Evaluation of Vinegar as a Disinfectant for Extracted Human Teeth - An in-Vitro Study.

Science.gov (United States)

Gogineni, Sindhuja; Ganipineni, Kiranmai; Babburi, Suresh; Venigalla, Aparna; Pinnisetti, Soujanya; Kotti, Ajay Benarji; Kalapala, Lavanya

2016-07-01

In dentistry, extracted human teeth are routinely used to learn technical and preclinical skills. Since human teeth harbour many pathogens these should be disinfected before use to minimize the risk of infections. Some commonly used disinfectants in laboratories are 10% formalin, 3% hydrogen peroxide (H2O2), 5.25% Sodium Hypochlorite (NaOCl), 70% alcohol and normal saline which have their own disadvantages like carcinogenicity, toxicity, cost effectiveness etc. Many studies have been conducted using these solutions but there is no evidence to suggest a suitable alternative for disinfecting extracted teeth. Vinegar is a sour liquid comprised mainly of acetic acid. It is cheap and commercially available shown to be effective in the prevention and control of microbial contamination. The present study was conducted for evaluation of vinegar as a disinfectant for extracted teeth. In this study a total of 40 (n=40) extracted non carious teeth were taken which were disinfected with various physical methods such as sterilization, autoclaving and chemical methods by using Vinegar, 70% Alcohol, 10% Formalin, 3% Hydrogen peroxide and 5.25% NaOCL. Later, teeth from each group were placed individually in separate test tubes containing 10ml of brain heart infusion broth at 37°C for 48 hrs to observe the evidence of growth of microorganisms. Results were analyzed using Kruskal-Wallis test. Vinegar, 10% Formalin and 3% Hydrogen peroxide were effective. The results were statistically significant with Kruskal-Wallis test value 28.053 and p-value was <0.001. Vinegar can be used as an effective disinfectant for extracted human teeth.

Determination of Radionuclide Concentration in Human Teeth in Najaf Governorate, Iraq

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Basim Almayahi

2017-12-01

Full Text Available Introduction: 238U decays with alpha particles emission into 234Th and the series ends with 206Pb. The unstable nucleus loses the energy with emitting ionizing alpha particles for reaching a stable state. It is undergoing alpha decay with decay energy (4.679 MeV. Alpha particles enter the human and animal bodies through inhalation of air or ingestion of contaminated food and water. This study aimed to perform a radiological analysis on the natural alpha particle emission rates of the human teeth as the biomarkers of radiation exposure and environmental pollution. Materials and Methods: This study was conducted on 68 teeth samples of 27 males and 41 females collected from the hospitals distributed across Najaf governorate, including many districts in Iraq. Alpha particle emission rates were measured using CR-39 nuclear track detector. Results: The mean emission rate of alpha particles in the female teeth was 0.0396±0.0070 mBq cm-2, which was relatively higher than that in the male teeth (0.0390±0.0048 mBq cm-2. Nevertheless, there was no significant difference between the female and male teeth regarding the emission rate of alpha particles. Furthermore, the emission rate of alpha particles in the teeth of the samples taken from Kufa (0.0417±0.0057 mBq cm-2 was higher than those obtained from Najaf (0.0384±0.0053 mBq cm-2. Conclusion: As the findings of this study revealed, Najaf governorate had a lower emission rate of alpha particles as compared to other sites of the worldwide. Therefore, it could be concluded that there is no negative consequence threatening the people’s health in this regard.

Atmospheric nuclear weapons test history narrated by carbon-14 in human teeth

International Nuclear Information System (INIS)

Nishizawa, Kunihide; Nagatsu, Toshiharu; Togari, Akifumi; Matsumoto, Shosei

1991-01-01

The atmospheric testing of nuclear weapons since 1945 caused a significant increase in the concentration of atmospheric 14 C. The 14 C concentration in plants that assimilate 14 C directly by photosynthesis reflects the atmospheric 14 C concentration. Carbon-14 is then transferred into the human body through the food chain. Based on animal experiments, the collagen in human teeth is metabolically inert after its formation. This implies that the collagen of each tooth retains the 14 C concentration which reflects the 14 C concentration in the blood at the time collagen metabolism ceased. The distribution of the 14 C concentration in the collagen of teeth from subjects of various ages would follow a pattern similar to that shown by soft tissues. In this paper the authors elucidate the relationship between the number of nuclear weapon tests and the distribution of 14 C concentration in teeth

Ancient pathogen DNA in human teeth and petrous bones

DEFF Research Database (Denmark)

Margaryan, Ashot; Hansen, Henrik B.; Rasmussen, Simon

2018-01-01

Recent ancient DNA (aDNA) studies of human pathogens have provided invaluable insights into their evolutionary history and prevalence in space and time. Most of these studies were based on DNA extracted from teeth or postcranial bones. In contrast, no pathogen DNA has been reported from the petro...

Sorption of zinc on human teeth

International Nuclear Information System (INIS)

Helal, A.; Amin, H.; Alian, G.

1997-01-01

Zinc containing dental amalgams are sometimes used as fillings by dentists. The freshly mixed mass of the amalgam alloy and liquid mercury packed or condensed into a prepared tooth cavity. Zinc has been included in amalgams alloys up to 2% as an aid in manufacturing by helping to produce clean sound castings of the ingots. Although such restorations have a relatively long service life, they are subject to corrosion and galvanic action, thus releasing metallic products into the oral environment. The aim of this paper is to investigate the uptake (sorption) of Zinc ionic species on human teeth using the radioactive tracer technique. For this purpose the isotope Zn-65 produced from pile-irradiation of zinc metal was used. The various liquids studied were drinking water (tap water), tea, coffee, red tea and chicken soup. Sorption was studied through immersion of a single human tooth (extracted) in each of these liquids

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

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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.

Measurement of Ca, Zn and Sr in enamel of human teeth by XRF

Energy Technology Data Exchange (ETDEWEB)

Wielopolski, L.; Featherstone, J.D.B.; Cohn, S.H.

1984-01-01

Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures.

Measurement of Ca, Zn and Sr in enamel of human teeth by XRF

International Nuclear Information System (INIS)

Wielopolski, L.; Featherstone, J.D.B.; Cohn, S.H.

1984-01-01

Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures

Measurement of Ca, Zn, and Sr in enamel of human teeth by XRF

International Nuclear Information System (INIS)

Wielopolski, L.; Featherstone, J.D.b.; Cohn, S.H.

1984-01-01

Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures

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

Science.gov (United States)

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.

Regional early development and eruption of permanent teeth: case report.

Science.gov (United States)

Al Mullahi, A M; Bakathir, A; Al Jahdhami, S

2017-02-01

Early development and eruption of permanent teeth are rarely reported in scientific literature. Early eruption of permanent teeth has been reported to occur due to local factors such as trauma or dental abscesses in primary teeth, and in systemic conditions. Congenital diffuse infiltrating facial lipomatosis (CDIFL) is a rare condition that belongs to a group of lipomatosis tumours. In this disorder, the mature adipocytes invade adjacent soft and hard tissues in the facial region. Accelerated tooth eruption is one of the dental anomalies associated with CDIFL. A 3-year-old boy presented with a swelling of the lower lip localised early development and eruption of permanent teeth and dental caries involving many primary teeth. The planned treatment included biopsy of the swollen lower lip to confirm the diagnosis, surgical reduction and reconstruction of lip aesthetics. The management of the carious primary teeth included preventative and comprehensive dental care and extractions. These procedures were completed under general anaesthesia due to the child's young age and poor cooperation. The lip biopsy showed features of CDIFL such as the presence of infiltrating adipose tissue, prominent number of nerve bundles and thickened vessels. The high recurrence rate of CDIFL mandates long-term monitoring during the facial growth period of the child. Follow-up care by the paediatric dentist and maxillofacial surgeon has been required to manage all aspects of this congenital malformation. This rare disorder has many implications affecting child's facial aesthetics, psychological well being, developing occlusion and risk of dental caries. A multi-disciplinary approach is needed for management of this condition.

Application of PIGE to determine fluorine concentration in human teeth. Contribution to fluorosis study

International Nuclear Information System (INIS)

Salah, H.; Arab, N.

2007-01-01

Fluorosis, osteoselerosis, and systemic illness may result when tolerance levels of fluorine intake are exceeded. To avoid these abnormalities, we shall be aware of the mechanisms of their development. For this, quantitative results gathered from different parts of the world are necessary. In this paper, PIGE method is used to determine fluorine concentration in human teeth, collected from different regions of the Algerian Sahara. Both enamel and dentine regions were inspected. The external and internal mappings of the analyzed teeth have shown more variation in the localized fluorine concentration in dentine than in enamel, and the lowest level of fluorine concentration was observed in the frontier crown-root zone. The obtained results reveal relatively high fluorine concentration lying within the limit of fluorosis, according to the standardised grading dental fluorosis. (author)

Precise chronology of differentiation of developing human primary dentition.

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Hu, Xuefeng; Xu, Shan; Lin, Chensheng; Zhang, Lishan; Chen, YiPing; Zhang, Yanding

2014-02-01

While correlation of developmental stage with embryonic age of the human primary dentition has been well documented, the available information regarding the differentiation timing of the primary teeth was largely based on the observation of initial mineralization and varies significantly. In this study, we aimed to document precise differentiation timing of the developing human primary dentition. We systematically examined the expression of odontogenic differentiation markers along with the formation of mineralized tissue in each developing maxillary and mandibular teeth from human embryos with well-defined embryonic age. We show that, despite that all primary teeth initiate development at the same time, odontogenic differentiation begins in the maxillary incisors at the 15th week and in the mandibular incisors at the 16th week of gestation, followed by the canine, the first primary premolar, and the second primary premolar at a week interval sequentially. Despite that the mandibular primary incisors erupt earlier than the maxillary incisors, this distal to proximal sequential differentiation of the human primary dentition coincides in general with the sequence of tooth eruption. Our results provide an accurate chronology of odontogenic differentiation of the developing human primary dentition, which could be used as reference for future studies of human tooth development.

Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS.

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Bello, Liciane Toledo; da Ana, Patricia Aparecida; Santos, Dário; Krug, Francisco José; Zezell, Denise Maria; Vieira, Nilson Dias; Samad, Ricardo Elgul

2017-04-01

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 µm.

Development and validation of a gas chromatography-mass spectrometry assay for opiates and cocaine in human teeth.

Science.gov (United States)

Pellegrini, Manuela; Casá, Adriana; Marchei, Emilia; Pacifici, Roberta; Mayné, Ruth; Barbero, Vanessa; Garcia-Algar, Oscar; Pichini, Simona

2006-02-24

A procedure based on gas chromatography-mass spectrometry (GC-MS) is described for determination of opiates (6-monoacetylmorphine, morphine and codeine) and cocaine and metabolites (cocaine, benzoylecgonine and cocaethylene) in human teeth. After addition of nalorphine as internal standard, pulverized samples were incubated in HCl at 37 degrees C for 18 h. Then, after pH adjustment to 6, and the analytes were extracted with two volumes of 3 ml of chloroform/isopropanol (9:1). Chromatography was performed on a fused silica capillary column and analytes were determined in the selected-ion-monitoring (SIM) mode. The assay was validated in the range 7.5 (6.0 in case of codeine) to 500 ng/g with mean absolute recoveries ranged between 74.1 and 92.1% for the different analytes and precision and accuracy always better than 15%. The method was applied to the analysis of teeth from drug-addicts to assess past chronic consumption and verify self-reported declarations. In case of opiates, concentration range was 36.5-570.0 ng/g for 6-monoacetylmorphine, 8.7-154.8 ng/g for morphine and 7.9-127.9 ng/g for codeine. Cocaine concentration ranged between 5.6 and 57.2 ng/g with its principal metabolite benzoylecgonine varying from 12.6 to 81.7 ng/g and cocaethylene present in only one sample at 10 ng/g value. Teeth can be a promising non-invasive biological matrix in biomedical analysis for both clinical and forensic purposes.

Allogeneic stem cells derived from human exfoliated deciduous teeth (SHED for the management of periapical lesions in permanent teeth: Two case reports of a novel biologic alternative treatment

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Madu Ghana Shyam Prasad

2017-06-01

Full Text Available Stem cells are the pluripotent cells that have the capacity to differentiate into other specialized cells. Recently, many experiments have been conducted to study the potentiality of stem cells in the tissue regeneration. We report two cases treated utilizing stem cells from human exfoliated deciduous teeth (SHED in the management of periapical lesions in permanent teeth. Two normal human deciduous teeth from children, 7‒8 years of age, were collected to isolate stem cells. Two patients, one with periapical pathology alone and the other with periapical lesion along with an open apex in young permanent teeth, were selected for the study. After initial debridement of the root canals, homing of SHED was carried out and the access cavity was sealed using glass-ionomer cement. Clinical examination after 7 days, 30 days, 90 days, 180 days and 365 days revealed no symptoms. Closure of open apex and periapical tissue healing were observed radiographically at one-month review and maintained until 365-day review. Positive response to electric pulp testing was recorded for the treated teeth from the 3- to 12-month follow-ups. The treated cases demonstrated complete resolution of periapical radiolucency in a span of 30 days, which was faster than the conventional methods. SHED could be considred effective in treating the periapical lesions and open apex in permanent teeth.

A novel mutation of adenomatous polyposis coli (APC) gene results in the formation of supernumerary teeth.

Science.gov (United States)

Yu, Fang; Cai, Wenping; Jiang, Beizhan; Xu, Laijun; Liu, Shangfeng; Zhao, Shouliang

2018-01-01

Supernumerary teeth are teeth that are present in addition to normal teeth. Although several hypotheses and some molecular signalling pathways explain the formation of supernumerary teeth, but their exact disease pathogenesis is unknown. To study the molecular mechanisms of supernumerary tooth-related syndrome (Gardner syndrome), a deeper understanding of the aetiology of supernumerary teeth and the associated syndrome is needed, with the goal of inhibiting disease inheritance via prenatal diagnosis. We recruited a Chinese family with Gardner syndrome. Haematoxylin and eosin staining of supernumerary teeth and colonic polyp lesion biopsies revealed that these patients exhibited significant pathological characteristics. APC gene mutations were detected by PCR and direct sequencing. We revealed the pathological pathway involved in human supernumerary tooth development and the mouse tooth germ development expression profile by RNA sequencing (RNA-seq). Sequencing analysis revealed that an APC gene mutation in exon 15, namely 4292-4293-Del GA, caused Gardner syndrome in this family. This mutation not only initiated the various manifestations typical of Gardner syndrome but also resulted in odontoma and supernumerary teeth in this case. Furthermore, RNA-seq analysis of human supernumerary teeth suggests that the APC gene is the key gene involved in the development of supernumerary teeth in humans. The mouse tooth germ development expression profile shows that the APC gene plays an important role in tooth germ development. We identified a new mutation in the APC gene that results in supernumerary teeth in association with Gardner syndrome. This information may shed light on the molecular pathogenesis of supernumerary teeth. Gene-based diagnosis and gene therapy for supernumerary teeth may become available in the future, and our study provides a high-resolution reference for treating other syndromes associated with supernumerary teeth. © 2017 The Authors. Journal of

Structure and microstructure of coronary dentin in non-erupted human deciduous incisor teeth

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Costa Luciane R.R S.

2002-01-01

Full Text Available The dentin structure of non-erupted human deciduous mandibular and maxillary central and lateral incisor teeth was studied employing light and scanning electron microscopy. For light microscopy, nitric-acid-demineralized and ground sections were used. The sections were stained by hematoxylin-eosin, picrosirius and azo-carmim methods, and ground specimens were prepared using a carborundum disk mounted in a handpiece. For SEM study, teeth were frozen in liquid nitrogen and fractured at longitudinal and transversal directions. Structurally, demineralization and ground methods revealed tubules with primary and secondary curvatures, canaliculi, giant tubules, interglobular dentin, predentin, and intertubular dentin. Scanning electron microscopy showed three-dimensional aspects of dentinal tubules, canaliculi, peritubular dentin, intertubular dentin, and predentin. This study contributes to knowledge about dentin morphology showing characteristics of teeth not yet submitted to mastication stress.

Atmospheric nuclear weapon test history as characterized by the deposition of 14C in human teeth

International Nuclear Information System (INIS)

Nishizawa, K.; Togari, A.; Matsumoto, S.; Nagatsu, T.

1990-01-01

The 14 C concentration in the collagen of human teeth was retrospectively investigated to determine whether its incorporation was related to atmospheric testing of nuclear weapons. Teeth were extracted for dental therapy from July 1987 to February 1988 from patients who were residents in Japan. Tooth collagen was extracted with HCl and converted to amorphous C by heating in a vacuum line. Specimens for 14 C analysis were prepared by mixing the amorphous C with silver powder. The 14 C concentration was measured by mass spectrometer. The 14 C concentration in tooth collagen rapidly increased in 1961 after the bomb tests, peaked around 1967-1968, and then gradually decreased. The collagen of human teeth maintains the 14 C concentration at the age of root completion for life. The results of this study indicate that the history of environmental contamination from atmospheric nuclear weapon's tests has been characterized by deposition of 14 C in the tooth collagen 14 C of human beings

Wisdom Teeth Management

Science.gov (United States)

Wisdom Teeth Management Wisdom teeth, or third molars, are the last teeth to develop and appear in your mouth. They come ... of third molars, disease status, and to suggest management options ranging from removal to a monitored retention ...

Minor and trace elements in human bones and teeth

Energy Technology Data Exchange (ETDEWEB)

Iyengar, G V; Tandon, L

1999-07-01

Chemical elements play a great role in the metabolism of bones and teeth. Some elements are beneficial (F at non toxic concentrations in bones and teeth, supplementation of Cu, Mn and Zn along with Ca to delay or prevent the onset of osteoporosis) and some others (chronic exposure to Pb even at moderate concentrations, and excessive exposures to F as in fluorosis situations) are detrimental for the normal functioning of the skeleton. Knowledge on the roles played by both groups of elements can be enhanced if reliable compositional picture is available for scrutiny. The present survey was undertaken to assess the literature status on chemical composition of bones and teeth, and revealed that much needs to be done in order to have tangible collection of meaningful data. In this context, there is a desperate need for harmonization (types of samples chosen, procedures adopted to process the specimens, and finally the determination of analytes) to generate comparable data. To begin with, it is necessary to develop a bioanalytical protocol that exemplifies the merits and demerits of analyzing bones and teeth. Identification of any particular type of bone as a representative sample for the whole skeleton appears to be a far cry. Even if such a representative segment of a particular bone is identified, the logistics related to medico-legal (autopsy) and anatomical (biopsy) parameters will prevail as decisive factors. For the sake of gaining a comprehensive insight into the distribution of various trace elements in different types of bones, it is necessary to carry out controlled investigations on different types of bones (and cortical and trabecular segments from the same sources) from the same cadaver under well defined sampling conditions. On the analytical side, development of hard tissue RMs for whole bone, as well as for cortical, trabecular and marrow segments separately, would be very helpful for future investigations. (author)

Minor and trace elements in human bones and teeth

International Nuclear Information System (INIS)

Iyengar, G.V.; Tandon, L.

1999-01-01

Chemical elements play a great role in the metabolism of bones and teeth. Some elements are beneficial (F at non toxic concentrations in bones and teeth, supplementation of Cu, Mn and Zn along with Ca to delay or prevent the onset of osteoporosis) and some others (chronic exposure to Pb even at moderate concentrations, and excessive exposures to F as in fluorosis situations) are detrimental for the normal functioning of the skeleton. Knowledge on the roles played by both groups of elements can be enhanced if reliable compositional picture is available for scrutiny. The present survey was undertaken to assess the literature status on chemical composition of bones and teeth, and revealed that much needs to be done in order to have tangible collection of meaningful data. In this context, there is a desperate need for harmonization (types of samples chosen, procedures adopted to process the specimens, and finally the determination of analytes) to generate comparable data. To begin with, it is necessary to develop a bioanalytical protocol that exemplifies the merits and demerits of analyzing bones and teeth. Identification of any particular type of bone as a representative sample for the whole skeleton appears to be a far cry. Even if such a representative segment of a particular bone is identified, the logistics related to medico-legal (autopsy) and anatomical (biopsy) parameters will prevail as decisive factors. For the sake of gaining a comprehensive insight into the distribution of various trace elements in different types of bones, it is necessary to carry out controlled investigations on different types of bones (and cortical and trabecular segments from the same sources) from the same cadaver under well defined sampling conditions. On the analytical side, development of hard tissue RMs for whole bone, as well as for cortical, trabecular and marrow segments separately, would be very helpful for future investigations. (author)

Characteristics of dental pulp in human upper first premolar teeth based on immunohistochemical and morphometric examinations.

Science.gov (United States)

Tomaszewska, Joanna Maria; Miskowiak, Bogdan; Matthews-Brzozowska, Teresa; Wierzbicki, Piotr

2013-01-01

Teeth extracted for orthodontic reasons are commonly considered as healthy. Therefore, it is possible to examine structure of the dental pulp can be fully recognized and how it is affected by malocclusion. The aim of the study was to evaluate by immunohistochemistry (IHC) and morphometry dental pulp in human upper first premolar teeth extracted for orthodontic reasons. The material comprised 36 teeth of 20 patients in the age range 16-26 years. By the use of IHC markers the presence of immunocompetent cells (CD20, CD45RO, and CD68), blood vessels (CD31) and nerves (PGP9.5) were examined in the pulp. Inflammatory infiltrates and tissue atrophy were observed in 24 and 10 teeth, respectively. Strong positive correlation between the width of the odontoblastic layer, the number of rows of odontoblast nuclei and the increase of MVA (microvessel area) in the pulp of atrophic teeth was found. The cellular infiltrations found in H&E-stained sections were identified by IHC as memory T cells (CD45RO+) and B lymphocytes (CD20+) with macrophages (CD68+) present at the periphery. The CD20 antigen was intensively expressed in 13 teeth, CD45RO in 33 teeth, and CD68 in 20 teeth. Thus, despite the lack of any clinical signs of pulp disease many teeth extracted for orthodontic reasons show focal pulp inflammation and atrophy which probably results from the malocclusion stress accompanying teeth crowding.

Measurement of uranium in human teeth and kidney stones with the fission track technique

International Nuclear Information System (INIS)

Vartanian, R.

1986-01-01

The measurement of uranium in human teeth and in kidney stones was carried out using the fission track activation technique. In this determination 2759 and 2205 absolute counts of tracks for teeth samples and 1689 tracks for kidney stone samples were performed, respectively. The results are as follows: xsub(tooth) (1)=(0.227+-0.006) ppm, xsub(tooth) (2)=(0.143+-0.007) ppm and xsub(kidney)=(0.568+-0.020) ppm. The experimental method is described and the results are discussed. (author)

A Histopathologic Study on Pulp Response to Glass Ionomer Cements in Human Teeth

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M. Ghavamnasiri

2005-12-01

Full Text Available Statement of Problem: Despite the wide range of new dental materials, there is still a need for biomaterials demonstrating high biocompatibility, antimicrobial effects and ideal mechanical properties.Purpose: The aim of this study was to histologically evaluate the pulpal response to a conventional glass ionomer, a resin modified glass ionomer and a calcium hydroxide in human teeth.Materials and Methods: Fifty five deep class V cavities were prepared in premolars of 31 patients and were divided into 3 groups based on application of the following liners:resin modified glass ionomer (Vivaglass Liner, conventional glass ionomer (ChembondSuperior and calcium hydroxide (Dycal. After applying varnish, teeth were filled with amalgam. Each group was further divided into three subgroups according to time intervals of 7, 30 and 60 days. Teeth were then extracted and their crowns were fixed in formalin. Each sample was assessed microscopically for odontoblastic changes,inflammatory cell infiltration, reactionary dentin formation, remaining dentinal thickness and presence of microorganisms. Statistical analysis including Kruskal Wallis and Mann Whitney was carried out for comparison of mean ranks. (P=0.05.Results: In the Vivaglass Liner group, pulpal response was significantly higher on day 7 as compared to days 30 and 60 (P0.05. There was no correlation between pulpal responses with micro-organisms and remaining dentin thickness (P>0.05.Conclusion: According to the results of this study, light-cured glass ionomer as well as the other tested lining materials were determined to be biologically compatible with vital pulps in deep cavities of sound human teeth.

Evaluation of the appreciation of virtual teeth with and without pathology.

Science.gov (United States)

de Boer, I R; Lagerweij, M D; Wesselink, P R; Vervoorn, J M

2015-05-01

Virtual teeth with and without tooth pathology have been developed for use in a virtual learning environment in dental education. The objective of this study was to evaluate the appearance of these virtual teeth for use in dental education and to compare them with contemporary educational models, such as plastic teeth (Frasaco GmbH) and extracted human teeth. Six sets of photographs representing six different teeth were shown to dentists, teachers (dentists) and dental students (bachelor's and master's degree students). Each set consisted of 15 pictures showing five views of the extracted human tooth, the similar virtual tooth and the plastic tooth. The five views represented the mesial, distal, occlusal, buccal and lingual surfaces. The virtual tooth was the same as the extracted tooth (scanned with a cone beam CT, coloured and edited in ColorMapEditor(®) ), and the plastic tooth presented the best possible match to the extracted tooth. The participants were asked to rate the appearance of the virtual teeth (overall and in terms of caries, restoration and colours), whether the virtual or plastic teeth resembled the extracted teeth better and from which teeth they expected to learn the most (extracted, virtual or plastic). Each group of participants found that the virtual teeth resembled the extracted teeth more than they resembled the plastic teeth; 71% of the participants expected to learn more from the virtual teeth than from the plastic teeth. The results show that the appearance of the virtual teeth was considered more realistic than the appearance of the plastic teeth. The expectation was that the learning opportunities of the virtual teeth are better than of the plastic teeth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Standardized method to produce tetracycline-stained human molar teeth in vitro.

Science.gov (United States)

Chan, Daniel C N; Rozier, Gregory Shayne; Steen, Angela; Browning, William D; Mozaffari, Mahmood S

2006-09-01

This study tested the hypothesis that exposure of human molar teeth to tetracycline (TCN) derivatives in vitro results in tooth discoloration resembling the clinical presentation of TCN staining. The effects of exposure of 20 extracted human molar teeth to distilled water, chlortetracycline, doxycycline, or minocycline were compared. The baseline color of each tooth was analyzed with a dental spectrophotometer. The pulp chambers were each filled with a TCN derivative solution and then sealed. The teeth were placed in a centrifuge tube and then centrifuged at 2800 rpm for 20 minutes. Color change was monitored weekly for 7 weeks. Digital images of the surfaces were recorded. For each specimen at every evaluation period, color change from baseline was calculated using Commission Internationale d'Eclairage (CIE) Delta E 2000 (deltae00). There was a significant association between the type of derivative used and deltae00, as well as between the evaluation period and deltae00. There was also a significant association between the interaction term, derivative x evaluation period, and deltae00. Results of the Holm-Sidak post hoc test demonstrated that all 3 TCN derivatives were associated with significantly larger deltae00 than the control group (P < or = .05). All 3 TCN derivative solutions produced significant color changes as time progressed. Different TCN derivatives produced a different L* (lightness), C* (chroma), and H* (hue), with minocycline behaving distinctly differently from chlortetracycline and doxycycline. The model could be used to study the underlying mechanisms of TCN staining as well as many aspects of vital tooth

Immunohistochemical studies of the periodontal membrane in primary teeth

DEFF Research Database (Denmark)

Bille, Marie-Louise Bastholm; Nolting, Dorrit; Kjær, Inger

2009-01-01

Objectives. To describe the periodontal membrane of human primary teeth immunohistochemically, while focusing on the epithelial layer of Malassez, fibers, and peripheral nerves, and to compare the findings with those of a previous study of human permanent teeth. Material and methods. Nineteen human...... could be identical to those in regions with no resorption. Conclusion. In regions without resorption, spatial organization of the periodontal membrane of primary teeth was similar to that of permanent teeth, although the number and distribution of epithelial cells and fibers differed. In regions...

Roentgenographic observation on development and formation of the teeth irradiated by 60Co-gamma ray

International Nuclear Information System (INIS)

Kaneko, Masayuki; Chiba, Hiroshige; Akiyama, Akihiro; Kitamura, Nobuyasu; Iwamoto, Hidemitsu

1978-01-01

On a 4-year-old boy who received radiotherapy for malignant tumor in his right mandibula, development of the teeth of 3rd to the 7th in the upper left side and the 3rd to the 7th in the upper right side was observed for 8 years. In the teeth of the 3rd to the 7th in the upper left side which were in irradiated field, and the teeth, except for the teeth of the 3rd to the 6th in the upper left side which had already completed development before irradiation, showed remarkable abnormalities in the shape of the crown such as atrophy, dwarfishness, and flatness. Also the teeth of the 3rd to the 7th of the upper right side which were not in irradiated field, teeth except for the those of the 3rd to the 6th in the upper right side showed slight abnormality in the shape of the crown and root. In irradiated teeth of the 3rd to the 7th in the upper left side, development and formation of teeth were remarkably interfered so that the teeth were almost rootless. In non-irradiated teeth of the 3rd to the 7th in the upper right side atrophy, dwarfishness, and hypoplasia in width and in diameter too. In irradiated teeth of the 3rd to the 7th in the upper left side, calcification was highly advanced in comparison with that in non-irradiated teeth of the 3rd to the 7th in the upper right side or that in normal upper right side. Also in non-irradiated teeth of the 3rd in the 7th in the upper right side, calcification was slightly advanced compared with that in normal teeth. In irradiated teeth of the 3rd to the 7th in the upper left side, the eruption of the teeth was remarkably facilitated. The irradiated tooth of the 6th in the upper left side fell out early and the other teeth were seen in planted condition on the mandibula. This seemed to be due to the foreign body eliminating mechanism. (Ueda, J.)

Human teeth with periapical pathosis after overinstrumentation and overfilling of the root canals: a scanning electron microscopic study.

Science.gov (United States)

Gutiérrez, J H; Brizuela, C; Villota, E

1999-01-01

The aim of this study was to determine whether overinstrumentation followed by immediate overfilling could be a potential risk in the treatment of infected root canals. Thirty-five human teeth with infected root canals were overinstrumented and overfilled approximately 45 min after their extraction. The experimental teeth were enlarged up to size 40 and the overinstrumentation and overfilling were checked with the aid of a magnifying glass. The specimens were fixed in glutaraldehyde plus sodium cacodylate solution and prepared for scanning electron microscope examination. Bacteria were detected on the flute of the files and mostly at the root apices around the main foramen, remaining firmly attached to resorptive lacunae despite the fact that the apices had undergone great changes, including fracture or zipping. A control group consisting of 10 human teeth root canals containing vital pulps were also overinstrumented and overfilled. No bacteria were detected on the flutes of the files, at the apices or on the extruded master cone overfilling these samples. The high percentage of bacteria adhering to the resorptive lacunae or in the flutes of files used in overinstrumented human teeth with infected root canals carry a potential risk for postoperative pain, clinical discomfort and flare-ups. The hazards observed in these circumstances do not support the one-visit treatment of teeth having acute or chronic periapical abscesses.

Evolutionary aspects of the development of teeth and baleen in the bowhead whale.

Science.gov (United States)

Thewissen, J G M; Hieronymus, Tobin L; George, John C; Suydam, Robert; Stimmelmayr, Raphaela; McBurney, Denise

2017-04-01

In utero, baleen whales initiate the development of several dozens of teeth in upper and lower jaws. These tooth germs reach the bell stage and are sometimes mineralized, but toward the end of prenatal life they are resorbed and no trace remains after birth. Around the time that the germs disappear, the keratinous baleen plates start to form in the upper jaw, and these form the food-collecting mechanism. Baleen whale ancestors had two generations of teeth and never developed baleen, and the prenatal teeth of modern fetuses are usually interpreted as an evolutionary leftover. We investigated the development of teeth and baleen in bowhead whale fetuses using histological and immunohistochemical evidence. We found that upper and lower dentition initially follow similar developmental pathways. As development proceeds, upper and lower tooth germs diverge developmentally. Lower tooth germs differ along the length of the jaw, reminiscent of a heterodont dentition of cetacean ancestors, and lingual processes of the dental lamina represent initiation of tooth bud formation of replacement teeth. Upper tooth germs remain homodont and there is no evidence of a secondary dentition. After these germs disappear, the oral epithelium thickens to form the baleen plates, and the protein FGF-4 displays a signaling pattern reminiscent of baleen plates. In laboratory mammals, FGF-4 is not involved in the formation of hair or palatal rugae, but it is involved in tooth development. This leads us to propose that the signaling cascade that forms teeth in most mammals has been exapted to be involved in baleen plate ontogeny in mysticetes. © 2017 Anatomical Society.

Insights into the processes behind the contamination of degraded human teeth and bone samples with exogenous sources of DNA

DEFF Research Database (Denmark)

Gilbert, M. T. P.; Hansen, Anders J.; Willerslev, E.

2006-01-01

A principal problem facing human DNA studies that use old and degraded remains is contamination from other sources of human DNA. In this study we have attempted to contaminate deliberately bones and teeth sampled from a medieval collection excavated in Trondheim, Norway, in order to investigate......, prior to assaying for the residual presence of the handler's DNA. Surprisingly, although our results suggest that a large proportion of the teeth were contaminated with multiple sources of human DNA prior to our investigation, we were unable to contaminate the samples with further human DNA. One...

Elemental composition of human teeth with emphasis on trace constituents: a review

Energy Technology Data Exchange (ETDEWEB)

Sachs, W H

1978-04-01

Literature covered by the current review is based on a search of Chemical Abstracts, 1917 through 1975. Early studies, pre-dating 1940, are referenced primarily for historical interest. Emphasis is on the micro-constituents of human teeth, those present at concentrations less than a few tenths of a percent by weight. Within this category of data, we have been primarily concerned with the radiochemically stable nuclides. The important relationship between caries and trace elements is covered only insofar as carious teeth exhibit properties with respect to trace element composition that differ from normal teeth. Having made these disclaimers, we note that an attempt has been made to cover the literature exhaustively; although some important results have undoubtedly been overlooked. It is our hope, however, that sufficient material has been included in this review to facilitate further recovery of data by interested individuals. In Chapter 1, analytical techniques that have been employed in this field are briefly presented; discussion centers on problems associated with preparation of specimens for analysis. Chapter 2 is devoted to topical coverage of data on the inorganic composition of teeth. An element-by-element tabulation of concentration data is provided, our statistical analysis of selected data explained, and evidence concerning several major factors thought to influence dental composition evaluated. These include provenance, age, sex, distribution, and tooth type/intermouth variation.

Fracture modes in human teeth.

Science.gov (United States)

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

2009-03-01

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

EPR dosimetry of irradiated human teeth

International Nuclear Information System (INIS)

Rodas Duran, J.E.; Panzeri, H.; Mascarenhas, S.

1985-01-01

The determination of the absorbed radiation dose in man may be made by Electron Paramagnetic Resonance (EPR) spectroscopy of dental enamel. We analysed the EPR signals for dental enamel submitted to gamma radiation in doses between 1 Gy and 25 Gy. We conclude that independent of the type of tooth analysed there exists a linear relation between the EPR signals and the absorbed doses. These studies were extended to enamel irradiated with gamma rays and with X rays in doses between 0.1 Gy and 0.6 Gy. The graph of the intensity of the EPR signals as a function of the dose has a slope of 0.22. This calibration may be used to calculate the absorbed dose for humans from a measurement of the EPR signal from small samples of enamel taken from any permanent tooth. Finally we comment on some EPR studies of effects of radiation of milk teeth. (author)

Fluorine determination in human healthy and carious teeth using the PIGE technique

International Nuclear Information System (INIS)

Carvalho, M.L.; Karydas, A.G.; Casaca, C.; Zarkadas, Ch.; Paradellis, Th.; Kokkoris, M.; Nsouli, B.; Cunha, A.S.

2001-01-01

The purpose of this study is to determine and compare the fluorine concentration in human teeth from two different populations, living in the Portuguese quite isolated islands of Acores: S. Miguel and Terceira. Both populations have similar dietary habits, similar occupational activities, mostly rural, and the age of both populations is more or less the same, around 40 years. No chronic diseases were registered in any of the donors. The two groups are exposed to different levels of fluorine in drinking water. Terceira island has moderate fluorine concentration levels (1-2 μg g -1 ) while S. Miguel island is known for the high fluorine concentration levels in its water (>3 μg g -1 ), especially in one area known as Furnas. Thirty-three teeth, 17 healthy and 16 carious without restoration (14 incisors and canines, 7 premolars and 12 molars), were collected and analyzed for the determination of fluorine concentration in the dentine region, using the nuclear reaction 19 F(p,αγ) 16 O. The teeth were cross-sectioned along the vertical plane and polished, in order to obtain a smooth and plane surface of about 1 mm thickness. In this work an association between caries prevalence and fluorine content of drinking water is discussed and the variation of fluorine concentration among different types of teeth (canines and incisors, premolars, molars) and physical state (carious and non-carious) is examined

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

Science.gov (United States)

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.

Shear bond strength and fracture analysis of human vs. bovine teeth.

Directory of Open Access Journals (Sweden)

Stefan Rüttermann

Full Text Available 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.

Teeth: Among Nature's Most Durable Biocomposites

Science.gov (United States)

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.

Isolation of Mesenchymal Stem Cells from Human Deciduous Teeth Pulp

Directory of Open Access Journals (Sweden)

Aileen I. Tsai

2017-01-01

Full Text Available This study aimed to identify predictors of success rate of mesenchymal stem cell (MSC isolation from human deciduous teeth pulp. A total of 161 deciduous teeth were extracted at the dental clinic of Chang Gung Memorial Hospital. The MSCs were isolated from dental pulps using a standard protocol. In total, 128 colonies of MSCs were obtained and the success rate was 79.5%. Compared to teeth not yielding MSCs successfully, those successfully yielding MSCs were found to have less severe dental caries (no/mild-to-moderate/severe: 63.3/24.2/12.5% versus 12.5/42.4/42.4%, P<0.001 and less frequent pulpitis (no/yes: 95.3/4.7% versus 51.5/48.5%, P<0.001. In a multivariate regression model, it was confirmed that the absence of dental caries (OR = 4.741, 95% CI = 1.564–14.371, P=0.006 and pulpitis (OR = 9.111, 95% CI = 2.921–28.420, P<0.001 was significant determinants of the successful procurement of MSCs. MSCs derived from pulps with pulpitis expressed longer colony doubling time than pulps without pulpitis. Furthermore, there were higher expressions of proinflammatory cytokines, interleukin- (IL- 6 and monocyte chemoattractant protein- (MCP- 1, P<0.01, and innate immune response [toll-like receptor 1 (TLR1 and TLR8, P<0.05; TLR2, TLR3, and TLR6, P<0.01] in the inflamed than noninflamed pulps. Therefore, a carious deciduous tooth or tooth with pulpitis was relatively unsuitable for MSC processing and isolation.

Hidden contributions of the enamel rods on the fracture resistance of human teeth

OpenAIRE

Yahyazadehfar, M.; Bajaj, Devendra; Arola, Dwayne D.

2012-01-01

The enamel of human teeth is generally regarded as a brittle material with low fracture toughness. Consequently, the contributions of this tissue in resisting tooth fracture and the importance of its complex microstructure have been largely overlooked. In this study an experimental evaluation of the crack growth resistance of human enamel was conducted to characterize the role of rod (i.e. prism) orientation and degree of decussation on the fracture behavior of this tissue. Incremental crack ...

[Cryopreservation of teeth].

Science.gov (United States)

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.

In situ analysis of human teeth by external PIXE

Energy Technology Data Exchange (ETDEWEB)

Rautray, Tapash R., E-mail: tapash77@hotmail.co [Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, 2-188-1 Samduk-dong, Jung-gu, Daegu (Korea, Republic of); ARASMIN, G. Udayagiri, Kandhamal, Orissa 762100 (India); Das, Saubhagyalaxmi [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Rautray, Alekh C. [ARASMIN, G. Udayagiri, Kandhamal, Orissa 762100 (India)

2010-07-15

The elemental profiles of the enamel, cementum and caries of human teeth were analysed by the external proton induced X-ray emission studies. Ten elements namely P, Ca, V, Mn, Fe, Cu, Zn, As, Sr and Pb were estimated in the present study. P and Ca were found to be the major elements whereas all other elements were found in trace level. It was observed that the respective concentrations of elements namely P, Ca, Fe, Zn and Pb in enamel are more than those in cementum. Concentration of P ranged between 6.37% and 25% whereas Ca ranged between 12.94% and 43.36%.

Ancient pathogen DNA in human teeth and petrous bones

DEFF Research Database (Denmark)

Margaryan, Ashot; Hansen, Henrik B.; Rasmussen, Simon

2018-01-01

pestis. Based on shotgun sequencing data, four of these five plague victims showed clearly detectable levels of Y.pestis DNA in the teeth, whereas all the petrous bones failed to produce Y.pestis DNA above baseline levels. A broader comparative metagenomic analysis of teeth and petrous bones from 10...

Designing protocols for the human teeth biobank of the Universidad Nacional de Colombia

Directory of Open Access Journals (Sweden)

Lina Constanza Gonzáles-Pita

2014-07-01

Full Text Available Protocols in a Tooth Bank are essential in order to assure smooth operation, reproducibility and standardization that minimize cross contamination, maintain original characteristics and physicochemical properties of teeth, fulll ethical and legal regulations and a proper disposal of residues. Objective: to propose the disinfection, storing and transportation protocols for the UNTB. Methods: A literature search was conducted using the words “teeth, human, tooth bank, disinfection, sterilization, storage, organization, biosecurity, biobank, protocol, prevention” in the Pubmed, Science Direct and Scielo databases. 37 papers ranging from 1988 up to 2014 were selected. International and Colombian ethical and legal regulations for organ donation, handling and investigation were taken into account as well as laboratory observations and chemical basic principles gained through several undergraduate and graduate thesis. All this input was carefully studied, analysed and critically modied for setting the recommended processes for the conversion of donated teeth into organs suitable for research. Results: Collection, transportation, cleaning/disinfection and storing protocols were planned and elaborated. Conclusions: Based on scientic literature, national and international regulations and experimental experience, several protocols for the UNTB were presented.

In vitro investigation of heat transfer phenomenon in human immature teeth.

Science.gov (United States)

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.

The identification of proteoglycans and glycosaminoglycans in archaeological human bones and teeth.

Science.gov (United States)

Coulson-Thomas, Yvette M; Coulson-Thomas, Vivien J; Norton, Andrew L; Gesteira, Tarsis F; Cavalheiro, Renan P; Meneghetti, Maria Cecília Z; Martins, João R; Dixon, Ronald A; Nader, Helena B

2015-01-01

Bone tissue is mineralized dense connective tissue consisting mainly of a mineral component (hydroxyapatite) and an organic matrix comprised of collagens, non-collagenous proteins and proteoglycans (PGs). Extracellular matrix proteins and PGs bind tightly to hydroxyapatite which would protect these molecules from the destructive effects of temperature and chemical agents after death. DNA and proteins have been successfully extracted from archaeological skeletons from which valuable information has been obtained; however, to date neither PGs nor glycosaminoglycan (GAG) chains have been studied in archaeological skeletons. PGs and GAGs play a major role in bone morphogenesis, homeostasis and degenerative bone disease. The ability to isolate and characterize PG and GAG content from archaeological skeletons would unveil valuable paleontological information. We therefore optimized methods for the extraction of both PGs and GAGs from archaeological human skeletons. PGs and GAGs were successfully extracted from both archaeological human bones and teeth, and characterized by their electrophoretic mobility in agarose gel, degradation by specific enzymes and HPLC. The GAG populations isolated were chondroitin sulfate (CS) and hyaluronic acid (HA). In addition, a CSPG was detected. The localization of CS, HA, three small leucine rich PGs (biglycan, decorin and fibromodulin) and glypican was analyzed in archaeological human bone slices. Staining patterns were different for juvenile and adult bones, whilst adolescent bones had a similar staining pattern to adult bones. The finding that significant quantities of PGs and GAGs persist in archaeological bones and teeth opens novel venues for the field of Paleontology.

Radiobiological long-term accumulation of environmental alpha radioactivity in extracted human teeth and animal bones in Malaysia.

Science.gov (United States)

Almayahi, B A; Tajuddin, A A; Jaafar, M S

2014-03-01

In this study, the radiobiological analysis of natural alpha emitters in extracted human teeth and animal bones from Malaysia was estimated. The microdistributions of alpha particles in tooth and bone samples were measured using CR-39 alpha-particle track detectors. The lowest and highest alpha emission rates in teeth in the Kedah and Perak states were 0.0080 ± 0.0005 mBq cm(-2) and 0.061 ± 0.008 mBq cm(-2), whereas those of bones in the Perlis and Kedah states were 0.0140 ± 0.0001 mBq cm(-2) and 0.7700 ± 0.0282 mBq cm(-2), respectively. The average alpha emission rate in male teeth was 0.0209 ± 0.0008 mBq cm(-2), whereas that of female teeth was 0.0199 ± 0.0010 mBq cm(-2). The alpha emission rate in teeth is higher in smokers (0.0228 ± 0.0008 mBq cm(-2)) than in non-smokers (0.0179 ± 0.0008 mBq cm(-2)). Such difference was found statistically significant (p < 0.01). Copyright © 2014 Elsevier Ltd. All rights reserved.

Heavy metals in human teeth dentine: A bio-indicator of metals exposure and environmental pollution.

Science.gov (United States)

Asaduzzaman, Khandoker; Khandaker, Mayeen Uddin; Binti Baharudin, Nurul Atiqah; Amin, Yusoff Bin Mohd; Farook, Mohideen Salihu; Bradley, D A; Mahmoud, Okba

2017-06-01

With rapid urbanization and large-scale industrial activities, modern human populations are being increasingly subjected to chronic environmental heavy metal exposures. Elemental uptake in tooth dentine is a bioindicator, the uptake occurring during the formation and mineralization processes, stored to large extent over periods of many years. The uptake includes essential elements, most typically geogenic dietary sources, as well as non-essential elements arising through environmental insults. In this study, with the help of the Dental Faculty of the University of Malaya, a total of 50 separate human teeth were collected from dental patients of various ethnicity, age, gender, occupation, dietary habit, residency, etc. Analysis was conducted using inductively coupled plasma-mass spectrometry (ICP-MS), most samples indicating the presence of the following trace elements, placed in order of concentration, from least to greatest: As, Mn, Ba, Cu, Cr, Pb, Zn, Hg, Sb, Al, Sr, Sn. The concentrations have been observed to increase with age. Among the ethnic groups, the teeth of ethnic Chinese showed marginally greater metal concentrations than those of the Indians and Malays, the teeth dentine of females generally showing greater concentrations than that of males. Greater concentrations of Hg, Cu and Sn were found in molars while Pb, Sr, Sb and Zn were present in greater concentrations in incisors. With the elevated concentration levels of heavy metals in tooth dentine reflecting pollution from industrial emissions and urbanization, it is evident that human tooth dentine can provide chronological information on exposure, representing a reliable bio-indicator of environmental pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth

Directory of Open Access Journals (Sweden)

Maryam Talebi

2014-12-01

Full Text Available 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 mod-els were used for heat transfer phenomenon in immature teeth. Sensitivity analysis and local tests were included in the mod-el 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 il-lustrated 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 re-quired to determine thermal conductivity of immature teeth.

The length of teeth : A statistical analysis of the differences in length of human teeth for radiologic purposes

NARCIS (Netherlands)

Verhoeven, J.W.; Aken, J. van; Weerdt, G.P. van der

Intraoral radiograms can be made according to the long tube paralleling technique utilizing aiming devices. An important factor in the design of these instruments is the length of the teeth to be radiographed. Reliable data regarding the length of the teeth in the different regions of the mouth are

The identification of proteoglycans and glycosaminoglycans in archaeological human bones and teeth.

Directory of Open Access Journals (Sweden)

Yvette M Coulson-Thomas

Full Text Available Bone tissue is mineralized dense connective tissue consisting mainly of a mineral component (hydroxyapatite and an organic matrix comprised of collagens, non-collagenous proteins and proteoglycans (PGs. Extracellular matrix proteins and PGs bind tightly to hydroxyapatite which would protect these molecules from the destructive effects of temperature and chemical agents after death. DNA and proteins have been successfully extracted from archaeological skeletons from which valuable information has been obtained; however, to date neither PGs nor glycosaminoglycan (GAG chains have been studied in archaeological skeletons. PGs and GAGs play a major role in bone morphogenesis, homeostasis and degenerative bone disease. The ability to isolate and characterize PG and GAG content from archaeological skeletons would unveil valuable paleontological information. We therefore optimized methods for the extraction of both PGs and GAGs from archaeological human skeletons. PGs and GAGs were successfully extracted from both archaeological human bones and teeth, and characterized by their electrophoretic mobility in agarose gel, degradation by specific enzymes and HPLC. The GAG populations isolated were chondroitin sulfate (CS and hyaluronic acid (HA. In addition, a CSPG was detected. The localization of CS, HA, three small leucine rich PGs (biglycan, decorin and fibromodulin and glypican was analyzed in archaeological human bone slices. Staining patterns were different for juvenile and adult bones, whilst adolescent bones had a similar staining pattern to adult bones. The finding that significant quantities of PGs and GAGs persist in archaeological bones and teeth opens novel venues for the field of Paleontology.

Radiobiological long-term accumulation of environmental alpha radioactivity in extracted human teeth and animal bones in Malaysia

International Nuclear Information System (INIS)

Almayahi, B.A.; Tajuddin, A.A.; Jaafar, M.S.

2014-01-01

In this study, the radiobiological analysis of natural alpha emitters in extracted human teeth and animal bones from Malaysia was estimated. The microdistributions of alpha particles in tooth and bone samples were measured using CR-39 alpha-particle track detectors. The lowest and highest alpha emission rates in teeth in the Kedah and Perak states were 0.0080 ± 0.0005 mBq cm −2 and 0.061 ± 0.008 mBq cm −2 , whereas those of bones in the Perlis and Kedah states were 0.0140 ± 0.0001 mBq cm −2 and 0.7700 ± 0.0282 mBq cm −2 , respectively. The average alpha emission rate in male teeth was 0.0209 ± 0.0008 mBq cm −2 , whereas that of female teeth was 0.0199 ± 0.0010 mBq cm −2 . The alpha emission rate in teeth is higher in smokers (0.0228 ± 0.0008 mBq cm −2 ) than in non-smokers (0.0179 ± 0.0008 mBq cm −2 ). Such difference was found statistically significant (p < 0.01). - Highlights: • Alpha emission rates in teeth from smokers slightly higher than non-smokers. • Difference between alpha rates in male and female tooth not statistically significant. • Alpha particles have the same effect at any age. • Difference between alpha rates in bones was statistically significant

Radiographic studies on the development of cheek teeth in donkeys

International Nuclear Information System (INIS)

Misk, N.A.; Seilem, S.M.

1997-01-01

The current study was carried out on 60 head specimens of donkeys in addition to five living animals. Specimens and animal's heads were radiographed. Radiographs were grouped from 1 day up to 15 years of age. Recorded data included the following points: 1) Time of radiographic appearance and different developmental stages of deciduous and permanent cheek teeth. 2) Length of deciduous cheek teeth from birth to shedding. 3) Length of permanent cheek teeth from birth to senility. 4) Body and root length from age 5 up to 15 years of age. 5) Wolf teeth: occurrence, time of eruption and shedding. All results were documented and illustrated in tables and photographs

In Vitro Investigation of Heat Transfer Phenomenon in Human Immature Teeth

OpenAIRE

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

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 ...

Biophysical dose measurement using electron paramagnetic resonance in rodent teeth

International Nuclear Information System (INIS)

Khan, R.F.H.; Rink, W.J.; Boreham, D.R.

2003-01-01

Electron paramagnetic resonance (EPR) dosimetry of human tooth enamel has been widely used in measuring radiation doses in various scenarios. However, there are situations that do not involve a human victim (e.g. tests for suspected environmental overexposures, measurements of doses to experimental animals in radiation biology research, or chronology of archaeological deposits). For such cases we have developed an EPR dosimetry technique making use of enamel of teeth extracted from mice. Tooth enamel from both previously irradiated and unirradiated mice was extracted and cleaned by processing in supersaturated KOH aqueous solution. Teeth from mice with no previous irradiation history exhibited a linear EPR response to the dose in the range from 0.8 to 5.5 Gy. The EPR dose reconstruction for a preliminarily irradiated batch resulted in the radiation dose of (1.4±0.2) Gy, which was in a good agreement with the estimated exposure of the teeth. The sensitivity of the EPR response of mouse enamel to gamma radiation was found to be half of that of human tooth enamel. The dosimetric EPR signal of mouse enamel is stable up at least to 42 days after exposure to radiation. Dose reconstruction was only possible with the enamel extracted from molars and premolars and could not be performed with incisors. Electron micrographs showed structural variations in the incisor enamel, possibly explaining the large interfering signal in the non-molar teeth

Comparison of Vibringe, EndoActivator, and needle irrigation on sealer penetration in extracted human teeth.

Science.gov (United States)

Bolles, Jordan A; He, Jianing; Svoboda, Kathy K H; Schneiderman, Emet; Glickman, Gerald N

2013-05-01

Vibringe is a new device that allows continuous sonic irrigation of the canal system during endodontic treatment. The aim of this study was to compare the effect of different irrigation systems on sealer penetration into dentinal tubules of extracted single-rooted teeth. Fifty single-rooted human teeth were instrumented and randomly divided into 4 groups: group 1 (control), saline; group 2 (conventional irrigation), 17% EDTA followed by 6% NaOCl; group 3 (EndoActivator), same irrigants as group 2; group 4 (Vibringe), same irrigants as group 2. Obturation of all teeth was done with gutta-percha and SimpliSeal labeled with fluorescent dye. Transverse sections at 1 mm and 5 mm from the root apex were examined by using confocal laser scanning microscopy. Percentage and maximum depth of sealer penetration were measured by using NIS-Elements Br 3.0 imaging software. Groups 3 and 4 had a significantly greater percentage of the canal wall penetrated by sealer at the 5-mm level than group 1 (P irrigation. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

An Evo-Devo perspective on ever-growing teeth in mammals and dental stem cell maintenance

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Elodie eRenvoisé

2014-08-01

Full Text Available A major challenge for current evolutionary and developmental biology research is to understand the evolution of morphogenesis and the mechanisms involved. Teeth are well suited for the investigation of developmental processes. In addition, since teeth are composed of hard-mineralized tissues, primarily apatite, that are readily preserved, the evolution of mammals is well documented through their teeth in the fossil record. Hypsodonty, high crowned teeth with shallow roots, and hypselodonty, ever-growing teeth, are convergent innovations that have appeared multiple times since the mammalian radiation 65 million years ago, in all tooth categories (incisors, canines, premolars and molars. A shift to hypsodonty, or hypselodonty, during mammalian evolution is often, but not necessarily, associated with increasingly abrasive diet during important environmental change events. Although the evolution of hypsodonty and hypselodonty is considered to be the result of heterochrony of development, little has been known about the exact developmental mechanisms at the origin of these morphological traits. Developmental biologists have been intrigued by the mechanism of hypselodonty since it requires the maintenance of continuous crown formation during development via stem cell niche activity. Understanding this mechanism may allow bioengineered tooth formation in humans. Hypsodonty and hypselodonty are thus examples of phenotypic features of teeth that have both impacts in understanding the evolution of mammals and holds promise for human tooth bioengineering.

Teeth Caries Decay in MR Imaging

International Nuclear Information System (INIS)

Tanasiewicz, M.M.; Kupka, T.W.; Weglarz, W.P.; Jasinski, A.

2005-01-01

X-ray based visualization techniques were for many years the only way to asses structure and state of the human teeth. MRI has been used in the research of the healthy and decayed teeth during last decade. Several papers were presented showing usefulness of spin echo and gradient echo imaging, Single Point Imaging, SPRITE and STRAFI techniques for visualization of the dental surface geometry as well as for distinction between soft tissue (pulp) and mineralized tissue (enamel, dentine and root cement) in the extracted teeth. Recently, MRI was used for estimation of the facial bone structure, in preparation to implantation, localization of the tumor in the facial bone tissue, and in detection of the osteoporosis. The aim of this work was to investigate potential of MRI for detection and estimation of the caries, on the level of laboratory pre-clinical tests. This work was done within the project to develop original, MRI based diagnostic technique for dentistry needs. MRI experiments were performed on the 5 decayed extracted human teeth (impossible conservative therapy), obtained at Dept. of Dental Surgery MUS. After extraction teeth were stored in saline. MRI measurements were done in MR Tomography Lab INP. Prior to the experiment, tooth was degassed to minimize magnetic susceptibility artifacts. A 3D spin echo pulse sequence on the 4.7 T research MRI system, equipped with Maran DRX console, and dedicated home-built probe head, was used to obtain three dimensional (256x128x128) images of the teeth. Corresponding resolution was 60x120x160 mm 3 . High intensity signal from water penetrated into the porous decayed regions of tooth, contrasted with lack of signal from mineralized tooth tissue, allow for visualization of the presence and extent of caries. Among the 5 measured teeth, MRI allows for detection of the caries in two most decayed tooth. High intensity signal from water penetrated into the porous decayed regions of tooth, contrasted with lack of signal from

Hidden contributions of the enamel rods on the fracture resistance of human teeth.

Science.gov (United States)

Yahyazadehfar, M; Bajaj, Devendra; Arola, Dwayne D

2013-01-01

The enamel of human teeth is generally regarded as a brittle material with low fracture toughness. Consequently, the contributions of this tissue in resisting tooth fracture and the importance of its complex microstructure have been largely overlooked. In this study an experimental evaluation of the crack growth resistance of human enamel was conducted to characterize the role of rod (i.e. prism) orientation and degree of decussation on the fracture behavior of this tissue. Incremental crack growth was achieved in-plane, with the rods in directions longitudinal or transverse to their axes. Results showed that the fracture resistance of enamel is both inhomogeneous and spatially anisotropic. Cracks extending transverse to the rods in the outer enamel undergo a lower rise in toughness with extension, and achieve significantly lower fracture resistance than in the longitudinal direction. Though cracks initiating at the surface of teeth may begin extension towards the dentin-enamel junction, they are deflected by the decussated rods and continue growth about the tooth's periphery, transverse to the rods in the outer enamel. This process facilitates dissipation of fracture energy and averts cracks from extending towards the dentin and vital pulp. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Autoradiographic pattern of the in vitro uptake of proline by the coronal areas of intact and carious human teeth

Energy Technology Data Exchange (ETDEWEB)

Karjalainen, S; Soederling, E [Turku Univ. (Finland)

1979-01-01

The biosynthesis of collagen in teeth was studied by following the uptake of proline in vitro. Whole crowns of human teeth were incubated for 6 h with (/sup 14/C)- or (/sup 3/H)-proline. Autoradiographs were prepared from sections of intact teeth and teeth with carious lesions of varying depths and location. The number of silver grains per cm/sup 2/ in the predentine, odontoblast layer and pulp were counted in selected fields magnified x 430 representing the deepest parts of the carious lesions. No differences in the labelling pattern were observed between the intact teeth incubated freshly after extraction and those preserved in liquid nitrogen. The densest labelling of intact teeth was seen in the predentine and odontoblast layer. The alterations under initial dentine caries appeared as increased labelling of the predentine and decreased labelling of the odontoblast layer; no alterations were observed in the underlying pulp. In advanced lesions, the predentine labelling decreased and that in the odontoblast layer and pulp increased. In the initial stages, caries seem to activate collagen synthesis in a relatively restricted area of the underlying structures, but in advanced stages, caries seem to increase the odontoblastic cellular polypeptide chain formation but prevent further maturation of the collagen.

About Kids' Teeth

Science.gov (United States)

... wear a mouthguard when playing sports like basketball, soccer, football and hockey. 17 – 21 Years Old The last teeth to appear are wisdom teeth at around ages 17 – 21. By age 21, all 32 of the adult teeth have usually appeared. Learn about Nutrition Baby Teething Baby Teeth and Teething Baby teeth ...

Strontium-90 concentrations in human teeth in South Ukraine, 5 years after the Chernobyl accident

International Nuclear Information System (INIS)

Kulev, Y.D.; Polikarpov, G.G.; Prigodey, E.V.; Assimakopoulos, P.A.

1994-01-01

Approximately 1000 human teeth, collected in South Ukraine, in 1990-1991, were measured for 90 Sr concentration. The teeth were grouped into 18 samples according to the age and sex of the donors. Measured levels of 90 Sr concentrations were lower by a factor of 10 than measurements taken in the mid-1960s and mid-1970s. An interesting feature of the data is a 3-fold enhancement of contamination levels in the 25-45 year-old age group of the male population. A possible explanation for this anomaly is that this age group contains a significant number of men who were mobilized immediately after the Chernobyl accident for clean-up operations within the 30-km zone around the damaged nuclear power plant

Distinctive genetic activity pattern of the human dental pulp between deciduous and permanent teeth.

Directory of Open Access Journals (Sweden)

Ji-Hee Kim

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

Distinctive genetic activity pattern of the human dental pulp between deciduous and permanent teeth.

Science.gov (United States)

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

2014-01-01

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

Supernumerary teeth in non-syndromic patients

International Nuclear Information System (INIS)

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

2012-01-01

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

90Sr specific activity of teeth of abandoned cattle after the Fukushima accident - teeth as an indicator of environmental pollution.

Science.gov (United States)

Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Urushihara, Yusuke; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

2018-03-01

90 Sr specific activity in the teeth of young cattle that were abandoned in Kawauchi village and Okuma town located in the former evacuation areas of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident were measured. Additionally, specific activity in contaminated surface soils sampled from the same area was measured. (1) All cattle teeth examined were contaminated with 90 Sr. The specific activity, however, varied depending on the developmental stage of the teeth during the FNPP accident; teeth that had started development before the accident exhibited comparatively lower values, while teeth developed mainly after the accident showed higher values. (2) Values of 90 Sr-specific activity in teeth formed after the FNPP accident were higher than those of the bulk soil but similar to those in the exchangeable fraction (water and CH 3 COONH 4 soluble fractions) of the soil. The findings suggest that 90 Sr was incorporated into the teeth during the process of development, and that 90 Sr in the soluble and/or leachable fractions of the soil might migrate into teeth and contribute to the amount of 90 Sr in the teeth. Thus, the concentration of 90 Sr in teeth formed after the FNPP accident might reflect the extent of 90 Sr pollution in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supernumerary teeth in non-syndromic patients

Energy Technology Data Exchange (ETDEWEB)

Mali, Santosh; Karjodkar, Freny Rashmiraj; Sontakke, Subodh; Sansare, Kaustubh [Nair Hospital Dental College, Maharashtra (India)

2012-03-15

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

In vitro evaluation of fluoride products in the development of carious lesions in deciduous teeth.

Science.gov (United States)

Santos, Lucineide de Melo; Reis, José Ivo Limeira dos; Medeiros, Maria Perolina de; Ramos, Sheyla Moreira; Araújo, Juliane Mendes de

2009-01-01

The purpose of this study was to evaluate the effect of the application of fluoride products on the development of enamel caries in deciduous teeth. A total of 108 deciduous teeth were chosen for the study. Acid-resistant varnish was applied on the teeth, leaving only one area of 5 mm x 1 mm of dental enamel exposed. The teeth were allocated randomly to one of the following groups: 1) control - toothpaste without fluoride; 2) 1.23% fluoride gel; 3) Duraflur fluoride varnish; 4) Duraphat fluoride varnish; 5) Fluorniz fluoride varnish; 6) Fluorphat fluoride varnish; 7) varnish with Duofluorid; 8) 12% silver fluoride diamine (Cariestop); 9) children's fluoride toothpaste (500 ppm). The tested products were applied on the teeth according to the manufacturer's recommendations and the teeth were stored in a moist environment for 24 hours. Each group of teeth was then subjected to a pH cycling model for 14 days, after which the teeth were cut through the center for an analysis of the depth of the carious lesion by polarized light microscopy. Comparisons were made between the treatments and the control group. The mean lesion depth values were 318 microm +/- 39 (control), 213 microm +/- 27 (fluoride gel), 203 microm +/- 34 (Duraflur), 133 microm +/- 25 (Duraphat), 207 microm +/- 27 (Fluor-niz), 212 microm +/- 27 (Fluorphat), 210 +/- 28 (Duofluorid), 146 +/- 31 (Cariestop) and 228 +/- 24 (fluoride toothpaste). None of the products used here was able to completely prevent the formation of lesions. The highest cariostatic effect was achieved by fluoride varnish Duraphat and the lowest by the fluoride toothpaste.

The autoradiographic pattern of the in vitro uptake of proline by the coronal areas of intact and carious human teeth

International Nuclear Information System (INIS)

Karjalainen, S.; Soederling, E.

1979-01-01

The biosynthesis of collagen in teeth was studied by following the uptake of proline in vitro. Whole crowns of human teeth were incubated for 6 h with ( 14 C)- or ( 3 H)-proline. Autoradiographs were prepared from sections of intact teeth and teeth with carious lesions of varying depths and location. The number of silver grains per cm 2 in the predentine, odontoblast layer and pulp were counted in selected fields magnified x 430 representing the deepest parts of the carious lesions. No differences in the labelling pattern were observed between the intact teeth incubated freshly after extraction and those preserved in liquid nitrogen. The densest labelling of intact teeth was seen in the predentine and odontoblast layer. The alterations under initial dentine caries appeared as increased labelling of the predentine and decreased labelling of the odontoblast layer; no alterations were observed in the underlying pulp. In advanced lesions, the predentine labelling decreased and that in the odontoblast layer and pulp increased. In the initial stages, caries seem to activate collagen synthesis in a relatively restricted area of the underlying structures, but in advanced stages, caries seem to increase the odontoblastic cellular polypeptide chain formation but prevent further maturation of the collagen. (author)

Concrescent triplets involving primary anterior teeth

Directory of Open Access Journals (Sweden)

Urvashi Sharma

2013-01-01

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

In vitro evaluation of fluoride products in the development of carious lesions in deciduous teeth

Directory of Open Access Journals (Sweden)

Lucineide de Melo Santos

2009-09-01

Full Text Available The purpose of this study was to evaluate the effect of the application of fluoride products on the development of enamel caries in deciduous teeth. A total of 108 deciduous teeth were chosen for the study. Acid-resistant varnish was applied on the teeth, leaving only one area of 5 mm x 1 mm of dental enamel exposed. The teeth were allocated randomly to one of the following groups: 1 control - toothpaste without fluoride; 2 1.23% fluoride gel; 3 Duraflur fluoride varnish; 4 Duraphat fluoride varnish; 5 Fluorniz fluoride varnish; 6 Fluorphat fluoride varnish; 7 varnish with Duofluorid; 8 12% silver fluoride diamine (Cariestop; 9 children's fluoride toothpaste (500 ppm. The tested products were applied on the teeth according to the manufacturer's recommendations and the teeth were stored in a moist environment for 24 hours. Each group of teeth was then subjected to a pH cycling model for 14 days, after which the teeth were cut through the center for an analysis of the depth of the carious lesion by polarized light microscopy. Comparisons were made between the treatments and the control group. The mean lesion depth values were 318 μm ± 39 (control, 213 μm ± 27 (fluoride gel, 203 μm ± 34 (Duraflur, 133 μm ± 25 (Duraphat, 207 μm ± 27 (Fluor-niz, 212 μm ± 27 (Fluorphat, 210 ± 28 (Duofluorid, 146 ± 31 (Cariestop and 228 ± 24 (fluoride toothpaste. None of the products used here was able to completely prevent the formation of lesions. The highest cariostatic effect was achieved by fluoride varnish Duraphat and the lowest by the fluoride toothpaste.

Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT)

International Nuclear Information System (INIS)

Heidrich, G.; Hassepass, F.; Dullin, C.; Grabbe, E.; Attin, T.; Hannig, C.

2005-01-01

Purpose: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). Materials and methods: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. Results: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as dentricles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 μm. Only around 73% of the main root canals detected with FD-VCT and 87% of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. (orig.)

An exploratory study of human teeth enamel by using Ft-Raman spectroscopy

International Nuclear Information System (INIS)

Afishah Alias; Siti Rahayu Mohd Hashim; Mihaly, Judith; Julyannie Wajir; Fauziah Abdul Aziz

2009-01-01

Unaffected , affected and heavily affected teeth enamel were studied by using FT-Raman spectroscopy. The 14 permanent teeths enamel surface were measured randomly, resulting in total n = 43 FT-Raman spectra. The results obtained from FT-Raman spectra of heavily affected, affected and unaffected tooths enamel surfaces did not show any significant difference. In this study, Kruskal-Wallis and Wilcoxon rank sum tests were used to compare the intensity between the categories of enamel as well as the surfaces of teeth samples. (author)

Early development of rostrum saw-teeth in a fossil ray tests classical theories of the evolution of vertebrate dentitions.

Science.gov (United States)

Smith, Moya Meredith; Riley, Alex; Fraser, Gareth J; Underwood, Charlie; Welten, Monique; Kriwet, Jürgen; Pfaff, Cathrin; Johanson, Zerina

2015-10-07

In classical theory, teeth of vertebrate dentitions evolved from co-option of external skin denticles into the oral cavity. This hypothesis predicts that ordered tooth arrangement and regulated replacement in the oral dentition were also derived from skin denticles. The fossil batoid ray Schizorhiza stromeri (Chondrichthyes; Cretaceous) provides a test of this theory. Schizorhiza preserves an extended cartilaginous rostrum with closely spaced, alternating saw-teeth, different from sawfish and sawsharks today. Multiple replacement teeth reveal unique new data from micro-CT scanning, showing how the 'cone-in-cone' series of ordered saw-teeth sets arrange themselves developmentally, to become enclosed by the roots of pre-existing saw-teeth. At the rostrum tip, newly developing saw-teeth are present, as mineralized crown tips within a vascular, cartilaginous furrow; these reorient via two 90° rotations then relocate laterally between previously formed roots. Saw-tooth replacement slows mid-rostrum where fewer saw-teeth are regenerated. These exceptional developmental data reveal regulated order for serial self-renewal, maintaining the saw edge with ever-increasing saw-tooth size. This mimics tooth replacement in chondrichthyans, but differs in the crown reorientation and their enclosure directly between roots of predecessor saw-teeth. Schizorhiza saw-tooth development is decoupled from the jaw teeth and their replacement, dependent on a dental lamina. This highly specialized rostral saw, derived from diversification of skin denticles, is distinct from the dentition and demonstrates the potential developmental plasticity of skin denticles. © 2015 The Authors.

Investigation of human teeth with respect to the photon interaction, energy absorption and buildup factor

Energy Technology Data Exchange (ETDEWEB)

Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Topcuoglu, Sinan [Faculty of Dentistry, Department of Endodontic, Ataturk University, 25240 Erzurum (Turkey)

2011-05-15

The effective atomic numbers and electron densities of human teeth have been calculated for total photon interaction (Z{sub PI{sub e{sub f{sub f}}}},Ne{sub PI{sub e{sub f{sub f}}}}) and photon energy absorption (Z{sub PEA{sub e{sub f{sub f}}}},Z{sub RW{sub e{sub f{sub f}}}}Ne{sub PEA{sub e{sub f{sub f}}}}) in the energy region 1 keV-20 MeV. Besides, the energy absorption (EABF) and exposure (EBF) buildup factors have been calculated for these samples by using the geometric progression fitting approximation in the energy region 0.015-15 MeV up to 40 mfp (mean free path). Wherever possible the results were compared with experiment. Effective atomic numbers (Z{sub PI{sub e{sub f{sub f}}}}) of human teeth were calculated using different methods. Discrepancies were noted in Z{sub PI{sub e{sub f{sub f}}}} between the direct and interpolation methods in the low and high energy regions where absorption processes dominate while good agreement was observed in intermediate energy region where Compton scattering dominates. Significant variations up to 22% were observed between Z{sub PI{sub e{sub f{sub f}}}} and Z{sub PEA{sub e{sub f{sub f}}}} in the energy region 30-150 keV which is the used energy range in dental cone beam computed tomography (CBCT) X-ray machines. The Z{sub eff} values of human teeth were found to relatively vary within 1% if different laser treatments are applied. In this variation, the Er:YAG laser treated samples were found to be less effected than Nd:YAG laser treated ones when compared with control group. Relative differences between EABF and EBF were found to be significantly high in the energy region 60 keV-1 MeV even though they have similar variations with respect to the different parameters viz. photon energy, penetration depth.

[Heat-induced symptomatology in human teeth. An in-vitro study].

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Baldissara, P; Bortolini, S; Papale, G; Scotti, R

1998-09-01

Various dental procedures can generate thermal increase in the dental pulp, in particular if they are incorrectly conducted. In literature the pulp cells are considered very heat sensitive. In this study the symptomatological response of patients during and after thermal administration to the dental crown has been recorded. The analysis of the symptomatology was used as an indication for the definition of the threshold of thermal damage. Twelve healthy teeth of four patients programmed for extraction were subdivided into six couples of homologous teeth. One tooth out of each couple was used for the immediate in vivo recording of the symptoms; the other, once extracted, was used to determine the thermal increase applied through the insertion of a thermocouple sensor. In each couple of teeth the thermal stimulus was equal. The average thermal increase was 11.2 degrees C. Pain starts at temperatures ranging from 39.5 to 50.4 degrees C with an average of 44.6 degrees C. This agrees with classical physiological data which reports the threshold of pain at 45 degrees C. The threshold of pain registered suggests that at temperatures below 44.6 degrees C damage to the dental pulp is improbable, at least in healthy teeth. The limit of 45 degrees C appears, therefore, to be a probable safe threshold, contrary to what is reported in literature.

Comparison of the antibacterial effect of sodium hypochlorite and aloe vera solutions as root canal irrigants in human extracted teeth contaminated with enterococcus faecalis.

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Sahebi, S; Khosravifar, N; Sedighshamsi, M; Motamedifar, M

2014-03-01

The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Sodium hypochlorite has excellent antibacterial properties, but also some negative features. The aim of the present study is to compare the antimicrobial effect of Aloe Vera solution with sodium hypochlorite on E.faecalis in the root canals of human extracted teeth. Sixty human extracted single rooted teeth were selected for this in vitro study. The teeth recruited in this study had no cracks, internal resorption, external resorption and calcification. Enterococcus faecalis was injected in the root canals of all teeth. The teeth were then divided into three groups randomly. Each group consisted of 20 teeth that were all rinsed with one of the following solutions: sodium hypochlorite 2.5%, Aloe vera and normal saline. Subsequent to rinsing, root canals of all teeth were sampled. The samples were cultured and growth of the bacteria was assessed after 48 hours. The number of colonies of the bacteria was then counted. The difference between the inhibitory effect of Aloe vera and normal saline on E.faecalis was not significant according to independent t-test (p= 0.966). The inhibitory effect of sodium hypochlorite on E.faecalis was much greater than that of Aloe vera and normal saline (pvera solution is not recommended as a root canal irrigator, but future studies are suggested to investigate the antibacterial effect of Aloe vera with longer duration of exposure and as an intra canal medicament.

Electron spin resonance dating of human teeth from Toca da Santa shelter of São Raimundo Nonato, Piauí, Brazil

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Kinoshita, A.; Figueiredo, A. M. G.; Felice, G. D.; Lage, M. C. S. M.; Guidon, N.; Baffa, O.

2008-02-01

Results of the dating of fossil human teeth excavated from a shelter in the surroundings areas of the Serra da Capivara National Park, São Raimundo Nonato, Piauí, Brazil are presented. This shelter was partially excavated to search for more data that could improve the archaeological context of the Garrincho’s limestone hill sites, where the Toca do Gordo do Garrincho shelter provided two human teeth dated by conventional C-14 in (12,170 ± 40) yBP (years before present) and calibrated age (2 Sigma, 95% probability) 15,245 14,690 yBP (Beta 136204) [E. Peyre, C. Guérin, N. Guidon, I. Coppens, CR Acad. Sci. Paris, Sciences de la terre et des planètes/ Earth & Planetary Sciences 327 (1998) 335, [1

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

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

2012-04-01

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

Evolutionary origins and development of saw-teeth on the sawfish and sawshark rostrum (Elasmobranchii; Chondrichthyes).

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Welten, Monique; Smith, Moya Meredith; Underwood, Charlie; Johanson, Zerina

2015-09-01

A well-known characteristic of chondrichthyans (e.g. sharks, rays) is their covering of external skin denticles (placoid scales), but less well understood is the wide morphological diversity that these skin denticles can show. Some of the more unusual of these are the tooth-like structures associated with the elongate cartilaginous rostrum 'saw' in three chondrichthyan groups: Pristiophoridae (sawsharks; Selachii), Pristidae (sawfish; Batoidea) and the fossil Sclerorhynchoidea (Batoidea). Comparative topographic and developmental studies of the 'saw-teeth' were undertaken in adults and embryos of these groups, by means of three-dimensional-rendered volumes from X-ray computed tomography. This provided data on development and relative arrangement in embryos, with regenerative replacement in adults. Saw-teeth are morphologically similar on the rostra of the Pristiophoridae and the Sclerorhynchoidea, with the same replacement modes, despite the lack of a close phylogenetic relationship. In both, tooth-like structures develop under the skin of the embryos, aligned with the rostrum surface, before rotating into lateral position and then attaching through a pedicel to the rostrum cartilage. As well, saw-teeth are replaced and added to as space becomes available. By contrast, saw-teeth in Pristidae insert into sockets in the rostrum cartilage, growing continuously and are not replaced. Despite superficial similarity to oral tooth developmental organization, saw-tooth spatial initiation arrangement is associated with rostrum growth. Replacement is space-dependent and more comparable to that of dermal skin denticles. We suggest these saw-teeth represent modified dermal denticles and lack the 'many-for-one' replacement characteristic of elasmobranch oral dentitions.

An ancient dental gene set governs development and continuous regeneration of teeth in sharks.

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Rasch, Liam J; Martin, Kyle J; Cooper, Rory L; Metscher, Brian D; Underwood, Charlie J; Fraser, Gareth J

2016-07-15

The evolution of oral teeth is considered a major contributor to the overall success of jawed vertebrates. This is especially apparent in cartilaginous fishes including sharks and rays, which develop elaborate arrays of highly specialized teeth, organized in rows and retain the capacity for life-long regeneration. Perpetual regeneration of oral teeth has been either lost or highly reduced in many other lineages including important developmental model species, so cartilaginous fishes are uniquely suited for deep comparative analyses of tooth development and regeneration. Additionally, sharks and rays can offer crucial insights into the characters of the dentition in the ancestor of all jawed vertebrates. Despite this, tooth development and regeneration in chondrichthyans is poorly understood and remains virtually uncharacterized from a developmental genetic standpoint. Using the emerging chondrichthyan model, the catshark (Scyliorhinus spp.), we characterized the expression of genes homologous to those known to be expressed during stages of early dental competence, tooth initiation, morphogenesis, and regeneration in bony vertebrates. We have found that expression patterns of several genes from Hh, Wnt/β-catenin, Bmp and Fgf signalling pathways indicate deep conservation over ~450 million years of tooth development and regeneration. We describe how these genes participate in the initial emergence of the shark dentition and how they are redeployed during regeneration of successive tooth generations. We suggest that at the dawn of the vertebrate lineage, teeth (i) were most likely continuously regenerative structures, and (ii) utilised a core set of genes from members of key developmental signalling pathways that were instrumental in creating a dental legacy redeployed throughout vertebrate evolution. These data lay the foundation for further experimental investigations utilizing the unique regenerative capacity of chondrichthyan models to answer evolutionary

Teeth characterization using ion beam analysis

International Nuclear Information System (INIS)

Rizzutto, M.A.; Added, N.; Tabacniks, M.H.; Falla-Sotelo, F.; Curado, J.F.; Francci, C.; Markarian, R.A.; Quinelato, A.; Youssef, F.; Mori, M.; Youssef, M.

2006-01-01

A collaboration project between the School of Dentistry and the Institute of Physics of the University of Sao Paulo has been established to measure elemental concentrations in teeth by proton induced X-ray emission (PIXE) and heavy ion elastic recoil detection analysis (HI-ERDA) techniques. Data on trace elements in human, bovine and swine teeth, analyzed by PIXE with a 2.4 MeV proton beam, were compared and concentrations for several elements were obtained with tens of μg/g sensitivity. HI-ERDA measurements employing a 52 MeV Cl beam were done to evaluate changes in elementary concentration in dental enamel after bleaching treatment with different products in 25 bovine incisors teeth. This nondestructive technique allowed the measurements of Ca, P, O and C concentrations above the limit of 100 μg/g. (author)

Ectopic Hard Tissue Formation by Odonto/Osteogenically In Vitro Differentiated Human Deciduous Teeth Pulp Stem Cells.

Science.gov (United States)

Kim, Seunghye; Song, Je Seon; Jeon, Mijeong; Shin, Dong Min; Kim, Seong-Oh; Lee, Jae Ho

2015-07-01

There have been many attempts to use the pulp tissue from human deciduous teeth for dentin or bone regeneration. The objective of this study was to determine the effects of odonto/osteogenic in vitro differentiation of deciduous teeth pulp stem cells (DTSCs) on their in vivo hard tissue-forming potential. DTSCs were isolated from extracted deciduous teeth using the outgrowth method. These cells were exposed to odonto/osteogenic stimuli for 4 and 8 days (Day 4 and Day 8 groups, respectively), while cells in the control group were cultured in normal medium. The in vitro differentiated DTSCs and the control DTSCs were transplanted subcutaneously into immunocompromised mice with macroporous biphasic calcium phosphate and sacrificed at 8 weeks post-implantation. The effect of odonto/osteogenic in vitro differentiation was evaluated using alkaline phosphatase (ALP) staining and quantitative reverse transcription polymerase chain reaction (RT-PCR). The in vivo effect was evaluated by qualitative RT-PCR, assessment of ALP activity, histologic analysis, and immunohistochemical staining. The amount of hard tissue was greater in Day 4 group than Day 8 group (p = 0.014). However, Day 8 group generated lamellar bone-like structure, which was immunonegative to anti-human dentin sialoprotein with significantly low expression level of DSPP compared with the control group (p = 0.008). This study demonstrates that odonto/osteogenic in vitro differentiation of DTSCs enhances the formation of bone-like tissue, instead of dentin-like tissue, when transplanted subcutaneously using MBCP as a carrier. The odonto/osteogenic in vitro differentiation of DTSCs may be an effective modification that enhances in vivo bone formation by DTSCs.

p63 protein is essential for the embryonic development of vibrissae and teeth

International Nuclear Information System (INIS)

Rufini, Alessandro; Weil, Miguel; McKeon, Frank; Barlattani, Alberto; Melino, Gerry; Candi, Eleonora

2006-01-01

Development of skin appendages strongly depends on epithelial-mesenchymal interactions. One of the genes involved in this process is p63, a member of the p53 family of transcription factors, essential for ectodermal development, as elucidated by the phenotype of p63 knock-out mice. Surprisingly, no information on p63 expression in tooth and hair is yet available. Here, we show p63 expression during teeth and vibrissae morphogenesis in mouse embryos and we also show a correlation with the expression patterns of the epithelial marker keratin 5 and the proliferation marker Ki67. Our results show that p63 colocalizes with both K5 and Ki67 in the epithelium of developing vibrissae, while in teeth p63 is expressed, together with K5, in the undifferentiated ectoderm (enamel organ), and in ameloblasts, a subpopulation of differentiated ectodermal cells. Moreover, p63 expression in tooth seems not to be fully colocalized with nuclear Ki67 expression

Depth profilometric case studies in caries diagnostics of human teeth using modulated laser radiometry and luminescence

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Jeon, Raymond J.; Mandelis, Andreas; Abrams, Stephen H.

2003-01-01

Simultaneous measurements from human teeth of photothermal radiometric (PTR) and luminescence (LM) signals induced by an intensity modulated laser have been performed to assess the feasibility of detecting deep lesions and near-surface cracks, to examine the effects of varying enamel thicknesses, the presence of fillings, and stains on the surface of teeth. A commercial dc luminescence monitoring instrument (DIAGNOdent by KaVo) was also used to examine a set of teeth for comparison purposes with PTR and LM. PTR amplitude signals from carious regions and from thin enamel were higher than those from healthy regions and thicker enamel. A crack produces a peak in the PTR amplitude scan, as well as a sudden change in the luminescence amplitude at the corresponding point. At low frequencies (5 Hz), the PTR amplitude showed high sensitivity to a deep (about 2 mm) lesion, while at high frequencies (700 Hz) it was more sensitive to surface cracks. It was concluded that by selecting proper modulation frequencies of the laser, measurements of PTR and LM signals could be used as a dental diagnostic technique with a small, inexpensive, low-power (<30 mW) semiconductor laser as a light source emitting in the optical window range of hard tissue (650-1000 nm).

Microtomography evaluation of dental tissue wear surface induced by in vitro simulated chewing cycles on human and composite teeth

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Rossella Bedini

2012-01-01

Full Text Available In this study a 3D microtomography display of tooth surfaces after in vitro dental wear tests has been obtained. Natural teeth have been compared with prosthetic teeth, manufactured by three different polyceramic composite materials. The prosthetic dental element samples, similar to molars, have been placed in opposition to human teeth extracted by paradontology diseases. After microtomography analysis, samples have been subjected to in vitro fatigue test cycles by servo-hydraulic mechanical testing machine. After the fatigue test, each sample has been subjected again to microtomography analysis to obtain volumetric value changes and dental wear surface images. Wear surface images were obtained by 3D reconstruction software and volumetric value changes were measured by CT analyser software. The aim of this work has been to show the potential of microtomography technique to display very clear and reliable wear surface images. Microtomography analysis methods to evaluate volumetric value changes have been used to quantify dental tissue and composite material wear.

Forensic DNA typing from teeth using demineralized root tips.

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Corrêa, Heitor Simões Dutra; Pedro, Fabio Luis Miranda; Volpato, Luiz Evaristo Ricci; Pereira, Thiago Machado; Siebert Filho, Gilberto; Borges, Álvaro Henrique

2017-11-01

Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization. Copyright © 2017 Elsevier B.V. All rights reserved.

Remarkable resilience of teeth.

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

2009-05-05

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.

A study of geographical variations in the concentrations of plutonium and radiostrontium in human teeth throughout the British Isles

International Nuclear Information System (INIS)

O'Donnell, Rauiri

1993-05-01

Concern has been expressed about the impact on humans of plutonium and radiostrontium releases from nuclear installations in the United Kingdom, with public interest focusing on reported leukaemia clusters in the vicinity of some of these installations. In particular, it is not clear whether such discharges result in and increase in the body burden of plutonium and radiostrontium (present as a consequence of global fallout) in the local population. In this collaborative study the comparative exposures to 239,240Pu and 90Sr of different geographically located child populations in the British Isles have been examined using teeth removed from children for orthodontic purposes. Minute traces on 239,240Pu were found to be present in children's teeth. The overall mean concentration was 5+4 mBq/kg (ash), which is three orders of magnitude lower than reported total activities. Approximately 75% of the samples analysed showed concentrations below the mean value. Although there is considerable scatter in the data, there is some evidence of a marginal enhancement in the 239,240Pu concentration measured in the general vicinity of Cumbria, where the BNF plc. nuclear fuel reprocessing complex is located. Concentrations of 90Sr in teeth exceeded those of plutonium by three orders of magnitude, the overall mean being 8+5Bq/kg (ash). However, there was no evidence of any enhancement in the levels throughout Cumbria. No correlation was observed between 239,240Pu or 90Sr concentrations and mean annual rainfall, not was there any correlation between the levels of these radionuclides in the same samples. The plutonium and radiostrontium concentrations measured in teeth are similar to those reported for human bone in the British Isles and suggests that teeth can be used as an indicator of skeletal burden. On the basis of the above mentioned data, estimates have been made of the approximate risks of leukaemia and non-Hodgkins lymphoma assuming chronic intakes of these radionuclides. The

Demineralization-remineralization dynamics in teeth and bone.

Science.gov (United States)

Abou Neel, Ensanya Ali; Aljabo, Anas; Strange, Adam; Ibrahim, Salwa; Coathup, Melanie; Young, Anne M; Bozec, Laurent; Mudera, Vivek

Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization-remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

Endodontic management of nonrestorable teeth in patients at risk of developing osteonecrosis of the jaw: Case series

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Fahd Alsalleeh

2016-01-01

Full Text Available Osteoradionecrosis of the jaws is one of the most serious oral complications of head and neck cancer radiation therapy. It is a self-progressive process of bone destruction that is very difficult to treat. In this report, four patients who are susceptible to osteonecrosis of the jaw presented for endodontic management of nonrestorable teeth. The first patient had two molar teeth with necrotic pulp and was treated with nonsurgical root canal therapy (NSRCT followed by crown amputation and hemisection. The second patient had a molar tooth that was previously treated with acute apical abscess. Crown amputation and hemisection were performed. The third patient had a molar tooth with necrotic pulp and asymptomatic apical periodontitis. NSRCT followed by occlusal reduction were completed. The fourth patient had a molar tooth with necrotic pulp and symptomatic apical periodontitis. NSRCT and crown amputation were performed. All cases had a minimum recall of 12-months. The tooth in case #1 developed a periapical pathosis, and other teeth in case #1–#3 had healing of periapical lesions. The tooth in case #4 was exfoliated. None had developed osteonecrosis. These results suggest that NSRCT is the treatment option to manage nonrestorable teeth in postradiation patients or patients taking bisphosphonate drugs to prevent osteonecrosis.

Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

Energy Technology Data Exchange (ETDEWEB)

Alomary, A. [Department of Chemistry, Yarmouk University, Irbid (Jordan)]. E-mail: ahmedalomary1000@hotmail.com; Al-Momani, I.F. [Department of Chemistry, Yarmouk University, Irbid (Jordan); Massadeh, A.M. [Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid (Jordan)

2006-10-01

The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 {mu}g/g and 0.44 {mu}g/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 {mu}g/g, Cd = 0.49 {mu}g/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 {mu}g/g, Cd = 0.37 {mu}g/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 {mu}g/g and Cd = 0.52 {mu}g/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 {mu}g/g and Cd = 0.41 {mu}g/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60.

Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

International Nuclear Information System (INIS)

Alomary, A.; Al-Momani, I.F.; Massadeh, A.M.

2006-01-01

The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 μg/g and 0.44 μg/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 μg/g, Cd = 0.49 μg/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 μg/g, Cd = 0.37 μg/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 μg/g and Cd = 0.52 μg/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 μg/g and Cd = 0.41 μg/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60

Non-syndromic supernumerary teeth: report of a case with 6 supernumerary teeth

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Taghibakhsh M

2011-02-01

Full Text Available "nBackground and Aims: Multiple supernumerary teeth are rare and often found in association with syndromes such as Gardner, Cleidocranial dysplasia and cleft lip and palate, with a much less chance for isolated"nnon-syndromic cases. The aim of this study was to report a case with 6 supernumerary teeth without syndromic association."nCase Report: The patient was a 33 year-old female, referred to oral diseases and diagnosis department with chief complaint of sensitivity to cold and hot food in right upper premolar region. Oral examination revealed 5 erupted lingually supernumerary teeth (four in mandibular and one in maxillary premolar region, respectively. Further panoramic radiography clarified an extra impacted tooth in the palatal region of left premolar maxillary area. All extra teeth had been appeared since the age of 17 during one year, as the patient claimed. Medical history and thorough clinical and paraclinical examinations were not significant except for the hypothyroidism, since 5 years ago. No other family member noticed to be the case. Based on our findings, a diagnosis of non-syndromic multiple supernumerary teeth was established."nConclusion: A thorough examination of each patient presented with supernumerary teeth, including panoramic and intraoral radiographic images may provide valuable information regarding accompanying syndromes and unerupted teeth. Early diagnosis is an essential step for orthodontic or surgical decisions making, preventing or avoiding worsening complications such as malocclusion, adjacent normal teeth delayed eruption or rotation, diasthema, cystic lesions and resorption of contiguous teeth.

Results of electron spin resonance measurement of cow teeth from a village around the Indian Nuclear Test Site and assessment of the human exposure to radiation

International Nuclear Information System (INIS)

Bhattacharjee, Deborshi; Hoshi, Masaharu; Ivannikov, Alexander; Ohtaki, Megu; Sarma, Haladhar D.

2010-01-01

A number of cow tooth samples are collected from the adjacent village of Khetolai, located 5 km from the actual Indian Nuclear Test Site in Rajasthan. The samples were processed and utilized for ESR measurements in this study by an X-band spectrometer from JEOL, Japan. The excess dose, determined by subtraction of the natural background dose from the dose absorbed by the enamel was found to the extent of 142 mGy. The intensity of ESR measurement of cow teeth, however, is lower than the human teeth in general. The detailed results obtained on dose estimation in the present study and its correlation with dose exposure for human beings as a result of nuclear test will be presented. The results of this study amply suggest that there is no direct evidence attributing to the development tumors in the cattle population of the locality. There are definitely other factors which were responsible for occurrence of such tumors and other congenital defects in the animal population in the area

Trace element analysis of teeth from pre-Columbian population groups in Mexico

International Nuclear Information System (INIS)

Solis, C.; Oliver, A.; Andrade, E.; Macias, R.; Mansilla, J.; Chavez-Lomeli, M.E.

1999-01-01

Human teeth from pre-Columbian and recent population groups have been analyzed by PIXE. Ancient teeth corresponding to children and adults were obtained from archaeological burials located in five geographic areas of Mexico. Inter-specific and inter-site differences in the trace element contents of enamel were compared in order to get some insight into differences in diet, environmental conditions, teeth health, disease state and post mortem alteration among the co-occurring populations. For permanent teeth from adults, small variations in trace element levels were found depending on the collection site or tooth health, but for deciduous teeth from children, the concentration of elements such as Mn, Fe and Sr varied considerably. In this work, the possible sources of variation are discussed. (author)

Phenotypic and growth characterization of human mesenchymal stem cells cultured from permanent and deciduous teeth

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Revathi Shekar

2012-01-01

Conclusions: Permanent and deciduous teeth are both viable sources of stem cells. The permanent teeth were easier to culture because of a lower chance of contamination with oral microflora. The growth characteristics of the cells obtained from both these sources were similar. However, there was a difference in the ratio of fibroblastoid cells to epithelioid cells between the cultures obtained from the permanent and deciduous teeth.

Coevolutionary patterning of teeth and taste buds

Science.gov (United States)

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

Coevolutionary patterning of teeth and taste buds.

Science.gov (United States)

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

2015-11-03

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.

Supernumerary teeth in clinical practice

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Anna K. Szkaradkiewicz

2011-07-01

Full Text Available Introduction: Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. The prevalence rates of supernumerary teeth in the permanent dentition amounts 0.1-6.9%, and in deciduous dentition 0.4-0.8%. The presence of supernumerary teeth can be found in everyday dental practice.Case presentation: We describe 3 cases of patients with supernumerary teeth. First patient had supernumerary lateral incisor 12s, second - premolar fused, multicuspid, supernumerary deciduous tooth 64s of having several interconnected roots, and third - erupted odontoma between teeth 13 and 14. In all cases treatment involved the removal of the supernumerary tooth.Conclusions: The decision on proceeding with the supernumerary teeth should be based on the full clinical picture and interview. Early diagnosis and removal of supernumerary teeth allow to avoid or reduce possible complications.

The effect of Trigona sp propolis from Luwu regency, South Sulawesi province, Indonesia on human enamel teeth (an in vitro study

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Ardo Sabir

2016-06-01

Full Text Available Propolis is a resinous substance produced by honey bees. It is well-known that propolis exhibits both antibacterial and anti-inflammatory activities therefore it has been used in folk medicine since primeval times.In recent years, propolis has been used as active component of mouthwashes in the attempt to treat gingivitis and periodontitis. The purpose of the present study is to know in vitro effect of Ethanolic Extract of Propolis (EEP solution on the microhardness of human enamel teeth. Solution of 0.125% EEP has been made from propolis which was collected from honeycombs in Luwu Regency, South Sulawesi Province. Aquadest and 1% povidone iodine were used as negative and positive control. Calcium, phosphate, fluoride concentrations and pH of the solutions were also measured using Atomic Absorption Spectroscopy and a digital pH meter. Ninety human maxillary first incisors which extracted for periodontal reasons were used in this study. The roots of the teeth were removed at the cementoenamel junction. The crowns were randomly divided into three groups of 30 each and were immersed in aquadest solution pH 8.4 (Group I; 0.125% EEP solution pH 4.3 (Group II or 1% povidone iodine solution pH 3.0 (Group III for 21, 42, 63, and 84 minutes respectively. A Vickers Hardness Tester was used to measure enamel surface microhardness before and after immersion. Data was statistically analyzed using one-way ANOVA and Tukey tests with significance level of 5%. The results showed that except immersed in aquadest, enamel microhardness increased after being immersed in EEP and povidone iodine solutions, although statistical analysis did not show significant differences (p>0.05 microhardness of enamel teeth before and after immersed in each group.In conclusion, immersion the teeth in 0.125% EEP solution pH 4.3 with 2.69 ppm phosphate, 1.49 ppm calcium, and 0.00 ppm fluoride concentrations for 84 minutes increased human enamel hardness in vitro.

Characterization of ancient teeth and bones from animal and pre-historic human by nuclear methods

International Nuclear Information System (INIS)

Pimjun, Surapong; Chongkum, Somporn; Asvavinijkulchai, Chanchai; Khaweerat, Sasiphan; Pramankij, Somsak; Subhavan, Vadhana

2004-01-01

The search for the evidence of the oldest homonid in Thailand was carried out in the upper northern part of the country consisting of Lampang, Chiang Mai, Phayao, Phrae, Nan, Chiang Rai and Mae Hong Son and Lampang was set up as a center. Three nuclear analytical techniques, i.e. X-ray fluorescence using X-ray tube and isotopic sources, neutron activation analysis and low-background gamma spectroscopy were employed to investigate the samples. The results of elemental composition in fossilised teeth can be used to classify the type of human and animal as it is related to the dietary behaviour. The relationship between elements in fossils and soil or rock can be used to identify the location where the fossils came from. The level of natural radioactivity in soil samples from different locations will be helpful in defining the surveyed region. All of the knowledge will support the development of nuclear analytical technique in archeological study. Besides, the research team found four pieces of fossils which assembled the right frontal region of a calvaria. It appears to be the first indication of a Homo Erectus partial cranial vault ever discovered in Thailand. This discovery is very important in human evolution study

Review of research on the mechanical properties of the human tooth

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Zhang, Ya-Rong; Du, Wen; Zhou, Xue-Dong; Yu, Hai-Yang

2014-01-01

‘Bronze teeth' reflect the mechanical properties of natural teeth to a certain extent. Their mechanical properties resemble those of a tough metal, and the gradient of these properties lies in the direction from outside to inside. These attributes confer human teeth with effective mastication ability. Understanding the various mechanical properties of human teeth and dental materials is the basis for the development of restorative materials. In this study, the elastic properties, dynamic mechanical properties (visco-elasticity) and fracture mechanical properties of enamel and dentin were reviewed to provide a more thorough understanding of the mechanical properties of human teeth. PMID:24743065

[Nutrition, diet and dental health--de- and remineralisation of teeth].

Science.gov (United States)

Imfeld, Thomas

2008-02-01

There is little if any evidence that nutrition during the time of tooth formation has any clinically significant effect on caries susceptibility of erupted teeth in man. Caries, erosion and demastication are not nutritional diseases. They are, however, diet-related diseases because erupted teeth are subject to local chemical and mechanical effects of the diet contacting the teeth. Caries is the result of a chronic undermining demineralisation of the teeth by organic acids that are produced by the bacteria of the dental biofilm while fermenting carbohydrates from the human diet. Dental erosion is the result of a chronic localised loss of dental hard tissue etched away from the surface by acids derived from the diet or from gastric reflux. The physicochemical grounds of de- and remineralisation of teeth are explained using detailed diagrams. Initial caries lesions without cavitation of the surface can remineralise (heal) under conditions of low cariogenic diet and good oral hygiene. However, once the surface has broken and cavitation occurred, there is no alternative to restorative dental therapy because remineralisation is no more possible.

Surgically facilitated experimental movement of teeth : systematic review

NARCIS (Netherlands)

Liem, A. M. L.; Hoogeveen, E. J.; Jansma, J.; Ren, Y.

Several surgical techniques based on corticotomy and dental distraction have been developed to improve the movement of teeth and reduce the duration of orthodontic treatment. In this systematic review we have critically assessed published studies on the experimental movement of teeth to find out

Zinc, lead and copper in human teeth measured by induced coupled argon plasma atomic emission spectroscopy (ICP-AES)

Energy Technology Data Exchange (ETDEWEB)

Chew, L.T.; Bradley, D.A. E-mail: D.A.Bradley@exeter.ac.uk; Mohd, Y.; Jamil, M

2000-11-15

Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 {mu}g (g tooth mass){sup -1} to 40.5 {mu}g (g tooth mass){sup -1}, with a median of 9.8 {mu}g (g tooth mass){sup -1}. A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 {mu}g (g tooth mass){sup -1} respectively. Present values for tooth-Zn are lower than published data for other ethnic groups.

Cryopreserved Dental Pulp Tissues of Exfoliated Deciduous Teeth Is a Feasible Stem Cell Resource for Regenerative Medicine

Science.gov (United States)

Yamaza, Haruyoshi; Akiyama, Kentaro; Hoshino, Yoshihiro; Song, Guangtai; Kukita, Toshio; Nonaka, Kazuaki; Shi, Songtao; Yamaza, Takayoshi

2012-01-01

Human exfoliated deciduous teeth have been considered to be a promising source for regenerative therapy because they contain unique postnatal stem cells from human exfoliated deciduous teeth (SHED) with self-renewal capacity, multipotency and immunomodulatory function. However preservation technique of deciduous teeth has not been developed. This study aimed to evaluate that cryopreserved dental pulp tissues of human exfoliated deciduous teeth is a retrievable and practical SHED source for cell-based therapy. SHED isolated from the cryopreserved deciduous pulp tissues for over 2 years (25–30 months) (SHED-Cryo) owned similar stem cell properties including clonogenicity, self-renew, stem cell marker expression, multipotency, in vivo tissue regenerative capacity and in vitro immunomodulatory function to SHED isolated from the fresh tissues (SHED-Fresh). To examine the therapeutic efficacy of SHED-Cryo on immune diseases, SHED-Cryo were intravenously transplanted into systemic lupus erythematosus (SLE) model MRL/lpr mice. Systemic SHED-Cryo-transplantation improved SLE-like disorders including short lifespan, elevated autoantibody levels and nephritis-like renal dysfunction. SHED-Cryo amended increased interleukin 17-secreting helper T cells in MRL/lpr mice systemically and locally. SHED-Cryo-transplantation was also able to recover osteoporosis bone reduction in long bones of MRL/lpr mice. Furthermore, SHED-Cryo-mediated tissue engineering induced bone regeneration in critical calvarial bone-defect sites of immunocompromised mice. The therapeutic efficacy of SHED-Cryo transplantation on immune and skeletal disorders was similar to that of SHED-Fresh. These data suggest that cryopreservation of dental pulp tissues of deciduous teeth provide a suitable and desirable approach for stem cell-based immune therapy and tissue engineering in regenerative medicine. PMID:23251621

Photon dose conversion coefficients for the human teeth in standard irradiation geometries

Energy Technology Data Exchange (ETDEWEB)

Ulanovsky, A; Wieser, A; Zankl, M; Jacob, P

2005-07-01

Photon dose conversion coefficients for the human tooth materials are computed in energy range from 0.01 to 10 MeV by the Monte Carlo method. The voxel phantom Golem of the human body with newly defined tooth region and a modified version of the EGS4 code have been used to compute the coefficients for 30 tooth cells with different locations and materials. The dose responses are calculated for cells representing buccal and lingual enamel layers. The computed coefficients demonstrate a strong dependence on energy and geometry of the radiation source and a weaker dependence on location of the enamel voxels. For isotropic and rotational radiation fields the enamel dose does not show a significant dependence on tooth sample locations. The computed coefficients are used to convert from absorbed dose in teeth to organ dose or to integral air kerma. Examples of integral conversion factors from enamel dose to air kerma are given for several photon fluences specific for the Mayak reprocessing plant in Russia. The integral conversion factors are strongly affected by the energy and angular distributions of photon fluence, which are important characteristics of an exposure scenario for reconstruction of individual occupational doses. (orig.)

The roentgenographic study on the thickness of the lamina dura in normal teeth

Energy Technology Data Exchange (ETDEWEB)

Park, Chang Sik; Ahn, Hyung Kyu [Department of Dental Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1976-11-15

The study was performed to investigate the thickness of laminadura of the human teeth in normal condition, which obtained from the intraoral roentgenograms of the 1200 cases taken by bisecting technique. All films were divided into the different ages, the different sexes, and the different location of the different teeth. The obtained results were as follows: 1. With advancing age in both sexes, the laminadura tends to become thinner as following. Average thickness of the whole cases. 2. In general, the alveolar crest is thickest among the root surfaces, apex, midroot followed, and the average thickness of the posterior teeth is thicker than that of the anterior teeth. 3. The mean value of the whole maxillary teeth is larger than the one of the whole mandibular teeth. 4. On the whole cases, the differences of male and female is about 0.019 mm, which is not a significant differences.

High-precision Pb isotopic measurements of teeth and environmental samples from Sofia (Bulgaria): insights for regional lead sources and possible pathways to the human body

Science.gov (United States)

Kamenov, George D.

2008-08-01

High-precision Pb isotopic measurements on teeth and possible sources in a given area can provide important insights for the lead (Pb) sources and pathways in the human body. Pb isotopic analyses on soils from the area of Sofia, Bulgaria show that Pb is contributed by three end-members represented by two natural sources and leaded gasoline. Sequential leaching experiments reveal that the alumosilicate fraction of the soils is mainly controlled by natural Pb derived from two mountain massifs bordering the city. Around 1/3 to a half of the Pb in the soil leachates, however, can be explained by contamination from leaded gasoline. Contemporary teeth from Sofia residents show very similar Pb isotopic compositions to the soil leachates, also indicating that around 1/3 to a half of the Pb can be explained by derivation from leaded gasoline. The remarkable isotopic similarities between the teeth and the most labile fractions of the local soils suggest that the lead can be derived from the latter. Pb incorporation in the human body via soil-plant-human or soil-plant-animal-human chains is unlikely due to the fact that no significant farming occurs in the city area. The isotopic compositions of the local soil labile fractions can be used as approximation of the bioaccessible lead for humans. Considering all possible scenarios it appears that soil and/or soil-born dust inhalation and/or ingestion is the most probable pathway for incorporation of local soil lead in the local population. The high-precision Pb isotope data presented in this work indicate that apparently the local soil is what plays major role in the human Pb exposure.

Trace Elements in Teeth by ICPMS

International Nuclear Information System (INIS)

Zahran, N.F.; Helal, A.I.; Amr, M.A.; Amr, M.A.; Al-saad, K.A.

2008-01-01

Teeth are reported to be suitable indicators of trace element exposure from environment and nutritional status. Inductively coupled plasma mass spectrometry (ICP-MS) is used to compare the trace element content of children's primary teeth and adult teeth. Primary teeth are collected from 28 children and 42 adult from non-industrial City. The data are assessed statistically using t-tests. The adult teeth contained significantly greater concentrations of Na, Mg, Al, Fe, Ni, Cu, Sr, Cd, Ba, Pb and U and significantly less Mn, Co, As, Se, Mo and Bi than the children teeth. Additional measurements on adult teeth pulps are performed. Comparison between trace element concentrations in health and caries teeth pulps show that the mean concentrations of Na, Al, K, Cr, Mn, Co, Cu, Zn, Mo, Ag, Bi and U are lower in caries than healthy teeth pulps. On the other hand, the mean concentrations of Mg, Cd and Pb are higher in caries samples than healthy teeth pulps

Disinfection/sterilization of extracted teeth for dental student use.

Science.gov (United States)

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).

Fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage

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Rafael Francisco Lia Mondelli

2009-06-01

Full Text Available OBJECTIVES: This in vitro study evaluated the fracture resistance of weakened human premolars (MOD cavity preparation and pulp chamber roof removal restored with condensable resin composite with and without cusp coverage. MATERIAL AND METHODS: Thirty human maxillary premolars were divided into three groups: Group A (control, sound teeth; Group B, wide MOD cavities prepared and the pulp chamber roof removed and restored with resin composite without cusp coverage; Group C, same as Group B with 2.0 mm of buccal and palatal cusps reduced and restored with the same resin. The teeth were included in metal rings with self-curing acrylic resin, stored in water for 24 h and thereafter subjected to a compressive axial load in a universal testing machine at 0.5 mm/min. RESULTS: The mean fracture resistance values ± standart deviation (kgf were: group A: 151.40 ± 55.32, group B: 60.54 ± 12.61, group C: 141.90 ± 30.82. Statistically significant differences were found only between Group B and the other groups (p<0.05. The condensable resin restoration of weakened human premolars with cusp coverage significantly increased the fracture resistance of the teeth as compared to teeth restored without cusp coverage. CONCLUSION: The results showed that cusp coverage with condensable resin might be a safe option for restoring weakened endodontically treated teeth.

Prevalence of two root canals in human mandibular anterior teeth in an Iranian population

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Saeed Rahimi

2013-01-01

Full Text Available Background: Complete debridement and obturation of the root canal system is a key factor in successful endodontic treatment and the operator should therefore have thorough knowledge of the root canal morphology of the teeth. Numerous studies have been carried out to investigate the canal configuration of different tooth types in various populations. Aims: The aim of the present study was to investigate the internal anatomy of mandibular incisors and canines in an Iranian population. Materials and Methods: A total of 463 mandibular anterior teeth, including 186 centrals, 128 laterals, and 149 canines, were examined. A standard clearing technique was used to make the teeth transparent. India ink was injected into the canals of the teeth and the samples were examined with a magnifying glass. The root canal configurations were categorized according to the Vertucci classification. Results: All the incisors in this study had one root, and 12.08% of the canines had two roots. We found a slightly higher prevalence of the second canal in incisors than in canines (36.62% vs. 20.48%. However, the probability of canines having two separate apical foramina was higher than that for incisors (12.08% vs. 0.64%. Conclusions: In view of the high prevalence of two-canaled mandibular anterior teeth found in this study, it would be prudent to assume that any mandibular anterior tooth being treated is two-canaled until a thorough search proves otherwise.

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

Science.gov (United States)

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

2005-01-01

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

Demineralization–remineralization dynamics in teeth and bone

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Abou Neel EA

2016-09-01

Full Text Available Ensanya Ali Abou Neel,1–3 Anas Aljabo,3 Adam Strange,3 Salwa Ibrahim,3 Melanie Coathup,4 Anne M Young,3 Laurent Bozec,3 Vivek Mudera4 1Division of Biomaterials, Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 2Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta, Egypt; 3Department of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, London, UK; 4UCL Institute of Orthopaedics and Musculoskeletal Sciences, Royal National Orthopaedic Hospital, Stanmore, London, UK Abstract: Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization–remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties

Saving Single-rooted Teeth with Combined Endodontic-periodontal Lesions.

Science.gov (United States)

Pico-Blanco, Alexandre; Castelo-Baz, Pablo; Caneiro-Queija, Leticia; Liñares-González, Antonio; Martin-Lancharro, Pablo; Blanco-Carrión, Juan

2016-12-01

Teeth affected by combined endodontic-periodontal lesions are usually considered by all prognosis classifications as hopeless teeth. The development of new biomaterials combined with modern endodontic and periodontal regeneration techniques may improve dental prognosis and maintain the affected teeth. Moreover, 1 of the replacement options for those teeth, dental implants, has shown an increasing number of biological and technical complications. Five patients were included in this case series study. Full periodontal and radiographic examination revealed generalized chronic periodontitis. Moreover, endodontic-periodontal lesions affecting single-rooted teeth were detected in those patients with tissue destruction beyond the apex. After splinting those teeth, conventional endodontic and nonsurgical periodontal treatment was performed. Three months later, periodontal regeneration was applied at those teeth in order to reconstruct supporting tissues and to improve dental prognosis. After a follow-up period ranging from 14 months to 17 years, it was observed that all teeth remain asymptomatic and in normal function. No signs of apical pathosis were observed, and the periodontium was stable. All patients were included in a strict maintenance program to check the periodontal and apical status. This case series shows that it is possible to change the prognosis of teeth affected by combined endodontic-periodontal lesions, even if the periodontal support is destroyed beyond the apex. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Teeth re-whitening effect of strawberry juice on coffee stained teeth

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Annisya Pramesti

2018-01-01

Full Text Available Many people favor coffee. However, regarding health and aesthetic dentistry, coffee gives a negative effect. Tanin in coffee causes a brown stain on the tooth surface. Therefore, in aesthetic dental care, teeth whitening has become popular matter. One of the natural ingredients used for teeth whitening treatment is strawberry. The purpose of this study was to obtained data regarding the effect of strawberry juice on the re-whitening process of the coffee-stained tooth enamel surface. This study was a pure experimental in-vitro using Friedman and Wilcoxon Matched Pairs Tests for statistical analysis. The population of this study was anterior teeth. The samples were maxillary central incisors. The sampling technique using sample size determination based on the testing formulas of the difference of two average data pairs resulted in 11 specimens. The result of the research showed that all coffee-stained teeth sample had an increasing enamel colour index. The samples were then applied with strawberry juice resulted in a significant average difference colour index value indicated by p<0.001. The conclusion of this research indicated that there was an effect of strawberry juice on the coffee-stained teeth re-whitening process.

The management of over closured anterior teeth due to attrition

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Eha Djulaeha

2009-12-01

Full Text Available Background: Tooth is the hardest tissue in human body, that can be injured because of attrition process. For old people, denture attrition process is caused by psysiological process relating with the mastication function which also supported by some bad habits such an bruxism, premature contact, and consuming habit of abrasive food. Attrition or abrasion can also be happened with patien’t dentition who does not have teeth subtutition for long time due the lost of their maxillary as well as mandibulary. The pasient will loose their vertical dimension of occlusion, injure, and the lower jaw becomes over closed which is called over closure. Purpose: This article reported the management of over closured anterior teeth due to attrition. Case: a seventy six year old woman patient came to Prosthodontic Clinic in Faculty of Dentistry, Airlangga University, to rehabilitate her upper and lower severe attrited anterior teeth and her posterior teeth. The patient has experienced of wearing acrylic removable mandibular partial denture ten years ago. Unfortunaly, the denture was uncomfortable, and she did not wear it anymore since five years ago. Case management: The severe attrition of anterior teeth with the lost of occlusal vertical dimension can be treated by improving the occlusal vertical dimension gradually. The treatment is then followed by the increasing of the height of the anterior teeth by lengthening the crown teeth of upper jaw with 12 units of span bridge and the acrylic removable partial denture of lower jaw. Conclusion: The severe attrition of anterior teeth with the lost of occlusal vertical dimension can be treated by improving the occlusal vertical dimension gradually, using long span bridge and acrylic removable partial denture.

The study of barium concentration in deciduous teeth, impacted teeth, and facial bones of Polish residents.

Science.gov (United States)

Fischer, Agnieszka; Malara, Piotr; Wiechuła, Danuta

2014-10-01

The study determines the concentration of Ba in mineralized tissues of deciduous teeth, permanent impacted teeth, and facial bones. The study covers the population of children and adults (aged 6-78) living in an industrial area of Poland. Teeth were analyzed in whole, with no division into dentine and enamel. Facial bones and teeth were subjected to the following preparation: washing, drying, grinding in a porcelain mortar, sample weighing (about 0.2 g), and microwave mineralization with spectrally pure nitric acid. The aim of the study was to determinate the concentration of Ba in deciduous teeth, impacted permanent teeth, and facial bones. The concentration of barium in samples was determined over the ICP OES method. The Ba concentration in the tested bone tissues amounted to 2.2-15.5 μg/g (6.6 μg/g ± 3.9). The highest concentration of Ba was present in deciduous teeth (10.5 μg/g), followed by facial bones (5.2 μg/g), and impacted teeth (4.3 μg/g) (ANOVA Kruskal-Wallis rank test, p = 0.0002). In bone tissue and impacted teeth, Ba concentration increased with age. In deciduous teeth, the level of Ba decreased with children's age.

Revitalization of open apex teeth with apical periodontitis using a collagen-hydroxyapatite scaffold.

Science.gov (United States)

Nevins, Alan J; Cymerman, Jerome J

2015-06-01

An enhanced revision of the revitalization endodontic technique for immature teeth with apical periodontitis has been described. It includes the addition of collagen-hydroxyapatite scaffold to the currently practiced revascularization technique. Four cases treated in series are presented in this report, 1 case involving 2 teeth. Periapical diagnoses of immature teeth included "asymptomatic apical periodontitis," "symptomatic apical periodontitis," and "acute apical abscess." Additionally, 1 fully developed tooth that had undergone root canal treatment that failed had a periapical diagnosis of acute apical abscess. An established revascularization protocol was used for all teeth. In addition to stimulating blood clots, all teeth were filled with collagen-hydroxyapatite scaffolds. Periapical radiolucencies healed in all teeth, and diffuse radiopacity developed within the coronal portions of canal spaces. Root development with root lengthening occurred in the immature nonvital maxillary premolar that had not undergone prior treatment. The technique of adding a collagen-hydroxyapatite scaffold to the existing revitalization protocol has been described in which substantial hard tissue repair has occurred. This may leave teeth more fully developed and less likely to fracture. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Syndromes with supernumerary teeth.

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Lubinsky, Mark; Kantaputra, Piranit Nik

2016-10-01

While most supernumerary teeth are idiopathic, they can be associated with a number of Mendelian syndromes. However, this can also be a coincidental finding, since supernumerary teeth occur in 6% or more of the normal population. To better define this relationship, we analyzed the evidence for specific associations. We excluded conditions with a single affected patient reported, supernumerary teeth adjacent to clefts or other forms of alveolar disruption (as secondary rather than primary findings), and natal teeth, which can involve premature eruption of a normal tooth. Since, the cause of supernumerary teeth shows considerable heterogeneity, certain findings are less likely to be coincidental, such as five or more supernumerary teeth in a single patient, or locations outside of the premaxilla. We found only eight genetic syndromes with strong evidence for an association: cleidocranial dysplasia; familial adenomatous polyposis; trichorhinophalangeal syndrome, type I; Rubinstein-Taybi syndrome; Nance-Horan syndrome; Opitz BBB/G syndrome; oculofaciocardiodental syndrome; and autosomal dominant Robinow syndrome. There is also suggestive evidence of an association with two uncommon disorders, Kreiborg-Pakistani syndrome (craniosynostosis and dental anomalies), and insulin-resistant diabetes mellitus with acanthosisnigricans. An association of a Mendelian disorder with a low frequency manifestation of supernumerary teeth is difficult to exclude without large numbers, but several commonly cited syndromes lacked evidence for clear association, including Hallermann-Streiff syndrome, Fabry disease, Ehlers-Danlos syndrome, Apert and Crouzon syndromes, Zimmermann-Laband syndrome, and Ellis-van Creveld syndrome. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Accuracy of three-dimensional printing for manufacturing replica teeth

OpenAIRE

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

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 sc...

Incremental lines in root cementum of human teeth: An approach to their role in age estimation using polarizing microscopy

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Aggarwal Pooja

2008-01-01

Full Text Available Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research indicates that tooth cementum annulations (TCA may be used more reliably than any other morphological or histological traits of the adult skeleton for age estimation. The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain the best method of studying cementum with respect to different forms of microscopy. Thirty nonrestorable teeth were extracted from 20 people, and longitudinal ground section of each tooth was prepared. Photomicrographs of the area at the junction of apical and middle third of the root under light and polarized microscope were taken. The cementum was composed of multiple light and dark bands that were counted on the photomicrograph with the help of image analysis software and added to the average eruption time of individual tooth. The predicted age of the individual was thus obtained. Results showed a significant correlation between the predicted age and actual chronological age of the individual. These data indicate that quantitation of cementum annuli is a moderately reliable means for age estimation in humans and polarizing microscopy is a better means of visualizing incremental lines of cementum compared to light microscopy.

Comparison of different techniques for disinfection of teeth internal space in preclinical teaching

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Tabrizizadeh M.

2009-12-01

Full Text Available "nBackground and Aim: Extracted teeth used in preclinic should be disinfected. The aim of this study was to evaluate the effects of some disinfectants on microorganisms cultured from pulp chamber of extracted teeth."nMaterials and Methods: In this experimental study 54 intact human teeth were collected. After access cavity preparation, 10 8 B. streothermophillus endospors were inoculated into pulp chamber. Then cavities were sealed with a temporary restorative material. Teeth were divided into 5 groups of 10 each. The teeth were then stored in these disinfectants: 5.25% hypochlorite sodium, 5% Microten, 5% Deconex, 2% Glutaraldehyd, and 10% Formalin for 48 hours. Two teeth were autoclaved as negative controls and two were stored in normal saline as positive controls. The teeth were then sectioned in cervical area and cultured in Trypticase Soy Broth. After three days turbidity in tubes was evaluated. Statistical analysis was done by Fisher's exact test."nResults: None of these solutions were able to prevent microorganism growth in all samples; however, Formalin was better in six cases than that of other disinfectants. Differences between these five groups were not statistically significant (P=0.384."nConclusion: Sterilization of the teeth with autoclave is the only absolute method for disinfecting the root canals of extracted teeth and disinfectants are not reliable for this purpose.

Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

International Nuclear Information System (INIS)

Silva, A.L.M.; Figueroa, R.; Jaramillo, A.; Carvalho, M.L.; Veloso, J.F.C.A.

2013-01-01

Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm 2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues. - Highlights: • Demonstration of an EDXRF imaging system based on a 2D-MHSP detector for biological analysis • Evaluation of the drift of the dental amalgam constituents, throughout the teeth • Observation of Hg diffusion, due to hydroxyapatite crystal defects that compose the teeth tissues

Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

Energy Technology Data Exchange (ETDEWEB)

Silva, A.L.M. [I3N, Physics Dept, University of Aveiro, 3810-193 Aveiro (Portugal); Figueroa, R.; Jaramillo, A. [Physics Department, Universidad de La Frontera, Temuco (Chile); Carvalho, M.L. [Atomic Physics Centre, University of Lisbon, 1649-03 Lisboa (Portugal); Veloso, J.F.C.A., E-mail: joao.veloso@ua.pt [I3N, Physics Dept, University of Aveiro, 3810-193 Aveiro (Portugal)

2013-08-01

Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm{sup 2} presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues. - Highlights: • Demonstration of an EDXRF imaging system based on a 2D-MHSP detector for biological analysis • Evaluation of the drift of the dental amalgam constituents, throughout the teeth • Observation of Hg diffusion, due to hydroxyapatite crystal defects that compose the teeth tissues.

Evaluation of thermal cooling mechanisms for laser application to teeth.

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Miserendino, L J; Abt, E; Wigdor, H; Miserendino, C A

1993-01-01

Experimental cooling methods for the prevention of thermal damage to dental pulp during laser application to teeth were compared to conventional treatment in vitro. Pulp temperature measurements were made via electrical thermistors implanted within the pulp chambers of extracted human third molar teeth. Experimental treatments consisted of lasing without cooling, lasing with cooling, laser pulsing, and high-speed dental rotary drilling. Comparisons of pulp temperature elevation measurements for each group demonstrated that cooling by an air and water spray during lasing significantly reduced heat transfer to dental pulp. Laser exposures followed by an air and water spray resulted in pulp temperature changes comparable to conventional treatment by drilling. Cooling by an air water spray with evacuation appears to be an effective method for the prevention of thermal damage to vital teeth following laser exposure.

Neanderthal teeth from Moula-Guercy, Ardèche, France.

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

2013-07-01

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

New models for age estimation and assessment of their accuracy using developing mandibular third molar teeth in a Thai population.

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Duangto, P; Iamaroon, A; Prasitwattanaseree, S; Mahakkanukrauh, P; Janhom, A

2017-03-01

Age estimation using developing third molar teeth is considered an important and accurate technique for both clinical and forensic practices. The aims of this study were to establish population-specific reference data, to develop age prediction models using mandibular third molar development, to test the accuracy of the resulting models, and to find the probability of persons being at the age thresholds of legal relevance in a Thai population. A total of 1867 digital panoramic radiographs of Thai individuals aged between 8 and 23 years was selected to assess dental age. The mandibular third molar development was divided into nine stages. The stages were evaluated and each stage was transformed into a development score. Quadratic regression was employed to develop age prediction models. Our results show that males reached mandibular third molar root formation stages earlier than females. The models revealed a high correlation coefficient for both left and right mandibular third molar teeth in both sexes (R = 0.945 and 0.944 in males, R = 0.922 and 0.923 in females, respectively). Furthermore, the accuracy of the resulting models was tested in randomly selected 374 cases and showed low error values between the predicted dental age and the chronological age for both left and right mandibular third molar teeth in both sexes (-0.13 and -0.17 years in males, 0.01 and 0.03 years in females, respectively). In Thai samples, when the mandibular third molar teeth reached stage H, the probability of the person being over 18 years was 100 % in both sexes.

Radiographic studies on the development of incisors and canine teeth in donkeys

International Nuclear Information System (INIS)

Misk, N.A.; Semieka, M.M.A.

1997-01-01

The aim of the present work is to study the time of radiographic appearance in donkeys of different stages of development of deciduous incisors, permanent incisors and canine teeth; the radiographic length of deciduous incisors, permanent incisors and canines; the process of root resorption of deciduous incisors; and the appearance of the pulp cavity and ifs relation to denial Infundibulum at different ages. Sixty specimens were used and all were radiographed. Interpretation was stated for each, from 1 day up to 17 years of age

Bacterial profile in primary teeth with necrotic pulp and periapical lesions.

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da Silva, Léa Assed Bezerra; Nelson-Filho, Paulo; Faria, Gisele; de Souza-Gugelmin, Maria Cristina Monteiro; Ito, Izabel Yoko

2006-01-01

The objective of this study was to evaluate the bacterial profile in root canals of human primary teeth with necrotic pulp and periapical lesions using bacterial culture. A total of 20 primary teeth with necrotic pulp and radiographically visible radiolucent areas in the region of the bone furcation and/or the periapical region were selected. After crown access, 4 sterile absorbent paper points were introduced sequentially into the root canal for collection of material. After 30 s, the paper points were removed and placed in a test tube containing reduced transport fluid (RTF) and were sent for microbiological evaluation. Anaerobic microorganisms were found in 100% of the samples, black-pigmented bacilli in 30%, aerobic microorganisms in 60%, streptococci in 85%, gram-negative aerobic rods in 15% and staphylococci were not quantified. Mutans streptococci were found in 6 root canals (30%), 5 canals with Streptococcus mutans and 1 canal with Streptococcus mutans and Streptococcus sobrinus. It was concluded that in root canals of human primary teeth with necrotic pulp and periapical lesions, the infection is polymicrobial with predominance of anaerobic microorganisms.

Hominin teeth from the Middle Pleistocene site of Yiyuan, Eastern China.

Science.gov (United States)

Xing, Song; Sun, Chengkai; Martinón-Torres, María; Bermúdez de Castro, José María; Han, Fei; Zhang, Yingqi; Liu, Wu

2016-06-01

In 1981-1982, some hominin fossils, including a relatively complete skull and seven isolated teeth, were recovered from the Middle Pleistocene site of Yiyuan in Eastern China. In the present study we provide a detailed metric and morphological comparison of the Yiyuan dental sample in order to characterize better the variability of the human populations that inhabited China during the Middle Pleistocene. Aside from taxonomic and phylogenetic questions, the lack of understanding and/or knowledge about the morphological variability of these populations have caused concern about the human versus non-human nature of some of the hominin dental remains found in East Asia during the Early and the Middle Pleistocene. Thus, our study aims to present a detailed description and comparison of the Yiyuan isolated teeth to 1) discuss and support their human nature and 2) to explore their taxonomic affinities with regard to other penecontemporaneous populations from Asia. Our results clearly differentiate the Yiyuan sample from Pongo specimens and support a human attribution for the Yiyuan material. Our analyses also suggest that the Yiyuan teeth form a morphologically coherent group together with samples from Zhoukoudian, Chaoxian and Hexian. They are different from the more derived specimens from Panxian Dadong, suggesting a pattern of biogeographic isolation and different evolutionary trends between northern and southern China during the Middle Pleistocene. In addition, and despite sharing a common morphological bauplan with Homo erectus sensu stricto (s.s.), the Yiyuan, Zhoukoudian and Hexian teeth are also different from the Indonesian Early Pleistocene samples. In particular, the expression of a highly crenulated or dendritic enamel-dentine surface could be unique to these groups. Our study supports the notion that the taxonomy of the Pleistocene hominins from Asia may have been oversimplified. Future studies should explore the variability of the Asian specimens and

Primate dental ecology: How teeth respond to the environment.

Science.gov (United States)

Cuozzo, Frank P; Ungar, Peter S; Sauther, Michelle L

2012-06-01

Teeth are central for the study of ecology, as teeth are at the direct interface between an organism and its environment. Recent years have witnessed a rapid growth in the use of teeth to understand a broad range of topics in living and fossil primate biology. This in part reflects new techniques for assessing ways in which teeth respond to, and interact with, an organism's environment. Long-term studies of wild primate populations that integrate dental analyses have also provided a new context for understanding primate interactions with their environments. These new techniques and long-term field studies have allowed the development of a new perspective-dental ecology. We define dental ecology as the broad study of how teeth respond to, or interact with, the environment. This includes identifying patterns of dental pathology and tooth use-wear, as they reflect feeding ecology, behavior, and habitat variation, including areas impacted by anthropogenic disturbance, and how dental development can reflect environmental change and/or stress. The dental ecology approach, built on collaboration between dental experts and ecologists, holds the potential to provide an important theoretical and practical framework for inferring ecology and behavior of fossil forms, for assessing environmental change in living populations, and for understanding ways in which habitat impacts primate growth and development. This symposium issue brings together experts on dental morphology, growth and development, tooth wear and health, primate ecology, and paleontology, to explore the broad application of dental ecology to questions of how living and fossil primates interact with their environments. Copyright © 2012 Wiley Periodicals, Inc.

Electron spin resonance dating of human teeth from Toca da Santa shelter of Sao Raimundo Nonato, Piaui, Brazil

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, A. [Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901 Ribeirao Preto, SP (Brazil); Universidade do Sagrado Coracao, Rua Irma Arminda 10-50, 17011-160 Bauru, SP (Brazil); Figueiredo, A.M.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Av. Lineu Prestes, 2242, Cidade Universitaria, 5422-970 Sao Paulo, SP (Brazil); Felice, G.D. [Fundacao Museu do Homem Americano-FUNDHAM, Rua Abdias Neves, no. 551, Centro, 64770-000 Sao Raimundo Nonato, Piaui (Brazil); Lage, M.C.S.M. [Universidade Federal do Piaui, Departamento de Quimica, Campus da Ininga, Ininga, 64049-550 Teresina, Piaui (Brazil); Guidon, N. [Fundacao Museu do Homem Americano-FUNDHAM, Rua Abdias Neves, no. 551, Centro, 64770-000 Sao Raimundo Nonato, Piaui (Brazil); Baffa, O. [Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901 Ribeirao Preto, SP (Brazil)], E-mail: baffa@usp.br

2008-02-15

Results of the dating of fossil human teeth excavated from a shelter in the surroundings areas of the Serra da Capivara National Park, Sao Raimundo Nonato, Piaui, Brazil are presented. This shelter was partially excavated to search for more data that could improve the archaeological context of the Garrincho's limestone hill sites, where the Toca do Gordo do Garrincho shelter provided two human teeth dated by conventional C-14 in (12,170 {+-} 40) yBP (years before present) and calibrated age (2 Sigma, 95% probability) 15,245-14,690 yBP (Beta 136204) [E. Peyre, C. Guerin, N. Guidon, I. Coppens, CR Acad. Sci. Paris, Sciences de la terre et des planetes/ Earth and Planetary Sciences 327 (1998) 335, ]. This region is challenging the classical theories about the peopling of America. In agreement with such theories the first human groups would have arrived in America, through Behring, only about 20,000 years ago. The site Toca do Boqueirao da Pedra Furada is a rock-shelter situated at the cliff that is the frontier between the Pre-Cambrian Sao Francisco plain and the Devonian-Permian highlands of the Maranhao-Piaui basin. It was excavated from 1978 till 1988 and presented a very consistent stratigraphy, with thousand of lithic implements and hearths [F. Parenti, Le gisement quaternaire de la Pedra Furada (Piaui, Bresil), Stratigraphie, chronologie, evolution culturelle, Editions Recherches sur les civilisations, Paris, 2002, ; F. Parenti, Le Gisement Quaternaire de la Toca do Boqueirao da Pedra Furada (Piaui, Bresil) dans le Contexte de la Prehistoire Americaine Fouilles, Stratigraphie, Chronologie, Evolution Culturelle, Ph.D. diss, Ecole des Hautes Etudes en Sciences Sociales, Paris, 1993, 411p, ; F. Parenti, M. Fontugne, N. Guidon, C. Guerin, M. Faure, Chronostratigraphie des gisements archeologiques et paleontologiques de Sao Raimundo Nonato (Piaui, Bresil): contribution a la connaissance du peuplement pleistocene de l'Amerique, Supplement de la Revue d

Electron spin resonance dating of human teeth from Toca da Santa shelter of Sao Raimundo Nonato, Piaui, Brazil

International Nuclear Information System (INIS)

Kinoshita, A.; Figueiredo, A.M.G.; Felice, G.D.; Lage, M.C.S.M.; Guidon, N.; Baffa, O.

2008-01-01

Results of the dating of fossil human teeth excavated from a shelter in the surroundings areas of the Serra da Capivara National Park, Sao Raimundo Nonato, Piaui, Brazil are presented. This shelter was partially excavated to search for more data that could improve the archaeological context of the Garrincho's limestone hill sites, where the Toca do Gordo do Garrincho shelter provided two human teeth dated by conventional C-14 in (12,170 ± 40) yBP (years before present) and calibrated age (2 Sigma, 95% probability) 15,245-14,690 yBP (Beta 136204) [E. Peyre, C. Guerin, N. Guidon, I. Coppens, CR Acad. Sci. Paris, Sciences de la terre et des planetes/ Earth and Planetary Sciences 327 (1998) 335, ]. This region is challenging the classical theories about the peopling of America. In agreement with such theories the first human groups would have arrived in America, through Behring, only about 20,000 years ago. The site Toca do Boqueirao da Pedra Furada is a rock-shelter situated at the cliff that is the frontier between the Pre-Cambrian Sao Francisco plain and the Devonian-Permian highlands of the Maranhao-Piaui basin. It was excavated from 1978 till 1988 and presented a very consistent stratigraphy, with thousand of lithic implements and hearths [F. Parenti, Le gisement quaternaire de la Pedra Furada (Piaui, Bresil), Stratigraphie, chronologie, evolution culturelle, Editions Recherches sur les civilisations, Paris, 2002, ; F. Parenti, Le Gisement Quaternaire de la Toca do Boqueirao da Pedra Furada (Piaui, Bresil) dans le Contexte de la Prehistoire Americaine Fouilles, Stratigraphie, Chronologie, Evolution Culturelle, Ph.D. diss, Ecole des Hautes Etudes en Sciences Sociales, Paris, 1993, 411p, ; F. Parenti, M. Fontugne, N. Guidon, C. Guerin, M. Faure, Chronostratigraphie des gisements archeologiques et paleontologiques de Sao Raimundo Nonato (Piaui, Bresil): contribution a la connaissance du peuplement pleistocene de l'Amerique, Supplement de la Revue d

Shaping Cutter Original Profile for Fine-module Ratchet Teeth Cutting

Science.gov (United States)

Sharkov, O. V.; Koryagin, S. I.; Velikanov, N. L.

2018-03-01

The methods for determining geometric characteristics of a theoretical original profile of the cutter for cutting ratchet teeth with a module of 0.3–1.0 mm are considered in the article. Design models describing the shaping process of cutting edges of cutter teeth are developed. Systems of expressions for determining coordinates of the points of front and back edges of cutter teeth; the workpiece angles of rotation during the cutting process; the minimum cutter radius are received. The basic data when using the proposed technique are: radii of circumferences passing through cavities of cutter teeth and external cut teeth; the gradient angle and length of straight section of the front edge of a cut tooth; angles of rotation of the cutter and the workpiece at the moment of shaping.

Effect of aquatine endodontic cleanser on smear layer removal in the root canals of ex vivo human teeth

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Faustino Garcia

2010-08-01

Full Text Available OBJECTIVES: The purpose of this study was to measure and compare the root canal cleanliness and smear layer removal effectiveness of Aquatine Endodontic Cleanser (Aquatine EC when used as an endodontic irrigating solution in comparison with 6% sodium hypochlorite (NaOCl. MATERIAL AND METHODS: Forty-five human teeth were randomly allocated to five treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to an ISO size #40. The teeth were then processed for scanning electron microscopy, and the root canal cleanliness and removal of smear layer were examined. RESULTS: The most effective removal of smear layer occurred with Aquatine EC and NaOCl, both with a rinse of EDTA. CONCLUSIONS: Aquatine EC appears to be the first hypochlorous acid approved by the FDA to be a possible alternative to the use of NaOCl as an intracanal irrigant. Further research is needed to identify safer and more effective alternatives to the use of NaOCl irrigation in endodontics.

Patterns of dental development in Homo, Australopithecus, Pan, and Gorilla.

Science.gov (United States)

Smith, B H

1994-07-01

Smith ([1986] Nature 323:327-330) distinguished patterns of development of teeth of juvenile fossil hominids as being "more like humans" or "more like apes" based on statistical similarity to group standards. Here, this central tendency discrimination (CTD) is tested for its ability to recognize ape and human patterns of dental development in 789 subadult hominoids. Tooth development of a modern human sample (665 black southern Africans) was scored entirely by an outside investigator; pongid and fossil hominid samples (59 Pan, 50 Gorilla, and 14 fossil hominids) were scored by the author. The claim of Lampl et al. ([1993] Am. J. Phys. Anthropol. 90:113-127) that Smith's 1986 method succeeds in only 8% of human cases was not sustained. Figures for overall success of classification (87% humans, 68% apes) mask important effects of teeth sampled and age class. For humans, the power of CTD varied between 53% and 92% depending on the number and kind of teeth available--nearly that of a coin toss when data described only two nearby teeth, but quite successful with more teeth or distant teeth. For apes, only age class affected accuracy: "Infant" apes (M1 development or = root 1/4), however, were correctly discriminated in 87% of cases. Overall, CTD can be considered reliable (accuracy of 92% for humans and 88% for apes) when data contrast development of distant dental fields and subjects are juveniles (not infants). Restricting analysis of fossils to specimens satisfying these criteria, patterns of dental development of gracile australopithecines and Homo habilis remain classified with African apes. Those of Homo erectus and Neanderthals are classified with humans, suggesting that patterns of growth evolved substantially in the Hominidae. To standardize future research, the computer program that operationalizes CTD is now available.

In vitro study of heat production during power reduction of equine mandibular teeth.

Science.gov (United States)

Allen, Martin L; Baker, Gordon J; Freeman, David E; Holmes, Kenneth R; Marretta, Sandra Manfra; Scoggins, R Dean; Constable, Peter

2004-04-01

To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. In vitro study. 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, and group-C2 (10) teeth were ground for 2 minutes with water for coolant. Mean temperature increase was 1.2 degrees C at the distal thermocouple and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C at the proximal thermocouple for group-C2 teeth. In general, an increase of 5 degrees C in human teeth is considered the maximum increase before there is permanent damage to tooth pulp. In group-NC2 teeth, temperature increased above this limit by several degrees, whereas in group-C2 teeth, there was little or no temperature increase. Our results suggest that major reduction of equine teeth by use of power instruments causes thermal changes that may cause irreversible pulp damage unless water cooling is used.

Accuracy of three-dimensional printing for manufacturing replica teeth.

Science.gov (United States)

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

2015-09-01

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. 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. 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. This study confirms that FDM and PolyJet technologies are accurate enough to be usable in orthodontic diagnosis and treatment.

Incidence of two canals in extracted mandibular incisors teeth of Saudi Arabian samples

Directory of Open Access Journals (Sweden)

Khalid S Al-Fouzan

2012-01-01

Full Text Available Aim: The purpose of this in vitro study is to provide clinical data on the presence of the second canal in mandibular incisor teeth of Saudi Arabian Samples. Materials and Methods: Eighty extracted human mandibular incisors were collected from Saudi patients. The teeth were accessed by small round bur then placed in 5.25% sodium hypochlorite for 24 hours to dissolve the organic debris. Indian ink was injected inside the root canal systems under negative pressure. The teeth were decalcified in 5% nitric acid for three days then dehydrated in different concentrations of ethyl alcohol. Following the decalcification process, the teeth were cleared in methyl salicylate and evaluated according to Vertucci′s classification. Result: Fifty six of both mandibular central and lateral incisor teeth (70% had type I canal configuration (one main canal and one main apical foramen, while the remaining 30% of the sample (24 teeth had a type III canal configuration (two separate canals and merged into one canal before exiting the tooth through single apical foramen. Conclusion : The incidence of two canals in mandibular incisor teeth is about one third of the examined Saudi Arabian samples with no difference between the centrals and laterals. The clinician should deal with these teeth as if they have two canals unless it is proved otherwise.

Rotary endodontics in primary teeth - A review.

Science.gov (United States)

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

2016-01-01

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

The history of Latin teeth names.

Science.gov (United States)

Šimon, František

2015-01-01

This paper aims to give an account of the Latin naming of the different types of teeth by reviewing relevant historical and contemporary literature. The paper presents etymologies of Latin or Greek teeth names, their development, variants and synonyms, and sometimes the names of their authors. The Greek names did not have the status of official terms, but the Latin terms for particular types of teeth gradually established themselves. Names for the incisors, canines and molars are Latin calques for the Greek ones (tomeis, kynodontes, mylai), dens serotinus is an indirect calque of the Greek name (odús) opsigonos, and the term pre-molar is created in the way which is now common in modern anatomical terminology, using the prefix prae- = pre and the adjective molaris. The Latin terms dentes canini and dentes molares occur in the Classical Latin literature, the term (dentes) incisivi is found first time in medieval literature, and the terms dentes premolares and dens serotinus are modern-age ones.

A comparative histologic study on furcal perforation repair with Root MTA and Pro Root MTA in fully developed teeth in dog

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Rahimi S.

2005-07-01

Full Text Available Background and Aim: The goal of endodontics is to seal the root canal system from the orifice to apical constriction completely and tridimensionally.Hence perforations during root canal therapy, because of caries or resorptions must be sealed and obturated with ideal materials. The aim of this study was to histologically compare two kinds of mineral trioxide aggregate Root MTA and Pro Root MTA for furcal perforation repair in developed teeth in dog. Materials and Methods: In this experimental study, thirty teeth consisting of second, third and fourth mandibular premolars of five German shepherd dogs were selected. Twenty-four teeth were randomly divided into four experimental groups (6 teeth each. One pair of Root MTA and Pro Root MTA groups studied in one month and the other in three months intervals. Positive and negative control groups was each contained three teeth. In positive control group, perforations were not treated and negative control group contained intact teeth. In experimental groups perforations repaired after one week exposure to oral cavity with Root MTA or Pro Root MTA. After time intervals animals were subjected to vital perfusion and 6 m histologic sections were prepared. Inflammation and hard tissue formation were ranked by Cox criteria. Data were analysed using Mann-Whitney and Chi-Square statistical tests with P0.05. Conclusion: Mineral Trioxide Aggregate is an adequate material for furcal perforation repair in dog’s teeth. Root MTA could be a good substitute for Pro Root MTA considering the lower cost and similar characteristics.

CORROSION IN ACIDIC BEVERAGES AND RECOVERY OF MICROHARDNESS OF HUMAN TEETH ENAMEL

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Petra Gaalova

2016-05-01

Full Text Available We studied the influence of corrosion in acidic beverages (white wine, pH~3.5 on micromechanical properties of human teeth. Simultaneously, the effect of fluorine-containing mouthwash (pH~4.4 and of artificial saliva (pH~5.3 in terms of their protective action against corrosion, and the recovery of mechanical properties through fluoridation and re-calcification was studied. The influence of the solutions on Vickers hardness of dental enamel was monitored on the basis of results from the corrosion tests carried out under quasi-dynamic conditions. The tests were performed at the temperature corresponding to the temperature of human body (37°C. The measurements confirmed a significant deterioration of microhardness with prolonged exposure to white wine. The Vickers hardness decreased from 347 HV0.2 in un-corroded specimens to 186 HV0.2 in samples corroded for 60 minutes in white wine. A recovery of Vickers hardness was observed after 60 minutes exposition time in the fluoridation solution, with the increase from 186 to 372 HV0.2. Similar effect was observed in the artificial saliva solution, with observed hardness increase from 186 to 320 HV0.2. Healing of corrosion-induced defects by the action of both solutions was observed by SEM, and associated with observed increase of hardness

Supernumerary teeth: case report and literature review

International Nuclear Information System (INIS)

Bolanos Lopez, Violeta

2008-01-01

Supernumerary teeth (ST) have been an anomaly of tooth development, this is refered to the increase in the number of pieces in the normal dentition. It can be unique, multiple, unilateral or bilateral, normal or altered form; appear erupted, impacted or retained. Both dentitions are affected, but is most common in the permanent. The literature review has covered and mentioned spanned supernumerary teeth, the definition, etiology, characteristics and classification according to number, position and shape; as diagnose, alterations or clinical sequelae - eruptive associated with them and possible treatments to be done when it occurs. The presence of mechanical accidents have been a frequent complication, within this, displacement of adjacent teeth has been the most common; is associated with different syndromes such as lip and palate cleft; however, they can not be related with pathologies; being mesiodens the most frequent. (author) [es

Shark teeth as edged weapons: serrated teeth of three species of selachians.

Science.gov (United States)

Moyer, Joshua K; Bemis, William E

2017-02-01

Prior to European contact, South Pacific islanders used serrated shark teeth as components of tools and weapons. They did this because serrated shark teeth are remarkably effective at slicing through soft tissues. To understand more about the forms and functions of serrated shark teeth, we examined the morphology and histology of tooth serrations in three species: the Tiger Shark (Galeocerdo cuvier), Blue Shark (Prionace glauca), and White Shark (Carcharodon carcharias). We show that there are two basic types of serrations. A primary serration consists of three layers of enameloid with underlying dentine filling the serration's base. All three species studied have primary serrations, although the dentine component differs (orthodentine in Tiger and Blue Sharks; osteodentine in the White Shark). Smaller secondary serrations are found in the Tiger Shark, formed solely by enameloid with no contribution from underlying dentine. Secondary serrations are effectively "serrations within serrations" that allow teeth to cut at different scales. We propose that the cutting edges of Tiger Shark teeth, equipped with serrations at different scales, are linked to a diet that includes large, hard-shelled prey (e.g., sea turtles) as well as smaller, softer prey such as fishes. We discuss other aspects of serration form and function by making analogies to man-made cutting implements, such as knives and saws. Copyright © 2016 Elsevier GmbH. All rights reserved.

Rotary endodontics in primary teeth – A review

OpenAIRE

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

2016-01-01

Endodontic treatment in primary teeth can be challenging and time consuming, especially during canal preparation, which is considered one of the most important steps in root canal therapy. The conventional instrumentation technique for primary teeth remains the “gold-standard” over hand instrumentation, which makes procedures much more time consuming and adversely affects both clinicians and patients. Recently nickel–titanium (Ni–Ti) rotary files have been developed for use in pediatric endod...

Incidence of Radiographic Cystic Lesions Associated With Unerupted Teeth in Dogs.

Science.gov (United States)

Babbitt, Sam G; Krakowski Volker, Mary; Luskin, Ira R

2016-12-01

Medical records and radiographs were retrospectively reviewed over a 3-year period (2012-2015) from dogs presented to a private dental referral practice. Medical records were evaluated for the diagnosis of impacted or embedded teeth. The identified dogs' radiographs were reviewed for the presence of radiographically significant cystic lesions that were associated with the impacted or embedded teeth. Radiographic criteria were established by the authors for the purposes of identifying cystic lesions in dogs of different breeds and sizes, using established indices from human dental pathology as a basis. When histopathology results were available, they were reviewed and reported. In this study, 136 dogs ranging in age from 3 months to 17 years were diagnosed with 213 unerupted teeth during the study period. There were 62 (29.1%) of the 213 radiographically apparent cystic lesions identified based on the criteria proposed in this study. In this study, 146 (68.5%) of the 213 unerupted teeth were identified as mandibular first premolar teeth. Histopathology was obtained on 28 (45.1%) of the 62 diagnosed cystic lesions. Dentigerous cysts accounted for 20 (71.4%) of the 28 cystic lesions. Brachycephalic breeds were overrepresented in this study. Boxer, pug, Shih Tzu, and Boston terrier dogs were most likely to present with cystic lesions associated with unerupted teeth. Seventeen (85%) of the 20 cases with a histopathologic diagnosis of dentigerous cyst were found within these 4 brachycephalic breeds.

Endotoxin content in endodontically involved teeth. 1975.

Science.gov (United States)

Schein, Benjamin; Schilder, Herbert

2006-04-01

Fluid was aspirated from the root canals of 40 endodontically involved teeth. This fluid was assayed for endotoxin with the limulus lysate test. Pulpless teeth contained greater concentrations of endotoxin than those with vital pulps. Symptomatic teeth also contained more endotoxin than asymptomatic teeth.

Trace element analysis of blackish staining on the crowns of human archaeological teeth

Energy Technology Data Exchange (ETDEWEB)

Stermer, E.M. [Univ. of Oslo, Dept. of Oral Radiology, Oslo (Norway); Risnes, S. [Univ. of Oslo, Dept. of Oral Biology, Faculty of Dentistry, Oslo (Norway); Fischer, P.M. [Chalmers Univ. of Technology, Dept. of Physics, SIMS Lab., Goeteborg (Sweden)

1996-10-01

A blackish staining found on the crowns of teeth of 51 skulls from the excavation of the medieval St. Olav`s church in Trondheim was analyzed using secondary ion mass spectrometry (SIMS) and atomic absorption spectrometry (AAS). In four teeth, mass spectra and step scan concentration profiles of SIMS were performed and compared with the grey scale pattern in photographs of the analyzed paths. The manganese curve showed the highest degree of conformity with the grey scale pattern. The AAS analysis confirmed the increased content of manganese in blackish stained enamel. It was concluded that manganese, probably in the form of an oxide deposited from the soil, was the cause of the blackish staining. (au).

Trace element analysis of blackish staining on the crowns of human archaeological teeth

International Nuclear Information System (INIS)

Stermer, E.M.; Risnes, S.; Fischer, P.M.

1996-01-01

A blackish staining found on the crowns of teeth of 51 skulls from the excavation of the medieval St. Olav's church in Trondheim was analyzed using secondary ion mass spectrometry (SIMS) and atomic absorption spectrometry (AAS). In four teeth, mass spectra and step scan concentration profiles of SIMS were performed and compared with the grey scale pattern in photographs of the analyzed paths. The manganese curve showed the highest degree of conformity with the grey scale pattern. The AAS analysis confirmed the increased content of manganese in blackish stained enamel. It was concluded that manganese, probably in the form of an oxide deposited from the soil, was the cause of the blackish staining. (au)

Association Between Odontoma and Impacted Teeth.

Science.gov (United States)

Isola, Gaetano; Cicciù, Marco; Fiorillo, Luca; Matarese, Giovanni

2017-05-01

Odontoma is considered to be the most common odontogenic tumor of the oral cavity. Most odontomas are asymptomatic and are discovered during routine radiographic investigations and can cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. By a retrospective study design, demographic and clinical data regarding patients who presented odontomas from year 1995 to 2015 were obtained in order and the influence of active therapy on the dentition and on the treatment of impacted teeth was analyzed. Forty-five patients (mean age 14.2 years) with 29 complex and 16 compound odontomas were included in this retrospective study. Initial symptoms were delayed eruption of permanent teeth (n = 25), pain (n = 6), swellings (n = 4), and no symptoms (n = 10); 31 patients were discovered by incidence, all of them via panoramic radiographs. The mandible/maxilla ratio was about 2:1 (31/15). Thirty-two out of 45 odontomas were in close proximity of at least 1 tooth (n = 21 at incisive). A total of 12 teeth were extracted (complex: n = 8; compound: n = 4). Of the nonextracted teeth, 33 teeth were displaced and retained. Of those, 29 teeth were aligned through orthodontic-surgical approach and 4 teeth erupted spontaneously after surgery during the follow-up period. An early detection of odontoma is more likely an accidental radiological finding, hence the need for routine radiographic analysis should be emphasized. Early diagnosis of odontomas in primary dentition is crucial in order to prevent later complications, such as impaction or failure of eruption of teeth.

[Retrospective analysis of pulp revascularization in immature permanent teeth with diffuse pulpitis].

Science.gov (United States)

Peng, C F; Zhao, Y M; Yang, Y; Liu, H; Qin, M

2017-01-09

Objective: To evaluate the treatment effectiveness of revascularization in immature permanent teeth with diffuse pulpitis and to provide an alternative approach for the treatment of these teeth. Methods: Clinical and radiographic data were collected from 17 immature permanent teeth which were diagnosed as diffuse pulpitis and with their pulp extirpated at Emergency Department of Peking University School and Hospital of Stomatology. All these teeth were treated using pulp revascularization at Department of Pediatric Dentistry. Clinical success rate was then evaluated based on the clinical and radiographic findings. The increase of root length and dentin wall thickness of the revascularized teeth and the contralateral control teeth were measured and compared according to the preoperative and recall periapical radiographs. Results: The average follow-uptime is (25.8±9.9) months (12-46 months). Totally 13 out of the 17 teeth showed normal clinical and radiographic manifestation and achieved the increasein root length and dentin wall thickness. They met criteria for success treatment. The rest 4 out of the 17 teeth also showed root length and dentin wall thickness increaseand apical foramen closure. However, periapical inflammations were observed during 12 to 36 monthfollow-ups. These cases were recognized as failed. In all the17 teeth, the increase of root length and dentin wall thickness was not significantly different between the revascularized teeth and the contralateral control teeth ( P> 0.05). Conclusions: Pulp revascularization in young permanent teeth with diffuse pulpitis resulted in similar clinical outcomes in root development and root canal wall formation compared with the contralateral control teeth. However, reinfection might occur during long-term follow-up.

Classical music and the teeth.

Science.gov (United States)

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.

Rotary endodontics in primary teeth – A review

Science.gov (United States)

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

Rotary endodontics in primary teeth – A review

Directory of Open Access Journals (Sweden)

Sageena George

2016-01-01

Full Text Available 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.

Relationship between crown placement and the survival of endodontically treated teeth.

Science.gov (United States)

Aquilino, Steven A; Caplan, Daniel J

2002-03-01

Crowns have been considered the restoration of choice for endodontically treated teeth, but their selection has been based primarily on anecdotal evidence. This study tested the hypothesis that crown placement (coronal coverage) is associated with improved survival of endodontically treated teeth when preaccess, endodontic, and restorative factors are controlled. A University of Iowa College of Dentistry treatment database was used to identify permanent teeth that had undergone initial obturation between July 1, 1985, and December 31, 1987. Study patients were restricted to persons with at least 1 dental visit in each 2-year interval from 1985 to 1996; a simple random sample of 280 patients (n = 400 teeth) was selected. Dental charts, radiographs, and computerized databases were examined to ascertain variables of interest and to verify study inclusion criteria. Kaplan-Meier survival estimates were generated for the 203 teeth that satisfied study inclusion criteria. Multivariate Cox proportional hazards regression models were developed, with standard errors adjusted to account for clustering of teeth within patients. When tooth type and radiographic evidence of caries at access were controlled, the final Cox model showed that endodontically treated teeth not crowned after obturation were lost at a 6.0 times greater rate than teeth crowned after obturation (95% confidence interval: 3.2 to 11.3). Within the limitations of this study, a strong association between crown placement and the survival of endodontically treated teeth was observed. These results may impact treatment planning if long-term tooth retention is the primary goal.

The determination of 90Sr and 228Ra in human teeth by age groups and in other substances

International Nuclear Information System (INIS)

Neuzil, E.F.; Dysart, M.E.

1984-01-01

The total 90 Sr content of human teeth peaks at a value of 0.65 pCi/g calcium in the age group of 20-30 years. It is not present in those 50 years or older. Various other substances show extensive amounts of 90 Sr especially in cow bones, bone meal and dry milk. The radionuclide 228 Ra (daughter of 232 Th) is present at a mean level of about 0.5 pCi/g Ca in all substances tested and in all age groups, but especially high in bone meal (5.60 pCi/g Ca) and calcium lactate tablets. (author)

A comparison of the antibacterial activity of the two methods of photodynamic therapy (using diode laser 810 nm and LED lamp 630 nm) against Enterococcus faecalis in extracted human anterior teeth.

Science.gov (United States)

Asnaashari, Mohammad; Mojahedi, Seyed Masoud; Asadi, Zahra; Azari-Marhabi, Saranaz; Maleki, Alireza

2016-03-01

Failure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments. The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth. Fifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu=23) and two control groups (nu=5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group. The Colony Forming Unit (CFU) in LED group (log10 CFUs=4.88±0.82) was significantly lower than the laser group (log CFUs=5.49±0.71) (p value=0.021). CFUs in positive control group (Log10 CFUs=10.96±0.44) were significantly higher than the treatment group (p˂0.001). No bacterial colony was found in negative control group. The results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth. Copyright © 2015 Elsevier B.V. All rights reserved.

The dentin-enamel junction and the fracture of human teeth

Science.gov (United States)

Imbeni, V.; Kruzic, J. J.; Marshall, G. W.; Marshall, S. J.; Ritchie, R. O.

2005-03-01

The dentin-enamel junction (DEJ), which is the interfacial region between the dentin and outer enamel coating in teeth, is known for its unique biomechanical properties that provide a crack-arrest barrier for flaws formed in the brittle enamel1. In this work, we re-examine how cracks propagate in the proximity of the DEJ, and specifically quantify, using interfacial fracture mechanics, the fracture toughness of the DEJ region. Careful observation of crack penetration through the interface and the new estimate of the DEJ toughness (~5 to 10 times higher than enamel but ~75% lower than dentin) shed new light on the mechanism of crack arrest. We conclude that the critical role of this region, in preventing cracks formed in enamel from traversing the interface and causing catastrophic tooth fractures, is not associated with the crack-arrest capabilities of the interface itself; rather, cracks tend to penetrate the (optical) DEJ and arrest when they enter the tougher mantle dentin adjacent to the interface due to the development of crack-tip shielding from uncracked-ligament bridging.

Teeth re-whitening effect of strawberry juice on coffee stained teeth

OpenAIRE

Annisya Pramesti; Tadeus Arufan Jasrin; Opik Taofik Hidayat

2018-01-01

Many people favor coffee. However, regarding health and aesthetic dentistry, coffee gives a negative effect. Tanin in coffee causes a brown stain on the tooth surface. Therefore, in aesthetic dental care, teeth whitening has become popular matter. One of the natural ingredients used for teeth whitening treatment is strawberry. The purpose of this study was to obtained data regarding the effect of strawberry juice on the re-whitening process of the coffee-stained tooth enamel surface. This stu...

Further investigation of the heavy metal content of the teeth of the bank vole as an exposure indicator of Environmental Pollution (1987)(1987)in Poland

Energy Technology Data Exchange (ETDEWEB)

Gdula-Argasinska, Joanna; Appleton, John; Sawicka-Kapusta, Katarzyna; Spence, Bill

2004-09-01

The content of heavy metals in mineralised dental tissues is an indicator of the exposure of their mineral phase to heavy metals during the time of tooth development and dental tissue formation. Therefore, teeth have been used as bio-indicators which accurately reflect the environmental or dietary exposure of animals and humans to heavy metals. This study follows from the earlier work in which it was demonstrated that the teeth from bank voles inhabiting various environmentally polluted and non-polluted forests in Southern Poland were reliable indicators of exposure to heavy metals. Using analytical techniques employed in the earlier study heavy metal concentrations were obtained in the teeth of bank voles trapped in 1998-2000 to determine if efforts to clean up the environment could be detected in changes in heavy metal concentrations in the teeth. The results show that these efforts are reflected in lower concentrations of heavy metals in the teeth but that cross border contamination remains a problem.

Evaluation of Teeth Development in Unilateral Cleft Lip and Palate ...

African Journals Online (AJOL)

2018-02-23

Feb 23, 2018 ... in patients with cleft lip and palate using medical software ... to be used in routine dental treatment and in particular the need to do more study. ... cleft palate/lip surgery were examined. ... segment from the “evaluate” tab of the program. Teeth .... cases of cleft palate or lip. ..... of maxillary canines: A CT study.

Iron deposition in modern and archaeological teeth

Energy Technology Data Exchange (ETDEWEB)

Williams, A.-M.M., E-mail: AnneMarie.Williams@utas.edu.au [School of Medicine, Private Bag 34, University of Tasmania, Hobart 7001 (Australia); Siegele, R. [Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

2014-09-15

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.

Iron deposition in modern and archaeological teeth

International Nuclear Information System (INIS)

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

2014-01-01

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

Human dental pulp stem cells derived from cryopreserved dental pulp tissues of vital extracted teeth with disease demonstrate hepatic-like differentiation.

Science.gov (United States)

Chen, Y K; Huang, Anderson H C; Chan, Anthony W S; Lin, L M

2016-06-01

Reviewing the literature, hepatic differentiation of human dental pulp stem cells (hDPSCs) from cryopreserved dental pulp tissues of vital extracted teeth with disease has not been studied. This study is aimed to evaluate the hypothesis that hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease could possess potential hepatic differentiation. Forty vital extracted teeth with disease recruited for hDPSCs isolation, stem cell characterization and hepatic differentiation were randomly and equally divided into group A (liquid nitrogen-stored dental pulp tissues) and group B (freshly derived dental pulp tissues). Samples of hDPSCs isolated from groups A and B but without hepatic growth factors formed negative controls. A well-differentiated hepatocellular carcinoma cell line was employed as a positive control. All the isolated hDPSCs from groups A and B showed hepatic-like differentiation with morphological change from a spindle-shaped to a polygonal shape and normal karyotype. Differentiated hDPSCs and the positive control expressed hepatic metabolic function genes and liver-specific genes. Glycogen storage of differentiated hDPSCs was noted from day 7 of differentiation-medium culture. Positive immunofluorescence staining of low-density lipoprotein and albumin was observed from day 14 of differentiation-medium culture; urea production in the medium was noted from week 6. No hepatic differentiation was observed for any of the samples of the negative controls. We not only demonstrated the feasibility of hepatic-like differentiation of hDPSCs from cryopreserved dental pulp tissues of vital extracted teeth with disease but also indicated that the differentiated cells possessed normal karyotype and were functionally close to normal hepatic-like cells. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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

Science.gov (United States)

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.

Probing around implants and teeth with healthy or inflamed peri-implant mucosa/gingival. A histologic comparison in cynomolgus monkeys. (Macaca fascicularis)

DEFF Research Database (Denmark)

Schou, Søren; Holmstrup, Palle; Stoltze, K.

2002-01-01

Osseointegrated oral implants; teeth; phathology; peri-implant mucositis; gingivitis; peri-implantitis; periodontitis; diagnosis; probing depth; non-human primates; cynomolgus monkeys: Macaca fascicularis......Osseointegrated oral implants; teeth; phathology; peri-implant mucositis; gingivitis; peri-implantitis; periodontitis; diagnosis; probing depth; non-human primates; cynomolgus monkeys: Macaca fascicularis...

Crack arrest within teeth at the dentinoenamel junction caused by elastic modulus mismatch

OpenAIRE

Bechtle, Sabine

2010-01-01

Enamel and dentin compose the crowns of human teeth. They are joined at the dentinoenamel junction (DEJ) which is a very strong and well-bonded interface unlikely to fail within healthy teeth despite the formation of multiple cracks within enamel during a lifetime of exposure to masticatory forces. These cracks commonly are arrested when reaching the DEJ. The phenomenon of crack arrest at the DEJ is described in many publications but there is little consensus on the underlying cause and mecha...

Monitoring of Environmental Contamination and Addressing Health Risks Through the Analysis of Teeth by Means of Nuclear Techniques

International Nuclear Information System (INIS)

Oliveira, M.C.C.; Arruda-Neto, J.D.T.; Deppman, A.; Likhachev, V.P.; Medero, D.R.; Luzardo, F.M.; Cazorla, L.L.; Dias, J.F.; Yoneama, M.L.

2003-01-01

Radionuclides (mostly uranium and thorium) and heavy metals (lead and cadmium) are environmental contaminants produced by agricultural and industrial activities, or are simply the result of soil and water pollution by non regular human activities (e.g. disposal of garbage in rivers and water ponds). Humans incorporate these contaminants via the food chain, where bones are the most important target-organ. The incidence of health risk and hazards would depend, obviously, on the time length and intensity of such incorporation. However, while in vivo monitoring of human bones is difficult, the analysis of teeth is a promising possibility, particularly for the quantification of lead and cadmium in deciduous tooth (milk tooth), and uranium in adult tooth. This study will be focused, initially, on the Guarapiranga dam and on the human settlements located in its surroundings. Their teeth will be collected and classified by age and social-economical status, with the collaboration of the Dentistry School from UNISA, which is developing several social tasks in the Guarapiranga region. Water, plants and fishes will be collected and analyzed too, aiming at biokinetic al study of contaminants, particularly the transfer dynamics among the species of the dam. (Author)

Pulp tissue from primary teeth: new source of stem cells

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Paloma Dias Telles

2011-06-01

Full Text Available SHED (stem cells from human exfoliated deciduous teeth represent a population of postnatal stem cells capable of extensive proliferation and multipotential differentiation. Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED are highly proliferative cells derived from an accessible tissue source, and therefore hold potential for providing enough cells for clinical applications. In this review, we describe the current knowledge about dental pulp stem cells and discuss tissue engineering approaches that use SHED to replace irreversibly inflamed or necrotic pulps with a healthy and functionally competent tissue that is capable of forming new dentin.

Supernumerary impacted teeth in a patient with SOX2 anophthalmia syndrome.

Science.gov (United States)

Numakura, Chikahiko; Kitanaka, Sachiko; Kato, Mitsuhiro; Ishikawa, Shigeo; Hamamoto, Yoshioki; Katsushima, Yuriko; Kimura, Toshiyuki; Hayasaka, Kiyoshi

2010-09-01

SOX2 anophthalmia syndrome characteristically presents as anophthalmia or microphthalmia, with various extraocular symptoms, such as hypogonadotropic hypogonadism, brain anomaly, and esophageal abnormalities. In this report, we describe a patient with SOX2 anophthalmia syndrome complicated with a dental anomaly, multiple supernumerary impacted teeth, and persistence of deciduous teeth. Multiple supernumerary teeth are usually not solitary symptoms, but indicate systemic syndrome such as cleidocranial dysplasia. In odontogenesis, many transcriptional factors, such as BMPs, FGFs, and Wnts, play significant roles and SOX2 is known to interact with some of them. The role of SOX2 in dental development remains unknown, however, multiple supernumerary teeth can be considered as extraocular symptoms of SOX2 anophthalmia syndrome, rather than the coincidence of two rare diseases.

The Effect of Multiple Sulfatase Deficiency (MSD) on Dental Development: Can We Use the Teeth as an Early Diagnostic Tool?

Science.gov (United States)

Zilberman, Uri; Bibi, Haim

2016-01-01

Multiple sulfatase deficiency (MSD) is a rare autosomal recessive inborn error of metabolism due to reduced catalytic activity of the different sulfatase. Affected individuals show neurologic deterioration with mental retardation, skeletal anomalies, organomegaly, and skin changes as in X-linked ichthyosis. The only organ that was not examined in MSD patients is the dentition. To evaluate the effect of the metabolic error on dental development in a patient with the intermediate severe late-infantile form of MSD (S155P). Histological and chemical study were performed on three deciduous and five permanent teeth from MSD patient and pair-matched normal patients. Tooth germ size and enamel thickness were reduced in both deciduous and permanent MSD teeth, and the scalloping feature of the DEJ was missing in MSD teeth causing enamel to break off from the dentin. The mineral components in the enamel and dentin were different. The metabolic error insults the teeth in the stage of organogenesis in both the deciduous and permanent dentition. The end result is teeth with very sharp cusp tips, thin hypomineralized enamel, and exposed dentin due to the break off of enamel. These findings are different from all other types of MPS syndromes.Clinically the phenotype of intermediate severe late-infantile form of MSD appeared during the third year of life. In children of parents that are carriers, we can diagnose the disease as early as birth using X-ray radiograph of the anterior upper region or as early as 6-8 months when the first deciduous tooth erupt and consider very early treatment to ameliorate the symptoms.

Ancient whales did not filter feed with their teeth.

Science.gov (United States)

Hocking, David P; Marx, Felix G; Fitzgerald, Erich M G; Evans, Alistair R

2017-08-01

The origin of baleen whales (Mysticeti), the largest animals on Earth, is closely tied to their signature filter-feeding strategy. Unlike their modern relatives, archaic whales possessed a well-developed, heterodont adult dentition. How these teeth were used, and what role their function and subsequent loss played in the emergence of filter feeding, is an enduring mystery. In particular, it has been suggested that elaborate tooth crowns may have enabled stem mysticetes to filter with their postcanine teeth in a manner analogous to living crabeater and leopard seals, thereby facilitating the transition to baleen-assisted filtering. Here we show that the teeth of archaic mysticetes are as sharp as those of terrestrial carnivorans, raptorial pinnipeds and archaeocetes, and thus were capable of capturing and processing prey. By contrast, the postcanine teeth of leopard and crabeater seals are markedly blunter, and clearly unsuited to raptorial feeding. Our results suggest that mysticetes never passed through a tooth-based filtration phase, and that the use of teeth and baleen in early whales was not functionally connected. Continued selection for tooth sharpness in archaic mysticetes is best explained by a feeding strategy that included both biting and suction, similar to that of most living pinnipeds and, probably, early toothed whales (Odontoceti). © 2017 The Authors.

Mothers Perception of Teething in Children

African Journals Online (AJOL)

TNHJOURNALPH

includes blistering, bleeding, placing leeches on the gum, applying cautery to the back of the head and lancing- a method where lancet was used to cut the gum in other for the teeth to appear.7 1t was thought that failure of the teeth to appear was due to lack of a pathway and that this was the cause of death from teething,.

Comparative study of the fluorescence intensity of dental composites and human teeth submitted to artificial aging.

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Jablonski, Tatiana; Takahashi, Marcos Kenzo; Brum, Rafeal Torres; Rached, Rodrigo Nunes; Souza, Evelise M

2014-01-01

The aim of this study was to evaluate quantitatively the fluorescence of resin composites and human teeth, and to determine the stability of fluorescence after aging. Ten specimens were built using a 1 mm thick increment of dentin composite overlapped by a 0.5 mm thick increment of enamel composite. Ten sound human molars were sectioned and silicon carbide-polished to obtain enamel and dentin slabs 1.5 mm in thickness. Fluorescence measurements were carried out by a fluorescence spectrophotometer before and after thermocycling (2000 cycles, 5°C and 55°C). One-way analysis of variance (ANOVA) with repeated measures and Tukey's test were performed at a significance level of 5%. Most of the tested composites showed significant differences in fluorescence both before and after aging (P 0.05), and was the only composite that showed comparable results of fluorescence to the tooth structure before and after thermocycling. With the exception of Filtek Supreme, there were significant reductions in fluorescence intensity for all the tested composites (P < 0.05).

Pulpal blood flow recorded from human premolar teeth with a laser Doppler flow meter using either red or infrared light.

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Kijsamanmith, Kanittha; Timpawat, Siriporn; Vongsavan, Noppakun; Matthews, Bruce

2011-07-01

To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human premolar teeth. Recordings were made from 11 healthy teeth in 9 subjects (aged 16-30 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. With infrared light, the dam significantly decreased the mean blood flow by 80%. Injecting LA and cavity preparation had no significant effect. Removal and replacement of the pulp reduced the mean blood flow by 58%. There was no further change when the pulp was removed. With red light, the dam reduced the signal from intact teeth by 60%. Injecting LA and cavity preparation had no significant effect. The signal fell by 67% after pulp removal and replacement and did not change significantly when the pulp was removed. Opaque rubber dam minimises the contribution of non-pulpal tissues to the laser Doppler signal recorded from premolars. Using dam, the pulp contributed about 60% to the blood flow signal with both red and infrared light. The difference between them in this respect was not significant. Copyright © 2010 Elsevier Ltd. All rights reserved.

Type VII collagen is enriched in the enamel organic matrix associated with the dentin-enamel junction of mature human teeth.

Science.gov (United States)

McGuire, Jacob D; Walker, Mary P; Mousa, Ahmad; Wang, Yong; Gorski, Jeff P

2014-06-01

The inner enamel region of erupted teeth is known to exhibit higher fracture toughness and crack growth resistance than bulk phase enamel. However, an explanation for this behavior has been hampered by the lack of compositional information for the residual enamel organic matrix. Since enamel-forming ameloblasts are known to express type VII collagen and type VII collagen null mice display abnormal amelogenesis, the aim of this study was to determine whether type VII collagen is a component of the enamel organic matrix at the dentin-enamel junction (DEJ) of mature human teeth. Immunofluorescent confocal microscopy of demineralized tooth sections localized type VII collagen to the organic matrix surrounding individual enamel rods near the DEJ. Morphologically, immunoreactive type VII collagen helical-bundles resembled the gnarled-pattern of enamel rods detected by Coomassie Blue staining. Western blotting of whole crown or enamel matrix extracts also identified characteristic Mr=280 and 230 kDa type VII dimeric forms, which resolved into 75 and 25 kDa bands upon reduction. As expected, the collagenous domain of type VII collagen was resistant to pepsin digestion, but was susceptible to purified bacterial collagenase. These results demonstrate the inner enamel organic matrix in mature teeth contains macromolecular type VII collagen. Based on its physical association with the DEJ and its well-appreciated capacity to complex with other collagens, we hypothesize that enamel embedded type VII collagen fibrils may contribute not only to the structural resilience of enamel, but may also play a role in bonding enamel to dentin. Copyright © 2014 Elsevier Inc. All rights reserved.

Simple replantation protocol to avoid ankylosis in teeth intended for orthodontic treatment

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Yuli Nugraeni

2009-03-01

Full Text Available Background: Dento-alveolar trauma resulted from accidents involving the oral regions mostly affect the upper central incisors. Overjet that is beyond 5 mm and incompetent lip also contribute to increase the risk. Several literatures had already discussed different methods of replantation of avulsed teeth. However, it was not meant for further orthodontic treatment. Purpose: The objective of this review is to propose a simple replantation protocol of avulsed teeth which also prevent from ankylosis. Reviews: Protruded teeth usually need orthodontic treatment; therefore, an appropriate management should be done to avoid the development of ankylosis. Ankylosis of the periodontal ligament (PDL becomes a problem in orthodontic tooth movement in repositioned or replanted teeth. In addition, ankylosed teeth also more susceptible to root resorption. Actually, it was caused by the endodontic treatment. In particular, severely protruded or unoccluded teeth are hypofunctional, therefore have narrow PDL, thus it may facilitate to ankylosis development. Ideal management protocol such as the use of root canal sealer i.e. mineral trioxide aggregate (MTA; the using of Emdogain, and resilient wiring or semi-rigid fixation with brackets has become a solution in avulsed teeth arranged for orthodontic treatment. Nevertheless, the presence of oral surgeon, endodontist and orthodontist in the same time, and also ideal preparations after an accident was difficult to achieve. Conclusion: Considering that reducing the ongoing PDL inflammation with intracanal medicaments and maintaining the functional force during mastication is possible; it is concluded that this simple replantation protocol is likely.

Changes in interdental papillae heights following alignment of anterior teeth.

Science.gov (United States)

Kandasamy, Sanjivan; Goonewardene, Mithran; Tennant, Marc

2007-05-01

Orthodontic alignment of overlapped incisors can reduce the apparent heights of the interdental papillae leading to unsightly dark triangles or open gingival embrasures. To determine if certain pretreatment contact point relationships between the maxillary anterior teeth were accompanied by changes in the heights of the interdental papillae after orthodontic alignment. Pre- and post-treatment intra-oral 35 mm slides, lateral cephalometric radiographs and study casts of 143 patients (60 males, 83 females) between 13 and 16 years of age were used. The patients had diastamata closed, imbricated teeth aligned and palatally or labially placed teeth repositioned. A sample of 25 patients (12 males, 13 females) between 13 and 16 years of age who had well-aligned anterior teeth at the start of treatment acted as a control group. All patients were treated for approximately 18 months. The clinical crowns of the maxillary incisors and the heights of the interdental papilla between the incisors were measured on projected images of the slides. The percentage increases or reductions in the heights of the interdental papillae were compared. The heights of the interdental papillae increased following palatal movement of labially placed (p teeth and the intrusion of one tooth relative to another. On the other hand, dark triangles are more likely to develop following labial movement of imbricated or palatally placed incisors and closure of a diastema. Clinicians should be alert to the possibility of dark triangles developing in the latter group, particularly in older patients.

Detection of stain formation on teeth by oral antiseptic solution using fiber optic displacement sensor

Science.gov (United States)

Rahman, H. A.; Rahim, H. R. A.; Harun, S. W.; Yasin, M.; Apsari, R.; Ahmad, H.; Wan Abas, W. A. B.

2013-02-01

The application of a simple intensity modulated fiber optic displacement sensor for the detection of stain formation on human teeth is demonstrated. The proposed sensor uses a concentric type bundled plastic optical fiber (POF) as a probe in conjunction with the surfaces of five human teeth as the reflecting targets. Prior to the experiment, the stains were produced extrinsically by soaking the teeth in different concentrations of oral antiseptic solution containing hexetidine. The concentration of the oral antiseptic solution is measured in volume%. For a concentration change from 0% to 80%, the peak voltage decreases exponentially from 1.15 mV to 0.41 mV with a measured resolution of 0.48% and 1.75% for concentration ranges of 0-40% and 40-80%, respectively. The correlation between the detector output and variation in the color of human tooth surface has successfully been examined. Simple in design and low in cost, this sensor can detect color changes due to hexetidine-induced stain on a tooth surface in a fast and convenient way. Thus, this sensor will be very promising in esthetic dentistry, dental color matching techniques, chemical and biomedical applications.

Mouth and Teeth (For Parents)

Science.gov (United States)

... the teeth are subject to disease. A common periodontal disease is gingivitis — inflammation of the gums characterized by redness, swelling, and sometimes bleeding. The accumulation of tartar (a hardened film of food particles and bacteria that builds up on teeth) usually causes this ...

Effect of amalgam cuspal coverage on the fracture resistance of endodontically treated teeth

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Mahshid Mohammdi Basir

2013-05-01

Full Text Available   Background and Aims: Endodontically treated teeth are prone to fracture because they loose a big amount of their structure. The treatment plan of those teeth is completed when they are rehabilitated with a strong and functional restoration. The purpose of this study was to evaluate the fracture resistance of endodontically treated teeth restored with amalgam cuspal coverage in comparison with other restorative techniques.   Materials and Methods: 40 human healthy maxillary premolars were divided into 4 groups: group1 (S: sound teeth, group 2(Co: endodontically treated teeth with MOD cavity restored with bonding and composite, group 3(Am-B: endodontically treated teeth with MOD cavity restored with bonding and amalgam and group 4 (Am-CC: endodontically treated teeth with MOD cavity restored with amalgam cuspal coverage. Then the restorations were stored in water and room temperature for 100 days at then thermocycled for 500 cycles between water baths at (5.5 ± 1 and (55 ± 1 0 C. The fracture resistance was evaluated by universal testing machine (Instron, 1195 UK with the compressive force of about 2000 N in 0.5 mm/min. The fracture modes were evaluated in four groups by a stereomicroscope. Statistical analysis (Scheffe test was done for all groups (P0.05. The lowest fracture resistance was found in group 2 (Co (384 ± 137.4 N that had no significant difference with group 3 (Am-B (P>0.05. The fracture resistance in group 4 was significantly higher than group 2 (Co and 3 (Am-B. The fracture mode in group 1 was cohesive within tooth and in group 2 (Co and 3 (Am-B was mixed cohesive and adhesive, and in group 4 was cohesive within in restorative material.   Conclusion: The highest fracture resistance was found in teeth that received amalgam cuspal coverage.

Prevalence of delayed emergence of permanent teeth as a result of local factors.

Science.gov (United States)

Johnsen, D C

1977-01-01

Delayed emergence of permanent teeth as a result of local etiologic factors was found in 45 of 1,032(4.3%) persons ages 8 through 18 in a dentally indigent population. In 36 persons (3.4%) delayed emergence resulted from causes other than those associated with premature primary molar extraction. This statistic probably approximates the potential for this problem in a treated population group. Teeth most commonly involved were mandibular second premolars, maxillary canines, and maxillary central incisors. The most common causes, respectively, were space loss, palatal position, and mesiodens. Supernumerary, malformed, and congenitally missing teeth were more frequent in persons with delayed emergence than in the rest of the population sampled. The difference was statistically significant. No correlation was found between delayed emergence and sex of the patient. In this study, teeth delayed in emergence behaved as other teeth in that they exhibited normal root development and did not contribute to resorption of adjacent roots. Except for maxillary canines, enlarged follicular spaces did not develop after eruption

ELECTRIC PULP TEST OF TEETH WITH PERIODONTAL DISEASE.

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Tsonko Uzunov

2014-10-01

Full Text Available Purpose: The aim of the research is to investigate the change in pulp vitality of teeth with periodontal disease using electric pulp tester (EPT. Methods: Subjected to observation were 108 patients with chronic periodontitis. Vitality of 805 teeth with periodontal pocket depth greater than 4 mm was studied by EPT. The research was conducted with EPT "Yonovit ". Results: The highest percentage of surveyed teeth (68.4% respond to the norm when they are tested with EPT – values between 3 μA and 10 μA . Teeth that respond to EPT with values ​​below 3 μA and between 35-100 μA are relatively equal - respectively 4.3% and 3.3%. With increased threshold of irritation – 10-35 μA react 23.4% of teeth. Small number of teeth have threshold of irritation over 100 μA - 0.6%. Conclusion: The value of EPT among periodontal damaged teeth depends on many factors - patient's age, extent of periodontal affect, group affiliation of teeth, etc.

Clinical Characteristics of Abutment Teeth with Gingival Discoloration.

Science.gov (United States)

Ristic, Ljubisa; Dakovic, Dragana; Postic, Srdjan; Lazic, Zoran; Bacevic, Miljana; Vucevic, Dragana

2017-04-06

The grey-bluish discoloration of gingiva (known as "amalgam tattoo") does not appear only in the presence of amalgam restorations. It may also be seen in cases of teeth restored with cast dowels and porcelain-fused-to-metal (PFM) restorations. The aim of this article was to determine the clinical characteristics of abutment teeth with gingival discoloration. This research was conducted on 25 patients referred for cast dowel and PFM restorations. These restorations were manufactured from Ni-Cr alloys. Ninety days after cementing the fixed prosthodontic restorations, the abutment teeth (n = 61) were divided into a group with gingival discoloration (GD) (n = 25) and without gingival discoloration (NGD) (n = 36). The control group (CG) comprised the contralateral teeth (n = 61). Plaque index, gingival index, clinical attachment level, and probing depth were assessed before fabrication and also 90 days after cementation of the PFM restorations. The gingival index, clinical attachment level, and probing depths of the abutment teeth that had GD were statistically higher before restoration, in comparison with the abutment teeth in the NGD and control groups. Ninety days after cementation, the abutment teeth with GD had significantly lower gingival indexes and probing depths, compared to the abutment teeth in the NGD group. Both abutment teeth groups (GD and NGD) had significantly higher values of clinical attachment levels when compared to the control group. There were no statistically significant differences in plaque index values between the study groups. The results of this study indicated that impairment of periodontal status of abutment teeth seemed to be related to the presence of gingival discolorations. Therefore, fabrication of fixed prosthodontic restorations requires careful planning and abutment teeth preparation to minimize the occurrence of gingival discolorations. With careful preparation of abutment teeth for cast dowels and crown restorations it may be

Inactivation of IL11 signaling causes craniosynostosis, delayed tooth eruption, and supernumerary teeth

DEFF Research Database (Denmark)

Nieminen, Pekka; Morgan, Neil V; Fenwick, Aimée L

2011-01-01

Craniosynostosis and supernumerary teeth most often occur as isolated developmental anomalies, but they are also separately manifested in several malformation syndromes. Here, we describe a human syndrome featuring craniosynostosis, maxillary hypoplasia, delayed tooth eruption, and supernumerary...... teeth. We performed homozygosity mapping in three unrelated consanguineous Pakistani families and localized the syndrome to a region in chromosome 9. Mutational analysis of candidate genes in the region revealed that all affected children harbored homozygous missense mutations (c.662C>G [p.Pro221Arg], c...... for the treatment of craniosynostosis....

Predictable management of cracked teeth with reversible pulpitis.

Science.gov (United States)

Abbott, P; Leow, N

2009-12-01

The aims of this study were to assess symptoms and signs caused by cracks in teeth and to assess a conservative management protocol. The symptoms and signs of 100 consecutive teeth that had reversible pulpitis associated with cracks were compared to findings from other reports. Teeth were managed with a conservative protocol which involved removal of cracks, caries and restorations, followed by placement of a sedative lining and interim restoration unless there were pulp exposures or insufficient tooth structure remaining. Teeth were monitored for pulp healing after three months and for up to five years. Eighty teeth did not require endodontic treatment. One tooth had an uncertain pulp status at review appointments. Fifteen teeth required endodontic treatment at the initial appointment because of carious pulp exposures (4 teeth), cracks extending into the pulp (2), and posts required (9). Four other teeth required endodontic treatment later following conservative pulp treatment due to continued pulpitis under the temporary restoration (1), pulpitis after core restoration (2), and pulp necrosis diagnosed at the review (1). Provided there is an accurate diagnosis of the pulp status and its cause, teeth with reversible pulpitis due to cracks can be treated conservatively without endodontic treatment in about 80 per cent of cases.

Changes in the chemical composition of mineralised teeth in children after antineoplastic treatment.

Science.gov (United States)

Krasuska-Sławińska, Ewa; Dembowska-Bagińska, Bożenna; Brożyna, Agnieszka; Olczak-Kowalczyk, Dorota; Czarnowska, Elżbieta; Sowińska, Agnieszka

2018-01-01

Chemotherapy, neoplasms, and their complications linked to malabsorption, malnutrition, and metabolic disorders may lead to improper tooth development and frequent severe caries in patients during/after antineoplastic treatment and to a more frequent improper tooth development in patients undergoing chemotherapy during odontogenesis. However, the causes of these abnormalities remain unknown; there are no studies on the impact of antineoplastic treatment and its complications on the chemical composition of mineralised teeth. To compare the chemical composition of mineralised teeth extracted due to complicated caries in children after chemotherapy, and of teeth extracted due to orthodontic treatment in generally healthy children. The treatment group included five teeth extracted due to complicated caries in children after antineoplastic treatment. The control group included five teeth extracted due to orthodontic treatment in generally healthy children. The chemical composition of enamel, dentine, cementum, interior of the canal, and enamel abnormalities in teeth extracted from patients after chemotherapy and in generally healthy patients were assessed with energy-dispersive X-ray spectroscopy. Results were analysed statistically. The magnesium (Mg) and zinc (Zn) mass contents in the enamel of patients after chemotherapy increased and so did the calcium (Ca) to phosphorus (P) ratio when compared to controls. Areas with abnormal enamel in patients after chemotherapy had lower concentrations of Ca and P, and higher concentrations of trace elements (Mg, Cl, and Na). The levels of the assessed elements in dentine, cementum, and inside the canal were similar in both groups of teeth.

Dental age estimation in Japanese individuals combining permanent teeth and third molars.

Science.gov (United States)

Ramanan, Namratha; Thevissen, Patrick; Fleuws, Steffen; Willems, G

2012-12-01

The study aim was, firstly, to verify the Willems et al. model on a Japanese reference sample. Secondly to develop a Japanese reference model based on the Willems et al. method and to verify it. Thirdly to analyze the age prediction performance adding tooth development information of third molars to permanent teeth. Retrospectively 1877 panoramic radiographs were selected in the age range between 1 and 23 years (1248 children, 629 sub-adults). Dental development was registered applying Demirjian 's stages of the mandibular left permanent teeth in children and Köhler stages on the third molars. The children's data were, firstly, used to validate the Willems et al. model (developed a Belgian reference sample), secondly, split ino a training and a test sample. On the training sample a Japanese reference model was developed based on the Willems method. The developed model and the Willems et al; model were verified on the test sample. Regression analysis was used to detect the age prediction performance adding third molar scores to permanent tooth scores. The validated Willems et al. model provided a mean absolute error of 0.85 and 0.75 years in females and males, respectively. The mean absolute error in the verified Willems et al. and the developed Japanese reference model was 0.85, 0.77 and 0.79, 0.75 years in females and males, respectively. On average a negligible change in root mean square error values was detected adding third molar scores to permanent teeth scores. The Belgian sample could be used as a reference model to estimate the age of the Japanese individuals. Combining information from the third molars and permanent teeth was not providing clinically significant improvement of age predictions based on permanent teeth information alone.

Do the levels of selected metals differ significantly between the roots of carious and non-carious teeth?

International Nuclear Information System (INIS)

Malara, Piotr; Kwapulinski, Jerzy; Malara, Beata

2006-01-01

Since the metals deposited in teeth during formation and mineralization processes are to a large extent retained, human teeth receive a considerable attention as the indicators of the heavy metal exposure. The use of permanent teeth is limited because the extraction of healthy permanent teeth just for this purpose is hardly acceptable. As the issue of the loss of elements from a carious lesion in the coronal part of a tooth remains controversial, the valuable material could only be the root of carious and fractured permanent teeth. However, to ensure the validity of the results, it should be ascertained that the levels of certain toxic and essential elements do not differ significantly between the roots of non-carious and carious teeth, and therefore this is the aim of this project. The levels of cadmium, chromium, copper, iron, manganese, lead, zinc, potassium, sodium, calcium and magnesium were determined in the roots of 344 permanent teeth (189 carious and 155 caries-free teeth) from the residents of Ruda Slaska, Poland, aged 18 to 34. No statistically significant difference between the concentration of these metals in the roots of non-carious and carious teeth was found. This finding applies to both the general population and after the grouping by donor's gender and tooth type. The concentration of lead, iron, calcium and manganese in the roots of non-carious and carious teeth exhibited dependence upon tooth type, as well as the concentration of potassium in the roots of carious teeth. Since the mineral composition of the roots of permanent teeth is similar for the non-carious, as well as the carious teeth, they can be indiscriminately selected for the tests required by a research project, as they will produce the comparable results. However, in the case of lead, iron, calcium, potassium and manganese, the comparison should be made after grouping by tooth type

Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

International Nuclear Information System (INIS)

Fraenzel, W.; Gerlach, R.; Hein, H.J.; Schaller, H.G.

2006-01-01

Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 registered or elmex gelee registered . The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 registered or elmex gelee registered led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

Energy absorption build-up factors in teeth

International Nuclear Information System (INIS)

Manjunatha, H.C.; Rudraswamy, B.

2012-01-01

Geometric progression fitting method has been used to compute energy absorption build-up factor of teeth [enamel outer surface, enamel middle, enamel dentin junction towards enamel, enamel dentin junction towards dentin, dentin middle and dentin inner surface] for wide energy range (0.015-15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption build-up factor on incident photon energy, penetration depth, electron density and effective atomic number has also been studied. The energy absorption build-up factors increases with the penetration depth and electron density of teeth. So that the degree of violation of Lambert-Beer (I = I 0 e -μt ) law is less for least penetration depth and electron density. The energy absorption build-up factors for different regions of teeth are not same hence the energy absorbed by the different regions of teeth is not uniform which depends on the composition of the medium. The relative dose of gamma in different regions of teeth is also estimated. Dosimetric implication of energy absorption build-up factor in teeth has also been discussed. The estimated absorption build up factors in different regions of teeth may be useful in the electron spin resonance dosimetry. (author)

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

International Nuclear Information System (INIS)

Frank, R.M.; Sargentini-Maier, M.L.; Turlot, J.C.; Leroy, M.J.

1990-01-01

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

Enamel hypoplasia in deciduous teeth of great apes: do differences in defect prevalence imply differential levels of physiological stress?

Science.gov (United States)

Lukacs, J R

1999-11-01

This paper presents new data on enamel hypoplasia in the deciduous canine teeth of great apes. The enamel defect under consideration is known as localized hypoplasia of primary canines (LHPC), and is characterized by an area of thin or missing enamel on the labial surface of deciduous canine teeth (Skinner [1986a] Am. J. Phys. Anthropol. 69:59-69). Goals of this study are: 1) to determine if significant differences in the frequency of LHPC occur among three genera of great apes, and 2) to evaluate variation in LHPC prevalence among great apes as evidence of differential physiological stress. Infant and juvenile apes with deciduous teeth were examined at the Cleveland Museum of Natural History (n = 100) and at the Smithsonian Institution, National Museum of Natural History (n = 36). Deciduous teeth were observed under oblique incandescent light, with the naked eye and with a 10x hand lens. Enamel hypoplasia was scored using Federation Dentaire International (FDI)-Defects of Dental Enamel (DDE) standards. Hypoplasias were recorded by drawing defect location and size on a dental chart, and by measuring defect size and location with Helios needlepoint dial calipers. The prevalence of LHPC is reported by genus and sex, using two approaches: 1) the frequency of affected individuals-those having one or more deciduous canine teeth scored positive for LHPC; and 2) the number of canine teeth scored positive for LHPC as a percentage of all canine teeth observed. Variation in defect size and location will be described elsewhere. Localized hypoplasia of primary canine teeth was found in 62.5% of 128 individual apes, and in 45.5% of 398 great ape deciduous canines. As in humans, LHPC is the most common form of enamel hypoplasia in deciduous teeth of great apes, while LEH is rare or absent. The distribution and pattern of expression of LHPC in great apes is similar to that described in humans: side differences are not significant, but mandibular canines exhibit the defect two to

Shaping of Rack Cutter Original Profile for Fine-module Ratchet Teeth Cutting

Science.gov (United States)

Sharkov, O. V.; Koryagin, S. I.; Velikanov, N. L.

2018-05-01

The design models and the process of shaping the cutting edges of the rack cutter for cutting fine-module ratchet teeth are considered in the article. The use of fine-module ratchet teeth can reduce the noise and impact loads during operation of the freewheel mechanisms. Mathematical dependencies for calculating the coordinates determining the geometric position of the points of the front and back edges of the cutting profile of the rack cutter, the workpiece angle of rotation during cutting the ratchet teeth were obtained. When applying the developed method, the initial data are: the radii of the workpiece circumferences passing through the dedendum of the external and internal cut teeth; gradient angles of the front and back edges of the rail.

Does hardness of food affect the development of pharyngeal teeth of the black carp, Mylopharyngodon piceus (Pisces: Cyprinidae)?

DEFF Research Database (Denmark)

Hung, Nguyen Manh; Ryan, Timothy M.; Stauffer, Jay R.

2015-01-01

We investigated whether food type influences development of the pharyngeal crushing apparatus of black carp (Mylopharyngodon piceus, Cyprinidae). Fish fed a hard diet had average standard lengths and weights larger than those fed a soft diet; these observations in part could be related to differe......We investigated whether food type influences development of the pharyngeal crushing apparatus of black carp (Mylopharyngodon piceus, Cyprinidae). Fish fed a hard diet had average standard lengths and weights larger than those fed a soft diet; these observations in part could be related...... to differences in nutritional value of the two food types. The lower pharyngeal bones, which bear molariform teeth were examined using three dimensional computed tomography (CT) scans. After adjusting for differences in the standard length of the fish, the total volume and exterior surface areas...... of the pharyngeal teeth were greater in fish fed hard diets than in those fed soft diets. Total weights of the pharyngeal arches were less in the fish fed a soft diet than in those fed a hard diet. These results indicated that food type affects development of the pharyngeal crushing mill of black carp and therefore...

A Systematic Review of Human Bat Rabies Virus Variant Cases: Evaluating Unprotected Physical Contact with Claws and Teeth in Support of Accurate Risk Assessments.

Science.gov (United States)

Dato, Virginia M; Campagnolo, Enzo R; Long, Jonah; Rupprecht, Charles E

2016-01-01

In the United States and Canada, the most recent documented cases of rabies have been attributed to bat rabies viruses (RABV). We undertook this systematic review in an effort to summarize and enhance understanding of the risk of infection for individuals who have been potentially exposed to a suspect or confirmed rabid bat. United States rabies surveillance summaries documented a total of 41 human bat-rabies virus variant verified non-transplant cases between 1990 and 2015. All cases were fatal. Seven (17.1%) of 41 cases reported a bite from a bat. Ten (24.3%) cases had unprotected physical contact (UPC); these included seven cases that had a bat land or crawl on them (contact with claws) and one case that touched a bat's teeth. Seven (17.1%) cases had probable UPC. Insectivorous bat teeth are extremely sharp and highly efficient for predation upon arthropod prey. Bats also have sharp claws on the end of their thumbs and feet. One of the most common bat RABV variants has an ability to replicate in non-neural cells. Questioning individuals about unprotected contact with bat teeth and claws (including a bat landing or crawling on a person) may help identify additional exposures.

Characteristics of Teeth: A Review of Size, Shape, Composition, and Appearance of Maxillary Anterior Teeth.

Science.gov (United States)

McGowan, Steve

2016-03-01

Although digital technologies play an increasingly integral role in dentistry, there remains a need for dental professionals to understand the fundamentals of tooth anatomy, form, occlusion, and color science. In this article, the size, shape, composition, and appearance of maxillary anterior teeth will be discussed from esthetic and functional perspectives. A total of 600 extracted maxillary incisors were studied: 200 each of central incisors, lateral incisors, and cuspids. The purpose of the article is to exhibit and discuss factors that make teeth unique and diverse. Understanding these aspects of teeth aids dental professionals in more effectively creating realistic and highly esthetic restorations for patients.

[Conservative treatment of deciduous teeth--a review].

Science.gov (United States)

Magnusson, B

1976-06-01

In all countries with a lack of manpower in dentistry, there is an unfortunate tendency to leave the primary teeth without proper conservative treatment. In addition to toothaches and poor esthetics, a neglected care of the primary dentition may result in several other untoward effects. Decayed deciduous teeth may cause such a discomfort during tooth-brushing that the child is prevented from learning good oral hygiene habits. With bad primary molars the child cannot chew properly, and may have to choose soft and often cariogenic food. When the permanent teeth erupt among the decayed deciduous teeth, there will be a greater chance for them to have carious attacks as well. Premature loss of primary molars may lead to malocclusion. It must also be kept in mind that the treatment of badly decayed teeth, including necessary extractions, may be difficult. This may cause fear of dental treatment. On the basis of current Swedish philosophies of treatment the author surveys various conservative procedures for deciduous teeth-amalgam therapy, stainless steel crowns, composites and disking.

A construction of standardized near infrared hyper-spectral teeth database: a first step in the development of reliable diagnostic tool for quantification and early detection of caries

Science.gov (United States)

Bürmen, Miran; Usenik, Peter; Fidler, Aleš; Pernuš, Franjo; Likar, Boštjan

2011-03-01

Dental caries is a disease characterized by demineralization of enamel crystals leading to the penetration of bacteria into the dentin and pulp. If left untreated, the disease can lead to pain, infection and tooth loss. Early detection of enamel demineralization resulting in increased enamel porosity, commonly known as white spots, is a difficult diagnostic task. Several papers reported on near infrared (NIR) spectroscopy to be a potentially useful noninvasive spectroscopic technique for early detection of caries lesions. However, the conducted studies were mostly qualitative and did not include the critical assessment of the spectral variability of the sound and carious dental tissues and influence of the water content. Such assessment is essential for development and validation of reliable qualitative and especially quantitative diagnostic tools based on NIR spectroscopy. In order to characterize the described spectral variability, a standardized diffuse reflectance hyper-spectral database was constructed by imaging 12 extracted human teeth with natural lesions of various degrees in the spectral range from 900 to 1700 nm with spectral resolution of 10 nm. Additionally, all the teeth were imaged by digital color camera. The influence of water content on the acquired spectra was characterized by monitoring the teeth during the drying process. The images were assessed by an expert, thereby obtaining the gold standard. By analyzing the acquired spectra we were able to accurately model the spectral variability of the sound dental tissues and identify the advantages and limitations of NIR hyper-spectral imaging.

Endodontic treatment of developmental anomalies in posterior teeth: treatment of geminated/fused teeth--report of two cases.

Science.gov (United States)

Tsesis, I; Steinbock, N; Rosenberg, E; Kaufman, A Y

2003-05-01

Gemination or fusion is a rare occurrence in the mandibular posterior teeth. Endodontic treatment of these teeth needs special care and attention to the bizarre anatomy. The aim of this article is to describe the problems encountered and the strategy in treating such cases. Two cases of complex endodontic treatment of fused/geminated teeth are presented. The first is an 11-year-old girl with an anomalous 'double' first mandibular molar and premolar diagnosed as having necrotic pulp with chronic apical abscess of endodontic origin; the second is a 16-year-old boy with 'double' second and supernumerary mandibular molars, who was diagnosed with irreversible pulpitis. Both cases were treated successfully in multiple appointments. The common features and treatment modalities are discussed. Failure to diagnose fused/geminated teeth leads to misdiagnosis and a treatment plan that could cause permanent damage and tooth loss. Generally, there is communication between root canal systems of fused/geminated teeth which should be treated as one entity. Use of magnification is an important aid during treatment.

Microprobe analysis of teeth by synchrotron radiation: environmental contamination

International Nuclear Information System (INIS)

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

1999-01-01

An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l'Utilisation du Rayonnement Electromagnetique (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

Tips for splinting traumatised teeth

LENUS (Irish Health Repository)

Leith, Rona

2017-10-01

A splint is required when teeth are mobile or need to be repositioned following a traumatic injury. The aim of splinting is to stabilise the injured tooth and maintain its position throughout the splinting period, improve function and provide comfort. Current best practice guidelines from the International Association for Dental Traumatology (IADT) recommend splinting for luxated, avulsed, root fractured and traumatically loosened permanent teeth.1,2 Splinting of primary teeth is usually not feasible. In general, the prognosis of a traumatised tooth is determined by the type of injury rather than the type of splint.3 However, correct splinting is important to maximise healing of the soft and hard tissues, and prevent further injury.1-6

Tips for splinting traumatised teeth

LENUS (Irish Health Repository)

Leith, Rona

2017-11-01

A splint is required when teeth are mobile or need to be repositioned following a traumatic injury. The aim of splinting is to stabilise the injured tooth and maintain its position throughout the splinting period, improve function and provide comfort. Current best practice guidelines from the International Association for Dental Traumatology (IADT) recommend splinting for luxated, avulsed, root fractured and traumatically loosened permanent teeth.1,2 Splinting of primary teeth is usually not feasible. In general, the prognosis of a traumatised tooth is determined by the type of injury rather than the type of splint.3 However, correct splinting is important to maximise healing of the soft and hard tissues, and prevent further injury.1

Root fracture in immature anterior teeth followed for 15 years.

Science.gov (United States)

Itoh, T; Kojima, Y; Nishioka, T; Maki, K; Kimura, M

2005-08-01

We report a case of injury to an immature tooth, observed over a period of 15 years. In 1987, a 9-year-old boy fell down in a schoolyard. The right central incisor demonstrated palato-version and radiographic observations revealed that the roots of both central incisors were incomplete. Further, a root fracture in the apical region of the central incisors was observed. During the first treatment visit, the right central incisor was repositioned and both teeth splinted. After confirming that the line of fracture was aligned, the fixation was continued for 2 months. The teeth were examined periodically for the next 15 years. Both teeth had favorable outcomes with continued root development of both the apical and coronal segments with good apposition of the fracture lines.

Non-syndrome multiple supernumerary teeth in Nigerians.

Science.gov (United States)

Umweni, A A; Osunbor, G E N

2002-09-01

The present study was carried out to ascertain frequency of multiple supernumerary teeth not associated with syndrome in Nigerians. A total of 13 patients comprising of 10 males (76.92%) and 3 female (23.07%) representing 0.098% of the study population had multiple supernumerary teeth. Multiple supernumerary teeth without any associated systemic diseases or syndrome are rare as reported by BLUMENTHAL (3) RUHLMAN and NEELY (17), KANTOR et al. (10) is not the case in this study. The maxillary region has the highest frequency of occurrence with 12 times (66.67%) followed by the mandibular premolar region with 4 times (22.22%) while maxillary premolar and mandibular anterior region shared (5.55%) respectively. The conical and tuberculate types of supernumerary teeth were found in the midline region, while the supplemental supernumerary teeth were more in the mandibular premolar region with 12 (70.58%) follow by maxillary midline 4 (23.52%) and the lower incisor region 1 (5.88%) which is in consonant with WINTER and BROOK (2), STAFNE (19) NAZIF, FUTALO ZULLO (15). The role of genetics in the aetiology of multiple supernumerary teeth as found in this study, the occurrence of supernumerary teeth on two brothers and a daughter to one of the affected brothers, tends, to suggest an autosomal dominant mode of inheritance and the challenges to management by the orthodontists are discussed.

The gothic arch tracing and the upper canine teeth as guides in the positioning of upper posterior teeth.

Science.gov (United States)

el-Gheriani, A S; Davies, A L; Winstanley, R B

1989-09-01

The relationship between the position of the buccal cusps of the natural upper posterior teeth and the distance between the lateral arms of the Gothic arch tracing or the distance between the upper canine teeth has been found to be constant to within +/- 2 mm. This may be of value when setting up artificial teeth for denture patients, enabling them to be positioned close to the natural predecessors.

Determination of /sup 90/Sr and /sup 228/Ra in human teeth by age groups and in other substances

Energy Technology Data Exchange (ETDEWEB)

Neuzil, E F; Dysart, M E [Western Washington Univ., Bellingham (USA)

1984-12-01

The total /sup 90/Sr content of human teeth peaks at a value of 0.65 pCi/g calcium in the age group of 20-30 years. It is not present in those 50 years or older. Various other substances show extensive amounts of /sup 90/Sr especially in cow bones, bone meal and dry milk. The radionuclide /sup 228/Ra (daughter of /sup 232/Th) is present at a mean level of about 0.5 pCi/g Ca in all substances tested and in all age groups, but especially high in bone meal (5.60 pCi/g Ca) and calcium lactate tablets.

Discrimination between intact and decayed pulp regions in carious teeth by ADC mapping.

Science.gov (United States)

Cankar, Ksenija; Nemeth, Lidija; Bajd, Franci; Vidmar, Jernej; Serša, Igor

2014-01-01

The aim of this study was to evaluate an advanced magnetic resonance imaging (MRI) method, apparent diffusion coefficient (ADC) mapping, in the functional assessment of carious teeth. 38 extracted human teeth with scores of 0, 3 and 6 according to International Caries Detection and Assessment System (ICDAS) criteria were screened and subsequently analyzed by MRI at 2.35 T. Histology sectioning of teeth was used for the gold standard by analyzing two extreme cases (intact and severely decayed). ADC maps of the same teeth were calculated from corresponding diffusion-weighted images and used to obtain ADC distributions along dental pulp as functions of the relative pulp length measured from the occlusal pulp side. The measured distributions were analyzed for the best fit by a four-parameter three-segment linear regression model for ADC distribution along the pulp. MRI results were in good agreement with findings in histological sections of identical teeth. The best fit model parameters, relative decayed region depth, relative transition region width and ADC values of intact and decayed pulp tissue, showed statistically significant differences between the ADC values of intact and decayed pulp tissue (1.0 × 10(-9) m(2)/s vs. 0.74-0.89 × 10(-9) m(2)/s) and the relative decayed region depth progressing with ICDAS score (3 vs. 46% with ICDAS 3 vs. ICDAS 6). The results of this feasibility study confirmed relevance of ADC mapping for the discrimination and localization of intact and decayed regions in dental pulps of carious teeth. © 2014 S. Karger AG, Basel.

Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

Energy Technology Data Exchange (ETDEWEB)

Fraenzel, W. [Dept. of Physics, Martin Luther Univ. Halle (Germany); Gerlach, R. [Univ. Clinic and Policlinic for Radiation Therapy, Martin Luther Univ. Halle (Germany); Hein, H.J. [Univ. Clinic and Policlinic for Orthopaedics and Physical Medicine, Martin Luther Univ. Halle (Germany); Schaller, H.G. [Dept. of Operative Dentistry and Periodontology, Martin Luther Univ. Halle (Germany)

2006-07-01

Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 {sup registered} or elmex gelee {sup registered}. The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 {sup registered} or elmex gelee {sup registered} led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

Karakterisasi stem cell pulpa gigi sulung dengan modifikasi enzim tripsin (The characterization of stem cells from human exfoliated deciduous teeth using trypsin enzym

Directory of Open Access Journals (Sweden)

Tri Wijayanti Puspitasari

2014-06-01

Full Text Available Background: Now a days, treatment in dentistry, using tissue regeneration that based on the stem cells from human exfoliated deciduous teeth (SHED, grows rapidly. For several reason, the isolated and cultured SHED is difficult to be applied in Indonesia, therefore the modification is needed. This difficulties were caused by the pulp anatomy, the heterogeneous populations in the pulp chamber and the limitations of tools and materials at the laboratory. Purpose: This research was aimed to examine that the modifications of isolation and culture technique of SHEDs for characterization by using the marker of CD105. Methods: The research was experimental laboratory with the cross sectional design. The samples were the human exfoliated deciduous teeth from the children patients of Pediatric Dentistry Department of Universitas Airlangga Dental Hospital which matched the criteria. Dental pulps were isolated and cultured by using the modifications of Trypsin enzymes. Results: The healthy SHEDs could be produced from the modifications of isolation and culture and positively shown the expression of marker CD105 which were indicated by the fluorencent microscope. Conclusion: SHED which isolated and cultured by using the modified techniques, positively characterized by using marker CD105.Latar Belakang: Pengobatan kedokteran gigi berkembang dengan pesat terutama di bidang regenerasi jaringan berbasis Stem Cells from Human Exfoliated Deciduous Teeth (SHED. Di Indonesia, isolasi dan kultur SHED sulit sehingga perlu dilakukan modifikasi. Kendala ini muncul karena jaringan pulpa yang kecil, heterogen dan keterbatasan alat dan bahan di laboratorium. Tujuan: Penelitian ini bertujuan untuk meneliti modifikasi pada cara isolasi dan kultur SHED untuk karakterisasi menggunakan maker CD105. Metode: Jenis penelitian ini adalah eksperimental laboratoris dengan rancangan cross sectional. Sampel penelitian adalah gigi sulung dari pasien anak di Klinik Kedokteran Gigi Anak

Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT); Zerstoerungsfreie praeklinische Evaluation der Wurzelkanalanatomie menschlicher Zaehne mittels Flaechendetektor-Volumen-CT (FD-VCT)

Energy Technology Data Exchange (ETDEWEB)

Heidrich, G.; Hassepass, F.; Dullin, C.; Grabbe, E. [Universitaetsklinikum Goettingen, Abt. Diagnostische Radiologie (Germany); Attin, T.; Hannig, C. [Universitaetsklinikum Goettingen, Abt. fuer Zahnerhaltung, Praeventive Zahnheilkunde und Paradontologie (Germany)

2005-12-15

Purpose: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). Materials and methods: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. Results: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as dentricles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 {mu}m. Only around 73% of the main root canals detected with FD-VCT and 87% of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. (orig.)

The detailed evaluation of supernumerary teeth with the aid of cone beam computed tomography

International Nuclear Information System (INIS)

Tumen, E.C.; Yavuz, I.; Atakul, F.; Tumen, D.S.; Hamamci, N.; Berber, G.; Uysal, E.

2010-01-01

The aim of this paper is to demonstrate the application of a recently developed three-dimensional imaging system, cone beam computed tomography, in the detailed evaluation of supernumerary teeth. Two-hundred and twenty three patients with supernumerary teeth (68 females and 155 males) were included in this study. Patients ranged in age from 12 to 25 years. Supernumerary teeth were detected by clinical examination and traditional radiographies. Moreover, careful investigation for more details was made with the cone beam computed tomography. Supernumerary teeth which were detected with the examinations of the cone beam computed tomography images were classified according to the number, location, shape and eruption rate. The prevalence of supernumerary teeth was determined to be 1.45% of the study population. Males were affected more than females in a ratio of 2.3:1. Supernumerary teeth were most frequently located in 86.2% of the cases in the maxilla; 10.1% in the mandible and 3.7% both in the maxilla and mandible. Supernumerary teeth were most commonly conical in shape (68.8%). One supernumerary tooth was present in 67.7% of the patients, 30.9% had two, and 1.4% had three supernumeraries. Definite and early diagnosis of the supernumerary teeth is very important. Detailed examinations and evaluations of these teeth with three-dimensional images is very beneficial in terms of treatment planning and preventing complications which may occur.

Osteoblastic differentiation of stem cells from human exfoliated deciduous teeth induced by thermosensitive hydrogels with strontium phosphate

Energy Technology Data Exchange (ETDEWEB)

Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Wei-Ling [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Chih-Ming [Department of Biochemistry, Taipei Medical University, Taipei, Taiwan (China)

2015-07-01

Stem cells from human exfoliated deciduous teeth (SHEDs) are a novel source of multi-potential stem cells for tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium exhibits an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. Hydrogels can mimic the natural cellular environment. The association of hydrogels with cell viability is determined using biological tests, including rheological experiments. In this study, osteogenic differentiation was investigated through SHED encapsulation in hydrogels containing strontium phosphate. Results of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and proliferating cell nuclear antigen (PCNA) immunofluorescence staining indicated that the cells grew well and SHEDs proliferated in the hydrogels. Strontium-loaded chitosan-based hydrogels induced the biomineralization and high expression of alkaline phosphatase. Moreover, the expression levels of bone-related genes, including type-I collagen, Runx2, osteopontin (OP), and osteonectin (ON), were up-regulated during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Elucidating the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate can enhance the osteogenic differentiation of SHEDs. • Hydrogels can mimic the natural cellular environment. • Bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering.

Neutron activation analysis of manganese in teeth of Japanese adults

Energy Technology Data Exchange (ETDEWEB)

Sasaki, Emiko [Nihon Univ., Tokyo. School of Dentistry

1982-01-01

In an investigation of the manganese (Mn) content of teeth in Japanese adults, neutron activation analysis was carried out of caries-free teeth, carious teeth and unerupted teeth gathered from three different districts of Japan. Regular logarithmic distribution of Mn in the dentin suggested that Mn had not been taken into account as an essential element of the teeth. Results of the study revealed no difference in Mn content among these districts, and between the caries-free teeth and the carious teeth, both in enamel and dentin. The Mn content of the enamel was about two times higher than that of the dentin.

Near-IR imaging of cracks in teeth

Science.gov (United States)

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.

PIXE analysis of trace elements in cetacean teeth

International Nuclear Information System (INIS)

Mitani, Yoko; Arai, Nobuaki; Sakamoto, Wataru; Yoshida, Koji

1997-01-01

PIXE was adopted for analysis of trace elements in teeth of two species of cetaceans, sperm whale (Physeter microcephalus) and pantropical spotted dolphin (Stenella attenuata). The analyses were performed along with the growth layer of the teeth, which is formed annually, suitable for age determination. Mn, Fe, Cu, Zu and Sr were detected in the teeth of sperm whale and pantropical spotted dolphin. Among these trace elements, gradual increase was observed for Zn/Ca ratio in the sperm whale's teeth. (author)

[Results of treatment of milk teeth pulp by modified formocresol method].

Science.gov (United States)

Wochna-Sobańska, M

1989-01-01

The purpose of the study was evaluation of the results of treatment of molar pulp diseases by the formocresol method from the standpoint of the development of inflammatory complications in periapical tissues, disturbances of physiological resorption of roots, disturbances of mineralization of crowns of homologous permanent teeth. For the treatment milk molars were qualified with the diagnosis of grade II pulpopathy in children aged from 3 to 9 years. The treatment was done using formocresol by a modified method of pulp amputation according to Buckley after previous devitalization with parapaste. The status of 143 teeth was examined again 1 to 4 years after completion of treatment. The proportion of positive results after one year was 94%, after two years it was 90%, after three years 87% and after four years 80%. The cause of premature loss of most teeth was root resorption acceleration by 18-24 months. No harmful action of formocresol on the buds of permanent teeth was noted.

Complex aesthetic treatment on anterior maxillary teeth with malposition

Directory of Open Access Journals (Sweden)

Febriastuti Febriastuti

2008-12-01

Full Text Available Background: Complex aesthetic treatment on anterior teeth involves more than one caries tooth with malformed shape and malposition. Purpose: The purpose of this paper is to find the alternative treatment for anterior maxillary teeth with malposition. Case: In this case, a 25 year-old man with a peg shaped teeth and caries on several teeth and malposition can be treated with complex aesthetic treatment. Case management: Endodontic pulpectomy treatment on anterior maxillary teeth and post construction with splint porcelain fused to metal crowns on 11, 12, and 21, 22 to correct the shape and position into normal position. Conclusion: Malformed and malpositioned teeth with caries can be treated with complex aesthetic treatment.

Examination of lead content in school children's teeth

Energy Technology Data Exchange (ETDEWEB)

Yamaga, M; Omori, K; Tozawa, T; Abe, K

1972-11-01

The results of examination on the relationship between air pollution by lead in auto exhaust and lead content of teeth of schoolchildren living in highly polluted, moderately polluted, and nonpolluted areas in Kanagawa Prefecture in 1968 are reported. The specimens were milk teeth which have fallen out and teeth in caries which were pulled out. The 177 specimens were brushed well, washed with distilled water and dried to be wet-calcined. Because of no difference of lead content between boys and girls teeth, the examination was carried on combined specimens. The findings were: (1) lead content was significantly higher in teeth of children in heavily and moderately polluted areas than in those in nonpolluted areas; (2) the lead content by area and by age showed lower values in older children in highly and nonpolluted areas. In general, the lead content of teeth was higher in children living in more polluted areas suggesting the effect of environmental pollution.

The Pb isotopic record of historical to modern human lead exposure

International Nuclear Information System (INIS)

Kamenov, George D.; Gulson, Brian L.

2014-01-01

Human teeth and bones incorporate trace amounts of lead (Pb) from the local environment during growth and remodeling. Anthropogenic activities have caused changes in the natural Pb isotopic background since historical times and this is reflected in the Pb isotopes of historical European teeth. Lead mining and use increased exponentially during the last century and the isotopic compositions of modern human teeth reflect the modern anthropogenic Pb. USA teeth show the most radiogenic Pb and Australian teeth show the least radiogenic Pb, a result of different Pb ores used in the two regions. During the last century the Australian Pb was exported to Europe, Asia, South America, and Africa, resulting in swamping of the local environmental Pb signal by the imported Pb. As a result, the modern human teeth in Europe show a significant drop to lower isotopic values compared with historical times. Similarly, modern human teeth in other regions of the world show similar Pb isotopic ratios to modern European teeth reflecting the Pb imports. The specific pattern of human Pb exposure allows us to use the Pb isotopic signal recorded in the skeleton as a geo-referencing tool. As historical European teeth show a distinct Pb signal, we can identify early European skeletal remains in the New World and likely elsewhere. In modern forensic investigations we can discriminate to some extent Eastern Europeans from Western and Northern Europeans. Australians can be identified to some extent in any region in the world, although there is some overlap with Western European individuals. Lead isotopes can be used to easily identify foreigners in the USA, as modern USA teeth are distinct from any other region of the world. By analogy, USA individuals can be identified virtually in any other region of the world. - Highlights: • We present high-precision Pb isotope data for historical and modern human teeth. • Human teeth reflect human Pb exposure since historical times. • Modern teeth show

The Pb isotopic record of historical to modern human lead exposure

Energy Technology Data Exchange (ETDEWEB)

Kamenov, George D., E-mail: kamenov@ufl.edu [Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, FL 32611 (United States); Gulson, Brian L. [Graduate School of the Environment, Faculty of Science, Macquarie University, Sydney, NSW 2109 (Australia)

2014-08-15

Human teeth and bones incorporate trace amounts of lead (Pb) from the local environment during growth and remodeling. Anthropogenic activities have caused changes in the natural Pb isotopic background since historical times and this is reflected in the Pb isotopes of historical European teeth. Lead mining and use increased exponentially during the last century and the isotopic compositions of modern human teeth reflect the modern anthropogenic Pb. USA teeth show the most radiogenic Pb and Australian teeth show the least radiogenic Pb, a result of different Pb ores used in the two regions. During the last century the Australian Pb was exported to Europe, Asia, South America, and Africa, resulting in swamping of the local environmental Pb signal by the imported Pb. As a result, the modern human teeth in Europe show a significant drop to lower isotopic values compared with historical times. Similarly, modern human teeth in other regions of the world show similar Pb isotopic ratios to modern European teeth reflecting the Pb imports. The specific pattern of human Pb exposure allows us to use the Pb isotopic signal recorded in the skeleton as a geo-referencing tool. As historical European teeth show a distinct Pb signal, we can identify early European skeletal remains in the New World and likely elsewhere. In modern forensic investigations we can discriminate to some extent Eastern Europeans from Western and Northern Europeans. Australians can be identified to some extent in any region in the world, although there is some overlap with Western European individuals. Lead isotopes can be used to easily identify foreigners in the USA, as modern USA teeth are distinct from any other region of the world. By analogy, USA individuals can be identified virtually in any other region of the world. - Highlights: • We present high-precision Pb isotope data for historical and modern human teeth. • Human teeth reflect human Pb exposure since historical times. • Modern teeth show

Performance of a gaseous detector based energy dispersive X-ray fluorescence imaging system: Analysis of human teeth treated with dental amalgam

Science.gov (United States)

Silva, A. L. M.; Figueroa, R.; Jaramillo, A.; Carvalho, M. L.; Veloso, J. F. C. A.

2013-08-01

Energy dispersive X-ray fluorescence (EDXRF) imaging systems are of great interest in many applications of different areas, once they allow us to get images of the spatial elemental distribution in the samples. The detector system used in this study is based on a micro patterned gas detector, named Micro-Hole and Strip Plate. The full field of view system, with an active area of 28 × 28 mm2 presents some important features for EDXRF imaging applications, such as a position resolution below 125 μm, an intrinsic energy resolution of about 14% full width at half maximum for 5.9 keV X-rays, and a counting rate capability of 0.5 MHz. In this work, analysis of human teeth treated by dental amalgam was performed by using the EDXRF imaging system mentioned above. The goal of the analysis is to evaluate the system capabilities in the biomedical field by measuring the drift of the major constituents of a dental amalgam, Zn and Hg, throughout the tooth structures. The elemental distribution pattern of these elements obtained during the analysis suggests diffusion of these elements from the amalgam to teeth tissues.

What are the longevities of teeth and oral implants?

DEFF Research Database (Denmark)

Holm-Pedersen, Poul; Lang, Niklaus P; Müller, Frauke

2007-01-01

To analyse tooth loss and to evaluate the longevity of healthy teeth and teeth compromised by diseases and influenced by therapy as well as that of oral implants.......To analyse tooth loss and to evaluate the longevity of healthy teeth and teeth compromised by diseases and influenced by therapy as well as that of oral implants....

Straight, white teeth as a social prerogative.

Science.gov (United States)

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. © 2015 Foundation for the Sociology of Health & Illness.

Stable isotope ratios in hair and teeth reflect biologic rhythms.

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Otto Appenzeller

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

Effect of cow and soy milk on enamel hardness of immersed teeth

Science.gov (United States)

Widanti, H. A.; Herda, E.; Damiyanti, M.

2017-08-01

Cow milk and soy milk have different mineral contents and this can affect the tooth remineralization process. The aim of this study was to determine the effect of cow and soy milk on immersed teeth after demineralization. Twenty-one specimens, of human maxillary premolars, were measured for enamel hardness before immersion and demineralization in orange juice. The teeth were divided into three groups (n = 7) with each group immersed in either distilled water, cow milk, or soy milk. There was a significant increase in enamel hardness in all groups (p Cow milk provided the highest increase in enamel hardness, of all the three groups, but was not able to restore the initial enamel hardness.

The effect of stem cell from human exfoliated deciduous teeth on T lymphocyte proliferation.

Science.gov (United States)

Alipour, Razieh; Adib, Minoo; Hashemi-Beni, Batool; Sadeghi, Farzaneh

2014-01-01

Mesenchymal stem cells (MSC), a specific type of adult tissue stem cell; have the immunosuppressive effects that make them valuable targets for regenerative medicine and treatment of many human illnesses. Hence, MSC have been the subject of numerous studies. The classical source of MSC is adult bone marrow (BM). Due to many shortcomings of harvesting MSC from BM, finding the alternative sources for MSC is an urgent. Stem cells from human exfoliated deciduous teeth (SHED) are relative new MSC populations that fulfill these criteria but their potential immunosuppressive effect has not been studied enough yet. Thus, in this work the effect of SHED on the proliferation of in vitro activated T lymphocytes were explored. In this study, both mitogen and alloantigen activated T cells were cultured in the presence of different numbers of SHED. In some co-cultures, activated T cells were in direct contact to MSCs and in other co-cultures; they were separated from SHED by a permeable membrane. In all co-cultures, the proliferation of T cells was measured by ELISA Bromodeoxyuridine proliferation assay. In general, our results showed that SHED significantly suppress the proliferation of activated T cells in a dose-dependent manner. Moreover, the suppression was slightly stronger when MSCs were in physical contact to activated T cells. This study showed that SHED likewise other MSC populations can suppress the activation of T lymphocytes, which can be used instead of BM derived MSCs in many investigational and clinical applications.

Recommendations for using regenerative endodontic procedures in permanent immature traumatized teeth.

Science.gov (United States)

Garcia-Godoy, Franklin; Murray, Peter E

2012-02-01

The regeneration of immature permanent teeth following trauma could be beneficial to reduce the risk of fracture and loss of millions of teeth each year. Regenerative endodontic procedures include revascularization, partial pulpotomy, and apexogenesis. Several case reports give these procedures a good prognosis as an alternative to apexification. Care is needed to deliver regenerative endodontic procedures that maintain or restore the vitality of teeth, but which also disinfect and remove necrotic tissues. Regeneration can be accomplished through the activity of the cells from the pulp, periodontium, vascular, and immune system. Most therapies use the host's own pulp or vascular cells for regeneration, but other types of dental stem cell therapies are under development. There are no standardized treatment protocols for endodontic regeneration. The purpose of this article is to review the recent literature and suggest guidelines for using regenerative endodontic procedures for the treatment of permanent immature traumatized teeth. Recommendations for the selection of regenerative and conventional procedures based on the type of tooth injury, fracture type, presence of necrosis or infection, periodontal status, presence of periapical lesions, stage of tooth development, vitality status, patient age, and patient health status will be reviewed. Because of the lack of long-term evidence to support the use of regenerative endodontic procedures in traumatized teeth with open apices, revascularization regeneration procedures should only be attempted if the tooth is not suitable for root canal obturation, and after apexogenesis, apexification, or partial pulpotomy treatments have already been attempted and have a poor prognosis. © 2011 John Wiley & Sons A/S.

A Diagnostic and Therapeutic Algorithm for Impacted Teeth for Plastic Surgeons: Outcomes of 242 Extracted Teeth

Directory of Open Access Journals (Sweden)

Nebil Yeşiloğlu

2016-09-01

Full Text Available Objective: Impacted teeth are important for plastic surgeons that frequently perform maxillofacial operations because of their tendency to affect dental occlusion, and thus, cephalometric results. Moreover, severe complications are also caused by the tooth and its surgical removal. In this study, retrospective analysis of 242 extracted teeth and 24 extracted roots was performed and an algorithmic approach to different types and the localizations of impacted teeth was presented. Possible complications and salvage procedures were also discussed. Material and Methods: A retrospective analysis of 128 patients who underwent impacted teeth removal surgery between 2013 and 2015 was performed. Mean age was 26 years (Range: 18–42 years, and the female to male ratio was 39/89. Sixteen of the patients were operated under regional nerve block, whereas the remaining were operated under general anesthesia. In 107 patients, the whole tooth was removed, whereas the residual root of the tooth was removed in 21 patients. In 89 patients, bone interventions like the creation of bone window or peridental milling to loosen the tooth were needed, whereas only oral mucosal incisions were performed in the remaining patients. Results: The most common onset symptom was localized pain, and the most common complications were swelling and edema. The most common extracted tooth was the mandibular 3rd molar. Lower lip hypoesthesia, which was continued up to eight months, was encountered in six patients who underwent mandibular 3rd molar extraction. Conclusion: In our opinion, a wide range of possible complications secondary to impacted teeth surgery makes them important for plastic surgeons who are more experienced than other disciplines, and learning teeth extraction is essential to learn in plastic surgery specialty training.

Implant site development by orthodontic forced eruption of nontreatable teeth: a case report.

Science.gov (United States)

Rokn, Amir Reza; Saffarpour, Anna; Sadrimanesh, Rouzbeh; Iranparvar, Kaveh; Saffarpour, Aida; Mahmoudzadeh, Majid; Soolari, Ahmad

2012-01-01

Loss of bone and soft tissue attachment are common sequelae of periodontitis that may jeopardize the aesthetic outcome and compromise the functional and aesthetic outcomes of treatment. The following case report describes one of the most predictable techniques of vertical ridge augmentation, which is orthodontic extrusion or forced eruption of hopeless teeth. A 34-year-old woman who presented with severe attachment loss and deep pockets was diagnosed with generalized aggressive periodontitis. The mobile maxillary incisors were consequently extracted and were replaced with dental implants. However, prior to extraction, orthodontic extrusion of the hopeless incisors was performed to correct vertical ridge defects. Following extrusion and extraction of the maxillary incisors, to prevent soft tissue collapse and to preserve the papillae during socket healing, the crowns of the extracted teeth were used as pontics on a removable partial provisional denture. After 8 weeks, the implants were placed, and an immediate functional restoration was delivered. After 4 months of healing, a fixed definitive partial prosthesis was fabricated and delivered. After periodontal treatment, over a 2-year period, the progression of aggressive periodontitis was controlled. The mean vertical movement of marginal bone was 3.6 mm. The use of the crowns of extracted teeth appears to be an effective method to maintain papillae. Orthodontic extrusion is a predictable method for the correction of vertical ridge defects. Orthodontic treatment does not aggravate or hasten the progression of aggressive periodontitis.

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

Directory of Open Access Journals (Sweden)

Girondot Marc

2008-09-01

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

External root resorption during orthodontic treatment in root-filled teeth and contralateral teeth with vital pulp: A clinical study of contributing factors.

Science.gov (United States)

Lee, Yun Ju; Lee, Tae Yeon

2016-01-01

There is a lack of research to support the belief that root canal treatment can be considered for stopping or decreasing external apical root resorption (EARR). There is conflicting evidence as to whether root-filled teeth are more or less likely to experience EARR after orthodontic treatment. The purpose of this study was to compare the degree of EARR of root-filled teeth with that of contralateral teeth with vital pulp after fixed orthodontic treatment. The study sample consisted of 35 patients aged 25.23 ± 4.92 years who had at least 1 root-filled tooth before orthodontic treatment. Digital panoramic radiographs of each patient taken before and after orthodontic treatment were used to measure the EARR. The Student t test for matched pairs and the Pearson correlation analysis were applied. The mean EARR values were 0.22 (0.14, 0.35) for root-filled teeth and 0.87 (0.59, 1.31) for contralateral teeth with vital pulp, indicating significantly less EARR for root-filled teeth compared with the contralateral teeth with vital pulp after orthodontic treatment. EARR was influenced by the patient's age, treatment duration, treatment type, and periapical pathosis, but not by tooth type and sex. Root-filled teeth appear to be associated with significantly less EARR than are contralateral teeth with vital pulp. This study suggests that the possible complication of EARR in root-filled teeth may not be an important consideration in orthodontic treatment planning, and root canal treatment can be considered for stopping or decreasing EARR when severe EARR occurs during orthodontic treatment. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

FT-Raman spectroscopy, µ-EDXRF spectrometry, and microhardness analysis of the dentin of primary and permanent teeth.

Science.gov (United States)

Torres, Carolina Paes; Miranda Gomes-Silva, Jaciara; Menezes-Oliveira, Maria Angélica Hueb; Silva Soares, Luís Eduardo; Palma-Dibb, Regina Guenka; Borsatto, Maria Cristina

2018-05-01

The chemical compositions (organic and inorganic contents) and mechanical behaviors of the dentin of permanent and deciduous teeth were analyzed and compared using X-ray fluorescence spectrometry (µ-EDXRF) Fourier transform Raman spectroscopy (FT-Raman) and a microhardness test (HD). Healthy fresh human primary and permanent molars (n = 10) were selected, The buccal surfaces facing upwards were stabilized in an acrylic plate, flattened, polished, and submitted to the µ-EDXRF, FT-Raman, and HD analysis. The results of the analysis were subjected to ANOVAs and Mann-Whitney U/Student's t multiple comparisons tests. The data showed similar values for the dentin of the primary and permanent teeth in P content, organic content (amide I peak), inorganic content ( PO43- - 430 and 590), and microhardness, Nevertheless, Ca content and Ca/P weight ratio were higher, and the CO32- peak was lower in the dentin of the permanent teeth compared to primary teeth. It be concluded that despite permanent teeth showed more Ca element, both substrates showed similar behavior of chemical and physical properties. © 2018 Wiley Periodicals, Inc.

Permanent magnet machines with air gap windings and integrated teeth windings

Energy Technology Data Exchange (ETDEWEB)

Alatalo, M [Chalmers Univ. of Technology, Goeteborg (Sweden). School of Electrical and Computer Engineering

1996-06-01

The Thesis deals with axial and radial flux permanent magnet machines with air gap windings and an integrated teeth winding. The aim is to develop a machine that produces a high torque per unit volume with as low losses as possible. The hypothesis is that an advanced three-phase winding, magnetized by a permanent magnet rotor should be better than other machine topologies. The finite element method is used to find favourable dimensions of the slotless winding, the integrated teeth winding and the permanent magnet rotor. Three machines were built and tested in order to verify calculations. It can be concluded that the analysis method shows good agreement with the calculated and the measured values of induced voltage and torque. The experiments showed that the slotless machine with NdFeB-magnets performs approximately like the slotted machine. A theoretical comparison of axial flux topology to radial flux topology showed that the torque production of the inner rotor radial flux machine is superior to that of the axial flux machine. An integrated teeth winding based on iron powder teeth glued to the winding was studied. The force density of a pole with integrated teeth is around three times the force density of a slotless pole. A direct drive wind power generator of 6.4 kW with integrated teeth can have the same power losses and magnet weight as a transversal flux machine. Compared to a standard induction machine the integrated teeth machine had approximately 2.5 times the power capacity of the induction machine with the same power losses and outer volume. 39 refs

Supernumerary Teeth in the Maxillary Anterior Region: The Dilemma of Early Versus Late Surgical Intervention.

Science.gov (United States)

Sarne, Ofer; Shapira, Yehoshua; Blumer, Sigalit; Finkelstein, Tamar; Schonberger, Shirley; Bechor, Naomi; Shpack, Nir

Supernumerary teeth are the most common developmental dental anomalies in the maxillary anterior region causing interference to the developing permanent incisors resulting in poor dental and facial esthetics. Two different opinions regarding the timing for surgical removal of the supernumerary teeth are presented. In this case report, three brothers with supernumerary teeth in the maxillary anterior region are presented, their surgical and orthodontic management and outcome are discussed.

In vivo EPR dosimetry of accidental exposures to radiation: experimental results indicating the feasibility of practical use in human subjects

International Nuclear Information System (INIS)

Miyake, Minoru; Liu, K.J.; Walczak, T.M.; Swartz, H.M.

2000-01-01

Low frequency electron paramagnetic resonance (EPR) provides the potential advantage of making accurate and sensitive measurements of absorbed radiation dose in teeth in situ, i.e. without removing the teeth from the potential victim. The potential limiting factors for making such measurements are: (1) whether low frequency EPR is sufficiently sensitive to detect radiation-induced signal in human teeth; (2) whether sufficient sensitivity can be maintained under in vivo conditions. In this manuscript, we summarize results indicating that this approach is feasible. Using 1.2 GHz EPR spectroscopy, we found that the lower limit for these measurements in isolated human teeth is 0.2 Gy or lower. Measurements of radiation-induced EPR signals in the teeth of living rats were achieved with sufficient sensitivity to indicate that, when taking into consideration the larger mass of human teeth, similar measurements in human teeth in situ would provide sensitivity in the dose range for potential accidental exposures. We estimate that the current lower limit for detecting radiation doses in human teeth in situ (in vivo) is 0.5-1.0 Gy; this would be sufficient for determining if a person has been exposed to potentially life threatening doses of ionizing radiation. The limiting factor for sensitivity appears to be background signals rather than signal/noise, and there are feasible means to overcome this problem and further increase sensitivity. The additional instrumental developments required to make an effective in vivo EPR dosimetric spectrometer for the measurements in teeth in human subjects in situ, seem quite achievable

Roentgenographical observation of impacted teeth

Energy Technology Data Exchange (ETDEWEB)

Choi, Hi Sup; Ahn, Hyung Kyu [College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

1972-11-15

The author observed on the impacted teeth of 11 cases from 484 full-mouth roentgenograms of dental students S.N.U. (except 3rd molar). These studies are very significant in oral surgery and orthodontic problems. Most of the impacted teeth are located in maxilla and among them 7 cases are impacted central incisors the others are lateral incisors, and cuspids. The form of impactions are vertical, horizontal and inverted positions.

"The Tempest" in an English Teapot: Colonialism and the Measure of a Man in Zadie Smith's "White Teeth"

Science.gov (United States)

Gustar, Jennifer J.

2010-01-01

Zadie Smith's "White Teeth" argues that we can take responsibility for the future if we refuse to act in thrall to the legacies of the past, which favour one human life over another, and act instead with the conviction that all lives are "lives" (Judith Butler). "White Teeth" examines the colonial legacy of violence…

Optimizing Hybrid Occlusion in Face-Jaw-Teeth Transplantation: A Preliminary Assessment of Real-Time Cephalometry as Part of the Computer-Assisted Planning and Execution Workstation for Craniomaxillofacial Surgery.

Science.gov (United States)

Murphy, Ryan J; Basafa, Ehsan; Hashemi, Sepehr; Grant, Gerald T; Liacouras, Peter; Susarla, Srinivas M; Otake, Yoshito; Santiago, Gabriel; Armand, Mehran; Gordon, Chad R

2015-08-01

The aesthetic and functional outcomes surrounding Le Fort-based, face-jaw-teeth transplantation have been suboptimal, often leading to posttransplant class II/III skeletal profiles, palatal defects, and "hybrid malocclusion." Therefore, a novel technology-real-time cephalometry-was developed to provide the surgical team instantaneous, intraoperative knowledge of three-dimensional dentoskeletal parameters. Mock face-jaw-teeth transplantation operations were performed on plastic and cadaveric human donor/recipient pairs (n = 2). Preoperatively, cephalometric landmarks were identified on donor/recipient skeletons using segmented computed tomographic scans. The computer-assisted planning and execution workstation tracked the position of the donor face-jaw-teeth segment in real time during the placement/inset onto recipient, reporting pertinent hybrid cephalometric parameters from any movement of donor tissue. The intraoperative data measured through real-time cephalometry were compared to posttransplant measurements for accuracy assessment. In addition, posttransplant cephalometric relationships were compared to planned outcomes to determine face-jaw-teeth transplantation success. Compared with postoperative data, the real-time cephalometry-calculated intraoperative measurement errors were 1.37 ± 1.11 mm and 0.45 ± 0.28 degrees for the plastic skull and 2.99 ± 2.24 mm and 2.63 ± 1.33 degrees for the human cadaver experiments. These results were comparable to the posttransplant relations to planned outcome (human cadaver experiment, 1.39 ± 1.81 mm and 2.18 ± 1.88 degrees; plastic skull experiment, 1.06 ± 0.63 mm and 0.53 ± 0.39 degrees). Based on this preliminary testing, real-time cephalometry may be a valuable adjunct for adjusting and measuring "hybrid occlusion" in face-jaw-teeth transplantation and other orthognathic surgical procedures.

[The elemental composition of teeth hard tissues depending on the state of the environment].

Science.gov (United States)

Suladze, N; Shishniashvili, T; Margvelashvili, V; Kobakhidze, K

2014-01-01

At present, great attention is paid to the origin of man-made micro elemental anomalies. To monitor the state of the environment and its effects on the human body, of great importance is the determination of the amount and distribution of various chemical elements in the dentin and enamel of the teeth. To determine the essential (Ca, Zn, Mn, Ni), conditionally essential (Rb, Ni, Sr) and toxic (Pb, Hg) trace elements in the mineralized tissues of the teeth and to identify the relationship between the elemental composition of the tooth structure and the state of the general and dental health depending on the state of the environment, we have examined 29 children aged 3-4 years who have carried out analysis of hard tissue of teeth (teeth used for remote medical reasons) for the maintenance of nine chemical elements. Children living in a relatively environmentally favorable conditions essential value and conditionally essential elements in the mineralized tissues of the teeth were within normal limits, and toxic elements slightly increased limits that differ from those of children living in environmentally disadvantaged areas. In particular, these essential elements were significantly reduced (except for zinc), as indicators of toxic elements - mercury and lead, increased by 12.5% and 44.5%, respectively, which is clearly reflected on the state of dental health because noted decompensated form of tooth decay. Thus, deviations in a state of general and dental health of children associated with an imbalance of macro-and microelements in the mineralized tissues of the teeth.

A Novel Marker Based Method to Teeth Alignment in MRI

Science.gov (United States)

Luukinen, Jean-Marc; Aalto, Daniel; Malinen, Jarmo; Niikuni, Naoko; Saunavaara, Jani; Jääsaari, Päivi; Ojalammi, Antti; Parkkola, Riitta; Soukka, Tero; Happonen, Risto-Pekka

2018-04-01

Magnetic resonance imaging (MRI) can precisely capture the anatomy of the vocal tract. However, the crowns of teeth are not visible in standard MRI scans. In this study, a marker-based teeth alignment method is presented and evaluated. Ten patients undergoing orthognathic surgery were enrolled. Supraglottal airways were imaged preoperatively using structural MRI. MRI visible markers were developed, and they were attached to maxillary teeth and corresponding locations on the dental casts. Repeated measurements of intermarker distances in MRI and in a replica model was compared using linear regression analysis. Dental cast MRI and corresponding caliper measurements did not differ significantly. In contrast, the marker locations in vivo differed somewhat from the dental cast measurements likely due to marker placement inaccuracies. The markers were clearly visible in MRI and allowed for dental models to be aligned to head and neck MRI scans.

Natal teeth in an infant with congenital hypothyroidism

Directory of Open Access Journals (Sweden)

C Venkatesh

2011-01-01

Full Text Available Teeth erupting at birth are referred to as natal teeth. It is a common and benign finding in the neonatal period. However, they may be associated with genetic syndromes like Ellis Van Creveld syndrome and Hallermann-Streiff syndrome. We report here a case of natal teeth in an infant with congenital hypothyroidism.

Dental Pulp Revascularization of Necrotic Permanent Teeth with Immature Apices.

Science.gov (United States)

El Ashiry, Eman A; Farsi, Najat M; Abuzeid, Sawsan T; El Ashiry, Mohamed M; Bahammam, Hammam A

The treatment of immature necrotic teeth with apical periodontitis presents challenges in endodontic and pediatric dentistry. Revascularization is a recent treatment for such cases as an alternative to conventional apexification. The purpose is to examine the effect of a pulpal revascularization procedure on immature necrotic teeth with apical periodontitis. Twenty patients were enrolled for pulp revascularization procedure by root canal disinfection using a triple antibiotic mixture for 1-2 weeks, followed by creating a blood clot, sealing the root canal orifice using white mineral trioxide aggregate and a coronal seal of composite resin. Patients were recalled periodically for up to 24 months. During follow-up, all patients were asymptomatic. Three cases of chronic apical periodontitis showed clinical disappearance of the sinus tract 2 weeks after treatment. Radiography revealed progressive periapical radiolucency resolution within the first 12 months. Within 12-24 months, the treated teeth showed progressive increases in dentinal wall thickness, root length and continued root development. Clinical and radiographic evidence showed successful revascularization treatments of immature necrotic permanent teeth with apical periodontitis. More studies are necessary to understand the underlying mechanisms and to perform histopathology of the pulp space contents after revascularization procedures.

Estimating Gear Teeth Stiffness

DEFF Research Database (Denmark)

Pedersen, Niels Leergaard

2013-01-01

The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffness’s of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact length is constant....

Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature

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Neha Khambete

2012-01-01

Full Text Available Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till date. The role of genetics in development of supernumerary teeth is highlighted.

Comparative gene expression analysis of the human periodontal ligament in deciduous and permanent teeth.

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Je Seon Song

Full Text Available 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.

Comparative gene expression analysis of the human periodontal ligament in deciduous and permanent teeth.

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Song, Je Seon; Hwang, Dong Hwan; 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.

Malocclusion (Misaligned Teeth)

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... and Dental Disorders Malocclusion Causes Treatment More Information Medical Dictionary Also of Interest (Quiz) Biology of the Mouth Additional Content Medical News Malocclusion ˌmal-ə-ˈklü-zhən (Misaligned Teeth) ...

External and Intrinsic Signatures in Human Teeth to Assist Forensic Identification Work

OpenAIRE

Alkass, Kanar

2011-01-01

In forensic medicine, dead victim identification constitutes an important task for forensic professionals including forensic pathologists, anthropologists, and odontologists. If no clues are at hand regarding the identity of the deceased, whether it is a victim of a mass disaster or a suspect homicide case, it is vital to know when a person died, and to know the sex and age of the decedent in order to limit the search for possible matching persons. In paper I, teeth from ...

226Ra concentration in the teeth of habitants of areas with high level of natural radioactivity in Ramsar

International Nuclear Information System (INIS)

Aghamiri, S. Mahmoud Reza; Ghorbani, Zahra; Darafsheh, Arash; Torabzadeh, Hasan; Fathivand, Ali Asghar; Minuchehr, Abdulhamid; Jalinoos, Alireza

2006-01-01

The level of natural radiation in some regions of Ramsar, a northern coastal city of Iran, is known to be among the highest levels of natural radiation in the world. 226 Ra existing in high concentrations in the soil of this region is washed by underground water and transferred to the surface. In this way, 226 Ra enters the food chain of residents and substitutes within the hard body tissues of humans. 226 Ra is one of the so-called bone seekers as its metabolic processes in the human body are similar to calcium and remains in hard tissues of body because of its long half-life, and being an α emitter causes dangerous effects on human health. The purpose of this study is to determine the concentration of 226 Ra in the teeth of residents of these high-level natural radiation areas, compared with a control group. Thirteen teeth in five groups were studied as the case group and thirteen teeth in five corresponding control groups were inspected. The mean values of the activity of 226 Ra in the case group and in the control group were 0.32 and 0.18 mBq g -1 , respectively

Targeted traction of impacted teeth with C-tube miniplates.

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Chung, Kyu-Rhim; Kim, Yong; Ahn, Hyo-Won; Lee, Dongjoo; Yang, Dong-Min; Kim, Seong-Hun; Nelson, Gerald

2014-09-01

Orthodontic traction of impacted teeth has typically been performed using full fixed appliance as anchorage against the traction force. This conventional approach can be difficult to apply in the mixed dentition if the partial fixed appliance offers an insufficient anchor unit. In addition, full fixed appliance can induce unwanted movement of adjacent teeth. This clinical report presents 3 cases where impacted teeth were recovered in the mixed or transitional dentition with skeletal anchorage on the opposite arch without full fixed appliance. Instead, intermaxillary traction was used to bring the impacted teeth into position. With this approach, side effects on teeth and periodontal tissues adjacent to the impaction were minimized.

Development of teeth in chick embryos after mouse neural crest transplantations

OpenAIRE

Mitsiadis, Thimios A.; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

2003-01-01

Teeth were lost in birds 70–80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick ...

Effect of inadequate ferrule segment location on fracture resistance of endodontically treated teeth

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Satheesh B Haralur

2018-01-01

Full Text Available Introduction: The circumferential 2 mm ferrule during the fabrication of the crown is strongly advocated for the long-term clinical success. During the routine clinical practice, the dentist encounters the endodontically treated tooth (ETT with inadequacy of the ferrule in some segment due to caries, abrasion, and erosions. The aim of this in vitro study was to investigate the consequence of inadequate segmental ferrule location on fracture strength of the root canal-treated anterior and posterior teeth. Materials and Methods: Fifty each maxillary canine and mandibular premolar intact human teeth were root canal treated and sectioned at 2 mm above the cementum-enamel junction. The teeth samples were divided into 5 groups of 10 each. The G-I and G-V samples had the 360° ferrule and complete absence of the ferrule, respectively. The G-II had the inadequate ferrule on the palatal surface, while G-III and G-IV had inadequate ferrule at buccal and proximal area. Teeth samples were subsequently restored with glass-reinforced fiber post, composite core, and full veneer metal crown. The samples were tested with universal testing machine under static load to record the fracture resistance. The acquired data were subjected to ANOVA and Tukey's post hoc statistical analysis. Results: The G-I with circumferential ferrule showed the higher fracture resistance. The teeth samples with lack of the ferrule had the least fracture resistance. Among the segmental absence of ferrule, teeth samples with lack of the proximal ferrule were least affected. Deficiency of a ferrule on the lingual wall significantly affected the fracture strength in both anterior and posterior ETT. Conclusions: The ETT with sectional inadequacy of the ferrule is significantly more effective in resisting the fracture in comparison to the complete absence of the ferrule.

The creation of virtual teeth with and without tooth pathology for a virtual learning environment in dental education.

Science.gov (United States)

de Boer, I R; Wesselink, P R; Vervoorn, J M

2013-11-01

To describe the development and opportunities for implementation of virtual teeth with and without pathology for use in a virtual learning environment in dental education. The creation of virtual teeth begins by scanning a tooth with a cone beam CT. The resulting scan consists of multiple two-dimensional grey-scale images. The specially designed software program ColorMapEditor connects these two-dimensional images to create a three-dimensional tooth. With this software, any aspect of the tooth can be modified, including its colour, volume, shape and density, resulting in the creation of virtual teeth of any type. This article provides examples of realistic virtual teeth with and without pathology that can be used for dental education. ColorMapEditor offers infinite possibilities to adjust and add options for the optimisation of virtual teeth. Virtual teeth have unlimited availability for dental students, allowing them to practise as often as required. Virtual teeth can be made and adjusted to any shape with any type of pathology. Further developments in software and hardware technology are necessary to refine the ability to colour and shape the interior of the pulp chamber and surface of the tooth to enable not only treatment but also diagnostics and thus create a greater degree of realism. The creation and use of virtual teeth in dental education appears to be feasible but is still in development; it offers many opportunities for the creation of teeth with various pathologies, although an evaluation of its use in dental education is still required. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Self-perception of teeth loss of the aged

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Beatriz Unfer

2006-01-01

Full Text Available The objective of this work was to analyze the perceptions of a group of the aged regarding teeth loss. A qualitative study was conducted using the Discourse of the Collective Subject as a methodological technique for ordering the data. The analysis of the interviews and the construction of the Discourse of the Collective Subject disclosed information on the thoughts and values associated with the loss of teeth within this group. The main results suggest that the lack of teeth caused functional and psychological problems, but that these appeared to be offset by solving the aesthetic problem. The justifications disclosed by the collective subject for edentulous predominantly reflect the healthcare model, which focuses on surgical, restorative and rehabilitation procedures, to the detriment of preventive actions and the promotion of health. Thus, the development of initiatives in the field of education and prevention regarding oral health is essential, emphasizing actions that target integral attention to the aged, detaching the social dimension of the illnesses, as well as the role of the State as supplier of health and quality of life to all citizens.

MULTIPLE RETAINED TEETH IN MANDIBLE: A Case Report

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Cvetan Cvetanov

2010-07-01

Full Text Available Purpose: The aim of this science report is to show a rare case of multiple impacted teeth at adult patient and our propose clinical approach.Materials and methods: The clinical case is showed from adult man /64-year old/ with multiple impacted teeth (6 impacted teeth in the anterior place on the mandible were not suggestive of any syndrome or metabolic disorder. The extraction of the impacted teeth was made on two stage with piezosurgery unit under local anaesthesia. For prevention of postsurgical complications, as a swelling and prevention of postsurgical resorbtion were used coneshapes from pressure xeno colagen. To base on clinical and radiological examination we will discuss the differential diagnosis and we will offer a clinical approach about decided the case.Result and Conclusion: The incidence of multiple retained teeth by literature research range from 10.9% to 40.4%, most frequently is the retention of the third molars. In the literature most rarely have clinical reports about multiple retained teeth which differ from third molars at adult patients. The rare clinical case we showed is very demonstrative and the medicative approach which we used gave excellent result.

PIXE studies on teeth

International Nuclear Information System (INIS)

Chaudhri, M.A.; Ainsworth, T.

1980-01-01

The elemental composition of healthy and diseased teeth from 25 children has been determined using thick-target proton induced x-ray emission, (PIXE), analysis. Various dental hard tissues: enamel, dentine and cementum, and their junctions, as well as different parts of the same tissue, have been examined individually. A number of elements: Na, Mg, Al, P, S, Cl, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb, has been determined in these dental tissues. The concentrations of some of the elements tend to vary considerably from tooth to tooth and tissue to tissue. Attempts have been made to correlate the concentrations of various elements in teeth with their health

Integrated Surgical and Orthodontic Treatment: A Twinned Teeth Dilemma

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Seema D Bargale

2015-01-01

Full Text Available Background: Twinned or geminated teeth may cause spacing, caries, aesthetic and periodontal problems which are usually seen in the anterior region. Various treatment methods can be used for correction of double teeth according to the demands of the condition. This article reports bilateral fused maxillary incisor teeth. The fused right side incisor was separated by hemisection and remaining mesial incisal margin was built using composite. Further, comprehensive orthodontic treatment was done to align the anterior maxillary teeth.

Dental Anomalies in Permanent Teeth after Trauma in Primary Dentition.

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Bardellini, Elena; Amadori, Francesca; Pasini, Stefania; Majorana, Alessandra

This retrospective study aims to evaluate the prevalence of dental anomalies in permanent teeth as a result of a trauma concerning the predecessor primary teeth. A total of 241 records of children (118 males and 123 females, mean age 3.62 ± 1.40) affected by trauma on primary teeth were analyzed. All patients were recalled to evaluate the status of the permanent successor teeth by clinical and radiographic investigations. Out of 241 patients, 106 patients (for a total of 179 traumatized primary teeth) presented at the recall. Dental anomalies on successor permanent teeth were detected in 21 patients (19.8%), for a total of 26 teeth (14.5%) and 28 anomalies. Anomalies of the eruptive process were the most observed disturbances (60.7%), followed by enamel hypoplasia (25%) and white spots (14.3%). A higher percentage of anomalies on permanent teeth was observed when trauma occurred at an age less than 36 months (38.5% of cases). Intrusive and extrusive luxation were related with the most cases of clinical disturbances in the successor permanent teeth. The results of this study highlight the risk of dental anomalies after a trauma in primary dentition, especially in early-aged children and in case of intrusive luxation.

On the development of life prediction methodologies for the failure of human teeth

Energy Technology Data Exchange (ETDEWEB)

Nalla, R.K.; Imbeni, V.; Kinney, J.H.; Marshall, S.J.; Ritchie, R.O.

2002-09-18

Human dentin is known to be susceptible to failure under cyclic loading. Surprisingly, there are few reports that quantify the effect of such loading, considering the fact that a typical tooth experiences a million or so loading cycles annually. In the present study, a systematic investigation is described of the effects of prolonged cyclic loading on human dentin in a simulated physiological environment. In vitro stress-life (S/N) data are discussed in the context of possible mechanisms of fatigue damage and failure.

Infant teething information on the world wide web: taking a byte out of the search.

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Kozuch, Mary; Peacock, Erica; D'Auria, Jennifer P

2015-01-01

The purpose of this study was to describe and evaluate the quality of infant teething information on selected popular parenting Web sites. Two checklists were used to evaluate the quality of the 16 parenting sites and infant teething-specific content included on each site. Three of the 16 parenting sites did not contain teething-specific articles. Teething-specific content found on 13 of the 16 sites supported a connection between the process of teething and nonspecific symptoms with a perception that management is required. Popular management strategies included chewing on chilled objects, gingival massage, and the use of over-the-counter medications. Information about possible adverse effects of administering medications for infant teething was not found on the majority of sites. Eleven of the 16 sites advised parents to contact their primary care provider if they were uncertain about management for infant teething or whether the symptoms were related to illness. Although infant teething has an evidence base from which parents and professionals can make safe decisions about symptoms and treatment, translating the evidence into professional practice and health-related information on the Internet remains a challenge. Parents and pediatric health providers would benefit greatly from the development of clinical practice guidelines summarizing our present-day understanding of teething symptoms and the limited evidence supporting the use of over-the-counter medications. Copyright © 2015 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.

Evaluation of crown mesiodistal diameter of permanent teeth

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H. Ravanmehr

1994-06-01

Full Text Available The aim of this study was to evaluate mesiodistal diameter of permanent teeth and evaluating it's distribution in Iran. In current study, 850 plastery impressions or 16590 teeth were precisely measured by a digital coulis with 0.01 mm accuracy.The obtained measures of the permanent teeth are shown in table 1. Table (4 demonstrates the symmetry of left and right maxillary and mandibular teeth. Obtainedmeasurements in Table 1 were compared with Gran's measures (Table 2 which are shown in Table (3.Bolton analysis was done and results were found close to the BolType text or a website address or translate a document.ton measures. It was concluded that it is better to replace measurements of our society instead of Bolton's. Since we found minor difference with the measures of other researchers, especially for teeth anterior to first molar, using our measures in treatment plans would not bring about any problem.

Bond strength test of acrylic artificial teeth with prosthetic base

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Erna Kurnikasari

2008-07-01

Full Text Available Denture consists of acrylic artificial teeth and acrylic prothesis base bond chemically with a bond strength of 315 kgF/cm2. Most of the commercial acrylic artificial teeth do not specify their specifications and all of those acrylic artificial teeth do not include mechanical data (bond strength. The aim of this study is to discover which acrylic artificial teeth meet ADA specification no. 15. This study is a descriptive analytic study performed to 5 acrylic artificial teeth posterior brands commonly used by dentists and technicians. From each brand, 3 sample teeth were taken. The acrylic artificial teeth were prepared into a rectangular shape and were attached between acrylic prothesis base simulation and jigs. The sample was given tensile load using a Universal Testing Machine. The amount of force that causes the teeth to be fractured was recorded and the bond strength was calculated. The results of the study show that the average value for the five acrylic artificial teeth for the five brands were as followed: Brand A, 125.993 kgF/cm2; B, 188.457 kgF/cm2; C, 175.880 kgF/cm2; D, 153.373 kgF/cm2; E, 82.839 kgF/cm2. The data can be tested statistically by using One Way ANOVA test and Dunnett test (alpha = 0.05. From the study, it is concluded that the five acrylic artificial teeth have a bond strength below the ADA specification no. 15.

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

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Weihua Shi

Full Text Available 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.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.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.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.

Spectrophotometric Evaluation of the Pulpal Peroxide Levels in Intact and Restored Teeth - An Invitro Study.

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Patri, Gaurav; Acharya, Gourismita; Agrawal, Pratik; Panda, Vijeta

2016-08-01

Hydrogen peroxide (30%) is a commonly used "in office" bleaching agent. Deleterious effects of hydrogen peroxide on the pulp have been observed. The present study was conducted with the aim to evaluate the penetration of 30% hydrogen peroxide into the pulp chamber through intact teeth and through the surface of teeth, restored with either hybrid composite or Resin Modified Glass Ionomer Cement (RMGIC). Sixty extracted human maxillary central incisors were selected and divided into six groups. Two groups were restored with hybrid composite resin and two with RMGIC, while two groups were left intact. The teeth with acetate buffer solution in their pulp cavity were then immersed in either 30% hydrogen peroxide or distilled water depending upon the group, for 60 minutes at 37°C. Then horseradish peroxidase and leucocrystal violet were added to the acetate buffer solution present in the pulp chamber after it was transferred to a test tube and the optical density of the resultant blue solution obtained was measured spectrophotometrically. The data obtained were analyzed using one way ANOVA and Student's t-test. The data obtained established that hydrogen peroxide penetrated into the pulp from the bleaching agent used. Hydrogen peroxide (30%) showed the highest pulpal peroxide level in teeth restored with RMGIC followed by teeth restored with hybrid composite resin and the least amount of penetration was observed in intact teeth. The amount of peroxide penetration into the tooth is more through restored tooth than intact tooth and is also dependant on the type of restorative materials used.

Orthodontics Align Crooked Teeth and Boost Self-Esteem

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

Determination of Fluorine and other light elements in Syrian teeth by PIGE and PIXE techniques

International Nuclear Information System (INIS)

Bakraji, E.; Ahmad, M.; Doueer, M.

2013-01-01

The aim of this study is to determine the concentration of Fluorine in Syrian teeth collected from Southern and Coastal regions where both populations have almost similar dietary habits and similar occupational activities. The conventional PIGE method is used to determine Fluorine concentration in human teeth since its play an important role in bony and dental tissues, the low levels of Fluorine can play positive role against teeth cariosity and an inhibitor against certain enzyme systems, where high levels can cause dental Fluorosis and bone abnormalities for the bone structure. Several cations and anions have been studied in the drinking water of studied areas in order to investigate the role played by these elements and whether fluoridation within the normal levels of worldwide standard grading. Na, Mg, P and Ca concentrations have been determined in studied samples in order to compare with earlier works. (author)

Pomegranate juice (punica granatum: a new storage medium for avulsed teeth.

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Sara Tavassoli-Hojjati

2014-04-01

Full Text Available There is evidence indicating that pomegranate juice contains many of the essential properties necessary to retain cell viability and cell proliferation. These properties indicate that pomegranate juice is a suitable storage medium for avulsed teeth. However, this idea has not yet been tested. In this study, the capacity of pomegranate juice (PJ as a storage medium for retaining avulsed teeth was evaluated.PDL fibroblasts were obtained from healthy human premolars and cultured in Dulbecco's Modified Eagle's Medium (DMEM. Cultured cells were subjected to different concentrations of pomegranate juice (PJ, 1% Hank's balanced salt solution (HBSS and tap water for 1, 3, 6 and 24 hours. PDL cell viability was assessed by the neutral red uptake assay.The results indicated that 7.5% PJ was the most effective solution for maintaining PDL cell viability amongst all the experimental solution's and time intervals (P<0.05. The results also showed that 1% PJ was as effective as HBSS for maintaining PDL cell viability. The amount of cell viability increased with increasing concentration of PJ at all time intervals (P<0.001. This effect is suggestive of the proliferative potential of PJ solution.In conclusion, PJ can be recommended as a suitable transport medium for avulsed teeth.

Evaluation of bond strength of a conventional adhesive system in irradiated teeth

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Emanuel Jordan de CARVALHO

Full Text Available Abstract Introduction One of the most common treatments of head and neck cancer patients is radiotherapy, a treatment method which uses ionizing radiation beam and destroys tumor cells, minimizing damage to neighbor cells. Purpose To evaluate the bond strength of a conventional adhesive system in irradiated teeth. Method 24 third human molars, 12 of which were randomly exposed to radiation and prepared from the removal of occlusal enamel, then exposed to a flat dentine surface. The adhesive system Stae was applied according to the manufacturer’s instructions. Next, two 2 mm increments of resin were implemented. The samples were hemi sectioned specimens, originating shapped toothpick. To evaluate the bond strength, a micro tensile test was done with 500N load and speed of 0.5 mm/minute. Result There was no statistically significant difference between the bond strength of teeth which were or were not exposed to radiation and which used a conventional adhesive system. Conclusion Although the radiation doses applied may cause some alterations in microscopic range in dental tissues, it can be concluded that these alterations do not influence in the bond strength in dentin of irradiated teeth.

21 CFR 872.6475 - Heat source for bleaching teeth.

Science.gov (United States)

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 a...

Injuries of deciduous and permanent teeth in children (diagnostic measures, medical tactics

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Yakovenko L.N.

2016-12-01

Full Text Available A retrospective analysis of 1147 patients’ records from the clinic of the department of surgical dentistry and maxillofacial surgery of childhood of NMU Bogomolets and 944 case histories of patients with traumatic injuries of maxillofacial region in the clinic of the department of pediatric dentistry of SE «Dnepropetrovsk medical academy of Health Ministry of Ukraine» has shown that traumatic damages to teeth make up 18.8% of all injuries in maxillofacial region. It was found that in most cases the cause of injury is fall of a child - 60%, punching on the face - 19%, other causes – 21%. Most often maxillary central incisors are affected - about 70-80%, lateral - 10-20% both in temporary and in shift bite. Lower incisors are injured only in 1-6% of cases. Injuries of the temporary teeth were observed in 30-45% of cases. The aim of the study was to determine the major diagnostic methods and therapeutic measures that have been used in trauma of permanent and temporary teeth in children of different ages. Diagnostic measures included clinical and instrumental studies. Of the additional survey methods of dental trauma in 90% of cases back-side X-ray, in 7-8% – orthopanto­mography, in 1-2% - CT were performed. In dislocations of temporary teeth X-ray examination was carried out only in impacted dislocation. Algorithm of treatment tactics for almost all kinds of temporary teeth dislocations was to remove it, not taking into account the degree of formation of the tooth root and functional ability of the tooth, that involves the development of the indications for their preservation. Most often, for the immobilization of the injured permanent teeth a smooth splin-clamp (85% was used, it is cheap, easy to manufacture, reliable for fixing, individual as for adaptation, but when applied it leads to injury of periodontal tissues, the development of inflammatory processes in them. Alternative methods of fixation were splint systems, splint-caps and

Prevalence, Characteristics, and Complications of Supernumerary Teeth in Nonsyndromic Pediatric Population of South India: A Clinical and Radiographic Study.

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Syriac, Gibi; Joseph, Elizabeth; Rupesh, S; Philip, John; Cherian, Sunu Alice; Mathew, Josey

2017-11-01

Supernumerary teeth are the presence of more number of teeth over the normal dental formula and may occur in permanent as well as early mixed dentition. This study determined the prevalence, characteristics, and complications caused by supernumerary teeth in nonsyndromic South Indian pediatric population. Characteristics of supernumerary teeth determined by clinical and radiographic examination were recorded. The age, sex, number of supernumerary teeth, eruption status, morphology, position, orientation, and complications (if any) associated with supernumerary teeth were recorded for each patient who had supernumerary teeth. The data collected were statistically analyzed. Supernumerary teeth were detected in 45 subjects (1.1%), of which 34 (75.6%) were male and 11 (24.4%) were female. There was no association between the number of supernumerary teeth and the gender of the patient. The total number of supernumerary teeth among the affected 45 patients was 54. The average number of supernumerary teeth per person was 1.2. The number of supernumerary teeth was one in 35 cases, two in 8 cases, and 3 in 1 case. Of the 45 patients, 8 patients with supernumerary teeth were in deciduous dentition stage, 29 patients were in mixed dentition stage, and 8 patients were in permanent dentition stage. Most supernumerary teeth presented in the anterior maxilla. Morphologically, conical-shaped supernumerary teeth were the most common finding. 68.5% of supernumerary teeth presented with straight orientation and inverted orientation was seen in 24.1%. Complications seen in patients with supernumerary teeth were delayed or noneruption of adjacent tooth malposition or rotation of adjacent teeth, diastema formation, and formation of dentigerous cyst. Supernumerary teeth have an incidence of 1.1% in South Indian population and can cause many complications that can harm the developing occlusion. Knowledge about supernumerary teeth may help the dentist in early diagnosis and early

Non-syndromic multiple impacted supernumerary teeth with peripheral giant cell granuloma

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Pankaj Bansal

2011-01-01

Full Text Available Peripheral giant cell granuloma (PGCG is a relatively frequent benign reactive lesion of the gingiva, originating from the periosteum or periodontal membrane following local irritation or chronic trauma. PGCG manifests as a red-purple nodule located in the region of the gingiva or edentulous alveolar margins. The lesion can develop at any age, although it is more common between the second and third decades of life, and shows a slight female predilection. PGCG is a soft tissue lesion that very rarely affects the underlying bone, although the latter may suffer superficial erosion. A supernumerary tooth is one that is additional to the normal series and can be found in almost any region of the dental arch. These teeth may be single, multiple, erupted or unerupted and may or may not be associated with syndrome. Usually, they cause one or the other problem in eruption or alignment of teeth, but may also present without disturbing the normal occlusion or eruption pattern. Management of these teeth depends on the symptoms. Presented here is a case of PGCG in relation to the lower left permanent first molar with three supernumerary teeth in the mandibular arch but no associated syndrome.

Congenital adrenal hyperplasia: a case report with premature teeth exfoliation and bone resorption.

Science.gov (United States)

Angelopoulou, Matina V; Kontogiorgos, Elias; Emmanouil, Dimitris

2015-06-01

Congenital adrenal hyperplasia (CAH) is an inherited autosomal recessive disorder characterized by insufficient production of cortisol. The aim of this case report was to present a child with CAH, premature exfoliation of primary teeth and accelerated eruption of his permanent teeth related to bone resorption. A 4.5-year-old Caucasian boy with CAH and long-term administration of glucocorticoids was referred for dental restoration. Clinical examination revealed primary molars with worn stainless steel crowns, severe attrition of the upper canines, and absence of the upper incisors. Before the completion of treatment, abnormal mobility of the first upper primary molars and the lower incisors was detected, and a few days later the teeth exfoliated prematurely. Histologic examination revealed normal tooth structure. Alkaline phosphatase and blood cells values were normal. Eruption of the permanent dentition was also accelerated. Tooth mobility was noticed in the permanent teeth as soon as they erupted, along with bone destruction. Examination revealed an elevated level of receptor activator of nuclear factor-κB ligand and lower-than-normal osteoprotegerin and vitamin D levels. The patient was treated with vitamin D supplements, and his teeth have been stable ever since. CAH is a serious chronic disorder appearing in children with accelerated dental development and possibly premature loss of primary teeth. Copyright © 2015 by the American Academy of Pediatrics.

Phototherapy up-regulates dentin matrix proteins expression and synthesis by stem cells from human-exfoliated deciduous teeth.

Science.gov (United States)

Turrioni, Ana Paula S; Basso, Fernanda G; Montoro, Liege A; Almeida, Leopoldina de Fátima D de; Costa, Carlos A de Souza; Hebling, Josimeri

2014-10-01

The aim of this study was to evaluate the effects of infrared LED (850nm) irradiation on dentin matrix proteins expression and synthesis by cultured stem cells from human exfoliated deciduous teeth (SHED). Near-exfoliation primary teeth were extracted (n=3), and SHED cultures were characterized by immunofluorescence using STRO-1, CD44, CD146, Nanog and OCT3/4 antibodies, before experimental protocol. The SHEDs were seeded (3×10(4) cells/cm(2)) with DMEM containing 10% FBS. After 24-h incubation, the culture medium was replaced by osteogenic differentiation medium, and the cells were irradiated with LED light at energy densities (EDs) of 0 (control), 2, or 4J/cm(2) (n=8). The irradiated SHEDs were then evaluated for alkaline phosphatase (ALP) activity, total protein (TP) production, and collagen synthesis (SIRCOL™ Assay), as well as ALP, collagen type I (Col I), dentin sialophosphoprotein (DSPP), and dentin matrix acidic phosphoprotein (DMP-1) gene expression (qPCR). Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=0.05). Increased ALP activity and collagen synthesis, as well as gene expression of DSPP and ALP, were observed for both EDs compared with non-irradiated cells. The ED of 4J/cm(2) also increased gene expression of COL I and DMP-1. In conclusion, infrared LED irradiation was capable of biostimulating SHEDs by increasing the expression and synthesis of proteins related with mineralized tissue formation, with overall better results for the energy dose of 4J/cm(2). Phototherapy is an additional approach for the clinical application of LED in Restorative Dentistry. Infrared LED irradiation of the cavity's floor could biostimulate subjacent pulp cells, improving local tissue healing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Study of external root resorption during orthodontic treatment in root filled teeth compared with their contralateral teeth with vital pulps.

Science.gov (United States)

Llamas-Carreras, J M; Amarilla, A; Solano, E; Velasco-Ortega, E; Rodríguez-Varo, L; Segura-Egea, J J

2010-08-01

To determine whether root filled teeth and those with vital pulps exhibit a similar degree of external root resorption (ERR) as a consequence of orthodontic treatment. The study sample consisted of 77 patients, with a mean age of 32.7 +/- 10.7 years, who had one root filled tooth before completion of multiband/bracket orthodontic therapy for at least 1 year. For each patient, digital panoramic radiographs taken before and after orthodontic treatment were used to determine the proportion of external root resorption (PRR), defined as the ratio between the root resorption in the root filled tooth and that in its contralateral tooth with a vital pulp. The student's t-test, anova and logistic regression analysis were used to determine statistical significance. The mean PRR was 1.00 +/- 0.13, indicating that, in the total sample, there were no significant differences in root resorption in the root filled teeth and their contralateral teeth with vital pulps. Multivariate logistic regression analysis suggested that PRR was significantly greater in incisors (P = 0.0014; odds ratio = 6.2885, C.I. 95% = 2.0-19.4), compared to other teeth, and in women (P = 0.0255; odds ratio = 4.2, C.I. 95% = 1.2-14.6), compared to men. There was no significant difference in the amount or severity of external root resorption during orthodontic movement between root filled teeth and their contralateral teeth with vital pulps.

Direct composite restoration of permanent anterior teeth uncomplicated crown fractures

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Ashley Evans Nicholas

2018-01-01

Full Text Available An uncomplicated crown fracture is a fracture that involves only the tooth enamel or the dentin and tooth enamel without any damage or exposure to the pulp. Crown fracture of the anterior teeth usually caused by traumatic forces such as falls, accidents, violence, or sports activities. Traumatic injuries of the oral region frequently involve the anterior teeth, especially maxillary incisors due to the anatomic factors which may affect the functional and aesthetical values of the teeth. The objective of this literature study was to know more about uncomplicated crown fracture of the anterior teeth and its restoration. This research was a literature study performed by researching, highlighting various interesting facts and compiling the relevant published journals. The most common and ideal direct restoration of the anterior teeth was the composite resin restoration. The anterior teeth restoration was considered to be a complex and challenging case to solves due to the fact that besides reconstructing the tooth and regaining the function, the aesthetical aspect was also becoming the main objectives. The permanent anterior teeth uncomplicated crown fracture was the most common case of tooth fractures which was mainly caused by traumatic injuries such as falls, accidents, excessive forces, violence, and also sports activities. Dental injuries of the anterior teeth also affected the aesthetical properties and the function of the tooth. Composite resin restoration was able to performed directly on the permanent anterior teeth uncomplicated crown fracture.

Indoleamine 2,3-Dioxygenase Is Dispensable for The Immunomodulatory Function of Stem Cells from Human Exfoliated Deciduous Teeth.

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Alipour, Razieh; Masoumi Karimi, Masoumeh; Hashemi-Beni, Batool; Adib, Minoo; Sereshki, Nasrin; Sadeghi, Farzaneh

2017-01-01

In this study, we sought to better understand the immunoregulatory function of stem cells derived from human exfoliated deciduous teeth (SHED). We studied the role of the interferon gamma (IFN-γ)-indoleamine 2,3-dioxygenase (IDO)-axis in immunoregulation of SHED compared to bone marrow derived mesenchymal stem cells (BMMSCs) under the same conditions. In this cross-sectional study, recently isolated human T cells were stimulated either by mitogen or inactivated allogeneic peripheral blood mononuclear cells (PBMCs). These T cells were subsequently co-cultured with, either SHED or BMMSCs in the presence or absence of 1-methyl-tryptophan (1-MT) or neutralizing anti- human-IFN-γ antibodies. In all co-cultures we evaluated lymphocyte activation as well as IDO activity. SHED, similar to conventional BMMSCs, had anti-proliferative effects on stimulated T cells and reduced their cytokine production. This property of SHED and BMMSCs was changed by IFN-γ neutralization. We detected IDO in the immunosuppressive supernatant of all co-cultures. Removal of IDO decreased the immunosuppression of BMMSCs. SHED, like BMMSCs, produced the IDO enzyme. Although IFN-γ is one of inducer of IDO production in SHED, these cells were not affected by IFN-γ in the same manner as BMMSCs. Unlike BMMSCs, the IDO enzyme did not contribute to their immunosuppression and might have other cell-type specific roles.

Improvement in properties of plastic teeth by electron beam irradiation

International Nuclear Information System (INIS)

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

2011-01-01

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 o 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. - Highlights: → Radiation improvement of polycarbonate for plastic teeth by EB irradiation 3.5 kGy at 150 o C in inert gas. → Water and glucose absorption and maltose adhesion on PC teeth were much reduced. → Bis-phenol-A content from PC teeth was lower than the detection limit after irradiation.

The Long-Term Effects of Mandibular Distraction Osteogenesis on Developing Deciduous Molar Teeth

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Paul Hong

2012-01-01

Full Text Available Background. Many studies have demonstrated the effectiveness of mandibular distraction osteogenesis (MDO in alleviating the micrognathia-associated upper airway obstruction but very few studies have focused on long-term dental outcomes. Objective. To report the effect of MDO on developing deciduous molars in the distraction area. Methods. A retrospective chart review was performed to identify patients with Pierre Robin sequence who underwent MDO with documented long-term dental assessments. Results. Ten children (mean age at surgery 69.8 days; 6 boys and 4 girls were included for analysis. All patients underwent bilateral MDO with an inverted L-shaped osteotomy to avoid injuring tooth buds. The dental developmental stage was primary dentition in all children. Overall, 3 patients developed minor dental problems involving 4 molar teeth (2 root malformations and 2 shape anomalies but they did not require any interventions. Conclusion. Significant primary molar developmental complications were not seen in our patients. The use of internal distractor device with an inverted L-shaped osteotomy seems to be a safe surgical approach in regards to dental outcomes.

Fatigue crack propagation path across the dentinoenamel junction complex in human teeth.

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Dong, X D; Ruse, N D

2003-07-01

The human tooth structures should be understood clearly to improve clinically used restorative materials. The dentinoenamel junction (DEJ) plays a key role in resisting crack propagation in teeth. The aim of this study was to determine the fracture toughness of the enamel-DEJ-dentin complex and to investigate the influence of the DEJ on the fatigue crack propagation path across it by characterizing fatigue-fractured enamel-DEJ-dentin complexes using optical and scanning electron microscopy. The results of this study showed that the fracture toughness of the enamel-DEJ-dentin complex was 1.50 +/- 0.28 Mpa x m(1/2). Based on the results of this investigation, it was concluded that the DEJ complex played a critical role in resisting crack propagation from enamel into dentin. The DEJ complex is, approximately, a 100 to 150 microm broad region at the interface between enamel and dentin. The toughening mechanism of the DEJ complex may be explained by the fact that crack paths were deflected as cracks propagated across it. Understanding the mechanism of crack deflection could help in improving dentin-composite as well as ceramic-cement interfacial qualities with the aim to decrease the risk of clinical failure of restorations. Both can be viewed as being composed from a layer of material of high strength and hardness bonded to a softer but tougher substratum (dentin). The bonding agent or the luting cement layer may play the critical role of the DEJ in improving the strength of these restorations in clinical situations. Copyright 2003 Wiley Periodicals, Inc.

Osteogenic differentiation and mineralization of human exfoliated deciduous teeth stem cells on modified chitosan scaffold

Energy Technology Data Exchange (ETDEWEB)

Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Wu, Pai-Shuen [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Ko, Chih-Sheng [PhytoHealth Corporation, Maywufa Biopharma Group, Taipei, Taiwan (China); Huang, Te-Yang [Mackay Memorial Hospital, Taipei, Taiwan (China)

2014-08-01

Stem cells from human exfoliated deciduous teeth (SHEDs) have been considered as alternative sources of adult stem cells in tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium has an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. In this study, the effects of strontium phosphate on the osteogenic differentiation of SHEDs were investigated. Strontium phosphate was found to enhance the osteogenic differentiation of SHEDs with up-regulated osteoblast-related gene expression. The proliferation of SHEDs was slightly inhibited by chitosan scaffolds; however, type-I collagen expression, alkaline phosphatase activity, and calcium deposition on chitosan scaffolds containing strontium were significantly enhanced. Furthermore, cells seeded in a 3D scaffold under dynamic culture at an optimal fluid rate might enhance cellular differentiation than static culture in osteoblastic gene expression. This experiment might provide a useful cell resource and dynamic 3D culture for tissue engineering and bone repair. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering • Strontium phosphate can enhance the osteogenic differentiation of SHEDs • 3D scaffold under dynamic culture with optimal fluid rate enhance cellular differentiation.

Osteogenic differentiation and mineralization of human exfoliated deciduous teeth stem cells on modified chitosan scaffold

International Nuclear Information System (INIS)

Su, Wen-Ta; Wu, Pai-Shuen; Ko, Chih-Sheng; Huang, Te-Yang

2014-01-01

Stem cells from human exfoliated deciduous teeth (SHEDs) have been considered as alternative sources of adult stem cells in tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium has an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. In this study, the effects of strontium phosphate on the osteogenic differentiation of SHEDs were investigated. Strontium phosphate was found to enhance the osteogenic differentiation of SHEDs with up-regulated osteoblast-related gene expression. The proliferation of SHEDs was slightly inhibited by chitosan scaffolds; however, type-I collagen expression, alkaline phosphatase activity, and calcium deposition on chitosan scaffolds containing strontium were significantly enhanced. Furthermore, cells seeded in a 3D scaffold under dynamic culture at an optimal fluid rate might enhance cellular differentiation than static culture in osteoblastic gene expression. This experiment might provide a useful cell resource and dynamic 3D culture for tissue engineering and bone repair. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering • Strontium phosphate can enhance the osteogenic differentiation of SHEDs • 3D scaffold under dynamic culture with optimal fluid rate enhance cellular differentiation

Occurrence and distribution of blackish staining on the crowns of human teeth obtained from an archeological excavation of a medieval site in Norway.

Science.gov (United States)

Beyer-Olsen, E M; Risnes, S

1993-04-01

An excavation in Trondheim, Norway, in 1984-85, uncovered a part of the medieval (1100-1600) cemetery of St Olav's Church. Of 388 excavated skeletons, 248 had skulls where the condition of the jaws and teeth allowed examination. In 51 of these skulls the teeth exhibited a characteristic blackish staining. A higher percentage of affected skulls was found in areas with organic, woodchip layers than in areas with gravelly sand. Affected skulls tended to have a high percentage of their teeth stained, but the staining tended to be restricted to only one or two of the three tooth surfaces scored. Posterior teeth were more often affected than anterior teeth, the occlusal/incisal part more often than the cervical part, and the buccal/labial part more often than the lingual part. Nonerupted third molars could also be stained. Staining seemed to be hampered by calculus. Occurrence of staining was independent of the presence or absence of a coffin and of coffin type. The extent of staining (% of stained surfaces within a dentition) was independent of sex and age. High correlation was found between all four jaw quadrants. There was no independence between color of the jawbone and occurrence of stained teeth. It was concluded that the staining phenomenon probably can be ascribed to factors in the soil. In vivo predisposing influences cannot be excluded.

Spektrofotometrijska procjena promjene boje zuba dugotrajno izloženih različitim uvjetima = Spectrophotometric evaluation of color alterations of teeth exposed to different conditions in time

NARCIS (Netherlands)

Dozic, A.; Zukanovic, A.; Bajsman, A.; Secic, S.; Petaros, A.

2011-01-01

Human teeth consist of organic and anorganic tissue components similair to bones. Therefore, it is assumable that the registration of structural changes of teeth color in different enviromental conditions may prove useful within forensic taphonomy field, for example, for verification of burial

Sox2 marks epithelial competence to generate teeth in mammals and reptiles

Science.gov (United States)

Juuri, Emma; Jussila, Maria; Seidel, Kerstin; Holmes, Scott; Wu, Ping; Richman, Joy; Heikinheimo, Kristiina; Chuong, Cheng-Ming; Arnold, Katrin; Hochedlinger, Konrad; Klein, Ophir; Michon, Frederic; Thesleff, Irma

2013-01-01

Tooth renewal is initiated from epithelium associated with existing teeth. The development of new teeth requires dental epithelial cells that have competence for tooth formation, but specific marker genes for these cells have not been identified. Here, we analyzed expression patterns of the transcription factor Sox2 in two different modes of successional tooth formation: tooth replacement and serial addition of primary teeth. We observed specific Sox2 expression in the dental lamina that gives rise to successional teeth in mammals with one round of tooth replacement as well as in reptiles with continuous tooth replacement. Sox2 was also expressed in the dental lamina during serial addition of mammalian molars, and genetic lineage tracing indicated that Sox2+ cells of the first molar give rise to the epithelial cell lineages of the second and third molars. Moreover, conditional deletion of Sox2 resulted in hyperplastic epithelium in the forming posterior molars. Our results indicate that the Sox2+ dental epithelium has competence for successional tooth formation and that Sox2 regulates the progenitor state of dental epithelial cells. The findings imply that the function of Sox2 has been conserved during evolution and that tooth replacement and serial addition of primary teeth represent variations of the same developmental process. The expression patterns of Sox2 support the hypothesis that dormant capacity for continuous tooth renewal exists in mammals. PMID:23462476

Fracture resistance of teeth submitted to several internal bleaching protocols.

Science.gov (United States)

Leonardo, Renato de Toledo; Kuga, Milton Carlos; Guiotti, Flávia Angélica; Andolfatto, Carolina; Faria-Júnior, Norberto Batista de; Campos, Edson Alves de; Keine, Kátia Cristina; Dantas, Andrea Abi Rached

2014-03-01

The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p endodontically-treated teeth, but there were no differences between each other. There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

Comparison of chronology of teeth eruption with body mass index among school children at Mangalore: A cross-sectional study

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Nagaratna B Bagewadi

2016-01-01

Full Text Available Introduction: The development and eruption of the teeth, chronologies of human dentitions, dental age, and tooth formation standards are important aspects applied to dental practice. Body mass index (BMI gives an indication about the nutritional status of the child. It is relevant to know whether BMI has influenced chronology of tooth eruption pattern. Aim: To determine the eruption age of the different permanent teeth and compare eruption age with BMI in a group of children from selected schools in Mangalore. Materials and Methods: A cross-sectional study was designed in which 2928 children ranging in age from 5.5 to 15 years were included in the study. The children were divided into 20 chronological age groups with half year intervals. All the children were examined by a single examiner with the help of a trained assistant. The teeth were examined under natural light with mouth mirror. The comparison was made between mean eruption ages in males and females using the independent t-test. Results: There were 1526 males constituting 52.1% and 1402 females constituting 47.9% of the total sample of 2928 children. The mean age of eruption of maxillary central incisor, maxillary lateral incisor, maxillary and mandibular canines, maxillary and mandibular premolars, maxillary and mandibular second molars were found to have statistical significant with BMI. The mean age of eruption of the teeth in females was found to be earlier than in males, with the exception of the maxillary first molar which is earlier in males. Conclusion: Different categories of BMI were underweight, normal weight, risk of overweight and overweight, wherein overweight children had early eruption of teeth. Girls had early eruption time compared to boys.

The chronology and sequence of eruption of human permanent teeth in Northern Ireland.

Science.gov (United States)

Kochhar, R; Richardson, A

1998-12-01

To ascertain the average and range of ages and sequence of eruption of human permanent teeth, taking into account the effect of premature loss of primary antecedents. Longitudinal study. Caucasian subjects in Northern Ireland. Study casts at 6-monthly intervals from age 5 to 15 years of 276 children (146 males and 130 females) enrolled in the Belfast Growth Study. The mean and range of ages of eruption of each individual tooth were computed. Comparisons were made between the mean ages of eruption with and without premature loss of primary antecedents, between upper and lower arches, between right and left sides and between males and females. The sequence of eruption was also investigated. The means and ranges of eruption ages are reported. Premature loss of primary antecedents delayed eruption of permanent successors except for the upper premolars which were accelerated. The differences relating to the upper first premolar and lower canine were not statistically significant. Each lower tooth erupted before its upper counterpart except for the premolars. There was no significant difference in age of eruption between right and left sides. Females tended to erupt teeth before males with the exception of the second molars in both arches; however, the only differences to reach statistical significance related to upper and lower canines and upper lateral incisors. The most frequent orders of eruption were unique to the subject. These occurred in 22% of upper and 33% of lower arches. The classic sequences: first molar-central incisor-lateral incisor-first premolar-canine-second premolar-second molar (M1-I1-I2-PM1-C-PM2-M2) in the upper arch and I1-M1-I2-C-PM1-PM2-M2 in the lower arch occurred in only 16% of upper arches and 13% of lower arches. Males adhered to the textbook sequence (20% upper, 17% lower) more than females (12% upper, 8% lower). In the upper arch of females, the order M1-I1-I2-PM1-PM2-C-M2 in 10% of subjects was almost as frequent as the classic sequence

AMS-14C analysis of modern teeth: A comparison between two sample preparation techniques

Science.gov (United States)

Solis, C.; Solis-Meza, E.; Morales, M. E.; Rodriguez-Ceja, M.; Martínez-Carrillo, M. A.; Garcia-Calderon, D.; Huerta, A.; Chávez, E.

2017-09-01

AMS-14C analysis of modern teeth has become important for forensic studies. 14C content in human teeth reflects the 14C atmospheric concentration during its formation and allows the calculation of the actual year of birth. Through AMS, it is possible to measure the 14C concentrations in a tissue with high precision. However, there is a debate about which should be the best fraction for teeth carbon dating: collagen or enamel. This work focuses on the results obtained from enamel and collagen extracted from Mexican people in order to compare them. Collagen from dental pieces donated from people older than 60-years-old have been included to understand the turnover process and usefulness of collagen to determine the date of birth. Our results indicate that when a single dental piece is available, enamel method allows the determination of the tooth formation date. Dating collagen of the same tooth helps to discriminate if the formation date belongs to the left or the right side of the peak bomb, but also corroborates, the ages obtained through enamel analysis.

Outcome of Endodontically Treated Cracked Teeth

Science.gov (United States)

2016-06-01

directed by: CAPT Te!Ty Webb, D.D.S., M.S. A " cracked tooth" is defined as a thin surface enamel and dentin disruption of unknown depth, and is often...OUTCOME OF ENDODONTICALL Y TREATED CRACKED TEETH by David Michael Dow II, D.D.S. Lieutenant Commander, Dental Corps United States Navy A thesis...copyrighted material in the thesis manuscript titled: "Outcome ofEndodontically Treated Cracked Teeth" is appropriately acknowledged and, beyond

The management of over closured anterior teeth due to attrition

OpenAIRE

Eha Djulaeha; Sukaedi Sukaedi

2009-01-01

Background: Tooth is the hardest tissue in human body, that can be injured because of attrition process. For old people, denture attrition process is caused by psysiological process relating with the mastication function which also supported by some bad habits such an bruxism, premature contact, and consuming habit of abrasive food. Attrition or abrasion can also be happened with patien’t dentition who does not have teeth subtutition for long time due the lost of their maxillary as well as ma...

Clinical research of teeth damage from radiotherapy

International Nuclear Information System (INIS)

Li Erzhou; Yan Maosheng; Chen Wei; Li Qing

2003-01-01

Objective: To analyze various factors inducing teeth damage from radiotherapy and the preventive and treatment methods. Methods: One hundred cases of patients treated by radiotherapy were divided into two groups. In group one there were 60 cases whose teeth were irradiated during treatment; in group two there were 40 cases whose teeth were not irradiated during treatment. Results: The caries incidence was 60% for group one and 15% for group two (P<0.01). By auto-control in 15 patients, the caries incidence on the sick side was obviously higher than that of the healthy side. Hundred percent caries incidence was found in 6 cases who received a dosage of 70 Gy. Conclusion: The authors believe that radiation damage to the teeth is associated with the following factors: 1. The dosage and location of irradiation are closely related to caries incidence; 2. The active dentinoblasts are very sensitive to radiation; 3. Damage to the salivary glands from radiotherapy can result in reduction of salvia and pH value, leading to a high growth rate of Streptococcus mutans. Following preventive measures could be considered in future cases: to apply a caries prevention coating or protective dental crown and TPS, to adjust the dose and time of irradiation, to select conformal radiotherapy technique. The key points for protecting the teeth and salivary gland from caries and damage are protection of the proliferation ability of pulp cells, anti-inflammation, promotion of microcirculation, and strengthening body resistance

Replacement of Missing Anterior Teeth in a Patient with Temporomandibular Disorder

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Satheesh B. Haralur

2014-01-01

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

Comparative study of nanomechanical properties of cements used in teeth restoration

International Nuclear Information System (INIS)

Peluccio, M S; Bignardi, C; Lombardo, S; Montevecchi, F M; Carossa, S

2007-01-01

The discipline of dental science includes the diagnosis of disease in the mouth and teeth, its manifestations and the procedures involved in the restoration of their integrity and function. Restoration of lost tooth structure with suitable materials plays an integral part in the successful rehabilitation of oral tissues. Several factors influence the performance of dental restorations. These factors include the type of cement used to bond crown restoration to prepared teeth. The nanoindentation method was used to explore the mechanical properties of different types of resin cement polymerized using different techniques. A Nano Indenter XP (from MTS Nano Instruments, USA) was used for the experimental tests. A sample of 40 extracted human teeth were restored using two different resin cements: Variolink II (Ivoclar Vivadent, Liechtenstein) and Venus A2 (Heraeus Kulzer, Germany). Both resin cements are light-cured and one of them is self-cured so that the degree of polymerization would be higher. The data obtained for nanohardness and the Young's modulus were analysed using ANOVA to evaluate the influence of different factors (the resin cement and polymerization technique used, the position on the tooth-restoration interface) and to determine the best performance for restoration. The results obtained could give a useful indication of the choice of cementation technique and of the materials used for the restoration of lost tooth structure in different clinical cases

Integrated Surgical and Orthodontic Treatment: A Twinned Teeth Dilemma

OpenAIRE

Seema D Bargale; D P Shital Kiran; KVR Anuradha; Smit Sikligar

2015-01-01

Background: Twinned or geminated teeth may cause spacing, caries, aesthetic and periodontal problems which are usually seen in the anterior region. Various treatment methods can be used for correction of double teeth according to the demands of the condition. This article reports bilateral fused maxillary incisor teeth. The fused right side incisor was separated by hemisection and remaining mesial incisal margin was built using composite. Further, comprehensive orthodontic treatment was done ...

Accuracy of Computer-Assisted Template-Guided Autotransplantation of Teeth With Custom Three-Dimensional Designed/Printed Surgical Tooling: A Cadaveric Study.

Science.gov (United States)

Anssari Moin, David; Verweij, Jop Pieter; Waars, Hugo; van Merkesteyn, Richard; Wismeijer, Daniel

2017-05-01

The aim of the present cadaveric study was to assess the accuracy of computer-assisted template-guided autotransplantation of teeth with custom 3-dimensional (3D) designed/printed surgical tooling. Ten partially edentulous human mandibular cadavers were scanned using a cone-beam computed tomography (CBCT) system and an intraoral scanning system. The 3D data of these cadavers were imported to specialized software and used to analyze the region of the recipient sites, and the donor teeth were selected. Subsequently, congruent to the donor teeth, custom surgical tooling and surgical-guided templates were designed and 3D printed. The guided osteotomies were performed and the donor teeth transplanted. To evaluate the planned donor teeth positions compared with the transplanted donor teeth positions, the mandibles were scanned again using the CBCT system, and software matching was applied to measure the accuracy of the procedure. The mean angular deflection of the transplanted donor teeth with the planned donor teeth positions was 5.6 ± 5.4°. Comparing the 3D positions of the shoulders, a mean deviation of 3.15 ± 1.16 mm and a mean apical deviation of 2.61 ± 0.78 mm were found. The described method of computer-assisted template-guided autotransplantation of teeth with custom 3D designed/printed surgical tooling could potentially provide a relatively accurate alternative for the currently available treatment approaches. Further research should focus on improving the accuracy of this technique and evaluating the clinical success and advantages of this method. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Enamel biorhythms of humans and great apes: the Havers-Halberg Oscillation hypothesis reconsidered.

Science.gov (United States)

Mahoney, Patrick; Miszkiewicz, Justyna J; Pitfield, Rosie; Deter, Chris; Guatelli-Steinberg, Debbie

2017-02-01

The Havers-Halberg Oscillation (HHO) hypothesis links evidence for the timing of a biorhythm retained in permanent tooth enamel (Retzius periodicity) to adult body mass and life history traits across mammals. Potentially, these links provide a way to access life history of fossil species from teeth. Recently we assessed intra-specific predictions of the HHO on human children. We reported Retzius periodicity (RP) corresponded with enamel thickness, and cusp formation time, when calculated from isolated deciduous teeth. We proposed the biorhythm might not remain constant within an individual. Here, we test our findings. RP is compared between deciduous second and permanent first molars within the maxillae of four human children. Following this, we report the first RPs for deciduous teeth from modern great apes (n = 4), and compare these with new data for permanent teeth (n = 18) from these species, as well as with previously published values. We also explore RP in teeth that retain hypoplastic defects. Results show RP changed within the maxilla of each child, from thinner to thicker enameled molars, and from one side of a hypoplastic defect to the other. When considered alongside correlations between RP and cusp formation time, these observations provide further evidence that RP is associated with enamel growth processes and does not always remain constant within an individual. RP of 5 days for great ape deciduous teeth lay below the lowermost range of those from permanent teeth of modern orangutan and gorilla, and within the lowermost range of RPs from chimpanzee permanent teeth. Our data suggest associations between RP and enamel growth processes of humans might extend to great apes. These findings provide a new framework from which to develop the HHO hypothesis, which can incorporate enamel growth along with other physiological systems. Applications of the HHO to fossil teeth should avoid transferring RP between deciduous and permanent enamel, or including

The effects of impacted premaxillary supernumerary teeth on permanent incisors

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Jung, Yun Hoa; Kim, Ji Yeon; Cho, Bong Hae [School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

2016-12-15

The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.

The effects of impacted premaxillary supernumerary teeth on permanent incisors

International Nuclear Information System (INIS)

Jung, Yun Hoa; Kim, Ji Yeon; Cho, Bong Hae

2016-01-01

The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape

Endodontic treatment of teeth with periapical lesion in one session with photodynamic therapy as an adjuvant: study "in vivo"

OpenAIRE

Supercilio Barros Filho

2012-01-01

Hypothesis of the study: It is assumed that the use of photodynamic therapy (PDT) as an adjuvant in root canal therapy can promote the repair of teeth with periapical lesions treated in one session. Objectives: This in vivo study was to evaluate the effects of photodynamic therapy as an adjuvant in root canal therapy in one session for the repair of periapical lesions. Method: Fourteen human teeth with mortification pulp and periapical lesions were randomly divided into two groups (n=7): G1- ...

ERUPTION PATTERN OF PERMANENT TEETH -IN TANZANIA ...

African Journals Online (AJOL)

was visible in the oral vacity. Generally permanent teeth erupted earlier in girls than in boys. The differences were 0.1 - 0.2 years for incisors and first molars, 0.2 - 0.4 years for canines and premolars and 0.3 - 0.5 years for second molars. Except for the second premolars, mandibular teeth erupted earlier than the maxillary in ...

Methodology for Structural Calculation of Gear Teeth with Unconventional Profile

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Radicella Andrea Chiaramonte

2016-01-01

Full Text Available After having made reference to the structural analysis used in the study of gear wheel teeth, we then move on to the state of the art on the topic. We proceed to identify the boundary conditions used in the structural analysis of unconventional teeth with sides having a profile of an involute of a circle but with different pressure angles in each of the two sides. A procedure for the discretization of traditional teeth and of innovative teeth is presented and compared with the discretization obtained using current software.

Prevalence of prematurely lost primary teeth in 5-10-year-old children in Thamar city, Yemen: A cross-sectional study.

Science.gov (United States)

Murshid, Sakhr A; Al-Labani, Mohammed A; Aldhorae, Khalid A; Rodis, Omar M M

2016-08-01

The premature loss of primary teeth is a potential risk factor for poor arch length development. Adequate arch length is important to the progression of the permanent teeth. Poor arch length can lead to crowding, ectopic eruption, or impaction of these teeth. This study is designed to assess the prevalence of premature loss of primary teeth in the 5-10-year-old age group. The study group included 185 children, that is, 91 boys and 94 girls. The dental examination was conducted by an experienced examiner under sufficient artificial light. Data including patient age and missing teeth were collected. Descriptive statistics were applied for data analysis, and from the results, Chi-square tests were used at a level of significance of 5% (P premature loss of primary teeth with no statistically significant difference between genders. The lower left primary second molar was the most commonly absent tooth in the dental arch (13.5%). The status of premature loss of primary teeth was high in the study group. Implementation of efficient educational and preventive programs to promote oral health would help children maintain a healthy primary dentition and eventually prevent the disturbances in the future development of normal occlusion. Early detection and management of the space problems associated with the early loss of primary teeth would help in reducing malocclusion problems.

Full Pulpotomy with Biodentine in Symptomatic Young Permanent Teeth with Carious Exposure.

Science.gov (United States)

Taha, Nessrin A; Abdulkhader, Sakhaa Z

2018-04-19

This prospective study evaluated the outcome of Biodentine (Septodont, Saint Maur des Fosses, France) pulpotomy in young permanent teeth with carious exposure. Twenty permanent molar teeth in 14 patients with carious pulp exposure were treated with Biodentine pulpotomy. The age of the patients ranged from 9-17 years (12.3 ± 2.7 years). A preoperative pulpal and periapical diagnosis was established. After informed consent, the tooth was anesthetized, isolated via a dental dam, and disinfected with 5% sodium hypochlorite before caries excavation. Full pulpotomy was performed by amputating the exposed pulp to the level of the canal orifices, hemostasis was achieved via a cotton pellet moistened with 2.5% sodium hypochlorite, a 3-mm layer of Biodentine was placed as the pulpotomy agent, a Vitrebond liner (3M ESPE, St Paul, MN) was applied, and the tooth was subsequently restored. Postoperative periapical radiographs were taken after placement of the permanent restoration. Clinical and radiographic evaluation was completed after 6 months and 1 year postoperatively. Pain levels were scored preoperatively and 2 days after treatment. Statistical analysis was performed using the Fisher exact test. Clinical signs and symptoms suggestive of irreversible pulpitis were established in all teeth and symptomatic apical periodontitis in 14 of 20 (70%). Two days after treatment, all patients reported complete relief of pain. All teeth were clinically successful at 6 months and 1 year postoperatively. Radiographically, immature roots showed continued root development; dentin bridge formation was detected in 5 of 20 teeth. Seven of 7 teeth with preoperative periapical rarefaction showed signs of healing; 1 tooth had signs of internal root resorption at 1 year with an overall success rate of 95% (19/20). Young permanent teeth with carious exposure can be treated successfully with full pulpotomy using Biodentine, and clinical signs and symptoms of irreversible pulpitis are

Development of teeth in chick embryos after mouse neural crest transplantations.

Science.gov (United States)

Mitsiadis, Thimios A; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

2003-05-27

Teeth were lost in birds 70-80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick chimeras obtained show evidence of tooth formation showing that avian oral epithelium is able to induce a nonavian developmental program in mouse neural crest-derived mesenchymal cells.

Early removal of odontoma resulting in spontaneous eruption of the impacted teeth

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Achmad Harijadi

2010-06-01

Full Text Available Background: Compound odontomas in the anterior maxilla during mixed dentition frequently cause obstruction to the eruption pathway of permanent upper anterior teeth. Removal of the odontomas may or may not lead to spontaneous eruption of the impacted teeth depending on the age when the surgery is performed, the size of the lesion, and the stage of tooth development of the involved teeth. Purpose: This paper attempts to emphasize the importance of early removal of compound odontoma to enable spontaneous eruption of the affected teeth. Case: A case of odontoma in the anterior maxilla causing failure of eruption and delayed root formation of upper right permanent lateral incisor and canine in a 10-year-old male patient is presented. Case management: The odontoma was surgically removed under general anesthesia and histology result confirmed the diagnosis of compound odontoma. A three-year post surgical follow up showed spontaneous eruption as well as continued root formation of the two affected teeth. Conclusion: Removal of odontoma may lead to spontaneous eruption of the affected teeth if their root development are not completed.Latar belakang: Compound odontoma pada daerah anterior maksila pada masa geligi pergantian sering menyebabkan hambatan erupsi pada gigi permanen penggantinya. Kemungkinan terjadinya erupsi spontan gigi permanen yang impaksi setelah pengambilan odontoma tergantung dari: umur penderita pada saat dilakukan operasi, ukuran lesi odontoma dan tahapan perkembangan gigi permanen yang terlibat. Tujuan: Laporan kasus ini ingin menekankan pentingnya pengambilan compound odontoma sedini mungkin untuk memberi kesempatan tumbuhnya gigi permanen yang terlibat dan erupsi secara spontan. Kasus: Ditampilkan sebuah kasus compound odontoma pada regio maksila anterior menyebabkan gagalnya erupsi dan terlambatnya pembentukan akar gigi insisif kedua dan kaninus permanent rahang atas kanan pada penderita anak laki-laki berumur 10 tahun

The aesthetic treatment for anterior teeth with lost crown by endorestoration

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Nanik Zubaidah

2009-06-01

Full Text Available Background: The aesthetic has an important role in social life, especially the anterior teeth. The aesthetic abnormality of anterior teeth i.e. discoloration, malpotition or the anterior teeth with crown damage for more than one third or all part of crown is lost due to caries or other causes, will influence its appearance especially during smile. Purpose: The aim of this case report, therefore, is to show how teeth with clinical crown lost or only the root left still can be treated by endorestoration treatment in order to reconstruct the shape and function of the teeth similar to the original ones. Case: Female 52 years old with the lost crown of anterior teeth. The patient did not want her teeth to be extracted. Case Management: The abnormality of these teeth are still able to be reconstructed by endorestoration i.e. endodontic treatment with post and core insertion in the root canal will increase its retention and recovery by the porcelain crown fused to metal to recover the original formation and aesthetic and thus has the normal refunction. The treatment, it improve the confidence of the patient, and also can function normally. The patient did not feel pain. Ronsenography showed the periapical lesion diminished, the neighbor gingival was going better in both function and color. Conclusion: Endorestoration treatment on the anterior teeth with lost crown could recover the normal function, dental aesthetic and self confidence.

Evaluation of bond strength of self-etching adhesives having different pH on primary and permanent teeth dentin.

Science.gov (United States)

Ozmen, Bilal; Koyuturk, Alp Erdin; Tokay, Ugur; Cortcu, Murat; Sari, Mustafa Erhan

2015-10-16

The purpose of this in vitro study was to evaluate the dentin shear bond strength of 4 self-etching adhesives having a different pH on primary and permanent teeth dentin. The occlusal enamel was removed from 60 freshly extracted third molar and 60 primary second molar human teeth, which were randomly separated into 4 groups (n = 15). Four adhesive systems were applied: G-Bond (GC Corporation, Tokyo, Japan, pH: 1.5), Futura Bond M (Voco, Cuxhaver, Germany, pH: 1.4), Adper Prompt L-Pop (3M/ESPE, St Paul, MN, USA, pH: 0.8), and Clearfil S(3) Bond (Kuraray Medical, Tokyo, Japan, pH: 2.7) according to the manufacturer's instructions. After the application of dentin bonding agents, a composite resin material (Z250 Restorative A2, 3M ESPE, St. Paul, MN, USA) for permanent teeth and a compomer resin material (Dyract Extra A2, Dentsply, Konstanz, Germany) for primary teeth was applied onto the prepared dentin surfaces. The data were obtained by using a universal test machine at a crosshead speed of 1 mm/min. The mean values were compared using Tukey's multiple comparison test. Although there was no difference between adhesives on the permanent teeth, Clearfil S3 adhesive showed higher bond (18.07 ± 0.58 MPa) (P>0.05). Lower bond strength values were obtained from primary teeth and especially G-Bond adhesive (9.36 ± 0.48 MPa) (Padhesives with different pH and solvent types can be used successfully for permanent teeth dentin but adhesives with low pH did not provide greater shear bond strength values.

Is biologic width of anterior and posterior teeth similar?

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Amir Alireza Rasouli Ghahroudi

2014-09-01

Full Text Available 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.

[Reinforcement for overdentures on abutment teeth].

Science.gov (United States)

Osada, Tomoko

2006-04-01

This study investigated the effect of the position of reinforcement wires, differences in artificial teeth, and framework designs on the breaking strength of overdentures. The basal surfaces of composite resin teeth and acrylic resin teeth were removed using a carbide bur. A reinforcement wire or a wrought palatal bar was embedded near the occlusal surface or basal surface. Four types of framework structures were designed : conventional skeleton (skeleton), housing with skeleton (housing), housing plus short metal backing (metal backing), and housing plus long metal backing (double structure). After the wires, bars, and frameworks were sand-blasted with 50 microm Al(2)O(3) powder, they were primed with a metal primer and embedded in a heat-polymerized denture base resin. The breaking strengths (N) and maximum stiffness (N/mm) of two-week aged (37 degrees C) specimens were measured using a bending test (n=8). All data obtained at a crosshead speed of 2.0 mm/min were analyzed by ANOVA/Tukey's test (alpha=0.01). There were no statistical differences between the two kinds of artificial teeth (p>0.01). The wrought palatal bar had significantly higher strength than the reinforcement wire (p0.01). The breaking strength and maximum stiffness of the double structure framework were significantly greater (poverdentures were influenced by the size and position of the reinforcement wires. Double structure frameworks are recommended for overdentures to promote a long-term prognosis without denture breakage.

Manipulation of Fgf and Bmp signaling in teleost fishes suggests potential pathways for the evolutionary origin of multicuspid teeth.

Science.gov (United States)

Jackman, William R; Davies, Shelby H; Lyons, David B; Stauder, Caitlin K; Denton-Schneider, Benjamin R; Jowdry, Andrea; Aigler, Sharon R; Vogel, Scott A; Stock, David W

2013-01-01

Teeth with two or more cusps have arisen independently from an ancestral unicuspid condition in a variety of vertebrate lineages, including sharks, teleost fishes, amphibians, lizards, and mammals. One potential explanation for the repeated origins of multicuspid teeth is the existence of multiple adaptive pathways leading to them, as suggested by their different uses in these lineages. Another is that the addition of cusps required only minor changes in genetic pathways regulating tooth development. Here we provide support for the latter hypothesis by demonstrating that manipulation of the levels of Fibroblast growth factor (Fgf) or Bone morphogenetic protein (Bmp) signaling produces bicuspid teeth in the zebrafish (Danio rerio), a species lacking multicuspid teeth in its ancestry. The generality of these results for teleosts is suggested by the conversion of unicuspid pharyngeal teeth into bicuspid teeth by similar manipulations of the Mexican Tetra (Astyanax mexicanus). That these manipulations also produced supernumerary teeth in both species supports previous suggestions of similarities in the molecular control of tooth and cusp number. We conclude that despite their apparent complexity, the evolutionary origin of multicuspid teeth is positively constrained, likely requiring only slight modifications of a pre-existing mechanism for patterning the number and spacing of individual teeth. © 2013 Wiley Periodicals, Inc.

Comparative investigation on electron spin resonance dosimetry of tooth enamel of cow and human

International Nuclear Information System (INIS)

Jiao Ling; Zhang Wenyi; Ding Yanqiu; Kou Mingying

2010-01-01

The enamel samples from cow teeth and human teeth were irradiated with 137 Cs γ ray. Their electron spin resonance (ESR) spectra pre and post-irradiation were weaker than those of human. Mass of each sample is 100 mg, the dosimetric signal intensity of cow enamel increased with the radiation dose; the averaged radiation response of cow samples was (34.4±2.0) Gy -1 , very close to the average response of human tooth samples (36.3±2.9) Gy -1 . Therefore cow teeth can be used for retrospective radiation dosimetry when human teeth are unavailable. (authors)

Bilateral supernumerary teeth in deciduous dentition-a rarity.

Science.gov (United States)

Acharya, Sonu; Ghosh, Chiranjit; Mondal, Pradeep Kumar

2014-05-01

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.

Elemental mapping of teeth using {mu}SRXRF

Energy Technology Data Exchange (ETDEWEB)

Anjos, M.J. E-mail: marcelin@lin.ufrj.br; Barroso, R.C.; Perez, C.A.; Braz, D.; Moreira, S.; Dias, K.R.H.C.; Lopes, R.T

2004-01-01

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

Teeth and numerology from zodiac signs. A correlative study.

Science.gov (United States)

Kudva, S; Bhat, A P

2000-01-01

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

INVESTIGATION OF IMPACTED SUPERNUMERARY TEETH: A CONE BEAM COMPUTED TOMOGRAPH (CBCT STUDY

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Gökhan GÜRLER

2017-10-01

Full Text Available Purpose: The purpose of this study was to investigate the impacted supernumerary teeth which were initially detected on panoramic radiographs by using cone beam computed tomography (CBCT. Materials and Methods: In this retrospective study, supernumerary teeth diagnosed on panoramic radiographs taken from patients who had admitted for routine dental treatment were evaluated using CBCT. Patients’ age, gender, systemic conditions as well as number of supernumerary teeth, unilateral-bilateral presence, anatomical localization (maxilla, mandible, anterior-premolar-molar, mesiodens-lateral-canine, parapremolar-paramolar-distomolar shape (rudimentary, supplemental, tuberculate, odontoma, position (palatal-lingual-buccal-labial-central, shortest distance between the tooth and adjacent cortical plate, complications and treatment were assessed. Results: A total of 47 impacted supernumerary teeth in 34 patients were investigated in this study. Of these, 33 (70.2% were unilateral and 14 (29.8% were bilateral. Only 1 supernumerary tooth was found in 27 patients (79.4% whereas 7 patients (20.6% had 2 or more supernumerary teeth. Most of the teeth located in the anterior region (74.4% of the jaws and maxilla (74.4%. Twenty teeth (42.5% were mesiodens, 11 (23.4% were lateral or canine, 14 (29.7% were parapremolar and 2(4.4% were distomolar. Twenty-seven teeth (57.4% were rudimentary, 15 (31.9% were supplemental and 5 (10.7% were odontoma in shape. The shortest distance between the supernumerary tooth and adjacent cortical plate varied between 0 to 2.5 mm with a mean of 0.66 mm. The most common clinical complaint was the non-eruption of permanent teeth (42.5%. All supernumerary teeth were removed under local anesthesia. Orthodontic traction was performed for those impacted permanent teeth if necessary. Conclusion: Impacted supernumerary teeth are usually in close proximity to cortical bone. Although this may facilitate surgical access, there is a risk of

Osteogenic differentiation of stem cells from human exfoliated deciduous teeth on poly(ε-caprolactone) nanofibers containing strontium phosphate

Energy Technology Data Exchange (ETDEWEB)

Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Wu, Pai-Shuen [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Huang, Te-Yang [Department of Orthopedic Surgery, Mackay Memorial Hospital, Taipei, Taiwan (China)

2015-01-01

Mimicking the architecture of the extracellular matrix is an effective strategy for tissue engineering. Composite nanofibers similar to natural bone structure can be prepared via an electrospinning technique and used in biomedical applications. Stem cells from human exfoliated deciduous teeth (SHEDs) can differentiate into multiple cell lineages, such as cells that are alternative sources of stem cells for tissue engineering. Strontium has important functions in bone remodeling; for example, this element can simulate bone formation and decrease bone resorption. Incorporating strontium phosphate into nanofibers provides a potential material for bone tissue engineering. This study investigated the potential of poly(ε-caprolactone) (PCL) nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs. Cellular morphology and MTT assay revealed that nanofibers effectively support cellular attachment, spreading, and proliferation. Strontium-loaded PCL nanofibers exhibited higher expressions of collagen type I, alkaline phosphatase, biomineralization, and bone-related genes than pure PCL nanofibers during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Understanding the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate into nanofibers provides a potential material for bone tissue engineering. • Nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs.

Osteogenic differentiation of stem cells from human exfoliated deciduous teeth on poly(ε-caprolactone) nanofibers containing strontium phosphate

International Nuclear Information System (INIS)

Su, Wen-Ta; Wu, Pai-Shuen; Huang, Te-Yang

2015-01-01

Mimicking the architecture of the extracellular matrix is an effective strategy for tissue engineering. Composite nanofibers similar to natural bone structure can be prepared via an electrospinning technique and used in biomedical applications. Stem cells from human exfoliated deciduous teeth (SHEDs) can differentiate into multiple cell lineages, such as cells that are alternative sources of stem cells for tissue engineering. Strontium has important functions in bone remodeling; for example, this element can simulate bone formation and decrease bone resorption. Incorporating strontium phosphate into nanofibers provides a potential material for bone tissue engineering. This study investigated the potential of poly(ε-caprolactone) (PCL) nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs. Cellular morphology and MTT assay revealed that nanofibers effectively support cellular attachment, spreading, and proliferation. Strontium-loaded PCL nanofibers exhibited higher expressions of collagen type I, alkaline phosphatase, biomineralization, and bone-related genes than pure PCL nanofibers during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Understanding the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate into nanofibers provides a potential material for bone tissue engineering. • Nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs

Interventions for treating asymptomatic impacted wisdom teeth in adolescents and adults.

NARCIS (Netherlands)

Mettes, T.G.P.H.; Nienhuijs, M.E.L.; Sanden, W.J.M. van der; Verdonschot, E.H.A.M.; Plasschaert, A.J.M.

2005-01-01

BACKGROUND: The prophylactic removal of asymptomatic impacted wisdom teeth is defined as the (surgical) removal of wisdom teeth in the absence of local disease. Impacted wisdom teeth have been associated with pathological changes, such as inflammation of the gums around the tooth, root resorption,

Prevalence of prematurely lost primary teeth in 5–10-year-old children in Thamar city, Yemen: A cross-sectional study

Science.gov (United States)

Murshid, Sakhr A.; Al-Labani, Mohammed A.; Aldhorae, Khalid A.; Rodis, Omar M. M.

2016-01-01

Objectives: The premature loss of primary teeth is a potential risk factor for poor arch length development. Adequate arch length is important to the progression of the permanent teeth. Poor arch length can lead to crowding, ectopic eruption, or impaction of these teeth. This study is designed to assess the prevalence of premature loss of primary teeth in the 5-10-year-old age group. Materials and Methods: The study group included 185 children, that is, 91 boys and 94 girls. The dental examination was conducted by an experienced examiner under sufficient artificial light. Data including patient age and missing teeth were collected. Descriptive statistics were applied for data analysis, and from the results, Chi-square tests were used at a level of significance of 5% (P premature loss of primary teeth with no statistically significant difference between genders. The lower left primary second molar was the most commonly absent tooth in the dental arch (13.5%). Conclusion: The status of premature loss of primary teeth was high in the study group. Implementation of efficient educational and preventive programs to promote oral health would help children maintain a healthy primary dentition and eventually prevent the disturbances in the future development of normal occlusion. Early detection and management of the space problems associated with the early loss of primary teeth would help in reducing malocclusion problems. PMID:27652244

The large superpredators' teeth from Middle Triassic of Poland

Science.gov (United States)

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.

Distraction osteogenesis of ankylosed front teeth with subsequent orthodontic fine adjustment.

Science.gov (United States)

Huck, Lothar; Korbmacher, Heike; Niemeyer, Karsten; Kahl-Nieke, Bärbel

2006-07-01

Conventional therapeutic approaches to correct ankylosed anterior teeth in infraposition require compromises involving esthetics and function. The combined approach of distraction and early orthodontic fine adjustment, not yet established as a routine, promises better results concerning the bone conditions and gingival development. Both female patients had suffered a trauma to the front teeth during early mixed dentition resulting in ankylosed central incisors in infraposition. At the ages of 14 years and 2 months and 15 years and 2 months, respectively, we carried out segment distraction by means of a bone-supported internal distractor followed by orthodontic fine adjustment after having shortened the consolidation phase. Both ankylosed front teeth could be successfully aligned, leading to an increase in bone and harmonization of the gingival margin in the dental arch. At ten and 14 months after the conclusion of treatment, we observed only few deviations in the dental situation compared to posttherapeutic findings. From a functional and esthetic point of view, therapy involving combined orthodontics and surgery is superior to conventional therapy. Orthodontic fine adjustment should be considered as a continuation of the distraction procedure.

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

DEFF Research Database (Denmark)

Andersen, Mette Guldbæk; Beck-Nielsen, Signe; Haubek, Dorte

2012-01-01

panoramic radiograph, which was scored for endodontically affected teeth (i.e. teeth with periapical radiolucencies and/or endodontically treated teeth). A total of 52 patients (age range: 5·7-74·5 years; 17 males and 35 females) were included. HR patients were characterised by a high number...... genetically. The aim of the present study was to describe the periapical and endodontic status of permanent teeth in patients with genetically and/or biochemically confirmed HR. The patients were recruited from a medical study on HR patients. The patients underwent a dental examination including a digital...... of endodontically affected teeth (mean: 4·2; s.d.: 5·0). The number of affected teeth rose significantly with age (P ...

The effect of Emdogain and 24% EDTA root conditioning on periodontal healing of replanted dog's teeth.

Science.gov (United States)

Guzmán-Martínez, Nayelli; Silva-Herzog, Flores Daniel; Méndez, González Verónica; Martín-Pérez, Silvia; Cerda-Cristerna, Bernardino Isaac; Cohenca, Nestor

2009-02-01

Controversies still exist as for the regenerative role of enamel matrix derivatives and the need for removal of the periodontal ligament in replanted teeth. The purpose of this study was to evaluate the effect of Emdogain and 24% ethylenediamine tetraacetic acid (EDTA) root conditioning on periodontal healing of replanted dog's teeth. Teeth were extracted, endodontically treated and preconditioned as follows: group 1, Emdogain; group 2, Emdogain + EDTA and group 3, EDTA. Teeth were replanted after 30 min extraoral time, splinted for 15 days and animals sacrificed after 8 weeks of observation. Histological evaluation was performed using hematoxylin/eosin and Masson trichrome and results scored based on previously reported criteria for histological evaluation. Replacement root resorption was histologically diagnosed in all groups except in the negative control. A parametric analysis showed no statistically significant differences between experimental groups. Root preconditioning with Emdogain alone or in combination with 24% EDTA showed no evidence of regeneration of collagen fibers and consequently did not prevent the development of replacement root resorption on replanted dog's teeth.

Influence of trace elements on fluoride uptake by teeth

Energy Technology Data Exchange (ETDEWEB)

Chaudhri, M A [Austin Hospital, Heidelberg (Australia). Dept. of Medical Physics; Melbourne Univ., Austin (Australia). Dept. of Medicine); Crawford, A [Melbourne Univ., Parkville (Australia). School of Physics

1981-03-01

To investigate the effect of various trace elements on fluoride uptake by teeth, the concentrations of F and other trace elements 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 /sup 19/F(p,..cap alpha gamma..)/sup 16/O reaction, C by activation through the /sup 12/C(/sup 3/He,n)/sup 14/O 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.

The creation of virtual teeth with and without tooth pathology for a virtual learning environment in dental education

NARCIS (Netherlands)

de Boer, I.R.; Wesselink, P.R.; Vervoorn, J.M.

2013-01-01

Purpose To describe the development and opportunities for implementation of virtual teeth with and without pathology for use in a virtual learning environment in dental education. Material and methods The creation of virtual teeth begins by scanning a tooth with a cone beam CT. The resulting scan

Reasons for extraction in primary teeth among 5-12 years school children in Haryana, India- A cross-sectional study.

Science.gov (United States)

Bansal, Mohit; Gupta, Nidhi; Gupta, Preety; Arora, Vikram; Thakar, Sahil

2017-04-01

Due to high prevalence of oral diseases extraction of primary teeth is a common and a major concern in developing countries. These teeth are given least importance as they are believed to shed off automatically, thus leading to serious problems like crowding and malocclusion. A cross sectional study was carried out among children aged 5 to 12 years among 1347 children. The data was recorded on a prestructured questionnaire. Reasons for extraction of teeth were based on Kay and Blinkhorn criteria. 20.4% children were having tooth loss due to various reasons. The main reason for extraction was found to be caries in 64.3% followed by trauma in maxillary teeth among 43.02% of children. Presence of early loss of primary teeth result in occlusal disturbances and space loss among children. Hence, proper treatment regimens must be followed by the dental professionals and should be the need of the hour. Key words: Extraction, children, primary teeth, caries.

Color stability of different denture teeth materials: an in vitro study.

Science.gov (United States)

Mutlu-Sagesen, L; Ergün, G; Ozkan, Y; Bek, B

2001-09-01

The aim of this in vitro study was to compare the color stability of commercially available porcelain, reinforced acrylic, and conventional acrylic denture teeth materials used in removable prostheses. Two brands of porcelain (Unilux-Enta Lactona-Holland and Vivoperl-Ivoclar-Liechtenstein), 2 brands of reinforced acrylic (Optodent-Bayer-Germany and Ivolek-Ivoclar-Liechtenstein), and 2 brands of conventional acrylic (Isodent-Güney Diş Deposu-Turkey and Samed-Turkey), were made, for a total of 6 different denture teeth groups. Denture teeth were subjected to 3 staining solutions (filtered coffee, tea, and cola) and distilled water. From each group of denture teeth, 4 sets of maxillary anterior denture teeth were immersed in each of the 4 solutions. The color values of denture teeth were measured colorimetrically with the Gardner XL 20 Tristimulus Colorimeter (Gardner Lab. Inc., Bethesda, Maryland, USA). Color changes were characterized in the CIEL*a*b* color space. Color change values were determined after 1 day, 1 week, 2 weeks, and 4 weeks. The color difference values were calculated and then evaluated by two-way ANOVA statistically. The filtered coffee solution was found to be more chromogenic than the other 2 staining solutions, while porcelain denture teeth materials were more color stable. Assuming the color change of deltaE* < 1.0 as a discernible limit and deltaE* = 3.3 as an acceptable value, the filtered coffee, tea, and cola had slight staining effects on all 6 groups of denture teeth.

Distribution of lead in teeth

Energy Technology Data Exchange (ETDEWEB)

Fremlin, J H; Tanti-Wipawin, W [Birmingham Univ. (UK). Dept. of Physics

1976-07-01

There is currently much concern with the amount of lead in the environment. Measurement of lead in teeth is being used to give information on the integrated uptake of lead by the individual over a period. The distribution of lead within individual teeth, is examined with the object of distinguishing lead deposited during formation or calcification from that taken up by the tooth over its working life after eruption. A tooth is sectioned and bombarded with 30-MeV ions of helium-3 from the Birmingham 1.52-m cyclotron, which produces polonium isotopes. The main useful activity is due to polonium-206, an ..cap alpha.. emitter, half-life 8 d. These ..cap alpha.. particles can be recorded by a plastic solid-state track detector.

Distribution of lead in teeth

International Nuclear Information System (INIS)

Fremlin, J.H.; Tanti-Wipawin, W.

1976-01-01

There is currently much concern with the amount of lead in the environment. Measurement of lead in teeth is being used to give information on the integrated uptake of lead by the individual over a period. The distribution of lead within individual teeth, is examined with the object of distinguishing lead deposited during formation or calcification from that taken up by the tooth over its working life after eruption. A tooth is sectioned and bombarded with 30-MeV ions of helium-3 from the Birmingham 1.52-m cyclotron, which produces polonium isotopes. The main useful activity is due to polonium-206, an α emitter, half-life 8 d. These α particles can be recorded by a plastic solid-state track detector. (U.K.)

Pulp nerve fibers distribution of human carious teeth: An immunohistochemical study

Directory of Open Access Journals (Sweden)

Tetiana Haniastuti

2010-12-01

Full Text Available Background: Human dental pulp is richly innervated by trigeminal afferent axons that subserve nociceptive function. Accordingly, they respond to stimuli that induce injury to the pulp tissue. An injury to the nerve terminals and other tissue components in the pulp stimulate metabolic activation of the neurons in the trigeminal ganglion which result in morphological changes in the peripheral nerve terminals. Purpose: The aim of the study was to observe caries-related changes in the distribution of human pulpal nerve. Methods: Under informed consents, 15 third molars with caries at various stages of decay and 5 intact third molars were extracted because of orthodontic or therapeutic reasons. All samples were observed by micro-computed tomography to confirm the lesion condition 3-dimensionally, before decalcifying with 10% EDTA solution (pH 7.4. The specimens were then processed for immunohistochemistry using anti-protein gene products (PGP 9.5, a specific marker for the nerve fiber. Results: In normal intact teeth, PGP 9.5 immunoreactive nerve fibers were seen concentrated beneath the odontoblast cell layer. Nerve fibers exhibited an increased density along the pulp-dentin border corresponding to the carious lesions. Conclusion: Neural density increases throughout the pulp chamber with the progression of caries. The activity and pathogenicity of the lesion as well as caries depth, might influence the degree of neural sprouting.Latar belakang: Pulpa gigi manusia diinervasi oleh serabut saraf trigeminal yang berespon terhadap stimuli penyebab perlukaan dengan menimbulkan rasa sakit. Perlukaan pada akhiran saraf dan komponen lain dari pulpa akan menstimulasi aktivasi metabolik dari neuron pada ganglion trigeminal sehingga mengakibatkan perubahan morfologi pada akhiran saraf perifer. Tujuan: Penelitian ini bertujuan untuk mengamati perubahan distribusi saraf pada pulpa gigi manusia yang disebabkan oleh proses karies. Metode: Penelitian ini menggunakan

Accuracy of Demirjian′s 8 teeth method for age prediction in South Indian children: A comparative study

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Rezwana Begum Mohammed

2015-01-01

Full Text Available Introduction: Demirjian′s method of tooth development is most commonly used to assess age in individuals with emerging teeth. However, its application on numerous populations has resulted in wide variations in age estimates and consequent suggestions for the method′s adaptation to the local sample. Original Demirjian′s method utilized seven mandibular teeth, to which recently third molar is added so that the method can be applied on a wider age group. Furthermore, the revised method developed regression formulas for assessing age. In Indians, as these formulas resulted in underestimation, India-specific regression formulas were developed recently. The purpose of this cross-sectional study was to evaluate the accuracy and applicability of original regression formulas (Chaillet and Demirjian 2004 and India-specific regression formulas (Acharya 2010 using Demirjian′s 8 teeth method in South Indian children of age groups 9-20 years. Methods: The present study consisted of 660 randomly selected subjects (330 males and 330 females were in the aged ranging from 9 to 20 years divided into 11 groups according to their age. Demirjian′s 8 teeth method was used for staging of teeth. Results: Demirjian′s method underestimated the dental age (DA by 1.66 years for boys and 1.55 years for girls and 1.61 years in total. Acharya′s method over estimated DA by 0.21 years for boys and 0.85 years for girls and 0.53 years in total. The absolute accuracy was better for Acharya′s method compared with Demirjian method. Conclusion: This study concluded that both the Demirjian and Indian regression formulas were reliable in assessing age making Demirjian′s 8 teeth method applicable for South Indians.

Comparison of Calcium Hydroxide and Bioactive Glass after Direct Pulp Capping in Primary Teeth

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R. Haghgoo

2007-12-01

Full Text Available Objective: Bioactive glass is often used as a filler material for repair of dental bone defects.In different studies osteogenic potential of this material was proved, but its dentinogenesisproperty is in doubt. The purpose of this study was to evaluate the histological pulp responses of Calcium hydroxide and Bioactive glass placed directly on exposed pulp tissues.Materials and Methods: Twenty teeth to be extracted due to orthodontic reasons were selected. These teeth were divided into two groups and treated with direct pulp capping.Calcium hydroxide was used for 10 teeth and Bioactive glass for 10 teeth. After 60 daysthe teeth were extracted and prepared for histological evaluation. Finally the data was analyzed with exact Fisher test.Results: All teeth treated with Calcium hydroxide showed inflammation. Internal resorption was seen in six teeth, abscess in five teeth and dentinal bridge in two teeth. Inflammationwas seen in three Bioactive glass samples and dentinal bridge in seven teeth, but internal resorption and abscess were not seen.Conclusion: Bioactive glass appears to be superior to Calcium hydroxide as a pulp capping agent in primary teeth.

Energy absorption and exposure build-up factors in teeth

International Nuclear Information System (INIS)

Manjunatha, H.C.; Rudraswamy, B.

2010-01-01

Full text: Gamma and X-radiation are widely used in medical imaging and radiation therapy. The user of radioisotopes must have knowledge about how radiation interacts with matter, especially with the human body, because when photons enter the medium/body, they degrade their energy and build up in the medium, giving rise to secondary radiation which can be estimated by a factor which is called the 'build-up factor'. It is essential to study the exposure build up factor in radiation dosimetry. G.P. fitting method has been used to compute energy absorption and exposure build-up factor of teeth (enamel outer surface (EOS), enamel middle (EM), enamel dentin junction towards enamel (EDJE), enamel dentin junction towards dentin (EDJD), dentin middle (DM) and dentin inner surface (DIS)) for wide energy range (0.015 MeV-15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption and exposure build up factor on incident photon energy, Penetration depth and effective atomic number has also been assessed. The relative dose distribution at a distance r from the point source is also estimated. The computed exposure and absorption build-up factors are useful to estimate the gamma and Bremsstrahlung radiation dose distribution teeth which is useful in clinical dosimetry

Development of 3D CAD/FEM Analysis System for Natural Teeth and Jaw Bone Constructed from X-Ray CT Images

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Aki Hasegawa

2010-01-01

Full Text Available A three-dimensional finite element model of the lower first premolar, with the three layers of enamel, dentin, and pulp, and the mandible, with the two layers of cortical and cancellous bones, was directly constructed from noninvasively acquired CT images. This model was used to develop a system to analyze the stresses on the teeth and supporting bone structure during occlusion based on the finite element method and to examine the possibility of mechanical simulation.

Study of the temporal evolution of Whitening Teeth immersed in Peroxide of hydrogen (H2O2) Using Digital Image Processing

International Nuclear Information System (INIS)

Díaz, L; Morales, Y; Torres, C

2015-01-01

The esthetic dentistry reference in our society is determined by several factors, including one that produces more dissatisfaction is abnormal tooth color or that does not meet the patient's expectations. For this reason it has been designed and implemented an algorithm in MATLAB that captures, digitizes, pre-processing and analyzed dental imaging by allowing to evaluate the degree of bleaching caused by the use of peroxide of hidrogen. The samples analyzed were human teeth extracted, which were subjected to different concentrations of peroxide of hidrogen and see if they can teeth whitening when using these products, was used different concentrations and intervals of time to analysis or study of the whitening of the teeth with the hydrogen peroxide

Removable partial denture on osseointegrated implants and natural teeth.

Science.gov (United States)

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

2007-01-01

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

Dental trauma. Combination injuries 2. The risk of pulp necrosis in permanent teeth with subluxation injuries and concomitant crown fractures

DEFF Research Database (Denmark)

Lauridsen, Eva Fejerskov; Hermann, Nuno Vibe; Gerds, Thomas Alexander

2012-01-01

on the risk of PN in permanent teeth with subluxation injury. Material and Methods:  The study included 404 permanent incisors with subluxation injury from 289 patients (188 male, 101 female). Of these teeth, 137 had also suffered a concomitant crown fracture. All the teeth were examined and treated according...... to a standardized protocol. Statistical Analysis:  The risk of PN was analysed separately for teeth with immature and mature root development by the Kaplan–Meier method, the log-rank test and Cox regression analysis. The level of significance was set at 5%. Risk factors included in the analysis were gender, patient......The reported risk of pulp necrosis (PN) is generally low in teeth with subluxation injuries. A concomitant crown fracture may increase the risk of PN in such teeth. Aim:  To analyse the influence of a concomitant trauma-related infraction, enamel-, enamel–dentin- or enamel–dentin–pulp fracture...

Application of x-ray method for measuring internal stress in the gear teeth surface layer

International Nuclear Information System (INIS)

Zaborowski, T.

1996-01-01

This paper presents the methodics of the internal stress measurements concerning cylindrical gear teeth of involute profile. There are the method selected, relation between stress and strain presented and conditions of investigation discussed in the study, including preparation of samples for investigation and conditions of the strain measurement. Exemplifying results of stress measurements for teeth of gears made of 4OH steel are shown. Suitability of the developed investigation method is indicated

RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

Directory of Open Access Journals (Sweden)

Yadav

2015-07-01

Full Text Available Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatment alternative for restoration of such teeth. The Richmond crown was introduced in 1878 and incorporated a threaded tube in the canal with a screw retained crown. It was later modified to eliminate the threaded tube and was redesigned as a one piece dowel and crown. This case report shows restoration of badly mutilated posterior teeth with Richmond crown.

A retrospective study of traumatic injuries to teeth at a Nigerian ...

African Journals Online (AJOL)

Enamel‑dentine fracture was the most common type of injury, seen in 73 (38.6%) of the traumatized teeth, 5 were avulsed and 20 posterior teeth had cuspal fracture. All the cases of avulsion and most (83.3%) of root fracture presented within 1 week of injury while teeth that presented late had pulpal necrosis. 22% of the ...

[Mechanism of the dentino-enamel junction on the resist-crack propagation of human teeth by the finite element method].

Science.gov (United States)

Jingjing, Zheng; Tiezhou, Hou; Hong, Tao; Xueyan, Guo; Cui, Wu

2014-10-01

This study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method. The finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS. The stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced. The dentino-enamel junction on human teeth may resist crack propagation through stress reduction.

Interappointment emergencies in teeth with necrotic pulps.

Science.gov (United States)

Alaçam, Tayfun; Tinaz, Ali Cemal

2002-05-01

The incidence of interappointment emergencies in symptomatic and asymptomatic teeth with necrotic pulps was evaluated, and severity of flare-ups was determined by a quantitative method using a flare-up index. There were no significant differences in the incidence of flare-ups attributable to gender, age, diameter of lesion, taking analgesics, placebos, or no medication, or preoperative symptomatic or asymptomatic tooth diagnoses (p > 0.05). There were significantly more painful flare-ups in mandibular teeth than in maxillary (p < 0.05).

Histological evaluation of the pulp in teeth from dogs with naturally occurring periodontal disease.

Science.gov (United States)

Nemec, Ana; Pavlica, Zlatko; Stiblar-Martincic, Draga; Petelin, Milan; Erzen, Damjan; Crossley, David

2007-12-01

The purpose of this investigation was to evaluate the pulp of dog teeth affected by advanced periodontal disease. Histological examination was done on demineralized teeth extracted during clinical treatment of mature, client owned small and medium-size breed dogs with either good periodontal health or with advanced naturally occurring periodontal disease. Routinely stained sections from 5 clinically normal teeth and 22 teeth with advanced periodontitis from dogs between 5 and 12-years of age were examined using light microscopy. The pulp cavities of most teeth were narrow with low cellularity and some fibrosis of the pulp. Findings specific to periodontally affected teeth included acute and chronic pulpitis, vascular congestion, and pulp necrosis. A glomus body was identified in the pulp of one tooth and areas of poorly mineralized cementum were seen in both normal and diseased teeth. Age related changes in dog teeth appear similar to those reported for man and the rat. In addition to age related changes, the pulp of dog teeth with advanced periodontal disease were frequently inflamed or necrotic. This may reflect the advanced periodontitis affecting these teeth or a mechanical effect related to excessive tooth mobility. Further study is required to determine the etiology and significance of these findings and to investigate pulp status in less severely diseased teeth.

Taking Care of Your Teeth

Science.gov (United States)

... your teeth and gums healthy. Toothpastes contain abrasives, detergents, and foaming agents. Fluoride, the most common active ... when they're eaten alone, possibly because the production of saliva, which washes away the sugar and ...

Insulin-Like Growth Factor Axis Expression in Dental Pulp Cells Derived From Carious Teeth

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Hanaa Esa Alkharobi

2018-04-01

Full Text Available The insulin-like growth factor (IGF axis plays an important role in dental tissue regeneration and most components of this axis are expressed in human dental pulp cells (DPCs. In our previous study, we analyzed IGF axis gene expression in DPCs and demonstrated a novel role of IGF binding protein (IGFBP-2 and -3 in coordinating mineralized matrix formation in differentiating DPCs. A more recent study from our laboratory partially characterized dental pulp stem cells from teeth with superficial caries (cDPCs and showed that their potential to differentiate odontoblasts and/or into osteoblasts is enhanced by exposure to the mild inflammatory conditions characteristic of superficial caries. In the present study, we examine whether changes apparent in IGF axis expression during osteogenic differentiation of healthy DPCs are also apparent in DPCs derived from carious affected teeth.

Isolation and Culture of Postnatal Stem Cells from Deciduous Teeth

OpenAIRE

Olávez, Daniela; Facultad de Odontología Universidad de Los Andes; Salmen, Siham; Instituto de Inmunología Clínica, Universidad de Los Andes.; Padrón, Karla; Facultad de Odontología. Univerisdad de Los Andes.; Lobo, Carmine; Facultad de Odontología. Univerisdad de Los Andes.; Díaz, Nancy; Facultad de Odontología, Universidad de Los Andes.; Berrueta, Lisbeth; Doctora en Inmunología por Instituto Venezolano de Investigaciones Científicas (IVIC). Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Venezuela.; Solorzanio, Eduvigis; Facultad de Odontología, Universidad de Los Andes.

2014-01-01

Background: Currently, degenerative diseases represent a public health problem; therefore, the development and implementation of strategies to fully or partially recover of damaged tissues has a special interest in the biomedical field. Therapeutic strategies based on mesenchymal stem cells transplantation from dental pulp have been proposed as an alternative. Purpose: To develop a mesenchymal stem cells culture isolated from dental pulp of deciduous teeth. Methods: The mesenchymal stem cells...

Genetic background of supernumerary teeth.

Science.gov (United States)

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.

Lead levels in deciduous teeth of children in Bahrain.

Science.gov (United States)

al-Mahroos, F; al-Saleh, F S

1997-06-01

To determine lead exposure among children in Bahrain, a total of 280 shed deciduous whole teeth were collected from 269 children. Teeth were analyzed for lead concentrations using atomic absorption spectrophotometry with electrothermal atomization. Children were between 5 and 15 years old. The study period extended from July 1993 to April 1994. The study showed that the overall mean tooth-lead level was 4.3 micrograms/g dry weight with a range of 0.1-60.8 micrograms/g dry weight. The cumulative frequency distribution revealed that 35% of the teeth had a lead concentration of more than 4 micrograms/g dry weight. The tooth-lead concentrations differed according to the tooth type age. The child's sex, nationality, area of residence and socio-economic status had no impact on tooth-lead level. In conclusion, lead is present in toxic concentrations in 35% of the teeth of the children studied. Urgent measures are needed to eliminate lead from gasoline, paint and other sources in the environment.

Development and refinement of computer-assisted planning and execution system for use in face-jaw-teeth transplantation to improve skeletal and dento-occlusal outcomes.

Science.gov (United States)

Hashemi, Sepehr; Armand, Mehran; Gordon, Chad R

2016-10-01

To describe the development and refinement of the computer-assisted planning and execution (CAPE) system for use in face-jaw-teeth transplants (FJTTs). Although successful, some maxillofacial transplants result in suboptimal hybrid occlusion and may require subsequent surgical orthognathic revisions. Unfortunately, the use of traditional dental casts and splints pose several compromising shortcomings in the context of FJTT and hybrid occlusion. Computer-assisted surgery may overcome these challenges. Therefore, the use of computer-assisted orthognathic techniques and functional planning may prevent the need for such revisions and improve facial-skeletal outcomes. A comprehensive CAPE system for use in FJTT was developed through a multicenter collaboration and refined using plastic models, live miniature swine surgery, and human cadaver models. The system marries preoperative surgical planning and intraoperative execution by allowing on-table navigation of the donor fragment relative to recipient cranium, and real-time reporting of patient's cephalometric measurements relative to a desired dental-skeletal outcome. FJTTs using live-animal and cadaveric models demonstrate the CAPE system to be accurate in navigation and beneficial in improving hybrid occlusion and other craniofacial outcomes. Future refinement of the CAPE system includes integration of more commonly performed orthognathic/maxillofacial procedures.

Optimizing the Esthetics of peg-shaped teeth

Directory of Open Access Journals (Sweden)

Fabia Danielle Sales da Cunha Medeiros e Silva

2008-01-01

Full Text Available In modern esthetic dentistry, recontouring peg-shaped teeth present the option of a technique for obtaining a harmonious smile. In thiscontext, the advancement of direct dental materials, such as resin composites and adhesive systems, allows this procedure to be performedsimply and efficiently, when compared with other available techniques. Thus, the aim of this report is to present a clinical case with an esthetic solution in peg-shaped lateral incisors (12 and 22. Initially, it was opted first to perform dental bleaching with a home bleaching gel (16% carbamide peroxide associated with an acetate mold duly made for this purpose. The peg-shaped teeth were recontoured with a microhybrid resin composite (shade EA1 and DA1 with the aid of a platinum guide in silicone, obtained after diagnostic waxing on the plaster model. It was concluded that the association of esthetic procedures is of the utmost importance for obtaining good looking, aligned and harmonious teeth.

RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

OpenAIRE

Yadav; Swetha

2015-01-01

Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatmen...

Spatial and functional modeling of carnivore and insectivore molariform teeth.

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Evans, Alistair R; Sanson, Gordon D

2006-06-01

The interaction between the two main competing geometric determinants of teeth (the geometry of function and the geometry of occlusion) were investigated through the construction of three-dimensional spatial models of several mammalian tooth forms (carnassial, insectivore premolar, zalambdodont, dilambdodont, and tribosphenic). These models aim to emulate the shape and function of mammalian teeth. The geometric principles of occlusion relating to single- and double-crested teeth are reviewed. Function was considered using engineering principles that relate tooth shape to function. Substantial similarity between the models and mammalian teeth were achieved. Differences between the two indicate the influence of tooth strength, geometric relations between upper and lower teeth (including the presence of the protocone), and wear on tooth morphology. The concept of "autocclusion" is expanded to include any morphological features that ensure proper alignment of cusps on the same tooth and other teeth in the tooth row. It is concluded that the tooth forms examined are auto-aligning, and do not require additional morphological guides for correct alignment. The model of therian molars constructed by Crompton and Sita-Lumsden ([1970] Nature 227:197-199) is reconstructed in 3D space to show that their hypothesis of crest geometry is erroneous, and that their model is a special case of a more general class of models. (c) 2004 Wiley-Liss, Inc.

Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

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Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

2016-01-01

Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

The morphology of amputated human teeth and its relation to mechanical properties after restoration treatment

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Gugger, Jonas; Krastl, Gabriel; Huser, Marius; Deyhle, Hans; Müller, Bert

2010-09-01

The increased susceptibility to fracture of root canal- and post-treated teeth is less affected by alterations of the dentin structure, but seems to crucially depend on the loss of coronal tooth substance. The surface, available for adhesion of the composite material in the root canal and in the coronal part of the tooth, is assumed to be of key importance for the fracture resistance. Thus, an appropriate three-dimensional method should be identified to determine the adhesive surface with necessary precision. For this purpose, severely decayed teeth were simulated decapitating clinical crowns. After root canal filling and post space preparation, impressions of the root canal and the amputation surface were obtained using silicone. Micro computed tomography scans of these impressions were acquired. For one selected specimen, an additional high-resolution scan was recorded at a synchrotron radiation source. Software of ImageLab served for the extraction of the amputation interface, the post surface and the post volume from the tomography data, which have been finally correlated with the Young's modulus and the maximal load derived from mechanical tests. The morphological parameters show a realistic relationship to the mechanical tests performed after the restoration treatments and are consequently important for improving the dental skills.

Quantifying the impact of µCT-scanning of human fossil teeth on ESR age results.

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Duval, Mathieu; Martín-Francés, Laura

2017-05-01

Fossil human teeth are nowadays systematically CT-scanned by palaeoanthropologists prior to any further analysis. It has been recently demonstrated that this noninvasive technique has, in most cases, virtually no influence on ancient DNA preservation. However, it may have nevertheless an impact on other techniques, like Electron Spin Resonance (ESR) dating, by artificially ageing the apparent age of the sample. To evaluate this impact, we µCT-scanned several modern enamel fragments following the standard analytical procedures employed by the Dental Anthropology Group at CENIEH, Spain, and then performed ESR dose reconstruction for each of them. The results of our experiment demonstrate that the systematic high-resolution µCT-scanning of fossil hominin remains introduces a nonnegligible X-ray dose into the tooth enamel, equivalent to 15-30 Gy depending on the parameters used. This dose may be multiplied by a factor of ∼8 if no metallic filter is used. However, this dose estimate cannot be universally extrapolated to any µCT-scan experiment but has instead to be specifically assessed for each device and set of parameters employed. The impact on the ESR age results is directly dependent on the magnitude of the geological dose measured in fossil enamel but could potentially lead to an age overestimation up to 40% in case of Late Pleistocene samples, if not taken into consideration. © 2017 Wiley Periodicals, Inc.

Standing intraoral extractions of cheek teeth aided by partial crown removal in 165 horses (2010-2016).

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Rice, M K; Henry, T J

2018-01-01

Diseased cheek teeth in horses often require invasive extraction techniques that carry a high rate of complications. Techniques and instrumentation were developed to perform partial crown removal to aid standing intraoral extraction of diseased cheek teeth in horses. To analyse success rates and post-surgical complications in horses undergoing cheek teeth extraction assisted by partial crown removal. Retrospective cohort study. This study included 165 horses with 194 diseased cheek teeth that were extracted orally assisted by partial crown removal between 2010 and 2016. Medical records were analysed, including case details, obtained radiographs, surgical reports and follow-up information. Follow-up information (≥2 months) was obtained for 151 horses (91.5%). There were 95 horses examined post-operatively by the authors and, 16 horses by the referring veterinarian; in 40 horses, post-operative follow up was obtained by informal telephone interviews with the owner. Successful standing intraoral extraction of cheek teeth was obtained in 164/165 horses (99.4%). Twenty-five of these horses (15.2%) required additional intraoral extraction methods to complete the extraction, including minimally invasive transbuccal approach (n = 21) and tooth sectioning (n = 4). There was one (0.6%) horse with intraoral extraction failure that required standing repulsion to complete the extraction. The intraoperative complication of fractured root tips occurred in 11/165 horses (6.7%). Post-operative complications occurred in 6/165 horses (3.6%), including alveolar sequestra (n = 4), mild delay of alveolar healing at 2 months (n = 1), and development of a persistent draining tract secondary to a retained root tip (n = 1). Specialised instrumentation and additional training in the technique are recommended to perform partial crown removal in horses. Horses with cheek teeth extraction by partial crown removal have an excellent prognosis for a positive outcome. The term partial coronectomy

Evaluation of resistance of teeth subjected to fracture after endodontic treatment using different root canal sealers: An in vitro study

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S S Bhat

2012-01-01

Full Text Available Aims: The aim of this study was to compare the ex-vivo effects of different root canal sealers on the fracture resistance of endodontically treated teeth. Materials and Methods: Seventy-five freshly extracted human mandibular premolars were used for the study. The length was standardized to 14 mm and all the teeth were biomechanically prepared and divided into five different groups based on the type of root canal sealers used. Group I:- Roeko seal + gutta percha, Group II: AH plus ® root canal sealer + gutta percha, Group III: PULPDENT root canal sealer + gutta percha, Group IV: Zinc oxide-eugenol sealer + gutta percha, Group V: Control (unobturated teeth. The teeth were embedded in acrylic resin blocks and compressive strengths were measured using universal testing machine (Instron. Statistical Analysis Used: One-way ANOVA, unpaired t- test Results: Data obtained were statistically evaluated using one-way ANOVA and unpaired t-test. All groups showed a statistically significant result (P < 0.05. Teeth obturated with Group I and Group II showed higher resistance to fracture than teeth obturated with other three Groups. It was seen that the teeth obturated with group III showed a better fracture resistance than Group IV and there was no statistical significance found between Group and Group V. Conclusions: From this study, it has been concluded that both the resin based sealers that were used in this study were equally effective compared to that of the zinc oxide-based sealers and the control group. However, no significant results were obtained when the comparison was made between zinc oxide-eugenol and gutta-percha and the control group.

Baby Teeth Link Autism and Heavy Metals, NIH Study Suggests

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... Release Thursday, June 1, 2017 Baby teeth link autism and heavy metals, NIH study suggests Cross-section ... Sinai Health System Baby teeth from children with autism contain more toxic lead and less of the ...

Peripheral Nerve Regeneration by Secretomes of Stem Cells from Human Exfoliated Deciduous Teeth.

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Sugimura-Wakayama, Yukiko; Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Ogata, Kenichi; Sakaguchi, Kohei; Hibi, Hideharu

2015-11-15

Peripheral nerve regeneration across nerve gaps is often suboptimal, with poor functional recovery. Stem cell transplantation-based regenerative therapy is a promising approach for axon regeneration and functional recovery of peripheral nerve injury; however, the mechanisms remain controversial and unclear. Recent studies suggest that transplanted stem cells promote tissue regeneration through a paracrine mechanism. We investigated the effects of conditioned media derived from stem cells from human exfoliated deciduous teeth (SHED-CM) on peripheral nerve regeneration. In vitro, SHED-CM-treated Schwann cells exhibited significantly increased proliferation, migration, and the expression of neuron-, extracellular matrix (ECM)-, and angiogenesis-related genes. SHED-CM stimulated neuritogenesis of dorsal root ganglia and increased cell viability. Similarly, SHED-CM enhanced tube formation in an angiogenesis assay. In vivo, a 10-mm rat sciatic nerve gap model was bridged by silicon conduits containing SHED-CM or serum-free Dulbecco's modified Eagle's medium. Light and electron microscopy confirmed that the number of myelinated axons and axon-to-fiber ratio (G-ratio) were significantly higher in the SHED-CM group at 12 weeks after nerve transection surgery. The sciatic functional index (SFI) and gastrocnemius (target muscle) wet weight ratio demonstrated functional recovery. Increased compound muscle action potentials and increased SFI in the SHED-CM group suggested sciatic nerve reinnervation of the target muscle and improved functional recovery. We also observed reduced muscle atrophy in the SHED-CM group. Thus, SHEDs may secrete various trophic factors that enhance peripheral nerve regeneration through multiple mechanisms. SHED-CM may therefore provide a novel therapy that creates a more desirable extracellular microenvironment for peripheral nerve regeneration.

Resistance of Bonded Composite Restorations on Fractures of Endodontically Treated Teeth

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AR Daneshkazemi

2005-01-01

Full Text Available Introduction: This study was performed to evaluate the effect of dentine bonding agents and Glass Ionomer cement beneath composite restorations and its resistance on fractures of endodontically treated teeth. Material and Methods: Forty sound maxillary teeth were selected; ten of them for positive control, and on the rest, RCT and MOD cavity preparations were done with standard methods. Then, the teeth were divided to four groups: 1-Sound teeth for positive control. 2-Prepared without any restoration for negative control. 3-Prepared and restored with Vitrabond(3M, USA, Single bond(3M, USA and Z100(3M, USA resin composite. 4-Prepared and restored by Single bond and Z100 resin composite. Specimens were subjected to compressive load by Instron 8502 until fracture occurred. Results: Group 1 showed the highest resistance to compressive forces followed by group 4,3&2 respectively. ANOVA, t test and Chi-square tests indicated significant difference between all the groups. Conclusion: Use of dentine bonding agents and resin composite increases resistance of endodontically treated teeth to fractures more than teeth restored with sandwich of glass ionomer cements, dentine bonding agents and resin composite.

Multiple Supernumerary Teeth in a Non-Syndromic Patient: A Case Report

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Majid Eshgh Pour

2013-01-01

Full Text Available Introduction: Multiple supernumerary teeth are a rare phenomenon. It occurs more often in patients with syndromes such as Gardner's syndrome, cleidocranial dysplasia and so on. This phenomenon in absence of such syndromes is rare. The purpose of this report was to introduce a case of non-syndromic multiple supernumerary impacted teeth.Case Report: A 29-year-old woman with no skeletal, metabolic, systemic and mental disorder was referred to oral and maxillofacial department of Mashhad dental school. In clinical evaluation, seven Permanent teeth were missing. In radiographic evaluation, there were a total of 15 impacted teeth which 7 of them were supernumerary.Conclusion: Missing or Excess of one or more teeth usually leads to occlusal and functional problems. In these cases, a complete clinical and radiographic examination accompanieal by a precise history should be performed to plan a suitable surgical-orthodontic-prosthetic treatment.

Developmental and evolutionary novelty in the serrated teeth of theropod dinosaurs.

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Brink, K S; Reisz, R R; LeBlanc, A R H; Chang, R S; Lee, Y C; Chiang, C C; Huang, T; Evans, D C

2015-07-28

Tooth morphology and development can provide valuable insights into the feeding behaviour and evolution of extinct organisms. The teeth of Theropoda, the only clade of predominantly predatory dinosaurs, are characterized by ziphodonty, the presence of serrations (denticles) on their cutting edges. Known today only in varanid lizards, ziphodonty is much more pervasive in the fossil record. Here we present the first model for the development of ziphodont teeth in theropods through histological, SEM, and SR-FTIR analyses, revealing that structures previously hypothesized to prevent tooth breakage instead first evolved to shape and maintain the characteristic denticles through the life of the tooth. We show that this novel complex of dental morphology and tissues characterizes Theropoda, with the exception of species with modified feeding behaviours, suggesting that these characters are important for facilitating the hypercarnivorous diet of most theropods. This adaptation may have played an important role in the initial radiation and subsequent success of theropods as terrestrial apex predators.

Comparison between rotary and manual instrumentation in primary teeth.

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Crespo, S; Cortes, O; Garcia, C; Perez, L

2008-01-01

The aim of this study was to compare the efficiency in both, preparation time and root canal shape, when using the Nickel Titanium (Ni-Ti) rotary and K-Files hand instrumentation on root canal preparation of single rooted primary teeth. Sixty single rooted primary teeth were selected and divided into two equal groups: Group (I) 30 teeth instrumented with manual K-files and group (II) 30 teeth instrumented with Ni-Ti rotary files (ProFile 0.04). Instrumentation times were calculated and root canal impressions were taken with light bodied silicone in order to evaluate the shape. The data was analyzed with SPSS program using the t-test and the Chi-square test to compare their means. The preparation time with group (I) K-files was significantly higher than in group (II) rotary files (ProFile 0.04), with a p= .005. The ProFile system showed a significantly more favorable canal taper when compared to the K-files system (P= .002). The use of rotary files in primary teeth has several advantages when compared with manual K files: the efficiency in both, preparation time and root canal shape. 1. A decreased working time, that helps maintain patient cooperation by diminishing the potential for tiredness. 2. The shape of the root canal is more conical, favoring a higher quality of the root canal filling, and increasing clinical success.

Device for congruent X-ray images of teeth

International Nuclear Information System (INIS)

Wegner, H.; Zeumer, H.

1987-01-01

This invention has to do with a device for congruent X-ray images of teeth by means of the long-tube parallel technique and the long-tube semi-angle technique. The aim is to have no disturbing lever forces in order to avoid mechanical tensions between patient and X-ray tube assembly and to achieve a true projection of teeth and jaw-bone part also under unfavourable anatomical conditions

Combined surgical and orthodontic treatment of bilaterial double teeth: a case report.

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Pearson, A I; Willmot, D R

1995-03-01

A case of bilateral 'double teeth' is described. The patient, aged 8 at initial presentation, was unhappy with the appearance of his two abnormally large upper central incisor teeth. Endodontic treatment was carried out on both teeth followed by surgical splitting and the removal of half of each so as to leave two reasonably-shaped central incisors. Comprehensive orthodontic treatment was then carried out to align the teeth and reduce the overjet, following which the central incisors exhibited no increased mobility or any periodontal problems.

Tuberculate and odontoma type supernumerary teeth.

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

2005-11-01

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

Human dental age estimation combining third molar(s) development and tooth morphological age predictors.

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Thevissen, P W; Galiti, D; Willems, G

2012-11-01

In the subadult age group, third molar development, as well as age-related morphological tooth information can be observed on panoramic radiographs. The aim of present study was to combine, in subadults, panoramic radiographic data based on developmental stages of third molar(s) and morphological measurements from permanent teeth, in order to evaluate its added age-predicting performances. In the age range between 15 and 23 years, 25 gender-specific radiographs were collected within each age category of 1 year. Third molar development was classified and registered according the 10-point staging and scoring technique proposed by Gleiser and Hunt (1955), modified by Köhler (1994). The Kvaal (1995) measuring technique was applied on the indicated teeth from the individuals' left side. Linear regression models with age as response and third molar-scored stages as explanatory variables were developed, and morphological measurements from permanent teeth were added. From the models, determination coefficients (R (2)) and root-mean-square errors (RMSE) were calculated. Maximal-added age information was reported as a 6 % R² increase and a 0.10-year decrease of RMSE. Forensic dental age estimations on panoramic radiographic data in the subadult group (15-23 year) should only be based on third molar development.

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

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Tatara, Marcin R; Szabelska, Anna; Krupski, Witold; Tymczyna, Barbara; Luszczewska-Sierakowska, Iwona; Bieniaś, Jarosław; Ostapiuk, Monika

2014-02-19

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

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

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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

Enamel hypoplasia in the deciduous teeth of great apes: variation in prevalence and timing of defects.

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Lukacs, J R

2001-11-01

The prevalence of enamel hypoplasia in the deciduous teeth of great apes has the potential to reveal episodes of physiological stress in early stages of ontogenetic development. However, little is known about enamel defects of deciduous teeth in great apes. Unresolved questions addressed in this study are: Do hypoplastic enamel defects occur with equal frequency in different groups of great apes? Are enamel hypoplasias more prevalent in the deciduous teeth of male or female apes? During what phase of dental development do enamel defects tend to form? And, what part of the dental crown is most commonly affected? To answer these questions, infant and juvenile skulls of two sympatric genera of great apes (Gorilla and Pan) were examined for dental enamel hypoplasias. Specimens from the Powell-Cotton Museum (Quex Park, UK; n = 107) are reported here, and compared with prior findings based on my examination of juvenile apes at the Cleveland Museum of Natural History (Hamman-Todd Collection; n = 100) and Smithsonian Institution (National Museum of Natural History; n = 36). All deciduous teeth were examined by the author with a x10 hand lens, in oblique incandescent light. Defects were classified using Fédération Dentaire International (FDI)/Defects of Dental Enamel (DDE) standards; defect size and location on the tooth crown were measured and marked on dental outline charts. Enamel defects of ape deciduous teeth are most common on the labial surface of canine teeth. While deciduous incisor and molar teeth consistently exhibit similar defects with prevalences of approximately 10%, canines average between 70-75%. Position of enamel defects on the canine crown was analyzed by dividing it into three zones (apical, middle, and cervical) and calculating defect prevalence by zone. Among gorillas, enamel hypoplasia prevalence increases progressively from the apical zone (low) to the middle zone to the cervical zone (highest), in both maxillary and mandibular canine teeth

Comparison between powder and slices diffraction methods in teeth samples

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Colaco, Marcos V.; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada; Porto, Isabel M. [Universidade Estadual de Campinas (FOP/UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia; Gerlach, Raquel F. [Universidade de Sao Paulo (FORP/USP), Rieirao Preto, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia, Estomatologia e Fisiologia; Costa, Fanny N. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

2011-07-01

Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10{sup -1}0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

Comparison between powder and slices diffraction methods in teeth samples

International Nuclear Information System (INIS)

Colaco, Marcos V.; Barroso, Regina C.; Porto, Isabel M.; Gerlach, Raquel F.; Costa, Fanny N.

2011-01-01

Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10 -1 0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

Biofilm forming ability of bacteria isolated from necrotic roots canals of teeth

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Alwan, Merriam Ghadhanfar; Usup, Gires; Heng, Lee Yook; Ahmad, Asmat

2018-04-01

The growth of microbes in biofilms are associated with repeated and chronic human infections and are extremely resistant to antimicrobial agents. The purpose of this study was to determine the diversity of bacteria from necrotic roots canals of teeth and to detect their biofilm formation ability. A total of 42 bacterial isolates were isolated and identified as belonging to 11 genera. These are Enterococcus sp. (21.4%) followed by Streptococcus sp. (16.8%), Bacillus sp. (11.9%), Peptostreptococcus sp. (9.5%), Staphylococcus sp. (9.5%), Bacteroides sp. (7.1%), Clostridium sp. (7.1%), Actinomyces sp. (7.1%), Fusobacterium sp. (4.76%), Provotella sp. (2.4%) and Chromobacterium sp. (2.4%). Three screening methods for biofilm forming ability were used. Congo Red Agar method (CRA), Tube method (TM) and Microtitre Plate (MTP). From the results, MTP method is a more reliable and quantitative method for the screening and detection of microorganism's ability to form biofilm. This method can be recommended and suggested as a general screening method for the detection of biofilm forming bacteria isolated from roots canals of teeth.

The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

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Kopke Susan

2012-09-01

Full Text Available Abstract Background Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages. Results Maxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05. In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most

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

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Venkataraghavan, Karthik; Chan, John; Karthik, Sandhya

2014-01-01

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

[Significance of proper oral hygiene for health condition of mouth and teeth].

Science.gov (United States)

Ljaljević, Agima; Matijević, Snezana; Terzić, Natasa; Andjelić, Jasmina; Mugosa, Boban

2012-01-01

Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. This cross-sectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

Significance of proper oral hygiene for health condition of mouth and teeth

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Ljaljević Agima

2012-01-01

Full Text Available Background/Aim. Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. Methods. This crosssectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. Results. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. Conclusion. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

Determination of iron, cobalt and zinc in caries teeth by neutron activation analysis

International Nuclear Information System (INIS)

Moriwaki, Kazunari; Shimpuku, Yasuhiro; Furuyama, Shunsuke

1999-01-01

The concentration of Fe, Zn and Co in caries teeth was determined by neutron activation analysis to compare with those of complete impacted wisdom teeth. In order to investigate the distribution of three elements, molar teeth were separated not by conventional method like precipitation or UV absorption method but by ashing method. Furthermore, the same elements for dental pulp and softened dentin were determined. The following results were obtained: The concentration of three elements (Fe, Zn and Co) in enamel, dentin and cementum of caries teeth was higher than that in control teeth. Enamel contained more Fe and Co than those in dentin or cementum, whereas Zn was found to be evenly distributed in three parts of the teeth. The concentration of the elements was Zn>Fe>Co in softened dentin, Fe>Zn>Co in dental pulp. (author)

On the mechanistic role of the dentin-enamel junction in preventing the fracture of human teeth

Energy Technology Data Exchange (ETDEWEB)

Imbeni, V.; Kruzic, J.J.; Marshall, G.W.; Marshall, S.J.; Ritchie, R.O.

2004-09-01

The dentin-enamel junction (DEJ), which is the interface between the dentin and outer enamel coating in teeth, is known for its unique biomechanical properties that provide a crack-arrest barrier for flaws formed in the brittle enamel. In this work, we re-examine how cracks propagate in the proximity of the DEJ, and specifically quantify, using interfacial fracture mechanics, the fracture toughness of the DEJ region. Additionally, we show that the vital function of the DEJ, in preventing cracks formed in enamel from traversing the interface and causing catastrophic tooth fractures, is not necessarily associated with the crack-arrest capabilities of the DEJ itself, but rather with the development of crack-tip shielding, primarily from uncracked-ligament bridging, in the mantle dentin adjacent to the DEJ. Measurements of the toughness of the DEJ region give estimates of G{sub c} {approx} 115 J/m{sup 2}, i.e., {approx}5 to 10 times higher than enamel and {approx}75 percent of that of dentin.

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

Science.gov (United States)

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.

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

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Rakesh N. Bahadure

2012-01-01

Full Text Available 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.

A comparison between red and infrared light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter.

Science.gov (United States)

Kijsamanmith, Kanittha; Timpawat, Siriporn; Vongsavan, Noppakun; Matthews, Bruce

2011-06-01

To compare red (635 nm) and infrared (780 nm) light for recording pulpal blood flow from human anterior teeth with a laser Doppler flow meter. Recordings were made from 7 healthy teeth in 5 subjects (aged 22-55 years) using a laser Doppler flow meter (Periflux 4001) equipped with both red and infrared lasers. Average blood flow signals were obtained with both light sources alternately from each tooth under five conditions: intact tooth without opaque rubber dam, intact tooth with dam, after injecting local anaesthetic (3% Mepivacaine) (LA) over the apex of the tooth and cavity preparation to almost expose the pulp, after removal and replacement of the pulp, and with the root canal empty. With infrared light, because of technical limitations, data were obtained for the first three conditions only. The dam significantly decreased the mean blood flow by 82%. Injecting LA and cavity preparation had no significant effect. With red light, dam produced a decrease of 56%, and the resulting signal was reduced by 33% after LA and cavity preparation. The remaining signal fell by 46% after pulp removal and replacement. This contribution of the pulp is similar to that recorded previously with infrared light. There was no significant further change when the pulp was finally removed. The importance of using opaque rubber dam is confirmed. With dam, there is no advantage to using red rather than infrared light, and in each case the pulp contributes less than 50% to the blood flow signal. Copyright © 2011 Elsevier Ltd. All rights reserved.

Patterns of bone loss around teeth restored with endodontic posts

NARCIS (Netherlands)

Katsamakis, S.; Timmerman, M.; van der Velden, U.; de Cleen, M.; van der Weijden, F.

2009-01-01

Objectives: This retrospective study described the pattern of bone loss around teeth with endodontic posts in periodontitis patients, and compared it with contra-lateral teeth without posts. Material and Methods: From full-mouth radiographic surveys of 146 periodontitis patients (35 years), 194

Difference in Striae Periodicity of Heilongjiang and Singaporean Chinese Teeth

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Sharon H. X. Tan

2017-06-01

Full Text Available Striae periodicity refers to the number of cross-striations between successive lines of Retzius in tooth enamel. A regular time dependency of striae periodicity, known as the circaseptan interval, has been proposed. Previous studies on striae periodicity have been carried out on both modern and early humans given its potential applications in forensic age estimations and anthropology. Nevertheless, research comparing striae periodicities across gender groups and populations in different geographical locations, particularly in Asia, is lacking. In this study, we compared the striae periodicities of Heilongjiang and Singaporean Chinese, as well as that of Singaporean Chinese males and females. Results showed that while the median striae periodicity counts of Heilongjiang Chinese and Singaporean Chinese teeth are both 7, Heilongjiang Chinese tend to have lower striae periodicity counts than Singaporean Chinese (p < 0.01. No significant gender difference was observed between the median striae periodicity of Singaporean Chinese Female and Singaporean Chinese Male teeth (p = 0.511. We concluded that the median striae periodicity may statistically differ with geographical location, but not gender, provided that ethnicity and geographical location are held constant. Further studies are required to examine the causes for variation in striae periodicities between geographical locations, as well as to verify the other bio-environmental determinants of striae periodicity.

Radiation doses for X-ray diagnosis teeth in dental medicine

International Nuclear Information System (INIS)

Direkov, Lyubomir

2009-01-01

X-rays are the first ionizing radiation, which are applied in medicine for diagnostic radiology and X-ray therapy. While in the beginning they are mainly used for X-ray photos of the chest /lungs and in severe fractures of the limbs, then in recent years they are widely applied in diagnostics of teeth in dental medicine. Considering that caries is a widespread disease, both in children and adults, and it requires repeated x-ray photographs of the damaged teeth for the individual, the total radiation doses, which reflect on people from the X-rays are at high values. In order to reduce external exposure to other organs /mainly thyroid gland/ by X-ray pictures of teeth, it should be used with special lead aprons with large coefficient of reduction. Keywords: doses of radiation, X-ray machines, dental, x-ray pictures of teeth, protection sources

Comparative evaluation of different mechanical modifications of denture teeth on bond strength between high-impact acrylic resin and denture teeth: An in vitro study.

Science.gov (United States)

Phukela, Sumit Singh; Chintalapudi, Siddesh Kumar; Sachdeva, Harleen; Dhall, Rupinder Singh; Sharma, Neeraj; Prabhu, Allama

2016-01-01

Acrylic teeth separates from the denture base and remains a major worry in day-to-day routine dental procedure. The present study was conducted to comparatively evaluate different mechanical modifications of acrylic teeth on bond strength between Lucitone 199 heat cure resin and cross-linked teeth. The test specimens, central incisors (21) were demarcated into four groups. Group 1 was the control group, whereas Group 2, Group 3, and Group 4 were experimental groups modified with round groove, vertical groove, and T-shaped groove, respectively. The preparation of masterpiece was done by aligning the long axis of the central incisor teeth at 45° to the base of a wax block (8 mm × 10 mm × 30 mm), with ridge lap surface contacting the base. These test specimen (21) was prepared by Lucitone 199 heat cure resin. Evaluation of bond strength of all the specimens was done using universal tester (materials testing machine). Shapiro-Wilk Test, one-way analysis of variance (ANOVA), and Bonferroni test were done to do statistical investigation. Group 1 specimens prepared by Lucitone 199 heat cure resin showed the lowest bond strength and Group 4 specimens prepared with T-shaped groove packed with Lucitone 199 exhibited the highest bond strength. The bond strength between Lucitone 199 heat cure resin and cross-linked teeth was increased when mechanical modifications was done on denture teeth. The specimens prepared with T-shaped groove packed with Lucitone 199 heat cure resin showed the highest bond strength followed by Group 3, Group 2, and lastly Group 1 prepared by Lucitone 199 heat cure resin.

Patients’ general satisfaction with the appearance of anterior maxillary teeth

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Lajnert Vlatka

2017-01-01

Full Text Available Background/Aim. Dental appearance plays an important role in practically all personal social interactions. The main factors that define the dental appearance are tooth colour, shape and position, quality of restoration, and the general position of the teeth in arch, especially in the anterior region. The aim of this study was to evaluate the impact of dental status (tooth shape, fracture, dental and prosthetic restorations and presence of plaque on patient''s satisfaction with the dental appearance, controlling for the age and gender. Methods. A total of 700 Caucasian subjects (439 women aged 18–86 (median 45 years participated in the cross-sectional study. Study included clinical examination and self-administrated questionnaire based on selfperceived aesthetics and satisfaction with the appearance of their maxillary anterior teeth. Results. A regression analysis demonstrated that presence of dental plaque, tooth fracture, composite fillings and crowns had significant independent contribution and were negative predictors of satisfaction with teeth appearance. Participants with presence of plaque on upper teeth (p < 0.001, fractures (p = 0.005, composite fillings (p < 0.001 and crowns (p = 0.032 were less satisfied than those without it. Model explains 12% or variance of general satisfaction with the appearance of maxillary frontal teeth (p < 0.001 and the major contributors are composite fillings (5.3% and plaque (3.2%. Tooth shape, age and gender were not significant predictors of satisfaction. Conclusion. Satisfaction with the teeth appearance is under the influence of many factors with significant negative influence of presence of dental plaque, fractures, composite restorations, and crowns.

Bilateral Supernumerary Teeth in Deciduous Dentition-A Rarity

OpenAIRE

Acharya, Sonu; 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 centr...

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

Directory of Open Access Journals (Sweden)

Karthik Venkataraghavan

2014-01-01

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

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

OpenAIRE

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. ...

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

Science.gov (United States)

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

2014-01-01

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

Immunomodulatory Role of Stem Cell from Human Exfoliated Deciduous Teeth on Periodontal Regeneration.

Science.gov (United States)

Gao, Xianling; Shen, Zongshan; Guan, Meiliang; Huang, Qiting; Chen, Lingling; Qin, Wei; Ge, Xiaohu; Chen, Haijia; Xiao, Yin; Lin, Zhengmei

2018-03-20

Periodontitis is initiated by the infection of periodontal bacteria and subsequent tissue inflammation due to immunoreaction, eventually leading to periodontal apparatus loss. Stem cells from human exfoliated deciduous teeth (SHEDs) have exhibited beneficial characteristics in dental tissue regeneration. However, the immunomodulatory functions of SHEDs have not been elucidated in the context of periodontitis treatment. In this study, we investigated the potential immunomodulatory effects of SHEDs on experimental periodontitis and demonstrated that multi-dose delivery of SHEDs led to periodontal tissue regeneration. SHEDs and monocytes/macrophages were cocultured in transwell systems and SHEDs were found to be capable of promoting monocyte/macrophages conversion to CD206+ M2-like phenotype. Bioluminescence imaging (BLI) was employed to assess the survival and distribution of SHEDs after delivery in periodontal tissues in an induced periodontitis model, and BLI revealed that SHEDs survived for approximately 7 days in periodontal tissues with little tissue diffusion. Then, multi-dose SHEDs delivery was applied to treat periodontitis at 7-day intervals. Results showed that muti-dose SHEDs altered the cytokine expression profile in gingival crevicular fluid, reduced gum bleeding, increased new attachment of periodontal ligament and decreased osteoclast differentiation. Micro-computed tomography analysis showed SHEDs administration significantly increased periodontal regeneration and alveolar bone volume, and decreased distance of cementoenamel junction to alveolar bone crest (CEJ-ABC). Furthermore, an increase in the number of CD206+ M2 macrophages was observed in periodontal tissues following the delivery of SHEDs, which aligned well with the promoted conversion to CD206+ M2-like cells from monocytes/macrophages in vitro after stimulation by SHEDs. This study demonstrated in a rat periodontitis model that local delivery of SHEDs attributed to the induction of M2

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Behjat-Al-Molook Ajami

2013-01-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration

Evaluation of Survival Time of Tooth Color Dental Materials in Primary Anterior Teeth

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Taraneh Movahhed

2012-09-01

Full Text Available Introduction: In restorative dentistry, selecting the proper material is an important factor for clinical success. The objective of this study was clinical evaluation of survival time of three tooth color materials in primary anterior teeth. Methods: In this interventional clinical trial study, 94 deciduous anterior teeth (36 teeth in boys, 58 teeth in girls belonging to 3-5 year old children in Pediatric Department of Mashhad Faculty of Dentistry, Iran were selected. Selective dental materials included compoglass, glass-ionomer Fuji II LC, and composite resin. The data were analyzed with Kaplan–Meyer and Log rank test. Results: compoglass had the highest survival time in comparison with composite and glass-ionomer. Nine months retention rate for teeth restored with compoglass, composite resin and glass-ionomer were estimated: 95%, 21%, and 12.5%, respectively. Conclusion: Compoglass can be a suitable material for anterior primary teeth restoration.

Late Middle Pleistocene hominin teeth from Panxian Dadong, South China.

Science.gov (United States)

Liu, Wu; Schepartz, Lynne A; Xing, Song; Miller-Antonio, Sari; Wu, Xiujie; Trinkaus, Erik; Martinón-Torres, María

2013-05-01

The hominin teeth and evidence of hominin activities recovered from 1991 to 2005 at the Panxian Dadong site in South China are dated to the late Middle Pleistocene (MIS 8-6 or ca. 130-300 ka), a period for which very little is known about the morphology of Asian populations. The present study provides the first detailed morphometric description and comparisons of four hominin teeth (I(1), C1, P(3) and P3) from this site. Our study shows that the Panxian Dadong teeth combine archaic and derived features that align them with Middle and Upper Pleistocene fossils from East and West Asia and Europe. These teeth do not display any typical Neanderthal features and they are generally more derived than other contemporaneous populations from Asia and Africa. However, the derived traits are not diagnostic enough to specifically link the Panxian Dadong teeth to Homo sapiens, a common problem when analyzing the Middle Pleistocene dental record from Africa and Asia. These findings are contextualized in the discussion of the evolutionary course of Asian Middle Pleistocene hominins, and they highlight the necessity of incorporating the Asian fossil record in the still open debate about the origin of H. sapiens. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diabetes or hypertension as risk indicators for missing teeth ...

African Journals Online (AJOL)

A negative binomial regression (NBR) model was generated. Results: Mean age was 50.7 ± 16.2 and 50.0% were women. Mean number of missing teeth was 4.98 ± 4.17. In the multivariate NBR model, we observed that individuals with T2DM had higher risk of more missing teeth (incidence rate ratios [IRRs] = 3.13; 95% ...

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

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Miguel Agostinho Beco Pinto Cardoso

2016-05-01

Full Text Available 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.

Tracking down human contamination in ancient human teeth

DEFF Research Database (Denmark)

Sampietro, María Lourdes; Gilbert, M Thomas P; Lao, Oscar

2006-01-01

DNA sequences can be used to support data authenticity is misleading in scenarios where the presence of old contaminant sequences is possible. We argue therefore that the typing of those involved in the manipulation of the ancient human specimens is critical in order to ensure that generated results......DNA contamination arising from the manipulation of ancient calcified tissue samples is a poorly understood, yet fundamental, problem that affects the reliability of ancient DNA (aDNA) studies. We have typed the mitochondrial DNA hypervariable region I of the only 6 people involved in the excavation...

Prevalence rate of supernumerary teeth among non-syndromic South Indian population: An analysis

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M Nazargi Mahabob

2012-01-01

Full Text Available Aim: Supernumerary teeth are considered as one of the most significant dental anomalies during the primary and early mixed dentition stage. The main objective of the study was to determine the prevalence rate of supernumerary teeth in the patients who reported to the Department of Oral Medicine and Radiology and to study the associated clinical complications. Materials and Methods: A longitudinal observational study was conducted of 2216 patients for a period of 4 months with the documentation of demographic data, the presence of supernumerary teeth, their location, and associated complications such as mechanical trauma, dental caries, and associated pathology. Results: The study recorded 27 supernumerary teeth from the examined 2216 patients. This yields a prevalence of 1.2%, with greater frequency in males which was 1.49% and in females the frequency was 0.85%. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (77.8%. Out of this, 85.7% were classified as mesiodens based on their location. The displacement of adjacent teeth was the most common finding, followed by dental caries. Conclusion: The prevalence of supernumerary teeth in this study was 1.2% which is in agreement with that reported in similar studies and the maxillary mesiodens was the most common location. Displacement of adjacent teeth was the most common finding.

INVESTIGATING THE MANAGEMENT OF CARIOUS PRIMARY TEETH IN GENERAL DENTAL PRACTICE: AN OVERVIEW OF THE DEVELOPMENT AND CONDUCT OF THE FICTION TRIAL.

Science.gov (United States)

Stewart, Matthew; Keightley, Alexander; Maguire, Anne; Chadwick, Barbara; Vale, Luke; Homer, Tara; Douglas, Gail; Deery, Chris; Marshman, Zoe; Ryan, Vicky; Innes, Nicola

2015-11-01

The management of carious primary teeth is a challenge for patients, parents and clinicians. Most evidence supporting different management strategies originates from a specialist setting and therefore its relevance to the primary care setting is questionable. The UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) has commissioned the FiCTION (Filling Children's Teeth: Indicated Or Not?) trial; a multi-centre primary dental care randomised controlled trial (RCT) to determine the most clinically and cost- effective approach to managing caries in the primary dentition in the UK. This large trial began in 2012, is due to be completed in late 2017 and involves 72 practices and 1,124 children initially aged three to seven years with dentine caries, following randomisation to one of three caries management strategies. Clinical, radiographic, quality of life, treatment acceptability and health economics data are collected during the three-year follow up period. This article provides an overview of the development and conduct of FiCTION and discusses some approaches adopted to manage challenges and achieve the patient recruitment target.

Cultural significance of primary teeth for caregivers in Northeast Brazil.

Science.gov (United States)

Nations, Marilyn K; Calvasina, Paola Gondim; Martin, Michele N; Dias, Hilma Fontenele

2008-04-01

This anthropological study critically evaluates Brazilian caregivers' symbolic production and significance of their malnourished offspring's primary teeth, as well as their own, and describes popular dental practices. From January to June 2004, ethnographic interviews of 27 poor, low-literacy mothers were conducted at a public Malnutrition Treatment Center in Fortaleza, Ceará State. Participant observation of clinical pathways and home environments supplemented the data. Content analysis was performed. Results confirm that primary teeth are imbued with cultural significance in Northeast Brazil. Mothers examine mouths, perceive signs of decay, associate primary with permanent tooth healthiness, identify ethnodental illnesses, seek assistance, and perform rituals with exfoliated teeth. The mother's motivation to care for primary teeth is sparked by her memories of past toothache and attempts to avoid stigma and discrimination. Social determinants, not mothers' beliefs or behaviors, are the most critical obstacles to effective dental care. Legitimizing lay knowledge and empowering caregivers and children can improve oral health in Northeast Brazil.

Photodynamic therapy with water-soluble phtalocyanines against bacterial biofilms in teeth root canals

Science.gov (United States)

Gergova, Raina; Georgieva, Tzvetelina; Angelov, Ivan; Mantareva, Vanya; Valkanov, Serjoga; Mitov, Ivan; Dimitrov, Slavcho

2012-06-01

The study presents the PDT with metal phthalocyanines on biofilms grown in root canals of ten representatives of the Gram-positive and the Gram-negative bacterial species and a fungus Candida albicans which cause aqute teeth infections in root canals.. The extracted human single-root teeth infected for 48 h with microorganisms in conditions to form biofilms of the above pathogens were PDT treated. The stage of biofilm formation and PDT effect of the samples of the teeth were determined by the scaning electron microscopy and with standard microbial tests. The PDT treating procedure included 10 min incubation with the respected phthalocyanine and irradiated with 660 nm Diode laser for 10 min. The most strongly antibacterial activity was achieved with zinc(II) phthalocyanine (ZnPc) against Enterococcus faecalis, Staphylococcus aureus and Moraxella catarrhalis. The other Gram-negative bacteria and Candida albicans were 10-100 times more resistant than the Gram-positive species. The Gram-negative Moraxella catarrhalis and Acinetobacter baumannii were more sensitive than the enterobacteria, but eradication of Pseudomonas aeruginosa in biofilm was insignificant. The influence of the stage of biofilm formation and the initial conditions (bacterial density, photosensitizer concentration and energy fluence of radiation) to the obtained level of inactivation of biofilms was investigated. The PDT with ZnPc photosensitizers show a powerful antimicrobial activity against the most frequent pathogens in endodontic infections and this method for inactivation of pathogens may be used with sucsses for treatment of the bacterial biofilms in the root canals.

Isolation and evaluation of dental pulp stem cells from teeth with advanced periodontal disease.

Science.gov (United States)

Derakhshani, Ali; Raoof, Maryam; Dabiri, Shahriar; Farsinejad, Ali Reza; Gorjestani, Hedayat; Yaghoobi, Mohammad Mehdi; Shokouhinejad, Noushin; Ehsani, Maryam

2015-04-01

Successful isolation of mesenchymal stem cells from waste tissues might be extremely promising for developing stem cell-based therapies. This study aimed to explore whether cells retrieved from teeth extracted due to advanced periodontal disease present mesenchymal stem cell-like properties. Pulp cells were isolated from 15 intact molars and 15 teeth with advanced periodontal disease. Cell proliferation and markers of mesenchymal stem cells were evaluated. Based on the RT-PCR and agarose gel electrophoresis, nucleostemin, Oct-4 and jmj2c, but not Nanog, were expressed in undifferentiated mesenchymal stem cells of both groups. Interestingly, diseased pulp exhibited higher gene expressions although it was not statistically significant. The average percentage of BrdU positive cells in the diseased group (84.4%, n = 5) was significantly higher than that of the control group (65.4%, n = 5) (t-test, P = 0.001). Our results indicate the successful isolation of mesenchymal stem cells from the pulp tissue of hopeless periodontally involved teeth.

Teeth grinding, oral motor performance and maximal bite force in cerebral palsy children.

Science.gov (United States)

Botti Rodrigues Santos, Maria Teresa; Duarte Ferreira, Maria Cristina; de Oliveira Guaré, Renata; Guimarães, Antonio Sergio; Lira Ortega, Adriana

2015-01-01

Identify whether the degree of oral motor performance is related to the presence of teeth grinding and maximal bite force values in children with spastic cerebral palsy. Ninety-five spastic cerebral palsy children with and without teeth grinding, according to caregivers' reports, were submitted to a comprehensive oral motor performance evaluation during the feeding process using the Oral Motor Assessment Scale. Maximal bite force was measured using an electronic gnathodynamometer. The teeth grinding group (n = 42) was younger, used anticonvulsant drugs, and was more frequently classified within the subfunctional oral motor performance category. Teeth grinding subfunctional spastic cerebral palsy children presented lower values of maximal bite force. The functional groups showing the presence or absence of teeth grinding presented higher values of maximal bite force compared with the subfunctional groups. In spastic cerebral palsy children, teeth grinding is associated with the worse oral motor performance. © 2015 Special Care Dentistry Association and Wiley Periodicals, Inc.

Studying the Relative Positions of the Teeth of Conjugated Wheels in the Double Harmonic Transmission

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Draghiţa Ianici

2017-11-01

Full Text Available The paper presents a detailed study of the gearing processes in the two stages of the double harmonic transmission. To highlight the graphics of the relative motion of the conjugates teeth it was developed an original calculation program, written in Visual Basic. By running the calculation program, the relative successive positions of the conjugate teeth were viewed and the basic parameters of the gearing were established: the angle profile (α, the tooth height (h and the size of the deformation of the flexible toothed wheel (w0.

Interdisciplinary treatment of a patient with multiple missing teeth and periodontitis.

Science.gov (United States)

Ahn, Jae-Chan; Lee, Jae-Hong; Yoon, Joon-Ho; Lee, Ji-Yeon; Kim, Jung-Hoon

2018-02-01

A 49-year-old woman with several missing and periodontically compromised teeth was referred to the orthodontic department of National Health Insurance Service Ilsan Hospital by the periodontic department for interdisciplinary treatment. Multiple posterior teeth had been extracted 10 days earlier. Her chief complaint was crowding of the anterior teeth, and she wanted to improve both esthetics and function. Orthodontic, periodontic, and prosthodontic treatments were undertaken in the proper timing and sequence with an interdisciplinary approach. As a result, improved periodontal health and a stable occlusion and vertical dimension were achieved. Although there were limited teeth and alveolar bone for anchorage, good esthetic and functional treatment results were obtained through the application of temporary anchorage devices and proper biomechanics. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Reconstruction of human exposure to heavy metals using synchrotron radiation microbeams in prehistoric and modern humans

International Nuclear Information System (INIS)

Koizumi, Akio; Azechi, Miki; Shirasawa, Koyo

2009-01-01

Teeth can serve as records of environmental exposure to heavy metals during their formation. We applied a new technology - synchrotron radiation microbeams (SRXRF) - for analysis of heavy metals in human permanent teeth in modern and historical samples. Each tooth was cut in half. A longitudinal section 200 μm in thickness was subjected to the determination of the heavy metal content by SRXRF or conventional analytical methods (ICP-MS analysis or reduction-aeration atomic absorption spectrometry). The relative concentrations of Pb, Hg, Cu and Zn measured by SRXRF were translated in concentrations (in g of heavy metal/g of enamel) using calibration curves by the two analytical methods. Concentrations in teeth in the modern females (n=5) were 1.2±0.5 μg/g (n=5) for Pb; 1.7±0.2 ng/g for Hg; 0.9±1.1 μg/g for Cu; 150±24.6 μg/g for Zn. The levels of Pb were highest in the teeth samples obtained from the humans of the Edo era (1603-1868 AD) (0.5-4.0 μg/g, n=4). No trend was observed in this study in the Hg content in teeth during 3,000 years. The concentrations of Cu were highest in teeth of two medieval craftsmen (57.0 and 220 μg/g). The levels of Zn were higher in modern subjects (P<0.05) than those in the Jomon (∼1000 BC) to Edo periods [113.2±27.4 (μg/g, n=11)]. Reconstruction of developmental exposure history to lead in a famous court painter of the Edo period (18th century) revealed high levels of Pb (7.1-22.0 μg/g) in his childhood. SRXRF is useful a method for reconstructing human exposures in very long trends. (author)

Preformed crowns for decayed primary molar teeth.

Science.gov (United States)

Innes, Nicola P T; Ricketts, David; Chong, Lee Yee; Keightley, Alexander J; Lamont, Thomas; Santamaria, Ruth M

2015-12-31

Crowns for primary molars are preformed and come in a variety of sizes and materials to be placed over decayed or developmentally defective teeth. They can be made completely of stainless steel (know as 'preformed metal crowns' or PMCs), or to give better aesthetics, may be made of stainless steel with a white veneer cover or made wholly of a white ceramic material. In most cases, teeth are trimmed for the crowns to be fitted conventionally using a local anaesthetic. However, in the case of the Hall Technique, PMCs are pushed over the tooth with no local anaesthetic, carious tissue removal or tooth preparation. Crowns are recommended for restoring primary molar teeth that have had a pulp treatment, are very decayed or are badly broken down. However, few dental practitioners use them in clinical practice. This review updates the original review published in 2007. Primary objectiveTo evaluate the clinical effectiveness and safety of all types of preformed crowns for restoring primary teeth compared with conventional filling materials (such as amalgam, composite, glass ionomer, resin modified glass ionomer and compomers), other types of crowns or methods of crown placement, non-restorative caries treatment or no treatment. Secondary objectiveTo explore whether the extent of decay has an effect on the clinical outcome of primary teeth restored with all types of preformed crowns compared with those restored with conventional filling materials. We searched the following electronic databases: Cochrane Oral Health Group Trials Register (to 21 January 2015), Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, 2014, Issue 12), MEDLINE via Ovid (1946 to 21 January 2015) and EMBASE via Ovid (1980 to 21 January 2015). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials and Open Grey for grey literature (to

Accuracy of computer-assisted template-guided autotransplantation of teeth with custom three-dimensional designed/printed surgical tooling : A cadaveric study

NARCIS (Netherlands)

Anssari Moin, D.; Verweij, J.P.; Waars, H.; van Merkesteyn, R.; Wismeijer, D.

2017-01-01

Purpose: The aim of the present cadaveric study was to assess the accuracy of computer-assisted template-guided autotransplantation of teeth with custom 3-dimensional (3D) designed/printed surgical tooling. Materials and Methods: Ten partially edentulous human mandibular cadavers were scanned using

Anti-dentine Salivary SIgA in young adults with a history of dental trauma in deciduous teeth

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Gabriela Fleury SEIXAS

2015-01-01

Full Text Available Anti-dentin autoantibodies are associated with inflammatory root resorption in permanent teeth and are modulated by dental trauma and orthodontic force. However, it is not known whether deciduous tooth trauma can stimulate the development of a humoral immune response against dentin. The aim of this study was to evaluate the levels of salivary SIgA reactivity against human dentin extract in young adults with a history of trauma in the primary dentition. A sample of 78 patients, aged 18 to 25, who had completed an early childhood (0 to 5 years old caries prevention program years earlier at the Universidade Estadual de LondrinaPediatric Clinic, underwent radiographic examination and salivary sampling. Anti-dentin SIgA levels were analyzed by immunoenzymatic assay and Western blotting. Although dental trauma to deciduous teeth had occurred in 34 (43.6% of the patients, no differences in SIgA levels were detected between individuals who had experienced trauma and those who had not (p > 0.05. Multivariate regression analysis showed no association between dental trauma and SIgA levels (p > 0.05. Patients with a history of deciduous trauma presented low levels of anti-dentin antibodies, associated with orthodontic root resorption (p

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