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Sample records for teeth prepared conventionally

  1. Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method

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    M. Ghandehari

    2012-01-01

    Full Text Available Objective: One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.Materials and Methods: Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.Results: The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05.Conclusion: Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.Key Words: Er:YAG laser, Glass ionomer, Microleakage

  2. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser

    International Nuclear Information System (INIS)

    Pulga, Neusa Vieira Galvao

    2001-01-01

    The evaluation of marginal microleakage in class V restorations of deciduous teeth prepared using Er:laser and comparison to the ones observed when conventionally prepared, using two photopolimerizable materials, composite resin and glass ionomer cement, was the subject of this study. Twenty eight complete deciduous teeth were divided into four groups Group 1 (G1) prepared with high speed drill + composite resin; Group 2 (G2) prepared with high speed drill + glass ionomer cement; Group 3 (G3) prepared using Er:YAG laser (2.94 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm 2 + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 μm), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm 2 + glass ionomer cement. After the preparation and restoration the specimens where stored at 37 deg C for 24 hours, thermally stressed, immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in the dark. The specimens were rinsed in water, soaked in photodeveloping solution and exposed to fluorescent light for 6 hours. After this process the samples were sectioned and observed by stereomicroscopy. For comparison the groups were divided into occlusive and cervical microleakage. The results were analysed under the Kruskal-Wallis test. For the occlusive microleakage the statistical significance was 5% among the groups and the average comparison showed higher microleakage for G1 (M=35.1) than for G2 (M=24.0) as well as compared to G3 (M=22.3). The other groups did not present statistical differences among them. For the cervical microleakage the Kruskal-Wallis test did not present any statistical difference. Comparing the occlusive and cervical microleakage data, for every group, using the Wilcoxon test, no statistical differences were observed. Concluding, this study showed the Er:YAG laser to be effective for class V restorations and to result in a smaller microleakage degree using the composite resin. These results indicate the viability

  3. Marginal microleakage evaluation in class V composite restorations of deciduous teeth prepared conventionally and using Er:YAG laser; Avaliacao da microinfiltracao marginal em cavidades classe V de dentes deciduos preparados com laser Er:YAG e alta rotacao

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    Pulga, Neusa Vieira Galvao

    2001-07-01

    The evaluation of marginal microleakage in class V restorations of deciduous teeth prepared using Er:laser and comparison to the ones observed when conventionally prepared, using two photopolimerizable materials, composite resin and glass ionomer cement, was the subject of this study. Twenty eight complete deciduous teeth were divided into four groups Group 1 (G1) prepared with high speed drill + composite resin; Group 2 (G2) prepared with high speed drill + glass ionomer cement; Group 3 (G3) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 mJ/cm{sup 2} + composite resin; Group 4 (G4) prepared using Er:YAG laser (2.94 {mu}m), 300 mJ, 3 Hz, handpiece 2051, energy density 86 J / cm{sup 2} + glass ionomer cement. After the preparation and restoration the specimens where stored at 37 deg C for 24 hours, thermally stressed, immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in the dark. The specimens were rinsed in water, soaked in photodeveloping solution and exposed to fluorescent light for 6 hours. After this process the samples were sectioned and observed by stereomicroscopy. For comparison the groups were divided into occlusive and cervical microleakage. The results were analysed under the Kruskal-Wallis test. For the occlusive microleakage the statistical significance was 5% among the groups and the average comparison showed higher microleakage for G1 (M=35.1) than for G2 (M=24.0) as well as compared to G3 (M=22.3). The other groups did not present statistical differences among them. For the cervical microleakage the Kruskal-Wallis test did not present any statistical difference. Comparing the occlusive and cervical microleakage data, for every group, using the Wilcoxon test, no statistical differences were observed. Concluding, this study showed the Er:YAG laser to be effective for class V restorations and to result in a smaller microleakage degree using the composite resin. These results indicate

  4. 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.

  5. Reliability of conventional shade guides in teeth color determination.

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    Todorović, Ana; Todorović, Aleksandar; Gostović, Aleksandra Spadijer; Lazić, Vojkan; Milicić, Biljana; Djurisić, Slobodan

    2013-10-01

    Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest deltaE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: deltaL, deltaC, deltaH, deltaE, deltaElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.

  6. A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.

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    Mokhtari, Negar; Shirazi, Alireza-Sarraf; Ebrahimi, Masoumeh

    2017-11-01

    Techniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth. In this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests ( P <0.05). There were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files ( P =0.000). Considering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words: Rotary technique, conventional technique, pulpectomy, primary teeth.

  7. Comparison of digital radiography and apex locator with the conventional method in root length determination of primary teeth

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    I E Neena

    2011-01-01

    Full Text Available Aim: The purpose of this study was to compare the Working length in primary teeth endodontics using intra oral digital radiovisiography and apex locator with conventional method for accuracy. Materials and Methods: This in vivo study was conducted on 30 primary teeth which were indicated for pulpectomy in the patients of the age group of 5-11 years All experimental teeth had adequate remaining tooth structure for rubber dam isolation and radiographicaly visible canals. Endodontic treatment was required due to irreversible pulpitis or pulp necrosis. A standardized intraoral periapical radiograph of the tooth was taken using conventional method by paralleling technique. The distance between the source and the tooth, tooth and the films were standardized using X-ray positioning device. During the pulpectomy procedure, the working length was determined by digital radiograph and apex locator. The measurements were then compared with the conventional method of root canal measurement technique for accuracy Result: From the results obtained we can conclude that Working length determined in primary molars using digital radiography and Apex locator did not show any significant difference in the mean working length measurements when compared with the conventional radiographic method. Conclusions: Apex locator is comparable to conventional radiograph in determining the working length without radiation in the primary teeth. Intraoral digital radiography is the safest method in determining the working length with significant reduction in radiation exposure.Hence, both the techniques can be safely used as alternatives to conventional radiographic methods in determining working length in primary teeth.

  8. Is there a best conventional material for restoring posterior primary teeth? A network meta-analysis.

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    Pires, Carine Weber; Pedrotti, Djessica; Lenzi, Tathiane Larissa; Soares, Fabio Zovico Maxnuck; Ziegelmann, Patricia Klarmann; Rocha, Rachel de Oliveira

    2018-03-01

    This study aimed to compare the longevity of different conventional restorative materials placed in posterior primary teeth. This systematic review was conducted following the PRISMA statement and registered in PROSPERO (CRD42016035775). A comprehensive electronic search without date or language restrictions was performed in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, Turning Research Into Practice (TRIP) and Clinical Trials databases up to January 2017, selecting randomized clinical trials that assessed the longevity of at least two different conventional restorative materials performed in primary molars. Seventeen studies were included in this systematic review. Pairwise and network meta-analyses were performed and relative risks and 95% confidence intervals (CI) calculated. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Restorations of primary molars with conventional glass ionomer cement showed increased risk of failure than compomer, resin-modified glass ionomer cement, amalgam, and composite resin. Risk of bias was low in most studies (45.38% of all items across studies). Pediatric dentists should avoid conventional glass ionomer cement for restoring primary molars.

  9. Anterior and middle superior alveolar nerve block for anesthesia of maxillary teeth using conventional syringe

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    Ignacio Velasco

    2012-01-01

    Full Text Available Background: Dental procedures in the maxilla typically require multiple injections and may inadvertently anesthetize facial structures and affect the smile line. To minimize these inconveniences and reduce the number of total injections, a relatively new injection technique has been proposed for maxillary procedures, the anterior and middle superior alveolar (AMSA nerve block, which achieves pulpal anesthesia from the central incisor to second premolar through palatal approach with a single injection. The purpose of this article is to provide background information on the anterior and middle superior alveolar nerve block and demonstrate its success rates of pulpal anesthesia using the conventional syringe. Materials and Methods: Thirty Caucasian patients (16 men and 14 women with an average age of 22 years-old, belonging to the School of Dentistry of Los Andes University, were selected. All the patients received an AMSA nerve block on one side of the maxilla using the conventional syringe, 1 ml of lidocaine 2% with epinephrine 1:100.000 was injected to all the patients. Results: The AMSA nerve block obtained a 66% anesthetic success in the second premolar, 40% in the first premolar, 60% in the canine, 23.3% in the lateral incisor, and 16.7% in the central incisor. Conclusions: Because of the unpredictable anesthetic success of the experimental teeth and variable anesthesia duration, the technique is disadvantageous for clinical application as the first choice, counting with other techniques that have greater efficacy in the maxilla. Although, anesthetizing the teeth without numbing the facial muscles may be useful in restorative dentistry.

  10. Root canal preparation in endodontics: conventional versus laser methods

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    Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.; Moskowitz, Emrey

    1992-06-01

    Conventional cleaning and shaping of root canal systems employs hand and/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into 2 groups. The first group was accessed and the root canal systems cleaned and shaped with a step back technique utilizing hand files and gates glidden burs. At completion of the procedure the teeth were again radiographed at the same positions as those prior to the procedure. The teeth were split longitudinally and examined under scanning electron microscopy to assess cleaning. The second group of teeth were accessed, and cleaning and shaping was accomplished using the Nd:YAG laser in combination with hand files and rotary instruments. These teeth were subjected to the same analysis as those in the first group. The before and after radiographs of each group were subjected to image analysis to determine effectiveness of the two methods in shaping the canal systems. We will discuss the ability of Nd:YAG to clean and shape root canal spaces and remove smear layer and organic tissue remnants from those areas.

  11. Comparison of microleakage between flowable nanocomposite, flowable Composite and Conventional sealant in fissure sealant therapy of the permanent teeth: an in- vitro study

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    Sara Maleki Kambakhsh

    2016-11-01

    Full Text Available Background and Aim: Novel dental materials including nanocomposites have been introduced in recent years. It is claimed that they have superior properties such as high esthetic., low wear, increased filler content resulting in better mechanical properties, and releasing ions i.e. fluoride and amorphous calcium phosphate that are important for enamel remineralization. Considering these features, if they have retention and microleakage rates comparable with conventional sealants, these materials can be appropriate alternatives to conventional resin sealants in future. The current study aimed at comparing . microleakage of a flowable nanocomposite, a flowable composite , and a conventional sealant in fissure sealant therapy of the permanent teeth. Materials and Methods: First of all ,42 extracted sound human maxillary first premolars were collected and were randomly divided into 3 equal groups. Then the teeth were embedded in self-cure acrylic resin. Occlusal fissures of the samples were cleaned using explorer, enameloplasty with ¼ round diamond bur and water/air spray was done. The prepared surfaces were etched using 36% phosphoric acid gel for 15s, rinsed and dried. Bonding agent was placed in the pits and fissures, cured for 10s after thinning with air. In the first, second , and the third group conventional sealant, flowable composite , and flowable nanocomposite were placed, respectively; and light cured for 40s. The samples were thermocycled (1000 cycles between 5-55ºC and then immersed in 2% basic Fuchsine solution for 24hs. They were then cut bucculingually and microleakage evaluation was done using stereomicroscope. The obtained data was analyzed using Kruskal wallis tests. Results: There was no significant difference in microleakage rate of the study groups. (P>0.05. Conclusion: Considering the condition of the study, it can be concluded that flowable composite and flowable nanocomposite can be used as suitable alternatives to

  12. Clinical comparative study between the use of lasers and conventional methods of diagnosis and treatment in deciduous teeth with presence of carious lesion

    International Nuclear Information System (INIS)

    Pulga, Fabiane Galvao

    2001-01-01

    The aim of this work was to evaluate the efficiency of deciduous tooth cavity preparation by the Er:YAG laser in comparison with the conventional burr rotary instrument. Besides, we have used the laser fluorescence technique (DIAGNOdent equipment) for diagnosis and compared it to the usual tactile and visual examination as well as X-ray diagnosis. For this purpose, 20 chronic occlusal carious deciduous molar teeth from children with the ages between 5 to 10 years old were selected. Selection was ma de according to visual inspection, X-ray periapical image and measures of the DIAGNOdent. For treatment the teeth were divided in two groups, 10 to be treated by the Er:YAG laser and 10 with conventional burr. For enamel, the laser energy used was in the interval from 200 to 300 mJ; for the dentine the range was from 100 mJ to 200 mJ. In both cases, the laser frequency was in the range from 2 to 4 Hz. The results have shown that the laser treatment was more accepted by the children than the conventional burro Clinical evaluation of the cavity preparation indicates that the Er:YAG laser treatment is recommend. The DIAGNOdent evaluation method was very effective for diagnosis of carious tissue for initial detection. After successful removal of the carious tissue, confirmed by visual inspection, the DIAGNOdent evaluation method was only effective for the treatment with conventional burro For evaluation of the tooth after cavity preparation with the Er:YAG laser, the measurements oscillate covering the full range of the equipment. Therefore, the use of the DIAGNOdent equipment is indicated only for initial caries diagnosis. (author)

  13. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

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    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Quantification of incisal tooth wear in upper anterior teeth: conventional vs new method using toolmakers microscope and a three-dimensional measuring technique.

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    Al-Omiri, Mahmoud K; Sghaireen, Mohd G; Alzarea, Bader K; Lynch, Edward

    2013-12-01

    This study aimed to quantify tooth wear in upper anterior teeth using a new CAD-CAM Laser scanning machine, tool maker microscope and conventional tooth wear index. Fifty participants (25 males and 25 females, mean age = 25 ± 4 years) were assessed for incisal tooth wear of upper anterior teeth using Smith and Knight clinical tooth wear index (TWI) on two occasions, the study baseline and 1 year later. Stone dies for each tooth were prepared and scanned using the CAD-CAM Laser Cercon System. Scanned images were printed and examined under a toolmaker microscope to quantify tooth wear and then the dies were directly assessed under the microscope to measure tooth wear. The Wilcoxon Signed Ranks Test was used to analyze the data. TWI scores for incisal edges were 0-3 and were similar at both occasions. Score 4 was not detected. Wear values measured by directly assessing the dies under the toolmaker microscope (range = 113 - 150 μm, mean = 130 ± 20 μm) were significantly more than those measured from Cercon Digital Machine images (range=52-80 μm, mean = 68 ± 23 μm) and both showed significant differences between the two occasions. Wear progression in upper anterior teeth was effectively detected by directly measuring the dies or the images of dies under toolmaker microscope. Measuring the dies of worn dentition directly under tool maker microscope enabled detection of wear progression more accurately than measuring die images obtained with Cercon Digital Machine. Conventional method was the least sensitive for tooth wear quantification and was unable to identify wear progression in most cases. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Accuracy assessment of high frequency 3D ultrasound for digital impression-taking of prepared teeth

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    Heger, Stefan; Vollborn, Thorsten; Tinschert, Joachim; Wolfart, Stefan; Radermacher, Klaus

    2013-03-01

    Silicone based impression-taking of prepared teeth followed by plaster casting is well-established but potentially less reliable, error-prone and inefficient, particularly in combination with emerging techniques like computer aided design and manufacturing (CAD/CAM) of dental prosthesis. Intra-oral optical scanners for digital impression-taking have been introduced but until now some drawbacks still exist. Because optical waves can hardly penetrate liquids or soft-tissues, sub-gingival preparations still need to be uncovered invasively prior to scanning. High frequency ultrasound (HFUS) based micro-scanning has been recently investigated as an alternative to optical intra-oral scanning. Ultrasound is less sensitive against oral fluids and in principal able to penetrate gingiva without invasively exposing of sub-gingival preparations. Nevertheless, spatial resolution as well as digitization accuracy of an ultrasound based micro-scanning system remains a critical parameter because the ultrasound wavelength in water-like media such as gingiva is typically smaller than that of optical waves. In this contribution, the in-vitro accuracy of ultrasound based micro-scanning for tooth geometry reconstruction is being investigated and compared to its extra-oral optical counterpart. In order to increase the spatial resolution of the system, 2nd harmonic frequencies from a mechanically driven focused single element transducer were separated and corresponding 3D surface models were calculated for both fundamentals and 2nd harmonics. Measurements on phantoms, model teeth and human teeth were carried out for evaluation of spatial resolution and surface detection accuracy. Comparison of optical and ultrasound digital impression taking indicate that, in terms of accuracy, ultrasound based tooth digitization can be an alternative for optical impression-taking.

  16. Treatment of abraded teeth using metal free ceramics and conventional metal-ceramic restorations

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    Bošković Mirjana V.

    2012-01-01

    Full Text Available Introduction. Contemporary reconstructive dentistry is considered to be a bioesthetic discipline, the study of the beauty of living creatures in their original form and functions. A discussion of esthetic dentistry, the sophisticated artificial restorations in the patient mouth, hardly discernible to an observer or expert eye, implies a whole series of qualities. Damage of hard tooth-tissue, which is not caused by caries, is a physiological process present throughout the whole life, but some factors can bring about great losses of the hard tissue. This damage can be caused by a combination of different etiological factors, such as genetical and functional ones. Case report. A patient is coming in dental surgery complaining of a large damage of the hard-tooth tissue, ugly appearance of his teeth, speech dysfunction and masticatory problems. An intraoral view shows the presence of a large teeth-abrasion. The treatment plan simplified the treatment with a combination of metal-ceramic restorations and a new ceramic system IPS e.max (Ivoclar Vivadentm Schaan, Liechtenstien. Conclusion. In this clinical case with presented abrasion the treatment was presented using all-ceramic restorations and classical metal-ceramic restorations to establish good health, function and estehetic. The use of restorations based on zirconium (IPS e.max ZirPress, Ivoclar Vivadent, Schaan, Liechtenstein can produce excellent clinical results in the frontal, as well as in lateral segments.

  17. Microleakage of conventional, resin-modified, and nano-ionomer glass ionomer cement as primary teeth filling material

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    Dita Madyarani

    2014-12-01

    Full Text Available Background: Glass ionomer cements are one of many dental materials that widely used in pediatric dentistry due to their advantage of fluoride release and chemical bond to tooth structure. Adherence of the filling material to the cavity walls is one of the most important characteristic that need to be examined its effect on microleakage. Purpose: This study was conducted to examine the microleakage of nano-ionomer glass ionomer cement compared with the conventional and resin-modified glass ionomer cements. Methods: Standard class V cavities sized 3 mm x 2 mm x 2 mm were made on a total of 21 extracted maxillary primary canine teeth and restored with the conventional, resin-modified, dan nano-ionomer glass ionomer cements. All the teeth were immersed in a 2% methylene blue dye for 4 hours. The depth of dye penetration was assessed using digital microscope after sectioning the teeth labio-palatally. The results were statistically analyzed using Kruskal-Wallis test. Results: All type of glass ionomer material showed microleakage. Conventional glass ionomer cement demonstrated the least microleakage with mean score 1.29. the resin-modified glass ionomer cements (mean score 1.57 and nano-ionomer glass ionomer cement (mean score 2.57. Conclusion: The conventional glassionomer, resin modified glassionomer, and nano-ionomer glassionomer showed micro leakage as filling material in primary teeth cavity. The micro leakage among three types was not significant difference. All three material were comparable in performance and can be used for filling material but still needs a coating material to fill the microleakage.Latar belakang: Semen ionomer kaca adalah salah satu dari banyak bahan gigi yang banyak digunakan dalam praktek kedokteran gigi anak karena bahan tersebut merilis fluoride dan berikatan kimia dengan struktur gigi. Perlekatan bahan tumpatan pada dinding kavitas adalah salah satu karakteristik paling penting yang perlu diteliti efeknya terhadap

  18. Measurement of the convergence angle in teeth prepared for single crown

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    NokarS

    2002-07-01

    Full Text Available Retention, resistance and marginal integrity mostly depend on tooth preparation. An appropriate convergence angle fulfil this purpose, to high extent. In this study, a new method was used to measure the convergence angle of the teeth prepared for single crowns in Genera! practitioners" offices in Tehran. In order to do this. 325 dyes, prepared by General dentists in Tehran, were collected from 10 laboratories. All dyes wore trimmed at the area below the finishing line and then were scanned (Genius Color page- FIR 6 buccoiingualiy and mesiodistaily. Convergence angle of dyes were also measured with Adobe Photoshop (5.0 software. Data were analyzed by variance analysis test and 1- student bv the help of SPSS software. Results showed that the average convergence angle ranged from 16.18+8.34 to 35.1 8~10.38 which belonged to maxillary canine and mandibular molars, respectively, and the measured convergence angle is more than the ideal value of 10-16 degrees. Dyes of the madibular molars were ma"illar" convergent. These conclusions are helpful for professors, dentistry students and dentists, and arc an indicative of the practice quality of General practitioners in Tehran. Due to the fact that a convergence angle, more than the allowed limitation, endangers retention, resistance and marginal integrity of the restoration, paying attention to the principles of tooth preparation and proper application of instruments and dental cements, can progress fwed restorations quality.

  19. Orthodontic forces released by low-friction versus conventional systems during alignment of apically or buccally malposed teeth.

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    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo; Defraia, Efisio

    2011-02-01

    The aim of the present study was to analyse the forces released by passive stainless steel self-ligating brackets (SLBs) and by a non-conventional elastomeric ligature-bracket system on conventional brackets ([slide ligatures on conventional brackets (SLCB)]) when compared with conventional elastomeric ligatures on conventional brackets (CLCB) during the alignment of apically or buccally malposed teeth in the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the three different bracket-ligature systems with 0.012-inch super-elastic (SE) nickel-titanium (NiTi) wires in the presence of different amounts of apical or buccal canine misalignment of the canine (ranging from 1.5 to 6 mm). The forces released by each wire/bracket/ligature combination with the three different amounts of apical or buccal canine misalignment were tested 20 times. Comparisons between the different types of wire/bracket/ligature systems were carried out by means of analysis of variance on ranks with Dunnett's post hoc test (P < 0.05). No difference in the amount of force released in presence of a misalignment of 1.5 mm was recorded among the three systems. At 3 mm of apical misalignment a significantly greater amount of orthodontic force was released by SLB or SLCB when compared with CLCB, while no significant differences were found among the three systems at 3 mm of buccal canine displacement. When correction of a large amount of misalignment (6 mm) was attempted, a noticeable amount of force for alignment was still generated by the passive SLB and SLCB systems while no force was released in presence of CLCB.

  20. A multileaf collimator field prescription preparation system for conventional radiotherapy

    International Nuclear Information System (INIS)

    Du, M.N.; Yu, C. X.; Symons, M.; Yan, D.; Taylor, R.; Matter, R.C.; Gustafson, G.; Martinez, A.; Wong, J.W.

    1995-01-01

    Purpose: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. Methods and Material: The multileaf collimator prescription preparation system developed by us acquires prescription images from different sources, including film scanner and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. Results: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. Conclusion: Our

  1. The quality of impressions for crowns and bridges: an assessment of the work received at three commercial dental laboratories. assessing the quality of the impressions of prepared teeth.

    Science.gov (United States)

    Storey, D; Coward, T J

    2013-06-01

    The literature is limited in studies directly assessing the quality of impressions for crowns and bridges in the UK. The aim of the study was to assess the quality of impressions for conventional crown and bridgework received by commercial dental laboratories. Three dental laboratories were visited over a 3-month period. All impressions for conventional crowns and bridges that arrived on the days of the visits were examined prior to any laboratory processing. A total of 206 impression cases were examined and assessed against criteria laid out in a custom-designed assessment form. Defects were commonly found in the recording of prepared teeth. Overall, 44.2% of impression cases were unsatisfactory. NHS impressions were more than twice as likely to be unsatisfactory compared to private impressions. If the results of this survey are typical then the general quality of impressions for fixed crown and bridgework is unacceptable. This is particularly true for work completed under the NHS contract.

  2. Standards of teeth preparations for anterior resin bonded all-ceramic crowns in private dental practice in Jordan

    Directory of Open Access Journals (Sweden)

    Ziad Nawaf AL-Dwairi

    2011-08-01

    Full Text Available OBJECTIVES: To investigate if general dental practitioners (GDPs in private practice in Jordan follow universal guidelines for preparation of anterior teeth for resin bonded all-ceramic crowns (RBCs. MATERIAL AND METHODS: A sample (n=100 of laboratory models containing 208 tooth preparations for IPS Empress and In Ceram, featuring work from different GDPs, was obtained from 8 commercial dental laboratories. Aspects of preparations were quantified and compared with accepted criteria defined following a review of the literature and recommendations of the manufactures' guidelines. RESULTS: Subgingival margins on the buccal aspect were noticed in 36% of the preparations, 54% demonstrated overpreparation with a tendency to overprepare the teeth on the mesiodistal plane more than buccolingual plane. Twenty percent of samples presented a shoulder finish line while a chamfer margin design was noticed in 39%. Twenty-nine percent and 12% of samples had either a feathered or no clear margin design respectively. Incisal underpreparation was observed in 18% of dies of each type. Only 17% of all preparations were found to follow the recommended anatomical labial preparations while 29% of the RBC preparations were found to have the recommended axial convergence angle. In total, 43% of preparations were found to have the recommended depth of the finish line. CONCLUSIONS: It was found that relevant guidelines for RBC preparations were not being fully adhered to in private practice in Jordan.

  3. Clinical performance of bulk-fill and conventional resin composite restorations in posterior teeth: a systematic review and meta-analysis.

    Science.gov (United States)

    Veloso, Sirley Raiane Mamede; Lemos, Cleidiel Aparecido Araújo; de Moraes, Sandra Lúcia Dantas; do Egito Vasconcelos, Belmiro Cavalcanti; Pellizzer, Eduardo Piza; de Melo Monteiro, Gabriela Queiroz

    2018-03-28

    The purpose of this systematic review was to compare the clinical performance of bulk-fill resin composites with conventional resin composites used for direct restorations of posterior teeth. This review followed the PRISMA statement. This review was registered at PROSPERO (registration number CRD42016053436). A search of the scientific literature was performed by two independent reviewers using the PubMed/MEDLINE, Embase, The Cochrane Library, and Web of Science databases from commencement until January 2018. The research question was "Do bulk-fill resin composites have a clinical performance comparable to conventional resin composites in posterior restorations?" Only studies evaluating class I and II direct restorations in permanent teeth with a follow-up period of at least 1 year were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (restoration failure or success). Ten articles were selected, comprising 941 analyzed restorations. The mean follow-up period was 33.6 months (12-72 months). No statistically significant differences in the failure rate were observed between conventional and base/flowable bulk-fill resin composites (p = 0.31; RR 1.49; 95% CI 0.69-3.25) or full-body/sculptable bulk-fill resin composites (p = 0.12; RR 1.89; 95% CI 0.84-4.24). The present systematic review and meta-analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months. Based on the results of this study, the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth. However, clinical trials of longer duration are required.

  4. 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.

  5. Revascularization and periapical repair after endodontic treatment using apical negative pressure irrigation versus conventional irrigation plus triantibiotic intracanal dressing in dogs' teeth with apical periodontitis.

    Science.gov (United States)

    da Silva, Lea Assed Bezerra; Nelson-Filho, Paulo; da Silva, Raquel Assed Bezerra; Flores, Daniel Silva Herzog; Heilborn, Carlos; Johnson, James D; Cohenca, Nestor

    2010-05-01

    The objective of this study was to evaluate in vivo the revascularization and the apical and periapical repair after endodontic treatment using 2 techniques for root canal disinfection (apical negative pressure irrigation versus apical positive pressure irrigation plus triantibiotic intracanal dressing) in immature dogs' teeth with apical periodontitis. Two test groups of canals with experimentally induced apical periodontitis were evaluated according to the disinfection technique: Group 1, apical negative pressure irrigation (EndoVac system), and Group 2, apical positive pressure irrigation (conventional irrigation) plus triantibiotic intracanal dressing. In Group 3 (positive control), periapical lesions were induced, but no endodontic treatment was done. Group 4 (negative control) was composed of sound teeth. The animals were killed after 90 days and the maxillas and mandibles were subjected to histological processing. The sections were stained with hematoxylin and eosin and Mallory Trichrome and examined under light microscopy. A description of the apical and periapical features was done and scores were attributed to the following histopathological parameters: newly formed mineralized apical tissue, periapical inflammatory infiltrate, apical periodontal ligament thickness, dentin resorption, and bone tissue resorption. Intergroup comparisons were done by the Kruskal-Wallis and Dunn's tests (alpha = 0.05). Although statistically significant difference was found only for the inflammatory infiltrate (P irrigation with the EndoVac system can be considered as a promising disinfection protocol in immature teeth with apical periodontitis, suggesting that the use of intracanal antibiotics might not be necessary. Copyright (c) 2010 Mosby, Inc. All rights reserved.

  6. Comparison between conventional and ultrasonic preparation of beef tallow biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Leonardo S.G. [Instituto de Quimica - Universidade Federal da Bahia, Campus Universitario de Ondina, 40.170-280 - Salvador, Bahia (Brazil); Assis, Julio C.R.; Santos, Iran T.V.; Guimaraes, Paulo R.B.; Pontes, Luiz A.M. [Universidade Salvador - UNIFACS - Departamento de Engenharia e Arquitetura, - Av. Cardeal da Silva 132, 40.220-141 - Salvador, Bahia (Brazil); Mendonca, Daniel R. [Escola Politecnica - Universidade Federal da Bahia, Av. Aristides Novis 2, 40.210-630, Salvador, Bahia (Brazil); Teixeira, Josanaide S.R. [Instituto Federal de Educacao Ciencia e Tecnologica da Bahia - IFBAHIA - Rua Emidio de Morais S/N, 40.625-650, Salvador - BA (Brazil)

    2009-09-15

    Tallow is biodiesel feedstock that, due to its highly centralized generation in slaughter/processing facilities and historically low prices, may have energetic, environmental, and economic advantages that could be exploited. Transesterification of fatty acids by means of ultrasonic energy has been used for biodiesel production from different vegetable oils. However, application of ultrasonic irradiation for biodiesel production from beef tallow has received little attention. In this work, the transesterification of beef tallow with methanol was performed in the presence of potassium hydroxide as a catalyst using ultrasound irradiation (400 W, 24 kHz). The reaction time, conversion and biodiesel quality were compared with that seen in conventional transesterification. The results indicated that the reaction conversion and biodiesel quality were similar; however, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative to the conventional method. (author)

  7. Comparison between conventional and ultrasonic preparation of beef tallow biodiesel

    International Nuclear Information System (INIS)

    Teixeira, Leonardo S.G.; Assis, Julio C.R.; Santos, Iran T.V.; Guimaraes, Paulo R.B.; Pontes, Luiz A.M.; Mendonca, Daniel R.; Teixeira, Josanaide S.R.

    2009-01-01

    Tallow is biodiesel feedstock that, due to its highly centralized generation in slaughter/processing facilities and historically low prices, may have energetic, environmental, and economic advantages that could be exploited. Transesterification of fatty acids by means of ultrasonic energy has been used for biodiesel production from different vegetable oils. However, application of ultrasonic irradiation for biodiesel production from beef tallow has received little attention. In this work, the transesterification of beef tallow with methanol was performed in the presence of potassium hydroxide as a catalyst using ultrasound irradiation (400 W, 24 kHz). The reaction time, conversion and biodiesel quality were compared with that seen in conventional transesterification. The results indicated that the reaction conversion and biodiesel quality were similar; however, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative to the conventional method. (author)

  8. [Clinical study of the effect of preventing dentine hypersensitiveness by using Fluor Protector and Green Or on the prepared vital pulp abutment teeth].

    Science.gov (United States)

    Qin, Jia-nan; Lu, Yu-miao; Zhou, Xiao-yan

    2005-04-01

    To study and evaluate the effect preventing dentine hypersensitiveness by using Fluor Protector or Green Or on the prepared vital pulp abutment teeth of PFM bridges. 118 cases, 246 prepared vital pulp abutment teeth, were randomly divided into three groups: Experimental Group A--treated with the Fluor Protector and temporary crown; Experimental Group B--treated with the Green Or and temporary crown, and Control Group--only using temporary crown. The results of desensitization in 3 groups were evaluated. F test was used for analysis (DSPV6.01). Significant differences were found between experimental Group A, B and the control group after 1 week (when cementing the PFM bridges); and also after 1 month (P0.05). The effect of preventing dental hypersensitiveness by using Fluor Protector or Green Or on the prepared vital pulp abutment teeth of PFM bridges is ideal. It is easy to use and worth being widely applied.

  9. Comparison of the force levels among labial and lingual self-ligating and conventional brackets in simulated misaligned teeth.

    Science.gov (United States)

    Alobeid, Ahmad; El-Bialy, Tarek; Khawatmi, Said; Dirk, Cornelius; Jäger, Andreas; Bourauel, Christoph

    2017-08-01

    The aim of this study was to evaluate force levels exerted by levelling arch wires with labial and lingual conventional and self-ligating brackets. The tested orthodontic brackets were of the 0.022-in slot size for labial and 0.018-in for lingual brackets and were as follows: 1. Labial brackets: (i) conventional bracket (GAC-Twin, Dentsply), (ii) passive self-ligating (SL) brackets (Damon-Q®, ORMCO; Ortho classic H4™, Orthoclassic; FLI®SL, Rocky Mountain Orthodontics) and (iii) active SL brackets (GAC In-Ovation®C, DENTSPLY and SPEED™, Strite). 2. Lingual brackets: (i) conventional brackets (Incognito, 3M and Joy™, Adenta); (ii) passive SL bracket (GAC In-Ovation®LM™, Dentsply and (iii) active SL bracket (Evolution SLT, Adenta). Thermalloy-NiTi 0.013-in and 0.014-in arch wires (Rocky Mountain Orthodontics) were used with all brackets. The simulated malocclusion represented a maxillary central incisor displaced 2 mm gingivally (x-axis) and 2 mm labially (z-axis). Lingual bracket systems showed higher force levels (2.4 ± 0.2 to 3.8 ± 0.2 N) compared to labial bracket systems (from 1.1 ± 0.1 to 2.2 ± 0.4 N). However, the differences between SL and conventional bracket systems were minor and not consistent (labial brackets: 1.2 ± 0.1 N for the GAC Twin and 1.1 ± 0.1 to 1.6 ± 0.1 N for the SL brackets with 0.013-in thermalloy; lingual brackets: 2.5 ± 0.2 to 3.5 ± 0.1 N for the conventional and 2.7 ± 0.3 to 3.4 ± 0.1 N for the SL brackets with 0.013-in Thermalloy). This is an in vitro study with different slot sizes in the labial and lingual bracket systems, results should be interpreted with caution. Lingual bracket systems showed higher forces compared to labial bracket systems that might be of clinical concern. We recommend highly flexible nickel titanium arch wires lower than 0.013-in for the initial levelling and alignment especially with lingual appliances. © The Author 2017. Published by Oxford University Press on behalf of the European

  10. How To Prepare Program Proposals for the American Psychological Association Annual Convention.

    Science.gov (United States)

    Tentoni, Stuart C.

    The purpose of this paper is to dispel myths about preparing program proposals for the American Psychological Association's annual convention. The report's goal is to increase the number of student presenters at future annual conventions. It has been determined that, for a variety of reasons, psychology graduate students participate more in poster…

  11. Microwave and conventional preparation of Zinc borate glass: Eu3+ ion as luminescent probe

    International Nuclear Information System (INIS)

    Mandal, Ashis K.; Balaji, S.; Sen, Ranjan

    2014-01-01

    Highlights: • IR transparent Zinc borate glass is prepared using microwave heating. • Glass transition temperature of microwave melted glass is found higher than that of glass prepared in conventional melting. • Low OH concentration in glass can be prepared in microwave heating. • We report higher reduction of Eu 3+ to Eu 2+ in microwave processing of Zinc borate glass. - Abstract: Transparent Zinc borate glass is melted using microwave energy as an alternative heating route to conventional resistive heating. A comparative study of the properties of the glasses prepared by both the methods is conducted by adopting X-ray diffraction (XRD), Differential scanning calorimetry (DSC), UV–VIS–NIR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Refractive Indices (RI). Amorphous nature of samples is confirmed by X-ray diffraction study. Glass transition temperature (T g ) of microwave melted glass is found ∼7–9 °C higher than that of glass prepared in conventional melting. OH content is found less than 250 ppm in microwave melted glass whereas it is above 330 ppm in conventional melted glasses. Photoluminescence study of Eu 2 O 3 doped glass prepared in microwave heating indicates higher reduction of Eu 3+ → Eu 2+ than the glass melted in conventional route. Thus, microwave processing can be an alternative energy efficient, time saving, environmental friendly glass preparation method

  12. Evaluation of the efficacy of rotary vs. hand files in root canal preparation of primary teeth in vitro using CBCT.

    Science.gov (United States)

    Musale, P K; Mujawar, S A V

    2014-04-01

    This in vitro study aimed to evaluate the efficacy of rotary ProFile, ProTaper, Hero Shaper and K-files in shaping ability, cleaning efficacy, preparation time and instrument distortion in primary molars. Sixty extracted primary mandibular second molars were divided into four equal groups: Group I K-file, Group II ProFile, Group III ProTaper file and Group IV Hero Shaper file. The shaping ability was determined by comparing pre- and post-instrumentation CBCT scans and data analysed with SPSS program using the Chi-square test. Cleaning efficacy was evaluated by the degree of India ink removal from the canal walls under stereomicroscopy. Instrumentation times were calculated for each tooth and instrument distortion was visually checked and duly noted. The cleaning efficacy and instrumentation time were determined using ANOVA with Tukey's correction. Instrument distortion was analysed using Chi-square test. The canal taper was significantly more conical for rotary files as compared to K-files with Chi-square test (p < 0.05). Cleaning efficacy of rotary files with average scores (Groups II- 0.68, III- 0.48 and IV- 0.58) was significantly better than K-files (Group I- 0.93) (p < 0.05). Mean instrumentation time with K-file (20.7 min) was significantly higher than rotary files (Groups II 8.9, III 5.6, and IV 8.1 min) (p < 0.05). Instrument distortion was observed in Group I (4.3%), while none of the rotary files were distorted. Rotary files prepared more conical canals in primary teeth than manual instruments. Reduced preparation time with rotary files enhances patient cooperation especially in young children.

  13. 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...

  14. Survival of self-etch adhesive Class II composite restorations using ART and conventional cavity preparations in primary molars.

    NARCIS (Netherlands)

    Eden, E.; Topaloglu-Ak, A.; Frencken, J.E.F.M.; Hof, M.A. van 't

    2006-01-01

    PURPOSE: To test the null-hypothesis that there was no difference in the survival percentages of Class II composite restorations in primary teeth produced through either ART or conventional approaches after 2 years. METHODS: 157 children with 325 Class II cavitated dentin lesions were included in a

  15. Preparation and evaluation of tolmetin sodium conventional and sustained-release suppositories

    OpenAIRE

    B., Baloǧlu; O., Kirkaǧaçhoǧlu

    2002-01-01

    Conventional suppositories of tolmetin sodium were prepared by using two different types of Witepsol as an oily base and two different ratios of polyethylene glycol 400: polyethylene glycol 4000 as an water-soluble base. In addition, sustained- release suppositories were prepared by adding Eudragit L-100 ta the suppositories. The effects of the suppository base and the ratios of the polyethylene glycol 400: polyethylene glycols 4000 on the in vitro release characteristics were investigated. T...

  16. Novel HPLC Analysis of Hydrocortisone in Conventional and Controlled-Release Pharmaceutical Preparations

    OpenAIRE

    Adi-Dako, Ofosua; Oppong Bekoe, Samuel; Ofori-Kwakye, Kwabena; Appiah, Enoch; Peprah, Paul

    2017-01-01

    An isocratic sensitive and precise reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the determination and quantification of hydrocortisone in controlled-release and conventional (tablets and injections) pharmaceutical preparations. Chromatographic separation was achieved on an ODS (C18), 5??m, 4.6 ? 150?mm, with an isocratic elution using a freshly prepared mobile phase of composition methanol?:?water?:?acetic acid (60?:?30?:?10, v/v/v) at ...

  17. Analysis of mechanical preparations in extracted teeth using ProTaper rotary instruments: value of the safety quotient.

    Science.gov (United States)

    Blum, J Y; Machtou, P; Ruddle, C; Micallef, J P

    2003-09-01

    The purpose of this study was to apply the Endographe to analyze the vertical forces and torque developed during mechanical preparations in extracted teeth. The data collected in this study may be used to calculate the safety quotient (SQ) as proposed by J.T. McSpadden. The SQ formula is defined as the torque required to break a file at D3 divided by the mean working torque required to cut dentin. The Endographe is a unique force-analyzer device equipped to measure, record, and generate graphs of the vertical forces and torque exerted during root canal preparation. All preparations were performed by endodontists in roots with narrow, more restrictive canals, larger, more open canals, or in roots sectioned in two halves. All canals, including the sectioned canals, were prepared with ProTaper files in accordance with the manufacturer's guidelines for use. For narrow canals, the mean values of the generated vertical forces (g) and torque (g.cm) varied from 80 (+/- 20) g (SX) to 232 (+/- 60) g (F2) and from 80 (+/- 24) g x cm (F1) to 150 (+/- 45) g x cm (S2), respectively. For large canals, the mean values of the generated vertical forces (g) and torque (g x cm) varied from 80 (+/- 20) g (SX) to 340 (+/- 20) g (F1) and from 31 (+/- 9) g x cm (S2) to 96 (+/- 35) g x cm (SX), respectively. The SQ varied from 0.93 to 7.95 for narrow canals and from 1.58 to 14.50 for large canals. The SQ is intended to provide values that can be analyzed to predict whether a rotary file will have a tendency to break or will work safely during clinical use. However, if the formula is going to provide useful information, it must index the "rotation to failure torque" with the "mean working torque" at a specific location along the cutting blades of a file. Additionally, this mathematical formula does not account for factors such as the concentration of forces, the way the instruments are used, or the wear of the instruments. A precise protocol for canal preparation should emphasize using

  18. Technical quality of root canal treatment of posterior teeth after rotary or hand preparation by fifth year undergraduate students, The University of Jordan.

    Science.gov (United States)

    Abu-Tahun, Ibrahim; Al-Rabab'ah, Mohammad A; Hammad, Mohammad; Khraisat, Ameen

    2014-12-01

    The aim of this study was to investigate the technical quality of root canal treatment provided by the undergraduate students as their first experience in molar endodontics using nickel-titanium (NiTi) files in a crown-down approach compared with stainless steel standard technique. This study was carried out by the fifth year undergraduate students attending peer review sessions as a part of their training programme, using two different questionnaires to assess the overall technical quality and potential problems regarding endodontic complications after root canal preparation with these two techniques. The overall results indicated a statistically significant difference in the performance of the two instrument techniques in difficult cases showing better performance of the NiTi system and mean rotary preparation time (P ProTaper rotary files, were able to prepare root canals faster with more preparation accuracy compared with canals of same teeth prepared with hand instruments. © 2014 Australian Society of Endodontology.

  19. 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.

  20. Clinical comparative study between the use of lasers and conventional methods of diagnosis and treatment in deciduous teeth with presence of carious lesion; Estudo clinico comparativo entre o uso de lasers e metodos convencionais de diagnostico e tratamento em dentes deciduos da presenca de lesao cariosa

    Energy Technology Data Exchange (ETDEWEB)

    Pulga, Fabiane Galvao

    2001-07-01

    The aim of this work was to evaluate the efficiency of deciduous tooth cavity preparation by the Er:YAG laser in comparison with the conventional burr rotary instrument. Besides, we have used the laser fluorescence technique (DIAGNOdent equipment) for diagnosis and compared it to the usual tactile and visual examination as well as X-ray diagnosis. For this purpose, 20 chronic occlusal carious deciduous molar teeth from children with the ages between 5 to 10 years old were selected. Selection was ma de according to visual inspection, X-ray periapical image and measures of the DIAGNOdent. For treatment the teeth were divided in two groups, 10 to be treated by the Er:YAG laser and 10 with conventional burr. For enamel, the laser energy used was in the interval from 200 to 300 mJ; for the dentine the range was from 100 mJ to 200 mJ. In both cases, the laser frequency was in the range from 2 to 4 Hz. The results have shown that the laser treatment was more accepted by the children than the conventional burro Clinical evaluation of the cavity preparation indicates that the Er:YAG laser treatment is recommend. The DIAGNOdent evaluation method was very effective for diagnosis of carious tissue for initial detection. After successful removal of the carious tissue, confirmed by visual inspection, the DIAGNOdent evaluation method was only effective for the treatment with conventional burro For evaluation of the tooth after cavity preparation with the Er:YAG laser, the measurements oscillate covering the full range of the equipment. Therefore, the use of the DIAGNOdent equipment is indicated only for initial caries diagnosis. (author)

  1. Intestinal preparation for colon enema with fosfo-soda fleet versus the conventional method

    International Nuclear Information System (INIS)

    Vecchioli Caldazza, A.; Celi, G.; De Franco, A.; Parrella, A.; Minordi, L.M.; Marano, P.

    1999-01-01

    The authors evaluate the possible optimization of a well-tolerated and versatile method of intestinal preparation able to adequately free the lumen and consequently improve diagnostic results with a lower risk of prolonged hospital stay for incorrectly prepared patients. They examined 40 patients, namely 20 men and 20 women referred to the Institute of radiology of the 'Sacro Cuore' Catholic University of Rome (Italy), Gastrointestinal tract unit, to undergo double contrast colonic enema. The statistical analysis of all data was performed with Wilcoxon test. Intestinal preparation with fosfo-soda fleet appeared to be definitely better than the conventional method relative to tolerance, while providing similarly satisfactory data relative to the other parameters [it

  2. Evaluation of apically extruded debris during root canal preparation in primary molar teeth using three different rotary systems and hand files.

    Science.gov (United States)

    Topçuoğlu, Gamze; Topçuoğlu, Hüseyin Sinan; Akpek, Firdevs

    2016-09-01

    To assess the amount of debris extruded apically during root canal preparation using various nickel titanium instrumentation systems and hand files in primary molar teeth. Sixty extracted primary first mandibular molar human teeth were randomly assigned to four groups (n = 15 teeth for each group). The canals were then instrumented with the following instrument systems: Revo-S, Mtwo, ProTaper Next, and hand files. Apically extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data were analyzed using one-way analysis of variance (anova) and Tukey's post hoc tests. ProTaper Next files were associated with less apically extruded debris than the Mtwo, Revo-S, and hand files (P Hand files extruded more debris than Mtwo and Revo-S instruments (P 0.05). All instruments were associated with apical extrusion of debris. ProTaper Next files caused less debris extrusion compared to the other systems used. © 2015 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. DIRECT USAGE OF MINISCREW ANCHORAGE TO INTRUDE OVERERUPTED MAXILLARY POSTERIOR TEETH BEFORE PROSTHODONTIC PREPARATION:A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Yasemin Bahar Acar

    2016-01-01

    Full Text Available Overeruption of maxillary molars due loss of opposing teeth creates occlusal and functional interferences. Before reconstruction can be initiated, intrusion of overerupted molars becomes essential. This report illustrates treatment of overerupted maxillary premolar and molar via direct use of miniscrew anchorage. A 24-year old female had lost first and second left mandibular molars due to pulpal necrotizing agents, resulting with a large alveolar bone defect and overerupted maxillary premolar and molar. She had a history of unsuccessful alveolar distraction of mandibular left premolars to increase the alveolar bone height prior to implant placement. Patient was satisfied with her smile and refused comprehensive orthodontic treatment. Maxillary premolar and molar were intruded segmentally for 4mm in 8 months, using a combination of a mini-implant and partialfixed edgewise appliances. Biological responses of teeth and surrounding bony structures to intrusion appeared normal and acceptable in radiographic and clinical examination.

  4. Novel HPLC Analysis of Hydrocortisone in Conventional and Controlled-Release Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ofosua Adi-Dako

    2017-01-01

    Full Text Available An isocratic sensitive and precise reverse phase high-performance liquid chromatography (RP-HPLC method was developed and validated for the determination and quantification of hydrocortisone in controlled-release and conventional (tablets and injections pharmaceutical preparations. Chromatographic separation was achieved on an ODS (C18, 5 μm, 4.6 × 150 mm, with an isocratic elution using a freshly prepared mobile phase of composition methanol : water : acetic acid (60 : 30 : 10, v/v/v at a flow rate of 1.0 ml/min. The detection of the drug was successfully achieved at a wavelength of 254 nm. The retention time obtained for the drug was 2.26 min. The proposed method produced linear detectable responses in the concentration range of 0.02 to 0.4 mg/ml of hydrocortisone. High recoveries of 98–101% were attained at concentration levels of 80%, 100%, and 120%. The intraday and interday precision (RSD were 0.19–0.55% and 0.33–0.71%, respectively. A comparison of hydrocortisone analyses data from the developed method and the official USP method showed no significant difference (p>0.05 at a 95% confidence interval. The method was successfully applied to the determination and quantification of hydrocortisone in six controlled-release and fifteen conventional release pharmaceutical preparations.

  5. Observation particle morphology of colloidal system by conventional SEM with an improved specimen preparation technique.

    Science.gov (United States)

    Xu, Jing; Hou, Zhaosheng; Yuan, Xiaojiao; Guo, Hong

    2011-08-01

    On the basis of our previous report that polymer emulsion with different viscosity can be investigated by conventional scanning electron microscopy (SEM), we have developed an improved specimen preparation technique for obtaining particle morphology and size of colloidal silver, collagen, glutin, and polymer microspheres. In this study, we expect to provide a means for charactering the three-dimensional surface microstructure of colloidal particles. Dilution of the samples with appropriate volatile solvent like ethanol is effective for SEM specimen preparation. At a proper ratio between sample and ethanol, the colloidal particles are dispersed uniformly in ethanol and then deposited evenly on the substrate. Different drying methods are studied to search a proper drying condition, in which the small molecule solvent is removed without destroying the natural particle morphology. And the effects of ethanol in the specimen preparation process are described by analyzing the physicochemical properties of ethanol. The specimen preparation technique is simple and can be achieved in common laboratory for charactering the particle morphology of colloidal system. Copyright © 2010 Wiley-Liss, Inc.

  6. Comparison of Shear Bond Strength of Orthodontic Brackets Bonded to Enamel Prepared By Er:YAG Laser and Conventional Acid-Etching

    Science.gov (United States)

    Hosseini, M.H.; Namvar, F.; Chalipa, J.; Saber, K.; Chiniforush, N.; Sarmadi, S.; Mirhashemi, A.H.

    2012-01-01

    Introduction: The purpose of this study was to compare shear bond strength (SBS) of orthodontic brackets bonded to enamel prepared by Er:YAG laser with two different powers and conventional acid-etching. Materials and Methods: Forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group 1- conventional etching with 37% phosphoric acid; Group 2- irradiation with Er:YAG laser at 1 W; and Group 3- irradiation with Er:YAG laser at 1.5 W. Metal brackets were bonded on prepared enamel using a light-cured composite. All groups were subjected to thermocycling process. Then, the specimens mounted in auto-cure acryle and shear bond strength were measured using a universal testing machine with a crosshead speed of 0.5 mm per second. After debonding, the amount of resin remaining on the teeth was determined using the adhesive remnant index (ARI) scored 1 to 5. One-way analysis of variance was used to compare shear bond strengths and the Kruskal-Wallis test was performed to evaluate differences in the ARI for different etching types. Results: The mean and standard deviation of conventional acid-etch group, 1W laser group and 1.5W laser group was 3.82 ± 1.16, 6.97 ± 3.64 and 6.93 ± 4.87, respectively. Conclusion: The mean SBS obtained with an Er:YAG laser operated at 1W or 1.5W is approximately similar to that of conventional etching. However, the high variability of values in bond strength of irradiated enamel should be considered to find the appropriate parameters for applying Er:YAG laser as a favorable alternative for surface conditioning. PMID:22924098

  7. Comparison of Shear Bond Strength of Orthodontic Brackets Bonded to Enamel Prepared By Er:YAG Laser and Conven-tional Acid-Etching

    Directory of Open Access Journals (Sweden)

    M.H. Hosseini

    2012-01-01

    Full Text Available Introduction: The purpose of this study was to compare shear bond strength (SBS of orthodontic brackets bonded to enamel prepared by Er:YAG laser with two different powers and conventional acid-etching.Materials and Methods: Forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: Group 1- conventional etching with 37% phosphoric acid; Group 2- irradiation with Er:YAG laser at 1 W; and Group 3- irradiation with Er:YAG laser at 1.5 W. Metal brackets were bonded on prepared enamel using a light-cured composite. All groups were subjected to thermocycling process. Then, the specimens mounted in auto-cure acryle and shear bond strength were measured using a universal testing machine with a crosshead speed of 0.5 mm per second. After debonding, the amount of resin remaining on the teeth was determined using the adhesive remnant index (ARI scored 1 to 5. One-way analysis of variance was used to compare shear bond strengths and the Kruskal-Wallis test was performed to evaluate differences in the ARI for different etching types.Results: The mean and standard deviation of conventional acid-etch group, 1W laser group and 1.5W laser group was 3.82 ± 1.16, 6.97 ± 3.64 and 6.93 ± 4.87, respectively.Conclusion: The mean SBS obtained with an Er:YAG laser operated at 1W or 1.5W is approximately similar to that of conventional etching. However, the high variability of values in bond strength of irradiated enamel should be considered to find the appropriate parameters for applying Er:YAG laser as a favorable alternative for surface conditioning.

  8. Conventional drilling versus piezosurgery for implant site preparation: a meta-analysis.

    Science.gov (United States)

    Sendyk, Daniel Isaac; Oliveira, Natacha Kalline; Pannuti, Claudio Mendes; Naclério-Homem, Maria da Graça; Wennerberg, Ann; Zindel Deboni, Maria Cristina

    2018-03-27

    The aim of this study was to evaluate the evidence of a correlation between the stability of dental implants placed by piezosurgery, compared with implants placed by conventional drilling. An electronic search in MEDLINE, SCOPUS and the Cochrane Library was undertaken until August 2016 and was supplemented by manual searches and by unpublished studies at OpenGray. Only randomized controlled clinical trials that reported implant site preparation with piezosurgery and with conventional drilling were considered eligible for inclusion in this review. Meta-analyses were performed to evaluate the impact of piezosurgery on implant stability. Of 456 references electronically retrieved, 3 were included in the qualitative analysis and quantitative synthesis. The pooled estimates suggest that there is no significant difference between piezosurgery and conventional drilling at baseline (WMD: 2.20; 95% CI: -5.09, 9,49; p = 0.55). At 90 days, the pooled estimates revealed a statistically significant difference (WMD: 3.63; 95% CI: 0.58, 6.67, p = 0.02) favouring piezosurgery. Implant stability is slightly improved when osteotomy was performed by a piezoelectric device. More randomized controlled clinical trials are needed to verify these findings.

  9. Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial

    OpenAIRE

    Priya Mittal; Ajay Logani; Naseem Shah; R M Pandey

    2016-01-01

    Aim: This study aims to compare the periapical healing of teeth with asymptomatic apical periodontitis treated either by conventional apical preparation (CAP) or apical clearing technique (ACT). Materials and Methods: T wenty subjects with bilateral nonvital similar teeth exhibiting comparable periapical index (PAI) score were enrolled and randomly allocated. Group I (CAP, n = 20): Apical preparation three sizes greater (master apical file [MAF]) than the first binding file at the establis...

  10. 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 ...

  11. Thermal analysis of different application techniques on Nd:YAG laser after root canal preparation of single-rooted teeth

    International Nuclear Information System (INIS)

    Archilla, Jose Ricardo de F.

    2001-01-01

    The experiment objective is to analyze temperature variation, by means of three different application techniques of Nd:YAG laser in the root canals of singlerooted anterior teeth. Three root canals were instrumented, irrigated, X-rayed to measure the remaining dentin in the apical area and submitted to laser irradiation techniques used by Gutknecht, Matsumoto and a new technique with oscillatory movement. The used laser parameters were: pulse energy 250 mJ, frequency 5 Hz, pulse fluency 354 J/cm 2 , average potency 1,25 W, pulse width 300 μs, fiber core diameter 300 μs and interval of thermal relaxation of 20 s. After temperature evaluation and interpretation of the obtained data, it was concluded: 1) the oscillatory technique provided a better heat distribution during the laser application, when analyzing the graphs separately; 2) all the used techniques are within a pattern of safety, analyzing the average and highest temperatures of the apical area and the middle third, even so, disrespecting the last application day and the middle third of root 'C'.(author)

  12. Effect of Post Space Preparation on Apical Obturation Quality of Teeth Obturated with Different Techniques: A Micro-computed Tomographic Study.

    Science.gov (United States)

    Küçükkaya Eren, Selen; Askerbeyli Örs, Sevinc; Yılmaz, Zeliha

    2017-07-01

    The purpose of this study was to evaluate the obturation quality of root canals filled with different techniques and to determine whether post space preparation had an effect on the quality of apical obturation using micro-computed tomographic (micro-CT) imaging. The root canals of 30 human mandibular premolar teeth were instrumented, and the specimens were divided into 3 groups according to the obturation technique used: cold lateral compaction (CLC), warm vertical compaction (WVC), or single-cone (SC) techniques. The specimens were stored at 37°C and 100% humidity for 1 week. Then, the coronal root filling material was removed in order to create a post space. Micro-CT scans were performed before and after post space preparation for the volumetric analysis of voids and filling materials. Data were analyzed using repeated-measures analysis of variance and Bonferroni tests. The CLC and SC groups showed a significantly greater percentage volume of voids than the WVC group (P space preparation (P > .05). The post space preparation caused a significant increase in the percentage volume of voids in the CLC and SC groups (P space preparation (P > .05). No root fillings were void free. The WVC group presented the best obturation quality. The post space preparation negatively influenced the apical integrity of the filling materials in the CLC and SC groups, whereas it had no significant effect in the WVC group. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Nuclear characteristics of the endometrial cytology: liquid-based versus conventional preparation.

    Science.gov (United States)

    Norimatsu, Yoshiaki; Shigematsu, Yumie; Sakamoto, Shingo; Ohsaki, Hiroyuki; Yanoh, Kenji; Kawanishi, Namiki; Kobayashi, Tadao K

    2013-02-01

    The aim of this study was to assess the utility of liquid-based cytologic preparation (LP) compared with conventional preparation (CP) for the assessment of nuclear findings in endometrial glandular and stromal breakdown (EGBD) which may be misdiagnosed as carcinoma in EGBD cases. The material consists of cytologic smears including 20 cases of proliferative endometrium (PE), 20 cases of EGBD, and 20 cases of endometrioid adenocarcinoma grade1 (G1) for which histopathological diagnosis was obtained by endometrial curettage at the JA Suzuka General Hospital. Nuclear findings were examined in PE cells, EGBD-stromal cells, EGBD-metaplastic cells, and G1 cells, respectively. It was examined about the following items; (1) nuclear shape; (2) A long/minor axis ratio in cell nuclei; (3) an area of cell nuclei; (4) overlapping nuclei. Results are as follows: (1) nuclear shape; as for the reniform shape of EGBD-stromal cells and spindle shape of EGBD-metaplastic cells, the ratio of the LP method was a higher value than the CP method. (2) The long axis and area of cell nuclei; LP in all groups was a recognizable tendency for nuclear shrinkage. (3) The long/minor axis ratio in cell nuclei; only EGBD-metaplastic cells recognize a significant difference between CP and LP. (4) Overlapping nuclei; LP was a higher value in comparison with CP in the other groups except PE cells, and the degree of overlapping nuclei was enhanced about three times. Therefore, although a cell of LP has a shrinking tendency, (1) it is excellent that LP preserves a characteristic of nuclear shape than CP; (2) a cellular characteristic becomes clearer, because three-dimensional architecture of LP is preserved of than CP. As for the standard preparation method for endometrial cytology samples, we considered that a concrete introduction of the LP method poses no problems. Copyright © 2011 Wiley Periodicals, Inc.

  14. 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

  15. 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.

  16. Satisfaction of undergraduate students at University of Jordan after root canal treatment of posterior teeth using rotary or hand preparation.

    Science.gov (United States)

    Abu-Tahun, Ibrahim; El-Ma'aita, Ahmad; Khraisat, Ameen

    2016-08-01

    The aim of this study was to report the satisfaction of fifth year undergraduate students on the clinical use of rotary endodontic preparation compared with stainless steel standard technique and to evaluate the impact of rotary nickel-titanium instruments on undergraduate teaching. This study was carried out by the fifth year undergraduate students attending peer review sessions as a part of their training program using a questionnaire to assess their satisfaction with these two techniques. The overall results indicated a statistically significant satisfaction of the undergraduate students with the use of the nickel-titanium system (P ProTaper rotary files and the need for undergraduate teaching of rotary nickel-titanium systems in Jordan. © 2015 Australian Society of Endodontology Inc.

  17. Wound healing of osteotomy defects prepared with piezo or conventional surgical instruments: a pilot study in rabbits.

    Science.gov (United States)

    Ma, Li; Mattheos, Nikos; Sun, Yan; Liu, Xi Ling; Yip Chui, Ying; Lang, Niklaus Peter

    2015-08-01

    The aim of the present study was to evaluate and compare the wound-healing process following osteotomies performed with either conventional rotary burs or piezoelectric surgery in a rabbit model. Two types of osteotomy window defects of the nasal cavities were prepared on the nasal bone of 16 adult New Zealand white rabbits with either a conventional rotary bur or piezo surgery. The defects were covered with a resorbable membrane. Four animals were killed at 1, 2, 3, and 5 weeks after the surgical procedure, respectively. Histological and morphometric evaluations were performed to assess the volumetric density of various tissue components: the blood clot, vascularized structures, provisional matrix, osteoid, mineralized bone, bone debris, residual tissue, and old bone. Significantly more bone debris was found at 1 week in the conventionally-prepared defects compared to the piezo surgically-prepared defects. At 2 and 3 weeks, a newly-formed hard tissue bridge, mainly composed of woven bone, was seen; however, no statistically-significant differences were observed. At 5 weeks, the defects were completely filled with newly-formed bone. The defects prepared by piezo surgery showed a significantly decreased proportion of bone debris at 1 week, compared to conventional rotary bur defect. © 2014 Wiley Publishing Asia Pty Ltd.

  18. VOLATILE CONSTITUENTS OF GINGER OIL PREPARED ACCORDING TO IRANIAN TRADITIONAL MEDICINE AND CONVENTIONAL METHOD: A COMPARATIVE STUDY.

    Science.gov (United States)

    Shirooye, Pantea; Mokaberinejad, Roshanak; Ara, Leila; Hamzeloo-Moghadam, Maryam

    2016-01-01

    Herbal medicines formulated as oils were believed to possess more powerful effects than their original plants in Iranian Traditional Medicine (ITM). One of the popular oils suggested for treatment of various indications was ginger oil. In the present study, to suggest a more convenient method of oil preparation (compared to the traditional method), ginger oil has been prepared according to both the traditional and conventional maceration methods and the volatile oil constituents have been compared. Ginger oil was obtained in sesame oil according to both the traditional way and the conventional (maceration) methods. The volatile oil of dried ginger and both oils were obtained by hydro-distillation and analyzed by gas chromatography/mass spectroscopy. Fifty five, fifty nine and fifty one components consisting 94 %, 94 % and 98 % of the total compounds were identified in the volatile oil of ginger, traditional and conventional oils, respectively. The most dominant compounds of the traditional and conventional oils were almost similar; however they were different from ginger essential oil which has also been to possess limited amounts of anti-inflammatory components. It was concluded that ginger oil could be prepared through maceration method and used for indications mentioned in ITM.

  19. 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 ...

  20. Comparison of liquid-based preparation and conventional smear of fine-needle aspiration cytology of lymph node

    Directory of Open Access Journals (Sweden)

    Priya Singh

    2016-01-01

    Conclusions: Liquid-based cytology (LBC is a relatively simple technique, which exhibits good nuclear and cytoplasmic details with the absence of obscuring background material. Even the number of slides and area per slide to be screened were less than the conventional preparation but caution must be applied to interpret the slides and secure a diagnosis, especially if LBC is the first and only method applied for diagnosis.

  1. Microstructural examination by TEM of WC/Co composites prepared by conventional and Microwave processes

    International Nuclear Information System (INIS)

    Agrawal, D.; Cheng, J.; Papworth, A.J.; Jain, H.; Williams, D.B.

    2001-01-01

    Recently, significant developments and advances have taken place in the field of microwave processing of ceramics, composites and metals. Microwave sintering technology of WC/Co based hard metal parts has been now developed for commercial products. Microwave processed WC/Co parts reportedly have exhibited superior performance over standard parts. Additionally, the microwave process requires only one tenth of the total cycle time employed in a conventional process. Laboratory corrosion and impact resistance tests have proved that microwave processed WC/Co parts are several times more resistant than the conventional parts of the same composition. The scanning transmission electron microscopic (STEM) examination conducted an conventionally and microwave sintered WC/Co samples exhibited remarkable difference in the chemistry of cobalt binder phase. It is understood that the superior mechanical properties of microwave sintered part are due to the pure cobalt phase present at the grain boundary of WC grains, while the conventionally sintered part showed there was substantial inter-alloying of Co with tungsten. (author)

  2. Comparative study of 6 rotary nickel-titanium systems and hand instrumentation for root canal preparation in severely curved root canals of extracted teeth.

    Science.gov (United States)

    Celik, Davut; Taşdemir, Tamer; Er, Kürşat

    2013-02-01

    Some improvements have been developed with new generations of nickel-titanium (NiTi) rotary instruments that led to their successful and extensive application in clinical practice. The purpose of this in vitro study was to compare the root canal preparations performed by using GT Series X and Twisted File systems produced by innovative manufacturing process with Revo-S, RaCe, Mtwo, and ProTaper Universal systems manufactured directly from conventional nitinol and with stainless steel K-Flexofile instruments. The mesiobuccal root canals of 140 maxillary first permanent molars that had between 30°-40° curvature angle and 4- to 9-mm curvature radius of the root canal were used. After root canal preparations made by using GT Series X, Twisted File, Revo-S, RaCe, Mtwo, and ProTaper Universal NiTi rotary systems and stainless steel K-Flexofile instruments, transportation occurred in the root canal, and alteration of working length (WL) was assessed by using a modified double-digital radiographic technique. The data were compared by the post hoc Tukey honestly significant difference test. NiTi rotary systems caused less canal transportation and alteration of WL than K-Flexofile instruments (P .05) except 2.5 mm from the WL. At this level ProTaper Universal system caused significant canal transportation (P ProTaper Universal rotary systems manufactured by traditional methods. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. 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

  4. 脉冲 Er:YAG 激光与常规涡轮高速车针治疗楔状缺损的效果比较%The Effect Comparasion between the Pulse Er:YAG Laser and the Conventional Turbine High-speed Dental Bur to the Remedy of Teeth Wedge-shaped Defect

    Institute of Scientific and Technical Information of China (English)

    范伟; 贺慧霞

    2015-01-01

    目的:比较Er:YAG激光与常规涡轮机高速车针治疗楔状缺损的效果。方法收集我院口腔科就诊的、双侧多个同名牙楔状缺损患者85例382颗牙,随机分为激光组和涡轮机组各191牙,其中每位患者每侧至少2颗牙采用激光表面预备,对侧高速涡轮机预备,脉冲照射采用激光剂量为300 mJ,20 Hz间歇操作。涡轮机组采用高速车针制备固位型,自体对照,两组均预备后光固化树脂黏充填。比较两组治疗后1周、1个月、6个月、12个月术后充填物保存率、边缘着色、继发龋等指标,评价其临床治疗效果。结果两组术中疼痛牙齿发生率激光组(16.7%)显著少于涡轮机组(74.8%),差异有统计学意义(P<0.05);术后1周、1个月激光组分别有35牙和12牙出现冷热刺激痛,而涡轮机组发生刺激痛分别为83牙和44牙,两者差异有统计学意义( P<0.05);术后6个月和12个月修复体保存率激光组显著高于涡轮机组,差异有统计学意义( P<0.05);但边缘适合性、边缘着色和继发龋发生率两组差异无统计学意义。结论激光组较涡轮机组在楔状缺损治疗中疼痛发生率低、治疗后疼痛反应轻;修复体保存率高。300 mJ,20 Hz的Er:YAG激光治疗楔状缺损具有无痛、安全、高效的优点。%Objective To compare the effects of Er: YAG laser and conventional high-speed burr in treatment of wedge-shaped tooth defects and to evaluate its applicability and reliability .Methods 382 bilateral multiple teeth with wedge-shaped defects in 85 patients were randomly divided into two groups with 191 teeth in each:laser group and the turbine burr group .At least two teeth of one side in all patients were irradiated by pulsed Er:YAG laser with doses of 300 mj, 20 Hz.Meanwhile, the caries cavities on the contralateral were prepared by high-speed burr .Then the prepared caries defects in both

  5. Comparison of the redox activities of sol-gel and conventionally prepared Bi-Mo-Ti mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Wildberger, M.; Grundwaldt, J.D.; Mallat, T.; Baiker, A. [Lab. of Technical Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, Zuerich (Switzerland)

    1998-12-31

    Novel sol-gel Bi-Mo-Ti oxides have been prepared and characterized by XRD, XPS, FT-Raman and HRTEM. The surface Bi{sup 3+} and Mo{sup 6+} species of some xerogels and an aerogel could be reduced and oxidized at room temperature, whereas the conventionally prepared reference materials were not reduced by H{sub 2} below 300 C. The unusual redox properties, under very mild conditions, are likely due to the unique morphology of Bi-Mo-oxides stabilized by titania. During butadiene oxidation to furan at above 400 C to sol-gel mixed oxides restructured considerably and their performance was barely better than that of titania-supported Bi-Mo oxides. (orig.)

  6. Preparation of severely curved simulated root canals using engine-driven rotary and conventional hand instruments.

    Science.gov (United States)

    Szep, S; Gerhardt, T; Leitzbach, C; Lüder, W; Heidemann, D

    2001-03-01

    This in vitro study evaluated the efficacy and safety of six different nickel-titanium engine-driven instruments used with a torque-controlled engine device and nickel-titanium hand and stainless steel hand instruments in preparation of curved canals. A total of 80 curved (36 degrees) simulated root canals were prepared. Images before and after were superimposed, and instrumentation areas were observed. Time of instrumentation, instrument failure, change in working length and weight loss were also recorded. Results show that stainless steel hand instruments cause significantly less transportation towards the inner wall of the canal than do nickel-titanium hand instruments. No instrument fracture occurred with hand instruments, but 30-60% breakage of instruments was recorded during instrumentation with the engine-driven devices. The working length was maintained by all types of instruments. Newly developed nickel-titanium rotary files were not able to prevent straightening of the severely curved canals when a torque-controlled engine-driven device was used.

  7. Microfluidic preparation of [18F]FE-SUPPY and [18F]FE-SUPPY:2 - comparison with conventional radiosyntheses

    International Nuclear Information System (INIS)

    Ungersboeck, Johanna; Philippe, Cecile; Mien, Leonhard-Key; Haeusler, Daniela; Shanab, Karem; Lanzenberger, Rupert; Spreitzer, Helmut; Keppler, Bernhard K.; Dudczak, Robert; Kletter, Kurt; Mitterhauser, Markus; Wadsak, Wolfgang

    2011-01-01

    Introduction: Recently, first applications of microfluidic principles for radiosyntheses of positron emission tomography compounds were presented, but direct comparisons with conventional methods were still missing. Therefore, our aims were (1) the set-up of a microfluidic procedure for the preparation of the recently developed adenosine A 3 -receptor tracers [ 18 F]FE-SUPPY [5-(2-[ 18 F]fluoroethyl)2,4-diethyl-3-(ethylsulfanylcarbonyl) -6-phenylpyridine-5-carboxylate] and [ 18 F]FE-SUPPY:2 [5-ethyl-2,4-diethyl-3-((2-[ 18 F]fluoroethyl)sulfanylcarbonyl) -6-phenylpyridine-5-carboxylate] and (2) the direct comparison of reaction conditions and radiochemical yields of the no-carrier-added nucleophilic substitution with [ 18 F]fluoride between microfluidic and conventional methods. Methods: For the determination of optimal reaction conditions within an Advion NanoTek synthesizer, 5-50 μl of precursor and dried [ 18 F]fluoride solution were simultaneously pushed through the temperature-controlled reactor (26 o C-180 o C) with defined reactant bolus flow rates (10-50 μl/min). Radiochemical incorporation yields (RCIYs) and overall radiochemical yields for large-scale preparations were compared with data from conventional batch-mode syntheses. Results: Optimal reaction parameters for the microfluidic set-up were determined as follows: 170 o C, 30-μl/min pump rate per reactant (reaction overall flow rate of 60 μl/min) and 5-mg/ml precursor concentration in the reaction mixture. Applying these optimized conditions, we observed a significant increase in RCIY from 88.2% to 94.1% (P 18 F]FE-SUPPY and that from 42.5% to 95.5% (P 18 F]FE-SUPPY:2 using microfluidic instead of conventional heating. Precursor consumption was decreased from 7.5 and 10 mg to 1 mg per large-scale synthesis for both title compounds, respectively. Conclusion: The direct comparison of radiosyntheses data applying a conventional method and a microfluidic approach revealed a significant increase of RCIY

  8. Comparison of porcelain bond strength of different metal frameworks prepared by using conventional and recently introduced fabrication methods.

    Science.gov (United States)

    Kaleli, Necati; Saraç, Duygu

    2017-07-01

    Most studies evaluating dental laser sintering systems have focused on the marginal accuracy of the restorations. However, the bond strength at the metal-ceramic interface is another important factor that affects the survival of restorations, and currently, few studies focus on this aspect. The purpose of this in vitro study was to compare the porcelain bond strength of cobalt-chromium (Co-Cr) metal frameworks prepared by using the conventional lost-wax technique, milling, direct metal laser sintering (DMLS), and laser cusing, a direct process powder-bed system. A total of 96 metal frameworks (n=24 in each group) were prepared by using conventional lost-wax (group C), milling (group M), DMLS (group LS), and direct process powder-bed (group LC) methods according to International Organization for Standardization standard ISO 9693-1. After porcelain application, a 3-point bend test was applied to each specimen by using a universal testing machine. Data were statistically analyzed using 1-way ANOVA and Tukey honest significant difference tests (α=.05). Failure types at the metal-ceramic interfaces were examined using stereomicroscopy. Additionally, 1 specimen from each group was prepared for scanning electron microscopy analysis to evaluate the surface topography of metal frameworks. The mean bond strength was 38.08 ±3.82 MPa for group C, 39.29 ±3.51 MPa for group M, 40.73 ±3.58 MPa for group LS, and 41.24 ±3.75 MPa for group LC. Statistically significant differences were observed among the 4 groups (P=.016). All groups, except for LS, exhibited adhesive and mixed type bond failure. Both of the laser sintering methods were found to be successful in terms of metal-ceramic bond strength. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Clinical analysis of the stability of dental implants after preparation of the site by conventional drilling or piezosurgery.

    Science.gov (United States)

    da Silva Neto, Ulisses Tavares; Joly, Julio Cesar; Gehrke, Sergio Alexandre

    2014-02-01

    We used resonance frequency analysis to evaluate the implant stability quotient (ISQ) of dental implants that were installed in sites prepared by either conventional drilling or piezoelectric tips. We studied 30 patients with bilateral edentulous areas in the maxillary premolar region who were randomised to have the implant inserted with conventional drilling, or with piezoelectric surgery. The stability of each implant was measured by resonance frequency analysis immediately after placement to assess the immediate stability (time 1) and again at 90 days (time 2) and 150 days (time 3). In the conventional group the mean (SD) ISQ for time 1 was 69.1 (6.1) (95% CI 52.4-77.3); for time 2, 70.7 (5.7) (95% CI 60.4-82.8); and for time 3, 71.7 (4.5) (95% CI 64.2-79.2). In the piezosurgery group the corresponding values were: 77.5 (4.6) (95% CI 71.1-84.3) for time 1, 77.0 (4.2) (95% CI, 69.7-85.2) for time 2, and 79.1 (3.1) (95% CI 74.5-87.3) for time 3. The results showed significant increases in the ISQ values for the piezosurgery group at each time point (p=0.04). The stability of implants placed using the piezoelectric method was greater than that of implants placed using the conventional technique. Copyright © 2013 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  10. 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.

  11. Targeted traction of impacted teeth with C-tube miniplates.

    Science.gov (United States)

    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.

  12. Evaluation of the effect of conventionally prepared swarna makshika bhasma on different bio-chemical parameters in experimental animals

    Directory of Open Access Journals (Sweden)

    Sudhaldev Mohapatra

    2011-01-01

    Full Text Available Swarna makshika (chalcopyrite bhasma (SMB has been used for different therapeutic purposes since long in Ayurveda. The present study is conducted to evaluate the effect of conventionally prepared SMB on different bio-chemical parameters in experimental animals, for providing scientific data base for its logical use in clinical practice. The genuine SMB was prepared by following classical techniques of shodhana and marana most commonly used by different Ayurvedic drug manufacturers. Shodhana was done by roasting raw swarna makshika with lemon juice for three days and marana was performed by 11 putas . The experimental animals (rats were divided into two groups. SMB mixed with diluted honey was administered orally in therapeutic dose to Group SMB and diluted honey only was administered to vehicle control Group, for 30 days. The blood samples were collected twice, after 15 days and after 30 days of drug administration and different biochemical investigations were done. Biochemical parameters were chosen based on references from Ayurvedic classics and contemporary medicine. It was observed that Hb% was found significantly increased and LDL and VLDL were found significantly decreased in Group SMB when compared with vehicle control group. This experimental data will help the clinician for the logical use of SMB in different disease conditions with findings like low Hb% and high LDL, VLDL levels.

  13. In vitro fracture resistance of molar teeth restored with a short fibre-reinforced composite material.

    Science.gov (United States)

    Fráter, Márk; Forster, András; Keresztúri, Márk; Braunitzer, Gábor; Nagy, Katalin

    2014-09-01

    The purpose of this in vitro study was to evaluate the efficiency of a short fibre-reinforced composite (SFRC) material compared to conventional composites when restoring class II. MOD cavities in molar teeth with different layering techniques. One hundred and thirty mandibular third molars were divided into 5 groups (n=26). Except for the control group (intact teeth), in all other groups MOD cavities were prepared. The cavities were restored by either conventional composite with horizontal and oblique layering or by SFRC with horizontal and oblique layering. The specimens were submitted to static fracture toughness test. Fracture thresholds and fracture patterns were evaluated. In general, no statistically significant difference was found in fracture toughness between the study groups, except for horizontally layered conventional composite restorations, which turned out to be significantly weaker than controls. However, SFRC yielded noticeably higher fracture thresholds and only obliquely applied SFRC restorations exhibited favourable fracture patterns above chance level. The application of SFRC did not lead to a statistically significant improvement of the fracture toughness of molar teeth with MOD cavities. Still, SFRC applied in oblique increments measurably reduces the chance of unrestorable fractures of molar teeth with class II MOD cavities. The restoration of severely weakened molar teeth with the use of SFRC combined with composite might have advantages over conventional composites alone. It was observed from the statistical data, that the application of SFRC with an oblique layering technique yielded not significantly but better fracture thresholds and more favourable fracture patterns than any other studied material/technique combination. Thus further investigations need to be carried out, to investigate the possible positive mechanical effects of SFRC. The application of the horizontal layering technique with conventional composite materials is inferior

  14. Effect of apical clearing technique on the treatment outcome of teeth with asymptomatic apical periodontitis: A randomized clinical trial.

    Science.gov (United States)

    Mittal, Priya; Logani, Ajay; Shah, Naseem; Pandey, R M

    2016-01-01

    This study aims to compare the periapical healing of teeth with asymptomatic apical periodontitis treated either by conventional apical preparation (CAP) or apical clearing technique (ACT). Twenty subjects with bilateral nonvital similar teeth exhibiting comparable periapical index (PAI) score were enrolled and randomly allocated. Group I (CAP, n = 20): Apical preparation three sizes greater (master apical file [MAF]) than the first binding file at the established working length. Group II (ACT, n = 20): Apical preparation three sizes greater than the MAF that was followed by dry reaming. Root canal therapy was accomplished in single-visit for all the teeth. They were pursued radiographically at 3, 6, 9 and 12 months. Pre- and post-treatment PAI scores were compared. To ascertain the proportion of healed teeth between the two groups, McNemar Chi-square test was applied. At 3, 6, and 9 months' time interval the proportion of healed teeth for Group II (ACT) was greater in comparison to Group I (CAP) (P < 0.05). However, at 12 months follow-up period this difference was not significant (P = 0.08). ACT enhanced the healing kinetics. However, the long-term (12 months) radiographic outcome was similar for either technique.

  15. [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.

  16. Comparative evaluation of endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe in obturation of primary teeth: An in vitro study

    OpenAIRE

    Hiremath, Mallayya C.; Srivastava, Pooja

    2016-01-01

    Purpose: The purpose of this in vitro study was to compare four methods of root canal obturation in primary teeth using conventional radiography. Materials and Methods: A total of 96 root canals of primary molars were prepared and obturated with zinc oxide eugenol. Obturation methods compared were endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe. The root canal obturations were evaluated by conventional radiography for the length of obturation and presenc...

  17. Syndromes with supernumerary teeth.

    Science.gov (United States)

    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.

  18. Malocclusion (Misaligned Teeth)

    Science.gov (United States)

    ... 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) ...

  19. 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

  20. Clinical Evaluation of Quality of Obturation and Instrumentation Time using Two Modified Rotary File Systems with Manual Instrumentation in Primary Teeth.

    Science.gov (United States)

    Govindaraju, Lavanya; Jeevanandan, Ganesh; Subramanian, Emg

    2017-09-01

    Pulp therapy in primary teeth has been performed using various instrumentation techniques. However, the conventional instrumentation technique used for root canal preparation in primary teeth is hand instrumentation. Various Nickel-Titanium (Ni-Ti) instruments are available to perform efficient root canal preparation in primary teeth. These Ni-Ti instruments has been designed to aid in better root canal preparation in permanent teeth but are rarely used in primary teeth. It is necessary to assess the feasibility of using these adult rotary files with a modified sequence in primary teeth. To compare the quality of obturation and instrumentation time during root canal preparation using hand files and modified rotary file systems in primary molars. Forty-five primary mandibular molars were randomly assigned to three experimental groups (n=15). Group I was instrumented using k-hand files, Group II with S2 ProTaper universal file and Group III with 0.25 tip 4% taper K3 rotary file. Standardized digital radiographs were taken before and after root canal instrumentation. Root canal preparation time was also recorded. Statistical analysis of the obtained data was done using SPSS Software version 17.0. An intergroup comparison of the instrumentation time and the quality of obturation was done using ANOVA and Chi-square test with the level of significance set at 0.05. No significant differences were noted with regard to the quality of obturation (p=0.791). However, a statistically significant difference was noted in the instrumentation time between the three groups (pProTaper rotary system had significantly lesser instrumentation time when compared to that of K3 rotary system and hand file system. The hand files, S2 ProTaper Universal and K3 0.25 tip 4% taper files systems performed similarly with respect to the quality of obturation. There was a significant difference in instrumentation time with manual instrumentation compared to the modified rotary file systems in primary

  1. A Comparative Evaluation of the Effect of Double Casting Technique Using Functionally Generated Path and Conventional Single Casting with Respect to Functional Articulation, Patient Satisfaction and Chair Side Time, in Single Unit Molar Teeth: An In Vivo Study.

    Science.gov (United States)

    Memon, Sarfaraz

    2014-12-01

    A stable centric occlusal position that shows no evidence of occlusal disease should not be altered. Confirmative restorative dentistry deals with making restorations that are in harmony with existing jaw relations. Conventional techniques for construction have been unsuccessful in producing a prosthesis that can be inserted without minor intraoral occlusal adjustment. This study was conducted to evaluate the benefits of the double casting technique with FGP over the conventional casting technique. Ten patients with root canal treated maxillary molar were selected for the fabrication of metal crown. Two techniques, one involving the conventional fabrication and other using functionally generated path with double casting were used to fabricate the prosthesis. A comparison based on various parameters which was done between the two techniques. The change in the height of castings for the double casting group was less compared to the conventional group and was highly statistically significant (P casting group than the conventional group (P casting group compared to conventional (P casting technique resulted in castings which had better dimensional accuracy, less occlusal correction and better patient satisfaction compared to the conventional castings.

  2. 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.)

  3. Implications of resin-based composite (RBC) restoration on cuspal deflection and microleakage score in molar teeth: Placement protocol and restorative material.

    Science.gov (United States)

    McHugh, Lauren E J; Politi, Ioanna; Al-Fodeh, Rami S; Fleming, Garry J P

    2017-09-01

    To assess the cuspal deflection of standardised large mesio-occluso-distal (MOD) cavities in third molar teeth restored using conventional resin-based composite (RBC) or their bulk fill restorative counterparts compared with the unbound condition using a twin channel deflection measuring gauge. Following thermocycling, the cervical microleakage of the restored teeth was assessed to determine marginal integrity. Standardised MOD cavities were prepared in forty-eight sound third molar teeth and randomly allocated to six groups. Restorations were placed in conjunction with (and without) a universal bonding system and resin restorative materials were irradiated with a light-emitting-diode light-curing-unit. The dependent variable was the restoration protocol, eight oblique increments for conventional RBCs or two horizontal increments for the bulk fill resin restoratives. The cumulative buccal and palatal cuspal deflections from a twin channel deflection measuring gauge were summed, the restored teeth thermally fatigued, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage score. The one-way analysis of variance (ANOVA) identified third molar teeth restored using conventional RBC materials had significantly higher mean total cuspal deflection values compared with bulk fill resin restorative restoration (all pmaterial selection is vital in the absence of clinical data. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  4. Fracture resistance of endodontically treated teeth restored with Zirconia filler containing composite core material and fiber posts.

    Science.gov (United States)

    Jeaidi, Zaid Al

    2016-01-01

    To assess the fracture resistance of endodontically treated teeth with a novel Zirconia (Zr) nano-particle filler containing bulk fill resin composite. Forty-five freshly extracted maxillary central incisors were endodontically treated using conventional step back preparation and warm lateral condensation filling. Post space preparation was performed using drills compatible for fiber posts (Rely X Fiber Post) on all teeth (n=45), and posts were cemented using self etch resin cement (Rely X Unicem). Samples were equally divided into three groups (n=15) based on the type of core materials, ZirconCore (ZC) MulticCore Flow (MC) and Luxacore Dual (LC). All specimens were mounted in acrylic resin and loads were applied (Universal testing machine) at 130° to the long axis of teeth, at a crosshead speed of 0.5 mm/min until failure. The loads and the site at which the failures occurred were recorded. Data obtained was tabulated and analyzed using a statistical program. The means and standard deviations were compared using ANOVA and Multiple comparisons test. The lowest and highest failure loads were shown by groups LC (18.741±3.02) and MC (25.16±3.30) respectively. Group LC (18.741±3.02) showed significantly lower failure loads compared to groups ZC (23.02±4.21) and MC (25.16±3.30) (pcomposite cores was comparable to teeth restored with conventional Zr free bulk fill composites. Zr filled bulk fill composites are recommended for restoration of endodontically treated teeth as they show comparable fracture resistance to conventional composite materials with less catastrophic failures.

  5. Buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: from protein buffer capacity prediction to bioprocess applications.

    Science.gov (United States)

    Bahrenburg, Sven; Karow, Anne R; Garidel, Patrick

    2015-04-01

    Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. 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

  7. 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....

  8. Supernumerary teeth in clinical practice

    Directory of Open Access Journals (Sweden)

    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.

  9. Preparation of nickel and Ni_3Sn nanoparticles via extension of conventional citric acid and ethylene diamine tetraacetic acid mediated sol–gel method

    International Nuclear Information System (INIS)

    Li, Pingyun; Deng, Guodong; Guo, Xiaode; Liu, Hongying; Jiang, Wei; Li, Fengsheng

    2016-01-01

    This work aims to extend the application field of sol–gel process from conventional oxides, carbides, sulfides to metallic nanocrystalline materials. Metallic ions were coordinated with chelating agents of citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) in aqueous solution. Then the solutions were dried at 383 K, resulting in the formation of sol and gel. Heating treatments of dried gels were then carried out with protection of N_2 atmosphere. Ni and Ni_3Sn alloy nanoparticles were obtained by this sol–gel method in the range of 623–823 K. The as-prepared Ni and Ni_3Sn alloy nanoparticles have average grain sizes of 15 and 30 nm, and have face-centred-cubic (fcc) crystalline phase. Our results provide new insight into the application of conventional sol–gel method. - Graphical abstract: Sol–gel method is conventionally applied to prepare oxides, carbides, and sulfides. In this work, the application field of sol–gel method is extended to metallic nanoparticles. By using citric acid (CA) and ethylene diamine tetraacetic acid (EDTA) mediated sol–gel method, metallic Ni (a and c) and Ni_3Sn (b and d) alloy nanoparticles can be prepared when the heating treatments are performed under N_2 protecting atmosphere. The Ni and Ni_3Sn nanoparticles have face-centered-cubic (fcc) crystalline phase and ultrafine grain sizes. Diffraction peaks of (110) superstructure reflection plane of Ni_3Sn nanoparticles can also be observed in Figure b, which can be considered as direct evidence of formation of alloy crystalline phase by performing this sol–gel method. - Highlights: • Ni and Ni_3Sn alloy nanoparticles have been prepared by sol–gel processes. • Citric acid and ethylene diamine tetraacetic acid were applied as chelating agent. • Diffraction peak of superstructure reflection plane of Ni_3Sn was detected by XRD. • A novel strategy for preparation of alloy nanoparticles has been presented.

  10. Magnetic resonance colonography with a limited bowel preparation and automated carbon dioxide insufflation in comparison to conventional colonoscopy: Patient burden and preferences

    Energy Technology Data Exchange (ETDEWEB)

    Paardt, M.P. van der, E-mail: m.p.vanderpaardt@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Boellaard, T.N., E-mail: t.n.boellaard@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Zijta, F.M., E-mail: fmzijta@yahoo.com [Department of Radiology, Medisch Centrum Haaglanden, Den Haag (Netherlands); Baak, L.C., E-mail: l.c.baak@olvg.nl [Department of Gastroenterology and Hepatology, Onze Lieve Vrouwe Gasthuis, Amsterdam (Netherlands); Depla, A.C.T.M., E-mail: actm.depla@slz.nl [Department of Gastroenterology and Hepatology, Slotervaartziekenhuis, Amsterdam (Netherlands); Dekker, E., E-mail: e.dekker@amc.uva.nl [Department of Gastroenterology and Hepatology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Nederveen, A.J., E-mail: a.j.nederveen@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Bipat, S., E-mail: s.bipat@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands); Stoker, J., E-mail: j.stoker@amc.uva.nl [Department of Radiology, Academic Medical Center Amsterdam, Amsterdam (Netherlands)

    2015-01-15

    Highlights: • MR colonography with a limited bowel preparation and automated carbon dioxide insufflation demonstrated less burden compared to colonoscopy. • When discarding the bowel preparation, the examinations were rated equally burdensome. • The majority of patients preferred MR colonography over colonoscopy for their future examination of the bowel. - Abstract: Objectives: To evaluate patient burden and preferences for MR colonography with a limited bowel preparation and automated carbon dioxide insufflation in comparison to conventional colonoscopy. Methods: Symptomatic patients were consecutively recruited to undergo MR colonography with automated carbon dioxide insufflation and a limited bowel preparation followed within four weeks by colonoscopy with a standard bowel cleansing preparation. Four questionnaires regarding burden (on a five-point scale) and preferences (on a seven-point scale) were addressed after MR colonography and colonoscopy and five weeks after colonoscopy. Results: Ninety-nine patients (47 men, 52 women; mean age 62.3, SD 8.7) were included. None of the patients experienced severe or extreme burden from the MR colonography bowel preparation compared to 31.5% of the patients for the colonoscopy bowel preparation. Colonoscopy was rated more burdensome (25.6% severe or extreme burden) compared to MR colonography (5.2% severe or extreme burden) (P < 0.0001). When discarding the bowel preparations, the examinations were rated equally burdensome (P = 0.35). The majority of patients (61.4%) preferred MR colonography compared to colonoscopy (29.5%) immediately after the examinations and five weeks later (57.0% versus 39.5%). Conclusion: MR colonography with a limited bowel preparation and automated carbon dioxide insufflation demonstrated less burden compared to colonoscopy. The majority of patients preferred MR colonography over colonoscopy.

  11. Overdentures on natural teeth: a new approach.

    Science.gov (United States)

    Previgliano, V; Barone Monfrin, S; Santià, G; Preti, G

    2004-01-01

    The study presents a new type of copings for overdentures on natural teeth. A new type of custom-made copings was prepared on 10 extracted teeth and their marginal fit was observed microscopically by means of a mechanical device, and software was employed to measure the gap. The marginal fit evaluation gave satisfactory values with mean values of the gap measurements below the clinically accepted limits (mean gap: 25.3 microm; minimum 7.3 microm, maximum 56.5 microm). The advantages of these new copings are: the rapidity of their preparation; the protection of the root canal treatment, because the coping with this chair-side method is prepared and cemented in one session; the low costs.

  12. How Graduate-Level Preparation Influences the Effectiveness of School Leaders: A Comparison of the Outcomes of Exemplary and Conventional Leadership Preparation Programs for Principals

    Science.gov (United States)

    Orr, Margaret Terry; Orphanos, Stelios

    2011-01-01

    Purpose: This study attempted to determine the influence of exemplary leadership preparation on what principals learn about leadership, their use of effective leadership practices, and how their practices influence school improvement and the school's learning climate. The authors also investigated how the frequency of effective leadership…

  13. Factors affecting the periapical healing process of endodontically treated teeth

    Directory of Open Access Journals (Sweden)

    Roberto Holland

    Full Text Available Abstract Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing, the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient that affect the outcome of root canal treatment prediction.

  14. Consumer acceptance and aroma characterization of navy bean (Phaseolus vulgaris) powders prepared by extrusion and conventional processing methods.

    Science.gov (United States)

    Szczygiel, Edward J; Harte, Janice B; Strasburg, Gale M; Cho, Sungeun

    2017-09-01

    Food products produced with bean ingredients are gaining in popularity among consumers due to the reported health benefits. Navy bean (Phaseolus vulgaris) powder produced through extrusion can be considered as a resource-efficient alternative to conventional methods, which often involve high water inputs. Therefore, navy bean powders produced with extrusion and conventional methods were assessed for the impact of processing on consumer liking in end-use products and odor-active compounds. Consumer acceptance results reveal significant differences in flavor, texture and overall acceptance scores of several products produced with navy bean powder. Crackers produced with extruded navy bean powder received higher hedonic flavor ratings than those produced with commercial navy bean powder (P < 0.001). GC-O data showed that the commercial powder produced through conventional processing had much greater contents of several aliphatic aldehydes commonly formed via lipid oxidation, such as hexanal, octanal and nonanal with descriptors of 'grassy', 'nutty', 'fruity', 'dusty', and 'cleaner', compared to the extruded powder. Extrusion processed navy bean powders were preferred over commercial powders for certain navy bean powder applications. This is best explained by substantial differences in aroma profiles of the two powders that may have been caused by lipid oxidation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts Efeito da carga cíclica na resistência de dentes tratados endodonticamente restaurados com pinos dentários convencionais e estéticos

    Directory of Open Access Journals (Sweden)

    Anuar Antônio Xible

    2006-08-01

    Full Text Available INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost and glass-ceramic cores (IPS Empress Cosmopost; group 2 with fiber reinforced composite posts (FibreKor and group 3 with titanium posts (AZthec Anchor. Direct resin composite (Build It FR Resin Composite was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2. A resin cement/adhesive system (Cement It/Bond It Primer A+B was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD in N were: group 1 = 886.5(170.6, group 2 = 762.2(113.6 and group 3 = 768.9(72.9; there was no difference among groups (p=0.08; the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142. CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite

  16. Wisdom teeth: mankind's future third vice-teeth?

    Science.gov (United States)

    Zou, DuoHong; Zhao, Jun; Ding, WangHui; Xia, LunGuo; Jang, XinQuan; Huang, YuanLiang

    2010-01-01

    The third molar teeth (wisdom teeth) represent the last eruption of the teeth in the human dentition. Throughout evolution, the mandible has had a tendency to decrease in size; the third molar teeth are often impacted, resulting in incomplete tooth eruption that often causes clinical pericoronitis, dental caries, and pericemental abscess. Therefore, the wisdom teeth are often extracted. Moreover, wisdom teeth are often removed for clinical orthodontic treatment. On the other hand, tooth loss due to periodontal disease, dental caries, trauma, or a variety of genetic disorders continues to affect people's lives. Autologous tissues for dental tissue regeneration that could replace lost teeth could provide a vital alternative to currently available clinical treatments. To pursue this goal, we hypothesize that human third molar tooth buds can be obtained during development. Human wisdom tooth germination tissue could then be placed into an embryonic stem cell bank for storage. When the donor's other teeth are missing, embryonic stem cell and tissue engineering technologies, will permit the restoration of the missing teeth. Therefore wisdom teeth will be mankind's future third vice-teeth.

  17. Remarkable resilience of teeth.

    Science.gov (United States)

    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.

  18. Single-visit endodontic treatment of mature teeth with chronic apical abscesses using mineral trioxide aggregate cement: a randomized clinical trial.

    Science.gov (United States)

    Alsulaimani, Reem Siraj

    2016-08-23

    Mature teeth with chronic apical abscesses characterized by intermittent discharge of pus through an associated sinus tract. This communication between oral mucosa and periapical inflammation is challenging for the sealing ability of root canal obturation material. Therefore, the study aim was to compare the outcomes of endodontic treatment using mineral trioxide aggregate (MTA) cement to the conventional gutta-percha cone and root canal sealer as an obturation material in mature teeth with chronic apical abscesses. Mature teeth with chronic apical abscesses referred to our clinic for root canal treatment between 2010 and 2012 were treated in a single visit and distributed among treatment (T) and control (C) groups using a predetermined randomization block (TCTC). After chemo-mechanical preparation, teeth in group T received MTA cement mixed in a 0.26 water to powder ratio, and teeth group C received gutta-percha and root canal sealer using the warm vertical technique. The treatment outcomes were defined as obturation length, periapical healing, resorption of extruded material, and survival rate at least 2.5 years after treatment. Three endodontists blinded to the type of obturation material documented treatment outcomes. Statistical analysis at P chronic apical abscesses using MTA cement were better, but not statistically significant, compared to conventional treatment. ISRCTN15285974 . Registered retrospectively 23 June 2015.

  19. Separation of radioimmunoassay in magnetic phase with particles prepared at the IPEN and its comparison with conventional methodologies

    International Nuclear Information System (INIS)

    Araujo, E.A. de.

    1991-01-01

    In the present work two main objectives were chosen. The first was the preparation for the execution of the magnetic phase separation technique, useful for the radioimmunoassay as well as for the most modern and most efficient immunoradiometric assay. The second objective, of a theoretical-practical kind and directly linked to the first, was the realization of a study about the precision of the technique with synthesized products compared with imported products and with two liquid phase separation techniques: the second antibody and polyethyleneglycol (PEG). This analysis was performed with the help of precision profiles built according to R.P.Ekins' recommendations. (author)

  20. Storage stability of margarines produced from enzymatically interesterified fats compared to those prepared by conventional methods - Chemical properties

    DEFF Research Database (Denmark)

    Zhang, Hong; Jacobsen, Charlotte; Pedersen, Lars Saaby

    2006-01-01

    margarines in a pilot plant. Storage stability studies were carried out at storage temperatures of 5 and 25øC for 12wk. Margarines from the enzymatically interesterified fats were compared to the margarines produced by the conventional methods (chemical interesterification and physical blending......In this study, four margarine hardstocks were produced, two from enzymatically interesterified fats at 80 and 100% conversion, one from chemically randomized fat and one from physically mixed fat. These four hardstocks, blended with 50% sunflower oil, were mainly used for the production of table...... interesterified fat had higher PV in weeks4, 8 and10 than the margarines produced from the enzymatically interesterified fats and the physically blended fat. These differences were not caused by different contents of tocopherols in the hardstocks. The differences between the processes for chemical and enzymatic...

  1. Preparation and study of tramadol imprinted micro-and nanoparticles by precipitation polymerization: microwave irradiation and conventional heating method.

    Science.gov (United States)

    Seifi, Mahmoud; Hassanpour Moghadam, Maryam; Hadizadeh, Farzin; Ali-Asgari, Safa; Aboli, Jafar; Mohajeri, Seyed Ahmad

    2014-08-25

    In the present work a series of tramadole imprinted micro- and nanoparticles were prepared and study their recognition properties. Methacrylic acid (MAA), as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker and different solvents (chloroform, toluene and acetonitrile (ACN)) were used for the preparation of molecularly imprinted polymers (MIPs) and non-imprinted polymers (NIPs). Several factors such as template/monomer molar ratio, volume of polymerization solvent, total monomers/solvent volume ratio, polymerization condition (heating or microwave irradiation) were also investigated. Particle size of the polymers, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), rebinding, selectivity tests and release study were applied for evaluation of the polymers. The optimized polymers with smaller particle size and superior binding properties were obtained in acetonitrile under heating method. MIPA4 with a size of 42.6 nm and a binding factor (BF) of 6.79 was selected for selectivity and release tests. The polymerization was not successful in acetonitrile and toluene under microwave irradiation. The MIPA4 could selectively adsorb tramadol, compared to imipramine, naltrexone and gabapentin. The data showed that tramadol release from MIPA4 was significantly slower than that of its non-imprinted polymer. Therefore, MIP nanoparticles with high selectivity, binding capacity and ability to control tramadol release could be obtained in precipitation polymerization with optimized condition. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. [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.

  3. Microstructural and Mechanical Properties of Porous 60NiTi Prepared by Conventional Press-and-sinter Method

    Directory of Open Access Journals (Sweden)

    Khanlari Khashayar

    2017-01-01

    Full Text Available An intermetallic nickel-titanium alloy, 60NiTi, comprised of approximately 60 wt.% Ni and 40 wt.% Ti, contains a broad combination of physical and mechanical properties such as high hardness, low elastic modulus, resistance to aqueous corrosion and good biocompatibility. These unique combinations make this alloy an attractive candidate for medical components such as implants and prosthesis, where biocompatible materials with high hardness and low stiffness are typically used. The conventional press-and-sinter method which represents the least complex, most flexible and economic powder metallurgy method was used to produce porous 60NiTi parts suitable for biomedical applications. The effect of sintering holding time on the microstructure and mechanical properties is investigated. The structure of the as sintered parts is quite porous which is beneficial based on the medical point of view. The ultimate compressive strength of the samples is higher than that of the compact human bone and can, therefore, meet the strength demand of implants for general bone replacement applications.

  4. Preparative Separation of Alkaloids from Picrasma quassioides (D. Don Benn. by Conventional and pH-Zone-Refining Countercurrent Chromatography

    Directory of Open Access Journals (Sweden)

    Qinghai Zhang

    2014-06-01

    Full Text Available Two high-speed countercurrent chromatography (HSCCC modes were compared by separation of major alkaloids from crude extract of Picrasma quassioides. The conventional HSCCC separation was performed with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (5:5:4.5:5.5, v/v/v/v with 200 mg loading. pH-Zone-refining CCC was performed with two-phase solvent system composed of petroleum ether–ethyl acetate–n-butanol–water (3:2:7:9, v/v/v/v where triethylamine (10 mM was added to the upper organic stationary phase and hydrochloric acid (5 mM was added to the lower aqueous phase with 2 g loading. From 2 g of crude extract, 87 mg of 5-methoxycanthin-6-one (a, 38 mg of 1-methoxy-β-carboline (b, 134 mg of 1-ethyl-4,8-dimethoxy-β-carboline (c, 74 mg of 1-ethoxycarbonyl-β-carboline (d, 56 mg of 1-vinyl-4,8-dimethoxy-β-carboline (e and 26 mg of 1-vinyl-4-dimethoxy-β-carboline (f were obtained with purities of over 97.0%. The results indicated that pH-zone-refining CCC is an excellent separations tool at the multigram level.

  5. Anterior makeover on fractured teeth by simple composite resin restoration

    Directory of Open Access Journals (Sweden)

    Eric Priyo Prasetyo

    2011-09-01

    Full Text Available Background: In daily practice dentists usually treat tooth fractures with more invasive treatments such as crown, veneer and bridges which preparation require more tooth structure removal. While currently there is trend toward minimal invasive dentistry which conserves more tooth structure. This is enhanced with the vast supply of dental materials and equipment in the market, including restorative materials. Provided with these supporting materials and equipment and greater patient’s demand for esthetic treatment, dentists must aware of the esthetics and basic principle of conserving tooth which should retain tooth longevity. Purpose: This article showed that a simple and less invasive composite resin restoration can successfully restore anterior esthetic and function of fractured teeth which generally treated with more invasive treatment options. Case: A 19 year-old female patient came with fracture on 21 and 22. This patient had a previous history of dental trauma about nine years before and was brought to a local dentist for debridement and was given analgesic, the involved teeth were not given any restorative treatment. Case management: The fractured 21 and 22 were conventionally restored with simple composite resin restoration. Conclusion: Fracture anterior teeth would certainly disturbs patient’s appearance, but these teeth could be managed conservatively and economically by simple composite resin restoration.Latar belakang: Dalam praktek sehari-hari pada umumnya dokter gigi merawat fraktur dengan restorasi invasif seperti mahkota, veneer dan jembatan yang semuanya memerlukan pengambilan jaringan gigi lebih banyak, sedangkan saat ini trend perawatan gigi lebih menuju kearah invasif minimal yang mempertahankan jaringan gigi sebanyak mungkin. Keadaan ini ditunjang oleh tersedianya berbagai macam bahan dan peralatan kedokteran gigi di pasaran, termasuk bahan restorasi. Dengan tersedianya bahan dan peralatan yang mendukung serta tingginya

  6. Microfluidic preparation of [{sup 18}F]FE-SUPPY and [{sup 18}F]FE-SUPPY:2 - comparison with conventional radiosyntheses

    Energy Technology Data Exchange (ETDEWEB)

    Ungersboeck, Johanna [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Inorganic Chemistry, University of Vienna, A-1090 Vienna (Austria); Philippe, Cecile [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, A-1090 Vienna (Austria); Mien, Leonhard-Key [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Haeusler, Daniela [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, A-1090 Vienna (Austria); Shanab, Karem [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Drug and Natural Product Synthesis, University of Vienna, A-1090 Vienna (Austria); Lanzenberger, Rupert [Department of Psychiatry and Psychotherapy, Medical University of Vienna, A-1090 Vienna (Austria); Spreitzer, Helmut [Department of Drug and Natural Product Synthesis, University of Vienna, A-1090 Vienna (Austria); Keppler, Bernhard K. [Department of Inorganic Chemistry, University of Vienna, A-1090 Vienna (Austria); Dudczak, Robert; Kletter, Kurt [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Mitterhauser, Markus [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, A-1090 Vienna (Austria); Hospital Pharmacy, General Hospital of Vienna, A-1090 Vienna (Austria); Wadsak, Wolfgang, E-mail: wolfgang.wadsak@meduniwien.ac.a [Department of Nuclear Medicine, Medical University of Vienna, A-1090 Vienna (Austria); Department of Inorganic Chemistry, University of Vienna, A-1090 Vienna (Austria)

    2011-04-15

    Introduction: Recently, first applications of microfluidic principles for radiosyntheses of positron emission tomography compounds were presented, but direct comparisons with conventional methods were still missing. Therefore, our aims were (1) the set-up of a microfluidic procedure for the preparation of the recently developed adenosine A{sub 3}-receptor tracers [{sup 18}F]FE-SUPPY [5-(2-[{sup 18}F]fluoroethyl)2,4-diethyl-3-(ethylsulfanylcarbonyl) -6-phenylpyridine-5-carboxylate] and [{sup 18}F]FE-SUPPY:2 [5-ethyl-2,4-diethyl-3-((2-[{sup 18}F]fluoroethyl)sulfanylcarbonyl) -6-phenylpyridine-5-carboxylate] and (2) the direct comparison of reaction conditions and radiochemical yields of the no-carrier-added nucleophilic substitution with [{sup 18}F]fluoride between microfluidic and conventional methods. Methods: For the determination of optimal reaction conditions within an Advion NanoTek synthesizer, 5-50 {mu}l of precursor and dried [{sup 18}F]fluoride solution were simultaneously pushed through the temperature-controlled reactor (26{sup o}C-180{sup o}C) with defined reactant bolus flow rates (10-50 {mu}l/min). Radiochemical incorporation yields (RCIYs) and overall radiochemical yields for large-scale preparations were compared with data from conventional batch-mode syntheses. Results: Optimal reaction parameters for the microfluidic set-up were determined as follows: 170{sup o}C, 30-{mu}l/min pump rate per reactant (reaction overall flow rate of 60 {mu}l/min) and 5-mg/ml precursor concentration in the reaction mixture. Applying these optimized conditions, we observed a significant increase in RCIY from 88.2% to 94.1% (P<.0001, n{>=}11) for [{sup 18}F]FE-SUPPY and that from 42.5% to 95.5% (P<.0001, n{>=}5) for [{sup 18}F]FE-SUPPY:2 using microfluidic instead of conventional heating. Precursor consumption was decreased from 7.5 and 10 mg to 1 mg per large-scale synthesis for both title compounds, respectively. Conclusion: The direct comparison of radiosyntheses data

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Sample preparation for avian and porcine influenza virus cDNA amplification simplified: Boilign vs. conventional RNA extraction

    International Nuclear Information System (INIS)

    Fereidouni, S.R.; Starick, E.; Ziller, M.; Harder, T.C.; Unger, H.; Hamilton, K.; Globig, A.

    2016-01-01

    Full text: RNA extraction and purification is a fundamental step that allows for highly sensitive amplification of specific RNA targets in PCR applications. However, commercial extraction kits that are broadly used because of their robustness and high yield of purified RNA are expensive and labor-intensive. In this study, boiling in distilled water or a commerical lysis buffer of different sample matrices containing avian or porcine influenza viruses was tested as an alternative. Real-time PCR (RTaPCR) for nucleoprotein gene fragment was used as read out. Results were compared with freshly extracted RNA by use of a commercial extraction kit. Different batches of virus containing material materials, including diluted virus positive allontoic fluid or cell culture supernatnat, and avian faecal, cloacal or oropharyngeal swab samples were used in this study. Simple boiling of samples without any additional purification steps can be used as an alternative RNA preparation method to detect influenza A virus nucleoprotein RNA in oropharyngeal swab samples, allantoic fluid or cell-culture supernatant. The boiling method is not applicable for sample matrices containing faecal material. (author)

  9. Environmental contamination by cyclophosphamide preparation: Comparison of conventional manual production in biological safety cabinet and robot-assisted production by APOTECAchemo.

    Science.gov (United States)

    Schierl, Rudolf; Masini, Carla; Groeneveld, Svenja; Fischer, Elke; Böhlandt, Antje; Rosini, Valeria; Paolucci, Demis

    2016-02-01

    The aim of this study was to compare environmental contamination of cyclophosphamide (CP) during 1 week of drug compounding by conventional manual procedure in a biological safety cabinet (BSC) with laminar airflow and a new robotic drug preparation system (APOTECAchemo). During four consecutive days, similar numbers of infusion bags with cyclophosphamide were prepared with both techniques in a cross-over design. Wipe samples (49 for BSC, 50 for APOTECAchemo) were taken at several locations (gloves, infusion bags, trays, BSC-benches, floor) in the pharmacy and analyzed for CP concentrations by GC-MSMS (LOD 0.2 ng/sample). The detection rate was 70% in the BSC versus 15% in APOTECAchemo. During manual preparation of admixtures using BSC contamination with CP was below 0.001 ng/cm(2) at most locations, but significant on gloves (0.0004-0.0967 ng/cm(2)) and the majority (70%) of infusion bags (preparation by APOTECAchemo, gloves (1 of 8: 0.0007 ng/cm(2)) and infusion bags (3 of 20: 0.0005, 0.0019, 0.0094 ng/cm(2)) were considerably less contaminated. Residual contamination was found on the surfaces under the dosing device in the compounding area (0.0293-0.1603 ng/cm(2)) inside the robotic system. Compared to outcomes of other studies, our results underline good manufacturing procedures in this pharmacy with low contamination for both techniques (BSC and APOTECAchemo). Comparison of both preparation procedures validated that contamination of infusion bags was much lower by using the robotic system. © The Author(s) 2014.

  10. Discrimination of gastrointestinal nematode eggs from crude fecal egg preparations by inhibitor-resistant conventional and real-time PCR.

    Directory of Open Access Journals (Sweden)

    Janina Demeler

    Full Text Available Diagnosis of gastrointestinal nematodes relies predominantly on coproscopic methods such as flotation, Kato-Katz, McMaster or FLOTAC. Although FLOTAC allows accurate quantification, many nematode eggs can only be differentiated to genus or family level. Several molecular diagnostic tools discriminating closely related species suffer from high costs for DNA isolation from feces and limited sensitivity since most kits use only small amounts of feces (<1 g. A direct PCR from crude egg preparations was designed for full compatibility with FLOTAC to accurately quantify eggs per gram feces (epg and determine species composition. Eggs were recovered from the flotation solution and concentrated by sieving. Lysis was achieved by repeated boiling and freezing cycles - only Trichuris eggs required additional mechanic disruption. Egg lysates were directly used as template for PCR with Phusion DNA polymerase which is particularly resistant to PCR inhibitors. Qualitative results were obtained with feces of goats, cattle, horses, swine, cats, dogs and mice. The finally established protocol was also compatible with quantitative real-time PCR in the presence of EvaGreen and no PCR inhibition was detectable when extracts were diluted at least fourfold. Sensitivity was comparable to DNA isolation protocols and spiked samples with five epg were reliably detected. For Toxocara cati a detection limit below one epg was demonstrated. It was possible to distinguish T. cati and Toxocara canis using high resolution melt (HRM analysis, a rapid tool for species identification. In human samples, restriction fragment length polymorphism (RFLP and HRM analysis were used to discriminate Necator americanus and Ancylostoma duodenale. The method is able to significantly improve molecular diagnosis of gastrointestinal nematodes by increasing speed and sensitivity while decreasing overall costs. For identification of species or resistance alleles, analysis of PCR products with many

  11. In vitro comparison of the effect of piezosurgery and conventional bone preparation technique on intraosseous heat generation.

    Science.gov (United States)

    Cziriak, N B; Szalma, J; Vag, J; Bogdan, S

    2016-09-01

    The aim of this in vitro study was to compare the effect of sagittal saw handpiece with a piezoelectric device on the rise in intraosseous temperature and on the preparation time. 100 native pieces of pork ribs were cut either with S-8 S handpiece connected to Elcomed surgical motor (W&H) (n = 30) or with B6 insert connected to Piezomed (W&H) using continuous movement (n = 30) or with B6 using short breaks to perform intermittent cutting (n = 30). The rest were cut either by S-8 S (n = 5) or by B6 (n = 5) both applied by permanent pressure. The intraosseous temperature was measured by K-type thermocouple connected to digital thermometer placed in the bone 1 mm away of the cutting line. The heat generated and the time of the complete cutting were recorded. In S-8 S group the temperature never rose above 47⁰C. Using the B6 with permanent movement the critical temperature was reached in 16.2 ± 3.53% of the cases while taking breaks decreased the results to 2.6 ? 0.96% (p <0.001). In no cases the temperature elevation above 4700 lasted more than 60 sec. Applying the B6 by permanent pressure resulted in heat up to 90.3⁰C. Our results suggest that piezoelectric device could use safely according to the factory instructions, however further reduce of heat load could be achieved if the intermittent cutting motion combined with short-time cooling periods.

  12. Discrimination of gastrointestinal nematode eggs from crude fecal egg preparations by inhibitor-resistant conventional and real-time PCR.

    Science.gov (United States)

    Demeler, Janina; Ramünke, Sabrina; Wolken, Sonja; Ianiello, Davide; Rinaldi, Laura; Gahutu, Jean Bosco; Cringoli, Giuseppe; von Samson-Himmelstjerna, Georg; Krücken, Jürgen

    2013-01-01

    Diagnosis of gastrointestinal nematodes relies predominantly on coproscopic methods such as flotation, Kato-Katz, McMaster or FLOTAC. Although FLOTAC allows accurate quantification, many nematode eggs can only be differentiated to genus or family level. Several molecular diagnostic tools discriminating closely related species suffer from high costs for DNA isolation from feces and limited sensitivity since most kits use only small amounts of feces (PCR from crude egg preparations was designed for full compatibility with FLOTAC to accurately quantify eggs per gram feces (epg) and determine species composition. Eggs were recovered from the flotation solution and concentrated by sieving. Lysis was achieved by repeated boiling and freezing cycles - only Trichuris eggs required additional mechanic disruption. Egg lysates were directly used as template for PCR with Phusion DNA polymerase which is particularly resistant to PCR inhibitors. Qualitative results were obtained with feces of goats, cattle, horses, swine, cats, dogs and mice. The finally established protocol was also compatible with quantitative real-time PCR in the presence of EvaGreen and no PCR inhibition was detectable when extracts were diluted at least fourfold. Sensitivity was comparable to DNA isolation protocols and spiked samples with five epg were reliably detected. For Toxocara cati a detection limit below one epg was demonstrated. It was possible to distinguish T. cati and Toxocara canis using high resolution melt (HRM) analysis, a rapid tool for species identification. In human samples, restriction fragment length polymorphism (RFLP) and HRM analysis were used to discriminate Necator americanus and Ancylostoma duodenale. The method is able to significantly improve molecular diagnosis of gastrointestinal nematodes by increasing speed and sensitivity while decreasing overall costs. For identification of species or resistance alleles, analysis of PCR products with many different post PCR methods can

  13. Tuberculate and odontoma type supernumerary teeth.

    Science.gov (United States)

    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.

  14. 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.

  15. 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.)

  16. Bond strength test of acrylic artificial teeth with prosthetic base

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

  18. Characterization and stability studies of a novel liposomal cyclosporin A prepared using the supercritical fluid method: comparison with the modified conventional Bangham method

    Directory of Open Access Journals (Sweden)

    Karn PR

    2013-01-01

    Full Text Available Pankaj Ranjan Karn,1,3 Wonkyung Cho,1,3 Hee-Jun Park,1,3 Jeong-Sook Park,3 Sung-Joo Hwang1,21Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Yeonsu-gu, Incheon, Republic of Korea; 2College of Pharmacy, Yonsei University, Yeonsu-gu, Incheon, Republic of Korea; 3College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, Republic of KoreaAbstract: A novel method to prepare cyclosporin A encapsulated liposomes was introduced using supercritical fluid of carbon dioxide (SCF-CO2 as an antisolvent. To investigate the strength of the newly developed SCF-CO2 method compared with the modified conventional Bangham method, particle size, zeta potential, and polydispersity index (PDI of both liposomal formulations were characterized and compared. In addition, entrapment efficiency (EE and drug loading (DL characteristics were analyzed by reversed-phase high-performance liquid chromatography. Significantly larger particle size and PDI were revealed from the conventional method, while EE (% and DL (% did not exhibit any significant differences. The SCF-CO2 liposomes were found to be relatively smaller, multilamellar, and spherical with a smoother surface as determined by transmission electron microscopy. SCF-CO2 liposomes showed no significant differences in their particle size and PDI after more than 3 months, whereas conventional liposomes exhibited significant changes in their particle size. The initial yield (%, EE (%, and DL (% of SCF-CO2 liposomes and conventional liposomes were 90.98 ± 2.94, 92.20 ± 1.36, 20.99 ± 0.84 and 90.72 ± 2.83, 90.24 ± 1.37, 20.47 ± 0.94, respectively, which changed after 14 weeks to 86.65 ± 0.30, 87.63 ± 0.72, 18.98 ± 0.22 and 75.04 ± 8.80, 84.59 ± 5.13, 15.94 ± 2.80, respectively. Therefore, the newly developed SCF-CO2 method could be a better alternative compared with the conventional method and may provide a promising approach for large-scale production of liposomes

  19. Combinative application of pH-zone-refining and conventional high-speed counter-current chromatography for preparative separation of caged polyprenylated xanthones from gamboge.

    Science.gov (United States)

    Xu, Min; Fu, Wenwei; Zhang, Baojun; Tan, Hongsheng; Xiu, Yanfeng; Xu, Hongxi

    2016-02-01

    An efficient method for the preparative separation of four structurally similar caged xanthones from the crude extracts of gamboge was established, which involves the combination of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography for the first time. pH-zone-refining counter-current chromatography was performed with the solvent system composed of n-hexane/ethyl acetate/methanol/water (7:3:8:2, v/v/v/v), where 0.1% trifluoroacetic acid was added to the upper organic stationary phase as a retainer and 0.03% triethylamine was added to the aqueous mobile phase as an eluter. From 3.157 g of the crude extract, 1.134 g of gambogic acid, 180.5 mg of gambogenic acid and 572.9 mg of a mixture of two other caged polyprenylated xanthones were obtained. The mixture was further separated by conventional high-speed counter-current chromatography with a solvent system composed of n-hexane/ethyl acetate/methanol/water (5:5:10:5, v/v/v/v) and n-hexane/methyl tert-butyl ether/acetonitrile/water (8:2:6:4,v/v/v/v), yielding 11.6 mg of isogambogenic acid and 10.4 mg of β-morellic acid from 218.0 mg of the mixture, respectively. The purities of all four of the compounds were over 95%, as determined by high-performance liquid chromatography, and the chemical structures of the four compounds were confirmed by electrospray ionization mass spectrometry and NMR spectroscopy. The combinative application of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography shows great advantages in isolating and enriching the caged polyprenylated xanthones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. 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 ...

  1. Comparison between rotary and manual instrumentation in primary teeth.

    Science.gov (United States)

    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.

  2. Evaluation of thermal cooling mechanisms for laser application to teeth.

    Science.gov (United States)

    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.

  3. Sorption of antimony on human teeth

    International Nuclear Information System (INIS)

    Nofal, M.; Amin, H.; Alian, G.

    1997-01-01

    The study of the uptake of toxic elements on human teeth represents an interesting research area, as the fate of these elements when present in the human food is of health significance. Since antimony is one of the common toxic elements and since, the chemical behaviour of antimony is similar to that of arsenic, one of the most important toxic elements commonly encountered in cases of food poisoning, it has been decided to investigate its uptake on human teeth and on other restoration materials. The radioactive tracer technique was used to evaluate the concentration of antimony sorbed on teeth. This tracer was obtained by irradiation of antimony metal in the reactor, subsequent dissolution in concentrated sulphuric acid, evaporation to dryness and making the solution 6 M in Hydrochloric acid (1). Antimony prepared in this way is in the trivalent state (Sb III). Sorption was studied in water, tea, coffee, red tea and chicken soup. The highest sorption was achieved from water and chicken soup and least sorption was noticed in case of coffee. The results are presented in the form of the depletion of the radioactivity (A) of antimony with time in presence of a tooth in water and other drinks

  4. Effects and control of long-range transboundary air pollution. Report prepared within the framework of the Convention on Long-range Transboundary Air Pollution

    International Nuclear Information System (INIS)

    1995-01-01

    This eleventh volume of the series of Air Pollution Studies, published under the auspices of the Executive Body for the Convention on Long-range Transboundary Air Pollution, contains the documents reviewed and approved for publication at the twelfth session of the Executive Body held at Geneva from 28 November to 1 December 1994. Part one focuses on the possible impact of acid deposition on the quality of groundwater in the ECE region. The objective of this report is to present an updated review of available knowledge on the possible impact of deposition of sulphur and nitrogen compounds on the status of groundwater, including a brief survey of recent research results in this field. It updates an earlier report on the effects of air pollutants on groundwater, prepared within the Convention (EB.AIR/WG.1/R.9). Part two is an executive summary of the 1993 Report on the Forest Condition in Europe (Forest Condition in Europe. Results of the 1993 Survey. 1994 Report, EC-UN/ECE, Brussels, Geneva, 1994). The report describes the results of both the national and the transnational surveys which are conducted annually within the International Cooperative Programme on the Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) of the United Nations Economic Commission for Europe (ECE) and under European Community Council Regulation (EEC) 3528/86 on the protection of the Community's Forests against Atmospheric Pollution. Part three is a summary report on the options for further reduction of nitrogen oxide emissions from road heavy-duty vehicles (HDVs). This report is primarily focused on reduction options for road HDVs, but some of the technical measures reviewed can, however, also be applied to some non-road diesel engines, such as machinery in construction, agriculture or forestry

  5. MoO3/Al2O3 catalyst: Comparison of catalysts prepared by new slurry impregnation with molybdic acid with conventional samples

    International Nuclear Information System (INIS)

    Spojakina, A.; Kostova, N.; Vit, Z.; Zdrazil, M.

    2003-01-01

    Alumina-supported molybdena catalysts were prepared by conventional impregnation with (NH 4 ) 6 Mo 7 O 24 (CIM) and by a new slurry impregnation method (SIM). SIM is the reaction of alumina support with a slurry of MoO 3 in water. Two commercial supports were used and the commercial Mo 3 /Al 2 O 3 catalyst was included for comparison. Maximum amount of MoO 3 deposited by SIM was about 19-20 % MoO 3 with the surface area of the support of 260-280 m 2 g -1 and this corresponded to saturation monolayer of similar density as described in literature for CIM catalysts. At the ratios of MoO 3 to Al 2 O 3 in the impregnation slurry below saturation monolayer, the pH of the slurry was 3.5-6 (depending on loading) and chemical erosion of alumina is negligible. However, using the large excess of MoO 3 (35% MoO 3 ) the pH was 2.4-3.4 and chemical erosion of alumina occurred. Silica contained in alumina supports was partly extracted as soluble silicomolybdic anions during SIM. The catalysts were characterized by BET, IR, DRS (UV-vis and NIR), TPR and catalytic activity in hydrodesulfurization of thiophene. Calcination had no significant effect on the properties of SIM catalysts and this proved that calcination is not needed in that method. All catalysts exhibited features of high monolayer dispersion of molybdena and no significant difference in structure and catalytic properties was observed between SIM and CIM catalysts. This confirmed that SIM is a simple, clean and reliable method of preparation of monolayer type MoO 3 /Al 2 O 3 catalysts. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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 ...

  8. Stability of encapsulated beef-like flavourings prepared from enzymatically hydrolysed mushroom proteins with other precursors under conventional and microwave heating.

    Science.gov (United States)

    Lotfy, Shereen N; Fadel, Hoda H M; El-Ghorab, Ahmed H; Shaheen, Mohamed S

    2015-11-15

    A comparative study was carried out between two beef-like flavourings prepared by conventional and microwave heating (CBF and MBF) of enzymatic hydrolysate of mushroom protein with other flavour precursors. GC-MS analysis of the isolated volatiles revealed that the thiol containing compounds were the predominate in both samples. However, MBF comprised higher concentration of these compounds (13.84 ± 0.06%) than CBF (10.74 ± 0.06%). The effect of microencapsulation with gum Arabic by using spray drying on the odour profile and volatile compounds of the two encapsulated samples (E-CBF and E-MBF) was investigated. The results revealed significant qualitative and quantitative variations in the volatiles of both samples. The highly volatile compounds decreased remarkably in concentration with encapsulation, while the pyrazines, thiazoles and disulphides showed opposite trend. The significant decrease in the thiol containing compounds in E-CBF and E-MBF were attributed to their oxidation to other compounds such as disulphide compounds which showed significant increase in the encapsulated samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The effect of load on heat production, thermal effects and expenditure of time during implant site preparation - an experimental ex vivo comparison between piezosurgery and conventional drilling.

    Science.gov (United States)

    Stelzle, Florian; Frenkel, Carsten; Riemann, Max; Knipfer, Christian; Stockmann, Philipp; Nkenke, Emeka

    2014-02-01

    Piezoelectric surgery (PS) is meant to be a gentle osteotomy method. The aim of this study was to compare piezosurgical vs. conventional drilling methods for implant site preparation (ISP) - focusing on load-dependent thermal effect on hard tissue and the expenditure of ISP time. Three hundred and sixty ISP were performed on ex vivo pig heads using piezosurgery, spiral burs (SB) and trephine burs (TB). The load applied was increased from 0 to 1000 g in 100-g intervals. Temperature within the bone was measured with a thermocouple, and duration was recorded with a stop watch. Thermal effects were histomorphometrically analysed. Twelve ISPs per technique were performed at the lateral wall of the maxillary sinus. PS yields the highest mean temperatures (48.6 ± 3.4°C) and thermal effects (200.7 ± 44.4 μm), both at 900-1000 g. Duration is reduced with a plus of load and significantly longer in either case for PS (P < 0.05). There is a correlation of the applied load with all other examined factors for PS and TB. Temperature and histological effects decrease for SB beyond 500 g. PS yields significantly higher temperatures and thermal tissue alterations on load levels higher than 500 g and is significantly slower for ISP compared to SB and TB. For ISP with PS, a maximum load of 400 g should be maintained. © 2012 John Wiley & Sons A/S.

  10. 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.

  11. Improvement of age estimation using amino acid racemization in a case of pink teeth.

    Science.gov (United States)

    Ohtani, S; Yamada, Y; Yamamoto, I

    1998-03-01

    Age was estimated from pink teeth using racemization of dentinal aspartic acid. Materials for identification were two lower second premolars. The body was determined to be that of a 40-year-old man; however, the age of the decedent had been estimated to be 29 and 30 years by the conventional method and 30 years from findings in the oral cavity. To clarify the cause of this difference, the powdered teeth were further washed in 0.01 mol/L hydrochloric acid. The racemization ratio (D/L ratio) of ordinary white teeth from persons of known age was slightly lower than that before washing, whereas that of the teeth used for identification was higher than before washing. The calculated age of the decedent using the racemization ratio of his teeth was between 36 and 37 years. These results suggest that age estimated from pink teeth is probably underestimated, but a more accurate age estimate can be obtained after adequate washing.

  12. 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)

  13. 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.

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

    Science.gov (United States)

    Vangala, Manogna Rl; Rudraraju, Amrutha; Subramanyam, R V

    2016-01-01

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

  15. [Observation of osteoclasts on the root surface during human deciduous teeth resorption].

    Science.gov (United States)

    Bao, Xiang-jun; Liang, Xing; Chen, Ming; Wang, Hang; Xie, Zhi-gang; Yang, Xiao-yu

    2004-08-01

    To observe osteoclasts on the resorbing surface of human deciduous teeth. After fixing the collected deciduous teeth, we prepared the tooth slices without decalcification, treated them with HE and TRAP dyestuff, and observed the osteoclasts under light and scanning electron microscope. There were large quantity of various forms of overlapping and huge osteoclasts with many nuclei and silk-like protuberances on the resorbing surface of deciduous teeth. The multinucleated osteoclasts align on the surface of coarse dentin. On the resorbing surface of human deciduous teeth there are large amount of osteoclasts which can be used as a source of studying human osteoclast.

  16. Quantitative and qualitative analysis of fluoride and multi elements of shark teeth by PIXE

    International Nuclear Information System (INIS)

    Sakurai, S.; Asakawa, R.; Hirota, F.; Sato, T.; Sera, K.; Itoh, J.

    2008-01-01

    Biomineralization has two types, biologically induced mineralization (BIM) and biologically controlled mineralization (BCM). Shark teeth is a typical representative of BCM. We have measured concentrations of fluorine and multi elements in shark teeth collected in the south of Japan. As a result, it was confirmed that the sample preparation method, which was established for the biological samples, is applicable to the shark teeth samples and the elemental concentration was obtained in good accuracy and reproducibility. Moreover, we clarified that the shark teeth is composed of Fluorapatite by the combination with X-ray Diffraction. Fluorine concentration is found to be 5500 μg/g in the shark teeth. We have 100 samples of Shark teeth and are planning on reporting the findings of a study with larger samples in the near future. (author)

  17. Identification of chemicals relevant to the Chemical Weapons Convention using the novel sample-preparation methods and strategies of the Mobile Laboratory of the Organization for the Prohibition of Chemical Weapons

    NARCIS (Netherlands)

    Terzic, O.; Gregg, H.; de Voogt, P.

    2015-01-01

    The standard approach to on-site sample preparation for gas chromatography-mass spectrometry analysis of chemicals relevant to the Chemical Weapons Convention provides relatively good coverage of the target analytes, but it suffers from a number of drawbacks, such as low sample throughput, use of

  18. 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

  19. 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

  20. Forensic DNA typing from teeth using demineralized root tips.

    Science.gov (United States)

    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.

  1. A Comparison of Different Volumes of Articaine for Inferior Alveolar Nerve Block for Molar Teeth with Symptomatic Irreversible Pulpitis.

    Science.gov (United States)

    Abazarpoor, Ramin; Parirokh, Masoud; Nakhaee, Nouzar; Abbott, Paul V

    2015-09-01

    Achieving anesthesia in mandibular molar teeth with irreversible pulpitis is very difficult. The aim of this study was to compare the efficacy of 1.8 mL and 3.6 mL articaine for an inferior alveolar nerve block (IANB) when treating molars with symptomatic irreversible pulpitis. In a randomized, double-blind clinical trial, 82 first mandibular molar teeth with symptomatic irreversible pulpitis randomly received conventional IANB injection either with 1 (1.8 mL) or 2 cartridges (3.6 mL) of 4% articaine with 1:100,000 epinephrine. The patients recorded their pain before and during access cavity preparation as well as during root canal instrumentation using a Heft-Parker visual analog scale. No or mild pain was considered as successful anesthesia. Data were analyzed by t and chi-square tests. Eighty patients were eligible to participate in this study, which showed that 3.6 mL articaine provided a significantly higher success rate (77.5%) of IANBs compared with 1.8 mL of the same anesthetic solution (27.5%) although neither group had 100% successful anesthesia (P < .001). Increasing the volume of articaine provided a significantly higher success rate of IANBs in mandibular first molar teeth with symptomatic irreversible pulpitis, but it did not result in 100% anesthetic success. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. 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

  5. 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,.

  6. 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.

  7. 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.

  8. 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.)

  9. 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.

  10. Delayed replantation of avulsed teeth

    Directory of Open Access Journals (Sweden)

    Adil N

    2007-05-01

    Full Text Available Dental injuries are very common and their extent has been classified by Ellis. Avulsion of tooth is a grievous injury and ranges from 1-16% among the traumatic injuries, of which maxillary anterior are commonest. Reimplantation of avulsed teeth is a standard procedure. However, it has certain limitations. Most often their management is very challenging. In this case report we are presenting the management of maxillary incisors by replantation after 36 hrs in a 12 year old girl.

  11. Study on the technical parameters of two different systems of RIA performed with solid-phase antibody test tubes prepared with magnetic microparticle covalence conjagation or conventional physical absorption

    International Nuclear Information System (INIS)

    Chen Zhiqiang; Wang Chengmin; Tang Baojun

    2007-01-01

    Objective: To investigate a new method of preparation of solid-phase antibody with flurorescein isothioeynate (FITC)-anti FITC magnetic nanoparticles system (for FT 3 and TSH). Methods: FT 3 and TSH monoclonal antibody IgC was la- belied with FITC. Anti-FITC magnetic mieroparticles was prepared and conjugated with the FITC labelled antibody to form the solid - phase coated test tube for RIA. Solid-phase test tube prepared with the conventional physical absorption method was also used for RIA and the technical parameters of the two systems were compared. Results: For FT 3 , the sensitivity was 0.18pmol/L with the new method and 0.43pmol/L with the conventional method. Other parameters were; intra-CV, 8.96% vs 16.26%; inter-CV, 15.25% vs 18.83%, correlation with PR method r=0.9825 vs r=0.9102. For TSH, sensitivity was 0.061 μIU/ml vs 0.04 μ IU/ml, intra- CV, 7.6% vs 6.92%, inter-CV, 8.55% vs 14.23%, correlation between the new and conventional method, r=0. 9987. TSH RIA was especially rapid with the new technic: 79 min vs 190 min. Conclusion: For FT 3 and TSH RIA, the new method takes much less time with increased homogeniety. (authors)

  12. 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.

  13. 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.

  14. 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

  15. Teething

    Science.gov (United States)

    ... that influence the process. In: Dean JA, ed. McDonald and Avery's Dentistry for the Child and Adolescent . ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  16. Dumping convention

    International Nuclear Information System (INIS)

    Roche, P.

    1992-01-01

    Sea dumping of radioactive waste has, since 1983, been precluded under a moratorium established by the London Dumping Convention. Pressure from the nuclear industry to allow ocean dumping of nuclear waste is reported in this article. (author)

  17. Resistance of Bonded Composite Restorations on Fractures of Endodontically Treated Teeth

    Directory of Open Access Journals (Sweden)

    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.

  18. A simple gold nanoparticle-mediated immobilization method to fabricate highly homogeneous DNA microarrays having higher capacities than those prepared by using conventional techniques

    International Nuclear Information System (INIS)

    Jung, Cheulhee; Mun, Hyo Young; Li, Taihua; Park, Hyun Gyu

    2009-01-01

    A simple, highly efficient immobilization method to fabricate DNA microarrays, that utilizes gold nanoparticles as the mediator, has been developed. The fabrication method begins with electrostatic attachment of amine-modified DNA to gold nanoparticles. The resulting gold-DNA complexes are immobilized on conventional amine or aldehyde functionalized glass slides. By employing gold nanoparticles as the immobilization mediator, implementation of this procedure yields highly homogeneous microarrays that have higher binding capacities than those produced by conventional methods. This outcome is due to the increased three-dimensional immobilization surface provided by the gold nanoparticles as well as the intrinsic effects of gold on emission properties. This novel immobilization strategy gives microarrays that produce more intense hybridization signals for the complementary DNA. Furthermore, the silver enhancement technique, made possible only in the case of immobilized gold nanoparticles on the microarrays, enables simple monitoring of the integrity of the immobilized DNA probe.

  19. Histopathological, Microbiological, and Radiographic Analysis of Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Study in Rats' Molars.

    Science.gov (United States)

    Trindade, Alessandra Cesar; de Figueiredo, José Antônio Poli; de Oliveira, Sílvia Dias; Barth Junior, Valdir Cristóvão; Gallo, Stephanie Wagner; Follmann, Carina; Wolle, Carlos Frederico Brilhante; Steier, Liviu; Morgental, Renata Dornelles; Weber, João Batista Blessmann

    2017-07-01

    The aim of this study was to evaluate in vivo, by histological and radiographic analysis, the response of apical tissues of rats' teeth with experimentally induced apical periodontitis, after one- and two-session endodontic treatment with and without photodynamic therapy (PDT). A microbiological analysis was also performed to verify bacterial reduction after each treatment. Studies carried out in recent years highlighted the antibacterial potential of PDT when associated with conventional endodontic therapy in vitro. Although the antimicrobial effect of PDT is well-established, tissue response to PDT in teeth with apical periodontitis lacks studies. Thirty-two rats' root canals were assigned to four groups: one session/PDT-[chemomechanical preparation (CMP)+root canal filling (RCF)]; two sessions/PDT- [CMP+calcium hydroxide (CH) for 14 days+RCF]; one session/PDT+ [CMP+PDT+RCF], and two sessions/PDT+ [CMP+PDT+CH for 14 days+RCF]. For microbiological evaluation, samples were collected before and after proposed treatments. For radiographic and histological analysis, the animals were euthanized after 28 days and the mandibles surgically removed. PDT associated with conventional endodontic therapy was able to promote significant bacterial reduction in root canals with induced apical periodontitis, but this reduction was not significantly different to conventional endodontic therapy alone. Although radiographic evaluation showed no significant differences, histological analysis showed lower scores for neutrophils/eosinophils in PDT-treated groups and macrophages/giant cells in CH groups. The use of low-level laser as light source did not promote major improvement on radiographic and histological repair, but since the number of inflammatory cells slightly decreased, it may optimize repair by modulating inflammatory process. PDT may be indicated as an adjunct to conventional endodontic therapy for teeth with apical periodontitis, in association with an interappointment

  20. 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.

  1. Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques

    International Nuclear Information System (INIS)

    Demiralp, Kemal Oeaguer; Uecok, Oezlem; Kamburoglu, Kivanc; Selcen Yuesel, Kahraman Guengoer; Demiralp, Gokcen

    2012-01-01

    To compare different radiographic methods for assessing endodontically treated teeth. Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm 3 and 0.2 mm'3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p 3 voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

  2. 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

  3. Bayes reconstruction of missing teeth

    DEFF Research Database (Denmark)

    Sporring, Jon; Jensen, Katrine Hommelhoff

    2008-01-01

    contains two major parts: A statistical model of a selection of tooth shapes and a reconstruction of missing data. We use a training set consisting of 3D scans of dental cast models obtained with a laser scanner, and we have build a model of the shape variability of the teeth, their neighbors...... or equivalently noise elimination and for data analysis. However for small sets of high dimensional data, the log-likelihood estimator for the covariance matrix is often far from convergence, and therefore reliable models must be obtained by use of prior information. We propose a natural and intrinsic...

  4. 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.

  5. Effects of acidified drinking water on the teeth of laboratory mice

    OpenAIRE

    Kostov, Marko

    2013-01-01

    The aim of this investigation was to determine the effects of hydrochloric acid used as hygienic measure in drinking water (pH2) on teeth of conventional and germfree laboratory mice. Four groups of 10 animals each were used. Group 1 : Conventional animals (tap water) Group 2 : Conventional animals (tap water, acidified ) Group 3 : Germfree animals (tap water, sterilized ) Group 4 : Germfree animals (tap water , acidified, sterilized ) The application of acidified drinking ...

  6. A comparative study of ternary Al-Sn-Cu immiscible alloys prepared by conventional casting and casting under high-intensity ultrasonic irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kotadia, H.R., E-mail: hiren.kotadia@kcl.ac.uk [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Das, A. [Materials Research Centre, College of Engineering, Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Doernberg, E.; Schmid-Fetzer, R. [Clausthal University of Technology, Institute of Metallurgy, Robert-Koch-Str. 42, D-38678 Clausthal-Zellerfeld (Germany)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Systematic investigation on the solidification microstructure of ternary Al-Sn-Cu immiscible system aided by computational thermodynamics calculations. Black-Right-Pointing-Pointer Comparative study of conventional casting and casting under high-intensity ultrasonic irradiation. Black-Right-Pointing-Pointer Demonstrated the high effectiveness of ultrasound exposure during solidification. Black-Right-Pointing-Pointer Effect of cavitation on nucleation and the relative effects of cavitation and acoustic streaming on the dispersion of Sn-rich liquid phases have been explained from the experimental observation. Cavitation was found to promote fragmentation and dispersion of Sn-rich liquid leading to homogeneous dispersion of refined Sn phase. Microstructural modification was found to be contributed by cavitation and associated shockwave generation while bulk fluid flow under acoustic streaming was found to be less effective on the microstructure evolution. Black-Right-Pointing-Pointer Globular and highly refined {alpha}-Al formed near the radiator through enhanced heterogeneous nucleation in contrast to dendritic {alpha}-Al observed in conventional solidification. - Abstract: A comparative study on the microstructure of four ternary Al-Sn-Cu immiscible alloys, guided by the recent thermodynamic assessment of the system, was carried out with specific focus on the soft Sn particulate distribution in hard Al-rich matrix in the presence and absence of ultrasonic irradiation during solidification. The results clearly demonstrate high effectiveness of ultrasonication in promoting significantly refined and homogeneously dispersed microstructure, probably aided by enhanced nucleation and droplet fragmentation under cavitation. While conventional solidification produced highly segregated Sn phase at the centre and bottom of Sn-rich alloy ingots, ultrasonic treatment produced effective dispersion irrespective of the alloy constitution in

  7. Effects of low-intensity GaAlAs laser radiation (λ=660 nm) on dentine-pulp interface after class I cavity preparation

    International Nuclear Information System (INIS)

    Godoy, Bruno Miranda

    2003-01-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, λ=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm 2 , directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  8. 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

  9. Antibacterial effect of root canal preparation and calcium hydroxide paste (Calen intracanal dressing in primary teeth with apical periodontitis Efeito antibacteriano do preparo biomecânico e do curativo de demora com pasta à base de hidróxido de cálcio (Calen em dentes decíduos com lesão periapical

    Directory of Open Access Journals (Sweden)

    Gisele Faria

    2005-12-01

    Full Text Available The aim of this study was to evaluate the antibacterial action of root canal mechanical preparation using 2.5% sodium hypochlorite as the irrigating solution and a calcium hydroxide paste as the antibacterial intracanal dressing in human primary teeth root canals with pulp necrosis and apical periodontitis by means of microbial culture. A total of 26 root canals of human primary teeth with pulp necrosis and apical periodontitis were used. Samples were collected before, 72h after biomechanical treatment and 72h after removal of the intracanal dressing. Comparison by Wilcoxon test showed that root canal mechanical preparation effectively eliminated all microorganisms in 20% of the root canals, and the intracanal dressing in 62.5%; however, the cumulative action of biomechanical treatment and intracanal dressing eliminated the microorganisms of 70% of the root canals (pO objetivo do presente estudo foi avaliar, por meio de cultura bacteriológica, a ação antibacteriana do preparo biomecânico utilizando como solução irrigadora o hipoclorito de sódio a 2,5% e da pasta Calen utilizada como curativo de demora em canais radiculares de dentes decíduos de humanos com necrose pulpar e lesão periapical. Foram selecionados 26 dentes decíduos de humanos portadores de necrose pulpar e lesão periapical. As colheitas microbiológicas foram efetuadas antes e 72 horas após o preparo biomecânico e 72 horas após a remoção do curativo de demora. A comparação por meio do teste de Wilcoxon mostrou que o preparo biomecânico foi eficaz na eliminação dos microrganismos dos canais radiculares em 20% dos casos e o curativo de demora em 62,5%, enquanto que a ação cumulativa do preparo biomecânico e do curativo de demora eliminou os microrganismos em 70,0% dos casos (p<0.001. Pôde-se concluir que o preparo biomecânico, isoladamente, apresentou resultados microbiológicos inferiores àqueles obtidos quando o mesmo foi associado ao curativo de demora

  10. 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.

  11. 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.

  12. The state of transboundary air pollution. Report prepared within the framework of the Convention on Long-range Transboundary Air Pollution

    International Nuclear Information System (INIS)

    1996-01-01

    This twelfth volume of the series of Air Pollution Studies, published under the auspices of the Executive Body for the Convention on Long-range Transboundary Air Pollution, contains the documents reviewed and approved for publication at the thirteenth session of the Executive Body held at Geneva from 28 November to 1 December 1995. Part One is the Annual Review of Strategies and Policies for Air Pollution Abatement. Part Two is an executive summary of the 1994 Report on the Forest Condition in Europe. The main objective of this report is to give a condensed description of the condition of forests in Europe, as it has been assessed by the transnational and national annual surveys, carried out jointly by ECE under the Convention on Long-range Transboundary Air Pollution and by the European Community (EC). Part Three is a summary report on the development of a library of default values for each of the input variables to the simple mass balance equation for the calculation of critical loads of nitrogen and for a range of ecosystems. Part Four presents the modelling results of European sulphur and nitrogen emissions, depositions for 1980 and 1993, and export/import budgets

  13. Effects of various cone-beam computed tomography settings on the detection of recurrent caries under restorations in extracted primary teeth

    OpenAIRE

    Kamburo?lu, K?van?; S?nmez, G?l; Berkta?, Zeynep Serap; Kurt, Hakan; ?zen, Do?ukan

    2017-01-01

    Purpose The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Materials and Methods Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The oth...

  14. 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).

  15. 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

    Directory of Open Access Journals (Sweden)

    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.

  16. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    International Nuclear Information System (INIS)

    Patters, M.R.; Landsberg, R.L.; Johansson, L.-A.; Trummel, C.L.; Robertson, P.R.

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated 45 Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis. (author)

  17. Bacteroides gingivalis antigens and bone resorbing activity in root surface fractions of periodontally involved teeth

    Energy Technology Data Exchange (ETDEWEB)

    Patters, M R; Landsberg, R L; Johansson, L A; Trummel, C L; Robertson, P R [Department of Periodontology, University of Connecticut, School of Dental Medicine, Farmington, Connecticut, U.S.A.

    1982-01-01

    Bone resorbing activity and the presence of antigens of Bacteroides gingivalis were assessed in plaque, calculus, cementum, and dentin obtained from roots of teeth previously exposed to periodontitis. Each fraction was obtained by scaling the root surface. The fraction were extracted by stirring and sonication, and the soluble centrifuged, sterilized, dialyzed, and adjusted to equivalent protein concentrations. Cementum and dentin extracts from impacted teeth were prepared similarly and served as controls. Stimulation of bone resorption by each extract was assessed in organ cultures of fetal rat bones by measurement of release of previously-incorporated /sup 45/Ca from the bone into the medium. In some groups of teeth, calculus and cementum were treated with acid prior to scaling. Citric acid washes were recovered and dialyzed. An enzyme-linked immunosorbent assay (ELISA) was used to assess the extracts for the presence of antigens reactive with an antiserum to B. gingivalis. Significant stimulation of bone resorption was found in all calculus and periodontally-involved cementum preparations. ELISA showed significant levels of B.gingivalis antigens in plaque, calculus, and cementum of periodontally-involved teeth, but not in involved dentin nor in cementum or dentin of impact teeth. Treatment with citric acid removed essentially all B.gingivalis antigens from cementum but not calculus. The results suggest that substances which stimulate bone resorption and substances which react with B. gingivalis antiserum are present in surface plaque, calculus, and cementum or periodontally-involved teeth. These substances are not present in cementum and dentin of impacted teeth nor in dentin of periodontally-involved teeth. Treatment by both scaling and citric demineralization will remove most of these substances from cementum of teeth previously exposed to periodontitis.

  18. Comparison of conventional L-thyroxine withdrawal and moderate hypothyroidism in preparation for whole-body 131-I scan and thyroglobulin testing.

    Science.gov (United States)

    Marturano, I; Russo, M; Spadaro, A; Latina, A; Malandrino, P; Regalbuto, C

    2015-09-01

    After thyroidectomy for thyroid cancer, patients often withdraw L-T4 for diagnostic or therapeutic purposes, showing signs and symptoms of hypothyroidism. A slighter hypothyroidism (reducing L-T4 to one-half) has been proposed to limit these inconveniences. We evaluated half-dose L-T4 protocol, in comparison to conventional L-T4 withdrawal, in terms of effectiveness and improvement of clinical and biochemical disorders. We randomized 55 thyroid cancer patients into two groups: 29 patients underwent 5 weeks of half-dose of previous L-T4 treatment (HD group); 26 patients replaced L-T4 with L-T3 for 3 weeks followed by 2 weeks of withdrawal (TW group). Clinical features (Zulewsky clinical score) and biochemical parameters (lipids, liver, and muscle enzymes) were evaluated in all patients at baseline and after 5 weeks. Total cholesterol, creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase increased at 5 weeks in both groups, but significantly more in TW, but no difference was found by clinical score. Patients who achieved the thyroid-stimulating hormone (TSH) target value (25 µU/ml) were 92.3% in TW group and 48.3% in HD group (p < 0.001). In the HD group, only basal TSH statistically correlated with the achievement of the TSH target. Receiver operating characteristic curves indicated that a basal TSH ≥0.52 μU/ml is required to reach an adequate TSH level. Half-dose L-T4 protocol, compared to conventional L-T4 withdrawal, is associated with less biochemical disorders but no significant clinical advantage. Therefore, the half-dose protocol reaches an adequate TSH target in 48.3% of patients and is not effective unless basal serum TSH is ≥0.52 μU/ml.

  19. Effects and control of long-range transboundary air pollution. Report prepared within the framework of the Convention on Long-range Transboundary Air Pollution

    International Nuclear Information System (INIS)

    1994-01-01

    This tenth volume of the series of Air Pollution Studies, published under the auspices of the Executive Body for the Convention on Long-range Transboundary Air Pollution, contains the documents reviewed and approved for publication at the eleventh session of the Executive Body held at Geneva from 1 to 3 December 1993. Part One is the Annual Review of Strategies and Policies for Air Pollution Abatement. National emission data and forecasts for sulphur dioxide (SO 2 ), nitrogen oxides (NO x ), volatile organic compounds (VOCs), ammonia (NH 3 ) and carbon dioxide (CO 2 ) from 1980 to 2005 are presented. Conclusions are drawn concerning the status of implementation of the sulphur and nitrogen oxides protocols on the basis of these data. Part Two is an executive summary of the 1992 Report on the Forest Condition in Europe. The main objective of this report is to give a condensed description of the condition of forests in Europe, as it has been assessed by the transnational and national annual surveys, carried out jointly by the ECE under the Convention on Long-range Transboundary Air Pollution and by the European Community (EC). Part Three is a summary report that focuses on the reduction of air pollution from heat and electric energy production. It is based on discussion papers submitted to the fifth ECE Seminar on Emission Control Technology for Stationary Sources, held in Nuremberg (Germany) from 10 to 14 June 1991. This chapter presents the main control techniques to reduce emissions from fuel combustion, which is a major contribution in most ECE countries to air pollution by sulphur and nitrogen compounds, carbon oxides, organic compounds, as well as heavy metals. Three principal abatement options are reviewed: fuel cleaning and fuel conversion, low-emission combustion processes, and flue gas cleaning processes. Both technical and economic aspects of the different measures are discussed

  20. 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.

  1. Cyclic testing of porcelain laminiate veneers on superficial enamel and dentin: Pressed vs. conventional layered porcelain

    Science.gov (United States)

    Tawde, Shweta

    Statement of Problem: Clinicians are inclined towards more aggressive teeth preparations to accommodate the thickness of the veneering material. The principle of conservative tooth preparation is compromised. Purpose: By using a conservative approach to treatment with porcelain veneers, long-lasting, esthetic and functional results may be achieved. Sacrificing as little tooth structure as possible and conserving the supporting tissues will facilitate prospective patients. Materials and Methods: Forty extracted human maxillary and mandibular canines were selected. The teeth were divided into one of two groups (pressable and stackable) and further subdivided according to tooth substrate (all-enamel or mixed enamel-dentin exposure). Twenty canine teeth were allotted to the pressable veneer group and 20 were allotted to the stackable veneer group. Of the 20 teeth in the pressable group, all were pressed with a lithium disilicate ceramic system (IPS e.max Press), 10 with labial tooth reduction of 0.3-0.5 mm maintaining superficial enamel (PEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (PDN). Of the 20 teeth in the stackable group, all were stacked/ layered with conventional feldspathic porcelain (Fortune; Williams/ Ivoclar); with labial veneer reduction of 0.3-0.5 mm maintaining superficial enamel (SEN) and the remaining 10 teeth with labial veneer reduction of 0.8-1.0 mm exposing superficial dentin (SDN). Silicon putty matrix was fabricated prior to teeth preparation to estimate the teeth reduction. The prepared facial reduction was limited to the incisal edge. No incisal or palatal/lingual reduction was performed. Impressions of the prepared teeth were taken in medium/light-bodied PVS. Master casts were made in Resin Rock. The stackable group specimens were made with fabricating refractory dies and after following the recommended steps of laboratory procedure, stackable veneers were processed. The pressable group

  2. The effects of NaF, Fluor-protector and Aminofluoride on the enamel of permanent teeth in children

    OpenAIRE

    Beloica, Dragan

    1984-01-01

    The effects of three fluor preparation (NaF, Fluor-Protector and Aminofluoride) on the enamel of permanent teeth has been studied by determinig the fluor concentrations in the enamel surface layer and the resistance of enamel to the effects of acids. The fluor preparations were applied to intact extracted teeth. Fluor concentrations were determined in the enamel samples using a Bedkman electrode with pH meter for fliuorides. Acid resistance was established by etching the enamnel samples, prev...

  3. Impacts of long-range transboundary air pollution. Report prepared within the framework of the Convention on Long-range Transboundary Air Pollution

    International Nuclear Information System (INIS)

    1992-01-01

    This eighth volume of the series of Air Pollution Studies, published under the auspices of the Executive Body for the Convention on Long-range Transboundary Air Pollution, contains the documents reviewed and approved for publication at the ninth session of the Executive Body held at Geneva from 18 to 22 November 1991. Part one is the Annual Review of Strategies and Policies for Air Pollution Abatement. Part two describes the critical load concept and the role of the best available technology and other approaches in air pollution abatement strategies. The report analyses the aim, elements and examples of the use of the receptor-oriented or effect-based critical load approach. It also evaluates the role of the source-oriented or technology-based approach as a supplement, rather than an alternative, to the critical load approach. The report contains a table with examples of national target loads for acidity or sulphur as well as preliminary European maps of critical loads of actual acidity, sulphur, present load computation of sulphur and the exceedance of the critical load of sulphur. Part three is an executive summary of the 1990 Forest Damage Survey in Europe, carried out under the International Co-operative Programme for Assessment and Monitoring of Air Pollution Effects on Forests. Part four is an executive summary of the interim report on cause/effect relationships in forest decline. Part five reviews recent research results on effects of acid deposition on atmospheric corrosion of materials

  4. 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.)

  5. Outcome of endodontic treatment of teeth filled using lateral condensation versus vertical compaction (Schilder's technique).

    Science.gov (United States)

    Aqrabawi, Jamal A

    2006-02-15

    The purpose of this prospective clinical and radiographic investigation was to assess the treatment results following endodontic therapy of teeth filled with lateral condensation versus teeth filled with vertical compaction of warm gutta-percha. A total of 290 patients were treated using the standardized step-back technique for canal preparation, which were filled with either lateral condensation or vertical compaction in one single session. Five years later, the treatment results were assessed clinically and radiographically and related to the type of the obturation technique using Chi-square analysis. Of the 340 teeth that were reexamined, 160 teeth were filled with lateral condensation, and 180 teeth were filled with vertical condensation. The results showed a significantly higher success rate for the vertical compaction versus the lateral condensation technique of teeth presented with preoperative periapical lesions P<0.04. Regardless of the preoperative periapical status of the teeth, no statistically significant difference was found between the two techniques. The overall success rate of both filling techniques was 80.3%.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.)

  8. 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.

  9. Fabrication of new magnetite-graphene nanocomposite and comparison of its laser-hyperthermia properties with conventionally prepared magnetite-graphene hybrid

    International Nuclear Information System (INIS)

    Tayyebi, Ahmad; Moradi, Shahab; Azizi, Fatemeh; Outokesh, Mohammad; Shadanfar, Kamran; Mousavi, Seyed Sadjad

    2017-01-01

    A single step supercritical method was introduced for synthesis of “magnetite - reduced graphene oxide (M-rGO)” composite in supercritical methanol. Modified surface, smaller size, lesser cytotoxicity, and homogenous dispersion of Fe 3 O 4 nanoparticles on the graphene surface were advantages of this new M-rGO composite in comparison to the materials synthesized by conventional wet chemical method (M-GO). Nanocomposites were injected in tissue equivalent phantoms of agarose gel in 10 mg/g dosage, and were irradiated by a 1600 mW laser beam at wavelength of 800–810 nm. The M-rGO and M-GO were found to be the most and the least efficient samples for increasing the temperature of the phantom. As for mathematical analysis of the heating process, a heat transfer model was developed and solved by the COMSOL Multiphysics software. Results showed an appreciable agreement with the experiments and revealed enhancement in thermal conductivity and light absorption coefficient of tissue by injecting of M-rGO sample. Our findings showed that M-rGO is a promising material for laser hyperthermia, which can deposit adequate heat dose with desirable effect in the tumorous cells in a short period. - Highlights: • Synthesis of magnetic Fe 3 O 4 -rGO with modified surface, smaller size and lesser cytotoxicity in supercritical methanol. • Development of a heat transfer model for prediction of tissue temperature in hyperthermia process. • Enhancement in thermal conductivity and light absorption coefficient of tissue by injecting of new magnetic Fe 3 O 4 -rGO. • Application of the nanocomposits in efficient laser hyperthermia in the tumorous cells.

  10. Fabrication of new magnetite-graphene nanocomposite and comparison of its laser-hyperthermia properties with conventionally prepared magnetite-graphene hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Tayyebi, Ahmad [Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of); Moradi, Shahab [Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of); Department of Physics, Sharif University of Technology, P.O. Box 11155-9161, Tehran (Iran, Islamic Republic of); Azizi, Fatemeh [Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of); Outokesh, Mohammad, E-mail: Outokesh@sharif.ir [Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of); Shadanfar, Kamran [Medical Committee of Handball Federation of Islamic Republic of Iran, Tehran (Iran, Islamic Republic of); Mousavi, Seyed Sadjad [Department of Energy Engineering, Sharif University of Technology, P.O. Box 11365-8639, Tehran (Iran, Islamic Republic of)

    2017-06-01

    A single step supercritical method was introduced for synthesis of “magnetite - reduced graphene oxide (M-rGO)” composite in supercritical methanol. Modified surface, smaller size, lesser cytotoxicity, and homogenous dispersion of Fe{sub 3}O{sub 4} nanoparticles on the graphene surface were advantages of this new M-rGO composite in comparison to the materials synthesized by conventional wet chemical method (M-GO). Nanocomposites were injected in tissue equivalent phantoms of agarose gel in 10 mg/g dosage, and were irradiated by a 1600 mW laser beam at wavelength of 800–810 nm. The M-rGO and M-GO were found to be the most and the least efficient samples for increasing the temperature of the phantom. As for mathematical analysis of the heating process, a heat transfer model was developed and solved by the COMSOL Multiphysics software. Results showed an appreciable agreement with the experiments and revealed enhancement in thermal conductivity and light absorption coefficient of tissue by injecting of M-rGO sample. Our findings showed that M-rGO is a promising material for laser hyperthermia, which can deposit adequate heat dose with desirable effect in the tumorous cells in a short period. - Highlights: • Synthesis of magnetic Fe{sub 3}O{sub 4}-rGO with modified surface, smaller size and lesser cytotoxicity in supercritical methanol. • Development of a heat transfer model for prediction of tissue temperature in hyperthermia process. • Enhancement in thermal conductivity and light absorption coefficient of tissue by injecting of new magnetic Fe{sub 3}O{sub 4}-rGO. • Application of the nanocomposits in efficient laser hyperthermia in the tumorous cells.

  11. Dilution Confusion: Conventions for Defining a Dilution

    Science.gov (United States)

    Fishel, Laurence A.

    2010-01-01

    Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect…

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

    Science.gov (United States)

    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.

  13. The state of transboundary air pollution 1992 update. Report prepared within the framework of the Convention on Long-range Transboundary Air Pollution

    International Nuclear Information System (INIS)

    1993-01-01

    This ninth volume of the series of Air Pollution Studies, published under the auspices of the Executive Body for the Convention on Long-range Transboundary Air Pollution, contains documents reviewed and approved for publication at the tenth session of the Executive Body held at Geneva from 17 to 19 November 1992. Part One is the Annual Review of Strategies and Policies for Air Pollution Abatement. It is compiled on the basis of national data and reports received up to 31 December 1992. National emission data and forecasts for sulphur dioxide (SO 2 ), nitrogen oxides (NO x ), volatile organic compounds (VOCs), ammonia (NH 3 ), and carbon dioxide (CO 2 ) from 1980 to the year 2005 is presented. Part Two contains results of scenario analysis for sulphur abatement strategies. It is concluded, inter alia, that strategies can be found which, by differentiating emission reductions, provide greater environmental benefit than a uniform reduction at the same cost. It is also shown that a small number of high-emitting countries in Central Europe have significant impact on deposition of sulphur throughout Europe, and that emission reduction in these countries proves to be a cost-effective way of moving towards critical loads in Europe as a whole. Most of the scenarios analysed are based on reductions of current deposition in relation to critical loads, i.e., a decrease in the exceedances of critical loads. Part Three is an executive summary of the 1992 Report on Forest Condition in Europe, carried out under the International Cooperative Programme for Assessment and Monitoring of Air Pollution Effects on Forests. The full report has been jointly published by ECE and the Commission of the European Communities. It summarizes the results of surveys carried out in 1991 in 28 European countries and in several additional regions, conducted in accordance with common guidelines. Of 214 million hectares of forest in Europe (including major parts of the forests in the western part of the

  14. In Vitro Comparative Study of the Working Length Determination with Radiovisiography and Conventional Radiography in Dilacerated Canals

    Directory of Open Access Journals (Sweden)

    Ali Bagherpour

    2015-06-01

    Full Text Available Introduction: The aim of this study was to compare digital and conventional radiography in determining the working length of dilacerated canals.Methods: Thirty nine human extracted single-rooted teeth with root curvature more than 35 degrees were included in this study. After access preparation, a file was inserted into the canal and advanced until the file tip was visualized at the foramen. With measurement of the file length using a millimeter ruler, true canal length was determined for each canal. Then, teeth were mounted in acrylic blocks and canal length was estimated by using on-screen digital radiography with both 3- and 6-clicks measurement and from conventional radiography by conforming a preserved file on the image of the root canal.Results: There were no significant differences in measurement accuracy between the true canal length and conventional radiographic length, but there were significant difference between both digital radiographic techniques with true canal length. There was no significant correlation between root curvature and canal length estimation error of studied methods.Conclusion: In dilacerated canals, the accuracy of determination of working length by using conventional radiography is higher than digital radiography

  15. 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.

  16. Orthodontics Align Crooked Teeth and Boost Self-Esteem

    Science.gov (United States)

    ... 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 ...

  17. 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.

  18. Natural tooth pontic with splinting of periodontally weakened teeth using fiber-reinforced composite resin

    Directory of Open Access Journals (Sweden)

    Gauri Srinidhi

    2014-01-01

    Full Text Available Replacement of missing anterior teeth due to periodontal reasons is challenging due to the poor support of abutment teeth. This prevents the use of fixed partial dentures (FPDs. Fiber-reinforced splinting provides a viable alternative to the dentist while choosing a treatment plan in replacing missing anterior teeth in periodontally compromised patients as opposed to conventional modalities like FPDs or removable partial dentures. Replacing missing teeth using either patient′s own tooth or a denture tooth as pontic can be done by splinting adjacent teeth with fiber reinforced composite. The splinting has an additional advantage of stabilizing adjacent mobile teeth. This case report details the case selection, procedure with follow-up of a case where the natural extracted tooth of the patient was used as pontic to replace a missing anterior tooth. The splinting was done with fiber reinforced composite resin. Fiber-reinforced composite resin splinting of patient′s extracted natural tooth is economical, fast, and easy to use chairside technique with the added benefit of periodontal stabilization.

  19. Root canal obturation of primary teeth: Disposable injection technique

    Directory of Open Access Journals (Sweden)

    S K Bhandari

    2012-01-01

    Full Text Available The aim of the study was to outline a simple, cost-effective technique for obturation of primary tooth root canals. A total of 75 primary teeth were treated in 52 subjects by the technique discussed, i.e. injecting plastic flowable material into the root canals after desired preparation, using disposable needle and syringe. All the patients were followed up for 3 years and 6 months, with no clinical or radiologic evidence of pathology or need for untimely extraction. In conclusion, the technique described is simple, economical, can be used with almost all filling materials used for the purpose, and is easy to master with minimal chances of failure.

  20. Bonding auto-polymerising acrylic resin to acrylic denture teeth.

    LENUS (Irish Health Repository)

    Nagle, Susan

    2009-09-01

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

  1. Considerations for ceramic inlays in posterior teeth: a review

    Science.gov (United States)

    Hopp, Christa D; Land, Martin F

    2013-01-01

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

  2. Periodontal regeneration around natural teeth.

    Science.gov (United States)

    Garrett, S

    1996-11-01

    1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

  3. Bruxism (Teeth Grinding or Clenching) (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Bruxism (Teeth Grinding or Clenching) KidsHealth / For Parents / Bruxism ( ... called bruxism , which is common in kids. About Bruxism Bruxism is the medical term for the grinding ...

  4. In vitro evaluation of marginal microleakage in class V restorations with composite resin in bovine teeth. Laser irradiation influences and the adhesive system in the dentin pre-treatment

    International Nuclear Information System (INIS)

    Carvalho, Wendell Lima de

    2003-01-01

    Microleakage is one of the most important reasons to restorations failure, it is the responsible for marginal colors changing, new caries, hipersensibility and pulpar diseases. Several techniques and materials have been studied to eliminate or, at least, to decrease microleakage. The cavities preparation with Er:YAG laser and autoconditioning adhesive are some of these techniques and materials. This research has the objective to compare, in vitro, microleakage in class V cavities, prepared with high rotation (conventional treatment), Er:YAG laser (Enamel-400 mj/2 Hz/128,38 J/Cm 2 , Dentin 250 mJ/ 2 Hz/ 80,24 J/Cm 2 ) and the treatment made at dentin with autoconditioning adhesive (Clerafil SE Bond) using Er:YAG laser (with water or not water) or not using Er:YAG laser. It was used 48 bovines teeth with cavities prepared in vestibular face and gingival wall on cement enamel junction and oclusal wall on enamel. The materials used were autoconditioning adhesive (Clerafil SE Bond) and composite resin Z250. Teeth were divided into four groups of twelve samples each one, according to dentin treatment. Group 1 - Conventional cavity and autoconditioning adhesive. Group 2- Cavity prepared with Er: YAG laser and autoconditioning adhesive. Group 3 - Cavity prepared with Er:YAG laser and dentin conditioning with Er:YAG laser associated to water and autoconditioning adhesive. Group 4 - Cavity prepared with Er:YAG laser and dentin conditioning with Er: YAG laser without water and associated to autoconditioning adhesive. Teeth were restored and stocked at 37 deg C, thermocycled and placed into a 50% silver nitrate solution. Right after, teeth were sliced and evaluated on a stereo microscopic magnifying glass in order to see microleakage degree trying to follow a score from 0 to 3. The findings were submitted to Fisher, Anderson-Darling tests and to the not parametric Sen and Puri test. The results indicated that in gingival edge, the Group 2 showed less microleakage than others

  5. 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

  6. 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 ...

  7. 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.

  8. 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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. 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....

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Detection of vertical root fractures in endodontically treated teeth by a cone beam computed tomography scan

    NARCIS (Netherlands)

    Hassan, B.; Metska, M.E.; Özok, A.R.; van der Stelt, P.; Wesselink, P.R.

    2009-01-01

    Our aim was to compare the accuracy of cone beam computed tomography (CBCT) scans and periapical radiographs (PRs) in detecting vertical root fractures (VRFs) and to assess the influence of root canal filling (RCF) on fracture visibility. Eighty teeth were endodontically prepared and divided into

  15. 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.

  16. Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Demiralp, Kemal Oeaguer; Uecok, Oezlem [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, Ankara (Turkmenistan); Kamburoglu, Kivanc [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan); Selcen Yuesel, Kahraman Guengoer [Dept. of Biostatistics, Faculty of Medicine, Ankara University, Ankara (Turkmenistan); Demiralp, Gokcen [Dept. of Endodontics, Tepebasi Dental Health Center, Ankara (Turkmenistan)

    2012-09-15

    To compare different radiographic methods for assessing endodontically treated teeth. Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm{sup 3} and 0.2 mm'3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05). The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 mm{sup 3} voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

  17. 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)

  18. Effects of low-intensity GaAlAs laser radiation ({lambda}=660 nm) on dentine-pulp interface after class I cavity preparation; Efeitos da radiacao laser GaAlAs ({lambda}=660 nm) em baixa intensidade na interface dentina-polpa pos-preparo cavitario classe 1

    Energy Technology Data Exchange (ETDEWEB)

    Godoy, Bruno Miranda

    2003-07-01

    The aim of this study was to investigate the effects of low-intensity irradiation with GaAlAs laser (red emission) on the ultrastructure of dentine-pulp interface after conventionally prepared class I cavity preparation. Two patients with 8 premolars for extraction indicated for orthodontic reasons. Class I cavities were prepared in these teeth that were then divided into two groups. The first group received a treatment with laser with continuous emission, {lambda}=660 nm, with maximum power output of 30 mW. The dosimetry applied was of approximately 2J/cm{sup 2}, directly and perpendicularly into the cavity in only one section. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. Twenty-eight days after the preparation, the teeth were extracted and were processed for transmission electron microscopy analysis. Two sound teeth, without any preparation, were also studied. The irradiated group presented odontoblastic processes in higher contact with the extracellular matrix and the collagen fibers appeared more aggregated and organized than those of control group. These results were also observed in the healthy-teeth. Thus, we suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the pre-dentine level. (author)

  19. 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

  20. Beta dosimetry in teeth from SR-90 exposed subjects

    International Nuclear Information System (INIS)

    Fattibene, P.; De Coste, V.; Onori, S.; Veronese, I.; Giussani, A.; Cantone, M.C.; Shishkina, E.

    2006-01-01

    Tooth enamel is a well recognized dosimeter for retrospective dose reconstruction of individuals accidentally exposed to ionizing radiation. The measurements of the absorbed dose in tooth enamel is conventionally carried out with the Electron Paramagnetic Resonance technique. Tooth enamel is sensitive to all kind of ionizing radiation. Its response to photons has been widely investigated. For application to contaminated teeth with 90 Sr, one of the most common osteo tropic radionuclides, the effectiveness of tooth enamel response to the β spectrum needs be evaluated. The response function to 90 Sr of the EPR/tooth enamel systems, its linearity and reproducibility have been investigated under a controlled geometry, and the results will be presented and compared to those obtained with photons. When the subject has been exposed to both external and internal radiation, a combined EPR/T.L. method can be used to distinguish the internal from the external contribution to the cumulative dose in tooth (Gosku et al., 2002;=Veronese et al. 2004, Shishkina et al. 2005). The T.L. measurement, performed putting thin ± Al 2 O 3 :C dosimeters at contact with the tooth surfaces, enables to estimate the beta dose rate due to the radionuclides present in tooth. The combination of this information with that coming from EPR allows, under specific assumptions, to evaluate separately the internal and external contribution to the tooth dose. In a previous work (Veronese et al., 2004) the dose in enamel measured by EPR in a tooth contaminated with 90 Sr of a Techa River resident was compared to the dose rate measured by TLDs. The test has been extended to a larger number of 90 Sr contaminated teeth. EPR measurements have been also performed in other portions of the teeth, i.e. tooth dentin and root. The correlation between the results, obtained from EPR and TLD measurements, and the evaluation of the relative proportion of internal and external dose are presented and discussed. (authors)

  1. Crop coefficient and water consumption of eggplant in no-tillage system and conventional soil preparation Coeficiente de cultura e consumo hídrico da berinjela em sistema de plantio direto e de preparo convencional do solo

    Directory of Open Access Journals (Sweden)

    Daniel F. de Carvalho

    2012-08-01

    Full Text Available Under organic management in Seropédica-RJ, Brazil, using a weighing lysimeter, the crop coefficients (kc, the maximum evapotranspiration and the productivity of eggplant cultivation under two cropping systems (no tillage with straw plus soil with conventional preparation were determined. A whole randomized layout with two treatments (no tillage and conventional and five replicates during 134 days of cultivation were adopted. There were no significant differences in the eggplant cultivation in the two cropping systems, with a maximum commercial productivity obtained from 47.42 Mg ha-1 for the no-tillage system, and 47.91 Mg ha-1 for the conventional tillage. The accumulated ETc was 285.15 and 323.44 mm for the no-tillage and conventional, respectively. The crop coefficients value for the phases: 1 - transplanting, flowering, 2 - flowering-fruiting, 3 - fruit- first harvesting, 4- first harvesting of the final crop cycle was 0.83, 0.77, 0.90 and 0.97 in no-tillage system for the respective phases and for the conventional one 0.81, 1.14, 1.17 and 1.05 for the same steps described above.Sob manejo orgânico, foram determinados em Seropédica-RJ, utilizando lisímetro de pesagem, os coeficientes de cultura (kc, a evapotranspiração máxima e a produtividade da cultura da berinjela, em dois sistemas de cultivo (plantio direto com adição de palha e em solo com o preparo convencional. Foi adotado o delineamento inteiramente casualizado, com dois tratamentos (plantio direto e convencional e com cinco repetições, durante 134 dias de cultivo. Não houve diferenças significativas na produtividade da cultura da berinjela nos dois sistemas de cultivo, sendo a produtividade comercial máxima obtida de 47,42 Mg ha-1, para o sistema de plantio direto, e de 47,91 Mg ha-1, para o sistema de plantio convencional. A ETc acumulada foi de 285,15 e 323,44 mm, para o sistema de plantio direto e plantio convencional, respectivamente. Os valores de coeficiente de

  2. 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)

  3. 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

  4. Facilitating play through communication: significance of teeth exposure in the gorilla play face.

    Science.gov (United States)

    Waller, Bridget M; Cherry, Lyndsay

    2012-02-01

    Primate facial expressions (FEs) likely play an important role in primate society: through facial signals, individuals can potentially send and receive information and may benefit from coordinating their behavior accordingly. Many primates use a relaxed open mouth (ROM) facial display or “play face” (PF) during play behavior, where the mouth is open but teeth are covered. In addition to this conventional PF, however, Western Lowland gorillas (Gorilla gorilla gorilla) also use a full PF where the upper teeth are exposed. As the teeth are similarly exposed in the bared-teeth expression (which is a signal of appeasement, submission and/or affiliation), the full PF may be a blend of the PF and bared-teeth face, and have a different signal function to the PF alone. Focal animal sampling of captive Western Lowland gorillas (N=10) showed that the full PF was more often observed in intense rather than gentle play, and intense play bouts that featured the full PF were longer than those that featured only the PF. Both expressions were associated with an increase in affinitive behavior between sender and receiver postplay, but only the full PF was associated with an increase higher than that of play alone. Overall, the findings suggest that the full PF has an additional role in coordinating and maintaining play, possibly though reducing uncertainty in the receiver and confirming that play is only play.

  5. Root canal preparation with Er:YSGG laser

    Science.gov (United States)

    Benthin, Hartmut; Ertl, Thomas P.; Onal, B.; Schruender, Stephan; Mueller, Gerhard J.

    1994-12-01

    The high level of efficiency of hard tissue ablation with Er:YAG and Er:YSGG lasers is well known. Of these lasers it is possible only to transmit Er:YSGG laser radiation with OH reduced quartz fibers. Most of the fibers we use in this study were prepared as hemispherical fiber tips. Fifty single rooted teeth were divided into ten groups (n equals 5). After conventional opening of the pulp chamber, root canal preparation was performed in five groups under water only using the laser. In the other five groups preparation with K-files to size 35 was performed before treatment with laser radiation. All teeth were axially separated with direct access to the root canal and examined in SEM investigations. The groups were compared by measuring the areas with patent dentin tubules. Representative areas were examined by TEM. The temperature at the root surface was measured during laser irradiation with thermocouples positioned at several points. The in-vitro study of the effect of the high delivered energy (50 - 100 mJ per pulse) in the root canal showed a good ablation effect. Most of the dentin tubules were opened. The increase in temperature at the root surface was tolerable.

  6. Soft tissue wound healing around teeth and dental implants.

    Science.gov (United States)

    Sculean, Anton; Gruber, Reinhard; Bosshardt, Dieter D

    2014-04-01

    To provide an overview on the biology and soft tissue wound healing around teeth and dental implants. This narrative review focuses on cell biology and histology of soft tissue wounds around natural teeth and dental implants. The available data indicate that: (a) Oral wounds follow a similar pattern. (b) The tissue specificities of the gingival, alveolar and palatal mucosa appear to be innately and not necessarily functionally determined. (c) The granulation tissue originating from the periodontal ligament or from connective tissue originally covered by keratinized epithelium has the potential to induce keratinization. However, it also appears that deep palatal connective tissue may not have the same potential to induce keratinization as the palatal connective tissue originating from an immediately subepithelial area. (d) Epithelial healing following non-surgical and surgical periodontal therapy appears to be completed after a period of 7–14 days. Structural integrity of a maturing wound between a denuded root surface and a soft tissue flap is achieved at approximately 14-days post-surgery. (e) The formation of the biological width and maturation of the barrier function around transmucosal implants requires 6–8 weeks of healing. (f) The established peri-implant soft connective tissue resembles a scar tissue in composition, fibre orientation, and vasculature. (g) The peri-implant junctional epithelium may reach a greater final length under certain conditions such as implants placed into fresh extraction sockets versus conventional implant procedures in healed sites. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. 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).

  8. Comparison between powder and slices diffraction methods in teeth samples

    Energy Technology Data Exchange (ETDEWEB)

    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)

  9. Clinical evaluation of isolated abutment teeth in removable partial dentures

    Directory of Open Access Journals (Sweden)

    Zarrati S

    2011-02-01

    Full Text Available "nBackground and Aims: Nowadays, removable partial dentures are applied to patients who are not able to use dental implants or fixed prosthesis. Although based on the studies the users of removable partial dentures are in the risk of plaque accumulation and unacceptable changes such as gingivitis, periodontitis and mobility in abutment tooth. It is not clear whether the negative effects of removable partial dentures are more on the isolated teeth which are a kind of abutment adjacent to endentulous area in both sides. The purpose of this study was to investigate the clinical condition of isolated abutment teeth without splinting in comparison to control abutment from the aspects of B.O.P (bleeding on probing, mobility, pocket depth and gingivitis."nMaterials and Methods: In this cross-sectional study, the prepared questionnaires were filled out by 50 patients who received removable partial dentures in department of removable prosthodontics of dental school of Tehran University of Medical Sciences. The patients had isolated abutment tooth and did not have any systemic disease. The obtained data were analyzed. Using Wilcoxon, exact Fisher and Kruskal-Wallis test."nResults: B.O.P (P=0.004, pocket depth (P=0.035, and mobility (P<0.001 in isolated abutments were more than those in control abutments, but there were not significant differences in the degree of caries (P=0.083 and gingivitis (P=0.07."nConclusion: This study showed that clinical condition of isolated abutments is worse than that of control abutments. More attention should be paid to healthiness of isolated teeth without splinting and periodic follow ups should be done in these cases.

  10. 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)

  11. Fracture resistance of endodontically treated teeth restored with short fiber composite used as a core material-An in vitro study.

    Science.gov (United States)

    Garlapati, Tejesh Gupta; Krithikadatta, Jogikalmat; Natanasabapathy, Velmurugan

    2017-10-01

    This in-vitro study tested the fracture resistance of endodontically treated molars with Mesial-Occluso-Distal (MOD) cavities restored with fibre reinforced composite material everX posterior in comparision with hybrid composite and ribbond fiber composite. Fifty intact freshly extracted human mandibular first molars were collected and were randomly divided into five groups (n=10). Group 1: positive control (PC) intact teeth without any endodontic preparation. In groups 2 through 6 after endodontic procedure standard MOD cavities were prepared and restored with their respective core materials as follows: group 2, negative control (NC) left unrestored or temporary flling was applied. Group 3, Hybrid composite (HC) as a core material (Te-Econom Plus Ivoclar Vivadent Asia) group 4, Ribbond (Ribbond; Seattle, WA, USA)+conventional composite resin (RCR) group 5, everX posterior (everX Posterior GC EUROPE)+conventional composite resin (EXP) after thermocycling fracture resistance for the samples were tested using universal testing machine. The results were analysed using ANOVA and Tukey's HSD post hoc tests. Mean fracture resistance (in Newton, N) was group 1: 1568.4±221.71N, group 2: 891.0±50.107N, group 3: 1418.3±168.71N, group 4:1716.7±199.51N and group 5: 1994.8±254.195N. Among the materials tested, endodontically treated teeth restored with everX posterior fiber reinforced composite showed superior fracture resistance. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  12. 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

  13. Potentiometric stripping analysis of lead and cadmium leaching from dental prosthetic materials and teeth

    Directory of Open Access Journals (Sweden)

    GORAN M. NIKOLIC

    2004-07-01

    Full Text Available Potentiometric stipping analysis (PSA was applied for the determination of lead and cadmium leaching from dental prosthetic materials and teeth. The soluble lead content in finished dental implants was found to be much lower than that of the individual components used for their preparation. Cadmium was not detected in dental implants and materials under the defined conditions. The soluble lead and cadmium content of teeth was slightly lower than the lead and cadmium content in whole teeth (w/w reported by other researchers, except in the case of a tooth with removed amalgam filling. The results of this work suggest that PSA may be a good method for lead and cadmium leaching studies for investigation of the biocompatibility of dental prosthetic materials.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

  16. Effect of preoperative alprazolam on the success of inferior alveolar nerve block for teeth with irreversible pulpitis.

    Science.gov (United States)

    Khademi, Abbas Ali; Saatchi, Masoud; Minaiyan, Mohsen; Rostamizadeh, Nasim; Sharafi, Fatemeh

    2012-10-01

    Success of inferior alveolar nerve (IAN) block decreases in patients with irreversible pulpitis. The purpose of this study was to evaluate the effect of preoperative administration of alprazolam on the success of the IAN block for teeth with irreversible pulpitis. Sixty patients with irreversible pulpitis of a mandibular molar were selected for this prospective, randomized, double-blind, placebo-controlled study. The patients received identical capsules of either 0.5 mg of alprazolam or placebo 45 minutes before the administration of a conventional IAN block. Access cavity preparation was initiated 15 minutes after the IAN block injection. Lip numbness was recorded for all the patients. Success was defined as no or mild pain on the basis of visual analogue scale recordings during access cavity preparation and initial instrumentation. Data were analyzed by t test, Mann-Whitney, and χ(2) tests. The success rate was 53% for alprazolam group and 40% for placebo group, with no significant difference between the 2 groups (P = .301). Within the scope of the current study, preoperative oral administration of 0.5 mg of alprazolam did not improve the success of the IAN block in mandibular molars in patients with irreversible pulpitis, and the success rate was not adequate to ensure profound pulpal anesthesia. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. 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.

  18. An unusual case of black teeth

    NARCIS (Netherlands)

    Schuurs, A. H.; Abraham-Inpijn, L.; van Straalen, J. P.; Sastrowijoto, S. H.

    1987-01-01

    Loss of enamel and a deep black stain of the teeth in a 40-year-old diabetic patient are strongly suggested to be caused by the daily consumption of a cheap white wine and, possibly, by the chewing of cayenne. The wine proved to be rather acid, thereby promoting abrasion as a result of gnashing, and

  19. 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.

  20. Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

    Science.gov (United States)

    Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

    2014-12-01

    This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (Pimpressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

  1. [A ten-year clinical study of cracked teeth restored with glass ceramic crowns].

    Science.gov (United States)

    Luo, X P; Yuan, Y; Shi, Y J; Qian, D D

    2016-10-09

    Objective: To evaluate the clinic performance of high strength glass ceramic crowns for the painful cracked teeth during a 10-year observation period. Methods: Forty-two posterior teeth from 36 patients were diagnosed as having a crack, biting painful and sensitivity to cold were selected in the Department of Prosthodontic, Institute and Hospital of Stomatology, Nanjing University Medical School. The lost-wax hot pressed glass ceramic crowns were bonded on the minimally invasive prepared teeth by modern adhesive technology. Patients were interviewed and went through clinic examination after one week, one month, and every six months. Results: The effectiveness of 42 glass ceramic crowns for cracked teeth was evaluated for a mean observation time over 10-year. At the first week, 29(81%) patients were free of pain, three still had sensitivity to cold and chewing pain, three still had sensitivity to cold, one had painful to cold and hot. After one month, two patients still had chewing pain, and one tooth needed endodontic treatment after six months. In 10 years, 2(5%) all ceramic crowns were broken, the other 40 restorations kept good clinical performances with a 10-year survival rate of 95%. Conclusions: The high strength glass ceramic crowns are very effective and successful in treating the cracked teeth and then keep the good mastication function and appearance.

  2. Conventional and digital radiographic methods in the detection of simulated external root resorptions: A comparative study

    Directory of Open Access Journals (Sweden)

    C J Sanjay

    2009-01-01

    Full Text Available Objective : To evaluate and compare the efficacy of conventional and digital radiographic methods in the detection of simulated external root resorption cavities and also to evaluate whether the detectability was influenced by resorption cavity sizes. Methods : Thirty-two selected teeth from human dentate mandibles were radiographed in orthoradial, mesioradial and distoradial aspect using conventional film (Insight Kodak F-speed; Eastman Kodak, Rochester, NY and a digital sensor (Trophy RVG advanced imaging system with 0.7mm and 1.0mm deep cavities prepared on their vestibular, mesial and distal surfaces at the cervical, middle and apical thirds. Three dental professionals, an endodontist, a radiologist and a general practitioner, evaluated the images twice with a one-week time interval. Results : No statistical significance was seen in the first observation for both conventional and digital radiographic methods in the detection of simulated external root resorptions and for small and medium cavities but statistical difference was noted in the second observation (P< 0.001 for both the methods. Conclusion : Considering the methodology and the overall results, conventional radiographic method (F-speed performed slightly better than the digital radiographic method in the detection of simulated radiographic method but better consistency was seen with the digital system. Overall size of the resorption cavity had no influence on the performance of both methods and suggests that initial external root resorption lesion is not well-appreciated with both the methods as compared to the advanced lesion.

  3. 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...

  4. 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.

  5. Baby Teeth Link Autism and Heavy Metals, NIH Study Suggests

    Science.gov (United States)

    ... 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 ...

  6. Treatment options for permanent teeth with deep caries.

    Science.gov (United States)

    Marending, Monika; Attin, Thomas; Zehnder, Matthias

    The goal of this narrative review was to summarize and compare treatment options for permanent teeth carious lesions that are radiographically close to the pulp chamber. Thanks to adhesive restorative materials, minimally invasive approaches are possible. In this context, the old question arises as to whether caries must be excavated completely, i.e., down to hard dentin, or whether it could be advantageous to leave some soft dentin, or even merely seal the whole lesion. To answer this question, the microbiological aspects of the lesion must be considered, along with the immunological response in the dental pulp, with the concurrent possible negative outcomes for the patient. Both aspects are considered in this review, and clinical studies comparing different treatment modalities are discussed. Situations in which calcium silicate cements could be advantageous over the gold standard calcium hydroxide preparations for covering the dentin/pulp wound are also discussed.

  7. Integrated Surgical and Orthodontic Treatment: A Twinned Teeth Dilemma

    Directory of Open Access Journals (Sweden)

    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.

  8. 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)

  9. 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...

  10. 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.

  11. Teaching parents to look after children's teeth.

    Science.gov (United States)

    Lloyd, S

    1994-03-01

    Children's toothpastes with fluoride help to prevent decay, but parents should ask their dentist before giving fluoride supplements to children. Overdosage is harmful. Sugars eaten as part of a meal do less harm to teeth than those eaten frequently as snacks. Sugar-free infant drinks and children's confectionery are now on the market and are more "tooth friendly". Look out for the "happy tooth" symbol. Babies can be registered with NHS dentists as soon as the first teeth start to come through, and should be taken regularly to the dentist throughout childhood. Under the NHS scheme, dentists are paid a capitation fee to provide continuing preventive care and treatment for children free of charge.

  12. Aesthetic treatment of discoloration of nonvital teeth.

    Science.gov (United States)

    Miara, P

    1995-09-01

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

  13. Pulpectomy procedures in primary molar teeth

    OpenAIRE

    Hany Mohamed Aly Ahmed

    2014-01-01

    Premature loss of primary molars can cause a number of undesirable consequences including loss of arch length, insufficient space for erupting premolars and mesial tipping of the permanent molars. Pulpectomy of primary molar teeth is considered as a reasonable treatment approach to ensure either normal shedding or a long-term survival in instances of retention. Despite being a more conservative treatment option than extraction, efficient pulpectomy of bizarre and tortuous root canals encased ...

  14. 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.

  15. Conventional imaging in paediatric uroradiology

    International Nuclear Information System (INIS)

    Riccabona, M.; Lindbichler, F.; Sinzig, M.

    2002-01-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options

  16. Conventional imaging in paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Riccabona, M. E-mail: michael.riccabona@kfunigraz.ac.at; Lindbichler, F.; Sinzig, M

    2002-08-01

    Objective: To briefly describe basic conventional imaging in paediatric uroradiology. Method: The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included. Result and conclusion: Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options.

  17. In vitro evaluation of marginal microleakage in class V restorations with composite resin in bovine teeth. Laser irradiation influences and the adhesive system in the dentin pre-treatment; Avaliacao in vitro da microinfiltracao marginal em restauracoes de classe V com resina composta em dentes bovinos. Influencia da irradiacao laser e sistema adesivo no pre-tratamento dentinario

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Wendell Lima de

    2003-07-01

    Microleakage is one of the most important reasons to restorations failure, it is the responsible for marginal colors changing, new caries, hipersensibility and pulpar diseases. Several techniques and materials have been studied to eliminate or, at least, to decrease microleakage. The cavities preparation with Er:YAG laser and autoconditioning adhesive are some of these techniques and materials. This research has the objective to compare, in vitro, microleakage in class V cavities, prepared with high rotation (conventional treatment), Er:YAG laser (Enamel-400 mj/2 Hz/128,38 J/Cm{sup 2}, Dentin 250 mJ/ 2 Hz/ 80,24 J/Cm{sup 2}) and the treatment made at dentin with autoconditioning adhesive (Clerafil SE Bond) using Er:YAG laser (with water or not water) or not using Er:YAG laser. It was used 48 bovines teeth with cavities prepared in vestibular face and gingival wall on cement enamel junction and oclusal wall on enamel. The materials used were autoconditioning adhesive (Clerafil SE Bond) and composite resin Z250. Teeth were divided into four groups of twelve samples each one, according to dentin treatment. Group 1 - Conventional cavity and autoconditioning adhesive. Group 2- Cavity prepared with Er: YAG laser and autoconditioning adhesive. Group 3 - Cavity prepared with Er:YAG laser and dentin conditioning with Er:YAG laser associated to water and autoconditioning adhesive. Group 4 - Cavity prepared with Er:YAG laser and dentin conditioning with Er: YAG laser without water and associated to autoconditioning adhesive. Teeth were restored and stocked at 37 deg C, thermocycled and placed into a 50% silver nitrate solution. Right after, teeth were sliced and evaluated on a stereo microscopic magnifying glass in order to see microleakage degree trying to follow a score from 0 to 3. The findings were submitted to Fisher, Anderson-Darling tests and to the not parametric Sen and Puri test. The results indicated that in gingival edge, the Group 2 showed less microleakage than

  18. 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

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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.

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

    Science.gov (United States)

    2013-01-01

    Background There is a lack of evidence for effective management of dental caries (decay) in children’s primary (baby) teeth and an apparent failure of conventional dental restorations (fillings) to prevent dental pain and infection for UK children in Primary Care. UK dental schools’ teaching has been based on British Society of Paediatric Dentistry guidance which recommends that caries in primary teeth should be removed and a restoration placed. However, the evidence base for this is limited in volume and quality, and comes from studies conducted in either secondary care or specialist practices. Restorations provided in specialist environments can be effective but the generalisability of this evidence to Primary Care has been questioned. The FiCTION trial addresses the Health Technology Assessment (HTA) Programme’s commissioning brief and research question “What is the clinical and cost effectiveness of restoration caries in primary teeth, compared to no treatment?” It compares conventional restorations with an intermediate treatment strategy based on the biological (sealing-in) management of caries and with no restorations. Methods/Design This is a Primary Care-based multi-centre, three-arm, parallel group, patient-randomised controlled trial. Practitioners are recruiting 1461 children, (3–7 years) with at least one primary molar tooth where caries extends into dentine. Children are randomized and treated according to one of three treatment approaches; conventional caries management with best practice prevention, biological management of caries with best practice prevention or best practice prevention alone. Baseline measures and outcome data (at review/treatment during three year follow-up) are assessed through direct reporting, clinical examination including blinded radiograph assessment, and child/parent questionnaires. The primary outcome measure is the incidence of either pain or infection related to dental caries. Secondary outcomes are

  3. The FiCTION dental trial protocol - filling children's teeth: indicated or not?

    Science.gov (United States)

    Innes, Nicola P T; Clarkson, Jan E; Speed, Chris; Douglas, Gail V A; Maguire, Anne

    2013-06-01

    There is a lack of evidence for effective management of dental caries (decay) in children's primary (baby) teeth and an apparent failure of conventional dental restorations (fillings) to prevent dental pain and infection for UK children in Primary Care. UK dental schools' teaching has been based on British Society of Paediatric Dentistry guidance which recommends that caries in primary teeth should be removed and a restoration placed. However, the evidence base for this is limited in volume and quality, and comes from studies conducted in either secondary care or specialist practices. Restorations provided in specialist environments can be effective but the generalisability of this evidence to Primary Care has been questioned. The FiCTION trial addresses the Health Technology Assessment (HTA) Programme’s commissioning brief and research question “What is the clinical and cost effectiveness of restoration caries in primary teeth, compared to no treatment?” It compares conventional restorations with an intermediate treatment strategy based on the biological (sealing-in) management of caries and with no restorations. This is a Primary Care-based multi-centre, three-arm, parallel group, patient-randomised controlled trial. Practitioners are recruiting 1461 children, (3-7 years) with at least one primary molar tooth where caries extends into dentine. Children are randomized and treated according to one of three treatment approaches; conventional caries management with best practice prevention, biological management of caries with best practice prevention or best practice prevention alone. Baseline measures and outcome data (at review/treatment during three year follow-up) are assessed through direct reporting, clinical examination including blinded radiograph assessment, and child/parent questionnaires. The primary outcome measure is the incidence of either pain or infection related to dental caries. Secondary outcomes are; incidence of caries in primary and

  4. Sensibility of Teeth Having Based versus Non-Based Amalgam Restorations: A Clinical Study.

    Science.gov (United States)

    1983-04-01

    50:129-34, Apr. 1980. 102. Morrant, G. Dental instrumentation and pulpal injury: clinical considerations. Brit. Endodont . Soc. J., 10:3-8, 55-63...on the teeth are suspected mechanisms. In general, the effects of rotary cavity preparations--cutting of dentinal tubules and odontoblastic processes...aspiration of odontoblasts is of no consequence to the pulp providing the cells in the cell rich zone are intact. The idea that heat production from rotary

  5. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba, E-mail: vanessalessa@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Escola de Odontologia. Departamento de Odontologia Restauradora

    2016-05-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm{sup 3}) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  6. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    International Nuclear Information System (INIS)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba

    2016-01-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm 3 ) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  7. 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)

  8. 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.

  9. 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.

  10. Fracture resistance of teeth restored with packable and hybrid composites

    Directory of Open Access Journals (Sweden)

    Ghavam M

    2006-06-01

    Full Text Available Background and Aim: With recent introduction of packable composites, it is claimed that they apply less stress on tooth structure because of reduced polymerization shrinkage, and similarity of coefficient of thermal expansion to tooth structure. However, the high viscosity may in turn cause less adaptation, so it is not clearly known whether these materials strengthen tooth structure or not. The aim of this study was to evaluate fracture resistance of maxillary premolars, receiving hybrid or packable composite restorations with different methods of application and curing. Materials and Methods: In this experimental study, seventy five intact premolars were randomly assigned to five groups of 15 teeth each. One group was maintained intact as the control group. Similar MOD cavities were prepared in the other teeth. The teeth in group two were restored with Spectrum in incremental layers and light cured with 500 mw/cm2 intensity. The third group were filled with Surefil and cured with light intensity of 500 mw/cm2. The groups four and five were restored with Surefil in bulk technique with two different modes: 500 mw/cm2 intensity and a ramp mode (100-900 mw/cm2 respectively. After thermocycling, force to fracture was assessed and degree of conversion (DC at the bottom of cavities was evaluated for different modes and methods. The curing and placement methods in groups tested for DC (A to D were the same as fracture resistance groups (2 to 5. Data were analyzed using one way ANOVA and Tukey HSD tests with p<0.05 as the limit of significance. Results: All the restored groups showed significantly less fracture resistance than the control group, but had no significant difference among themselves. DC of Spectrum was higher than Surefil. Bulk method with 500 mw/cm2 light intensity, significantly decreased DC. DC in bulk method with high light intensity was not significantly different from incremental method with 500 mw/cm2 light intensity. Conclusion

  11. 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.

  12. In Vitro Evaluation of the Effect of Tooth Structure Loss on Fracture Resistance of Endodontically Treated Teeth

    Directory of Open Access Journals (Sweden)

    Shirinzad M

    2017-06-01

    Full Text Available Introduction: Since preserving the structure of treated teeth is a critical success factor, studying the effects of tooth structure loss on fracture resistance of the tooth tissue appears necessary. The aim of this study was to evaluate the consequences of the loss of different tissues regarding fracture resistance of teeth undergoing root canal treatment without the use of indirect restorations. Methods :In this experimental study, 70 healthy maxillary first premolar teeth were randomly divided into 7 groups of 10 members, including control group, endodontic access preparation only, MOD cavity preparation, cutting buccal cusp, cutting palatal cusp, cutting buccal cusp and marginal ridge, and cutting the palatal cusp and marginal ridge. The coronal section of teeth was restored incrementally with light cure composite. Finally, samples underwent compressive load with 45˚ angle from each cusp slope in the middle of cusp with an instant speed of 1 mm per min in the Instron machine. Fracture resistance was measured and samples were examined under stereo-microscope to evaluate the mode of failure. Results: The resistance to fracture in root canal treated teeth in different groups in order from first to seventh was 797.13 ± 52.92, 722.50 ± 131.40, 432.15 ± 203.20, 592.66 ± 195.86 124.53 ± 33.09, 85.17 ± 18.45, and 26.03 ± 5.21 Newton. ANOVA test showed statistically significant differences between the groups in terms of their fracture resistance (P = 0.000. Conclusions: The results showed that fracture resistance levels of teeth were significantly affected by amount of their tissue loss. In this study, removal of teeth palatal cusp and marginal ridge had a significant effect on decreasing the fracture resistance, while removing the buccal cusps alone cannot have a significant effect.

  13. Replacing Heavily Damaged Teeth by Third Molar Autotransplantation With the Use of Cone-Beam Computed Tomography and Rapid Prototyping.

    Science.gov (United States)

    Verweij, Jop P; Anssari Moin, David; Wismeijer, Daniel; van Merkesteyn, J P Richard

    2017-09-01

    This article describes the autotransplantation of third molars to replace heavily damaged premolars and molars. Specifically, this article reports on the use of preoperative cone-beam computed tomographic planning and 3-dimensional (3D) printed replicas of donor teeth to prepare artificial tooth sockets. In the present case, an 18-year-old patient underwent autotransplantation of 3 third molars to replace 1 premolar and 2 molars that were heavily damaged after trauma. Approximately 1 year after the traumatic incident, autotransplantation with the help of 3D planning and rapid prototyping was performed. The right maxillary third molar replaced the right maxillary first premolar. The 2 mandibular wisdom teeth replaced the left mandibular first and second molars. During the surgical procedure, artificial tooth sockets were prepared with the help of 3D printed donor tooth copies to prevent iatrogenic damage to the actual donor teeth. These replicas of the donor teeth were designed based on the preoperative cone-beam computed tomogram and manufactured with the help of 3D printing techniques. The use of a replica of the donor tooth resulted in a predictable and straightforward procedure, with extra-alveolar times shorter than 2 minutes for all transplantations. The transplanted teeth were placed in infraocclusion and fixed with a suture splint. Postoperative follow-up showed physiologic integration of the transplanted teeth and a successful outcome for all transplants. In conclusion, this technique facilitates a straightforward and predictable procedure for autotransplantation of third molars. The use of printed analogues of the donor teeth decreases the risk of iatrogenic damage and the extra-alveolar time of the transplanted tooth is minimized. This facilitates a successful outcome. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Structural deformities of deciduous teeth in patients with hypophosphatemic vitamin D-resistant rickets

    International Nuclear Information System (INIS)

    Abe, K.; Ooshima, T.; Lily, T.S.; Yasufuku, Y.; Sobue, S.

    1988-01-01

    Structural deformities of deciduous teeth from patients with hypophosphatemic vitamin D-resistant rickets (HVDRR) (1 male and 2 female patients) were examined by means of transmitted light microscopy, contact microradiography, and x-ray microanalysis. Freshly extracted teeth were fixed in formalin and subsequently hemisected longitudinally through the midline. One half was prepared for ground sections and the other half for decalcified sections. Neither gross nor microscopic abnormalities were present in enamel of patients with HVDRR. The concentration of calcium and phosphorus and the calcium/phosphorus ratio of the enamel of patients with HVDRR were nearly equal to those of normal teeth, although the degree of radiopacity was less in HVDRR. On the other hand, numerous microscopic abnormalities in the dentin of patients with HVDRR were found, such as interglobular dentin, wide predentin zones, and tubular defects. The concentration of phosphorus in the dentin of a patient with familial HVDRR was extremely low. Furthermore, formation of reparative dentin was observed at the pulp horn of teeth in patients with HVDRR that had been subjected to definite attrition at the corresponding dentin site

  15. 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.

  16. Concentrations of amoxicillin and clindamycin in teeth following a single dose of oral medication.

    Science.gov (United States)

    Schüssl, Yvonne; Pelz, Klaus; Kempf, Jürgen; Otten, Jörg-Elard

    2014-01-01

    The main purpose of this study is the detection of amoxicillin and clindamycin concentrations in teeth. Eleven patients received 2 g of amoxicillin, and 11 patients received 600 mg of clindamycin in a single dose of oral medication at least 60 min prior to tooth extraction due to systemic diseases. The concentrations were determined in crowns and roots separately using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Amoxicillin (13 samples) and clindamycin (12 samples) were detected in the samples of the root and crown preparations of the extracted teeth. The mean concentration of amoxicillin was 0.502 μg/g in the roots and 0.171 μg/g in the crowns. The mean concentration of clindamycin was 0.270 μg/g in the roots and 0.064 μg/g in the crowns. A single dose of oral amoxicillin and clindamycin leads to concentrations of both antibiotics in teeth which exceed the minimal inhibition concentration of some oral bacteria. The proof of antibacterial activity in dental hard tissue after oral single-dose application is new. The antimicrobial effect of amoxicillin and clindamycin concentrations in roots of teeth may be of clinical relevance to bacterial reinfection from dentinal tubules.

  17. Dynamics of soft tissue healing at implants and teeth: a study in a dog model.

    Science.gov (United States)

    Sukekava, Flávia; Pannuti, Claudio M; Lima, Luiz A; Tormena, Mariana; Araújo, Mauricio G

    2016-05-01

    The aim of this study was to describe and to compare some characteristics of the soft tissue healing process around teeth and implants after flap surgery. Five adult beagle dogs had their third and fourth lower premolars extracted. After 3 months, four implants per dog were placed on the healed alveolar ridge and allowed to heal non-submerged during 3 months. After 3 months, four regions characterized by one implant and one adjacent tooth were identified in each dog. One region was randomly selected and soft tissue ressective flap surgery was performed at its buccal aspect. The remaining three regions were randomly treated in an identical manner, and the dogs were sacrificed to provide biopsies representing healing intervals of 1, 2, 4, and 12 weeks. The biopsies were prepared for histological and morphological analyses. Morphometric and histometric analyses have shown that the gingival tissues surrounding teeth were completely healed after a 4-week interval. However, it took from 4 to 12 weeks for the peri-implant mucosa to heal completely. The healing process around teeth and implants follows a similar sequence of events. Nevertheless, the complete process of healing and maturation of the peri-implant tissues takes longer than around teeth. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Evaluation of Metal Ion Concentration in Hard Tissues of Teeth in Residents of Central Poland

    Directory of Open Access Journals (Sweden)

    Piotr Wychowanski

    2017-01-01

    Full Text Available Objectives. The aim of the study was an assessment of the content of trace elements in enamel and dentin of teeth extracted in patients residing in urban and agricultural areas of Poland. Methods. The study included 30 generally healthy patients with retained third molars. 65 samples of enamel and dentin from individuals living in urban areas and 85 samples of enamel and dentin from individuals living in agricultural areas were prepared. The content of manganese, lead, cadmium, and chromium in the studied enamel and dentin samples from retained teeth was determined by Graphite Furnace Atomic Absorption Spectrometry. In the process of statistical hypothesis testing, the level of significance was assumed at α=0.05. Results. A comparative analysis of the data showed that enamel and dentin of inhabitants of industrialized areas contain significantly higher amounts of lead and cadmium than hard tissues of teeth in residents of agricultural areas and comparable amounts of manganese and chromium. Significance. It appears that hard tissues of retained teeth may constitute valuable material for assessment of long-term environmental exposure to metal ions. The study confirms that the risk of exposure to heavy metals depends on the place of residence and environmental pollution.

  19. Newer methods of extraction of teeth

    Directory of Open Access Journals (Sweden)

    MHendra Chandha

    2016-06-01

    Full Text Available Atraumatic extraction methods are deemed to be important to minimize alveolar bone loss after tooth extraction. With the advent of such techniques, exodontia is no more a dreaded procedure in anxious patients. Newer system and techniques for extraction of teeth have evolved in the recent few decades. This article reviews and discusses new techniques to make simple and complex exodontias more efficient with improved patient outcomes. This includes physics forceps, powered periotome, piezosurgery, benex extractor, sonic instrument for bone surgery, lasers.

  20. James Madison and the Constitutional Convention.

    Science.gov (United States)

    Scanlon, Thomas M.

    1987-01-01

    Part 1 of this three-part article traces James Madison's life and focuses primarily on those events that prepared him for leadership in the U.S. Constitutional Convention of 1787. It describes his early love of learning, education, and public service efforts. Part 2 chronicles Madison's devotion to study and preparation prior to the Constitutional…

  1. Resin-modified and conventional glass ionomer restorations in primary teeth: 8-year results

    DEFF Research Database (Denmark)

    Qvist, V.; Manscher, E.; Teglers, P.T.

    2004-01-01

    clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer......clinical trial, cariostatic effects, dental restorations, glass ionomer cement, long-term behaviour, pedodontics, resin-modified glass ionomer...

  2. Fracture behaviour of teeth with conventional and mini-invasive access cavity designs

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Žižka, R.; Kania, J.; Přibyl, M.

    2017-01-01

    Roč. 37, č. 14 (2017), s. 4423-4429 ISSN 0955-2219. [FAC 2016 - International Conference on Fractography of Advanced Ceramic s /5./. Smolenice, 09.10.2016-12.10.2016] R&D Projects: GA ČR GA14-11234S; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : endodontically treated premolars * in-vitro * maxillary premolars * stress-distribution * cusp coverage * resistance * composite * resin * restorations * scaffolds * Fracture resistance * Cavity * Tooth * Compressive test * Fractography Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass OBOR OECD: Ceramic s Impact factor: 3.411, year: 2016

  3. 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.

  4. The ability of different nickel-titanium rotary instruments to induce dentinal damage during canal preparation

    NARCIS (Netherlands)

    Bier, C.A.S.; Shemesh, H.; Tanomaru-Filho, M.; Wesselink, P.R.; Wu, M.K.

    2009-01-01

    The purpose of this study was to compare the incidence of dentinal defects (fractures and craze lines) after canal preparation with different nickel-titanium rotary files. Two hundred sixty mandibular premolars were selected. Forty teeth were left unprepared (n = 40). The other teeth were prepared

  5. A clinical comparison of cordless and conventional displacement systems regarding clinical performance and impression quality.

    Science.gov (United States)

    Acar, Özlem; Erkut, Selim; Özçelik, Tuncer Burak; Ozdemır, Erdem; Akçil, Mehtap

    2014-05-01

    It is not clear whether newly introduced cordless displacement systems are better able to manage gingiva than conventional systems. The purpose of this in vivo study was to evaluate the gingival management ability of 4 different displacement methods with a standardized subgingival preparation finish line. The effects of 4 displacement techniques on gingival management and impression quality were evaluated by means of 6 evaluation criteria. A subgingival preparation finish line of between 1 and 2 mm was ensured, and the buccal aspects of 252 (n=63) teeth were clinically assessed for ease of application, time spent, bleeding, remnants, and dilatation. The complete reproduction of the preparation finish line and the bubble and void formations on polyether impressions were also evaluated. The data were statistically analyzed with the χ(2) test (α=.05). The Bonferroni correction was used to control Type I error for the pairwise comparison groups (α=.008). Statistically significant differences were found for all criteria among the groups (Pimpression quality (Pimpression quality (P>.008). The retraction cap with paste group showed better results for ease of application, time spent, and bleeding than the aluminum chloride impregnated cord group (Pimpression qualities. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  6. 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.

  7. 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.

  8. 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.

  9. Histopathologic study on irradiated human developing teeth

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yasunori (Iwate Medical Coll., Morioka (Japan). School of Dentistry)

    1982-12-01

    The patient was a 7-year-old boy who had been suffering from Ewing's sarcoma originating in the mandible. Irradiation with 8000 rad of Linac was performed on the mandible prior to mandibulectomy. The results of the histopathologic examination of the teeth including resected material were as follows: 1. Although the tumor tissue was not found in the resected material, complete resoption of the medullar trabecular bone with fibrosis was noted in the area between the first molar region and the mandibular ramus. 2. The first and the second premolar teeth were in the early stage of root formation, and conglomerates of dysplastic dentin were formed in the proliferative zones. This dysplastic dentin was surrounded by loose fibrous connective tissues. 3. The dysplastic dentin showed low mineralization, embedded irregular arranged-fibrous tissue matrix and scattered various-sized lacunae containing a few tiny and pyknotic cells. 4. Irregularly arranged odontoblasts with a pyknotic appearance were found along the tubular dentin, but diffuse fibrosis occurred in the pulpal tissues. 5. The first molar tooth had completed its root formation. Various amounts of osteodentin were formed at the secondary dentin layer. Inner-resorption of dentin and fibrosis of the pulpal tissue were also found. These changes concerning the first molar tooth were also due to the effects of irradiation. 6. The second molar tooth was resorbed by tumor infiltration, and dysplastic dentin was on the resorbed surface of the dentin.

  10. Radiographic localization of unerupted mandibular anterior teeth.

    Science.gov (United States)

    Jacobs, S G

    2000-10-01

    The parallax method and the use of 2 radiographs taken at right angles to each other are the 2 methods generally used to accurately localize teeth. For the parallax method, the combination of a rotational panoramic radiograph with an occlusal radiograph is recommended. This combination involves a vertical x-ray tube shift. Three case reports are presented that illustrate: (1) how this combination can accurately localize unerupted mandibular anterior teeth, (2) how a deceptive appearance of the labiolingual position of the unerupted tooth can be produced in an occlusal radiograph, (3) how increasing the vertical angle of the tube for the occlusal radiograph makes the tube shift easier to discern, (4) why occlusal radiographs are preferable to periapical radiographs for tube shifts, and (5) how localization can also be carried out with 2 radiographs at right angles to each other, one of which is an occlusal radiograph taken with the x-ray tube directed along the long axis of the reference tooth.

  11. 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 ...

  12. 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...

  13. Chemical Weapons Convention

    National Research Council Canada - National Science Library

    1997-01-01

    On April 29, 1997, the Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on Their Destruction, known as the Chemical Weapons Convention (CWC...

  14. 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...

  15. 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.

  16. Methodology for Structural Calculation of Gear Teeth with Unconventional Profile

    Directory of Open Access Journals (Sweden)

    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.

  17. Direct composite restoration of permanent anterior teeth uncomplicated crown fractures

    Directory of Open Access Journals (Sweden)

    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.

  18. Dental Anomalies in Permanent Teeth after Trauma in Primary Dentition.

    Science.gov (United States)

    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.

  19. 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

  20. Pulpectomy in hyperemic pulp and accelerated root resorption in primary teeth: A review with associated case report

    Directory of Open Access Journals (Sweden)

    Tarun Walia

    2014-01-01

    Full Text Available Persistent hemorrhage after complete amputation of coronal pulp is a common clinical finding during pulpotomy procedure in primary teeth. These teeth are best managed with pulpectomy, but they have hyperemic pulp with some remaining vital tissue. Good chemico-biomechanical preparation of primary canals cannot guarantee complete removal of this vital tissue from inaccessible areas. Use of Ca(OH 2 containing root filling pastes in vital pulp tissue can cause accelerated resorption of primary roots. The possible mechanism behind such extensive root resorption is discussed with review of literature. A case report of a child with 30 months follow-up is presented and discussed.

  1. The Hague Judgments Convention

    DEFF Research Database (Denmark)

    Nielsen, Peter Arnt

    2011-01-01

    The Hague Judgments Convention of 2005 is the first global convention on international jurisdiction and recognition and enforcement of judgments in civil and commercial matters. The author explains the political and legal background of the Convention, its content and certain crucial issues during...

  2. Effect of bulk-fill base material on fracture strength of root-filled teeth restored with laminate resin composite restorations.

    Science.gov (United States)

    Taha, N A; Maghaireh, G A; Ghannam, A S; Palamara, J E

    2017-08-01

    To evaluate the effect of using a bulk-fill flowable base material on fracture strength and fracture patterns of root-filled maxillary premolars with MOD preparations restored with laminate restorations. Fifty extracted maxillary premolars were selected for the study. Standardized MOD cavities with endodontic treatment were prepared for all teeth, except for intact control. The teeth were divided randomly into five groups (n=10); (Group 1) sound teeth, (Group 2) unrestored teeth; (Group 3) MOD cavities with Vitrebond base and resin-based composite (Ceram. X One Universal); (Group 4) MOD cavities with 2mm GIC base (Fuji IX GP) and resin-based composite (Ceram. X One Universal) open laminate, (Group 5) MOD cavities were restored with 4mm of bulk-fill flowable base material (SDR) and resin-based composite (Ceram. X One Universal). All teeth were thermocycled and subjected to a 45° ramped oblique load in a universal testing machine. Fracture load and fracture patterns were recorded. Data were analyzed using one-way ANOVA and Dunnett's T3 test. Restoration in general increased the fracture strength compared to unrestored teeth. The fracture strength of group 5 (bulk-fill) was significantly higher than the fracture strength of the GIC laminate groups and not significantly different from the intact teeth (355±112N, P=0.118). The type of failure was unfavorable for most of the groups, with the majority being mixed failures. The use of a bulk-fill flowable base material significantly increased the fracture strength of extracted root-filled teeth with MOD cavities; however it did not improve fracture patterns to more favorable ones. Investigating restorative techniques that may improve the longevity of root-filled premolar teeth restored with direct resin restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Comparative evaluation of endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe in obturation of primary teeth: An in vitro study.

    Science.gov (United States)

    Hiremath, Mallayya C; Srivastava, Pooja

    2016-01-01

    The purpose of this in vitro study was to compare four methods of root canal obturation in primary teeth using conventional radiography. A total of 96 root canals of primary molars were prepared and obturated with zinc oxide eugenol. Obturation methods compared were endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe. The root canal obturations were evaluated by conventional radiography for the length of obturation and presence of voids. The obtained data were analyzed using Chi-square test. The results showed significant differences between the four groups for the length of obturation (P tube showed the poor results (37.5% optimal fillings) for the length of obturation. The insulin syringe (79.2% optimal fillings) and local anesthetic syringe (66.7% optimal fillings) showed acceptable results for the length of root canal obturation. However, minor voids were present in all the four techniques used. Endodontic pressure syringe produced the best results in terms of length of obturation and controlling paste extrusion from the apical foramen. However, insulin syringe and local anesthetic syringe can be used as effective alternative methods.

  4. Comparative study between manual injection intraosseous anesthesia and conventional oral anesthesia

    OpenAIRE

    Peñarrocha-Oltra, David; Ata-Ali, Javier; Oltra-Moscardó, María J.; Peñarrocha-Diago, María; Peñarrocha, Miguel

    2011-01-01

    Objective: To compare intraosseous anesthesia (IA) with the conventional oral anesthesia techniques. Materials and methods: A simple-blind, prospective clinical study was carried out. Each patient underwent two anesthetic techniques: conventional (local infiltration and locoregional anesthetic block) and intraosseous, for res-pective dental operations. In order to allow comparison of IA versus conventional anesthesia, the two operations were similar and affected the same two teeth in opposite...

  5. Comparative evaluation of surface topography of tooth prepared using erbium, chromium: Yttrium, scandium, gallium, garnet laser and bur and its clinical implications.

    Science.gov (United States)

    Verma, Mahesh; Kumari, Pooja; Gupta, Rekha; Gill, Shubhra; Gupta, Ankur

    2015-01-01

    Erbium, chromium: Yttrium, scandium, gallium, garnet (Er, Cr: YSGG) laser has been successfully used in the ablation of dental hard and soft tissues. It has been reported that this system is also useful for preparing tooth surfaces and etching, but no consensus exist in the literature regarding the advantage of lasers over conventional tooth preparation technique. Labial surfaces of 25 extracted human maxillary central incisors were divided into two halves. Right half was prepared with diamond bur and left half with Er, Cr; YSGG laser and a reduction of 0.3-0.5 mm was carried out. Topography of prepared surfaces of five teeth were examined under scanning electron microscope (SEM). The remaining samples were divided into 4 groups of 10 specimens each based on the surface treatment received: One group was acid etched and other was nonetched. Composite resin cylinders were bonded on prepared surfaces and shear bond strength was assessed using a universal testing machine. The SEM observation revealed that the laser prepared surfaces were clean, highly irregular and devoid of a smear layer. Bur prepared surfaces were relatively smooth but covered with smear layer. Highest bond strength was shown by laser prepared acid etched group, followed by bur prepared the acid etched group. The bur prepared nonacid etched group showed least bond strength. Er, Cr: YSGG laser can be used for preparing tooth and bond strength value achieved by laser preparation alone without surface treatment procedure lies in the range of clinical acceptability.

  6. 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.

  7. A prospective study of the incidence of asymptomatic pulp necrosis following crown preparation.

    Science.gov (United States)

    Kontakiotis, E G; Filippatos, C G; Stefopoulos, S; Tzanetakis, G N

    2015-06-01

    To determine the incidence of asymptomatic pulp necrosis following crown preparation as well as the positive predictive value of the electric pulp testing. A total of 120 teeth with healthy pulps scheduled to receive fixed crowns (experimental teeth) were included. Teeth were divided into two groups according to the preoperative crown condition (intact teeth and teeth with preoperative caries, restorations or crowns) and into four groups according to tooth type (maxillary anterior teeth, maxillary posterior teeth, mandibular anterior teeth and mandibular posterior teeth). Experimental and control teeth were submitted to electric pulp testing on three different occasions before treatment commencement (stage 0), at the impression making session (stage 1) and just before the final cementation of the crown (stage 2). Teeth that were considered to contain necrotic pulps were submitted to root canal treatment. Upon access, absence of bleeding was considered as a confirmation of pulp necrosis. Data were analysed using bivariate (chi-square) and multivariate analysis (logistic regression). All reported probability values (P-values) were based on two-sided tests and compared to a significance level of 5%. The overall incidence of pulp necrosis was 9%. Intact teeth had a significantly lower incidence of pulp necrosis (5%) compared with preoperatively structurally compromised teeth (13%) [(OR: 9.113, P = 0.035)]. No significant differences were found amongst the four groups with regard to tooth type (P = 0.923). The positive predictive value of the electric pulp testing was 1.00. The incidence of asymptomatic pulp necrosis of teeth following crown preparation is noteworthy. The presence of preoperative caries, restorations or crowns of experimental teeth correlated with a significantly higher incidence of pulp necrosis. Electric pulp testing remains a useful diagnostic instrument for determining the pulp condition. © 2014 International Endodontic Journal. Published by

  8. Guideline for the acquisition and preparation of conventional and endobronchial ultrasound-guided transbronchial needle aspiration specimens for the diagnosis and molecular testing of patients with known or suspected lung cancer

    NARCIS (Netherlands)

    Heijden, E. van der; Casal, R.F.; Trisolini, R.; Steinfort, D.P.; Hwangbo, B.; Nakajima, T.; Guldhammer-Skov, B.; Rossi, G.; Ferretti, M.; Herth, F.F.; Yung, R.; Krasnik, M.

    2014-01-01

    RATIONALE: Conventional transbronchial needle aspiration (TBNA) and endobronchial ultrasound (EBUS)-TBNA are widely accepted tools for the diagnosis and staging of lung cancer and the initial procedure of choice for staging. Obtaining adequate specimens is key to provide a specific histologic and

  9. Oxygen isotope analysis of shark teeth phosphates from Bartonian (Eocene) deposits in Mangyshlak peninsula, Kazakhstan

    Science.gov (United States)

    Pelc, Andrzej; Hałas, Stanisław; Niedźwiedzki, Robert

    2011-01-01

    We report the results of high-precision (±0.05‰) oxygen isotope analysis of phosphates in 6 teeth of fossil sharks from the Mangyshlak peninsula. This precision was achieved by the offline preparation of CO2 which was then analyzed on a dual-inlet and triple-collector IRMS. The teeth samples were separated from Middle- and Late Bartonian sediments cropping out in two locations, Usak and Kuilus. Seawater temperatures calculated from the δ18O data vary from 23-41°C. However, these temperatures are probably overestimated due to freshwater inflow. The data point at higher temperature in the Late Bartonian than in the Middle Bartonian and suggest differences in the depth habitats of the shark species studied.

  10. 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)

  11. Applying tribology to teeth of hoofed mammals.

    Science.gov (United States)

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

    2010-01-01

    Mammals inhabit all types of environments and have evolved chewing systems capable of processing a huge variety of structurally diverse food components. Surface textures of cheek teeth should thus reflect the mechanisms of wear as well as the functional traits involved. We employed surface textures parameters from ISO/DIS 25178 and scale-sensitive fractal analysis (SSFA) to quantify dental wear in herbivorous mammals at the level of an individual wear enamel facet. We evaluated cheek dentitions of two grazing ungulates: the Blue Wildebeest (Connochaetes taurinus) and the Grevy's Zebra (Equus grevyi). Both inhabit the east African grassland savanna habitat, but they belong to fundamentally different taxonomic units. We tested the hypothesis that the foregut fermenting wildebeest and the hindgut fermenting zebra show functional traits in their dentitions that relate to their specific mode of food-composition processing and digestion. In general, surface texture parameters from SSFA as well as ISO/DIS 25178 indicated that individual enamel ridges acting as crushing blades and individual wear facets of upper cheek teeth are significantly different in surface textures in the zebra when compared with the wildebeest. We interpreted the complexity and anisotropy signals to be clearly related to the brittle, dry grass component in the diet of the zebra, unlike the wildebeest, which ingests a more heterogeneous diet including fresh grass and herbs. Thus, SSFA and ISO parameters allow distinctions within the subtle dietary strategies that evolved in herbivorous ungulates with fundamentally different systematic affinities but which exploit a similar dietary niche. © 2010 Wiley Periodicals, Inc.

  12. Calcium hydroxide as intracanal dressing for teeth with apical periodontitis

    Directory of Open Access Journals (Sweden)

    Sari Dewiyani

    2011-03-01

    Full Text Available Background: Root canal infection and periapical diseases are caused by bacteria and their products. Long term infection may spread bacteria throughout the root canal system. Apical periodontitis caused by infectious microbe that persistent in root canals can cause radiographic and histopathology periapical changes. Chemomechanical preparation and intracanal dressing then are recommended to be conducted and used in between visits to eliminate microbes in root canals. Calcium hydroxide (Ca(OH2 can be used as intracanal dressing since it can be used as musical physical defense barrier to eliminate re-infection in root canal and to disturb nutrition supply for bacterial development. Purpose: The aim of this study is observe the effectiveness of Ca(OH2 in treating endodontic teeth with apical periodontitis. Cases: Case 1 and 3 are about patients whose left posterior mandibular teeth had spontaneous intermittent pain. Case 2 is about a patient whose left posterior maxillary teeth had gingival abscess and fracture history. Based on the radiographic examination, it was known that the filling of root canal was incomplete and there was radiolucency in the apical area. Case management: The cases were treated with triad endodontics, which involves preparation, disinfection by using 2.5% NaOCl as irrigation substance and calcium hydroxide as intracanal dressing, and then the filling of root canal with gutta percha and endomethasone root canal cement. Evaluations were conducted one month, 12 months, and 24 months after the treatment. Conclusion: Calcium hydroxide is effective to be used as intracanal dressing in apical periodontitis cases.Latar belakang: Infeksi saluran akar dan penyakit periapeks disebabkan oleh mikroba dan produknya. Infeksi yang berlangsung lama memungkinkan bakteri masuk ke dalam seluruh sistem saluran akar. Periodontitis apikal disebabkan oleh infeksi persisten mikroba di dalam sistem saluran akar disertai perubahan radiografik dan

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Effect of sodium bicarbonate-buffered lidocaine on the success of inferior alveolar nerve block for teeth with symptomatic irreversible pulpitis: a prospective, randomized double-blind study.

    Science.gov (United States)

    Saatchi, Masoud; Khademi, Abbasali; Baghaei, Badri; Noormohammadi, Hamid

    2015-01-01

    The purpose of this prospective, randomized, double-blind study was to compare the anesthetic efficacy of buffered with nonbuffered 2% lidocaine with 1:80,000 epinephrine solution for inferior alveolar nerve (IAN) block in patients with mandibular posterior teeth experiencing symptomatic irreversible pulpitis. Eighty adult patients diagnosed with symptomatic irreversible pulpitis of a mandibular posterior tooth were selected. The patients received 2 cartridges of either 2% lidocaine with 1:80,000 epinephrine buffered with 0.18 mL 8.4% sodium bicarbonate or 2% lidocaine with 1:80,000 epinephrine with 0.18 mL sterile distilled water using conventional IAN block injections. Endodontic access preparation was initiated 15 minutes after injection. Lip numbness was required for all the patients. Success was determined as no or mild pain on the basis of Heft-Parker visual analog scale recordings upon access cavity preparation or initial instrumentation. Data were analyzed by the t, Mann-Whitney, and chi-square tests. The success rates were 62.5% and 47.5% for buffered and nonbuffered groups, respectively, with no significant differences between the two groups (P = .381). Buffering the 2% lidocaine with 1:80,000 epinephrine with 8.4% sodium bicarbonate did not improve the success of the IAN block in mandibular molars in patients with symptomatic irreversible pulpitis. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Shrinkage stress compensation in composite-restored teeth: relaxation or hygroscopic expansion?

    Science.gov (United States)

    Meriwether, Laurel A; Blen, Bernard J; Benson, Jarred H; Hatch, Robert H; Tantbirojn, Daranee; Versluis, Antheunis

    2013-05-01

    Polymerization of composite restorations causes shrinkage, which deforms and thus stresses restored teeth. This shrinkage deformation, however, has been shown to decrease over time. The objective was to investigate whether this reduction was caused by hygroscopic expansion or stress relaxation of the composite/tooth complex. Extracted molars were mounted in rigid stainless steel rings with four spherical reference areas. Twelve molars were prepared with large mesioocclusodistal slots, etched, bonded, and restored with a composite material (Filtek Supreme, 3M ESPE) in two horizontal layers. Ten intact molars were the controls. The teeth were stored either in deionized water or silicone oil. They were scanned after preparation (baseline), restoration (0-week), and after 1, 2, and 4 weeks storage. Scanned tooth surfaces were aligned with the baseline using the unchanged reference areas. Cuspal flexure was calculated from lingual and buccal surface deformation. To verify that the restorations had remained bonded, dye penetration at the interfaces was assessed using basic fuchsin dye. Statistical assessment was done by ANOVA followed by Student-Newman-Keuls post hoc test (p=0.05). Substantial cuspal contraction was found for restored teeth after the composite was cured (13-14 μm cuspal flexure). After 4 weeks cuspal contraction decreased significantly for restored teeth stored in water (7.3 ± 3.2) but not for those stored in silicone oil (11.4 ± 5.0). Dye penetration of the occlusal interface was minimal in both groups (106 ± 87 and 21 ± 28 μm in water and silicone oil, respectively). The results suggest that hygroscopic expansion was the main mechanism for shrinkage stress compensation. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Comparative evaluation of the efficacy of chemomechanical caries removal agent (Papacarie and conventional method of caries removal: An in vitro study

    Directory of Open Access Journals (Sweden)

    Jawa D

    2010-06-01

    Full Text Available Painless dentistry, minimal intervention and thus giving comfort, relief and solace and instill positive attitude toward dental treatments, are some of the factors justifying the specialty of pediatric dentistry. Thus, this in vitro study was undertaken to compare the efficacy of a new chemomechanical caries removal agent, Papacarie (Formula and Acao, with conventional slow-speed rotary instrument (bur. Papacarie is a new formulation and has the main active ingredient papain, an endoprotein with bactericidal, bacteriostatic and anti-inflammatory actions. Twenty extracted human molar teeth with deep dentine caries and no enamel coverage were selected for the study. After the preparation of the teeth and removal of the caries with the respective methods, they were decalcified, dehydrated and embedded in paraffin blocks for histologic studies. Serial sections of 5 μm thickness were examined for the presence of bacteria under light microscope. Though complete removal of caries was achieved significantly in both the methods, there was less marked destruction of dentinal tubules in chemomechanical caries removal method by Papacarie. Thus, Papacarie is recommended as an efficient, easy to perform, comfortable and less destructive solution for the patient seeking an alternative to the conventional method.

  18. Modelling of teeth of a gear transmission for modern manufacturing technologies

    Science.gov (United States)

    Monica, Z.; Banaś, W.; Ćwikla, G.; Topolska, S.

    2017-08-01

    The technological process of manufacturing of gear wheels is influenced by many factors. It is designated depending on the type of material from which the gear is to be produced, its heat treatment parameters, the required accuracy, the geometrical form and the modifications of the tooth. Therefor the parameters selection process is not easy and moreover it is unambiguous. Another important stage of the technological process is the selection of appropriate tools to properly machine teeth in the operations of both roughing and finishing. In the presented work the focus is put first of all on modern production methods of gears using technologically advanced instruments in comparison with conventional tools. Conventional processing tools such as gear hobbing cutters or Fellows gear-shaper cutters are used from the beginning of the machines for the production of gear wheels. With the development of technology and the creation of CNC machines designated for machining of gears wheel it was also developed the manufacturing technology as well as the design knowledge concerning the technological tools. Leading manufacturers of cutting tools extended the range of tools designated for machining of gears on the so-called hobbing cutters with inserted cemented carbide tips. The same have be introduced to Fellows gear-shaper cutters. The results of tests show that is advantaged to use hobbing cutters with inserted cemented carbide tips for milling gear wheels with a high number of teeth, where the time gains are very high, in relation to the use of conventional milling cutters.

  19. 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. ...

  20. 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.

  1. ELECTRIC PULP TEST OF TEETH WITH PERIODONTAL DISEASE.

    Directory of Open Access Journals (Sweden)

    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.

  2. The effects of impacted premaxillary supernumerary teeth on permanent incisors

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. 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...

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Marginal microleakage in vitro study of occlusal fissures sealing prepared and etched or not with Er: YAG laser

    International Nuclear Information System (INIS)

    Youssef, Fernanda de Almeida

    2004-01-01

    The aim of this in vitro study was to evaluate the degree of marginal microleakage in occlusal sealing by invasive techniques, after preparation with Er:YAG laser followed or not by Er:YAG laser etching and compared to the conventional technique. Thirty human premolars were divided into three groups: A (control group) - cavities were prepared with high speed and etched with 37% orthophosphoric acid; group B - cavities were prepared with Er:YAG (350 mJ, 4 Hz and 112 J /cm 2 ) and etched with 37% orthophosphoric acid; group C - cavities were prepared with Er:YAG laser (350 mJ, 4 Hz and 112 J/cm 2 ), and etched with Er:YAG laser (80 mJ, 4 Hz and 25 m/cm 2 ). All cavities were treated with the same adhesive system and restored with flow composite according to manufacturer instructions. Teeth were submitted to thermal cycling procedures and immersed in 50% Silver Nitrate Solutions for 8 hours in total darkness. Teeth were sectioned longitudinally in the bucco-lingual direction, in slices of 1 mm thick. Each slice was immersed into photo developing solution under 16 hours of fluorescent light. Slices were photographed and microleakage was scored from 0 to 7 J by three standard examiners. Results showed statistically significant differences for group C (Er:YAG laser preparation and etching). We concluded that Er:YAG laser can be used for cavity preparation of occlusal sealing, like the conventional high speed method. However, this laser, used as enamel etching agent, could not promote an adequate surface for adhesive procedures. (author)

  9. 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.

  10. Saving Natural Teeth: Intentional Replantation-Protocol and Case Series.

    Science.gov (United States)

    Grzanich, Derek; Rizzo, Gabriella; Silva, Renato Menezes

    2017-12-01

    Intentional replantation is a reliable and predictable treatment for cases in which nonsurgical endodontic retreatment failed or is impractical and endodontic surgery is hampered because of anatomic limitations. This article presents a protocol for intentional replantation illustrated with some interesting cases. The cases presented here are from patients (average age, 61 years) with no contributing medical history. The cases are molars with previous failed endodontic treatment/retreatment and diagnosed with apical periodontitis. Treatment procedures included atraumatic extractions with minimal manipulations of the periodontal ligament, followed by root-end resection, root-end preparation with ultrasonic tips, root-end fill with bioceramic cement, and rapid tooth replacement into the socket. Granulomatous tissue was gently curetted when applicable. All procedures were performed under the microscope. Intentional replantation with careful case selection may be considered as a last option for preserving hopeless teeth. Atraumatic extraction by using state-of-the-art equipment, instruments, and materials, minimal extra-alveolar time, and maintaining an aseptic technique are key factors for success. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of crown mesiodistal diameter of permanent teeth

    Directory of Open Access Journals (Sweden)

    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.

  12. Root canal treatment of pulpless immature teeth using calcium hydroxide paste. Roentgenographic study

    International Nuclear Information System (INIS)

    Leite, R.M.G.V.; Abbud, R.

    1986-01-01

    Calcium hydroxide paste was used as a temporary dressing and the renewal was done each three months in the root treatment of immature teeth with open apex and necrotic pulps. Clinical and radiographic controls were made to observe foraminal closure. After that, the root canals were filled, employing the conventional technique with gutta-percha cones and zinc oxide eugenol cements. The calcium hydroxide paste was applied in the apical region before the root canal filling. The follow-up was done periodically and the cases have more than two years of control. (author) [pt

  13. Imaging technique for the complete edentulous patient treated conventionally or with mini implant overdenture

    Science.gov (United States)

    Meleşcanu Imre, M; Preoteasa, E; Țâncu, AM; Preoteasa, CT

    2013-01-01

    Rationale. The imaging methods are more and more used in the clinical process of modern dentistry. Once the implant based treatment alternatives are nowadays seen as being the standard of care in edentulous patients, these techniques must be integrated in the complete denture treatment. Aim. The study presents some evaluation techniques for the edentulous patient treated by conventional dentures or mini dental implants (mini SKY Bredent) overdentures, using the profile teleradiography. These offer data useful for an optimal positioning of the artificial teeth and the mini dental implants, favoring to obtain an esthetic and functional treatment outcome. We proposed also a method to conceive a simple surgical guide that allows the prosthetically driven implants placement. Material and method. Clinical case reports were made, highlighting the importance of cephalometric evaluation on lateral teleradiographs in complete edentulous patients. A clinical case that gradually reports the surgical guide preparation (Bredent silicon radio opaque), in order to place the mini dental implants in the best prosthetic and anatomic conditions, was presented. Conclusions. The profile teleradiograph is a useful tool for the practitioner. It allows establishing the optimal site for implant placement, in a good relation with the overdenture. The conventional denture can be easily and relatively costless transformed in a surgical guide used during implant placement. PMID:23599828

  14. Comparison of retention and demineralization inhibition potential of adhesive banding cements in primary teeth.

    Science.gov (United States)

    Prabhakar, A R; Mahantesh, T; Ahuja, Vipin

    2010-01-01

    The purpose of this study was to evaluate the efficacy of banding cements in terms of retentive capability and demineralization inhibition potential. We included 48 non-carious primary mandibular second molar teeth. Preformed stainless steel bands were adapted onto the teeth. All teeth were randomly assigned to four groups: Group I (Adaptation of bands without cementation), Group II (Cementation of bands using conventional Glass Ionomer Cement), Group III (Cementation of bands using Resin-modified Glass Ionomer Cement), Group IV (Cementation of bands using Resin cement), and placed in artificial saliva. Each day, specimens were taken from artificial saliva and suspended in an artificial caries solution for 35 minutes, every 8 hours. At the end of 3 months, retention of bands was estimated using an Instron Universal Testing Machine. The mode of failure was recorded and specimens were sectioned and examined under polarized microscope for demineralized lesions. The mean retention value was highest with resin cement, followed by RMGIC, GIC, and Control group respectively. The RMGIC group showed more favorable modes of failures. All the experimental groups showed significant demineralization inhibition potential. RMGIC is the preferable banding cement and can be used effectively to cement bands in primary dentition.

  15. 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.

  16. Accuracy of single-tooth restorations based on intraoral digital and conventional impressions in patients.

    Science.gov (United States)

    Boeddinghaus, Moritz; Breloer, Eva Sabina; Rehmann, Peter; Wöstmann, Bernd

    2015-11-01

    The purpose of this clinical study was to compare the marginal fit of dental crowns based on three different intraoral digital and one conventional impression methods. Forty-nine teeth of altogether 24 patients were prepared to be treated with full-coverage restorations. Digital impressions were made using three intraoral scanners: Sirona CEREC AC Omnicam (OCam), Heraeus Cara TRIOS and 3M Lava True Definition (TDef). Furthermore, a gypsum model based on a conventional impression (EXA'lence, GC, Tokyo, Japan) was scanned with a standard laboratory scanner (3Shape D700). Based on the dataset obtained, four zirconia copings per tooth were produced. The marginal fit of the copings in the patient's mouth was assessed employing a replica technique. Overall, seven measurement copings did not fit and, therefore, could not be assessed. The marginal gap was 88 μm (68-136 μm) [median/interquartile range] for the TDef, 112 μm (94-149 μm) for the Cara TRIOS, 113 μm (81-157 μm) for the laboratory scanner and 149 μm (114-218 μm) for the OCam. There was a statistically significant difference between the OCam and the other groups (p < 0.05). Within the limitations of this study, it can be concluded that zirconia copings based on intraoral scans and a laboratory scans of a conventional model are comparable to one another with regard to their marginal fit. Regarding the results of this study, the digital intraoral impression can be considered as an alternative to a conventional impression with a consecutive digital workflow when the finish line is clearly visible and it is possible to keep it dry.

  17. 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

  18. Thermal analysis of different application techniques on Nd:YAG laser after root canal preparation of single-rooted teeth; Analise termica de diferentes tecnicas de utilizacao do laser de Nd:YAG apos o preparo quimico-cirurgico de dentes unirradiculares

    Energy Technology Data Exchange (ETDEWEB)

    Archilla, Jose Ricardo de F

    2001-07-01

    The experiment objective is to analyze temperature variation, by means of three different application techniques of Nd:YAG laser in the root canals of singlerooted anterior teeth. Three root canals were instrumented, irrigated, X-rayed to measure the remaining dentin in the apical area and submitted to laser irradiation techniques used by Gutknecht, Matsumoto and a new technique with oscillatory movement. The used laser parameters were: pulse energy 250 mJ, frequency 5 Hz, pulse fluency 354 J/cm{sup 2}, average potency 1,25 W, pulse width 300 {mu}s, fiber core diameter 300 {mu}s and interval of thermal relaxation of 20 s. After temperature evaluation and interpretation of the obtained data, it was concluded: 1) the oscillatory technique provided a better heat distribution during the laser application, when analyzing the graphs separately; 2) all the used techniques are within a pattern of safety, analyzing the average and highest temperatures of the apical area and the middle third, even so, disrespecting the last application day and the middle third of root 'C'.(author)

  19. Thermal analysis of different application techniques on Nd:YAG laser after root canal preparation of single-rooted teeth; Analise termica de diferentes tecnicas de utilizacao do laser de Nd:YAG apos o preparo quimico-cirurgico de dentes unirradiculares

    Energy Technology Data Exchange (ETDEWEB)

    Archilla, Jose Ricardo de F

    2001-07-01

    The experiment objective is to analyze temperature variation, by means of three different application techniques of Nd:YAG laser in the root canals of singlerooted anterior teeth. Three root canals were instrumented, irrigated, X-rayed to measure the remaining dentin in the apical area and submitted to laser irradiation techniques used by Gutknecht, Matsumoto and a new technique with oscillatory movement. The used laser parameters were: pulse energy 250 mJ, frequency 5 Hz, pulse fluency 354 J/cm{sup 2}, average potency 1,25 W, pulse width 300 {mu}s, fiber core diameter 300 {mu}s and interval of thermal relaxation of 20 s. After temperature evaluation and interpretation of the obtained data, it was concluded: 1) the oscillatory technique provided a better heat distribution during the laser application, when analyzing the graphs separately; 2) all the used techniques are within a pattern of safety, analyzing the average and highest temperatures of the apical area and the middle third, even so, disrespecting the last application day and the middle third of root 'C'.(author)

  20. X-ray fluorescence with synchrotron radiation to elemental analysis of lead and calcium content of primary teeth

    International Nuclear Information System (INIS)

    Souza Guerra, Carolina de; Fernanda Gerlach, Raquel; Graciele Villela Pinto, Nivia; Coutinho Cardoso, Simone; Moreira, Silvana; Pereira de Almeida, Andre; Teixeira Alves Peixoto, Iza; Henrique Meloni, Carlos; Lemos Mota, Carla; Fernando de Oliveira, Luis; Braz, Delson; Cely Barroso, Regina

    2010-01-01

    Primary teeth were analyzed by micro-SRXRF. The aim of this study was to determine the elemental distribution of lead and calcium in different regions of primary incisor of children living in a notoriously contaminated area (Santo Amaro da Purificacao, Bahia State, Brazil). 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).

  1. Experimental and numerical determination of the mechanical response of teeth with reinforced posts

    International Nuclear Information System (INIS)

    Papadopoulos, Triantafillos; Papadogiannis, Dimitris; Mouzakis, Dionysios E; Giannadakis, Konstantinos; Papanicolaou, George

    2010-01-01

    The aim of this study was to evaluate the mechanical behavior of endodontically treated teeth restored with fiber reinforced composite posts versus titanium posts, by both experimental testing and numerical simulation (finite element analysis (FEA)). Forty maxillary central incisors were endodontically treated to a size 45 file and then obturated using gutta-percha points and sealer with the lateral condensation technique. The teeth were divided into four groups of ten teeth each. All the posts were of similar dimensions. The first group was restored using carbon fiber reinforced posts (CB), the second and third groups were restored using glass fiber reinforced posts (DP and FW, respectively), and the fourth group (control group) was restored using conventional titanium posts (PP). Half of the specimens of every group were submitted to hydrothermal cycling (2000 cycles, at 5 0 C and 55 0 C, respectively). All specimens were loaded until failure at a 45 0 angle with respect to the longitudinal axis at a crosshead speed of 0.5 mm min -1 . A two-dimensional finite element model was designed in order to simulate the experimentally obtained results. Mechanical testing revealed that teeth restored with titanium posts exhibited the highest fracture strength. Debonding of the core was the main failure mode observed in glass fiber posts, whereas vertical root fractures were observed in the titanium posts. FEA revealed that the maximum stresses were developed at the interface between the post, dentin and the composite core critical regions in all three cases. Hydrothermal cycling had no significant effect on the fracture behavior of fiber reinforced composite posts.

  2. Prospective clinical study comparing intraligamentary anesthesia and inferior alveolar nerve block for extraction of posterior mandibular teeth.

    Science.gov (United States)

    Kämmerer, P W; Adubae, A; Buttchereit, I; Thiem, D G E; Daubländer, M; Frerich, B

    2018-04-01

    The aim of the study was to compare the efficacy of intraligamentary anesthesia (ILA) with conventional inferior alveolar nerve block (IANB) for extraction of mandibular posterior teeth. In a prospective clinical trial, a total of 301 mandibular posterior teeth were extracted in 266 patients. Randomization was conducted into those who received ILA (patients n = 98; teeth n = 105) and those who received IANB (patient n = 140; teeth n = 140). Twenty-eight patients were subjected to bilateral mandibular dental extractions and received both ILA und IANB (teeth n = 56 (ILA n = 28; IANB n = 28)). The primary objective was to evaluate the differences in pain during injection, in pain during tooth extraction (numeric rating scale (NRS)), and in anesthetic quality (complete/sufficient vs. insufficient/no effect). Differences in latency time, amount of anesthetic solution, need for second injection, and duration of local numbness as well as in the incidence of dry socket were assessed. ILA had significant lower pain of injection (p < 0.001), shorter latency time (p < 0.001), and shorter duration of local numbness (p < 0.001) and required lesser amount of local anesthetic solution (p < 0.001) together with a similar anesthetic quality (p = 0.082) compared to IANB. Concerning pain during extraction (p = 0.211), frequency of second injection (p = 0.197), and incidence of dry socket (p = 0.178), no significant differences were detected. ILA fulfills the requirements of a minimal invasive and patient-friendly local anesthetic technique. In accordance, it represents a safe and reliable alternative to IANB for extraction of mandibular posterior teeth. ILA can be recommended for routine dental extractions.

  3. 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.

  4. 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)

  5. Influence of one- or two-stage methods for polymerizing complete dentures on adaptation and teeth movements

    Directory of Open Access Journals (Sweden)

    Moises NOGUEIRA

    Full Text Available Abstract Introduction The quality of complete dentures might be influenced by the method of confection. Objective To evaluate the influence of two different methods of processing muco-supported complete dentures on their adaptation and teeth movements. Material and method Denture confection was assigned in two groups (n=10 for upper and lower arches according to polymerization method: 1 conventional one-stage - a wax trial base was made, teeth were arranged and polymerized; 2 two-stage method - the base was waxed and first polymerized. With the denture base polymerized, the teeth were arranged and then, performed the final polymerization. Teeth movements were evaluated in the distances between incisive (I-I, pre-molars (P-P, molars (M-M, left incisor to left molar (LI-LM and right incisor to right molar (RI-RM. For the adaptation analysis, dentures were cut in three different positions: (A distal face of canines, (B mesial face of the first molars, and (C distal face of second molars. Result Denture bases have shown a significant better adaptation when polymerized in the one-stage procedure for both the upper (p=0.000 and the lower (p=0.000 arches, with region A presenting significant better adaptation than region C. In the upper arch, significant reduction in the distance between I-I was observed in the one-stage technique, while the two-stage technique promoted significant reduction in the RI-RM distance. In the lower arch, one-stage technique promoted significant reduction in the distance for RI-RM and two-stage promoted significant reduction in the LI-LM distance. Conclusion Conventional one-stage method presented the better results for denture adaptation. Both fabrication methods presented some alteration in teeth movements.

  6. 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

  7. Numerical fatigue 3D-FE modeling of indirect composite-restored posterior teeth.

    Science.gov (United States)

    Ausiello, Pietro; Franciosa, Pasquale; Martorelli, Massimo; Watts, David C

    2011-05-01

    In restored teeth, stresses at the tooth-restoration interface during masticatory processes may fracture the teeth or the restoration and cracks may grow and propagate. The aim was to apply numerical methodologies to simulate the behavior of a restored tooth and to evaluate fatigue lifetimes before crack failure. Using a CAD-FEM procedure and fatigue mechanic laws, the fatigue damage of a restored molar was numerically estimated. Tessellated surfaces of enamel and dentin were extracted by applying segmentation and classification algorithms, to sets of 2D image data. A user-friendly GUI, which enables selection and visualization of 3D tessellated surfaces, was developed in a MatLab(®) environment. The tooth-boundary surfaces of enamel and dentin were then created by sweeping operations through cross-sections. A class II MOD cavity preparation was then added into the 3D model and tetrahedral mesh elements were generated. Fatigue simulation was performed by combining a preliminary static FEA simulation with classical fatigue mechanical laws. Regions with the shortest fatigue-life were located around the fillets of the class II MOD cavity, where the static stress was highest. The described method can be successfully adopted to generate detailed 3D-FE models of molar teeth, with different cavities and restorative materials. This method could be quickly implemented for other dental or biomechanical applications. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  8. Distribution of the amelogenin protein in developing, injured and carious human teeth

    Directory of Open Access Journals (Sweden)

    Thimios eMitsiadis

    2014-12-01

    Full Text Available Amelogenin is the major enamel matrix protein with key roles in amelogenesis. Although for many decades amelogenin was considered to be exclusively expressed by ameloblasts, more recent studies have shown that amelogenin is also expressed in other dental and no-dental cells. However, amelogenin expression in human tissues remains unclear. Here, we show that amelogenin protein is not only expressed during human embryonic development but also in pathological conditions such as carious lesions and injuries after dental cavity preparation. In developing embryonic teeth, amelogenin stage-specific expression is found in all dental epithelia cell populations but with different instensities. In the different layers of enamel matrix, waves of positive versus negative immunostaining for amelogenin are detected suggesting that the secretion of amelogenin protein is orchestreted by a biological clock. Amelogenin is also expressed transiently in differentiating odontoblasts during predentin formation, but was absent in mature functional odontoblasts. In intact adult teeth, amelogenin was not present in dental pulp, odontoblasts, and dentin. However, in injured and carious adult human teeth amelogenin is strongly re-expressed in newly differentiated odontoblasts and is distributed in the dentinal tubuli under the lesion site. In an in vitro culture system, amelogenin is expressed preferentially in human dental pulp cells that start differentiating into odontoblast-like cells and form mineralization nodules. These data suggest that amelogenin plays important roles not only during cytodifferentiation, but also during tooth repair processes in humans.

  9. Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

    Science.gov (United States)

    Chávez de Paz, L E; Molander, A; Dahlén, G

    2004-09-01

    To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.

  10. Guided Autotransplantation of Teeth: A Novel Method Using Virtually Planned 3-dimensional Templates.

    Science.gov (United States)

    Strbac, Georg D; Schnappauf, Albrecht; Giannis, Katharina; Bertl, Michael H; Moritz, Andreas; Ulm, Christian

    2016-12-01

    The aim of this study was to introduce an innovative method for autotransplantation of teeth using 3-dimensional (3D) surgical templates for guided osteotomy preparation and donor tooth placement. This report describes autotransplantation of immature premolars as treatment of an 11-year-old boy having suffered severe trauma with avulsion of permanent maxillary incisors. This approach uses modified methods from guided implant surgery by superimposition of Digital Imaging and Communications in Medicine files and 3D data sets of the jaws in order to predesign 3D printed templates with the aid of a fully digital workflow. The intervention in this complex case could successfully be accomplished by performing preplanned virtual transplantations with guided osteotomies to prevent bone loss and ensure accurate donor teeth placement in new recipient sites. Functional and esthetic restoration could be achieved by modifying methods used in guided implant surgery and prosthodontic rehabilitation. The 1-year follow-up showed vital natural teeth with physiological clinical and radiologic parameters. This innovative approach uses the latest diagnostic methods and techniques of guided implant surgery, enabling the planning and production of 3D printed surgical templates. These accurate virtually predesigned surgical templates could facilitate autotransplantation in the future by full implementation of recommended guidelines, ensuring an atraumatic surgical protocol. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. National report of Brazil. Nuclear Safety Convention

    International Nuclear Information System (INIS)

    1998-09-01

    This document represents the national report prepared as a fulfillment of the brazilian obligations related to the Convention on Nuclear Safety. In chapter 2 some details are given about the existing nuclear installations. Chapter 3 provides details about the legislation and regulations, including the regulatory framework and the regulatory body. Chapter 4 covers general safety considerations as described in articles 10 to 16 of the Convention. Chapter 5 addresses to the safety of the installations during siting, design, construction and operation. Chapter 6 describes planned activities to further enhance nuclear safety. Chapter 7 presents the final remarks related to the degree of compliance with the Convention obligations

  12. 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.

  13. Digital vs. conventional implant impressions: efficiency outcomes.

    Science.gov (United States)

    Lee, Sang J; Gallucci, German O

    2013-01-01

    The aim of this pilot study was to evaluate the efficiency, difficulty and operator's preference of a digital impression compared with a conventional impression for single implant restorations. Thirty HSDM second year dental students performed conventional and digital implant impressions on a customized model presenting a single implant. The outcome of the impressions was evaluated under an acceptance criteria and the need for retake/rescan was decided. The efficiency of both impression techniques was evaluated by measuring the preparation, working, and retake/scan time (m/s) and the number of retakes/rescans. Participants' perception on the level of difficulty for the both impressions was assessed with a visual analogue scale (VAS) questionnaire. Multiple questionnaires were obtained to assess the participants' perception on preference, effectiveness and proficiency. Mean total treatment time was of 24:42 m/s for conventional and 12:29 m/s for digital impressions (P impressions (P impression (P impression technique and 30.63 (±17.57) for digital impression technique (P = 0.006). Sixty percent of the participants preferred the digital impression, 7% the conventional impression technique and 33% preferred either technique. Digital impressions resulted in a more efficient technique than conventional impressions. Longer preparation, working, and retake time were consumed to complete an acceptable conventional impression. Difficulty was lower for the digital impression compared with the conventional ones when performed by inexperienced second year dental students. © 2012 John Wiley & Sons A/S.

  14. Marginal Micro-leakage of Self-etch and All-in One Adhesives to Primary Teeth, with Mechanical or Chemo-Mechanical Caries Removal

    Directory of Open Access Journals (Sweden)

    Nouzari A

    2016-06-01

    Full Text Available Statement of Problem: Chemo-mechanical caries removal is an effective alternative to the traditional rotary drilling method. One of the factors that can influence micro-leakage is the method of caries removal. Objectives: To compare the micro-leakage of resin composite in primary dentition using self-etch and all-in one adhesives following conventional and chemo-mechanical caries removal. Materials and Methods: Sixty extracted human primary anterior teeth with class III carious lesions were collected. The selected teeth were divided randomly into two groups each consisting of 30 teeth. In group1 carious lesions were removed using Carisolv multi mix gel. In group 2, caries was removed using round steel burs in a slow–speed hand piece. Then, the specimens in each group were randomly divided into two subgroups (A and B of 15 and treated by either Clearfil SE Bond (CSEB or Scotch bond. All prepared cavities were filled with a resin composite (Estellite. All the specimens were stored in distilled water at 37ºC for 24 hours and then thermocycled in 5ºC and 55ºC water with a dwell time of 20 seconds for 1500 cycles. The specimens were immersed in 1% methylene blue solution for 24 hours, removed, washed and sectioned mesiodistally. The sectioned splits were examined under a stereomicroscope to determine the micro-leakage scores. The data were analyzed using Kruskal-Wallis Test in SPSS version 21. Results: There were no significant differences between micro-leakage scores among the four groups (p = 0.127. Score 0 of micro-leakage was detected for 60% of the specimens in group 1-A (Carisolv + CSEB, 73% of the group 2-A (hand piece + CSEB, 80% of the group 1-B (Carisolv + Scotch bond, and 93% of the group 2-B in which caries was removed using hand piece and bonded with Scotch bond . Conclusions: Although caries removal using hand piece bur along with using Scotch bond adhesive performed less micro-leakage, it would seems that the use of Carisolv

  15. 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.

  16. 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.

  17. Procedure for the automatic mesh generation of innovative gear teeth

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.

  18. [Advantages and disadvantages of endocrown restorations of endodontically treated teeth with large coronal destruction].

    Science.gov (United States)

    Bao, X D

    2018-04-09

    The strength of endodontically treated teeth were reduced apparently because of structural damage, therefore further reduction of healthy tissue should be avoided as much as possible in restoration. Endocrown made by chair-side CAD/CAM is some kind of minimal invasive restoration, and the retention of restoration is achieved by reliable bonding and macromechanial retention forces. Without post preparation, the root structure could be resevered. Following the indications and use of biomechanical dentin-like CAD/CAM materials could reduce the adverse effect of tensile stress on cervical part.

  19. Convention on nuclear safety

    International Nuclear Information System (INIS)

    1994-01-01

    The Convention on Nuclear Safety was adopted on 17 June 1994 by Diplomatic Conference convened by the International Atomic Energy Agency at its Headquarters from 14 to 17 June 1994. The Convention will enter into force on the ninetieth day after the date of deposit with the Depository (the Agency's Director General) of the twenty-second instrument of ratification, acceptance or approval, including the instruments of seventeen States, having each at leas one nuclear installation which has achieved criticality in a reactor core. The text of the Convention as adopted is reproduced in the Annex hereto for the information of all Member States

  20. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Directory of Open Access Journals (Sweden)

    Vanessa Lessa ARAÚJO

    2016-01-01

    Full Text Available Abstract The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT. Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26 and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each. Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3 in the apical region was analyzed using the two-way ANOVA and post-hoc Student–Newman–Keuls test (α = ٠.٠٥. The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009 and Endofill (0.103 ± 0.010. The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008 and Sealer 26 (0.109 ± 0.018 (p > 0.05. Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012 (p < 0.05. Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique.

  1. Minamata Convention on Mercury

    Science.gov (United States)

    On November 6, 2013 the United States signed the Minamata Convention on Mercury, a new multilateral environmental agreement that addresses specific human activities which are contributing to widespread mercury pollution

  2. Case Report: Multiple Unerupted Permanent Teeth Associated with ...

    African Journals Online (AJOL)

    The present report describes a case of Noonan's syndrome from a dental viewpoint. ... and malocclusions are some of the frequently observed clinical features. ... fixed orthodontic therapy for forced eruption of unerupted permanent teeth.

  3. 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.

  4. 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.

  5. The longevity of different restorations in primary teeth

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper reviews three published papers and adds results from a fourth study which aimed to determine which restorative material would be the best alternative(s) to amalgam (AM) in primary teeth....

  6. Forces produced by different nonconventional bracket or ligature systems during alignment of apically displaced teeth.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo; Defraia, Efisio; Barbato, Ersilia

    2009-05-01

    To analyze the forces released by four types of passive stainless steel self-ligating brackets (SLBs), and by two nonconventional elastomeric ligature-bracket systems when compared with conventional elastomeric ligatures on conventional stainless steel brackets during the alignment of apically displaced teeth at the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the seven different ligature-bracket systems with 0.012'' or 0.014'' superelastic nickel titanium wire in the presence of different amounts of apical displacement of the canine (ranging from 1.5 mm to 6 mm). Comparisons between the different types of bracket/wire/ ligature systems were carried out by means of ANOVA on ranks with Dunnett's post hoc test (P < .05). When correction of a misalignment greater than 3 mm is attempted, a noticeable amount of force for alignment is generated by passive SLBs and nonconventional elastomeric ligature-bracket systems, and a null amount of force is released in the presence of conventional elastomeric ligatures on conventional brackets. When minimal apical displacement is needed (1.5 mm), the differences in performance between low-friction and conventional systems are minimal. These differences become significant when correction of a misalignment of greater than 3.0 mm is attempted.

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

    Directory of Open Access Journals (Sweden)

    Mahtab Memarpour,

    2014-08-01

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

  8. 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

  9. 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...

  10. 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% ...

  11. The management of over closured anterior teeth due to attrition

    Directory of Open Access Journals (Sweden)

    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.

  12. Comparative analysis of human and bovine teeth: radiographic density

    Directory of Open Access Journals (Sweden)

    Jefferson Luis Oshiro Tanaka

    2008-12-01

    Full Text Available Since bovine teeth have been used as substitutes for human teeth in in vitro dental studies, the aim of this study was to compare the radiographic density of bovine teeth with that of human teeth to evaluate their usability for radiographic studies. Thirty bovine and twenty human teeth were cut transversally in 1 millimeter-thick slices. The slices were X-rayed using a digital radiographic system and an intraoral X-ray machine at 65 kVp and 7 mA. The exposure time (0.08 s and the target-sensor distance (40 cm were standardized for all the radiographs. The radiographic densities of the enamel, coronal dentin and radicular dentin of each slice were obtained separately using the "histogram" tool of Adobe Photoshop 7.0 software. The mean radiographic densities of the enamel, coronal dentin and radicular dentin were calculated by the arithmetic mean of the slices of each tooth. One-way ANOVA demonstrated statistically significant differences for the densities of bovine and human enamel (p 0.05. Based on the results, the authors concluded that: a the radiographic density of bovine enamel is significantly higher than that of human enamel; b the radiodensity of bovine coronal dentin is statistically lower than the radiodensity of human coronal dentin; bovine radicular dentin is also less radiodense than human radicular dentin, although this difference was not statistically significant; c bovine teeth should be used with care in radiographic in vitro studies.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. MULTIPLE RETAINED TEETH IN MANDIBLE: A Case Report

    Directory of Open Access Journals (Sweden)

    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.

  15. Spatial and functional modeling of carnivore and insectivore molariform teeth.

    Science.gov (United States)

    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.

  16. [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.

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

    Science.gov (United States)

    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.

  18. 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.

  19. Climate change convention

    International Nuclear Information System (INIS)

    Russell, D.

    1992-01-01

    Principles that guide Canada's Green Plan with respect to global warming are outlined. These include respect for nature, meeting environmental goals in an economically beneficial manner, efficient use of resources, shared responsibilities, federal leadership, and informed decision making. The policy side of the international Framework Convention on Climate Change is then discussed and related to the Green Plan. The Convention has been signed by 154 nations and has the long-term objective of stabilizing anthropogenic greenhouse gas concentrations in the atmosphere at levels that prevent dangerous interference with the climate system. Some of the Convention's commitments toward achieving that objective are only applicable to the developed countries. Five general areas of commitment are emissions reductions, assistance to developing countries, reporting requirements, scientific and socioeconomic research, and education. The most controversial area is that of limiting emissions. The Convention has strong measures for public accountability and is open to future revisions. Canada's Green Plan represents one country's response to the Convention commitments, including a national goal to stabilize greenhouse gas emissions at the 1990 level by the year 2000

  20. Effects of various cone-beam computed tomography settings on the detection of recurrent caries under restorations in extracted primary teeth

    Energy Technology Data Exchange (ETDEWEB)

    Kamburoglu, Kivanc; Sonmez, Gul; Kurt, Hakan; Berktas, Zeynep Serap [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan); Ozen, Dogukan [Dept. of Biostatistics, Faculty of Veterinary Medicine, Ankara University, Ankara (Turkmenistan)

    2017-06-15

    The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The other 26 intact teeth that did not have caries served as controls. Teeth were imaged using a 100×90-mm field of view and a 0.2-mm voxel size with 9 different CBCT settings. Four observers assessed the images using a 5-point scale. Kappa values were calculated to assess observer agreement. CBCT settings were compared with the gold standard using a receiver operating characteristic analysis. The area under the curve (AUC) values for each setting were compared using the chi-square test, with a significance level of α=.05. Intraobserver kappa values ranged from 0.366 to 0.664 for observer 1, from 0.311 to 0.447 for observer 2, from 0.597 to 1.000 for observer 3, and from 0.869 to 1 for observer 4. Furthermore, interobserver kappa values among the observers ranged from 0.133 to 0.814 for the first reading and from 0.197 to 0.805 for the second reading. The highest AUC values were found for setting 5 (0.5916) and setting 3 (0.5886), and were not found to be statistically significant (P>.05). Variations in tube voltage and tube current did not affect the detection of recurrent caries under amalgam restorations in primary teeth.

  1. Effects of various cone-beam computed tomography settings on the detection of recurrent caries under restorations in extracted primary teeth.

    Science.gov (United States)

    Kamburoğlu, Kıvanç; Sönmez, Gül; Berktaş, Zeynep Serap; Kurt, Hakan; Özen, Doĝukan

    2017-06-01

    The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The other 26 intact teeth that did not have caries served as controls. Teeth were imaged using a 100×90-mm field of view and a 0.2-mm voxel size with 9 different CBCT settings. Four observers assessed the images using a 5-point scale. Kappa values were calculated to assess observer agreement. CBCT settings were compared with the gold standard using a receiver operating characteristic analysis. The area under the curve (AUC) values for each setting were compared using the chi-square test, with a significance level of α=.05. Intraobserver kappa values ranged from 0.366 to 0.664 for observer 1, from 0.311 to 0.447 for observer 2, from 0.597 to 1.000 for observer 3, and from 0.869 to 1 for observer 4. Furthermore, interobserver kappa values among the observers ranged from 0.133 to 0.814 for the first reading and from 0.197 to 0.805 for the second reading. The highest AUC values were found for setting 5 (0.5916) and setting 3 (0.5886), and were not found to be statistically significant ( P >.05). Variations in tube voltage and tube current did not affect the detection of recurrent caries under amalgam restorations in primary teeth.

  2. Effects of various cone-beam computed tomography settings on the detection of recurrent caries under restorations in extracted primary teeth

    International Nuclear Information System (INIS)

    Kamburoglu, Kivanc; Sonmez, Gul; Kurt, Hakan; Berktas, Zeynep Serap; Ozen, Dogukan

    2017-01-01

    The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The other 26 intact teeth that did not have caries served as controls. Teeth were imaged using a 100×90-mm field of view and a 0.2-mm voxel size with 9 different CBCT settings. Four observers assessed the images using a 5-point scale. Kappa values were calculated to assess observer agreement. CBCT settings were compared with the gold standard using a receiver operating characteristic analysis. The area under the curve (AUC) values for each setting were compared using the chi-square test, with a significance level of α=.05. Intraobserver kappa values ranged from 0.366 to 0.664 for observer 1, from 0.311 to 0.447 for observer 2, from 0.597 to 1.000 for observer 3, and from 0.869 to 1 for observer 4. Furthermore, interobserver kappa values among the observers ranged from 0.133 to 0.814 for the first reading and from 0.197 to 0.805 for the second reading. The highest AUC values were found for setting 5 (0.5916) and setting 3 (0.5886), and were not found to be statistically significant (P>.05). Variations in tube voltage and tube current did not affect the detection of recurrent caries under amalgam restorations in primary teeth

  3. 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.

  4. Administration of olive oil followed by a low volume of polyethylene glycol-electrolyte lavage solution improves patient satisfaction with right-side colonic cleansing over administration of the conventional volume of polyethylene glycol-electrolyte lavage solution for colonoscopy preparation.

    Science.gov (United States)

    Abut, Evren; Guveli, Hakan; Yasar, Bulent; Bolukbas, Cengiz; Bolukbas, Filiz Fusun; Ince, Ali Tuzun; Kendir, Tulin; Dalay, Ali Remzi; Kurdas, Oya Ovunc

    2009-09-01

    Proper bowel cleansing before colonoscopy is essential for satisfactory evaluation of the colon. The required consumption of a large volume of salty-tasting liquid, 4 L of polyethylene glycol-electrolyte lavage solution (PEG-ELS), is the primary limitation to achieving this goal. To achieve better patient satisfaction with efficient bowel cleansing, we compared the effects of the conventional volume (4 L) of PEG-ELS with those of a low volume (2 L) in combination with pretreatment using different laxatives, such as magnesium hydroxide (milk of magnesia) and olive oil. Randomized, controlled study. A single research hospital. Patients undergoing elective colonoscopy. A total of 120 patients were randomized to 1 of 3 different preparation regimens: 39 patients were prepared with a conventional volume (4 L) of PEG-ELS (Preparation [Prep] 1), and the remaining patients were prepared with a lower volume (2 L) of PEG-ELS and pretreatment with a laxative, either 15 g of magnesium hydroxide (40 patients, Prep 2) or 60 mL of olive oil (41 patients, Prep 3) 3 hours before PEG-ELS administration. The primary outcome was the efficacy of colonic cleansing on the left and right sides. Secondary outcomes were patient satisfaction and side effects. The olive oil regimen (Prep 3) resulted in significantly more adequate bowel cleansing of the right colon than administration of the conventional volume of PEG-ELS (Prep 1) and the magnesium hydroxide (Prep 2) regimen (97.6% vs 74.5% and 72.5%, respectively, P = .007). However, this difference was not observed in the left colon (91.5%, 85.5%, and 91.8% for Preps 1, 2, and 3, respectively, P = .776). When asked, 38 patients (95%) taking Prep 2, 35 patients (85.3%) taking Prep 3, and only 11 patients (28.2%) taking Prep 1 preferred the same preparation regimen if they required a future colonoscopy (P =.006), based on ease of use and taste. The side effects were comparable in each group. The limitations of this study include the relatively

  5. In vivo energy dispersive X-ray fluorescence for measuring the content of essential and toxic trace elements in teeth

    International Nuclear Information System (INIS)

    Zaichick, V.; Ovchjarenko, N.; Zaichick, S.

    1999-01-01

    The calibration and application of a facility, based on energy dispersive X-ray fluorescent analysis (EDXRF) using 109 Cd as an excitation source, for in vivo and in vitro estimation of Ca, Pb, Sr and Zn in tooth enamel is described. During the in vivo measurements, the device ensures tissue protection of face and mouth cavity from radiation, and only a small part of tooth surface under study is irradiated. To calibrate the facility, the contents of Ca, Sr and Zn were analyzed simultaneously in the enamel of 50 teeth by EDXRF and instrumental neutron activation analysis (INAA). Standards prepared from powdered tooth enamel with additions of chemically pure lead compounds were used to calibrate for lead graduation. Enamel calcium is suggested as an internal standard during in vivo EDXRF of teeth. The content of enamel Sr, Zn and Pb was determined by EDXRF in 35 permanent intact teeth of teenagers and adults. It was shown that lead concentration didn't exceed 3 μg/g for all the teeth

  6. Assisted eruption of impacted teeth into an alveolar bone graft in a patient with cleft lip and palate.

    Science.gov (United States)

    Peamkaroonrath, Chonthicha; Manosudprasit, Montien; Godfrey, Keith

    2008-11-01

    To assist the eruption of impacted upper teeth into an alveolar bone graft in a patient with a unilateral cleft lip and palate. An 8-year-old Thai boy with left unilateral complete cleft lip and palate had the chief complaint of anterior crossbite. He presented with a mild skeletal 3, dental Class III subdivision malocclusion, anterior crossbite, left unilateral posterior crossbite, moderate crowding in the upper arch with impaction of upper the left lateral incisor (tooth 22) and canine (tooth 23). In the first phase of treatment the posterior crossbite was corrected with a removable appliance with a 3-way screw. In the second phase the impacted teeth were surgically exposed, moved into the alveolar bone graft and the teeth aligned with fixed appliances. The upper left lateral incisor was extracted because of its questionable longevity. The orthodontic treatment resulted in normal overjet, overbite and an acceptable facial profile. A prosthesis replaced tooth 22. Forced eruption of impacted teeth can be carried out successfully in the cleft patients after an appropriate treatment plan has been formulated and following preparation of alveolar bone graft in the cleft site.

  7. Implementing the chemical weapons convention

    Energy Technology Data Exchange (ETDEWEB)

    Kellman, B.; Tanzman, E. A.

    1999-12-07

    In 1993, as the CWC ratification process was beginning, concerns arose that the complexity of integrating the CWC with national law could cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States as to how the CWC would be carried out. As a result, the author's colleagues and the author prepared the Manual for National Implementation of the Chemical Weapons Convention and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Committee of CWC Legal Experts, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Central Europe, reviewed the Manual. In February 1998, they finished the second edition of the Manual in order to update it in light of developments since the CWC entered into force on 29 April 1997. The Manual tries to increase understanding of the Convention by identifying its obligations and suggesting methods of meeting them. Education about CWC obligations and available alternatives to comply with these requirements can facilitate national response that are consistent among States Parties. Thus, the Manual offers options that can strengthen international realization of the Convention's goals if States Parties act compatibly in implementing them. Equally important, it is intended to build confidence that the legal issues raised by the Convention are finite and addressable. They are now nearing competition of an internet version of this document so that interested persons can access it electronically and can view the full text of all of the national implementing legislation it cites. The internet address, or URL, for the internet version of the Manual is http: //www.cwc.ard.gov. This paper draws from the Manual. It comparatively addresses approximately thirty

  8. Implementing the chemical weapons convention

    International Nuclear Information System (INIS)

    Kellman, B.; Tanzman, E. A.

    1999-01-01

    In 1993, as the CWC ratification process was beginning, concerns arose that the complexity of integrating the CWC with national law could cause each nation to implement the Convention without regard to what other nations were doing, thereby causing inconsistencies among States as to how the CWC would be carried out. As a result, the author's colleagues and the author prepared the Manual for National Implementation of the Chemical Weapons Convention and presented it to each national delegation at the December 1993 meeting of the Preparatory Commission in The Hague. During its preparation, the Committee of CWC Legal Experts, a group of distinguished international jurists, law professors, legally-trained diplomats, government officials, and Parliamentarians from every region of the world, including Central Europe, reviewed the Manual. In February 1998, they finished the second edition of the Manual in order to update it in light of developments since the CWC entered into force on 29 April 1997. The Manual tries to increase understanding of the Convention by identifying its obligations and suggesting methods of meeting them. Education about CWC obligations and available alternatives to comply with these requirements can facilitate national response that are consistent among States Parties. Thus, the Manual offers options that can strengthen international realization of the Convention's goals if States Parties act compatibly in implementing them. Equally important, it is intended to build confidence that the legal issues raised by the Convention are finite and addressable. They are now nearing competition of an internet version of this document so that interested persons can access it electronically and can view the full text of all of the national implementing legislation it cites. The internet address, or URL, for the internet version of the Manual is http: //www.cwc.ard.gov. This paper draws from the Manual. It comparatively addresses approximately thirty

  9. Enamel thickness after preparation of tooth for porcelain laminate.

    Science.gov (United States)

    Pahlevan, Ayoub; Mirzaee, Mansoreh; Yassine, Esmaeil; Ranjbar Omrany, Ladan; Hasani Tabatabaee, Masumeh; Kermanshah, Hamid; Arami, Sakineh; Abbasi, Mehdy

    2014-07-01

    In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers. Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope. Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05). The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

  10. Enamel thickness after preparation of tooth for porcelain laminate.

    Directory of Open Access Journals (Sweden)

    Ayoub Pahlevan

    2014-08-01

    Full Text Available In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acrylic resin. Cross section was preformed through the midline of the incisal, middle and cervical one-third of the labial surface of the teeth. The samples were observed under reflected stereomicroscope and the thickness of enamel was recorded. Part II, the effect of different types of preparation on dentin exposure was evaluated. Thirty maxillary central incisor teeth were randomly divided into two groups: A: Knife-edge preparation. B: Chamfer preparation. All samples were embedded in autopolimerize acrylic resin using a silicon mold. The samples were cut through the midline of the teeth. The surface of the samples were polished and enamel and dentin were observed under the stereomicroscope.Data were analyzed by ANOVA-one way test. The results of this study showed that the least enamel thickness in the central incisor was 345 and in lateral incisor is 235 μ this thickness is related to the one-third labial cervical area. Maximum thickness in maxillary central and lateral incisors in the one-third labial incisal surface was 1260 μ and 1220μ, respectively. In the second part of the study, the tendency of dentinal exposure was shown with the chamfer preparation, but no dentinal exposure was found in the knife-edge preparation. The differences between groups were significant (p<0.05.The knowledge of enamel thickness in different part of labial surface is very important. The thickness of enamel in the gingival area does not permit a chamfer preparation. The knife edge preparation is preferable in gingival area.

  11. Accessing developmental information of fossil hominin teeth using new synchrotron microtomography-based visualization techniques of dental surfaces and interfaces.

    Directory of Open Access Journals (Sweden)

    Adeline Le Cabec

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

  12. Accessing developmental information of fossil hominin teeth using new synchrotron microtomography-based visualization techniques of dental surfaces and interfaces.

    Science.gov (United States)

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

    2015-01-01

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

  13. Comparison of the Effect of Canal Preparation by Step Back Technique Using Hand Instruments and Gates Glidden Drills with ProTaper Universal Rotary System on the Root Resistance to Vertical Fracture

    Directory of Open Access Journals (Sweden)

    A Abbaszadegan

    2013-06-01

    Full Text Available Introduction: Cleaning and shaping of the root canal system with an efficient and safe technique are the major goals of root canal treatment. The aim of this study was to compare the conventional root canal preparation technique by hand instruments and Gates Glidden drills with ProTaper Universal Rotary system on the root susceptibility to vertical fracture. Methods: Thirty extracted human mandibular premolars were randomly assigned to two groups. In group I, apical preparation was performed with k-files up to #40 utilizing step back technique and coronal flaring was done with Gates Glidden drills. In group II, ProTaper Universal Rotary instruments were used up to the file F4. All teeth were obturated with lateral compaction technique using gutta-percha and AH26 sealer. A simulated periodontal ligament was fabricated, and the teeth were mounted. A stainless steel finger spreader #35 was mounted in an Instron testing machine and the necessary load to cause a root fracture was inserted and recorded. The obtained data were analyzed statistically using T-test. Results: The force required to fracture was significantly lower for the roots prepared by ProTaper instruments in comparison with the specimens prepared by hand instruments and Gates Glidden drills (P< 0.001. Conclusion: Canal preparation with ProTaper rotary instruments can make the roots more susceptible to vertical fracture than traditional instrumentation with k-files and Gates Glidden drills.

  14. Tritium and OSPAR convention

    International Nuclear Information System (INIS)

    2009-01-01

    The missions and the organisation of the OSPAR convention on protection of the NE Atlantic marine environment are given. The OSPAR strategy for the radioactive substances is stated. The results of work programme of the radioactive Substances committee are described and the consensus reached by contracting parties on the appropriate arrangements for this radionuclide is presented. (authors)

  15. Revised C++ coding conventions

    CERN Document Server

    Callot, O

    2001-01-01

    This document replaces the note LHCb 98-049 by Pavel Binko. After a few years of practice, some simplification and clarification of the rules was needed. As many more people have now some experience in writing C++ code, their opinion was also taken into account to get a commonly agreed set of conventions

  16. Global climate convention

    International Nuclear Information System (INIS)

    Simonis, U.E.

    1991-01-01

    The effort of negotiate a global convention on climate change is one of mankind's great endeavours - and a challenge to economists and development planners. The inherent linkages between climate and the habitability of the earth are increasingly well recognized, and a convention could help to ensure that conserving the environment and developing the economy in the future must go hand in hand. Due to growing environmental concern the United Nations General Assembly has set into motion an international negotiating process for a framework convention on climate change. One the major tasks in these negotiations is how to share the duties in reducing climate relevant gases, particularly carbon dioxide (CO 2 ), between the industrial and the developing countries. The results and proposals could be among the most far-reaching ever for socio-economic development, indeed for global security and survival itself. While the negotiations will be about climate and protection of the atmosphere, they will be on fundamental global changes in energy policies, forestry, transport, technology, and on development pathways with low greenhouse gas emissions. Some of these aspects of a climate convention, particularly the distributional options and consequences for the North-South relations, are addressed in this chapter. (orig.)

  17. Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study

    Directory of Open Access Journals (Sweden)

    Sang-Won Kwak

    2014-11-01

    Full Text Available Objectives The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan or JT-5B (B&L Biotech Ltd.. The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1, J1 (JT-5B / Power-1, K4 (KIS-1D / Power-4, and J4 (JT-5B / Power-4. The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05. The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

  18. Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study.

    Science.gov (United States)

    Kwak, Sang-Won; Moon, Young-Mi; Yoo, Yeon-Jee; Baek, Seung-Ho; Lee, WooCheol; Kim, Hyeon-Cheol

    2014-11-01

    The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

  19. 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.

  20. 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.

  1. Correlation between three color coordinates of human teeth

    Science.gov (United States)

    Lee, Yong-Keun

    2014-11-01

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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results.

    Science.gov (United States)

    Sabir, Mohammad; Alam, Mohammad Nazish

    2015-06-01

    The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months. A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used. The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket. The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved.

  7. Diagnostic accuracy of artificially induced vertical root fractures: a comparison of direct digital periapical images with conventional periapical images

    International Nuclear Information System (INIS)

    Lee, Ji Un; Kwon, Ki Jeong; Koh, Kwang Joon

    2004-01-01

    To compare the diagnostic accuracy for the detection of root fractures in CMOS-based digital periapical images with conventional film-based periapical images. Sixty extracted single-root human teeth with closed apices were prepared endodontically and divided into two groups; artificially induced vertical root fracture group and control group. All radiographs were obtained using the paralleling technique. The radiographs were examined by 4 observers three times within a 4 week interval. Receiver operating characteristic (ROC) analysis was carried out using data obtained from four observers. Intra- and inter-examiner agreements were computed using kappa analysis. The area under the ROC curve (Az) was used as an indicator of the diagnostic accuracy of the imaging system. Az values were as follows: direct-digital images; 0.93, film-based images; 0.92, and inverted digital images; 0.91. There was no significant difference between imaging modalities(P<0.05). The kappa value of inter-observer agreement was 0.42(range:0.28-0.60) and intra-observer agreement was 0.57(range:0.44-0.75). There is no statistical difference in diagnostic accuracy for the detection of vertical root fractures between digital periapical images and conventional periapical images. The results indicate that the CMOS sensor is a good image detector for the evaluation of vertical root fractures.

  8. Photoelastic analysis of stress generated by wires when conventional and self-ligating brackets are used: A pilot study

    Directory of Open Access Journals (Sweden)

    Guilherme Caiado Sobral

    2014-10-01

    Full Text Available OBJECTIVE: By means of a photoelastic model, this study analyzed the stress caused on conventional and self-ligating brackets with expanded arch wires. METHOD: Standard brackets were adhered to artificial teeth and a photoelastic model was prepared using the Interlandi 19/12 diagram as base. Successive activations were made with 0.014-in and 0.018-in rounded cross section Nickel-Titanium wires (NiTi and 0.019 x 0.025-in rectangular stainless steel wires all of which made on 22/14 Interlandi diagram. The model was observed on a plane polariscope - in a dark field microscope configuration - and photographed at each exchange of wire. Then, they were replaced by self-ligating brackets and the process was repeated. Analysis was qualitative and observed stress location and pattern on both models analyzed. CONCLUSIONS: Results identified greater stress on the region of the apex of premolars in both analyzed models. Upon comparing the stress between models, a greater amount of stress was found in the model with conventional brackets in all of its wires. Therefore, the present pilot study revealed that alignment of wires in self-ligating brackets produced lower stress in periodontal tissues in expansive mechanics.

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

    Science.gov (United States)

    Samson, Jimson; John, Reena; Jayakumar, Shalini

    2010-01-01

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

  10. Mapping the structure, composition and mechanical properties of human teeth

    International Nuclear Information System (INIS)

    Low, I.M.; Duraman, N.; Mahmood, U.

    2008-01-01

    The structure-property relationship in human adult and baby teeth was characterised by grazing-incidence synchrotron radiation diffraction, optical and atomic-force microscopy, in addition to Vickers indentation. Similarities and differences between both types of teeth have been highlighted and discussed. Depth-profiling results indicated the existence of contrasting but distinct gradual changes in crystal disorder, phase abundance, crystallite size and hardness within the baby and adult enamel, thus confirming the graded nature of human teeth. When compared to the adult tooth, the baby enamel is softer, more prone to fracture, but has larger hydroxyapatite grains. Vickers hardness of the enamel was load-dependent but load-independent in the dentine. The use of a 'bonded-interface' technique revealed the nature and evolution of deformation-microfracture damage around and beneath Vickers contacts

  11. Mapping the structure, composition and mechanical properties of human teeth

    Energy Technology Data Exchange (ETDEWEB)

    Low, I.M. [Materials Research Group, Department of Applied Physics, Curtin University of Technology, Perth, WA 6845 (Australia)], E-mail: j.low@curtin.edu.au; Duraman, N.; Mahmood, U. [Materials Research Group, Department of Applied Physics, Curtin University of Technology, Perth, WA 6845 (Australia)

    2008-03-10

    The structure-property relationship in human adult and baby teeth was characterised by grazing-incidence synchrotron radiation diffraction, optical and atomic-force microscopy, in addition to Vickers indentation. Similarities and differences between both types of teeth have been highlighted and discussed. Depth-profiling results indicated the existence of contrasting but distinct gradual changes in crystal disorder, phase abundance, crystallite size and hardness within the baby and adult enamel, thus confirming the graded nature of human teeth. When compared to the adult tooth, the baby enamel is softer, more prone to fracture, but has larger hydroxyapatite grains. Vickers hardness of the enamel was load-dependent but load-independent in the dentine. The use of a 'bonded-interface' technique revealed the nature and evolution of deformation-microfracture damage around and beneath Vickers contacts.

  12. 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.

  13. [Overdenture supported by natural teeth: analysis of clinical advantages].

    Science.gov (United States)

    Scotti, R; Melilli, D; Pizzo, G

    2003-05-01

    Hybrid prosthesis supported by natural teeth (overdenture) is widely used in clinical practice and should be executed whenever the clinical conditions suggest it. Through a critical review of the literature, the anatomical, functional, psychological and clinical advantages are emphasized. Among the first ones, the prophylaxis of residual anatomical components, due to the limitation of bone resorption, and the preservation of sensorial proprioception are relevant. Important advantages are also represented by a better crown-root ratio of residual teeth supporting overdenture, with the consequent improvement of the longitudinal prognosis of such teeth. The greater retention and stability of overdenture in comparison with complete denture greatly improve the masticatory efficacy. The psychological advantages resulting from the dental anchorage, which allows the patient to be more confident in social life, are also relevant. Finally, when the dental support is lost, converting overdenture into complete denture is simple and quick, and makes easier the longitudinal clinical maintenance of the denture.

  14. 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.

  15. Analysis of cracks generated in the spinning-mandrel teeth

    Directory of Open Access Journals (Sweden)

    M. Haghshenas

    2014-10-01

    Full Text Available The spinning process, using a splined mandrel, is always prone to premature failure of the splined mandrels. Such a failure is thought to be related to the magnitude of the forming forces exerted on the mandrel by the forming rollers during the spinning process. In the present paper, the characteristic of corner cracks in the mandrel teeth (made of S7 tool steel of a spinning process has been investigated. The rotational speed of the mandrel is about 300 rpm during spinning process and the sheet metal (i.e. AISI 1020 is in contact with mandrel teeth to get the mandrel shape at the end of process. During this process, the mandrel teeth eventually break away. Fractography analyses using scanning electron microscopy (SEM clearly confirm “fatigue” as being the main reason for the failure.

  16. 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.

  17. Conventions and Institutional Logics

    DEFF Research Database (Denmark)

    Westenholz, Ann

    Two theoretical approaches – Conventions and Institutional Logics – are brought together and the similarities and differences between the two are explored. It is not the intention to combine the approaches, but I would like to open both ‘boxes’ and make them available to each other with the purpose...... of creating a space for dialog. Both approaches were developed in the mid-1980s as a reaction to rational-choice economic theory and collectivistic sociological theory. These two theories were oversimplifying social life as being founded either in actor-micro level analyses or in structure-macro level...... analyses. The theoretical quest of both Conventions and Institutional Logics has been to understand the increasing indeterminacy, uncertainty and ambiguity in people’s lives where a sense of reality, of value, of moral, of feelings is not fixed. Both approaches have created new theoretical insights...

  18. The effect of a nanofilled resin-based coating on water absorption by teeth restored with glass ionomer.

    Science.gov (United States)

    Hankins, Amanda D; Hatch, Robert H; Benson, Jarred H; Blen, Bernard J; Tantbirojn, Daranee; Versluis, Antheunis

    2014-04-01

    A nanofilled, resin-based light-cured coating (G-Coat Plus, GC America, Alsip, Ill.) may reduce water absorption by glass ionomers. The authors investigated this possibility by measuring cuspal flexure caused by swelling of glass ionomer-restored teeth. The authors cut large mesio-occlusodistal slots (4-millimeter wide, 4-mm deep) in 12 extracted premolars and restored them with a glass ionomer cement (Fuji IX GP Extra, GC America). Six teeth were coated, and the other six were uncoated controls. The authors digitized the teeth in three dimensions by using an optical scanner after preparation and restoration and during an eight-week storage in water. They calculated cuspal flexure and analyzed the results by using an analysis of variance and Student-Newman-Keuls post hoc tests (significance level .05). They used dye penetration along the interface to verify bonding. Inward cuspal flexure indicated restoration shrinkage. Coated restorations had significantly higher flexure (mean [standard deviation], -11.9 [3.5] micrometers) than did restorations without coating (-7.3 [1.5] μm). Flexure in both groups decreased significantly (P < .05) during water storage and, after eight weeks, it changed to expansion for uncoated control restorations. Dye penetration along the interfaces was not significant, which ruled out debonding as the cause of cuspal relaxation. Teeth restored with glass ionomer cement exhibited shrinkage, as seen by inward cuspal flexure. The effect of the protective coating on water absorption was evident in the slower shrinkage compensation. The study results show that teeth restored with glass ionomers exhibited setting shrinkage that deformed tooth cusps. Water absorption compensated for the shrinkage. Although the coating may be beneficial for reducing water absorption, it also slows the shrinkage compensation rate (that is, the rate that hygroscopic expansion compensates for cuspal flexure from shrinkage).

  19. 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.

  20. Manado Convention Centre (Megastructures)

    OpenAIRE

    Anggianto, Rio M; Rate, Johannes Van

    2013-01-01

    Proyek Manado Convention Center ini pada dasarnya merupakan wadah atau sarana komunikasi antara dua pihak dengan penerapkan berbagai metode komunikasi langsung tatap muka baik itu dari perorangan terhadap kelompok, kelompok terhadap kelompok atau kelompok terhadap masyarakat. Dan pada era kini hal ini menjadi suatu kebutuhan yang dianganggap penting. Kota Manado seringkali menjadi tuan rumah suatu konverensi dengan jumlah peserta yang tergolong besar karena cakupannya sampai manca negara....

  1. The conventional quark picture

    International Nuclear Information System (INIS)

    Dalitz, R.H.

    1976-01-01

    For baryons, mesons and deep inelastic phenomena the ideas and the problems of the conventional quark picture are pointed out. All observed baryons fit in three SU(3)-multiplets which cluster into larger SU(6)-multiplets. No mesons are known which have quantum numbers inconsistent with belonging to a SU(3) nonet or octet. The deep inelastic phenomena are described in terms of six structure functions of the proton. (BJ) [de

  2. Demineralization–remineralization dynamics in teeth and bone

    Directory of Open Access Journals (Sweden)

    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

  3. Pulpal status of human primary teeth with physiological root resorption.

    Science.gov (United States)

    Monteiro, Joana; Day, Peter; Duggal, Monty; Morgan, Claire; Rodd, Helen

    2009-01-01

    The overall aim of this study was to determine whether any changes occur in the pulpal structure of human primary teeth in association with physiological root resorption. The experimental material comprised 64 sound primary molars, obtained from children requiring routine dental extractions under general anaesthesia. Pulp sections were processed for indirect immunofluorescence using combinations of: (i) protein gene product 9.5 (a general neuronal marker); (ii) leucocyte common antigen CD45 (a general immune cell marker); and (iii) Ulex europaeus I lectin (a marker of vascular endothelium). Image analysis was then used to determine the percentage area of staining for each label within both the pulp horn and mid-coronal region. Following measurement of the greatest degree of root resorption in each sample, teeth were subdivided into three groups: those with physiological resorption involving less than one-third, one-third to two-thirds, and more than two-thirds of their root length. Wide variation was evident between different tooth samples with some resorbed teeth showing marked changes in pulpal histology. Decreased innervation density, increased immune cell accumulation, and increased vascularity were evident in some teeth with advanced root resorption. Analysis of pooled data, however, did not reveal any significant differences in mean percentage area of staining for any of these variables according to the three root resorption subgroups (P > 0.05, analysis of variance on transformed data). This investigation has revealed some changes in pulpal status of human primary teeth with physiological root resorption. These were not, however, as profound as one may have anticipated. It is therefore speculated that teeth could retain the potential for sensation, healing, and repair until advanced stages of root resorption.

  4. 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.

  5. Patients’ general satisfaction with the appearance of anterior maxillary teeth

    Directory of Open Access Journals (Sweden)

    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.

  6. The significance of biometric parameters in determining anterior teeth width

    Directory of Open Access Journals (Sweden)

    Strajnić Ljiljana

    2013-01-01

    Full Text Available Background/Aim. An important element of prosthetic treatment of edentulous patients is selecting the size of anterior artificial teeth that will restore the natural harmony of one’s dentolabial structure as well as the whole face. The main objective of this study was to determine the correlation between the inner canthal distance (ICD and interalar width (IAW on one side and the width of both central incisors (CIW, the width of central and lateral incisors (CLIW, the width of anterior teeth (ATW, the width between the canine cusps (CCW, which may be useful in clinical practice. Methods. A total of 89 subjects comprising 23 male and 66 female were studied. Their age ranged from 19 to 34 years with the mean of 25 years. Only the subjects with the preserved natural dentition were included in the sample. All facial and intraoral tooth measurements were made with a Boley Gauge (Buffalo Dental Manufacturing Co., Brooklyn NY, USA having a resolution of 0.1mm. Results. A moderate correlation was established between the interalar width and combined width of anterior teeth and canine cusp width (r = 0.439, r = 0.374. A low correlation was established between the inner canthal distance and the width of anterior teeth and canine cusp width (r = 0.335, r = 0.303. The differences between the two genders were highly significant for all the parameters (p < 0.01. The measured facial distances and width of anterior teeth were higher in men than in women. Conclusion. The results of this study suggest that the examined interalar width and inner canthal distance cannot be considered reliable guidelines in the selection of artificial upper anterior teeth. However, they may be used as a useful additional factor combined with other methods for objective tooth selection. The final decision should be made while working on dentures fitting models with the patient’s consent.

  7. The Effect of Canal Preparation with Four Different Rotary Systems on Formation of Dentinal Cracks: An In Vitro Evaluation.

    Science.gov (United States)

    Khoshbin, Elham; Donyavi, Zakiyeh; Abbasi Atibeh, Erfan; Roshanaei, Ghodratollah; Amani, Faranak

    2018-01-01

    Endodontic rotary systems may result in dentinal cracks. They may propagate to vertical root fracture that compromises the outcome of endodontic treatment. This study aimed to compare Neolix and Reciproc (single-file systems), Mtwo and ProTaper (conventional rotary systems) in terms of dentinal crack formation in root canal walls. This in vitro study was conducted on 110 extracted human single-rooted teeth. The teeth were randomly divided into four experimental groups ( n =25) for root canal preparation with Neolix, Reciproc, Mtwo and ProTaper systems and two control groups ( n =5). The first control group underwent root canal instrumentation with hand files while the second control group received no preparation and was only irrigated. After instrumentation, root canals were horizontally sectioned at 3, 6 and 9 mm from the apex and inspected under a stereomicroscope under 12× magnification for detection of cracks. The data were analyzed using Chi-square, GEE test and Bonferroni tests ( P ProTaper, Reciproc, Mtwo and Neolix caused cracks in 92%, 80%, 68% and 48% of samples. ProTaper caused significantly more cracks than Neolix and Mtwo ( P 0.05). All rotary systems cause dentinal cracks and it is significantly different in apical, middle and coronal third of the root. Neolix appears to be a suitable alternative to other rotary systems since use of this single-file system saves time and cost and minimizes trauma to dentinal walls.

  8. Lead levels in deciduous teeth of children in Yemen

    International Nuclear Information System (INIS)

    Ismail, Rokhsana M.

    2001-01-01

    To determine lead exposure among children in Yemen a total of 280 shed deciduous whole teeth were collected from 269 children. Teeth were analyzed for lead concentrations using atomic absorption spectrophotometry (SP9 Philips) with electrothermal atomization. Children were between 5 and 15 years old. The study period extended from April 1999 to August 2000. The study showed that the overall mean tooth - lead level was 2.15 mg/g dry weight with a range of 0.05-30.4 mg/g dry weight. (author)

  9. Múltiples dientes supernumerarios distomolares Multiple distomolars supernumerary teeth

    OpenAIRE

    F.J. Rodríguez Romero; S. Cerviño Ferradanes

    2009-01-01

    En una dentición normal, los dientes supernumerarios son aquellos descritos como adicionales a la serie. La etiología no esta clara. Se han descritos tanto en dentición primaria como en permanente, aunque son mas frecuentes en la dentición permanente. El objetivo de este informe es presentar un caso de una paciente con múltiples dientes supernumerarios distomolares. Cuartos molares bilaterales simétricos son sumamente raros.Supernumerary teeth are described as the teeth formed in excess of th...

  10. On The Evolution of Human Jaws and Teeth: A Review

    Directory of Open Access Journals (Sweden)

    Serhat Yalcin

    2011-06-01

    Full Text Available The jaws and teeth of Homo sapiens have evolved, from the last common ancestor of chimpanzee and men to their current form. Many factors such as the foods eaten and the processing of foods by fire and tools have effected this evolution course. The evolution of the masticatory complex is related to other anatomical features such as brain size and bipedal posture, and leads to important proceedings like the formation of speech and language. In this review, the evolution of human jaws and teeth and its impact on the general course of human evolution is discussed.

  11. Digital evaluation of absolute marginal discrepancy: A comparison of ceramic crowns fabricated with conventional and digital techniques.

    Science.gov (United States)

    Liang, Shanshan; Yuan, Fusong; Luo, Xu; Yu, Zhuoren; Tang, Zhihui

    2018-04-05

    Marginal discrepancy is key to evaluating the accuracy of fixed dental prostheses. An improved method of evaluating marginal discrepancy is needed. The purpose of this in vitro study was to evaluate the absolute marginal discrepancy of ceramic crowns fabricated using conventional and digital methods with a digital method for the quantitative evaluation of absolute marginal discrepancy. The novel method was based on 3-dimensional scanning, iterative closest point registration techniques, and reverse engineering theory. Six standard tooth preparations for the right maxillary central incisor, right maxillary second premolar, right maxillary second molar, left mandibular lateral incisor, left mandibular first premolar, and left mandibular first molar were selected. Ten conventional ceramic crowns and 10 CEREC crowns were fabricated for each tooth preparation. A dental cast scanner was used to obtain 3-dimensional data of the preparations and ceramic crowns, and the data were compared with the "virtual seating" iterative closest point technique. Reverse engineering software used edge sharpening and other functional modules to extract the margins of the preparations and crowns. Finally, quantitative evaluation of the absolute marginal discrepancy of the ceramic crowns was obtained from the 2-dimensional cross-sectional straight-line distance between points on the margin of the ceramic crowns and the standard preparations based on the circumferential function module along the long axis. The absolute marginal discrepancy of the ceramic crowns fabricated using conventional methods was 115 ±15.2 μm, and 110 ±14.3 μm for those fabricated using the digital technique was. ANOVA showed no statistical difference between the 2 methods or among ceramic crowns for different teeth (P>.05). The digital quantitative evaluation method for the absolute marginal discrepancy of ceramic crowns was established. The evaluations determined that the absolute marginal discrepancies were

  12. Effect of topical alendronate on root resorption of dried replanted dog teeth.

    Science.gov (United States)

    Levin, L; Bryson, E C; Caplan, D; Trope, M

    2001-06-01

    Alendronate (ALN) is a third generation bisphosphonate with demonstrated osteoclast inhibitory activity that may slow down the resorptive process after severe traumatic injuries. Eighty-two premolar roots of five mongrel dogs were endodontically treated and restored, extracted and treated as follows: 70 roots were bench dried for either 40 or 60 min. Thirty-eight of these roots were then soaked for 5 min in a 1 mM solution of ALN in Hanks' Balanced Salt Solution (HBSS) and replanted. Thirty-two roots were soaked for 5 min in HBSS and replanted. In the remaining 12 roots which were not exposed to the bench drying procedure, a 0.5 mM deep lingual mid-root cemental defect was made. Six of these roots were soaked in a 1 mM solution of ALN in HBSS for 5 min and replanted. The other six roots were soaked for 5 min in HBSS and replanted. Historical negative and positive controls were used from similarly treated teeth in our previous studies. After 4 months the dogs were killed and the roots prepared for histological evaluation. Five-microm-thick cross-sections of the root and surrounding tissue taken every 70 microm were evaluated for healing according to the criteria of Andreasen. In the 12 roots with cemental defects, healing with cementum of the damaged root surface was evaluated. In addition, residual root mass was also measured to determine the extent of root structure loss for each soaking method. Cemental healing took place in all 12 artificially damaged roots, indicating that these soaking media did not inhibit cementogenesis. The alendronate-soaked roots had statistically significantly more healing than the roots soaked in HBSS without alendronate. This improvement in healing was seen in all dogs except one and in all teeth except the first premolar. Soaking in alendronate also resulted in significantly less loss in root mass due to resorption compared to those teeth soaked in HBSS without alendronate.

  13. Guided Endodontics: a novel treatment approach for teeth with pulp canal calcification and apical pathology.

    Science.gov (United States)

    Krastl, Gabriel; Zehnder, Marc S; Connert, Thomas; Weiger, Roland; Kühl, Sebastian

    2016-06-01

    To present a new treatment approach for teeth with pulp canal calcification (PCC) which require root canal treatment. A 15-year-old male patient presented with pain of his upper right central incisor. The tooth showed signs of apical periodontitis. Due to PCC, location of the root canal was judged to be difficult and associated with a high risk of perforation. A cone beam computed tomography (CBCT) and an intra-oral surface scan were performed and matched using software for virtual implant planning. After planning the position of the drill for root canal location, a virtual template was designed, and the data were exported as an STL file and sent to a 3D printer for template fabrication. The template was positioned on the anterior maxillary teeth. A specific drill was used to penetrate through the obliterated part of the root canal and obtain minimally invasive access to the apical part. The root canal was accessible at 9 mm distance from the apex. Further root canal preparation was carried out using an endodontic rotary instrumentation system. After an interappointment dressing for 4 weeks, the root canal was filled with vertically condensed gutta-percha using an epoxy sealer. The access cavity was restored with a composite material. After 15 months, the patient was clinically asymptomatic with no pain on percussion. The radiograph showed no apical pathology. The presented guided endodontic approach seems to be a safe, clinically feasible method to locate root canals and prevent root perforation in teeth with PCC. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries

    Energy Technology Data Exchange (ETDEWEB)

    Kayipmaz, Saadettin, E-mail: kayipmaz@ktu.edu.tr [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Sezgin, Omer Said, E-mail: omersaidsezgin@gmail.com [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Saricaoglu, Senem Tugra, E-mail: senem_tugra@hotmail.com [Karadeniz Technical University, Faculty of Dentistry, Department of Oral Diagnosis and Radiology, Farabi, 61080 Trabzon (Turkey); Can, Gamze, E-mail: gcanktu@yahoo.com [Karadeniz Technical University Faculty of Medicine Department of Public Health (Turkey)

    2011-11-15

    Aim: The aim of this study was to compare conventional radiography, storage phosphor plate, and cone beam computed tomography for in vitro determination of occlusal and approximal caries. Methods: A total of 72 extracted human premolar and molar teeth were selected. Teeth were radiographed with conventional intraoral radiography, a storage phosphor plate system, and cone beam computed tomography and evaluated by two observers. The teeth were then separated and examined with a stereomicroscope and a scanner at approximately 8x magnification. Results: CBCT was statistically superior to conventional radiography and phosphor plate for determining occlusal caries. No significant difference from CBCT, conventional radiography and the phosphor plate system for determining approximal caries was found. Conclusion: The CBCT system may be used as an auxiliary method for the detection of caries.

  15. An in vitro comparison of diagnostic abilities of conventional radiography, storage phosphor, and cone beam computed tomography to determine occlusal and approximal caries

    International Nuclear Information System (INIS)

    Kayipmaz, Saadettin; Sezgin, Omer Said; Saricaoglu, Senem Tugra; Can, Gamze

    2011-01-01

    Aim: The aim of this study was to compare conventional radiography, storage phosphor plate, and cone beam computed tomography for in vitro determination of occlusal and approximal caries. Methods: A total of 72 extracted human premolar and molar teeth were selected. Teeth were radiographed with conventional intraoral radiography, a storage phosphor plate system, and cone beam computed tomography and evaluated by two observers. The teeth were then separated and examined with a stereomicroscope and a scanner at approximately 8x magnification. Results: CBCT was statistically superior to conventional radiography and phosphor plate for determining occlusal caries. No significant difference from CBCT, conventional radiography and the phosphor plate system for determining approximal caries was found. Conclusion: The CBCT system may be used as an auxiliary method for the detection of caries.

  16. A study on FlexMaster : a Ni-Ti rotary engine driven system for root canal preparation.

    Science.gov (United States)

    Alam, M S; Bashar, A K; Begumr, J A; Kinoshita, J I

    2006-07-01

    In the present study, the effectiveness of recently introduced rotary Nickel Titanium FlexMaster engine driven system was evaluated for cleaning and shaping of root canals in extracted human teeth and compared with that done by the Nickel Titanium Flexofile hand instruments. A total of 40 root canals from 36 extracted mandibular and maxillary teeth with curvature ranging between 20 and 30 degree were divided into two groups, consisting 20 canals in each. FlexMaster instrumentation was done in 20 canals, using crown-down technique and manual filing with Flexofile was done in other 20 canals, using conventional and step-back techniques. 5.25% sodium hypochlorite (NaOCl) solution and 17% ethelene di-amine tetra-acetic acid (EDTA) were used alternatively for irrigation after canal preparation by each instrument size. Time needed for canal preparation of individual canal was recorded. A procedural error such as instrument breakage was also noted. After preparation, all the roots were cut longitudinally by using diamond burs in turbine handpiece and examined under scanning electron microscope. Apical region was quantified for debris and smear layer based on a 5-score numerical evaluation scale. The data established for scoring the debris and smear layer and preparation time of individual canal were analyzed statistically using the Mann-Whitney U test. Completely cleaned root canals were not found with any of the two instruments and none of the instruments maintained the original canal uniformity and regular dentine surface. Because significantly less debris was found in the apical region using the manual filing technique (p< 0.05). Thus the flexmaster system was found to produce less cleaner root canal walls than manual technique. Only one FlexMaster finishing file sized 30 was separated in the apical region during preparation of 30 degree curved canal. The time taken by FlexMaster was significantly better (p< 0.01) than that of hand instruments.

  17. 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.

  18. THE PAR (PEER ASSESSMENT RATING) CALCULATION ON 2 DIMENSIONAL TEETH MODEL IMAGE FOR THE CENTERLINE COMPONENT AND TEETH SEGMENTATION ON THE OCCLUSAL SURFACE TEETH MODEL IMAGE

    OpenAIRE

    Hanif Arief Wisesa; Ratna Rustamadji; Miesje Karmiati Purwanegara; Benny Hardjono

    2014-01-01

    Abstract The PAR (Peer Assessment Rating) Index is used by orthodontists around the world to calculate the severeness of a malocclusion. A malocclusion is a dental disease where the teeth are not properly aligned. In Indonesia, the number of malocclusion is relatively high. The occurrence of orthodontics who can treat malocclusion is also low in Indonesia. In 2013, a research is done to create the telehealth monitoring system to provide better treatment of malocclusion in Indonesia. The rese...

  19. Influence of connection type on the biomechanical behavior of distal extension mandibular removable partial dentures supported by implants and natural teeth.

    Science.gov (United States)

    Xiao, Wei; Li, Zhiyong; Shen, Shiqian; Chen, Shaowu; Chen, Sulin; Wang, Jiawei

    2016-02-01

    Few studies are performed to evaluate the influence of connection type on the stress distribution of distal extension mandibular removable partial dentures (RPDs) supported by both implants and natural teeth. In this study, five three-dimensional finite element models were prepared to simulate mandibular bilateral partially edentulous arches. Four were RPDs supported by both implants and natural teeth, and the other one was RPDs supported only by natural teeth. The maximum equivalent (EQV) stress values of bone around implants, the abutments, and the mucosa displacements of the related supporting structures were measured. It was found that a non-rigid telescopic coping was more favorable to protect the implant than a rigid telescopic coping. Compared with other connection types, the easy resilient attachment (ERA) system seemed to be effective to associate implant without complications. However, the results obtained in the present study should be cautiously interpreted in the clinic.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Strategic interaction and conventions

    Directory of Open Access Journals (Sweden)

    Espinosa, María Paz

    2012-03-01

    Full Text Available The scope of the paper is to review the literature that employs coordination games to study social norms and conventions from the viewpoint of game theory and cognitive psychology. We claim that those two alternative approaches are in fact complementary, as they provide different insights to explain how people converge to a unique system of self-fulfilling expectations in presence of multiple, equally viable, conventions. While game theory explains the emergence of conventions relying on efficiency and risk considerations, the psychological view is more concerned with frame and labeling effects. The interaction between these alternative (and, sometimes, competing effects leads to the result that coordination failures may well occur and, even when coordination takes place, there is no guarantee that the convention eventually established will be the most efficient.

    El objetivo de este artículo es presentar la literatura que emplea los juegos de coordinación para el estudio de normas y convenciones sociales, que se han analizado tanto desde el punto de vista de la teoría de juegos como de la psicología cognitiva. Argumentamos en este trabajo que estos dos enfoques alternativos son en realidad complementarios, dado que ambos contribuyen al entendimiento de los procesos mediante los cuales las personas llegan a coordinarse en un único sistema de expectativas autorrealizadas, en presencia de múltiples convenciones todas ellas igualmente viables. Mientras que la teoría de juegos explica la aparición de convenciones basándose en argumentos de eficiencia y comportamientos frente al riesgo, el enfoque de la psicología cognitiva utiliza en mayor medida consideraciones referidas al entorno y naturaleza de las decisiones. La interacción entre estos efectos diferentes (y en ocasiones, rivales desemboca con frecuencia en fallos de coordinación y, aun cuando la coordinación se produce, no hay garantía de que la convención en vigor sea la m

  2. Digitization of conventional radiographs

    International Nuclear Information System (INIS)

    Wenz, W.; Buitrago-Tellez, C.; Blum, U.; Hauenstein, K.H.; Gufler, H.; Meyer, E.; Ruediger, K.

    1992-01-01

    The diagnostic value of a digitization system for analogue films based on a charge-coupled-device (CCD) scanner with adjustable resolution of 2.5 or 5 lp/mm was assessed. Some 110 skeletal radiographs, 50 contrast studies, including 25 of patients with Crohn's disease, and 70 abdominal plain films before and after successful lithotripsy for renal stones were digitized. Receiver operating characteristic (ROC) studies showed improved detection of cortical and trabecular defects with contrast-optimized digitized films. Edge enhancement algorithms yielded no additional information. Inflammatory lesions of Crohn's disease were detected equally well by conventional films and digitized images. A statistically significant improvement (p [de

  3. Conventional RF system design

    International Nuclear Information System (INIS)

    Puglisi, M.

    1994-01-01

    The design of a conventional RF system is always complex and must fit the needs of the particular machine for which it is planned. It follows that many different design criteria should be considered and analyzed, thus exceeding the narrow limits of a lecture. For this reason only the fundamental components of an RF system, including the generators, are considered in this short seminar. The most common formulas are simply presented in the text, while their derivations are shown in the appendices to facilitate, if desired, a more advanced level of understanding. (orig.)

  4. Conventional magnets. Pt. 1

    International Nuclear Information System (INIS)

    Marks, N.

    1994-01-01

    The design and construction of conventional, steel-cored, direct-current magnets are discussed. Laplace's equation and the associated cylindrical harmonic solutions in two dimensions are established. The equations are used to define the ideal pole shapes and required excitation for dipole, quadrupole and sextupole magnets. Standard magnet geometries are then considered and criteria determining the coil design are presented. The use of codes for predicting flux density distributions and the iterative techniques used for pole face design are then discussed. This includes a description of the use of two-dimensional codes to generate suitable magnet end geometries. Finally, standard constructional techniques for cores and coils are described. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Janaina Freitas BORTOLATTO

    2016-01-01

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

  6. Air pollution: UNCED convention on climate change

    International Nuclear Information System (INIS)

    Pieri, M.

    1992-01-01

    In addition to United Nations papers delineating the Organization's convention on climate change and strategies concerning the protection of the earth's atmosphere, this booklet presents four papers expressing the views of Italian and American strategists. The central theme is the establishment of current global air pollution trends, the determination of suitable air pollution limits, and the preparation of feasible socio-economic strategies to allow industrialized and developing countries to work together effectively to achieve the proposed global air quality goals

  7. Guided access cavity preparation using cone-beam computed tomography and optical surface scans - an ex vivo study

    DEFF Research Database (Denmark)

    Buchgreitz, J; Buchgreitz, M; Mortensen, D

    2016-01-01

    AIM: To evaluate ex vivo, the accuracy of a preparation procedure planned for teeth with pulp canal obliteration (PCO) using a guide rail concept based on a cone-beam computed tomography (CBCT) scan merged with an optical surface scan. METHODOLOGY: A total of 48 teeth were mounted in acrylic bloc...

  8. Clinical Efficiency of Two Sequences of Orthodontic Wires to Correct Crowding of the Lower Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Cláudia Maria de Castro Serafim

    2015-01-01

    Full Text Available This study compared time to correction of mandibular anterior crowding using two arch wire sequences, one with conventional nickel-titanium (NiTi arch wires and the other with conventional and NiTi heat-activated arch wires. Twenty-two boys and girls (mean age: 16.68 ± 2.66 with moderate crowding (3–6 mm were assigned randomly to one of two groups and followed up for five months (six assessments when arch wires were changed. Time to crowding correction was analyzed statistically using the Kaplan-Meier method. Data were collected during the five-month follow-up, and time to correction was compared between groups using the log rank test. At the end of follow-up, mandibular crowding was corrected in 100% of the cases in the group treated with the sequence that included NiTi heat-activated arch wires, whereas about 30% of those treated with NiTi arch wires were not completely corrected. There was a significant difference in time to complete treatment between groups (log rank = 5.996; p<0.05. In the group treated with the sequence that included heat-activated wires, alignment and leveling of mandibular anterior teeth were completed earlier than in the group treated only with conventional NiTi arch wires. Clinical trial registration is found at RBR-7g5zng.

  9. Do general dental practitioners leave teeth on 'open drainage'?

    Science.gov (United States)

    Eliyas, S; Barber, M W; Harris, I

    2013-12-01

    There is a need to ascertain the use of evidence-based dentistry in both primary and secondary care in order to tailor education. This study aims to evaluate the use of 'open drainage' as part of endodontic treatment in primary care in South Yorkshire. A questionnaire was circulated to 141 randomly selected general dental practitioners in the South Yorkshire area between January 2012 and January 2013. The response rate was 79% (112/141). Five of the returned questionnaires were incomplete and therefore not usable. Seventy-nine percent of respondents were general dental practitioners (GDPs) working in mainly NHS or mixed practices. The year of graduation varied between 1970 and 2011. Forty-one percent (44/107) stated that they had never left a tooth on open drainage. Twenty-nine percent (31/107) stated that they sometimes leave teeth on open drainage. Of those respondents who currently leave teeth on open drainage, most (68%) would leave teeth on open drainage for one to two days or less. This survey revealed that the practice of leaving teeth on open drainage is still present in general dental practice. Current guidelines do not comment on the use of this treatment modality. There is a need to ascertain further information about practices throughout the United Kingdom in order to provide clear evidence-based guidelines.

  10. 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.

  11. Mercury Amalgam Diffusion in Human Teeth Probed Using Femtosecond LIBS.

    Science.gov (United States)

    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.

  12. Ferromanganese oxides on sharks' teeth from Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    The mineralogy, composition and growth rates of ferromanganese (Fe-Mn) oxides over the sharks' teeth from the Central Indian Ocean Basin are presented. The trends of metal enrichment (Mn, Ni, Cu and Zn) and depletion (Fe and Co), the Mn/Fe ratio...

  13. Implants and/or teeth: consensus statements and recommendations

    DEFF Research Database (Denmark)

    Gotfredsen, K; Carlsson, G E; Jokstad, A

    2008-01-01

    In August 23-25, 2007, the Scandinavian Society for Prosthetic Dentistry in collaboration with the Danish Society of Oral Implantology arranged a consensus conference on the topic 'Implants and/or teeth'. It was preceded by a workshop in which eight focused questions were raised and answered in e...

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

    Science.gov (United States)

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

    2015-01-01

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

  15. 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...

  16. Clinical and Radiographic Evaluation of Double Teeth in Primary ...

    African Journals Online (AJOL)

    2016-01-16

    Jan 16, 2016 ... Conclusion: The findings of this study have clinical relevance for the diagnosis of ... dentition, with fusion in 94% of cases and gemination in 6% of cases. .... orthodontic problems, including spacing or crowding of teeth, loss of ...

  17. Knowledge of Consequences of missing teeth in patients attending ...

    African Journals Online (AJOL)

    There was no significant difference between the knowledge of the consequences of missing teeth and sex or on level of education (p 0.05). Dentists constituted the largest source of information to these patients (25.6%) while the media constituted the least (0.5%). Conclusion: The result of this study showed poor knowledge ...

  18. Outcome of Endodontically Treated Teeth Diagnosed With Cracked Tooth

    Science.gov (United States)

    2015-06-01

    However, variable symptoms complicate the diagnosis (9). In a study of 32 patients presenting with diffuse longstanding orofacial pain eventually...883-92. 22)Byrnjulsen A, Fristad I, Grevstad T, Hals-Kvinnsland I. Incompletely fractured teeth associated with diffuse longstanding orofacial pain ...cracked tooth is highly associated with discomfort. Patients often describe a momentary, sudden, sharp, lancinating pain that results in continuous tooth

  19. 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

  20. Assessment of root surfaces of apicected teeth: A scanning electron ...

    African Journals Online (AJOL)

    2014-05-15

    May 15, 2014 ... exposed dentinal tubules, which may prevent the leakage ... stored in sterile distilled water at 37°C. Teeth with intact roots and mature apexes ..... 29. von Arx T, Kunz R, Schneider AC, Burgin W, Lussi A. Detection of dentinal.

  1. Assessment of the periapical health of abutment teeth: A ...

    African Journals Online (AJOL)

    2014-11-29

    Nov 29, 2014 ... teeth restored with crowns and bridge retainers through a retrospective analysis of orthopantomographs (OPTGs) in an adult Turkish .... The fixed dentures were either single .... design, population selection, evaluation criteria, and length ... fixed partial dentures: Life‑span and causes for loss of serviceability.

  2. 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.

  3. Short Communications Vestigial teeth in the genus Scotoecus ...

    African Journals Online (AJOL)

    1997-02-03

    Feb 3, 1997 ... cusp tip of these teeth, the majority of which are sharp or rounded with no signs of erosion (Figure I a). In some, how- ever, where the cusp tip is level with the surface of the cingu- lum of the canine and following premolar (and thus also level with the surface of the gum, or else protruding slightly above.

  4. Three-year clinical follow-up of posterior teeth restored with leucite-reinforced ips empress onlays and partial veneer crowns.

    Science.gov (United States)

    Murgueitio, Rafael; Bernal, Guillermo

    2012-07-01

    The aim of this study was to analyze the survival rate and failure mode of IPS leucite-reinforced ceramic onlays and partial veneer crowns regarding thickness under the following clinical conditions: vital versus nonvital teeth, tooth location, and type of opposing dentition. Teeth were prepared according to established guidelines for ceramic onlays and partial veneer crowns. Before cementation, the restorations were measured for occlusal thickness at the central fossa, mesial, and distal marginal ridges, and functional and nonfunctional cusps. A total of 210 ceramic restorations were cemented in 99 patients within a mean observation period of 2.9 ± 1.89 years. The mode of failure was classified and evaluated as (1) adhesive, (2) cohesive, (3) combined failure, (4) decementation, (5) tooth sensitivity, and (6) pulpal necrosis. Kaplan, log-rank, and Cox regression tests were used for statistical analysis. The failure rate was 3.33% (7/210). Increased material thickness produced less probability of failures. Vital teeth were less likely to fail than nonvital teeth. Second molars were five times more susceptible to failure than first molars. Tooth sensitivity postcementation and the type of opposing dentition were not statistically significant in this study. In this study, thickness of the restorations, tooth vitality, and location of teeth in the dental arch influenced restoration failures. © 2012 by the American College of Prosthodontists.

  5. Histological Evaluation of Allium sativum Oil as a New Medicament for Pulp Treatment of Permanent Teeth.

    Science.gov (United States)

    Mohammad, Shukry Gamal; Raheel, Syed Ahmed; Baroudi, Kusai

    2015-02-01

    The objective of this study was to evaluate the histo pathology effects of two medicaments Allium sativum oil and formocresol on the remaining pulp tissue of the permanent teething children. A total of 18 premolars were included in this study. Two sound premolars were extracted and subjected to histological examination to show the normal pulp tissue. Pulpo tomy procedure was performed in the rest of the remaining 16 premolars; half of them using Allium sativum oil and the rest of the tested premolars were medicated using formocresol and all were sealed with suitable restoration. Then, premolars extracted at variable intervals (48 hours, 2 weeks, 1 month, 2 months), stained using hemotoxylin and eosin etain (H&E) and prepared for histopathology examination. Histological evaluation seemed far more promising for Allium sativum oil than formocresol. Histological evaluation revealed that teeth treated with Allium sativa oil showed infammatory changes that had been resolved in the end of the study. On the contrary, the severe chronic infammation of pulp tissue accompanied with formocresol eventually produced pulp necrosis with or without fibrosis. In addition, pulp calcification was evidenced in certain cases. Allium sativum oil is a biocompatible material that is compatible with vital human pulp tissue. It offers a good healing potential, leaving the remaining pulp tissue healthy and functioning.

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

    Science.gov (United States)

    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.

  7. Retentive strength of different intracanal posts in restorations of anterior primary teeth: an in vitro study

    Directory of Open Access Journals (Sweden)

    Mahtab Memarpour

    2013-11-01

    Full Text Available Objectives To determine the retentive strength and failure mode of undercut composite post, glass fiber post and polyethylene fiber post luted with flowable composite resin and resin-cement. Materials and Methods Coronal parts of 120 primary canine teeth were sectioned and specimens were treated endodontically. The teeth were randomly divided into 6 groups (n = 20. Prepared root canals received intracanal retainers with a short composite post, undercut composite post, glass fiber post luted with flowable resin or resin-cement, and polyethylene fiber post luted with flowable resin or resin-cement. After crown reconstruction, samples were tested for retentive strength and failure mode. Statistical analysis was done with one-way ANOVA and Tukey tests (p < 0.05. Results There were statistically significant differences between groups (p = 0.001. Mean bond strength in the undercut group was significantly greater than in the short composite post (p = 0.030, and the glass fiber post (p = 0.001 and the polyethylene fiber post group luted with resin-cement (p = 0.008. However, the differences between the undercut group and the groups with flowable composite as the luting agent were not significant (p = 0.068, p = 0.557. Adhesive failure was more frequent in the fiber post groups. Conclusions Although the composite post with undercutting showed the greatest resistance to dislodgement, fiber posts cemented with flowable composite resin provided acceptable results in terms of retentive strength and fracture mode.

  8. Marginal microleakage in vitro study of occlusal fissures sealing prepared and etched or not with Er: YAG laser; Avaliacao in vitro da microinfiltracao marginal em selamentos oclusais preparados e condicionados ou nao pelo laser de Er:YAG

    Energy Technology Data Exchange (ETDEWEB)

    Youssef, Fernanda de Almeida

    2004-07-01

    The aim of this in vitro study was to evaluate the degree of marginal microleakage in occlusal sealing by invasive techniques, after preparation with Er:YAG laser followed or not by Er:YAG laser etching and compared to the conventional technique. Thirty human premolars were divided into three groups: A (control group) - cavities were prepared with high speed and etched with 37% orthophosphoric acid; group B - cavities were prepared with Er:YAG (350 mJ, 4 Hz and 112 J /cm{sup 2}) and etched with 37% orthophosphoric acid; group C - cavities were prepared with Er:YAG laser (350 mJ, 4 Hz and 112 J/cm{sup 2}), and etched with Er:YAG laser (80 mJ, 4 Hz and 25 m/cm{sup 2}). All cavities were treated with the same adhesive system and restored with flow composite according to manufacturer instructions. Teeth were submitted to thermal cycling procedures and immersed in 50% Silver Nitrate Solutions for 8 hours in total darkness. Teeth were sectioned longitudinally in the bucco-lingual direction, in slices of 1 mm thick. Each slice was immersed into photo developing solution under 16 hours of fluorescent light. Slices were photographed and microleakage was scored from 0 to 7 J by three standard examiners. Results showed statistically significant differences for group C (Er:YAG laser preparation and etching). We concluded that Er:YAG laser can be used for cavity preparation of occlusal sealing, like the conventional high speed method. However, this laser, used as enamel etching agent, could not promote an adequate surface for adhesive procedures. (author)

  9. Preparation of nitinol by non-conventional powder metallurgy techniques

    Czech Academy of Sciences Publication Activity Database

    Novák, P.; Moravec, H.; Salvetr, P.; Průša, F.; Drahokoupil, Jan; Kopeček, Jaromír; Karlík, M.; Kubatík, Tomáš František

    2015-01-01

    Roč. 31, č. 15 (2015), s. 1886-1893 ISSN 0267-0836 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:68378271 ; RVO:61389021 Keywords : shape memory alloys * SHS process * SEM * powder metallurgy Subject RIV: JG - Metallurgy Impact factor: 1.008, year: 2015

  10. Histologic Outcomes of Uninfected Human Immature Teeth Treated with Regenerative Endodontics: 2 Case Reports.

    Science.gov (United States)

    Nosrat, Ali; Kolahdouzan, Alireza; Hosseini, Farzaneh; Mehrizi, Ehsan A; Verma, Prashant; Torabinejad, Mahmoud

    2015-10-01

    A growing body of evidence exists showing the possibility of growing vital tissues in the root canal spaces of teeth with necrotic pulps and open apices. However, there is very limited histologic information regarding characteristics of tissues formed in the root canal space of human teeth after regenerative endodontics. The aim of this study was to examine clinically and histologically the outcomes of human immature teeth treated with regenerative endodontics. Two healthy birooted human maxillary first premolar teeth scheduled for extraction were included. Preoperative radiographs confirmed that these teeth had immature apices. Vitality tests showed the presence of vital pulps in these teeth. After receiving consent forms, the teeth were isolated with a rubber dam, and the pulps were completely removed. After the formation of blood clots in the canals, the teeth were covered with mineral trioxide aggregate. Four months later, the teeth were clinically and radiographically evaluated, extracted, and examined histologically. Both patients remained asymptomatic after treatment. Radiographic examination of the teeth showed signs of root development after treatment. Histologic examination of tissues growing into the root canal space of these teeth shows the presence of connective tissue, bone and cementum formation, and thickening of roots. Based on our findings, it appears that when canals of teeth with open apices are treated with regenerative endodontics, tissues of the periodontium grow into the root canals of these teeth. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. SUSTENTAÇÃO DE ESMALTE COM IONÔMEROS DE VIDRO E RESINA COMPOSTA: EFEITO NA RESISTÊNCIA À FRATURA DAS CÚSPIDES DE DENTES RESTAURADOS SUPPORTING ENAMEL WITH GLASS IONOMER CEMENT AND COMPOSITE RESIN: EFFECT ON FRACTURE RESISTANCE OF CUSPS OF RESTORED TEETH

    Directory of Open Access Journals (Sweden)

    Angelo Stefano SECCO

    1997-10-01

    Full Text Available Este estudo determinou a resistência e o tipo de fratura do esmalte suportado pelos materiais restauradores ionômeros de vidro convencional e modificado por resina e resina composta, bem como a influência dessa técnica restauradora na resistência das cúspides dos dentes. A remoção da estrutura dental para o preparo de cavidades tipo classe II e a presença de esmalte socavado diminuiram significativamente a resistência das cúspides dos dentes em relação ao dente hígido (p This study determined the resistance to fracture and its pattern for enamel supported with conventional and modified glass ionomer cements, and composite resin restorative materials, as well as the influence of these restorative techniques on cuspal strength of teeth. Removal of dental structure by class II cavity preparations and unsupported enamel had decreased significantly the cuspal strength in relation to healthy teeth (p < 0.01. Restorative materials used to support enamel reduced the fracture rate of restored cusps, but did not increase the fracture resistance values statistically. All tested groups presented alterations in the fracture pattern

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

    Directory of Open Access Journals (Sweden)

    Adrian Lussi

    Full Text Available This study aimed at analysing the erosive potential of 30 substances (drinks, candies, and medicaments on deciduous enamel, and analyse the associated chemical factors with enamel dissolution. We analysed the initial pH, titratable acidity (TA to pH 5.5, calcium (Ca, inorganic phosphate (Pi, and fluoride (F concentration, and degree of saturation ((pK -pIHAP, (pK -pIFAP, and (pK-pICaF2 of all substances. Then, we randomly distributed 300 specimens of human deciduous enamel into 30 groups (n = 10 for each of the substances tested. We also prepared 20 specimens of permanent enamel for the sake of comparison between the two types of teeth, and we tested them in mineral water and Coca-Cola®. In all specimens, we measured surface hardness (VHN: Vickers hardness numbers and surface reflection intensity (SRI at baseline (SH baseline and SRI baseline, after a total of 2 min (SH2 min and after 4 min (SH4 min and SRI4 min erosive challenges (60 ml of substance for 6 enamel samples; 30°C, under constant agitation at 95 rpm. There was no significant difference in SH baseline between deciduous and permanent enamel. Comparing both teeth, we observed that after the first erosive challenge with Coca-Cola®, a significantly greater hardness loss was seen in deciduous (-90.2 ± 11.3 VHN than in permanent enamel (-44.3 ± 12.2 VHN; p = 0.007, but no differences between the two types of teeth were observed after two challenges (SH4 min. After both erosive challenges, all substances except for mineral water caused a significant loss in relative surface reflectivity intensity, and most substances caused a significant loss in surface hardness. Multiple regression analyses showed that pH, TA and Ca concentration play a significant role in initial erosion of deciduous enamel. We conclude that drinks, foodstuffs and medications commonly consumed by children can cause erosion of deciduous teeth and erosion is mainly associated with pH, titratable acidity and calcium

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

    Science.gov (United States)

    Lussi, Adrian; Carvalho, Thiago Saads

    2015-01-01

    This study aimed at analysing the erosive potential of 30 substances (drinks, candies, and medicaments) on deciduous enamel, and analyse the associated chemical factors with enamel dissolution. We analysed the initial pH, titratable acidity (TA) to pH 5.5, calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentration, and degree of saturation ((pK -pI)HAP, (pK -pI)FAP, and (pK-pI)CaF2) of all substances. Then, we randomly distributed 300 specimens of human deciduous enamel into 30 groups (n = 10 for each of the substances tested. We also prepared 20 specimens of permanent enamel for the sake of comparison between the two types of teeth, and we tested them in mineral water and Coca-Cola®. In all specimens, we measured surface hardness (VHN: Vickers hardness numbers) and surface reflection intensity (SRI) at baseline (SH baseline and SRI baseline), after a total of 2 min (SH2 min) and after 4 min (SH4 min and SRI4 min) erosive challenges (60 ml of substance for 6 enamel samples; 30°C, under constant agitation at 95 rpm). There was no significant difference in SH baseline between deciduous and permanent enamel. Comparing both teeth, we observed that after the first erosive challenge with Coca-Cola®, a significantly greater hardness loss was seen in deciduous (-90.2 ± 11.3 VHN) than in permanent enamel (-44.3 ± 12.2 VHN; p = 0.007), but no differences between the two types of teeth were observed after two challenges (SH4 min). After both erosive challenges, all substances except for mineral water caused a significant loss in relative surface reflectivity intensity, and most substances caused a significant loss in surface hardness. Multiple regression analyses showed that pH, TA and Ca concentration play a significant role in initial erosion of deciduous enamel. We conclude that drinks, foodstuffs and medications commonly consumed by children can cause erosion of deciduous teeth and erosion is mainly associated with pH, titratable acidity and calcium

  14. 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.

  15. 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.

  16. Dental anomalies in primary dentition and their corresponding permanent teeth.

    Science.gov (United States)

    Gomes, R R; Fonseca, J A C; Paula, L M; Acevedo, A C; Mestrinho, H D

    2014-05-01

    The objectives of this paper are to estimate the prevalence of dental anomalies in primary dentition in a sample of 2- to 5-year-old Brazilian preschool children, determine their distribution, and investigate their occurrence in the succedaneous teeth of the sample compared with a control group of children with no dental anomalies in the primary dentition. The one-stage sample comprised 1,718 two to five-year-old children with fully erupted primary dentition clinically examined for dental anomalies. All children presenting dental anomalies underwent panoramic radiographs. Descriptive statistics were performed for the studied variables. A control group matched by sex and age was studied to compare the prevalence ratio for dental anomalies in the permanent dentition. The prevalence of dental anomalies in the primary dentition was 1.8 %, with no significant statistical difference between sexes. Double teeth were the most frequently observed. Dental anomalies on the succedaneous permanent teeth were diagnosed in 54.8 % of the children with affected primary dentition. The prevalence ratio (PR) for dental anomalies in the succedaneous permanent teeth was 17.1 (confidence interval (CI) 5.33-54.12) higher compared with the control group, higher in children with bilateral anomalies (PR = 31.2, CI 10.18-94.36). An association between anomalies of the permanent dentition and the presence of dental anomalies in primary teeth was observed, especially when they occur bilaterally. The results in the present study have a clinical relevance in the diagnosis of children with dental anomalies in primary dentition. Early identification of these anomalies can aid the dentist in planning dental treatment at the appropriate time.

  17. Non-Conventional Methodologies in the Synthesis of 1-Indanones

    Directory of Open Access Journals (Sweden)

    Manuela Oliverio

    2014-04-01

    Full Text Available 1-Indanones have been successfully prepared by means of three different non-conventional techniques, namely microwaves, high-intensity ultrasound and a Q-tube™ reactor. A library of differently substituted 1-indanones has been prepared via one-pot intramolecular Friedel-Crafts acylation and their efficiency and “greenness” have been compared.

  18. Comparison of Tooth Color Change After Bleaching With Conventional and Different Light-Activated Methods.

    Science.gov (United States)

    Shahabi, Sima; Assadian, Hadi; Mahmoudi Nahavandi, Alireza; Nokhbatolfoghahaei, Hanieh

    2018-01-01

    Introduction: The demand for esthetic dental treatments is increasing in recent years mainly due to improved oral hygiene and better maintenance of oral health and teeth in older individuals. Bleaching of discolored anterior teeth is the most popular among esthetic dental treatments. Even individuals with sound teeth and adequate esthetics seek to have whiter teeth in the anterior region. The aim of this study was to evaluate tooth color changes following conventional in-office bleaching techniques compared to light-activated methods using different light sources. Methods: Seventy sound anterior teeth (devoided of caries and/or fracture), extracted for periodontal and orthodontic reasons were selected and allocated to 7 groups: (A) control, (B) conventional bleaching (C) LED-activated bleaching, (D) KTP laser-activated bleaching, (E) diode laser-activated bleaching, (F) Nd:YAG laser-activated bleaching and (G) CO2 laser-activated bleaching. Colorimetric evaluation was carried out before and after treatment using a spectrophotoradiometer. Data were analyzed by one- and two-way analysis of variance (ANOVA) as well as multiple comparison methods. Results: The results showed that all bleaching procedures were effective in reducing the yellowness index. However, the KTP laser-activated bleaching was significantly more effective than the other techniques in 95% confidence level. It was also seen that CO2 laser activated method has outperformed groups E, F and G and the conventional bleaching without light activation was not effective at all and represented similar results with the control group. Furthermore, the groups E and G had almost the same results in decreasing the yellowness index. Conclusion: The results showed that all bleaching techniques were effective however, the KTP laser-activated bleaching was significantly more efficient, closely followed by the CO2 laser-activated bleaching technique.

  19. Imaging of the human tooth cementum ultrastructure of archeological teeth, using hard x-ray microtomography to determine age-at-death and stress periods

    Science.gov (United States)

    Mani-Caplazi, Gabriela; Schulz, Georg; Deyhle, Hans; Hotz, Gerhard; Vach, Werner; Wittwer-Backofen, Ursula; Müller, Bert

    2017-09-01

    Tooth cementum annulation (TCA) is used by anthropologists to decipher age-at-death and stress periods based on yearly deposited incremental lines (ILs). The destructive aspect of the TCA method, which requires cutting the tooth root in sections to display the ILs, using transmission light microscopy, can be problematic for archeological teeth, and so a non-invasive imaging technique is preferred. The purpose of this study is to evaluate conventional micro computed tomography (μCT) and synchrotron radiation-based X-ray micro computed tomography (SRμCT) as a non-destructive technique to explore the tooth cementum ultrastructure and to display ILs. Seven archeological teeth from the Basel- Spitalfriedhof collection (patients died between 1845 and 1868 in the city hospital) were selected for the μCT experiments. This collection is considered a unique worldwide reference series in the anthropological science community, due to the high level of documented life history data in the medical files and the additionally collected and verified birth history by genealogists. The results demonstrate that the conventional μCT is complementary to the SRμCT allowing to prescreen the teeth using conventional μCT to identify the appropriate specimens and areas for the SRμCT measurements. SRμCT displayed cementum ring structure corresponding to the ILs in the microscope view in archeological teeth in a non-invasive fashion with the potential for more accurate assessments of ILs compared to conventional techniques. The ILs were mainly clearly visible, and it was possible to count them for age-at-death assessment and identify qualitatively irregular ILs which could constitute stress markers.

  20. Cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials.

    Science.gov (United States)

    Moorthy, A; Hogg, C H; Dowling, A H; Grufferty, B F; Benetti, A R; Fleming, G J P

    2012-06-01

    To assess the cuspal deflection and cervical microleakage of standardised Class II cavities incrementally filled with a dimethacrylate RBC or bulk-fill flowable RBC bases. Twenty-four sound upper premolar teeth with Class II cavities were allocated to three groups (n=8). Restoration of the teeth involved the placement of an RBC (GrandioSO) in eight oblique increments (Group A) or Groups B and C were restored to within 2 mm of the palatal cusp in a single increment with bulk-fill flowable RBC bases (SDR and x-tra base) before the two occlusal cavity increments were placed with GrandioSO. Buccal and palatal cusp deflections were recorded postirradiation using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in 0.2% basic fuchsin dye for 24h, sectioned and examined for cervical microleakage. The mean total cuspal deflection for the oblique incremental restoration technique was 11.26 (2.56) μm (Group A) and 4.63 (1.19) μm (Group B) and 4.73 (0.99) μm (Group C) for the bulk-fill flowable RBC bases. A significant increase in the mean total cuspal deflection for the incrementally filled GrandioSO compared with the SDR (P=0.007) and x-tra base (P=0.005) restored teeth was evident. No significant difference in the cervical microleakage scores was recorded between groups AC (P>0.05). The bulk-fill flowable RBC bases significantly reduced cuspal deflection compared with a conventional RBC restored in an oblique incremental filling technique with no associated change in cervical microleakage recorded. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Evaluation of the antimicrobial activity of three irrigating solutions in teeth with pulpal necrosis.

    Science.gov (United States)

    Ferreira, C M; Bonifácio, K C; Fröner, I C; Ito, I Y

    1999-01-01

    The antimicrobial activity of 0.4% papaine gel (FCF-USP), an antibacterial product derived from 3.3% castor oil (IQSC-USP), and 0.5% sodium hypochlorite (FORP-USP) was evaluated in teeth with radiographically visible pulpal necrosis and periapical lesion in vivo. After cavity access, under aseptic conditions, a first harvesting was performed. The 3 irrigating solutions were used for biomechanical preparation. After 72 hours, a second harvesting was performed, also under aseptic conditions. The number of colony forming units (cfu) was counted with a stereomicroscope under reflected light. Castor oil and 0.5% sodium hypochlorite presented similar antimicrobial activities for the reduction of the anaerobe number, S. mutans and streptococci; however, the papaine gel showed lower activity. We conclude that both castor oil and sodium hypochlorite are effective as antimicrobial agents and can be used in the treatment of root canals with pulpal necrosis.

  2. 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...

  3. The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

    Directory of Open Access Journals (Sweden)

    Masoud Parirokh

    2015-05-01

    Full Text Available Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

  4. The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

    Science.gov (United States)

    Yosefi, Mohammad Hosein; Nakhaee, Nouzar

    2015-01-01

    Objectives Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Materials and Methods Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment. PMID:25984478

  5. The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain.

    Science.gov (United States)

    Parirokh, Masoud; Yosefi, Mohammad Hosein; Nakhaee, Nouzar; Abbott, Paul V; Manochehrifar, Hamed

    2015-05-01

    Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

  6. 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 ...

  7. Multiple congenitally missing teeth: treatment outcome with autologous transplantation and orthodontic space closure.

    Science.gov (United States)

    Fiorentino, Giuseppe; Vecchione, Pietro

    2007-11-01

    Treatment for patients with congenitally missing teeth can be challenging. The treatment options include retaining the deciduous teeth, extracting the deciduous teeth and allowing the space to close spontaneously, implant replacement, autotransplantation, prosthetic replacement, and orthodontic space closure. Autologous transplantation and space closure with orthodontic appliances are demonstrated in this case report.

  8. Surgical removal versus retention for the management of asymptomatic disease-free impacted wisdom teeth

    NARCIS (Netherlands)

    Ghaeminia, H.; Perry, J.; Nienhuijs, M.E.L.; Toedtling, V.; Tummers, M.J.; Hoppenreijs, T.J.; Sanden, W.J.M. van der; Mettes, T.G.P.H.

    2016-01-01

    BACKGROUND: Prophylactic removal of asymptomatic disease-free impacted wisdom teeth is surgical removal of wisdom teeth in the absence of symptoms and with no evidence of local disease. Impacted wisdom teeth may be associated with pathological changes, such as pericoronitis, root resorption, gum and

  9. 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,

  10. Analysis 'in vivo' of the employ of the Er:YAG laser and conventional method to remove carious tissue

    International Nuclear Information System (INIS)

    Ribeiro, Rafael Cardoso

    2002-01-01

    The aim of this study was to evaluate the removal of carious tissue employing the use of Er:YAG laser in comparison with the conventional burr rotary instrument. The wavelength of this laser is 2,64 μm and have a good absorption by the water and hydroxyapatite present in dental hard tissue. For this purpose were selected 24 molar teeth with occlusal carious, which were divided in random in two groups. For enamel, the laser energy used was in the interval from 250 mJ to 400 mJ, and the frequency range from 2 Hz to 4 Hz; for the dentine the energy laser range was from 150 mJ to 200 mJ and the laser frequency was in the range from 2 Hz to 6 Hz. For the evaluation of the results was used a questionaire to critical evaluation of the professional and another one to evaluation of the patient. The results have shown that the Er:YAG laser is able to remove carious enamel and dentin, without cause crunch or fracture and the irradiated surface was creasy. The patients reported greatest comfort when the cavity preparation was done with the Er:YAG laser than the conventional burr and all the patients treated reported prefer to future treatments the use of the Er:YAG laser. In conclusion, for the critical evaluation of the professional the treatment with the Er:YAG laser is a safe and effective method, and for the critical evaluation of the patient the treatment is one alternative more comfortable than the conventional method to remove caries. (author)

  11. Effectiveness of Rotary Endodontic Instruments on Smear Layer Removal in Root Canals of Primary Teeth: A Scanning Electron Microscopy Study.

    Science.gov (United States)

    Subramaniam, Priya; Girish Babu, K L; Tabrez, T A

    2016-01-01

    The present SEM study was undertaken to evaluate the effect of root canal instrumentation using both manual and rotary files in the root canals of primary anterior teeth. Thirty freshly extracted primary maxillary incisors were divided into 3 groups of 10 teeth each. In Group I, root canals were instrumented with rotary NiTi files; in Group II, the root canals were instrumented using manual NiTi K files and; in Group III, manual instrumentation was done with stainless steel K files. Longitudinal sections were prepared and processed for observation under SEM at the coronal, middle and apical thirds. Scoring of smear layer was done according to Hulsmann and the data obtained was subjected to statistical analysis. Rotary files cleaned the coronal and middle thirds of root canals more effectively. Statistically there was no significant difference between the groups. Lowest score of 2.6 in the apical third of root canals was seen with hand NiTi files. Rotary instrumentation was as effective as manual instrumentation in removal of smear layer in the root canals of primary anterior teeth.

  12. A comparison between new dentinal adhesives (fifth generation and traditional varnish in microleakage reduction of amalgam restorations in primary teeth

    Directory of Open Access Journals (Sweden)

    Mortazavi M. Associate Professor

    2003-06-01

    Full Text Available Statement of Problem: Microleakage presents the major cause for restorations failure in the oral cavity resulting in postoperative sensitivity, pulp irritation and secondary caries formation."nAim: The aim of this study was to compare two dentinal adhesive systems of fifth generation and copalite varnish in reducing microleakage of amalgam restorations in primary teeth."nMaterials and Methods: In this in-vitro study, 100 class V amalgam restorations were prepared on the buccal or lingual surfaces of primary molar and canine teeth. Samples were randomly divided into four groups (25 samples each. No liner was used for the first group and the second group restorations were lined with copalite varnish. Two dentin adhesives, called Syntac C and Single Bond, were used for the third and fourth groups, respectively. At the next stage, the samples were immersed in 5% fuschin solution for 24 hours, then sectioned buccolingually, and examined under a stereomicroscope for microleakage evaluation."nResults: There was a significant difference between four groups statistically (PO.000I, Comparing"nfour groups, the first and fourth ones, demonstrated the most and the least microleakage, respectively."nConclusion: The present study showed that new dentinal adhesive systems caused microleakage"nreduction in amalgam restorations of primary teeth.

  13. Effect of Thermocycling on Microleakage of New Adhesive Systems on Primary Teeth: An In-Vitro Study

    Directory of Open Access Journals (Sweden)

    Ramin Atash

    2013-09-01

    Full Text Available Introduction: This study investigated the sealing ability of three different adhesives in primary bovine teeth. Methods: Facial and lingual class V cavities were prepared half in enamel and half in cementum, in 48 bovine primary mandibular incisors and randomly divided into three groups and each group divided to two subgroups. The tested adhesives were XPBond (XP, ClearfilS3 Bond (S3, and Xeno III (XE. All cavities were restored with composite and light cured. After 24 hours storage in 37°C distilled water and polishing, teeth were thermocycled and sealed with nail varnish. Then, they were stored in 2% methylene blue and dye penetration was evaluated under a stereomicroscope. Results: No significant differences were recorded in the microleakage value between three adhesives in enamel and dentin margins (p>0.0.5 before and after thermocycling. The lowest microleakage value was obtained in XE followed by XP and S3. Conclusion: There were not any differences between adhesives in enamel and dentin margins of class V cavities on primary bovine teeth.