hitched to the teeth to get a watertight seal. We describe a technique to hitch the flap to the adjacent teeth in such an instance. Materials and Methods: The technique was applied in 10 patients with oral cancer, resected, and reconstructed with cutaneous flaps. Results: The technique was found to be effective in all 10 patients. Adequate seal was obtained in all patients. Oral diet was started within 7 days. Conclusion: An effective and simple technique to approximate a cutaneous flap to the teeth-bearing mandible, when all the mucosa is removed as part of oncological resection, is reported.

Thankappan, Krishnakumar; Iyer, Subramania; Rajapurkar, Mayuri; Sharma, Mohit; Subash, Pramod

2012-01-01

309

Fracture resistance of teeth restored with dentin-bonded crowns.  

PubMed

While dentin-bonded crowns may hold esthetic advantages over metal-ceramic restorations, and minimal tooth preparation may also be appropriate, resistance to fracture of the restored unit is an important consideration. Dentin-bonded crowns were placed on standardized preparations in two groups of 10 maxillary premolar teeth in vitro. The preparations differed only in degree of taper. The restored specimens were subjected to compressive loading at 1 mm/min from a steel bar placed along the midline fissure. Mean fracture loads of 0.77 kN (6-degree taper) and 0.71 kN (8-degree taper) were recorded for the groups of prepared teeth, and a mean fracture load of 0.97 kN was obtained for a group of unprepared controls. Statistical analysis indicated that there was no significant difference between the fracture load of the 6-degree taper group and that of the sound control teeth. PMID:7938418

Burke, F J; Watts, D C

1994-05-01

310

"En masse" retraction of maxillary anterior teeth with anterior headgear.  

PubMed

In the treatment of the first premolar extraction cases with certain techniques, incisor retraction is realized after canine distalization. In maximum anchorage cases, retraction of anterior segments require more posterior anchorage. This treatment concept is still valid, however, the difficult anchorage control is considered a major drawback. The purpose of this study is to introduce our technique for the "en masse" retraction of maxillary anterior teeth after first premolar extraction and discuss its effects. The technique consists of the application of extraoral traction on canines, followed by banding of maxillary anterior teeth, to form them as a mass. Advantages of our mechanics are as follows: (1) Anterior headgear may have the advantage of retracting anterior teeth with minimum strain on posterior anchorage. (2) The adjustability of the outer bow in relation to the premaxilla's center of resistance, provides effective desired movements. (3) Intrusion and torque control are achieved in the course of anterior segment retraction. PMID:9387832

Güray, E; Orhan, M

1997-11-01

311

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

PubMed Central

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

Gunes, Betul; Aydinbelge, Hale Ari

2012-01-01

312

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

PubMed Central

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

Komabayashi, Takashi; Zhu, Qiang

2010-01-01

313

[Modulation of soleus H-reflex by teeth clenching].  

PubMed

Modulation of the human soleus H-reflex (Sol. H-R) was studied during voluntary teeth clenching in 11 healthy adult volunteers, to investigate the possible correlation of motor functions between the jaw and body. The following results were obtained: (1) Sol. H-R was facilitated during the maximum voluntary teeth clenching more than during the maximum voluntary efforts in the other parts of the body, i.e., Jendrassik maneuver and clenching of both hands. (2) The amount of the Sol. H-R facilitation increased with the masseter EMG activity. (3) Facilitation of the Sol. H-R in association with teeth clenching started ca 60ms before the onset of the masseter EMG activity, reached its peak ca. 100ms after the onset and thereafter decreased to a certain plateau level in accordance with the masseter EMG activity level. (4) During the inhibition of the masseter EMG reflexively evoked by electrical stimulation of the lower lip, the amount of the facilitation of the Sol. H-R during teeth clenching decreased compared with that without lip stimulation, though the facilitation was still retained. It was concluded that: 1) The excitability of the Sol. H-R is remarkably elevated during teeth clenching. 2) There is a positive correlation between the amount of the facilitation of the Sol. H-R and the teeth clenching force level. 3) The facilitation is due to both the descending influence from the higher brain and the afferent inputs from the oral structures. It is assumed that the oral motor activity exerts a strong influence on the bodily motor function in general. PMID:1795137

Miyahara, T

1991-12-01

314

Substantivity of Three Concentrations of Tetraclean in Bovine Root Dentin  

PubMed Central

In the present study, the residual antibacterial activity, or substantivity, of three concentrations of Tetraclean (Ogna Laboratori Farmaceutici, Muggiò, Italy) was assessed in bovine root dentin in vitro. One hundred ten dentin tubes prepared from bovine incisor teeth were infected in vitro for 14 days with Enterococcus faecalis. Thereafter, the specimens were divided into five groups as follows: 100% Tetraclean, 10% Tetraclean, 1% Tetraclean, sterile dentin tubes (negative control), and infected dentin tubes (positive control). Dentin chips were collected with round burs into tryptic soy broth and, after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimal in the first cultures in all experimental groups, and the results obtained were significantly different in the different groups at all time periods (p<0.05). At all five experimental periods, the 100% Tetraclean group showed the most effective antibacterial action (p<0.05). In each group, the number of CFU increased significantly with time (p<0.05). There was a direct relationship between the concentration of Tetraclean and its substantivity. In conclusion, under the conditions of the study presented here, the substantivity of 100% Tetraclean was significantly higher than that of lower concentrations.

Giardino, L; Palazzi, F; Shalavi, S; Farahani, M F

2012-01-01

315

Substantivity of three concentrations of tetraclean in bovine root dentin.  

PubMed

In the present study, the residual antibacterial activity, or substantivity, of three concentrations of Tetraclean (Ogna Laboratori Farmaceutici, Muggiò, Italy) was assessed in bovine root dentin in vitro. One hundred ten dentin tubes prepared from bovine incisor teeth were infected in vitro for 14 days with Enterococcus faecalis. Thereafter, the specimens were divided into five groups as follows: 100% Tetraclean, 10% Tetraclean, 1% Tetraclean, sterile dentin tubes (negative control), and infected dentin tubes (positive control). Dentin chips were collected with round burs into tryptic soy broth and, after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimal in the first cultures in all experimental groups, and the results obtained were significantly different in the different groups at all time periods (p<0.05). At all five experimental periods, the 100% Tetraclean group showed the most effective antibacterial action (p<0.05). In each group, the number of CFU increased significantly with time (p<0.05). There was a direct relationship between the concentration of Tetraclean and its substantivity. In conclusion, under the conditions of the study presented here, the substantivity of 100% Tetraclean was significantly higher than that of lower concentrations. PMID:23323220

Mohammadi, Z; Giardino, L; Palazzi, F; Shalavi, S; Farahani, M F

2012-12-01

316

An interim obturator prosthesis with duplicated teeth and palate.  

PubMed

A technique for fabrication of an interim obturator has been described in which the palatal and arch form can be reproduced with relative accuracy. The duplication aids in rehabilitation of the patient, because an environment for the tongue similar to the preoperative environment may simplify speech and deglutition (Fig. 7). In addition, the technique permits replacement of anterior teeth in the same position and of the same size and shape as were present preoperatively (Fig. 8). The technique is also more economic because of the time saved, the ease of the procedure, and the use of duplicated teeth. PMID:6389840

Kouyoumdjian, J H; Chalian, V A

1984-10-01

317

A clinical study of patients with hypersensitive teeth.  

PubMed

Hypersensitive teeth have been a nemesis to patients in every dental practice. This clinical study was done to find a causal relationship of hypersensitive teeth and other organs of special senses, namely, sight, hearing, taste, smell, and touch. The analysis of the findings offers a basis for conclusion that dentition hypersensitivity and hypersensitivity of the special senses have a causal relationship. The dental clinician can provide the patient with an understanding and explanation of the cause(s) of hypersensitivity that will assist in a cooperative analysis of the symptoms and aid in the treatment to alleviate the pain. PMID:12572184

Bitter, Norman C

2002-01-01

318

Occupation times on a comb with ramified teeth  

NASA Astrophysics Data System (ADS)

We investigate occupation time statistics for random walks on a comb with ramified teeth. This is achieved through the relation between the occupation time and the first passage times. Statistics of occupation times in half space follows Lamperti's distribution, i.e., the generalized arcsine law holds. Transitions between different behaviors are observed, which are controlled by the size of the backbone and teeth of the comb, as well as bias. Occupation time on a nonsimply connected domain is analyzed with a mean-field theory and numerical simulations. In that case, the generalized arcsine law is not valid.

Rebenshtok, A.; Barkai, E.

2013-11-01

319

Delayed replantation of avulsed mature teeth with calcium hydroxide treatment.  

PubMed

Three avulsed teeth that were replanted and splinted after approximately a 200-min dry extraoral period in two patients are presented. In case 1 calcium hydroxide treatment was performed 1 month after replantation, because the patient did not come for endodontic treatment on the day after replantation as requested. In case 2, calcium hydroxide treatment was initiated on the day after replantation. Calcium hydroxide treatment was used to prevent or treat inflammatory root resorption. During the follow-up periods the teeth reported in these cases have remained in a stable, functional position and did not reveal clinical ankylosis or replacement resorption. PMID:11199783

Cali?kan, M K; Türkün, M; Gökay, N

2000-08-01

320

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.

2014-01-01

321

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

PubMed Central

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

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

2013-01-01

322

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

PubMed

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

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

2013-01-01

323

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

324

Permanent deformation of flexible pavements  

NASA Astrophysics Data System (ADS)

Seven pairs of pavements with granular bases were tested under controlled conditions. One pavement in each pair contained fabric inclusions. An improved testing facility was developed, including: (1) servo-hydraulic system for the loading carriage; (2) amplification and read-out system for pressure cells; (3) linearizing unit for strain coils; (4) transducers for measuring vertical and resilient deflection; (5) techniques for measuring in situ strain on fabric inclusions; (6) extensive use of nuclear density meter to monitor pavement and foundation materials. The following conclusions are drawn: (1) No improvement in performance resulted from fabric inclusions. (2) No consistent reduction in in-situ stresses, resilient strains, or permanent strains was observed as a result of fabric inclusion. (3) No consistent improvement in densities resulted from fabric inclusions. (4) Some slip apparently occurred between fabric and soil on those pavements which involved large deformations. The slip occurred between fabric and crushed limestone base rather than between fabric and silty-clay subgrade.

Brown, S. F.; Broderick, B. V.; Pappin, J. W.

1980-06-01

325

Gating of Permanent Molds for Aluminum Casting  

Microsoft Academic Search

This report summarizes a two-year project, DE-FC07-011D13983 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 to determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity

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

2004-01-01

326

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...

327

Evaluation of High Energy Rate Forged Gears with Integral Teeth.  

National Technical Information Service (NTIS)

The fatigue properties of gears forged with integral teeth were compared with those of gears machined from bar stock and gears machined from simple upset forgings. The gears tested were manufactured from both air melt and vacuum-melt 9310 steel and tested...

F. L. Parkinson

1967-01-01

328

Green teeth in a premature infant following hemolytic jaundice.  

PubMed

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

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

2013-07-01

329

Influence of Cavity Geometry on Heat Transmission in Restored Teeth.  

National Technical Information Service (NTIS)

In the oral cavity thermal changes can be responsible for tooth damage resulting in pulpitis and pain. The relationship between pain and temperature has been investigated 1-6 widely. Thermal analysis of human teeth however has not been reported frequently...

T. A. M. Spierings J. H. P. de Vree M. C. R. B. Peters A. J. M. Plasschaert

1983-01-01

330

CO2 laser on apical seal of retrofilled teeth  

NASA Astrophysics Data System (ADS)

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

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

1997-05-01

331

Marginal ridge strength of teeth with tunnel preparations.  

PubMed

The aim of this study was to investigate how the cavity design of tunnel preparations influences the strength of the marginal ridge and to assess the ability of a restoration to support it. Extracted upper premolars were divided into eight experimental groups and one control group of intact teeth. The size and the position of the tunnel preparation in relation to the marginal ridge differed in four of the groups, the preparations remaining unfilled, while teeth in four corresponding groups were filled. The teeth were subjected to incremental dynamic forces until fracture of the marginal ridge occurred at which point a 'maximum energy-index' was calculated. The relationship between this index and the experimental variables was analysed by the Cox proportional hazards model. The results for both filled and unfilled teeth indicated that the distance from the preparation to the marginal ridge is more influential on weakening the ridge than is the buccopalatinal size of the opening. A conservative tunnel restoration situated 2 mm from the marginal ridge, does not significantly weaken an otherwise intact tooth. PMID:7558348

Strand, G V; Tveit, A B; Gjerdet, N R; Eide, G E

1995-04-01

332

SHED: Stem cells from human exfoliated deciduous teeth  

Microsoft Academic Search

To isolate high-quality human postnatal stem cells from accessible resources is an important goal for stem-cell research. In this study we found that exfoliated human deciduous tooth contains multipotent stem cells [stem cells from human exfoliated deciduous teeth (SHED)]. SHED were identified to be a population of highly proliferative, clonogenic cells capable of differentiating into a variety of cell types

Masako Miura; Stan Gronthos; Mingrui Zhao; Bai Lu; Larry W. Fisher; Pamela Gehron Robey; Songtao Shi

2003-01-01

333

The density and branching of dentinal tubules in human teeth  

Microsoft Academic Search

Detailed knowledge of dentine structure, and especially that of the dentinal tubules, is essential in order to understand dentine permeability and to interpret data from investigations on dentine adhesive materials. The aim here was to examine the density and branching of dentinal tubules in human teeth by light and scanning electron microscopy. Stained and unstained demineralized sections and undemineralized fractured

I. A. Mjör; I. Nordahl

1996-01-01

334

Microwear of Mammalian Teeth as an Indicator of Diet  

Microsoft Academic Search

Microwear details on teeth of two sympatric species of hyrax are correlated with major dietary differences observed in the wild. Grazing (Procavia johnstoni) and browsing (Heterohyrax brucei) species can be distinguished. The results show that diets of extinct species may be deduced from tooth microwear.

Alan Walker; Hendrick N. Hoeck; Linda Perez

1978-01-01

335

Microbiological status of root-filled teeth with apical periodontitis.  

PubMed

The present study examined the microbiological status of 100 root-filled teeth with radiographically verified apical periodontitis--the pathology (P) group--and of 20 teeth without signs of periapical pathosis--the technical (T) group. In the P group 117 strains of bacteria were recovered in 68 teeth. In most of the cases examined one or two strains were found. Facultative anaerobic species predominated among these isolates (69% of identified strains). Growth was classified as 'sparse' or 'very sparse' in 53%, and as 'heavy' or 'very heavy' in 42%. Enterococci were the most frequently isolated genera, showing 'heavy' or 'very heavy' growth in 25 out of 32 cases (78%). In 11 teeth of the T group no bacteria were recovered, whilst the remaining nine yielded 13 microbial strains. Eight of these grew 'very sparsely'. It is concluded that the microflora of the obturated canal differs from that found normally in the untreated necrotic dental pulp, quantitatively as well as qualitatively. Nonsurgical retreatment strategies should be reconsidered. PMID:9823122

Molander, A; Reit, C; Dahlén, G; Kvist, T

1998-01-01

336

Carbon dioxide laser oral safety parameters for teeth  

Microsoft Academic Search

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

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

1990-01-01

337

Method and Device for Determining Viability of Intact Teeth.  

National Technical Information Service (NTIS)

The invention relates to a method and device for assessing the viability, in other words vitality, of intact teeth, and more particularly to a device and method for assessing the amount of blood in a tooth of a patient based on the ratio of transmission o...

G. M. Maxwell R. L. Webber

1987-01-01

338

Perikymata spacing and distribution on hominid anterior teeth.  

PubMed

We documented the spacing and distribution of perikymata on the buccal enamel surface of fossil hominin anterior teeth with reference to a sample of modern human and modern great ape teeth. A sample of 27 anterior teeth attributed to Australopithecus (5 to A. afarensis, 22 to A. africanus) and of 33 attributed to Paranthropus (6 to P. boisei, and 27 to P. robustus) were replicated and sputter-coated with gold to enable reflected light microscopy of their surface topography. Anterior teeth were then divided into 10 equal divisions of buccal crown height. The total perikymata count in each division of crown height was recorded using a binocular microscope fitted with a vernier micrometer eyepiece. Then the mean number of perikymata per millimeter was calculated for each division. Similar comparative data for a modern sample of 115 unworn human anterior teeth and 30 African great ape anterior teeth were collected from ground sections. Perikymata counts in each taxon (together with either known or presumed periodicities of perikymata) were then used to estimate enamel formation times in each division of crown height, for all anterior tooth types combined. The distributions of these estimates of time taken to form each division of crown height follow the same trends as the actual perikymata counts and differ between taxa in the same basic way. The distinction between modern African great apes and fossil hominins is particularly clear. Finally, we calculated crown formation times for each anterior tooth type by summing cuspal and lateral enamel formation times. Estimates of average crown formation times in australopiths are shorter than those calculated for both modern human and African great ape anterior teeth. The data presented here provide a better basis for exploring differences in perikymata spacing and distribution among fossil hominins, and provide the first opportunity to describe four specimens attributed to Homo in this context. Preliminary data indicate that differences may exist among the species attributed to early Homo, especially between Homo ergaster and Homo rudolfensis on the one hand, and Homo habilis sensu strico on the other. PMID:11596000

Dean, M C; Reid, D J

2001-11-01

339

76 FR 26239 - Bovine Tuberculosis and Brucellosis; Public Meetings  

Federal Register 2010, 2011, 2012, 2013

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

2011-05-06

340

76 FR 38602 - Bovine Tuberculosis and Brucellosis; Program Framework  

Federal Register 2010, 2011, 2012, 2013

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

2011-07-01

341

In vitro wear resistance, hardness and elastic modulus of artificial denture teeth.  

PubMed

In this study, the wear resistance, hardness, elastic modulus, and the correlations between them of artificial denture teeth at the sub-enamel layer were examined. Four types of tested artificial denture teeth consisted of 3 conventional acrylic resin teeth (Cosmo HXL, Major Dent, and Yamahachi FX), 1 high cross-linked acrylic resin teeth (Trubyte Bioform IPN), 2 composite resin teeth (SR Orthosit PE, and Yamahachi PX), and 1 porcelain teeth (ACE Teeth). The two-body wear test was performed using a custom made pin on disc apparatus. Volume and weight loss were measured. Hardness and elastic modulus were also assessed by using a nanoindentation system. The results suggested wear resistance varied among the denture tooth materials. Wear resistance of high cross-linked acrylic resin teeth was the lowest. A definite relation between wear resistance and mechanical properties of materials could not be found in this study. PMID:21778606

Suwannaroop, Pii; Chaijareenont, Pisaisit; Koottathape, Natthavoot; Takahashi, Hidekazu; Arksornnukit, Mansuang

2011-01-01

342

Hen's teeth with enamel cap: from dream to impossibility  

PubMed Central

Background The ability to form teeth was lost in an ancestor of all modern birds, approximately 100-80 million years ago. However, experiments in chicken have revealed that the oral epithelium can respond to inductive signals from mouse mesenchyme, leading to reactivation of the odontogenic pathway. Recently, tooth germs similar to crocodile rudimentary teeth were found in a chicken mutant. These "chicken teeth" did not develop further, but the question remains whether functional teeth with enamel cap would have been obtained if the experiments had been carried out over a longer time period or if the chicken mutants had survived. The next odontogenetic step would have been tooth differentiation, involving deposition of dental proteins. Results Using bioinformatics, we assessed the fate of the four dental proteins thought to be specific to enamel (amelogenin, AMEL; ameloblastin, AMBN; enamelin, ENAM) and to dentin (dentin sialophosphoprotein, DSPP) in the chicken genome. Conservation of gene synteny in amniotes allowed definition of target DNA regions in which we searched for sequence similarity. We found the full-length chicken AMEL and the only N-terminal region of DSPP, and both are invalidated genes. AMBN and ENAM disappeared after chromosomal rearrangements occurred in the candidate region in a bird ancestor. Conclusion These findings not only imply that functional teeth with enamel covering, as present in ancestral Aves, will never be obtained in birds, but they also indicate that these four protein genes were dental specific, at least in the last toothed ancestor of modern birds, a specificity which has been questioned in recent years.

2008-01-01

343

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

PubMed

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

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

2013-01-01

344

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

Microsoft Academic Search

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

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

2009-01-01

345

E- and N-Cadherin Distribution in Developing and Functional Human Teeth under Normal and Pathological Conditions  

PubMed Central

Cadherins are calcium-dependent cell adhesion molecules involved in the regulation of various biological processes such as cell recognition, intercellular communication, cell fate, cell polarity, boundary formation, and morphogenesis. Although previous studies have shown E-cadherin expression during rodent or human odontogenesis, there is no equivalent study available on N-cadherin expression in dental tissues. Here we examined and compared the expression patterns of E- and N-cadherins in both embryonic and adult (healthy, injured, carious) human teeth. Both proteins were expressed in the developing teeth during the cap and bell stages. E-cadherin expression in dental epithelium followed an apical-coronal gradient that was opposite to that observed for N-cadherin. E-cadherin was distributed in proliferating cells of the inner and outer enamel epithelia but not in differentiated cells such as ameloblasts, whereas N-cadherin expression was up-regulated in differentiated epithelial cells. By contrast to E-cadherin, N-cadherin was also expressed in mesenchymal cells that differentiate into odontoblasts and produce the hard tissue matrix of dentin. Although N-cadherin was not detected in permanent intact teeth, it was re-expressed during dentin repair processes in odontoblasts surrounding carious or traumatic sites. Similarly, N-cadherin re-expression was seen in vitro, in cultured primary pulp cells that differentiate into odontoblast-like cells. Taken together these results suggest that E- and N-cadherins may play a role during human tooth development and, moreover, indicate that N-cadherin is important for odontoblast function in normal development and under pathological conditions.

Heymann, Robert; About, Imad; Lendahl, Urban; Franquin, Jean-Claude; Obrink, Bjorn; Mitsiadis, Thimios A.

2002-01-01

346

Evaluating permanent deformation in asphalt rubber mixtures  

Microsoft Academic Search

Permanent deformation or rutting, one of the most important distresses in flexible pavements, has long been a problem in asphalt mixtures, mainly in countries with high temperatures such as Brazil. Throughout the years, researchers have used different test methods to estimate the rutting performance of asphalt mixtures. One of the alternatives to reduce permanent deformation in asphalt pavement layers is

Liseane P. T. L. Fontes; Glicério Trichês; Jorge C. Pais; Paulo A. A. Pereira

2010-01-01

347

Personal computer-based three-dimensional computed tomographic images of the teeth for evaluating supernumerary or ectopically impacted teeth.  

PubMed

This study describes the use of personal computer (PC)-based three-dimensional computed tomographic (3D CT) images in the evaluation of supernumerary and ectopically impacted teeth. Three selected cases were presented as examples of the more complex cases in which 3D CT imaging added information not readily available from periapical, occlusal, or panoramic radiographs. Patients were CT scanned from the occlusal plane to the periapical region of the impacted teeth. Digital Image and Communications in Medicine CT data were transferred to a personal laptop computer using a network line. 3D volume rendering was performed using PC-based volumetric analysis software. 3D CT-reformatted imaging of the teeth is a useful way to investigate and localize supernumerary or impacted teeth. Newer software that enables this investigation using a PC provides a relatively inexpensive way to carry out such investigations, making it easier for dental practitioners to request such investigations and to view the results in real time in their own offices. PMID:14580032

Kim, Kee-Deog; Ruprecht, Axel; Jeon, Kug-Jin; Park, Chang-Seo

2003-10-01

348

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

NASA Astrophysics Data System (ADS)

In the southern Spring of 1995 (mid-October) the active volcano Mt Ruapehu in the central North Island of New Zealand erupted explosively, spreading up to 40 million m 3 of rhyolite tephra over thousands of km 2 of farmland during the lambing season. This ash contained a high concentration of soluble fluoride, and more than 2000 lactating ewes died of acute fluoride poisoning. To investigate the effects of this brief but acute dose on the teeth of grazing animals we examined the distributions of fluorine and calcium in the permanent incisor teeth of sheep which were one year old at the time. Where part of an incisor had been in the first (secretory) stage of calcification the erupted tooth disclosed surface pitting, a thin layer of enriched mineral across the enamel with as much as 1000 ppm F w/w, and a separate layer with ˜4000 ppm down the dentine. The part of an incisor which had attained the later (maturation) stage showed enriched layers only in the outer enamel and in the dentine. This study has demonstrated some important features of the calcification process, and the risk of fluoride toxicity to grazing animals.

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

1997-07-01

349

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

350

Amalgam components drift in teeth-toxicity risks: A preliminary approach  

Microsoft Academic Search

The use of ion beam techniques applied to teeth studies have been extensive in what concerns the major elements distribution. However, it is not clarified whether amalgam components are absorbed and drifted through teeth material, although the toxicity of the elements used in amalgams, such as Hg, are well known. This work is an attempt to assess a possible teeth

M. L. Carvalho; T. Pinheiro; M. A. Barreiros; C. Casaca; A. S. Cunha; P. Chevallier

1998-01-01

351

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

PubMed

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

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

2013-03-11

352

Colour stability of denture teeth submitted to different cleaning protocols and accelerated artificial aging.  

PubMed

Acrylic resin is widely used for artificial teeth manufacturing due to several important characteristics; however, this material do not present acceptable colour stability over the course of time. This study evaluated the effect of different cleaning protocols and accelerated artificial aging on colour stability of denture teeth made of acrylic resin. Sixty denture teeth in dark and light shades were used, and separated according to the treatment to which they were submitted. Results demonstrated that colour stability of artificial teeth is influenced by the cleaning solution and artificial aging, being dark teeth more susceptible to colour alteration than lighter ones. PMID:24922996

Freire, T S; Aguilar, F G; Garcia, L da Fonseca Roberti; Pires-de-Souza, F de Carvalho Panzeri

2014-03-01

353

Restoration of endodontically treated teeth: criteria and technique considerations.  

PubMed

The restoration of endodontically treated teeth is often required and may represent a challenge as there is no consensus on ideal treatment. The failure of endodontically treated teeth is usually not a consequence of endodontic treatment, but inadequate restorative therapy or periodontal reasons. Prior to the initiation of endodontic treatment the restorability, occlusal function, periodontal health, biologic width, and crown-to-root ratio need to be assessed. If acceptable, the appropriate technique, material, and type of restoration to restore function need to be considered. Posts are used to provide retention for the core material and to replace missing tooth structure. The residual amount of tooth structure will determine its stability for restoration. The creation of adequate ferrule (approaching 2 mm circumferentially is ideal) minimizes the damaging effects of lateral and rotational forces on the restoration and post. PMID:24847494

Trushkowsky, Richard D

2014-01-01

354

Detecting cracks in teeth using ultrasonic excitation and infrared imaging  

NASA Astrophysics Data System (ADS)

We describe a new technique, Thermosonics, that can be used to detect cracks in teeth. This technique was initially invented and developed for finding cracks in industrial and aerospace applications. The thermosonics technique employs a single short pulse (typically tens of milliseconds) of ultrasound excitation combined with infrared imaging. Ultrasonic waves vibrate the target material. This vibration causes rubbing and clapping between faying surfaces of any cracks which are present, resulting in a temperature rise around the cracks. An infrared camera is used to image the temperature distribution during and after the ultrasound excitation. Thus, cracks in teeth can be detected. Although this technique is still under development, it shows promise for clinical use by dentists.

Han, Xiaoyan; Favro, Lawrence D.; Thomas, Robert L.

2001-06-01

355

Collagen degradation in endodontically treated teeth after clinical function.  

PubMed

Endodontically treated teeth restored with posts are susceptible to coronal leakage after long-term function. We hypothesize that demineralized collagen matrices (DCMs) created in dentin by acidic zinc phosphate cement within the dowel spaces degrade with time. Forty-two post-restored teeth were extracted after three periods of clinical service and were examined, by means of scanning and transmission electron microscopy, for the status of the DCMs. SEM revealed a progressive degradation of the DCMs, becoming less dense after 3 to 5 years, losing structural integrity after 6 to 9 years, and partially disappearing after 10 to 12 years. TEM revealed evidence of collagenolytic activity within the DCMs, with loss of cross-banding and unraveling into microfibrils, and gelatinolytic activity that resulted in disintegration of the microfibrils. Bacterial colonization and the release of bacterial enzymes and of host-derived matrix metalloproteinases may contribute to the degradation of collagen fibrils in root dentin after clinical function. PMID:15111635

Ferrari, M; Mason, P N; Goracci, C; Pashley, D H; Tay, F R

2004-05-01

356

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

357

Dentin Alteration of Deciduous Teeth in Human Hypophosphatemic Rickets  

Microsoft Academic Search

Familial hypophosphatemic rickets is in most cases transmitted as an X-linked dominant trait and results from mutation of\\u000a the PHEX gene, predominantly expressed in osteoblast and odontoblast. Patients have been reported to display important dentin defects,\\u000a and therefore, we explored the dentin structure, composition, and distribution of extracellular matrix (ECM) molecules in\\u000a hypophosphatemic human deciduous teeth. Compared to age-matched controls,

T. Boukpessi; D. Septier; S. Bagga; M. Garabedian; M. Goldberg; C. Chaussain-Miller

2006-01-01

358

Residual stresses in the teeth of quenched gears  

Microsoft Academic Search

1.The method of polishing the valleys of gear segments makes it possible to obtain data on the stress distribution at the base of the teeth. With careful experimental work it is possible to determine the stresses in the surface zone (at a depth of 0.01 mm).2.With fairly sharp quenching, using induction heating by high-frequency current, high compressive stresses of thermal

I. Ya. Arkhipov; V. A. Kanunnikova

1970-01-01

359

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

360

Multiple Unerupted Teeth with Amelogenesis Imperfecta in Siblings  

PubMed Central

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

Hegde, Shruthi

2012-01-01

361

[Relation between teeth clenching and grip force production characteristics].  

PubMed

This study investigated the possible contributing effect of oral motor function on maximal and explosive grip force production characteristics. Fourteen healthy male subjects (age 22.5 +/- 2.1 years) were asked to exert maximal explosive grip strength with their dominant hands under the following four conditions: 1. Teeth clenching before and during grip strength exertion (C-C), 2. Teeth clenching before grip strength exertion and mandibular resting position during grip strength exertion (C-R), 3. Mandibular resting position before grip strength exertion and teeth clenching during grip strength exertion (R-C), and 4. Mandibular resting position before and during grip strength exertion (R-R). Maximal force (maxF), average force for every 0.1 s (aveF), maximal rate of force development (maxRFD) and time required to reach 90% of maxF (T 90% max) were analyzed for 1 s from the onset of grip force production. MaxF under C-C and R-C were significantly greater than that under R-R by 12.1% and 12.3%, respectively. AveF under C-C was significantly greater by 10.0-41.2% than that under R-R for all ten periods. AveF under C-R was significantly larger by 9.8-19.0% than that under R-R conditions from 0 to 0.4 s. Compared with under R-R conditions, maxRFD under C-C and C-R increased by 15.8% and 8.5%, respectively, and T 90% max under C-C, C-R and R-C decreased by 22.3%, 12.3% and 12.8%, respectively. These findings suggest that oral motor functions such as teeth clenching may influence not only maximal grip strength generation but also the rapidity of grip force production. PMID:12879850

Hiroshi, Churei

2003-06-01

362

Stable Isotope Ratios in Hair and Teeth Reflect Biologic Rhythms  

PubMed Central

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

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

2007-01-01

363

Characterization, diagnosis and ablation of human teeth using blue laser at 457 nm  

NASA Astrophysics Data System (ADS)

The light interaction with tissue is governed by the specific wavelength of the laser used and the optical properties of target tissue. Absorption, scattering and fluorescence together can probably be used as the basis of quantitative diagnostic methods for teeth caries. The absorption coefficient of human teeth was determined from detached wet teeth (incisors and premolars). Laser absorption of these teeth was measured using compact blue laser source at wavelength of 457 nm and a high resolution spectrometer equipped with an integrating sphere. The average absorption coefficient of abnormal caries tissue of human teeth is observed to be higher than the normal ones. Detection and diagnosis of caries tissues were monitored by high resolution translational scanning of human teeth. We have a powerful tool to diagnosis a caries region of human teeth using blue laser at 457 nm. Ablations of caries region are investigated using higher power of blue laser at 457 nm.

El-Sherif, Ashraf F.; Gomaa, Walid; El-Sharkawy, Yasser H.

2014-02-01

364

Amalgam components drift in teeth-toxicity risks: A preliminary approach  

NASA Astrophysics Data System (ADS)

The use of ion beam techniques applied to teeth studies have been extensive in what concerns the major elements distribution. However, it is not clarified whether amalgam components are absorbed and drifted through teeth material, although the toxicity of the elements used in amalgams, such as Hg, are well known. This work is an attempt to assess a possible teeth contamination originated by the amalgams. Therefore, teeth with metallic amalgam, as well as healthy ones, were studied. The teeth were longitudinally cut and each slice was scanned from the inner region to the surface enamel for elemental profiles determination purposes using Particle Induced X-ray Emission (PIXE) and Synchrotron Radiation X-ray Fluorescence (SRXRF) techniques. High levels of Zn, Ag, Sn, Hg and Pb were found along the scanned teeth restored with the metallic amalgam. The elemental distribution patterns suggest diffusion of these elements in the teeth material from amalgam constituents.

Carvalho, M. L.; Pinheiro, T.; Barreiros, M. A.; Casaca, C.; Cunha, A. S.; Chevallier, P.

1998-03-01

365

Color alteration in teeth subjected to different bleaching techniques  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

366

Recovery and identification of mature enamel proteins in ancient teeth.  

PubMed

Proteins in mineralized tissues provide a window to the past, and dental enamel is peculiar in being highly resistant to diagenesis and providing information on a very narrow window of time, such as the developing period; however, to date, complete proteins have not been extracted successfully from ancient teeth. In this work we tested the ability of a whole-crown micro-etch technique to obtain enamel protein samples from mature enamel of recently extracted (n = 2) and ancient (n = 2; ad 800 to 1100) third molars. Samples were analyzed using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry, and the resulting spectra were searched against the Swiss-Prot protein database using the Mascot software for protein identification. In our protocol, the separation of proteins in gel is not necessary. Successful identification of specific enamel proteins was obtained after whole-crown superficial enamel etching with 10% HCl. Most protein fragments recovered from dry teeth and mummy teeth contained amino-terminal amelogenin peptides. Only one peptide specific for the amelogenin X-isoform was identified. In conclusion, the reported techniques allowed the successful recovery of proteins specific to dental enamel from samples obtained in a very conservative manner, which may also be important in forensic and/or archeological science. PMID:22243232

Porto, Isabel M; Laure, Helen J; Tykot, Robert H; de Sousa, Frederico B; Rosa, Jose C; Gerlach, Raquel F

2011-12-01

367

Apical infection spreading to adjacent teeth: a case report.  

PubMed

This case report describes apical infection on tooth number 24 that spread to adjacent teeth, resulting in devitalized teeth numbers 23 and 25. The 25-year-old Caucasian female patient was referred to the endodontic resident clinic because of uncontrolled apical infection. Root-end surgery and root-end filling of teeth numbers 23, 24, and 25 were performed. The histopathological diagnosis was a periapical cyst; however, the clinical surgical finding of a purulence-filled bone cavity also revealed a periapical abscess. After root-end surgery and regenerative therapy using Mineral Trioxide Aggregate, Bio-Oss xenograft material, and Bio-Gide resorbable collagen membrane, the patient had no symptoms. Radiographs showed the apical lesion had healed satisfactorily at the 6-month, 1-year, and 2-year follow-ups. The clinical implication of this rare case suggests the importance of standard endodontic diagnostic procedures for pulpal and apical diagnosis, prevention of apical periodontitis exacerbation by reducing bacterial factors, and the effectiveness of healing large bone defects using regenerative materials. PMID:21458327

Komabayashi, Takashi; Jiang, Jin; Zhu, Qiang

2011-06-01

368

Bending strength model for internal spur gear teeth  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

369

Bleaching of nonvital teeth. A clinically relevant literature review.  

PubMed

Today, the bleaching of nonvital, discolored teeth is a low-risk routine treatment for improving esthetics. This review article focuses on the etiology of tooth discolorations, different treatment techniques, and risks of bleaching procedures. Some tooth discolorations in endodontically treated teeth are caused by dental treatments. The three most popular techniques for nonvital tooth bleaching are the walking bleach technique, inside/outside bleaching, and in-office bleaching. The walking bleach technique is a relatively reliable, fairly simple technique for dentists and patients. Inside/outside bleaching can be used additionally when internal and external bleaching must be combined. In-office bleaching seems to be a short-term solution, the effects of which can largely be attributed to dehydration of the teeth. There are still some open questions concerning the bleaching agents. Improved safety seems desirable with regard to adding thiourea as a scavenger of radicals or newer materials such as sodium percarbonate. The thermocatalytic technique, insufficient cervical sealing, and high concentrations of bleaching agents should be avoided, as this can increase the risk of cervical root resorptions. Patients should be informed about the low predictability of bleaching success and the risk of recurrent discoloration. The risk of cervical root resorption should be discussed with the patient. There is a strong correlation between root resorption and dental trauma. PMID:20514558

Zimmerli, Brigitte; Jeger, Franziska; Lussi, Adrian

2010-01-01

370

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

371

A Method for Rapid Demineralization of Teeth and Bones  

PubMed Central

Tooth and bone specimen require extensive demineralization for careful analysis of cell morphology, as well as gene and protein expression levels. The LacZ gene, which encodes the ß-galactosidase enzyme, is often used as a reporter gene to study gene-structure function, tissue-specific expression by a promoter, cell lineage and fate. This reporter gene is particularly useful for analyzing the spatial and temporal gene expression pattern, by expressing the LacZ gene under the control of a promoter of interest. To analyze LacZ activity, and the expression of other genes and their protein products in teeth and bones, it is necessary to carry out a complete demineralization of the specimen before cutting sections. However, strong acids, such as formic acid used for tooth demineralization, destroy the activities of enzymes including those of ß-galactosidase. Therefore, most protocols currently use mild acids such as 0.1 M ethylene diamine tetra-acetic acid (EDTA) for demineralization of tooth and bone specimen, which require a longer period of treatment for complete demineralization. A method by which hard tissue specimens such as teeth and bones can be rapidly, but gently, decalcified is necessary to save time and effort. Here, we report a suitable method for rapid demineralization of mouse teeth in 0.1M EDTA at 42?C without any loss of ß-galactosidase activity.

Cho, Andrew; Suzuki, Shigeki; Hatakeyama, Junko; Haruyama, Naoto; Kulkarni, Ashok B

2010-01-01

372

[Initial masseter muscle fatigue in maximal voluntary teeth clenching].  

PubMed

Fatigue of striated muscles is defined as the impossibility to generate the expected or required force during the repeated contraction. During the maximal voluntary teeth contraction in the position of central occlusion the initial fatigue in masticatory muscles during the isometric contraction occurs. If a person can clench its teeth continuously and voluntarily it has a diagnostic significance since the peripheral fatigue is that important factor in the masticatory muscles activity, which is in direct correlation with the function of the masticatory system. The aim was to compare the obtained results of the initial fatigue of masseter muscles during the maximal voluntary teeth contraction in subjects with naturally healthy intact dentition and subjects with a pair of new full dentures. The investigation comprised 20 subjects with healthy stomatognathic system of the skeletal class I by Angle. Comparison of the values of the obtained results was performed electromyographically by synchronous registration of action potentials of masseter muscles. Results of the investigation of the onset of initial fatigue of masseter muscles in the subjects with natural healthy intact dentions showed lower values, i.e., faster development of the muscular fatigue (31.5 s) compared to the subjects with a pair of new full dentures (44.5 s). PMID:11928190

Miljkovi?, Hivorad; Zeljkovi?, Milan; Anojci?, Milos

2002-01-01

373

A microbiological profile of symptomatic teeth with primary endodontic infections.  

PubMed

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

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

2008-05-01

374

U.S. Legal Permanent Residents: 2006. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or 'green card' recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, ...

K. Jefferys

2007-01-01

375

U.S. Legal Permanent Residents: 2007. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or green card recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, LP...

2008-01-01

376

U.S. Legal Permanent Residents: 2005. Annual Flow Report.  

National Technical Information Service (NTIS)

Every year, hundreds of thousands of persons become legal permanent residents (LPR's) or 'green card' recipients of the United States. LPR's, as defined by immigration law, are persons who have been granted lawful permanent residence. Permanent resident s...

K. Jefferys N. Rytina

2006-01-01

377

U.S. Legal Permanent Residents: 2009. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or 'green card' recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, ...

R. Monger

2010-01-01

378

U.S. Legal Permanent Residents: 2008. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or green card recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, LP...

N. Rytina R. Monger

2008-01-01

379

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

380

29 CFR 2582.8478-3 - Permanent bonding requirements.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Permanent bonding requirements. 2582.8478-3 Section...REGULATIONS FOR FIDUCIARY RESPONSIBILITY Permanent Bonding Rules § 2582.8478-3 Permanent bonding requirements. (a) General....

2009-07-01

381

U.S. Legal Permanent Residents: 2010. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or 'green card' recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, ...

J. Yankay R. Monger

2011-01-01

382

U.S. Legal Permanent Residents: 2004. Annual Flow Report.  

National Technical Information Service (NTIS)

Every year, hundreds of thousands of persons become legal permanent residents (LPR's) or 'green card' recipients of the United States. LPR's, as defined by immigration law, are persons who have been granted lawful permanent residence. Permanent resident s...

N. F. Rytina

2005-01-01

383

U.S. Legal Permanent Residents: 2012. Annual Flow Report.  

National Technical Information Service (NTIS)

A legal permanent resident (LPR) or green card recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United States. Permanent resident status confers certain rights and responsibilities. For example, LP...

J. Yankay R. Monger

2013-01-01

384

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

385

Investigation for Low-Cost Permanent Magnets.  

National Technical Information Service (NTIS)

This work focused on the search for materials and processing techniques that provide the potential of low-cost, high performance permanent magnets. The principal processing method was rapid solidification and annealing. Crystallized amorphus alloys of Fe,...

J. J. Becker

1985-01-01

386

78 FR 14122 - Revocation of Permanent Variances  

Federal Register 2010, 2011, 2012, 2013

...and Health Administration [Docket No. OSHA-2011-0054] Revocation of Permanent...Occupational Safety and Health Administration (OSHA), Labor. ACTION: Notice of revocation...SUMMARY: With this notice, OSHA is revoking twenty-four (24)...

2013-03-04

387

Micromachined permanent magnets and their MEMS applications  

NASA Astrophysics Data System (ADS)

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

Cho, Hyoung Jin

2002-01-01

388

Design Calculations for Permanent-Magnet Generators  

Microsoft Academic Search

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

David Ginsberg; Leo J. Misenheimer

1953-01-01

389

Ultraminiaturized Milliwatt-Scale Permanent Magnet Generators  

Microsoft Academic Search

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

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

2007-01-01

390

Object permanence in cats and dogs  

Microsoft Academic Search

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

Estrella Triana; Robert Pasnak

1981-01-01

391

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

392

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

393

10 CFR 34.33 - Permanent radiographic installations.  

Code of Federal Regulations, 2010 CFR

...false Permanent radiographic installations. 34.33 Section 34.33...REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY...33 Permanent radiographic installations. (a) Each entrance...

2010-01-01

394

10 CFR 34.33 - Permanent radiographic installations.  

Code of Federal Regulations, 2010 CFR

...false Permanent radiographic installations. 34.33 Section 34.33...REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY...33 Permanent radiographic installations. (a) Each entrance...

2009-01-01

395

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.

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

2013-01-01

396

Mechanical Test to Bovine Bone  

NASA Astrophysics Data System (ADS)

The Young modulus in compression of fresh and inorganic bovine bone was obtained, in the longitudinal and transversal directions of the trabeculae, using an Instron universal machine. It was found that the elastic properties of the bone depend strongly on the orientation of the force regarding the direction of the trabeculae, specially for fresh bone.

Presbítero Espinosa, Gerardo; Maciel Cerda, Alfredo; Tejeda Cruz, Adriana; Piña Barba, Cristina

2006-09-01

397

Bovine Bacillus anthracis in Cameroon ? †  

PubMed Central

Bovine Bacillus anthracis isolates from Cameroon were genetically characterized. They showed a strong homogeneity, and they belong, together with strains from Chad, to cluster A?, which appears to be predominant in western Africa. However, one strain that belongs to a newly defined clade (D) and cluster (D1) is penicillin resistant and shows certain phenotypes typical of Bacillus cereus.

Pilo, Paola; Rossano, Alexandra; Bamamga, Hamadou; Abdoulkadiri, Souley; Perreten, Vincent; Frey, Joachim

2011-01-01

398

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

399

Case report: pulp revascularization of a necrotic, infected, immature, permanent tooth.  

PubMed

The purpose of this report is to present the case of a patient wherein revascularization of the necrotic infected pulp space of an immature permanent maxillary central incisor tooth was induced in vivo by stimulation of a blood clot from the periapical tissues into the canal space. This was achieved after disinfecting the canal space with a topical antibiotic paste followed by inducing a blood clot scaffold from the periapical tissues. This treatment approach offers great potential to avoid the need for traditional apexification with calcium hydroxide or the need to achieve an artificial apical barrier with mineral trioxide aggregate. Furthermore, this treatment approach can help rescue infected immature teeth by physiologically strengthening the root walls. PMID:19455934

Thibodeau, Blayne

2009-01-01

400

Esthetic-functional recovery of permanent posterior tooth using autogenous biological restoration.  

PubMed

Occlusal morphology and difficult access for cleaning permanent molars result in the buildup of bacterial plaque and the development of caries. One method known as biological restoration was carried out. This technique known as biological restoration, has as main restorative material a fragment obtained from a duly donated extracted human tooth. This case report describes the restoration of an extensively decayed molar through the bonding of a fragment obtained from a third molar extracted from the patient himself. Biological restoration is a low-cost option that offers satisfactory aesthetic, morphological and functional results.The morphological/functional reestablishment of posterior teeth can be obtained through biological restoration, which allows the recovery of properties inherent to the dental structure, offers satisfactory aesthetic results and low cost. PMID:23514687

Botelho, A M; Tavano, K T A; Correa-Faria, P; Morato, L N S; Viana, M R

2012-01-01

401

Root Canal Configuration of Maxillary First Permanent Molars in an Iranian Population  

PubMed Central

Background and aims It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The purpose of this study was to investigate variations in the root canal system of maxillary first permanent molars in an Iranian population. Materials and methods In this study, 137 maxillary first molars were decalcified, dye-injected, cleared and studied. Results The results demonstrated that 37.96% of the maxillary first molars under study had three canals, 58.4% had four canals and 3.64% had five canals. Conclusion According to the results of this study and considering variations in the root canal systems of maxillary first molars, it seems that great care should be taken in the root canal treatment of these teeth.

Shahi, Shahriar; Yavari, Hamid Reza; Rahimi, Saeed; Ahmadi, Ali

2007-01-01

402

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

PubMed Central

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

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

2014-01-01

403

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

Microsoft Academic Search

Different ideas have been presented to describe the mechanism of augmented laser ablation of dental enamel with different\\u000a shapes by adding water to the working environment. In this study, the influence of water–laser interaction on the surface\\u000a of enamel during ablation was investigated at a wavelength of 2.94 ?m with different distances between the laser tip and the\\u000a enamel surface. A

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

2008-01-01

404

Arrangement of anatomic-type artificial teeth into balanced occlusion.  

PubMed

The mechanical factors which are involved in the arrangement of anatomic type artificial teeth into balanced occlusion have been described. Many of the mechanical problems encountered during artificial tooth arrangement have been listed, together with suggestions for their solution. Hanau's Laws of Articulation have been utilized in a practical manner in formulating some of the solutions to tooth arrangement problems when establishing balanced occlusion. Trial dentures which present ideal occlusions in the articulator may not always do so when examined in the patient's mouth. Possible reasons for these differences are listed, and methods for making the necessary corrections are described. PMID:349138

Jordan, L G

1978-05-01

405

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.

Hopp, Christa D; Land, Martin F

2013-01-01

406

Restoration of badly broken, endodontically treated posterior teeth  

PubMed Central

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

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

2009-01-01

407

Propose of Speech Recognition using Acceleration Sensor Attached to Teeth  

NASA Astrophysics Data System (ADS)

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

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

408

Movement adds bite to the evolutionary morphology of mammalian teeth  

PubMed Central

Selection and constraints put limits on morphological evolution. Mammalian teeth are no exception, and the need for them to meet precisely exerts exacting constraints on a staggering array of developmental and functional factors that must be integrated to maintain their performance as they evolve. A study in BMC Evolutionary Biology demonstrates that mandibular movement is an important component of this integration, and one that should not be neglected in the quantitiative study of the evolution of tooth morphology. See research article http://www.biomedcentral.com/1471-2148/12/146/

2012-01-01

409

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

PubMed

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

Wiper, Susan M; Semple, Stuart

2007-10-01

410

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.

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

2014-01-01

411

Permanent magnetic system design for the wall-climbing robot  

Microsoft Academic Search

This paper presents the design of the permanent magnetic system for the wall climbing robot with permanent magnetic tracks. A proposed wall climbing robot with permanent magnetic adhesion mechanism for inspecting the oil tanks is briefly put forward, including the mechanical system architecture. The permanent magnetic adhesion mechanism and the tracked locomotion mechanism are employed in the robot system. By

Weimin Shen; Jason Gu; Yanjun Shen

2005-01-01

412

A new understanding of oral and dental pathology of the equine cheek teeth.  

PubMed

Equine dental disease has a high prevalence. Because of developmental, functional, and anatomic differences, limited inference can be made from brachydont dental pathology to that of equine cheek teeth. This article reviews the pathology of equine cheek teeth and their associated oral tissues, with specific information on periodontitis, pulpitis, maxillary infundibular changes, dental fractures, dental overgrowths, mucosal ulceration, and the regenerative capacity of equine teeth. PMID:23915662

Casey, Miriam

2013-08-01

413

Assessment of the periapical and clinical status of crowned teeth over 25 years  

Microsoft Academic Search

Objectives: The purpose of this study was to examine radiographically changes in the periapical status and compare the clinical status of teeth with a vital pulp and root-filled teeth restored with crowns and bridge retainers during 25 years.Methods: During 1967\\/68, 114 patients received prosthodontic treatment by senior dental students at the Oslo Dental Faculty. In all, 291 teeth with a

J. Valderhaug; A. Jokstad; E. Ambjørnsen; P. W. Norheim

1997-01-01

414

Clinical evaluation of diluted formocresol pulpotomies in primary teeth of school children  

Microsoft Academic Search

The present investigation was undertaken to clinically and radiograplu'caily observe human p~mary teeth after pulpotomy using one-fifth dilution of formocresol. Seventy- seven teeth of 59 ctuTdren, average age seven years, were treated. Seventy teeth were available for follow-up over a peHod varying from 4 to 36 months. The degree of root resorption was evaiuated comparing pairs of treated and homologous

Anna B. Fuks; Enrique Bimstein

1981-01-01

415

Laced permanent magnet quadrupole drift tube magnets  

SciTech Connect

Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.

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

1989-03-01

416

Antimicrobial activity of bovine psoriasin  

Microsoft Academic Search

Human psoriasin (S100A7) has originally been described as a member of the family of S100 calcium-binding proteins which is overexpressed in patients suffering from psoriasis. The bovine homolog was first identified as a cow-derived respiratory allergen. As Escherichia coli mastitis is a common problem in dairy cattle, and human psoriasin was found to exhibit antimicrobial activity preferentially against E. coli,

Petra Regenhard; Matthias Leippe; Sabine Schubert; Rainer Podschun; Ernst Kalm; Joachim Grötzinger; Christian Looft

2009-01-01

417

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.

Pol, Chetan A; Gosavi, Suchitra R

2014-01-01

418

Pulpal regeneration and root development after subcutaneous transplantation of cryopreserved immature teeth in rats.  

PubMed

The purpose of this in vivo study was to investigate revascularization and root growth after autotransplantation of cryopreserved immature teeth. Immature molar teeth were extracted in 4-week-old Wistar rats. In the test group, teeth were cryopreserved for 1 week and transplanted subcutaneously to the abdomen. In the control group, teeth were transplanted subcutaneously immediately after extraction. Material was collected in test and control animals at intervals of 1, 2, 4 and 10 weeks post-transplantation and histological and microradiographical examination was performed. Results showed that during the first weeks after transplantation, pulpal repair was similar in both groups although degenerated pulpal tissue was replaced slower in cryopreserved teeth and some differences in types of hard tissue formation were found between test and control teeth. After 10 weeks, the differences in the regenerated pulpal tissue between cryopreserved and control teeth observed during the first weeks were no longer detectable. No root growth was detected microradiographically 10 weeks after transplantation in any of the transplanted teeth. The presence of dentin-like tissue in the pulp cavity of some autotransplanted cryopreserved teeth, suggests survival of pulpal tissue after cryopreservation. PMID:22138351

Temmerman, L; Vral, A; Meire, M; Verbeeck, R M; Deschepper, E; Dermaut, L R; De Pauw, G A

2012-04-01

419

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

PubMed Central

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

Agrawal, Neeraj K

2012-01-01

420

Intracoronal bleaching of discolored non-vital teeth using laser irradiation: a case report  

NASA Astrophysics Data System (ADS)

Dissemination of blood into the dentinal tubules caused by pulp extirpation or traumatically induced internal pulp bleeding is a possible cause of discoloration of non-vital teeth. Discolored teeth, especially in the anterior region, can result in considerable cosmetic impairment. The whitening of these teeth is an alternative therapeutic method that is relatively non-invasive and conserves dental hard tissue. Recently, intracoronal bleaching of pulpless discolored teeth can be performed with the association of laser irradiation to hydrogen and carbamide peroxide and can even be accomplished in one session. This report shows a clinical case of an endodontically treated tooth submitted to bleaching using LED light and infrared LLLT therapy.

Marchesan, Melissa A.; de Castro, Fabiana C.; Matarazzo, Alexandre T.; Pecora, Jesus D.; Zanin, Fatima A.; Brugnera, Aldo, Jr.

2004-09-01

421

Prevalence of transposed teeth as seen on panoramic radiographs in children with cleft lip and palate.  

PubMed

Objective : To assess the prevalence of complete and incomplete transpositions of teeth in subjects with repaired cleft lip and/or palate. Design : Retrospective review. Panoramic radiographs from 364 subjects with repaired cleft lip and/or palate and with or without syndromes were compared with 364 panoramic radiographs from noncleft controls. The percentages of completely or incompletely transposed teeth, missing teeth, and pegged teeth were recorded for each subject and control. Setting : Primary care dental clinic in a university affiliated, not-for-profit hospital. Main Outcome Measures : Presence of complete and incomplete transposed teeth, missing teeth, and pegged teeth detected on subjects' panoramic radiographs. Results : This study revealed greater prevalence of tooth transposition in subjects with cleft lip and/or palate (52/364 = 14.3%) as compared with noncleft controls (1/364 = 0.3%; P < .001). Conclusions : There was a higher prevalence of tooth transpositions in subjects with repaired cleft lip and/or palate with/or without syndromes than in noncleft controls. There was a weak association between transpositions and missing teeth (P = .12) and between transpositions and pegged teeth (.23). PMID:24060002

Campbell, Richard E; Levin, Linda; Mauseth, Spencer E; Hu, Junyi; Zheng, Shu; Wilson, Stephen; Saal, Howard

2014-07-01

422

[Biology of root resorption process in deciduous teeth. Review of the literature].  

PubMed

Aim of this paper, is to examine, with a review of the literature the different aspects of physiological process of root resorption of deciduous teeth. The process of development of mouth and teeth and their structure is also described. Studies made during the last period, in most part by Japanese authors, improved our knowledge about the process of root resorption of deciduous teeth, even if many aspects are still unknown. The involvement of the pulp and the periodontal ligament and the presence of enzimatic activity and immunologic cells have been confirmed; all these elements seem to have a definite role in the process of root resorption of the deciduous teeth. PMID:11420565

Scarola, V; Galmozzi, A

2001-05-01

423

Infectious bovine keratoconjunctivitis: a review.  

PubMed

The economic impact of infectious bovine keratoconjunctivitis (IBK) warrants continued investigation of the mechanisms by which Moraxella bovis survives on and colonizes the corneal surface. Virulent strains of M bovis produce hemolysin and exhibit different plasmid profiles than nonvirulent strains. Interactions among host, environment, vector, season, and concurrent infection influence the prevalence of IBK. Mycoplasma sp. or infectious bovine rhinotracheitis virus may enhance or hasten the disease process. The manifestations of IBK may range from mild conjunctivitis to severe ulceration, corneal perforation, and blindness. Treatment of IBK is dictated by economic considerations, intended animal use, and feasibility of administration. Antibiotic therapy is aimed at achieving drug concentrations in tears to meet or exceed the minimum inhibitory concentration for prolonged periods. At present, IBK is not a preventable disease. Affected animals must be separated from the herd and vector control vigorously instituted. Carrier animals must be identified and removed from the herd. Vaccination trials have been unsuccessful because of pili antigen cross-reactivity, variable strains, and uncontrolled environmental factors. Recent investigations have determined that M bovis may utilize host iron sources via iron-repressible outer membrane proteins and siderophores for growth. Elucidation of normal defense mechanisms of the bovine eye may lead to new strategies to enhance the immune response against M bovis. PMID:9686385

Brown, M H; Brightman, A H; Fenwick, B W; Rider, M A

1998-01-01

424

A study on the permanent magnet overhang effect in permanent magnetic actuator using 3-dimension equivalent magnetic circuit network method  

Microsoft Academic Search

This paper presents the analysis of the permanent magnet overhang effect for permanent magnetic actuator. Generally, The overhang is often used to increase the force density in permanent magnet machineries. The overhang is especially profitable to reduce the volume after increasing the force density per volume when using the overhang effect of the permanent magnet. Therefore, 3D equivalent magnetic circuit

Ho Kwon; S.-Y. Kwon; Ju Lee; Seung-kil Choi; Soo-Hyun Baek

2003-01-01

425

The phylogeny of permanent prostate brachytherapy  

PubMed Central

Permanent prostate brachytherapy has been practiced for more than a century. This review examines the influence of earlier procedures on the modern transperineal ultrasound-directed technique. A literature review was conducted to examine the origin of current clinical practice. The dimensions of the modern brachytherapy seed, the prescription dose, and implant/teletherapy sequencing are vestigial features, which may be suboptimal in the current era of low-energy photon-emitting radionuclides and computerized dose calculations. Although the modern transperineal permanent prostate implant procedure has proven to be safe and effective, it should undergo continuous re-evaluation and evolution to ensure that its potential is maximized.

Aronowitz, Jesse N.

2013-01-01

426

Bovine viral diarrhea in a newborn calf.  

PubMed

Bovine viral diarrhea virus was believed to be the cause of ill-thrift since birth, resulting in death of a Holstein calf. Bovine viral diarrhea virus was isolated from Peyer's patches and mesenteric lymph nodes, but serum neutralizing antibodies were not detected. The lymphoid depletion and myeloid suppression seen in this case may be a factor in the immune system dysfunction described for bovine viral diarrhea. Typical ulcerative lesions within the alimentary tract were not observed. PMID:3988595

Lloyd, K C; Morris, D D

1985-03-15

427

Management of furcation-involved teeth. A retrospective analysis.  

PubMed

In the present study, data from more than 550 periodontally diseased patients with more than 1100 furcation invasions were retrospectively analysed. There were apparent differences in the distribution of different furcation degrees in patient populations treated by 2 differently experienced operators. However, treatment modality patterns were rather similar. Scaling during periodontal flap surgery was the most often performed treatment procedure in degree I (97-98%) and II (75-83%) involvements. About 44% of degree III involved teeth were extracted. In order to determine the influence of degree of furcation involvement, tooth type and operator variability on treatment modality, logistic regression analysis was applied. Degree of furcation involvement was an important indicator variable in all models. Scaling as a sole measure was mainly performed in relation to degree I of furcation involvement. With every increase in degree, the odds of scaling decreased by factor 12.7. The odds of root resection was upper 1st molars 46 x higher than in wisdom teeth or lower 2nd molars with the same degree of involvement, but only 3.3 x higher than in lower 1st molars. Tunnel preparation as well as regenerative procedures were mainly confirmed to lower molars. Operator variability was only introduced as a covariate in the extraction model. hence, despite of different operator skill and severity of periodontal disease in treated populations, decision for one or the other treatment modality seems to depend essentially on degree of furcation involvement as well as tooth type. PMID:8613558

Müller, H P; Eger, T; Lange, D E

1995-12-01

428

Stem Cells in Dental Pulp of Deciduous Teeth  

PubMed Central

Dental pulp from deciduous (baby) teeth, which are discarded after exfoliation, represents an advantageous source of young stem cells. Herein, we discuss the methods of deciduous teeth stem cell (DTSC) isolation and cultivation. We show that based on these methods, at least three different stem cell populations can be identified: a population similar to bone marrow–derived mesenchymal stem cells, an epithelial stem–like cells, and/or a mixed population composed of both cell types. We analyzed the embryonic origin and stem cell niche of DTSCs with respect to the advantages they can provide for their future use in cell therapies and regenerative medicine. In vitro and in vivo differentiation of the DTSC populations, their developmental potential, immunological compatibility, tissue engineering, and transplantation use in studies in animal models are also the focus of the current report. We briefly describe the derivation of induced pluripotent stem (iPS) cells from DTSCs, which can be obtained more easily and efficiently in comparison with human fibroblasts. These iPS cells represent an interesting model for the investigation of pediatric diseases and disorders. The importance of DTSC banking is also discussed.

Caplan, Arnold I.

2012-01-01

429

Wear Resistance of Coating Films on Hob Teeth  

NASA Astrophysics Data System (ADS)

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

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

430

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.

Mirikar, Pragati

2012-01-01

431

Health Technology Assessment of CEM Pulpotomy in Permanent Molars with Irreversible Pulpitis.  

PubMed

Introduction: Teeth with irreversible pulpitis usually undergo root canal therapy (RCT). This treatment modality is often considered disadvantageous as it removes vital pulp tissue and weakens the tooth structure. A relatively new concept has risen which suggests vital pulp therapy (VPT) for irreversible pulpitis. VPT with calcium enriched mixture (VPT/CEM) has demonstrated favorable treatment outcomes when treating permanent molars with irreversible pulpitis. This study aims to compare patient related factors, safety and organizational consideration as parts of health technology assessment (HTA) of the new VPT/CEM biotechnology when compared with RCT. Materials and Methods: Patient related factors were assessed by looking at short- and long-term clinical success; safety related factors were evaluated by a specialist committee and discussion board involved in formulating healthcare policies. Organizational evaluation was performed and the social implications were assessed by estimating the costs, availability, accessibility and acceptability. The impact of VPT/CEM biotechnology was assessed by investigating the incidence of irreversible pulpitis and the effect of this treatment on reducing the burden of disease. Results: VPT/CEM biotechnology was deemed feasible and acceptable like RCT; however, it was more successful, accessible, affordable, available and also safer than RCT. Conclusion: When considering socioeconomic implications on oral health status and oral health-related quality of life of VPT/CEM, the novel biotechnology can be more effective and more efficient than RCT in mature permanent molars with irreversible pulpitis. PMID:24396372

Yazdani, Shahram; Jadidfard, Mohammad-Pooyan; Tahani, Bahareh; Kazemian, Ali; Dianat, Omid; Alim Marvasti, Laleh

2014-01-01

432

Permanent tooth mineralization in bonobos (Pan paniscus) and chimpanzees (P. troglodytes).  

PubMed

The timing of tooth mineralization in bonobos (Pan paniscus) is virtually uncharacterized. Analysis of these developmental features in bonobos and the possible differences with its sister species, the chimpanzee (P. troglodytes), is important to properly quantify the normal ranges of dental growth variation in closely related primate species. Understanding this variation among bonobo, chimpanzee and modern human dental development is necessary to better contextualize the life histories of extinct hominins. This study tests whether bonobos and chimpanzees are distinguished from each other by covariance among the relative timing and sequences of tooth crown initiation, mineralization, root extension, and completion. Using multivariate statistical analyses, we compared the relative timing of permanent tooth crypt formation, crown mineralization, and root extension between 34 P. paniscus and 80 P. troglodytes mandibles radiographed in lateral and occlusal views. Covariance among our 12 assigned dental scores failed to statistically distinguish between bonobos and chimpanzees. Rather than clustering by species, individuals clustered by age group (infant, younger or older juvenile, and adult). Dental scores covaried similarly between the incisors, as well as between both premolars. Conversely, covariance among dental scores distinguished the canine and each of the three molars not only from each other, but also from the rest of the anterior teeth. Our study showed no significant differences in the relative timing of permanent tooth crown and root formation between bonobos and chimpanzees. PMID:23097136

Boughner, Julia C; Dean, M Christopher; Wilgenbusch, Chelsea S

2012-12-01

433

Causes and prevalence of traumatic injuries to the permanent incisors of school children aged 10-14 years in Maseru, Lesotho.  

PubMed

Traumatic dental injuries are widespread in the population and the prevalence of traumatic dental injuries among school children in different parts of the world varies from about 3% to 45%. Most injuries involve the anterior teeth, which may lead to eating restrictions, changes in physical appearance, speech defects and psychological impacts that affect the child's quality of life. A cross-sectional survey was carried out to investigate the prevalence, aetiology and types of injuries to permanent incisors among schoolchildren aged 10-14 years from Maseru, Lesotho. Upper and lower permanent incisors were examined for dental injuries. The prevalence of traumatic injuries to the permanent incisor teeth was 9.3% (13.3% boys and 6.3% girls). Significantly more boys than girls suffered injury. The most common type of injury was enamel fractures and most common cause was falls. Health promotion policies should aim to create an appropriate and safe environment for children. Soft playground surfaces, school-crossing patrols, marked zebra crossings and bicycle lanes would help create a safe environment. Speed limits for cars and the use of seat belts, air bags, special car seats for children and bicycle helmets should be enforced. Mouth guards should be used when playing sport, in particular contact sports. Education regarding the epidemiology of dental injuries and their prevention through health promotion may play a major role in reducing the prevalence of dental injury and avoiding the financial costs of treatment, especially in developing countries. PMID:18689347

Lin, H; Naidoo, Sudeshni

2008-04-01

434

Cobalt-Free Permanent Magnet Alloys.  

National Technical Information Service (NTIS)

We have undertaken the study of cobalt-free alloys for evaluation of their use in permanent magnet fabrication. A two-phase study was carried out. In the first phase, the plasma arc process was employed for the production of fine powder of MnAlC and the s...

K. S. V. L. Narasimhan B. M. Ma T. Lizzi

1984-01-01

435

Permanence, Durability and Unique Properties of Hanji  

Microsoft Academic Search

This research project presents new information about the permanence and durability of contemporary Korean handmade papers, explains the particular methods of traditional hanji papermakers while introducing the possibilities of utilizing the products of Korean papermills in conservation. Traditional Korean papermaking uses a unique technique, known as webal, to form a sheet which distributes fibers evenly in both directions theoretically resulting

MINAH SONG; JESSE MUNN

436

Removal of a Permanent IVC Filter  

Microsoft Academic Search

Inferior vena cava (IVC) filters are increasingly used for prevention of life-threatening pulmonary emboli in patients who\\u000a have contraindications to anticoagulation therapy. We report a case of the removal of a permanent IVC filter, which was inadvertently\\u000a inserted due to an incorrect ultrasound report.

Bangalore C. Anil Kumar; Sam Chakraverty; Ian Zealley

2006-01-01

437

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

438

PERMANENCE - AN ADAPTATIONIST SOLUTION TO FERMI'S PARADOX?  

Microsoft Academic Search

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

Milan M. ?irkovi?

439

Permanent Magnet Generators for Portable Military Power.  

National Technical Information Service (NTIS)

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

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

1971-01-01

440

Permanent Magnet Generator Rotor Containment Study.  

National Technical Information Service (NTIS)

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

E. U. A. Siddiqui

1983-01-01

441

Circadian rhythms and behavior of permanent nightworkers  

Microsoft Academic Search

Summary This paper describes rest\\/activity rhythms of permanent shift workers: rotary printers. They reported during one week the hours of their sleep onset and of their meals, and their subjective appreciation of tiredness and mood. The average sleep duration (7.84 h) can be compared with that of day workers and is fairly longer than the duration of day sleep of

M. Lortie; J. Foret; C. Teiger; A. Laville

1979-01-01

442

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

443

War Crimes Tribunals: A Permanent Criminal Court?  

ERIC Educational Resources Information Center

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

Dorsey, James E.; Rudelius-Palmer, Kristi

1997-01-01

444

Lowering the Permanent Rate of Unemployment.  

ERIC Educational Resources Information Center

The first section of the study on lowering the permanent rate of unemployment discusses the effects and limitations of increasing aggregate demand through fiscal and monetary policy and indicates the inability to achieve the desired level of unemployment simply by stimulating demand. Section 2 analyzes the characteristics and structure of our…

Feldstein, Martin S.

445

Storage of Timber under Permanent Irrigation  

Microsoft Academic Search

The storage of 9 624 m pine sawtimber under permanent sprinkler irrigation is described. After the plantation fire at Entabeni on 3 October 1989 the immediate utilisation of all badly burnt sawtimber was not possible. Sawlogs were prepared in uniform length of 6,3 m and stacked in rows. Sprinkler irrigation, normally used for agricultural purposes, was installed on top of

G. H. von dem Bussche

1993-01-01

446

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

447

Stability of Permanent-Magnet Parameters.  

National Technical Information Service (NTIS)

Data are presented on the time, temperature, and radiation-stability characteristics of permanent magnets composed of barium ferrite, ALNICO alloys, and SmCo sub 5 . Magnetic characteristics are constant over a period of 10 exp 4 to 10 exp 5 h. Results ar...

V. I. Ilyushchenko

1981-01-01

448

Trends in rare earth permanent magnets  

Microsoft Academic Search

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

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

1994-01-01

449

Applications of rare earth permanent magnets  

Microsoft Academic Search

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

R. H. J. Fastenau; E. J. van Loenen

1996-01-01

450

Atom optics with permanent magnetic components  

Microsoft Academic Search

We have fabricated and investigated efficient magnetic lenses, waveguides, and mirrors from rare earth permanent materials. They are affordable and maintenance free. In contrast to corresponding light force components they do not need any supplies, they have large apertures, high reflectivity, and there is no spontaneous emission. The cylindrical shape of magnetic components is furthermore well suited to steer atomic

Dieter Meschede; Immanuel Bloch; A. Goepfert; D. Haubrich; M. Kreis; F. Lison; R. Schuetze; Robert Wynands

1997-01-01

451

Trends in rare earth permanent magnets  

Microsoft Academic Search

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

K. H. J. Buschow

1994-01-01

452

Atom optics with permanent magnetic components  

NASA Astrophysics Data System (ADS)

We have fabricated and investigated efficient magnetic lenses, waveguides, and mirrors from rare earth permanent materials. They are affordable and maintenance free. In contrast to corresponding light force components they do not need any supplies, they have large apertures, high reflectivity, and there is no spontaneous emission. The cylindrical shape of magnetic components is furthermore well suited to steer atomic beams.

Meschede, Dieter; Bloch, Immanuel; Goepfert, A.; Haubrich, D.; Kreis, M.; Lison, F.; Schuetze, R.; Wynands, Robert

1997-05-01

453

Multispectral near-IR reflectance and transillumination imaging of teeth  

PubMed Central

NIR imaging methods do not require ionizing radiation and have great potential for detecting caries lesions (tooth decay) on high-risk proximal and occlusal tooth surfaces and at the earliest stages of development. Previous in vitro and in vivo studies at 1300-nm demonstrated that high contrast reflectance and transillumination images could be acquired of caries lesions on tooth proximal and occlusal surfaces where most new decay is found. Water absorption varies markedly between 1200 and 1600-nm and the scattering properties of enamel and the underlying dentin have not been characterized in this region. Hyperspectral reflectance studies show lower reflectivity from sound enamel and dentin at NIR wavelengths with higher water absorption. The purpose of this imaging study was to determine which NIR wavelengths between 1200 and 1600-nm provide the highest contrast of demineralization or caries lesions for each of the different modes of NIR imaging, including transillumination of proximal and occlusal surfaces along with cross polarization reflectance measurements. A tungsten halogen lamp with several spectral filters and a Ge-enhanced CMOS focal plane array (FPA) sensitive from 400 to 1600-nm were used to acquire the images of caries lesions on extracted teeth. Artificial interproximal lesions were created on twelve tooth sections of 5 & 6-mm thickness that were used for transillumination imaging. Fifty-four extracted teeth with suspected occlusal lesions were also examined in both occlusal transillumination and reflectance imaging modes. Cavity preparations were also cut into whole teeth and filled with composite and used to compare the contrast between composite and enamel at NIR wavelengths. NIR wavelengths longer than 1400-nm are likely to have better performance for the transillumination of occlusal caries lesions while 1300-nm appears best for the transillumination of proximal surfaces. Loss of mobile water in enamel markedly reduced the transparency of the enamel at all NIR wavelengths. Significantly higher