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Sample records for bovine permanent teeth

  1. Multiple Unerupted Permanent Teeth Associated with Noonan Syndrome

    PubMed Central

    Uloopi, KS; Madhuri, V; Gopal, AS; Vinay, C; Chandrasekhar, R

    2015-01-01

    The present report describes a case of Noonan's syndrome from a dental viewpoint. Noonan syndrome is an autosomal dominant multisystem disorder. Congenital heart deformities, short stature, thoracic deformities, short neck with webbing, hypertelorism, and malocclusions are some of the frequently observed clinical features. Atypical dental anomalies such as multiple unerupted permanent teeth, multiple submerged and retained deciduous teeth, and supernumerary teeth were found in the present case. Oral prophylaxis and preventive resin restorations were done following which the supernumerary teeth were extracted. 54, 55, 64, 65, 74, 75 and 84 were extracted after orthodontic consultation to facilitate the eruption of permanent teeth. The patient is undergoing fixed orthodontic therapy for forced eruption of unerupted permanent teeth. General dentists should correlate dental anomalies with other systemic features in the diagnosis of such syndromes because of the variability in presentation and the need for multidisciplinary care. PMID:26229724

  2. The distribution of nerves in human deciduous and permanent teeth.

    PubMed

    Itoh, K

    1976-11-01

    Human permanent teeth without caries, obtained from 10-16 year old males and females and noncarious human deciduous teeth in which roots remained intact or were only poorly resorbed, were studied histologically. The distribution of sensory nerves in deciduous teeth were compared with that in permanent teeth by means of the silver-nitrate technique. 1. In radicular pulp, the sensory nerve fiber bundles accompany blood vessels in the axial area and several nerve single-fibers occur in the peripheral area of the pulp. 2. The subodontoblastic nerve plexus is formed in or beneath the cell-rich zone of the coronal pulp, and further, the marginal nerve plexus is built up near the pulpo-predentinal border. 3. The nerve fibers entering the predentin can be classified into 3 types by their courses. In the first type, nerve fibers pass directly toward the calcification front along the dentinal tubules in the predentin. In the second type, nerve fibers run obliquely or transversely in the predentin. The transversal fibers form a plexus-like structure by dividing and interlacing at various levels of predentin. The third type nerve fibers pass along the dentinal tubules in the predentin and, after reaching the predentino-dentinal border, reverse the odontoblast layer, thus forming a looped course. 4. There is no essential difference between the nerve supply in the deciduous and in the permanent teeth, but the nerves in the deciduous teeth are less dense in distribution and lower in amount than in the permanent teeth. Moreover, a typical marginal nerve plexus, which occurs constantly in the permanent teeth, is only occasionally found in the deciduous teeth; and no nerve fiber was observed to penetrate into the calcified dentin in the deciduous teeth. This finding seems to account for the fact that the deciduous teeth are less sensitive than their permanent successors. PMID:798562

  3. Bovine teeth as substitute for human teeth in dental research: a review of literature.

    PubMed

    Yassen, Ghaeth H; Platt, Jeffrey A; Hara, Anderson T

    2011-09-01

    The aim of this paper was to review in vitro and in situ studies that directly compared the use of bovine teeth as a substitute for human teeth in dental experiments. A PubMed search was conducted for papers published from 1953 to December 30, 2010 using the following keywords: "human bovine enamel" or "human bovine dentin" or "human bovine teeth". The abstracts of the studies resulting from the keyword search were read, and all papers that compared human and bovine teeth were fully read. Only original articles written in English and directly comparing human and bovine substrates were included in the review. The search was supplemented by manual searches of the reference lists from each identified paper. Out of 76 studies initially selected, 68 fulfilled the selection criteria for inclusion. The studies covered seven categories: dental morphology, chemical composition, physical properties, dental caries, dental erosion/abrasion, bonding/adhesive strength, and marginal microleakage. Inconsistent data exist regarding whether bovine teeth can be considered an appropriate substitute for human teeth in dental research. Morphological, chemical compostion and physical property differences between the two substrates must be considered when interpreting results obtained from any experiment using bovine tooth substrate. PMID:21959653

  4. Prevalence of congenitally missing permanent teeth in Iran

    PubMed Central

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

    2012-01-01

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

  5. Factors influencing permanent teeth eruption. Part one--general factors.

    PubMed

    Almonaitiene, Ruta; Balciuniene, Irena; Tutkuviene, Janina

    2010-01-01

    Variation in the normal eruption of teeth is a common finding, but significant deviation from established norms should alert the clinician to take some diagnostic procedures in order to evaluate patient health and development. Disturbance in tooth eruption time could be a symptom of general condition or indication of altered physiology and craniofacial development. The aim of this review is to analyze general factors that could influence permanent teeth eruption. The articles from 1965 to 2009 in English related to topic were identified. 84 articles were selected for data collection. Although permanent teeth eruption is under significant genetic control, various general factors such as gender, socioeconomic status, craniofacial morphology, body composition can influence this process. Most significant disturbance in teeth emergence is caused by systemic diseases and syndromes. PMID:21063135

  6. 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

  7. Shear Bond Strength and Fracture Analysis of Human vs. Bovine Teeth

    PubMed Central

    Rüttermann, Stefan; Braun, Anika; Janda, Ralf

    2013-01-01

    Purpose To evaluate if bovine enamel and dentin are appropriate substitutes for the respective human hard tooth tissues to test shear bond strength (SBS) and fracture analysis. Materials and Methods 80 sound and caries-free human erupted third molars and 80 freshly extracted bovine permanent central incisors (10 specimens for each group) were used to investigate enamel and dentine adhesion of one 2-step self-etch (SE) and one 3-step etch and rinse (E&R) product. To test SBS the buccal or labial areas were ground plane to obtain appropriate enamel or dentine areas. SE and E&R were applied and SBS was measured prior to and after 500 thermocycles between +5 and +55°C. Fracture analysis was performed for all debonded areas. Results ANOVA revealed significant differences of enamel and dentin SBS prior to and after thermocycling for both of the adhesives. SBS- of E&R-bonded human enamel increased after thermocycling but SE-bonded did not. Bovine enamel SE-bonded showed higher SBS after TC but E&R-bonded had lower SBS. No differences were found for human dentin SE- or E&R-bonded prior to or after thermocycling but bovine dentin SE-bonded increased whereas bovine dentine E&R-bonded decreased. Considering the totalized and adhesive failures, fracture analysis did not show significances between the adhesives or the respective tooth tissues prior to or after thermocycling. Conclusion Although SBS was different on human and bovine teeth, no differences were found for fracture analysis. This indicates that solely conducted SBS on bovine substrate are not sufficient to judge the perfomance of adhesives, thus bovine teeth are questionnable as a substrate for shear bond testing. PMID:23527125

  8. Boon of MTA Apexification in Young Permanent Posterior Teeth.

    PubMed

    Kumar, Vinod; Zameer, Mohammed; Prasad, Vijaya; Mahantesh, T

    2014-01-01

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

  9. Boon of MTA Apexification in Young Permanent Posterior Teeth

    PubMed Central

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

    2014-01-01

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

  10. Effect of the mineralizing agent on the permanent teeth.

    PubMed

    Kolmakow, S; Honkala, E; Borovsky, E V; Kuzmina, E M; Vasina, S A

    1991-01-01

    In a two-year pragmatic clinical trial, the effect of the mineralizing agent was evaluated on permanent teeth of the first eruption group among Finnish children (7-years old at the beginning of the study) with a low prevalence of DFS. In the test group (n = 123, biweekly mouthrinsing with a 2% solution of mineralizing agent and 0.2% NaF solution) the percentage reduction in increment of both EFDS and DFS was high, whereas in the control group (n = 123, biweekly mouthrinsing with placebo and 0.2% NaF solutions) the incidence for symptoms of caries disease did not differ from that normally found in this age cohort. Positive clinical effect of tested solution was age-related and was associated with remineralization of old and inhibition of occurrence of new EFD lesions. PMID:1878329

  11. Clinical complications in the revascularization of immature necrotic permanent teeth.

    PubMed

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

    2012-01-01

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

  12. 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.

  13. 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

  14. Relations between anterior permanent teeth, dental arches and hard palate.

    PubMed

    Petricević, Nikola; Stipetić, Jasmina; Antonić, Robert; Borcić, Josipa; Strujić, Mihovil; Kovacić, Ivan; Celebić, Asja

    2008-12-01

    The width and length of the anterior teeth, the dimensions of the frontal dental arches and the dimensions of the hard palate were measured (24 men and 56 women, age range of 18-30 years). The results showed gender-related dimorphism only for the cervical width of the maxillary canine, which were wider in men, p < 0.05. The width-to-length ratios of the maxillary frontal teeth varied from 0.82 to 0.91. The tooth-to-tooth width ratios among different maxillary frontal teeth varied from 0.78 to 0.91. The sum of all anterior maxillary teeth widths was equal to the hamular width and to the distal maxillary arch width (p > 0.05), meaning that the sum of the frontal artificial teeth width may be selected upon the measurement of the hamular width on the hard palate. The ratios between the maxillary and the mandibular frontal dental arch dimensions are representative values for the skeletal class I. PMID:19149214

  15. [Wire/composite splinting of traumatically injured permanent teeth].

    PubMed

    Szöke, J; Kacsó, Z; Kozma, M; Tóbel, M

    1991-01-01

    For splinting traumatically loosened and/or reimplanter remaining front teeth wire splints are used which are fixed by means of composite substance, gluing technique. Kinds of employed splints are disclosed and the steps of the practical carrying out of splinting are described. Indications, advantages and disadvantages of its employment are discussed. PMID:1680755

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

    PubMed

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

    2013-01-01

    Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. It is a developmental anomaly and has been argued to arise from multiple aetiologies. The most common site is the maxillary incisor region; but the prevalence of more than three teeth supernumerary tooth is less than 1%. A case of 13 year male patient is reported with a multiple impacted supernumerary tooth in maxillary anterior region hindering the eruption of right permanent central incisor. The supernumerary tooth was treated via surgical approach followed by an interim prosthesis for permanent central incisor which later on erupted in due course of time. Background Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. The presence of supernumerary teeth in the premaxillary region often poses unique diagnostic and managerial concerns for the practitioner. Rarely is the surplus number compensated by an absence or deficiency of other teeth. Therefore, the dysfunctional nature of supernumerary teeth and their ability to create a variety of pathological disturbances in the normal eruption and position of adjacent teeth warrants their early detection and prudent management. Approximately 76-86% of cases represent single-tooth hyperdontia, with two supernumerary teeth noted in 12-23% and three or more extra teeth noted in less than 1% of cases. Multiple supernumerary teeth are also associated with many syndromes like cleidocranial dysplasia and Gardner’s syndrome etc. However, it is rare to find multiple supernumeraries in individuals with no other associated disease or syndrome. In such cases, the maxillary anterior region is the common site of occurrence. The exact aetiology is not clearly understood. The supernumerary teeth result from any disturbance in the initiation and proliferation stages of odontogenesis. There are several theories regarding the

  17. Overview of trauma management for primary and young permanent teeth.

    PubMed

    McTigue, Dennis J

    2013-01-01

    This overview covers diagnosis and management of the most common dental injuries in children and identifies those children at greatest risk. Crown fractures and luxation injuries in both the primary and permanent dentition are discussed and treatment options based on current international guidelines are detailed. PMID:23174609

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

    PubMed Central

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

    2013-01-01

    Introduction To evaluate the clinical and radiographic outcomes of pulpotomy treatment with mineral trioxide aggregate (MTA) in symptomatic mature permanent teeth with carious exposure. Materials and Methods Ten patients aged 27-54 years presented with 11 symptomatic permanent teeth (n=11). Each offending carious tooth was clinically and radiographically determined. We removed caries as conservatively as possible; however pulp exposure was inevitable. ProRoot MTA pulpotomy was performed on these teeth. The patients were followed-up clinically and radiographically for 24-42 months. Results Immediate relief of patients` symptoms occurred. Moreover, teeth responses to the electric pulp tester were within normal range on follow-up appointment and the radiographs did not reveal any abnormality/lesion in the periapical areas. Conclusion Pulpotomy using MTA could be a good alternative for root canal therapy (RCT) for managing symptomatic mature permanent teeth with carious exposure, however further large-scale multicenter clinical trials are highly encouraged to confirm this hypothesis. PMID:23717332

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

    PubMed

    Barrieshi-Nusair, Kefah Mahmood; Qudeimat, Muawia Abdulla

    2006-08-01

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

  20. 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

  1. 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

  2. Effect of skewing the rotor teeth on the performance of doubly salient permanent magnet motors

    NASA Astrophysics Data System (ADS)

    Sheth, N. K.; Sekharbabu, A. R. C.; Rajagopal, K. R.

    2006-04-01

    This paper presents the effects of skewing the rotor teeth on the performance characteristics such as flux linkage, back emf, phase inductance, and reluctance torque of an 8/6 doubly salient permanent magnet motor using a simple method, which utilizes the results obtained from the two-dimensional finite element analysis. The optimum skewing angle is obtained as 12°-15° for the least ripple torque without much reduction in the back emf. Skewing the rotor teeth of an 8/6 doubly salient permanent magnet motor by 12°-15° will reduce the total harmonic distortion of the back emf profile to 29.69% from the original value of 44.69%. The reduction in the amplitude of the back emf in this case will be 18.79% only.

  3. Contribution of prosthetic treatment considerations for dental extractions of permanent teeth.

    PubMed

    Fernández-Barrera, Miguel Ángel; Medina-Solís, Carlo Eduardo; Casanova-Rosado, Juan Fernando; Mendoza-Rodríguez, Martha; Escoffié-Ramírez, Mauricio; Casanova-Rosado, Alejandro José; Navarrete-Hernández, José de Jesús; Maupomé, Gerardo

    2016-01-01

    Background. Tooth loss is an easily identifiable outcome that summarizes a complex suite of factors in an individual's history of dental disease and its treatment by dental services over a lifetime. Assessment of overall tooth loss data is essential for epidemiologically evaluating the adequacy of dental care provided at a systems level, as well as for placing in context tooth loss for non-disease causes. For example, when derived from prosthetic treatment planning, the latter may unfortunately lead to some teeth being extracted (pulled) for the sake of better comprehensive clinical results. The objective of the present manuscript was to identify the contribution to overall tooth loss, by extraction of permanent teeth because of prosthetic treatment reasons. Material and Methods. A cross-sectional study included sex, age, total number of extractions performed by subject, sextant (anterior vs. posterior), group of teeth (incisors, canines, premolars and molars), upper or lower arch, and the main reason underlying extraction (extraction for any reason vs. prosthetic treatment), in patients 18 years of age and older seeking care at a dental school clinic in Mexico. A multivariate logistic regression model was generated. Results. A total of 749 teeth were extracted in 331 patients; 161 teeth (21.5% of total) were extracted for explicit prosthetic treatment indications. As age increased, the likelihood of having an extraction for prosthetic reasons increased 3% (OR = 1.03, p < 0.001). Women (OR = 1.57, p < 0.05) were more likely to be in this situation, and molars (OR = 2.70, p < 0.001) were most at risk. As the total number of extractions increased, the risk of having an extraction for prosthetic reasons decreased (OR = 0.94, p < 0.05). Conclusions. A significant amount (21.5%) of the extractions of permanent teeth were performed for prosthetic reasons in this dental school clinical environment; age, sex, type of tooth, and the total number of extractions moderated

  4. Contribution of prosthetic treatment considerations for dental extractions of permanent teeth

    PubMed Central

    Fernández-Barrera, Miguel Ángel; Casanova-Rosado, Juan Fernando; Mendoza-Rodríguez, Martha; Escoffié-Ramírez, Mauricio; Casanova-Rosado, Alejandro José; Navarrete-Hernández, José de Jesús; Maupomé, Gerardo

    2016-01-01

    Background. Tooth loss is an easily identifiable outcome that summarizes a complex suite of factors in an individual’s history of dental disease and its treatment by dental services over a lifetime. Assessment of overall tooth loss data is essential for epidemiologically evaluating the adequacy of dental care provided at a systems level, as well as for placing in context tooth loss for non-disease causes. For example, when derived from prosthetic treatment planning, the latter may unfortunately lead to some teeth being extracted (pulled) for the sake of better comprehensive clinical results. The objective of the present manuscript was to identify the contribution to overall tooth loss, by extraction of permanent teeth because of prosthetic treatment reasons. Material and Methods. A cross-sectional study included sex, age, total number of extractions performed by subject, sextant (anterior vs. posterior), group of teeth (incisors, canines, premolars and molars), upper or lower arch, and the main reason underlying extraction (extraction for any reason vs. prosthetic treatment), in patients 18 years of age and older seeking care at a dental school clinic in Mexico. A multivariate logistic regression model was generated. Results. A total of 749 teeth were extracted in 331 patients; 161 teeth (21.5% of total) were extracted for explicit prosthetic treatment indications. As age increased, the likelihood of having an extraction for prosthetic reasons increased 3% (OR = 1.03, p < 0.001). Women (OR = 1.57, p < 0.05) were more likely to be in this situation, and molars (OR = 2.70, p < 0.001) were most at risk. As the total number of extractions increased, the risk of having an extraction for prosthetic reasons decreased (OR = 0.94, p < 0.05). Conclusions. A significant amount (21.5%) of the extractions of permanent teeth were performed for prosthetic reasons in this dental school clinical environment; age, sex, type of tooth, and the total number of extractions moderated

  5. 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

  6. 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

  7. Comparison of the microhardness of primary and permanent teeth after immersion in two types of carbonated beverages

    PubMed Central

    Haghgou, Hamid R.; Haghgoo, Roza; Asdollah, Fatemah Molla

    2016-01-01

    Objectives: The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages. Materials and Methods: This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test. Results: Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P < 0.05). This reduction was also statistically significant in the permanent teeth (P < 0.05). A comparison of the enamel changes in the primary teeth with permanent teeth after immersion in both beverages showed a greater microhardness reduction in the primary teeth in both the experimental groups. Conclusions: Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster. PMID:27583223

  8. Vascular status in human primary and permanent teeth in health and disease.

    PubMed

    Rodd, Helen D; Boissonade, Fiona M

    2005-04-01

    The present study sought to compare the vascular status of human primary teeth with that of human permanent teeth, and to determine whether caries or painful pulpitis was associated with changes in vascularity. Coronal pulps were removed from 62 primary and 62 permanent mandibular molars with a known pain history. Teeth were categorized as intact, moderately carious or grossly carious. Pulp sections were labelled with Ulex europaeus I lectin (UEIL), which is a marker of human vascular endothelium. Image analysis was then used to quantify the percentage area of UEIL-labelled tissue (vascularity) and the number of blood vessels present within three regions: the pulp horn, the subodontoblastic region, and the mid-coronal pulp. Only the mid-coronal region of the primary tooth pulp was found to be significantly more vascular than the corresponding area of the permanent tooth pulp. Both dentitions showed a significant increase in vascularity within the pulp horn region with caries progression, but this was not accompanied by an increase in vessel number. There was no correlation between vascularity and pain symptoms. These findings suggest that the primary tooth pulp is more vascular than its successor within the mid-coronal region. However, the functional and clinical significance of this finding remains speculative. PMID:15819818

  9. Root maturation and dentin–pulp 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 dentin–pulp 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 dentino–pulpal complex regeneration. PMID:24551447

  10. Root maturation and dentin-pulp response to enamel matrix derivative in pulpotomized permanent teeth.

    PubMed

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

    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 dentin-pulp 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 dentino-pulpal complex regeneration. PMID:24551447

  11. Clinical, histological and microbiological study of hand-excavated carious dentine in extracted permanent teeth.

    PubMed

    Bönecker, M; Grossman, E; Cleaton-Jones, P E; Parak, R

    2003-08-01

    Changes in cultivable flora in dentine samples collected before and after hand excavation were examined in association with clinical status of the cavity surface, light microscopy and scanning electron microscopy (SEM). Thirty-five extracted permanent molar teeth with an occlusal caries lesion were excavated with hand instruments according to the atraumatic restorative treatment (ART) approach. Excavation pressure, dentine colour and consistency were recorded at the dentine-enamel junction (DEJ) prior to carious dentine removal and at the cavity floor after the final excavation; a microbiological sample of dentine was taken at both stages. Twelve restored teeth; six with positive and six with negative bacterial growth on the second sample, were selected for light microscopy and SEM. The hand-excavation removed tooth structure was soft, irreversibly damaged, dark and highly infected. Hand excavation reached dentine of increased hardness with a more normal colour to provide a sound structural base for restoration. Light and SEM examination of the cavity floor showed infected dentinal tubules in all 12 teeth examined. Linear logistic analysis showed a statistical association between light-yellow dentine on the cavity floor and an absence of bacterial growth (P = 0.006). This short-term in vitro study showed that caries-producing bacteria remained in dentine close to the cavity floor in 26/35 teeth despite clinical observations that indicated a suitably prepared cavity floor. PMID:14649040

  12. 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; Sørensen, 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<5×10(-8) and were replicated in four independent study groups from the United States and Denmark with a total of 3,762 individuals; all combined P-values were below 10(-11). Two loci agreed with previous findings in primary tooth eruption and were also known to influence height and breast cancer, respectively. The two other loci pointed to genomic regions without any previous significant genome-wide association study results. The intronic SNP rs7924176 in ADK could be linked to gene expression in monocytes. The combined effect of the four genetic variants was most pronounced between age 10 and 12 years, where children with 6 to 8 delayed tooth eruption alleles had on average 3.5 (95% confidence interval: 2.9-4.1) fewer permanent teeth than children with 0 or 1 of these alleles. PMID:21931568

  13. 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

  14. Observations on the eruption of the permanent incisor teeth of farmed Javan rusa deer (Cervus timorensis russa) in New Caledonia.

    PubMed

    Bianchi, M; Hurlin, J C; Lebel, S; Chardonnet, P

    1997-08-01

    The eruption of the permanent incisor teeth of 14 farmed Javan rusa deer (Cervus timorensis russa) of known birth date and their live weights were observed about every 2 weeks from 12 to 30 months of age. The permanent incisor pattern was 11, 14-17 months; 12, 18-23 months; 13, 20-26 months; and 14, 22-27 months. There was no significant relationship between body weight and timing of permanent incisor eruption. PMID:16031978

  15. 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

  16. Immunohistochemical localization of components of the insulin-like growth factor system in human permanent teeth.

    PubMed

    Götz, Werner; Heinen, Michael; Lossdörfer, Stefan; Jäger, Andreas

    2006-05-01

    There is growing evidence that the insulin-like growth factor (IGF) system plays an important role in the biology of oro-dento-facial tissues and organs, including the development, homeostasis and regeneration of the periodontium. To obtain basic data on the occurrence and distribution of IGF components in human permanent teeth we immunohistochemically investigated 25 extracted, decalcified and paraffin-embedded teeth using mono and polyclonal antibodies against the ligands IGF-I and -II, the IGF1 receptor (IGF1R) and all six IGF binding proteins (IGFBP-1 to -6). In the extracellular matrix (ECM) of the adhering periodontal ligament (PDL), immunoreactivity for IGF-I, -II and IGFBP-1 and -6 was observed. PDL fibroblasts showed immunostaining for the IGF1R. For the cementum, in the acellular cementum only IGF-II could be detected, while outer cementum layers with inserting Sharpey's fibers reacted with all antibodies applied except for IGFBP-4 and -6. In the pulp, mainly fibrotic areas and areas around denticles were immunoreactive for IGF-I, IGFBP-1, -3, -5 and -6. Predentin and odontoblastic processes were stained for IGF-I and IGFBP-3. The spatially oriented occurrence of components of the IGF system in human permanent teeth indicates that specific functions of the IGFs may be localized in particular tissue compartments. In the cementum, several IGF components were found indicating roles in tissue homeostasis or attachment. The PDL may function as a reservoir for IGFs probably bound to ECM components. PDL fibroblasts could then respond in a paracrine manner. In the pulp, the IGF system may be involved in odontoblast biology, fibrosis and denticle formation. PMID:16321360

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

    PubMed

    Vongsavan, Kadkao; Surarit, Rudee; Rirattanapong, Praphasri

    2014-03-01

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

  18. 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

  19. Sealing Ability of MTA Used in Perforation Repair of Permanent Teeth; Literature Review

    PubMed Central

    Baroudi, Kusai; Samir, Samah

    2016-01-01

    There were several materials used to seal different types of perforation defects. MTA is one of these restorative materials that is considered the most effective, biocompatible, non-toxic, and non-irritant; promote bone healing and cementum regeneration. The objective of this article was to review and summarize the sealing ability of MTA compared with the other materials used for sealing different types of root perforations of permanent teeth. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2005 to 2015 searching for articles related to sealing ability of MTA. This study found that factors affecting prognosis are the size, site of the perforation and time elapsed as well as the repair material. MTA is an important filling material to be used for sealing different types of perforations when perforated sites sealed immediately with MTA. PMID:27347231

  20. Sealing Ability of MTA Used in Perforation Repair of Permanent Teeth; Literature Review.

    PubMed

    Baroudi, Kusai; Samir, Samah

    2016-01-01

    There were several materials used to seal different types of perforation defects. MTA is one of these restorative materials that is considered the most effective, biocompatible, non-toxic, and non-irritant; promote bone healing and cementum regeneration. The objective of this article was to review and summarize the sealing ability of MTA compared with the other materials used for sealing different types of root perforations of permanent teeth. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2005 to 2015 searching for articles related to sealing ability of MTA. This study found that factors affecting prognosis are the size, site of the perforation and time elapsed as well as the repair material. MTA is an important filling material to be used for sealing different types of perforations when perforated sites sealed immediately with MTA. PMID:27347231

  1. Responses of the pulp, periradicular and soft tissues following trauma to the permanent teeth.

    PubMed

    Yu, C Y; Abbott, P V

    2016-03-01

    Trauma to the permanent teeth involves not only the teeth but also the pulp, the periodontal ligament, alveolar bone, gingiva and other associated structures. There are many variations in the types of injuries with varying severity and often a tooth may sustain more than one injury at the same time. In more severe trauma cases, there are many different cellular systems of mineralized hard and unmineralized soft tissues involved, each with varying potential for healing. Furthermore, the responses of the different tissues may be interrelated and dependent on each other. Hence, healing subsequent to dental trauma has long been known to be very complex. Because of this complexity, tissue responses and the consequences following dental trauma have been confusing and puzzling for many clinicians. In this review, the tissue responses are described under the tissue compartments typically involved following dental trauma: the pulp, periradicular and associated soft tissues. The factors involved in the mechanisms of trauma are analysed for their effects on the tissue responses. A thorough understanding of the possible tissue responses is imperative for clinicians to overcome the confusion and manage dental trauma adequately and conservatively in order to minimize the consequences following trauma. PMID:26923447

  2. 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

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

    PubMed

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

    2009-01-01

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

  4. 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…

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

    PubMed

    Costa, Ana Rosa; Correr, Américo Bortolazzo; Puppin-Rontani, Regina Maria; Vedovello, Silvia Amélia Scudeler; Valdrighi, Heloísa Cristina; Correr-Sobrinho, Lourenço; Vedovello Filho, Mário

    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 (α = 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

  6. 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

  7. An evaluation of microleakage of various glass ionomer based restorative materials in deciduous and permanent teeth: An in vitro study

    PubMed Central

    Singla, Teena; Pandit, I.K.; Srivastava, Nikhil; Gugnani, Neeraj; Gupta, Monika

    2011-01-01

    Aim To evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth. Method One hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope. Result Significant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth. Conclusions GC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage. PMID:23960526

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

    PubMed

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

    2011-04-01

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

  9. Characterization of Apical Papilla and its Residing Stem Cells from Human Immature Permanent Teeth –A Pilot Study

    PubMed Central

    Sonoyama, Wataru; Liu, Yi; Yamaza, Takayoshi; Tuan, Rocky S.; Wang, Songlin; Shi, Songtao; Huang, George T.-J.

    2009-01-01

    Mesenchymal stem cells (MSCs) have been isolated from the pulp tissue of permanent teeth (dental pulp stem cells or DPSCs) and deciduous teeth (stem cells from human exfoliated deciduous teeth or SHED). We recently discovered another type of MSCs in the apical papilla of human immature permanent teeth termed stem cells from apical papilla (SCAP). Here we further characterized the apical papilla tissue and stem cell properties of SCAP using histological, immunohistochemical and immunocytofluorescent analyses. We found that apical papilla is distinctive to pulp in terms of containing less cellular and vascular components than those in pulp. Cells in apical papilla proliferated 2- to 3-fold greater than those in pulp in organ cultures. Both SCAP and DPSCs were as potent in osteo/dentinogenic differentiation as MSCs from bone marrows while weaker in adipogenic potential. The immunophenotype of SCAP is similar to that of DPSCs on the osteo/dentinogenic and growth factor receptor gene profiles. Double staining experiments showed that STRO-1 co-expressed with dentinogenic markers such as bone sialophosphoprotein (BSP), osteocalcin (OCN) and growth factors FGFR1 and TGFβRI in cultured SCAP. Additionally, SCAP express a wide variety of neurogenic markers such as nestin and neurofilament M upon stimulation with a neurogenic medium. We conclude that SCAP are similar to DPSCs but a distinct source of potent dental stem/progenitor cells. Their implications in root development and apexogenesis are discussed. PMID:18215674

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

    PubMed

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

    2007-09-01

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

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

    PubMed

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

    2013-01-01

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

  12. 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: 11–15 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: 0.34–0.66) and boys (range of r: 0.28–0.77). 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

  13. 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

  14. Apical Closure of Nonvital Permanent Teeth: 15 Months Follow-up Study of Four Cases

    PubMed Central

    Umashetty, Girish; Patil, Basanagouda; Rao, Nandan; Ajgaonkar, Nishant

    2015-01-01

    Obtaining a complete seal of the root canal system is a major problem in performing root canal treatment in nonvital teeth with incomplete root development and wide open apices. The aim was to study apexification using mineral trioxide aggregate (MTA), clinically and radiographically over a period of 15 months. MTA was used in four cases of teeth with incomplete root development in order to achieve an apical seal and the remaining canal was obturated with gutta-percha. Clinical and radiographic assessments of teeth were done. The clinical and radiographic results indicated that apexification procedure was predictable by using MTA. The total number of patients’ visits and the total time duration required to obtain an apical barrier using MTA was markedly less than that of conventional techniques using calcium hydroxide. PMID:26028910

  15. 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

  16. Traumatised permanent teeth in 11-16-year-old Saudi Arabian children with a sensory impairment attending special schools.

    PubMed

    AlSarheed, M; Bedi, R; Hunt, N P

    2003-06-01

    - The aim of this study was to determine the prevalence of traumatised permanent teeth among sensory (visual (VI) and hearing (HI)) impaired children attending special schools in Riyadh, Saudi Arabia. All the dental injuries involved incisor teeth, and trauma was noted in 33 (6.7%) children attending government schools (control group) compared to 7 (9%) VI children and 24 (11.4%) HI children. Differences in the dental trauma only reached statistical significance between the HI and control group (P < 0.05). Gender differences were only apparent in the HI group, with males having higher levels of traumatised teeth. In addition, HI children aged 11-12 years were more prone to trauma than children in the control group of the same age (P < 0.05). In conclusion, sensory impaired children do have a tendency for more dental trauma. However, this was only statistically significant for HI children. Whereas a gender difference was most noticeable for the HI group, with males having higher levels of trauma, this was noticeable by its absence among VI children. PMID:12752532

  17. Analysis of Reporting Pattern in Children Aged 7 to 14 Years with Traumatic Injuries to Permanent Teeth

    PubMed Central

    Ravi, KS; Roshan, NM; Shashikiran, ND

    2010-01-01

    Aim To analyze the pattern of traumatic injuries to permanent anterior teeth reporting to the dental department with regards to age, gender, cause, proportion of different types of injury and time of reporting. Materials and Methods Children aged 7 to 14 years with trauma or related sequelae were included. The data was collected retrospectively on the basis of case history, clinical findings, radiographs and vitality tests. Ellis’ classification was used to record injuries to anterior teeth. Results Boys had more injuries with the highest injuries at 12 years. Various causes of trauma included Falls, RTA, hits by object/person and bicycle related. The most common injury reported were cases of Ellis’ class IV (50.7%) and the maxillary central incisors being the teeth most frequently involved (75%). The time lapsed after injury was more than 1 year in 42.8% cases and 62% cases reported with complications. Conclusion Our findings suggest that a large number of cases reported in the age group 10 to 13 years with Class IV Ellis’ fracture largely when symptoms appear. Reporting was delayed by more than a year in several cases, the barriers for which need to be analyzed, to develop strategies regarding prevention of traumatic injuries and their consequences.

  18. Pulp revascularization of immature permanent teeth: a review of the literature and a proposal of a new clinical protocol.

    PubMed

    Namour, Mélanie; Theys, Stephanie

    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

  19. 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

  20. 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

  1. Radiographic and Clinical Outcomes of the Treatment of Immature Permanent Teeth by Revascularization or Apexification: A Pilot Retrospective Cohort Study

    PubMed Central

    Alobaid, Adel S.; Cortes, Lina M.; Lo, Jeffery; Nguyen, Thuan T.; Albert, Jeffery; Abu-Melha, Abdulaziz S; Lin, Louis M.; Gibbs, Jennifer L.

    2014-01-01

    Introduction This retrospective cohort study compared clinical and radiographic outcomes of endodontic treatment performed in immature non-vital permanent teeth, by apexification (calcium hydroxide or apical barrier with Mineral Trioxide Aggregate (MTA)), versus revascularization. Methods A comprehensive chart review was performed to obtain a cohort of sequential previously completed cases with recalls. Clinical and radiographic data were collected for 31 treated teeth (19 revascularization and 12 apexification) with an average follow up time of 17 months and a recall rate of 63%. Tooth survival, success rate, and adverse events were analyzed. Changes in radiographic root length, width and area were quantified. Results The majority of treated teeth survived throughout the study period with 30/31 (97%) teeth surviving (18/19 (95%) revascularization, 12/12 apexification). Most cases were also clinically successful with 27/31 (87%) meeting criteria for success, (15/19 (78%) revascularization and 12/12 apexification; non-significant difference). A greater incidence of adverse events was observed in the revascularization group (8/19 (42%) versus 1/12 (11%) in apexification (Risk Ratio= 5.1, p=0.04, 95%CI (0.719, 35.48)). Although more revascularization cases than apexification cases demonstrated an increase in radiographic root area and width, the effect was not statistically significant. Conclusion In this study, revascularization was not superior to other apexification techniques in either clinical or radiographic outcomes. Studies with large subject cohorts, and long follow up periods are needed to evaluate outcomes of revascularization and apexification, while accounting for important co-variants relevant to clinical success. PMID:25069909

  2. Partial and total luxations of permanent teeth in children: Clinical management.

    PubMed

    Chafaie, Amir

    2016-03-01

    Dentoalveolar trauma, very frequent during childhood and adolescence, generally results in tooth fracture and/or partial or total luxation. Management of the pulpal and periodontal aspects of these traumatic cases is complex. The prognosis is improved if treatment is initiated promptly. Multidisciplinary management of these situations and regular patient follow-up make it possible to detect complications quickly and take the necessary action to maintain the teeth as long as possible in a healthy periodontal environment that allows harmonious development and the application of appropriate treatment in adulthood. PMID:26826972

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

    PubMed

    Pohl, Yango; Filippi, Andreas; Kirschner, Horst

    2005-04-01

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

  4. Permanent teeth development in a Spanish sample. Application to dental age estimation.

    PubMed

    Feijóo, Gonzalo; Barbería, Elena; De Nova, Joaquín; Prieto, Jose Luis

    2012-01-10

    The purpose of this study is to clarify the chronology of different stages of dental development, according to Demirjian, in a sample of Spanish children, which will enable us to build a database that will be used as a reference in regard to the dental development of individuals of our socio-geographic environment. In the same studied sample, a calculation of the dental age according to Demirjian was carried out. This study was conducted in a final sample consisting of 1010 orthopantograms, corresponding to Spanish children (485 boys and 525 girls) ages 2-16. Comparing the age of onset of the different stages among the children, evidence was found that girls had an earlier general development than boys. These differences were only statistically significant in teeth and concrete stages. The canine teeth revealed greater gender dimorphism, with significant differences in all stages compared with the upper canines. The method proposed by Demirjian for dental age calculation resulted in a significant overestimation of dental age in relation to the chronological age in boys (average of 0.87 years) and girls (average of 0.55 years). Data from this study may be used as reference for dental maturity, as well as a standard for estimating age in Spanish children. PMID:21940122

  5. Factors influencing caries incidence in permanent teeth in children/adolescents under and after anti-neoplastic treatment

    PubMed Central

    Brożyna, Agnieszka; Dembowska-Bagińska, Bożenna; Olczak-Kowalczyk, Dorota

    2016-01-01

    Aim of the study To determine reasons for the increase in caries among children/adolescents treated for neoplasms. Material and methods Health promoting behaviour, oral hygiene (PLI), gingiva (GI), dentition (DMFt/DMFs), number of teeth with white spot lesions (WSL), and enamel defects (ED) were assessed in three groups of 60 patients each. The three groups were as follows: under chemotherapy (CH), after chemotherapy (PCH), and generally healthy (CG). Medical files supplied information on neoplasm type, chemotherapeutic type and dose, age at treatment start, chemotherapy duration, and complications. Statistical analysis was performed with Mann-Whitney U test and Spearman's rho test. Results The age at which chemotherapy was started/its duration was 5.9 ±4.0/1.3 ±0.5 years in PCH and 9.12 ±4.44/0.8 ±0.3 years in CH; PCH completed treatment 4.9 ±3.4 years ago. Chemotherapy most often included vincristine (VCR), etoposide (VP-16), adriamycin (ADM), cyclophosphamide (CTX), cisplatin (CDDP), and ifosphamide (IF). Mucositis occurrence was 28.33% in PCH and 45.00% in CH; vomiting occurrence was 43.33% and 50.00%, respectively. Nutrition and prophylaxis mistakes occurred more often in CH/PCH than in CG; PLI, GI, caries incidence and severity, and the number of teeth with WSL were higher. Correlation between caries incidence and chemotherapeutic type and dose, age at treatment start and treatment duration, mucositis, emesis, PLI, GI, ED, no fluoride prophylaxis, and nutritional mistakes was established. Ifosphamide and mucositis treatment played a major role in chemotherapy; after chemotherapy – ED and CTX, ADM, IF, and VP-16. Conclusions Caries in permanent teeth in children/adolescents undergoing chemotherapy result from nutritional mistakes, poor prophylaxis, and indirectly from chemotherapy complications (first mucositis and emesis, and later developmental ED). PMID:27095939

  6. 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

  7. 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

  8. Secretome Profiling of Periodontal Ligament from Deciduous and Permanent Teeth Reveals a Distinct Expression Pattern of Laminin Chains

    PubMed Central

    Giovani, Priscila A.; Salmon, Cristiane R.; Martins, Luciane; Paes Leme, Adriana F.; Rebouças, Pedro; Puppin Rontani, Regina M.; Mofatto, Luciana S.; Sallum, Enilson A.; Nociti, Francisco H.; Kantovitz, Kamila R.

    2016-01-01

    It has been suggested that there are histological and functional distinctions between the periodontal ligament (PDL) of deciduous (DecPDL) and permanent (PermPDL) teeth. Thus, we hypothesized that DecPDL and PermPDL display differences in the constitutive expression of genes/proteins involved with PDL homeostasis. Primary PDL cell cultures were obtained for DecPDL (n = 3) and PermPDL (n = 3) to allow us to perform label-free quantitative secretome analysis. Although a highly similar profile was found between DecPDL and PermPDL cells, comparative secretome analysis evidenced that one of the most stickling differences involved cell adhesion molecules, including laminin subunit gamma 1 (LAMC1) and beta 2 (LAMB2). Next, total RNA and protein extracts were obtained from fresh PDL tissues of deciduous (n = 6) and permanent (n = 6) teeth, and Western blotting and qPCR analysis were used to validate our in vitro findings. Western blot analysis confirmed that LAMC1 was increased in DecPDL fresh tissues (p<0.05). Furthermore, qPCR data analysis revealed that mRNA levels for laminin subunit beta 1 (LAMB1), beta 3 (LAMB3), LAMC1, and gamma 2 (LAMC2) were higher in DecPDL fresh tissues, whereas transcripts for LAMB2 were increased in PermPDL (p<0.05). In conclusion, the differential expression of laminin chains in DecPDL and PermPDL suggests an involvement of laminin-dependent pathways in the control of physiological differences between them. PMID:27149379

  9. 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

  10. Superoxide dismutase activity in healthy and inflamed pulp tissues of permanent teeth in children.

    PubMed

    Tulunoglu, O; Alacam, A; Bastug, M; Yavuzer, S

    1998-01-01

    The free radicals play an important role in the tissue damage. Oxygen-derived free radicals are controlled by various cellular defense mechanisms consisting of enzymatic such as superoxide dismutase, catalase, glutathion peroxidase and nonenzymatic scavenger components. Superoxide dismutase (SOD) is responsible for the dismutation of the superoxide radicals into hydrogen peroxide and molecular oxygen. In this study, pulp samples extirpated from the teeth of the 27 children between 10-15 ages which diagnosed to be healthy, reversible pulpitis or symptomatic irreversible pulpitis were evaluated for the activity of superoxide dismutase enzyme. There were statistically significant differences between healthy and reversible pulpitis, and between reversible and symptomatic irreversible pulpitis groups. The SOD activity of the reversible pulpitis group were significantly lower than the irreversible pulpitis and healthy pulp groups. The evaluation of the data revealed that the quantity of SOD as a vitality protector enzyme is low at the beginning of the inflammation as a consequence of rapidly depletion and/or destruction of this enzyme, but as the inflammation proceeds the pulp tissue showed adaptation to this situation. PMID:9796506

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

    PubMed

    Sabokseir, Aira; Golkari, Ali; Sheiham, Aubrey

    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

  12. 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

  13. 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

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

    PubMed Central

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

    2013-01-01

    Objective: The aim of this study was to compare the production of the chemokines CCL3 and CXCL12 by cultured dental pulp fibroblasts from permanent (PDPF) and deciduous (DDPF) teeth under stimulation by Porphyromonas gingivalis LPS (PgLPS). Material and Methods: Primary culture of fibroblasts from permanent (n=3) and deciduous (n=2) teeth were established using an explant technique. After the fourth passage, fibroblasts were stimulated by increasing concentrations of PgLPS (0 - 10 µg/mL) at 1, 6 and 24 h. The cells were tested for viability through MTT assay, and production of the chemokines CCL3 and CXCL12 was determined through ELISA. Comparisons among samples were performed using One-way ANOVA for MTT assay and Two-way ANOVA for ELISA results. Results: Cell viability was not affected by the antigen after 24 h of stimulation. PgLPS induced the production of CCL3 by dental pulp fibroblasts at similar levels for both permanent and deciduous pulp fibroblasts. Production of CXCL12, however, was significantly higher for PDPF than DDPF at 1 and 6 h. PgLPS, in turn, downregulated the production of CXCL12 by PDPF but not by DDPF. Conclusion: These data suggest that dental pulp fibroblasts from permanent and deciduous teeth may present a differential behavior under PgLPS stimulation. PMID:23739851

  15. 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 Fátima 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.

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

    PubMed

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

    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. PMID:22559697

  17. 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

  18. 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 study’s aim was to evaluate and compare the shear bond strength of different pit and fissure sealants placed on Primary molars and Permanent Premolars. Materials & Methods: Sixty noncarious extracted teeth comprising of thirty Primary molars and thirty Permanent Premolars were divided into four groups of 15 each. The buccal surfaces of all teeth were dried, etched and the etched surfaces of Primary molars (Group I) and Permanent Premolars (Group III) were placed with Helioseal-F while Groups II and IV, that included Primary molars and Permanent Premolars received Clinpro. Shear bond strength was evaluated and the mean was obtained for all the groups. The results were analyzed using twoway analysis of variance followed by Tukeys post hoc procedure to check for significant differences. Results: The specimens of unfilled sealant Clinpro (Groups II & IV) showed higher Shear bond strength when compared to the specimens of filled sealant Helioseal-F (Groups I & III). Conclusion: The unfilled sealant showed a better Shear bond strength compared to the filled sealant. The bond strength in Primary molars was slightly higher compared to Permanent Premolars. How to cite the article: Pushpalatha HM, Ravichandra KS, Srikanth K, Divya G, Done V, Krishna KB, Patil V. Comparative evaluation of Shear bond strength of different Pit and fissure Sealants in Primary and Permanent teeth - An In-Vitro Study. J Int Oral Health 2014;6(2):84-9. PMID:24876707

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

    PubMed

    Pekkan, Gurel; Ozcan, Mutlu

    2012-01-01

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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Immunohistological Evaluation of Revascularized Immature Permanent Necrotic Teeth Treated by Platelet-Rich Plasma: An Animal Investigation

    PubMed Central

    Moradi, Saeed; Talati, Ali; Forghani, Maryam; Jafarian, Amir Hossein; Naseri, Mandana; Shojaeian, Shiva

    2016-01-01

    Objective Pulp regeneration within the root canal of necrotic teeth is considered an ideal treatment to allow for continued root development and recover teeth vitality. This study aims to evaluate the inductive effect of platelet-rich plasma (PRP) on expression of angiogenesis factors and pulpal revascularization of immature necrotic teeth. Materials and Methods In this experimental animal study, we randomly divided 28 immature premolars from two mixed breed dogs into four groups, two experimental, negative and a positive control. Premolars in negative control group were left intact to develop normally. In the positive control and experimental groups, we removed the pulps and induced pulp necrosis, after which the chambers were sealed. Then, we applied the revascularization protocol in the experimental teeth located in the right quadrant. Two months later, the same protocol was applied to the left quadrant. The root canals were disinfected by irrigation with sodium hypochlorite (NaOCl) solution and application a triple antibiotic past. Following the induction of a blood clot (BC) inside the canal space, the coronal portion of the canals was assigned to either of two experimental groups: group 1 [BC+PRP+ mineral trioxide aggregate (MTA)], group 2 (BC+MTA). Access cavities were sealed with a Glass Ionomer. The jaws that held the teeth were processed for histologic analysis of newly formed tissue and immunohistochemical evaluation according to vascular endothelial growth factor (VEGF) and factor VIII expressions in the canals. Results Histological analysis demonstrated no significant difference in the formation of new vital tissue inside the root canals between groups1 (42.8%) and 2 (43.5%, P>0.05). Based on immunohistochemical evaluation, micro-vessel density (MVD) of the granulation tissues in both groups were similar and were higher compared with the normal pulp. We observed strongly positive expressions of VEGF and factor VIII in the stromal and endothelial cells

  5. 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

  6. COMPARISON OF CHILDREN'S FOLLOW-ON INSTANT POWDERED COW'S MILK FORMULA, BUFFALO MILK FORMULA AND CHICKEN-BASED FORMULA ON ENAMEL MICROHARDNESS OF BOVINE TEETH IN VITRO.

    PubMed

    Vongsavan, Kadkao; Rirattanapong, Praphasri; Surarit, Rudee

    2016-03-01

    Dental caries are a major public health problem worldwide. The aim of this study was to compare the effects of children's follow-on instant powdered cow's milk formula, buffalo milk formula and a chicken-based formula on microhardness of bovine enamel with artificial caries-like lesions. Forty bovine teeth were each placed in acrylic blocks and the enamel surfaces were polished to create flat 5 x 5 millimeter surfaces. The teeth surfaces were then demineralized using 0.1M lactic acid (pH 4.5) to achieve an enamel microhardness of 35-65 Vickers Hardness Numbers (VHN). All specimens were then randomly allocated into one of 4 groups (n=10/group). For remineralization, each group was soaked in a different kind of milk formula for 2 hours at 37°C except group 1 which was a negative control (artificial saliva) group. Group 2 was soaked in Murrah™ buffalo milk formula (a positive control ), group 3 in S-26-Promil-Gold™ (cow's milk formula) and group 4 in a chicken-based formula (Siriraj Hospital, Mahidol University). The microhardness of the specimens was then measured again. Data were analyzed using a one-way ANOVA and paired t-test with a 95% confidence interval. After exposure to the formula, the mean VHN for each study group was significantly higher (paired t-test, p < 0.05) except for group 1 (p = 0.345). The mean VHN for the the Murrah™ buffalo milk formula, the chicken-based formula and the S-26-Promil-Gold™ formula group were not significantly different from each other (one-way ANOVA, p > 0.05). In conclusion, S-26-Promil-Gold™ follow-on cow milk formula, Murrah™ buffalo milk formula and the chicken-based formula all increased bovine enamel microhardness after soaking for 2 hours. PMID:27244971

  7. 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

  8. 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

  9. The diffusion in vitro of fluoride and chlorhexidine in the enamel of human deciduous and permanent teeth.

    PubMed

    Lindén, L A; Björkman, S; Hattab, F

    1986-01-01

    The permeability of human dental enamel was studied by following the diffusion of [51Cr]-ethylenediaminetetraacetate (EDTA), F and [14C]-chlorhexidine using two-chamber diffusion cells. The [51Cr]-EDTA served as a marker to control the change in enamel permeability during the diffusion process. An average increase in enamel permeability of about 1.6-fold was recorded following the initial diffusion of the test compounds in the deciduous and permanent enamel. The permeability of deciduous enamel was much higher than that of permanent enamel. For [51Cr]-EDTA and [14C]-chlorhexidine, the average diffusion coefficient was about 30-fold more than in permanent enamel; for F it was 150-fold more. The difference was statistically significant (p less than 0.001). Co-administration of F and [14C]-chlorhexidine showed a higher diffusion rate for each compound than when separately diffused. Whether this is due to a synergetic effect or to increased enamel permeability following the initial diffusion of the compound, or both, is still uncertain. PMID:3085643

  10. Clinical and radiographic assessment of mineral trioxide aggregate and calcium hydroxide as apexification agents in traumatized young permanent anterior teeth: A comparative study

    PubMed Central

    Damle, S. G.; Bhattal, Hiteshwar; Damle, Dhanashree; Dhindsa, Abhishek; Loomba, Ashish; Singla, Sumit

    2016-01-01

    Background: To evaluate and compare the efficacy of mineral trioxide aggregate (MTA) and traditionally used calcium hydroxide (Ca(OH)2) in inducing root end formation of immature roots of traumatized young permanent anterior teeth. Materials and Methods: The study was carried out on 22 nonvital, immature permanent maxillary incisors. Samples were allotted into two groups - Group I MTA and Group II Ca(OH)2 Success rate was determined based upon the time duration required for apical barrier formation. The canals were obturated using gutta-percha points in MTA group, after 24 h, whereas in Ca(OH)2 group, obturation was carried out after radiographic confirmation of the apical barrier. The clinical and radiographic evaluation was carried out at a follow-up periods of 3, 6, and 9 months and statistical analysis was carried out by SPSS version 15.0 statistical analysis software (Chi-square test and fisher exact test). Results: In MTA Group, barrier formation was observed in 90.90% of the patients after 9 months whereas in Ca(OH)2 Group, the same was observed in 81.81%. The mean time required for barrier formation in MTA group was 4.90 months and 5.33 months in Ca(OH)2 group. Conclusion: MTA and Ca(OH)2, as medicaments for apexification, were comparable in terms of the evaluation parameters. However, MTA was beneficial in terms of immediate obturation of immature roots with wide open apices. PMID:27274351

  11. Differential Neuronal Plasticity of Dental Pulp Stem Cells From Exfoliated Deciduous and Permanent Teeth Towards Dopaminergic Neurons.

    PubMed

    Majumdar, Debanjana; Kanafi, Mohammad; Bhonde, Ramesh; Gupta, Pawan; Datta, Indrani

    2016-09-01

    Based on early occurrence in chronological age, stem-cells from human exfoliated deciduous teeth (SHED) has been reported to possess better differentiation-potential toward certain cell-lineage in comparison to stem-cells from adult teeth (DPSCs). Whether this same property between them extends for the yield of functional central nervous system neurons is still not evaluated. Hence, we aim to assess the neuronal plasticity of SHED in comparison to DPSCs toward dopaminergic-neurons and further, if the difference is reflected in a differential expression of sonic-hedgehog (SHH)-receptors and basal-expressions of tyrosine-hydroxylase [TH; through cAMP levels]. Human SHED and DPSCs were exposed to midbrain-cues [SHH, fibroblast growth-factor8, and basic fibroblast growth-factor], and their molecular, immunophenotypical, and functional characterization was performed at different time-points of induction. Though SHED and DPSCs spontaneously expressed early-neuronal and neural-crest marker in their naïve state, only SHED expressed a high basal-expression of TH. The upregulation of dopaminergic transcription-factors Nurr1, Engrailed1, and Pitx3 was more pronounced in DPSCs. The yield of TH-expressing cells decreased from 49.8% to 32.16% in SHED while it increased from 8.09% to 77.47% in DPSCs. Dopamine release and intracellular-Ca(2+) influx upon stimulation (KCl and ATP) was higher in induced DPSCs. Significantly lower-expression of SHH-receptors was noted in naïve SHED than DPSCs, which may explain the differential neuronal plasticity. In addition, unlike DPSCs, SHED showed a down-regulation of cyclic adenosine-monophosphate (cAMP) upon exposure to SHH; possibly another contributor to the lesser differentiation-potential. Our data clearly demonstrates for the first time that DPSCs possess superior neuronal plasticity toward dopaminergic-neurons than SHED; influenced by higher SHH-receptor and lower basal TH expression. J. Cell. Physiol. 231: 2048-2063, 2016. © 2016

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

    PubMed Central

    Bani, Mehmet; Sungurtekin-Ekçi, Elif; Odabaş, 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 1–4 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

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

    PubMed

    Bani, Mehmet; Sungurtekin-Ekçi, Elif; Odabaş, 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 1-4 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

  14. Malocclusion of teeth

    MedlinePlus

    ... are easier to clean and decrease risk of tooth decay and periodontal diseases ( gingivitis or periodontitis ). Eliminate strain ... braces and may permanently mark teeth or cause tooth decay if not properly cared for. You will need ...

  15. Comparative Immunophenotypic Characteristics, Proliferative Features, and Osteogenic Differentiation of Stem Cells Isolated from Human Permanent and Deciduous Teeth with Bone Marrow.

    PubMed

    Aghajani, Farzaneh; Hooshmand, Tabassom; Khanmohammadi, Manijeh; Khanjani, Sayeh; Edalatkhah, Haleh; Zarnani, Amir-Hassan; Kazemnejad, Somaieh

    2016-06-01

    To find out differences and similarities in phenotypic, proliferative, and trans-differentiation properties of stem cells isolated from pulp of deciduous (SHEDs) and permanent (DPSCs) teeth with human bone marrow stem cells (BMSCs), we examined the expression of mesenchymal and embryonic stem cell markers in relation to the proliferation and osteogenic differentiation potentials of these cells. In this way, after isolating SHEDs, DPSCs, and BMSCs, cell proliferation was evaluated and population doubling time was calculated accordingly. Expression patterns of mesenchymal, hematopoietic, and embryonic stem cell markers were assessed followed by examining differentiation potential toward osseous tissue through alizarin red staining and qRT-PCR. Based on the results, the proliferation rates of SHEDs and DPSCs were significantly higher than that of BMSCs (P < 0.0001). High expression of mesenchymal stem cell markers and weak expression of hematopoietic markers were observed in all the three groups. The mean expression of OCT-4 was significantly higher in SHEDs and DPSCs (P = 0.028), while the expression of SSEA-4 was lower (P = 0.006) compared to BMSCs. Osteogenic differentiation potential of SHEDs was greater than DPSCs; however, it was lower than that of BMSCs. Conclusively, the distinctive immunophenotyping, proliferation rate, and differentiation pattern of SHEDs and DPSCs discriminate these cells from BMSCs. Furthermore, dissimilarity in differentiation potential is evidence implying that SHEDs might be more primitive stem cell population compared to DPSCs. PMID:27126695

  16. 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

  17. Problems of supernumerary teeth, hyperdontia or dentes supernumerarii.

    PubMed

    Proff, Peter; Fanghänel, Jochen; Allegrini, Sergio; Bayerlein, Thomas; Gedrange, Tomas

    2006-03-01

    Supernumerary teeth are extra teeth or toothlike structures which may have either erupted or unerupted in addition to the 20 deciduous teeth and the 32 permanent teeth. This article provides an overview of frequency, distribution and classification of supernumerary teeth. The etiology of supernumerary teeth is still unknown, yet various theories have been presented based on epidemiological studies. Four clinical cases representing the possible manifestations of supernumerary teeth are discussed. PMID:16551014

  18. Your Teeth

    MedlinePlus

    ... sound. Treating Teeth Kindly Brushing your teeth with fluoride toothpaste is your best bet when it comes ... in your mouth. You also might get a fluoride treatment while you're there. In between dentist ...

  19. 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.

  20. Endodontic management of nonvital permanent teeth having immature roots with one step apexification, using mineral trioxide aggregate apical plug and autogenous platelet-rich fibrin membrane as an internal matrix: Case series

    PubMed Central

    Sharma, Vivek; Sharma, Sarang; Dudeja, Pooja; Grover, Shibani

    2016-01-01

    A tooth with blunderbuss canal and open apex can be an endodontic challenge because of difficulty in obtaining an apical seal, and existing thin radicular walls which are susceptible to fracture. To overcome the limitations of traditional long-term calcium hydroxide apexification procedures, nonsurgical one step apexification using an array of materials such as mineral trioxide aggregate (MTA) has been suggested. However, adequate compaction of MTA in teeth with wide open apices can be an arduous task, and an internal matrix is required for controlled placement of MTA against which obturating material can be condensed. Platelet-rich fibrin (PRF), a second generation platelet concentrate containing several growth factors that promotes hard and soft-tissue healing, has been used as an internal matrix to create an apical plug of MTA and hence prevent extrusion of filling materials. This case series presents the endodontic management of immature permanent teeth with open apices using internal matrix of autologous PRF membrane and one step apical barrier placement of MTA. PMID:27041904

  1. Endodontic management of nonvital permanent teeth having immature roots with one step apexification, using mineral trioxide aggregate apical plug and autogenous platelet-rich fibrin membrane as an internal matrix: Case series.

    PubMed

    Sharma, Vivek; Sharma, Sarang; Dudeja, Pooja; Grover, Shibani

    2016-01-01

    A tooth with blunderbuss canal and open apex can be an endodontic challenge because of difficulty in obtaining an apical seal, and existing thin radicular walls which are susceptible to fracture. To overcome the limitations of traditional long-term calcium hydroxide apexification procedures, nonsurgical one step apexification using an array of materials such as mineral trioxide aggregate (MTA) has been suggested. However, adequate compaction of MTA in teeth with wide open apices can be an arduous task, and an internal matrix is required for controlled placement of MTA against which obturating material can be condensed. Platelet-rich fibrin (PRF), a second generation platelet concentrate containing several growth factors that promotes hard and soft-tissue healing, has been used as an internal matrix to create an apical plug of MTA and hence prevent extrusion of filling materials. This case series presents the endodontic management of immature permanent teeth with open apices using internal matrix of autologous PRF membrane and one step apical barrier placement of MTA. PMID:27041904

  2. Teething troubles?

    PubMed

    McIntyre, G T; McIntyre, G M

    2002-03-01

    The relationship between the eruption of the deciduous teeth and the general health of infants has been documented for over 5,000 years. A variety of physical disturbances (anything from minor upsets to potentially fatal illnesses) have historically been attributed to teething, however a number of recent publications have alluded to a clarification of some of the disputed features of teething. It is now accepted that the localised symptoms of teething vary between individuals, however, 'teething' continues to be an inappropriate diagnosis proffered by both healthcare professionals and lay people. Severe systemic upsets are unrelated to teething and, if present, the infant should be promptly referred to a physician for an accurate diagnosis and appropriate treatment. The treatment modalities used in teething have been diverse throughout the ages, frequently depending on the tenets of the medical profession and lay people, but now principally involve pain relief. This article examines the signs and symptoms frequently attributed to teething and their possible alternative causes. The contemporary principles of the management of teething are discussed, including supportive measures, the diverse range of available topical and systemic pharmacological preparations and the 'alternative' holistic therapies. PMID:11924952

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

    PubMed Central

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

    2014-01-01

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

  4. Caries-preventive effect of glass ionomer and resin-based fissure sealants on permanent teeth: An update of systematic review evidence

    PubMed Central

    2011-01-01

    Background This article constitutes a partial update of the original systematic review evidence by Yengopal et al. from 15 January 2008 (published in the Journal of Oral Science in 2009) with primary focus on research quality in regard to bias risk in trials. Its aim is to update the existing systematic review evidence from the English literature as to whether caries occurrence on pits and fissures of teeth sealed with either GIC or resin is the same. Methods In addition to the 12 trials included during the original systematic review, 5 new trials were identified during the database search (up to 26 August 2010) and 2 further trials were included from a hand search and reference check. Of these, 3 trials were excluded and 16 were accepted for data extraction and quality assessment. The quality of accepted trials was assessed, using updated quality criteria, and the risk of bias was investigated in more depth than previously reported. In addition, the focus of quantitative synthesis was shifted to single datasets that were extracted from the accepted trials. Results Twenty-six dichotomous and 4 continuous datasets were extracted. Meta-analysis and cumulative meta-analysis were used in combining clinically homogenous datasets. The overall outcome of the computed datasets suggest no difference between the caries-preventive effects of GIC- and resin-based fissure sealants. Conclusions This overall outcome is in agreement with the conclusions of the original systematic review. Although the findings of the trials identified in this update may be considered to be less affected by attrition- and publication bias, their risk of selection- and detection-/performance bias is high. Thus, verification of the currently available results requires further high quality randomised control trials. PMID:21276215

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

    PubMed Central

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

    2014-01-01

    Purpose Current evidence in dentistry recommends non-surgical treatment to manage enamel caries lesions. However, surveyed practitioners report they would restore enamel lesions that are confined to the enamel. We used actual clinical data to evaluate patient, dentist, and practice characteristics associated with restoration of enamel caries, while accounting for other factors. Methods We combined data from a National Dental Practice-Based Research Network observational study of consecutive restorations placed in previously unrestored permanent tooth surfaces and practice/demographic data from 229 participating network dentists. Analysis of variance and logistic regression, using generalized estimating equations (GEE) and variable selection within blocks, were used to test the hypothesis that patient, dentist, and practice characteristics were associated with variations in enamel restorations of occlusal and proximal caries compared to dentin lesions, accounting for dentist and patient clustering. Results Network dentists from 5 regions placed 6,891 restorations involving occlusal and/or proximal caries lesions. Enamel restorations accounted for 16% of enrolled occlusal caries lesions and 6% of enrolled proximal caries lesions. Enamel occlusal restorations varied significantly (p<0.05) by patient age and race/ethnicity, dentist use of caries risk assessment, network region, and practice type. Enamel proximal restorations varied significantly (p<0.05) by dentist race/ethnicity, network region, and practice type. CLINICAL SIGNIFICANCE Identifying patient, dentist, and practice characteristics associated with enamel caries restorations can guide strategies to improve provider adherence to evidence-based clinical recommendations. PMID:25000667

  6. Natal teeth

    MedlinePlus

    ... will be done. Alternative Names Fetal teeth References Smith JB. Initial evaluation. In: Gleason CA, Devaskar SU. ... commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Contact ...

  7. Keeping Your Child's Teeth Healthy

    MedlinePlus

    ... colored material called amalgam (a special mix of metals) was once the substance of choice for most fillings in permanent teeth. But now, other materials like composite resins are becoming popular. Resins bond to ... — a mouth filled with metal wires and braces — is a relic of the ...

  8. Avulsion of permanent teeth: theory to practice.

    PubMed

    Trope, Martin

    2011-08-01

    This paper presents clinical protocols for the emergency, early and post treatment complications of the avulsed tooth. The biological basis for these protocols is presented so that the reader understands the clinical decisions that have been made. Most of the protocols described in this article, but not all, have been adopted in the official guidelines of the International Association of Dental Traumatology. Some experimental results are promising and they have therefore been included in the review to stimulate colleagues to further research. PMID:21635689

  9. Teeth Injuries (For Parents)

    MedlinePlus

    ... Things to Know About Zika & Pregnancy First Aid: Teeth Injuries KidsHealth > For Parents > First Aid: Teeth Injuries ... or young child injures the gums or baby teeth: Apply pressure to the area (if it's bleeding) ...

  10. Oxalic acid in saliva, teeth and tooth tartar.

    PubMed

    Wahl, R; Kallee, E

    1994-11-01

    Oxalic acid was determined in human saliva, teeth, tartar, and in animal teeth. Saliva from dentally healthy male subjects contained 0.10 +/- 0.09 mmol/l (n = 41) and those of dentally healthy female subjects 0.18 +/- 0.17 mmol/l (n = 40). Oxalic acid in tartar from 16 patients was 3.3 +/- 1.2 mmol/kg tartar. In human teeth, oxalic acid was 1.0 +/- 0.3 mmol/kg in milk teeth (n = 12) and 0.9 +/- 0.6 mmol/kg in permanent teeth (n = 60). Human teeth were sorted into age groups and into molars, incisors and premolars. In animal teeth, oxalic acid content varied widely. The formed calcium oxalate is proposed to be a 'physiological' protective mechanism for teeth. PMID:7888477

  11. 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

  12. Late Developing Supernumeraries in a Case of Nonsyndromic Multiple Supernumerary Teeth

    PubMed Central

    Bozkurt, Mine; Tüzüner Öncül, Ayşegül; Göçer, Rukiye; Sarı, Şaziye

    2015-01-01

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

  13. Supernumerary teeth: Report of four unusual cases

    PubMed Central

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

    2012-01-01

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

  14. Bilateral Supernumerary Teeth in Deciduous Dentition-A Rarity

    PubMed Central

    Ghosh, Chiranjit; Mondal, Pradeep Kumar

    2014-01-01

    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 and more often seen in males. A supernumerary tooth in the primary dentition can cause ectopic or delayed eruption of permanent central incisors which will further alter occlusion and may compromise esthetics and formation of dentigerous cysts. Here we discuss a case of bilateral supernumerary teeth in deciduous dentition in a female child. PMID:24995257

  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. Widely spaced teeth

    MedlinePlus

    Teeth - widely spaced ... Acromegaly Ellis-van Creveld syndrome Injury Morquio syndrome Normal growth (temporary widening) Possible gum disease Sanfilippo syndrome Tooth shifting due to gum disease or missing teeth

  17. Malocclusion (Misaligned Teeth)

    MedlinePlus

    ... Dry Mouth Mouth Growths Mouth Sores and Inflammation Toothache Malocclusion Teeth Grinding Recurrent Aphthous Stomatitis Malocclusion is ... Dry Mouth Mouth Growths Mouth Sores and Inflammation Toothache Malocclusion Teeth Grinding Recurrent Aphthous Stomatitis NOTE: This ...

  18. About Kids' Teeth

    MedlinePlus

    ... in baby teeth. Keep Baby’s Gums and Teeth Clean Begin cleaning your baby's mouth during the first ... every feeding, wipe your baby's gums with a clean gauze pad. This removes plaque and food, and ...

  19. Brushing your infant's teeth

    MedlinePlus

    ... gov/ency/patientinstructions/000769.htm Brushing Your Child’s Teeth To use the sharing features on this page, ... how to brush their teeth on their own. Tooth and Gum Care for Young Children You should ...

  20. Factors influencing trace element composition in human teeth

    SciTech Connect

    Tandon, L.; Iyengar, G.V.

    1997-12-01

    The authors recently compiled and reviewed the literature published in or after 1978 for 45 major, minor, and trace elements in human teeth as a part of an International Atomic Energy Agency (IAEA) study. The purpose of this paper is to discuss the various factors that influence the concentration levels of certain trace elements in human teeth. The sampling practices and analytical techniques that are applicable for trace element analysis are also discussed. It is also our intention to identify reference range of values, where data permit such conclusions. The scrutiny was designed to identify only the healthy permanent teeth, and values from teeth with fillings, caries, or periodontal diseases were eliminated.

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

    PubMed Central

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

  2. Natal teeth: a review.

    PubMed Central

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

    2006-01-01

    The incidence of natal teeth is approximately 1:2,000 to 1:3,000 live births. The most commonly affected teeth are the lower primary central incisors. Natal teeth usually occur in pairs. The eruption of more than two natal teeth is rare. The majority of natal teeth represent the early eruption of normal primary deciduous dentition. Less than 10% of natal teeth are supernumerary. Natal teeth might resemble normal primary dentition in size and shape; however, the teeth are often smaller, conical and yellowish, and have hypoplastic enamel and dentin with poor or absent root formation. Complications include discomfort during suckling, sublingual ulceration, laceration of the mother's breasts and aspiration of the teeth. A dental roentgenogram is indicated to differentiate the premature eruption of a primary tooth from a supernumerary tooth. Tooth extraction is indicated if the tooth is supernumerary or excessively mobile. If the tooth does not interfere with breastfeeding and is otherwise asymptomatic, no treatment is necessary. Images Figure 1 PMID:16708508

  3. [Cryopreservation of teeth].

    PubMed

    Zimmerli, Melanie; Filippi, Andreas

    2010-01-01

    After tooth loss dental implants or fixed prosthetic restorations are not indicated in children and adolescents due to incomplete maxillary and mandibular development. Cryopreservation is a method for long-term storage of healthy teeth which were removed for orthodontic reasons or due to traumatic origin. These preserved teeth can be used as autogenous replants or transplants after tooth loss. During transport to and from the freezing facilities prior to freezing the teeth are stored in a cell culture medium. The tooth is transferred into a freezing tube containing cell culture medium and cryoprotectant DMSO. Teeth autotransplanted after cryopreservation show vitality of the PDL cells. Usually no enamel and/or dentinal cracks can be observed. After tooth loss transplantation of cryopreserved teeth could be an effective and biological therapy for tooth replacement. PMID:21545030

  4. Clinical and radiographic evaluation of vital pulp therapy in open apex teeth with MTA and ZOE.

    PubMed

    Ghoddusi, Jamileh; Shahrami, Fatemeh; Alizadeh, Mahyareh; Kianoush, Kamyar; Forghani, Maryam

    2012-04-01

    The purpose of this study was to report the success rate of using mineral trioxide aggregate (MTA) and zinc oxide eugenol (ZOE) as vital pulp therapy agents in immature permanent teeth with carious or traumatic pulp exposure. Subjects were children with permanent teeth requiring pulpotomy (apexogenesis) and without systemic diseases. Both ZOE and MTA treatments as pulpotomy agents showed clinical and radiographic success in immature permanent teeth. Although MTA was more successful, it is more expensive, and dentin bridges may develop over canal orifices, complicating future root canal therapy. PMID:22803275

  5. Detection of Enterococcus faecalis in Necrotic Teeth Root Canals by Culture and Polymerase Chain Reaction Methods

    PubMed Central

    Cogulu, Dilsah; Uzel, Atac; Oncag, Ozant; Aksoy, Semiha C.; Eronat, Cemal

    2007-01-01

    Objectives The aim of this study was to investigate the presence of Enterococcus faecalis in endodontic infections in both deciduous and permanent teeth by culture and polymerase chain reaction (PCR) methods. Methods A total of 145 children aged 5–13 years old were involved in this study. The presence of E. faecalis in necrotic deciduous and permanent teeth root canals was studied using culture and polymerase chain reaction methods. Results Among 145 molar teeth, 57% (n=83) presented necrotic asymptomatic pulp tissues and were included in this study. Culture and PCR methods detected the test species in 18 and 22 of 83 teeth involved, respectively. E. faecalis was cultured from 8 (18%) of 45 necrotic deciduous teeth and from 10 (26%) of 38 necrotic permanent teeth. PCR detection identified the target species in 10 (22%) and 12 (32%) of necrotic deciduous and permanent teeth respectively. Statistically significant difference in the presence of E. faecalis in deciduous and permanent teeth was found by culture and PCR methods (P=0.03 and 0.02, respectively). The difference in the presence of E. faecalis between two different methods was not statistically significant (P>.05). Conclusions The results of the present study confirm that both culture and PCR methods are sensitive to detect E. faecalis in root canals. PMID:19212470

  6. Report of a case with 19 supernumerary teeth in a non-syndromic patient

    PubMed Central

    Yan, Lei; Yu, Long Wang; Bhandari, Kishor; Shan, Chang Li

    2014-01-01

    Supernumerary teeth occur frequently in human dentition, but presence of multiple supernumerary teeth in patients without any associated syndrome or systemic disorder is a rare phenomenon. Presence of supernumerary teeth in itself is not a problem and may not require removal in all cases but in certain conditions, they may be associated with several clinical complications and require removal. Here, we present a 14 year old female who complained of non emergence of permanent teeth. Orthopantomogram initially showed presence of fifteen impacted supernumerary teeth distributed in all quadrants, but later, cone-beam computed tomography further revealed four additional teeth, totaling to nineteen supernumerary teeth. Consultation with concerned specialists ruled out any syndromes or systemic disorders which led us to the diagnosis of “non-syndromic multiple supernumerary teeth” and this probably is the highest number of supernumerary teeth reported in a single non-syndromic patient till date. PMID:25565732

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

    PubMed Central

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

    2013-01-01

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

  8. Impacted wisdom teeth

    PubMed Central

    2014-01-01

    Introduction The incidence of impacted wisdom teeth (third molars) is high, with some 72% of Swedish people aged 20 to 30 years having at least one impacted wisdom tooth. Impacted wisdom teeth occur because of a lack of space, obstruction, or abnormal position. They can cause inflammatory dental disease manifested by pain and swelling of infected teeth and may destroy adjacent teeth and bone. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: Should asymptomatic, disease-free impacted wisdom teeth be removed prophylactically? What are the effects of different operative (surgical) techniques for removing impacted wisdom teeth? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2013 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We performed a GRADE evaluation of the quality of evidence for interventions. Results We found 11 studies that met our inclusion criteria. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: prophylactic extraction, active surveillance, and different operative (surgical) techniques for extracting impacted wisdom teeth. PMID:25170946

  9. Orthodontic treatment of bilateral geminated maxillary permanent incisors.

    PubMed

    Le Gall, Michel; Philip, Camille; Aboudharam, Gérard

    2011-05-01

    Geminated teeth occur more frequently in the deciduous dentition than in the permanent dentition, with prevalence figures of 0.6% and 0.1%, respectively. Bilateral presentation is rare. A survey of the literature showed that the prevalence estimates for bilateral double teeth range from 0.01% to 0.04% in the deciduous dentition, and 0.05% in the permanent dentition. In this article, we report a rare case of bilateral fusion of the maxillary permanent incisors, discuss possible histogenetic mechanisms related to this anomaly, and explain the treatment management. PMID:21536214

  10. Use of Cantilever Mechanics for Impacted Teeth: Case Series

    PubMed Central

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

    2013-01-01

    This paper describes the orthodontic treatment, and the biomechanics of cantilevers for the impaction of permanent teeth in youngs, adolescents, and adults. In these case series, multibracket straightwire fixed appliances, together with cantilever mechanics, were used to treat the impaired occlusion. PMID:24511332

  11. Orthodontic movement in traumatically intruded teeth: a case report.

    PubMed

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

    2003-10-01

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

  12. 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

  13. Age-Dependent Changes in Pb Concentration in Human Teeth.

    PubMed

    Fischer, Agnieszka; Wiechuła, Danuta

    2016-09-01

    The result of exposure to Pb is its accumulation in mineralized tissues. In human body, they constitute a reservoir of approx. 90 % of the Pb reserve. The conducted research aimed at determining the accumulation of Pb in calcified tissues of permanent teeth. The concentration of Pb in 390 samples of teeth taken from a selected group of Polish people was determined using the AAS method. Average concentration of Pb in teeth amounted to 14.3 ± 8.18 μg/g, range of changes: 2.21-54.8 μgPb/g. Accumulation of Pb in human body was determined based on changes in Pb concentration in teeth of subjects aged 13-84 years. It was found that in calcified tissues of teeth, the increase in concentration of Pb that occurs with age is a statistically significant process (p = 0.02, the ANOVA Kruskal-Wallis test). It was determined that the annual increase in concentration of Pb in tissues of teeth is approx. 0.1 μg/g. Moreover, a different course of changes in Pb concentration in tissues of teeth in people born in different years was observed. The level of Pb concentration in teeth of the oldest subjects (>60 years) decreased for those born in the 1930s compared to those in the 1950s. Teeth from younger persons (<60 years) were characterized by an increasing level of Pb concentration. The analysis of changes of Pb indicates that for low exposure, a relatively greater accumulation of Pb concentration in calcified tissues of teeth can occur. PMID:26888348

  14. Two cases with supernumerary teeth in lower incisor region.

    PubMed

    Yokose, Taishi; Sakamoto, Teruo; Sueishi, Kenji; Yatabe, Kenichi; Tsujino, Keiichirou; Kubo, Shuhei; Yakushiji, Masashi; Yamaguchi, Hideharu

    2006-02-01

    Abnormalities in number of teeth are occasionally noted in clinical cases. Many theories have been proposed as regards the causes of the occurrence of supernumerary teeth, including atavism theory, mechanical tooth germ separation theory, tissue induction theory, and dental laminar morphological disturbance theory. However, none of these theories alone offers a sufficient explanation for this phenomenon. The incidence of supernumerary permanent teeth is approximately 1-3%. These are the maxillary anterior teeth, the maxillary molars, and the maxillo-mandibular premolars in terms of descending order of site of occurrence. On the other hand, incidence in the mandibular anterior tooth area, of which there have been few detailed reports, is about 0.01%, a markedly low value. In this paper, we report two rare cases of supernumerary teeth in the mandibular incisor area. We discuss their etiology and orthodontic treatment, and detail a differential diagnosis between the normal and supernumerary teeth. We found that it was difficult to establish a clear etiology and differentiation between the normal and supernumerary teeth. PMID:16924155

  15. 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

  16. Remarkable resilience of teeth

    PubMed Central

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

    2009-01-01

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

  17. [Reconstruction of pulpectomized teeth].

    PubMed

    Colon, P; Picard, B

    1990-04-01

    The general principles governing the choice of materials for reconstruction of devitalized teeth are determined on the basis of mechanical and biological imperatives as well as degradation phenomena. In describing the various techniques for clinical implementation, particular emphasis is placed on the imperatives and limitations of each protocol. A decisive factor in the durability of restorations is their homogeneity, as well as the clinical conditions under which they are performed. PMID:2135782

  18. 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

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

    PubMed

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

    2005-01-01

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

  20. 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 anæsthesia on the dental pulp, some of the causes of odontalgia and neuralgia and the effect of old age and general disease on the dental innervation. He has failed with lethal or continued sublethal doses of ethyl and methyl alcohol, lead or tetanus and diphtheria toxins, using the oral, gastric, subcutaneous and intravenous route, to produce dental neuronic change. The effects of fracture of teeth and jaws, the introduction of arsenic into the pulp chamber and amputation and extirpation of the pulp are examined. The vital resistance of the pulp and the significance of granulomata as a protective mechanism are discussed. The author has found that after extraction although there is at first degeneration of the nerve-fibres concerned, there may subsequently be regeneration, sometimes in the form of plexiform neuroma. He has produced degenerative changes in

  1. Autotransplantation of Teeth Associated with Dentigerous Cyst: A Case Report.

    PubMed

    Rajanikanth, B R; Kavitha Prasad; Vineeth, K

    2015-09-01

    This paper discusses the treatment of impacted permanent incisors and unerupted ectopic canine associated with a dentigerous cyst in mixed dentition that was successfully managed by the combined approach of decompression followed by enucleation, primary closure, autotransplantation and endodontic therapy which enabled the utilization of teeth which were hitherto nonfunctional, transferred to an optimal functional and esthetic position. Decompression is a less invasive technique which reduces the cystic pressure, avoids a more stressful surgical procedure and necessity for general anesthesia. It gives more pleasing results as the body's own mechanism heals the defect gradually. Autotransplantation of teeth induces bone formation around the root with the help of viable periodontal ligament on their root surface. In this case, bone lost by cyst was regenerated and lamina dura was appreciable in the follow up radiographs and transplanted teeth are functioning well. PMID:26225081

  2. 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

  3. Essure Permanent Birth Control

    MedlinePlus

    ... Implants and Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... evaluation of the Essure System Essure is a permanent birth control method for women (female sterilization). Implantation of Essure ...

  4. Parental behavior regarding traumatically avulsed teeth: case reports.

    PubMed

    Barreira, Alice Kelly; Gotze, Gabriela da Rosa; Primo, Laura Salignac de Souza Guimaraes; Maia, Lucianne Cople

    2008-01-01

    The prognosis for an avulsed tooth depends primarily on appropriate emergency management, which usually must be provided by lay people prior to the child's initial dental contact. As immediate replantation is considered the best therapy for an avulsed tooth in permanent dentition, parents should be made aware of first aid procedures for this situation. This article describes three cases involving avulsed teeth in children and discusses the parents' approaches concerning emergency procedures. PMID:18348377

  5. The orthodontic extraction of permanent molars: a literature review.

    PubMed

    Chua, Emilia S L; Felicita, A Sumathi

    2015-05-01

    The most common cause of dental crowding is the presence of an arch-length--tooth-size discrepancy. Conventional methods of gaining space in orthodontics involve the extraction of teeth, often premolars. However, there are a number of clinical situations in which the extraction of permanent molars might be considered. This paper highlights the indications, advantages, disadvantages and timing of the extraction of the first, second and third permanent molars in the treatment of a crowded malocclusion. PMID:26219149

  6. Accuracy of age estimation of radiographic methods using developing teeth.

    PubMed

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

    2006-05-15

    Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci

  7. Take Care of Your Teeth

    MedlinePlus

    ... other particles, they constantly form a sticky, colorless "plaque" on teeth. Brushing and flossing help get rid of plaque. ... can result in gum damage and loss of teeth. Photos: Center for Disease Control and Prevention (CDC) Illustration: Krames Do you have ...

  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. Bacteriological analysis of necrotic pulp and fistulae in primary teeth

    PubMed Central

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

    2014-01-01

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

  10. Analysis of eroded bovine teeth through laser speckle imaging

    NASA Astrophysics Data System (ADS)

    Koshoji, Nelson H.; Bussadori, Sandra K.; Bortoletto, Carolina C.; Oliveira, Marcelo T.; Prates, Renato A.; Deana, Alessandro M.

    2015-02-01

    Dental erosion is a non-carious lesion that causes progressive tooth wear of structure through chemical processes that do not involve bacterial action. Its origin is related to eating habits or systemic diseases involving tooth contact with substances that pose a very low pH. This work demonstrates a new methodology to quantify the erosion by coherent light scattering of tooth surface. This technique shows a correlation between acid etch duration and laser speckle contrast map (LASCA). The experimental groups presented a relative contrast between eroded and sound tissue of 17.8(45)%, 23.4 (68)% 39.2 (40)% and 44.3 (30)%, for 10 min, 20 min, 30 min and 40 min of acid etching, respectively.

  11. Take Care of Your Child's Teeth

    MedlinePlus

    ... Baby teeth hold space for adult teeth. Take care of your child’s teeth to protect your child from tooth decay (cavities). Tooth decay can: Cause your child pain Make it hard for your child to chew ...

  12. Take Care of Your Teeth and Gums

    MedlinePlus

    ... Brush your teeth 2 times a day with fluoride (“FLOOR-ide”) toothpaste. Floss between your teeth every ... a toothbrush with soft bristles and toothpaste with fluoride. Fluoride is a mineral that helps protect teeth ...

  13. [Traumatic injuries to the teeth for children].

    PubMed

    Hieda, T

    1989-01-01

    For modern medical care, social background may be an essential factor, and medical care through out the individual's life time appears to have significant meaning. From this point of view, total dental care throughout childhood is being carried out in the field of pediatric dentistry. It can be stated that we pedodontists have a degree of farsight in the treatment of traumatic injuries to the teeth regarding children (the theme of the lecture), since the injured teeth are treated not only as items to be restored but also as a part of the growing body with careful consideration on the effects with regard to orlo-facial growth. It is obvious that epidemiological surveilance is necessary to understand the cause of dental injuries, and also careful attention ought to be paid to the activity of the children to grasp the potential background of dental trauma. Here, I would like to explain the consequences of the serial work on the traumatic injuries to teeth which were carried out in our department. 1) The prevalence of dental injuries in children appeares to be on the increase according to a judgement based on the surveilances form in and out of the country. Also as the parental recognition for dental injuries became higher, more patients visited dental clinic or hospital looking for improved treatment techniques. 2) Careful consideration must be paid to the succedaneus permanent tooth germ, when a deciduous tooth suffered from traumatic injury. The effect of the direction applied and the area of the traumatic force on the root of the deciduous tooth, the successor and the surrounding tissue was investigated by means of kinetic analysis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2577384

  14. [Molecular biological studies on teeth inquests].

    PubMed

    Yamamoto, K

    1992-12-01

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

  15. Adjuncts to traditional local anesthesia techniques in instance of hypomineralized teeth.

    PubMed

    Discepolo, Keri E; Baker, Suher

    2011-11-01

    Molar incisor hypomineralization (MIH) is a defect in the enamel of permanent and/or primary molars and incisors. This disorder allows for rapid breakdown of the teeth and often calls for extensive restorative procedures. Due to the chronic pulpitis condition that is often associated with hypomineralized teeth, local anesthesia complications can result. This paper is a systematic review of the literature for the purpose of investigating adjuncts to traditional local anesthesia techniques in the case of hyper-responsive, hypomineralized-involved teeth during restorative procedures. PMID:22338814

  16. Teeth white and fair.

    PubMed

    Reed, R V

    1998-03-01

    Most dentists practicing today, in fact most dentists living today, accept porcelain, in one form or another, as a fundamental determinant of dental armamentarium. It must be remembered, however, that porcelain, in spite of some admonishments by the Chicken Littles, has not and is not about to fall like the sky. A great amount of purpose, intellect, and dedication proffered by porcelain's protagonists was the springboard that eventually led to near total acceptance of that product by dentists and the public they treated. Porcelain's introduction, however, was not accompanied by a professional unity that orchestrated its arrival with a blare of bugles and a ruffle of drums. Rather, the early proponents and opponents churned and swiped at each other for some decades. Teeth White and Fair recounts the origin, struggle, and growth of an early porcelain manufacturing company; the diversity of the men involved in the production of porcelain; the profession's dichotomy regarding the acceptance of porcelain; and the details of manufacture of that then embryonic dental product. Finally, the reader is given a peek at evolving cosmetic oriented materials that desire to garner ascension as valued players on the stages of cosmetic dental restorative materials. PMID:9709660

  17. [Epidemiology of teeth hypersensitivity].

    PubMed

    Lutskaia, I K; Zinovenko, O G; Kovalenko, I P

    2015-01-01

    A clinical examination of 98 patients aged 20 to 75 years was carried out to identifyclinical and epidemiological features of hard tooth tissueshypersensitivity. The survey found out what stimuli (cold, hot, sour, mechanical, chemical) cause the appearance of dental hyperesthesia. The detailed survey of the affected area aimed to determine the presence of dental caries, gingival recession, wedge-shaped defects, erosions, microcracks and chipped enamel, as well as wear of the tooth crown. Forty-threepatients of 98 (43.88%) had tooth sensitivity. Most affected age group was 25-34 years (33%). Among patients studied with hyperesthesia 86% complained of pain. It was establishedthat dental hyperesthesia most often causes an intense, but quickly passing pain response, wherein upon exposure of several types of stimuli. Teeth with high sensitivity showed signs of abrasion (74.1%), most often--on the vestibular surface (44.4%). Patients under 45 years had notable cracks and wedge-shaped defects. In patients 45 years and older cracks and increased abrasion of hard dental tissues was seen. PMID:26271696

  18. Do Fluoride Ions Protect Teeth?

    ERIC Educational Resources Information Center

    Parkin, Christopher

    1998-01-01

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

  19. Taking Care of Your Teeth

    MedlinePlus

    ... but it won't remove the plaque and particles of food between your teeth, under the gumline, ... frequency sound waves to loosen plaque deposits. The particles are then rinsed off with water. After cleaning, ...

  20. Restoring primary anterior teeth.

    PubMed

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will 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. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. 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 those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen. PMID:12412967

  1. 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 28°C to 38°C in IIT (intact immature tooth) and PIT (cavity-prepared immature tooth). When a high-intensity LED LCU was used, tooth temperature increased from 28°C to 48°C. The results of the experimental tests and mathematical modeling illustrated that using LED LCU on immature teeth did not have any detrimental effect on the pulp temperature. Conclusion. Using LED LCU in immature teeth had no effect on pulp temperature in this study. Sensitivity analysis showed that variations of heat conductivity might affect heat transfer in immature teeth; therefore, further studies are required to determine thermal conductivity of immature teeth. PMID:25587383

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

    PubMed

    Gulevskiĭ, A K; Trifonova, A V; Lavrik, A A

    2008-01-01

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

  3. Fracture resistance of weakened teeth restored using accessory glass fiber posts.

    PubMed

    da Rosa, Ricardo Abreu; Barreto, Mirela Sangoi; da Rosa, Tiago Abreu; Reis, Katia Rodrigues; Kaizer, Osvaldo Bazzan

    2013-01-01

    This study used differential root weakening to evaluate the fracture resistance of bovine teeth restored using glass fiber posts (with or without accessory glass fiber posts). Fifty bovine mandibular incisors were sectioned 14 mm from the apex, fixed in acrylic resin blocks, and divided into 5 groups: healthy roots with a glass fiber post (Group 1), partially weakened teeth with a glass fiber post (Group 2), partially weakened teeth with a glass fiber post and 2 accessory glass fiber posts (Group 3), extensively weakened teeth with a glass fiber post (Group 4), and extensively weakened teeth with a glass fiber post and 5 accessory glass fiber posts (Group 5). Posts were luted with resin cement, cores were prepared using composite resin, and metallic crowns were cemented. The specimens were stored in distilled water at 37°C for more than 72 hours until the fracture resistance test. Specimens were loaded at 135 degrees relative to the long axis of the tooth at a crosshead speed of 0.5 mm/minute in a universal testing machine. All groups predominantly exhibited favorable failure patterns and there were no statistically significant differences between groups (two-way ANOVA, α = 0.05). PMID:23454321

  4. Concentration of {sup 226}Ra in human teeth

    SciTech Connect

    Yamamoto, Masayoishi; Ueno, Kaoru; Hinoide, Moriyo; Ohkubo, Yoshiteru

    1994-11-01

    {sup 226}Ra concentrations in human teeth from several cities, mainly Tokyo, Japan, were determined with emphasis on the measurement of low-level {sup 226}Ra by alpha-ray spectrometry following chemical separation. No appreciable differences in {sup 226}Ra concentration were found among various permanent teeth samples of different age groups in Tokyo. The mean {sup 226}Ra concentration for Tokyo was 0.51 {+-} 0.06 mBq (g CA){sup -1}. {sup 226}Ra concentration [mean: 0.67 {+-} 0.11 mBq (g Ca){sup -1}] in teeth in western regions of the country was statistically higher than that [mean: 0.48 {+-} 0.09 mBq (g Ca){sup -1}] in eastern ones. The mean {sup 226}Ra concentration [0.51 mBq (g CA){sup -1}] in teeth from Tokyo was less than the concentration [1.11 mBq (g CA){sup -1}] reported for vertebral bone samples of this city. 27 refs., 1 fig., 5 tabs.

  5. Prevalence and patterns of permanent tooth agenesis in individuals with Down syndrome: a meta-analysis.

    PubMed

    Palaska, Pinelopi K; Antonarakis, Gregory S

    2016-08-01

    The aims of the present study were to evaluate the prevalence and patterns of permanent tooth agenesis in individuals with Down syndrome, using meta-analysis methodology. Two independent investigators carried out a literature search to locate articles pertaining to permanent tooth agenesis in individuals with Down syndrome. The outcomes of interest were the prevalence and pattern of permanent tooth agenesis. Thirteen articles were selected for inclusion. The estimated overall prevalence of permanent tooth agenesis, excluding third molars, was 54.6% (95% CI: 44-66%). Considerable heterogeneity was present across the studies. Among subjects with tooth agenesis, approximately half had three or more missing teeth. The permanent teeth with the highest prevalence of agenesis were the maxillary lateral incisor (27%), mandibular second premolar (21%) and maxillary second premolar (18%). The single most commonly absent tooth, however, was the mandibular left second mandibular premolar (19.9%), followed by the maxillary left lateral incisor (19.4%). Little data describing specific tooth-agenesis patterns were available. In conclusion, individuals with Down syndrome display high prevalence rates and severity of agenesis of permanent teeth. Proper and timely diagnosis of missing permanent teeth is thus necessary, to allow a more comprehensive long-term treatment plan and a more favorable prognosis in these individuals. PMID:27311636

  6. 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

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

    PubMed Central

    Kalaskar, Ritesh R.; Kalaskar, Ashita R.

    2011-01-01

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

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

    PubMed

    Kalaskar, Ritesh R; Kalaskar, Ashita R

    2011-01-01

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

  9. [Ancient teeth: research on teeth and jaws from archaeological sites].

    PubMed

    Jelsma, J

    2016-05-01

    Archaeology aims to enhance our understanding of the human past. An archaeologist devotes him- or herself to material remains, most often from the earth. The best sources of information about human behaviour and the earlier conditions of life for human beings are gravesites. In addition to being a source of cultural information, well-preserved skeletons offer vast possibilities for biochemical and genetic research. Teeth in particular can provide a treasure trove of information about the lives of our ancestors. With DNA analysis, gender and genetic relationships can be determined, however, the surface of the teeth also provides information about gender, age and genetic relationships and, of course, about the use of the teeth. New discoveries are being made and new (bio-)archaeological analyses are being carried out all the time. PMID:27166454

  10. 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.

  11. Pulpotomy of carious vital teeth with periapical involvement.

    PubMed

    Calişkan, M K

    1995-05-01

    Twenty-six permanent vital molars with carious pulp exposures and periapical involvement presenting as radiolucencies or radiopacities on radiographic examination, in patients aged between 10-24 years, were treated using an atraumatic surgical technique with calcium hydroxide alone. The healing was evaluated using clinical and radiographic criteria: absence of clinical symptoms, sensitivity of the radicular pulp, formation of a hard tissue barrier in the exposed area, resolution of periapical involvement and no intraradicular pathosis radiographically. Assessed by these criteria, successful results were achieved in 24 teeth. The observation period following pulpotomy treatment was 16-72 months. The favourable results of this study demonstrate that pulpotomy treatment in teeth with cariously exposed vital pulps and with periapical involvement may be an alternative treatment to root canal therapy. PMID:8626202

  12. Wear of artificial denture teeth by use of toothbrushes. Part 1: Abrasive wear of anterior teeth.

    PubMed

    Satoh, Y; Ohtani, K; Maejima, K; Morikawa, M; Matsuzu, M; Nagai, E; Toyoma, H; Ohwa, M; Ohki, K; Kaketani, M

    1990-12-01

    High-strength denture teeth (HS teeth) were developed in order to improve the hardness and wear resistance of conventional plastic denture teeth (PL teeth), while retaining their feature of easy occlusal adjustment. The objective of this study was to evaluate the abrasive wear resistance of HS teeth. We conducted wear tests and measured surface roughness using six types of anterior artificial teeth, i.e., three types of HS teeth and three types of PL teeth, the latter serving as the control. The results of the toothbrush abrasion test revealed that the HS teeth had about 5 times greater wear resistance than the PL teeth. It was also found that the type of artificial teeth and the number of abrasive wear-testing strokes had a significant (P less than 0.05) influence on the surface roughness of artificial teeth. PMID:2074493

  13. Management of an infant having natal teeth

    PubMed Central

    Khandelwal, Vishal; Nayak, Ullal Anand; Nayak, Prathibha Anand; Bafna, Yash

    2013-01-01

    Eruption of teeth at or immediately after birth is a relatively rare phenomenon. These teeth are known as ‘natal’ teeth if present at birth and ‘neonatal’ teeth if they erupt during the first 30 days of life. Natal teeth might resemble normal primary dentition in size and shape; however, the teeth are often smaller, conical and yellowish and have hypoplastic enamel and dentin with poor or absent root formation. Complications include difficulty and discomfort during suckling, sublingual ulceration, laceration of the mother’s breasts and aspiration of the teeth. These situations would warrant extraction. If the tooth does not interfere with breast feeding and is otherwise asymptomatic, no treatment is necessary. Negative cultural attitudes towards natal teeth demand good parental counselling and vigilant management in relation to child protection. Both general practice dentists and paediatric dental specialists may be involved in the supervision or treatment of patients with natal and neonatal teeth. PMID:23737593

  14. Root Maturation in Teeth Treated by Unsuccessful Revitalization: 2 Case Reports.

    PubMed

    Žižka, Radovan; Buchta, Tomáš; Voborná, Iva; Harvan, Luboš; Šedý, Jiří

    2016-05-01

    This article deals with the unusual course of failed revascularization/revitalization cases. Up to this date the evidence of success and failure rates of revascularization/revitalization treatment is scarce. These case reports present "unsuccessful" revascularization/revitalization treatment of permanent immature teeth with apical periodontitis. Although the teeth were treated by protocol suggested by the American Association of Endodontists and the symptoms disappeared, maturation of teeth continued, and periapical lesion was reduced, the teeth went symptomatic during the follow-up. Subsequently, regular root canal treatment was performed. Despite chronic infection that was probably left inside the root canal after a disinfection protocol, the secondary aims of the treatment were achieved even when the primary ones were not. The possible causes of failures of revascularization/revitalization treatment and their prevention are discussed. PMID:26960577

  15. 3 Dimensional Diagnosis Unravelling Prognosis of Multiple Impacted Teeth – A Case Report

    PubMed Central

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

    2013-01-01

    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

  16. Current restorative modalities for young patients with missing anterior teeth.

    PubMed

    Dietschi, D; Schatz, J P

    1997-04-01

    The early loss of permanent teeth following trauma or congenital aplasia may be corrected by orthodontic or prosthetic means, sometimes combined with implant therapy. The orthodontic solution results usually in different anatomic, functional, and esthetic problems. Prosthetic and implant procedures, on the other hand, are very demanding and require long-term maintenance. Considering these limitations, a comprehensive diagnostic and treatment plan is mandatory to achieve the most satisfactory clinical result. Modern restorative modalities, such as recontouring, bleaching, and resin composite bonding, may improve the final clinical result after orthodontic space closure. In more difficult situations, veneers and crowns may also be indicated. PMID:10332371

  17. 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.

  18. [Extraction of the deciduous anterior teeth and its consequences in children with the nursing bottle syndrome].

    PubMed

    Wetzel, W E; Grieb, A; Pabst, W

    1993-01-01

    On eighty children, whose rampant carious and predominant periapical diseased deciduous maxillary incisors had been formerly extracted, the outcomes of the early extraction were inspected in regard to the later development of the permanent teeth and the general state of health. For 68 children gypsum models were analysed, whether the early loss of deciduous incisors had led to deficiency of place in the front of the upper jaw. The early tooth extraction and conservation therapy resulted in a clear improvement of children's physical condition and ameliorated the starting situation of permanent teeth to be preserved healthy. The earlier the milk-incisors had to been extracted the greater was the danger of a belated eruption of the permanent incisors. PMID:8511550

  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. Method and apparatus for assembling permanent magnet rotors

    DOEpatents

    Hsu, John S.; Adams, Donald J.

    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.

  2. 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.

  3. Cracked Teeth: A Review of the Literature

    PubMed Central

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

    2013-01-01

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

  4. Biodentine Pulpotomy in Mature Permanent Molar: A Case Report

    PubMed Central

    2016-01-01

    Irreversible pulpitis is the most common reason for endodontic treatment in primary and permanent teeth. Root canal therapy and extraction are the two viable and most documented treatment options for the same. Studies with regards to management of mature permanent teeth with carious exposure and treatment with vital pulp therapies such as adult permanent tooth pulpotomy are scarce. However, permanent tooth pulpotomy with the new calcium-silicate based cements (Mineral Trioxide Aggregate and Biodentine) can help preserve the tooth pulp vitality and promote healing and repair foregoing the more invasive root canal therapy procedure. A 12-year old male patient with irreversible pulpitis in right mandibular first permanent molar was treated with complete coronal pulpotomy with placement of Biodentine in the pulp chamber and a full coronal coverage using stainless steel crown. Clinical and radiographic examinations were performed at three, six, twelve and eighteen months. At the end of 18 months, the patient was completely asymptomatic and the tooth was free of any clinical and radiographic signs of inflammation and infection.

  5. 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.

  6. 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

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

    PubMed

    Mansilla, J; Solis, C; Chávez-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

  8. 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 Trico–Rhino–Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed. PMID:25713500

  9. Genetic background of supernumerary teeth.

    PubMed

    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 Trico-Rhino-Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed. PMID:25713500

  10. Coronectomy of mandibular teeth other than third molars: a case series.

    PubMed

    Samani, Meera; Henien, Marianne; Sproat, Christopher

    2016-09-01

    Coronectomy is gaining popularity for the management of mandibular third molars that pose a risk of injury to the inferior dental nerve, as it considerably reduces the risk when compared with extraction. The technique could also be beneficial to other teeth. We report 17 patients who had coronectomy of mandibular teeth that were not third molars. Clinical and radiographic follow up for a median (range) of 12 (1-79) months showed satisfactory healing and no transient or permanent injury to the nerve. None of the retained roots have required retrieval. PMID:27256801

  11. [Conservative restoration of pulpectomized teeth].

    PubMed

    Lasfargues, J J

    1990-04-01

    In endodontic treatment of teeth, partial or "conservative" crown reconstructions are clinically acceptable where loss of substance is limited and recourse to radicular pivots is contraindicated. Such reconstructions bring into play a variety of currently available biomaterials, including those inserted in the plastic phase. They make it possible to delay a prosthetic solution (full crown restoration) without impinging on the conservation of the devitalized tooth. PMID:2135781

  12. 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.

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

    NASA Astrophysics Data System (ADS)

    Enomoto, Yuji; Ito, Motoya; Masaki, Ryozo; Asaka, Kazuo

    We examined the claw type teeth motor as one application of the soft magnetic composite to a motor core. In order to understand quantitatively the characteristics of the claw type teeth motor, we used the 3-dimensional electromagnetic field analysis to predict its characteristics in advance and manufactured a trial motor to estimate it. And we examined the advantages of the claw type teeth motor comparing with a conventional slot type motor. The results are: 1. By using the 3-dimensional electromagnetic field analysis, it is able to estimate with high accuracy the characteristics of the 3-phase permanent magnet synchronous claw type teeth motor having a core composed of the soft magnetic composite. 2. The claw type teeth motor is able to achieve about 20% higher output than a conventional slot type motor having an electromagnetic steel core, while both volumes are equal. 3. The motor efficiency of the claw type teeth motor is about 3.5% higher than the conventional motor.

  14. [Supernumerary teeth in the maxilla and mandible-an interdisciplinary challenge. Part 1: epidemiology, etiology, classification and associated complications].

    PubMed

    Mossaz, Jessica; Suter, Valerie G A; Katsaros, Christos; Bornstein, Michael M

    2016-01-01

    Supernumerary teeth develop in addition to the normal dentition and are a therapeutic challenge for pedodontists, orthodontists and oral surgeons alike. Therefore, interdisciplinary treatment concepts are needed for the benefit of the patient. In the present, two-parted literature review on supernumerary teeth, current classification, associated complications, diagnostic steps and different therapeutic approches are presented and discussed. Supernumerary teeth are diagnosed in the primary and permanent dentition. Supernumerary incisors, canines, premolars, and molars, as well as distomolars and mesiodentes can be seen according to the location of the supernumerary teeth. Furthermore, based on the morphology of the supernumeraries four different types can be differentiated: conical, tuberculate, supplemental, and odontoma. Supernumerary teeth often remain asymptomatic, and are only diagnosed incidentally during a routine dental visit on radiographs (often intraoral). Nevertheless, various complications have been reported in the literature for supernumerary teeth such as disturbed eruption, malpositioning/rotation, root resorption of neighbouring teeth, and development of dentigerous cysts in impacted supernumeraries. Root resorption of neighbouring teeth can be radiographically diagnosed in up to 22.8% of the cases. PMID:26915750

  15. 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

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

    PubMed Central

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

    2015-01-01

    Tooth impaction is defined as any tooth that fails to erupt into a normal functional position and remains unerupted beyond the time at which it should normally erupt. Reports of impaction and eruption failure in primary teeth are relatively rare compared to permanent teeth. We report 2 rare cases where the second premolar was located on the occlusal side of the impacted mandibular second primary molar. In the first case, the succedaneous permanent tooth erupted after extraction of the primary tooth, fenestration, and traction. In the second case, the succedaneous permanent tooth erupted without fenestration or traction. Although the etiology of the tooth displacement was unknown in both cases, inhibition of the eruptive movement of the primary molar may have been associated with displacement of the succedaneous permanent premolar. PMID:25810929

  17. Bovine colostrum immunoglobulin concentrate for cryptosporidiosis in AIDS.

    PubMed Central

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

    1993-01-01

    Lactobin-R is a commercial hyperimmune bovine colostrum with potent anticryptosporidial activity. It was administered to a 4 year old child with AIDS and severe diarrhoea associated with cryptosporidiosis. There was significant clinical improvement in the diarrhoea and permanent elimination of the parasite from the gut as assessed through serial jejunal biopsy and stool specimens. Images PMID:8259880

  18. Teething

    MedlinePlus

    ... Accessed November 20, 2014. American Academy of Pediatric Dentistry. Guideline on infant oral health care. Revised 2014. Available at: www.aapd.org/media/Policies_Guidelines/G_infantOralHealthCare.pdf. Accessed November 20, 2014.

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

    PubMed Central

    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

  20. Radicular cysts arising from deciduous teeth. Review of the literature and report of 23 cases.

    PubMed

    Lustmann, J; Shear, M

    1985-04-01

    Radicular cysts arising from deciduous teeth are rare. 28 such cases have been recorded in the literature since 1898. In this study, we present 23 personally-observed cases of radicular cysts arising from deciduous teeth. The patients' ages ranged from 4 to 12 years with one exceptional case aged 19 years. The M:F ratio was 1.6:1. The mandible was affected more frequently than the maxilla and the deciduous molars were the teeth most commonly involved. 2 of the cysts presented multi-locular radiolucency; in 9 cases, buccal expansion was noticed and in 8 cases, permanent buds were displaced. Caries was the most common etiologic factor in the formation of the cysts. Histologically, cysts in varying stages of development were lined by proliferating non-keratinized stratified squamous epithelium. PMID:3920159

  1. 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, Érica Gouveia; Reis, José Maurício 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 (α=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

  2. Study of teeth phosphorescence detection technique

    NASA Astrophysics Data System (ADS)

    Cai, De-Fang; Wang, Shui-ping; Yang, Zhen-jiang; An, Yuying; Huang, Li-Zi; Liang, Yan

    1995-05-01

    On the basis of research and analysis into optical properties of teeth, this paper introduces the techniques to transform teeth phosphorescence excited by ultraviolet light into electric signals and following steps for data collection, analysis and processing. Also presented are the methods to diagnose pulp-vitality, decayed teeth, and, especially, infant caries and pre-caries diseases. By measurement of a tooth's temperature, other stomatic illnesses can be diagnosed.

  3. Management of a Nonvital Young Permanent Tooth by Pulp Revascularization

    PubMed Central

    Chandran, Vidya; Sivadas, G

    2014-01-01

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

  4. Management of a nonvital young permanent tooth by pulp revascularization.

    PubMed

    Chandran, Vidya; Chacko, Varghese; Sivadas, G

    2014-01-01

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

  5. Uncommon fusion of teeth and lateral periodontal cyst in a Chinese girl: a case report.

    PubMed

    Yang, Yuan; Xia, Xue; Wang, Wenjun; Qin, Man

    2011-10-01

    Fusion is a developmental anomaly of dental hard tissues. Most cases occur in the anterior region of both the primary and permanent dentitions. Occasionally, fusion of permanent and supernumerary teeth may occur in the maxillary anterior region; however, a supernumerary tooth fused with a premolar is a rare case. Developmental lateral periodontal cyst is also an uncommon developmental odontogenic cyst with no clinical symptoms, and the lesion is often discovered on routine radiographic examination. In the present case, we report the uncommon fusion of teeth and lateral periodontal cyst in a Chinese girl. Using cone beam computed tomography we are able to acquire a better understanding of the complicated root canal morphology of the fused tooth and successfully manage the lateral periodontal cyst. PMID:21621436

  6. Cavity lining in primary teeth.

    PubMed

    Chauhan, Ravi

    2016-03-01

    Data sourcesEmbase, Medline, Cochrane Central, Biomed Central and Open Grey databases and bibliographies of identified studies.Study selectionRandomised controlled trials investigating humans with primary caries lesions receiving operative treatment involving caries removal and restoration, with minimum two treatment groups comparing different cavity treatments before restoration (no lining versus lining) were included.Data extraction and synthesisData were extracted independently by two reviewers and study quality assessed using the Cochrane risk of bias tool. Random effect meta-analysis was carried out.ResultsThree studies involving a total of 89 patients were included. All the studies involved primary teeth and were conducted in Brazil. Follow-up periods ranged from 26-53 months. All the studies were considered to be at high risk of bias. Restoring the cavity without lining did not significantly affect the risk of failure. The quality of the evidence was low.ConclusionsCurrent evidence does not support strong recommendations to use or not to use liners after caries removal and before restoring cavities. Our findings are restricted to primary teeth after selective excavation, with only one liner (calcium hydroxide) being used for comparison. PMID:27012571

  7. Lead concentrations in teeth from people living in Kosovo and Austria.

    PubMed

    Kamberi, Blerim; Kqiku, Lumnije; Hoxha, Veton; Dragusha, Edmond

    2011-03-01

    The objective of this study was to compare lead concentrations in 86 human permanent teeth extracted from residents of three different geographical regions. The study included 31 permanent teeth from residents of Mitrovica (Kosovo), 32 from Klina (Kosovo) and 23 from Graz (Austria). The concentrations of lead were measured using Agilent 7500c inductively coupled plasma mass spectrometer (ICP-MS) (Agilent, Waldbronn, Germany). The comparisons between groups were based on the geographic area, age and gender. The highest lead level was found in teeth extracted from Mitrovica residents (22.3 mg/kg), followed by Klina (3.2 mg/kg), and Graz (1.7 mg/kg). Lead levels in teeth from Mitrovica residents are significantly higher (p < 0.0001) than in other two groups, possibly due to environmental contamination with lead. Overall results in this study support the concept that tooth lead level may present an important indicator in evaluating environmental exposure of human population to heavy metals. PMID:21667533

  8. 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.

  9. 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

  10. 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…

  11. Transplantation of cryopreserved teeth: a systematic review.

    PubMed

    Osathanon, Thanaphum

    2010-06-01

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

  12. 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…

  13. Sorption of tin on human teeth.

    PubMed

    Helal, A A; Alian, Gh A; Madbouly, H A

    2002-01-01

    The sorption of tin ions on human teeth from water and other drinks has been studied by the radioactive tracer technique using the isotope 113Sn (T(1/2) = 115.1 d) as a tracer. The tooth holds a minimum amount of tin from coffee and a maximum amount is held from water and from tea with sugar. The same technique was also used to study the desorption of tin already taken up on the teeth. It has been found that sorbed tin is hardly desorbed from the teeth specimens. The high uptake of tin on human teeth from various drinks showed that teeth act as a natural sieve holding trace elements. PMID:11768790

  14. 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...

  15. 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...

  16. Fracture resistance of posterior teeth restored with modern restorative materials

    PubMed Central

    Hamouda, Ibrahim M.; Shehata, Salah H.

    2011-01-01

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

  17. Supernumerary Teeth: An Investigating Tool in Forensic Crime Investigation

    PubMed Central

    Multani, Rupinder Kaur; Sangeri, Kishore Kumar; Ramalakshmi, M; Pavithra, S; Rajesh, M; Singh, Laiphrakpam Girindra

    2015-01-01

    Background: Supernumerary tooth is an additional entity to the normal series and is seen in all the quadrants of the jaw. The prevalence rates of supernumerary teeth in the permanent dentition, reported in the literature, vary between 0.1% and 6.9%. The presence of supernumerary teeth may be part of developmental disorders. As supernumerary tooth is a rare condition, it can be used as identification tool for crime investigation. Material and Methods: A total of 30 volunteers with a supernumerary tooth were analyzed and casts were made after taking alginate impression. All the casts were coded and were given to five observers for correct identification of those volunteers with respective prepared cast. Result: Personal identification and the cast identification of volunteers were done (cast of the volunteers). The matching identification is followed as below: Of five observers 1st observer able to detect 25 (83%), 2nd observer 27 (90%), 3rd observer 26 (87%), 4th observer 25 (83%) and 5th observer 28 (91%). Conclusion: As positive matching identification was 87%, supernumerary tooth can be used for crime investigation and used as greatest weapon in criminal identification. PMID:26028905

  18. The pulp capping procedure in primary teeth "revisited".

    PubMed

    Kopel, H M

    1997-01-01

    The purpose of this review is to "revisit" an earlier paper (1992) on the subject of direct pulp capping in primary teeth and bring some new considerations for the procedure by the use of dentin bonding adhesives. It has come to be recognized that the customary employment of calcium hydroxide for this therapy has some shortcomings that reduce the prognosis for a favorable outcome. For at least a decade, many investigations have found that postoperative sensitivity, thermal stimuli, pulp inflammation and pathosis can be attributed not to the composition of various dental materials and their insertion techniques, but to microleakage with subsequent bacterial invasion at the enamel/restoration and the dentin/pulp interfaces. It is imperative, as pointed out, that there be an impervious resinous bond between the dentin and the dentinopulpal complex which can be achieved by the use of dentinal adhesive agents to eliminate microleakage outward movement of pulpal fluids. Various steps in the bonding technique for the treatment of deep dentin caries and/or a pulp exposure has raised some concerns for their effect on the pulp. This review discusses these concerns, which can lead to the conclusion that the use of dentinal bonding adhesives is a safe and biologically feasible procedure, whether it be in permanent or primary teeth. PMID:9391709

  19. Infrared Spectroscopic Identification of Chosen Dental Materials and Natural Teeth

    NASA Astrophysics Data System (ADS)

    Hędzelek, W.; Marcinkowska, A.; Domka, L.; Wachowiak, R.

    2008-08-01

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

  20. Permanent Maxillary Canine Agenesis: A Rare Case Report.

    PubMed

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

    2015-01-01

    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

  1. 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

  2. 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. ...

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. Romundina and the evolutionary origin of teeth.

    PubMed

    Rücklin, 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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  9. Etiology, Classification and Management of Ectopic Eruption of Permanent First Molars.

    PubMed

    Hsiao, Chu-Chun; Boynton, James R

    2016-01-01

    Ectopic eruption of a permanent tooth involves abnormal resorption of a portion or all of the adjacent primary tooth. Among the most commonly ectopically erupted teeth are the permanent first molars. Ectopically erupting molars may require intervention to allow for full eruption, or they may spontaneously self-correct and erupt into occlusion. Decisions regarding the necessity of intervention, its ideal timing, and intervention type are multifactorial. Treatment options for the ectopically erupting permanent first molar include the elastomeric separator, brass wire, pre-fabricated clip separator, custom made appliances (Humphrey appliance, Halterman appliance), or extraction of the primary molar. Early intervention when indicated can ensure proper full eruption of the permanent first molar and prevent mesial angulation, arch perimeter loss, tooth impaction and ankylosis. Two cases are described that manage ectopic eruption of the permanent first molar. PMID:26882645

  10. 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.

  11. Filling cavities or restoring teeth?

    PubMed

    Versluis, Antheunis; Versluis-Tantbirojn, Daranee

    2011-01-01

    Teeth seldom fracture under normal functional loading. This indicates that the natural tooth design is optimized for the distribution of regular masticatory forces by means of its properties and structure. When a tooth is restored with an intracoronal restoration, however, the incidence of tooth fracture increases. Since remaining tissues do not change, the restorative actions apparently alter the original stress distributions. In this study, the effect of different restoration types (unbonded amalgam and bonded composite restorations) were compared with the original stress conditions of the intact tooth, using finite element analysis. It was shown that an unbonded amalgam restoration did not restore the original stress conditions but led to much higher stresses in the buccal and lingual enamel and to higher tensile stresses in the cavity floor. The unbonded amalgam thus filled the cavity but did not restore the tooth. In contrast, a bonded composite restoration restored the original stress pattern in the tooth if there was no polymerization shrinkage. Polymerization shrinkage causes residual tensile stresses in the dentin around the cavity and in the buccal and lingual enamel. Residual tensile stresses in the buccal and lingual enamel are momentary compensated by compressive stress components during occlusal loading. It was concluded that bonding and elimination of residual stresses are prerequisites for restoring the original tooth integrity. PMID:21748978

  12. Brushing Your Child’s Teeth

    MedlinePlus

    ... the toothpaste rather than swallowing it. For children under age 3, use just a small amount of toothpaste ... floss and brush your teeth every day. Children under age 6 may be able to handle a toothbrush ...

  13. How Acid Reflux Disease Damages Teeth

    MedlinePlus

    ... an advanced stage of destruction." The potential of hydrogen, or pH, is a standard way to measure ... January 2012 Related Articles: Tooth Erosion Sports and Energy Drinks Responsible for Irreversible Damage to Teeth What ...

  14. Take Care of Your Child's Teeth

    MedlinePlus

    ... Decay 3 of 7 sections Take Action: Use Fluoride Protect your child’s teeth with fluoride. Fluoride is ... Brushing Tips 4 of 7 sections Take Action: Fluoride Supplements Ask for supplements if your water doesn' ...

  15. Taking Care of Your Teeth and Mouth

    MedlinePlus

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

  16. [Wisdom teeth: which way to go?].

    PubMed

    Yitschaky, O; Segev-Neuhof, M; Laviv, A

    2016-01-01

    The debate regarding prophylactic extraction of mandibular third molar (Wisdom teeth) is not new. There is wide agreement among clinicians and researchers that an extraction in young age is easier and safer, but it may result in overtreatment, which means an unnecessary extraction of teeth that might have been functional and healthy. In order to avoid such overtreatment the clinician is obliged to be able to predict accurately the chances of third molar eruption, years before they are due to erupt. Additionally, the clinician has to estimate the chances for future pathology or infection that will force the patient to extract the tooth in years to come. In order to do so the clinician has to meticulously examine the teeth both clinically (including caries assessment of neighboring teeth, periodontal pocket depth measurements etc.) and radiographically. The purpose of this literature review is to present a balanced approach towards the issue of early prophylactic extraction of mandibular third molar. PMID:27295932

  17. [A Rare Case of Neonatal Teeth].

    PubMed

    Martins, Andreia A; Ferraz, Cláudia; Vaz, Rute

    2015-01-01

    Neonatal teeth is a rare disorder of tooth eruption, arising in the oral cavity, usually in the anterior mandible, in the first month of life. Its etiology is unknown. This condition can cause breastfeeding difficulties, besides aspiration or swallowing of the teeth. We describe the case of a premature infant in the second day of life presented with gingival edema, redness and discrete swelling in the region of the mandibular central incisors. Ten days later, two small teeth with hypermobility were detected. Extraction of those teeth was performed. With this clinical case we intend to show the rarity of this entity, especially in premature infants, the possible association with various syndromes and the need for a multifactorial approach to the treatment decision (extraction / conservative treatment). PMID:26849764

  18. 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.

  19. 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.

  20. Liquids with permanent porosity.

    PubMed

    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

    2015-11-12

    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

  1. 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.

  2. Permanent Turbidity-Standards

    PubMed Central

    Roessler, William G.; Brewer, Carl R.

    1967-01-01

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

  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. 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

  5. Straight, white teeth as a social prerogative.

    PubMed

    Khalid, Abeer; Quiñonez, 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

  6. Re-attachment of anterior fractured teeth: fracture strength using different techniques.

    PubMed

    Reis, A; Francci, C; Loguercio, A D; Carrilho, M R; Rodriques Filho, L E

    2001-01-01

    Fracture of anterior teeth by trauma is a common problem in children and teenagers. Complex metal-ceramic crowns with considerable loss of remaining sound structure are no longer necessary due to adhesive techniques, such as composite restorations and re-attachment techniques. This study compared the fracture strength of sound and restored anterior teeth using a resin composite and four re-attachment techniques. A "one bottle" adhesive system (One-Step, BISCO) and a dual cure resin cement (Duo-Link, BISCO) were applied. Thirty-five sound permanent lower central incisors were fractured by an axial load applied to the buccal area and randomly divided into five groups. The teeth were restored as follows: 1) bonded only = just bonding the fragment; 2) chamfer-group = after bonding, a chamfer was prepared on the enamel at the bonding line and filled with composite; 3) overcontour group = after bonding, a thin composite overcontour was applied on the buccal surface around the fracture line; 4) internal dentinal groove = before bonding, an internal groove was made and filled with a resin composite; 5) resin composite group = after a bevel preparation on the enamel edge, the adhesive system was applied and the fractured part of the teeth rebuilt by resin composite. Restored teeth were subjected to the same loading in the same buccal area. Fracture strength after restorative procedure was expressed as a percentage of the original fracture strength and the results analyzed by Kruskal-Wallis statistical analysis. The mean percentages of fracture strength were: Group 1: 37.09%, Group 2: 60.62%, Group 3: 97.2%, Group 4: 90.54% and Group 5: 95.8%. It was concluded that the re-attachment techniques used in Groups 3 and 4, as well as the composite restored group (Group 5), were statistically similar and reached the highest fracture resistance, similar to the fracture resistance of sound teeth. PMID:11357572

  7. Nonsurgical endodontic retreatment of fused teeth with transposition: a case report

    PubMed Central

    Noites, Rita Brandão; Martins, Miguel André Duarte; Paulo, Manuel Pedro da Fonseca

    2016-01-01

    Tooth transposition is a disorder in which a permanent tooth develops and erupts in the normal position of another permanent tooth. Fusion and gemination are developmental disturbances presenting as the union of teeth. This article reports the nonsurgical retreatment of a very rare case of fused teeth with transposition. A patient was referred for endodontic treatment of her maxillary left first molar in the position of the first premolar, which was adjacent to it on the distobuccal side. Orthopantomography and periapical radiography showed two crowns sharing the same root, with a root canal treatment and an associated periapical lesion. Tooth fusion with transposition of a maxillary molar and a premolar was diagnosed. Nonsurgical endodontic retreatment was performed. At four yr follow-up, the tooth was asymptomatic and the radiolucency around the apical region had decreased, showing the success of our intervention. The diagnosis and treatment of fused teeth require special attention. The canal system should be carefully explored to obtain a full understanding of the anatomy, allowing it to be fully cleaned and obturated. Thermoplastic techniques were useful in obtaining hermetic obturation. A correct anatomical evaluation improves the set of treatment options under consideration, leading to a higher likelihood of esthetically and functionally successful treatment. PMID:27200284

  8. Nonsurgical endodontic retreatment of fused teeth with transposition: a case report.

    PubMed

    Cardoso, Miguel Agostinho Beco Pinto; Noites, Rita Brandão; Martins, Miguel André Duarte; Paulo, Manuel Pedro da Fonseca

    2016-05-01

    Tooth transposition is a disorder in which a permanent tooth develops and erupts in the normal position of another permanent tooth. Fusion and gemination are developmental disturbances presenting as the union of teeth. This article reports the nonsurgical retreatment of a very rare case of fused teeth with transposition. A patient was referred for endodontic treatment of her maxillary left first molar in the position of the first premolar, which was adjacent to it on the distobuccal side. Orthopantomography and periapical radiography showed two crowns sharing the same root, with a root canal treatment and an associated periapical lesion. Tooth fusion with transposition of a maxillary molar and a premolar was diagnosed. Nonsurgical endodontic retreatment was performed. At four yr follow-up, the tooth was asymptomatic and the radiolucency around the apical region had decreased, showing the success of our intervention. The diagnosis and treatment of fused teeth require special attention. The canal system should be carefully explored to obtain a full understanding of the anatomy, allowing it to be fully cleaned and obturated. Thermoplastic techniques were useful in obtaining hermetic obturation. A correct anatomical evaluation improves the set of treatment options under consideration, leading to a higher likelihood of esthetically and functionally successful treatment. PMID:27200284

  9. 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.

  10. 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

  11. Teeth clenching reduces arm abduction force.

    PubMed

    Sato, Hajime; Kawano, Tsutomu; Saito, Mitsuru; Toyoda, Hiroki; Maeda, Yoshinobu; Türker, 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

  12. Graded permanent magnets

    NASA Astrophysics Data System (ADS)

    Skomski, R.; Hadjipanayis, G. C.; Sellmyer, D. J.

    2009-04-01

    The effect of semihard magnetic phases and interfaces on the performance of nanostructured two-phase permanent magnets is investigated by model calculations. In addition to the trivial coercivity increase due to the replacement of soft regions by semihard regions, there is a coercivity enhancement even if the volume-averaged anisotropy is kept constant during the introduction of the semihard phase. A variational approach is used to derive analytical results for representative anisotropy profiles. The improvement is operative on length scales slightly larger than that of the soft phase in hard-soft composites, but the main challenge is to find semihard light or heavy transition metal phases with a high magnetization. There are several Fe- and Co-based phases, but most are thin-film systems and difficult to use in bulk magnets. Very hard nanostructured magnets may also be created from soft phases with negative but large anisotropy constants (hard-magnetic soft-soft magnets).

  13. 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

  14. [Clinical validation of the caries preventive effect of mouth rinses with a mineralizing solution on the recently erupted permanent dentition].

    PubMed

    Rodríguez Miró, M J; Rodríguez Lucas, A; Gispert Abreu, E; Fonte Martínez, M

    1989-01-01

    This research was performed with the purpose of learning about effect of oral rinsing, every two weeks, with mineralizing solution (Minersol) on recently erupted permanent dentition. Reduction obtained in the incidence of caries at one year term ranged between 49.2 and 82.1% for first molar teeth and 23.4 and 36.3% for second molar teeth; both differences were significant, but no reduction was obtained in the incidence of caries in the bicuspid teeth. Preventing effect obtained is attributed to ionic incorporation in enamel superficial levels, which decreases the diffusion of acids acting in demineralization. It is concluded that the use of mineralizing solution in those ages of eruption of permanent dentition reduces incidence of caries and, therefore, its use as preventing method is recommended. PMID:2701032

  15. Fluoridated drinking water and maturation of permanent teeth at age 12.

    PubMed

    Campagna, L; Tsamtsouris, A; Kavadia, K

    1995-01-01

    Dental age was evaluated in 88 children aged 12 years + 6 months in both areas of Boston with fluoridated drinking water and nonfluoridated areas surrounding Athens, Greece. Fluoridation of drinking water in the Boston areas was 1.0 ppm, a level considered 'optimal' in the USA. Girls from the fluoridated Boston area were shown in this study to have a significantly (p<0.05) delayed dental age when compared to their chronological age according to the tables of Nolla. Boys from the Boston area and boys and girls from the Athens area showed no significant difference when comparing dental age to chronological age. PMID:8611493

  16. Solid modeling of fossil small mammal teeth

    NASA Astrophysics Data System (ADS)

    Marschallinger, Robert; Hofmann, Peter; Daxner-Höck, 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 components—enamel, dentine and pulp. Forwarding these data to a voxel modeling system, they can be quantitatively analyzed in an unprecedented manner: going beyond the possibilities of the state-of-art surface models, solid models are capable of unambiguously portraying the entire object volume—teeth can be peeled by material properties, subvolumes can be extracted and automatically analyzed by Boolean operations. The proposed method, which can be flexibly extended to handle a range of paleontological and geological micro-objects, is demonstrated with two typical fossil small mammal teeth.

  17. 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

  18. 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

  19. 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

  20. 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

  1. Human teeth model using photoacoustic frequency response

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    In this paper, a novel photo-acoustic technique modality utilizing a frequency- modulated Q-switch Nd:YAG laser at 1064 nm and coherent frequency domain signal processing is introduced for impulse and frequency responses of biological tissues. We present a photoacoustic technique to monitor the temporal behavior of temperature and pressure in an excised sample of human teeth after either a single laser pulse or during multiple laser pulses at pulse repetition frequencies (PRF) from 5 Hz to 100 Hz. Knowledge of the dynamic characteristics of structural elements often means the difference between normal and abnormal tissue. The determination of the resonance characteristics of structures is termed "modal analysis." The results of our study suggest that it is possible to identify the impulse, frequency response and resonance modes of simplified human teeth. This data provided a powerful tool to differentiate between normal and decay teeth.

  2. Fractures of posterior teeth in adults.

    PubMed

    Eakle, W S; Maxwell, E H; Braly, B V

    1986-02-01

    Examined in this study were 191 patients with 206 complete or incomplete fractures of posterior teeth. The patients ranged in age from 14 to 76 years, with 66.5% younger than 40 years. The number of fractures occurring in each arch was almost equal. The mandibular first molar was the most frequently fractured posterior tooth. The lingual cusps of mandibular molars fractured more often than did the buccal cusps of mandibular molars by a ratio of 2 to 1. In maxillary molars, buccal and lingual cusps fractured with almost equal frequency, but, in maxillary premolars, the lingual cusps fractured slightly more often than buccal cusps. Data gathered on the widths of the isthmuses of restorations in 109 teeth showed that fewer fractures occurred in teeth with more conservative restorations, with widths of isthmuses a quarter of the inter-cusp distance, and intact marginal ridges. PMID:3456380

  3. 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

  4. A modified technique on the reattachment of permanent tooth fragments following dental trauma. Case report.

    PubMed

    Arapostathis, Konstantinos; Arhakis, Aristidis; Kalfas, Sotiris

    2005-01-01

    Fractured anterior teeth can be restored by adhesive bonding of the fractured fragment to the remaining tooth structure. One of the major challenges for the practitioner treating traumatized anterior teeth with immediate fragment reattachment is disguising the fracture line, through the correct use of masking and restorative resins to make the restorations imperceptible to the eye as well as improve the retention of the restoration. This paper discusses a modified technique for reattaching a permanent tooth fragment following dental trauma. The initial procedure involved simple reattachment using light cured composite resin between the fragment and the remnant part of the tooth, without additional preparation. The surplus resin was spread across it in an attempt to optimize marginal seal and improve the aesthetics of the restoration. Finally, after taking into account the occlusion, the lingual surfaces of the teeth were veneered with microfilled composite to improve the retention of the reattached fragments. PMID:16302596

  5. Diagnosis and Management of a Patient with Congenitally Missing Maxillary First Permanent Molars: A Rare Case Report.

    PubMed

    Gupta, Megha; Panda, Suman; Mutawwam, Fahad Ahmed; Kariri, Fahad Musawi Mohammed

    2016-01-01

    Congenitally missing teeth are the most commonly seen dental anomalies. Agenesis of the permanent first molar has the least frequency of all the tooth types, and it usually occurs in association with oligodontia or anodontia. Thus, agenesis of the bilateral maxillary first permanent molar is an extremely rare occurrence, and no such case has been reported in ethnic Saudi Arabian population. We hereby report a case of nonsyndromic bilateral congenitally missing maxillary first permanent molar in an eight-year-old Saudi female patient. Comprehensive oral rehabilitation was done for the patient. The implications of the tooth agenesis are also discussed. The prognosis of this case is presented. PMID:27525130

  6. Diagnosis and Management of a Patient with Congenitally Missing Maxillary First Permanent Molars: A Rare Case Report

    PubMed Central

    Panda, Suman; Kariri, Fahad Musawi Mohammed

    2016-01-01

    Congenitally missing teeth are the most commonly seen dental anomalies. Agenesis of the permanent first molar has the least frequency of all the tooth types, and it usually occurs in association with oligodontia or anodontia. Thus, agenesis of the bilateral maxillary first permanent molar is an extremely rare occurrence, and no such case has been reported in ethnic Saudi Arabian population. We hereby report a case of nonsyndromic bilateral congenitally missing maxillary first permanent molar in an eight-year-old Saudi female patient. Comprehensive oral rehabilitation was done for the patient. The implications of the tooth agenesis are also discussed. The prognosis of this case is presented. PMID:27525130

  7. ESR dating of teeth from Brazilian megafauna

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

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

  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. Stepwise Excavation Allows Apexogenesis in Permanent Molars with Deep Carious Lesions and Incomplete Root Formation.

    PubMed

    Hernandéz-Gatón, Patrícia; Serrano, César Ruiz; Nelson Filho, Paulo; De Castañeda, Esther Ruiz; Lucisano, Marília P; Silva, Raquel A B da; Silva, Léa A B da

    2015-01-01

    This study evaluated the stepwise excavation technique in 138 permanent molars with deep carious lesions and incomplete root formation within a 24-month clinical and radiographic follow-up period. In 96.7% of the cases, success was observed (no pain, integrity of restoration margins, absence of radiographic alterations and apexogenesis). The cases of failure (3.3%) were due to the loss of the temporary restoration. In conclusion, the stepwise excavation is a promising technique for permanent teeth with deep carious lesions and incomplete root formation as a minimally invasive approach because it allows the preservation of pulp vitality and occurrence of apexogenesis. PMID:26655853

  10. 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

  11. Permanent dots in radiation therapy.

    PubMed

    Uyeda, L M

    1987-01-01

    Currently the word tattoo is used to describe the permanent marks used on patients in radiation therapy. This article offers alternative wording and the reasons why a new term is suggested. Guidelines for the standardization and administration of permanent marks concludes the article. PMID:3588884

  12. 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.

  13. The solvent action of sodium hypochlorite on bovine tendon collagen, bovine pulp, and bovine gingiva.

    PubMed

    Nakamura, H; Asai, K; Fujita, H; Nakazato, H; Nishimura, Y; Furuse, Y; Sahashi, E

    1985-09-01

    The purpose of this study was to determine the optimum temperature and concentration of sodium hypochlorite solution required to dissolve bovine tendon collagen, pulp, and gingiva. The 10% concentration of sodium hypochlorite solution at 37 degrees C was found to be most effective in dissolving bovine tendon collagen, pulp, and gingiva. Sodium hypochlorite solution was more effective in dissolving bovine pulp or tendon collagen than in dissolving bovine gingiva. PMID:3862046

  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 failure—nature's strategy is to contain damage rather than avoid it. Tests on model glass-shell systems simulating the basic elements of the tooth enamel/dentin layer structure help to identify important damage modes. Fracture and deformation mechanics provide a basis for analyzing critical conditions for each mode, in terms of characteristic tooth dimensions and materials properties. Comparative tests on extracted human and animal teeth confirm the validity of the model test approach and point to new research directions. Implications in biomechanics, especially as they relate to dentistry and anthropology, are outlined.

  15. 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

  16. Simulation of a flow around biting teeth

    NASA Astrophysics Data System (ADS)

    Narusawa, Hideaki; Yamamoto, Eriko; Kuwahara, Kunio

    2008-11-01

    We simulated a flow around biting teeth. The decayed tooth is a disease that a majority of people are annoyed. These are often generated from a deep groove at occlusal surface. It is known that a person who bites well doesn't suffer from a decayed tooth easily. Biting forces reach as much as 60 kg/cm^2 by an adult male, and when chewing, upper and lower teeth approach to bite by those forces. The crushed food mixed with saliva becomes high viscosity fluid, and is pushed out of ditches of teeth in the direction of the cheek or the tongue. Teeth with complex three dimension curved surface are thought to form venturi at this time, and to generate big pressure partially. An excellent dental articulation will possibly help a natural generation of a flow to remove dental plaque, i.e. the cause of the decayed tooth. Moreover, the relation of this flow with the destruction of the filled metal or the polymer is doubted. In this research, we try to clarify the pressure distributions by this flow generation as well as its dynamics when chewing. One of our goals is to enable an objective design of the shape of the dental fillings and the artificial tooth. Tooth has a very small uneven ground and a bluff body. In this case, to calculate a computational numerical simulation to solve the Navier-Stokes equations three dimension Cartesian coordinate system is employed.

  17. [Bleaching of devitalized teeth with ultrasonic assistance].

    PubMed

    Nishiyama, C K; Lacerda, A G; Souza, M H; Francischone, C E; Ishikiriama, A; Berbert, A

    1989-03-01

    A new bleaching technique for pulpless teeth is demonstrated by a clinical case. The principle of the method is to clean the dentinal tubules by an 1% sodium hypochlorite solution activated by a 40 endosonofile. A mixture of sodium perborate and a 3% hydrogen peroxide is left in the pulp chamber between the treatment sessions. PMID:2633222

  18. 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.

  19. 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…

  20. Computing Contact Stresses In Gear Teeth

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  1. Modification Of Gear Teeth To Reduce Vibrations

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  2. Riga-Fede disease and neonatal teeth

    PubMed Central

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

    2012-01-01

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

  3. Simulating Clinical Carious Lesions in Composition Teeth.

    ERIC Educational Resources Information Center

    Ambrose, E. R.; And Others

    1981-01-01

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

  4. How to Care for Your Baby's Teeth

    MedlinePlus

    ... twice a day as soon as the first tooth appears. Until your child is 1 year old, you can use a wet washcloth or gauze to clean your baby's teeth and gums. Start using a soft baby toothbrush and a small dab of toothpaste that does not have fluoride in it when your baby is between 1 ...

  5. The relationship between teething and handedness.

    PubMed

    Orbak, Recep; Sezer, Ufuk; Dilsiz, Alpaslan; Cicek, Yasin; Orbak, Zerrin

    2007-03-01

    The aim of this study was to evaluate the role of tooth eruption sequences as an indicator of handedness. The investigation was carried out on 92 healthy children. The questionnaire form was filled out for each child. The form consisted of two parts. In the first part there were questions to determine the demographic features of the children. The second part consisted of the questions to clarify the eruption time and sequence of first primary teeth. Hand preference was evaluated by placing colored pencils directly in front of the child, who was asked to write an "X" on a piece of paper with each pencil. According to left-, right-, and indetermined handedness, all children regardless of sex were divided into three groups. The data were analyzed for statistical evaluation using tests for the difference between two population propositions. The mean eruption time of the first tooth in children was 7.5 +/- 1.7 months. The eruption time was found similar in both groups. No statistically significant difference was determined between the teeth eruption time and handedness (p >.05). The first tooth erupted was generally the lower central incisor. There was no difference tooth eruption and sex, gestation week (p >.05). No statistically significant difference was found between the teeth eruption time and sequence of the primary teeth (p >.05). There was statistically significant difference between sequence of the tooth eruption and handedness (p <.001). Consequently, the tooth eruption sequences may play an important role as an indicator in handedness. PMID:17365123

  6. 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.

  7. Teething in children and the alleviation of symptoms.

    PubMed

    Jones, Mark

    2002-01-01

    Teething is a normal process by which an infant begins to cut the first teeth (primary dentition). On average, infants begin teething at six months and by the age of three years all the first teeth have erupted. A variety of symptoms can accompany teething including sensitive and painful gums, mouth ulceration, drooling, feeding difficulties, lack of sleep and crying, all of which result in a distressed child and anxious parent. Some teething symptoms can be alleviated effectively at home with teething aids such as cold teething rings. In addition, over-the-counter treatments are available which provide pain relief and are mainly in the form of analgesic and anaesthetic gels, some of which also possess antiseptic properties. Gels such as those containing choline salicylate can be applied direct to the gums specifically to relieve pain and inflammation. PMID:12415773

  8. 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.

  9. Natal teeth: Case report and review of literature

    PubMed Central

    Rao, Roopa S; Mathad, Sudha V

    2009-01-01

    The presence of teeth at birth or within a month post-delivery is a rare condition. A newborn, a 2 days old female, with two mandibular incisor natal teeth was examined. The teeth were mobile and were extracted because of the fear of aspiration and refusal to feed. The purpose of this report is to review the literature related to natal teeth epidemiology and discuss their possible etiology and treatment. PMID:21886998

  10. Periodic permanent magnet focused klystron

    SciTech Connect

    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.

  11. 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.

  12. 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...

  13. [Bovine spongiform encephalopathy].

    PubMed

    Suárez Fernández, G

    2001-01-01

    An histórical 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

  14. 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...

  15. 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 ...

  16. 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 ...

  17. 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

  18. Whitening non vital teeth – a case report

    PubMed Central

    Moraru, Iren; Ţuculină, Mihaela; Bătăiosu, Marilena; Gheorghiţă, 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 it’s a known fact that these teeth can have a grey or pink-grey coloration when they are not correctly endodontical treated. PMID:24778849

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Effect of Cervitec on mutans streptococci in plaque and on caries formation on occlusal fissures of erupting permanent molars.

    PubMed

    Araujo, A M P G; Naspitz, G M C C; Chelotti, A; Cai, S

    2002-01-01

    The aim of this study was to evaluate the effect of Cervitec on the abundance of mutans streptococci (MS) in occlusal dental plaque and on 2-year caries increment of partly erupting first permanent molars. Sixteen healthy schoolchildren aged 6-8 years, with at least 2 sound contralateral partly erupted permanent molars, received diet counselling and daily parental supervised toothbrushing with a fluoride dentifrice. Stimulated saliva samples were collected at baseline and after 1 year to evaluate MS levels. In a split-mouth design, Cervitec varnish was applied to one of the teeth at baseline and after 3 and 6 months, while the other tooth in the same jaw was a control. At the 9-month follow-up the teeth were in occlusal contact. At this time, varnish was not applied. At 3 and 6 months after the first application of varnish a significant suppression of MS was observed in plaque. Caries investigations, performed at baseline and every 3 months during the 2 years after the start of the study, showed that all the teeth treated with the varnish were free of caries after 2 years, whereas 8/16 control teeth developed incipient caries. In conclusion, our results suggest that treatment with Cervitec reduces MS in plaque on erupting permanent molars and can lead to a significant decrease in caries incidence. PMID:12399699

  5. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  7. Effect of Diode Laser Irradiation Combined with Topical Fluoride on Enamel Microhardness of Primary Teeth

    PubMed Central

    Bahrololoomi, Zahra; Lotfian, Malihe

    2015-01-01

    Objectives: Laser irradiation has been suggested as an adjunct to traditional caries prevention methods. But little is known about the cariostatic effect of diode laser and most studies available are on permanent teeth.The purpose of the present study was to investigate the effect of diode laser irradiation combined with topical fluoride on enamel surface microhardness. Materials and Methods: Forty-five primary teeth were used in this in vitro study. The teeth were sectioned to produce 90 slabs. The baseline Vickers microhardness number of each enamel surface was determined. The samples were randomly divided into 3 groups. Group 1: 5% NaF varnish, group 2: NaF varnish+ diode laser at 5 W power and group 3: NaF varnish+ diode laser at 7 W power. Then, the final microhardness number of each surface was again determined. The data were statistically analyzed by repeated measures ANOVA at 0.05 level of significance. Results: In all 3 groups, microhardness number increased significantly after surface treatment (P<0.05). However, Microhardness change after treatment was not significantly different among groups (P >0.05). Conclusion: The combined application of diode laser and topical fluoride varnish on enamel surface did not show any significant additional effect on enamel resistance to caries. PMID:26056517

  8. 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

  9. 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

  10. 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, José

    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

  11. 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 (SH baseline and SRI baseline), after a total of 2 min (SH2 min) and after 4 min (SH4 min and SRI4 min) erosive challenges (60 ml of substance for 6 enamel samples; 30°C, under constant agitation at 95 rpm). There was no significant difference in SH baseline 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 (SH4 min). 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

  12. 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

  13. Optimized nanoscale composite behaviour in limpet teeth

    PubMed Central

    Lu, Dun; Barber, Asa H.

    2012-01-01

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

  14. 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 Électromagnétique (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 μm 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.

  15. Bleaching non vital primary teeth: case report.

    PubMed

    Bussadori, Sandra Kalil; Roth, Faynna; Guedes, Carolina Cardoso; Fernandes, Kristiane Porta; Domingues, Manoela Martins; Wanderley, Márcia Turolla

    2006-01-01

    Trauma and pulpal infections in primary dentition are part of the routine of the pediatric dentist. Common consequences in these cases are alterations in dental color, compromising patient's esthetics and his interaction in social environment. Bleaching intends to preserve dental structure already weakened and to show immediate esthetic results. This clinical case shows a bleaching technique in devitalized primary teeth using bleaching agent with 35% hydrogen peroxide activated by photo polymerizer. This technique is simple and shows immediate satisfactory results. PMID:16683662

  16. Management of Multiple Impacted Teeth: A Case Report and Review

    PubMed Central

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

    2014-01-01

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

  17. Dissolution of human teeth-derived hydroxyapatite.

    PubMed

    Seo, Dong Seok; Lee, Jong Kook

    2008-01-01

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

  18. Can we trust visual methods alone for detecting caries in teeth?

    PubMed

    Hoskin, Eileen R; Keenan, Analia Veitz

    2016-06-01

    Data sourcesElectronic Databases searched in PubMed, Embase and Scopus. Unpublished literature was traced through OpenSIGLE, annals of IADR/AADR (International and American Associations for Dental Research) and ORCA (European Organisation for Caries Research) from 2003-2014. Studies were limited to English.Study selectionStudies involving visual inspection for detection of primary coronal caries lesions in primary or permanent human teeth were considered. All papers needed to include a clearly defined reference standard and the reporting of absolute numbers of true positives, false positives, true negatives and false negatives or a presentation of sufficient data to calculate these figures. Reference methods considered appropriate were histologic evaluation, operative intervention, direct visual inspection after temporary tooth separation and radiography. For studies with the same data set only the most complete study was included. Articles that reported caries detection using artificial caries, root caries or recurrent decay adjacent to restorations were excluded.Data extraction and synthesisStudy selection for inclusion was performed independently by two reviewers and disagreements were resolved by discussion with a third reviewer. Data were collected by two reviewers on structured tables. Discrepancies were resolved by consensus. A meta-analysis was performed. The following information was extracted; reference standard method, setting (clinical or laboratory), type of teeth (primary or permanent), surface evaluated (smooth, proximal or occlusal), sample size, examiner's experience. Also recorded were visual scoring systems. Studies that did not report any criteria were classified as 'with no criteria'. If authors used criteria with no reference to previously published studies they were classified as 'own criteria'. The PRISMA guideline was followed to report the review and the QUADAS-2 checklist (Quality assessment of studies of diagnostic performance included

  19. INFLUENCE OF HUMAN AND BOVINE SUBSTRATE ON THE MICROLEAKAGE OF TWO ADHESIVE SYSTEMS

    PubMed Central

    Almeida, Karoline Guará Brusaca; Scheibe, Kristine Guará Brusaca Almeida; Oliveira, Ana Emília Figuerêdo; Alves, Cláudia Maria Coêlho; Costa, José Ferreira

    2009-01-01

    The aim of this study was to evaluate in vitro the marginal sealing of two adhesive systems and to analyze the influence of human and bovine substrates on marginal microleakage in enamel. Rectangular-shaped class V cavities (4 mm wide × 2 mm high × 2 mm deep) were made as follows: 8 cavities were prepared on the buccal and lingual surfaces of the human teeth with margins located on enamel and 16 cavities were prepared on the buccal surfaces of the bovine teeth. The cavities were randomly assigned to 4 groups of 8 cavities according to the adhesive system and substrate: G1 - Prime & Bond 2.1 (Dentsply)/human substrate; G2 - Adhese (Ivoclar/Vivadent)/human substrate; G3 - Prime & Bond 2.1 (Dentsply)/bovine substrate; G4 - Adhese (Ivoclar/Vivadent)/bovine substrate. The cavities were filled with microhybrid composite resin (Fillmagic) and after polishing/finishing procedures, the teeth were subjected to a thermocycling regimen of 500 cycles with 1-min immersions in water at 55° ±2°C and 5° ± 2°C. Next, the teeth were coated with two layers of nail polish to within 1 mm of the margin, submerged in a 50% silver nitrate solution for 2 h, rinsed thoroughly in running tap and immersed in developing solution for 8 h. The restorations were bisected resulting in 16 specimens. Microleakage was observed under a stereomicroscope at x25 and recorded using four-point (0-3) scoring system. The data were analyzed statistically by the Mann Whitney U-test at 5% significance level. Leakage was present in all specimens and there was statistically significant difference between the adhesive systems. Adhese self-etching system showed significantly more leakage in both substrates (human - p= 0.0001 and bovine - p= 0.0031). There was no statistically significant difference between human and bovine substrates for either of the adhesive systems based on different bonding mechanisms (Prime & Bond 2.1 - p= 0.6923 and Adhese - p= 0.6109). Neither of the adhesive systems was capable to

  20. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor.

    PubMed

    Achary, Ravindranath C; Ravi, G R

    2016-01-01

    Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155. PMID:27365939

  1. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor

    PubMed Central

    Ravi, GR

    2016-01-01

    ABSTRACT Dilaceration of the permanent tooth usually is a consequence of traumatic injuries to the primary teeth. Although it may appear anywhere in the long axis of the tooth, i.e., crown, cementoenamel junction, or root, most often the root is involved. However, crown dilaceration is a rare condition representing 3% of the total injuries. Maxillary incisors are more susceptible to such injury and affected tooth may either erupt buccally or lingually or remain impacted. Hitherto, the treatment options also differ as per the clinical scenario. This article proposes a novel technique of restoring esthetic function of the affected permanent maxillary lateral incisor with crown-root dilaceration while preserving the vitality of tooth. How to cite this article: Achary RC, Ravi GR. A Novel approach of Esthetic Management and preserving Vitality of Dilacerated Permanent Maxillary Lateral Incisor. Int J Clin Pediatr Dent 2016;9(2):152-155. PMID:27365939

  2. Three-dimensional analysis of tubular permanent magnet machines

    NASA Astrophysics Data System (ADS)

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

    2006-04-01

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

  3. 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

  4. On the pulpal nerve supply in primary human teeth: evidence for the innervation of primary dentine.

    PubMed

    Egan, C A; Hector, M P; Bishop, M A

    1999-03-01

    The presence of nerves in human tooth pulp has been recognized for over a hundred years, and the innervation of dentine for about 40 years. These observations have been made in permanent teeth. Very few studies have reported on the innervation of the primary pulp and dentine. The purpose of this study was to describe the innervation of the primary tooth pulp-dentine complex. Ten mature primary teeth (one incisor, six canines and three molars) were used. Immediately following extraction they were divided into three sections using a diamond disc and saline coolant. They were then immersion fixed in a solution of formaldehyde and picric acid dissolved in a phosphate buffer pH 7.4). The teeth were then demineralized for 1-3 weeks in formic acid. Following complete demineralization, 30 microns sections were cut on a freezing microtome. Neural tissue was stained using a specific antibody to calcitonin gene related peptide (CGRP). Sections were mounted on glass slides and examined using light microscopy. No individual nerve fibres were seen in the control sections, suggesting that the method used was specific for CGRP-containing nerve fibres. The primary teeth appeared to be well innervated. Myelinated and unmyelinated nerves were seen. There was a dense but variable subodontoblastic plexus of nerves (plexus of Raschkow) and nerve fibres were seen to leave this to travel towards the odontoblast layer. Most terminated here, but a few penetrated the odontoblast layer to enter predentine and the dentine tubules. The maximum penetration was 125 microns but most terminated within 30 microns of the dentinopulpal junction. The coronal region was more densely innervated than the root. Within the crown the cervical third was the most densely innervated region, followed by the pulp horn and the middle third. In conclusion, this study has demonstrated that mature primary tooth contains a pulp which is well innervated and has many nerve endings terminating in or near the odontoblast

  5. The FiCTION dental trial protocol – filling children’s teeth: indicated or not?

    PubMed Central

    2013-01-01

    ; incidence of caries in primary and permanent teeth, patient quality of life, cost-effectiveness, acceptability of treatment strategies to patients and parents and their experiences, and dentists’ preferences. Discussion FiCTION will provide evidence for the most clinically-effective and cost-effective approach to managing caries in children’s primary teeth in Primary Care. This will support general dental practitioners in treatment decision making for child patients to minimize pain and infection in primary teeth. The trial is currently recruiting patients. Trial registration Protocol ID: NCTU: ISRCTN77044005 PMID:23725316

  6. 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

  7. 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.

  8. How Permanent Is Permanent Placement for Substance-Exposed Infants?

    ERIC Educational Resources Information Center

    Twomey, Jean E.; Lester, Barry M.

    2007-01-01

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

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

    PubMed

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

    2013-11-01

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

  10. Semipermanent and permanent injectable fillers.

    PubMed

    Jones, Derek H

    2009-10-01

    Today, an impressive array of injectable dermal fillers for facial soft-tissue augmentation is available in the United States. These agents, most of which were introduced in the last half decade, represent a variety of semipermanent and permanent fillers across several categories. Physicians can choose between semipermanent fillers, such as hyaluronic acid derivatives (HA), calcium hydroxylapatite (CaHA), and poly-L-lactic acid (PLA), and longer-lasting, so-called "permanent fillers," such as polymethyl methacrylate microspheres (PMMA), highly purified forms of liquid silicone, and hydrogel polymers. PMID:19850193

  11. 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

  12. 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

  13. Bovine leukocyte adhesion deficiency (BLAD): a review.

    PubMed

    Nagahata, Hajime

    2004-12-01

    Bovine leukocyte adhesion deficiency (BLAD) in Holstein cattle is an autosomal recessive congenital disease characterized by recurrent bacterial infections, delayed wound healing and stunted growth, and is also associated with persistent marked neutrophilia. The molecular basis of BLAD is a single point mutation (adenine to guanine) at position 383 of the CD18 gene, which caused an aspartic acid to glycine substitution at amino acid 128 (D128G) in the adhesion molecule CD18. Neutrophils from BLAD cattle have impaired expression of the beta2 integrin (CD11a,b,c/CD18) of the leukocyte adhesion molecule. Abnormalities in a wide spectrum of adherence dependent functions of leukocytes have been fully characterized. Cattle affected with BLAD have severe ulcers on oral mucous membranes, severe periodontitis, loss of teeth, chronic pneumonia and recurrent or chronic diarrhea. Affected cattle die at an early age due to the infectious complications. Holstein bulls, including carrier sires that had a mutant BLAD gene in heterozygote were controlled from dairy cattle for a decade. The control of BLAD in Holstein cattle by publishing the genotypes and avoiding the mating between BLAD carriers was found to be successful. This paper provides an overview of the genetic disease BLAD with reference to the disease in Holstein cattle. PMID:15644595

  14. Thermographic analysis of surface damage in teeth

    NASA Astrophysics Data System (ADS)

    Conde-Contreras, M.; Bante-Guerra, J.; Hernandez-Garcia, E.; Hernandez, A. M.; Trujillo, S.; Quintana, P.; Alvarado-Gil, J. J.

    2008-02-01

    The analysis of the surface of teeth is an important field of research and technological development due to the importance of dental pieces in health and aesthetics. The presence of cracks as well as the etching effects on teeth surface, due to different chemical agents, affects not only the appearance of teeth but its integrity. In this work, laser thermography analysis of dental pieces with damage in the form of cracks is presented. The technique consists in the illumination of the surface at the center of the sample, using a 300 mW pulsed solid state laser beam focused with a gradium lens, and monitoring the spatial and temporal distribution of the temperature field. The heating of the sample is monitored using a focal plane array infrared camera, sensitive in the spectral range 7.5-13 μm with a noise equivalent temperature difference of 0.12°C. The data acquisition was performed by the PC firewire port using a PCI-8254R card and a home-made program in Labview 8.0 was used for data acquisition. The images were processed in a home-made linux program to obtain the experimental table values. Our results are compared with position and frequency scans obtained by infrared photothermal radiometry. It is shown that the crack in the tooth appears as an increase in the photothermal signal. In contrast, the thermographic image shows a more detailed structure in which close to the crack the temperature increases, but at the crack the signal falls.

  15. Linear Odontometric Analysis of Permanent Dentition as A Forensic Aid: A Retrospective Study

    PubMed Central

    Nair, Sunil Sukumaran; Gopakumar, Devi; Kurian, Nisha; Parameswar, Arjun; Baby, Tibin Kaithappillil

    2016-01-01

    Introduction Sex determination in forensic anthropology is an essential step for medico-legal purposes and crucial for identification as the number of possible matches is reduced to 50%. Teeth are an excellent material for anthropological, genetic, odontological and forensic investigations as they are known to resist a variety of ante-mortem and post-mortem insults. Sexual dimorphism in tooth size and the accuracy of odontometric sex prediction is found to vary in different population and therefore it is necessary to determine specific population values in order to make identification possible. Hence, the present study was undertaken to evaluate the existence of sexual dimorphism in South Kerala population. Aim To evaluate and estimate the degree of odontometric sexual dimorphism in all permanent teeth except third molars and the variations in odontometric dimensions between the left and right side teeth of the maxillary and mandibular arches in male and female groups. Materials and Methods The MesioDistal (MD) and BuccoLingual (BL) measurements of 28 teeth were estimated from the preorthodontic casts of 132 subjects; male group (66 males) and female group (66 females) of age range 15-25 years using digital Verniers’ Caliper. The data obtained were analysed using SPSS version 17 and the Students’ t-test for two independent samples. Results The MesioDistal (MD) and BuccoLingual (BL) parameters of all permanent teeth in the study group showed sexual dimorphism. Over 39% of the tooth variables showed reverse dimorphism. The comparison of mean values of MD and BL diameters of the maxillary and mandibular, right and left side teeth in male and female groups showed statistical significance in males whereas females show non-significant values in both MD and BL diameters. Conclusion The study showed a varied percentage of sexual dimorphism and variation in the mean values of MD and BL dimensions in males, but not in females between right and left side teeth of the

  16. Inflammatory Diseases of the Teeth and Jaws.

    PubMed

    Zohrabian, Vahe M; Abrahams, James J

    2015-10-01

    The teeth are unique in that they provide a direct pathway for spread of infection into surrounding osseous and soft tissue structures. Periodontal disease is the most common cause of tooth loss worldwide, referring to infection of the supporting structures of the tooth, principally the gingiva, periodontal ligament, cementum, and alveolar bone. Periapical disease refers to an infectious or inflammatory process centered at the root apex of the tooth, usually occurring when deep caries infect the pulp chamber and root canals. We review the pathogenesis, clinical features, and radiographic findings (emphasis on computed tomography) in periodontal and periapical disease. PMID:26589697

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

    PubMed

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

    2015-01-01

    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

  18. Numerical Simulation Of Cutting Of Gear Teeth

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  19. 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

  20. 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)

  1. 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)

  2. 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.

  3. Bovine myocardial epithelial inclusions.

    PubMed

    Baker, D C; Schmidt, S P; Langheinrich, K A; Cannon, L; Smart, R A

    1993-01-01

    Light microscopic, histochemical, immunohistochemical, and ultrastructural methods were used to examine myocardial epithelial masses in the hearts of ten cattle. The tissues consisted of paraffin-embedded or formalin-fixed samples from eight hearts that were being inspected in slaughter houses and from two hearts from calves that died of septicemia. The ages of the cattle ranged from 4 days to 12 years; the breeds were unspecified for all but one Hereford female and the two Holstein calves; and there were three males, four females, and three steers. The masses in these cases were compared with similar appearing lesions found in other animal species. The lesions in the bovine hearts were single to multiple, well circumscribed, found in the left ventricle wall, and composed of squamous to cuboidal epithelial cells that formed tubular, ductular, and acinar structures with lumens that were void or filled with amorphous protein globules. Electron microscopic examination revealed epithelial cells that had sparse apical microvilli, tight apical intercellular junctions, perinuclear bundles of filaments, and rare cilia. Almost half of the bovine epithelial masses (4/9) had occasional diastase-resistant periodic acid-Schiff-positive granules in their cytoplasm, and few had hyaluronidase-resistant alcian blue-positive granules (2/9) or colloidal iron-positive granules (1/9). All myocardial masses had abundant collagen surrounding the tubular and acinar structures, and 2/9 had elastin fibers as well. None of the myocardial masses had Churukian-Schenk or Fontana Masson's silver staining granules in epithelial cells. Immunohistochemically, all bovine myocardial tumors stained positively for cytokeratin (8/8), and occasional masses stained positively for vimentin (3/8) or carcinoembryonic antigen (3/8). None of the masses stained positively for desmin. The myocardial epithelial tumors most likely represent endodermal rests of tissue misplaced during organogenesis. PMID:7680178

  4. Enzootic Bovine Leukosis

    PubMed Central

    Reed, V. Ivan

    1981-01-01

    The author emphasizes the significance of enzootic bovine leukosis in Canada. He describes in detail diagnostic methods, various types of the disease and methods of transmission. Various aspects of the disease in Canada are compared with those in other countries. Prevention and control are discussed in a Canadian context and include the current policies of the Government of Canada in relationship to this disease. The possibility of developing a certification program for herds free of the disease is also discussed. The paper includes incidence in various parts of Canada. PMID:6265053

  5. 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

  6. Application of dimorphism in teeth to age calculation.

    PubMed

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

    1996-06-01

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

  7. Exodontics: extraction of teeth in the dog and cat.

    PubMed

    Gengler, Bill

    2013-05-01

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

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

    PubMed Central

    Boughner, Julia C.

    2011-01-01

    While mandible proportions do not appear to constrain permanent molar initiation times, how adequate space is created in the corpus for these teeth in a timely way is not well understood. This question is important for explaining how primate tooth and jaw development and evolution are coordinated. Landmark and linear measurement data were used to characterize mandible shape, growth trajectory, and growth rate between two genera, Papio and Pan, with contrasting permanent molar initiation schedules and mandible proportions. 3D geometric morphometric and 2D bivariate analyses showed genus-level differences in mandible morphology from birth that were amplified by different postnatal growth trajectories. Different corpus proportions and regional variation in corpus growth rates helped create space in a timely way for the molars. Regional corpus growth rates may evolve alongside permanent molar morphology and developmental timing to modify space available in the corpus for these teeth. PMID:22567294

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

    NASA Astrophysics Data System (ADS)

    Suzuki, Kenji; Ishikawa, Atsushi; Dohmeki, Hideo

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

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

    PubMed Central

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

    2008-01-01

    Background and aims The knowledge of variations in root canal morphology is critical for a successful endodontic treatment. The purpose of this study was to investigate variations in the root canal system of human mandibular first permanent molars in an Iranian population. Materials and methods In this study, 209 mandibular first molar teeth were decalcified, dye-injected, and cleared in order to determine the number and configuration of the root canals. Results The results demonstrated that 65.56% of the mandibular first molars under study had three, 31.57% had four and 2.87% had two canals. Conclusion According to the results of this study and considering variations in the root canal systems of the mandibular first molars, it seems that great care should be taken in the root canal treatment of these teeth. PMID:23285325

  11. In vitro assessment of a gel base containing 2% chlorhexidine as a sodium perborate's vehicle for intracoronal bleaching of discolored teeth.

    PubMed

    Oliveira, Daniel Pinto de; Gomes, Brenda Paula Figueiredo de Almeida; Zaia, Alexandre Augusto; Souza-Filho, Francisco José de; Ferraz, Caio Cezar Randi

    2006-07-01

    The purpose of this study was to assess a gel base containing 2% chlorhexidine (CHX) as a vehicle to be mixed with sodium perborate for intracoronal bleaching of discolored teeth, comparing its bleaching efficacy to sodium perborate mixed with other vehicles; 37% carbamide peroxide and 30% hydrogen peroxide. There were 110 fresh bovine incisors artificially stained using whole blood. The samples were divided into 11 groups and the intracoronal bleaching was performed using the "walking bleach technique". The bleaching agents were replaced three times at 7-day intervals. Using digital photos and a shade guide created for bovine teeth, the samples were evaluated at day 0, 7, 14, 21, and 28. On evaluation day, the photos were examined by three endodontists giving scores from 1 to 5 based on the shade guide created. Data were analyzed statistically by Kruskall-Wallis test. After 28 days, all evaluated teeth received scores that were statistically similar. Groups that used sodium perborate and a liquid vehicle bleached faster than those that used a gel based vehicle. The CHX gel allowed dissociation for the bleaching agent. The 2% CHX gel exhibited a good potential for use as a vehicle for sodium perborate or as a complement for carbamide peroxide. PMID:16793478

  12. 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 Mendonça, Marcos Rogério; Panzarini, Sônia Regina

    2013-01-01

    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

  13. [Bovine immunodeficiency virus: short review].

    PubMed

    Bouillant, A M; Archambault, D

    1990-01-01

    A bovine visna-like virus was isolated by Van Der Maaten et al (1972) but it did not draw attention since, at that time, most efforts were directed towards research on bovine leukemia virus. However, new interest was shown on the bovine visna-like virus after the isolation of the human immunodeficiency virus (HIV), because of the urgent need for developing animal models for the acquired immunodeficiency syndrome (AIDS). The purpose of this paper is to describe the different stages of the identification of the bovine virus and to up-date knowledge about it. The bovine visna-like virus has recently been named the bovine immuno-deficiency-like virus (BIV) and is the sole bovine lentivirus known to-date. BIV shares morphologic, antigenic and genomic characteristics with other lentiviruses. It grows and induces large syncytia in vitro and generates virus-productive and latent infections in cell culture. It causes persistent infection and slow progressive disease in cattle and probably in sheep. As target cells of the virus are leukocytes, the type of which is unknown, perturbations of the immune system are expected. Consequently, BIV may potentiate the occurrence of secondary infections and play a role in retroviral, multiple infections. It is not oncogenic. Transmission appears to occur in cattle by contact, but evidence of transmission in human beings has not been shown. Finally, BIV may be a potential model in vitro and in vivo for HIV and AIDS. PMID:1963056

  14. Biomechanical Stress Analysis of Mandibular First Permanent Molar; Restored with Amalgam and Composite Resin: A Computerized Finite Element Study

    PubMed Central

    Prabhakar, AR

    2010-01-01

    Normal mastication with its varying magnitude and direction generates considerable reactionary stresses in teeth and their supporting tissues. The structure of the human tooth and its supporting tissues is a complex assemblage of materials of varied mechanical properties. The finite element method (FEM), a modern technique of numerical stress analysis, has the great advantage of being applicable to solids of irregular geometry and heterogeneous material properties and therefore ideally suited to the examination of structural behavior of teeth. The mandibular first permanent molar is one of the earliest permanent teeth to erupt in the oral cavity and hence most prone to caries. The purpose of the present study was to construct a two-dimensional FE model of the mandibular first permanent molar and its supporting structures, using a FE software called NISA II-Display III, EMRC, USA to study the following: • To compare stress distributions patterns when a modeled Class I Cavity was restored with dental amalgam and composite resin. • To compare the stress distributions pattern when the load was applied to different to locations, i.e.: At the mesial cusp tip, and at the center of the occlusal surface. Both amalgam and composite resin showed similar stress distribution pattern, however, the magnitudes of stresses generated in the tooth restored with composite resin were higher. Thus, amalgam is a better restorative material in distributing stresses.

  15. 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

  16. 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

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

    PubMed Central

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

    2009-01-01

    Aim: This study compares the effect of formalin and autoclaving the tooth samples by evaluating microleakage in-vitro. Materials and Methods: Forty-five extracted human permanent incisor teeth were taken and randomly divided into three groups (with different methods of storage and disinfection) with 15 teeth each: Group 1: Control-extracted teeth in this group were stored in normal saline, Group 2: the extracted teeth in this group were stored in 10 % formalin for two weeks and Group 3: the extracted teeth were Autoclaved at 121°C, at 15 psi pressure for 40 minutes. In all the groups after the specified storage period, class V cavities were prepared on the labial surface and restoration was performed with Z100 restorative. Finished and polished samples were subjected to 500 cycles of thermocycling. All specimens were immersed in methylene blue for 24 hours. After sectioning, the margins of restoration were evaluated for dye leakage at 10 X magnification, using an optical microscope. Data were subjected to nonparametric Kruskal Wallis one way analysis of variance. Inter-group comparisons were performed using the Mann Whitney test (P < 0.05). Results: The authors found that the microleakage in the formalin group was considerably lower than that in the control group. The autoclave group showed slightly higher mean microleakage, but the difference was not statistically significant. Conclusion: Both autoclaving and formalin storage affect, to a varying degree, the microleakage values in vitro. The results in the autoclaving group matched those of the control group more closely, with only a slight difference. PMID:20379437

  18. 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

  19. Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials.

    PubMed

    Guven, Yeliz; Tuna, Elif Bahar; Dincol, M Emir; Ozel, Emre; Yilmaz, Bulent; Aktoren, Oya

    2016-01-01

    Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA), mineral trioxide aggregate (MTA), and EndoSequence® Root Repair Material (ERRM). Material and Methods. 40 teeth, simulated to average root length of 13 ± 1 mm (Cvek's stage 3), were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P), Group 3: MTA-Angelus (MTA-A), and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers' instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD) failure loads (MPa) were 20.46 ± 2.53 for BA, 18.88 ± 5.13 for MTA-P, 14.12 ± 1.99 for MTA-A, and 17.65 ± 4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p < 0.001), MTA-P and MTA-A (p < 0.05), and ERRM and MTA-A (p < 0.05). Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested. PMID:27382564

  20. Long-Term Fracture Resistance of Simulated Immature Teeth Filled with Various Calcium Silicate-Based Materials

    PubMed Central

    Dincol, M. Emir; Ozel, Emre; Yilmaz, Bulent; Aktoren, Oya

    2016-01-01

    Objective. The aim of this in vitro study was to evaluate the long-term fracture resistance of simulated human immature permanent teeth filled with BioAggregate™ (BA), mineral trioxide aggregate (MTA), and EndoSequence® Root Repair Material (ERRM). Material and Methods. 40 teeth, simulated to average root length of 13 ± 1 mm (Cvek's stage 3), were included in the study. The teeth were randomly divided into four groups: Group 1: DiaRoot® BA, Group 2: MTA-Plus™ (MTA-P), Group 3: MTA-Angelus (MTA-A), and Group 4: ERRM. The root canal filling materials were applied according to the manufacturers' instructions. After 24 months of incubation, the roots of the teeth were embedded in acrylic blocks and subjected to fracture testing. The resultant data were analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests. Results. Mean (±SD) failure loads (MPa) were 20.46 ± 2.53 for BA, 18.88 ± 5.13 for MTA-P, 14.12 ± 1.99 for MTA-A, and 17.65 ± 4.28 for ERRM groups. BA group exhibited the highest and MTA-A group showed the lowest resistance to fracture. Significant differences in fracture resistance were found between the groups of BA and MTA-A (p < 0.001), MTA-P and MTA-A (p < 0.05), and ERRM and MTA-A (p < 0.05). Conclusion. Within the limitations of this study, data suggests that BA-filled immature teeth demonstrate higher fracture resistance than other groups at 24 months appearing to be the most promising material tested. PMID:27382564

  1. Prognosis of teeth in the line of mandibular fractures

    PubMed Central

    Kumar, P. Prasanna; Sridhar, B. S.; Palle, Ramaiah; Singh, Nishanth; Singamaneni, Vijay Kumar; Rajesh, Panchineni

    2014-01-01

    Introduction: The purpose of this study was to evaluate teeth involved in the line of fracture, clinically and radiographically, and their associated complications so as to indicate if they should be managed conservatively or extracted. Materials and Methods: Data were collected from patients records treated of mandibular fractures. It was included pre and postoperative panoramic radiographs, information such as demographic data, age, and sex, fracture location, mobility, and vitality of teeth in the line of fracture, teeth stabilizing the fracture segment. Results: The sample presented 25 patients with teeth in the line of mandibular fractures. A total of 16 patients teeth in the line of fracture were vital during the 6th week postoperative follow-up and 9 patients with their teeth in the line of fracture were nonvital of which 4 were endodontically treated and the rest 5 patients teeth in the line of fracture were extracted as they showed signs of infection. Conclusion: This study demonstrated that the presence of teeth in the line of fracture is not a limiting factor for the treatment. Despite the risk of complications, tooth in the fracture line should be preserved for its merits. A regular clinical and radiological follow-up should be mandatory for at least a period of 1 year. PMID:25210395

  2. Determination of Radius of Curvature for Teeth With Cycloid Profile

    NASA Astrophysics Data System (ADS)

    Shatalov, E. V.; Efremenkov, E. A.; Shibinskiy, K. G.

    2016-04-01

    In the article the geometric determination of curvature radius is considered for teeth with cycloid profile. The equations are obtained for the determination of a radius of curvature with point coordinates of a cycloid profile. The conditions of convexo-concavity of a teeth profile are defined for transmission with intermediate rollers.

  3. Mouth and Teeth: How To Keep Them Healthy

    MedlinePlus

    ... care as an adult can help you avoid tooth loss, painful gums or other problems. Here are some helpful things you can do: Brush your teeth at least twice a day with a fluoride toothpaste. Floss your teeth at least once a ...

  4. Do NCCHC Dental Standards Have Any Teeth?

    PubMed

    Douds, Anne S; Ahlin, Eileen M

    2016-07-01

    Federal civil rights law establishes legal parameters for correctional dental care, but it does not provide specific standards for implementation. Thus, courts have developed guidelines on a case-by-case basis, often rendering the National Commission on Correctional Health Care (NCCHC) standards on dental care the de facto benchmark for institutions. This systematic review of all court cases that apply NCCHC standards for dentistry in prisons examines how courts use NCCHC standards and provides insights into whether those standards have any "teeth," or power, in a legal sense. These findings consider the legal relevance of NCCHC standards and speak more broadly to the role of professional organizations in the legal and correctional communities. PMID:27302703

  5. Smooth Teeth: Why Multipoles Are Perfect Gears

    NASA Astrophysics Data System (ADS)

    Schönke, 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.

  6. The Vikings bare their filed teeth.

    PubMed

    Arcini, Caroline

    2005-12-01

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

  7. Viper fangs: functional limitations of extreme teeth.

    PubMed

    Cundall, David

    2009-01-01

    The fangs of vipers are extremely long, rotating, hollow teeth. Analysis of video records of more than 750 strikes recorded at 60 or 250 frames per second for 285 individuals representing 86 species in 31 genera shows that vipers reposition fangs after initial contact with prey in more than a third of the strikes. Repositioning resulted when fangs missed prey entirely or hit prey regions that did not permit adequate penetration. The prevalence of repositioning, even among species that normally release prey, suggests strong selective pressure for rapid neuromotor response to fang placement error. The rapidity of repositioning suggests the existence of (a) fine-scale sensory detection of fang penetration depth, (b) rapid modulation of contraction of antagonistic muscles, and (c) possibly neurological modifications to shorten transmission time between sensory input and motor output. Extreme fang length has apparently coevolved with extreme functions. PMID:19025501

  8. 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

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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.…

  19. Correlation of calcification of permanent mandibular canine, mandibular premolars, and permanent mandibular first and second molars with skeletal maturity in Indian population

    PubMed Central

    Motghare, Pawan C.; Bedia, Aarti S.; Degwekar, Shirish S.; Indurkar, Atul D.; Bedia, Sumit

    2016-01-01

    Context: Morphological variation in children can be understood by the knowledge of growth and development. The state of dental development can be used in forensic odontology to ascertain the age of an unidentified child. Aims: This study aims to investigate the relationship of the stages of calcification of the permanent mandibular canine, mandibular premolars, and permanent mandibular first and second molars with skeletal maturity using panoramic and hand–wrist radiographs. Settings and Design: This descriptive work was designed as a cross-sectional study. Materials and Methods: The study was conducted on 300 healthy subjects (150 males and 150 females) ranging 7–20 years of age. Demirjian's method and Björk, Grave, and Brown's method were used to correlate teeth calcification and skeletal maturity, respectively. Statistical Analysis Used: Descriptive statistics and Spearman's rank correlation coefficient were used. Results: 1. Correlation coefficients between the skeletal maturity stages and the developmental stages of the five teeth ranged 0.461–0.877 for females and 0.480–0.790 for males. 2. The second molar showed the highest and the first molar showed the lowest relationship for female and male subjects in the Indian population. Conclusions: The findings of this study indicate that tooth calcification stages might be clinically used as a maturity indicator of the pubertal growth period.

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

    PubMed

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

    2009-10-01

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

  1. Natal and Neonatal Teeth: A Retrospective Study of 15 Cases

    PubMed Central

    Basavanthappa, Nagaveni N; Kagathur, Umashankara; Basavanthappa, Radhika N; Suryaprakash, Satisha T

    2011-01-01

    Objectives: To present 17 natal/neonatal teeth in 15 patients and describe their clinical characteristics, associated disorders, complications and treatment. Methods: A retrospective study of neonates who visited the Department of Pedodontics and Preventive Dentistry, College of Dental Sciences, Davangere, India, between 2003 and 2006 was carried out. It was a study of clinical data, such as the age and gender of the patients, the history and chief complaints of mothers, the clinical appearance and location of natal/neonatal teeth, and associated complications and treatments. Results: A total of 17 teeth (6 natal, 11 neonatal) were found in 15 patients. No significant gender predilection (8 male, 7 female) was found. Sixteen natal/neonatal teeth were placed in mandibular incisor area (10 on the right side and 6 on the left side) and one tooth in the maxillary incisor area. In 13 patients, the occurrence of natal/neonatal teeth was unilateral, and in 2 patients, it was bilateral. Three cases were associated with enamel hypoplasia, 3 cases with Riga-Fede disease, and 1 case with gingival hyperplasia. One case involved a patient with cleft lip and palate. Radiographic examination confirmed these teeth to be supernumerary, and all teeth exhibited hypermobility. Extraction had been done in all the cases. Eleven of the extracted teeth exhibited only rudimentary roots, and six teeth showed no roots. Conclusions: The occurrence of a natal/neonatal tooth is a rare phenomenon. When it occurs, the teeth have a variety of clinical characteristics and lead to different complications. Knowledge of the management of these structures is essential for the overall well being of a child. PMID:21494384

  2. Design considerations of electromagnetic force in a direct drive permanent magnet brushless motor

    NASA Astrophysics Data System (ADS)

    Chen, H. S.; Tsai, M. C.

    2008-04-01

    In this paper, a numerical study of electromagnetic force associated with the width of stator teeth, width of rotor back iron, and slot opening for a ten-pole nine-slot direct drive permanent magnet brushless motor is presented. The study calculates the amplitude of the electromagnetic force on the rotating rotor by using the finite-element method. The results show that the amplitude of electromagnetic force, which may cause the noise and vibration of motors, changes with the variation of these above mentioned three factors. The relationship between the considerations of output torque and the minimization of noise and vibration is also established in this paper.

  3. 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.

  4. Permanent-File-Validation Utility Computer Program

    NASA Technical Reports Server (NTRS)

    Derry, Stephen D.

    1988-01-01

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

  5. 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.

  6. Method of making permanent magnets

    DOEpatents

    McCallum, R. William; Dennis, Kevin W.; Lograsso, Barbara K.; Anderson, Iver 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.

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

    NASA Astrophysics Data System (ADS)

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

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

  8. 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

  9. 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

  10. Structure, composition, and mechanical properties of shark teeth.

    PubMed

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

    2012-06-01

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

  11. Indirect pulp therapy: an alternative to pulpotomy in primary teeth.

    PubMed

    Seale, N Sue

    2010-11-01

    Preservation of the primary teeth until their normal exfoliation is essential for normal oral function and facial growth of the child. To that end, treatment of primary teeth with large carious lesions approximating the pulp should be aimed at preserving the tooth. Currently, the pulpotomy is the most frequently used pulp treatment for cariously involved primary teeth. The purpose of this manuscript is to describe the use of an alternative to the pulpotomy, indirect pulp therapy (IPT), for the treatment of vital, primary teeth with carious involvement approaching the pulp. Accurate diagnosis of the vitality status of the pulp is critical to the success of IPT and involves careful radiographic and clinical assessment of the teeth to be sure they are healthy or at worst, reversibly inflamed. The indications for IPT are the same as for pulpotomy. The technique involves one appointment, requires that some carious dentin be left to avoid pulp exposure and requires the placement of a biologically sealing base and sealing final restoration. Teeth treated with IPT have success rates at least as good as those treated with pulpotomies, and IPT offers an acceptable alternative to pulpotomy as a treatment for vital, asymptomatic, cariously involved primary teeth. PMID:21309277

  12. 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

  13. 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.

  14. Evaluation of pigmented intraorifice barriers in endodontically treated teeth.

    PubMed

    Wolcott, J F; Hicks, M L; Himel, V T

    1999-09-01

    The purpose of this study was to evaluate the effectiveness of three pigmented glass ionomer cements used as intraorifice barriers to prevent coronal microleakage. One hundred ten extracted mandibular human premolars were divided into four experimental groups of 25 teeth each and two control groups of 5 teeth each. The experimental teeth were instrumented and obturated using thermoplasticized gutta-percha and AH26 sealer. Group 1 teeth received no further treatment. Teeth in groups 2 through 4 had 1 of 3 pigmented glass ionomers (Vitrebond, GC America, and Ketac-Bond) placed as an intraorifice barrier. Positive control teeth were instrumented but not obturated. The negative control teeth were instrumented, obturated, and externally sealed with epoxy resin. The coronal 3 mm of each root was sealed into the lumen of an 18-mm segment of latex surgical tubing. After the apparatus was sterilized, 2.0 ml of a 24 h growth of Proteus vulgaris in trypticase soy broth (TSB) was placed in the coronal reservoir of the tooth. The inoculated apparatus was placed into a presterilized test tube containing 1.5 ml of TSB and incubated for 90 days at 37 degrees C. The TSB in the lower reservoir was observed daily for turbidity, which would indicate leakage along the full length of the obturated root canal. To determine if differences in microbial leakage occurred among the four experimental groups, Pearson's chi 2 and Fisher's exact tests were performed. The confidence level was set at 95%. The positive and negative controls validated the microbial testing method. The teeth without an intraorifice barrier leaked significantly more than teeth with Vitrebond intraorifice barriers (p < 0.05). The difference in leakage among the experimental glass ionomer barriers was not significant (p > 0.05). PMID:10687533

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

    PubMed Central

    Zilberman, Uri; Lasilla, Lippo

    2014-01-01

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

  16. 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 βERR=-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 βERR 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

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

    PubMed

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

    2014-12-01

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

  18. Incompletely fractured teeth--a survey of endodontists.

    PubMed

    Maxwell, E H; Braly, B V; Eakle, W S

    1986-01-01

    By means of questionnaires, 303 endodontists were asked about their experiences in the diagnosis and treatment of incompletely fractured teeth. The present article discloses the results relative to which teeth are most likely to fracture, which predisposing factors involve higher or lower risk, how endodontists prefer to treat root-fractured teeth, and the success rate they have had with them. The endodontists also reported the frequency of endodontic treatment failures attributable to root fractures. These results are discussed with respect to the potential implications for clinical dental practice. PMID:3456133

  19. Biocompatibility of a restorative resin-modified glass ionomer cement applied in very deep cavities prepared in human teeth.

    PubMed

    Soares, Diana Gabriela; Basso, Fernanda Gonçalves; Scheffel, Débora Lopes Sales; Giro, Elisa Maria Aparecida; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2016-01-01

    This study evaluated whether a restorative resin-modified glass ionomer cement, Vitremer (VM), would be biocompatible with pulp tissue when used as a liner in very deep cavities prepared in young human permanent teeth. Two dental cements in current use as liner materials, Vitrebond (VB) and Dycal (DY), were compared to VM. Class V cavities were prepared in 36 sound premolars that were scheduled for extraction, and the cavity floor was lined with the restorative cement (VM) or a liner/base control cement (VB or DY). For VM specimens, the cavity floor was pretreated with a primer (polyacrylic acid plus 2-hydroxyethyl methacrylate). Teeth were extracted after 7 or 30 days and processed for microscopic evaluation. In the VM group, inward diffusion of dental material components through dentinal tubules, associated with disruption of the odontoblastic layer, moderate to intense inflammatory response, and resorption of inner dentin, was observed in 2 teeth at 7 days. These histologic features were observed in 1 tooth at 30 days. In the VB group, mild inflammatory reactions and tissue disorganization observed at 7 days were resolved at 30 days. No pulpal damage occurred in the DY specimens. Of the materials tested, only Vitremer was not considered biocompatible, because it caused persistent pulpal damage when applied in very deep cavities (remaining dentin thickness less than 0.3 mm). PMID:27367631

  20. 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...

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

    PubMed Central

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

  2. [Permanent vascular access for haemodialysis].

    PubMed

    Manafov, E N; Batrashov, V A; Sergeev, O G; Yudaev, S S

    2015-01-01

    The presence of a permanent vascular access (PVA) is the pledge of successful treatment of patients being on chronic haemodialysis (CD). Creation and maintenance of a functioning PVA is the priority task of vascular and endovascular surgeons, nephrologists and specialists of haemodialysis departments. According to the KDOQI guidelines, the most preferable type of PVA is a native arteriovenous fistula (AVF). As an alternative it is possible to use a synthetic prosthesis for creating an arteriovenous shunt (AVS) or implantation of a central venous catheter (CVC). Various complications of vascular accesses leading to their loss create the necessity of forming just another PVA, thus negatively influencing the life span and quality of life of this cohort of patients. Improving surgical technique and approaches to treatment, as well as carrying out dynamic monitoring of the condition of the created PVA make it possible to considerably decrease the incidence rate of such complications and to improve the quality of medical care rendered. PMID:26451410

  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. 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

  5. Green pigmentation in human teeth. A stereomicroscopic study.

    PubMed

    Rakauskaite, Asta; Juodzbalys, Gintaras; Pauza, Dainius H; Cicciù, Marco

    2014-01-01

    Green pigmentation in teeth is an uncommon condition associated with bilirubin deposits in hard dental tissues. Its occurrence can cause anxiety to both the child and parents and is not diagnosed easily by clinicians. The aim of this study is to analyze the current knowledge about the etiology, the intraoral alterations, and the macroscopic and microscopic features of green teeth pigmentation related to a high bilirubin levels. A primary tooth was extracted and manually sliced into 600 microns thin sections. The slenderized slices were examined with a light microscope AxioImager M1 to evaluate the microscopic teeth structure. The clinical characteristics of teeth may help in the diagnosis of current or past systemic diseases. Pediatricians should be able to quickly note the signs in order to perform the proper diagnosis. This study may help clinicians gain more knowledge about the current status of this uncommon pathology. PMID:25571689

  6. Relationship between torus mandibularis and number of present teeth.

    PubMed

    Eggen, S; Natvig, B

    1986-06-01

    Comparison of incidence of torus mandibularis and average number of present teeth among 2010 consecutive dental patients over 10 yr of age revealed that these variables seemed to be positively related: patients with torus mandibularis had on the average more teeth present than those without torus (P less than 0.0000001). The difference was statistically significant in all age classes except 50 years and over. In the adolescent age class, 10-19-yr, patients with torus mandibularis had on the average fewer unerupted canines than those without torus indicating that the hyperostosis seemed to be associated with more adequately developed jaws. The decreasing incidence of torus mandibularis with age approximately paralleled the decreasing number of present teeth, indicating that number of functioning teeth seems to be a factor of importance for the maintenance of the trait. PMID:3461543

  7. A review on vital pulp therapy in primary teeth.

    PubMed

    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

  8. Effect of bonded gold inlays on fracture resistance of teeth.

    PubMed

    Eakle, W S; Staninec, M

    1992-06-01

    The purpose of this study was to determine if bonding gold inlays to tooth structure with an adhesive resin cement would increase the fracture resistance of restored teeth. Extracted paired maxillary premolars were prepared for mesio-occlusodistal inlays, and the inlays were cast in type II gold. In one tooth of each pair, the inlay was sandblasted with aluminium oxide, tin plated, and cemented with an adhesive resin into the etched preparation. For the other (control) tooth in each pair, the inlay was sandblasted and then cemented into the preparation with zinc phosphate cement. The teeth were thermocycled and loaded until fracture. The teeth in the bonded group had a statistically significantly higher fracture resistance than did the teeth in the control group. Scanning electron microscopic examination revealed that failure in the bonded group occurred predominantly within the resin. PMID:1502322

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

    NASA Technical Reports Server (NTRS)

    1993-01-01

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

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

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

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

  11. 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

  12. [Teeth decoration back after a long and forgotten history].

    PubMed

    Dijs, F

    2004-09-01

    After the last ice-age modern man started to remove, file, dye and inlay teeth. The teeth had such a central role in the imagination that the habit of more or less ritual decoration by incurable manipulation of the teeth spread all over the world. The most skillful and artistic work was done by craftsmen of the Maya. Between 1500 and 1900 modern researchers classified the habits as primitive and barbarian but during the twentieth century some of them took the question seriously. In the last decennium tooth jewelery is sold more and more often. In two articles the history of teeth decoration is outlined. In this article the significance of the manipulations is emphasized. The second will focus on the changing appreciation of the phenomenon. PMID:15495505

  13. The innervation of the zebrafish pharyngeal jaws and teeth.

    PubMed

    Crucke, Jeroen; Van de Kelft, Annelore; Huysseune, Ann

    2015-07-01

    Zebrafish (Danio rerio) teeth are increasingly used as a model to study odontogenesis in non-mammalians. Using serial semi-thin section histology and immunohistochemistry, the nerves innervating the pharyngeal jaws and teeth have been identified. The last pair of branchial arches, which are non-gill bearing but which carry the teeth, are innervated by an internal branch of a post-trematic ramus of the vagal nerve. Another, external, branch is probably responsible for the motor innervation of the branchiomeric musculature. Nerve fibres appear in the pulp cavity of the teeth only late during cytodifferentiation, and are therefore likely not involved in early steps of tooth formation. The precise role of the nervous system during continuous tooth replacement remains to be determined. Nonetheless, this study provides the necessary morphological background information to address this question. PMID:26018453

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

    NASA Astrophysics Data System (ADS)

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

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

  15. 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.

  16. Caries imaging by teeth (auto)luminescence spectral analysis

    NASA Astrophysics Data System (ADS)

    Jonusauskas, Gediminas; Abraham, Emmanuel; Oberle, Jean; Rulliere, Claude; Peli, Jean-Francoic; Dorignac, Georges

    2003-10-01

    We propose a new technique for caries imaging by the spectral analysis of teeth luminescence excited by the near UV light. This diagnostic/control method can be applied for the all optically accessible teeth surfaces. The photo-physical studies suggest that hydroxylapatite luminescence, excited in the near UV, comes from de-excitation of crystalline structure defects in interaction with charge donating/accepting en ironment.

  17. 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

  18. Erupted complex odontoma delayed eruption of permanent molar.

    PubMed

    Ohtawa, Yumi; Ichinohe, Saori; Kimura, Eri; Hashimoto, Sadamitsu

    2013-01-01

    Odontomas, benign tumors that develop in the jaw, rarely erupt into the oral cavity. We report an erupted odontoma which delayed eruption of the first molar. The patient was a 10-year-old Japanese girl who came to our hospital due to delayed eruption of the right maxillary first molar. All the deciduous teeth had been shed. The second premolar on the right side had erupted, but not the first molar. Slight inflammation of the alveolar mucosa around the first molar had exposed a tooth-like, hard tissue. Panoramic radiography revealed a radiopaque mass indicating a lesion approximately 1 cm in diameter. The border of the image was clear, and part of the mass was situated close to the occlusal surface of the first molar. The root of the maxillary right first molar was only half-developed. A clinical diagnosis of odontoma was made. The odontoma was subsequently extracted, allowing the crown of the first molar to erupt almost 5 months later. The dental germ of the permanent tooth had been displaced by the odontoma. However, after the odontoma had been extracted, the permanent tooth was still able to erupt spontaneously, as eruptive force still remained. When the eruption of a tooth is significantly delayed, we believe that it is necessary to examine the area radiographically. If there is any radiographic evidence of a physical obstruction that might delay eruption, that obstruction should be removed before any problems can arise. Regular dental checkups at schools might improve our ability to detect evidence of delayed eruption earlier. PMID:24521551

  19. Augmented railgun using a permanent magnet

    SciTech Connect

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

    1995-08-01

    The use of a permanent magnet instead of an electromagnet has been proposed for the augmentation of the magnetic field of a railgun driven by a current of approximately 20 kA. A permanent magnet has the following advantages in comparison with conventional augmentations using additional turns: (1) simple configuration of the system, (2) temporally and spatially constant magnetic fields, and (3) high efficiency. Here, the operation of a conventional railgun and that of an augmented railgun using a permanent magnet are compared experimentally, and the usefulness of the permanent magnet is described. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  20. Is biologic width of anterior and posterior teeth similar?

    PubMed

    Rasouli Ghahroudi, Amir Alireza; Khorsand, Afshin; Yaghobee, Siamak; Haghighati, Farideh

    2014-01-01

    The biologic width (BW) includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD) as well as the distance between free gingival margin and the bone crest (FB) of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm) was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002). BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments. PMID:25325207

  1. 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

  2. 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

  3. Early Childhood Caries and Caries Experience in Permanent Dentition: A 15-year Cohort Study.

    PubMed

    Jordan, A Rainer; Becker, Natascha; Jöhren, Hans-Peter; Zimmer, Stefan

    2016-01-01

    In Germany, caries of young people has been declining since the late 1980s, while the prevalence of early childhood caries has remained steady. Data from a number of regional studies suggest a current prevalence between 10% and 15%. However, there is a dearth of longitudinal observational study data on the risk of caries in the permanent teeth of persons who as children had to undergo comprehensive treatment for caries under intubation general anesthesia. The aim of this study was to compare caries experience in the permanent teeth of patients who had to undergo surgical treatment under general anesthesia as a result of non-compliance with caries treatment in early childhood with the experience of patients who did not develop caries at a young age. Analysis of the data revealed that severe caries experience during early childhood resulted in a more severe caries experience during adulthood (difference: 14.8 DMFS; p = 0.001). This increase in caries experience applied to both untreated and treated carious surfaces, and was also apparent in relation to tooth extractions. When compared with persons whose first teeth had been caries-free, patients with severe childhood caries experience tended to show poorer dental hygiene in relation to smooth (p < 0.06) and interproximal (p < 0.04) surfaces. Patients who had been non-compliant as young children were not found to suffer from dental anxiety as young adults. Patients in the treatment and control groups differed with regard to dental health. Aside from being statistically relevant, these differences also have implications for clinical dental practice. PMID:26915485

  4. 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.

  5. Fine structural and immunohistochemical detection of collar enamel in the teeth of Polypterus senegalus, an actinopterygian fish.

    PubMed

    Sasagawa, I; Yokosuka, H; Ishiyama, M; Mikami, M; Shimokawa, H; Uchida, T

    2012-02-01

    This is the first detailed report about the collar enamel of the teeth of Polypterus senegalus. We have examined the fine structure of the collar enamel and enamel organ of Polypterus during amelogenesis by light and transmission electron microscopy. An immunohistochemical analysis with an antibody against bovine amelogenin, an antiserum against porcine amelogenin and region-specific antibodies or antiserum against the C-terminus, middle region and N-terminus of porcine amelogenin has also been performed to examine the collar enamel matrix present in these teeth. Their ameloblasts contain fully developed Golgi apparatus, rough endoplasmic reticulum and secretory granules. During collar enamel formation, an amorphous fine enamel matrix containing no collagen fibrils is found between the dentin and ameloblast layers. In non-demineralized sections, the collar enamel (500 nm to 1 μm thick) is distinguishable from dentin, because of its higher density and differences in the arrangement of its crystals. The fine structural features of collar enamel in Polypterus are similar to those of tooth enamel in Lepisosteus (gars), coelacanths, lungfish and amphibians. The enamel matrix shows intense immunoreactivity to the antibody and antiserum against mammalian amelogenins and to the middleregion- and C-terminal-specific anti-amelogenin antibodies. These findings suggest that the proteins in the enamel of Polypterus contain domains that closely resemble those of bovine and porcine amelogenins. The enamel matrix, which exhibits positive immunoreactivity to mammalian amelogenins, extends to the cap enameloid surface, implying that amelogenin-like proteins are secreted by ameloblasts as a thin matrix layer that covers the cap enameloid after enameloid maturation. PMID:22287040

  6. 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

  7. 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

  8. An Interdisciplinary Approach in Rehabilitation of an Adult Mutilated Dentition with Multiple Missing Permanent Teeth--A Case Report.

    PubMed

    Agrawal, Sarvesh; Jose, Nidhin Philip; Bandi, Rohan S; Jain, Nimit; Rodrigues, Shobha J

    2015-01-01

    Adult orthodontics has been an area of increasing focus in recent times. Comprehensive treatment of adults is more challenging due to a myriad of problems that coexist in an adult that makes treatment planning more challenging. A large number of individuals seek dental care because of aesthetic reasons, that is, the desire to look more attractive by improving their smiles. The role an attractive smile plays on a person's self-image and confidence cannot be overemphasized. Evaluating and treating patients for the purpose of smile design often involves a multi-discipline approach. Achieving an ideal smile may require orthodontics, orthognathic surgery, periodontal therapy, including soft tissue repositioning and bone re-contouring, cosmetic dentistry, and plastic surgery. This aesthetic approach to patient care produces the best dental and dental-facial beauty. This paper describes a case report in which an orthodontist, an endodontist, and a prosthodontist worked as a team to improve the patients smile and confidence. PMID:27029092

  9. 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 Spearman’s rank correlation coefficient was used to explore the correlation of the distribution of CAST codes among the evaluated teeth. The level of statistical significance was established at p < 0.05. The intra-examiner reliability was determined by the unweighted kappa coefficient. Results With regard to the 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 < 0.001), respectively. For the neighbouring primary and 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

  10. 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

  11. 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.

  12. Permanent magnet multipole with adjustable strength

    DOEpatents

    Halbach, Klaus

    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.

  13. 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.

  14. 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 Junior, 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

  15. Sequelae of iatrogenic periodontal destruction associated with elastics and permanent incisors: literature review and report of 3 cases.

    PubMed

    Lin, Yan-Ting; Huang, Yu-Lan; Chang, Shih-Hao; Hong, Hsiang-Hsi

    2011-01-01

    The purpose of this paper was to report 3 cases of localized aggressive periodontal bone destruction related to improper use of orthodontic elastic bands to close diastemas in permanent anterior teeth and to compare the results to previous studies. Some common signs and symptoms of this particular destruction were observed with these patients that had been previously reported when the comparisons of these cases were made. The patients usually experienced a painful sensation, and an isolated pyogenic-like granuloma appeared at the interdental area. Radiographs revealed localized periodontal destruction, with tooth extrusion and clinical crown divergence and radiographic root convergence; the two involved teeth moved simultaneously during mobility testing. Surgical intervention and treatment of the cases was described. The prognosis is usually decided by the severity of the condition, and many factors may influence the healing of treated cases. PMID:22353413

  16. 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.

  17. The influence of trace elements of fluoride uptake by teeth

    NASA Astrophysics Data System (ADS)

    Anwar Chaudhri, M.; Crawford, A.

    1981-03-01

    To investigate the effect of various trace elements on fluoride uptake by teeth, the concentrations F and other trace elemenys have been simultaneously determined in different regions of the teeth from children of South Australia. Teeth cross sectioned along the median plane have been used in these investigations, and their inside enamel, dentine and amelodentinal junctions investigated separately for the trace elemental composition. Fluoride has been determined by observing the 6-7 MeV gammas for the 19F(p, αγ) 16O reaction, C by activation through the 12C( 3He, n) 14O reaction, while other trace elements have been measured by the thick target PIXE technique. Linear correlation coefficients have been calculated between the F concentrations in teeth, and those of other trace elements observed. Fluoride is found to correlate best with C, Cu and Pb, poorly with Fe, Sr, Ni and Ag, while with Br and Zn it has -ve coefficients. Student's t-test has been applied to the data to examine the significance of the variation of Fand other trace elements amongst different dental tissues from healthy and diseased teeth.

  18. 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

  19. 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 (α=0.01). The influence of two color coordinates on the other color coordinate was determined with a multiple regression analysis (α=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.

  20. [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

  1. Photoacoustic diagnosis of human teeth using interferometric detection scheme

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    We have investigated the mechanical and acoustic properties of human teeth using the laser generation of surface acoustic wave (SAW) technique. The materials investigated included normal and decayed teeth, which have similar grain sizes and different thicknesses. The tissue responds to the laser-induced stress by thermoelastic expansion. The informative features of this method allow one to determine sample thermal, optical, and acoustical properties that depend on the peculiarities of the sample compositional structure. An interferometric detection experimental scheme is applied for detection generated SAW pulses. The surface displacement curves shape of normal and decayed human teeth are shown. The dispersion curves for SAW pulses were determined by Fourier analysis. The result is an almost linear dependence of SAW velocity on frequency for a normal tooth, the magnitude of the thermoelastic expansion of the normal tooth reaches its peak at 0.344 μs, a SAW phase velocity of 2500 ms-1 between 0.0008 and 5 MHz was determined. For abnormal teeth, the magnitude of thermoelastic expansion of the normal tooth reaches its peak at 1.3 μs, the measured velocity was 3225 ms-1. Due to the inhomogeneity of abnormal teeth perpendicular to the propagation direction, strong differences in their dispersion curves were obtained. The detection of acoustic waves is the basis of photoacoustic methods, which can be used for diagnostic purposes.

  2. Near-IR imaging of cracks in teeth

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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.

  3. 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

  4. 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...

  5. 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

  6. Clinical management of supernumerary teeth: a report of two cases.

    PubMed

    Mittal, M; Sultan, A

    2010-01-01

    Supernumerary tooth may closely resemble the teeth of the group to which it belongs, i.e. molars, premolars or anterior teeth, or it may bear little resemblance in size or shape to which it is associated. Many complications can be associated with supernumeraries, like impaction, delayed eruption or ectopic eruption of adjacent teeth, crowding, development of median diastema and eruption into floor of the nasal cavity. This may also cause the formation of follicular cysts with significant bone destruction. Early intervention to remove it is usually required to obtain reasonable alignment and occlusal relationship. This article will present the clinical management of an (i) impacted supernumerary tooth impeding the eruption of maxillary central incisor and (ii) erupted supernumerary tooth with midline diastema. PMID:21157058

  7. 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

  8. [Natal and neonatal teeth: Update on current knowledge and treatments].

    PubMed

    Gouédard, C; de Vries, P; Darbin-Luxcey, C; Foray, H; d'Arbonneau, F

    2016-09-01

    Being born with a tooth is indeed possible! Teeth may be present at birth (natal tooth) or they may appear within the 1st month of life (neonatal tooth). In their shape and composition, they look like physiological primary teeth. Of still unknown etiology, natal and neonatal teeth remain an uncommon phenomenon. Hereditary, endocrine, or environmental factors may be involved: no conclusive relationship has been proven. The treatment must be adapted to each tooth and each child. Several treatments are available to dental surgeons: extraction or arch maintenance. The aim of this article is to help doctors and pediatricians understand this phenomenon and provide them with tools to support these children and their parents optimally. PMID:27451381

  9. Effect of composite containing an iodonium salt on the bond strength of brackets to bovine enamel.

    PubMed

    Soares, Eveline Freitas; Costa, Ana Rosa; Correr, Américo Bortolazzo; Vedovello, Silvia Amélia; Vedovello Filho, Mário; Ogliari, Fabrício Aulo; de Moraes, Rafael Ratto; Correr-Sobrinho, Lourenço

    2014-01-01

    This study investigated the effect of the incorporation of an iodonium salt in experimental composites, on the bond strength of metallic brackets bonded to bovine teeth. Two hundred and seventy bovine teeth were embedded in self-curing acrylic resin and divided into 18 groups (n=15), according to the experimental composite with an iodonium salt at molar concentrations 0 (control), 0.5, or 1%; the light-activation times (8, 20 and 40 s); and the storage times (10 min or 24 h). Metallic brackets were fixed on the tooth surface using experimental composites. Photoactivation was performed with a quartz-tungsten-halogen light-curing unit curing unit for 8, 20 and 40 s. The specimens were stored in distilled water at 37 °C for 10 min or 24 h and submitted to bond strength test at 0.5 mm/min. The data were subjected to three-way ANOVA and Tukey's test (α=0.05). The Adhesive Remnant Index (ARI) was used to classify the failure modes. The shear bond strengths (MPa) at 10 min for light-activation times of 8, 20 and 40 s were: G1 - 4.6, 6.9 and 7.1; G2 - 8.1, 9.2 and 9.9; G3 - 9.1, 10.4 and 10.7; and at 24 h were: G1 - 10.9, 11.1 and 11.7; G2 - 11.8, 12.7 and 14.2; G3 - 12.1, 14.4 and 15.8. There was a predominance of ARI score 3 for groups with 10 min storage time, and ARI score 2 for groups with 24 h storage time. In conclusion, the addition of iodonium salt (C05 and C1) to the experimental composite may increase the bond strength of brackets to bovine enamel using reduced light exposure times. PMID:25252260

  10. 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.

  11. 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.

  12. 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.

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

    PubMed

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

    2008-12-01

    The aim of this study was to compare one-visit indirect pulp treatment (IPT), two-visit IPT, and direct complete excavation (DCE) of deciduous and young permanent molars with deep carious lesions from clinical and microbiological points of view. One hundred thirty-five teeth (83 deciduous molars and 52 young permanent molars) were included in the study. The teeth were randomly selected and treated either with one-visit IPT, two-visit IPT, or DCE. For two-visit IPT, the final excavation was performed after a period of 3 months. The color, consistency, and humidity of the dentin at the cavity floor were recorded for clinical assessment, and dentin samples were obtained from all teeth. Dentin samples were microbiologically investigated for the total number of colony forming units, mutans streptococci, and lactobacilli. The results showed bacterial growth in 63.8% of the dentin samples in one-visit IPT, while in two-visit IPT, bacterial growth was observed in all of the samples (100%) after the first excavation. When the cavities were reopened before the final excavation, the number of samples with positive growth had decreased significantly (44.4%), and after the final excavation, the number of the samples with positive growth had decreased to 2.2%. In the DCE group, only 25.6% of the samples revealed bacterial growth. No statistical difference was found between deciduous and permanent molars in any of the treatment groups in terms of microbiologic results (p > 0.05). In conclusion, although none of the treatment methods completely eliminated the viable microorganisms during the initial excavations, a dramatic reduction in bacterial growth was detected during the treatment stages of two-visit IPT. PMID:18548292

  14. 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

  15. Associations between the number of natural teeth and renal dysfunction.

    PubMed

    Choi, Hye Min; Han, Kyungdo; Park, Yong Gyu; Park, Jun-Beom

    2016-08-01

    The purpose of the present study was to investigate the association between the number of natural teeth and measures of kidney dysfunction, such as urinary albumin/creatinine ratio (ACR) and estimated glomerular filtration (eGFR) rate, using nationally representative data.The data used were from the Korea National Health and Nutrition Examination Survey with cross-sectional design, which was conducted between 2011 and 2012; the sample analyzed in this study consisted of a total of 10,388 respondents, each of whom was 19 years or older and had no missing outcome variables. The association between the number of natural teeth and kidney function was assessed by multiple logistic regression and model was adjusted for age, sex, waist conference, smoking, drinking, exercise, education, income, frequency of tooth brushing per day, diabetes, metabolic syndrome, urinary ACR, and eGFR.The mean age, body mass index, and waist circumference were significantly higher among those with lower kidney function (urinary ACR ≥30 mg/g and eGFR <60 mL/min/1.73m). Urinary ACR and eGFR were associated with loss of natural teeth. As urinary ACR increased, the number of natural teeth decreased accordingly. Conversely, the number of natural teeth increased with an increase in eGFR.This study showed that the number of natural teeth is inversely associated with the presence of kidney disease. Severity of tooth loss may be considered an independent risk indicator for kidney disease among Koreans. More epidemiological studies are warranted to investigate the role of tooth loss in kidney disease, to confirm this relationship and to test possible underlying mechanisms. PMID:27559974

  16. Middle Pleistocene hominin teeth from Longtan Cave, Hexian, China.

    PubMed

    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

  17. 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

  18. 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

  19. Observation of Children's Teeth as a Diagnostic Aid

    PubMed Central

    Gibson, Wm. M.; Conchie, John M.

    1964-01-01

    Current interest in tetracycline staining of teeth and other enamel defects led to this review. In the handicapped child structural defects that were seen in the dental enamel may provide a most accurate etiological clue. The method of determining the time of insult is described. Comments are made on seven states in which enamel dysplasia may be frequently observed. A simple means of identifying tetracycline pigment incorporated in dental enamel is outlined. Bilirubin staining of teeth is also shown and warnings are given about the indelible nature of these pigments. ImagesFig. 2Fig. 3Fig. 4 PMID:14118684

  20. 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

  1. [Should we or should we not extract impacted teeth?].

    PubMed

    Lechien, P

    1995-01-01

    Do we have to remove the impacted teeth? The pathology of an impacted tooth is reviewed by the author as well as the possible complications of its removal and others treatment possibilities. Seeing the increase of pathology and operative complications owing to the age, the author propounds the management of immature impacted third molars when they are not in a propitious position or when the posterior eruption space is reduced. About the impacted teeth covered partially or completely by soft tissue, his advice consists too in removing them if they don't have the possibility to take up good position on the dental arch. PMID:7480929

  2. 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.

  3. 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

  4. 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

  5. Maturogenesis of a cariously exposed immature permanent tooth using MTA for direct pulp capping: a case report.

    PubMed

    Patel, Rajiv; Cohenca, Nestor

    2006-12-01

    Successful direct pulp capping of cariously exposed permanent teeth with reversible pulpitis and incomplete apex formation can prevent the need for root canal treatment. A case report is presented which demonstrates the use of mineral trioxide aggregate (MTA) as a direct pulp capping material for the purpose of continued maturogenesis of the root. Clinical and radiographic follow-up demonstrated a vital pulp and physiologic root development in comparison with the contralateral tooth. MTA can be considered as an effective material for vital pulp therapy, with the goal of maturogenesis. PMID:17073926

  6. Cone-Beam Computed Tomography Study Of Crown Dilaceration With a Talon Cusp in an Unerupted Permanent Maxillary Tooth.

    PubMed

    Esmaeilzadeh, Mohammad; Donyavi, Zakiyeh; Shokri, Abbas

    2016-03-01

    This article describes a rare case of crown dilaceration with a talon cusp in an unerupted permanent maxillary central incisor. Our patient was a 7-year-old boy with a history of trauma to his primary maxillary teeth (#51 and 52), at 3 years of age complaining of failure of eruption of tooth #11. Periapical radiography showed incomplete formation of tooth root #11 and more superior position of tooth bud #11 relative to tooth bud #12. A cone-beam computed tomography was ordered, which revealed crown dilaceration with a talon cusp in tooth bud #11. The patient was scheduled for follow-up at 6 months. PMID:26854775

  7. 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.

  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. Characterizing hydrologic permanence in headwater streams

    EPA Science Inventory

    The presentation will be an overview of research to inform jurisdictional determinations for the Clean Water Act, in particular research that hydrographic comparisons of the extent and hydrologic permanence of headwater streams, indicator development, and an evaluation of a rapid...

  10. A Histopathological Comparison of Pulpal Response to Chitra-CPC and Formocresol used as Pulpotomy Agents in Primary Teeth: A Clinical Trial.

    PubMed

    Ratnakumari, N; Thomas, Bijimol

    2012-01-01

    Preventive measures have helped to minimize the occurrence of dental caries. However, premature loss of primary teeth on account of dental caries still remains a common problem among children. The pulpotomy technique has been the choice for treating vital primary and young permanent teeth with carious, mechanical and traumatic pulp exposures. The ideal pulpotomy medicament should be bioinductive or at least biocompatible, bactericidal and harmless to the pulp and surrounding structures. It should also promote healing of the radicular pulp and prevent bacterial microleakage with the least interference in the physiological process of root resorption. Since the best criteria for judging the effectiveness of a medicament when used for vital pulp therapy is the response that it produces in the pulp. The purpose of the present study was to evaluate and compare the response of human pulp tissue to recently developed Indian material, Sree Chitra-Calcium Phosphate Cement (Chitra-CPC) and formocresol, used as pulpotomy agent in deciduous teeth. Chitra-CPC has been compared with formocresol, taking into account that formocresol is still considered the gold standard in primary tooth pulpotomy. The study was conducted among 10 children in the age group of 8 to 12 years focusing on 20 noncarious primary canines indicated for serial extraction. Each patient received two different pulpotomy procedures-one in each of the primary canines using formocresol and the other with Chitra-CPC as pulpotomy agents. After 70 days, the teeth were extracted and subjected to histological examination. The results did not reveal statistically significant difference between the two groups. But Chitra-CPC gave more favorable results, in respect of pulpal inflammation, dentin bridge formation, quality of dentin bridge and connective tissue in dentin bridge. How to cite this article: Ratnakumari N, Thomas B. A Histopathological Comparison of Pulpal Response to Chitra- CPC and Formocresol used as

  11. Bovine ephemeral fever: a review.

    PubMed

    Nandi, S; Negi, B S

    1999-04-01

    Bovine ephemeral fever is a viral disease of cattle and buffaloes besides subclinical involvement of a variety of ruminant species. The subtropical and temperate regions of Africa, Asia and Australia have experienced the major epidemic of the bovine ephemeral fever but the occurrence in the tropics can not be overlooked. Although the substantial role played by the vectors viz., mosquitoes and culicoides in bovine ephemeral fever perpetuation and dissemination, other vector involvement if any should be extensively studied. The clinical severity of the disease is not apparent and the mortality is low. However, high morbidity, enormous economic losses in terms of significant reduction in production, disruption of national and international trade and finally a variety of complications resulting from the disease have drawn appreciable attention from the researchers around the world to resolve the unsolved questions in this area. In this review, detailed informations of all the aspects of the disease has been provided in a simple, lucid and easily understandable manner. PMID:10051179

  12. Permanent Darkness at the Lunar North Pole

    NASA Astrophysics Data System (ADS)

    Bussey, B.; Robinson, M. S.; Spudis, P. D.; Lucey, P. G.

    2001-12-01

    The Clementine mission provided the first dynamic temporal look at the illumination conditions of both lunar poles. Data of the lunar north pole were collected during summer in the northern hemisphere and are therefore ideal for placing a constraint on the maximum amount of permanent shadowed regions that exist. An early estimate of permanent shadow using Clementine data by Nozette and coworkers, based on a conservative measurement of permanently shadowed small craters close to the pole, was 530 km2. A later estimate, produced using Earth based radar topography data (by Margot et al), extended the area analyzed to lower latitudes (85oN), and indicated an increased permanently shadowed area of 2650 km2. By producing movies using Clementine UVVIS data it is possible to study dynamically how the illumination conditions vary during the length of a lunar day (708 hours). These movies show that small areas of permanent shadow possibly exist at lower latitudes than included in the Margot study, including regions of the farside that are inaccessible to Earth based study. An initial analysis shows that portions of north facing crater walls, as far out as 80oN, appear to be permanently shadowed. A preliminary examination of such features has raised the value of the permanently shadowed terrain area to greater than 10,000km2. A recent control network for the north pole will permit a more precise determination of the amount of permanently shadowed terrain. Comparison of this value, together with the data returned by Lunar Prospectors neutron spectrometer will place constraints on the amount of ice present at the lunar north pole as presented by Feldman and coworkers.

  13. Permanent magnet edge-field quadrupole

    DOEpatents

    Tatchyn, Roman O.

    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.

  14. 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.

  15. 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

  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

  17. 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

  18. Anesthetic efficacy of meperidine in teeth with symptomatic irreversible pulpitis.

    PubMed

    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

  19. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    MedlinePlus

    ... for Early Childhood Tooth Decay? The History of Dental Advances What is Orofacial Pain? Are You Biting Off More Than You Can Chew? Check Menstrual Calendar for Tooth Extraction Learn what those dental words mean. Check out how your teeth and ...

  20. 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

  1. Orthodontic management of non-syndromic multiple supernumerary teeth

    PubMed Central

    Singhvi, Vijay; Nambiar, Supriya; Shetty, Siddarth

    2013-01-01

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

  2. Fracture resistance of premolar teeth restored with different filling techniques.

    PubMed

    França, Fabiana Mantovani Gomes; Worschech, Claudia Cia; Paulillo, Luis Alexandre Maffei Sartini; Martins, Luis Roberto Marcondes; Lovadino, José Roberto

    2005-08-15

    The aim of this study is to verify the fracture resistance of premolars with large mesiocclusodistal (MOD) preparations with composite resin using different incremental techniques when subjected to an occlusal load. Forty maxillary premolar teeth were randomly divided into four groups (n=10). Class II MOD cavities were prepared in all specimens with parallel walls and no approximal boxes. The resulting isthmus width was 1/3 the distance between the cusp tips and (3/4) the height of the crown. Teeth in group I, the control group, were not restored. Specimens in group II were restored in three incremental vertical layers. Group III specimens were restored in three horizontal layers, and finally, specimens in group IV were restored in oblique layers. With exception of the placement technique, specimens in groups II, III and IV were restored using the Single Bond adhesive system and P60 composite resin following manufacturer's recommendations. A 4 mm diameter steel sphere contacted the buccal and lingual cusps of the tested teeth at a crosshead speed of 0.5 mm/min until fracture occurred. The values obtained in this study were subjected to Analysis of Variance (ANOVA) and a Tukey-Kramer test. Only group I (non-restored) obtained a minor means of fracture resistance. No significant differences among groups II, III, and IV were found. This study shows on large MOD cavities the incremental filling techniques do not influence the fracture resistance of premolar teeth restored with composite resin. PMID:16127473

  3. CO2 laser on apical seal of retrofilled teeth

    NASA Astrophysics Data System (ADS)

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

    1997-05-01

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

  4. 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...

  5. Lingual nerve injury subsequent to wisdom teeth removal--a 5-year retrospective audit from a high street dental practice.

    PubMed

    Malden, N J; Maidment, Y G

    2002-08-24

    Lingual nerve damage subsequent to lower wisdom tooth removal affects a small number of patients, sometimes producing permanent sensory loss or impairment. A number of surgical techniques have been described which are associated with low incidences of this distressing post-operative complication. When a technique is adopted by an individual clinician then a personal audit may be prudent to establish how effective it is in relation to established nerve injury rates. This audit looks at a technique involving the minimal interference of lingual soft tissues during lower wisdom tooth removal in a high street practice situation for patients having mild to moderate impacted wisdom teeth removed under local anaesthetic. It was concluded that the technique employed was associated with a low incidence of lingual nerve trauma, comparable with that reported elsewhere. PMID:12222906

  6. Perikymata spacing and distribution on hominid anterior teeth.

    PubMed

    Dean, M C; Reid, D J

    2001-11-01

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

  7. A Fatal Fad? Tongue Studs Cause More Problems Than Chipped Teeth

    MedlinePlus

    ... Jaw Pain? Check Your Posture! The History of Dental Advances What is Orofacial Pain? How Do I Care for My Child's Baby Teeth? Temporomandibular Joint Disorder Learn what those dental words mean. Check out how your teeth and ...

  8. Take Care of Your Teeth | NIH MedlinePlus the Magazine

    MedlinePlus

    ... please turn Javascript on. Feature: Fighting Gum Disease Take Care of Your Teeth Past Issues / Fall 2010 Table ... or gets worse depends on how well you take care of your teeth and gums every day, from ...

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

    MedlinePlus

    ... Conditions SHORT syndrome short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething delay Enable Javascript to ... Close All Description Short stature, hyperextensibility, hernia, ocular depression, Rieger anomaly, and teething delay , commonly known by ...

  10. Mounting ground sections of teeth: Cyanoacrylate adhesive versus Canada balsam

    PubMed Central

    Vangala, Manogna RL; Rudraraju, Amrutha; Subramanyam, RV

    2016-01-01

    Introduction: Hard tissues can be studied by either decalcification or by preparing ground sections. Various mounting media have been tried and used for ground sections of teeth. However, there are very few studies on the use of cyanoacrylate adhesive as a mounting medium. Aims: The aim of our study was to evaluate the efficacy of cyanoacrylate adhesive (Fevikwik™) as a mounting medium for ground sections of teeth and to compare these ground sections with those mounted with Canada balsam. Materials and Methods: Ground sections were prepared from twenty extracted teeth. Each section was divided into two halves and mounted on one slide, one with cyanoacrylate adhesive (Fevikwik™) and the other with Canada balsam. Scoring for various features in the ground sections was done by two independent observers. Statistical Analysis Used: Statistical analysis using Student's t-test (unpaired) of average scores was performed for each feature observed. Results: No statistically significant difference was found between the two for most of the features. However, cyanoacrylate was found to be better than Canada balsam for observing striae of Retzius (P < 0.0205), enamel lamellae (P < 0.036), dentinal tubules (P < 0.0057), interglobular dentin (P < 0.0001), sclerotic dentin – transmitted light (P < 0.00001), sclerotic dentin – polarized light (P < 0.0002) and Sharpey's fibers (P < 0.0004). Conclusions: This initial study shows that cyanoacrylate is better than Canada balsam for observing certain features of ground sections of teeth. However, it remains to be seen whether it will be useful for studying undecalcified sections of carious teeth and for soft tissue sections. PMID:27194857

  11. 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

  12. 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

  13. Partial Pulpotomy of Immature Teeth with Apical Periodontitis using Bioceramics and Mineral Trioxide Aggregate: A Report of Three Cases.

    PubMed

    Jiang, Shan; Wu, Hao; Zhang, Cheng Fei

    2016-06-01

    Pulpal necrosis of an immature permanent tooth with an open apex poses a challenge for the clinician. The conventional apexification technique using calcium hydroxide has yielded short-term success, but this technique has inevitable shortcomings. Hence, this case series aimed to evaluate the effectiveness of using bioceramics (iRoot BP) or mineral trioxide aggregate (MTA) for partial pulpotomies. Three boys aged 9 to 11 years old presented with partial pulp necrosis and symptomatic apical periodontitis of the mandibular right and left second premolar. The involved teeth were treated with a partial pulpotomy using either iRoot BP (case 1 and 2) or MTA (case 3). At the 8-month follow-up, no abnormal clinical signs or symptoms were observed. Periapical radiographs revealed a significant reduction in periapical radiolucency, a marked increase in the root canal wall thickness and ongoing closure of the apical opening. The bioceramic material (iRoot BP) and MTA both produced successful outcomes in the partial pulpotomy of immature teeth with partial pulp necrosis and apical periodontitis. However, iRoot BP was superior in terms of ease of clinical application, and would therefore be a better treatment alternative than MTA. PMID:27379350

  14. 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

  15. Correlated physiochemical and age changes in embryonic bovine enamel.

    PubMed

    Landis, W J; Navarro, M

    1983-01-01

    Whole enamel scrapings from unerupted teeth of embryonic calves have been separated into fractions of varying density by stepwise centrifugation in bromoform-toluene mixtures of increasing specific gravity. Partition of enamel in this manner yields individual fractions of increasing mineral phase age and maturation. Whole scrapings and isolated fractions of the fetal bovine enamel were examined by X-ray powder diffraction, scanning electron microscopy, and atomic absorption and infrared spectroscopy to determine time-related changes in the physiochemical nature of the constituent mineral phase particles. These analyses showed poorly crystalline hydroxyapatite (HA) as the only detectable solid phase of calcium phosphate present in all fractions, its degree of crystallinity increasing with increasing density. Molar Ca/P ratios and magnesium content were highest in lowest density fractions. Carbonate vibration bands at 875 and 1420-1450 cm-1, common to mineralized tissue, were observed in intermediate and higher density fractions and in whole unfractionated enamel. Another carbonate band at approximately 705 cm-1, unusual to vertebrate calcified tissue, was detected in low density fractions and disappeared rapidly with increasing enamel maturation. Its precise relation with the enamel mineral phase has not been determined. PMID:6839190

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

    PubMed Central

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

    2007-01-01

    Background and aims It is critical to have a proper knowledge of the normal anatomy of the pulp and its variations for the success of endodontic treatment. The purpose of this study was to investigate variations in the root canal system of maxillary first permanent molars in an Iranian population. Materials and methods In this study, 137 maxillary first molars were decalcified, dye-injected, cleared and studied. Results The results demonstrated that 37.96% of the maxillary first molars under study had three canals, 58.4% had four canals and 3.64% had five canals. Conclusion According to the results of this study and considering variations in the root canal systems of maxillary first molars, it seems that great care should be taken in the root canal treatment of these teeth. PMID:23277826

  17. Clinical decision-making for coronal caries management in the permanent dentition.

    PubMed

    Anusavice, K

    2001-10-01

    Optimal conservative treatment decisions to prevent, arrest, and reverse tooth demineralization caused by caries require probability estimates on caries risk and treatment outcomes. This review is focused on the use of the best scientific evidence to recommend treatment strategies for management of coronal caries in permanent teeth as a function of caries risk. Evidence suggests that assigning therapeutic regimens to individuals according to their risk levels should yield a significantly greater probability of success and better cost effectiveness than applying identical treatments to all patients independent of risk. Depending on caries risk levels, treatment decisions based on risk can minimize unnecessary surgical intervention by incorporating the best evidence to prescribe treatment regimens for the use of fluoride-releasing agents, sealants, chlorhexidine, or combinations of these products. PMID:11699991

  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. Serum susceptibility of bovine pasteurellas.

    PubMed Central

    Blau, K A; Ward, A C; Prieur, D J; Corbeil, L B

    1987-01-01

    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

  20. 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.