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Sample records for bovine permanent teeth

  1. Characterization of primary and permanent teeth using terahertz spectroscopy

    PubMed Central

    Yetimoĝlu, N Ö; Altan, H

    2014-01-01

    Objectives: To analyse teeth samples by using terahertz time-domain spectroscopy (THz-TDS) system that was developed in the laboratory to measure the properties of sliced teeth sections in transmission mode. Methods: Using home-built THz-TDS system, we analysed a total of 25 teeth samples (9 primary and 16 permanent teeth). For transmission measurements, the refractive index and absorptive properties of the teeth sections were calculated. Difference between groups was tested using Mann–Whitney U-test statistics at the specific frequency of 0.5 THz, which was at the midpoint of the bandwidth. Median and minimum–maximum values were given as descriptive statistics. Type-I error rate was taken as α = 0.05. Results: Median refractive index values for permanent and primary teeth were found to be 2.53 and 2.54, respectively. Median absorption coefficient values for permanent and primary teeth were found to be 26.29 and 29.67, respectively. Median refractive index values for both healthy and carious teeth were found to be 2.54. Median absorption coefficient values for healthy and carious teeth were found to be 26.52 and 27.13, respectively. Although higher median absorption coefficient values were found for primary and carious teeth than those of permanent and healthy teeth, the differences were insignificant (p > 0.05). In addition, no statistical differences were found for refractive index values among different groups (p > 0.05). Conclusions: THz imaging has the potential to be used in assessing dental structures. PMID:24940807

  2. New Approaches in Vital Pulp Therapy in Permanent Teeth

    PubMed Central

    Ghoddusi, Jamileh; Forghani, Maryam; Parisay, Iman

    2014-01-01

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

  3. Maturogenesis of non-vital immature permanent teeth.

    PubMed

    Kalaskar, Ritesh R; Kalaskar, Ashita R

    2013-04-01

    Pulpal necrosis in young permanent teeth often results in teeth with open apex, thin root walls and poor crown root ratio. Out of the available treatment options maturogenesis has been the most conservative option that exploits full potential of pulp for dentin deposition. Maturogenesis involves disinfecting the root canal system followed by stimulation of blood clot from the periapical tissue, which provides a matrix into which the cell could grow and sealing the coronal excess. In the present case report, tri antibacterial paste (3 Mix) was used as an intracanal medicament that proved successful in stimulating vital pulp cells of the periapical region for maturogenesis. Five months radiograph follow-up showed thickening of lateral dentinal walls, which progress until 15 months resulting in apical closure, thickening of lateral dentinal walls and increase root length. PMID:24015025

  4. Celiac disease and mineralisation disturbances of permanent teeth.

    PubMed

    Rasmusson, C G; Eriksson, M A

    2001-05-01

    In a study from Finland in 1986 it was shown that celiac disease was often associated with tooth enamel defects of permanent teeth. This study also showed a strong association between the time of gluten challenge in the diagnostic procedure and enamel defects. In the current study, dental examinations were carried out for a group of 40 children and adolescents suffering from celiac disease diagnosed according to the criteria of The European Society of Paediatric Gastroenterology and Nutrition (ESPGAN) at the Department of Paediatrics, Hospital of Uddevalla, Sweden. A control group made of 40 healthy children of the same age, sex and living area was examined in the same way. The results failed to show disturbances of the same type, degree of severity or frequency as was reported in Finland and no statistically significant differences concerning enamel defects were found between the patients with celiac disease and the controls. PMID:11484467

  5. Angle Class II malocclusion treated with extraction of permanent teeth.

    PubMed

    Barreto, Gustavo Mattos

    2013-01-01

    Angle Class II malocclusion associated with anterior open bite in adult patients demands a carefully elaborated orthodontic planning, aiming at restoring not only harmonious dental and facial esthetics, but also a balanced masticatory function. Orthognathic surgery or permanent teeth extraction are often the choice of treatment, therefore, treatment decision is related to all dental, skeletal and functional aspects. The present report discusses orthodontic compensation carried out by means of upper premolar extraction performed to correct the Class II canine relationship and, consequently, the anterior open bite, accepting that the upper incisors be retroclined. This clinical case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as part of the requirements for obtaining the BBO Certification. PMID:24262426

  6. Bond strength with various etching times on young permanent teeth

    SciTech Connect

    Wang, W.N.; Lu, T.C. )

    1991-07-01

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

  7. Supragingival Microbial Profiles of Permanent and Deciduous Teeth in Children with Mixed Dentition

    PubMed Central

    Shi, Weihua; Qin, Man; Chen, Feng; Xia, Bin

    2016-01-01

    Objectives The present study was designed to investigate the microbial profiles of teeth in different locations in mixed-dentition-stage children, and to compare the microbiomes of permanent and deciduous teeth in the same healthy oral cavity. Methods Supragingival plaque samples of teeth in various locations—the first permanent molars, deciduous molars, deciduous canines and incisors and permanent incisors—were collected from 20 healthy mixed-dentition-stage children with 10–12 permanent teeth erupted. Plaque DNA was extracted, and the V3–V4 hypervariable region of the bacterial 16S rRNA gene was amplified and subjected to sequencing. Results On average, 18,051 high-quality sequences per sample were generated. Permanent tooth sites tended to host more diverse bacterial communities than those of deciduous tooth sites. A total of 12 phyla, 21 classes, 38 orders, 66 families, 74 genera were detected ultimately. Five predominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria) were highly variable among sites. Of 26 genera with a mean relative abundance of >0.1%, 16 showed significant differences in relative abundance among the groups. More than 20% of the total operational taxonomical units were detected only in permanent or deciduous teeth. The variation in the microbial community composition was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema. The core microbiome of supragingival plaque in mixed dentition comprised 19 genera with complex correlationships. Conclusion Our results suggest differences in microbial diversity and composition between permanent and deciduous teeth sites in mixed dentition. Moreover, the core microbiome of these sites was determined. These findings enhance our understanding of the development of the native oral microbiota with age. PMID:26752284

  8. Predentin thickness analysis in developing and developed permanent teeth

    PubMed Central

    Basandi, Praveen S.; Madammal, Ram Manohar; Adi, Ravi Prakash; Donoghue, Mandana; Nayak, Sushruth; Manickam, Selvamani

    2015-01-01

    Background: Predentin, the unmineralized organic matrix is important in maintaining the integrity of dentin. It is usually thick where active dentinogenesis occurs. A wide variation in its thickness is reported. Hence, we determined the variation in predentin thickness at various sites of different age groups. Materials and Methods: 60 freshly extracted teeth (maxillary and mandibular first premolars) were divided into three groups with 20 teeth in each as, Group 1 - teeth with incomplete root formation (age <16 years), Group 2 - teeth with complete root formation (aged between 16 and 30 years), Group 3 - teeth of patients aged above 30 years. The teeth were fixed, decalcified and sections of 6 ? thickness were obtained, and stained with hematoxylin and eosin. The distance between the odontoblastic cell layers of the pulp to the border line of the dentin was considered for the measurement of the predentin thickness. A total of nine sites were considered for each specimen. Results: The present study revealed varied mean predentin thickness at all nine sites in all three age groups. Maximum and minimum thickness was observed at the apex and pulp floor respectively in all three groups. There was a statistical significant difference in predentin thickness between groups 1 and 3 and 2 and 3. Conclusion: The predentin thickness in the first group gradually increased toward the growing end near the apex, while it was relatively constant in the second group and increased overall thickness at all the sites in the third group. A notable finding was a linear increase with age in width of the predentin and the thickness vary as a function of odontoblastic activity during different stages of tooth development. PMID:26283819

  9. Educational material of dental anatomy applied to study the morphology of permanent teeth.

    PubMed

    Siéssere, Selma; Vitti, Mathias; de Sousa, Luiz Gustavo; Semprini, Marisa; Regalo, Simone Cecílio Hallak

    2004-01-01

    The purpose of this report is to present educational material that would allow the dental student to learn to easily identify the morphologic characteristics of permanent teeth, and how they fit together (occlusion). In order to do this, macro models of permanent teeth with no attrition were carved in wax and later molded with alginate. These molds were filled with plaster, dental stone and/or cold-cured acrylic resin. The large individual dental stone tooth models were mounted on a wax base, thus obtaining maxillary and mandibular arches which were occluded. These dental arches were molded with plaster or dental stone. The authors suggest that these types of macro models allow an excellent visualization of the morphologic characteristics of permanent teeth and occlusion. Dental students are able to carve the permanent dentition in wax with great facility when they can observe macro models. PMID:15798830

  10. Agenesis of multiple primary and permanent teeth unilaterally and its possible management.

    PubMed

    Ephraim, Rena; Rajamani, T; Feroz, Tp Mohammed; Abraham, Sajith

    2015-05-01

    Oligodontia is the agenesis of numerous teeth (more than six teeth). Agenesis of teeth in primary and permanent dentition is a rare incidence and very few are reported in the dental literature. Although the etiology of congenital agenesis of teeth is unclear, several factors such as a tendency toward genetic predilection, metabolic disorders, trauma, infection, radiation or idiopathic reasons are found to be responsible. Available literature reports agenesis most often of third molars, maxillary lateral incisors, mandibular central and lateral incisors, and mandibular second premolars in decreasing order of frequency of occurrence. Males are more often affected than females. Maxillary primary teeth are more often found affected by agenesis than mandibular primary teeth. Available literature reports missing teeth to be found unilaterally or orbilaterally with a predisposition toward a similar phenomenon occurring in the permanent dentition. In congenital agenesis impaired growth of the alveolar process, reduced lower facial height, speech impairment, deep bite, restriction in the movement of the tongue due to ankyloglossia, asymmetry of the affected side of the face are clinical features evident. There has been no report of complete agenesis of primary and permanent teeth in a whole mandibular quadrant in conjunction with the absence of maxillary second and third molars on the affected side. Here, we report an incidence of a rare occurrence of complete agenesis of more than 10 primary and permanent teeth, unilaterally, in the right mandibular quadrant, in a child of 10 years presenting with a chief complaint of several missing primary teeth and difficulty in speech due to its complete absence. Treatment strategies included various orthodontic and restorative procedures to improve esthetics and function. The orthodontic procedures involved expansion of the narrow maxillary arch to obtain a functionally adapted occlusion and creation of space for future alignment, and uprighting and protecting maxillary right posteriors to accommodate the tongue and rectify speech. Restorative procedures involved fabrication of a removable partial denture as a temporary measure to restore missing teeth, improve esthetics, give lingual support to the lower lip, prevent further downward growth of the right maxillary ridge and to prevent supra eruption of these teeth. PMID:26028909

  11. Angle Class I malocclusion with anterior open bite treated with extraction of permanent teeth.

    PubMed

    Pithon, Matheus Melo

    2013-01-01

    This clinical case reports the orthodontic treatment of a Class I malocclusion with anterior open bite and bimaxillary dentoalveolar protrusion in a 28-year-old female patient. The treatment of choice was to perform tooth extractions followed by retraction of the anterior teeth, with consequent closure of the anterior open bite and better accommodation of the teeth on their bony bases. This case was presented to the Brazilian Board of Orthodontics and Facial Orthopedics (BBO), representing the Category 2 -- i.e., an Angle Class I malocclusion, with anterior open bite, treated with extraction of permanent teeth --, as part of the requisites to become a BBO diplomate. PMID:23916443

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

    PubMed Central

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

    2013-01-01

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

  13. Splinting rationale and contemporary treatment options for luxated and avulsed permanent teeth.

    PubMed

    Lambert, Douglas L

    2015-01-01

    The continued growth in athletic participation among children and adults has increased the potential incidence of sports-related dental injuries. Regardless of preventive measures, damage and injury to the oral cavity can occur during participation in sports. Luxations, root fractures, bony fractures, and avulsions involving 1 or more teeth are a possibility. Many of these injuries require specific protocols for splinting of the traumatized tooth or teeth to allow the best possible outcomes. This article identifies luxation and avulsion injuries, explains the rationale for splinting, reviews guidelines for splint duration, and discusses contemporary material options available to stabilize affected permanent dentition. PMID:26545276

  14. Time of mineralization of permanent teeth in children and adolescents in Gaborone, Botswana.

    PubMed

    Cavri?, Jelena; Vodanovi?, Marin; Marui?, Ana; Gali?, Ivan

    2016-01-01

    The mineralization sequence of permanent dentition can be used to assess the stage of development and age of individuals. The most commonly used methods are based on the assessment of developmental stages of target groups of teeth on one side of the lower jaw. When compared with the rest of the world, fewer studies have been done on dental age in Sub-Saharan Africa, particularly in the region of Southern Africa. The aim of this study was to determine the chronology of mineralization of permanent teeth by the evaluation of developmental stages according to the Demirjian's method from 1973 and to evaluate dental age by using sex-specific self-weighted scores for dental stages and 50th percentile conversion tables of total maturity scores of seven mandibular teeth. We used a sample of panoramic radiographs (OPTs) of black African children and adolescents from the city of Gaborone, Botswana, with the aim of forming an appropriate sample to evaluate the development of the teeth in this socio-geographic environment. The final sample consisted of 1760 OPTs (807 males and 953 females) of individuals aged 6-23 years. The developmental stages of the all permanent teeth in the left side of the maxilla and the mandible were evaluated. Comparing the maxilla and the mandible, we found similar development within different stages for most of the teeth. In comparison to the average age at each stage of development, including the third molars between males and females, it is evident that females are slightly faster in developing permanent teeth, but without statistical significance for most of the developmental stages. Applying 50th percentile conversion tables for calculating the dental age for the first seven mandibular teeth, 616 OPTs of the children (299 males and 317 females), aged 6.08-16.80 years, were evaluated and their dental age was calculated. Mean dental age was overestimated in comparison to chronological age by 1.251.11 years and 0.721.02 years for males and females, respectively (p<0.001). These findings indicate that Demirjian's method from 1973 is not suitable for routine use and that there is a need for establishing specific standards for Botswana children of black African origin for dental age estimation. PMID:26342513

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

    PubMed Central

    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

    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 1114 years were extirpated and mRNA was isolated for cDNA microarray analysis, and quantitative real-time PCR (qPCR). Other teeth were used for immunohistochemical analysis (IHC). Microarray analysis identified 263 genes with a twofold or greater difference in expression level between the two types of pulp tissue, 43 and 220 of which were more abundant in deciduous and permanent pulp tissues, respectively. qPCR analysis was conducted for eight randomly selected genes, and the findings were consistent with the cDNA microarray results. IHC confirmed that insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) was broadly expressed in deciduous dental pulp tissue, but minimally expressed in permanent dental pulp tissue. Immunohistochemical analysis showed that calbindin 1 (CALB1), leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), and gamma-aminobutyric acid A receptor beta 1 (GABRB1) were abundantly expressed in permanent predentin/odontoblasts, but only minimally expressed in deciduous dental pulp tissue. These results show that deciduous and permanent pulp tissues have different characteristics and gene expression, suggesting that they may have different functions and responses to therapies focused on pulp or dentin regeneration. PMID:25047033

  16. [Eruption times of permanent teeth in children and adolescents in Latakia (Syria)].

    PubMed

    Friedrich, Reinhard E; Habib, Sarab; Scheuer, Hanna A

    2009-01-01

    The eruption times of permanent teeth and the sequence of tooth eruption were investigated in 1000 individuals aged 5 to 13 years (female: 469, male: 531). Wisdom teeth were excluded from the evaluation. All individuals were inhabitants of Latakia (Syria). The results were compared to dentition studies originating from neighbour countries and Germany, published in recent years. The teeth emerged symmetrically in each jaw. However, teeth erupted earlier in the mandible than in the maxilla, excluding the slightly earlier eruption of maxillary premolars and first molars. The sequence of emerging teeth in the maxilla of females is: first molar, central incisor, lateral incisor, first premolar, second premolar, canine, and second molar. The sequence of tooth eruption of the mandible of females differs from the maxillary sequence: first molar, central incisor, lateral incisor, first premolar, canine, second premolar, second molar. The sequence of emerging teeth in the maxilla of males is: first molar, central incisor, lateral incisor, first premolar, second premolar, canine, and second molar. The sequence of tooth eruption of the mandible of males differs from the maxillary sequence: first molar, central incisor, lateral incisor, first premolar, canine, second premolar, second molar. The results of this study show some differences compared to the dentition of children and adolescents of other countries, emphasizing the need for further dentition studies to be performed in defined regions and obtained by the same method. Concerning the demands of forensic odontology the age of Syrian children might be underestimated if German standards for age estimation are used. PMID:19432087

  17. Hardness and modulus of elasticity of primary and permanent teeth after wear against different dental materials

    PubMed Central

    Galo, Rodrigo; Contente, Marta Maria Martins Giamatei; Galafassi, Daniel; Borsatto, Maria Cristina

    2015-01-01

    Objectives: The purpose of this study was to determine the Young's modulus and the hardness of deciduous and permanent teeth following wear challenges using different dental materials. Materials and Methods: Wear challenges were performed against four dental materials: A resin-based fissure sealant (Fluoroshield®), a glass ionomer based fissure sealant (Vitremer®), and two microhybrid composite resins (Filtek Z250 and P90®). Using the pin-on-plate design, a deciduous or a permanent tooth was made into a pin (4 mm × 4 mm × 2 mm) working at a 3 N vertical load, 1 Hz frequency, and 900 cycles (15 min) with Fusayama artificial saliva as a lubricant. Before and after the tribological tests, the hardness and elasticity modulus of the tooth samples were measured by creating a nanoindentation at load forces up to 50 mN and 150 mN. All of the results were statistically analyzed using ANOVA and post-hoc Duncan's tests (P < 0.05). Results: No difference in hardness was encountered between deciduous and permanent teeth (P < 0.05) or modulus of elasticity (P < 0.05) before or after the wear challenges for all of the dental materials tested. Conclusions: Wear challenges against the studied dental materials did not alter the properties of permanent or deciduous teeth after the application of a 3 N load. PMID:26929700

  18. Preformed metal crowns for primary and permanent molar teeth: review of the literature.

    PubMed

    Randall, Ros C

    2002-01-01

    The aim of this study was to carry out a review of the use and efficiency of preformed metal crowns (PMCs) for primary and permanent molar teeth. A literature search of English language journals was carried out using MEDLINE. Papers that addressed areas related to the use of PMCs regarding indications for use, placement techniques, risks, longevity, cost effectiveness and utilization were included in the review. Eighty-three papers were traced which fulfilled the above criteria, the majority addressing PMCs in primary molar teeth. Over half the papers were concerned with placement techniques and indications for use, with fewer papers reporting on clinical studies. The clinical data on PMCs spanned a considerable number of years and involved heterogeneous populations of patients, different makes and designs of crown, and differences among the operators and evaluators who were involved in the studies. The results, however, were in agreement that PMCs are superior to amalgam restorations for multisurface cavities in primary molar teeth. PMID:12412964

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

    PubMed Central

    Asgary, Saeed; Ehsani, Sara

    2013-01-01

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

  20. Miniature Pulpotomy of Symptomatic Mature Permanent Teeth: A Report of Two Cases.

    PubMed

    Asgary, Saeed; Nourzadeh, Mahdieh; Eghbal, Mohammad Jafar

    2016-01-01

    Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis. PMID:26843883

  1. Miniature Pulpotomy of Symptomatic Mature Permanent Teeth: A Report of Two Cases

    PubMed Central

    Asgary, Saeed; Nourzadeh, Mahdieh; Eghbal, Mohammad Jafar

    2016-01-01

    Human dental pulp inflammation can progress to periapical lesion formation and conventional root canal treatment (RCT) has been the traditional method for disease management. This observational study presents two cases of vital pulp therapy in mature molars diagnosed with irreversible pulpitis and associated with apical periodontitis. In these two clinical cases, the involved teeth had deep carious lesions with a history of spontaneous/lingering pain and radiographic examinations revealed the presence of apical radiolucencies. A conservative miniature pulpotomy (MP) using calcium-enriched mixture (CEM) was performed and the teeth were permanently restored with amalgam. Clinical evaluations indicated resolution of pain 24 hours after treatment; the teeth showed normal vitality, remained asymptomatic and maintained normal function after recall examinations. Furthermore, the 18-month radiographic evaluation showed healing of the apical lesions. Vital pulp therapy using the MP technique with CEM appeared successful in avoiding RCT intervention. These two reports of case outcome suggest that simple MP using a CEM bioregenerative technique may provide a favorable outcome for permanent teeth diagnosed with irreversible pulpitis and associated with apical periodontitis. PMID:26843883

  2. Root maturation and dentinpulp response to enamel matrix derivative in pulpotomized permanent teeth

    PubMed Central

    Darwish, Sherif S; Abd El Meguid, Shadia H; Wahba, Nadia A; Mohamed, Ahmed A-R; Chrzanowski, Wojciech

    2014-01-01

    The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentinpulp complex to the enamel matrix derivative (Emdogain gel) compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentinopulpal complex regeneration. PMID:24551447

  3. Teething

    MedlinePLUS

    ... because this can lead to infection. Avoid teething powders. NEVER give your child aspirin or place it against the gums or teeth. DO NOT rub alcohol on your baby's gums. DO NOT use homeopathic remedies, as they ...

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

    SciTech Connect

    Lan, Shoujen; Yen, Yeayin; Ko, Yingchin; Chen, Engrin )

    1989-06-01

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

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

    PubMed Central

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

    2014-01-01

    Background: To estimate the age by evaluating the area and length of dentin translucency in single-rooted ground sections of extracted teeth using digital Vernier caliper and stereomicroscope. Materials and Methods: Ground sections of single rooted permanent anterior teeth were made and stained with 1% methylene blue. The area and length of dentin translucency were measured using digital Vernier caliper and with the help of stereomicroscope. Results: Linear regressive analysis showed that estimation of age by assessing the area of dentin translucency with Vernier caliper was statistically significant and showed a high regression co-efficient (R = 0.7738) when compared to evaluation of age by assessment of length. Multilinear regressive analysis done to calculate age by both area and length also showed a high co-efficient of regression (R = 0.7797). Conclusion: The area of dentin translucency showed good correlation with age when compared to the length. PMID:25628481

  6. The chronological distribution of enamel hypoplasia in human permanent incisor and canine teeth.

    PubMed

    Goodman, A H; Armelagos, G J

    1985-01-01

    The frequencies and chronology, based on a standard tooth development chart, of enamel hypoplasia derived from permanent upper central incisors and mandibular canines were compared for 42 prehistoric Amerindians. Between 0.5 and 4.5 years, when the crowns of both these teeth are developing, hypoplasias were 1.36 times more common on the incisors (54 hypoplasias/incisor; 40 hypoplasias/canine). Hypoplasias on incisors occurred earlier (mean = 2.50; median at 2.0-2.5 years) compared to the canine (mean = 3.51; median at 3.5-4.0 years). Differences in published frequencies and chronologies of hypoplasias may be explained, in part, by an indefinable variation in the teeth studied. The highest density of hypoplasias on both tooth crowns was just cervical to the midpoint, suggesting that developmental rates and crown geometry may influence the ability of the crown to record stressful events. PMID:3901982

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    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.; Srensen, Thorkild I. A.; Melbye, Mads

    2011-01-01

    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<510?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: 2.94.1) fewer permanent teeth than children with 0 or 1 of these alleles. PMID:21931568

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

    PubMed

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

    2011-09-01

    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<510(-8) and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10(-11). Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9-4.1) fewer permanent teeth than children with 0 or 1 of these alleles. PMID:21931568

  10. Teething Tots

    MedlinePLUS

    ... decay makes them fall out more quickly, leaving gaps before the permanent teeth are ready to come ... crowd together to attempt to fill in the gaps, which may cause the permanent teeth to come ...

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

    PubMed Central

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

    2013-01-01

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

  12. Clinical and Radiographic Outcomes of Traumatized Immature Permanent Necrotic Teeth after Revascularization/Revitalization Therapy

    PubMed Central

    Saoud, Tarek Mohamed A.; Zaazou, Ashraf; Nabil, Ahmed; Moussa, Sybel; Lin, Louis M.; Gibbs, Jennifer L.

    2014-01-01

    Introduction Revascularization treatment is rapidly becoming an accepted alternative for the management of endodontic pathology in immature permanent teeth with necrotic dental pulps. However, the success and timing of clinical resolution of symptoms and of radiographic outcomes of interest, such as continued hard tissue deposition within the root, are largely unknown. Methods In this prospective cohort study, 20 teeth were treated with a standardized revascularization treatment protocol, and monitored for clinical and radiographic changes for one year. Standardized radiographs were collected at regular intervals and radiographic changes were quantified. Results All 20 treated teeth survived during the 12 month follow up period and all 20 also met the clinical criteria for success at 12 months. As a group, the treated teeth demonstrated a statistically significant increase in radiographic width and length, and a decrease in apical diameter, although the changes in many cases were quite small such that the clinical significance is unclear. The within-case percent change in apical diameter after 3 months was 16% and had increased to 79% by 12 months, with 55% (11/20) showing complete apical closure. The within-case percent change in root length averaged less than 1% at 3 months and increased to 5% at 12 months. The within-case percent change in root thickness averaged 3% at 3 months and 21% at 12 months. Conclusions Although clinical success was highly predictable with this procedure, clinically meaningful radiographic root thickening and lengthening is less predictable at one year of follow up. Apical closure is the most consistent radiographic finding. PMID:25443280

  13. Regenerative potential of immature permanent non-vital teeth following different dentin surface treatments.

    PubMed

    El Ashry, Salma H; Abu-Seida, Ashraf M; Bayoumi, Amr A; Hashem, Ahmed A

    2016-01-01

    This study evaluates the regenerative potential of immature permanent non-vital teeth following different dentin surface treatments in dogs. Periapical lesions and necrotic pulps were induced in 288 roots of 144 teeth in twelve dogs. Teeth were randomly divided into 3 equal groups according to the evaluation period. Each group was subdivided into 8 subgroups according to the treatment modalities including; blood clot, blood clot and collagen, blood clot and Ethylenediaminetetraacetic acid (EDTA), blood clot, collagen and EDTA, blood clot and Mixture Tetracycline Citric Acid and Detergent (MTAD), blood clot, collagen and MTAD, positive control and negative control. Apart from control subgroups, all infected root canals were cleaned with sodium hypochlorite solution and triple antibiotics paste before different treatment protocols. After different treatments, the root length, thickness and apical diameter were evaluated by radiographic examination. Histopathological examination was carried out to evaluate the inflammation, bone/root resorption, tissue in-growth in pulp space, new hard tissue formation and apical closure. Using EDTA solution as a surface modifier showed significantly higher levels of tissue in-growth in the pulp space after 6 weeks and 3 months. Addition of collagen as a scaffold caused significantly more bone/root resorption than the other subgroups while EDTA caused significantly lower inflammatory cell counts only after 2 weeks. Final rinse with 17% EDTA solution before blood clot induction has positive impact on tissue interaction along dentinal walls without modification of the cell type. Moreover, the use of collagen as a scaffold material and MTAD as a surface modifier did not improve the quality of the regenerative process. PMID:26683411

  14. The pathogenesis of excessive wear in the permanent teeth of sheep.

    PubMed

    Thurley, D C

    1985-03-01

    The two central pairs of permanent incisor teeth (l1P, I2P) were compared post mortem in sheep from two flocks, one of which showed excessive wear. Sheep were usually killed in groups of six. Excessive wear occurred during the winter and spring after the eruption of l1P. When l1P erupted at an early age it was also subject to that season;s wear but when it erupted at a later age, it was subject to less wear according to the amount of time it was in apposition with the dental pad during the high wear season. A small amount of compensatory growth at the root of the tooth occurred in some sheep when cementum was deposited on the apex. Apparent eruption of the crown of the tooth was actually due to gum recession. Normal reparative dentine was laid down in the pulp cavity of the crown of the tooth in anticipation of wear, but where wear was excessive unstructured dentine was deposited. In two cases the rate of wear was so great that the reparative dentine could not keep up and infection was able to gain access to the pulp cavity. There was no evidence of difference in the rate of wear of the molar teeth between the two flocks. PMID:16031135

  15. Bacteria of dental caries in primary and permanent teeth in children and young adults.

    PubMed

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

    2008-04-01

    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. PMID:18216213

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

    PubMed Central

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

    2008-01-01

    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. PMID:18216213

  17. Marginal Microleakage of Conventional Fissure Sealants and Self-Adhering Flowable Composite as Fissure Sealant in Permanent Teeth

    PubMed Central

    Rahimian-Imam, Sara; Fayazi, Mohammad Reza

    2015-01-01

    Objectives: Application of sealants is a safe and effective way to prevent occlusal caries in the posterior teeth. A successful sealant therapy depends on good isolation. Decreased steps of adhesive application may enable proper isolation and use of self-adhering flowable composites for sealant therapy. This study sought to compare the marginal microleakage of fissure sealants and self-adhering flowable composites in permanent teeth. Materials and Methods: This in vitro, experimental study was conducted on 60 extracted human premolar teeth. The teeth were divided randomly into two groups of 30. In the first group, fissure sealant (Clinpro, 3M ESPE, USA) was placed on the teeth. In the second group, self-adhering flowable composite (Vertise Flow, Kerr, USA) was applied as the sealant. Then, both groups were immersed in 0.5% fuchsin dye solution for 24 hours. Sectioned samples were observed with a stereomicroscope for the extent of dye penetration. Data were analyzed using SPSS 21 and the Mann-Whitney test (P<0.05). Results: Microleakage in the fissure sealant group was significantly higher than that in the self-adhering flowable composite group (P<0.001). Conclusion: Microleakage was less using self-adhering flowable composite compared to conventional fissure sealant; therefore, self-adhering flowable composite can be used as a suitable fissure sealant in permanent teeth. PMID:26884777

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

    ERIC Educational Resources Information Center

    Lind, Patricia; Germano, Catherine

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

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

    ERIC Educational Resources Information Center

    Lind, Patricia; Germano, Catherine

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

  20. Effects of thermocycling and light source on the bond strength of metallic brackets to bovine teeth.

    PubMed

    Costa, Ana Rosa; Correr, Amrico Bortolazzo; Puppin-Rontani, Regina Maria; Vedovello, Silvia Amlia Scudeler; Valdrighi, Helosa Cristina; Correr-Sobrinho, Loureno; Vedovello Filho, Mrio

    2011-01-01

    This study evaluated the effects of thermocycling and different light sources on the bond strength of metallic brackets to bovine tooth enamel using an adhesive resin. Bovine teeth were etched with 35% phosphoric acid gel for 20 s. After application of primer, metallic brackets were bonded to the buccal surface using Transbond XT, forming 8 groups (n = 20), depending on the light source used for photoactivation (AccuCure 3000 argon laser--20 s, Apollo 95E plasma arc--12 s, UltraLume 5 LED--40 s and XL2500 halogen light--40 s) and experimental conditions without (Groups 1 to 4) or with thermocycling (Groups 5 to 8). Shear bond testing was carried out after 24 h of distilled water storage (Groups 1 to 4) or storage and thermocycling in distilled water (groups 5 to 8; 1,500 cycles--5/55 C). Data were subjected to two-way ANOVA and Tukey's test (? = 0.05). The Adhesive Remnant Index (ARI) was evaluated at 8 magnification. No significant differences (p>0.05) in bond strength were found when the conditions without and with thermocycling were compared for any of the light sources. No significant differences (p>0.05) in bond strength were found among the light sources, irrespective of performing or not thermocycling. There was a predominance of ARI scores 1 in all groups. In conclusion, light sources and thermocycling had no influence on the bond strength of brackets to bovine enamel. PMID:22189644

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

    PubMed

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

    2015-05-01

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

  2. Tunnel restorations in permanent teeth. A 7 year follow up study.

    PubMed

    Hasselrot, L

    1998-01-01

    The aim of the study was to perform a long-time evaluation of tunnel restorations made in a general dental practice concerning survival time and type of failures. 267 Class I (87%) and II (13%) tunnel restorations in permanent teeth on 193 patients--mostly teenagers and young adults--were evaluated at annual recalls. The observation time-span was 1-7 years. The restoration material was a conventional glass ionomer cement in Class I tunnels and a silver cermet glass ionomer cement in Class II tunnels. The yearly failure rate was 7% and the 50% survival time was 6 years. The reasons for replacement were: marginal ridge fracture (41%), recurrent caries (40%) and cavitation in approximal enamel (19%). No differences in failure rate between Class I and II tunnels could be seen, but recurrent caries was more frequent in Class I tunnels. Restorations made during the second year of the study were more successful, indicating a learning effect. Class I tunnel restorations in general practice can be an alternative to conventional Class II restorations with narrow indications, i.e. patients with relatively low caries activity, small approximal lesions in combination with small demineralization zones in the enamel wall. PMID:9646387

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

    PubMed Central

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

    2013-01-01

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

  4. Prediction of canine and premolar size using the widths of various permanent teeth combinations: A cross-sectional study

    PubMed Central

    Vanjari, Kalasandhya; Nuvvula, Sivakumar; Kamatham, Rekhalakshmi

    2015-01-01

    Aims: To suggest the best predictor/s for determining the mesio-distal widths (MDWs) of canines (C) and premolars (Ps), and propose regression equation/s for hitherto unreported population. Methods: Impressions of maxillary and mandibular arches were made for 201 children (100 boys and 101 girls; age range: 1115 years) who met the inclusion criteria and poured with dental stone. The maximum MDWs of all the permanent teeth were measured using digital vernier caliper. Thirty-three possible combinations (patterns) of permanent maxillary and mandibular first molars, central and lateral incisors were framed and correlated with MDWs of C and Ps using Pearson correlation test. Results: There were significant correlations between the considered patterns and MDWs of C and Ps, with difference noted between girls (range of r: 0.340.66) and boys (range of r: 0.280.77). Simple linear and multiple regression equations for boys, girls, and combined sample were determined to predict MDW of C and Ps in both the arches. Conclusions: The accuracy of prediction improved considerably with the inclusion of as many teeth as possible in the regression equations. The newly proposed equations based on the erupted teeth may be considered clinically useful for space analysis in the considered population. PMID:26604576

  5. Micro-computed tomographic analysis of progression of artificial enamel lesions in primary and permanent teeth after resin infiltration.

    PubMed

    Ozgul, Betul Memis; Orhan, Kaan; Oz, Firdevs Tulga

    2015-09-01

    We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions. PMID:26369480

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

    PubMed Central

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

    2015-01-01

    Dental trauma is an important public health problem due to high prevalence and associated limitations. The external impact accounting for trauma may result in different injury types to teeth and supporting structures. This paper describes a clinical case of tooth trauma in an 8-year-old patient exhibiting the displacement of three permanent teeth with open root apexes. Although the traumatic impact resulted in two injury types to teeth and supporting tissues (lateral luxation and alveolar bone fracture), the therapeutic approach was the same in both situations. The bone and teeth were repositioned by digital pressure, stabilized by semirigid splint, and followed up at every week. After six weeks, the splint was removed. At that moment, the clinical and radiographic findings indicated normal soft/hard tissues and absence of pulp/periodontal pathologies. At the fifth year of follow-up, the treatment success of the case was confirmed, although it has been observed that all lower incisors exhibited pulp obliteration as a consequence of the dental trauma. PMID:25838950

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

    PubMed Central

    Namour, Mélanie

    2014-01-01

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

  8. Outcomes of vital pulp therapy in permanent teeth with different medicaments based on review of the literature.

    PubMed

    Akhlaghi, Najmeh; Khademi, Abbasali

    2015-01-01

    Vital pulp therapy (VPT) is a biologic and conservative treatment modality to preserve the vitality and function of the coronal or remaining radicular pulp tissue in vital permanent teeth. A search was conducted via the Cochrane database, PubMed, MEDLINE, and Ovid for any articles with the criteria for "pulp-capping," or "pulp-capping materials" and "VPT outcomes" from 1978 to mid 2014. All articles were evaluated and the valid papers were selected. The outcomes of various VPT techniques, including indirect pulp treatment, direct pulp treatment, partial pulpotomy, and complete pulpotomy in vital permanent teeth were extracted. Although various studies have different research approach, most studies noted a favorable treatment outcome. Mineral trioxide aggregate (MTA) appears to be more effective than calcium hydroxide (Ca(OH)2) for maintaining long-term pulp vitality after indirect and direct pulp-capping. However, it seems that the success rate for partial pulpotomy and pulpotomy with Ca(OH)2 is similar to MTA. PMID:26604953

  9. Outcomes of vital pulp therapy in permanent teeth with different medicaments based on review of the literature

    PubMed Central

    Akhlaghi, Najmeh; Khademi, Abbasali

    2015-01-01

    Vital pulp therapy (VPT) is a biologic and conservative treatment modality to preserve the vitality and function of the coronal or remaining radicular pulp tissue in vital permanent teeth. A search was conducted via the Cochrane database, PubMed, MEDLINE, and Ovid for any articles with the criteria for “pulp-capping,” or “pulp-capping materials” and “VPT outcomes” from 1978 to mid 2014. All articles were evaluated and the valid papers were selected. The outcomes of various VPT techniques, including indirect pulp treatment, direct pulp treatment, partial pulpotomy, and complete pulpotomy in vital permanent teeth were extracted. Although various studies have different research approach, most studies noted a favorable treatment outcome. Mineral trioxide aggregate (MTA) appears to be more effective than calcium hydroxide (Ca(OH)2) for maintaining long-term pulp vitality after indirect and direct pulp-capping. However, it seems that the success rate for partial pulpotomy and pulpotomy with Ca(OH)2 is similar to MTA. PMID:26604953

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

    PubMed

    Grecka, V; Suliborski, S; Biskupski, T

    2000-04-01

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

  11. An assessment of coronal leakage of permanent filling materials in endodontically treated teeth: An in vitro study

    PubMed Central

    Shetty, Kishore; Habib, V. Ashiq; Shetty, S. Vidhyadhara; Khed, Jaishri N.; Prabhu, Vishnudas Dinesh

    2015-01-01

    Introduction: The present in vitro study was undertaken to evaluate and compare the sealing ability of hybrid composite, glass ionomer cement type II, silver amalgam and Ketac molar as permanent filling material in root canal treated teeth. Methodology: Hundred maxillary central incisors were selected for the study. After cleaning all the teeth, root canal treatment was carried out on all of them. The crown portion was cut-off at the cervical level. Three millimeter of coronal Gutta-percha was replaced by four different restorative materials. Then after thermocycling, samples were immersed in dye for 2 weeks. The amount of dye penetration was measured using stereomicroscope. Data were collected and analyzed statistically with ANOVA test and Student–Newman–Keuls test. Results: Coronal leakage was seen in all groups. Composite hybrid showed least amount of microleakage as compared to the other three experimental groups, and Ketac molar showed more leakage compared to other experimental groups. Conclusion: This study showed that hybrid composites offer better sealing ability compared to other materials tested in this study. PMID:26538928

  12. Effect of effervescent vitamin C preparations on bovine teeth and on some clinical and salivary parameters in man.

    PubMed

    Meurman, J H; Murtomaa, H

    1986-12-01

    Eight effervescent preparations and one chewable vitamin C preparation were tested with regard to dental erosion by immersing bovine tooth specimens for 100 h in 100 ml of the test solutions. For comparison, two effervescent calcium preparations were studied. All the vitamin C products caused distinct erosion and disclosure of dentin in the specimens which could not be found in calcium preparations. Calcium release from the bovine teeth varied from 1.08 to 12.99 micrograms Ca/mm2/h. Softening of the dental tissue assessed as the Vickers hardness units, was most prominent among the specimens where most calcium release was observed. A crossover clinical trial using a test pannel assigned to 1-week periods of excellent vs no mechanical cleaning, and with a consumption of 6.6 times more vitamin C tablets than the recommended daily use, revealed no particular impact of the preparation on a variety of oral health parameters. Except for a slight stimulation of the subjects' salivary flow rate 30 min after consuming the vitamin C, all other differences observed could be explained by the accumulation of plaque during the period without mechanical cleaning. Thus, in patients with normal salivary flow rate a short-term consumption of vitamin C preparations, even in excess, may be regarded as harmless from the dental point of view. However, all the studied preparations are potentially erosive if left in direct contact with the teeth. PMID:3468598

  13. Prevalence of dental caries in primary and permanent teeth and its relation with tooth brushing habits among schoolchildren in Eastern Saudi Arabia

    PubMed Central

    Farooqi, Faraz A.; Khabeer, Abdul; Moheet, Imran A.; Khan, Soban Q.; Farooq, Imran; ArRejaie, Aws S.,

    2015-01-01

    Objectives: To determine the prevalence of dental caries in the primary and permanent teeth, and evaluate the brushing habits of school children in Dammam, Kingdom of Saudi Arabia (KSA). Methods: This study was conducted at Dammam, KSA. Oral examination of the participants was conducted from February to May 2014. The total sample size for this cross-sectional study was 711. There were 397 children between the age of 6-9 years, who were examined for primary teeth caries, and 314 between the age 10-12 years were examined for permanent teeth caries. Primary and permanent dentitions were studied for decayed, missing, and filled teeth (dmft [primary teeth], DMFT [permanent teeth]). Results: The overall prevalence of dental caries in primary and permanent teeth was almost 73% (n=711). Among the 6-9-year-old, the prevalence of caries was approximately 78% (n=397) whereas, among the 10-12-year-old children, it was approximately 68% (n=314). Mean dmft value among the 6-9-year-olds was 3.663.13 with decayed (d) component of 3.282.92, missing (m) component of 0.110.69, and filled (f) component of 0.260.9. Mean DMFT value among the 10-12-year-old children was 1.942.0 with decayed (D) component of 1.761.85, missing (M) component of 0.030.22, and filled (F) of component 0.150.73. Daily tooth brushing had a positive effect on caries prevention, and this effect was statistically significant for caries in primary teeth. Conclusion: Although the prevalence of dental caries in primary and permanent teeth was not found to be as high as other researchers reported from different cities of KSA, still the prevalence was high considering the World Health Organization future oral health goals. Awareness should be provided to students, as well as, teachers and parents regarding the importance of good brushing habits and regular dental visits. PMID:25987118

  14. Comparing the Effect of Different Voxel Resolutions for Assessment of Vertical Root Fracture of Permanent Teeth

    PubMed Central

    Uzun, Ismail; Gunduz, Kaan; Celenk, Peruze; Avsever, Hakan; Orhan, Kaan; Canitezer, Gozde; Ozmen, Bilal; Cicek, Ersan; Egrioglu, Erol

    2015-01-01

    Background: The teeth with undiagnosed vertical root fractures (VRFs) are likely to receive endodontic treatment or retreatment, leading to frustration and inappropriate endodontic therapies. Moreover, many cases of VRFs cannot be diagnosed definitively until the extraction of tooth. Objectives: This study aimed to assess the use of different voxel resolutions of two different cone beam computerized tomography (CBCT) units in the detection VRFs in vitro. Materials and Methods: The study material comprised 74 extracted human mandibular single rooted premolar teeth without root fractures that had not undergone any root-canal treatment. Images were obtained by two different CBCT units. Four image sets were obtained as follows: 1) 3D Accuitomo 170, 4 4 cm field of view (FOV) (0.080 mm3); 2) 3D Accuitomo 170. 6 6 cm FOV (0.125 mm3); 3) NewTom 3G, 6? (0.16 mm3) and 4) NewTom 3G, 9? FOV (0.25 mm3). Kappa coefficients were calculated to assess both intra- and inter-observer agreements for each image set. Results: No significant differences were found among observers or voxel sizes, with high average Z (Az) results being reported for all groups. Both intra- and inter-observer agreement values were relatively better for 3D Accuitomo 170 images than the images from NewTom 3G. The highest Az and kappa values were obtained with 3D Accuitomo 170, 4 4 cm FOV (0.080 mm3) images. Conclusion: No significant differences were found among observers or voxel sizes, with high Az results reported for all groups. PMID:26557279

  15. 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

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

    2012-05-01

    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

  16. Distinguishing between enamel fluorosis and other enamel defects in permanent teeth of children

    PubMed Central

    Sabokseir, Aira

    2016-01-01

    Background. The inconsistent prevalence of fluorosis for a given level of fluoride in drinking water suggests developmental defects of enamel (DDEs) other than fluorosis were being misdiagnosed as fluorosis. The imprecise definition and subjective perception of fluorosis indices could result in misdiagnosis of dental fluorosis. This study was conducted to distinguish genuine fluorosis from fluorosis-resembling defects that could have adverse health-related events as a cause using Early Childhood Events Life-grid method (ECEL). Methods. A study was conducted on 400 9-year-old children from areas with high, optimal and low levels of fluoride in the drinking water of Fars province, Iran. Fluorosis cases were diagnosed on the standardized one view photographs of the anterior teeth using Dean’s and TF (Thylstrup and Fejerskov) Indices by calibrated dentists. Agreements between examiners were tested. Early childhood health-related data collected retrospectively by ECEL method were matched with the position of enamel defects. Results. Using both Dean and TF indices three out of four dentists diagnosed that 31.3% (115) children had fluorosis, 58.0%, 29.1%, and 10.0% in high (2.12–2.85 ppm), optimal (0.62–1.22 ppm), and low (0.24–0.29 ppm) fluoride areas respectively (p < 0.001). After matching health-related events in the 115 (31.3%) of children diagnosed with fluorosis, 31 (8.4%) of children had fluorosis which could be matched with their adverse health-related events. This suggests that what was diagnosed as fluorosis were non-fluoride related DDEs that resemble fluorosis. Discussion. The frequently used measures of fluorosis appear to overscore fluorosis. Use of ECEL method to consider health related events relevant to DDEs could help to differentiate between genuine fluorosis and fluorosis-resembling defects. PMID:26966672

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

    PubMed

    Pekkan, Gürel; Ozcan, Mutlu

    2012-02-01

    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

  18. Tunnel restorations. A 3 1/2-year follow up study of Class I and II tunnel restorations in permanent and primary teeth.

    PubMed

    Hasselrot, L

    1993-01-01

    During 1988-89, 224 patients with approximal caries in the premolar/molar regions were provided with 318 tunnel restorations. In case of perforation of the enamel in the enamel/dentin border, (23%), complete Class II-tunnel restorations with glass ionomer cement and composite resin were made. In case of "intact" enamel, (77%), partial Class I-tunnel restorations were made. The restorations were controlled at annual routine recalls and the success rate after 3 1/2 years was 74% for permanent teeth, and 10% for primary teeth. Restorations in permanent teeth, made during the second year of the study were successful in 82%, as compared with 62% for restorations made during the first year, indicating a learning effect. Failures in the permanent dentition were due to marginal ridge fracture (35%), cavitation in the approximal enamel (31%), and recurrent caries (38%). Failures in primary teeth were predominantly due to marginal ridge fractures (84%). A comparison with the longevity of conventional Class II restorations is made and the possible advantages of the present method are presented. PMID:8291027

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2012-01-01

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

  1. Secular trend in the maturation of permanent teeth in a sample of Turkish children over the past 30 years.

    PubMed

    Kaygisiz, Emine; Uzuner, Fatma Deniz; Yeniay, Altug; Darendeliler, Nilufer

    2016-02-01

    This study was performed to evaluate the influence of secular trends on dental maturation among Turkish children over the past 30 years. Orthopantomograms of 757 (385 boys, 372 girls) Turkish children born in the 1980s, 1990s, and 2000s were evaluated. Three groups were formed based on decade with five subgroups by age from 9 to 13 years old for each gender. The number of samples in each age group and gender were matched. The mandibular left seven permanent teeth were evaluated based on formation stage to determine the overall dental maturity score. The groups were compared based on decade and gender. The Bonferroni-corrected Mann-Whitney U test and Kruskal-Wallis tests were used for statistical evaluation. Among 11-, 12-, and 13-year-olds born in the 2000s, girls exhibited significantly more mature dentition than did boys (p<0.01, p<0.05, and p<0.05, respectively). Twelve-year-old girls born in the 1990s and 2000s exhibited significantly more mature dentition than did girls born in the 1980s (p<0.01). Girls generally exhibited more mature dentition than boys. No significant positive secular trends in dental maturity were observed from the 1980s through the 2000s. Dental maturation among Turkish children was not affected by a secular trend. PMID:26773225

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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.

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

    PubMed Central

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

    2014-01-01

    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 studys 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

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

    PubMed Central

    Xue, Dai Juan and Feng

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

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

  6. An in vitro evaluation of the demineralization inhibitory effect of F− varnish and casein phosphopeptide-amorphous calcium phosphate on enamel in young permanent teeth

    PubMed Central

    Duraisamy, Vinola; Xavier, Ananda; Nayak, Ullal Anand; Reddy, Venugopal; Rao, Arun Prasad

    2015-01-01

    Aims and Objectives: To determine the demineralization inhibitory potential of fluoride varnish and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and to compare and evaluate the additive effect of fluoride varnish + CPP-ACP. Materials and Methods: Ten healthy premolar teeth that were extracted for orthodontic purposes were collected, and each tooth was longitudinally sectioned buccolingually and mesiodistally into four sections. The teeth were then assigned to four different treatment groups namely fluoride varnish, CPP-ACP, F− varnish followed by CPP-ACP and control. The prepared enamel samples were suspended in an artificial caries challenge for 10 days. The demineralizing inhibitory effects of the groups were recorded using polarized light microscopy. Statistical Analysis Used: Statistical analysis was carried out using analysis of variance and Duncan's multiple range tests. Results: The mean lesion depths of all the groups were Group 1 (fluoride varnish): 104.71, Group 2 (CPP-ACP): 127.09, Group 3: (F− varnish + CPP-ACP): 82.34, Group 4 (control): 146.93. Conclusion: Demineralization inhibitory potential on the additive use of F− varnish and casein phosphopeptide was superior to fluoride varnish or CPP-ACP applied alone on the enamel of young permanent teeth. PMID:26538909

  7. Cone-beam computed tomography study of the root and canal morphology of mandibular permanent anterior teeth in a Chongqing population

    PubMed Central

    Zhengyan, Yang; Keke, Lu; Fei, Wang; Yueheng, Li; Zhi, Zhou

    2016-01-01

    Objective To investigate the root and canal morphology of permanent mandibular anterior teeth in a Chongqing population using cone-beam computed tomography (CBCT). Methods CBCT images of 1,725 patients in a Chongqing population were selected, and a total of 9,646 mandibular anterior teeth were analyzed. The number of root canals and the canal configurations were investigated. Results In total, 0.3% (11/3,257) of lateral incisors and 0.8% (26/3,014) of canines had double roots, and 3.8% (127/3,375) of central incisors, 10.6% (345/3,257) of lateral incisors, and 4.2% (127/3,014) of canines had multi-root canals. The difference in the incidence of multi-canals in lateral incisors between female and male was statistically significant. The frequency of multi-canals in the different age groups was 5.0% for central incisors for ages 21–30 years, 14.7% for lateral incisors for ages 41–50 years, and 8.1% for canines for ages 41–50 years. Conclusion With the limitations of the current study, we found that a high percentage of mandibular anterior teeth had multiple canals in the studied Chinese Chongqing population. The current data may provide clinicians practicing in Chongqing with a more thorough understanding of root canal morphology. PMID:26730198

  8. Comparison of Clinical Success of Applying a Kind of Fissure Sealant on the Lower Permanent Molar Teeth in Dry and Wet Conditions

    PubMed Central

    Eskandarian, Tahereh; Baghi, Saeid; Alipoor, Abbas

    2015-01-01

    Statement of the Problem Fissure sealant therapy is among the most effective methods of preventing dental caries. However, it is lengthy and isolation of the teeth is difficult in this procedure especially in young children. Using new hydrophilic fissure sealant may reduce such problems. Purpose This study aimed to evaluate the clinical success of a hydrophilic fissure sealant on the lower permanent molar teeth in dry and wet conditions. Materials and Method This clinical trial assessed 31 patients (mean age 8.13±1.77 years) who needed fissure sealant therapy on their first or second mandibular permanent molar. Having performed dental prophylaxis, the teeth were etched and rinsed. Then one of the two was randomly selected and sealed with smartseal & loc in isolated and dry conditions; while, the other was wetted on the etched enamel by using a saliva-contaminated micro brush, and was then sealed with the same fissure as the first tooth. Six and 12 months later, two independent observers examined the clinical success of sealant through checking the marginal integrity, marginal discoloration, and anatomical form. Data were analyzed by using SPSS software, version 16. The bivariate Chi-square and Exact Fisher tests were used to compare the clinical success of the two treatment methods. Results There was a high interpersonal reliability between the two examiners (K= 0.713). After 12 months, 90.3% clinical success was observed in dry conditions and 83.9% in wet conditions for smartseal & loc; however, the difference was not statistically significant (p= 0.0707). Conclusion According to the results of this study, it seems that using new hydrophilic fissure sealant can reduce technical sensitivities and consequently decreases the apprehensions on saliva contamination of etched enamel during treatment procedures. PMID:26331144

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

    PubMed Central

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

    2012-01-01

    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 221.9926.27 and 224.5028.64 for the first and second groups, respectively. Post treatment SMH values were 232.5224.34 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. PMID:22924104

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

    PubMed

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

    2008-01-01

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

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

    PubMed Central

    Velmurugan, N; Sooriaprakas, C; Jain, Preetham

    2014-01-01

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

  12. Are extrinsic black stains of teeth iron-saturated bovine lactoferrin and a sign of iron deficient anemia or iron overload?

    PubMed

    Mesonjesi, Ilir

    2012-08-01

    Extrinsic black stains on teeth are shown to have a relation with a low incidence of caries and are made of a ferric compound. Whole composition and why those stains are formed are not fully understood. Studies have shown low incidence of caries in individuals eating cheese. Lactoferrin is the major iron-binding protein, constituent of milk, stays almost intact during cheese making and has antibacterial activity against dental cavity-inducing Streptococcus mutans. Lactoferrin has a high affinity for iron and whenever it is present it will bind iron and release it only in values of pH<4. In a small survey that I made in dental practice, patients (patients did not report taking any medication; had no frequent gingival bleeding) that had extrinsic black stains on teeth eat >50 g of cheese per day and a good number of them, in addition to cheese, drink one cup of milk per day. Cheese stays much longer in contact with tooth surface than does' milk and bovine lactoferrin has four glycan chains that may contribute to a better adherence. Extrinsic black stains are made of a ferric compound, and people that eat good amounts of cheese (where lactoferrin plays a central role) show to have black stains. Iron must be in sufficient amounts in saliva so that lactoferrin can bind it and as a result making the black stains appear. In iron deficient anemia and in iron overload the concentration of iron present in saliva is much higher than in individuals with no anemia. In conclusion, extrinsic black stains of teeth may be iron-saturated bovine lactoferrin and a sign of iron deficient anemia or iron overload if no iron supplements are taken or individuals have no frequent gingival bleeding. PMID:22632844

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

    PubMed Central

    Hasan, Muhammad; Raza Khan, Farhan

    2014-01-01

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

  14. Failure Rate of Direct High-Viscosity Glass-Ionomer Versus Hybrid Resin Composite Restorations in Posterior Permanent Teeth - a Systematic Review

    PubMed Central

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2015-01-01

    Purpose Traditionally, resin composite restorations are claimed by reviews of the dental literature as being superior to glass-ionomer fillings in terms of restoration failures in posterior permanent teeth. The aim of this systematic review is to answer the clinical question, whether conventional high-viscosity glass-ionomer restorations, in patients with single and/or multi-surface cavities in posterior permanent teeth, have indeed a higher failure rate than direct hybrid resin composite restorations. Methods Eight databases were searched until December 02, 2013. Trials were assessed for bias risks, in-between datasets heterogeneity and statistical sample size power. Effects sizes were computed and statistically compared. A total of 55 citations were identified through systematic literature search. From these, 46 were excluded. No trials related to high-viscosity glass-ionomers versus resin composite restorations for direct head-to-head comparison were found. Three trials related to high-viscosity glass-ionomers versus amalgam and three trials related to resin composite versus amalgam restorations could be included for adjusted indirect comparison, only. Results The available evidence suggests no difference in the failure rates between both types of restoration beyond the play of chance, is limited by lack of head-to-head comparisons and an insufficient number of trials, as well as by high bias and in-between-dataset heterogeneity risk. The current clinical evidence needs to be regarded as too poor in order to justify superiority claims regarding the failure rates of both restoration types. Sufficiently large-sized, parallel-group, randomised control trials with high internal validity are needed, in order to justify any clinically meaningful judgment to this topic. PMID:26962372

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

    PubMed Central

    Narang, Isha; Mittal, Neelam; Mishra, Navin

    2015-01-01

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

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

    PubMed

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

    2012-01-01

    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

  17. Comparative Study of the Shear Bond Strength of Flowable Composite in Permanent Teeth Treated with Conventional Bur and Contact or Non-Contact Er:YAG Laser

    PubMed Central

    Parhami, Parisa; Pourhashemi, Seyed Jalal; Ghandehari, Mehdi; Mighani, Ghasem; Chiniforush, Nasim

    2014-01-01

    Introduction: The aim of this study was to evaluate and compare the in vitro effect of the Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser with different radiation distances and high-speed rotary treatment on the shear bond strength of flowable composite to enamel of human permanent posterior teeth. Methods: freshly extracted human molar teeth with no caries or other surface defects were used in this study (n=45). The teeth were randomly divided into 3 groups. Group 1: treated with non-contact Er:YAG Laser and etched with Er:YAG laser, Group 2: treated with contact Er:YAG Laser and etched with Er:YAG laser, Group 3 (control): treated with diamond fissure bur and etched with acid phosphoric 37%. Then the adhesive was applied on the surafces of the teeth and polymerized using a curing light appliance. Resin cylinders were fabricated from flowable composite. Shear bond strength was tested at a crosshead speed of 0.5 mm/min. Results: The amount of Shear Bond Strength (SBS) in the 3 treatment groups was not the same (P<0.05).The group in which enamel surfaces were treated with diamond fissure bur and etched with acid (conrtol group) had the highest mean shear bond strength (19.924.76) and the group in which the enamel surfaces were treated with contact Er:YAG laser and etched with Er:YAG laser had the lowest mean shear bond strength (10.892.89). Mann-whitney test with adjusted P-value detected significant difference in shear bond strength between the control group and the other 2 groups (P < 0.05). Conclusion: It was concluded that both contact and non-contact Er:YAG laser treatment reduced shear bond strength of flowable resin composite to enamel in comparison with conventional treatment with high speed rotary. Different Er:YAG laser distance irradiations did not influence the shear bond strength of flowable composite to enamel. PMID:25653813

  18. Efficacy of Biodentine as an Apical Plug in Nonvital Permanent Teeth with Open Apices: An In Vitro Study

    PubMed Central

    Bani, Mehmet; Sungurtekin-Eki, Elif; Odaba?, Mesut Enes

    2015-01-01

    The aim of this study was to evaluate the apical microleakage of Biodentine and MTA orthograde apical plugs and to compare the effect of thickness of these biomaterials on their sealing ability. A total of eighty maxillary anterior teeth were used. The apices were removed by cutting with a diamond disc (Jota, Germany) 2?mm from the apical root end in an attempt to standardize the working length of all specimens to 15 1?mm. Both materials were placed in 14?mm thickness as apical plugs root canal. Root canal leakage was evaluated by the fluid filtration technique. One-way ANOVA was used in order to determine normality of dispersal distribution of parameters; thereafter, results were analyzed by Kolmogorov-Smirnov test. Overall, between microleakage values of MTA and Biodentine regardless of apical plug thickness, no difference was observed. In terms of plug thickness, a statistically significant difference was observed between the subgroups of MTA and Biodentine (p < 0.05). The apical sealing ability of Biodentine was comparable to MTA at any apical plug thickness. PMID:26436090

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

    PubMed

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

    1997-01-01

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

  20. Validation of DIAGNOdent laser fluorescence and the International Caries Detection and Assessment System (ICDAS) in diagnosis of occlusal caries in permanent teeth: an in vivo study.

    PubMed

    Castilho, Lia S; Cotta, Fernanda V M D; Bueno, Audrey C; Moreira, Allyson N; Ferreira, Efigênia F; Magalhães, Cláudia S

    2016-04-01

    The aim of this in vivo study was to validate the DIAGNOdent laser fluorescence method and the International Caries Detection and Assessment System (ICDAS) for caries classification against the gold standard, histological examination, for detecting occlusal caries on permanent molars; the thresholds used were the outer enamel (D1), the inner enamel and outer third of the dentine (D2), and the inner two-thirds of the dentine (D3). Patients with non-impacted third molars (n = 43) were recruited from a university clinic. A trained examiner performed the examinations. After the teeth were extracted, the histological criterion was used to determine the severity of the lesions. Intra-examiner agreement (weighted kappa) for ICDAS was 0.60 and reliability (intraclass correlation coefficient) for DIAGNOdent was 0.968. The correlations with the histological reference were weak for DIAGNOdent (rs = 0.369) and moderate for ICDAS (rs = 0.515). The areas under the receiver-operating characteristics (ROC) curve at D1, D2, and D3 were 0.60, 0.69, and 0.91, respectively, for ICDAS and 0.55, 0.65, and 0.92, respectively, for DIAGNOdent. ICDAS and DIAGNOdent proved to be reproducible methods with similar performance in the detection of occlusal carious lesions in dentine. The ability of DIAGNOdent to detect initial enamel lesions was higher than that of ICDAS, but with low specificity. The usefulness of DIAGNOdent as an adjunct method for assessment of initial occlusal caries in permanent molars is questionable. PMID:26917102

  1. Caries-Preventive Effect of High-Viscosity Glass Ionomer and Resin-Based Fissure Sealants on Permanent Teeth: A Systematic Review of Clinical Trials

    PubMed Central

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2016-01-01

    Background Glass-ionomers are traditionally regarded to be inferior to resin as fissure sealants in protecting teeth from dental caries, due to their comparatively lower retention rate. Unlike low-viscosity glass-ionomers, high-viscosity glass-ionomer cements (HVGIC) are placed as sealants by pressing the material into pits and fissures with a petroleum-jelly-coated index finger. Hence, HVGIC sealants are assumed to penetrate pits and fissures deeper, resulting in a higher material retention rate, which may increase its caries-preventive effect. Methods The aim of this review was to answer the question as to whether, in patients with fully erupted permanent molar teeth, HVGIC based fissure sealants are less effective to protect against dental carious lesions in occlusal pits and fissures than resin-based fissure sealants? A systematic literature search in eight databases was conducted. Heterogeneity of accepted trials and imprecision of the established evidence were assessed. Extracted sufficiently homogenous datasets were pooled by use of a random-effects meta-analysis. Internal trial validity was evaluated. The protocol of this systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO / Nr.: CRD42015016007). Results Seven clinical trials were provisionally included for further review. Of these, one was excluded. Seven trial reports reporting on six trials were accepted. From these, 11 datasets were extracted and pooled in four meta-analyses. The results suggest no statistically significant differences after up to 48 months and borderline significant differences in favour of HVGIC sealants after 60 months (RR 0.29; 95% CI: 0.09–0.95; p = 0.04 / RD -0.07; 95% CI: -0.14, -0.01). The point estimates and upper confidence levels after 24, 36, 48 and 60 months of RR 1.36; RR 0.90; RR 0.62; RR 0.29 and 2.78; 1.67; 1.21; 0.95, respectively, further suggest a chronological trend in favour of HVGIC above resin-based sealants. The internal trial validity was judged to be low and the bias risk high for all trials. Imprecision of results was considered too high for clinical guidance. Conclusion It can be concluded that: (i) Inferiority claims against HVGIC in comparison to resin-based sealants as current gold-standard are not supported by the clinical evidence; (ii) The clinical evidence suggests similar caries-preventive efficacy of HVGIC and resin-based sealants after a period of 48 months in permanent molar teeth but remains challenged by high bias risk; (iii) Evidence concerning a possible superiority of HVGIC above resin-based sealants after 60 months is poor (even if the high bias risk is disregarded) due to imprecision and requires corroboration through future research. PMID:26799812

  2. Orthodontic movement in deciduous teeth

    PubMed Central

    Consolaro, Alberto

    2015-01-01

    Deciduous teeth exfoliate as a result of apoptosis induced by cementoblasts, a process that reveals the mineralized portion of the root while attracting clasts. Root resorption in deciduous teeth is slow due to lack of mediators necessary to speed it up; however, it accelerates and spreads in one single direction whenever a permanent tooth pericoronal follicle, rich in epithelial growth factor (EGF), or other bone resorption mediators come near. The latter are responsible for bone resorption during eruption, and deciduous teeth root resorption and exfoliation. Should deciduous teeth be subjected to orthodontic movement or anchorage, mediators local levels will increase. Thus, one should be fully aware that root resorption in deciduous teeth will speed up and exfoliation will early occur. Treatment planning involving deciduous teeth orthodontic movement and/or anchorage should consider: Are clinical benefits relevant enough as to be worth the risk of undergoing early inconvenient root resorption? PMID:25992982

  3. 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)

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

    1998-04-01

    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.

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

    MedlinePLUS

    ... swallowing too much fluoride toothpaste can cause permanent stains on their teeth. What about using fluoride tablets? ... swallowed toothpaste, too much oral fluoride can cause stains on your child's teeth. What are cavities? Cavities ...

  5. Recovering teeth from a large dentigerous cyst: A case report.

    PubMed

    Maltoni, Ivano; Santucci, Giorgia; Maltoni, Manuela; Zoli, Lucia; Perri, Alessandro; Gracco, Antonio

    2015-06-01

    A dentigerous cyst is an odontogenic lesion caused by the expansion of the follicle surrounding the crown of impacted, embedded or unerupted teeth. These cysts may cause destruction of the bone, displacement of adjacent teeth, resorption of their roots and prevent the eruption of cyst-associated permanent teeth. This paper discusses successful use of marsupialization combined with orthodontic treatment to treat cyst-associated impacted permanent teeth and to correct a class II open bite malocclusion. PMID:25986707

  6. Teething Tots

    MedlinePLUS

    ... teeth to come in crooked and out of place. Daily dental care should begin even before your baby's first tooth emerges. Wipe your baby's gums daily with a clean, damp washcloth or gauze, or brush them gently ...

  7. Natal teeth

    MedlinePLUS

    ... by the health care provider shortly after birth. Dental x-rays may be done in some cases. If there are signs of another condition that may be linked with natal teeth, exams and testing for that condition will be ...

  8. Brutus' Teeth

    USGS Multimedia Gallery

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

  9. Regional odontodysplasia (Ghost teeth). A case report.

    PubMed

    Kannan, S K; Saraswathi, K

    2001-01-01

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

  10. Malocclusion (Misaligned Teeth)

    MedlinePLUS

    ... jaw and teeth Habitual thumb-sucking and/or tongue thrusting Lost teeth Certain birth defects of the ... who habitually suck their thumb or push their tongue up against their front teeth may cause the ...

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2013-01-01

    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

  13. Teeth Injuries (For Parents)

    MedlinePLUS

    ... With Bullies Pregnant? What to Expect 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) ...

  14. Mouth and Teeth (For Parents)

    MedlinePLUS

    ... continue Normal Development of the Mouth and Teeth Humans are diphyodont, meaning that they develop two sets of teeth. The first set of 20 deciduous teeth are also called the milk, primary, temporary, or baby teeth. They begin to ...

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

    PubMed Central

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

    2012-01-01

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

  16. Strontium in 19th century Australian children's teeth

    NASA Astrophysics Data System (ADS)

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

    2002-05-01

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

  17. Ectopic eruption of permanent incisors after predecessor pulpectomy: five cases.

    PubMed

    Tannure, Patricia Nivoloni; Fidalgo, Tatiana Kelly da Silva; Barcelos, Roberta; Gleiser, Rogerio; Primo, Laura Guimaraes

    2011-01-01

    Pulpectomy in primary teeth is a common technique that preserves teeth in the oral environment and maintains or recovers periapical tissues to a healthy condition. This article describes the ectopic eruption of permanent incisors whose primary predecessors underwent pulpectomy using ZOE filler paste. In a group of 135 teeth that received pulpectomy therapy due to caries, 10 primary maxillary incisors had overretention and were followed for at least 3.5 years (mean time of 4.2 years), both clinically and radiographically, until the permanent teeth erupted. The proposed treatment included extraction of the overretained primary incisors based on permanent successor eruption chronology and contralateral eruption. Seven permanent teeth erupted ectopically. Autocorrection of the permanent tooth positions was observed in five cases. It can be concluded that periodic clinical and radiographic assessments are essential to verify radicular and filling paste resorptions and to avoid overretention and any subsequent malocclusion. PMID:21903556

  18. A Novel Technique in Restoring Fractured Anterior Teeth

    PubMed Central

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

    2014-01-01

    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 patients appearance, but also on function and speech. This case report describes a novel technique in restoring an uncomplicated fractured maxillary anterior tooth in a young patient with direct composite, which is economical and requires less chair side time. PMID:24701546

  19. Delayed Replantation of Avulsed Teeth: Two Case Reports

    PubMed Central

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

    2015-01-01

    This case report presents two cases of delayed replantation of avulsed maxillary central incisors after an extended dry extra-alveolar period. Eight-year-old boy and 10-year-old boy presented with avulsed maxillary central incisors due to trauma occurring 27 and 7 hours earlier, respectively. Treatment guidelines for avulsed mature/immature permanent teeth with prolonged extra-oral time were carried out for the teeth and the extra-oral endodontic treatment was completed. After having been repositioned, the teeth were stabilized for 4 weeks and prophylactic antibiotic was prescribed. Clinical and radiographic controls were done after 18 months for Case I and 12 months for Case II. During the follow-up periods the teeth reported in these cases have remained in a stable, functional position but revealed clinical initial replacement resorption and ankylosis. PMID:25810928

  20. Taking Care of Your Teeth

    MedlinePLUS

    ... re choosing a toothpaste, make sure it contains fluoride . Fluoride makes your teeth strong and protects them from ... MORE ON THIS TOPIC Movie: Teeth How Does Fluoride Work? Bad Breath Going to the Dentist Going ...

  1. Keeping Your Child's Teeth Healthy

    MedlinePLUS

    ... medlineplus/news/fullstory_157387.html Keeping Your Child's Teeth Healthy Oral health expert offers tips on preventing ... help their children enjoy a lifetime with healthy teeth and gums, a dental expert says. Start by ...

  2. Mouth and Teeth (For Parents)

    MedlinePLUS

    ... healing usually occurring in 1 to 3 weeks. Cleft lip and cleft palate . These are birth defects in ... Your Child's Teeth Healthy Movie: Teeth Your Tongue Cleft Lip and Cleft Palate How Does Fluoride Work? Bad ...

  3. Management of Internal Root Resorption on Permanent Teeth

    PubMed Central

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

    2013-01-01

    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. PMID:24348560

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

    PubMed Central

    Mukhopadhyay, Santanu; Mitra, Sanjib

    2014-01-01

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

  5. The Innervation of Teeth

    PubMed Central

    Bradlaw, Robert

    1936-01-01

    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 ansthesia 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 rle of innervation in tooth movement during eruption and orthodontic correction, and after the extraction of anterior teeth, has been investigated, the latter by roentgencinematography. ImagesFig. 3Fig. 4Fig. 1Fig. 2Fig. 5Fig. 6 PMID:19990651

  6. Classical music and the teeth.

    PubMed

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

    2013-01-01

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

  7. Teeth and posture.

    PubMed

    Schunke, Stefan; Enssle, Armin; Kreisl, Alexandra; Schlee, Markus

    2011-01-01

    Esthetics is a topic that has become much discussed both in medicine and in dentistry. However, it should be questioned how reliable and reproducible the guidelines and protocols for esthetic procedures really are. This article will describe in detail the interactions between the musculoskeletal and masticatory systems. Dentists are frequently misled by their false interpretation of existing reference lines, without recognizing the true problem. The close relationship between skeletal and dental problems and their impact on the masticatory and musculoskeletal systems will be explained in this paper. Esthetics and function - not only of the teeth - form an entity that needs to be viewed and treated as a whole. Many of these interactions are thought of as "alternative medicine" and are therefore hardly considered at all in conventional mainstream medicine. This holistic approach will be further explained and discussed with a patient case. PMID:22238724

  8. Sterilization of Extracted Human Teeth.

    ERIC Educational Resources Information Center

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

    1990-01-01

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

  9. Specialized stem cell niche enables repetitive renewal of alligator teeth.

    PubMed

    Wu, Ping; Wu, Xiaoshan; Jiang, Ting-Xin; Elsey, Ruth M; Temple, Bradley L; Divers, Stephen J; Glenn, Travis C; Yuan, Kuo; Chen, Min-Huey; Widelitz, Randall B; Chuong, Cheng-Ming

    2013-05-28

    Reptiles and fish have robust regenerative powers for tooth renewal. However, extant mammals can either renew their teeth one time (diphyodont dentition) or not at all (monophyodont dentition). Humans replace their milk teeth with permanent teeth and then lose their ability for tooth renewal. Here, we study tooth renewal in a crocodilian model, the American alligator, which has well-organized teeth similar to mammals but can still undergo life-long renewal. Each alligator tooth is a complex family unit composed of the functional tooth, successional tooth, and dental lamina. Using multiple mitotic labeling, we map putative stem cells to the distal enlarged bulge of the dental lamina that contains quiescent odontogenic progenitors that can be activated during physiological exfoliation or artificial extraction. Tooth cycle initiation correlates with β-catenin activation and soluble frizzled-related protein 1 disappearance in the bulge. The dermal niche adjacent to the dermal lamina dynamically expresses neural cell adhesion molecule, tenascin-C, and other molecules. Furthermore, in development, asymmetric β-catenin localization leads to the formation of a heterochronous and complex tooth family unit configuration. Understanding how these signaling molecules interact in tooth development in this model may help us to learn how to stimulate growth of adult teeth in mammals. PMID:23671090

  10. Triple Teeth: Report of an Unusual Case

    PubMed Central

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

    2012-01-01

    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

  11. Reasons for permanent tooth extractions in Taiwan.

    PubMed

    Lee, Chen-Yi; Chang, Yong-Yuan; Shieh, Tien-Yu; Chang, Chin-Shun

    2015-03-01

    There has been no study in Taiwan on reasons for extraction of permanent teeth. This study aimed to determine the reasons for permanent teeth extraction in Taiwan. This study performed a secondary data analysis based on the National Health Insurance Research Database. The 2009 database was adopted and there are 131 104 records of dental visits in the database; among them, 4958 visits (from 4811 patients) have a coding of extraction. The results showed that dental caries (55.3%) was the main reason for tooth extraction, followed by periodontal disease (22.1%). Extraction because of dental caries was commonly observed in all age-groups, and extractions because of periodontal disease increased in those older than 35 years. Maxillary and mandibular third molar were the most frequently removed tooth types, and most were extracted because of dental caries and impaction respectively. PMID:22743854

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

    PubMed Central

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

    2013-01-01

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

  13. Natal teeth in premature dizygotic twin girls.

    PubMed

    Dahake, Prasanna T; Shelke, Anup U; Kale, Yogesh J; Iyer, Vidya Vijay

    2015-01-01

    Presence or eruption of teeth immediately at or after birth is a rarely reported phenomenon. This condition is referred to as natal teeth, neonatal teeth, congenital teeth, fetal teeth, predeciduous teeth and dentitia praecox. The most affected teeth are lower primary central incisors with the incidence of 1:2000 for natal and 1:3500 for neonatal teeth. The aetiology of this anomaly is still not clear, however, attributes have been reported in relation to congenital teeth, multiple factors and some syndromes. The management of such cases depends on clinical characteristics of natal or neonatal teeth, as well as complications that they might cause. The aim of this paper is to discuss a rare case of occurrence of two natal teeth in both premature dizygotic twin female babies with specific emphasis on the literature review related to concerns regarding prevalence, aetiology, clinical characteristics, differential diagnosis, complications and management. PMID:26682836

  14. Keeping Your Child's Teeth Healthy

    MedlinePLUS

    ... Your Child All About Food Allergies Keeping Your Child's Teeth Healthy KidsHealth > For Parents > Keeping Your Child's ... brushing and regular flossing. previous continue If Your Child Has a Problem If you are prone to ...

  15. A facial talon cusp on maxillary permanent central incisors

    PubMed Central

    Chinni, Suneelkumar; Nanneboyina, Mayuri; Ramachandran, Anilkumar; Chalapathikumar, Hanuman

    2012-01-01

    Talon cusp is a dental anomaly that occurs as an accessory cusp like structure, from the cingulum of maxillary and mandibular anterior teeth. Lingual location is usually considered pathognomic. This case report discuss about the unusual appearance of talon cusp on the facial surface of the maxillary left permanent central incisor and a mild talon cusp on the facial surface of the maxillary right permanent central incisor. PMID:22368344

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

    PubMed

    dos Santos, Cludia Letcia Vendrame; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Snia Regina; Sundefeld, Maria Lcia Maral Mazza; Negri, Mrcia Regina

    2009-02-01

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

  17. In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth

    PubMed Central

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

    2014-01-01

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

  18. Bilateral agenesis of maxillary permanent canines: Review of the literature

    PubMed Central

    Borzabadi-Farahani, Ali

    2015-01-01

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

  19. Restoration of endodontically treated teeth.

    PubMed

    Mannocci, F; Cowie, J

    2014-03-01

    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

  20. Non-syndromic concomitant hypodontia and supernumerary teeth in an orthodontic population.

    PubMed

    Varela, Margarita; Arrieta, Patricia; Ventureira, Cesar

    2009-12-01

    The simultaneous occurrence of hypodontia and supernumerary teeth in the same individual is termed 'concomitant hypo-hyperodontia' (CHH). There appears to be a correlation between CHH and some syndromes, but this anomaly is very rare in the general population. The aim of this study was to investigate the frequency of CHH in a large sample of non-syndromic orthodontic patients. The records of 2108 consecutive non-syndromic orthodontic patients aged from 7 to 16 years were examined retrospectively. Every patient had at least one panoramic radiograph. When the diagnosis of hypodontia and/or hyperodontia was made in a child under 10 years of age, a second panoramic film was taken 2-4 years later. Statistical analysis of the data was undertaken using a chi-square test. Single or multiple hypodontia was diagnosed in 137 patients (6.5 per cent), 62 males and 75 females. One or more supernumerary teeth were found in 42 patients (2 per cent), 22 males and 20 females. CHH was diagnosed in seven subjects (0.33 per cent), four males and three females. In the CHH subpopulation, the total number of absent and supernumerary teeth was nine and eight, respectively. Hypodontia always occurred in the permanent dentition and was more frequent in the mandible than in the maxilla (four versus three teeth). Supernumerary teeth were more frequent in the permanent than in the primary dentition (six versus two teeth). Five supernumeraries were located in the maxilla and three in the mandible. PMID:19535605

  1. Materials for Paediatric Dentistry. Part 1: Background to the Treatment of Carious Primary Teeth.

    PubMed

    Jenkins, Natalie

    2015-12-01

    Dental caries is a disease that affects many people, including children, and presents numerous challenges to healthcare providers. As clinicians it is important that we consider the advantages and disadvantages of treating carious primary teeth, and make an informed decision about when it is appropriate or not. This paper describes the background to the treatment of carious primary teeth, looking at the differences between primary and permanent teeth, and the relevance of this. It also suggests points to consider when looking at restoration survival studies, as the ability to appraise the literature critically is important for us all in this 'evidence-based' age. CPD/Clinical Relevance: Our early life experiences have the ability to shape our future attitudes and behaviour. Children with carious teeth require careful management so that pain and suffering is minimized, and positive attitudes towards dentistry are fostered. PMID:26855995

  2. 3 dimensional diagnosis unravelling prognosis of multiple impacted teeth - a case report.

    PubMed

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

    2013-08-01

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

  3. Whitening non vital teeth a case report

    PubMed Central

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

    2012-01-01

    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 its a known fact that these teeth can have a grey or pink-grey coloration when they are not correctly endodontical treated. PMID:24778849

  4. Genetic background of supernumerary teeth

    PubMed Central

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

    2015-01-01

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

  5. Natal Teeth: A Case Report and Reappraisal

    PubMed Central

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

    2015-01-01

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

  6. Nasal teeth associated with rhinosinusitis.

    PubMed

    Sokolov, Maxim; Jecker, Peter; Roth, Yehudah

    2004-09-01

    Intranasal ectopic dentition is a rare clinical entity. It may be asymptomatic or can be associated with different symptoms. In 25% of the reported cases an association with rhinosinisitis is suspected. The possible pathophysiology, diagnosis and treatment are discussed. Teeth in the floor of both nasal cavities, associated with chronic rhinosinusitis, are reported for the first time, and a new treatment option of endonasal extraction under microscopic control is presented. PMID:15521672

  7. Nasal teeth associated with rhinosinusitis.

    PubMed

    Sokolov, Maxim; Jecker, Peter; Roth, Yehudah

    2004-06-01

    Intranasal ectopic dentition is a rare clinical entity. It may be asymptomatic or can be associated with different symptoms. In 25% of the reported cases an association with rhinosinusitis is suspected. The possible pathophysiology, diagnosis and treatment are discussed. Teeth in the floor of both nasal cavities, associated with chronic rhinosinusitis, are reported for the first time, and a new treatment option of endonasal extraction under microscopic control is presented. PMID:15224639

  8. Analysis of colored teeth from Precolumbian Tlatelolco: postmortem transformation or intravitam processes?

    PubMed

    Mansilla, J; Solis, C; Chvez-Lomeli, M E; Gama, J E

    2003-01-01

    The etiological basis of the abnormal coloration of archaeological teeth has been an unsolved question for a long time. Differences in the appearance of some archaeological teeth from Precolumbian adult and infant skeletons, detected by external optical inspection, led us to study this problem. A blue stain is visible in a few of the deciduous erupted teeth, and a brown color in various unerupted teeth in the collection, while brown spots appear on some permanent teeth. Several processes or factors that may occur during one's life, others around the time of death, and still others resulting from postmortem alterations have been reported as potential causes of abnormal tooth coloration.A sample of 35 colored teeth and two soil layers taken from Tlatelolco were analyzed by particle-induced X-ray emission (PIXE) as well as selective dissolution techniques. Concentrations of total and extractable elements in enamel and soil layers (Cg1-Cg2) were obtained. This paper describes the occurrence and implications of a substantial secondary concentration of Zinc (Zn), manganese (Mn), strontium (Sr), and iron (Fe) in the deciduous erupted and nonerupted teeth as compared to that in the adult teeth. Our interpretation is that, in this archaeological context, the brown spots and blue stains on the teeth are due to differences in tooth enamel porosity and to a postmortem biogeochemical process. The alterations involve cumulization and diagenesis of iron, manganese, and organic matter solutions that were eluviated from the soil and are not the result of antemortem or perimortem conditions such as trauma or disease. PMID:12489138

  9. Iron deposition in modern and archaeological teeth

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  10. Elemental Analysis of Asian Elephant (Elephas maximus) Teeth Using X-ray Fluorescence and a Comparison to Other Species.

    PubMed

    Nganvongpanit, Korakot; Brown, Janine L; Buddhachat, Kittisak; Somgird, Chaleamchat; Thitaram, Chatchote

    2016-03-01

    Elemental composition in bone of the different species has variation depending on genetic and environmental factors especially their food habitat. The aims of this study were to conduct an elemental analysis of Asian elephant teeth, both deciduous (first molar, second molar, and tusk) and permanent (molar and tusk), and compare the elemental composition of permanent teeth among 15 species, mostly mammalian. These teeth were analyzed using X-ray fluorescence at two voltages: 15 and 50 kV. In Asian elephants, deciduous tusk showed a lower Ca/Zn ratio compared to permanent tusk, because of the lack of Zn in permanent molars. Ca/Fe ratio was higher in deciduous than permanent molars. For permanent teeth, elephant molars presented a high Ca/Pb ratio but no Ca/Zn, Ca/Sr, and Zn/Fe ratios because of the lack of Zn and Sr in the samples tested. The key elemental ratios for differentiating elephant deciduous and permanent tusk were Ca/P and Ca/Zn. The considerable variation in elemental ratio data across 15 species was observed. All tooth samples contained Ca and P, which was not surprising; however, Pb also was present in all samples and Cd in a large majority, suggesting exposure to environmental contaminants. From discriminant analysis, the combination of Ca/P+Ca/Zn+Ca/Pb+Ca/Fe+Ca/Sr+Zn/Fe can generate two equations that successfully classified six (dog, pig, goat, tapir, monkey, and elephant) out of 15 species at 100 % specificity. In conclusion, determining the elemental profile of teeth may serve as a tool to identify the tooth "type" of elephants and to potentially classify other species. PMID:26194819

  11. Rare earth permanent magnets

    SciTech Connect

    Major-Sosias, M.A.

    1993-10-01

    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 (Fe{sub 3}O{sub 4}). 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 in permanent magnetic materials soared. Four major types of permanent magnets have been developed since the turn of the century.

  12. The restoration of traumatized teeth.

    PubMed

    Liddelow, G; Carmichael, G

    2016-03-01

    The restoration of a traumatized tooth may require minimally invasive or more extensive treatment options. The majority of injuries occur in the younger population, so management should consider the long-term outcome, failure and future treatment needs over the course of, often, many decades. The aim should be to provide a tooth-restoration complex that closely mimics the functional and aesthetic qualities of an intact tooth for as long as possible. This narrative review will assess the relevant literature pertinent to restoration of traumatized teeth in order to provide guidance for the practising clinician. PMID:26923452

  13. Dentin dysplasia type I: report of atypical cases in the permanent and mixed dentitions.

    PubMed

    Ozer, Levent; Karasu, Hakan; Aras, Kerem; Tokman, Benay; Ersoy, Ersan

    2004-07-01

    Dentin dysplasia type I is a rare hereditary disturbance of dentin formation characterized clinically by nearly normal appearing crowns and severe hypermobility of teeth. Radiographic analysis shows obliteration of all pulp chambers, short, blunted, and malformed roots, and periapical radiolucencies of noncarious teeth. This paper presents 2 cases demonstrating both classic and atypical features of type I dentin dysplasia in the mixed and permanent dentitions. The clinical, radiographic, and histopathologic\\findings of this condition and treatment are described. PMID:15243476

  14. Dovetail spoke internal permanent magnet machine

    DOEpatents

    Alexander, James Pellegrino; EL-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Shah, Manoj Ramprasad; VanDam, Jeremy Daniel

    2011-08-23

    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.

  15. 77 FR 29914 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... RIN 0579-AC68 Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products AGENCY... live bovines and products derived from bovines with regard to bovine spongiform encephalopathy. This... with regard to bovine spongiform encephalopathy. Comments on the proposed rule were required to......

  16. A coding solution for supernumerary teeth.

    PubMed

    van der Westhuijzen, A J; Morkel, J A

    2011-08-01

    In South Africa payments for treatment rendered are routinely delayed because of the medical fund industry's apparent inability to capture codes denoting supernumerary teeth. The suggested protocol allows for up to 13 supernumerary teeth to be identified by two digits. Meetings planned between SADA and key funding stakeholders to "ensure that protocols related to tooth numbering are acceptable", provide the ideal opportunity to introduce the suggested two-digit protocol for numbering supernumerary teeth. If this proposal is implemented, it could alleviate the frustration associated with the rejection of accounts where supernumerary teeth are appropriately identified. PMID:23198467

  17. Method and apparatus for assembling permanent magnet rotors

    DOEpatents

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

    1999-06-22

    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.

  18. Method and apparatus for assembling permanent magnet rotors

    DOEpatents

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

    1999-01-01

    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.

  19. Permanent contraception for women.

    PubMed

    Micks, Elizabeth A; Jensen, Jeffrey T

    2015-11-01

    Permanent methods of contraception are used by an estimated 220 million couples worldwide, and are often selected due to convenience, ease of use and lack of side effects. A variety of tubal occlusion techniques are available for female permanent contraception, and procedures can be performed using a transcervical or transabdominal approach. This article reviews currently available techniques for female permanent contraception and discusses considerations when helping patients choose a contraceptive method and tubal occlusion technique. PMID:26626698

  20. Oscillating Permanent Magnets.

    ERIC Educational Resources Information Center

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

    1989-01-01

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

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

    PubMed

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

    2013-01-01

    This case report aimed to present the long-term clinical performance of mineral trioxide aggregate (MTA) pulpotomies in immature permanent teeth. Four patients with complicated crown fractures of five maxillary immature central incisor teeth were treated with pulpotomy using gray MTA. An immature mandibular first molar showing signs of reversible pulpitis that was exposed mechanically during cavity preparation was also treated with MTA pulpotomy. Four of the 6 immature teeth were diagnosed vitally with complete root maturation and with the presence of dentin bridges after 55 months (mean time of follow-ups). MTA pulpotomy was assessed unsuccessfully in two fractured central incisors. Severe discoloration in the crowns was present in all 6 cases. MTA may induce pulp healing with dentin bridge formation and prevent necrosis at long-term periods in most of the pulpotomy cases. However, discoloration following MTA pulpotomy is a significant clinical complication. PMID:23408174

  2. More lingual surface attrition of the maxillary anterior teeth in American Indians: prehistoric Panamanians.

    PubMed

    Irish, J D; Turner, C G

    1987-06-01

    Lingual surface attrition of the maxillary anterior teeth (LSA-MAT) has been found in additional prehistoric Latin American Indian skeletons. LSAMAT was first observed in crania from an Archaic Brazilian site. This second finding occurs in teeth from Venado Beach, a late prehistoric site in Panama. LSAMAT is also present in some fragmentary specimens from the Archaic Cerro Mangote site in Panama. LSAMAT at Venado Beach is present in 57% of 28 adult crania. As in the Brazilian study, LSAMAT is associated with a high caries rate (82% of 50 adults; 11.7% of 852 permanent teeth). As first suggested, eating and processing of some type of abrasive carbohydrate food, such as manioc, is the possible cause of LSAMAT. However, other possible causes relating to habitation on or near marine coasts cannot be totally ruled out. PMID:3303956

  3. Fracture resistance of simulated immature teeth after different intra-radicular treatments.

    PubMed

    Sivieri-Araujo, Gustavo; Tanomaru-Filho, Mario; Guerreiro-Tanomaru, Juliane Maria; Bortoluzzi, Eduardo Antunes; Jorge, rica Gouveia; Reis, Jos Maurcio Dos Santos Nunes

    2015-01-01

    The aim of this study was to evaluate the fracture resistance of simulated immature teeth after different intra-radicular treatments. Crowns and roots of bovine incisors were cut transversally and removed to simulate immature teeth. Root canal preparation and flaring were performed using a bur in crown-apex and apex-crown direction. The samples were distributed into 5 groups (n=10): Positive control (PoC) - no root canal flaring or filling; Negative control (NeC) - teeth were sectioned and their root canals were flared; Direct anatomical glass fiber post (RaP) - #2 Reforpost main glass fiber post relined with composite resin; Double tapered conical glass fiber posts (ExP) - #3 Exacto glass fiber post; and #2 Reforpost main glass fiber + Reforpin accessory glass fiber posts (RrP). In RaP, ExP and RrP, 4.0-mm apical plugs were done with MTA Angelus. The specimens were embedded in polystyrene resin inside cylinders and the periodontal ligament was simulated with a polyether-based impression material. The specimens were submitted to compressive fracture strength test (0.5 mm/min at 135 relative to the long axis of the tooth) in a servo-hydraulic mechanical testing machine MTS 810. Data were subjected to one-way ANOVA and Dunnett's C or Tukey's tests (?=0.05). The control groups (PoC and NeC) showed lower fracture strength than the experimental groups. NeC presented the lowest resistance and ExP presented the highest resistance among the experimental groups. The flaring procedures produced a detrimental effect on the fracture resistance of the bovine teeth. Glass fiber intra-radicular posts increased significantly the fracture resistance of simulated immature teeth. PMID:26200142

  4. A removable appliance to extrude teeth.

    PubMed

    Lew, K K

    1993-03-01

    A simple removable appliance to effect minor tooth extrusion of anterior teeth is described and its use is illustrated. This technique uses a labial bow in conjunction with a composite resin button bonded to the labial surface of the tooth or teeth to be extruded. PMID:8511273

  5. Disinfection of Human Teeth for Educational Purposes.

    ERIC Educational Resources Information Center

    Tate, William H.; White, Robert S.

    1991-01-01

    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

  6. Disinfection of Human Teeth for Educational Purposes.

    ERIC Educational Resources Information Center

    Tate, William H.; White, Robert S.

    1991-01-01

    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…

  7. Permanent magnet assembly

    DOEpatents

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

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

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

    NASA Astrophysics Data System (ADS)

    tumberger, B.; tumberger, G.; Hadiselimovi?, M.; Hamler, A.; Gori?an, V.; Jesenik, M.; Trlep, M.

    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.

  9. Evaluation of caries in deciduous second molar and adjacent permanent molar in mixed dentition

    PubMed Central

    Srinivasan, Daya; Louis, C. Joe

    2015-01-01

    Aim: This study was done to evaluate association of caries in deciduous second molar and adjacent permanent first molar, tooth surface more involved in permanent first molar and to assess the parental awareness regarding the eruption of permanent first molar. Subjects and Methods: Three hundred and ten children (160 boys, 150 girls) of mixed dentition aged between 6 and 11 years were included. Presence or absence of paired association of caries in primary second molar and adjacent permanent first molar, of both the jaws, were noted. Parental awareness regarding the child's dentition was asked by pointing the maxillary and mandibular permanent first molar. Results: Pearson Chi-square test was used. Significance was noted in both sexes between paired nonassociation of caries in mandibular primary second molar and mandibular permanent molar (P =0.01) and paired nonassociation of caries in primary maxillary second molar and maxillary permanent first molar in girls only (P =0.04). Parental awareness that permanent first molar has erupted was 24.83% and not to be exfoliated and replaced was 22.9% for both the sexes. In permanent teeth of both the sexes, the occlusal surface was more involved with caries in maxillary teeth; the buccal surface was more involved in mandibular teeth. About 10% of the sample did not have caries in both maxillary and mandibular permanent first molar. Conclusions: Paired association of caries of primary second molar and permanent first molar though found in large number of cases was not significant. It is clear that parental awareness is less regarding the child's oral health. Thus, community-based awareness program has to be conducted to emphasize on pediatric oral health status and care. PMID:26538920

  10. Does Timing of Eruption in First Primary Tooth Correlate with that of First Permanent Tooth? A 9-years Cohort Study

    PubMed Central

    Poureslami, Hamidreza; Asl Aminabadi, Naser; Sighari Deljavan, Alireza; Erfanparast, Leila; Sohrabi, Azin; Jamali, Zahra; Ghertasi Oskouei, Sina; Hazem, Kameliya; Shirazi, Sajjad

    2015-01-01

    Background and aims. Predicting the teeth eruption time is a valuable tool in pediatric dentistry since it can affects scheduling dental and orthodontic treatments. This study investigated the relationship between the eruption time of first primary and permanent teeth and the variation in the eruption time considering socioeconomic status (SES) in a 9-year population- based cohort study. Materials and methods. 307 subjects were examined at bimonthly intervals during the first and second years of life and then at six-month intervals until the eruption of first permanent tooth. Eruption times of primary and permanent tooth were recorded for each child. A modified form of Kuppuswamy’s scale was used to assess the SES. Results. Among 267 subjects completed all follow-ups, the eruption time for first primary and permanent teeth indicated a direct strong correlation; in that one month delayed or early eruption of firstprimary tooth resulted in 4.21 months delayed or early eruption of first appearing permanent tooth (r = 0.91, n = 267, P <0.001). No significant correlation was observed between the eruption time of first primary and first permanent teeth and SES (P = 0.67, P = 0.75, respectively). Conclusion. The eruption timing for the first primary tooth had a correlation with the first permanent tooth eruption tim-ing, while SES did not have any influence on eruption times. PMID:26236432

  11. Canal filling in primary teeth. Description of two particular cases.

    PubMed

    Di Nardo Di Maio, F; D'Arcangelo, C; Varvara, G

    2000-09-01

    Endopedodontics is that branch of child dentistry that regards pulp treatment in childhood. It involves endodontic treatment of all primary teeth and incisives, and of the first permanent molars with immature apex. The pedodontist has to exactly evaluate the techniques and the material to use in treating his patients. It is important to realize that we are facing a continuously evolving and absolutely unstable dentition. Therefore, the success of our work is the result of a careful evaluation of diagnostic parameters and of the techniques and the material. In the current clinical cases it is obvious how the lack of only one of the parameters listed, could represent the cause of severe damage to the patient's dental health and it could lead to psychological discomfort (if not damage), considering the age of the patient. PMID:11256205

  12. Morphological changes in development of pharyngeal teeth in Mylopharyngodon piceus

    NASA Astrophysics Data System (ADS)

    Nakajima, Tsuneo; Yue, Pei-Qi

    1995-09-01

    Adult pharyngeal teeth in Mylopharyngodon piceus are molariform. Based on SEM observations of the developing teeth, this paper describes the morphological diversification of pharyngeal teeth in M. piceus. The larval and juvenile teeth are changed from conical to adult molariform teeth through seven stages. Comparisons are made between each stage and corresponding types in some species of different subfamilies in Cyprinidae. It is considered that the ontogenetic resemblances of the pharyngeal teeth bear relationship to the phylogeny of cyprinids.

  13. Strontium metabolism in teeth and enamel dose assessment: analysis of the Techa river data.

    PubMed

    Tolstykh, E I; Degteva, M O; Kozheurov, V P; Shishkina, E A; Romanyukha, A A; Wieser, A; Jacob, P

    2000-09-01

    People living on the banks of the Techa river were exposed to 90Sr in the early 1950s. Data obtained by radiochemical measurements of extracted permanent teeth, 90Sr autopsy measurements in bone and tooth samples, in vivo measurements of surface beta activity of the anterior teeth and whole-body counter (WBC) measurements of 90Sr in the skeleton have been analyzed. Surface beta activity measurements indicate a biological half-life of 90Sr of about 35 years in enamel. The WBC measurements have been performed since 1974 and a model for the age-dependent strontium retention in human bone has been used to extrapolate to previous time periods when the other measurement results were obtained. For the first decade after the intake, the ratio of the 90Sr concentrations in teeth and bones were found to decrease with age at the time of major intake, from about 10 for 1-year-old children to about 0.3 for adults. There was a considerable variability of individual data within each age group. For adults, the correlation between 90Sr in skeleton and teeth was not high at 0.47 according to radiochemical data for posterior teeth (molars and premolars) and 0.43 according to measurements of surface beta activity for anterior teeth. For children and adolescents there was no correlation between individual measurements in the skeleton and teeth. The absorbed dose in enamel due to 90Sr in dentine has been calculated by Monte Carlo simulations of the electron transport. The results are in agreement with EPR measurements of the absorbed dose in the enamel of persons exposed, mainly due to 90Sr ingestion. PMID:11095146

  14. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    MedlinePLUS

    ... desktop! more... Orthodontics Align Crooked Teeth and Boost Self- esteem Article Chapters Orthodontics Align Crooked Teeth and Boost Self- esteem Orthodontics print full article print this chapter email ...

  15. Romundina and the evolutionary origin of teeth.

    PubMed

    Rcklin, Martin; Donoghue, Philip C J

    2015-06-01

    Theories on the origin of vertebrate teeth have long focused on chondrichthyans as reflecting a primitive condition-but this is better informed by the extinct placoderms, which constitute a sister clade or grade to the living gnathostomes. Here, we show that 'supragnathal' toothplates from the acanthothoracid placoderm Romundina stellina comprise multi-cuspid teeth, each composed of an enameloid cap and core of dentine. These were added sequentially, approximately circumferentially, about a pioneer tooth. Teeth are bound to a bony plate that grew with the addition of marginal teeth. Homologous toothplates in arthrodire placoderms exhibit a more ordered arrangement of teeth that lack enameloid, but their organization into a gnathal, bound by layers of cellular bone associated with the addition of each successional tooth, is the same. The presence of enameloid in the teeth of Romundina suggests that it has been lost in other placoderms. Its covariation in the teeth and dermal skeleton of placoderms suggests a lack of independence early in the evolution of jawed vertebrates. It also appears that the dentition-manifest as discrete gnathal ossifications-was developmentally discrete from the jaws during this formative episode of vertebrate evolution. PMID:26109615

  16. Romundina and the evolutionary origin of teeth

    PubMed Central

    Rcklin, Martin; Donoghue, Philip C. J.

    2015-01-01

    Theories on the origin of vertebrate teeth have long focused on chondrichthyans as reflecting a primitive conditionbut this is better informed by the extinct placoderms, which constitute a sister clade or grade to the living gnathostomes. Here, we show that supragnathal toothplates from the acanthothoracid placoderm Romundina stellina comprise multi-cuspid teeth, each composed of an enameloid cap and core of dentine. These were added sequentially, approximately circumferentially, about a pioneer tooth. Teeth are bound to a bony plate that grew with the addition of marginal teeth. Homologous toothplates in arthrodire placoderms exhibit a more ordered arrangement of teeth that lack enameloid, but their organization into a gnathal, bound by layers of cellular bone associated with the addition of each successional tooth, is the same. The presence of enameloid in the teeth of Romundina suggests that it has been lost in other placoderms. Its covariation in the teeth and dermal skeleton of placoderms suggests a lack of independence early in the evolution of jawed vertebrates. It also appears that the dentitionmanifest as discrete gnathal ossificationswas developmentally discrete from the jaws during this formative episode of vertebrate evolution. PMID:26109615

  17. Rugometric and microtopographic inspection of teeth enamel

    NASA Astrophysics Data System (ADS)

    Costa, Manuel F.; Pereira, Pedro B.

    2013-06-01

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

  18. Laser and LED external teeth-bleaching

    NASA Astrophysics Data System (ADS)

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

    2004-05-01

    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.

  19. Laser and LED external teeth-bleaching

    NASA Astrophysics Data System (ADS)

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

    2004-09-01

    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.

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

    PubMed

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

    1975-07-01

    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

  1. Coevolutionary patterning of teeth and taste buds

    PubMed Central

    Bloomquist, Ryan F.; Parnell, Nicholas F.; Phillips, Kristine A.; Fowler, Teresa E.; Yu, Tian Y.; Sharpe, Paul T.; Streelman, J. Todd

    2015-01-01

    Teeth and taste buds are iteratively patterned structures that line the oro-pharynx of vertebrates. Biologists do not fully understand how teeth and taste buds develop from undifferentiated epithelium or how variation in organ density is regulated. These organs are typically studied independently because of their separate anatomical location in mammals: teeth on the jaw margin and taste buds on the tongue. However, in many aquatic animals like bony fishes, teeth and taste buds are colocalized one next to the other. Using genetic mapping in cichlid fishes, we identified shared loci controlling a positive correlation between tooth and taste bud densities. Genome intervals contained candidate genes expressed in tooth and taste bud fields. sfrp5 and bmper, notable for roles in Wingless (Wnt) and bone morphogenetic protein (BMP) signaling, were differentially expressed across cichlid species with divergent tooth and taste bud density, and were expressed in the development of both organs in mice. Synexpression analysis and chemical manipulation of Wnt, BMP, and Hedgehog (Hh) pathways suggest that a common cichlid oral lamina is competent to form teeth or taste buds. Wnt signaling couples tooth and taste bud density and BMP and Hh mediate distinct organ identity. Synthesizing data from fish and mouse, we suggest that the Wnt-BMP-Hh regulatory hierarchy that configures teeth and taste buds on mammalian jaws and tongues may be an evolutionary remnant inherited from ancestors wherein these organs were copatterned from common epithelium. PMID:26483492

  2. Straight, white teeth as a social prerogative.

    PubMed

    Khalid, Abeer; Quionez, Carlos

    2015-06-01

    A distinguishing feature of North American society is preoccupation with self-image, as seen in the ritualistic nature of bodily practices aimed at constantly improving the body. Nowhere is this more apparent than in the prevailing fixation with straight, white teeth. While there is an ever-expanding literature on the sociology of body, very little has been written on teeth in this context. Using literature from anthropology, biology, dentistry, sociology and social psychology, this study attempts to answer: (1) Why have straight, white teeth become a beauty ideal in North American society? (2) What is the basis for this ideal? (3) How is this ideal propagated? It demonstrates that dental aesthetic tendencies are biologically, culturally and socially patterned. Concepts from the works of Pierre Bourdieu and Michel Foucault are used to illustrate how straight, white teeth contribute towards reinforcing class differences and how society exercises a disciplinary power on individuals through this ideal. It is concluded that modified teeth are linked to self and identity that are rooted in social structure. Moreover, teeth demonstrate the ways in which class differences are embodied and projected as symbols of social advantage or disadvantage. Implications on professional, public health, sociological and political levels are considered. PMID:25923766

  3. Coevolutionary patterning of teeth and taste buds.

    PubMed

    Bloomquist, Ryan F; Parnell, Nicholas F; Phillips, Kristine A; Fowler, Teresa E; Yu, Tian Y; Sharpe, Paul T; Streelman, J Todd

    2015-11-01

    Teeth and taste buds are iteratively patterned structures that line the oro-pharynx of vertebrates. Biologists do not fully understand how teeth and taste buds develop from undifferentiated epithelium or how variation in organ density is regulated. These organs are typically studied independently because of their separate anatomical location in mammals: teeth on the jaw margin and taste buds on the tongue. However, in many aquatic animals like bony fishes, teeth and taste buds are colocalized one next to the other. Using genetic mapping in cichlid fishes, we identified shared loci controlling a positive correlation between tooth and taste bud densities. Genome intervals contained candidate genes expressed in tooth and taste bud fields. sfrp5 and bmper, notable for roles in Wingless (Wnt) and bone morphogenetic protein (BMP) signaling, were differentially expressed across cichlid species with divergent tooth and taste bud density, and were expressed in the development of both organs in mice. Synexpression analysis and chemical manipulation of Wnt, BMP, and Hedgehog (Hh) pathways suggest that a common cichlid oral lamina is competent to form teeth or taste buds. Wnt signaling couples tooth and taste bud density and BMP and Hh mediate distinct organ identity. Synthesizing data from fish and mouse, we suggest that the Wnt-BMP-Hh regulatory hierarchy that configures teeth and taste buds on mammalian jaws and tongues may be an evolutionary remnant inherited from ancestors wherein these organs were copatterned from common epithelium. PMID:26483492

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

    PubMed Central

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

    2014-01-01

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

  5. New perspectives about molecular arrangement of primary and permanent dentin

    NASA Astrophysics Data System (ADS)

    Borges, Ana Flvia Sanches; Bitar, Renata Andrade; Kantovitz, Kamila Rosamilia; Correr, Amrico Bortollazo; Martin, Airton Abraho; Puppin-Rontani, Regina Maria

    2007-12-01

    The dentin quality of primary and permanent teeth was inspected by Fourier transformed Raman spectroscopy (FT-Raman); scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and hardness test. Middle dentin of crowns were reached by carbide bur abrading providing a uniform smear layer. Phosphoric acid was applied in order to simulate the etching of total etching adhesive systems. The groups were ( n = 10): G1 (primary dentin smear layer); G2 (35% phosphoric acid etched primary dentin); G3 (permanent dentin smear layer); G4 (35% phosphoric acid etched permanent dentin). FT-Raman results were subjected to cluster analysis. SEM/EDS were made in order to add the data obtained by FT-Raman. The hardness data were subjected to ANOVA and Tukey test. FT-Raman showed differences among groups, either to organic or inorganic content. For the organic content, primary and permanent dentin became similar after the etching; conversely, the inorganic content showed differences for the two substrates. Hardness test showed no significant differences between primary and permanent dentin, before or after etching, but the etching decreased these values. The mineral content arrangement of primary dentin is different from permanent dentin, independently of the etching. The substrate type did no influence the hardness, but the etching decreased it.

  6. Permanent versus disconnectable FPSOs

    NASA Astrophysics Data System (ADS)

    Luo, Yong; Wang, Hong-Wei

    2009-06-01

    Floating production storage and offloading (FPSO) vessels offer a cost-effective field development solution, especially in deepwater areas lacking an adequate pipeline network. Most FPSOs are permanently moored, i.e. the complete system is designed to withstand any kind of extreme environment at the field location. FPSOs that can be quickly disconnected from their moorings and risers have also been designed and deployed. The key feature of this type of disconnectable FPSO is that it can be disconnect and so avoid dangerous environmental conditions such as icebergs, hurricanes in the Gulf of Mexico and typhoons in the South China Sea. In this paper, the concept of disconnectable FPSOs for deepwater field development is presented. Key technologies and their engineering analyses are highlighted. The merits and demerits of disconnectable vs permanent FPSOs are then evaluated. The paper concludes that both permanent and disconnectable FPSOs are versatile floating systems and their selection depends on safety, technological, cost and operational considerations.

  7. Forensic identification in teeth with caries.

    PubMed

    Alia-García, Esther; Parra-Pecharromán, David; Sánchez-Díaz, Ana; Mendez, Susy; Royuela, Ana; Gil-Alberdi, Laura; López-Palafox, Juan; Del Campo, Rosa

    2015-12-01

    Human teeth are biological structures that resist extreme conditions thus becoming a useful source of DNA for human forensic identification purposes. When it is possible, forensic prefer only non-damaged teeth whereas those with cavities are usually rejected to avoid both external and internal bacterial contamination. Cavities are one of the most prevalent dental pathology and its incidence increases with ageing. The aim of this study was to validate the use of teeth with cavities for forensic identification. A total of 120 individual teeth from unrelated patients (60 healthy and 60 with cavities, respectively) extracted by a dentist as part of the normal process of treatment, were submitted for further analysis. Dental pulp was obtained after tooth fragmentation, complete DNA was extracted and the corresponding human identification profile was obtained by the AmpFlSTR® NGM SElect™ kit. Cariogenic microbiota was determined by PCR-DGGE with bacterial universal primers and bands were excised, re-amplified and sequenced. From the 120 dental pieces analyzed, a defined genetic profile was obtained in 81 (67.5%) of them, with no statistical differences between the healthy and the cavities-affected teeth. Statistical association between teeth status, DNA content and genetic profiles was not observed. Complex bacterial communities were only detected in the cavities group, being the Streptococcus/Enterococcus, and Lactobacillus genera the most represented. We conclude that teeth with cavities are as valid as healthy dental pieces for forensic human identification. Moreover, the severity of the cariogenic lesion as well as associated bacterial communities seems not to influence the establishment of human dental profiles. PMID:26386340

  8. Teeth clenching reduces arm abduction force.

    PubMed

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

    2014-07-01

    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

  9. [Furcation lesions in deciduous teeth].

    PubMed

    Demars-Fremault, C; Pilipili Muhima, C

    1991-03-01

    The area of furcation of temporary molars constitutes a zone of exchanges and rearrangements relating to the evolution of the sub-adjacent permanent tooth. It is subjected to the eruption of the latter and to the physiological modifications of the temporary tooth. Moreover, this area is the site of above-mentioned inflammatory or infections conditions, maintained or aggravated by anatomical factors (accessory canals, thin pulpar floor, with little calcified dentine and broad tubuli), physiological factors (multiplication of accessory canals, decrease in the floor and migration of the epithelial attachment), endodontic factors (pulpal involvement and its complications) and periodontal factors (septum syndrome). The pathology of furcation is an evolving lesion. When discovered early it can be treated by endodontic therapy, while, in a later phase, it will require the extraction of the tooth. The assessment is made on the basis of a X-Ray examination which permits the temporary tooth to be situated in its stable or labile phase, the condition of the pulpal floor to be evaluated and the stage of sub-adjacent germ mineralisation to be estimated. A periodontal arrangement, by coronal reconstitution, conditions the reliability of the endodontic therapies. PMID:1853749

  10. Ferric sulfate as pulpotomy agent in primary teeth: twenty month clinical follow-up.

    PubMed

    Ibricevic, H; al-Jame, Q

    2000-01-01

    Seventy primary molar teeth, carious exposed, symptom free, without any sign of root resorption in children aged from 3 to 6 years (main age 4.3 yr) were treated with conventional pulpotomy procedures. Ferric sulfate 15.5% solution (applied for 15 second for 35 teeth) and formocresol solution (five minute procedure of Buckley's formula for next 35 teeth) have been used as pulpotomy agents. In both groups, pulp stumps were covered with zinc-oxide eugenol paste. Permanent restorations were stainless steel crowns. Clinical check up was every three-months and radiographic follow-up time was six and twenty months after treatment. Our results within this period revealed 100% clinical success rate in both groups. Radiographic success rate was in both groups 97.2%, while in 2.8% cases has shown internal root resorption. On the basis of these results, we can recommend ferric sulfate as a pulpotomy agent in primary teeth in substitution for formocresol at the moment. PMID:11314410

  11. Photomechanical investigations on post endodontically rehabilitated teeth.

    PubMed

    Kishen, A; Asundi, A

    2002-04-01

    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

  12. Solid modeling of fossil small mammal teeth

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  13. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    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…

  14. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    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

  15. Permanent Maxillary Canine Agenesis: A Rare Case Report

    PubMed Central

    Jain, Somya; Patil, Raju Umaji; Asokan, Alexander; Kambalimath, Deepashri

    2015-01-01

    ABSTRACT Congenitally missing teeth (CMT) are among one of the commonly known dental anomalies. The most frequently missing teeth in the permanent dentition, excluding the third molars, are mandibular second premolars and maxillary lateral incisors. Exclusive agenesis of both maxillary canines is an extremely rare occurrence and only a few cases have been reported. Previous studies showed that the prevalence of maxillary canine agenesis varies between 0.07 and 0.13%. In recent studies on Indian population, no cases of maxillary canine agenesis have been documented. This paper reports a case of non-syndromic bilateral agenesis of permanent maxillary canines, along with agenesis of both mandibular central incisors in a healthy 13-year-old Indian female patient; and a brief literature review on prevalence, etiology and treatment modalities of the condition. How to cite this article: Kambalimath HV, Jain S, Patil RU, Asokan A, Kambalimath D. Permanent Maxillary Canine Agenesis: A Rare Case Report. Int J Clin Pediatr Dent 2015; 8(3):242-246. PMID:26604546

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

    PubMed

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

    2014-06-01

    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

  17. Extreme strength observed in limpet teeth

    PubMed Central

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

    2015-01-01

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

  18. Rotary endodontics in primary teeth - A review.

    PubMed

    George, Sageena; Anandaraj, S; Issac, Jyoti S; John, Sheen A; Harris, Anoop

    2016-01-01

    Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the "gold-standard" over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel-titanium (Ni-Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel-titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed. PMID:26792964

  19. Extreme strength observed in limpet teeth.

    PubMed

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

    2015-04-01

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

  20. 77 FR 20319 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 9 CFR Part 93 RIN 0579-AC68 Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products Correction In proposed rule...

  1. 78 FR 73993 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Health Inspection Service 9 CFR Parts 92, 93, 94, 95, 96, and 98 RIN 0579-AC68 Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products Corrections In rule document 2013-28228 appearing...

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

    Rakhshan, Vahid

    2015-01-01

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

  4. Teeth loss, teeth brushing and esophageal carcinoma: a systematic review and meta-analysis

    PubMed Central

    Chen, Hui; Nie, Shuping; Zhu, Yuhui; Lu, Ming

    2015-01-01

    Esophageal carcinoma (EC) is a serious malignancy, and its epidemiologic etiology is not fully explained. We performed this review to investigate the association between teeth loss and teeth brushing and the risk of EC. A systematic search was conducted to identify all relevant studies. The Q test and I2 statistic were used to examine between-study heterogeneity. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were considered by fixed or random effects models. Furthermore, we conducted subgroup analyses based on study design, the studies geographic regions and case type of origin. Modified Egger linear regression test was used to estimate publication bias. Ten articles were included. Pooled analyses indicated that teeth loss was associated with an increased risk of EC for Asians (OR, 1.52; 95% CI: 1.30, 1.78), and high frequency of teeth brushing was associated with a lower incidence of EC (OR, 0.62; 95%CI: 0.43, 0.89). Subgroup analyses showed consistent results and no publication bias existed. Teeth loss and teeth brushing play potential roles in the progressing of EC. People should take care of their oral health in daily life. And large well-designed researches are needed to fully describe the association between teeth health and EC risk. PMID:26462879

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

    PubMed Central

    Gulson, B L; Gillings, B R

    1997-01-01

    Stable lead isotopes and lead concentrations were measured in the enamel and dentine of permanent (n = 37) and deciduous teeth (n = 14) from 47 European immigrants to Australia to determine whether lead exchange occurs in teeth and how it relates to lead exchange in bone. Enamel exhibits no exchange of its European-origin lead with lead from the Australian environment. In contrast, dentine lead exchanges with Australian lead to the extent of approximately 1% per year. In one subject, trabecular bone from the tooth socket exchanged almost all its European lead with Australian lead over a a 15-year period (turnover of approximately 6% per year), similar to the approximately 8% per year proposed for lead turnover in trabecular bone. The repository characteristics of intact circumpulpal dentine were investigated by analyses of four sets of contiguous slices from six teeth: 1) a set consisting of slices with intact circumpulpal dentine and cementum; 2) a set in which these areas were removed; 3) another set consisting of slices with intact circumpulpal dentine and cementum; and 4) a set without cementum. These analyses show relatively small differences in isotopic composition between contiguous slices except that circumpulpal dentine appears to be the dominant control on lead concentration. There is a significant correlation (R2 = 0.19, p = 0.01, n = 34) of dentine lead concentration and rate of exchange with residence time from the country of origin and Australian lead, but there is no such correlation with enamel lead concentration. Analyses of permanent and deciduous teeth of subjects from other countries who have resided in Australia for varying lengths of time should resolve some of the questions arising from this pilot study. Images Figure 1. PMID:9347897

  6. Unlocking the bovine genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. IDENTIFICATION OF BOVINE MICRORNAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Bovine viral diarrhea viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Variable Permanent Magnet Quadrupole

    SciTech Connect

    Mihara, T.; Iwashita, Y.; Kumada, M.; Spencer, C.M.; /SLAC

    2007-05-23

    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.

  10. Permanent magnet design methodology

    NASA Technical Reports Server (NTRS)

    Leupold, Herbert A.

    1991-01-01

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

  11. Postoperative permanent pressure alopecia.

    PubMed

    Chang, Zi Yun; Ngian, Jan; Chong, Claudia; Chong, Chin Ted; Liew, Qui Yin

    2016-04-01

    A 49-year-old Chinese female underwent elective laparoscopic assisted Whipple's surgery lasting 12 h. This was complicated by postoperative pressure alopecia at the occipital area of the scalp. Pressure-induced hair loss after general anaesthesia is uncommon and typically temporary, but may be disconcerting to the patient. We report this case of postoperative permanent pressure alopecia due to its rarity in the anaesthesia/local literature, and review the risk factors for its development. PMID:26611234

  12. Permanent Peripheral Neuropathy

    PubMed Central

    Higgins, Elizabeth

    2014-01-01

    The health risks and side effects of fluoroquinolone use include the risk of tendon rupture and myasthenia gravis exacerbation, and on August 15, 2013, the Food and Drug Administration updated its warning to include the risk of permanent peripheral neuropathy. We present a case of fluoroquinolone-induced peripheral neuropathy in a patient treated for clinically diagnosed urinary tract infection with ciprofloxacin antibiotic. PMID:26425618

  13. Elephant teeth from the atlantic continental shelf

    USGS Publications Warehouse

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

    1967-01-01

    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.

  14. Teeth: Among Nature's Most Durable Biocomposites

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

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

  15. Generalized Familial Crown Resorptions in Unerupted Teeth

    PubMed Central

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

    2011-01-01

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

  16. Teeth syndrome: diagnosis, complications and management

    PubMed Central

    Sbai, Mohamed Ali; Benzarti, Sofien; Boussen, Monia; Maalla, Riadh

    2015-01-01

    Teeth syndrome or fight bite is a specific entity in hand surgery that is little known. It includes infectious complications of the hand following a fist against the teeth. Neglected or misdiagnosed this injury frequently leads to serious complications that could compromise the function of the hand. A retrospective study was performed on 20 patients treated for teeth syndrome at our department, during a period of 12 years (January 2003 to April 2015). All young adults with a mean age of 28 years and a significant male predominance. The dominant side was involved in 15 patients. Lesions were divided into 4 cases of simple dorsal wounds facing the MP joint, 8 cases of dorsal hand cellulitis, and 8 cases of arthritis and osteoarthritis of the metacarpophalangeal (MP) joint of the long fingers. The index was the most affected finger. Treatment consisted in debridement of necrotic tissues, stabilization with external fixation for arthritis, skin reconstruction was performed secondarily. Result was assessed as good in 60% of cases. Clenched fist injuries to the mouth (teeth syndrome or fight bite) are known as being the worst human bites. Usually treated as minor injuries, without realizing a breach of the joint capsule, a lesion of the extensor tendon, or a contamination by oral flora. Any patient with a wound near the joint of the hand and was involved in a fight, need an appropriate evaluation and a specialized treatment to avoid serious complications. PMID:26834924

  17. Hierarchical structure and biomineralization in cricket teeth

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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.

  18. Do We Need National Standards with Teeth?

    ERIC Educational Resources Information Center

    Usiskin, Zalman

    2007-01-01

    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…

  19. Microstructure and chemical composition of primary teeth in children with Down syndrome and cerebral palsy.

    PubMed

    Keinan, David; Smith, Patricia; Zilberman, Uri

    2006-10-01

    This study was designed to test the hypothesis that prenatal growth insults leave permanent signs in the developing primary teeth that can be identified in later life. To test this hypothesis we examined exfoliated and extracted lower second primary molars of children with Down syndrome (DS) and cerebral palsy (CP). Teeth of children with no adverse medical history were used as a control group. Informed consent of parents and children was obtained in all cases. On each tooth two thin sections were cut, one bisecting the mesial cusps and one bisecting the distal cusps. Using a light microscope, the width of prenatal enamel and postnatal enamel was measured on each section at standardized locations from the dentin-enamel junction (DEJ) with the neonatal line used to distinguish between prenatal and postnatal enamel. Chemical analysis of each section was carried out using an energy dispersive spectrophotometer (ESR). The Ca/P ratios of enamel and dentin for each cusp were calculated and intercusp and intergroup differences analysed using non-parametric statistical tests. The results showed that significantly less enamel was laid down prenatally in DS and CP teeth than in the control group and that the enamel of the mesial cusps in these groups was less highly mineralised than that of the controls. The results also showed that in DS teeth growth and mineralisation of all cusps was affected. Based on these findings we propose that analysis of exfoliated deciduous teeth in developmentally challenged children may help in identifying the onset and severity of growth insults in utero and its impact on later development. PMID:16756941

  20. Microflora around teeth and dental implants

    PubMed Central

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

    2012-01-01

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

  1. The large superpredators' teeth from Middle Triassic of Poland

    NASA Astrophysics Data System (ADS)

    Surmik, Dawid; Brachaniec, Tomasz

    2013-09-01

    An unusual large teeth, finding from time to time in marine sediments of Muschelkalk, Silesia, Poland indicate the superpredators occurrence. According to size and morphological features the teeth are similar to archosaurs or giant marine reptiles.

  2. Performance of teeth of lingcod, Ophiodon elongatus, over ontogeny.

    PubMed

    Galloway, Katherine A; Anderson, Philip S L; Wilga, Cheryl D; Summers, Adam P

    2016-02-01

    Fish teeth can play several roles during feeding; capture, retention, and processing. In many fish lineages teeth may be present on non-jaw cranial bones that lack opposing teeth, such as the vomer and palatine. We hypothesized that teeth on different bones have different functions, and that the function of a set of teeth may vary over ontogeny. In this study, puncture, and draw performance of in situ vomerine teeth are compared to premaxillary teeth of the piscivorous lingcod, Ophiodon elongatus. The force required to pierce prey and to draw prey out of the mouth once the teeth were embedded was measured in ten individuals ranging from 205 to 836 mm SL to test for ontogenetic effects. Vomerine teeth in juvenile lingcod required proportionally less force to puncture prey items than adult lingcod, while premaxillary teeth showed the opposite trend. Draw force required to remove prey from the grasp of both toothed bones show the same shift with ontogeny. These results suggest that there is a shift in tooth function from vomerine to premaxillary teeth over ontogeny of lingcods. In juvenile lingcod, vomerine teeth function more effectively during initial puncture. In contrast, the premaxillary teeth pierce more effectively in adults. Juvenile lingcod are expected to use the premaxillary teeth while adult lingcod are expected to use the vomerine teeth to retain prey due to the larger force required for the prey to escape. The curvature of vomerine teeth increases over ontogeny suggesting increasing functional performance in retaining prey. J. Exp. Zool. 9999A:1-7, 2015. © 2015 Wiley Periodicals, Inc. PMID:26411475

  3. Teeth whitening versus the influence of extrinsic factors on teeth stains.

    PubMed

    Nakonieczna-Rudnicka, Marta; Bachanek, Teresa; Madejczyki, Marlena; Grajewskai, Iwona; Koby?ecka, Elzbieta

    2015-01-01

    The improvement of teeth colour is the effect of using whitening toothpastes, professional removal of dental deposits, pulpless teeth and vital teeth whitening. The aim of the study was evaluation of various methods of teeth whitening in relation to sex and age of the investigated as well as the extrinsic factors causing teeth stains such as cigarette smoking, consumption of coffee and tea. Questionnaire survey was conducted in the group of 204 patients, reporting for a dental treatment at the Chair and Department of Conservative Dentistry with Endodontics of the Medical University of Lublin as well as private dental practice in Lublin. Questionnaire survey was elaborated for the needs of the planned investigation and included questions concerning, among others, socio-demographic data of the investigated, methods of teeth whitening, cigarette smoking, consumption of coffee and tea. Statistic analysis was performed with the use of descriptive statistics, Chi2 test, Mann-Whitney test. The values of p < 0.05 were considered statistically essential. Women used whitening toothpastes more frequently in comparison with men (?2 = 7.96, p < 0.01). People who declared drinking at least one coffee cup used whitening toothpastes more frequently in comparison with the people drinking coffee occasionally and those who didn't drink it (?2 = 9.99, p < ?0.05). PMID:26731868

  4. Something to sink your teeth into: The presence of teeth augments ERPs to mouth expressions.

    PubMed

    daSilva, Elizabeth B; Crager, Kirsten; Geisler, Danika; Newbern, Powell; Orem, Benjamin; Puce, Aina

    2016-02-15

    If the whites of the sclera can impact neural processing of eye expressions (Hardee, Thompson, & Puce, 2008; Whalen et al., 1998), do seen teeth affect neural responses to mouth expressions? Twenty participants (10 females; ages 22-31) viewed avatar mouth images depicting grimaces, smiles and open mouth expressions that were presented with and without teeth. A continuous 256 channel electroencephalogram (EEG) was recorded while subjects completed two tasks: an implicit task evaluating stimulus color and an explicit task evaluating mouth expression valence. Event related potential (ERP) peak amplitudes and latencies and area under the curve (AUC) were measured in individual subject averaged ERPs. Statistical testing revealed a main effect of the presence of Teeth for P100, N170, and vertex positive potential (VPP) amplitudes and for slow positive wave (SPW) AUC. Task by teeth interactions occurred for P250 amplitude, underscoring how explicit task demands can influence neural processing. Arousal ratings co-varied with teeth presence, suggesting that low-level visual features such as teeth may drive the saliency of emotional expressions, and lie at the core of differences in neural processing to different emotional expressions. PMID:26706446

  5. Liquids with permanent porosity

    NASA Astrophysics Data System (ADS)

    Giri, Nicola; Del Pópolo, Mario G.; Melaugh, Gavin; Greenaway, Rebecca L.; Rätzke, Klaus; Koschine, Tönjes; Pison, Laure; Gomes, Margarida F. Costa; Cooper, Andrew I.; James, Stuart L.

    2015-11-01

    Porous solids such as zeolites and metal–organic frameworks are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption–desorption cycles, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble ‘scrambled’ porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities.

  6. Liquids with permanent porosity.

    PubMed

    Giri, Nicola; Del Ppolo, Mario G; Melaugh, Gavin; Greenaway, Rebecca L; Rtzke, Klaus; Koschine, Tnjes; Pison, Laure; Gomes, Margarida F Costa; Cooper, Andrew I; James, Stuart L

    2015-11-12

    Porous solids such as zeolites and metal-organic frameworks are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption-desorption cycles, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble 'scrambled' porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities. PMID:26560299

  7. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  8. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  9. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  10. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  11. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  12. Management of incompletely developed teeth requiring root canal treatment.

    PubMed

    Harlamb, S C

    2016-03-01

    Endodontic management of the permanent immature tooth continues to be a challenge for both clinicians and researchers. Clinical concerns are primarily related to achieving adequate levels of disinfection as 'aggressive' instrumentation is contraindicated and hence there exists a much greater reliance on endodontic irrigants and medicaments. The open apex has also presented obturation difficulties, notably in controlling length. Long-term apexification procedures with calcium hydroxide have proven to be successful in retaining many of these immature infected teeth but due to their thin dentinal walls and perceived problems associated with long-term placement of calcium hydroxide, they have been found to be prone to cervical fracture and subsequent tooth loss. In recent years there has developed an increasing interest in the possibility of 'regenerating' pulp tissue in an infected immature tooth. It is apparent that although the philosophy and hope of 'regeneration' is commendable, recent histologic studies appear to suggest that the calcified material deposited on the canal wall is bone/cementum rather than dentine, hence the absence of pulp tissue with or without an odontoblast layer. PMID:26923451

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

    NASA Technical Reports Server (NTRS)

    Childs, Dara W.; Scharrer, Joseph K.

    1987-01-01

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

  14. Cryogenic Permanent Magnet Undulators

    SciTech Connect

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

    2010-06-23

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

  15. MTA pulpotomy of human permanent molars with irreversible pulpitis.

    PubMed

    Eghbal, Mohammad Jafar; Asgary, Saeed; Baglue, Reza Ali; Parirokh, Masoud; Ghoddusi, Jamileh

    2009-04-01

    The histological success of mineral trioxide aggregate (MTA) pulpotomy for treatment of irreversible pulpitis in human teeth as an alternative treatment was investigated in this study. Fourteen molars which had to be extracted were selected from patients 16-28 years old. The selection criteria include carious pulp exposure with a history of lingering pain. After isolation, caries removal and pulp exposure, MTA was used in pulpotomy treatment. Patients were evaluated for pain after 24 h. Two patients were lost from this study. Twelve teeth were extracted after 2 months and were assessed histologically. Recall examinations confirmed that none of the patients experienced pain after pulpotomy. Histological observation revealed that all samples had dentin bridge formation completely and that the pulps were vital and free of inflammation. Although the results favour the use of MTA as a pulpotomy material, more studies with larger samples and a longer recall period are suggested to justify the use of MTA for treatment of irreversible pulpitis in human permanent teeth. PMID:19335509

  16. Intraradicular reinforcement for traumatized immature teeth.

    PubMed

    Chhabra, Nidhi; Chhabra, Anuj

    2014-01-01

    Immature necrotic teeth after trauma pose both endodontic and restorative challenges because of incomplete closure of the apex, and thin and weakened dentinal walls that make them prone to fracture. The use of light-transmitting plastic posts, in combination with adhesive materials, enable intraradicular reinforcement of flared canals, helping to rehabilitate fractured immature teeth and maintain a functional unit within the dental arch. The purpose of this paper is to present the case of a nine-year-old patient who had a complicated fracture of an immature anterior tooth, which was endodontically treated with mineral trioxide aggregate in the apical third. The dentinal root walls were successfully reinforced with composite resin and a light-transmitting glass fiber post, followed by the placement of a glass fiber composite post and a metal ceramic crown. PMID:24709431

  17. An attractive solution to unerupted teeth.

    PubMed

    Sandler, J P

    1991-12-01

    A user- and patient-friendly method of treating unerupted teeth is described. A neodymium iron boron magnet is attached to the unerupted tooth, and a second, larger magnet is incorporated in a removable appliance. The resulting forces provide a friction-free system, requiring little or no adjustment, which rapidly encourages the unerupted tooth into a position in which it may be bonded and thereby aligned by more conventional methods. PMID:1962602

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

    PubMed

    Forghani, Maryam; Parisay, Iman; Maghsoudlou, Amir

    2013-08-01

    Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Endodontic treatment is often complicated in premature tooth with an uncertain prognosis. This article describes successful treatment of two traumatized maxillary central incisors with complicated crown fracture three months after trauma. The radiographic examination showed immature roots in maxillary central incisors of a 9-year-old boy with a radiolucent lesion adjacent to the right central incisor. Apexogenesis was performed for the left central incisor and revascularization treatment was considered for the right one. In 18-month clinical and radiographic follow-up both teeth were asymptomatic, roots continued to develop, and periapical radiolucency of the right central incisor healed. Considering the root development of these contralateral teeth it can be concluded that revascularization is an appropriate treatment method in immature necrotic teeth. PMID:24010086

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

    PubMed Central

    Forghani, Maryam; Maghsoudlou, Amir

    2013-01-01

    Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Endodontic treatment is often complicated in premature tooth with an uncertain prognosis. This article describes successful treatment of two traumatized maxillary central incisors with complicated crown fracture three months after trauma. The radiographic examination showed immature roots in maxillary central incisors of a 9-year-old boy with a radiolucent lesion adjacent to the right central incisor. Apexogenesis was performed for the left central incisor and revascularization treatment was considered for the right one. In 18-month clinical and radiographic follow-up both teeth were asymptomatic, roots continued to develop, and periapical radiolucency of the right central incisor healed. Considering the root development of these contralateral teeth it can be concluded that revascularization is an appropriate treatment method in immature necrotic teeth. PMID:24010086

  20. Microprobe analysis of teeth by synchrotron radiation: environmental contamination

    NASA Astrophysics Data System (ADS)

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

    1999-10-01

    An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l'Utilisation du Rayonnement lectromagntique (LURE) synchrotron (France) was used for elemental determination in teeth. To evaluate the influence of living habits in dental elemental composition nine teeth collected post-mortem were analysed, five from a miner and four from a fisherman. All teeth from the fisherman were healthy. From the miner some teeth were carious and one of them was filled with metallic amalgam. Teeth were sliced under the vertical plane and each slice was scanned from the root to the enamel for elemental profile determination. The synchrotron microprobe resolution was of 100 ?m and incident photons of 18 keV energy were used. The elemental concentration values found suggest heterogeneity of the teeth material. Moreover, the distinct profiles for Mn, Sr, Br and Pb were found when teeth from the miner and from the fisherman are compared which can be associated with dietary habits and environmental influence. Higher concentrations of Mn and Sr were found for the fisherman teeth. In addition, Br was only observed in this group of teeth. Pb levels are higher for the miner teeth in particular for dentine regions. The influence of amalgam, such as, increase of Zn and Hg contents in the teeth material, is only noticed for the immediate surroundings of the treated cavity.

  1. Cone-beam computed tomography as a surgical guide to impacted anterior teeth.

    PubMed

    Jeremias, Fabiano; Fragelli, Camila Maria Bullio; Mastrantonio, Simone Di Salvo; Dos Santos-Pinto, Lourdes; Dos Santos-Pinto, Ary; Pansani, Cyneu Aguiar

    2016-01-01

    Surgical procedure for removal of impacted teeth is a challenge for clinicians as it involves accuracy in the diagnosis and localization of the dental elements. The cone-beam computed tomography (CBCT), compared to the conventional radiography, has a greater potential to provide complementary information because of its three-dimensional (3D) images, reducing the possibility of failures in surgical procedures. Two 10-year-old boys presented with aesthetic issues associated with the juxtaposition of ectopic teeth with the permanent ones. Both two-dimensional and 3D preoperative radiographic diagnostic sets were produced. The occlusal and panoramic radiographs were not enough for proper localization of impacted incisors. Thus, the CBCT was used as a surgical guide. After 2 years of longitudinal following, no lesion was recorded, and the orthodontic treatment has proven successful. In all cases, CBCT contributed to both diagnosis and correct localization of supernumerary teeth, aiding the professional in the treatment planning, and consequently in the clinical success. The surgeries were completely safe, avoiding damage in noble structures, and providing a better recovering of the patients. PMID:26962322

  2. Progression of root resorption following replantation of human teeth after extended extraoral storage.

    PubMed

    Andersson, L; Bodin, I; Srensen, S

    1989-02-01

    Avulsed human permanent teeth subjected to a minimum of 1 h dry extraoral storage before replantation were followed radiographically for an average of 4.8 years. The depth of root resorption cavities was assessed using a radiographic index, and the rate of root resorption was defined as the index change over time. The frequency of inflammatory and replacement resorption was determined at each observation time. Replacement resorption increased in frequency with time in all patients. In teeth endodontically treated within 3 weeks of replantation, minimal inflammatory resorption was found regardless of the age of the patients. In teeth where endodontic treatment was performed more than 3 weeks after replantation, the frequency of inflammatory resorption was significantly higher in young patients but not in older patients, up to more than 3 years after replantation. The rate of root resorption was found to be related to age. In patients 8-16 years old at the time of avulsion the rate of root resorption was significantly higher compared with patients 17-39 years old. Age had a higher impact on the rate of root resorption compared with the delay in endodontic treatment after replantation. It was concluded that a tooth replanted with a necrotic periodontal membrane will become ankylosed and resorbed within 3-7 years in young patients, whereas a tooth replanted under similar conditions in older patients may remain in function for a considerably longer time. PMID:2598883

  3. Cone-beam computed tomography as a surgical guide to impacted anterior teeth

    PubMed Central

    Jeremias, Fabiano; Fragelli, Camila Maria Bullio; Mastrantonio, Simone Di Salvo; dos Santos-Pinto, Lourdes; dos Santos-Pinto, Ary; Pansani, Cyneu Aguiar

    2016-01-01

    Surgical procedure for removal of impacted teeth is a challenge for clinicians as it involves accuracy in the diagnosis and localization of the dental elements. The cone-beam computed tomography (CBCT), compared to the conventional radiography, has a greater potential to provide complementary information because of its three-dimensional (3D) images, reducing the possibility of failures in surgical procedures. Two 10-year-old boys presented with aesthetic issues associated with the juxtaposition of ectopic teeth with the permanent ones. Both two-dimensional and 3D preoperative radiographic diagnostic sets were produced. The occlusal and panoramic radiographs were not enough for proper localization of impacted incisors. Thus, the CBCT was used as a surgical guide. After 2 years of longitudinal following, no lesion was recorded, and the orthodontic treatment has proven successful. In all cases, CBCT contributed to both diagnosis and correct localization of supernumerary teeth, aiding the professional in the treatment planning, and consequently in the clinical success. The surgeries were completely safe, avoiding damage in noble structures, and providing a better recovering of the patients. PMID:26962322

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    Amini, Fariborz; Rakhshan, Vahid; Babaei, Pardis

    2012-01-01

    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 (α = 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. PMID:23087726

  6. Analyses of the Erosive Effect of Dietary Substances and Medications on Deciduous Teeth.

    PubMed

    Lussi, Adrian; Carvalho, Thiago Saads

    2015-01-01

    This study aimed at analysing the erosive potential of 30 substances (drinks, candies, and medicaments) on deciduous enamel, and analyse the associated chemical factors with enamel dissolution. We analysed the initial pH, titratable acidity (TA) to pH 5.5, calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentration, and degree of saturation ((pK -pI)HAP, (pK -pI)FAP, and (pK-pI)CaF2) of all substances. Then, we randomly distributed 300 specimens of human deciduous enamel into 30 groups (n = 10 for each of the substances tested. We also prepared 20 specimens of permanent enamel for the sake of comparison between the two types of teeth, and we tested them in mineral water and Coca-Cola. In all specimens, we measured surface hardness (VHN: Vickers hardness numbers) and surface reflection intensity (SRI) at baseline (SHbaseline and SRIbaseline), after a total of 2 min (SH2min) and after 4 min (SH4min and SRI4min) erosive challenges (60 ml of substance for 6 enamel samples; 30C, under constant agitation at 95 rpm). There was no significant difference in SHbaseline between deciduous and permanent enamel. Comparing both teeth, we observed that after the first erosive challenge with Coca-Cola, a significantly greater hardness loss was seen in deciduous (-90.211.3 VHN) than in permanent enamel (-44.312.2 VHN; p = 0.007), but no differences between the two types of teeth were observed after two challenges (SH4min). After both erosive challenges, all substances except for mineral water caused a significant loss in relative surface reflectivity intensity, and most substances caused a significant loss in surface hardness. Multiple regression analyses showed that pH, TA and Ca concentration play a significant role in initial erosion of deciduous enamel. We conclude that drinks, foodstuffs and medications commonly consumed by children can cause erosion of deciduous teeth and erosion is mainly associated with pH, titratable acidity and calcium concentration in the solution. PMID:26700481

  7. Analyses of the Erosive Effect of Dietary Substances and Medications on Deciduous Teeth

    PubMed Central

    Lussi, Adrian; Carvalho, Thiago Saads

    2015-01-01

    This study aimed at analysing the erosive potential of 30 substances (drinks, candies, and medicaments) on deciduous enamel, and analyse the associated chemical factors with enamel dissolution. We analysed the initial pH, titratable acidity (TA) to pH 5.5, calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentration, and degree of saturation ((pK -pI)HAP, (pK -pI)FAP, and (pK−pI)CaF2) of all substances. Then, we randomly distributed 300 specimens of human deciduous enamel into 30 groups (n = 10 for each of the substances tested. We also prepared 20 specimens of permanent enamel for the sake of comparison between the two types of teeth, and we tested them in mineral water and Coca-Cola®. In all specimens, we measured surface hardness (VHN: Vickers hardness numbers) and surface reflection intensity (SRI) at baseline (SHbaseline and SRIbaseline), after a total of 2 min (SH2min) and after 4 min (SH4min and SRI4min) erosive challenges (60 ml of substance for 6 enamel samples; 30°C, under constant agitation at 95 rpm). There was no significant difference in SHbaseline between deciduous and permanent enamel. Comparing both teeth, we observed that after the first erosive challenge with Coca-Cola®, a significantly greater hardness loss was seen in deciduous (−90.2±11.3 VHN) than in permanent enamel (−44.3±12.2 VHN; p = 0.007), but no differences between the two types of teeth were observed after two challenges (SH4min). After both erosive challenges, all substances except for mineral water caused a significant loss in relative surface reflectivity intensity, and most substances caused a significant loss in surface hardness. Multiple regression analyses showed that pH, TA and Ca concentration play a significant role in initial erosion of deciduous enamel. We conclude that drinks, foodstuffs and medications commonly consumed by children can cause erosion of deciduous teeth and erosion is mainly associated with pH, titratable acidity and calcium concentration in the solution. PMID:26700481

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    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.

  9. Post-traumatic apexogenesis of immature non-vital permanent incisors.

    PubMed

    Ghafoor, Robia

    2012-07-01

    Injury to an immature permanent tooth may result in cessation of dentin deposition and root maturation leaving an open root apex and thin dentinal walls that are prone to fracture. Endodontic treatment is often complicated and protracted with an uncertain prognosis frequently resulting in pre-mature tooth loss. 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. This case report highlights the role of Hertwig root sheath and dental papilla in continued root formation of immature permanent tooth, even diagnosed with necrotic pulp. PMID:22747867

  10. Achieving permanency for LGBTQ youth.

    PubMed

    Jacobs, Jill; Freundlich, Madelyn

    2006-01-01

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

  11. Non-syndromic multiple supernumerary teeth: report of a case with 13 supplemental teeth

    PubMed Central

    Ansari, Afroz Alam; Malhotra, Seema; Pandey, Ramesh Kumar; Bharti, Kusum

    2013-01-01

    The presence of supernumerary teeth (STs) may give rise to a variety of clinical problems. These include failure of a tooth to erupt, delayed eruption, ectopic eruption, diastema, rotation of adjacent teeth, displacement of teeth and crowding. This case describes a 14-year-old male patient who presented with the complaint of pain in the left mandibular posterior region. Intraoral examination revealed the presence of carious retained deciduous second molar in this region. An orthopantomogram was advised which initially revealed 11 STs, positioned in all four quadrants in posterior regions. Two more STs were detected in the following investigations totalling 13. Dental literature rarely reports presence of STs in such a large number. The objective of this case is to report detection of STs, radiographic examination, extraction of the retained deciduous molars and STs in the mandible to facilitate eruption of mandibular premolars. PMID:23470670

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

    PubMed Central

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

    2008-01-01

    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 hardsoft 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. PMID:18304207

  13. Sexing bovine embryos using PCR amplification of bovine SRY sequence.

    PubMed

    Zeng, Y T; Zhang, M L; Chen, M J; Zhou, X D; Huang, Y; Ren, Z R; Huang, S Z; Hu, M X; Wu, X Q; Gao, J M

    1994-02-01

    This study analyses the bovine SRY DNA sequence by direct sequencing procedure, followed by the designation of the PCR primers specific for bovine SRY. Using PCR amplification of bovine SRY gene, the embryo sex was determined. The results of the embryo sex identification were confirmed after the embryo transfer and pregnancies. PMID:8068189

  14. Eight-year study on conventional glass ionomer and amalgam restorations in primary teeth.

    PubMed

    Qvist, Vibeke; Laurberg, Lone; Poulsen, Agneta; Teglers, Poul Thorpen

    2004-02-01

    The aim of this randomized clinical study was to compare the longevity and the cariostatic effects of conventional glass ionomer and amalgam restorations in primary teeth placed in everyday practice in the Danish Public Dental Health Service. All restorations inserted during a 7-month period by 14 clinicians in 2 municipalities were included in the study. The sample consisted of 515 conventional glass ionomer restorations and 543 amalgam restorations in 666 children aged between 2.8 and 13.5 years. The restorations were in contact with 592 unrestored surfaces in primary and permanent teeth. The study was terminated after 8 years, with 2% of the restorations in function and 7% patient dropouts. Fifty percent of the teeth restored with glass ionomer and 63% of those with amalgam were exfoliated with the restoration in situ, while 42% of the glass ionomer and 20% of the amalgam restorations had been repaired or replaced. Fracture of restoration, endodontic complication, and loss of retention were the major reasons for failure. The 50% survival time for glass ionomer restorations in all cavity types was 42 months, while the median survival time for amalgam restorations could not be estimated but exceeded 7.8 years (P < 0.001). Progression of caries lesions on tooth surfaces adjacent to amalgam restorations required operative treatment on 30% of the teeth, while only on 16% of teeth adjacent to glass ionomer restorations. The 75% survival time was 40 months for surfaces in contact with glass ionomer compared to 25 months for surfaces in contact with amalgam (P = 0.005). Multivariate analyses were performed in order to assess the influence of a number of factors on the longevity of restorations, occurrence of prevalent failures, and caries treatment of surfaces in contact with the restorations. Owing to the high frequency of failures of the conventional glass ionomer restorations, it was concluded that they are not an appropriate, universal alternative to amalgam for restorations in primary teeth, although they reduce caries progression and the need for operative treatment of adjacent surfaces. PMID:15124781

  15. Permanent-Magnet Meissner Bearing

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1994-01-01

    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.

  16. Tutankhamun's Dentition: The Pharaoh and his Teeth.

    PubMed

    Pausch, Niels Christian; Naether, Franziska; Krey, Karl Friedrich

    2015-12-01

    Tutankhamun was a Pharaoh of the 18th Dynasty (New Kingdom) in ancient Egypt. Medical and radiological investigations of his skull revealed details about the jaw and teeth status of the mummy. Regarding the jaw relation, a maxillary prognathism, a mandibular retrognathism and micrognathism have been discussed previously. A cephalometric analysis was performed using a lateral skull X-ray and a review of the literature regarding King Tutankhamun´s mummy. The results imply diagnosis of mandibular retrognathism. Furthermore, third molar retention and an incomplete, single cleft palate are present. PMID:26963220

  17. Stem Cells in Teeth and Craniofacial Bones.

    PubMed

    Zhao, H; Chai, Y

    2015-11-01

    Stem cells are remarkable, and stem cell-based tissue engineering is an emerging field of biomedical science aiming to restore damaged tissue or organs. In dentistry and reconstructive facial surgery, it is of great interest to restore lost teeth or craniofacial bone defects using stem cell-mediated therapy. In the craniofacial region, various stem cell populations have been identified with regeneration potential. In this review, we provide an overview of the current knowledge concerning the various types of tooth- and craniofacial bone-related stem cells and discuss their in vivo identities and regulating mechanisms. PMID:26350960

  18. Histological appearance of postmortem pink teeth: Report of two cases.

    PubMed

    Gowda, Bk Charan; Sivapathasundharam, B; Chatterji, Ananjan; Chatterji, B L

    2015-01-01

    This article presents images and histological changes in the dentin of two cases involving posmortem pink teeth. Postmortem pink teeth were noted among two deceased male individuals. Pink teeth were noted during autopsy examination after twelve days in one corpse, and eight days following death in the second case. During the examination decomposition and putrefaction of the body was noted. Cause of death was drowning in one case and haemorrhages and shock in another. A central incisor tooth was obtained from each body. Both teeth exhibited a pink appearance and the intensity was more pronounced in the cervical region. Although pink teeth can be noted in death due to asphyxia, carbon monoxide poisoning and so on, it is necessary to study the exact role behind the appearance of pink teeth and try to incorporate the finding medico legally. PMID:26005309

  19. Histological appearance of postmortem pink teeth: Report of two cases

    PubMed Central

    Gowda, BK Charan; Sivapathasundharam, B; Chatterji, Ananjan; Chatterji, BL

    2015-01-01

    This article presents images and histological changes in the dentin of two cases involving posmortem pink teeth. Postmortem pink teeth were noted among two deceased male individuals. Pink teeth were noted during autopsy examination after twelve days in one corpse, and eight days following death in the second case. During the examination decomposition and putrefaction of the body was noted. Cause of death was drowning in one case and haemorrhages and shock in another. A central incisor tooth was obtained from each body. Both teeth exhibited a pink appearance and the intensity was more pronounced in the cervical region. Although pink teeth can be noted in death due to asphyxia, carbon monoxide poisoning and so on, it is necessary to study the exact role behind the appearance of pink teeth and try to incorporate the finding medico legally. PMID:26005309

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

    PubMed Central

    Haghgoo, Roza; Arfa, Sara; Asgary, Saeed

    2013-01-01

    Introduction: Iatrogenic furcal perforation is a procedural accident in endodontic treatments of primary/permanent teeth; prognosis may be favorable if a complete seal with biomaterial is immediately established. The purpose of this in vitro study was to evaluate microleakage of calcium enriched mixture (CEM) cement and ProRoot mineral trioxide aggregate (MTA) for sealing primary molar furcal perforations. Materials and Methods This study was conducted on 38 extracted human primary molars. Furcation perforations were created in the pulp chamber floor. The teeth were divided randomly in two experimental groups (n=17) and two positive and negative controls (n=2). Perforations were then repaired with biomaterials. After 72 h, the teeth were submerged in 2% fuchsin dye solution for 24h. The samples were sectioned longitudinally and evaluated for dye leakage. Data analyzed statistically using ANOVA test. Results: The negative and positive controls behaved as expected. Dye microleakage was observed in all experimental samples; however, there was no statistically significant difference between the microleakage of MTA (4.411±2.042 mm) and CEM (3.647±1.040 mm) groups (P>0.05). Conclusion: Based on the findings of this in vitro study, CEM and tooth-colored ProRoot MTA have similar sealing ability for furcal perforation repair of primary molar teeth. PMID:24171027

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

    PubMed Central

    Kianimanesh, Nasrin; Shayeghi, Bahareh

    2014-01-01

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

  2. Restoring primary anterior teeth: updated for 2014.

    PubMed

    Waggoner, William F

    2015-01-01

    The purpose of this paper was to review the current literature associated with the techniques and materials for the restoration of primary anterior teeth and make clinical recommendations based upon the available literature. A variety of esthetic restorative materials are available to utilize for restoring primary incisors. Awareness of the specific strengths, weakness, and properties of each material can enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and crowns that are luted onto the tooth and are either some type of stainless steel or zirconia crown. There is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. Operator preferences, esthetic demands by parents, the child's behavior, the amount of tooth structure remaining, and moisture and hemorrhage control are all variables that affect the decision and ultimate outcome of whatever restorative solution is chosen. PMID:25905657

  3. Diagnostic of human teeth using photoacoustic response

    NASA Astrophysics Data System (ADS)

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

    2006-02-01

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

  4. Sterilization of teeth by gamma radiation.

    PubMed

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

    1994-09-01

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

  5. Applying tribology to teeth of hoofed mammals.

    PubMed

    Schulz, Ellen; Calandra, Ivan; Kaiser, Thomas M

    2010-01-01

    Mammals inhabit all types of environments and have evolved chewing systems capable of processing a huge variety of structurally diverse food components. Surface textures of cheek teeth should thus reflect the mechanisms of wear as well as the functional traits involved. We employed surface textures parameters from ISO/DIS 25178 and scale-sensitive fractal analysis (SSFA) to quantify dental wear in herbivorous mammals at the level of an individual wear enamel facet. We evaluated cheek dentitions of two grazing ungulates: the Blue Wildebeest (Connochaetes taurinus) and the Grevy's Zebra (Equus grevyi). Both inhabit the east African grassland savanna habitat, but they belong to fundamentally different taxonomic units. We tested the hypothesis that the foregut fermenting wildebeest and the hindgut fermenting zebra show functional traits in their dentitions that relate to their specific mode of food-composition processing and digestion. In general, surface texture parameters from SSFA as well as ISO/DIS 25178 indicated that individual enamel ridges acting as crushing blades and individual wear facets of upper cheek teeth are significantly different in surface textures in the zebra when compared with the wildebeest. We interpreted the complexity and anisotropy signals to be clearly related to the brittle, dry grass component in the diet of the zebra, unlike the wildebeest, which ingests a more heterogeneous diet including fresh grass and herbs. Thus, SSFA and ISO parameters allow distinctions within the subtle dietary strategies that evolved in herbivorous ungulates with fundamentally different systematic affinities but which exploit a similar dietary niche. PMID:20949615

  6. Periodic permanent magnet focused klystron

    DOEpatents

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  7. Vitreoretinal aspects of permanent keratoprosthesis.

    PubMed

    Klufas, Michael A; Yannuzzi, Nicolas A; D'Amico, Donald J; Kiss, Szilárd

    2015-01-01

    Permanent keratoprosthesis (KPro) is a treatment option in patients with severe corneal disease not amenable to traditional penetrating keratoplasty. There are several types of permanent keratoprostheses available for use worldwide, including the Boston KPro, osteo-odonto KPro, and AlphaCor, among others. A multidisciplinary team of cornea, glaucoma, and vitreoretinal specialists is necessary to ensure proper patient selection, preoperative planning, keratoprosthesis placement, postoperative monitoring and management of complications. We provide a comprehensive review of the vitreoretinal aspects of permanent keratoprostheses. PMID:25890625

  8. Ghost teeth: Regional odontodysplasia of maxillary first molar associated with eruption disorders in a 10-year-old girl

    PubMed Central

    Mathew, Anju; Dauravu, Liju Mercley; Reddy, S. N.; Kumar, K. Retna; Venkataramana, V.

    2015-01-01

    Regional odontodysplasia (RO) is an uncommon, developmental anomaly of the dental hard tissues that affects ectodermal and mesodermal dental components with characteristic clinical and radiographic findings. Clinically, RO affects a particular segment in either or both dentitions in the maxilla or mandible or both jaws. Radiographic features have consistently demonstrated thin and defective layers of enamel and dentine, resulting in a faint, fuzzy outline, creating a ghost-like appearance. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. A case of RO in a 10-year-old girl whose chief complaint were forwardly placed upper front teeth and the absence of eruption of permanent teeth. Clinical and radiographic features are described. PMID:26538974

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

    PubMed Central

    2012-01-01

    Introduction Cleidocranial dysplasia is a rare congenital defect of autosomal dominant inheritance caused by mutations in the Cbfa1 gene, also called Runx2, located on the short arm of chromosome 6. It primarily affects bones which undergo intramembranous ossification. This condition is of clinical significance to dentistry due to the involvement of the facial bones, altered eruption patterns and multiple supernumerary teeth. Case presentation Our patient, a 15-year-old Indian girl, presented with the typical features of prolonged retention of deciduous dentition and delayed eruption of permanent teeth, that is, mandibular prognathism along with other skeletal abnormalities like shrugged shoulder and the absence of clavicles. A multidisciplinary approach was followed, comprising orthodontic, surgical and pedodontic teams for management. Conclusion Successful treatment of such a case lies in a holistic approach that takes care of all aspects, including the primary pathology, the deformity itself and even the psychological angle. PMID:22260259

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

    PubMed Central

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

    2013-01-01

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

  11. [Bovine spongiform encephalopathy].

    PubMed

    Surez Fernndez, G

    2001-01-01

    An histrical and conceptual review is made about Bovine Spongiform Encephalopathy or mad cows disease and an epidemiological analysis as a present and future health problem. This analysis of BSE should not be negative, considering the truths that we know today. PMID:11783042

  12. DIAGNOSIS OF BOVINE NEOSPOROSIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Bovine Spongiform Encephalopathy

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Bovine Spongiform Encephalopathy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine spongiform encephalopathy (BSE), also referred to as mad cow disease is a chronic, non-febrile, neuro-degenerative disease affecting the central nervous system. The transmissible spongiform encephalopathies (TSEs) of domestic animals, of which BSE is a member includes scrapie of sheep...

  15. BOVINE VIRAL DIARRHEA VIRUSES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine viral diarrhea virus (BVDV) is an umbrella term for two species of viruses, BVDV1 and BVDV2, within the Pestivirus genus of the Flavivirus family. BVDV viruses are further subclassified as cytopathic and noncytopathic based on their activity in cultured epithelial cells. Noncytopathic BVDV p...

  16. Bovine milk exosome proteome

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. Protein Crystal Bovine Insulin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    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.

  18. Genotyping bovine coronaviruses.

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. Genetics Home Reference: Permanent neonatal diabetes mellitus

    MedlinePLUS

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

  20. Root resorption of primary molars without successor teeth. An experimental study in the beagle dog.

    PubMed

    Lin, Bi-Chen; Zhao, Yu-Ming; Yang, Jie; Ge, Li-Hong

    2012-04-01

    Tooth agenesis is a common craniofacial congenital malformation in humans, but little is known about the mechanisms of root resorption in this condition. The purpose of this study was to investigate the mechanisms of root resorption in primary molars without successors. An animal model without permanent tooth germs was established by surgery in beagles. The times of onset of primary molar root resorption, with and without successors, were compared. The distribution of immune cells, odontoclasts, and their activating factors were determined by histochemistry and immunohistochemistry. Root resorption of primary mandibular molars without successors began later than physiological resorption. In primary molars without permanent germs, odontoclasts and immune cells were present mainly in the apical pulp at the start of root resorption, whereas in control teeth receptor activator of nuclear factor-?B ligand (RANKL)-positive cells were found mainly in the region of the periodontal ligament. CD14(+) and CD3(+) cells were found in both the pulp and the periodontal ligament region. These results suggest that the dental pulp of primary molars, as well as immune cells, may play an important role in root resorption in primary molars without permanent tooth germs. PMID:22409221

  1. Storage media for avulsed teeth: a literature review.

    PubMed

    Poi, Wilson Roberto; Sonoda, Celso Koogi; Martins, Christine Men; Melo, Moriel Evangelista; Pellizzer, Eduardo Pizza; de Mendona, Marcos Rogrio; Panzarini, Snia Regina

    2013-01-01

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

  2. Smooth Teeth: Why Multipoles Are Perfect Gears

    NASA Astrophysics Data System (ADS)

    Schnke, Johannes

    2015-12-01

    A type of gear is proposed based on the interaction of individual multipoles. The underlying principle relies on previously unknown continuous degenerate ground states for pairs of interacting multipoles which are free to rotate around specific axes. These special rotation axes, in turn, form a one-parameter family of possible configurations. This allows for the construction of magnetic bevel gears with any desired inclination angle between the in- and output axes. Further, the design of gear systems with more than two multipoles is possible and facilitates tailored applications. Ultimately, an analogy between multipoles and mechanical gears is revealed. In contrast to the mechanical case, the multipole "teeth" mesh smoothly. As an illustrative application, the example of a quadrupole-dipole interaction is then used to construct a 1 ?2 gear ratio.

  3. Mammal teeth from the Cretaceous of Africa.

    PubMed

    Jacobs, L L; Congleton, J D; Brunet, M; Dejax, J; Flynn, L J; Hell, J V; Mouchelin, G

    1988-11-10

    We report here the discovery of two mammal teeth from the early Cretaceous of Cameroon. These, and some jaw fragments, all from Cameroon, are the only fossil evidence of mammalian evolution from Africa between late Jurassic and Paleocene, a span of at least 85 million years. A triangular upper tooth lacks the principal internal cusp of marsupials and placentals and is therefore of a similar evolutionary grade to most Jurassic and early Cretaceous therian mammals, but more primitive than the metatherian-eutherian grade. Early Cretaceous, or older, therian mammals are now known from all southern continents except Antarctica. The new find from Cameroon is consistent with the hypothesis that marsupials, the dominant living mammals of South America and Australia, were not present on any Gondwana continents until after the early Cretaceous separation of Africa by the opening of the South Atlantic. PMID:3054565

  4. Facial lesions in piglets with intact or grinded teeth

    PubMed Central

    2012-01-01

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

  5. Improvement in properties of plastic teeth by electron beam irradiation

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

    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.

  6. [Clinical anatomy of the horse: teeth and dentition].

    PubMed

    Staszyk, C

    2015-12-01

    The routine inspection of the equine oral cavity allows a numerical assessment of the teeth and provides information about positional changes within the dentition. By use of appropriate dental equipment, the occlusal surfaces of all teeth can be inspected and diagnosed. However, neither the teeth nor their occlusal surfaces are constant structures. Instead, equine teeth and, in particular, their occlusal surfaces are subjected to continuous morphological and positional changes due to the effects of aging and the equine-specific high amount of occlusal wear. Therefore, it is mandatory to define anatomical criteria, which allow us to distinguish between anatomical variations and pathological conditions. Moreover, an unambiguous nomenclature with regard to the equine-specific dental anatomy is essential. This article provides a tutorial overview of the equine dental anatomy as well as recent findings in the field of equine dentistry. Special attention is paid to dynamic changes within both individual teeth and dentition. PMID:26603675

  7. A double-sided linear primary permanent magnet vernier machine.

    PubMed

    Du, Yi; Zou, Chunhua; Liu, Xianxing

    2015-01-01

    The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed. PMID:25874250

  8. A Double-Sided Linear Primary Permanent Magnet Vernier Machine

    PubMed Central

    2015-01-01

    The purpose of this paper is to present a new double-sided linear primary permanent magnet (PM) vernier (DSLPPMV) machine, which can offer high thrust force, low detent force, and improved power factor. Both PMs and windings of the proposed machine are on the short translator, while the long stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. The key of this new machine is the introduction of double stator and the elimination of translator yoke, so that the inductance and the volume of the machine can be reduced. Hence, the proposed machine offers improved power factor and thrust force density. The electromagnetic performances of the proposed machine are analyzed including flux, no-load EMF, thrust force density, and inductance. Based on using the finite element analysis, the characteristics and performances of the proposed machine are assessed. PMID:25874250

  9. Torque Characteristics of Saturated Permanent-Magnet Synchronous Motors

    NASA Astrophysics Data System (ADS)

    Takahashi, Akeshi; Kikuchi, Satoshi; Wakui, Shinichi; Mikami, Hiroyuki; Ide, Kazumasa; Shima, Kazuo

    The evaluation of torque characteristics in a saturated magnetic field for permanent-magnet (PM) synchronous motors is presented. The torque saturation characteristics of non-salient and salient pole machines are investigated by finite element analysis and measurement. Thus, it is found that the torque saturation originates in the magnetic saturation in both the stator teeth, which are located on the leading position toward the direct axis, and in the stator back yoke, which is located on the lagging position toward the direct axis. This mechanism can also explain the reason for the significant torque saturation in the salient-pole machine; the higher inductance of the quadrature axis of the salient-pole machine causes a significant magnetic saturation in the stator back yoke. Therefore, less saliency or a wider back yoke can improve the torque saturation.

  10. Accessing Developmental Information of Fossil Hominin Teeth Using New Synchrotron Microtomography-Based Visualization Techniques of Dental Surfaces and Interfaces

    PubMed Central

    Le Cabec, Adeline; Tang, Nancy; Tafforeau, Paul

    2015-01-01

    Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine) and matching of stress patterns (internal accentuated lines and hypoplasias) are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands). Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ) were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong’s algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual’s dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were found to form over a rather surprisingly long time (> 4.5 years). This approach provides tools for maximizing the recovery of developmental information in teeth, especially in the most difficult cases. PMID:25901602

  11. Effect of Er:YAG Laser on Shear Bond Strength of Composite to Enamel and Dentin of Primary Teeth

    PubMed Central

    Bahrololoomi, Zahra; Kabudan, Mona; Gholami, Leila

    2015-01-01

    Objectives: Bond strength of composite resin to enamel and dentin of primary teeth is lower than that to permanent teeth; therefore, it may compromise the adhesive bonding. New methods, such as laser application have been recently introduced for tooth preparation. The purpose of this study was to evaluate the effect of tooth preparation with bur and Er:YAG laser on shear bond strength of composite to enamel and dentin of primary teeth. Materials and Methods: Seventy-five primary molar teeth were collected and 150 specimens were obtained by mesiodistal sectioning of each tooth. In each of the enamel and dentin groups, the teeth were randomly assigned to 3 subgroups with the following preparations: bur preparation + etching (37% H3PO4), laser preparation + etching, and laser preparation without etching. Single Bond adhesive and Z250 composite were applied to all samples. After thermocycling, the shear bond strength testing was preformed using the Instron Testing Machine. Data were analysed using SPSS-17 and two-way ANOVA. Results: The bond strength of enamel specimens was significantly higher than that of dentin specimens, except for the laser-non-etched groups. The enamel and dentin laser-non-etched groups had no significant difference in bond strength. In both enamel and dentin groups, bur preparation + etching yielded the highest bond strength, followed by laser preparation + etching, and the laser preparation without etching yielded the lowest bond strength (P < 0.001). Conclusion: In both enamel and dentin groups, laser preparation caused lower shear bond strength compared to bur preparation. PMID:26622267

  12. Oral anomalies associated with the oculocerebrorenal syndrome of Lowe: case report with multiple unerupted teeth and pericoronal radiolucencies.

    PubMed

    Brooks, John K; Ahmad, Rizwan

    2009-03-01

    The oculocerebrorenal syndrome of Lowe (OCRL) is a rare X-linked recessive disorder, chiefly characterized by ocular involvement, mental retardation, and kidney disease. A literature review is provided, detailing the diversity of oral anomalies associated with the OCRL syndrome. Reported abnormalities include delayed tooth eruption, odontogenic cyst formation, and constricted dental arches. In addition, we present an unusual case of an 18-year-old male affected with the OCRL syndrome and fetal alcohol syndrome. The oral radiographic examination was significant for multiple impacted permanent teeth, many with pericoronal radiolucencies, and an underdeveloped mandible. PMID:19217010

  13. The ins and outs of the evolutionary origin of teeth.

    PubMed

    Donoghue, Philip C J; Rcklin, Martin

    2016-01-01

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

  14. The Windowed Removable Partial Denture: A Treatment Option for Patients with Lone-Standing Teeth.

    PubMed

    Jum'ah, Ahmad A; Haite, Terence; Nattress, Brian

    2015-03-01

    The decision as to whether to retain or extract a single remaining natural tooth prior to the provision of dentures can be a difficult one. If the tooth is left in situ, the development of an adequate peripheral seal around the denture is not possible thereby compromising the appliance' retention. If the tooth is extracted the possibility of gaining direct retention with the use of clasps or attachments is lost. This paper aims to illustrate the use of windowed removable partial denture design and review the literature relevant to this area. The use of such a design can enhance the retention of the appliance by encircling the lone standing tooth/teeth utilising an elastomeric permanent soft lining material. PMID:26415337

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

    USGS Publications Warehouse

    French, John R. P., III

    1997-01-01

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

  16. Alternative treatment modalities for immature intruded permanent incisors: report of 2 cases.

    PubMed

    Gondim, Juliana Oliveira; Diniz, Michele Baffi; de Abreu-e-Lima, Fbio Cesar Braga; Pansani, Cyneu Aguiar; Moreira Neto, Jos Jeov Siebra

    2009-01-01

    Intrusion of permanent teeth is one of the most severe types of traumatic injuries. Different treatment strategies have been proposed, and the best approach for each case depends on the stage of root development, severity of the intrusive luxation, presence of alveolar fracture and number of intruded teeth. The purpose of this paper is to describe the treatment management of 2 cases of severely intruded immature permanent maxillary central incisors in 7 1/2- and 8-year-old children. In case 1, the traumatized tooth was treated by surgical repositioning, while in case 2 watchful waiting for spontaneous re-eruption was the treatment of choice. Treatment strategies were successful in both cases, as demonstrated by the continuation of root development, maintenance of pulp vitality, and absence of signs of periapical pathosis during the follow-up period. Regardless of the treatment strategy traumatically intruded teeth should undergo periodical clinical and radiographic surveillance on a long-term basis to allow early detection of possible complications. PMID:19722445

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

    PubMed

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

    2004-03-01

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

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

    PubMed

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

    2004-06-01

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

  19. Diagnostic imaging in bovine orthopedics.

    PubMed

    Kofler, Johann; Geissbhler, Urs; Steiner, Adrian

    2014-03-01

    Although a radiographic unit is not standard equipment for bovine practitioners in hospital or field situations, ultrasound machines with 7.5-MHz linear transducers have been used in bovine reproduction for many years, and are eminently suitable for evaluation of orthopedic disorders. The goal of this article is to encourage veterinarians to use radiology and ultrasonography for the evaluation of bovine orthopedic disorders. These diagnostic imaging techniques improve the likelihood of a definitive diagnosis in every bovine patient but especially in highly valuable cattle, whose owners demand increasingly more diagnostic and surgical interventions that require high-level specialized techniques. PMID:24534658

  20. Sterilization of extracted human teeth: A comparative analysis

    PubMed Central

    Sandhu, Simarpreet V.; Tiwari, Rajiv; Bhullar, RamanPreet K.; Bansal, Himanta; Bhandari, Rajat; Kakkar, Tushaar; Bhusri, Ridhima

    2012-01-01

    Background Extracted human teeth are regularly used for practice and educational purposes in dental institutions at undergraduate and postgraduate levels. Different materials and methods are used for sterilizing extracted teeth to avoid infection from them. Aims The present study was done to determine the efficacy of some frequently used methods for disinfection/sterilization of extracted human teeth. Materials and methods A total of 120 intact, non-carious teeth extracted due to periodontal or orthodontic purpose were divided randomly into 8 groups consisting of 15 teeth in each group. Agents used for sterilization included 10% formalin, 0.1% thymol in distilled water, 5.25% sodium hypochlorite, 2% glutaraldehyde, 3% hydrogen peroxide, boiled in water (100C), autoclave (121C, 15lbs psi), normal saline. Samples were collected with the help of inoculating loop and then streaked over the surface of Mc-Conkey agar medium and Blood agar medium. The media were then incubated at 37C for 24h. No visible growth in the culture medium was considered as the method of effective sterilization. Results 10% formalin, autoclaving, 5.25% sodium hypochlorite could be efficiently used for sterilization and disinfection of extracted human teeth. Conclusion Extracted teeth should be handled with extreme care as these are potential source of infection and need to be disinfected before they are used in the laboratories. PMID:25737861

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

    PubMed

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

    2009-10-01

    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

  2. A Curriculum Vitae of Teeth: Evolution, Generation, Regeneration

    PubMed Central

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

    2009-01-01

    The ancestor of recent vertebrate teeth was a tooth-like structure on the outer body surface of jawless fishes. Over the course of 500,000,000 years of evolution, many of those structures migrated into the mouth cavity. In addition, the total number of teeth per dentition generally decreased and teeth morphological complexity increased. Teeth form mainly on the jaws within the mouth cavity through mutual, delicate interactions between dental epithelium and oral ectomesenchyme. These interactions involve spatially restricted expression of several, teeth-related genes and the secretion of various transcription and signaling factors. Congenital disturbances in tooth formation, acquired dental diseases and odontogenic tumors affect millions of people and rank human oral pathology as the second most frequent clinical problem. On the basis of substantial experimental evidence and advances in bioengineering, many scientists strongly believe that a deep knowledge of the evolutionary relationships and the cellular and molecular mechanisms regulating the morphogenesis of a given tooth in its natural position, in vivo, will be useful in the near future to prevent and treat teeth pathologies and malformations and for in vitro and in vivo teeth tissue regeneration. PMID:19266065

  3. Lodestone: Nature's own permanent magnet

    NASA Technical Reports Server (NTRS)

    Wasilewski, P.

    1976-01-01

    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.

  4. Overeruption of teeth opposing removable partial dentures: a preliminary study.

    PubMed

    Matsuda, Ken-Ichi; Miyashita, Yuji; Ikebe, Kazunori; Enoki, Kaori; Kurushima, Yuko; Mihara, Yusuke; Maeda, Yoshinobu

    2014-01-01

    One of the purposes of prosthodontic treatment is to prevent overeruption of opposing teeth, but there is currently minimal literature describing the efficacy of removable partial dentures (RPDs) in performing this function. This study investigated overeruption following RPD treatment. The study participants were 33 patients treated with RPDs, and overeruption was evaluated by comparing the surface computeraided design data of dental casts made at two different time points-before and after RPD treatment. Overeruption was observed in 38.1% of teeth opposed by the RPD, which was much less than the proportion of teeth that overerupted when not opposed by the RPD. PMID:25191893

  5. A novel double-sided flux-switching permanent magnet linear motor

    NASA Astrophysics Data System (ADS)

    Xiao, Feng; Du, Yi; Sun, Yuxin; Zhu, Huangqiu; Zhao, Wenxiang; Li, Wenlong; Ching, T. W.; Qiu, Chun

    2015-05-01

    This paper proposes a novel double-sided flux-switching permanent magnet (PM) linear (DS-FSPML) motor which is suitable for low speed and high thrust force applications. In order to balance the normal force, the motor adopts double-sided arrangement in which the mover is sandwiched between two stators. The mover teeth alternately located on both sides of the mover are composed of laminated iron core segments between which the axially magnetized PMs of alternate polarity are inserted. Similar to conventional flux-switching PM (FSPM) motor, the 3-phase concentrated windings are employed. And the stator is designed as a double-sided simple iron core with salient teeth so that it is very robust to transmit high thrust force. By using the finite element method, the characteristics and performances of the proposed motor are analyzed and compared with the conventional single-sided FSPM linear motor.

  6. Control of the illegal use of clenbuterol in bovine production.

    PubMed

    Cristino, Assuno; Ramos, Fernando; da Silveira, Maria Irene Noronha

    2003-06-01

    This study is based on a plan of collecting different matrices (hair, eye, muscle, liver and kidney) in order to define a strategy for the control of the illegal use of clenbuterol in bovine production. Of all matrices utilised, hair is recommended for the analytical control of clenbuterol in living animals, due to its being permanently available and easy to collect. The eye, or rather the retina, is the matrix which gives the most trustworthy result, after the animal slaughter, and the one that best helps in the determination of the illegal use of clenbuterol in a perspective of gradual food safety improvement. PMID:12763540

  7. Magnetic Fields: Visible and Permanent.

    ERIC Educational Resources Information Center

    Winkeljohn, Dorothy R.; Earl, Robert D.

    1983-01-01

    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)

  8. Frictionless Bearing Uses Permanent Magnets

    NASA Technical Reports Server (NTRS)

    1965-01-01

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

  9. Microfilm Permanence and Archival Quality

    ERIC Educational Resources Information Center

    Avedon, Don M.

    1972-01-01

    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)

  10. Age estimation in children by measurement of open apices in teeth with Bayesian calibration approach.

    PubMed

    Cameriere, R; Pacifici, A; Pacifici, L; Polimeni, A; Federici, F; Cingolani, M; Ferrante, L

    2016-01-01

    Age estimation from teeth by radiological analysis, in both children and adolescents, has wide applications in several scientific and forensic fields. In 2006, Cameriere et al. proposed a regression method to estimate chronological age in children, according to measurements of open apices of permanent teeth. Although several regression models are used to analyze the relationship between age and dental development, one serious limitation is the unavoidable bias in age estimation when regression models are used. The aim of this paper is to develop a full Bayesian calibration method for age estimation in children according to the sum of open apices, S, of the seven left permanent mandibular teeth. This cross-sectional study included 2630 orthopantomographs (OPGs) from healthy living Italian subjects, aged between 4 and 17 years and with no obvious developmental abnormalities. All radiographs were in digital format and were processed by the ImageJ computer-aided drawing program. The distance between the inner side of the open apex was measured for each tooth. Dental maturity was then evaluated according to the sum of normalized open apices (S). Intra- and inter-observer agreement was satisfactory, according to an intra-class correlation coefficient of S on 50 randomly selected OPGs. Mean absolute errors were 0.72 years (standard deviation 0.60) and 0.73 years (standard deviation 0.61) in boys and girls, respectively. The mean interquartile range (MIQR) of the calibrating distribution was 1.37 years (standard deviation 0.46) and 1.51 years (standard deviation 0.52) in boys and girls, respectively. Estimate bias was ?ERR=-0.005 and 0.003 for boys and girls, corresponding to a bias of a few days for all individuals in the sample. Neither of the ?ERR values was significantly different from 0 (p>0.682). In conclusion, the Bayesian calibration method overcomes problems of bias in age estimation when regression models are used, and appears to be suitable for assessing both age and age distribution in children according to tooth maturity. PMID:26650061

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

    PubMed

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

    2010-01-01

    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

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

    PubMed Central

    Yildiz, Gul; Celik, Esra Uzer

    2013-01-01

    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. PMID:24932129

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

    PubMed

    Dominguez-Rodriguez, Maria Victoria

    2011-01-01

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

  14. Computerized 3-D reconstruction of two "double teeth".

    PubMed

    Lyroudia, K; Mikrogeorgis, G; Nikopoulos, N; Samakovitis, G; Molyvdas, I; Pitas, I

    1997-10-01

    "Double teeth" is a root malformation in the dentition and the purpose of this study was to reconstruct three-dimensionally the external and internal morphology of two "double teeth". The first set of "double teeth" was formed by the conjunction of a mandibular molar and a premolar, and the second by a conjunction of a maxillary molar and a supernumerary tooth. The process of 3-D reconstruction included serial cross-sectioning, photographs of the sections, digitization of the photographs, extraction of the boundaries of interest for each section, surface representation using triangulation and, finally, surface rendering using photorealistic effects. The resulting three-dimensional representations of the two teeth helped us visualize their external and internal anatomy. The results showed: a) in the first case, fusion of the radical and coronal dentin, as well as fusion of the pulp chambers; and b) in the second case, fusion only of the radical dentin and the pulp chambers. PMID:9550051

  15. A Review on Vital Pulp Therapy in Primary Teeth

    PubMed Central

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

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

  16. Secondhand Smoke in Infancy May Harm Kids' Teeth

    MedlinePLUS

    ... html Secondhand Smoke in Infancy May Harm Kids' Teeth Exposure increased risk of cavities, researchers report To ... University who is a spokesman for the American Dental Association, said evidence of a link between exposure ...

  17. Lead concentrations in white-tailed deer mandibles and teeth

    SciTech Connect

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

    1982-05-01

    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)

  18. Multiple teeth fractures in dentinogenesis imperfecta: a case report.

    PubMed

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

    2014-01-01

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

  19. Comparative investigation of the traumatic injuries' prevalence of primary and permanent incisors at children aged 3 to 14.

    PubMed

    Belcheva, Anni B; Ilieva, Emilia L; Veleganova, Vania Kr

    2003-01-01

    Traumatic injures distribution of children's teeth is determined of different factors at different ages: beginning to walk, games, sport, orthodontic anomalies. The aim of this investigation is to compare tooth traumatic injures distribution of temporary and permanent incisors at children aged 3 to 14. Object of investigation are 1825 children aged 3 to 14 from the town of Plovdiv. A clinical dental examination has been carried out and had been registrated: expulsio dentis, fractura coronae dentis involving only the enamel, involving and the dentin, exposing the pulp. There also has been pointed out if the fracture is treated or not. The data received has been statistically processed. The results show that tooth traumatic injures distribution at primary teeth is 31-40 per cent of boys and 16-30 per cent of girls and at permanent teeth is 12-33 per cent of boys and 4-19 per cent of girls. There is a statistical significance of differences between tooth traumatic injures of primary and permanent incisors. PMID:12943058

  20. Permanent GPS Network Project In Latvia

    NASA Astrophysics Data System (ADS)

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

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

  1. Accuracy of three-dimensional printing for manufacturing replica teeth

    PubMed Central

    Lee, Keun-Young; Cho, Jin-Woo; Chang, Na-Young; Chae, Jong-Moon; Kang, Kyung-Hwa; Kim, Sang-Cheol

    2015-01-01

    Objective Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Methods Fifty extracted molar teeth were selected as samples. They were scanned to generate high-resolution 3D surface model stereolithography files. These files were converted into physical models using two types of 3D printing technologies: Fused deposition modeling (FDM) and PolyJet technology. All replica teeth were scanned and 3D images generated. Computer software compared the replica teeth to the original teeth with linear measurements, volumetric measurements, and mean deviation measurements with best-fit alignment. Paired t-tests were used to statistically analyze the measurements. Results Most measurements of teeth formed using FDM tended to be slightly smaller, while those of the PolyJet replicas tended to be slightly larger, than those of the extracted teeth. Mean deviation measurements with best-fit alignment of FDM and PolyJet group were 0.047 mm and 0.038 mm, respectively. Although there were statistically significant differences, they were regarded as clinically insignificant. Conclusions This study confirms that FDM and PolyJet technologies are accurate enough to be usable in orthodontic diagnosis and treatment. PMID:26445716

  2. A computer aided design procedure for generating gear teeth

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

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

    PubMed Central

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

    2014-01-01

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

  4. Bleaching effect of ozone on pigmented teeth

    PubMed Central

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

    2015-01-01

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

  5. New insights into the complex architecture of siliceous copepod teeth.

    PubMed

    Michels, Jan; Vogt, Jrgen; Simon, Paul; Gorb, Stanislav N

    2015-06-01

    Copepods belong to the dominant marine zooplankton taxa and play an important role in particle and energy fluxes of the marine water column. Their mandibular gnathobases possess tooth-like structures, so-called teeth. In species feeding on large proportions of diatoms these teeth often contain silica, which is very probably the result of a coevolution with the siliceous diatom frustules. Detailed knowledge of the morphology and composition of the siliceous teeth is essential for understanding their functioning and their significance in the context of feeding interactions between copepods and diatoms. Based on analyses of the gnathobases of the Antarctic copepod Rhincalanus gigas, the present study clearly shows, for the first time, that the silica in the siliceous teeth features large proportions of crystalline silica that is consistent with the mineral ?-cristobalite and is doped with aluminium. The siliceous structures have internal chitinous fibre networks, which are assumed to serve as scaffolds during the silicification process. The compact siliceous teeth of R. gigas are accompanied by structures with large proportions of the elastic protein resilin, likely reducing the mechanical damage of the teeth when the copepods feed on diatoms with very stable frustules. The results indicate that the coevolution with diatom frustules has resulted in gnathobases exhibiting highly sophisticated composite structures. PMID:25622509

  6. Antioxidant therapy enhances pulpal healing in bleached teeth

    PubMed Central

    Lima, Adriano Fonseca; Marques, Marcelo Rocha; Soares, Diana Gabriela; Hebling, Josimeri; Marchi, Giselle Maria

    2016-01-01

    Objectives The purpose of this study was to evaluate the histopathological effects of an antioxidant therapy on the pulp tissue of rat teeth exposed to a bleaching gel with 35% hydrogen peroxide. Materials and Methods Forty rats were subjected to oral ingestion by gavage of distilled water (DW) or ascorbic acid (AA) 90 min before the bleaching therapy. For the bleaching treatment, the agent was applied twice for 5 min each to buccal surfaces of the first right mandibular molars. Then, the animals were sacrificed at 6 hr, 24 hr, 3 day, or 7 day post-bleaching, and the teeth were processed for microscopic evaluation of the pulp tissue. Results At 6 hr, the pulp tissue showed moderate inflammatory reactions in all teeth of both groups. In the DW and AA groups, 100% and 80% of teeth exhibited pulp tissue with significant necrosis and intense tissue disorganization, respectively. At 24 hr, the AA-treated group demonstrated a greater regenerative capability than the DW group, with less intense inflammatory reaction and new odontoblast layer formation in 60% of the teeth. For up to the 7 day period, the areas of pulpal necrosis were replaced by viable connective tissue, and the dentin was underlined by differentiated odontoblast-like cells in most teeth of both groups. Conclusions A slight reduction in initial pulpal damage during post-bleaching was promoted by AA therapy. However, the pulp tissue of AA-treated animals featured faster regenerative potential over time. PMID:26877990

  7. Characteristics of 351 supernumerary molar teeth In Turkish population

    PubMed Central

    Kara, Muhammed ?.; Ay, Sinan; Bereket, Cihan; ?ener, ?smail; Blbl, Mehmet; Ezirganl?, ?eref; Polat, Hidayet B.

    2012-01-01

    Objective: The aim of the present study was to evaluate the demographic profile of supernumerary molar (SM) teeth in people in various regions of Turkey. Study Design: A retrospective analysis was carried out on an initial sample of 104,902 subjects drawn from the ortopantographics files from 10 clinics in 7 Turkish cities with documentation of demographic data, the presence of SM teeth, their location, eruption, morphology, and position within the arch. In one region associated pathologies and treatments were also evaluated. Results: Three hundred fifty-one SMs were detected in 288 patients, constituting 0.33% of the study subjects, with a greater frequency in females (56.4%). SMs were found more frequently in the maxilla (87.7%) than in the mandible, and distomolars (62.9%) were more common than paramolars. The SMs encountered were mostly of conical shape (45.7%), impacted (81.1%), and in a vertical position (52.1). The 33% of SM teeth were related to impacted molar teeth. Conclusion: The most common complication involving these teeth was soft tissue irritation. Demographic data from such specific extensive studies are crucial for improved diagnosis of SM teeth. Early detection allows for measures against complications and more successful therapy. Key words:Supernumerary molars, distomolar, paramolar, prevalence. PMID:22143736

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

    PubMed Central

    Jordana, Xavier; Marn-Moratalla, Nekane; Moncunill-Sol, Blanca; Bover, Pere; Alcover, Josep Antoni; Khler, Meike

    2013-01-01

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

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

    PubMed

    Jordana, Xavier; Marn-Moratalla, Nekane; Moncunill-Sol, Blanca; Bover, Pere; Alcover, Josep Antoni; Khler, Meike

    2013-01-01

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

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

    PubMed

    Sciulli, P W

    1979-05-01

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

  11. Spectrophotometric color evaluation of permanent incisors, canines and molars. A cross-sectional clinical study

    PubMed Central

    POP-CIUTRILA, IOANA-SOFIA; COLOSI, HORATIU ALEXANDRU; DUDEA, DIANA; BADEA, MANDRA EUGENIA

    2015-01-01

    Background and aims An accurate color reproduction represents the final validation level of an esthetic anterior or posterior restoration. The aim of this study was to evaluate the color of permanent maxillary incisors, canines and molars, using a clinical spectrophotometer. Methods The Vita Easyshade Advance 4.0® intraoral spectrophotometer was used by one clinician to determine the color of 369 permanent maxillary incisors, canines and molars. The best matches to Vitapan Classical® and 3D-Master® shade guides were recorded. A one-way analysis of variance and Kruskal-Wallis test were used to compare L*, a*, b*, c* and h* color coordinates among the 3 types of teeth. Differences between the mean values of all color coordinates were evaluated by use of Bonferroni corrections. Color difference (ΔE*) between incisors, canines and molars was calculated from ΔL*, Δa* and Δb* data and the results were compared to ΔE*=3.3 acceptability threshold. Results Except for Δa* and Δh* between canines and molars, statistically significant differences among the mean differences of all color coordinates were found when the 3 types of teeth were compared by pairs. The most frequently measured shades were A1 (48.4%), respectively 1M1 (31.5%) for incisors, B3 (36.6%), respectively 2M3 (39.8%) for canines and B3 (44.7%), respectively 2M3 (52%) for molars. Incisors had the highest lightness values, followed by canines and molars. Molars were the most chromatic with the highest a* and b* values. Conclusions Despite the limitations of this study, color differences among incisors, canines and molars were found to be statistically significant, above the clinical acceptability threshold established. In conclusion, successful esthetic restorations of permanent teeth of the same patient need an individual color assessment and reproduction of every type of tooth. PMID:26733753

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

    PubMed

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

    2013-08-01

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

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

    PubMed

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

    2005-01-01

    Tooth replacement poses many questions about development, pattern formation, tooth attachment mechanisms, functional morphology and the evolution of vertebrate dentitions. Although most vertebrate species have polyphyodont dentitions, detailed knowledge of tooth structure and replacement is poor for most groups, particularly actinopterygians. We examined the oral dentition of the bluefish, Pomatomus saltatrix, a pelagic and coastal marine predator, using a sample of 50 individuals. The oral teeth are located on the dentary and premaxillary bones, and we scored each tooth locus in the dentary and premaxillary bones using a four-part functional classification: absent (A), incoming (I), functional (F=fully ankylosed) or eroding (E). The homodont oral teeth of Pomatomus are sharp, deeply socketed and firmly ankylosed to the bone of attachment. Replacement is intraosseus and occurs in alternate tooth loci with long waves of replacement passing from rear to front. The much higher percentage of functional as opposed to eroding teeth suggests that replacement rates are low but that individual teeth are quickly lost once erosion begins. Tooth number increases ontogenetically, ranging from 15-31 dentary teeth and 15-39 premaxillary teeth in the sample studied. Teeth increase in size with every replacement cycle. Remodeling of the attachment bone occurs continuously to accommodate growth. New tooth germs originate from a discontinuous dental lamina and migrate from the lingual (dentary) or labial (premaxillary) epithelium through pores in the bone of attachment into the resorption spaces beneath the existing teeth. Pomatomus shares unique aspects of tooth replacement with barracudas and other scombroids and this supports the interpretation that Pomatomus is more closely related to scombroids than to carangoids. PMID:16351980

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

    PubMed

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

    2015-03-01

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

  15. Permanently calibrated interpolating time counter

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  16. Trans-permanent magnetic actuation

    NASA Astrophysics Data System (ADS)

    Farmer, Daniel Jay

    The demands for an actuator to deploy, position and shape large spaced-based structures form a unique set of design criteria. In many applications it is desirable to hold displacements or forces between two points to within specified requirements (the regulation problem) and to periodically to change position (the tracking problem). Furthermore, the interest generally lies in satisfying the dynamic performance requirements while expending minimal power, while meeting tight tolerances and while experiencing little wear and fatigue. The actuator must also be able to withstand a variety of operational conditions such as impacts and thermal changes over an extended period of time. Current trends in large-scale structures have addressed the demands by using conventional actuators and motors, along with elaborate linkages or mechanisms to shape, position, protect and deploy. The developed designs use unique characteristics of permanent magnets to create simple direct-acting actuators and motors very suitable for space based structures. The developed trans-permanent magnetic (T-PM) actuators and motors are systems consisting of one or more permanent magnets, some of whose magnetic strengths can be switched on-board by surrounding pulse-coils. The T-PM actuator and motors expend no power during regulation. The T-PM can periodically change or remove the strength of its own magnets thereby enabling both fine-tune adjustments (microsteps) and large-scale adjustments (rotation). The fine (microstep) adjustments are particularly helpful in thermally varying space environments. The large-scale adjustments (rotation) are particularly helpful in deployment where the structure or antenna must experience large-angle rotations and/or large displacements. T-PM concepts are illustrated in direct acting actuators and built into stepper motor and permanent magnet motor applications. Several examples of design, analysis and testing are developed to verify the technology and supporting equipment. Also discussed is the convergence of technology that has made this technology timely and practical.

  17. Genetics Home Reference: Permanent neonatal diabetes mellitus

    MedlinePLUS

    ... Permanent neonatal diabetes mellitus may be caused by mutations in several genes. About 30 percent of individuals with permanent neonatal diabetes mellitus have mutations in the KCNJ11 gene. An additional 20 percent ...

  18. Effect of Cigarette Smoke on Acrylic Resin Teeth

    PubMed Central

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

    2013-01-01

    Background: The discolouration of artificial teeth, which hampers aesthetics, is one of the negative effects of cigarette smoking. Therefore, the effect of cigarette smoke on the colour stability of commercially available acrylic resin teeth needs to be evaluated for clinical success and to ascertain as to which brand has superior properties. Material and Methods: Three commercially available acrylic teeth were evaluated, after division into Group A (Premadent), Group B (Astra), and Group C (Sanyo- Dent). Selected brands were subdivided as study group and control group. Each set of acrylic resin teeth were stored in artificial saliva at 371C for 24 hours. After 24 hours of immersion, the colour measurement of each tooth (T0) was performed. Second colour measurements were done after 21 days (T21) of exposure to cigarette smoke for study group and after immersion in artificial saliva for control group. All data was statistically analyzed by using Repeated Measures ANOVA and Two-way ANOVA (p<0.05). Results: Group A showed least total colour change on exposure to cigarette smoke, followed by Group B and Group C had the highest total colour change. In control group, after immersion in artificial saliva, a slight increase in total colour change was observed for all groups, which was clinically acceptable. Conclusion: Group A (crosslinked acrylic resin teeth) was more colour stable and more resistant to the discolouration which was caused by cigarette smoke, followed by Group B (crosslinked acrylic resin teeth). Group C (Non-crosslinked acrylic resin teeth) was least colour stable and most susceptible to discolouration which was caused by cigarette smoke. PMID:24179942

  19. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 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 Washington, in the District...

  20. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 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 Washington, in the District...

  1. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 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 Washington, in the District...

  2. Teaching Object Permanence: An Action Research Study

    ERIC Educational Resources Information Center

    Bruce, Susan M.; Vargas, Claudia

    2013-01-01

    "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.…

  3. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  4. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  5. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false 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 Washington, in the District...

  6. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  7. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  8. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  9. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 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 Washington, in the District...

  10. Teaching Object Permanence: An Action Research Study

    ERIC Educational Resources Information Center

    Bruce, Susan M.; Vargas, Claudia

    2013-01-01

    "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.

  11. Bovine thelaziasis in Massachusetts.

    PubMed

    Geden, C J; Stoffolano, J G

    1980-10-01

    A survey for Thelazia sp. in Massachusetts bovines was conducted in 1977-1978. Two species of eyeworms, Thelazia gulosa and T. skrjabini, were recovered from cattle eyes obtained from abattoirs. Of 795 eyes examined 97 (12.2%) were infected with Thelazia sp. Seventy-four eyes were parasitized by T. gulosa and 8 by T. skrjabini alone, with 15 showing mixed infections. Infections were almost entirely subclinical on postmortem examination, however, in one eye a nodule of T. gulosa worms just under the surface of the conjunctiva was associated with extensive lesions and general conjunctivitis. In another instance, a mass of juvenile T. gulosa parasites in the conjunctival sac appeared to have resulted in slight scarification, localized edema and redness. PMID:7193108

  12. Infection of the Bovine Udder with Bovine Herpesvirus

    PubMed Central

    Greig, A. S.; Bannister, G. L.

    1965-01-01

    Infectious bovine rhinotracheitis infectious pustular vulvovaginitis (bovine herpesvirus) grown in tissue culture was used as inoculum in trials to infect the lactating bovine udder. Six experiments were undertaken in which one or more quarters were infused with 1 ml. of tissue culture fluids containing 106 to 107 tissue culture infectious doses (TCID) of virus. In four of the experiments the inoculated quarters showed marked evidence of infection in the form of acute inflammation, swelling, reduced milk secretion and profound changes in the physical appearance of the milk. In each case virus was recovered in high titres in the milk from about the second until the tenth to fifteenth days following exposure. Uninfected quarters remained normal in appearance and virus could not be recovered from the milk. In three of the experiments it was shown that serum and milk antibodies appeared shortly after the disappearance of virus from the milk. One experiment involving two animals showed that about 1000 TCID of virus were required to produce infection. In one experiment a cow having a pre-inoculation serum titre for bovine herpesvirus proved resistant to infection. The experiments indicate that the bovine udder is readily susceptible to bovine herpesvirus in non-immune animals, and that the virus produces an acute, limited infection leading to a temporary disfunction of the gland. It appears that natural invasion of the udder through the teat canal is not readily accomplished by the virus. PMID:14295992

  13. Field capability of dogs to locate individual human teeth.

    PubMed

    Cablk, Mary E; Sagebiel, John C

    2011-07-01

    Avulsed teeth can be difficult if not impossible to recover in the outdoor environment, yet are important for victim identification. This study assessed dog teams as a resource to locate human teeth in a field setting and related performance in training with field capability. Standardized, objective training data were recorded and analyzed followed by double-blind capability trials. In the double-blind trials, 10 teeth were placed in each of six (10 m(2)) plots. Search time per plot ranged from 27 to 50 min, and the proportion of teeth found by the teams varied between 0.20 and 0.79. Using 0.45 m as a distance criterion for a "find," the proportion of false positives ranged between 0.07 and 0.75. Results show that dog teams are capable of recovering individual human teeth in the field setting with high precision although capability varies. Training records support a team's expected field performance. Additional studies are needed. PMID:21554306

  14. Near-IR imaging of cracks in teeth

    PubMed Central

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

    2014-01-01

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

  15. Radiographic assessment of impacted teeth and associated pathosis prevalence

    PubMed Central

    El-Khateeb, Sara M.; Arnout, Eman A.; Hifnawy, Tamer

    2015-01-01

    Objectives: To assess the prevalence of both impaction and associated pathosis in a Saudi population in Al-Madinah, Saudi Arabia based on digital panoramic radiographs. Methods: This study was carried out from December 2013 to February 2015. Panoramic radiographs of 359 male patients attending the Oral Diagnosis Clinics, Faculty of Dentistry, Taibah University, Al-Madinah, Saudi Arabia were reviewed. All images were evaluated to determine the prevalence and pattern of impacted third molars and canines, and associated pathosis. Results: Among 359 panoramic radiographs examined, 124 patients had impacted teeth. The impacted mandibular third molars were the most prevalent impacted teeth, 77.6% had class II pattern of impaction. Among the impacted maxillary canines, 75% were mesioangular and among 66 impacted maxillary third molars, 63.6% had class C. Our study showed that 5.8% of Saudi patients had 3 or more impacted teeth, 13.1% had 2 impacted teeth, and 15.6% had one impacted tooth. Associated pathosis was found in 18.2% among impacted maxillary third molars, and 31.5% among impacted mandibular third molars. The incidence of impaction decreases with age. Conclusion: The prevalence and pattern of impacted third molars among Saudis are almost similar to other racial populations. The number of missing wisdom increases with age. Although the percentage of pathosis associated with impaction was considerably low, it is essential to carry you regular oral examinations to preserve asymptomatic impacted teeth in good health. PMID:26219449

  16. Periodontal regeneration of transplanted rat teeth subcutaneously after cryopreservation.

    PubMed

    Izumi, N; Yoshizawa, M; Ono, Y; Kobayashi, T; Hamamoto, Y; Saito, C

    2007-09-01

    The periodontal regeneration of transplanted teeth after cryopreservation in liquid nitrogen overnight was previously examined using an animal model. The results showed that overnight cryopreservation did not have any severe adverse effects on periodontal healing. For clinical application, it is necessary to make the period of storage longer than in the preliminary study. In this study, the regeneration of periodontal tissues after cryopreservation for 4 weeks was examined. The maxillary molars of 4-week-old Wistar rats were extracted and transplanted into the abdominal subcutaneous tissue either immediately or after cryopreservation in a deep freezer at -80 degrees C. The donor teeth were frozen in a rate-controlling freezer. At 1, 2 and 4 weeks after transplantation, they were excised and observed under light microscopy. The cryopreserved teeth had acellular cementum with a rough surface at 1 week. With an increase in cementoblasts and the appearance of periodontal ligament and alveolar bone, the surface had become smooth at 2 weeks. There was no progressive root resorption. Although the process took somewhat more time, the teeth cryopreserved for 4 weeks showed regeneration that was similar to that of the immediately transplanted teeth. PMID:17804198

  17. [Effectivity and durability of telescopic dentures on abutment teeth].

    PubMed

    van den Wijngaarden, E; van Pelt, A W J; Meisberger, E W; Tams, J; Cune, M S

    2016-03-01

    In a study, the effectivity and durability of telescopic dentures on abutment teeth provided with telescope crowns were investigated. The prognosis for the prosthetic structure and for the abutment teeth were both investigated. The survival rate of 234 telescopic dentures (886 abutment teeth) in 147 patients in a general dental practice were retrospectively evaluated on the basis of a status study. The mean survival rate was calculated. This is the moment when 50% of the telescopic dentures had failed. For telescopic dentures in the maxilla, this was 22.3 ± 2.8 years, which did not represent a statistically significant difference from the mandible (20.9 ± 1.9 years). Of the 886 abutment teeth that were used, 127 (14.3%) were extracted after an average period of 11.7 years. Periodontal complications were the primary reason for extraction. Based on this investigation, one could conclude that telescopic dentures are also a durable and sustainable solution in the long term. Loss of abutment teeth is relatively rare and has limited influence on the survival of the prosthetic structure. PMID:26973985

  18. Correlation between three color coordinates of human teeth

    NASA Astrophysics Data System (ADS)

    Lee, Yong-Keun

    2014-11-01

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

  19. The development and replacement of teeth in viviparous caecilians.

    PubMed

    Wake, M H

    1976-01-01

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

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

    PubMed Central

    Al-Kahtani, Ahmed

    2013-01-01

    The endodontic management of immature permanent incisors in young children can be challenging. This case reported an avulsed immature maxillary central incisors that underwent complete endodontic obturation using mineral trioxide aggregate. A 10-year-old male who suffered a fall injury avulsed both his central incisors. The revascularization process was not possible due to patient compliance and geographic reasons. Mineral trioxide aggregate was utilized as a novel endodontic treatment. After one year post-injury, the teeth remained symptom-free, the clinical and radiographic follow-up showed evidence of healthy periodontium. How to cite this article: Al-Kahtani A. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report. J Int Oral Health 2013; 5(3):88-96. PMID:24155609

  1. Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study.

    PubMed

    Bortolatto, Janaina Freitas; Dantas, Andrea Abi Rached; Roncolato, Ávery; Merchan, Hugo; Floros, Michael Christopher; Kuga, Milton Carlos; Oliveira, Osmir Batista de

    2016-01-01

    The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) - after in-office or at-home bleaching treatment; T1 - immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001). Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration. PMID:26981757

  2. Rotary endodontics in primary teeth – A review

    PubMed Central

    George, Sageena; Anandaraj, S.; Issac, Jyoti S.; John, Sheen A.; Harris, Anoop

    2015-01-01

    Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti) rotary files have been developed for use in pediatric endodontics. Using rotary instruments for primary tooth pulpectomies is cost effective and results in fills that are consistently uniform and predictable. This article reviews the use of nickel–titanium rotary files as root canal instrumentation in primary teeth. The pulpectomy technique is described here according to different authors and the advantages and disadvantages of using rotary files are discussed. PMID:26792964

  3. The optimal design of involute gear teeth with unequal addenda

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  4. Overlay removable denture for treatment of worn teeth.

    PubMed

    Beyth, Nurit; Tamari, Israel; Buller Sharon, Anat

    2014-01-01

    Rehabilitation of partially edentulous patients with excessively worn dentitions can be challenging. Factors including medical history as well as the cost of the treatment and patient wishes for simpler approaches must be considered. This manuscript describes the use of an overlay partial denture to treat patients with excessive wear of the maxillary teeth. We describe a technique to restore severely worn teeth using heat-cured acrylic as part of a partial or full denture. Minimal preparations of the teeth are required, and the restoration provides protection from further wear, and stabilizes the occlusion. This solution was functionally and esthetically suitable to the patients. The technique can be used in medically complex patients where extractions are contraindicated, such as post radiation therapy or bisphosphonate treatment. PMID:24393072

  5. Teeth in the Line of Fracture: To Retain or Remove?

    PubMed Central

    Samson, Jimson; John, Reena; Jayakumar, Shalini

    2010-01-01

    The purpose of this study was to analyze mandibular fracture site, relationship of the fracture line to the periodontium, vitality of teeth, displacement of the fracture segments and their implications, and determine whether to retain or remove the teeth in the fracture line. Fifty patients with 62 fractures were involved in this study. An electric pulp tester was used to measure the pulpal response. The degree of fracture displacement and the relationship of the fracture line to the periodontium were evaluated using panoramic radiographs. Fractures of the parasymphysis region constituted a majority of 60.87% in the gross displacement category. Four of 50 patients showed no response presurgically and minimal response postoperatively on pulp vitality testing. Patients with teeth in the fracture line showing no response on pulp vitality testing should be advised extraction to avoid further complications. PMID:22132255

  6. Teeth in Rare Locations with Rare Complications: An Overview.

    PubMed

    Dhingra, Shruti; Gulati, Achal

    2015-12-01

    Ectopic presence of teeth within the dentate region is common in clinical practice. However, the presence of teeth in non-dentate areas such as the nasal cavity or the maxillary sinus is rare. These may remain asymptomatic for years, may be misdiagnosed as foreign bodies, or may present with some serious complications involving the nose and paranasal sinuses. Complications such as nasal obstruction, epistaxis, headaches, rhinolith formation, epiphora, sinusitis and oro-antral fistula have been well described in literature, however, very few cases of antro-cutaneous fistulas have been reported. We discuss three cases of ectopic eruptions of teeth, all occurring in children. The clinical and radiographic findings of the cases, possible etiology, complication, diagnosis and treatment are discussed. PMID:26693467

  7. Permanent magnet undulator for SPEAR

    SciTech Connect

    Halbach, K.; Chin, J.; Hoyer, E.; Winick, H.; Cronin, R.; Yang, J.; Zambre, Y.

    1981-03-01

    A 30 period permanent magnet (SmCo/sub 5/) undulator has been designed, built and tested. The period is 6.1 cm, overall length is 1.95 m, and the gap is variable from 2.7 cm to 6.0 cm. Magnetic measurements at the midplane with a 2.7 cm gap show that the field is sinusoidal with a peak value of .28 T. Construction details and magnetic measurements are presented along with the spectral distribution of radiation produced by 3.0 GeV electrons traversing the undulator.

  8. Method of making permanent magnets

    DOEpatents

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

    1993-09-07

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

  9. Method of making permanent magnets

    DOEpatents

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

    1993-09-07

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

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

    SciTech Connect

    Ruse, N.D.; Smith, D.C.; Torneck, C.D.; Titley, K.C. )

    1990-09-01

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

  11. Middle Pleistocene Hominin Teeth from Longtan Cave, Hexian, China

    PubMed Central

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

    2014-01-01

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

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

    PubMed

    Komabayashi, Takashi; Zhu, Qiang

    2010-05-01

    Direct pulp capping is 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 the 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 noninflamed status and lead to a high rate of long-term success. PMID:20416524

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

    PubMed Central

    Komabayashi, Takashi; Zhu, Qiang

    2010-01-01

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

  14. Sex estimation using diagonal diameter measurements of molar teeth in African American populations.

    PubMed

    Peckmann, Tanya R; Meek, Susan; Dilkie, Natasha; Mussett, Michelle

    2015-11-01

    Teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate the degree of sexual dimorphism in the permanent molars of African Americans using crown and cervical diagonal diameters. Discriminant functions developed from a modern Greek population were tested for accuracy of sex estimation in an African American population. One hundred and three (53 males and 50 females) individuals ranging in age from 16 years to 66 years old were used from the Robert J. Terry Anatomical Skeletal Collection. Four diagonal diameter measurements were taken for each of the left mandibular and maxillary molars: mesiobuccal-distolingual crown diameter, mesiolingual-distobuccal crown diameter, mesiobuccal-distolingual cervical diameter, and mesiolingual-distobuccal cervical diameter. The overall percentage of accuracy of the modern Greek discriminant functions when applied to the African American sample was between 53.8% and 63.6%. Males were more accurately classified (93.6%-100%) than females (0%-18.2%). The African American population specific direct discriminant functions showed accuracy rates from 72.6% to 100% for the original data and 40%-72.3% for the cross-validated data. The African American stepwise discriminant functions showed accuracy rates from 63.9% to 77.6% for the original and cross-validated data. Comparisons to other populations were made. The results suggest that, in teeth, there is variation in the degree of sexual dimorphism between populations and discriminant functions for sex estimation in dentition are population specific. PMID:26408392

  15. Modified intracanal post for severely mutilated primary anterior teeth

    PubMed Central

    Rallan, Mandeep; Rallan, Neelakshi Singh; Navit, Pragati; Malhotra, Garima

    2013-01-01

    Early childhood caries leads to early damage, discolouration and gross destruction of the maxillary anterior teeth. This leads to difficulty in speech, decreased masticatory efficiency, development of abnormal tongue thrust and subsequent malocclusion, psychological problems and problem with self-esteem, if aesthetics are compromised. Thus, restoration of severely mutilated primary anterior teeth is often considered as a special challenge, especially in an emotionally immature child. This case documents the restoration of severely mutilated incisors in a patient with early childhood caries. PMID:23605834

  16. Carbon dioxide laser oral safety parameters for teeth

    SciTech Connect

    Powell, G.L.; Whisenant, B.K.; Morton, T.H. )

    1990-01-01

    The carbon dioxide laser is used in the oral cavity for a variety of procedures. Although the procedures may not involve the teeth directly, precaution should be exercised to preserve their integrity. The results of this study indicate that the most limiting parameter for oral use of the CO{sub 2} laser is damage to the enamel surface, which could be inflicted with as little as 5 W for 0.2 second and a 1 mm beam. Care should be exercised to prevent inadvertent damage to the surface enamel of teeth even at very low energy levels.

  17. Odontomas and Supernumerary Teeth: Is There a Common Origin?

    PubMed Central

    Pippi, Roberto

    2014-01-01

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

  18. Delayed replantation of avulsed mature teeth with calcium hydroxide treatment.

    PubMed

    Cali?kan, M K; Trkn, M; Gkay, N

    2000-08-01

    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

  19. High-performance permanent magnets.

    PubMed

    Goll, D; Kronmller, H

    2000-10-01

    High-performance permanent magnets (pms) are based on compounds with outstanding intrinsic magnetic properties as well as on optimized microstructures and alloy compositions. The most powerful pm materials at present are RE-TM intermetallic alloys which derive their exceptional magnetic properties from the favourable combination of rare earth metals (RE = Nd, Pr, Sm) with transition metals (TM = Fe, Co), in particular magnets based on (Nd.Pr)2Fe14B and Sm2(Co,Cu,Fe,Zr)17. Their development during the last 20 years has involved a dramatic improvement in their performance by a factor of > 15 compared with conventional ferrite pms therefore contributing positively to the ever-increasing demand for pms in many (including new) application fields, to the extent that RE-TM pms now account for nearly half of the worldwide market. This review article first gives a brief introduction to the basics of ferromagnetism to confer an insight into the variety of (permanent) magnets, their manufacture and application fields. We then examine the rather complex relationship between the microstructure and the magnetic properties for the two highest-performance and most promising pm materials mentioned. By using numerical micromagnetic simulations on the basis of the Finite Element technique the correlation can be quantitatively predicted, thus providing a powerful tool for the further development of optimized high-performance pms. PMID:11129942

  20. Scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

    SciTech Connect

    Ikeda, N.; Watanabe, G.; Harada, A.; Suzuki, T.

    1988-11-01

    Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules.

  1. Infundibula of equine maxillary cheek teeth: Part 2: Morphological variations and pathological changes.

    PubMed

    Suske, A; Pöschke, A; Müller, P; Wöber, S; Staszyk, C

    2016-03-01

    Incomplete cemental filling of the infundibula of equine maxillary cheek teeth (CT) is a common feature. Depending on the extent of the defect, three stages of infundibular decay have been suggested. However, histomorphological criteria to identify non-pathological abnormalities and destructive changes have not been defined. Six hundred and eighty eight CT with no evidence of dental diseases and 55 diseased permanent, fully erupted maxillary CT were evaluated on a macroscopic level by assessing the occlusal surface and horizontal sections, including porphyrin assays to detect residual blood within the infundibular cementum. Selected specimens were investigated on a microscopic level using routine and immunohistological staining methods to identify possible routes for the spread of infectious agents from the infundibulum into the endodontic system. Infundibular cemental hypoplasia was defined as a non-pathological developmental abnormality and was detected in >50% of CT with no evidence of dental diseases and in >70% of diseased CT. The first molar (Triadan 09) showed the highest prevalence (75%) of infundibular cemental hypoplasia. The mesial infundibulum was more often affected than the distal infundibulum. Infundibular erosion was considered as the most appropriate term to describe destructive infundibular changes. Infundibular erosion was present in <6% of CT with no evidence of dental diseases, but was detected in >27% of diseased teeth, always accompanied by endodontic disease. This suggests that teeth affected by infundibular cemental hypoplasia are prone to destructive erosion, which possibly leads to endodontic disease. Morphological factors that supplement this ethological hypothesis were described. In 74% of infundibula residual blood was identified, although no vital blood vessels were detected. It is assumed that this content of blood remained in the ample infundibular cemental blood system after tooth eruption and creates a favorable environment for microbial growth. The infundibular enamel was characterised by numerous infoldings to variable degrees and depths. In certain areas focal enamel aplasia was observed. These morphological features might contribute to microbiological settlement and spread of infectious agents through the infundibular wall into the endodontic system. PMID:26831172

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

    PubMed

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

    2014-12-01

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

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

    DOEpatents

    Alexander, James Pellegrino; EL-Refaie, Ayman Mohamed Fawzi; Lokhandwalla, Murtuza; Shah, Manoj Ramprasad; VanDam, Jeremy Daniel

    2011-09-13

    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.

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

    PubMed

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

    2005-11-01

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

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

    PubMed Central

    2014-01-01

    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. PMID:24739085

  6. Bovine thelaziasis in Iowa.

    PubMed

    Krafsur, E S; Church, C J

    1985-06-01

    The prevalence of developing Thelazia nematodes in face flies (Musca autumnalis) was studied for 7 yr at a beef farm in central Iowa. Juvenile nematodes were not found among flies in reproductive diapause in autumn, nor among nulliparous, overwintered flies in spring, but only among actively reproducing insects. Thus Thelazia probably do not overwinter in face flies. A mean prevalence of 2.0% infected was recorded among flies in 7 fly breeding seasons. No heterogeneity in Thelazia prevalence was detected within fly breeding seasons. The frequency distribution of Thelazia among face flies by year of occurrence was homogeneous, with a mean of 2.75 larval nematodes per infected fly. Thelazia gulosa and T. skrjabini were recovered in necropsy from the eyes of bovines from central Iowa. Prevalence among fat cattle 18-27 mo old was 15%; among cows 3-15 yr old, prevalence was only 3%. Thelazia skrjabini was found in 29 eyes and T. gulosa in 4 eyes. Infections were randomly distributed among the eyes of subject cattle. The mean worm burden was 2.3 T. skrjabini and 12 T. gulosa per infected eye. Thelaziasis is clearly enzootic in Iowa. PMID:4040164

  7. Mouth and Teeth: How To Keep Them Healthy

    MedlinePLUS

    ... some medicines may cause you to have a dry mouth.) Look inside your mouth regularly for sores that don't heal, irritated gums or other changes. See your dentist every 6 months for regular check-ups and cleanings. If you have any problems with your teeth ...

  8. Axonal Degeneration in Dental Pulp Precedes Human Primary Teeth Exfoliation.

    PubMed

    Suzuki, K; Lovera, M; Schmachtenberg, O; Couve, E

    2015-10-01

    The dental pulp in human primary teeth is densely innervated by a plethora of nerve endings at the coronal pulp-dentin interface. This study analyzed how the physiological root resorption (PRR) process affects dental pulp innervation before exfoliation of primary teeth. Forty-four primary canine teeth, classified into 3 defined PRR stages (early, middle, and advanced) were fixed and demineralized. Longitudinal cryosections of each tooth were stained for immunohistochemical and quantitative analysis of dental pulp nerve fibers and associated components with confocal and electron microscopy. During PRR, axonal degeneration was prominent and progressive in a Wallerian-like scheme, comprising nerve fiber bundles and nerve endings within the coronal and root pulp. Neurofilament fragmentation increased significantly during PRR progression and was accompanied by myelin degradation and a progressive loss of myelinated axons. Myelin sheath degradation involved activation of autophagic activity by Schwann cells to remove myelin debris. These cells expressed a sequence of responses comprising dedifferentiation, proliferative activity, GAP-43 overexpression, and Büngner band formation. During the advanced PRR stage, increased immune cell recruitment within the dental pulp and major histocompatibility complex (MHC) class II upregulation by Schwann cells characterized an inflammatory condition associated with the denervation process in preexfoliative primary teeth. The ensuing loss of dental pulp axons is likely to be responsible for the progressive reduction of sensory function of the dental pulp during preexfoliative stages. PMID:26149320

  9. Anesthetic Efficacy of Meperidine in Teeth With Symptomatic Irreversible Pulpitis

    PubMed Central

    Mohajeri, Ladan; Salehi, Farnaz; Mehrvarzfar, Payman; Arfaee, Hamide; Bohluli, Behnam; Hamedy, Reza

    2015-01-01

    Achieving adequate pulpal anesthesia in mandibular teeth is always a challenge. Supplementary injections and using drugs in combination are some methods implemented to overcome this hurdle. In this randomized clinical trial, use of meperidine in conjunction with lidocaine in intraligamentary injection did not exhibit significant improvement in anesthesia. PMID:25849469

  10. 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...

  11. Age estimation from physiological changes of teeth by Gustafson's method.

    PubMed

    Shrigiriwar, Manish; Jadhav, Vijay

    2013-04-01

    Age determination is crucial in medicolegal cases. Various factors are considered for determination of age, out of which teeth are the most durable structures in human body which are better preserved even in the acidic soil. In many archaeological sites and forensic cases, teeth are the only available human remains for the identification and age determination purpose. We conducted this study to know the changes in teeth with advancement of age. In our study, 80 cases in the age group of 26-70 years were studied, out of which 58 were men and 22 women. The six physiological changes in teeth, viz. attrition, periodontosis, secondary dentin deposition, root translucency, cementum apposition and root resorption, were studied with each parameter having score ranging from 0 to 3. Total score was calculated by adding the scores of all the six physiological factors. The regression analysis was done by plotting the total score allotted against the actual age of the person. This regression line was used to derive the regression formula which came out as y = 3.71x + 16.03 and from this, age of the person was calculated. The average age difference between known and estimated age in this study was found to be 4.43 years. PMID:23275430

  12. Personalized Orthodontic Accurate Tooth Arrangement System with Complete Teeth Model.

    PubMed

    Cheng, Cheng; Cheng, Xiaosheng; Dai, Ning; Liu, Yi; Fan, Qilei; Hou, Yulin; Jiang, Xiaotong

    2015-09-01

    The accuracy, validity and lack of relation information between dental root and jaw in tooth arrangement are key problems in tooth arrangement technology. This paper aims to describe a newly developed virtual, personalized and accurate tooth arrangement system based on complete information about dental root and skull. Firstly, a feature constraint database of a 3D teeth model is established. Secondly, for computed simulation of tooth movement, the reference planes and lines are defined by the anatomical reference points. The matching mathematical model of teeth pattern and the principle of the specific pose transformation of rigid body are fully utilized. The relation of position between dental root and alveolar bone is considered during the design process. Finally, the relative pose relationships among various teeth are optimized using the object mover, and a personalized therapeutic schedule is formulated. Experimental results show that the virtual tooth arrangement system can arrange abnormal teeth very well and is sufficiently flexible. The relation of position between root and jaw is favorable. This newly developed system is characterized by high-speed processing and quantitative evaluation of the amount of 3D movement of an individual tooth. PMID:26208593

  13. Bovine respiratory disease model based on dual infections with infection with bovine viral diarrhea virus and bovine corona virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine respiratory disease complex (BRDC) is the leading cause of economic loss in the U.S. cattle industry. BRDC likely results from simultaneous or sequential infections with multiple pathogens including both viruses and bacteria. Bovine viral diarrhea virus (BVDV) and bovine corona virus (BoCV...

  14. Is CO2 ice permanent?

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard Lee

    1992-01-01

    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.

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

    PubMed Central

    2014-01-01

    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 Spearmans rank correlation coefficient was used to explore the correlation of the distribution of CAST codes among the evaluated teeth. The level of statistical significance was established at p?permanent molars, caries was observed in 14.8% to 17.3% of the molar and most lesions were scored at the non-cavitation level. Caries in primary molars was most often recorded at the stage of cavitated dentine lesion. Teeth with pulpal involvement, sepsis and extracted due to caries were found to be more prevalent in first, and then in second primary molars. A strong correlation was found between the status of teeth from the right and left sides of the oral cavity. The correlation of the status of first and second primary teeth was stronger for the left than for the right side of the mouth, r was 0.627 and 0.472 in maxilla and 0.513 and 0.483 in mandible (p?permanent molars the correlation was assessed to be weak. With regard to the teeth situated in opposite jaws the study revealed that the correlations were moderate - r between 0.33 and 0.49. The intra-examiner reliability was established at 0.96 for the primary dentition and at 0.878 for permanent molars. Conclusion The strongest correlation found in the evaluated population concerned the distribution of caries in primary molars on the left side of the mouth. The study proved the usefulness of the CAST index in epidemiological surveys. PMID:24952612

  16. Steady-state permanent magnet MPD thruster

    SciTech Connect

    Arakawa, Y.; Sasoh, A.

    1987-01-01

    A steady-state MPD arc thruster with permanent magnets has been made. The effect of the permanent magnets on thruster performance and the plasma acceleration mechanism was examined through measurements of thrust, chamber pressure, current densities, and plasma properties in the exhaust plume. Experimental results show that the use of the permanent magnets is desirable in steady-state MPD thrusters of the greater than 10 kW power range. 7 references.

  17. Disinfection/sterilization of extracted teeth for dental student use.

    PubMed

    Dominici, J T; Eleazer, P D; Clark, S J; Staat, R H; Scheetz, J P

    2001-11-01

    Extracted human teeth are used in many preclinical courses. While there has been no report of disease transmission with extracted teeth, sterilization of teeth used in the teaching laboratory should be a concern. The purpose of this study was to determine the effectiveness of different sterilization/disinfection methods of extracted human teeth using Bacillus stearothermophilus, a bacteria resistant to heat and frequently used to test sterilizers. In this study, 110 extracted molars with no carious lesions were collected and stored in buffered saline. An endodontic occlusal access preparation was cut into the pulp chamber of each tooth. Pulp tissue in the chamber was removed with a broach. Approximately 1 x 10(5) B. stearothermophilus endospores in culture medium were injected into the pulp chamber, sealed with Cavit G, and then placed in sterile saline for twelve hours. Ten teeth were placed into each of eleven groups. Seven groups were immersed for one week in one of the following solutions: a) sterile saline (control group), b) 5.25% NaOCl, c) 2.6% NaOCl, d) 1% NaOCl, e) 10% buffered formalin, f) 2% gluteraldehyde, g) 0.28% quaternary ammonium. Four additional groups were treated by h) 10% formalin for two days, i) 10% formalin for four days, j) autoclaving at 240 degrees F and 20 psi for twenty minutes, and k) autoclaving at 240 degrees F and twenty psi for forty minutes. Each tooth was then aseptically split and placed in an individual test tube with growth medium. Samples were examined for evidence of growth (turbidity) at forty-eight hours. Only autoclaving for forty minutes at 240 degrees F and 20 psi or soaking in 10 percent formalin for one week were 100 percent effective in preventing growth. A chi-square analysis of the data indicates these two methods were significantly better than all other methods (p<0.001). PMID:11765875

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

    MedlinePLUS

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

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

    PubMed

    Hale, F A

    2001-03-01

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

  20. Permanent Magnet Materials and their Application

    NASA Astrophysics Data System (ADS)

    Campbell, Peter

    1996-06-01

    This book is a comprehensive design text on permanent magnets and their applications. The author begins with a brief overview of the theory of magnetism and explains the behavior of the different classes of permanent magnets and the various production processes that lead to quite diverse material characteristics. The core of the book is a detailed treatment of the methods used to design permanent magnets, including assessments of the changes they experience under practical operating conditions. The volume also describes modern analytical techniques including the finite element method, with reference to the accurate simulation of permanent magnetic materials. Electrical engineers, condensed matter physicists and materials scientists will find this book useful.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  2. An in vitro Evaluation of Microleakage of Posterior Teeth Restored with Amalgam, Composite and Zirconomer – A Stereomicroscopic Study

    PubMed Central

    Punia, Sandhya Kapoor; Bhat, Surekha; Singh, Gautam; Goyal, Pravesh; Oza, Swapnil; Raiyani, Chirag M.

    2015-01-01

    Background Numerous restorative materials are being used in dentistry to achieve adequate strength and restore aesthetics. However, a perfect ideal restorative material has still eluded dentist. Dental amalgam is versatile material with self-sealing property, but is unaesthetic. Other restorative materials like, composites require conservative preparation, but exhibits polymerisation shrinkage resulting in microleakage. To overcome these drawbacks a high strength restorative material reinforced with ceramic and zirconia fillers known as zirconomer has been introduced. The aim of this study was to evaluate the micro-leakage of these three different restorative materials. Materials and Methods Thirty non-carious human permanent first and second molars were utilized in this study. Class I cavities were prepared on the occlusal surface; cavities were then restored with amalgam, composite and zirconomer as per manufacture’s instruction. All samples were stored for 24 hours in distilled water followed by thermocycling. The entire tooth surface was painted with two coats of varnish to within 1mm of the restoration margins. The teeth were immersed in dye. Teeth were sectioned and observed under stereomicroscope. Results In this study the zirconomer exhibited the highest micro leakage as compared to composite and amalgam but composite having higher micro leakage as compared to amalgam and lower micro leakage as compared to zirconomer. Conclusion Even though composite and amalgam are being marketed aggressively and new material like zirconomer are on origin, amalgam still proves to be one of the best materials. PMID:26393208

  3. Material Properties of Inorganic Bovine Cancellous Bovine: Nukbone

    NASA Astrophysics Data System (ADS)

    Piña, Cristina; Palma, Benito; Munguía, Nadia

    2006-09-01

    In this work, inorganic cancellous bovine bone implants prepared in the Instituto de Investigaciones en Materiales — UNAM were characterized. Elementary chemical analysis was made, toxic elements concentration were measured and the content of organic matter also. These implants fulfill all the requirements of the ASTM standards, and therefore it is possible their use in medical applications.

  4. Influences on the stable oxygen and carbon isotopes in gerbillid rodent teeth in semi-arid and arid environments: Implications for past climate and environmental reconstruction

    NASA Astrophysics Data System (ADS)

    Jeffrey, Amy; Denys, Christiane; Stoetzel, Emmanuelle; Lee-Thorp, Julia A.

    2015-10-01

    The stable isotope composition of small mammal tissues has the potential to provide detailed information about terrestrial palaeoclimate and environments, because their remains are abundant in palaeontological and archaeological sites, and they have restricted home ranges. Applications to the Quaternary record, however, have been sparse and limited by an acute lack of understanding of small mammal isotope ecology, particularly in arid and semi-arid environments. Here we document the oxygen and carbon isotope composition of Gerbillinae (gerbil) tooth apatite across a rainfall gradient in northwestern Africa, in order to test the relative influences of the 18O/16O in precipitation or moisture availability on gerbil teeth values, the sensitivity of tooth apatite 13C/12C to plant responses to moisture availability, and the influence of developmental period on the isotopic composition of gerbil molars and incisors. The results show that the isotopic composition of molars and incisors from the same individuals differs consistent with the different temporal periods reflected by the teeth; molar teeth are permanently rooted and form around the time of birth, whereas incisors grow continuously. The results indicate that tooth choice is an important consideration for applications as proxy Quaternary records, but also highlights a new potential means to distinguish seasonal contexts. The oxygen isotope composition of gerbil tooth apatite is strongly correlated with mean annual precipitation (MAP) below 600 mm, but above 600 mm the teeth reflect the oxygen isotope composition of local meteoric water instead. Predictably, the carbon isotope composition of the gerbil teeth reflected C3 and C4 dietary inputs, however arid and mesic sites could not be distinguished because of the high variability displayed in the carbon isotope composition of the teeth due to the microhabitat and short temporal period reflected by the gerbil. We show that the oxygen isotope composition of small mammal teeth strongly reflects moisture availability in semi-arid and arid environments and would provide an excellent record of palaeo-aridity in a terrestrial setting. The results illustrate that an understanding of an animal's physiology is essential for interpreting the animal's isotopic responses to external contexts, especially in arid zones.

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

    PubMed Central

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

    2014-01-01

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

  6. Leadership in a (permanent) crisis.

    PubMed

    Heifetz, Ronald; Grashow, Alexander; Linsky, Marty

    2009-01-01

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

  7. Permanent-magnet multipole with adjustable strength

    DOEpatents

    Halbach, K.

    1982-09-20

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

  8. Permanent magnet multipole with adjustable strength

    DOEpatents

    Halbach, Klaus (Berkeley, CA)

    1985-01-01

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

  9. Gating of Permanent Molds for ALuminum Casting

    SciTech Connect

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

    2004-03-30

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

  10. A simulation model for transient thermal analysis of restored teeth.

    PubMed

    de Vree, J H; Spierings, T A; Plasschaert, A J

    1983-06-01

    A theoretical model was developed to analyze the influence of various cement bases on temperature distribution and heat flow in restored teeth. A physical model of a molar was developed to simulate different thermal processes by simple parameter variation. The time-dependent temperature field was calculated using the finite element method (FEM). The values for material properties and thermal load were chosen from the dental literature. The results are in good agreement with clinical experimental research as published by Trowbridge et al. It is concluded that the model is a valid tool for further research with regard to the influence of restorative materials and cavity design on the thermal behavior of restored teeth. PMID:6574159

  11. Restoration of Long Standing Traumatized Teeth: A Case Report

    PubMed Central

    Kadkol, Prasanna Kumar; Reddy, K. Veera Kishore Kumar; Ainapur, Raghavendra

    2015-01-01

    Children are uniquely susceptible to craniofacial trauma. Injuries to the teeth occur often as a result of falls and sport activities. The pulp often gets infected after dental trauma resulting in to numerous complications. The authors present a case report of successful restoration of traumatized teeth with open apex which were weakened due to long standing infection and internal resorption. Initially antibiotic combination of 3- mix was used to disinfect the root canals. One tooth is treated with conventional endodontic treatment and the other tooth with open apex and perforation is managed by MTA apexification followed by canal reinforcement using glass ionomer cement and fiber reinforced composite post. Core build up is done using light cure composite resin followed by aesthetic crowns. The patient also presented with the peg shaped lateral incisors, which were built to an aesthetic appearance using light cure composite resins. PMID:26436062

  12. Calcite orientations and composition ranges within teeth across Echinoidea

    PubMed Central

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

    2016-01-01

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

  13. Restoration of Long Standing Traumatized Teeth: A Case Report.

    PubMed

    Battepati, Prashant Manjunath; Kadkol, Prasanna Kumar; Reddy, K Veera Kishore Kumar; Ainapur, Raghavendra

    2015-08-01

    Children are uniquely susceptible to craniofacial trauma. Injuries to the teeth occur often as a result of falls and sport activities. The pulp often gets infected after dental trauma resulting in to numerous complications. The authors present a case report of successful restoration of traumatized teeth with open apex which were weakened due to long standing infection and internal resorption. Initially antibiotic combination of 3- mix was used to disinfect the root canals. One tooth is treated with conventional endodontic treatment and the other tooth with open apex and perforation is managed by MTA apexification followed by canal reinforcement using glass ionomer cement and fiber reinforced composite post. Core build up is done using light cure composite resin followed by aesthetic crowns. The patient also presented with the peg shaped lateral incisors, which were built to an aesthetic appearance using light cure composite resins. PMID:26436062

  14. Peripheral opioid analgesia in teeth with symptomatic inflamed pulps.

    PubMed Central

    Uhle, R. A.; Reader, A.; Nist, R.; Weaver, J.; Beck, M.; Meyers, W. J.

    1997-01-01

    The purpose of this study was to investigate the ability of low-dose fentanyl to produce analgesia when administered via the periodontal ligament injection in teeth with symptomatic, inflamed pulps. All subjects presented for emergency treatment with moderate to severe pain and had a posterior tooth with a clinical diagnosis of irreversible pulpitis. Twenty subjects randomly received either 10 micrograms fentanyl citrate or saline placebo via the periodontal ligament injection in a double-blind manner. The subjects rated their pain prior to injection and rated pain intensity and pain half gone for 59 min postinjection. Low-dose fentanyl delivered via the periodontal ligament injection in inflamed teeth provided significantly greater analgesia than the saline placebo (P < 0.05). Since the dose of fentanyl used was less than the dose required to provide analgesia by a central mechanism, the results of this study may be consistent with a peripheral opioid mechanism of action. PMID:9481968

  15. Avoiding "the space" by the treatment of compromised teeth.

    PubMed

    Heithersay, G S

    2000-10-01

    The advent of implant therapy has given new a dimension to dentistry particularly where teeth have been irretrievably damaged or pathologically involved. There are many situations however, where endodontic or combined therapy may effectively retain compromised teeth and clinicians should carefully evaluate evidence-based treatment. The main areas discussed are: transverse and crown root fractures and invasive cervical resorption. Transverse root fractures have an excellent natural healing capacity and will also respond favourably to treatment if pulp necrosis occurs in the coronal segment. Studies have shown that crown root fractures can be effectively treated by combined endodontic-orthodontic-periodontic and prosthodontic therapy. Invasive cervical resorption has been classified into four classes depending on the degree of infiltration of resorptive tissue into the tooth structure. A study of treatment results following the topical application of 90% aqueous trichloracetic acid, curettage and restoration indicated that this regimen could be successfully applied to Classes 1, 2 and 3 resorption. PMID:11709947

  16. Detecting cracks in teeth using ultrasonic excitation and infrared imaging

    NASA Astrophysics Data System (ADS)

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

    2001-06-01

    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.

  17. [Endodontically treated teeth. Success--failure. Endorestorative treatment plan].

    PubMed

    Zabalegui, B

    1990-01-01

    More and more often the general dentist is finding the presence of endodontically treated teeth during his treatment planning procedure. He has to ask himself if the endo-treated tooth functions and will continue to function function successfully, when deciding which final endo-restorative procedure to apply. For this reason the dentist or the endodontist with whom he works should clinically evaluate these teeth, establish a diagnostic criteria of their success or failure and a treatment plan according to the prognosis. The purpose of this article is to offer an organized clinical view of the steps to follow when evaluating an endodontically treated tooth and how to establish a final endo-restorative plan. PMID:2168732

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

    PubMed

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

    2014-12-12

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

  19. What is the Best Root Surface Treatment for Avulsed Teeth?

    PubMed Central

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

    2014-01-01

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

  20. Multidisciplinary approach in the treatment of subgingivally fractured anterior teeth.

    PubMed

    Türker, Sebnem Begüm; Köse, Kemal Naci

    2008-04-01

    With the advances in adhesive technology, dentists have gained great popularity with their esthetics treatment options. The enamel and partially dentin adhesive systems have proved their potential effect. This study presents the multidisciplinary approach in the treatment of subgingivally fractured anterior teeth. Empress II crowns were cemented entirely on the prepared root portion of a left maxillary lateral incisor and canine after orthodontic eruption. The clinical results after 2 years were successful. PMID:18352933

  1. Modular turbine airfoil and platform assembly with independent root teeth

    DOEpatents

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

    2013-07-30

    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).

  2. Bending strength model for internal spur gear teeth

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  3. Esthetic direct restorations in endodontically treated anterior teeth.

    PubMed

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

    2013-01-01

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

  4. Linking development with generation of novelty in mammalian teeth.

    PubMed

    Jernvall, J

    2000-03-14

    The evolution of mammalian teeth is characterized by the frequent and convergent evolution of new cusps. The evolution of new cusps can be linked to tooth development via population-level variation. This allows testing whether development increases the capacity to evolve, or evolvability, by facilitating and even directing morphological change. In a population sample of living seals, variation in cusp number of individual teeth is from three to five cusps, the variably present cusps being the shortest ones that also develop last. By factoring in recent evidence on development, I show that the variation in cusp number can be explained by a patterning cascade mode of cusp development that cumulatively increases and directs height variation in short cusps. The biased variation in seal tooth cusps supports the recognition of teeth as highly evolvable because only small developmental changes are needed to produce large changes in size and number of small cusps. This evolvability of tooth cusps may have facilitated the fast and independent acquisition of new cusps in mammalian evolution. In phylogenetic studies, small cusps may be unreliable as phylogenetic signals. Population level variation can be a powerful tool in testing and generating hypotheses in developmental evolution studies. PMID:10706636

  5. Improving access to endogenous DNA in ancient bones and teeth

    PubMed Central

    Damgaard, Peter B.; Margaryan, Ashot; Schroeder, Hannes; Orlando, Ludovic; Willerslev, Eske; Allentoft, Morten E.

    2015-01-01

    Poor DNA preservation is the most limiting factor in ancient genomic research. In the majority of ancient bones and teeth, endogenous DNA molecules represent a minor fraction of the whole DNA extract, rendering shot-gun sequencing inefficient for obtaining genomic data. Based on ancient human bone samples from temperate and tropical environments, we show that an EDTA-based enzymatic ‘pre-digestion’ of powdered bone increases the proportion of endogenous DNA several fold. By performing the pre-digestion step between 30 min and 6 hours on five bones, we observe an asymptotic increase in endogenous DNA content, with a 2.7-fold average increase reached at 1 hour. We repeat the experiment using a brief pre-digestion (15 or 30 mins) on 21 ancient bones and teeth from a variety of archaeological contexts and observe an improvement in 16 of these. We here advocate the implementation of a brief pre-digestion step as a standard procedure in ancient DNA extractions. Finally, we demonstrate on 14 ancient teeth that by targeting the outer layer of the roots we obtain up to 14 times more endogenous DNA than when using the inner dentine. Our presented methods are likely to increase the proportion of ancient samples that are suitable for genome-scale characterization. PMID:26081994

  6. Color alteration in teeth subjected to different bleaching techniques

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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 (α = 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.

  7. Effect of mica and glass on acrylic teeth material's color.

    PubMed

    Dikbas, Idil; Koksal, Temel; Unalan, Fatma; Gurbuz, Ozlem; Noyun, Fuat; Kazazoglu, Ender

    2006-06-01

    The purpose of this study was to evaluate the effect of two different ratios of silanized mica filler and milled glass fiber reinforcement on the color of acrylic denture teeth materials. Ten acrylic resin discs made of acrylic denture teeth material (PMMA) obtained from the manufacturer were used as the control group. Four experimental groups were modified from the control group's PMMA material by adding a ratio of 5% or 10% by weight of silane-treated mica filler or milled glass fibers. Each group consisted of 10 specimens. Measurements were performed using a spectrophotometer CM-2600d, and the color changes were characterized in the Commission Internationale d'Eclairage L*a*b* color space. deltaE* values of 5% mica-, 10% mica-, 5% glass-, and 10% glass-containing sample groups were 2.46, 3.03, 2.16, and 2.59 respectively. There were statistically significant differences in L*, a*, and b* values between the control group and each test group. It was shown that when PMMA denture teeth material was modified with silane-treated mica filler or silane-treated milled glass fibers for the purpose of reinforcement, it would also cause significant changes to the original color of the material. PMID:16916247

  8. A Method for Rapid Demineralization of Teeth and Bones

    PubMed Central

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

    2010-01-01

    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 -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 -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 -galactosidase activity. PMID:21339898

  9. Demineralization and hydrogen peroxide penetration in teeth with incipient lesions.

    PubMed

    Briso, André Luiz Fraga; Gonçalves, Rafael Simões; Costa, Fernanda Bernardi da; Gallinari, Marjorie de Oliveira; Cintra, Luciano Tavares Angelo; Santos, Paulo Henrique dos

    2015-01-01

    The aim of this study was to evaluate the demineralization and hydrogen peroxide (HP) penetration in teeth with incipient lesions submitted to bleaching treatment. For analysis of HP penetration, sound and demineralized enamel/dentin discs were placed in artificial pulp chambers containing acetate buffer solution. After bleaching treatment, this solution was subjected for analysis of optical density by spectrophotometry and the disc surfaces were analyzed with scanning electron microscopy (SEM) and polarized light microscopy (PLM). The remaining discs were subjected for cross-sectional hardness analysis at different depths. Data were analyzed by repeated measures ANOVA and PLSD Fisher test (a=0.05). It was observed that previously demineralized teeth showed greater HP penetration (p<0.05). The bleaching treatment caused changes to a depth of 20 µm in sound enamel and up to 90 µm in demineralized enamel. SEM and PLM images revealed that the bleaching treatment caused superficial changes that were considerably more accentuated in previously demineralized teeth. It may be concluded that the enamel mineralization level influences HP penetration and the bleaching agent contributed to increase the demineralization depth. PMID:25831103

  10. Recovery and identification of mature enamel proteins in ancient teeth.

    PubMed

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

    2011-12-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    1998-03-01

    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.

  12. Concrescence of permanent maxillary second and third molars: case report of non-surgical root canal treatment.

    PubMed

    Foran, Denise; Komabayashi, Takashi; Lin, Louis M

    2012-03-01

    Concrescence is a rare developmental anomaly with an overall incidence of 0.8% in the permanent dentition. While many case reports describe the treatment of concrescence with extraction, there are few reports of non-surgical root canal treatment (NSRCT), due to the atypical root form, canal morphology, and technical difficulties involved in concrescence. This unique case report describes a technical modification of NSRCT that can retain joined posterior maxillary teeth to maintain natural posterior occlusion without surgical intervention or dental implants, thereby avoiding the risk of damage to a large portion of the alveolar bone near the maxillary sinus. PMID:22466898

  13. 78 FR 72979 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ..., 2012, we published in the Federal Register (77 FR 15848-15913, Docket No. APHIS-2008-0010) a proposal... January 4, 2005 (70 FR 460-553, Docket No. 03-080-3). The delay of applicability was removed in a final... Products Derived from Bovines,'' published in the Federal Register on September 18, 2007 (72 FR...

  14. Permanency and the Foster Care System.

    PubMed

    Lockwood, Katie K; Friedman, Susan; Christian, Cindy W

    2015-10-01

    Each year over 20,000 youth age out of the child welfare system without reaching a permanent placement in a family. Certain children, such as those spending extended time in foster care, with a diagnosed disability, or adolescents, are at the highest risk for aging out. As young adults, this population is at and increased risk of incarceration; food, housing, and income insecurity; unemployment; educational deficits; receipt of public assistance; and mental health disorders. We reviewed the literature on foster care legislation, permanency, outcomes, and interventions. The outcomes of children who age out of the child welfare system are poor. Interventions to increase permanency include training programs for youth and foster parents, age extension for foster care and insurance coverage, an adoption tax credit, and specialized services and programs that support youth preparing for their transition to adulthood. Future ideas include expanding mentoring, educational support, mental health services, and post-permanency services to foster stability in foster care placements and encourage permanency planning. Children in the child welfare system are at a high risk for physical, mental, and emotional health problems that can lead to placement instability and create barriers to achieving permanency. Failure to reach the permanency of a family leads to poor outcomes, which have negative effects on the individual and society. Supporting youth in foster care throughout transitions may mediate the negative outcomes that have historically followed placement in out-of-home care. PMID:26403649

  15. Comparison of shear bond strength of amalgam bonded to primary and permanent dentin.

    PubMed

    Mahdi, S; Bahman, S; Arghavan, A B; Fatemeh, M

    2008-06-01

    Amalgam's non-adhesive characteristics necessitate cavity preparations incorporating retentive features, which often require the removal of non-carious tooth structure. Use of adhesives beneath amalgam restorations, would be helpful to overcome this disadvantage. This study was undertaken to compare the mean shear bond strength of amalgam bonded to primary and permanent dentin, to evaluate the efficacy of amalgam adhesives in pediatric dentistry.27 primary and 28 permanent posterior teeth with intact buccal or lingual surfaces were grounded to expose dentin and wet-polished with 400-grit silicone carbide paper. Scotchbond Multi Purpose Plus adhesive system was applied to the dentin surfaces and light cured. Amalgam was condensed onto the treated dentin through a plastic mold.shear bond strength testing was done using an Instron Universal testing machine, at a crosshead speed of 0.5 mm/min.The data were analyzed by independent samples t-test The difference among the two groups was not statistically significant (p>0.05) Bonded amalgam showed the same level of bond strength to primary and permanent dentin; so, application of amalgam bonding agents in pediatric dentistry can be recommended. PMID:18603732

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

    PubMed

    Paulsamy, Sivachandran

    2014-01-01

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

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

    PubMed Central

    Paulsamy, Sivachandran

    2014-01-01

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

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

    PubMed

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

    2007-05-01

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

  19. Permanent Magnetic Bearing for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Morales, Winfredo; Fusaro, Robert; Kascak, Albert

    2008-01-01

    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.

  20. Prospects for nanoparticle-based permanent magnets

    SciTech Connect

    Balamurugan, B; Sellmyer, DJ; Hadjipanayis, GC; Skomski, R

    2012-09-01

    Magnetic nanoparticles smaller than similar to 15 nm in diameter and with high magnetocrystalline anisotropies K-1 >= 1 MJ m(-3) can be used as building blocks for next-generation permanent magnets. Advances in processing steps are discussed, such as self-assembly, alignment of the easy axes and appropriate nanostructuring that will enable the fabrication of densely packed nanopartide assemblies with improved permanent-magnet properties. This study also proposes an idealized nanocomposite structure for nanoparticle-based future permanent magnets with enhanced energy products. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Permanent multipole magnets with adjustable strength

    SciTech Connect

    Halbach, K.

    1983-03-01

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

  2. Macroscopic simulation of isotropic permanent magnets

    NASA Astrophysics Data System (ADS)

    Bruckner, Florian; Abert, Claas; Vogler, Christoph; Heinrichs, Frank; Satz, Armin; Ausserlechner, Udo; Binder, Gernot; Koeck, Helmut; Suess, Dieter

    2016-03-01

    Accurate simulations of isotropic permanent magnets require to take the magnetization process into account and consider the anisotropic, nonlinear, and hysteretic material behaviour near the saturation configuration. An efficient method for the solution of the magnetostatic Maxwell equations including the description of isotropic permanent magnets is presented. The algorithm can easily be implemented on top of existing finite element methods and does not require a full characterization of the hysteresis of the magnetic material. Strayfield measurements of an isotropic permanent magnet and simulation results are in good agreement and highlight the importance of a proper description of the isotropic material.

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

    PubMed

    Fukase, Hitoshi; Kondo, Osamu; Ishida, Hajime

    2015-03-01

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

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

    PubMed

    Leonetti, Eduardo dos Santos; Rodrigues, Jos Augusto; Reis, Andr Figueiredo; Navarro, Ricardo Scarparo; Aranha, Ana Ceclia Correa; Cassoni, Alessandra

    2012-01-01

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

  5. 30 CFR 817.132 - Cessation of operations: Permanent.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR PERMANENT PROGRAM PERFORMANCE STANDARDS PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.132 Cessation of operations: Permanent. (a) The person who conducts underground mining... equipment, structures, or other facilities not required for continued underground mining activities...

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

    PubMed

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

    2014-01-01

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

  7. Nonuniform radiation damage in permanent magnet quadrupoles

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  8. Nonuniform radiation damage in permanent magnet quadrupoles.

    PubMed

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

    2014-08-01

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

  9. Nonuniform radiation damage in permanent magnet quadrupoles

    SciTech Connect

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

    2014-08-15

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

  10. Permanent magnet edge-field quadrupole

    DOEpatents

    Tatchyn, R.O.

    1997-01-21

    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.

  11. Permanent magnet edge-field quadrupole

    DOEpatents

    Tatchyn, Roman O. (Mountain View, CA)

    1997-01-01

    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.

  12. Sporadic hemiplegic migraine with permanent neurological deficits

    PubMed Central

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

    2014-01-01

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

  13. Permanent education in health: a review

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

    ABSTRACT Aim: This study was undertaken to evaluate the percentage of gutta-percha-filled area (PGFA) using microscopic analysis of the cross-sections in the apical third of root canals when filled either with Thermafil technique, Warm Vertical Condensation technique and Cold Lateral Condensation technique without using sealers. Materials and methods: Sixty single rooted extracted per-manent teeth were collected. After crown amputation, the teeth were randomly divided into three experimental groups of 20 specimens each. Group IThermafil obturation technique, group IIwarm vertical condensation obturation technique and group IIIcold lateral condensation obturation technique. Obturation was performed by specific techniques without using sealers. After obturation, the teeth were cross-sectioned horizontally at 2 to 3 mm from apex with the help of double sided diamond disk. Sections were digitally photographed and measured under Stereomicroscope at magnification of 50. Using a KS 100 imaging system the area of canals and the gutta-percha was recorded, also the percentage of gutta-percha filled area (PGFA) was calculated. The observations thus ob-tained were subjected to statistical analysis using ANOVA and student t test. Results: Maximum group difference was observed between groups I and III (3.558 0.138) while minimum difference was observed between groups I and II (1.223 0.137). Thus, all the between group differences were statistically significant. Conclusion: This study supports the belief that the Thermafil Obturation technique produces significantly higher percentage of gutta-percha filled area (PGFA) than the warm vertical condensation technique or cold lateral condensation technique. How to cite this article: Samadi F, Jaiswal JN, Saha S, Garg N, Chowdhary S, Samadi F, Tripathi VP. A Comparative Evaluation of Efficacy of Different Obturation Techniques used in Root Canal Treatment of Anterior Teeth: An in vitro Study. Int J Clin Pediatr Dent 2014;7(1):1-5. PMID:25206229

  15. Sequence homology between bovine and human adenoviruses.

    PubMed Central

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

    1984-01-01

    Cross-hybridization has been detected between corresponding regions of the genomes of bovine adenovirus type 3 and human adenovirus type 2. The most conserved region on the viral genomes encodes the hexon polypeptide. The nucleotide sequence of this region in bovine adenovirus type 3 has been determined. Comparison of the predicted amino acid sequences of the bovine adenovirus type 3 and human adenovirus type 2 hexon polypeptides reveals three regions of nonhomology. Images PMID:6694264

  16. EDITORIAL: Permanent revolution - or evolution?

    NASA Astrophysics Data System (ADS)

    Dobson, Ken

    1998-03-01

    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.

  17. Tailored order: the mesocrystalline nature of sea urchin teeth.

    PubMed

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

    2014-09-01

    We investigated the pattern of crystal co-orientation at different length scales, together with variations in chemical composition and nanomechanical properties in the teeth of the modern sea urchin Paracentrotus lividus with electron backscatter diffraction (EBSD), electron probe microanalysis, energy-dispersive X-ray spectroscopy and nanoindentation testing. Modern sea urchin teeth are Mg-dominated calcite composite materials. They are distinctly harder than inorganically precipitated calcite. Some parts exceed even the hardness of dolomite. The teeth show a structuring of their mechanical properties that can be correlated to variations in major element chemical composition, such that their hardness is positively correlated to their magnesium contents. Mg/Ca ratio in Paracentrotus lividus varies between 10 and 26mol.%. Nanohardness of the tooth scatters between 3.5 and >8GPa compared to values of 3.00.2, 7.30.1 and 9.20.9GPa measured on the (104) planes of inorganic calcite, dolomite and magnesite, respectively. High-resolution EBSD shows that major structural units and subunits of the tooth of Paracentrotus lividus are tilted to each other by ?3-5 and 1-2, respectively. This indicates that the tooth is not a single crystal. With EBSD we can show that the tooth of the sea urchin Paracentrotus lividus is a hierarchically assembled biological mesocrystal with a mosaic texture. In comparison to the misorientation spread of 0.5 of calcite grown from solution, misorientation in the tooth varies between 2 and 4. Thus, the self-sharpening feature of the tooth is enabled by a close interplay of its highly evolved micro- to nanostructure, structural unit size variations with a varying degree of crystal orientation, chemical structuring of the mineral component and a gradation of incorporated organic polymers. PMID:24937138

  18. Scanning Electron Microscope Characterization of Erosive Enamel in Human Teeth.

    PubMed

    Worawongvasu, Ratthapong

    2015-12-01

    This study aimed to examine the surface characteristics of erosive enamel in extracted human teeth by scanning electron microscopy. Morphologic changes in naturally eroded enamel depend on the stages of dental erosion. In its early stages, the enamel surfaces show a honeycomb appearance due to the dissolution of enamel rod ends. In its advanced stages, the erosive process involves the underlying dentin and the eroded dentin shows exposed dentinal tubules and the dentinal matrix may be exposed due to the dissolution of the peri- and intertubular dentin. Evidence of remineralization is seen at the early stage of natural dental erosion. PMID:26214120

  19. Restoration of Fluorosis Stained Teeth: A Case Study.

    PubMed

    Slaska, Barbara; Liebman, Arnold I; Kukleris, Diana

    2015-07-01

    Dental fluorosis manifests by too much ingestion of fluoride resulting in disturbances in enamel mineralization. The result is intrinsic discolorations in the maxillary and mandibular teeth with a poor esthetic appearance. In challenging cases, an esthetic result may be achieved only by a combination of techniques. This case report demonstrates a combination of modalities used to treat a patient presenting with atypical staining as a result of high-level exposure to ingested fluoride present in the drinking water as a child. Conservative treatment consisted of a combination of in-office bleaching to reduce the discoloration and porcelain veneers to create an esthetic result. PMID:26140966

  20. Movement adds bite to the evolutionary morphology of mammalian teeth

    PubMed Central

    2012-01-01

    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/ PMID:22898247

  1. Considerations for ceramic inlays in posterior teeth: a review

    PubMed Central

    Hopp, Christa D; Land, Martin F

    2013-01-01

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

  2. Self inflicted human teeth bites: a case report

    PubMed Central

    Singh, Satinder Pal; Aggarwal, Akashdeep; Kaur, Sumeet; Singh, Dalbir

    2014-01-01

    Human infighting has been a part of our civilization since times immemorial. These incidences may go unnoticed or may attract attention of law enforcing agencies depending upon the severity of the offence. Though weapons are generally employed to inflict injuries, rare cases have been reported in literature where human teeth have been used to serve this purpose. Human bites may be self inflicted or self suffered in connivance with others to level an allegation against an adversary. We are presenting here such a case where such injuries were produced to bring a false charge against a neighbor. PMID:25932066

  3. Teeth and numerology from zodiac signs. A correlative study.

    PubMed

    Kudva, S; Bhat, A P

    2000-01-01

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

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

    PubMed

    Rubel, Barry; Hill, Edward E

    2014-08-01

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

  5. Replacement of Maxillary Permanent Central Incisors Lost Due to Trauma in the Mixed-Dentition.

    PubMed

    Rubel, Barry; Hill, Edward E

    2015-04-01

    Traumatic injuries to anterior teeth in children range from minor chipping to total tooth loss and occur more often in boys than in girls. The treatment of permanent tooth loss in younger patients is complicated by the difficulty of doing restorative procedures which may be influenced by pulpal size, clinical crown height, and a dental profile that is constantly changing. This case report presented a situation involving a 9-year-old boy who had experienced traumatic loss of the maxillary central incisors. Innovative materials coupled with sound principles of removable partial denture design were utilized to fabricate a cast metal removable denture prosthesis to satisfy the esthetic, functional and psychological dental needs of the patient and his parents. PMID:26268010

  6. Identification of supernumerary teeth in 2D and 3D: review of literature and a proposal.

    PubMed

    Toureno, Leo; Park, Jae Hyun; Cederberg, Robert A; Hwang, Eui Hwan; Shin, Je-Won

    2013-01-01

    Supernumerary teeth occur in both syndromic and nonsyndromic patients, and dental professionals are likely to encounter such teeth in their professional careers. There are three main numbering systems used to identify teeth today: the Universal/ National, the Palmer/Zsigmondy notation, and the Federation Dentaire Internationale (FDI) numbering systems. However, a review of the literature suggests that none of these three consistently addresses the identification of supernumerary teeth. Being able to communicate the location of supernumerary teeth is important for dental professionals, especially in interdisciplinary situations. This article proposes a guideline to locate and identify supernumerary teeth in two and three dimensions, which may reduce treatment errors and improve communication among health care providers and third-party administrators. PMID:23314464

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

    SciTech Connect

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

    1983-04-01

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

  8. Esthetic Correction of Orthodontically Transposed Teeth with Veneers and Laser Periodontal Modification.

    PubMed

    Magid, Kenneth S; Juma, Zahid

    2015-07-01

    Missing teeth in the esthetic zone, whether congenital or as a result of other factors, present difficult choices in clinical management. The missing teeth can be replaced by surgical or restorative intervention but are often treated orthodontically. These repositioned teeth often lead to an unaesthetic result because of differences in morphology, color, and particularly in gingival architecture. This article describes the use of multiple lasers for periodontal modification and feldspathic porcelain veneers to achieve a highly esthetic result. PMID:26140971

  9. Wisdom teeth extraction in a patient with moyamoya disease.

    PubMed

    Seto, Mika; Aoyagi, Naoko; Koga, Sayo; Kikuta, Toshihiro

    2013-12-01

    Moyamoya disease is a rare neurovascular disorder that involves constriction of certain arteries in the brain. In patients with moyamoya disease, it is very important to prevent cerebral ischemic attacks and intracerebral bleeding caused by fluctuating blood pressure and increased respiration. A 40-year-old woman with moyamoya disease was scheduled for extraction of her right upper and lower impacted wisdom teeth. Her lower impacted wisdom tooth was situated close to the inferior alveolar nerve. We decided to continue her oral antiplatelet therapy and planned intravenous sedation with analgesic agents administered approximately five minutes prior to extraction of the root of the mandibular wisdom tooth. Oral analgesic medications were regularly administered postoperatively to alleviate pain and anxiety. During the perioperative period, no cerebrovascular event occurred, and the wisdom teeth were successfully extracted as per the planned procedure. It is thought that the perioperative risks of wisdom tooth extraction in patients with moyamoya disease can be minimized with the use of our protocols. PMID:24516819

  10. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage Ci given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage Ci decreased as both the adjacent P1 and M1 matured. The modal stage at P2 Ci was P1 Coc (cusp outline complete) and M1 Crc (crown complete). Initial mineralisation of P2 was observed up to P1 Crc and M1 stage R (root half). The chance of observing P2 at least Coc (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond Crc and M1 is beyond R. PMID:26673218

  11. Wear Resistance of Coating Films on Hob Teeth

    NASA Astrophysics Data System (ADS)

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

    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.

  12. Jaws and teeth of the earliest bony fishes.

    PubMed

    Botella, Hector; Blom, Henning; Dorka, Markus; Ahlberg, Per Erik; Janvier, Philippe

    2007-08-01

    Extant jawed vertebrates, or gnathostomes, fall into two major monophyletic groups, namely chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods). Fossil representatives of the osteichthyan crown group are known from the latest Silurian period, 418 million years (Myr) ago, to the present. By contrast, stem chondrichthyans and stem osteichthyans are still largely unknown. Two extinct Palaeozoic groups, the acanthodians and placoderms, may fall into these stem groups or the common stem group of gnathostomes, but their relationships and monophyletic status are both debated. Here we report unambiguous evidence for osteichthyan characters in jaw bones referred to the late Silurian (423-416-Myr-old) fishes Andreolepis hedei and Lophosteus superbus, long known from isolated bone fragments, scales and teeth, and whose affinities to, or within, osteichthyans have been debated. The bones are a characteristic osteichthyan maxillary and dentary, but the organization of the tooth-like denticles they bear differs from the large, conical teeth of crown-group osteichthyans, indicating that they can be assigned to the stem group. Andreolepis and Lophosteus are thus not only the oldest but also the most phylogenetically basal securely identified osteichthyans known so far. PMID:17671501

  13. Pulp revascularization for immature replanted teeth: a case report.

    PubMed

    Nagata, J Y; Rocha-Lima, T F; Gomes, B P; Ferraz, C C; Zaia, A A; Souza-Filho, F J; De Jesus-Soares, A

    2015-09-01

    Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8-year-old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow-up period, periapical repair, apical closure and calcification in the apical 4mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra-alveolar period and maintained in a viable storage medium may be treated with revascularization. PMID:26219350

  14. Neanderthal teeth from Moula-Guercy, Ardche, France.

    PubMed

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

    2013-07-01

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

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

    PubMed Central

    Pol, Chetan A; Gosavi, Suchitra R

    2014-01-01

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

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

    PubMed

    Belikova, N; Petrushanko, T

    2013-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-09-01

    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.

  18. Cylindrical Hall Thrusters with Permanent Magnets

    SciTech Connect

    Raitses, Yevgeny; Merino, Enrique; Fisch, Nathaniel J.

    2010-10-18

    The use of permanent magnets instead of electromagnet coils for low power Hall thrusters can offer a significant reduction of both the total electric power consumption and the thruster mass. Two permanent magnet versions of the miniaturized cylindrical Hall thruster (CHT) of different overall dimensions were operated in the power range of 50W-300 W. The discharge and plasma plume measurements revealed that the CHT thrusters with permanent magnets and electromagnet coils operate rather differently. In particular, the angular ion current density distribution from the permanent magnet thrusters has an unusual halo shape, with a majority of high energy ions flowing at large angles with respect to the thruster centerline. Differences in the magnetic field topology outside the thruster channel and in the vicinity of the channel exit are likely responsible for the differences in the plume characteristics measured for the CHTs with electromagnets and permanent magnets. It is shown that the presence of the reversing-direction or cusp-type magnetic field configuration inside the thruster channel without a strong axial magnetic field outside the thruster channel does not lead to the halo plasma plume from the CHT. __________________________________________________

  19. QUANTITATIVE TRAIT LOCI FOR INFECTIOUS BOVINE KERATOCONJUNCTIVITIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. 13 CFR 120.900 - Sources of permanent financing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans,...

  1. 13 CFR 120.900 - Sources of permanent financing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans,...

  2. 13 CFR 120.900 - Sources of permanent financing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans,...

  3. 13 CFR 120.900 - Sources of permanent financing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans,...

  4. 13 CFR 120.900 - Sources of permanent financing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Sources of permanent financing... Development Company Loan Program (504) Permanent Financing 120.900 Sources of permanent financing. Permanent financing for each Project must come from three sources: the Borrower's contribution, Third-Party Loans,...

  5. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  6. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  7. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  8. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  9. 31 CFR 515.335 - Permanent resident alien.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Permanent resident alien. 515.335... Definitions § 515.335 Permanent resident alien. As used in § 515.208, the term permanent resident alien means an alien lawfully admitted for permanent residence into the United States....

  10. 38 CFR 62.11 - Participants-occupying permanent housing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... permanent housing. (a) Occupying permanent housing. A very low-income veteran family will be considered to be occupying permanent housing if the very low-income veteran family: (1) Is residing in permanent... veteran family's needs and preferences. Note to paragraph (a): For limitations on and continuations of...

  11. 38 CFR 62.11 - Participants-occupying permanent housing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... permanent housing. (a) Occupying permanent housing. A very low-income veteran family will be considered to be occupying permanent housing if the very low-income veteran family: (1) Is residing in permanent... veteran family's needs and preferences. Note to paragraph (a): For limitations on and continuations of...

  12. 38 CFR 62.11 - Participants-occupying permanent housing.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... permanent housing. (a) Occupying permanent housing. A very low-income veteran family will be considered to be occupying permanent housing if the very low-income veteran family: (1) Is residing in permanent... veteran family's needs and preferences. Note to paragraph (a): For limitations on and continuations of...

  13. 38 CFR 62.11 - Participants-occupying permanent housing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... permanent housing. (a) Occupying permanent housing. A very low-income veteran family will be considered to be occupying permanent housing if the very low-income veteran family: (1) Is residing in permanent... veteran family's needs and preferences. Note to paragraph (a): For limitations on and continuations of...

  14. Laced permanent magnet quadrupole drift tube magnets

    SciTech Connect

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

    1989-03-01

    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.

  15. Serum susceptibility of bovine pasteurellas.

    PubMed

    Blau, K A; Ward, A C; Prieur, D J; Corbeil, L B

    1987-04-01

    In this study, the serum sensitivity of 23 P. haemolytica isolates and 18 P. multocida isolates was determined by incubating dilutions of bacteria with equal volumes of fresh or heat-inactivated bovine serum for one, two, or three hours. Clinical isolates of both Pasteurella species were resistant to serum, whereas isolates from asymptomatic cattle varied in serum susceptibility. The classical pathway of complement appeared to be the principal means of complement mediated killing as detected by incubation in the presence or absence of EGTA-MgCl2. Lyzozyme and iron saturation of serum did not greatly affect serum susceptibility with either of the Pasteurella species. PMID:3300919

  16. Models of bovine babesiosis including juvenile cattle.

    PubMed

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

    2015-03-01

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

  17. Magnetic guns with cylindrical permanent magnets

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

  18. Permanent isolation surface barrier: Functional performance

    SciTech Connect

    Wing, N.R.

    1993-10-01

    This document presents the functional performance parameters for permanent isolation surface barriers. Permanent isolation surface barriers have been proposed for use at the Hanford Site (and elsewhere) to isolate and dispose of certain types of waste in place. Much of the waste that would be disposed of using in-place isolation techniques is located in subsurface structures, such as solid waste burial grounds, tanks, vaults, and cribs. Unless protected in some way, the wastes could be transported to the accessible environment via transport pathways, such as water infiltration, biointrusion, wind and water erosion, human interference, and/or gaseous release.

  19. Prevalence and management of natal/neonatal teeth in cleft lip and palate patients

    PubMed Central

    Yilmaz, R. Burcu Nur; Cakan, Derya Germec; Mesgarzadeh, Nasim

    2016-01-01

    Objective: The aim of this study was to determine the prevalence and distribution of natal/neonatal teeth in infants with cleft lip and palate (CLP) according to gender, involving jaw and side and to show the management of some cases. Materials and Methods: A retrospective study was carried out on medical history and photographic records of 69 infants with CLP, who were treated at the CLP clinic of Yeditepe University between years 2014–2015. The presence of neonatal teeth was determined, and if present the gender, type of cleft, and position were recorded. Statistical analysis was performed. Results: Neonatal teeth were observed in 7% of the study group. No significant differences were found between cleft types and gender (P > 0.05). The prevalence of neonatal teeth in bilateral, unilateral and isolated cleft type was 16.5%, 6.5%, and none, respectively. All neonatal teeth were located in the maxilla and on the cleft-side (100%). Conclusion: The presence of natal/neonatal teeth in infants with CLP was not rare. In all of these cases the teeth were located adjacent to the cleft region. In isolated palatal cleft, where the alveolar region including the teeth buds are away from the cleft, no neonatal teeth were observed. It may be concluded that neonatal teeth in infants with CLP are frequently present and located inside the borders of the presurgical orthopedic treatment (POT) plate. Therefore, if possible, immediate extraction of the neonatal teeth is advised or if not possible because of systemic health reasons, modifications of the plate are required. PMID:27011740

  20. Bovine somatic cell nuclear transfer.

    PubMed

    Ross, Pablo J; Cibelli, Jose B

    2010-01-01

    Somatic cell nuclear transfer (SCNT) is a technique by which the nucleus of a differentiated cell is introduced into an oocyte from which its genetic material has been removed by a process called enucleation. In mammals, the reconstructed embryo is artificially induced to initiate embryonic development (activation). The oocyte turns the somatic cell nucleus into an embryonic nucleus. This process is called nuclear reprogramming and involves an important change of cell fate, by which the somatic cell nucleus becomes capable of generating all the cell types required for the formation of a new individual, including extraembryonic tissues. Therefore, after transfer of a cloned embryo to a surrogate mother, an offspring genetically identical to the animal from which the somatic cells where isolated, is born. Cloning by nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. Cattle were the second mammalian species to be cloned after Dolly the sheep, and it is probably the most widely used species for SCNT experiments. This is, in part due to the high availability of bovine oocytes and the relatively higher efficiency levels usually obtained in cattle. Given the wide utilization of this species for cloning, several alternatives to this basic protocol can be found in the literature. Here we describe a basic protocol for bovine SCNT currently being used in our laboratory, which is amenable for the use of the nuclear transplantation technique for research or commercial purposes. PMID:20336522

  1. [Toxinology of bovine paraplegic syndrome].

    PubMed

    Sevcik, C; Brito, J C; D'Suze, G; Mijares, A J; Domnguez, M G

    1993-01-01

    A clinical entity named "Bovine Paraplegic Syndrome" ("Sndrome Parapljico de los Bovinos") has spread alarmingly, in the cattle growing areas of the central and eastern plains of Venezuela. Approximately four million cattle are bread in the area were the disease occurs. The mortality index due to the disease ranges 5 to 25% of the animals at risk, mostly cows, pregnant or lactating. The principal characteristic of the bovine paraplegic syndrome is decubitus, ventral or sternal, in animals that make vane efforts to stand when stimulated. The diagnosis is established ruling out, clinically and with laboratory findings, that the animals are suffering known diseases with similar symptoms such as paralytic rabies, botulism and blood parasites such Trypanosoma sp., Babesia sp., and Anaplasma sp.. Death occurs always, usually after few days, and to this date there is no known treatment able to save the sick cows. In this work, we describe results that suggest the presence of a toxin in the cattle suffering and prone to suffer the syndrome; it is a natural toxin produced by ruminal bacteria. In squid giant axons under voltage clamp conditions, this toxin is very specific to block sodium current during nerve electrical activity. PMID:8085407

  2. Genome of Bovine Herpesvirus 5

    PubMed Central

    Delhon, G.; Moraes, M. P.; Lu, Z.; Afonso, C. L.; Flores, E. F.; Weiblen, R.; Kutish, G. F.; Rock, D. L.

    2003-01-01

    Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138,390-bp genome encodes 70 putative proteins and resembles the ?2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 is very similar to BHV-1, the etiological agent of infectious bovine rhinotracheitis, as reflected by the high level of amino acid identity in their protein repertoires (average, 82%). The highest similarity to BHV-1 products (?95% amino acid identity) is found in proteins involved in viral DNA replication and processing (UL5, UL15, UL29, and UL39) and in virion proteins (UL14, UL19, UL48, and US6). Among the least conserved (?75%) are the homologues of immediate-early (IE) proteins BICP0, BICP4, and BICP22, the three proteins being longer in BHV-5 than in BHV-1. The structure of the BHV-5 latency-related (LR) region departs markedly from that of BHV-1 in both coding and transcriptional regulatory regions. Given the potential significance of IE genes and the LR region in virus-neuron interactions, it is likely these differences contribute to BHV-5 neuropathogenicity. PMID:12970418

  3. Adipogenesis of bovine perimuscular preadipocytes

    SciTech Connect

    Taniguchi, Masaaki; Le Luo Guan; Zhang Bing; Dodson, Michael V.; Okine, Erasmus; Moore, Stephen S.

    2008-02-01

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

  4. Bovine milk antibodies for health.

    PubMed

    Korhonen, H; Marnila, P; Gill, H S

    2000-11-01

    The immunoglobulins of bovine colostrum provide the major antimicrobial protection against microbial infections and confer a passive immunity to the newborn calf until its own immune system matures. The concentration in colostrum of specific antibodies against pathogens can be raised by immunising cows with these pathogens or their antigens. Immune milk products are preparations made of such hyperimmune colostrum or antibodies enriched from it. These preparations can be used to give effective specific protection against different enteric diseases in calves and suckling pigs. Colostral immunoglobulin supplements designed for farm animals are commercially available in many countries. Also, some immune milk products containing specific antibodies against certain pathogens have been launched on the market. A number of clinical studies are currently in progress to evaluate the efficacy of immune milks in the prevention and treatment of various human infections, including those caused by antibiotic resistant bacteria. Bovine colostrum-based immune milk products have proven effective in prophylaxis against various infectious diseases in humans. Good results have been obtained with products targeted against rotavirus, Shigella flexneri, Escherichia coli, Clostridium difficile, Streptococcus mutans, Cryptosporidium parvum and Helicobacter pylori. Some successful attempts have been made to use immune milk in balancing gastrointestinal microbial flora. Immune milk products are promising examples of health-promoting functional foods, or nutraceuticals. This review summarises the recent progress in the development of these products and evaluates their potential as dietary supplements and in clinical nutrition. PMID:11242458

  5. Sensory transduction in human teeth with inflamed pulps.

    PubMed

    Ajcharanukul, O; Chidchuangchai, W; Charoenlarp, P; Vongsavan, N; Matthews, B

    2011-05-01

    The effects of pulpal inflammation on the sensitivity of dentin to cold (5C) and negative hydrostatic pressure (-300 mm Hg) stimuli in man were compared, since recent evidence suggests that these stimuli excite different classes of sensory receptors. Dentin was exposed in premolars in 14 participants aged 15-25 years. Stimuli were applied to etched dentin immediately after cavity preparation and after the cavity had been filled with gutta percha for 7 days. This treatment increased significantly the intensity of pain produced by cold, and at the same time decreased that evoked by negative pressure stimuli. Pulpal blood flow was increased in the treated teeth, indicating that their pulps were inflamed. It is concluded that the sensory receptors responsible for the response to cold were probably sensitive to some change other than an outward flow of fluid in dentinal tubules, which would be caused by both forms of stimulus. PMID:21224409

  6. Contact stresses in gear teeth: A new method of analysis

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  7. A new procedure for calculating contact stresses in gear teeth

    NASA Technical Reports Server (NTRS)

    Somprakit, Paisan; Huston, Ronald L.

    1991-01-01

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

  8. Multiple Bilateral Taurodontic Teeth in Primary Dentition: A Case Report

    PubMed Central

    Dwivedi, Swati; Arora, Satyaki; Mayall, Sandeep

    2013-01-01

    ABSTRACT Taurodontism describes the tendency for the body of the tooth to enlarge at the expense of the roots. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. These anatomic variations may hinder location of canal orifices, complete removal of pulp, proper instrumentation and obturation. Importance of radiographic interpretation for the diagnosis of this alteration cannot be overlooked. This article describes a case of multiple bilateral taurodontism involving all the deciduous molars in a 3 year old female. The child reported with a chief complaint of multiple carious lesions. How to cite this article: Vashisth P, Dwivedi S, Arora S, Mayall S. Multiple Bilateral Taurodontic Teeth in Primary Dentition: A Case Report. Int J Clin Pediatr Dent 2013;6(2):132-133. PMID:25206208

  9. Multiple bilateral taurodontic teeth in primary dentition: a case report.

    PubMed

    Vashisth, Pallavi; Dwivedi, Swati; Arora, Satyaki; Mayall, Sandeep

    2013-05-01

    Taurodontism describes the tendency for the body of the tooth to enlarge at the expense of the roots. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. These anatomic variations may hinder location of canal orifices, complete removal of pulp, proper instrumentation and obturation. Importance of radiographic interpretation for the diagnosis of this alteration cannot be overlooked. This article describes a case of multiple bilateral taurodontism involving all the deciduous molars in a 3 year old female. The child reported with a chief complaint of multiple carious lesions. How to cite this article: Vashisth P, Dwivedi S, Arora S, Mayall S. Multiple Bilateral Taurodontic Teeth in Primary Dentition: A Case Report. Int J Clin Pediatr Dent 2013;6(2):132-133. PMID:25206208

  10. Contact stresses in gear teeth - A new method of analysis

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  11. An Experimental Study of Fretting of Gear Teeth

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.

    2008-01-01

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

  12. Esthetic Rehabilitation of Anterior Teeth with Laminates Composite Veneers

    PubMed Central

    Riva, Giancarlo

    2014-01-01

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

  13. The effect of various storage methods and media on shear-bond strengths of dental composite resin to bovine dentine.

    PubMed

    Titley, K C; Chernecky, R; Rossouw, P E; Kulkarni, G V

    1998-04-01

    A variety of media and methods have been used to store teeth used in bond-strength studies of resin restorative materials to dentine. This study examined the effect of 2 months of storage using 11 different methods and media on the shear-bond strength of Z100 resin composite to bovine dentine mediated by Scotchbond Multi Purpose adhesive. Freshly harvested teeth were used as controls. The results showed that 7 of the l1 storage methods or media were similar in shear-bond strengths and bond-failure characteristics. Four of the 11 methods (irradiation, or storage in thymol, methanol, and glutaraldehyde) resulted in significantly lower shear-bond strengths and atypical shear-bond failure, indicating that these are the least desirable methods of tooth storage for studies of this type. This study has further shown that if insufficient numbers of fresh teeth are available for studies of shear-bond strength, then freezing is the preferred method of storage for the registration of high shear-bond strengths. It is also apparent that further investigations are needed to examine what post mortem changes occur in dentine, whether these changes are modified by various storage conditions, and whether they have any significant effect on bonding of resin composites. PMID:9839706

  14. Tissue engineering of teeth using adult stem cells.

    PubMed

    Modino, Sonie A C; Sharpe, Paul T

    2005-02-01

    Tooth development, a process which occurs in the developing embryo, involves the reciprocal and sequential signalling between epithelial and mesenchymal tissue of the developing first branchial arch. The oral epithelium produces the first inductive signals for odontogenesis at around E10.0, which trigger off a cascade of events that result in the formation of a tooth. We have engineered a tooth in vitro by harnessing the basic principles of odontogenesis and the inductive capability of the oral epithelium of the developing embryo. We replaced the mesenchymal portion of the developing mandibular primordium with aggregates of stem cells from embryos as well as stem cells taken from adult mice. The cell aggregates were covered with embryonic epithelium from E10.0 mouse embryos to form recombinant explants. In vitro culture of these recombinant explants resulted in the induction of early tooth marker genes in the cell aggregates, indicating that the cells were able to respond to the odontogenic signals produced by the oral epithelium. In vivo culture of explants resulted in the induction of Dspp within the cell aggregates indicating that tooth tissue was present. Three recombinant explants, where the cell aggregates consisted of adult bone marrow cells, produced teeth. To determine whether the oral cavity would be able to sustain the growth of an implanted tooth germ, E14.5 molar rudiments were implanted into the diastema region of the maxilla of adult mice. The resulting teeth appeared to be normal in size and were connected to the underlying bone. These experiments are an indication that it is possible to induce odontogenesis and engineer a tooth using adult cells of non-dental origin. They also indicate that developing tooth germs could be successfully implanted into the gingiva of patients. PMID:15721158

  15. The soft tissue barrier at implants and teeth.

    PubMed

    Berglundh, T; Lindhe, J; Ericsson, I; Marinello, C P; Liljenberg, B; Thomsen, P

    1991-01-01

    In the present animal experiment, analyses and comparisons were made between the structure and composition of clinically healthy supraalveolar soft tissues adjacent to implants and teeth. 5 beagle dogs were used. The right mandibular premolar region was selected in each dog for placement of titanium implants, while the left mandibular premolar region served as control. Extractions of the mandibular premolars were preformed, healing allowed, following which titanium fixtures were installed in the edentolous premolar region. Abutment connection was carried out 3 months later. After another 2 months of healing, plaque control was initiated and maintained for 8 weeks. At the end of the plaque control period, clinical examinations were performed and biopsies harvested from the implant site and the contralateral premolar tooth region. Following fixation and decalcification, all tissue samples were embedded in EPON and examined by histometric and morphometric means. The result from the analyses demonstrated that the periimplant mucosa which formed at titanium implants following abutment connection had many features in common with gingival tissue at teeth. Thus, like the gingiva, the peri-implant mucosa established a cuff-like barrier which adhered to the surface of the titanium abutment. Further, both the gingiva and the peri-implant mucosa had a well-keratinized oral epithelium which was continuous with a junctional epithelium that faced the enamel or the titanium surface. In the periimplant mucosa, the collagen fibers appeared to commence at the marginal bone and were parallel with the abutment surface. All gingival and periimplant units examined were free from infiltrates of inflammatory cells. It was suggested that under the conditions of study, both types of soft tissues, gingiva and periimplant mucosa, have a proper potential to prevent subgingival plaque formation. PMID:1809403

  16. A set of hypotheses on tribology of mammalian herbivore teeth

    NASA Astrophysics Data System (ADS)

    Kaiser, Thomas M.; Clauss, Marcus; Schulz-Kornas, Ellen

    2016-03-01

    Once erupted, mammal cheek teeth molars are continuously worn. Contact of molar surfaces with ingesta and with other teeth contribute to this wear. Microscopic wear features (dental surface texture) change continuously as new wear overprints old texture features. These features have been debated to indicate diet. The general assumption in relating occlusal textures to diet is that they are independent of masticatory movements and forces. If this assumption is not accepted, one needs to propose that occlusal textures comprise signals not only from the ‘last supper’ but also from masticatory events that represent ecological, species- or taxon-specific adaptations, and that occlusal textures therefore give a rather unspecific, somehow diet-related signal that is functionally inadequately understood. In order to test for mechanical mechanisms of wear, we created a hypothesis matrix that related sampled individuals with six tribological variables. Three variables represent mechanically relevant ingesta properties, and three represent animal-specific characteristics of the masticatory system. Three groups of mammal species (free ranging Cetartiodactyla and Perissodactyla, free ranging primates, and artificially fed rabbits) were investigated in terms of their 3D dental surface textures, which were quantified employing ten ISO 25178 surface texture parameters. We first formulated a set of specific predictions based on theoretical reflections on the effects of diet properties and animal characteristics, and subsequently performed discriminant analysis to test which parameters actually followed these predictions. We found that parameters Vvc, Vmc, Sp, Sq allowed the prediction of both, ingesta properties and properties of the masticatory system, if combined with other parameters. Sha, Sda and S5v had little predictive power in our dataset. Spd seemed rather unrelated to ingesta properties and made this parameter a suitable indicator of masticatory system properties.

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

    PubMed

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

    2005-08-01

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

  18. Sequential development of multiple supernumerary teeth in the mandibular premolar region -- a radiographic case report.

    PubMed

    Moore, S R; Wilson, D F; Kibble, J

    2002-03-01

    This report presents a case of multiple supernumerary teeth developing in the mandibular premolar region in an Asian female patient. A series of radiographs taken over a 10-year period, demonstrate the sequential development of these teeth during the patient's early and middle teenage years. The importance of regular radiographic review and appropriate management for such cases is discussed. PMID:11966892

  19. 90Sr in deciduous teeth from 1950 to 2002: the Swiss experience.

    PubMed

    Froidevaux, P; Geering, Jean-Jacques; Valley, J-F

    2006-08-31

    Switzerland has recorded the level of activity of 90Sr in the milk teeth of children from different regions of the country since the first atomic explosions in the atmosphere. Activity peaked at 0.421 Bq g-1 Ca at the beginning of the sixties, coinciding with the detonation of many large nuclear devices. Following the Nuclear Test Ban Treaty that ended atmospheric nuclear weapon tests, a steady and significant decrease in 90Sr activity in milk teeth has been observed-down to a value of 0.03 Bq g-1 Ca for children born in 1994. The apparent half-life of 90Sr in milk teeth is 9.8+/-3 years. With the exception of the period from 1962 to 1964, there is no correlation between the activity in the teeth of children born in a given year and the year of extraction. Between 1953 and 1992, the milk teeth of children born in Zrich county showed 16% less activity than teeth from children born in Vaud county. Dairy consumption habits might be responsible for this trend. The effect of the 90Sr deposition from Chernobyl is barely measurable in milk teeth, and no effect is seen from the five Swiss nuclear reactors. This paper emphasizes the necessity of a very high purity chemical separation of 90Sr or 90Y to determine 90Sr activity in milk teeth or other samples. PMID:16546237

  20. Light-enhanced chemical whitening of teeth: new in vitro investigation

    NASA Astrophysics Data System (ADS)

    Todorovska, R.; Dimitrov, S.; Pavlova, P.; Todorov, G.

    2007-03-01

    We report new results on the light enhanced teeth whitening obtained in a research collaboration financed by the Medical Science Council of the Medical University of Sofia. The project is an extension of previous research and its basic goal is to develop new teeth bleaching substances and procedures, in which the activators are diode lamps (LED).